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Lim YZ, Teoh BT, Sam SS, Azizan NS, Khor CS, Nor'e SS, Abd-Jamil J, AbuBakar S. A TaqMan minor groove binder probe-based quantitative reverse transcription polymerase chain reaction for detection and quantification of chikungunya virus. Trop Biomed 2023; 40:313-319. [PMID: 37897164 DOI: 10.47665/tb.40.3.007] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/29/2023]
Abstract
Chikungunya virus (CHIKV) is a mosquito-borne alphavirus with widespread distribution across the globe. Since 2016, CHIKV re-emerged in several countries including Indian subcontinent and Southeast Asia. A proper diagnostic tool for early diagnosis of CHIKV infection is crucial to facilitate patient management and control virus transmission at the earliest stage of outbreak. Therefore, a TaqMan minor groove binder (MGB) probe-based quantitative reverse transcription polymerase chain reaction (qRT-PCR) assay was developed to detect and quantify the CHIKV. The primers and probe were designed based on a conserved genomic region of 730 global CHIKV sequences that is located between nsP1 and nsP2 genes. The nucleotide mismatches of primers and probe with 730 global CHIKV sequences and 13 alphaviruses were then analysed in silico. In this study, the last 5 nucleotides at 3' end of primers and 5' end of probe were considered to be the critical regions for priming. In silico analysis revealed that the critical regions of primers and probe were at least 99.6% matched with the 730 global CHIKV sequences. Besides, the primers and probe showed at least 5/20 (25.0%) and 4/17 (23.5%) nucleotide mismatches with 13 alphaviruses respectively. The amplification efficiency of qRT-PCR assay was 100.59% (95% CI= 93.06, 109.33) with a R2 score of 0.957. Its limit of detection (LOD) at 95% probability level was 16.6 CHIKV RNA copies (95% CI= 12.9, 28.9). The qRT-PCR assay was specific to CHIKV without cross-reacting with all dengue virus serotypes, Getah virus, Tembusu virus and Zika virus. The diagnostic results of qRT-PCR assay were perfectly agreed (k=1.000, p=0.003) with a commercial trioplex assay, with sensitivity of 100% (95% CI= 61, 100) and specificity of 100% (95% CI= 44, 100). Overall, the developed qRT-PCR assay is ideal for rapid, sensitive and specific detection as well as quantification of CHIKV.
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Affiliation(s)
- Y Z Lim
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Centre 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 Centre of Excellence (HICoE), Universiti Malaya, 50603 Kuala Lumpur, Malaysia
| | - S S Sam
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Centre of Excellence (HICoE), Universiti Malaya, 50603 Kuala Lumpur, Malaysia
| | - N S Azizan
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Centre of Excellence (HICoE), Universiti Malaya, 50603 Kuala Lumpur, Malaysia
| | - C S Khor
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Centre of Excellence (HICoE), Universiti Malaya, 50603 Kuala Lumpur, Malaysia
| | - S S Nor'e
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Centre of Excellence (HICoE), Universiti Malaya, 50603 Kuala Lumpur, Malaysia
| | - J Abd-Jamil
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Centre of Excellence (HICoE), Universiti Malaya, 50603 Kuala Lumpur, Malaysia
| | - S AbuBakar
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Centre of Excellence (HICoE), Universiti Malaya, 50603 Kuala Lumpur, Malaysia
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2
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Phoon WH, Bell-Sakyi L, AbuBakar S, Chang LY. Experimental infection of tick cells with Nipah virus. Trop Biomed 2023; 40:29-36. [PMID: 37356001 DOI: 10.47665/tb.40.1.009] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/27/2023]
Abstract
Nipah virus (NiV), a highly pathogenic henipavirus of the family Paramyxoviridae, which causes fatal encephalitis in 40-70% of affected patients, was first reported in Malaysia over 20 years ago. Pteropid bats are the natural hosts of henipaviruses, and ticks have been proposed as a possible link between bats and mammalian hosts. To investigate this hypothesis, infection of the tick cell line IDE8 with NiV was examined. Presence of viral RNA and antigen in the NiV-infected tick cells was confirmed. Infectious virions were recovered from NiV-infected tick cells and ultrastructural features of NiV were observed by electron microscopy. These results suggest that ticks could support NiV infection, potentially playing a role in transmission.
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Affiliation(s)
- W H Phoon
- Department of Medical Microbiology, Universiti Malaya, 50603 Kuala Lumpur, Malaysia
| | - L Bell-Sakyi
- Institute of Infection, Veterinary and Ecological Science, University of Liverpool, 146 Brownlow Hill, Liverpool L3 5RF, United Kingdom
| | - S AbuBakar
- Tropical Infectious Diseases Research & Education Centre, Universiti Malaya, 50603 Kuala Lumpur, Malaysia
| | - L Y Chang
- Department of Medical Microbiology, Universiti Malaya, 50603 Kuala Lumpur, Malaysia
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3
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Suria MM, Yap PC, Lov VL, AbuBakar S, Lee HY. Lactic acid bacteria waste infusion as a source of attraction and oviposition stimulation of gravid female Aedes albopictus mosquitoes. Trop Biomed 2022; 39:499-503. [PMID: 36602207 DOI: 10.47665/tb.39.4.004] [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
Aedes albopictus poses a public health risk in tropical countries and temperate countries in recent decades due to its capability to transmit various human arboviruses including dengue, yellow fever, and chikungunya. Vector control is the key for preventing transmission of these pathogenic viruses. Improving the effectiveness of currently utilized collection methods, such as ovitraps, is important for best species abundance monitoring, assessment of the threat of arbovirus transmission, and optimizing control activities. Therefore, this study aimed to assess the potential use of lactic acid bacteria (LAB) waste as an infusion-baited ovitrap for Aedes collection. The performance of overnight tap water, grass hay infusion and LAB waste infusion were compared for their ability in attracting gravid female Ae. albopictus. In this study, the LAB waste infusion was substantially more alluring to Ae. albopictus mosquitoes than the two controls grass hay infusion and tap water.
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Affiliation(s)
- M M Suria
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Centre of Excellence, Universiti Malaya, 50603 Kuala Lumpur, Malaysia
| | - P C Yap
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Centre of Excellence, Universiti Malaya, 50603 Kuala Lumpur, Malaysia
| | - V L Lov
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Centre of Excellence, Universiti Malaya, 50603 Kuala Lumpur, Malaysia
| | - S AbuBakar
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Centre of Excellence, Universiti Malaya, 50603 Kuala Lumpur, Malaysia
| | - H Y Lee
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Centre of Excellence, Universiti Malaya, 50603 Kuala Lumpur, Malaysia
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4
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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.
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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
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Mokhtar AS, Sahimin N, Hanapi IRM, Lau YL, Zain SNM, AbuBakar S, Ya'çob Z. Molecular survey of head lice (Pediculus humanus capitis) infestation among disadvantaged children in Klang Valley, Malaysia. Trop Biomed 2021; 38:590-593. [PMID: 35001925 DOI: 10.47665/tb.38.4.102] [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
Ectoparasitic infestations including pediculosis capitis are common in people of disadvantaged communities as they live in overcrowded institutions, a condition that often favourable for disease transmission. In this study, we evaluated the prevalence of head lice infestation among disadvantaged children aged between five to 14 years-old living in five poor conditions located across the Klang Valley, Malaysia. Of total 335 children examined, 14% were positively infected with head lice. Molecular analysis using the universal cytochrome c oxidase subunit I ( COI) barcoding gene on total of 167 head lice collected in this study indicated they are belonging to the A and C clades; confirming the global distribution of clade A and expansion of clade C in Southeast Asia, which is reported for the first time in Malaysia.
