1
|
Abstract
Dengue, an arboviral disease is a global threat to public health as the number of Dengue cases increases through the decades and this trend is predicted to continue. Non-communicable diseases such as diabetes and obesity are also on an upward trend. Moreover, past clinical studies have shown comorbidities worsen the clinical manifestation of especially Severe Dengue. However, discussion regarding the underlying mechanisms regarding the association between these comorbidities and dengue are lacking. The hallmark of Severe Dengue is plasma leakage which is due to several factors including presence of pro-inflammatory cytokines and dysregulation of endothelial barrier protein expression. The key factors of diabetes affecting endothelial functions are Th1 skewed responses and junctional-related proteins expression. Additionally, obesity alters the lipid metabolism and immune response causing increased viral replication and inflammation. The similarity between diabetes and obesity individuals is in having chronic inflammation resulting in endothelial dysfunction. This review outlines the roles of diabetes and obesity in severe dengue and gives some insights into the plausible mechanisms of comorbidities in Severe Dengue.
Collapse
Affiliation(s)
- S D Sekaran
- Faculty of Medicine and Health Sciences, UCSI University Springhill Campus, Port Dickson, 70100, Negri Sembilan, Malaysia.
| | - Z M Liew
- Faculty of Applied Science, UCSI University Kuala Lumpur, Kuala Lumpur, 56000, Malaysia
| | - H C Yam
- Faculty of Applied Science, UCSI University Kuala Lumpur, Kuala Lumpur, 56000, Malaysia
| | - C S Raju
- Department of Medical Microbiology, Faculty of Medicine, University Malaya, Kuala Lumpur, 50603, Malaysia
| |
Collapse
|
2
|
Jindal HM, Chandramathi S, Sekaran SD, Suresh K. Evaluation of bactericidal and virucidal activity of novel disinfectant Aaride AGT-1 compared to other commercially available disinfectants against hospital-acquired infections (HAIs). Trop Biomed 2020; 37:626-636. [PMID: 33612777 DOI: 10.47665/tb.37.3.626] [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
Hand hygiene is the topmost crucial procedure to prevent hospital-acquired infections. Choosing an effective hand disinfectant is necessary in enforcing good hand hygiene practice especially in hospital settings. The aim of the study was to investigate the efficacy of Aaride AGT-1 as a hand disinfectant for the inhibition of pathogenic microorganisms' transmission among both patients and personnel in the health care system compared to other commercially available disinfectants. In the present study, a new hand disinfectant Aaride AGT-1 was tested against several bacterial and viral pathogens to evaluate its antimicrobial activity profile. The results revealed that Aaride AGT-1 displayed the highest antibacterial activity against five pathogenic bacteria including MRSA when compared to other commercially available hand sanitizers. Aaride AGT-1 showed the lowest percentage needed to inhibit the growth of bacterial pathogens. In addition, results obtained from time killing assay revealed that Aaride AGT-1 demonstrated the best killing kinetics, by eradicating the bacterial cells rapidly within 0.5 min with 6 log reduction (>99.99% killing). Also, Aaride AGT1 was able to reduce 100% plaque formed by three viruses namely HSV-1, HSV-2 and EV-71. In conclusion, Aaride AGT-1 is capable of killing wide-spectrum of pathogens including bacteria and viruses compared to other common disinfectants used in hospital settings. Aaride AGT-1's ability to kill both bacteria and viruses contributes as valuable addition to the hand disinfection portfolio.
Collapse
Affiliation(s)
- H M Jindal
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - S Chandramathi
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - S D Sekaran
- School of Basic Medical Sciences, Faculty of Medicine and Biomedical Sciences, Mahsa University, 42610 Jenjarom, Selangor, Malaysia
| | - K Suresh
- Department of Parasitology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| |
Collapse
|
3
|
Ismail AA, Mahboob T, Samudi Raju C, Sekaran SD. Zika virus modulates blood-brain barrier of brain microvascular endothelial cells. Trop Biomed 2019; 36:888-897. [PMID: 33597462] [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: 06/12/2023]
Abstract
Zika virus (ZIKV) is a mosquito-borne Flaviviruses. ZIKV is known to cause birth defect in pregnant women, especially microcephaly in the fetus. Hence, more study is required to understand the infection of Zika virus towards human brain microvascular endothelial cells (MECs). In this study, brain MECs were infected with ZIKV at MOI of 1 and 5 in vitro. The changes in barrier function and membrane permeability of ZIKV-infected brain MECs were determined using electric cell-substrate impedance sensing (ECIS) system followed by gene expression of ZIKV-infected brain MECs at 24 hours post infection using one-color gene expression microarray. The ECIS results demonstrated that ZIKV infection enhances vascular leakage by increasing cell membrane permeability via alteration of brain MECs barrier function. This was further supported by high expression of proinflammatory cytokine genes (lnc-IL6-2, TNFAIP1 and TNFAIP6), adhesion molecules (CERCAM and ESAM) and growth factor (FIGF). Overall, findings of this study revealed that ZIKV infection could alter the barrier function of brain MECs by altering adhesion molecules and inflammatory response.
