1
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Wong JE, Zainal N, AbuBakar S, Tan KK. Monitoring Changes in Human Umbilical Vein Endothelial Cells upon Viral Infection Using Impedance-Based Real-Time Cell Analysis. J Vis Exp 2023. [PMID: 37212555 DOI: 10.3791/64887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/23/2023] Open
Abstract
Endothelial cells line the inner surface of all blood and lymphatic vessels, creating a semi-permeable barrier regulating fluid and solute exchange between blood or lymph and their surrounding tissues. The ability of a virus to cross the endothelial barrier is an important mechanism that facilitates virus dissemination in the human body. Many viruses are reported to alter endothelial permeability and/or cause endothelial cell barrier disruption during infection, which is able to cause vascular leakage. The current study describes a real-time cell analysis (RTCA) protocol, using a commercial real-time cell analyzer to monitor endothelial integrity and permeability changes during Zika virus (ZIKV) infection of the human umbilical vein endothelial cells (HUVECs). The impedance signals recorded before and after ZIKV infection were translated to cell index (CI) values and analyzed. The RTCA protocol allows the detection of transient effects in the form of cell morphological changes during a viral infection. This assay could also be useful for studying changes in the vascular integrity of HUVECs in other experimental setups.
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Affiliation(s)
- Jo-Ern Wong
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Center of Excellence (HICoE), Universiti Malaya
| | - Nurhafiza Zainal
- Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya
| | - Sazaly AbuBakar
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Center of Excellence (HICoE), Universiti Malaya
| | - Kim-Kee Tan
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Center of Excellence (HICoE), Universiti Malaya;
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2
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Tan JY, Wong JE, Zainal N, AbuBakar S, Tan KK. Virus Propagation and Cell-Based Colorimetric Quantification. J Vis Exp 2023. [PMID: 37092849 DOI: 10.3791/64578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2023] Open
Abstract
Zika virus (ZIKV) is a mosquito-borne virus belonging to the genus Flavivirus. ZIKV infection has been associated with congenital brain abnormalities and potentially Guillain-Barré syndrome in adults. Research on ZIKV to understand the disease mechanisms is important to facilitate vaccine and treatment development. The method of quantifying viruses is crucial and fundamental in the field of virology. The focus forming assay (FFA) is a virus quantification assay that detects the viral antigen with antibodies and identifies the infection foci of cells using the peroxidase immunostaining technique. The current study describes the virus propagation and quantification protocol using both 24-well and 96-well (high throughput) formats. Compared with other similar studies, this protocol has further described foci size optimization, which can serve as a guide to expand the use of this assay for other viruses. Firstly, ZIKV propagation is performed in Vero cells for 3 days. The culture supernatant containing ZIKV is harvested and quantitated using the FFA. Briefly, the virus culture is inoculated onto Vero cells and incubated for 2-3 days. Foci formation is then determined after optimized staining processes, including cell fixation, permeabilization, blocking, antibody binding, and incubation with peroxidase substrate. The stained virus foci are visualized using a stereo microscope (manual counting in 24-well format) or software analyzer (automated counting in 96-well format). The FFA provides reproducible, relatively fast results (3-4 days) and is suitable to be used for different viruses, including non-plaque-forming viruses. Subsequently, this protocol is useful for the study of ZIKV infection and could be used to detect other clinically important viruses.