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Affiliation(s)
- A S Mokhtar
- Department of Microbiology, Faculty of Medicine, Manipal University College Malaysia, Jalan Batu Hampar, 75150 Bukit Baru, Melaka, Malaysia
| | - N Sahimin
- Higher Centre of Excellence (HICoE), Tropical Infectious Diseases Rese arch & Education Centre (TIDREC), Universiti Malaya, 5060 3 Kuala Lumpur, Malaysia
| | - I R M Hanapi
- Institute of Biological Sciences, Faculty of Science, Universiti Malaya, 50603 Kuala Lumpur, Malaysia
| | - Y L Lau
- Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, 50603 Kuala Lumpur, Malaysia
| | - S N M Zain
- Institute of Biological Sciences, Faculty of Science, Universiti Malaya, 50603 Kuala Lumpur, Malaysia
| | - S AbuBakar
- Higher Centre of Excellence (HICoE), Tropical Infectious Diseases Rese arch & Education Centre (TIDREC), Universiti Malaya, 5060 3 Kuala Lumpur, Malaysia
| | - Z Ya'çob
- Higher Centre of Excellence (HICoE), Tropical Infectious Diseases Rese arch & Education Centre (TIDREC), Universiti Malaya, 5060 3 Kuala Lumpur, Malaysia
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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.
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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
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7
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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.
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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
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Abd Majid MA, Khoo JJ, Lim FS, Khor CS, Loong SK, Low VL, Lee HY, AbuBakar S. Bacterial profiling of head lice isolated from the Orang Asli: A first report in Malaysia. Trop Biomed 2020; 37:884-895. [PMID: 33612742 DOI: 10.47665/tb.37.4.884] [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
This study was carried out to determine from bacterial profiling to the bacterial profiles of head lice among the Orang Asli communities. The head lice were collected from Orang Asli community volunteers. The surface sterilized head lice pools were subjected to genomic DNA extraction while next generation sequencing of the 16S rRNA gene was performed using the Illumina MiSeq platform. Six female and three male head lice identified as Pediculus humanus capitis were collected. A total of 111 368 number of NGS sequencing reads were recorded while another 223 bacterial taxa sequences were obtained. Symbiotic bacteria showed the highest number of reads, with Arsenophonus and Rhodococcus sequences being the most abundant genera in the female and male samples, respectively. The female head lice contained a more distinct microbial diversity. Amongst the pathogenic bacterial species sequences noted were the methicillin-resistant Staphylococcus aureus, Streptobacillus moniliformis, Haemophilus influenzae, Bordetella pertussis and Acinetobacter baumannii. The 16S rRNA genome sequencing revealed a number of rare and pathogenic bacterial species within the head lice of the Orang Asli. The socio-economic practices of the community which involved forest foraging and hunting, and their poor living conditions potentially facilitated the transmission of zoonotic bacterial pathogens, including those found within the head lice. Hence, there is the possibility that the head lice could serve as vectors for the transmission of pathogenic bacteria. This study highlighted the diverse microbial community found within the head lice's gut of the Orang Asli, with the detection of multiple rare and pathogenic bacteria capable of causing severe infections.
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Affiliation(s)
- M A Abd Majid
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - J-J Khoo
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, 50603 Kuala Lumpur, Malaysia
| | | | - C-S Khor
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - S-K Loong
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - V-L Low
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - H-Y Lee
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - S 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
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Loong SK, Lim FS, Khoo JJ, Lee HY, Suntharalingam C, Ishak SN, Mohd-Taib FS, AbuBakar S. Culturable pathogenic bacteria in ticks parasitizing farm animals and rodents in Malaysia. Trop Biomed 2020; 37:803-811. [PMID: 33612793 DOI: 10.47665/tb.37.3.803] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [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
Ticks are vectors of bacteria, protozoa and viruses capable of causing serious and life threatening diseases in humans and animals. Disease transmission occurs through the transfer of pathogen from tick bites to susceptible humans or animals. Most commonly known tick-borne pathogens are obligate intracellular microorganisms but little is known on the prevalence of culturable pathogenic bacteria from ticks capable of growth on artificial nutrient media. One hundred and forty seven ticks originating from dairy cattle, goats and rodents were collected from nine selected sites in Peninsular Malaysia. The culture of surfacesterilized tick homogenates revealed the isolation of various pathogenic bacteria including, Staphylococcus sp., Corynebacterium sp., Rothia sp., Enterococcus faecalis, Klebsiella pneumoniae, Escherichia coli and Bacillus sp. and its derived genera. These pathogens are among those that affect humans and animals. Findings from this study suggest that in addition to the regular intracellular pathogens, ticks could also harbor extracellular pathogenic bacteria. Further studies, hence, would be needed to determine if these extracellular pathogens could contribute to human or animal infection.
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Affiliation(s)
- S K Loong
- Tick Cell Biobank Asia Outpost, Tropical Infectious Diseases Research and Education Centre, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - F S Lim
- Tick Cell Biobank Asia Outpost, Tropical Infectious Diseases Research and Education Centre, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - J J Khoo
- Tick Cell Biobank Asia Outpost, Tropical Infectious Diseases Research and Education Centre, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - H Y Lee
- Centre of Excellence for Vaccine and Protein Therapeutics Process Development, Tropical Infectious Diseases Research and Education Centre, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - C Suntharalingam
- Economics and Social Science Research Centre, Malaysian Agricultural Research and Development Institute (MARDI), 43400 Serdang, Malaysia
| | - S N Ishak
- School of Environmental Science and Natural Resources, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Malaysia
| | - F S Mohd-Taib
- School of Environmental Science and Natural Resources, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Malaysia
| | - S AbuBakar
- Tick Cell Biobank Asia Outpost, Tropical Infectious Diseases Research and Education Centre, University of Malaya, 50603 Kuala Lumpur, Malaysia.,Centre of Excellence for Vaccine and Protein Therapeutics Process Development, Tropical Infectious Diseases Research and Education Centre, University of Malaya, 50603 Kuala Lumpur, Malaysia.,Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
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10
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Wong LP, Wong PF, AbuBakar S. Vaccine hesitancy and the resurgence of vaccine preventable diseases: the way forward for Malaysia, a Southeast Asian country. Hum Vaccin Immunother 2020; 16:1511-1520. [PMID: 31977285 DOI: 10.1080/21645515.2019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023] Open
Abstract
This study engaged health professionals in in-depth, semi-structured interviews to explore their opinions concerning the issues surrounding vaccine hesitancy in Malaysia and strategies to improve vaccination to stamp the rise of vaccine preventable diseases (VPDs). Opinions on how to address the resurgence of VPDs in the era of increasing vaccine hesitancy were obtained. Eight health professionals, including geriatricians, pediatricians, microbiologists, public health specialists, and family medicine specialists were interviewed. The influence of anti-vaccination propaganda, past-experience of adverse event following immunization (AEFI), perceived religious prohibition, a belief that traditional complementary and alternative medicine (TCAM) use is safer, pseudoscience beliefs, and anti-vaccine conspiracy theories were identified as reasons for refusing to vaccinate. The interplay of social, cultural and religious perspectives in influencing perceived religious prohibition, pseudoscience beliefs, and the use of TCAM contributing to vaccine refusal was found. Five broad themes emerged from the health professionals regarding strategies to address vaccine hesitancy, including establishing an electronic vaccination registry, increasing public awareness initiatives, providing feedback to the public on the findings of AEFI, training of front-line healthcare providers, and banning the dissemination of anti-vaccine information via social media. With regards to identifying strategies to address the resurgence of VPDs, mandatory vaccination received mixed opinions; many viewed supplementary immunization activity and the prevention of travel and migration of unvaccinated individuals as being necessary. In conclusion, the present study identified unique local cultural, traditional and religious beliefs that could contribute to vaccine hesitancy in addition to issues surrounding vaccination refusal similarly faced by other countries around the world. This information are important for the formulation of targeted intervention strategies to stamp vaccine hesitancy in Malaysia which are also a useful guide for other countries especially in the Southeast Asia region facing similar vaccine hesitancy issues.