Collapse
Affiliation(s)
- A A Ismail
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - T Mahboob
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - C Samudi Raju
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - S D Sekaran
- Faculty of Medicine and Biomedical Science, MAHSA University, Selangor, Malaysia
| |
Collapse
|
4
|
Tang SS, Prodhan ZH, Biswas SK, Le CF, Sekaran SD. Antimicrobial peptides from different plant sources: Isolation, characterisation, and purification. Phytochemistry 2018; 154:94-105. [PMID: 30031244 DOI: 10.1016/j.phytochem.2018.07.002] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [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: 05/05/2018] [Revised: 07/03/2018] [Accepted: 07/07/2018] [Indexed: 05/20/2023]
Abstract
Antimicrobial peptides (AMPs), the self-defence products of organisms, are extensively distributed in plants. They can be classified into several groups, including thionins, defensins, snakins, lipid transfer proteins, glycine-rich proteins, cyclotides and hevein-type proteins. AMPs can be extracted and isolated from different plants and plant organs such as stems, roots, seeds, flowers and leaves. They perform various physiological defensive mechanisms to eliminate viruses, bacteria, fungi and parasites, and so could be used as therapeutic and preservative agents. Research on AMPs has sought to obtain more detailed and reliable information regarding the selection of suitable plant sources and the use of appropriate isolation and purification techniques, as well as examining the mode of action of these peptides. Well-established AMP purification techniques currently used include salt precipitation methods, absorption-desorption, a combination of ion-exchange and reversed-phase C18 solid phase extraction, reversed-phase high-performance liquid chromatography (RP-HPLC), and the sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) method. Beyond these traditional methods, this review aims to highlight new and different approaches to the selection, characterisation, isolation, purification, mode of action and bioactivity assessment of a range of AMPs collected from plant sources. The information gathered will be helpful in the search for novel AMPs distributed in the plant kingdom, as well as providing future directions for the further investigation of AMPs for possible use on humans.
Collapse
Affiliation(s)
- Swee-Seong Tang
- Division of Microbiology, Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia.
| | - Zakaria H Prodhan
- Division of Microbiology, Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia; Department of Agronomy, Institute of Crop Science, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China.
| | - Sudhangshu K Biswas
- Division of Microbiology, Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia.
| | - Cheng-Foh Le
- School of Biosciences, Faculty of Science, The University of Nottingham Malaysia Campus, Semenyih, Selangor, Malaysia.
| | - Shamala D Sekaran
- Faculty of Medicine, MAHSA University, Saujana Putra Campus, 42610, Jenjarum, Selangor, Malaysia.
| |
Collapse
|
5
|
Al-Obaidi MMJ, Bahadoran A, Wang SM, Manikam R, Raju CS, Sekaran SD. Disruption of the blood brain barrier is vital property of neurotropic viral infection of the central nervous system. Acta Virol 2018. [PMID: 29521099 DOI: 10.4149/av_2018_102] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The blood brain barrier consisting of astrocytes, pericytes and brain microvascular endothelial cells plays a vital role in the pathogenesis of neurotropic viruses by controlling the access of circulating molecules, immune cells or viruses into the central nervous system (CNS). However, this barrier is not impenetrable and neuroviruses have evolved to disrupt and evade it. This review aims to describe the underlying entry mechanisms of several neuroviruses such as (Japanese encephalitis virus (JEV), West Nile virus (WNV), Zika virus (ZIKV), Nipah virus (NiV), Rabies virus (RABV), Herpes simplex virus (HSV) and Human immunodeficiency virus (HIV)) into the CNS through BBB disruption. The mechanisms, through which neurotropic viruses enter the BBB, are being studied and are becoming clearer, however, some aspects still remain unknown. Some of these viruses are able to invade the brain parenchyma by a 'Trojan horse' mechanism, through diapedesis of infected immune cells that either cross the BBB paracellularly or transcellularly. Important mechanisms of BBB disruption associated with paracellular entry of viruses include alterations in expression or phosphorylation of tight junction proteins, disruption of the basal lamina and disruption of the actin cytoskeleton. In the absence of such mechanisms, indirect effects of viruses on the immune system are likely causes of barrier disruption.
