1
|
Loong SK, Liam CK, Karunakaran R, Tan KK, Mahfodz NH, AbuBakar S. Non-classical Bordetella sp. (closely related to Bordetella hinzii and Bordetella pseudohinzii) lower respiratory tract infection in a patient with extensive bronchiectasis: a case report. J Int Med Res 2024; 52:3000605231214464. [PMID: 38216150 PMCID: PMC10787532 DOI: 10.1177/03000605231214464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2024] Open
Abstract
An increasing number of reports have described the pathogenic nature of several non-classical Bordetella spp. Among them, Bordetella hinzii and Bordetella pseudohinzii have been implicated in a myriad of respiratory-associated infections in humans and animals. We report the isolation of a genetically close relative of B. hinzii and B. pseudohinzii from the sputum of a woman in her early 60s with extensive bronchiectasis who presented with fever and brown colored sputum. The isolate had initially been identified as Bordetella avium by API 20NE, the identification system for non-enteric Gram-negative rod bacteria. Sequencing of the 16S rDNA, ompA, nrdA, and genes used in the Bordetella multilocus sequence typing scheme could not resolve the identity of this Bordetella isolate. Whole-genome single nucleotide polymorphism analysis positioned the isolate between B. hinzii and B. pseudohinzii in the phylogenetic tree, forming a distinct cluster. Whole-genome sequencing enabled the further identification of this rare organism, and should be considered for wider applications, especially the confirmation of organism identity in the clinical diagnostic microbiology laboratory.
Collapse
Affiliation(s)
- Shih Keng Loong
- Tropical Infectious Diseases Research & Education Centre, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Chong Kin Liam
- Department of Medicine, University Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia
- Department of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Rina Karunakaran
- Department of Medical Microbiology, University Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia
- Department of Medical Microbiology, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Kim-Kee Tan
- Tropical Infectious Diseases Research & Education Centre, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Nur Hidayana Mahfodz
- Tropical Infectious Diseases Research & Education Centre, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Sazaly AbuBakar
- Tropical Infectious Diseases Research & Education Centre, Universiti Malaya, Kuala Lumpur, Malaysia
| |
Collapse
|
2
|
Beliavskaia A, Tan KK, Sinha A, Husin NA, Lim FS, Loong SK, Bell-Sakyi L, Carlow CKS, AbuBakar S, Darby AC, Makepeace BL, Khoo JJ. Metagenomics of culture isolates and insect tissue illuminate the evolution of Wolbachia, Rickettsia and Bartonella symbionts in Ctenocephalides spp. fleas. Microb Genom 2023; 9:mgen001045. [PMID: 37399133 PMCID: PMC10438800 DOI: 10.1099/mgen.0.001045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 05/16/2023] [Indexed: 07/05/2023] Open
Abstract
While fleas are often perceived simply as a biting nuisance and a cause of allergic dermatitis, they represent important disease vectors worldwide, especially for bacterial zoonoses such as plague (transmitted by rodent fleas) and some of the rickettsioses and bartonelloses. The cosmopolitan cat (Ctenocephalides felis ) and dog (Ctenocephalides canis ) fleas, as well as Ctenocephalides orientis (restricted to tropical and subtropical Asia), breed in human dwellings and are vectors of cat-scratch fever (caused by Bartonella spp.) and Rickettsia spp., including Rickettsia felis (agent of flea-borne spotted fever) and Rickettsia asembonensis , a suspected pathogen. These Rickettsia spp. are members of a phylogenetic clade known as the ‘transitional group’, which includes both human pathogens and arthropod-specific endosymbionts. The relatively depauperate flea microbiome can also contain other endosymbionts, including a diverse range of Wolbachia strains. Here, we present circularized genome assemblies for two C. orientis -derived pathogens (Bartonella clarridgeiae and R. asembonensis ) from Malaysia, a novel Wolbachia strain (w Cori), and the C. orientis mitochondrion; all were obtained by direct metagenomic sequencing of flea tissues. Moreover, we isolated two Wolbachia strains from Malaysian C. felis into tick cell culture and recovered circularized genome assemblies for both, one of which (w CfeF) is newly sequenced. We demonstrate that the three Wolbachia strains are representatives of different major clades (‘supergroups’), two of which appear to be flea-specific. These Wolbachia genomes exhibit unique combinations of features associated with reproductive parasitism or mutualism, including prophage WO, cytoplasmic incompatibility factors and the biotin operon of obligate intracellular microbes. The first circularized assembly for R. asembonensis includes a plasmid with a markedly different structure and gene content compared to the published plasmid; moreover, this novel plasmid was also detected in cat flea metagenomes from the USA. Analysis of loci under positive selection in the transitional group revealed genes involved in host–pathogen interactions that may facilitate host switching. Finally, the first B. clarridgeiae genome from Asia exhibited large-scale genome stability compared to isolates from other continents, except for SNPs in regions predicted to mediate interactions with the vertebrate host. These findings highlight the paucity of data on the genomic diversity of Ctenocephalides -associated bacteria and raise questions regarding how interactions between members of the flea microbiome might influence vector competence.
Collapse
Affiliation(s)
- Alexandra Beliavskaia
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool L3 5RF, UK
| | - Kim-Kee Tan
- Tropical Infectious Diseases Research & Education Centre (TIDREC), Higher Institution Centre of Excellence (HICoE), Universiti Malaya, Kuala Lumpur 50603, Malaysia
| | - Amit Sinha
- New England Biolabs, Ipswich, Massachusetts, 01938, USA
| | - Nurul Aini Husin
- Tropical Infectious Diseases Research & Education Centre (TIDREC), Higher Institution Centre of Excellence (HICoE), Universiti Malaya, Kuala Lumpur 50603, Malaysia
| | - Fang Shiang Lim
- Tropical Infectious Diseases Research & Education Centre (TIDREC), Higher Institution Centre of Excellence (HICoE), Universiti Malaya, Kuala Lumpur 50603, Malaysia
| | - Shih Keng Loong
- Tropical Infectious Diseases Research & Education Centre (TIDREC), Higher Institution Centre of Excellence (HICoE), Universiti Malaya, Kuala Lumpur 50603, Malaysia
| | - Lesley Bell-Sakyi
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool L3 5RF, UK
| | | | - Sazaly AbuBakar
- Tropical Infectious Diseases Research & Education Centre (TIDREC), Higher Institution Centre of Excellence (HICoE), Universiti Malaya, Kuala Lumpur 50603, Malaysia
| | - Alistair C. Darby
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool L3 5RF, UK
| | - Benjamin L. Makepeace
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool L3 5RF, UK
| | - Jing Jing Khoo
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool L3 5RF, UK
| |
Collapse
|
3
|
Wong JE, Zainal N, AbuBakar S, Tan KK. Monitoring Changes in Human Umbilical Vein Endothelial Cells upon Viral Infection Using Impedance-Based Real-Time Cell Analysis. J Vis Exp 2023. [PMID: 37212555 DOI: 10.3791/64887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/23/2023] Open
Abstract
Endothelial cells line the inner surface of all blood and lymphatic vessels, creating a semi-permeable barrier regulating fluid and solute exchange between blood or lymph and their surrounding tissues. The ability of a virus to cross the endothelial barrier is an important mechanism that facilitates virus dissemination in the human body. Many viruses are reported to alter endothelial permeability and/or cause endothelial cell barrier disruption during infection, which is able to cause vascular leakage. The current study describes a real-time cell analysis (RTCA) protocol, using a commercial real-time cell analyzer to monitor endothelial integrity and permeability changes during Zika virus (ZIKV) infection of the human umbilical vein endothelial cells (HUVECs). The impedance signals recorded before and after ZIKV infection were translated to cell index (CI) values and analyzed. The RTCA protocol allows the detection of transient effects in the form of cell morphological changes during a viral infection. This assay could also be useful for studying changes in the vascular integrity of HUVECs in other experimental setups.
Collapse
Affiliation(s)
- Jo-Ern Wong
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Center of Excellence (HICoE), Universiti Malaya
| | - Nurhafiza Zainal
- Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya
| | - Sazaly AbuBakar
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Center of Excellence (HICoE), Universiti Malaya
| | - Kim-Kee Tan
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Center of Excellence (HICoE), Universiti Malaya;
| |
Collapse
|
4
|
Tan JY, Wong JE, Zainal N, AbuBakar S, Tan KK. Virus Propagation and Cell-Based Colorimetric Quantification. J Vis Exp 2023. [PMID: 37092849 DOI: 10.3791/64578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2023] Open
Abstract
Zika virus (ZIKV) is a mosquito-borne virus belonging to the genus Flavivirus. ZIKV infection has been associated with congenital brain abnormalities and potentially Guillain-Barré syndrome in adults. Research on ZIKV to understand the disease mechanisms is important to facilitate vaccine and treatment development. The method of quantifying viruses is crucial and fundamental in the field of virology. The focus forming assay (FFA) is a virus quantification assay that detects the viral antigen with antibodies and identifies the infection foci of cells using the peroxidase immunostaining technique. The current study describes the virus propagation and quantification protocol using both 24-well and 96-well (high throughput) formats. Compared with other similar studies, this protocol has further described foci size optimization, which can serve as a guide to expand the use of this assay for other viruses. Firstly, ZIKV propagation is performed in Vero cells for 3 days. The culture supernatant containing ZIKV is harvested and quantitated using the FFA. Briefly, the virus culture is inoculated onto Vero cells and incubated for 2-3 days. Foci formation is then determined after optimized staining processes, including cell fixation, permeabilization, blocking, antibody binding, and incubation with peroxidase substrate. The stained virus foci are visualized using a stereo microscope (manual counting in 24-well format) or software analyzer (automated counting in 96-well format). The FFA provides reproducible, relatively fast results (3-4 days) and is suitable to be used for different viruses, including non-plaque-forming viruses. Subsequently, this protocol is useful for the study of ZIKV infection and could be used to detect other clinically important viruses.
Collapse
Affiliation(s)
- Jia-Yi Tan
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Center of Excellence (HICoE), Universiti Malaya
| | - Jo-Ern Wong
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Center of Excellence (HICoE), Universiti Malaya
| | - Nurhafiza Zainal
- Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya
| | - Sazaly AbuBakar
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Center of Excellence (HICoE), Universiti Malaya
| | - Kim-Kee Tan
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Center of Excellence (HICoE), Universiti Malaya;
| |
Collapse
|
5
|
Chan YT, Cheok YY, Cheong HC, Tang TF, Sulaiman S, Hassan J, Looi CY, Tan KK, AbuBakar S, Wong WF. Immune Recognition versus Immune Evasion Systems in Zika Virus Infection. Biomedicines 2023; 11:biomedicines11020642. [PMID: 36831177 PMCID: PMC9952926 DOI: 10.3390/biomedicines11020642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 01/17/2023] [Accepted: 01/19/2023] [Indexed: 02/22/2023] Open
Abstract
The reemergence of the Zika virus (ZIKV) infection in recent years has posed a serious threat to global health. Despite being asymptomatic or mildly symptomatic in a majority of infected individuals, ZIKV infection can result in severe manifestations including neurological complications in adults and congenital abnormalities in newborns. In a human host, ZIKV is primarily recognized by RIG-like receptors and Toll-like receptors that elicit anti-viral immunity through the secretion of type I interferon (IFN) to limit viral survival, replication, and pathogenesis. Intriguingly, ZIKV evades its host immune system through various immune evasion strategies, including suppressing the innate immune receptors and signaling pathways, mutation of viral structural and non-structural proteins, RNA modulation, or alteration of cellular pathways. Here, we present an overview of ZIKV recognition by the host immune system and the evasion strategies employed by ZIKV. Characterization of the host-viral interaction and viral disease mechanism provide a platform for the rational design of novel prophylactic and therapeutic strategies against ZIKV infection.
Collapse
Affiliation(s)
- Yee Teng Chan
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia
| | - Yi Ying Cheok
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia
| | - Heng Choon Cheong
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia
| | - Ting Fang Tang
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia
| | - Sofiah Sulaiman
- Department of Obstetrics and Gynecology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia
| | - Jamiyah Hassan
- Department of Obstetrics and Gynecology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia
| | - Chung Yeng Looi
- School of Biosciences, Faculty of Health & Medical Sciences, Taylor’s University, 1, Jalan Taylors, Subang Jaya 47500, Malaysia
| | - Kim-Kee Tan
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Education Center of Excellence (HICoE), University of Malaya, Kuala Lumpur 50603, Malaysia
| | - Sazaly AbuBakar
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Education Center of Excellence (HICoE), University of Malaya, Kuala Lumpur 50603, Malaysia
| | - Won Fen Wong
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia
- Correspondence: ; Tel.: +60-(3)-7967-6672
| |
Collapse
|
6
|
Chin KL, Teoh BT, Sam SS, Loong SK, Tan KK, Azizan NS, Lim YK, Khor CS, Nor'e SS, Abd-Jamil J, AbuBakar S. Development of a TaqMan minor groove binding probe-based quantitative reverse transcription polymerase chain reaction for the detection and quantification of Zika virus. Trop Biomed 2022; 39:518-523. [PMID: 36602210 DOI: 10.47665/tb.39.4.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Zika virus (ZIKV) infection has emerged as a global health concern following epidemic outbreaks of severe neurological disorders reported in Pacific and Americas since 2016. Therefore, a rapid, sensitive and specific diagnostic test for ZIKV infection is critical for the appropriate patient management and the control of disease spread. A TaqMan minor groove binding (MGB) probe-based quantitative reverse transcription-polymerase chain reaction (qRT-PCR) assay was developed based on the conserved sequence regions of 463 ZIKV NS2B genes. The designed ZIKV qRT-PCR assay was evaluated for its detection limit, strain coverage and cross-reactivity. We further assessed the clinical applicability of qRT-PCR assay for ZIKV RNA detection using a total 18 simulated clinical specimens. The detection limit of the qRT-PCR assay was 11.276 ZIKV RNA copies at the 95% probability level (probit analysis, p<= 0.05). Both Asian and African ZIKV strains were detected by the qRT-PCR assay without cross-reacting with DENV-1, DENV-2, DENV-3, DENV-4, CHIKV, JEV, LGTV, GETV and SINV. The qRT-PCR assay demonstrated a perfect agreement (k = 1.000, P < 0.001) with the reference assay; the sensitivity and specificity of the qRT-PCR assay were 100% (95% CI= 79.6-100) and 100% (95% CI= 43.9-100) respectively. The qRT-PCR assay developed in this study is a useful diagnostic tool for the broad coverage detection and quantification of both the Asian and African ZIKV strains.