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Affiliation(s)
- L P Wong
- Centre for Epidemiology and Evidence-Based Practice, Department of Social and Preventive Medicine, Faculty of Medicine, University of Malaya , Kuala Lumpur, Malaysia
| | - P F Wong
- Department of Pharmacology, Faculty of Medicine, University of Malaya , Kuala Lumpur, Malaysia
| | - S AbuBakar
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya , Kuala Lumpur, Malaysia
- Tropical Infectious Diseases Research and Educational Centre (TIDREC), University of Malaya , Kuala Lumpur, Malaysia
- WHO Collaborating Centre for Arbovirus Reference and Research (Dengue and Severe Dengue) MAA-12, University of Malaya , Kuala Lumpur, Malaysia
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Wong LP, Wong PF, AbuBakar S. Vaccine hesitancy and the resurgence of vaccine preventable diseases: the way forward for Malaysia, a Southeast Asian country. Hum Vaccin Immunother 2020; 16:1511-1520. [PMID: 31977285 DOI: 10.1080/21645515.2019.1706935] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
This study engaged health professionals in in-depth, semi-structured interviews to explore their opinions concerning the issues surrounding vaccine hesitancy in Malaysia and strategies to improve vaccination to stamp the rise of vaccine preventable diseases (VPDs). Opinions on how to address the resurgence of VPDs in the era of increasing vaccine hesitancy were obtained. Eight health professionals, including geriatricians, pediatricians, microbiologists, public health specialists, and family medicine specialists were interviewed. The influence of anti-vaccination propaganda, past-experience of adverse event following immunization (AEFI), perceived religious prohibition, a belief that traditional complementary and alternative medicine (TCAM) use is safer, pseudoscience beliefs, and anti-vaccine conspiracy theories were identified as reasons for refusing to vaccinate. The interplay of social, cultural and religious perspectives in influencing perceived religious prohibition, pseudoscience beliefs, and the use of TCAM contributing to vaccine refusal was found. Five broad themes emerged from the health professionals regarding strategies to address vaccine hesitancy, including establishing an electronic vaccination registry, increasing public awareness initiatives, providing feedback to the public on the findings of AEFI, training of front-line healthcare providers, and banning the dissemination of anti-vaccine information via social media. With regards to identifying strategies to address the resurgence of VPDs, mandatory vaccination received mixed opinions; many viewed supplementary immunization activity and the prevention of travel and migration of unvaccinated individuals as being necessary. In conclusion, the present study identified unique local cultural, traditional and religious beliefs that could contribute to vaccine hesitancy in addition to issues surrounding vaccination refusal similarly faced by other countries around the world. This information are important for the formulation of targeted intervention strategies to stamp vaccine hesitancy in Malaysia which are also a useful guide for other countries especially in the Southeast Asia region facing similar vaccine hesitancy issues.
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Affiliation(s)
- L P Wong
- Centre for Epidemiology and Evidence-Based Practice, Department of Social and Preventive Medicine, Faculty of Medicine, University of Malaya , Kuala Lumpur, Malaysia
| | - P F Wong
- Department of Pharmacology, Faculty of Medicine, University of Malaya , Kuala Lumpur, Malaysia
| | - S AbuBakar
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya , Kuala Lumpur, Malaysia.,Tropical Infectious Diseases Research and Educational Centre (TIDREC), University of Malaya , Kuala Lumpur, Malaysia.,WHO Collaborating Centre for Arbovirus Reference and Research (Dengue and Severe Dengue) MAA-12, University of Malaya , Kuala Lumpur, Malaysia
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Loong SK, Khor CS, Chen HW, Chao CC, Ling ISC, Abdul Rahim NF, Hassan HS, Nellis S, Ching WM, AbuBakar S. Serological evidence of high Leptospira exposure among indigenous people (Orang Asli) in Peninsular Malaysia using a recombinant antigen-based ELISA. Trop Biomed 2018; 35:1-9. [PMID: 33601771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The lifestyles of the indigenous people (Orang Asli) of Peninsular Malaysia who traditionally live close to the forest, put them at higher risk of exposure to zoonotic diseases. Leptospirosis has recently emerged as one of the most important diseases of public health concern. Here, we aimed to obtain a baseline data on the level of Leptospira exposure among the 107 Orang Asli volunteers using a recombinant antigen-based ELISA, previously shown to have sensitivity of ~90.0% in comparison to the microscopic agglutination test (MAT). Among the Orang Asli volunteers in this study, 60.7% had IgM against Leptospira and 57.9% were antiLeptospira IgG positive. Of these seropositive individuals, 29.9% had both anti-Leptospira IgM and IgG antibodies. Age was found to be a significant predictor for exposure to Leptospira (P < 0.05) with the younger Orang Asli population more likely to be tested positive for antiLeptospira IgM. The finding of high Leptospira exposure among the Orang Asli volunteers could be due to their socio-economic practices and dependency on the forest for their livelihood. The rapid and sensitive recombinant antigen-based ELISA used in the study, could possibly complement MAT for the epidemiological surveillance of leptospirosis, especially among the underserved populations.
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Affiliation(s)
- S K Loong
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - C S Khor
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, 50603 Kuala Lumpur, Malaysia
- Department of Preventive Medicine and Biostatistics, Uniformed Services University of the Health Sciences, Bethesda, Maryland 20814, United States of America
| | - H W Chen
- Naval Medical Research Center, 503 Robert Grant Avenue, Silver Spring, Maryland 20910, United States of America
- Department of Preventive Medicine and Biostatistics, Uniformed Services University of the Health Sciences, Bethesda, Maryland 20814, United States of America
| | - C C Chao
- Naval Medical Research Center, 503 Robert Grant Avenue, Silver Spring, Maryland 20910, United States of America
| | - I S C Ling
- 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
| | - N F Abdul Rahim
- 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
| | - H S Hassan
- 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
| | - S Nellis
- 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
| | - W M Ching
- Naval Medical Research Center, 503 Robert Grant Avenue, Silver Spring, Maryland 20910, United States of America
- Department of Preventive Medicine and Biostatistics, Uniformed Services University of the Health Sciences, Bethesda, Maryland 20814, United States of America
| | - S 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
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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.
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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
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Loong SK, Che Mat Seri NAA, Mahfodz NH, Ahmad Nasrah SN, Teoh BT, AbuBakar S. Emergence of Enterococcus gallinarum carrying vanA gene cluster displaying atypical phenotypes. Trop Biomed 2016; 33:837-841. [PMID: 33579083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Motile enterococci such as Enterococcus gallinarum has the ability to acquire and transfer antibiotic resistance genes to other enterococci. Even though infections caused by E. gallinarum are rare, the discovery of this bacteria in food sources and in clinical environments is disturbing. Here, we report the isolation and identification of E. gallinarum from the wound of a hospital in-patient. The isolate was identified using 16S rDNA sequencing. Isolate 146 harboured the vanA and vanC1 gene clusters, was vancomycin-susceptible, and displayed resistance to ampicillin, penicillin, erythromycin and teicoplanin. This isolate also showed intermediate resistance to linezolid and sequencing of the 23S rRNA peptidyl transferase region did not unveil any known mutations associated to the conferment of linezolid resistance. The presence of vanA did not confer resistance to vancomycin. Structural analyses into the Tn1546 transposon carrying the vanA gene revealed distinct genetic variations in the vanS, vanY and vanS-vanH intergenic region that could be associated to the atypical antibiotic resistance phenotypes of isolate 146. Finding from this study are suggestive of the occurrence of interspecies horizontal gene transfer and that similarities in genotypic characteristic may not necessarily correlate with actual antibiotic resistance pattern of E. gallinarum.
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Affiliation(s)
- S K Loong
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - N A A Che Mat Seri
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - N H Mahfodz
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - S N Ahmad Nasrah
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - B T Teoh
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - S 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
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Loong SK, Johari J, Che Mat Seri NAA, AbdulRazak O, Douadi B, Ahmad Nasrah SN, Mohd Zain SN, AbuBakar S. Isolation and Identification of an Emerging Pathogen, Kocuria marina, from Rattus rattus diardii. Trop Biomed 2016; 33:589-593. [PMID: 33579133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Members of the genus Kocuria are commonly found in the environment and they are also commensals of the mammalian skin and oropharynx mucosa. Human infections, although rare, are increasingly being reported recently suggesting that this genus has mostly been overlooked or misidentified. Its transmission route however, is still not known. We report here the isolation and identification of a Kocuria marina isolate from the lung of a wild urban rat (Rattus rattus diardii) caught at a wet market. The isolate was susceptible to most of the commonly used antibiotics. The finding suggests a possibility that rats could be a vector for K. marina.