Collapse
|
6
|
Darwish NT, Sekaran SD, Alias Y, Khor SM. Immunofluorescence–based biosensor for the determination of dengue virus NS1 in clinical samples. J Pharm Biomed Anal 2018; 149:591-602. [DOI: 10.1016/j.jpba.2017.11.064] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 11/27/2017] [Accepted: 11/28/2017] [Indexed: 02/08/2023]
|
7
|
Yong YK, Tan HY, Jen SH, Shankar EM, Natkunam SK, Sathar J, Manikam R, Sekaran SD. Aberrant monocyte responses predict and characterize dengue virus infection in individuals with severe disease. J Transl Med 2017; 15:121. [PMID: 28569153 PMCID: PMC5452397 DOI: 10.1186/s12967-017-1226-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Accepted: 05/27/2017] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Currently, several assays can diagnose acute dengue infection. However, none of these assays can predict the severity of the disease. Biomarkers that predicts the likelihood that a dengue patient will develop a severe form of the disease could permit more efficient patient triage and allows better supportive care for the individual in need, especially during dengue outbreaks. METHODS We measured 20 plasma markers i.e. IFN-γ, IL-10, granzyme-B, CX3CL1, IP-10, RANTES, CXCL8, CXCL6, VCAM, ICAM, VEGF, HGF, sCD25, IL-18, LBP, sCD14, sCD163, MIF, MCP-1 and MIP-1β in 141 dengue patients in over 230 specimens and correlate the levels of these plasma markers with the development of dengue without warning signs (DWS-), dengue with warning signs (DWS+) and severe dengue (SD). RESULTS Our results show that the elevation of plasma levels of IL-18 at both febrile and defervescence phase was significantly associated with DWS+ and SD; whilst increase of sCD14 and LBP at febrile phase were associated with severity of dengue disease. By using receiver operating characteristic (ROC) analysis, the IL-18, LBP and sCD14 were significantly predicted the development of more severe form of dengue disease (DWS+/SD) (AUC = 0.768, P < 0.0001; AUC = 0.819, P < 0.0001 and AUC = 0.647, P = 0.014 respectively). Furthermore, we also found that the levels of VEGF were directly correlated and sCD14 was inversely correlated with platelet count, suggesting that the endothelial activation and microbial translocation may played a role in pathogenesis of dengue disease. CONCLUSIONS Given that the elevation IL-18, LBP and sCD14 among patients with severe form of dengue disease, our findings suggest a pathogenic role for an aberrant inflammasome and monocyte activation in the development of severe form of dengue disease.
Collapse
Affiliation(s)
- Yean K Yong
- Centre of Excellence for Research in AIDS (CERiA), Department of Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Hong Y Tan
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Lembah Pantai, 50603, Kuala Lumpur, Malaysia
| | - Soe Hui Jen
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Lembah Pantai, 50603, Kuala Lumpur, Malaysia
| | - Esaki M Shankar
- Division of Infection Biology and Microbiology, Department of Life Sciences, School of Basic and Applied Sciences, Central University of Tamil Nadu (CUTN), Neelakudi Campus, Tiruvarur, India
| | - Santha K Natkunam
- Hospital Tengku Ampuan Rahimah, Persiaran Tengku Ampuan Rahimah, Klang, Selangor, Malaysia
| | - Jameela Sathar
- Clinical Hematology Laboratory, Department of Hematology, Hospital Ampang, Ampang, Selangor, Malaysia
| | - Rishya Manikam
- Department of Trauma and Emergency Medicine, University Malaya Medical Centre, Kuala Lumpur, Malaysia
| | - Shamala D Sekaran
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Lembah Pantai, 50603, Kuala Lumpur, Malaysia.
| |
Collapse
|
8
|
Bahadoran A, Lee SH, Wang SM, Manikam R, Rajarajeswaran J, Raju CS, Sekaran SD. Immune Responses to Influenza Virus and Its Correlation to Age and Inherited Factors. Front Microbiol 2016; 7:1841. [PMID: 27920759 PMCID: PMC5118461 DOI: 10.3389/fmicb.2016.01841] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 11/01/2016] [Indexed: 12/28/2022] Open
Abstract
Influenza viruses belong to the family Orthomyxoviridae of enveloped viruses and are an important cause of respiratory infections worldwide. The influenza virus is able to infect a wide variety species as diverse as poultry, marine, pigs, horses, and humans. Upon infection with influenza virus the innate immunity plays a critical role in efficient and rapid control of viral infections as well as in adaptive immunity initiation. The humoral immune system produces antibodies against different influenza antigens, of which the HA-specific antibody is the most important for neutralization of the virus and thus prevention of illness. Cell mediated immunity including CD4+ helper T cells and CD8+ cytotoxic T cells are the other arms of adaptive immunity induced upon influenza virus infection. The complex inherited factors and age related changes are associated with the host immune responses. Here, we review the different components of immune responses against influenza virus. Additionally, the correlation of the immune response to age and inherited factors has been discussed. These determinations lead to a better understanding of the limitations of immune responses for developing improved vaccines to control influenza virus infection.