Collapse
Affiliation(s)
- K L Chin
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Center of Excellence (HICoE), Universiti Malaya, 50603 Kuala Lumpur, Malaysia.,Institute for Advanced Studies, Universiti Malaya, 50603 Kuala Lumpur, Malaysia
| | - B T Teoh
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Center of Excellence (HICoE), Universiti Malaya, 50603 Kuala Lumpur, Malaysia
| | - S S Sam
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Center of Excellence (HICoE), Universiti Malaya, 50603 Kuala Lumpur, Malaysia
| | - S K Loong
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Center of Excellence (HICoE), Universiti Malaya, 50603 Kuala Lumpur, Malaysia
| | - K K Tan
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Center of Excellence (HICoE), Universiti Malaya, 50603 Kuala Lumpur, Malaysia
| | - N S Azizan
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Center of Excellence (HICoE), Universiti Malaya, 50603 Kuala Lumpur, Malaysia
| | - Y K Lim
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Center of Excellence (HICoE), Universiti Malaya, 50603 Kuala Lumpur, Malaysia
| | - C S Khor
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Center of Excellence (HICoE), Universiti Malaya, 50603 Kuala Lumpur, Malaysia
| | - S S Nor'e
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Center of Excellence (HICoE), Universiti Malaya, 50603 Kuala Lumpur, Malaysia
| | - J Abd-Jamil
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Center of Excellence (HICoE), Universiti Malaya, 50603 Kuala Lumpur, Malaysia
| | - S AbuBakar
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Center of Excellence (HICoE), Universiti Malaya, 50603 Kuala Lumpur, Malaysia.,Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, 50603 Kuala Lumpur, Malaysia
| |
Collapse
|
7
|
Azami NAM, Perera D, Thayan R, AbuBakar S, Sam IC, Salleh MZ, Isa MNM, Ab Mutalib NS, Aik WK, Suppiah J, Tan KK, Chan YF, Teh LK, Azzam G, Rasheed ZBM, Chan JCJ, Kamel KA, Tan JY, Khalilur Rahman O, Lim WF, Johari NA, Ishak M, Yunos RIM, Anasir MI, Wong JE, Fu JYL, Noorizhab MNF, Sapian IS, Mokhtar MFM, Md Shahri NAA, Ghafar K, Yusuf SNHM, Noor YM, Jamal R. SARS-CoV-2 genomic surveillance in Malaysia: displacement of B.1.617.2 with AY lineages as the dominant Delta variants and the introduction of Omicron during the fourth epidemic wave. Int J Infect Dis 2022; 125:216-226. [PMID: 36336246 PMCID: PMC9632236 DOI: 10.1016/j.ijid.2022.10.044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 10/25/2022] [Accepted: 10/30/2022] [Indexed: 11/06/2022] Open
Abstract
OBJECTIVES This study reported SARS-CoV-2 whole genome sequencing results from June 2021 to January 2022 from seven genome sequencing centers in Malaysia as part of the national surveillance program. METHODS COVID-19 samples that tested positive by reverse transcription polymerase chain reaction and with cycle threshold values <30 were obtained throughout Malaysia. Sequencing of SARS-CoV-2 complete genomes was performed using Illumina, Oxford Nanopore, or Ion Torrent platforms. A total of 6163 SARS-CoV-2 complete genome sequences were generated over the surveillance period. All sequences were submitted to the Global Initiative on Sharing All Influenza Data database. RESULTS From June 2021 to January 2022, Malaysia experienced the fourth wave of COVID-19 dominated by the Delta variant of concern, including the original B.1.617.2 lineage and descendant AY lineages. The B.1.617.2 lineage was identified as the early dominant circulating strain throughout the country but over time, was displaced by AY.59 and AY.79 lineages in Peninsular (west) Malaysia, and the AY.23 lineage in east Malaysia. In December 2021, pilgrims returning from Saudi Arabia facilitated the introduction and spread of the BA.1 lineage (Omicron variant of concern) in the country. CONCLUSION The changing trends of circulating SARS-CoV-2 lineages were identified, with differences observed between west and east Malaysia. This initiative highlighted the importance of leveraging research expertise in the country to facilitate pandemic response and preparedness.
Collapse
Affiliation(s)
- Nor Azila Muhammad Azami
- UKM Medical Molecular Biology Institute, Universiti Kebangsaan Malaysia (UKM), Kuala Lumpur, Malaysia
| | - David Perera
- Institute of Health and Community Medicine, Universiti Malaysia Sarawak, Sarawak, Malaysia
| | - Ravindran Thayan
- Virology Unit, Infectious Diseases Research Centre, Institute for Medical Research, National Institutes of Health, Ministry of Health, Selangor, Malaysia
| | - Sazaly AbuBakar
- Tropical Infectious Diseases Research & Education Centre (TIDREC), Higher Institution Center of Excellence (HICoE), Universiti Malaya, Kuala Lumpur, Malaysia
| | - I-Ching Sam
- Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia; Department of Medical Microbiology, University Malaya Medical Centre, Kuala Lumpur, Malaysia
| | - Mohd Zaki Salleh
- Integrative Pharmacogenomics Institute, Universiti Teknologi Mara (UiTM) Selangor Branch, Puncak Alam Campus, Selangor, Malaysia
| | - Mohd Noor Mat Isa
- Malaysia Genome and Vaccine Institute, National Institutes of Biotechnology Malaysia, Selangor, Malaysia
| | - Nurul Syakima Ab Mutalib
- UKM Medical Molecular Biology Institute, Universiti Kebangsaan Malaysia (UKM), Kuala Lumpur, Malaysia
| | - Wong Kiing Aik
- Institute of Health and Community Medicine, Universiti Malaysia Sarawak, Sarawak, Malaysia
| | - Jeyanthi Suppiah
- Virology Unit, Infectious Diseases Research Centre, Institute for Medical Research, National Institutes of Health, Ministry of Health, Selangor, Malaysia
| | - Kim-Kee Tan
- Tropical Infectious Diseases Research & Education Centre (TIDREC), Higher Institution Center of Excellence (HICoE), Universiti Malaya, Kuala Lumpur, Malaysia
| | - Yoke Fun Chan
- Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Lay Kek Teh
- Integrative Pharmacogenomics Institute, Universiti Teknologi Mara (UiTM) Selangor Branch, Puncak Alam Campus, Selangor, Malaysia
| | - Ghows Azzam
- Malaysia Genome and Vaccine Institute, National Institutes of Biotechnology Malaysia, Selangor, Malaysia; School of Biological Sciences, Universiti Sains Malaysia, Penang, Malaysia
| | | | - Jonathan Chia Jui Chan
- Institute of Health and Community Medicine, Universiti Malaysia Sarawak, Sarawak, Malaysia
| | - Khayri Azizi Kamel
- Virology Unit, Infectious Diseases Research Centre, Institute for Medical Research, National Institutes of Health, Ministry of Health, Selangor, Malaysia
| | - Jia-Yi Tan
- Tropical Infectious Diseases Research & Education Centre (TIDREC), Higher Institution Center of Excellence (HICoE), Universiti Malaya, Kuala Lumpur, Malaysia
| | - Omar Khalilur Rahman
- Department of Medical Microbiology, University Malaya Medical Centre, Kuala Lumpur, Malaysia
| | - Wai Feng Lim
- Integrative Pharmacogenomics Institute, Universiti Teknologi Mara (UiTM) Selangor Branch, Puncak Alam Campus, Selangor, Malaysia
| | - Nor Azfa Johari
- Malaysia Genome and Vaccine Institute, National Institutes of Biotechnology Malaysia, Selangor, Malaysia
| | - Muhiddin Ishak
- UKM Medical Molecular Biology Institute, Universiti Kebangsaan Malaysia (UKM), Kuala Lumpur, Malaysia
| | - Ryia Illani Mohd Yunos
- UKM Medical Molecular Biology Institute, Universiti Kebangsaan Malaysia (UKM), Kuala Lumpur, Malaysia
| | - Mohd Ishtiaq Anasir
- Virology Unit, Infectious Diseases Research Centre, Institute for Medical Research, National Institutes of Health, Ministry of Health, Selangor, Malaysia
| | - Jo-Ern Wong
- Tropical Infectious Diseases Research & Education Centre (TIDREC), Higher Institution Center of Excellence (HICoE), Universiti Malaya, Kuala Lumpur, Malaysia
| | - Jolene Yin Ling Fu
- Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Mohd Nur Fakhruzzaman Noorizhab
- Integrative Pharmacogenomics Institute, Universiti Teknologi Mara (UiTM) Selangor Branch, Puncak Alam Campus, Selangor, Malaysia
| | - Irni Suhayu Sapian
- Malaysia Genome and Vaccine Institute, National Institutes of Biotechnology Malaysia, Selangor, Malaysia
| | | | | | - Khairun Ghafar
- UKM Medical Molecular Biology Institute, Universiti Kebangsaan Malaysia (UKM), Kuala Lumpur, Malaysia
| | | | - Yusuf Muhammad Noor
- Malaysia Genome and Vaccine Institute, National Institutes of Biotechnology Malaysia, Selangor, Malaysia
| | - Rahman Jamal
- UKM Medical Molecular Biology Institute, Universiti Kebangsaan Malaysia (UKM), Kuala Lumpur, Malaysia.
| |
Collapse
|
8
|
Khoo HY, Lee HY, Khor CS, Tan KK, bin Hassan MR, Wong CM, Agustar HK, Samsusah NA, Rahim SSSA, bin Jeffree MS, Yusof NA, Haron NA, binti Amin Z, Hod R, AbuBakar S. Seroprevalence of Zika Virus among Forest Fringe Communities in Peninsular Malaysia and Sabah: General Population-Based Study. Am J Trop Med Hyg 2022; 107:tpmd210988. [PMID: 35895331 PMCID: PMC9490650 DOI: 10.4269/ajtmh.21-0988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 04/19/2022] [Indexed: 11/07/2022] Open
Abstract
Zika virus (ZIKV) has had a history in Malaysia since its first isolation in 1966. However, it is believed that the immunity status among forest fringe communities has been underreported. We conducted cross-sectional surveillance of forest fringe communities from 10 Orang Asli villages and their peripheral communities in Perak, Pahang, and Sabah in Malaysia. A total of 706 samples were collected from 2019 to 2020 and screened for ZIKV exposure using an anti-ZIKV IgG ELISA kit. A neutralization assay against ZIKV was used to confirm the reactive samples. The seroprevalence results reported from the study of this population in Malaysia were 21.0% (n = 148, 95% CI, 0.183-0.273) after confirmation with a foci reduction neutralization test. The presence of neutralizing antibodies provides evidence that the studied forest fringe communities in Malaysia have been exposed to ZIKV. Multivariate analysis showed that those older than 44 years and those with an education below the university level had been exposed significantly to ZIKV. In addition, higher seropositivity rates to ZIKV were also reported among secondary school students from Bentong (Pahang) and residents from Segaliud (Sabah). No associations were identified between Zika seropositivity and gender, household size, house radius to the jungle, and income level. The presence of neutralizing antibodies against ZIKV among the study population might indicate that the causative pathogen had already circulated widely in forest fringe regions. Intervention for vector control, protection from mosquito bites, and awareness improvement should be encouraged in this population.
Collapse
Affiliation(s)
- Hooi-Yuen Khoo
- Tropical Infectious Diseases Research & Education Centre, Higher Institution Centre of Excellence, University Malaya, Kuala Lumpur, Malaysia
| | - Hai-Yen Lee
- Tropical Infectious Diseases Research & Education Centre, Higher Institution Centre of Excellence, University Malaya, Kuala Lumpur, Malaysia
| | - Chee-Sieng Khor
- Tropical Infectious Diseases Research & Education Centre, Higher Institution Centre of Excellence, University Malaya, Kuala Lumpur, Malaysia
| | - Kim-Kee Tan
- Tropical Infectious Diseases Research & Education Centre, Higher Institution Centre of Excellence, University Malaya, Kuala Lumpur, Malaysia
| | - Mohd Rohaizat bin Hassan
- Department of Community Health, Faculty of Medicine, University Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - Chin Mun Wong
- Department of Community Health, Faculty of Medicine, University Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - Hani Kartini Agustar
- Department of Earth Sciences and Environment, Faculty of Science & Technology, University Kebangsaan Malaysia, Selangor, Malaysia
| | - Nadia Aqilla Samsusah
- Department of Earth Sciences and Environment, Faculty of Science & Technology, University Kebangsaan Malaysia, Selangor, Malaysia
| | | | | | - Nur Athirah Yusof
- Biotechnology Research Institute, University Malaysia Sabah, Sabah, Malaysia
| | - Noor Ain Haron
- Biotechnology Research Institute, University Malaysia Sabah, Sabah, Malaysia
| | - Zarina binti Amin
- Biotechnology Research Institute, University Malaysia Sabah, Sabah, Malaysia
| | - Rozita Hod
- Department of Community Health, Faculty of Medicine, University Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - Sazaly AbuBakar
- Tropical Infectious Diseases Research & Education Centre, Higher Institution Centre of Excellence, University Malaya, Kuala Lumpur, Malaysia
- Department of Medical Microbiology, Faculty of Medicine, University Malaya, Kuala Lumpur, Malaysia
| |
Collapse
|
9
|
Khoo HY, Lee HY, Khor CS, Tan KK, AbuBakar S. Evaluation of commercial serological assays in Malaysia for detection of anti-Zika virus antibodies. Trop Biomed 2021; 38:613-621. [PMID: 35001928 DOI: 10.47665/tb.38.4.105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The recommended test guidelines for Zika virus (ZIKV) include using both molecular and serological tools. While the molecular tools are useful for detecting acute infection, the serological tools are useful for the detection of previous infections. Nevertheless, detection of ZIKV-specific antibodies remains a challenge due to the high cross-reactivity between ZIKV and other flaviviruses such as dengue virus (DENV) and Japanese encephalitis virus (JEV). The objective of this study is to evaluate the commercially available enzyme-linked immunosorbent assay (ELISA) for the detection of ZIKV IgG. In this study, we evaluated 6 commercially available anti-ZIKV IgG ELISA kits. Pre-characterized serum panels consisting of 70 sera were selected for the evaluation. The diagnostic accuracy of each ELISA kits was determined and compared to the gold standard, Foci Reduction Neutralization Test (FRNT). The present study established that the performance of the NS1-based anti-ZIKV IgG ELISA kit was superior to that which uses of the E protein as antigen. Overall, commercial ZIKV IgG ELISA showed varying test performances, with some achieving moderate to high test sensitivities and specificities. When compared against the FRNT, the test sensitivities ranged from 7.1% to 78.6%, whereas, the test specificities ranged from 40.0% to 100%. Limitation to the study includes the cross reactivity between flavivirus and specificity of the kit in addressing the cross reactivity.