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Affiliation(s)
- Jia-Yi Tan
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Center of Excellence (HICoE), Universiti Malaya
| | - Jo-Ern Wong
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Center of Excellence (HICoE), Universiti Malaya
| | - Nurhafiza Zainal
- Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya
| | - Sazaly AbuBakar
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Center of Excellence (HICoE), Universiti Malaya
| | - Kim-Kee Tan
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Higher Institution Center of Excellence (HICoE), Universiti Malaya;
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3
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Arham AF, Hasim NA, Mokhtar MI, Zainal N, Rusly NS, Amin L, Saifuddeen SM, Mustapa MAC, Mahadi Z. The Lesser of Two Evils: Application of Maslahah-Mafsadah Criteria in Islamic Ethical-Legal Assessment of Genetically Modified Mosquitoes in Malaysia. J Bioeth Inq 2022; 19:587-598. [PMID: 36350531 DOI: 10.1007/s11673-022-10216-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Accepted: 06/07/2022] [Indexed: 06/16/2023]
Abstract
The release of over 6,000 genetically modified mosquitoes (GMM) into uninhabited Malaysian forests in 2010 was a frantic step on the part of the Malaysian government to combat the spread of dengue fever. The field trial was designed to control and reduce the dengue vector by producing offspring that die in the early developmental stage, thus decreasing the local Aedes aegypti population below the dengue transmission threshold. However, the GMM trials were discontinued in Malaysia despite being technologically feasible. The lack of systematic studies in terms of cost-benefit analysis, questionable research efficacy and safety-related concerns might have contributed to the termination of the field trial. Hence, this research aims to evaluate the feasibility of GMM release in Malaysia by using a holistic approach based on an Islamic ethical-legal assessment under the maslahah-mafsadah (benefit-risk) concept. Three main strategies based on the maslahah-mafsadah concept approach have been applied: 1) an evidence-based approach, 2) an impact-based approach and, 3) a priority approach. The analysis concluded that GMM could be categorised as zanniyyah (probable). GMM is a promising alternative for dengue control, but many issues must be addressed before its widespread adoption.
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Affiliation(s)
- Ahmad Firdhaus Arham
- Pusat Pengajian Citra Universiti, Universiti Kebangsaan Malaysia, UKM, 43600, Bangi, Selangor, Malaysia.
| | - Nur Asmadayana Hasim
- Pusat Pengajian Citra Universiti, Universiti Kebangsaan Malaysia, UKM, 43600, Bangi, Selangor, Malaysia
- The Institute of Islam Hadhari, Universiti Kebangsaan Malaysia, UKM, 43600, Bangi, Selangor, Malaysia
| | - Mohd Istajib Mokhtar
- Department of Science and Technology Studies, Faculty of Science, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Nurhafiza Zainal
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Noor Sharizad Rusly
- Institute for Environment and Development (LESTARI), Universiti Kebangsaan Malaysia, UKM, 43600, Bangi, Selangor, Malaysia
| | - Latifah Amin
- Pusat Pengajian Citra Universiti, Universiti Kebangsaan Malaysia, UKM, 43600, Bangi, Selangor, Malaysia.
- The Institute of Islam Hadhari, Universiti Kebangsaan Malaysia, UKM, 43600, Bangi, Selangor, Malaysia.
| | - Shaikh Mohd Saifuddeen
- Centre for Science and Environment Studies, Institute of Islamic Understanding Malaysia, (IKIM), No. 2, Langgak Tunku Off Jalan Tuanku Abdul Halim, 50480, Kuala Lumpur, Malaysia
- Academy of Islamic Civilisation, Faculty of Social Sciences and Humanities, Universiti Teknologi Malaysia, UTM, 81310, Johor Bahru, Johor, Malaysia
| | | | - Zurina Mahadi
- Pusat Pengajian Citra Universiti, Universiti Kebangsaan Malaysia, UKM, 43600, Bangi, Selangor, Malaysia
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4
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Teoh BT, Chin KL, Samsudin NI, Loong SK, Sam SS, Tan KK, Khor CS, Abd-Jamil J, Zainal N, Wilder-Smith A, Zandi K, AbuBakar S. A reverse transcription loop-mediated isothermal amplification for broad coverage detection of Asian and African Zika virus lineages. BMC Infect Dis 2020; 20:947. [PMID: 33308203 PMCID: PMC7731766 DOI: 10.1186/s12879-020-05585-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 11/04/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Early detection of Zika virus (ZIKV) infection during the viremia and viruria facilitates proper patient management and mosquito control measurement to prevent disease spread. Therefore, a cost-effective nucleic acid detection method for the diagnosis of ZIKV infection, especially in resource-deficient settings, is highly required. METHODS In the present study, a single-tube reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay was developed for the detection of both the Asian and African-lineage ZIKV. The detection limit, strain coverage and cross-reactivity of the ZIKV RT-LAMP assay was evaluated. The sensitivity and specificity of the RT-LAMP were also evaluated using a total of 24 simulated clinical samples. The ZIKV quantitative reverse transcription-polymerase chain reaction (qRT-PCR) assay was used as the reference assay. RESULTS The detection limit of the RT-LAMP assay was 3.73 ZIKV RNA copies (probit analysis, P ≤ 0.05). The RT-LAMP assay detected the ZIKV genomes of both the Asian and African lineages without cross-reacting with other arthropod-borne viruses. The sensitivity and specificity of the RT-LAMP assay were 90% (95% CI = 59.6-98.2) and 100% (95% CI = 78.5-100.0), respectively. The RT-LAMP assay detected ZIKV genome in 9 of 24 (37.5%) of the simulated clinical samples compared to 10 of 24 (41.7%) by qRT-PCR assay with a high level of concordance (κ = 0.913, P < 0.001). CONCLUSION The RT-LAMP assay is applicable for the broad coverage detection of both the Asian and African ZIKV strains in resource-deficient settings.