Collapse
Affiliation(s)
- Azadeh Bahadoran
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya Kuala Lumpur, Malaysia
| | - Sau H Lee
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya Kuala Lumpur, Malaysia
| | - Seok M Wang
- Department of Biochemistry and Molecular Medicine, Faculty of Medicine, MARA University of Technology Selangor, Malaysia
| | - Rishya Manikam
- Department of Trauma and Emergency Medicine, University Malaya Medical Centre Kuala Lumpur, Malaysia
| | - Jayakumar Rajarajeswaran
- Department of Molecular Medicine, Faculty of Medicine, University of Malaya Kuala Lumpur, Malaysia
| | - Chandramathi S Raju
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya Kuala Lumpur, Malaysia
| | - Shamala D Sekaran
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya Kuala Lumpur, Malaysia
| |
Collapse
|
9
|
Lee SH, Jaganath IB, Atiya N, Manikam R, Sekaran SD. Suppression of ERK1/2 and hypoxia pathways by four Phyllanthus species inhibits metastasis of human breast cancer cells. J Food Drug Anal 2016; 24:855-865. [PMID: 28911625 PMCID: PMC9337293 DOI: 10.1016/j.jfda.2016.03.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 03/14/2016] [Accepted: 03/23/2016] [Indexed: 12/20/2022] Open
Abstract
Chemotherapies remain far from ideal due to drug resistance; therefore, novel chemotherapeutic agents with higher effectiveness are crucial. The extracts of four Phyllanthus species, namely Phyllanthus niruri, Phyllanthus urinaria, Phyllanthus watsonii, and Phyllanthus amarus, were shown to induce apoptosis and inhibit metastasis of breast carcinoma cells (MCF-7). The main objective of this study was to determine the pathways utilized by these four Phyllanthus species to exert anti-metastatic activities. A cancer 10-pathway reporter was used to investigate the pathways affected by the four Phyllanthus species. Results indicated that these Phyllanthus species suppressed breast carcinoma metastasis and proliferation by suppressing matrix metalloprotein 2 and 9 expression via inhibition of the extracellular signal-related kinase (ERK) pathway. Additionally, inhibition of hypoxia-inducible factor 1-α in the hypoxia pathway caused reduced vascular endothelial growth factor and inducible nitric oxide synthase expression, resulting in anti-angiogenic effects and eventually anti-metastasis. Two-dimensional gel electrophoresis identified numerous proteins suppressed by these Phyllanthus species, including invasion proteins, anti-apoptotic protein, protein-synthesis proteins, angiogenic and mobility proteins, and various glycolytic enzymes. Our results indicated that ERK and hypoxia pathways are the most likely targets of the four Phyllanthus species for the inhibition of MCF-7 metastasis.
Collapse
Affiliation(s)
- Sau H. Lee
- Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, 50603, Kuala Lumpur,
Malaysia
| | - Indu B. Jaganath
- Biotechnology Centre, Malaysia Agricultural Research and Development Institute (MARDI), 43400, Serdang,
Malaysia
| | - Nadia Atiya
- Department of Trauma and Emergency Medicine, University Malaya Medical Centre, 50603, Kuala Lumpur,
Malaysia
| | - Rishya Manikam
- Department of Trauma and Emergency Medicine, University Malaya Medical Centre, 50603, Kuala Lumpur,
Malaysia
| | - Shamala D. Sekaran
- Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, 50603, Kuala Lumpur,
Malaysia
- Corresponding author. Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, 50603, Kuala Lumpur, Malaysia. E-mail address: (S.D. Sekaran)
| |
Collapse
|
10
|
Saeidi A, Chong YK, Yong YK, Tan HY, Barathan M, Rajarajeswaran J, Sabet NS, Sekaran SD, Ponnampalavanar S, Che KF, Velu V, Kamarulzaman A, Larsson M, Shankar EM. Concurrent loss of co-stimulatory molecules and functional cytokine secretion attributes leads to proliferative senescence of CD8(+) T cells in HIV/TB co-infection. Cell Immunol 2015; 297:19-32. [PMID: 26071876 DOI: 10.1016/j.cellimm.2015.05.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Revised: 05/18/2015] [Accepted: 05/18/2015] [Indexed: 12/15/2022]
Abstract
The role of T-cell immunosenescence and functional CD8(+) T-cell responses in HIV/TB co-infection is unclear. We examined and correlated surrogate markers of HIV disease progression with immune activation, immunosenescence and differentiation using T-cell pools of HIV/TB co-infected, HIV-infected and healthy controls. Our investigations showed increased plasma viremia and reduced CD4/CD8 T-cell ratio in HIV/TB co-infected subjects relative to HIV-infected, and also a closer association with changes in the expression of CD38, a cyclic ADP ribose hydrolase and CD57, which were consistently expressed on late-senescent CD8(+) T cells. Up-regulation of CD57 and CD38 were directly proportional to lack of co-stimulatory markers on CD8(+) T cells, besides diminished expression of CD127 (IL-7Rα) on CD57(+)CD4(+) T cells. Notably, intracellular IFN-γ, perforin and granzyme B levels in HIV-specific CD8(+) T cells of HIV/TB co-infected subjects were diminished. Intracellular CD57 levels in HIV gag p24-specific CD8(+) T cells were significantly increased in HIV/TB co-infection. We suggest that HIV-TB co-infection contributes to senescence associated with chronic immune activation, which could be due to functional insufficiency of CD8(+) T cells.