Collapse
Affiliation(s)
- H Y Khoo
- Tropical Infectious Diseases Research & Education Centre (TIDREC), Higher Institution Centre of Excellence (HICoE), Universiti Malaya, 50603 Kuala Lumpur, Malaysia
| | - H Y Lee
- Tropical Infectious Diseases Research & Education Centre (TIDREC), Higher Institution Centre of Excellence (HICoE), Universiti Malaya, 50603 Kuala Lumpur, Malaysia
| | - C S Khor
- Tropical Infectious Diseases Research & Education Centre (TIDREC), Higher Institution Centre of Excellence (HICoE), Universiti Malaya, 50603 Kuala Lumpur, Malaysia
| | - K K Tan
- Tropical Infectious Diseases Research & Education Centre (TIDREC), Higher Institution Centre of Excellence (HICoE), Universiti Malaya, 50603 Kuala Lumpur, Malaysia
| | - S AbuBakar
- Tropical Infectious Diseases Research & Education Centre (TIDREC), Higher Institution Centre of Excellence (HICoE), Universiti Malaya, 50603 Kuala Lumpur, Malaysia.,WHO Collaboration Centre for Arbovirus Reference and Research Malaysia, Universiti Malaya, 50603 Kuala Lumpur, Malaysia (MAA-12 ).,Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, 50603 Kuala Lumpur, Malaysia
| |
Collapse
|
10
|
Hon SA, Lee LT, Tan KK, Lee RA, Low QJ. Hepatic Sarcoidosis: Diagnostic approach and management. Med J Malaysia 2021; 76:914-917. [PMID: 34806684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Sarcoidosis is a multi-systemic, non-caseating granulomatous disorder with an idiopathic aetiology. We report a 58-year-old Malay woman, with underlying type II diabetes mellitus, hypertension and history of stage II pulmonary sarcoidosis presenting with incidental finding of multiple hypodense liver lesions. Her recent contrasted enhanced computed tomography of the abdomen and pelvis demonstrated multiple intra-abdominal lymphadenopathies with evidence of liver and splenic infiltrations. Her ageappropriate malignancy screening was negative while liver biopsy showed non-caseating granulomatous hepatitis consistent with hepatic sarcoidosis. In view of her normal liver enzymes and normalised serum calcium levels, no immunosuppressive therapy was commenced. She remains asymptomatic and is currently under our close monitoring.
Collapse
Affiliation(s)
- S A Hon
- Hospital Sultanah Nora Ismail, Department of Internal Medicine, Batu Pahat, Johor, Malaysia.
| | - L T Lee
- Hospital Sultanah Aminah, Department of Surgery, Johor Bahru, Johor, Malaysia
| | - K K Tan
- Hospital Pakar Sultanah Fatimah, Department of Pathology, Muar, Johor, Malaysia
| | - R A Lee
- Hospital Sultanah Nora Ismail, Department of Radiology, Batu Pahat, Johor, Malaysia
| | - Q J Low
- Hospital Sultanah Nora Ismail, Department of Internal Medicine, Batu Pahat, Johor, Malaysia
| |
Collapse
|
11
|
Tan KK, Tiong V, Tan JY, Wong JE, Teoh BT, Abd-Jamil J, Johari J, Nor'e SS, Khor CS, Yaacob CN, Zulkifli MMS, CheMatSeri A, Mahfodz NH, Azizan NS, AbuBakar S. Multiplex sequencing of SARS-Cov-2 genome directly from clinical samples using the Ion Personal Genome Machine (PGM). Trop Biomed 2021; 38:283-288. [PMID: 34362871 DOI: 10.47665/tb.38.3.069] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Various methods have been developed for rapid and high throughput full genome sequencing of SARS-CoV-2. Here, we described a protocol for targeted multiplex full genome sequencing of SARS-CoV-2 genomic RNA directly extracted from human nasopharyngeal swabs using the Ion Personal Genome Machine (PGM). This protocol involves concomitant amplification of 237 gene fragments encompassing the SARS-CoV-2 genome to increase the abundance and yield of viral specific sequencing reads. Five complete and one near-complete genome sequences of SARS-CoV-2 were generated with a single Ion PGM sequencing run. The sequence coverage analysis revealed two amplicons (positions 13 751-13 965 and 23 941-24 106), which consistently gave low sequencing read coverage in all isolates except 4Apr20-64- Hu. We analyzed the potential primer binding sites within these low covered regions and noted that the 4Apr20-64-Hu possess C at positions 13 730 and 23 929, whereas the other isolates possess T at these positions. The genome nucleotide variations observed suggest that the naturally occurring variations present in the actively circulating SARS-CoV-2 strains affected the performance of the target enrichment panel of the Ion AmpliSeq™ SARS CoV 2 Research Panel. The possible impact of other genome nucleotide variations warrants further investigation, and an improved version of the Ion AmpliSeq™ SARS CoV 2 Research Panel, hence, should be considered.
Collapse
Affiliation(s)
- K K Tan
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Centre of Excellence (HICoE), University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - V Tiong
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Centre of Excellence (HICoE), University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - J Y Tan
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Centre of Excellence (HICoE), University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - J E Wong
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Centre of Excellence (HICoE), University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - B T Teoh
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Centre of Excellence (HICoE), University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - J Abd-Jamil
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Centre of Excellence (HICoE), University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - J Johari
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Centre of Excellence (HICoE), University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - S S Nor'e
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Centre of Excellence (HICoE), University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - C S Khor
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Centre of Excellence (HICoE), University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - C N Yaacob
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Centre of Excellence (HICoE), University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - M M S Zulkifli
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Centre of Excellence (HICoE), University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - A CheMatSeri
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Centre of Excellence (HICoE), University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - N H Mahfodz
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Centre of Excellence (HICoE), University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - N S Azizan
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Centre of Excellence (HICoE), University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - S AbuBakar
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Centre of Excellence (HICoE), University of Malaya, 50603 Kuala Lumpur, Malaysia.,Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| |
Collapse
|
12
|
AbuBakar S, Loong S, Che-Mat-Seri NA, Tan KK, Azizan NS, Ahmad-Nasrah S, Mohd-Zain S. Isolation of Kytococcus schroeteri from the brown rat Rattus norvegicus. ASIAN PAC J TROP MED 2021. [DOI: 10.4103/1995-7645.312515] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
|
13
|
Teoh BT, Chin KL, Samsudin NI, Loong SK, Sam SS, Tan KK, Khor CS, Abd-Jamil J, Zainal N, Wilder-Smith A, Zandi K, AbuBakar S. A reverse transcription loop-mediated isothermal amplification for broad coverage detection of Asian and African Zika virus lineages. BMC Infect Dis 2020; 20:947. [PMID: 33308203 PMCID: PMC7731766 DOI: 10.1186/s12879-020-05585-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 11/04/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Early detection of Zika virus (ZIKV) infection during the viremia and viruria facilitates proper patient management and mosquito control measurement to prevent disease spread. Therefore, a cost-effective nucleic acid detection method for the diagnosis of ZIKV infection, especially in resource-deficient settings, is highly required. METHODS In the present study, a single-tube reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay was developed for the detection of both the Asian and African-lineage ZIKV. The detection limit, strain coverage and cross-reactivity of the ZIKV RT-LAMP assay was evaluated. The sensitivity and specificity of the RT-LAMP were also evaluated using a total of 24 simulated clinical samples. The ZIKV quantitative reverse transcription-polymerase chain reaction (qRT-PCR) assay was used as the reference assay. RESULTS The detection limit of the RT-LAMP assay was 3.73 ZIKV RNA copies (probit analysis, P ≤ 0.05). The RT-LAMP assay detected the ZIKV genomes of both the Asian and African lineages without cross-reacting with other arthropod-borne viruses. The sensitivity and specificity of the RT-LAMP assay were 90% (95% CI = 59.6-98.2) and 100% (95% CI = 78.5-100.0), respectively. The RT-LAMP assay detected ZIKV genome in 9 of 24 (37.5%) of the simulated clinical samples compared to 10 of 24 (41.7%) by qRT-PCR assay with a high level of concordance (κ = 0.913, P < 0.001). CONCLUSION The RT-LAMP assay is applicable for the broad coverage detection of both the Asian and African ZIKV strains in resource-deficient settings.
Collapse
Affiliation(s)
- Boon-Teong Teoh
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Universiti Malaya, Kuala Lumpur, Malaysia.
| | - Kim-Ling Chin
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Universiti Malaya, Kuala Lumpur, Malaysia.,Institute for Advanced Studies (IAS), Universiti Malaya, Kuala Lumpur, Malaysia
| | - Nur-Izyan Samsudin
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Universiti Malaya, Kuala Lumpur, Malaysia
| | - Shih-Keng Loong
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Universiti Malaya, Kuala Lumpur, Malaysia
| | - Sing-Sin Sam
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Universiti Malaya, Kuala Lumpur, Malaysia
| | - Kim-Kee Tan
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Universiti Malaya, Kuala Lumpur, Malaysia
| | - Chee-Sieng Khor
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Universiti Malaya, Kuala Lumpur, Malaysia
| | - Juraina Abd-Jamil
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Universiti Malaya, Kuala Lumpur, Malaysia
| | - Nurhafiza Zainal
- Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Annelies Wilder-Smith
- Department of Public Health and Clinical Medicine, Epidemiology and Global Health, Umeå University, Umeå, Sweden.,Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Republic of Singapore
| | - Keivan Zandi
- Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia.,Center for AIDS Research, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - Sazaly AbuBakar
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Universiti Malaya, Kuala Lumpur, Malaysia. .,Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia.
| |
Collapse
|
14
|
Teoh B, Chin K, Samsudin N, Loong S, Sam S, Tan K, Khor C, Abd-jamil J, Zainal N, Wilder-smith A, Zandi K, Abubakar S. A reverse transcription loop-mediated isothermal amplification for broad coverage detection of Asian and African Zika virus lineages.. [DOI: 10.21203/rs.3.rs-56856/v2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Abstract
Abstract
Background: Early detection of Zika virus (ZIKV) infection during the viremia and viruria facilitates proper patient management and mosquito control measurement to prevent disease spread. Therefore, a cost-effective nucleic acid detection method for the diagnosis of ZIKV infection, especially in resource-deficient settings, is highly required.Methods: In the present study, a single-tube reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay was developed for the detection of both the Asian and African-lineage ZIKV. The detection limit, strain coverage and cross-reactivity of the ZIKV RT-LAMP assay was evaluated. The sensitivity and specificity of the RT-LAMP were also evaluated using a total of 24 simulated clinical samples. The ZIKV quantitative reverse transcription-polymerase chain reaction (qRT-PCR) assay was used as the reference assay.Results: The detection limit of the RT-LAMP assay was 3.73 ZIKV RNA copies (probit analysis, P ≤ 0.05). The RT-LAMP assay detected the ZIKV genomes of both the Asian and African lineages without cross-reacting with other arthropod-borne viruses. The sensitivity and specificity of the RT-LAMP assay were 90% (95% CI = 59.6 – 98.2) and 100% (95% CI = 78.5 – 100.0), respectively. The RT-LAMP assay detected ZIKV genome in 9 of 24 (37.5%) of the simulated clinical samples compared to 10 of 24 (41.7%) by qRT-PCR assay with a high level of concordance (k = 0.913, P < 0.001).Conclusion: The RT-LAMP assay is applicable for the broad coverage detection of both the Asian and African ZIKV strains in resource-deficient settings.
Collapse
|
15
|
Teoh B, Chin K, Samsudin N, Loong S, Sam S, Tan K, Khor C, Abd-jamil J, Zainal N, Wilder-smith A, Zandi K, Abubakar S. A Reverse Transcription Loop-mediated Isothermal Amplification for Broad Coverage Detection of Asian and African Zika Virus Lineages.. [DOI: 10.21203/rs.3.rs-56856/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Abstract
Abstract
Background: Early detection of Zika virus (ZIKV) infection during the viremia and viruria facilitates proper patient management and mosquito control measurement to prevent disease spread. Therefore, a cost-effective nucleic acid detection method for the diagnosis of ZIKV infection, especially in resource-deficient settings, is highly required.Methods: In the present study, a single-tube reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay was developed for the detection of both the Asian and African-lineage ZIKV. The detection limit, strain coverage and cross-reactivity of the ZIKV RT-LAMP assay was evaluated. The sensitivity and specificity of the RT-LAMP were also evaluated using a total of 24 simulated clinical samples. The ZIKV quantitative reverse transcription-polymerase chain reaction (qRT-PCR) assay was used as the reference assay.Results: The detection limit of the RT-LAMP assay was 3.73 ZIKV RNA copies (probit analysis, P ≤ 0.05). The RT-LAMP assay detected the ZIKV genomes of both the Asian and African lineages without cross-reacting with other arthropod-borne viruses. The sensitivity and specificity of the RT-LAMP assay were 90% (95% CI = 59.6 – 98.2) and 100% (95% CI = 78.5 – 100.0), respectively. The RT-LAMP assay detected ZIKV genome in 9 of 24 (37.5%) of the simulated clinical samples compared to 10 of 24 (41.7%) by qRT-PCR assay with a high level of concordance ( = 0.913, P < 0.001).Conclusion: The RT-LAMP assay is applicable for the broad coverage detection of both the Asian and African ZIKV strains in resource-deficient settings.
Collapse
|
16
|
Khor CS, Mohd-Rahim NF, Hassan H, Tan KK, Zainal N, Teoh BT, Sam SS, Khoo JJ, Lee HY, Lim YAL, Abubakar S. Serological evidence of DENV, JEV, and ZIKV among the indigenous people (Orang Asli) of Peninsular Malaysia. J Med Virol 2019; 92:956-962. [PMID: 31814135 DOI: 10.1002/jmv.25649] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Accepted: 12/04/2019] [Indexed: 11/07/2022]
Abstract
Dengue virus (DENV), Japanese encephalitis virus (JEV), and Zika virus (ZIKV) are mosquito-borne flavivirus of medical importance in tropical countries such as Malaysia. However, much remains unknown regarding their prevalence among the underserved indigenous people (Orang Asli) living in communities in the forest fringe areas of Peninsular Malaysia. Information on the prevalence of diseases is necessary to elevate the effectiveness of disease control and preventive measures. This study aimed to determine the seroprevalence of the three major flaviviruses among the Orang Asli and investigate the association between demographic factors and seropositivities. Sampling activities were conducted in the Orang Asli villages to obtain serum samples and demographic data from consenting volunteers. The presence of DENV, JEV, and ZIKV immunoglobulin G (IgG) antibodies in the sera were examined using commercial enzyme-linked immunosorbent assay kits. A focus reduction neutralization assay was performed to measure virus-specific neutralizing antibodies. A total of 872 serum samples were obtained from the Orang Asli volunteers. Serological assay results revealed that DENV IgG, JEV IgG, and ZIKV IgG seropositivities among the Orang Asli were at 4.9%, 48.4%, and 13.2%, respectively. Neutralizing antibodies (FRNT50 ≥ 1:40) against JEV and ZIKV were found in 86.7% and 100.0%, respectively, out of the samples tested. Positive serology to all three viruses corresponded significantly to the age of the volunteers with increasing seropositivity in older volunteers. Findings from the study suggest that Orang Asli are at significant risk of contracting JEV and ZIKV infections despite the lack of active transmission of the viruses in the country.