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Affiliation(s)
- Boon-Teong Teoh
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Universiti Malaya, Kuala Lumpur, Malaysia.
| | - Kim-Ling Chin
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Universiti Malaya, Kuala Lumpur, Malaysia.,Institute for Advanced Studies (IAS), Universiti Malaya, Kuala Lumpur, Malaysia
| | - Nur-Izyan Samsudin
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Universiti Malaya, Kuala Lumpur, Malaysia
| | - Shih-Keng Loong
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Universiti Malaya, Kuala Lumpur, Malaysia
| | - Sing-Sin Sam
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Universiti Malaya, Kuala Lumpur, Malaysia
| | - Kim-Kee Tan
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Universiti Malaya, Kuala Lumpur, Malaysia
| | - Chee-Sieng Khor
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Universiti Malaya, Kuala Lumpur, Malaysia
| | - Juraina Abd-Jamil
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Universiti Malaya, Kuala Lumpur, Malaysia
| | - Nurhafiza Zainal
- Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Annelies Wilder-Smith
- Department of Public Health and Clinical Medicine, Epidemiology and Global Health, Umeå University, Umeå, Sweden.,Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Republic of Singapore
| | - Keivan Zandi
- Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia.,Center for AIDS Research, Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - Sazaly AbuBakar
- Tropical Infectious Diseases Research and Education Centre (TIDREC), Universiti Malaya, Kuala Lumpur, Malaysia. .,Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia.
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5
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Teoh B, Chin K, Samsudin N, Loong S, Sam S, Tan K, Khor C, Abd-jamil J, Zainal N, Wilder-smith A, Zandi K, Abubakar S. A reverse transcription loop-mediated isothermal amplification for broad coverage detection of Asian and African Zika virus lineages.. [DOI: 10.21203/rs.3.rs-56856/v2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Abstract
Abstract
Background: Early detection of Zika virus (ZIKV) infection during the viremia and viruria facilitates proper patient management and mosquito control measurement to prevent disease spread. Therefore, a cost-effective nucleic acid detection method for the diagnosis of ZIKV infection, especially in resource-deficient settings, is highly required.Methods: In the present study, a single-tube reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay was developed for the detection of both the Asian and African-lineage ZIKV. The detection limit, strain coverage and cross-reactivity of the ZIKV RT-LAMP assay was evaluated. The sensitivity and specificity of the RT-LAMP were also evaluated using a total of 24 simulated clinical samples. The ZIKV quantitative reverse transcription-polymerase chain reaction (qRT-PCR) assay was used as the reference assay.Results: The detection limit of the RT-LAMP assay was 3.73 ZIKV RNA copies (probit analysis, P ≤ 0.05). The RT-LAMP assay detected the ZIKV genomes of both the Asian and African lineages without cross-reacting with other arthropod-borne viruses. The sensitivity and specificity of the RT-LAMP assay were 90% (95% CI = 59.6 – 98.2) and 100% (95% CI = 78.5 – 100.0), respectively. The RT-LAMP assay detected ZIKV genome in 9 of 24 (37.5%) of the simulated clinical samples compared to 10 of 24 (41.7%) by qRT-PCR assay with a high level of concordance (k = 0.913, P < 0.001).Conclusion: The RT-LAMP assay is applicable for the broad coverage detection of both the Asian and African ZIKV strains in resource-deficient settings.