Collapse
Affiliation(s)
- Alireza Saeidi
- Tropical Infectious Disease Research and Education Center (TIDREC), University of Malaya, Lembah Pantai, 50603 Kuala Lumpur, Malaysia
| | - Yee K Chong
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur, Malaysia
| | - Yean K Yong
- Center of Excellence for Research in AIDS (CERiA), University of Malaya, Lembah Pantai, 50603 Kuala Lumpur, Malaysia
| | - Hong Y Tan
- Center of Excellence for Research in AIDS (CERiA), University of Malaya, Lembah Pantai, 50603 Kuala Lumpur, Malaysia
| | - Muttiah Barathan
- Tropical Infectious Disease Research and Education Center (TIDREC), University of Malaya, Lembah Pantai, 50603 Kuala Lumpur, Malaysia
| | - Jayakumar Rajarajeswaran
- Department of Molecular Medicine, Faculty of Medicine, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur, Malaysia
| | - Negar S Sabet
- Faculty of Medicine, SEGi University, Kota Damansara, 47810 Selangor, Malaysia
| | - Shamala D Sekaran
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur, Malaysia
| | - Sasheela Ponnampalavanar
- Center of Excellence for Research in AIDS (CERiA), University of Malaya, Lembah Pantai, 50603 Kuala Lumpur, Malaysia
| | - Karlhans F Che
- Institute for Environmental Medicine, Karolinska Institute, Solna, 17 177 Stockholm, Sweden
| | - Vijayakumar Velu
- Department of Microbiology and Immunology, Emory Vaccine Center, 954 Gatewood Road, Atlanta, GA 30329, USA
| | - Adeeba Kamarulzaman
- Center of Excellence for Research in AIDS (CERiA), University of Malaya, Lembah Pantai, 50603 Kuala Lumpur, Malaysia
| | - Marie Larsson
- Division of Molecular Virology, Department of Clinical and Experimental Medicine, Linköping University, 58185 Linköping, Sweden
| | - Esaki M Shankar
- Tropical Infectious Disease Research and Education Center (TIDREC), University of Malaya, Lembah Pantai, 50603 Kuala Lumpur, Malaysia; Center of Excellence for Research in AIDS (CERiA), University of Malaya, Lembah Pantai, 50603 Kuala Lumpur, Malaysia; Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur, Malaysia.
| |
Collapse
|
11
|
Rukumani DV, Kamar AA, Ardita DR, Nee TS, Yusof YM, Sekaran SD, Shankar EM. Recalcitrant coagulase‐negative methicillin‐sensitive Staphylococcus aureus in an extremely low‐birth‐weight pre‐term infant with thrombocytopaenia. JMM Case Rep 2014. [DOI: 10.1099/jmmcr.0.004242] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Devi V. Rukumani
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur, Malaysia
| | - Azanna A. Kamar
- Neonatology Unit, Department of Paediatrics, Faculty of Medicine, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur, Malaysia
| | - Dewi R. Ardita
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur, Malaysia
| | - Tang S. Nee
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur, Malaysia
| | - Yasim M. Yusof
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur, Malaysia
| | - Shamala D. Sekaran
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur, Malaysia
| | - Esaki M. Shankar
- Tropical Infectious Disease Research and Education Center (TIDREC), Faculty of Medicine, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur, Malaysia
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur, Malaysia
| |
Collapse
|
12
|
Farooq SM, Boppana NB, Asokan D, Sekaran SD, Shankar EM, Li C, Gopal K, Bakar SA, Karthik HS, Ebrahim AS. C-phycocyanin confers protection against oxalate-mediated oxidative stress and mitochondrial dysfunctions in MDCK cells. PLoS One 2014; 9:e93056. [PMID: 24691130 PMCID: PMC3972226 DOI: 10.1371/journal.pone.0093056] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Accepted: 03/02/2014] [Indexed: 12/04/2022] Open
Abstract
Oxalate toxicity is mediated through generation of reactive oxygen species (ROS) via a process that is partly dependent on mitochondrial dysfunction. Here, we investigated whether C-phycocyanin (CP) could protect against oxidative stress-mediated intracellular damage triggered by oxalate in MDCK cells. DCFDA, a fluorescence-based probe and hexanoyl-lysine adduct (HEL), an oxidative stress marker were used to investigate the effect of CP on oxalate-induced ROS production and membrane lipid peroxidation (LPO). The role of CP against oxalate-induced oxidative stress was studied by the evaluation of mitochondrial membrane potential by JC1 fluorescein staining, quantification of ATP synthesis and stress-induced MAP kinases (JNK/SAPK and ERK1/2). Our results revealed that oxalate-induced cells show markedly increased ROS levels and HEL protein expression that were significantly decreased following pre-treatment with CP. Further, JC1 staining showed that CP pre-treatment conferred significant protection from mitochondrial membrane permeability and increased ATP production in CP-treated cells than oxalate-alone-treated cells. In addition, CP treated cells significantly decreased the expression of phosphorylated JNK/SAPK and ERK1/2 as compared to oxalate-alone-treated cells. We concluded that CP could be used as a potential free radical-scavenging therapeutic strategy against oxidative stress-associated diseases including urolithiasis.