Collapse
Affiliation(s)
- Chee-Sieng Khor
- Tropical Infectious Diseases Research & Education Centre, University of Malaya, Kuala Lumpur, Malaysia
| | - Nurul-Farhana Mohd-Rahim
- Tropical Infectious Diseases Research & Education Centre, University of Malaya, Kuala Lumpur, Malaysia.,Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Habibi Hassan
- Tropical Infectious Diseases Research & Education Centre, University of Malaya, Kuala Lumpur, Malaysia.,Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Kim-Kee Tan
- Tropical Infectious Diseases Research & Education Centre, University of Malaya, Kuala Lumpur, Malaysia
| | - Nurhafiza Zainal
- Tropical Infectious Diseases Research & Education Centre, University of Malaya, Kuala Lumpur, Malaysia.,Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Boon-Teong Teoh
- Tropical Infectious Diseases Research & Education Centre, University of Malaya, Kuala Lumpur, Malaysia
| | - Sing-Sin Sam
- Tropical Infectious Diseases Research & Education Centre, University of Malaya, Kuala Lumpur, Malaysia
| | - Jing-Jing Khoo
- Tropical Infectious Diseases Research & Education Centre, University of Malaya, Kuala Lumpur, Malaysia
| | - Hai-Yen Lee
- Tropical Infectious Diseases Research & Education Centre, University of Malaya, Kuala Lumpur, Malaysia
| | - Yvonne Ai-Lian Lim
- Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Sazaly Abubakar
- Tropical Infectious Diseases Research & Education Centre, University of Malaya, Kuala Lumpur, Malaysia.,Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| |
Collapse
|
17
|
Abstract
Zika virus (ZIKV) infection is a serious public health concern. ZIKV infection has been associated with increased occurrences of microcephaly among newborns and incidences of Guillain-Barré syndrome among adults. No specific therapeutics or vaccines are currently available to treat and protect against ZIKV infection. Here, a plant-secreted phytoalexin, resveratrol (RES), was investigated for its ability to inhibit ZIKV replication in vitro. Several RES treatment regimens were used. The ZIKV titers of mock- and RES-treated infected cell cultures were determined using the focus-forming assay and the Zika mRNA copy number as determined using qRT-PCR. Our results suggested that RES treatment reduced ZIKV titers in a dose-dependent manner. A reduction of >90% of virus titer and ZIKV mRNA copy number was achieved when infected cells were treated with 80 µM of RES post-infection. Pre-incubation of the virus with 80 µM RES showed >30% reduction in ZIKV titers and ZIKV mRNA copy number, implying potential direct virucidal effects of RES against the virus. The RES treatment reduced >70% virus titer in the anti-adsorption assay, suggesting the possibility that RES also interferes with ZIKV binding. However, there was no significant decrease in ZIKV titer when a short-period of RES treatment was applied to cells before ZIKV infection (pre-infection) and after the virus bound to the cells (virus internalization inhibition), implying that RES acts through its continuous presence in the cell cultures after virus infection. Overall, our results suggested that RES exhibited direct virucidal activity against ZIKV and possessed anti-ZIKV replication properties, highlighting the need for further exploration of RES as a potential antiviral molecule against ZIKV infection.
Collapse
Affiliation(s)
- Azirah Mohd
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, Kuala Lumpur, Malaysia.,Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Nurhafiza Zainal
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, Kuala Lumpur, Malaysia.,Department of Medical Microbiology, University of Malaya, Kuala Lumpur, Malaysia.,Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Kim-Kee Tan
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, Kuala Lumpur, Malaysia.,Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Sazaly AbuBakar
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, Kuala Lumpur, Malaysia. .,Department of Medical Microbiology, University of Malaya, Kuala Lumpur, Malaysia. .,Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
| |
Collapse
|
18
|
Alghazali KA, Teoh BT, Loong SK, Sam SS, Che-Mat-Seri NAA, Samsudin NI, Yaacob CN, Azizan NS, Oo A, Baharudin NA, Tan KK, Abd-Jamil J, Nor'e SS, Khor CS, Johari J, Mahdy MAK, AbuBakar S. Dengue Outbreak during Ongoing Civil War, Taiz, Yemen. Emerg Infect Dis 2019; 25:1397-1400. [PMID: 30924766 PMCID: PMC6590741 DOI: 10.3201/eid2507.180046] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
We identified dengue in ≈51% of patients given a clinical diagnosis of suspected dengue in Taiz, Yemen, during 2016. The cosmopolitan genotype of dengue virus type 2 was most common; viruses appeared to have originated in Saudi Arabia. Damage to public health infrastructure during the ongoing civil war might enable dengue to become endemic to Yemen.
Collapse
|
19
|
Faheem NAA, Kwan Z, Yong ASW, Ch'ng CC, Tan KK, Naicker M, Tan LL. Syringocystadenoma papilliferum arising in a naevus sebaceous. Malays J Pathol 2019; 41:47-49. [PMID: 31025637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Naevus sebaceus is a cutaneous hamartoma with the potential of developing into benign or malignant neoplasms. Syringocystadenoma papilliferum (SCAP) have been reported to originate from naevus sebaceus. SCAP is a rare, benign adnexal skin tumour of apocrine or eccrine type of differentiation which typically presents as a nodule or a plaque on the scalp or face. We report a case of syringocystadenoma papilliferum arising in an undiagnosed pre-existing naevus sebaceus in a 56-year-old female.
Collapse
Affiliation(s)
- N A A Faheem
- University of Malaya, Faculty of Medicine, Department of Medicine, Division of Dermatology, Kuala Lumpur, Malaysia.
| | | | | | | | | | | | | |
Collapse
|
20
|
Zainal N, Tan KK, Johari J, Hussein H, Wan Musa WR, Hassan J, Lin YS, AbuBakar S. Sera of patients with systemic lupus erythematosus cross-neutralizes dengue viruses. Microbiol Immunol 2018; 62:659-672. [PMID: 30259549 DOI: 10.1111/1348-0421.12652] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 07/16/2018] [Accepted: 09/10/2018] [Indexed: 11/28/2022]
Abstract
Dengue is the most prevalent mosquito-borne disease in Southeast Asia, where the incidence of systemic lupus erythematosus (SLE) is approximately 30 to 53 per 100,000. Severe dengue, however, is rarely reported among individuals with SLE. Here, whether sera of patients with SLE cross-neutralize dengue virus (DENV) was investigated. Serum samples were obtained from individuals with SLE who were dengue IgG and IgM serology negative. Neutralization assays were performed against the three major DENV serotypes. Of the dengue serology negative sera of individuals with SLE, 60%, 61% and 52% of the sera at 1/320 dilution showed more than 50% inhibition against dengue type-1 virus (DENV-1), DENV-2 and DENV-3, respectively. The neutralizing capacity of the sera was significantly greater against DENV-1 (P < 0.001) and DENV-3 (P < 0.01) than against DENV-2 (P < 0.05). Neutralization against the DENV correlated with dengue-specific IgG serum titers below the cut-off point for dengue positivity. Depletion of total IgG from the sera of patients with SLE resulted in significant decreases of up to 80% in DENV inhibition, suggesting that IgG plays an important role. However, some of the SLE sera was still able to neutralize DENV, even with IgG titers <0.1 OD absorbance. Our findings suggest that sera of patients with SLE contain IgG, and possibly other type of antibodies, that can cross-neutralize DENV, which may explain the rarity of severe dengue in individuals with SLE. Further studies, are needed to further substantiate this finding and to elucidate the specific neutralizing epitopes recognized by the sera of individuals with SLE.
Collapse
Affiliation(s)
- Nurhafiza Zainal
- Institute of Graduate Studies, University of Malaya, Kuala Lumpur, Malaysia.,Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.,Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Kim-Kee Tan
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.,Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, Kuala Lumpur, Malaysia
| | - Jefree Johari
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, Kuala Lumpur, Malaysia
| | | | | | - Jamiyah Hassan
- Department of Obstetrics and Gynaecology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Yee-Shin Lin
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Centre of Infectious Disease and Signalling Research, National Cheng Kung University, Tainan, Taiwan
| | - Sazaly AbuBakar
- Institute of Graduate Studies, University of Malaya, Kuala Lumpur, Malaysia.,Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.,Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, Kuala Lumpur, Malaysia
| |
Collapse
|
21
|
Sam SS, Teoh BT, Chee CM, Mohamed-Romai-Noor NA, Abd-Jamil J, Loong SK, Khor CS, Tan KK, AbuBakar S. A quantitative reverse transcription-polymerase chain reaction for detection of Getah virus. Sci Rep 2018; 8:17632. [PMID: 30518924 PMCID: PMC6281642 DOI: 10.1038/s41598-018-36043-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 11/09/2018] [Indexed: 11/13/2022] Open
Abstract
Getah virus (GETV), a mosquito-borne alphavirus, is an emerging animal pathogen causing outbreaks among racehorses and pigs. Early detection of the GETV infection is essential for timely implementation of disease prevention and control interventions. Thus, a rapid and accurate nucleic acid detection method for GETV is highly needed. Here, two TaqMan minor groove binding (MGB) probe-based quantitative reverse transcription-polymerase chain reaction (qRT-PCR) assays were developed. The qRT-PCR primers and TaqMan MGB probe were designed based on the conserved region of nsP1 and nsP2 genes of 23 GETV genome sequences retrieved from GenBank. Only the qRT-PCR assay using nsP2-specific primers and probe detected all two Malaysia GETV strains (MM2021 and B254) without cross-reacting with other closely related arboviruses. The qRT-PCR assay detected as few as 10 copies of GETV RNA, but its detection limit at the 95% probability level was 63.25 GETV genome copies (probit analysis, P ≤ 0.05). Further validation of the qRT-PCR assay using 16 spiked simulated clinical specimens showed 100% for both sensitivity and specificity. In conclusion, the qRT-PCR assay developed in this study is useful for rapid, sensitive and specific detection and quantification of GETV.
Collapse
Affiliation(s)
- Sing-Sin Sam
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, Kuala Lumpur, Malaysia
| | - Boon-Teong Teoh
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, Kuala Lumpur, Malaysia
| | - Cheah-Mun Chee
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, Kuala Lumpur, Malaysia
| | | | - Juraina Abd-Jamil
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, Kuala Lumpur, Malaysia
| | - Shih-Keng Loong
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, Kuala Lumpur, Malaysia
| | - Chee-Sieng Khor
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, Kuala Lumpur, Malaysia
| | - Kim-Kee Tan
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, Kuala Lumpur, Malaysia
| | - Sazaly AbuBakar
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, Kuala Lumpur, Malaysia. .,Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
| |
Collapse
|
22
|
Koo CY, Tai BC, Chan KHD, Tan KK, Lee CH. P3499Predictors of major adverse cardiac and cerebrovascular events in patients newly diagnosed with colorectal carcinoma after surgical resection. Eur Heart J 2018. [DOI: 10.1093/eurheartj/ehy563.p3499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- C Y Koo
- National University Heart Centre, Cardiology, Singapore, Singapore
| | - B C Tai
- National University of Singapore, Saw Swee Hock School of Public Health, Singapore, Singapore
| | - K H D Chan
- National University Health System, General Surgery, Singapore, Singapore
| | - K K Tan
- National University Health System, General Surgery, Singapore, Singapore
| | - C H Lee
- National University Heart Centre, Cardiology, Singapore, Singapore
| |
Collapse
|
23
|
Tan KK, Zulkifle NI, Sulaiman S, Pang SP, NorAmdan N, MatRahim N, Abd-Jamil J, Shu MH, Mahadi NM, AbuBakar S. Emergence of the Asian lineage dengue virus type 3 genotype III in Malaysia. BMC Evol Biol 2018; 18:58. [PMID: 29699483 PMCID: PMC5921268 DOI: 10.1186/s12862-018-1175-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Accepted: 04/11/2018] [Indexed: 01/16/2023] Open
Abstract
Background Dengue virus type 3 genotype III (DENV3/III) is associated with increased number of severe infections when it emerged in the Americas and Asia. We had previously demonstrated that the DENV3/III was introduced into Malaysia in the late 2000s. We investigated the genetic diversity of DENV3/III strains recovered from Malaysia and examined their phylogenetic relationships against other DENV3/III strains isolated globally. Results Phylogenetic analysis revealed at least four distinct DENV3/III lineages. Two of the lineages (DENV3/III-B and DENV3/III-C) are current actively circulating whereas the DENV3/III-A and DENV3/III-D were no longer recovered since the 1980s. Selection pressure analysis revealed strong evidence of positive selection on a number of amino acid sites in PrM, E, NS1, NS2a, NS2b, NS3, NS4a, and NS5. The Malaysian DENV3/III isolates recovered in the 1980s (MY.59538/1987) clustered into DENV3/III-B, which was the lineage with cosmopolitan distribution consisting of strains actively circulating in the Americas, Africa, and Asia. The Malaysian isolates recovered after the 2000s clustered within DENV3/III-C. This DENV3/III-C lineage displayed a more restricted geographical distribution and consisted of isolates recovered from Asia, denoted as the Asian lineage. Amino acid variation sites in NS5 (NS5–553I/M, NS5–629 T, and NS5–820E) differentiated the DENV3/III-C from other DENV3 viruses. The codon 629 of NS5 was identified as a positively selected site. While the NS5-698R was identified as unique to the genome of DENV3/III-C3. Phylogeographic results suggested that the recent Malaysian DENV3/III-C was likely to have been introduced from Singapore in 2008 and became endemic. From Malaysia, the virus subsequently spread into Taiwan and Thailand in the early part of the 2010s and later reintroduced into Singapore in 2013. Conclusions Distinct clustering of the Malaysian old and new DENV3/III isolates suggests that the currently circulating DENV3/III in Malaysia did not descend directly from the strains recovered during the 1980s. Phylogenetic analyses and common genetic traits in the genome of the strains and those from the neighboring countries suggest that the Malaysian DENV3/III is likely to have been introduced from the neighboring regions. Malaysia, however, serves as one of the sources of the recent regional spread of DENV3/III-C3 within the Asia region. Electronic supplementary material The online version of this article (10.1186/s12862-018-1175-4) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Kim-Kee Tan
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, 50603, Kuala Lumpur, Malaysia.,Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Nurul-Izzani Zulkifle
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Syuhaida Sulaiman
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Sui-Ping Pang
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - NurAsyura NorAmdan
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - NorAziyah MatRahim
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Juraina Abd-Jamil
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Meng-Hooi Shu
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Nor Muhammad Mahadi
- Malaysia Genome Institute, Ministry of Science, Technology and Innovation, Jalan Bangi, 43000, Kajang, Selangor, Malaysia
| | - Sazaly AbuBakar
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, 50603, Kuala Lumpur, Malaysia. .,Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia.