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Affiliation(s)
- S K Loong
- Tropical Infectious Diseases Research and Education Centre, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - J Johari
- Tropical Infectious Diseases Research and Education Centre, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - N A A Che Mat Seri
- Tropical Infectious Diseases Research and Education Centre, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - O AbdulRazak
- Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - B Douadi
- Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - S N Ahmad Nasrah
- Department of Medical Microbiology, Faculty of Medicine, 50603 Kuala Lumpur, Malaysia
| | - S N Mohd Zain
- Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - S AbuBakar
- Tropical Infectious Diseases Research and Education Centre, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
- Department of Medical Microbiology, Faculty of Medicine, 50603 Kuala Lumpur, Malaysia
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Loong SK, Mat Seri NAA, Mahfodz NHH, Ahmad Nasrah SN, Akbar SZ, AbuBakar S. A Report of Vancomycin-susceptible, Teicoplanin-resistant Enterococcus faecalis ST6 in Malaysia. Trop Biomed 2016; 33:577-582. [PMID: 33579131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The ability to acquire antibiotic resistance and virulence has propelled Enterococcus faecalis to become a major nosocomial pathogen. In Malaysia, data on the antibiotic resistance determinants and virulence of Enterococcus circulating strains are still scarce. This study aimed to assess the genotype of an E. faecalis isolate initially identified as Streptococcus uberis, examine the antibiotic resistance genotypes, analyze the genetic variations within Tn1546 and investigate the presence of virulence genes. The E. faecalis isolate was genetically characterized using multilocus sequence typing (MLST). Minimum inhibitory concentrations to vancomycin and teicoplanin were determined. Antibiotic resistance and other virulence genes were amplified using nucleic acid polymerase chain reaction. Mapping of the Tn1546 transposon was performed and compared to the prototype sequences. The E. faecalis isolate was found to have a MLST profile corresponding to sequence type 6. The isolate was resistant to teicoplanin but susceptible to vancomycin. Its genome consisted the vanA and vanC1 genes. Novel genetic variations in the vanS, vanS-vanH intergenic region and vanY genes were present and six virulence genes were detected. The detection of the vanC1 gene, thought to be non-transferable, suggests the potential emergence of inter-species enterococcal vanC1 gene transfer. The peculiar antibiotics resistance phenotype of this E. faecalis isolate could be associated to the novel genetic variations found. This study highlights the presence of E. faecalis belonging to the high-risk clonal complex with multiple virulence factors in Malaysia.
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Affiliation(s)
- S K Loong
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - N A A Mat Seri
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - N H H Mahfodz
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - S N Ahmad Nasrah
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - S Z Akbar
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - S 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
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Tiong V, Abd-Jamil J, Mohamed Zan HA, Abu-Bakar RS, Ew CL, Jafar FL, Nellis S, Fauzi R, AbuBakar S. Evaluation of land cover and prevalence of dengue in Malaysia. Trop Biomed 2015; 32:587-597. [PMID: 33557448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Serological confirmation of dengue in 1,410 school-going children aged 7-18 years provided prevalence data for 16 different sites in Malaysia. These sites ranged from highly urbanized cities to small towns. We found that at least ~7 % of children in the study group had been exposed to dengue by age 12 and ~16% by age 18. Here we report that the dengue seroprevalence correlates with i) increasing land development and decreased vegetation, and ii) the overall population growth. Water bodies did not significantly affect dengue prevalence. High prevalence of dengue was also recorded in few of the non-urban sites suggesting the expanding geographical locality of those who get dengue in Malaysia in tandem with increased land usage activities. These findings highlight the need to give closer consideration to future urban planning and development, taking into consideration the changing demography and the importance of built environment to mitigate the increasing incidence of dengue in the non-urban areas of Malaysia.
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Affiliation(s)
- V Tiong
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - J Abd-Jamil
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - H A Mohamed Zan
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - R S Abu-Bakar
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - C L Ew
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - F L Jafar
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - S Nellis
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - R Fauzi
- Department of Geography, Faculty of Arts and Social Sciences, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - S AbuBakar
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
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18
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Abstract
Inheritance of polymorphisms in the interleukin (IL)-10 promoter and IL-12B genes, which influence cytokine production and activities, may define the balance in T helper response in infection and autoimmune diseases. In the present study, we investigated the distribution of the IL-10 promoter and IL-12B gene polymorphisms in a multiethnic Malaysian population. Overall, our findings suggest that the IL-12B and IL-10 -592 genotypes were distributed homogenously across all major ethnic groups, including Malays, Chinese, and Indians, except for polymorphisms at IL-10 -1082. At this gene locus, the ethnic Chinese showed a significantly lower allele frequency of -1082G (2.1%) compared to the Malay (12.2%) and Indian (15.3%) populations. Results for the IL-12B and IL-10 gene polymorphisms were consistent with those reported for the Asian population, but markedly different from those of the African and Caucasian populations. Our findings suggest that there are specific genetic variations between different ethnic groups, which should be examined in all gene population-based association studies.
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Affiliation(s)
- S S Sam
- Tropical Infectious Diseases Research and Education Center, Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - B T Teoh
- Tropical Infectious Diseases Research and Education Center, Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - S AbuBakar
- Tropical Infectious Diseases Research and Education Center, Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
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Lani R, Mohd Rahim NF, Hassan H, Yaghoobi R, Chang LY, AbuBakar S, Zandi K. First report on the seroprevalence of the Crimean-Congo haemorrhagic fever virus, a tick-borne virus, in Malaysia's Orang Asli population. Eur Rev Med Pharmacol Sci 2015; 19:461-466. [PMID: 25720719] [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: 06/04/2023]
Abstract
OBJECTIVE The Crimean-Congo haemorrhagic fever virus (CCHFV), which is transmitted by the ticks of Hyalomma spp. in general and H. marginatumin particular, can cause severe disease in humans, with mortality rates of 3-30%. Other than from the bites of infected ticks, CCHFV can also be transmitted through contact with patients with the acute phase of infection or contact with blood or tissues from viraemic livestock. Outbreaks of human cases of haemorrhagic manifestations have been documented since 1945 and described in parts of Africa, Asia, Eastern Europe and the Middle East and most recently India in 2011. In addition, serological evidence of the disease has been reported in some countries where no human cases were reported. As regional neighbours China and India have been affected by this virus, this study was conducted to determine the seroprevalence of CCHFV among Orang Asli population of Malaysia as the most at risk people who residing in the deep forests. PATIENTS AND METHODS A total of 682 serum samples were collected from the Orang Asli population residing in eight states in peninsular Malaysia and analysed for the presence of anti-CCHFV immunoglobulin G (IgG) using a commercial enzyme-linked immunosorbent assay kit. RESULTS The study subjects comprised 277 (40.6%) men and 405 (59.4%) women. However, anti-CCHFV IgG was detected in only one female serum sample (0.1%). The presence of anti-CCHFV IgG could not be correlated to age or sex from these findings. CONCLUSIONS The results of this screening survey showed that the seroprevalence of the anti-CCHFV IgG among Malaysia's Orang Asli population is too low for detection or totally negative compared with that in neighbouring countries, such as India and China.
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Affiliation(s)
- R Lani
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Department of Medical Microbiology, Faculty of Medicine, University Malaya, Kuala Lumpur, Malaysia.
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Nor'e SS, Sam IC, Mohamad Fakri EF, Hooi PS, Nathan AM, de Bruyne JA, Jafar F, Hassan A, AbuBakar S, Chan YF. Phylogenetic analysis of human metapneumovirus among children with acute respiratory infections in Kuala Lumpur, Malaysia. Trop Biomed 2014; 31:562-566. [PMID: 25382484] [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: 06/04/2023]
Abstract
Human metapneumovirus (HMPV) is a recently discovered cause of viral respiratory infections. We describe clinical and molecular epidemiology of HMPV cases diagnosed in children with respiratory infection at University of Malaya Medical Centre, Kuala Lumpur, Malaysia. The prevalence rate of HMPV between 2010 and 2012 was 1.1%, and HMPV contributed 6.5% of confirmed viral respiratory infections. The HMPV patients had a median age of 1.6 years, and a median hospital admission of 4 days. The most common clinical presentations were fever, rhinitis, pneumonia, vomiting/diarrhoea, and bronchiolitis. Based on the partial sequences of F fusion gene from 26 HMPV strains, 14 (54%) were subgenotype A2b, which was predominant in 2010; 11 (42%) were subgenotype B1, which was predominant in 2012; and 1 (4%) was subgenotype A2a. Knowledge of the circulating subgenotypes in Malaysia, and the displacement of predominant subgenotypes within 3 years, is useful data for future vaccine planning.