Collapse
Affiliation(s)
- Shukkur M. Farooq
- Department of Pharmacy Practice, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, Michigan, United States of America
- * E-mail: (ASE); ) (SMF); ) (EMS)
| | - Nithin B. Boppana
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, Michigan, United States of America
| | - Devarajan Asokan
- Department of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Shamala D. Sekaran
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Esaki M. Shankar
- Tropical Infectious Diseases Research and Education Center (TIDREC), Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
- * E-mail: (ASE); ) (SMF); ) (EMS)
| | - Chunying Li
- Department of Biochemistry and Molecular Biology, Wayne State University, School of Medicine, Detroit, Michigan, United States of America
| | - Kaliappan Gopal
- Department of Orthopedics, National Orthopedics Center for Excellence in Research and Learning (NOCERAL), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Sazaly A. Bakar
- Tropical Infectious Diseases Research and Education Center (TIDREC), Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Harve S. Karthik
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Abdul S. Ebrahim
- Department of Internal Medicine, Wayne State University, Detroit, Michigan, United States of America
- * E-mail: (ASE); ) (SMF); ) (EMS)
| |
Collapse
|
13
|
Tan YY, Sekaran SD, Wang SM, Ahmed F, Hossain A, Sil BK. Development of ASSURE Dengue IgA Rapid Test for the Detection of Anti-dengue IgA from Dengue Infected Patients. J Glob Infect Dis 2011; 3:233-40. [PMID: 21887054 PMCID: PMC3162809 DOI: 10.4103/0974-777x.83528] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Background: Rapid and early dengue diagnosis is essential for patient management and early disease intervention. MP Diagnostics ASSURE® Dengue IgA Rapid Test (Dengue IgA RT) was developed for the rapid detection of anti-dengue IgA in patients’ biological samples. The performance of Dengue IgA RT was examined using multiple categories of well-characterized samples. Materials and Methods: Dengue IgA RT was designed and developed. Following characterization of samples by reference ELISAs, the performance of the kit was evaluated. Results: The overall sensitivity and specificity of Dengue IgA RT were 86.70% (n=233) and 86.05% (n=681) respectively; in which Dengue IgA RT detected 77.42% primary and 92.86% secondary cases; compared to 70.97% and 72.14% by IgM-Cap ELISA and 89.25% and 20% by Non-Structural Protein 1 (NS1) Ag ELISA respectively. Using 125 paired samples, Dengue IgA RT showed 84.80% sensitivity at acute phase and 99.20% sensitivity at convalescent phase; with 92% specificity at both phases. Dengue IgA RT also demonstrated a consistent performance (sensitivity: 85.53%, specificity: 80%) with 76 whole blood samples. In detecting all four serotypes of DENV (n=162), the performance of Dengue IgA RT was comparable with in-house IgM-Cap ELISA. Kinetics of anti-dengue IgA production was elucidated with 42.86% detection level as early as one-two days after fever onset, which increased to 83.33% between five and seven days after fever onset. Conclusion: Dengue IgA RT demonstrated a good performance and is applicable as one of the dengue early diagnostic tools at all levels of health care system.
Collapse
Affiliation(s)
- Yun Ying Tan
- Department of Research and Development, MP Biomedicals Asia Pacific Pte Ltd, Singapore
| | | | | | | | | | | |
Collapse
|
14
|
Tan HY, Nagoor NH, Sekaran SD. Cloning, expression and protective capacity of 37 kDa outer membrane protein gene (ompH) of Pasteurella multocida serotype B:2. Trop Biomed 2010; 27:430-441. [PMID: 21399583] [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
The major outer membrane protein (OmpH) of 4 local Malaysian strains of Pasteurella multocida serotype B:2 were characterized in comparison to ATCC strains. Three major peptide bands of MW 26, 32 and 37 kDa were characterized using SDSPAGE. Two of these fragments, the 32 kDa and 37 kDa were observed to be more reactive with a mouse polyclonal antiserum in all of the local isolates as well as the ATCC strains in a Western blot. However, the 32 kDa fragment was found to cross react with other Gram negative bacteria. Therefore, the 37 kDa OmpH was selected as vaccine candidate. The 37 kDa ompH gene of the isolated strain 1710 was cloned into an Escherichia coli expression vector to produce large amounts of recombinant OmpH (rOmpH). The 37 kDa ompH gene of strain 1710 was sequenced. In comparison to a reference strain X-73 of the ompH of P. multocida, 39bp was found deleted in the 37 kDa ompH gene. However, the deletion did not shift the reading frame or change the amino acid sequence. The rOmpH was used in a mice protection study. Mice immunized and challenged intraperitoneally resulted 100% protection against P. multocida whilst mice immunized subcutaneously and challenged intraperitoneally only resulted 80% protection. The rOmpH is therefore a suitable candidate for vaccination field studies. The same rOmpH was also used to develop a potential diagnostic kit in an ELISA format.