| |
Collapse
|
24
|
Tan KK, Azizan NS, Yaacob CN, Che Mat Seri NAA, Samsudin NI, Teoh BT, Sam SS, AbuBakar S. Operational utility of the reverse-transcription recombinase polymerase amplification for detection of dengue virus. BMC Infect Dis 2018; 18:169. [PMID: 29642856 PMCID: PMC5896040 DOI: 10.1186/s12879-018-3065-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 03/26/2018] [Indexed: 02/02/2023] Open
Abstract
Background A method for rapid detection of dengue virus using the reverse-transcription recombinase polymerase amplification (RT-RPA) was recently developed, evaluated and made ready for deployment. However, reliance solely on the evaluation performed by experienced researchers in a well-structured and well-equipped reference laboratory may overlook the potential intrinsic problems that may arise during deployment of the assay into new application sites, especially for users unfamiliar with the test. Appropriate assessment of this newly developed assay by users who are unfamiliar with the assay is, therefore, vital. Methods An operational utility test to elucidate the efficiency and effectiveness of the dengue RT-RPA assay was conducted among a group of researchers new to the assay. Nineteen volunteer researchers with different research experience were recruited. The participants performed the RT-RPA assay and interpreted the test results according to the protocol provided. Deviation from the protocol was identified and tabulated by trained facilitators. Post-test questionnaires were conducted to determine the user satisfaction and acceptability of the dengue RT-RPA assay. Results All the participants completed the test and successfully interpreted the results according to the provided instructions, regardless of their research experience. Of the 19 participants, three (15.8%) performed the assay with no deviations and 16 (84.2%) performed the assay with only 1 to 5 deviations. The number of deviations from protocol, however, was not correlated with the user laboratory experience. The accuracy of the results was also not affected by user laboratory experience. The concordance of the assay results against that of the expected was at 89.3%. The user satisfaction towards the RT-RPA protocol and interpretation of results was 90% and 100%, respectively. Conclusions The dengue RT-RPA assay can be successfully performed by simply following the provided written instructions. Deviations from the written protocols did not adversely affect the outcome of the assay. These suggest that the RT-RPA assay is indeed a simple, robust and efficient laboratory method for detection of dengue virus. Furthermore, high new user acceptance of the RT-RPA assay suggests that this assay could be successfully deployed into new laboratories where RT-RPA was not previously performed. Electronic supplementary material The online version of this article (10.1186/s12879-018-3065-1) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Kim-Kee Tan
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, 50603, Kuala Lumpur, Malaysia.,WHO Collaborating Centre for Arbovirus Research and Reference (Dengue and Severe Dengue), University of Malaya, 50603, Kuala Lumpur, Malaysia.,Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Noor Syahida Azizan
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, 50603, Kuala Lumpur, Malaysia.,WHO Collaborating Centre for Arbovirus Research and Reference (Dengue and Severe Dengue), University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Che Norainon Yaacob
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, 50603, Kuala Lumpur, Malaysia.,WHO Collaborating Centre for Arbovirus Research and Reference (Dengue and Severe Dengue), University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Nurul Asma Anati Che Mat Seri
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, 50603, Kuala Lumpur, Malaysia.,WHO Collaborating Centre for Arbovirus Research and Reference (Dengue and Severe Dengue), University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Nur Izyan Samsudin
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, 50603, Kuala Lumpur, Malaysia.,WHO Collaborating Centre for Arbovirus Research and Reference (Dengue and Severe Dengue), University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Boon-Teong Teoh
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, 50603, Kuala Lumpur, Malaysia.,WHO Collaborating Centre for Arbovirus Research and Reference (Dengue and Severe Dengue), University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Sing-Sin Sam
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, 50603, Kuala Lumpur, Malaysia.,WHO Collaborating Centre for Arbovirus Research and Reference (Dengue and Severe Dengue), University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Sazaly AbuBakar
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, 50603, Kuala Lumpur, Malaysia. .,WHO Collaborating Centre for Arbovirus Research and Reference (Dengue and Severe Dengue), University of Malaya, 50603, Kuala Lumpur, Malaysia. .,Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia.
| |
Collapse
|
25
|
Abstract
Kocuria marina has recently emerged as a cause for catheter-related bloodstream infections in patients with underlying health complications. One K. marina strain was recently isolated from the lung tissues of a wild urban rat (Rattus rattus diardii) caught during rodent surveillance. Here, we present the draft genome of the first K. marina animal isolate, K. marina TRE150902.
Collapse
Affiliation(s)
- Shih Keng Loong
- University of Malaya, Faculty of Medicine, Tropical Infectious
Diseases Research & Education Centre, Kuala Lumpur, Malaysia
| | - Kim-Kee Tan
- University of Malaya, Faculty of Medicine, Tropical Infectious
Diseases Research & Education Centre, Kuala Lumpur, Malaysia
- University of Malaya, Faculty of Medicine, Department of Medical
Microbiology, Kuala Lumpur, Malaysia
| | - Nurhafiza Zainal
- University of Malaya, Faculty of Medicine, Tropical Infectious
Diseases Research & Education Centre, Kuala Lumpur, Malaysia
- University of Malaya, Faculty of Medicine, Department of Medical
Microbiology, Kuala Lumpur, Malaysia
| | - Wai Hong Phoon
- University of Malaya, Faculty of Medicine, Tropical Infectious
Diseases Research & Education Centre, Kuala Lumpur, Malaysia
- University of Malaya, Faculty of Medicine, Department of Medical
Microbiology, Kuala Lumpur, Malaysia
| | - Siti Nursheena Mohd Zain
- University of Malaya, Faculty of Science, Institute of
Biological Sciences, Kuala Lumpur, Malaysia
| | - Sazaly AbuBakar
- University of Malaya, Faculty of Medicine, Tropical Infectious
Diseases Research & Education Centre, Kuala Lumpur, Malaysia
- University of Malaya, Faculty of Medicine, Department of Medical
Microbiology, Kuala Lumpur, Malaysia
| |
Collapse
|
26
|
Khoo JJ, Lim FS, Tan KK, Chen FS, Phoon WH, Khor CS, Pike BL, Chang LY, AbuBakar S. Detection in Malaysia of a Borrelia sp. From Haemaphysalis hystricis (Ixodida: Ixodidae). J Med Entomol 2017; 54:1444-1448. [PMID: 28874019 DOI: 10.1093/jme/tjx131] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Indexed: 06/07/2023]
Abstract
Spirochetes from the Borrelia genus are known to cause diseases in humans, namely Lyme disease and relapsing fever. These organisms are commonly transmitted to humans by arthropod vectors including ticks, mite, and lice. Here, we report the molecular detection of a Borrelia sp. from a Haemaphysalis hystricis Supino tick collected from wildlife in an Orang Asli settlement in Selangor, Malaysia. Phylogenetic analyses of partial 16s rRNA and flaB gene sequences revealed that the Borrelia sp. is closely related to the relapsing fever group borreliae, Borrelia lonestari, Borrelia miyamotoi, and Borrelia theileri, as well as a number of uncharacterized Borrelia sp. from ticks in Portugal and Japan. To our knowledge, this is the first report of a Borrelia sp. detected in H. hystricis, and in Malaysia. The zoonotic potential of this Borrelia sp. merits further investigation.
Collapse
Affiliation(s)
- J J Khoo
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, Kuala Lumpur, 50603, Malaysia
| | - F S Lim
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, Kuala Lumpur, 50603, Malaysia
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, 50603, Malaysia
| | - K K Tan
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, Kuala Lumpur, 50603, Malaysia
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, 50603, Malaysia
| | - F S Chen
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, Kuala Lumpur, 50603, Malaysia
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, 50603, Malaysia
| | - W H Phoon
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, Kuala Lumpur, 50603, Malaysia
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, 50603, Malaysia
| | - C S Khor
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, Kuala Lumpur, 50603, Malaysia
| | - B L Pike
- Naval Medical Research Center-Asia (NMRC-A), Singapore
| | - L Y Chang
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, Kuala Lumpur, 50603, Malaysia
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, 50603, Malaysia
| | - S AbuBakar
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, Kuala Lumpur, 50603, Malaysia
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, 50603, Malaysia
| |
Collapse
|
27
|
Joanne S, Vythilingam I, Teoh BT, Leong CS, Tan KK, Wong ML, Yugavathy N, AbuBakar S. Vector competence of Malaysian Aedes albopictus with and without Wolbachia to four dengue virus serotypes. Trop Med Int Health 2017; 22:1154-1165. [PMID: 28653334 DOI: 10.1111/tmi.12918] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
OBJECTIVE To determine the susceptibility status of Aedes albopictus with and without Wolbachia to the four dengue virus serotypes. METHODS Two newly colonised colonies of Ae. albopictus from the wild were used for the study. One colony was naturally infected with Wolbachia while in the other Wolbachia was removed by tetracycline treatment. Both colonies were orally infected with dengue virus-infected fresh blood meal. Dengue virus load was measured using quantitative RT-PCR at four-time intervals in the salivary glands, midguts and ovaries. RESULTS Wolbachia did not significantly affect Malaysian Ae. albopictus dengue infection or the dissemination rate for all four dengue virus serotypes. Malaysian Ae. albopictus had the highest replication kinetics for DENV-1 and the highest salivary gland and midgut infection rate for DENV-4. CONCLUSION Wolbachia, which naturally exists in Malaysian Ae. albopictus, does not significantly affect dengue virus replication. Malaysian Ae. albopictus is susceptible to dengue virus infections and capable of transmitting dengue virus, especially DENV-1 and DENV-4. Removal of Wolbachia from Malaysian Ae. albopictus would not reduce their susceptibility status.
Collapse
Affiliation(s)
- Sylvia Joanne
- Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Indra Vythilingam
- Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Boon-Teong Teoh
- Department of Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Cherng-Shii Leong
- Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Kim-Kee Tan
- Department of Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Meng-Li Wong
- Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Nava Yugavathy
- Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Sazaly AbuBakar
- Department of Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| |
Collapse
|
28
|
Tan KK, Zulkifle NI, Abd-Jamil J, Sulaiman S, Yaacob CN, Azizan NS, Che Mat Seri NAA, Samsudin NI, Mahfodz NH, AbuBakar S. Disruption of predicted dengue virus type 3 major outbreak cycle coincided with switching of the dominant circulating virus genotype. Infect Genet Evol 2017; 54:271-275. [PMID: 28698156 DOI: 10.1016/j.meegid.2017.07.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 07/04/2017] [Accepted: 07/06/2017] [Indexed: 10/19/2022]
Abstract
Dengue is hyperendemic in most of Southeast Asia. In this region, all four dengue virus serotypes are persistently present. Major dengue outbreak cycle occurs in a cyclical pattern involving the different dengue virus serotypes. In Malaysia, since the 1980s, the major outbreak cycles have involved dengue virus type 3 (DENV3), dengue virus type 1 (DENV1) and dengue virus type 2 (DENV2), occurring in that order (DENV3/DENV1/DENV2). Only limited information on the DENV3 cycles, however, have been described. In the current study, we examined the major outbreak cycle involving DENV3 using data from 1985 to 2016. We examined the genetic diversity of DENV3 isolates obtained during the period when DENV3 was the dominant serotype and during the inter-dominant transmission period. Results obtained suggest that the typical DENV3/DENV1/DENV2 cyclical outbreak cycle in Malaysia has recently been disrupted. The last recorded major outbreak cycle involving DENV3 occurred in 2002, and the expected major outbreak cycle involving DENV3 in 2006-2012 did not materialize. DENV genome analyses revealed that DENV3 genotype II (DENV3/II) was the predominant DENV3 genotype (67%-100%) recovered between 1987 and 2002. DENV3 genotype I (DENV3/I) emerged in 2002 followed by the introduction of DENV3 genotype III (DENV3/III) in 2008. These newly emerged DENV3 genotypes replaced DENV3/II, but there was no major upsurge of DENV3 cases that accompanied the emergence of these viruses. DENV3 remained in the background of DENV1 and DENV2 until now. Virus genome sequence analysis suggested that intrinsic differences within the different dengue virus genotypes could have influenced the transmission efficiency of DENV3. Further studies and continuous monitoring of the virus are needed for better understanding of the DENV transmission dynamics in hyperendemic regions.
Collapse
Affiliation(s)
- Kim-Kee Tan
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, 50603 Kuala Lumpur, Malaysia; Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia.
| | - Nurul-Izzani Zulkifle
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Juraina Abd-Jamil
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, 50603 Kuala Lumpur, Malaysia.
| | - Syuhaida Sulaiman
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Che Norainon Yaacob
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, 50603 Kuala Lumpur, Malaysia.
| | - Noor Syahida Azizan
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, 50603 Kuala Lumpur, Malaysia.
| | - Nurul Asma Anati Che Mat Seri
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, 50603 Kuala Lumpur, Malaysia.
| | - Nur Izyan Samsudin
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, 50603 Kuala Lumpur, Malaysia.
| | - Nur Hidayana Mahfodz
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, 50603 Kuala Lumpur, Malaysia.
| | - Sazaly AbuBakar
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, 50603 Kuala Lumpur, Malaysia; Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia.
| |
Collapse
|
29
|
Tan KK, Tan YC, Chang LY, Lee KW, Nor'e SS, Yee WY, Hoh CC, AbuBakar S. Geographical distribution of Brucella melitensis inferred from rpoB gene variation. J Infect Dev Ctries 2017; 11:420-425. [PMID: 30943180 DOI: 10.3855/jidc.7598] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 03/25/2016] [Indexed: 10/31/2022] Open
Abstract
INTRODUCTION Currently available tests have limitations for the identification of Brucella species and strains, and their genetic lineage. The genome sequence of the rpoB gene encoding the β-subunit of DNA-dependent RNA polymerase was investigated for its use in genotyping Brucella melitensis. METHODOLOGY Complete rpoB gene sequences of globally distributed Brucella melitensis strains were analyzed. Single nucleotides polymorphisms (SNPs) of the rpoB gene sequences were identified and used to type Brucella melitensis strains. RESULTS Six DNA polymorphisms were identified, of which two (nucleotides 3201 and 558) were novel. Analysis of the geographical distribution of the strains revealed a spatial clustering pattern with rpoB type 1 representing European and American strains, rpoB type 2 representing European, African, and Asian strains, rpoB type 3 representing Mediterranean strains, and rpoB type 4 representing African (C3201T) and European (C3201T/T558A) strains. CONCLUSIONS We report the discovery of two novel SNPs of rpoB gene that can serve as useful markers for epidemiology and geographical tracking of B. melitensis.