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Affiliation(s)
- S S Nor'e
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Department of Medical Microbiology, Faculty of Medicine, University Malaya, 50603 Kuala Lumpur, Malaysia
| | - I C Sam
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Department of Medical Microbiology, Faculty of Medicine, University Malaya, 50603 Kuala Lumpur, Malaysia
| | - E F Mohamad Fakri
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Department of Medical Microbiology, Faculty of Medicine, University Malaya, 50603 Kuala Lumpur, Malaysia
| | - P S Hooi
- Diagnostic Virology Laboratory, University Malaya Medical Centre, Kuala Lumpur, Malaysia
| | - A M Nathan
- Department of Paediatrics, Faculty of Medicine, University Malaya, 50603 Kuala Lumpur, Malaysia
| | - J A de Bruyne
- Department of Paediatrics, Faculty of Medicine, University Malaya, 50603 Kuala Lumpur, Malaysia
| | - F Jafar
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Department of Medical Microbiology, Faculty of Medicine, University Malaya, 50603 Kuala Lumpur, Malaysia
| | - A Hassan
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Department of Medical Microbiology, Faculty of Medicine, University Malaya, 50603 Kuala Lumpur, Malaysia
| | - S AbuBakar
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Department of Medical Microbiology, Faculty of Medicine, University Malaya, 50603 Kuala Lumpur, Malaysia
| | - Y F Chan
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Department of Medical Microbiology, Faculty of Medicine, University Malaya, 50603 Kuala Lumpur, Malaysia
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Mohd Zim MA, Sam IC, Omar SFS, Chan YF, AbuBakar S, Kamarulzaman A. Chikungunya infection in Malaysia: comparison with dengue infection in adults and predictors of persistent arthralgia. J Clin Virol 2012. [PMID: 23201456 DOI: 10.1016/j.jcv.2012.10.019] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND Chikungunya virus (CHIKV) and dengue virus (DENV) co-circulate in areas endemic with the Aedes mosquito vectors. Both viruses cause similar illnesses which may be difficult to distinguish clinically. CHIKV is also associated with persistent arthralgia. OBJECTIVES To compare and describe factors which differentiate between DENV and CHIKV infections on presentation; and to describe predictors of persistent arthralgia in CHIKV patients. STUDY DESIGN Patients aged >14 years diagnosed with acute CHIKV and DENV infections in Kuala Lumpur, Malaysia were retrospectively identified. Clinical and laboratory data were obtained from medical records, and compared. CHIKV patients were telephoned 15-24 months later and interviewed about persistent symptoms. Logistic regression analysis was performed. RESULTS A total of 53 CHIKV and 113 DENV patients were included. CHIKV patients were older and more likely to be female. CHIKV was independently associated with arthralgia and rash, while DENV was associated with myalgia, raised aspartate transaminase, and leucopaenia. Forty CHIKV patients were followed up, with a median duration of self-reported arthralgia of 3 months (range, 0-24 months). Eighteen (45%) had persistent arthralgia beyond 4 months, for which age >40 years was an independent predictor. At 1 year, 9 (22.5%) patients had arthralgia. CONCLUSION In Kuala Lumpur, selected clinical and laboratory predictors help to distinguish between DENV and CHIKV infections. Persistent arthralgia was a frequent sequel of CHIKV infection in this cohort.
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Affiliation(s)
- M A Mohd Zim
- Department of Medicine, Universiti Teknologi MARA, Shah Alam, Malaysia
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Sam IC, Kamarulzaman A, Ong GSY, Veriah RS, Ponnampalavanar S, Chan YF, AbuBakar S. Chikungunya virus-associated death in Malaysia. Trop Biomed 2010; 27:343-347. [PMID: 20962735] [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: 05/30/2023]
Abstract
Chikungunya virus (CHIKV) is a mosquito-borne alphavirus which causes fever, rash, and arthralgia. In the past, life-threatening complications were very rarely reported. However, during the recent worldwide outbreaks, there have been several reports of unusually severe complications and deaths. Malaysia is experiencing a nationwide outbreak of CHIKV, with over 10 000 patients affected since April 2008. We report the first case of culture-confirmed CHIKV-associated death in Malaysia, in a patient with fever, rash, acute exacerbation of pre-existing heart failure, rhabdomyolysis, and multiple organ failure. CHIKV infections may cause atypical, severe or fatal presentations.
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Affiliation(s)
- I C Sam
- Tropical Infectious Diseases Research and Education Centre, Department of Medical Microbiology, Faculty of Medicine, University Malaya, Kuala Lumpur 50603, Malaysia.
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Kahar-Bador M, Nathan AM, Soo MH, Mohd Noor S, AbuBakar S, Lum LCS, Syed Hassan S, Sam IC. Fatal influenza A (H3N2) and Campylobacter jejuni coinfection. Singapore Med J 2009; 50:e112-e113. [PMID: 19352555] [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: 05/27/2023]
Abstract
The rapid diagnosis and subtyping of influenza is particularly important in areas where avian influenza (H5N1) is present. The ability to recognise both typical and atypical presentations of influenza is also critical in such settings. A six-month-old male child who visited a H5N1-affected area subsequently died from a severe febrile diarrhoeal illness with minimal respiratory symptoms, and was initially diagnosed with influenza A of an unknown subtype. The final microbiological results showed a highly unusual combination of influenza A (H3N2) and Campylobacter jejuni infection.
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Affiliation(s)
- M Kahar-Bador
- Tropical Infectious Diseases Research and Education Centre, Department of Medical Microbiology, Faculty of Medicine, University Malaya, Kuala Lumpur 50603, Malaysia
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Abd-Jamil J, Teoh B, Hassan E, AbuBakar S. Species C Adenovirus is The Most Common Adenovirus Causing Respiratory Tract Infection of Malaysian Pediatric Patients. Int J Infect Dis 2008. [DOI: 10.1016/j.ijid.2008.05.256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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Chan S, Chan Y, Sam I, AbuBakar S. Analysis of Chikungunya Genome Sequences from Bagan Panchor, Malaysia. Int J Infect Dis 2008. [DOI: 10.1016/j.ijid.2008.05.885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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26
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Chan Y, AbuBakar S. Redesignation of Enterovirus 71 Genotypes. Int J Infect Dis 2008. [DOI: 10.1016/j.ijid.2008.05.811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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27
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MatRahim N, AbuBakar S. DNA Vaccine Construct in the Presence of EV71 IRES Elicited Higher Neutralizing Antibody Titre. Int J Infect Dis 2008. [DOI: 10.1016/j.ijid.2008.05.689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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Abd-Jamil J, Cheah CY, AbuBakar S. Dengue virus type 2 envelope protein displayed as recombinant phage attachment protein reveals potential cell binding sites. Protein Eng Des Sel 2008; 21:605-611. [DOI: 10.1093/protein/gzn041] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/02/2023] Open
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29
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Sam IC, AbuBakar S. Chikungunya virus infection. Med J Malaysia 2006; 61:264-9. [PMID: 16898330] [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: 05/11/2023]
Abstract
Chikungunya virus (CHIKV) is a mosquito-borne alphavirus which causes epidemic fever, rash and polyarthralgia in Africa and Asia. Two outbreaks have been reported in Malaysia, in Klang, Selangor (1998) and Bagan Panchor, Perak (2006). It is not known if the outbreaks were caused by the recent introduction of CHIKV, or if the virus was already circulating in Malaysia. Seroprevalence studies from the 1960s suggested previous disease activity in certain parts of the country. In Asia, CHIKV is thought to be transmitted by the same mosquitoes as dengue, Aedes aegypti and Ae. albopictus. Due to similarities in clinical presentation with dengue, limited awareness, and a lack of laboratory diagnostic capability, CHIKV is probably often underdiagnosed or misdiagnosed as dengue. Treatment is supportive. The prognosis is generally good, although some patients experience chronic arthritis. With no vaccine or antiviral available, prevention and control depends on surveillance, early identification of outbreaks, and vector control. CHIKV should be borne in mind in sporadic cases, and in patients epidemiologically linked to ongoing local or international outbreaks or endemic areas.