Collapse
MESH Headings
- Animals
- Antibodies, Bacterial/blood
- Antibodies, Bacterial/immunology
- Bacterial Outer Membrane Proteins/chemistry
- Bacterial Outer Membrane Proteins/genetics
- Bacterial Outer Membrane Proteins/immunology
- Bacterial Vaccines/administration & dosage
- Bacterial Vaccines/immunology
- Blotting, Western
- Cloning, Molecular
- Disease Models, Animal
- Electrophoresis, Polyacrylamide Gel
- Escherichia coli/genetics
- Mice
- Mice, Inbred BALB C
- Molecular Weight
- Pasteurella Infections/immunology
- Pasteurella Infections/prevention & control
- Pasteurella multocida/genetics
- Pasteurella multocida/immunology
- Sequence Deletion
- Survival Analysis
- Vaccines, Subunit/administration & dosage
- Vaccines, Subunit/immunology
- Vaccines, Synthetic/administration & dosage
- Vaccines, Synthetic/immunology
Collapse
Affiliation(s)
- H Y Tan
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | | | | |
Collapse
|
15
|
Wong EW, Yusof MYM, Mansor MB, Anbazhagan D, Ong SY, Sekaran SD. Disruption of adeB gene has a greater effect on resistance to meropenems than adeA gene in Acinetobacter spp. isolated from University Malaya Medical Centre. Singapore Med J 2009; 50:822-826. [PMID: 19710984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
INTRODUCTION The AdeABC pump of Acinetobacter spp. confers resistance to various antibiotic classes. This pump is composed of the AdeA, AdeB, and AdeC proteins where AdeB is a member of the resistance-nodulation-division efflux pump superfamily. The adeA, adeB, and adeC genes are contiguous and adjacent to adeS and adeR, which are transcribed in the opposite direction and which specify proteins homologous to sensors and regulators of two-component systems, respectively. In this study, an attempt is made to elucidate the role of the AdeABC efflux pump in carbapenem resistance in Acinetobacter spp. METHODS 39 carbapenem-resistant clinical isolates of Acinetobacter spp. were used. Minimum inhibitory concentrations were evaluated using the agar dilution method according to Clinical and Laboratory Standards Institute standards. The presence of carbapenem hydrolysing oxacillinases and AdeABC efflux pump genes were determined by PCR amplification. Subsequently, each gene was inactivated by plasmid insertion in order to study the contribution of these genes in developing antibiotic resistance and the resulting mutants were tested for their antimicrobial susceptibilities. RESULTS Among the multidrug-resistant strains, 36 strains had all the three (A, B, C) genes detected, while the remaining three strains had one or two of the genes detected. Inactivation of these individual genes showed decreased antimicrobial susceptibility indicating its contribution towards the development of antimicrobial resistance. CONCLUSION The presence of AdeABC multidrug efflux pump plays a major role in the development of antimicrobial resistance in Acinetobacter spp. The presence of either one or an interplay between these genes may have an effect on antimicrobial resistance in Acinetobacter spp.
Collapse
Affiliation(s)
- E W Wong
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia
| | | | | | | | | | | |
Collapse
|
16
|
Hunsperger EA, Yoksan S, Buchy P, Nguyen VC, Sekaran SD, Enria DA, Pelegrino JL, Vázquez S, Artsob H, Drebot M, Gubler DJ, Halstead SB, Guzmán MG, Margolis HS, Nathanson CM, Rizzo Lic NR, Bessoff KE, Kliks S, Peeling RW. Evaluation of commercially available anti-dengue virus immunoglobulin M tests. Emerg Infect Dis 2009; 15:436-40. [PMID: 19239758 PMCID: PMC2681117 DOI: 10.3201/eid1503.080923] [Citation(s) in RCA: 153] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Anti–dengue virus immunoglobulin M kits were evaluated. Test sensitivities were 21%–99% and specificities were 77%–98% compared with reference ELISAs. False-positive results were found for patients with malaria or past dengue infections. Three ELISAs showing strong agreement with reference ELISAs will be included in the World Health Organization Bulk Procurement Scheme.
Collapse
Affiliation(s)
- Elizabeth A Hunsperger
- Serology Diagnostics and Viral Pathogenesis Research Section, Centers for Disease Control and Prevention, San Juan, Puerto Rico
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Kumari N, Subramaniam G, Navaratnam P, Sekaran SD. Molecular characterization of genes encoding the quinolone resistance determining regions of Malaysian Streptococcus pneumoniae strains. Indian J Med Microbiol 2008; 26:148-50. [PMID: 18445951 DOI: 10.4103/0255-0857.40529] [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: 11/04/2022]
Abstract
Genes encoding the quinolones resistance determining regions (QRDRs) in Streptococcus pneumoniae were detected by PCR and the sequence analysis was carried out to identify point mutations within these regions. The study was carried out to observe mutation patterns among S. pneumoniae strains in Malaysia. Antimicrobial susceptibility testing of 100 isolates was determined against various antibiotics, out of which 56 strains were categorised to have reduced susceptibility to ciprofloxacin (>or=2 microg/mL). These strains were subjected to PCR amplification for presence of the gyrA, parC , gyrB and parE genes. Eight representative strains with various susceptibilities to fluoroquinolones were sequenced. Two out of the eight isolates that were sequenced were shown to have a point mutation in the gyrA gene at position Ser81. The detection of mutation at codon Ser81 of the gyrA gene suggested the potential of developing fluoroquinolone resistance among S. pneumoniae isolates in Malaysia. However, further experimental work is required to confirm the involvement of this mutation in the development of fluoroquinolone resistance in Malaysia.