Collapse
Affiliation(s)
- Kim-Kee Tan
- University of Malaya, Kuala Lumpur, Malaysia.
| | | | | | - Kok Wei Lee
- Codon Genomics S/B, Seri Kembangan, Malaysia.
| | | | - Wai-Yan Yee
- Codon Genomics S/B, Seri Kembangan, Malaysia.
| | | | | |
Collapse
|
30
|
Loong SK, Tan KK, Sulaiman S, Wong PF, AbuBakar S. Draft genome of Bordetella pseudohinzii BH370 isolated from trachea and lung tissues of a laboratory mouse. Genom Data 2017; 12:69-70. [PMID: 28377885 PMCID: PMC5369867 DOI: 10.1016/j.gdata.2017.03.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 03/19/2017] [Indexed: 01/09/2023]
Abstract
In this study, we present the draft genome sequence of B. pseudohinzii BH370 recovered from the trachea and lung tissues of an ICR mouse in Malaysia. The genome consists of 4,474,040 bp with a GC content of 66.4%. Annotation using RAST algorithm displayed 5119 protein encoding and 52 RNA genes. The CRISPR-cas genomic sequences previously reported in B. pseudohinzii were identified. The nucleotide sequences of BH370 was deposited into the European Nucleotide Archive under the genome assembly accession number FPJN01000000.
Collapse
Affiliation(s)
- Shih Keng Loong
- Tropical Infectious Diseases Research & Education Centre (TIDREC), Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Kim-Kee Tan
- Tropical Infectious Diseases Research & Education Centre (TIDREC), Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia; Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Syuhaida Sulaiman
- Tropical Infectious Diseases Research & Education Centre (TIDREC), Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia; Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Pooi Fong Wong
- Animal Experimental Unit, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia; Department of Pharmacology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Sazaly AbuBakar
- Tropical Infectious Diseases Research & Education Centre (TIDREC), Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia; Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| |
Collapse
|
31
|
Wu LT, Low MMJ, Tan KK, Lopez V, Liaw SY. Why not nursing? A systematic review of factors influencing career choice among healthcare students. Int Nurs Rev 2016; 62:547-62. [PMID: 26572517 DOI: 10.1111/inr.12220] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND A global shortage of healthcare professionals calls for effective recruitment and retention strategies. The nursing profession faces greater staffing shortages compared with other healthcare professions. Identifying these factors for choosing a career in health care is an important step in structuring future nursing recruitment strategies. AIM This systematic review examined the motivations for choosing a career in health care, then compared them to factors that influence the choice to pursue a career in nursing. METHODS A literature search of the CINAHL, PubMed, Web of Science and Scopus databases for articles published between 2002 and 2013 was conducted. The search included studies that focused on factors influencing career choice among undergraduate medicine, dentistry, pharmacy and nursing students. RESULTS A total of 29 papers were included in the review. The themes and subthemes that emerged from this review included: (1) intrinsic factors, including a desire to help others and a personal interest in health care, (2) extrinsic factors, such as financial remuneration, job security, professional prestige and job autonomy, (3) socio-demographic factors such as gender and socio-economic status, and (4) interpersonal factors, encompassing the influence of family and other professional individuals. DISCUSSION Healthcare professionals were generally motivated by intrinsic factors. However, public perceptions of nursing as a low-paying and low-status job have significantly hindered the participants' choice to pursue it as a career. CONCLUSION AND IMPLICATIONS FOR NURSING AND/OR HEALTH POLICY Nursing institutions could provide more platforms to help school leavers better understand the nursing career. In turn, hospital administrators could invite parents to nursing career fairs, increase financial remuneration for nurses, and provide decision-making avenues aimed at recruiting and retaining more nurses.
Collapse
Affiliation(s)
- L T Wu
- National University Hospital, Singapore
| | - M M J Low
- National University Hospital, Singapore
| | - K K Tan
- Department of Nursing Science, Faculty of Health Science, University of Eastern Finland, Kuopio, Finland
| | - V Lopez
- Alice Lee Centre for Nursing Studies, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - S Y Liaw
- Alice Lee Centre for Nursing Studies, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| |
Collapse
|
32
|
Wong CH, Tan TR, Heng Hy HY, Ramesh T, Ting PW, Lee WS, Teng CL, Sivalingam N, Tan KK. Parental preferences with regards to disclosure following adverse events occurring in relation to medication use or diagnosis in the care of their children - perspectives from Malaysia. Med J Malaysia 2016; 71:186-192. [PMID: 27770117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
INTRODUCTION Open disclosure is poorly understood in Malaysia but is an ethical and professional responsibility. The objectives of this study were to determine: (1) the perception of parents regarding the severity of medical error in relation to medication use or diagnosis; (2) the preference of parents for information following the medical error and its relation to severity; and (3) the preference of parents with regards to disciplinary action, reporting, and legal action. METHODS We translated and contextualised a questionnaire developed from a previous study. The questionnaire consisted of four case vignettes that described the following: medication error with a lifelong complication; diagnostic error with a lifelong complication; diagnostic error without lifelong effect; and medication error without lifelong effect. Each case vignette was followed by a series of questions examining the subject's perception on the above areas. We also determined the content validity of the questionnaire. We invited parents of Malaysian children admitted to the paediatric wards of Tuanku Jaafar Hospital to participate in the study. RESULTS One hundred and twenty-three parents participated in the study. The majority of parents wanted to be told regarding the event. As the severity of the case vignettes increased, the desire for information, remedial action, acknowledgement of responsibility, compensation, punishment, legal action, and reporting to a higher agency also increased. The findings did not have strong evidence of a relationship with subject's demographics. CONCLUSION This study gives insights into previously unexplored perspectives and preferences of parents in Malaysia regarding open disclosure. It also highlights the opportunity for more research in this area with potentially broad applications.
Collapse
Affiliation(s)
- C H Wong
- International Medical University, Department of Family Medicine, Jalan Rasah, 70300 Seremban, Negeri Sembilan, Malaysia.
| | - T R Tan
- International Medical University, IMU Clinical School, Jalan Rasah, 70300 Seremban, Negeri Sembilan, Malaysia
| | - H Y Heng Hy
- International Medical University, IMU Clinical School, Jalan Rasah, 70300 Seremban, Negeri Sembilan, Malaysia
| | - T Ramesh
- International Medical University, IMU Clinical School, Jalan Rasah, 70300 Seremban, Negeri Sembilan, Malaysia
| | - P W Ting
- International Medical University, IMU Clinical School, Jalan Rasah, 70300 Seremban, Negeri Sembilan, Malaysia
| | - W S Lee
- International Medical University, IMU Clinical School, Jalan Rasah, 70300 Seremban, Negeri Sembilan, Malaysia
| | - C L Teng
- International Medical University, Department of Family Medicine, Jalan Rasah, 70300 Seremban, Negeri Sembilan, Malaysia
| | - N Sivalingam
- International Medical University, Department of Obstetrics and Gynaecology, Jalan Rasah, 70300 Seremban, Negeri Sembilan, Malaysia
| | - K K Tan
- Tuanku Jaafar Hospital, Department of Paediatrics, Seremban, Malaysia
| |
Collapse
|
33
|
Khoo JJ, Chen F, Kho KL, Ahmad Shanizza AI, Lim FS, Tan KK, Chang LY, AbuBakar S. Bacterial community in Haemaphysalis ticks of domesticated animals from the Orang Asli communities in Malaysia. Ticks Tick Borne Dis 2016; 7:929-937. [PMID: 27132518 DOI: 10.1016/j.ttbdis.2016.04.013] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 04/08/2016] [Accepted: 04/20/2016] [Indexed: 12/24/2022]
Abstract
Ticks are vectors in the transmission of many important infectious diseases in human and animals. Ticks can be readily found in the semi-forested areas such as the settlements of the indigenous people in Malaysia, the Orang Asli. There is still minimal information available on the bacterial agents associated with ticks found in Malaysia. We performed a survey of the bacterial communities associated with ticks collected from domestic animals found in two Orang Asli villages in Malaysia. We collected 62 ticks, microscopically and molecularly identified as related to Haemaphysalis wellingtoni, Haemaphysalis hystricis and Haemaphysalis bispinosa. Bacterial 16s rRNA hypervariable region (V6) amplicon libraries prepared from the tick samples were sequenced on the Ion Torrent PGM platform. We detected a total of 392 possible bacterial genera after pooling and sequencing 20 samples, indicating a diverse bacterial community profile. Dominant taxa include the potential tick endosymbiont, Coxiella. Other dominant taxa include the tick-associated pathogen, Rickettsia, and environmental bacteria such as Bacillus, Mycobacterium, Sphingomonas and Pseudomonas. Other known tick-associated bacteria were also detected, including Anaplasma, Ehrlichia, Rickettsiella and Wolbachia, albeit at very low abundance. Specific PCR was performed on selected samples to identify Rickettsia and Coxiella. Sequence of Rickettsia felis, which causes spotted fever in human and cats, was identified in one sample. Coxiella endosymbionts were detected in three samples. This study provides the baseline knowledge of the microbiome of ticks in Malaysia, focusing on tick-associated bacteria affecting the Orang Asli communities. The role of the herein found Coxiella and Rickettsia in tick physiology or disease transmission merits further investigation.
Collapse
Affiliation(s)
- Jing-Jing Khoo
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia; Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia.
| | - Fezshin Chen
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia; Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia.
| | - Kai Ling Kho
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia.
| | - Azzy Iyzati Ahmad Shanizza
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia; Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia.
| | - Fang-Shiang Lim
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia.
| | - Kim-Kee Tan
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia; Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia.
| | - Li-Yen Chang
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia; Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia.
| | - Sazaly AbuBakar
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia; Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia.
| |
Collapse
|
34
|
Ab-Rahman HA, Wong PF, Rahim H, Abd-Jamil J, Tan KK, Sulaiman S, Lum CS, Syed-Omar SF, AbuBakar S. Dengue death with evidence of hemophagocytic syndrome and dengue virus infection in the bone marrow. Springerplus 2015; 4:665. [PMID: 26558168 PMCID: PMC4630261 DOI: 10.1186/s40064-015-1463-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Accepted: 10/21/2015] [Indexed: 01/09/2023]
Abstract
INTRODUCTION HPS is a potentially life-threatening histiocytic disorder that has been described in various viral infections including dengue. Its involvement in severe and fatal dengue is probably more common but is presently under recognized. CASE DESCRIPTION A 38-year-old female was admitted after 5 days of fever. She was deeply jaundiced, leukopenic and thrombocytopenic. Marked elevation of transaminases, hyperbilirubinemia and hypoalbuminemia were observed. She had deranged INR values and prolonged aPTT accompanied with hypofibrinogenemia. She also had splenomegaly. She was positive for dengue IgM. Five days later she became polyuric and CT brain image showed gross generalized cerebral edema. Her conditions deteriorated by day 9, became confused with GCS of 9/15. Her BMAT showed minimal histiocytes. Her serum ferritin level peaked at 13,670.00 µg/mL and her sCD163 and sCD25 values were markedly elevated at 4750.00 ng/mL and 4191.00 pg/mL, respectively. She succumbed to the disease on day 10 and examination of her tissues showed the presence of dengue virus genome in the bone marrow. DISCUSSION AND EVALUATION It is described here, a case of fatal dengue with clinical features of HPS. Though BMAT results did not show the presence of macrophage hemophagocytosis, other laboratory features were consistent with HPS especially marked elevation of ferritin, sCD163 and sCD25. Detection of dengue virus in the patient's bone marrow, fifteen days after the onset of fever was also consistent with the suggestion that the HPS is associated with dengue virus infection. CONCLUSIONS The findings highlight HPS as a possible complication leading to severe dengue and revealed persistent dengue virus infection of the bone marrow. Detection of HPS markers; ferritin, sCD163 and sCD25, therefore, should be considered for early recognition of HPS-associated dengue.
Collapse
Affiliation(s)
- Hasliana Azrah Ab-Rahman
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia ; Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia ; Department of Pharmacology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Pooi-Fong Wong
- Department of Pharmacology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Hafiz Rahim
- Department of Medicine, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Juraina Abd-Jamil
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Kim-Kee Tan
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia ; Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Syuhaida Sulaiman
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia ; Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Chai-See Lum
- Department of Medicine, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia ; Department of Paediatrics, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | | | - Sazaly AbuBakar
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia ; Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| |
Collapse
|
35
|
Lau YL, Lai MY, Teoh BT, Abd-Jamil J, Johari J, Sam SS, Tan KK, AbuBakar S. Colorimetric Detection of Dengue by Single Tube Reverse-Transcription-Loop-Mediated Isothermal Amplification. PLoS One 2015; 10:e0138694. [PMID: 26384248 PMCID: PMC4575147 DOI: 10.1371/journal.pone.0138694] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Accepted: 09/02/2015] [Indexed: 11/18/2022] Open
Abstract
Dengue is usually diagnosed by isolation of the virus, serology or molecular diagnostic methods. Several commercial kits for the diagnosis of dengue are existing, but concerns have arisen regarding to the affordability and performance characteristics of these kits. Hence, the loop-mediated isothermal amplification (LAMP) is potentially ideal to be used especially in resource limited environments. Serum was collected from healthy donors and patients diagnosed with dengue infection. RNA extracted from the serum samples were tested by reverse-transcription-LAMP assay developed based on 3′-NCR gene sequences for DENV 1–4. Results were interpreted by a turbidity meter in real time or visually at the end of the assay. Sensitivity and specificity of RT-LAMP results were calculated and compared to qRT-PCR and ELISA. RT-LAMP is highly sensitive with the detection limit of 10 RNA copies for all serotypes. Dengue virus RNA was detected in all positive samples using RT-LAMP and none of the negative samples within 30–45 minutes. With continuing efforts in the optimization of this assay, RT-LAMP may provide a simple and reliable test for detecting DENV in areas where dengue is prevalent.