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Affiliation(s)
- I-C Sam
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur
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Misbah S, Hassan H, Yusof MY, Hanifah YA, AbuBakar S. Genomic species identification of Acinetobacter of clinical isolates by 16S rDNA sequencing. Singapore Med J 2005; 46:461-4. [PMID: 16123830] [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: 05/04/2023]
Abstract
INTRODUCTION This study aims to identify Acinetobacter of clinical isolates from the University of Malaya Medical Centre (UMMC), Kuala Lumpur, to the species level by 16S rDNA sequencing. METHODS 12 representative Acinetobacter isolates of the UMMC inpatients were randomly picked and used for the study. The 16S rDNA sequences were determined and phylogenetic relationships to all known Acinetobacter species were established. RESULTS Based on the 16S rDNA sequences, all the UMMC isolates were identified as Acinetobacter baumannii. The isolates shared a common ancestral lineage with the prototypes Acinetobacter baumannii DSM30007 and DSM30008 with 99-100 percent sequence similarities. The isolates could be differentiated into two groups by a single nucleotide difference (thymine-cytosine) within the 16S rRNA sequence. Three different genotypes, 1, 3 and 4, were recognised using REP-PCR. CONCLUSION The previously uncharacterised Acinetobacter isolates from the UMMC were identified by their 16S rDNA sequences as Acinetobacter baumannii. The isolates were distinguished into at least three different genotypes by REP-PCR genotyping. These findings confirmed for the first time the presence of Acinetobacter baumannii of different genotypes among patients at UMMC.
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Affiliation(s)
- S Misbah
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
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Misbah S, AbuBakar S, Hassan H, Hanifah YA, Yusof MY. Antibiotic susceptibility and REP-PCR fingerprints of Acinetobacter spp. isolated from a hospital ten years apart. J Hosp Infect 2005; 58:254-61. [PMID: 15564001 DOI: 10.1016/j.jhin.2004.07.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2004] [Accepted: 06/23/2004] [Indexed: 02/06/2023]
Abstract
The antibiotic susceptibility profiles and the repetitive extragenic palindromic sequence-based polymerase chain reaction (REP-PCR)-determined genotypes of 109 Acinetobacter strains collected from the University Malaya Medical Center (UMMC), Kuala Lumpur, Malaysia, in 1987 (N=21) and 1996-1998 (N=88) were established. Twelve antibiotic susceptibility profiles of antibiotics used at the UMMC were obtained. In descending order of effectiveness, imipenem, amikacin and ciprofloxacin were the most effective against the Acinetobacter strains. Compared with 1987 isolates, the isolates obtained in 1996-1998 had decreased susceptibility to these antibiotics and were tolerant to the antibiotics up to an MIC90 of > or =256 mg/L. REP-PCR DNA fingerprints of all the isolates revealed the presence of four Acinetobacter spp. lineages; 92% of all the isolates belonged to two dominant lineages (genotypes 1 and 4). Genotype 4 isolates predominant in 1987 showed increased resistance and antibiotic tolerance to imipenem, amikacin and ciprofloxacin compared with the 1996-1998 isolates. In contrast, genotype 1 isolates from 1996-1998 were mainly sensitive to these antibiotics. These findings demonstrate the presence of at least two independent Acinetobacter spp. lineages in the same hospital, and suggest the possibility that genotype 4 Acinetobacter spp. acquired the resistance phenotype in situ, whereas most of the genotype 1 isolates were probably introduced to the hospital in recent years.
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Affiliation(s)
- S Misbah
- Department of Medical Microbiology, Faculty of Medicine, University Malaya, 50603 Kuala Lumpur, Malaysia
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Chua KB, Lam SK, AbuBakar S, Lim ST, Paranjothy M, Koh MT, Lee WS. The predictive value of uvulo-palatoglossal junctional ulcers as an early clinical sign of exanthem subitum due to human herpesvirus 6. J Clin Virol 2000; 17:83-90. [PMID: 10942088 DOI: 10.1016/s1386-6532(00)00077-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND The clinical sign of uvulo-palatoglossal junctional (UPJ) ulcers was first noted in 1983 in a 5.5-month-old baby with exanthem subitum (ES). An earlier prospective clinical study showed that there was a strong association of UPJ ulcers and occurrence of ES with a positive predictive value of 95.3% and negative predictive value of 100%. OBJECTIVE To determine the value of uvulo-palatoglossal junctional (UPJ) ulcers as an early clinical sign of exanthem subitum (ES) due to human herpesvirus 6 (HHV 6) infection. STUDY DESIGN A case-control study of 20 febrile children with UPJ ulcers versus 26 febrile children without UPJ ulcers. These children were followed up for any development of ES and investigated for human herpesvirus 6 (HHV 6) as the causative agents of the febrile episodes. RESULTS In this study, 20 out of 46 febrile children aged 3 months to 3 years with UPJ ulcers were virologically and/or serologically confirmed to be due to primary HHV 6 infection. The rest of the 26 children without ulcers did not have HHV 6 infection. Of the 20 children with UPJ ulcers, only 17 of the 19 children with adequate follow-up till subsidence of fever developed ES. None of the 26 children without UPJ ulcers developed ES. CONCLUSION Statistically, there was a significant association of UPJ ulcers as an early sign of ES with a positive predictive value of 89.5% and negative predictive value of 100%. This finding also suggests that the presence of UPJ ulcers is a useful pathognomic clinical sign of symptomatic primary HHV 6 infection.
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Affiliation(s)
- K B Chua
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
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AbuBakar S, Chee HY, Al-Kobaisi MF, Xiaoshan J, Chua KB, Lam SK. Identification of enterovirus 71 isolates from an outbreak of hand, foot and mouth disease (HFMD) with fatal cases of encephalomyelitis in Malaysia. Virus Res 1999; 61:1-9. [PMID: 10426204 DOI: 10.1016/s0168-1702(99)00019-2] [Citation(s) in RCA: 165] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Thirteen enterovirus 71 (EV71) isolates were obtained from both fatal and non-fatal infections of patients seen in Peninsula Malaysia and in Sarawak during an outbreak of hand, foot and mouth disease (HFMD) in Malaysia in 1997, with incidences of fatal brainstem encephalomyelitis. The isolates were identified using immunofluorescence staining, neutralization assays, and partial sequencing of the 5' untranslated regions (UTR). Assessment of the potential genetic relationships of the isolates using the partial 5'UTR sequences suggested clustering of the isolates into at least two main clusters. Isolates from Peninsula Malaysia were found in both clusters whereas Sarawak-derived isolates clustered only in cluster II. Isolates derived from fatal infections, however, occurred in both clusters and no distinctive nucleotide sequences could be attributed to the fatal isolates. Examination of the nucleotide sequences revealed at least 13 nucleotide positions in all the isolates which differ completely from the previously reported EV71 5'UTR sequences. In addition, at least 11 nucleotide position differences within the 5'UTR were noted which differentiated cluster I from cluster II. Predicted secondary RNA structures drawn using the nucleotide sequences also suggested differences between isolates from the two clusters. These findings suggest the presence of at least two potentially virulent EV71 co-circulating in Malaysia during the 1997 HFMD outbreak.
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Affiliation(s)
- S AbuBakar
- Department of Medical Microbiology, University Malaya Medical Center, Kuala Lumpur, Malaysia.
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Abstract
During an outbreak of hand-foot-mouth disease caused by enterovirus 71 (EV-71) in 1997, 4 children presented with sudden cardiopulmonary collapse and minimal neurologic features. All children received cardiopulmonary resuscitation but died within a few hours of admission. Postmortem studies showed infection by EV-71 with extensive damage to the medulla and pons. We postulate an etiologic link between EV-71 and brainstem encephalomyelitis as the cause of pulmonary edema and death.