Collapse
Affiliation(s)
- N Kumari
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya Kuala Lumpur-50603, Malaysia
| | | | | | | |
Collapse
|
18
|
Kumari N, Subramaniam G, Navaratnam P, Sekaran SD. MOLECULAR CHARACTERIZATION OF GENES ENCODING THE QUINOLONE RESISTANCE DETERMINING REGIONS OF MALAYSIAN STREPTOCOCCUS PNEUMONIAE STRAINS. Indian J Med Microbiol 2008. [DOI: 10.1016/s0255-0857(21)01931-9] [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: 11/26/2022]
|
19
|
Wong EH, Subramaniam G, Navaratnam P, Sekaran SD. RAPID DETECTION OF NON-ENTEROBACTERIACEAE DIRECTLY FROM POSITIVE BLOOD CULTURE USING FLUORESCENT IN SITU HYBRIDIZATION. Indian J Med Microbiol 2007. [DOI: 10.1016/s0255-0857(21)02058-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
20
|
Desa MN, Sekaran SD, Vadivelu J, Parasakthi N. Distribution of CBP genes in Streptococcus pneumoniae isolates in relation to vaccine types, penicillin susceptibility and clinical site. Epidemiol Infect 2007; 136:940-2. [PMID: 17678563 PMCID: PMC2870887 DOI: 10.1017/s0950268807009363] [Citation(s) in RCA: 7] [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: 11/07/2022] Open
Abstract
Choline-binding proteins (CBP) have been associated with the pathogenesis of Streptococcus pneumoniae. We screened, using PCR, for the presence of genes (cbpA, D, E, G) encoding these proteins in 34 isolates of pneumococci of known serotypes and penicillin susceptibility from invasive and non-invasive disease. All isolates harboured cbpD and cbpE whereas cbpA and cbpG were found in 47% and 59% respectively; the latter were more frequent in vaccine-associated types and together accounted for 77% of these isolates. No association was observed with penicillin susceptibility but 85% of non-invasive isolates were positive for these genes.
Collapse
Affiliation(s)
- M N Desa
- Department of Biomedical Sciences, Faculty of Medicine & Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia.
| | | | | | | |
Collapse
|
21
|
Yong YK, Thayan R, Chong HT, Tan CT, Sekaran SD. Rapid detection and serotyping of dengue virus by multiplex RT-PCR and real-time SYBR green RT-PCR. Singapore Med J 2007; 48:662-8. [PMID: 17609830] [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: 05/16/2023]
Abstract
INTRODUCTION Dengue fever and dengue haemorrhagic fever currently rank highly among the newly-emerging infectious diseases, and are considered to be the most important arboviral disease worldwide. The definitive diagnosis is culture analysis, but practical considerations limit its use. Also, the period for viral detection is limited. Within a day or two after fever subsides, rising levels of antibodies interfere with viral cultures. An alternative to this quandary is the use of viral RNA detection assays. In our laboratory, a reverse transcriptase polymerase chain reaction (RT-PCR) assay was developed using a set of degenerate primers. METHODS This multiplex RT-PCR assay was evaluated with 280 samples collected during the year 2003. These groups include prototype dengue virus (serotypes 1-4), acute serum from which the dengue virus was isolated, seronegative acute samples (culture negative) but whose convalescent samples seroconverted, and sera positive for other microbial diseases. This assay was then modified into a real-time SYBR Green RT-PCR assay. Sensitivity and specificity of both assays were compared. RESULTS The multiplex RT-PCR assay was able to detect 134 samples whereas SYBR Green RT-PCR assay was able to detect 178 out of 306 samples. Both assays were 100 percent specific. Further analysis of 53 samples showed that the virus could be amplified at IgM positive/negative values of up to 4.2, and up to six days after onset of fever. The viral detection rate was inversely proportional to the day of fever onset as well as IgM values. CONCLUSION The sensitivity and specificity of the conventional multiplex RT-PCR assay are 98.18 percent and 100 percent, respectively, and for the real-time SYBR Green assay, 99.09 percent and 100 percent, respectively. The melting curve analysis allows all four dengue serotypes to be discriminated based on distinct melting temperature value. The accuracy and speed of this multiplex RTPCR assay makes it a suitable test for the diagnosis of dengue and for epidemiological surveillance.
Collapse
Affiliation(s)
- Y K Yong
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia
| | | | | | | | | |
Collapse
|
22
|
Sekaran SD, Wong EH, Subramaniam G, Navaratnam P. Rapid detection of non-enterobacteriaceae directly from positive blood culture using fluorescent In situ hybridization. Indian J Med Microbiol 2007; 25:391-4. [DOI: 10.4103/0255-0857.37346] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
23
|
Gebriel AM, Subramaniam G, Sekaran SD. The detection and characterization of pathogenic Leptospira and the use of OMPs as potential antigens and immunogens. Trop Biomed 2006; 23:194-207. [PMID: 17322822] [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: 05/14/2023]
Abstract
The detection of leptospires in patient blood in the first week of the disease using PCR provides an early diagnostic tool. PCR using two sets of primers (G1/G2 and B64-I/B64-II) tested with samples seeded with 23 leptospiral strains from pathogenic and non-pathogenic strains was able to amplify leptospiral DNA from pathogenic strains only. Of the 39 antibody negative samples collected from patients suspected for leptospirosis, only 1 sample (2.6%) was PCR positive. Using LSSP-PCR, the G2 primers allowed the characterization of Leptopira species to 10 different genetic signatures which may have epidemiological value in determining species involved in outbreaks. Leptospiral outer membrane proteins from three strains were purified and reacted against patients sera and gave rise to different profiles for pathogenic and non-pathogenic strains. Lymphocytes of mice injected with OMPs proliferated and released IFN(-3) when stimulated in vitro using Leptospira OMP as antigens. This suggests that an immune response could be established using leptospiral OMPs as a putative vaccine. OMPs were also used in a Dot-ELISA to detect antibodies against Leptospira pathogens in humans.
Collapse
Affiliation(s)
- A M Gebriel
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | | | | |
Collapse
|