Collapse
Affiliation(s)
- Yee-Ling Lau
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Department of Parasitology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
- * E-mail:
| | - Meng-Yee Lai
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Department of Parasitology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Boon-Teong Teoh
- Tropical Infectious Diseases Research and Education Center (TIDREC), Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Juraina Abd-Jamil
- Tropical Infectious Diseases Research and Education Center (TIDREC), Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Jefree Johari
- Tropical Infectious Diseases Research and Education Center (TIDREC), Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Sing-Sin Sam
- Tropical Infectious Diseases Research and Education Center (TIDREC), Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Kim-Kee Tan
- Tropical Infectious Diseases Research and Education Center (TIDREC), Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Sazaly AbuBakar
- Tropical Infectious Diseases Research and Education Center (TIDREC), Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| |
Collapse
|
36
|
Abstract
Outbreaks involving the Asian genotype Chikungunya virus (CHIKV) caused over one million infections in the Americas recently. The outbreak was preceded by a major nationwide outbreak in the Philippines. We examined the phylogenetic and phylogeographic relationships of representative CHIKV isolates obtained from the 2012 Philippines outbreak with other CHIKV isolates collected globally. Asian CHIKV isolated from the Philippines, China, Micronesia and Caribbean regions were found closely related, herein denoted as Cosmopolitan Asian CHIKV (CACV). Three adaptive amino acid substitutions in nsP3 (D483N), E1 (P397L) and E3 (Q19R) were identified among CACV. Acquisition of the nsP3-483N mutation in Compostela Valley followed by E1-397L/E3-19R in Laguna preceded the nationwide spread in the Philippines. The China isolates possessed two of the amino acid substitutions, nsP3-D483N and E1-P397L whereas the Micronesian and Caribbean CHIKV inherited all the three amino acid substitutions. The unique amino acid substitutions observed among the isolates suggest multiple independent virus dissemination events. The possible biological importance of the specific genetic signatures associated with the rapid global of the virus is not known and warrant future in-depth study and epidemiological follow-up. Molecular evidence, however, supports the Philippines outbreak as the possible origin of the CACV.
Collapse
Affiliation(s)
- Kim-Kee Tan
- 1] Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, 50603 Kuala Lumpur, Malaysia [2] Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Ava Kristy D Sy
- Virology Department, Research Institute for Tropical Medicine, Department of Health, FCC Compound, Alabang, Muntinlupa City, Philippines
| | - Amado O Tandoc
- Virology Department, Research Institute for Tropical Medicine, Department of Health, FCC Compound, Alabang, Muntinlupa City, Philippines
| | - Jing-Jing Khoo
- 1] Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, 50603 Kuala Lumpur, Malaysia [2] Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Syuhaida Sulaiman
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Li-Yen Chang
- 1] Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, 50603 Kuala Lumpur, Malaysia [2] Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Sazaly AbuBakar
- 1] Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, 50603 Kuala Lumpur, Malaysia [2] Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| |
Collapse
|
37
|
Abstract
Jejunal artery aneurysms are rare, with only six cases reported in the literature to date. Endovascular embolisation of the jejunal artery is rarely performed. Herein, we report the case of a 57-year-old man who successfully underwent endovascular embolisation for bleeding caecal diverticulosis, during which a 9-mm fusiform jejunal artery aneurysm was incidentally diagnosed. Subsequently, the jejunal aneurysm was successfully embolised using Vortex coils.
Collapse
Affiliation(s)
- Z J Lo
- Department of General Surgery, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore 308433.
| | | | | | | |
Collapse
|
38
|
Tan KK, Tan YC, Chang LY, Lee KW, Nore SS, Yee WY, Mat Isa MN, Jafar FL, Hoh CC, AbuBakar S. Full genome SNP-based phylogenetic analysis reveals the origin and global spread of Brucella melitensis. BMC Genomics 2015; 16:93. [PMID: 25888205 PMCID: PMC4409723 DOI: 10.1186/s12864-015-1294-x] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2014] [Accepted: 01/29/2015] [Indexed: 11/17/2022] Open
Abstract
Background Brucellosis is an important zoonotic disease that affects both humans and animals. We sequenced the full genome and characterised the genetic diversity of two Brucella melitensis isolates from Malaysia and the Philippines. In addition, we performed a comparative whole-genome single nucleotide polymorphism (SNP) analysis of B. melitensis strains collected from around the world, to investigate the potential origin and the history of the global spread of B. melitensis. Results Single sequencing runs of each genome resulted in draft genome sequences of MY1483/09 and Phil1136/12, which covered 99.85% and 99.92% of the complete genome sequences, respectively. The B. melitensis genome sequences, and two B. abortus strains used as the outgroup strains, yielded a total of 13,728 SNP sites. Phylogenetic analysis using whole-genome SNPs and geographical distribution of the isolates revealed spatial clustering of the B. melitensis isolates into five genotypes, I, II, III, IV and V. The Mediterranean strains, identified as genotype I, occupied the basal node of the phylogenetic tree, suggesting that B. melitensis may have originated from the Mediterranean regions. All of the Asian B. melitensis strains clustered into genotype II with the SEA strains, including the two isolates sequenced in this study, forming a distinct clade denoted here as genotype IId. Genotypes III, IV and V of B. melitensis demonstrated a restricted geographical distribution, with genotype III representing the African lineage, genotype IV representing the European lineage and genotype V representing the American lineage. Conclusion We showed that SNPs retrieved from the B. melitensis draft full genomes were sufficient to resolve the interspecies relationships between B. melitensis strains and to discriminate between the vaccine and endemic strains. Phylogeographic reconstruction of the history of B. melitensis global spread at a finer scale by using whole-genome SNP analyses supported the origin of all B. melitensis strains from the Mediterranean region. The possible global distribution of B. melitensis following the ancient trade routes was also consistent with whole-genome SNP phylogeny. The whole genome SNP phylogenetics analysis, hence is a powerful tool for intraspecies discrimination of closely related species. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1294-x) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Kim-Kee Tan
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, 50603, Kuala Lumpur, Malaysia. .,Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia.
| | - Yung-Chie Tan
- Codon Genomics S/B, No 26, Jalan Dutamas 7, Taman Dutamas, Balakong, 43200, Seri Kembangan, Selangor, Malaysia.
| | - Li-Yen Chang
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, 50603, Kuala Lumpur, Malaysia. .,Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia.
| | - Kok Wei Lee
- Codon Genomics S/B, No 26, Jalan Dutamas 7, Taman Dutamas, Balakong, 43200, Seri Kembangan, Selangor, Malaysia.
| | - Siti Sarah Nore
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, 50603, Kuala Lumpur, Malaysia.
| | - Wai-Yan Yee
- Codon Genomics S/B, No 26, Jalan Dutamas 7, Taman Dutamas, Balakong, 43200, Seri Kembangan, Selangor, Malaysia.
| | - Mohd Noor Mat Isa
- Malaysia Genome Institute, Ministry of Science, Technology and Innovation, Jalan Bangi, 43000, Kajang, Selangor, Malaysia.
| | - Faizatul Lela Jafar
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia.
| | - Chee-Choong Hoh
- Codon Genomics S/B, No 26, Jalan Dutamas 7, Taman Dutamas, Balakong, 43200, Seri Kembangan, Selangor, Malaysia.
| | - Sazaly AbuBakar
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, 50603, Kuala Lumpur, Malaysia. .,Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia.
| |
Collapse
|
39
|
Tan KK, Pal S, Lee PJ, Rodwell L, Solomon MJ. Pelvic exenteration for recurrent squamous cell carcinoma of the pelvic organs arising from the cloaca--a single institution's experience over 16 years. Colorectal Dis 2014; 15:1227-31. [PMID: 23714581 DOI: 10.1111/codi.12306] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Accepted: 02/03/2013] [Indexed: 02/08/2023]
Abstract
AIM Minimal data are available on the role of pelvic exenteration in patients with recurrent squamous cell carcinoma (SCC) of the pelvic organs. This study aimed to highlight our experience of pelvic exenteration in patients with recurrent and re-recurrent SCC of the pelvic organs. METHOD A retrospective review of all patients who underwent pelvic exenteration for recurrent SCC of the pelvic organs arising from the embryological cloaca from 1994 to 2010 was performed. RESULTS Twenty-four patients (median age 59, range, 27-79 years) underwent pelvic exenteration for recurrent SCC of the anus (18), cervix and upper vagina (2), lower vagina (1) and the vulva (3). Nine patients with anal SCC had undergone abdominoperineal excision prior to pelvic exenteration. Ten (41.7%) patients underwent a complete pelvic exenteration procedure, while sacrectomy was performed in 13 (54.2%) patients. There was no 30-day inpatient mortality. An R0 resection was achieved in 15 (62.5%) patients. Three (12.5%) had R1 resections while 6 (25%) had R2 resections. In the 15 patients with an R0 resection, 7 (46.7%) developed metastatic disease at a median of 18 (range 10-131) months. After a median follow-up of 26 (range 4-169) months, 1- and 2-year overall survival rates were 64% [95% confidence interval (CI), 44-84%] and 57% (95% CI 35-79%), respectively. CONCLUSION Pelvic exenteration for recurrent SCC of the cloaca is safe and feasible even after previous salvage surgery. An R0 resection can be achieved in 62.5% of the patients with reasonable early survival though less than published recurrent rectal cancer studies.
Collapse
Affiliation(s)
- K K Tan
- Department of Colorectal Surgery, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia
| | | | | | | | | |
Collapse
|
40
|
Shamsul BS, Tan KK, Chen HC, Aminuddin BS, Ruszymah BHI. Posterolateral spinal fusion with ostegenesis induced BMSC seeded TCP/HA in a sheep model. Tissue Cell 2014; 46:152-8. [PMID: 24630213 DOI: 10.1016/j.tice.2014.02.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Revised: 02/06/2014] [Accepted: 02/06/2014] [Indexed: 11/26/2022]
Abstract
Autogenous bone graft is the gold standard for fusion procedure. However, pain at donor site and inconsistent outcome have left a surgeon to venture into some other technique for spinal fusion. The objective of this study was to determine whether osteogenesis induced bone marrow stem cells with the combination of ceramics granules (HA or TCP/HA), and fibrin could serve as an alternative to generate spinal fusion. The sheep's bone marrow mesenchymal stem cells (BMSCs) were aspirated form iliac crest and cultured for several passages until confluence. BMSCs were trypsinized and seeded on hydroxyapatite scaffold (HA) and tricalcium phosphate/hydroxyapatite (TCP/HA) for further osteogenic differentiation in the osteogenic medium one week before implantation. Six adult sheep underwent three-level, bilateral, posterolateral intertransverse process fusions at L1-L6. Three fusion sites in each animal were assigned to three treatments: (a) HA constructs group/L1-L2, (b) TCP/HA constructs group/L2-L3, and (c) autogenous bone graft group/L5-L6. The spinal fusion segments were evaluated using radiography, manual palpation, histological analysis and scanning electron microscopy (SEM) 12 weeks post implantation. The TCP/HA constructs achieved superior lumbar intertransverse fusion compared to HA construct but autogenous bone graft still produced the best fusion among all.
Collapse
Affiliation(s)
- B S Shamsul
- Tissue Engineering Centre, Universiti Kebangsaan Malaysia Medical Centre, Malaysia
| | - K K Tan
- Orthopedic and Spinal Surgery Consultant Clinic, Johor Specialist Hospital, Malaysia
| | - H C Chen
- Faculty of Veterinary Medicine, Universiti Putra Malaysia, Malaysia
| | - B S Aminuddin
- Ear, Nose & Throat Consultant Clinic, Ampang Puteri Specialist Hospital, Malaysia; Tissue Engineering Centre, Universiti Kebangsaan Malaysia Medical Centre, Malaysia
| | - B H I Ruszymah
- Tissue Engineering Centre, Universiti Kebangsaan Malaysia Medical Centre, Malaysia; Department of Physiology, Medical Faculty Universiti Kebangsaan Malaysia, Malaysia.
| |
Collapse
|
41
|
Teoh BT, Sam SS, Tan KK, Johari J, Shu MH, Danlami MB, Abd-Jamil J, MatRahim N, Mahadi NM, AbuBakar S. Dengue virus type 1 clade replacement in recurring homotypic outbreaks. BMC Evol Biol 2013; 13:213. [PMID: 24073945 PMCID: PMC3850903 DOI: 10.1186/1471-2148-13-213] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Accepted: 09/25/2013] [Indexed: 11/23/2022] Open
Abstract
Background Recurring dengue outbreaks occur in cyclical pattern in most endemic countries. The recurrences of dengue virus (DENV) infection predispose the population to increased risk of contracting the severe forms of dengue. Understanding the DENV evolutionary mechanism underlying the recurring dengue outbreaks has important implications for epidemic prediction and disease control. Results We used a set of viral envelope (E) gene to reconstruct the phylogeny of DENV-1 isolated between the periods of 1987–2011 in Malaysia. Phylogenetic analysis of DENV-1 E gene revealed that genotype I virus clade replacements were associated with the cyclical pattern of major DENV-1 outbreaks in Malaysia. A total of 9 non-conservative amino acid substitutions in the DENV-1 E gene consensus were identified; 4 in domain I, 3 in domain II and 2 in domain III. Selection pressure analyses did not reveal any positively selected codon site within the full length E gene sequences (1485 nt, 495 codons). A total of 183 (mean dN/dS = 0.0413) negatively selected sites were found within the Malaysian isolates; neither positive nor negative selection was noted for the remaining 312 codons. All the viruses were cross-neutralized by the respective patient sera suggesting no strong support for immunological advantage of any of the amino acid substitutions. Conclusion DENV-1 clade replacement is associated with recurrences of major DENV-1 outbreaks in Malaysia. Our findings are consistent with those of other studies that the DENV-1 clade replacement is a stochastic event independent of positive selection.
Collapse
Affiliation(s)
- Boon-Teong Teoh
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
42
|
Teoh BT, Sam SS, Tan KK, Johari J, Danlami MB, Hooi PS, Md-Esa R, AbuBakar S. Detection of dengue viruses using reverse transcription-loop-mediated isothermal amplification. BMC Infect Dis 2013; 13:387. [PMID: 23964963 PMCID: PMC3846474 DOI: 10.1186/1471-2334-13-387] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Accepted: 08/16/2013] [Indexed: 11/15/2022] Open
Abstract
Background Early and rapid detection of dengue virus (DENV) infection during the febrile period is crucial for proper patient management and prevention of disease spread. An easy to perform and highly sensitive method is needed for routine implementation especially in the resource-limited rural healthcare settings where dengue is endemic. Methods A single-tube reverse transcription-loop-mediated isothermal amplification (RT-LAMP) assay with a set of nine primers was developed for the detection of all four DENV serotypes and their different genotypes. The sensitivity and specificity of the RT-LAMP were evaluated. The clinical applicability of RT-LAMP assay for detection of DENV RNA was assessed in a total of 305 sera of clinically-suspected dengue patients. The test results of RT-LAMP were statistically compared to those of quantitative reverse transcription-polymerase chain reaction (qRT-PCR), IgM- and IgG-capture enzyme-linked immunosorbent assays (ELISA). Results Acute DENV infection was confirmed in 171 samples (n = 305); 43.3% (74/171) and 46.8% (80/171) of the samples were positive for DENV using RT-LAMP and qRT-PCR, respectively. The combination of RT-LAMP with the dengue IgM and IgG ELISA increased detection of acute DENV infection to 97.7% (167/171), in comparison to only 70.8% (121/171) when dengue IgM and IgG ELISA alone were used. The RT-LAMP assays showed high concordance (κ = 0.939) with the qRT-PCR. The RT-LAMP assay detected up to 10 copies of virus RNA within an hour but 100% reproducibility (12/12) was achieved with 100 copies. There was no cross reactivity of RT-LAMP with other closely related arboviruses. Conclusion The RT-LAMP assay developed in this study is sensitive, specific and simple to perform. The assay improved the detection of dengue when used in combination with serological methods.