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Affiliation(s)
- L C Lum
- Department of Pediatrics, the Department of Pathology, the Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
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Chua KB, Lam SK, AbuBakar S. Isolation and identification of human herpesvirus 7 from an infant with exanthem subitum. Med J Malaysia 1998; 53:296-301. [PMID: 10968172] [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: 02/17/2023]
Abstract
Exanthem subitum (ES) is a common childhood exanthematous disease. In a recent study of ES due to human herpesvirus 6 (HHV 6), we isolated human herpesvirus 7 (HHV 7) from the peripheral blood mononuclear cells (PBMC) of a seven month-old infant with typical symptoms of ES. The identity of the virus was confirmed by indirect immunofluorescence using HHV 7 specific monoclonal antibody and by amplification of the HHV 7 specific genomic sequences using the polymerase chain reaction (PCR). Paired serum samples from the infant showed serological conversion to the isolated virus. The clinical manifestations of ES in this infant appeared to be milder than the classical ES due to HHV 6.
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Affiliation(s)
- K B Chua
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur
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AbuBakar S, Shafee N, Chee HY. Detection of apoptotic cells in Vero cell cultures inoculated with samples derived from fatal cases of Sarawak acute childhood viral infection. Med J Malaysia 1998; 53:293-5. [PMID: 10968171] [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: 02/17/2023]
Abstract
Infectious agent(s) causing the fatal Sarawak acute childhood viral infection (SACVI) has not been identified. In the present study, results indicating that inocula prepared from the fatal cases of SACVI induced apoptosis in Vero cell cultures are presented. These findings suggest the possible involvement of apoptotic cellular responses in SACVI.
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Affiliation(s)
- S AbuBakar
- Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur
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Ong CC, Lam SK, AbuBakar S. Cellular proteins bind to the 3' and 5' untranslated regions of dengue 2 virus genome. Malays J Pathol 1998; 20:11-7. [PMID: 10879258] [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: 02/16/2023]
Abstract
In vitro generated cloned full length dengue 2 virus untranslated regions (UTRs) were used in RNA gel mobility shift assays to examine cellular factors binding to the virus genomes. Cellular factors in lysates of Vero (monkey) and C6/36 (mosquito) cells bound specifically and non-specifically to the dengue 2 virus 3' UTR. Non-specific interaction with the 5' UTR, resulting in formation of at least 4 band shift complexes was noted with lysate of the C6/36 cells only. Pre-treating the cell lysates with proteinase K affected binding of cellular factors to the dengue 2 virus UTRs, suggesting that the cellular factors were proteins. These findings suggest that cellular proteins could interact with specific sites on the dengue virus genomes.
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Affiliation(s)
- C C Ong
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
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Chua KB, Lam SK, AbuBakar S, Koh MT, Lee WS. The incidence of human herpesvirus 6 infection in children with febrile convulsion admitted to the University Hospital, Kuala Lumpur. Med J Malaysia 1997; 52:335-41. [PMID: 10968110] [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: 02/17/2023]
Abstract
From October 1996 to March 1997, 31 children with febrile convulsions were admitted to the University Hospital, Kuala Lumpur. Human Herpesvirus 6 (HHV 6) was virologically and/or serologically confirmed to be the cause of the febrile episode in 5 of these children (16.1%). Age, sex and other associated clinical features (diarrhoea, cough, running nose and type of seizure) were not useful in differentiating cases of febrile convulsion due to HHV 6 from those of other aetiology. However, uvulo-palatoglossal junctional ulcers were noted in children in whom the cause of the seizure could be attributed to HHV 6 but not in the remaining cases in the study group. HHV 6 DNA was detected in peripheral blood mononuclear cells from all patients with febrile convulsions attributed to HHV6, and in patients shown serologically to have already been exposed to the virus by nested polymerase chain reaction amplification. Only genotype HHV 6B was detected from patients with seizure due to HHV 6 but both genotype 6A and 6B were detected in the remaining cases studied.
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Affiliation(s)
- K B Chua
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
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AbuBakar S, Azmi A, Mohamed-Saad N, Shafee N, Chee HY. Antibody responses of dengue fever patients to dengue 2 (New Guinea C strain) viral proteins. Malays J Pathol 1997; 19:41-51. [PMID: 10879241] [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: 02/16/2023]
Abstract
The present study was undertaken to investigate the antibody responses of dengue fever (DF) patients to specific dengue virus proteins. Partially purified dengue 2 New Guinea C (NGC) strain virus was used as antigen. Under the present experimental protocols, it was observed that almost all DF patients' sera had detectable presence of antibodies which recognize the dengue 2 envelope (E) protein. The convalescent-phase sera especially had significant detectable IgG, IgM and IgE against the protein. In addition, IgGs specific against the NS1 dimer and PrM were also detected. Antibody against the core (C) protein, however, was not detectable in any of the DF patients' sera. The substantial presence of IgG against the PrM in the convalescent-phase sera, and the presence of IgE specific for the E, reflect the potential importance of these antibody responses in the pathogenesis of dengue.
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Affiliation(s)
- S AbuBakar
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur
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Deng CZ, AbuBakar S, Fons MP, Boldogh I, Albrecht T. Modulation of the frequency of human cytomegalovirus-induced chromosome aberrations by camptothecin. Virology 1992; 189:397-401. [PMID: 1318615 DOI: 10.1016/0042-6822(92)90724-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The effects of selected DNA repair inhibitors on the frequency of human cytomegalovirus (HCMV)-induced chromosome aberrations were evaluated in human peripheral blood lymphocytes (PBLs). Treatment of HCMV-infected PBLs with camptothecin (0.05 to 0.3 micrograms/ml), an inhibitor of topoisomerase I, for 30 hr resulted in a significant (P less than 0.01) synergistic enhancement of the frequency of HCMV-induced chromosome damage. On the other hand, a significant increase in the frequency of chromosome damage was not noted for infected PBLs treated with either 3-aminobenzamide (3-AB; 3 to 30 micrograms/ml), an inhibitor of poly(ADP-ribose) polymerase, or novobiocin (3 to 30 micrograms/ml), an inhibitor of topoisomerase II or excision repair processes, for 30 hr. Chromatid-type breaks and exchanges were the predominant type of chromosome aberrations observed in the HCMV-infected cells treated with camptothecin, suggesting that HCMV infection is associated with the induction of single-strand DNA breaks. Furthermore, these findings suggest that HCMV infection does not inflict direct DNA damage which is repaired through 3-AB- or novobiocin-sensitive pathways.
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Affiliation(s)
- C Z Deng
- Department of Microbiology, University of Texas Medical Branch, Galveston 77550
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Boldogh I, AbuBakar S, Millinoff D, Deng CZ, Albrecht T. Cellular oncogene activation by human cytomegalovirus. Lack of correlation with virus infectivity and immediate early gene expression. Arch Virol 1991; 118:163-77. [PMID: 1712580 DOI: 10.1007/bf01314027] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The contribution of expression of human cytomegalovirus (HCMV) immediate early (IE) genes to the rapid and transient increase in cellular (c)-oncogene (fos, jun, myc) transcription following HCMV infection was investigated. A partial temporal overlap was observed between the increases in c-oncogene RNA levels and the increase in either transcripts from HCMV IE genes or the number of cells in which HCMV IE proteins were detected. The increases in c-oncogene RNA levels, however, slightly preceded the increase in the detection of HCMV IE transcripts or proteins. To distinguish between the temporal coincidence and a direct relationship between expression of HCMV IE genes and the increased transcription of c-oncogenes, the number of cells synthesizing HCMV IE proteins was reduced by infecting with virus stock enriched in defective particles. Alternatively, the synthesis of HCMV IE proteins was essentially eliminated by ultra-violet (UV) irradiation of virus stock or by inhibitors of protein synthesis. Virus stocks enriched in defective particles demonstrated a substantially reduced capacity to direct the synthesis of HCMV IE proteins, but were more efficient in activating c-oncogene expression than infectious virus stocks. Elimination of expression of HCMV IE genes by UV-irradiation of virus stock or by inhibiting de novo viral and/or cellular protein synthesis with cycloheximide (100 micrograms/ml) or anisomycin (100 micrograms/ml) did not eliminate the HCMV-induced increase in RNA levels of c-oncogenes. These data indicate that activation of these early response cellular genes is independent from de novo expression of HCMV IE proteins, and possibly involves biologically active virion proteins that are related to the induction of a cascade of cellular events associated with the binding of HCMV to its cellular receptor.