Collapse
Affiliation(s)
- Boon-Teong Teoh
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia.
| | | | | | | | | | | | | | | |
Collapse
|
43
|
Tan KK, Chong CS, Tsang CB, Koh DC. Outcomes Following Surgery for Distal Rectal Cancers: A Comparison between Laparoscopic and Open Abdomino-Perineal Resection. Med J Malaysia 2013; 68:348-352. [PMID: 24145265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
PURPOSE Oncologic outcomes following laparoscopic abdomino-perineal resection (APR) for distal rectal cancer are infrequently reported. This study aims to compare the long term outcomes between laparoscopic and open APR in distal rectal cancers. METHODS A retrospective review of all patients who underwent APR for distal rectal cancer from May 2001 to November 2009 was performed. RESULTS Forty-two patients, median age 60 (24 - 86) years, formed the study group. Laparoscopic resection was attempted in 16 patients and was successful in all but one. Patients with recurrent diseases, previous abdominal operations and neoadjuvant chemoradiation were more likely to undergo open APR. There were no differences in the T-staging, number of lymph nodes harvested or the final stage of the disease between the two groups. The laparoscopic APR group had a shorter median length of hospitalization (7 vs. 10 days, p < 0.05), but longer operative duration (300 vs. 240 minutes, p > 0.05). Excluding the 9 (21.4%) patients with metastatic disease on presentation, 13 (39.4%) developed recurrence after a median follow up of 24 (4 - 107) months. Twenty (47.6%) patients died from their advanced disease subsequently while one (2.4%) died from a noncancer related cause. Analysis showed that tumour stage and circumferential resection margin positivity were associated with a poorer survival. The types of approach had no significant impact on the survival. CONCLUSION Laparoscopic APR for distal rectal cancer yields similar oncologic outcomes as open APR. Long-term outcome is determined by the tumour stage and circumferential resection margin and not the approach.
Collapse
Affiliation(s)
- K K Tan
- National University Health System, Department of Surgery, Division of Colorectal Surgery, Singapore.
| | | | | | | |
Collapse
|
44
|
Zandi K, Lim TH, Rahim NA, Shu MH, Teoh BT, Sam SS, Danlami MB, Tan KK, Abubakar S. Extract of Scutellaria baicalensis inhibits dengue virus replication. BMC Complement Altern Med 2013; 13:91. [PMID: 23627436 PMCID: PMC3655864 DOI: 10.1186/1472-6882-13-91] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Accepted: 04/24/2013] [Indexed: 12/18/2022]
Abstract
BACKGROUND Scutellaria baicalensis (S. baicalensis) is one of the traditional Chinese medicinal herbs that have been shown to possess many health benefits. In the present study, we evaluated the in vitro antiviral activity of aqueous extract of the roots of S. baicalensis against all the four dengue virus (DENV) serotypes. METHODS Aqueous extract of S. baicalensis was prepared by microwave energy steam evaporation method (MEGHE™), and the anti-dengue virus replication activity was evaluated using the foci forming unit reduction assay (FFURA) in Vero cells. Quantitative real-time polymerase chain reaction (qRT-PCR) assay was used to determine the actual dengue virus RNA copy number. The presence of baicalein, a flavonoid known to inhibit dengue virus replication was determined by mass spectrometry. RESULTS The IC(50) values for the S. baicalensis extract on Vero cells following DENV adsorption ranged from 86.59 to 95.19 μg/mL for the different DENV serotypes. The IC(50) values decreased to 56.02 to 77.41 μg/mL when cells were treated with the extract at the time of virus adsorption for the different DENV serotypes. The extract showed potent direct virucidal activity against extracellular infectious virus particles with IC(50) that ranged from 74.33 to 95.83 μg/mL for all DENV serotypes. Weak prophylactic effects with IC(50) values that ranged from 269.9 to 369.8 μg/mL were noticed when the cells were pre-treated 2 hours prior to virus inoculation. The concentration of baicalein in the S. baicalensis extract was ~1% (1.03 μg/gm dried extract). CONCLUSIONS Our study demonstrates the in vitro anti-dengue virus replication property of S. baicalensis against all the four DENV serotypes investigated. The extract reduced DENV infectivity and replication in Vero cells. The extract was rich in baicalein, and could be considered for potential development of anti-DENV therapeutics.
Collapse
Affiliation(s)
- Keivan Zandi
- Tropical Infectious Disease Research and Education Center (TIDREC), Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Tong-Hye Lim
- Herbitec Sendirian Berhad, G-3-7, Plaza Damas Jalan Sri Hartamas, Sri Hartamas, Kuala Lumpur, Malaysia
| | - Nor-Aziyah Rahim
- Tropical Infectious Disease Research and Education Center (TIDREC), Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Meng-Hooi Shu
- Tropical Infectious Disease Research and Education Center (TIDREC), Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Boon-Teong Teoh
- Tropical Infectious Disease Research and Education Center (TIDREC), Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Sing-Sin Sam
- Tropical Infectious Disease Research and Education Center (TIDREC), Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Mohammed-Bashar Danlami
- Tropical Infectious Disease Research and Education Center (TIDREC), Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Kim-Kee Tan
- Tropical Infectious Disease Research and Education Center (TIDREC), Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Sazaly Abubakar
- Tropical Infectious Disease Research and Education Center (TIDREC), Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| |
Collapse
|
45
|
Abstract
Zhang et al. presented an excellent neural-network (NN) controller for a class of nonlinear control designs. The singularity issue is completely avoided. Based on a modified Lyapunov function, their lemma illustrates the existence of an ideal control which is important in establishing the NN approximator. In this paper, we provide a Lyapunov function to realize an alternative ideal control which is more direct and simpler. The major contributions of this paper are divided into two parts. First, it proposes a control scheme which results in a smaller dimensionality of NN than that of Zhang et al. In this way, the proposed NN controller is easier to implement and more reliable for practical purposes. Second, by removing certain restrictions from the design reported by Zhang et al., we further develop a new NN controller, which can be applied to a wider class of systems.
Collapse
Affiliation(s)
- S N Huang
- Dept. of Electr. and Comput. Eng., Nat. Univ. of Singapore, Singapore
| | | | | |
Collapse
|
46
|
Tan KK, Tang KZ, Putra AS, Pu X, Huang S, Lee TH, Ng SC, Tan LG. An auto-perfusing umbilical cord blood collection instrument. ISA Trans 2012; 51:420-429. [PMID: 22342030 DOI: 10.1016/j.isatra.2012.01.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2011] [Revised: 12/30/2011] [Accepted: 01/03/2012] [Indexed: 05/31/2023]
Abstract
In this paper, the development of an automated umbilical cord blood (UCB) collection instrument, comprising of mechanical, electronics and control components, is provided in detail. UCB from the placenta provides a rich source of highly proliferative cells for many clinical uses as it contains rich Hematopoietic Stem Cells (HSCs) which yield many benefits over traditional sources such as the bone marrow and periphery blood. Current collection of UCB uses a syringe to extract blood from placenta, which is highly limited in volume and cell numbers. This paper will present the development of an automated UCB collection instrument to yield improved performance which comprised four subsystems. First, a placenta handling system is designed to produce air pressure which can realize the emulation of the uterus compression on the placenta. Second, an auto-medium injector system is presented to enable perfusion automatically. Third, a time window widening system is developed which generates vibrations during the perfusion phase and helps the exposed end of the cord cool down to a low temperature. Finally, a control platform is used to integrate all systems working together, hosting the control algorithms which operate the instrument automatically.
Collapse
Affiliation(s)
- K K Tan
- Department of Electrical & Computer Engineering, National University of Singapore, Singapore.
| | | | | | | | | | | | | | | |
Collapse
|
47
|
Tan KK, Chiu MT, Vijayan A. Management of isolated splenic injuries after blunt trauma: an institution's experience over 6 years. Med J Malaysia 2010; 65:304-306. [PMID: 21901951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Forty-two patients with traumatic blunt splenic injuries were admitted over a six year period. Vehicular-related collisions and fall from height accounted for the injuries in 38 (90.5%) of them. Eleven (26.2%) underwent immediate surgery (7 splenectomy and 4 splenorrhaphy), while the remaining 31 patients were treated nonoperatively of which 3 underwent angio-embolisation. Twenty seven patients had either grade III or IV splenic injuries. Operative management was more likely in patients with lower haemoglobin or with more severe splenic injury. Nonoperative management can be adopted in patients with blunt isolated splenic injuries but operative management is still indispensable in certain instances.
Collapse
Affiliation(s)
- K K Tan
- Department of General Surgery, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore 308433.
| | | | | |
Collapse
|
48
|
Chong CF, Adi MIW, Thien A, Suyoi A, Mackie AJ, Tin AS, Tripathi S, Jaman NH, Tan KK, Kok KY, Mathew VV, Paw O, Chua HB, Yapp SK. Development of the RIPASA score: a new appendicitis scoring system for the diagnosis of acute appendicitis. Singapore Med J 2010; 51:220-225. [PMID: 20428744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
INTRODUCTION Acute appendicitis is one of the most common surgical emergencies. The Alvarado and modified Alvarado scores have been developed to aid diagnosis, but both scoring systems have poor sensitivity and specificity when applied in Middle Eastern and Asian populations. The aim of this study was to develop a new scoring system that is suitable for the local population. METHODS Clinical data from 312 patients who had undergone an emergency appendicectomy was retrospectively collected and used to generate 15 parameters. The probability was calculated and a score of 0.5, 1.0 or 2.0 was allocated to each parameter. The receiver operating curve (ROC), sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the new scoring system were derived using the StatsDirect statistical software. RESULTS The 15 parameters and the scores generated were age (less than 40 years is 1 point; greater than 40 years is 0.5 point), gender (male is 1 point; female is 0.5 point), right iliac fossa (RIF) pain (0.5 point), migration of pain to RIF (0.5 point), nausea and vomiting (1 point), anorexia (1 point), duration of symptoms (less than 48 hours is 1 point; more than 48 hours is 0.5 point), RIF tenderness (1 point), guarding (2 points), rebound tenderness (1 point), Rovsing's sign (2 points), fever (1 point), raised white cell count (1 point), negative urinalysis (1 point) and foreign national registration identity card (1 point). The optimal cut-off threshold score from the ROC was 7.5, with a sensitivity of 88 percent, a specificity of 67 percent, a PPV of 93 percent and an NPV of 53 percent. The negative appendicectomy rate decreased significantly from 16.3 percent to 6.9 percent, which was a 9.4 percent reduction (p is 0.0007). CONCLUSION The new appendicitis scoring system looked promising when applied to our settings, and had a better sensitivity and specificity than the Alvarado score when applied to Asian populations. A significant reduction in the negative appendicectomy rate was also predicted. A prospective evaluation of this new appendicitis scoring system, referred to as the RIPASA score, is ongoing.
Collapse
Affiliation(s)
- C F Chong
- Department of Surgery, Raja Isteri Pengiran Anak Saleha Hospital, Bandar Seri Begawan BA1710, Brunei Darussalam.
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
49
|
Tan KK, Yan ZY, Vijayan A, Chiu MT. Management of diaphragmatic rupture from blunt trauma. Singapore Med J 2009; 50:1150-1153. [PMID: 20087550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
INTRODUCTION Diagnosis of diaphragmatic rupture is difficult, and delays could result in a catastrophic outcome. We reviewed our institution's management of patients with diaphragmatic rupture after blunt trauma. METHODS All patients in this study were treated at Tan Tock Seng Hospital, Singapore, from March 2002 to October 2008. Patients with penetrating injuries were excluded. The parameters included age, mechanism of injury, haemodynamic status at admission, Glasgow coma scale (GCS) score, injury severity score (ISS), imaging studies, location of diaphragmatic injuries, associated injuries and outcome. RESULTS 14 patients with a median age of 38 years formed the study group. Vehicular-related incidents accounted for 71.4 percent of the injuries. The median GCS score on admission was 14 (range 3-15), while the median systolic blood pressure and heart rate were 94 (range 50-164) mmHg and 110 (range 76-140) beats per minute, respectively. The median ISS was 41 (range 14-66). All had chest radiographs performed in the emergency department, six (42.9 percent) had computed tomography performed before surgery, while the remaining eight (57.1 percent) were sent straight to the operating theatre from the emergency department. There were five (35.7 percent) right-sided and nine (64.3 percent) left-sided diaphragmatic ruptures. The mortality rate was 35.7 percent. Some of the associated injuries included eight (57.1 percent) splenic lacerations, five (35.7 percent) haemothorax and lung injuries, four (28.6 percent) bone fractures and three (21.4 percent) liver lacerations. 12 (85.7 percent) patients underwent repair of the diaphragmatic rupture using interrupted polypropylene suture, while the remaining two (14.3 percent) were too haemodynamically unstable to undergo definitive treatment. Advanced age, haemodynamic instability and raised ISS were associated with mortality. CONCLUSION An accurate diagnosis of diaphragmatic rupture in trauma patients is difficult, and a thorough examination of both the hemidiaphragms is mandatory during emergency laparotomy for these patients. Those with more severe injuries and decreased physiological reserves usually fare worse.
Collapse
Affiliation(s)
- K K Tan
- Department of General Surgery, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore.
| | | | | | | |
Collapse
|
50
|
Islam S, Tan KK. Bleeding inflammatory polyp formation as a complication of argon plasma coagulation therapy on a flat gastric angiodysplasia. Endoscopy 2009; 41 Suppl 2:E86. [PMID: 19370526 DOI: 10.1055/s-0029-1214592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Affiliation(s)
- S Islam
- Department of Gastroenterology, Wellington Hospital, Wellington, New Zealand.
| | | |
Collapse
|