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Affiliation(s)
- I Boldogh
- Department of Microbiology, University of Texas Medical Branch, Galveston
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Boldogh I, AbuBakar S, Fons MP, Deng CZ, Albrecht T. Activation of cellular oncogenes by clinical isolates and laboratory strains of human cytomegalovirus. J Med Virol 1991; 34:241-7. [PMID: 1719130 DOI: 10.1002/jmv.1890340409] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The effect on cellular (c) oncogene RNA levels was investigated after infection of permissive cells with cell culture adapted strains (AD-169, C-87, Davis) and unadapted clinical isolates (82-1, 84-2, 85-1) of human cytomegalovirus (HCMV). The results indicate that both adapted and unadapted strains of HCMV induce substantial increases in c-oncogene RNA levels for fos, jun, and myc measured by Northern blot hybridization. Elimination of immediate early (IE) protein synthesis between 0 and 3 hrs or reduction of virus infectivity (99.99%) by UV-irradiation did not reduce the increase in c-oncogene RNA levels. Inhibition of viral and cellular protein synthesis by cycloheximide resulted in a high abundance (superinduction) of specific RNAs which hybridized to c-oncogene probes after infection with either adapted or unadapted strains of HCMV. These data suggest that IE viral gene expression is not essential for activation of c-oncogenes. Inhibition of DNA-dependent RNA synthesis by blocking RNA elongation with actinomycin-D or by inhibiting the activity of RNA polymerase II with alpha-amanitin significantly reduced the increase in c-oncogene RNA levels, suggesting that activation of cellular genes by HCMV is controlled at the level of transcription. Activation of c-oncogenes by HCMV may be particularly important because their protein products appear to be involved in initiation and regulation of viral and cellular gene expression.
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Affiliation(s)
- I Boldogh
- Department of Microbiology, University of Texas Medical Branch, Galveston 77550
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Albrecht T, Fons MP, Boldogh I, AbuBakar S, Deng CZ, Millinoff D. Metabolic and cellular effects of human cytomegalovirus infection. Transplant Proc 1991; 23:48-54, discussion 54-5. [PMID: 1648835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- T Albrecht
- University of Texas Medical Branch, Galveston 77550
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Abstract
The mechanisms responsible for the human cytomegalovirus (HCMV)-induced increase in cellular oncogene RNAs for c-jun, c-fos, and c-myc in human embryo lung cells (I. Boldogh, S. AbuBakar, and T. Albrecht, Science 247:561-564, 1990) were investigated. Results of transcription assays indicated that the rapid increase in RNA levels for the above-noted oncogenes was controlled at the transcriptional level and was related to enhanced transcription. The maximum rates of transcription for c-jun and c-fos genes occurred at 40 min postinfection, while for the c-myc gene the maximum rate occurred at about 60 min. The magnitude of HCMV-induced activation of these cellular genes was similar to the activation induced by serum. The half-lives of the cellular oncogenes showed similar decay rates after either serum or HCMV activation when measured by dactinomycin chase. The half-life for c-fos or c-jun was about 20 min, and that for c-myc was about 40 min. Furthermore, inhibition of the RNA increase by dactinomycin or by alpha-amanitin suggested that the increase in RNA levels was due to an increase in the transcriptional activity of oncogenes triggered by HCMV.
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Affiliation(s)
- I Boldogh
- Department of Microbiology, University of Texas Medical Branch, Galveston 77550
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Abstract
Exposure of human lung fibroblasts to human cytomegalovirus (HCMV) stimulated a rapid increase in the release of [3H] from cells prelabelled with radiolabelled arachidonic acid ([3H]AA). Maximum stimulation of [3H] release was observed at 20 min postinfection and was quantitatively similar to that induced by the tumor promoter 12-O-tetradecanoylphorbol 13-acetate (TPA: 10 nM) or fetal calf serum (5%). The level of [3H] release was dependent on the multiplicity of infection, and appeared to be mediated by a component(s) of the virion, since the findings from three series of experiments suggested that neither infectious virus, nor HCMV-specific macromolecular synthesis was required for stimulation of [3H] release. (1) Inactivation of HCMV infectivity with ultra-violet (UV) light (approximately 254 nm, 4.80 x 10(4) ergs/mm2) did not diminish the stimulation of [3H] release. (2) Significant reduction in the level of [3H] release was not observed when infected cells were maintained in the presence of a protein synthesis inhibitor, cycloheximide (50 micrograms/ml), or an inhibitor of mRNA synthesis, 3'-deoxyadenosine (cordycepin, 50 micrograms/ml). (3) No correlation was established between the expression of HCMV immediate early (IE) antigens and the induction of [3H] release, since there was little, if any, synthesis of HCMV IE antigen detectable by anticomplement immunofluorescence through the first 30 min postinfection. These findings suggesting that the HCMV particle rapidly stimulates AA metabolism are consistent with the view that the interaction of a HCMV virion component(s) with the cell surface may initiate membrane-associated events similar to those induced by growth factors.
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Affiliation(s)
- S AbuBakar
- Department of Microbiology, University of Texas Medical Branch, Galveston
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Abstract
A rapid increase in the RNA levels of the proto-oncogenes c-fos, c-jun, and c-myc was detected after human cytomegalovirus infection. Neither inactivation of viral infectivity with ultraviolet irradiation (with or without psoralen), nor inhibition of translation with cycloheximide or anisomycin adversely affected the enhanced expression of proto-oncogenes, even though these treatments substantially reduced or eliminated the detection of immediate early viral antigens. The increase in the RNA levels of the proto-oncogenes was prevented in the presence of alpha-amanitin or actinomycin D. Thus, expression of these oncogenes appears to be induced by events occurring before the onset of viral protein synthesis, perhaps by the interaction of viral particles with the cell surface.
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Affiliation(s)
- I Boldogh
- Department of Microbiology, University of Texas Medical Branch, Galveston 77550
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AbuBakar S, Boldogh I, Albrecht T. Human cytomegalovirus stimulates arachidonic acid metabolism through pathways that are affected by inhibitors of phospholipase A2 and protein kinase C. Biochem Biophys Res Commun 1990; 166:953-9. [PMID: 2154225 DOI: 10.1016/0006-291x(90)90903-z] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Inhibitors of phospholipase A2, tetracaine and quinacrine, inhibitors of protein kinases, H-7 and H-8, and a diacylglycerol lipase inhibitor reduced the level of CMV-induced [3H]AA release. A combination of H-7 and quinacrine inhibited stimulation of [3H]AA by about 80%. LU cells chronically treated with TPA and infected with CMV, had a reduced level of CMV-induced [3H]AA release and in the presence of quinacrine it was completely inhibited. These results suggest that CMV-induced stimulation of AA metabolism is mediated by pathways which are associated with activation of PLA2 and protein kinase C.
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Affiliation(s)
- S AbuBakar
- Department of Microbiology, University of Texas Medical Branch, Galveston 77550
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Abstract
Cytomegalovirus (CMV) infection induces a series of cellular responses that resemble those observed in cells activated by growth factors or hormones including: hydrolysis of phosphatidylinositol-4,5-bisphosphate; Ca2+ influx and an increase in the cytosolic free [Ca2+]; an increase in Na+ entry; and, increases in cellular levels of cyclic AMP and cyclic GMP. The time courses for some of these responses appear to be markedly protracted relative to those observed for growth factors. The prolonged physiologic responses in CMV-infected cells appear to be related to modifications in the intracellular environment that are associated with the development of cytomegaly and with the phasing of CMV-directed macromolecular synthesis. For example, as the infected cell enlarges, the rate of CMV DNA synthesis increases by about 4-fold, late nuclear inclusions develop and progeny viruses are formed. When the CMV-induced activation signals are inhibited or their physiologic responses are blocked, then the yields of infectious CMV are substantially reduced. Furthermore, perturbation of the cell cycle resulting from induction of the cell activation process by CMV may be causally related to the induction of cellular damage by CMV, even in the absence of productive infection. Accordingly, the CMV-induced pathophysiologic cell activation responses represent potential targets for novel antiviral therapy.
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Affiliation(s)
- T Albrecht
- Department of Microbiology, University of Texas Medical Branch, Galveston 77550
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