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6
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Teoh B, Chin K, Samsudin N, Loong S, Sam S, Tan K, Khor C, Abd-jamil J, Zainal N, Wilder-smith A, Zandi K, Abubakar S. A Reverse Transcription Loop-mediated Isothermal Amplification for Broad Coverage Detection of Asian and African Zika Virus Lineages.. [DOI: 10.21203/rs.3.rs-56856/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Abstract
Abstract
Background: Early detection of Zika virus (ZIKV) infection during the viremia and viruria facilitates proper patient management and mosquito control measurement to prevent disease spread. Therefore, a cost-effective nucleic acid detection method for the diagnosis of ZIKV infection, especially in resource-deficient settings, is highly required.Methods: In the present study, a single-tube reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay was developed for the detection of both the Asian and African-lineage ZIKV. The detection limit, strain coverage and cross-reactivity of the ZIKV RT-LAMP assay was evaluated. The sensitivity and specificity of the RT-LAMP were also evaluated using a total of 24 simulated clinical samples. The ZIKV quantitative reverse transcription-polymerase chain reaction (qRT-PCR) assay was used as the reference assay.Results: The detection limit of the RT-LAMP assay was 3.73 ZIKV RNA copies (probit analysis, P ≤ 0.05). The RT-LAMP assay detected the ZIKV genomes of both the Asian and African lineages without cross-reacting with other arthropod-borne viruses. The sensitivity and specificity of the RT-LAMP assay were 90% (95% CI = 59.6 – 98.2) and 100% (95% CI = 78.5 – 100.0), respectively. The RT-LAMP assay detected ZIKV genome in 9 of 24 (37.5%) of the simulated clinical samples compared to 10 of 24 (41.7%) by qRT-PCR assay with a high level of concordance ( = 0.913, P < 0.001).Conclusion: The RT-LAMP assay is applicable for the broad coverage detection of both the Asian and African ZIKV strains in resource-deficient settings.
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7
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Khor CS, Mohd-Rahim NF, Hassan H, Tan KK, Zainal N, Teoh BT, Sam SS, Khoo JJ, Lee HY, Lim YAL, Abubakar S. Serological evidence of DENV, JEV, and ZIKV among the indigenous people (Orang Asli) of Peninsular Malaysia. J Med Virol 2019; 92:956-962. [PMID: 31814135 DOI: 10.1002/jmv.25649] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Accepted: 12/04/2019] [Indexed: 11/07/2022]
Abstract
Dengue virus (DENV), Japanese encephalitis virus (JEV), and Zika virus (ZIKV) are mosquito-borne flavivirus of medical importance in tropical countries such as Malaysia. However, much remains unknown regarding their prevalence among the underserved indigenous people (Orang Asli) living in communities in the forest fringe areas of Peninsular Malaysia. Information on the prevalence of diseases is necessary to elevate the effectiveness of disease control and preventive measures. This study aimed to determine the seroprevalence of the three major flaviviruses among the Orang Asli and investigate the association between demographic factors and seropositivities. Sampling activities were conducted in the Orang Asli villages to obtain serum samples and demographic data from consenting volunteers. The presence of DENV, JEV, and ZIKV immunoglobulin G (IgG) antibodies in the sera were examined using commercial enzyme-linked immunosorbent assay kits. A focus reduction neutralization assay was performed to measure virus-specific neutralizing antibodies. A total of 872 serum samples were obtained from the Orang Asli volunteers. Serological assay results revealed that DENV IgG, JEV IgG, and ZIKV IgG seropositivities among the Orang Asli were at 4.9%, 48.4%, and 13.2%, respectively. Neutralizing antibodies (FRNT50 ≥ 1:40) against JEV and ZIKV were found in 86.7% and 100.0%, respectively, out of the samples tested. Positive serology to all three viruses corresponded significantly to the age of the volunteers with increasing seropositivity in older volunteers. Findings from the study suggest that Orang Asli are at significant risk of contracting JEV and ZIKV infections despite the lack of active transmission of the viruses in the country.
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Affiliation(s)
- Chee-Sieng Khor
- Tropical Infectious Diseases Research & Education Centre, University of Malaya, Kuala Lumpur, Malaysia
| | - Nurul-Farhana Mohd-Rahim
- Tropical Infectious Diseases Research & Education Centre, University of Malaya, Kuala Lumpur, Malaysia.,Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Habibi Hassan
- Tropical Infectious Diseases Research & Education Centre, University of Malaya, Kuala Lumpur, Malaysia.,Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Kim-Kee Tan
- Tropical Infectious Diseases Research & Education Centre, University of Malaya, Kuala Lumpur, Malaysia
| | - Nurhafiza Zainal
- Tropical Infectious Diseases Research & Education Centre, University of Malaya, Kuala Lumpur, Malaysia.,Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Boon-Teong Teoh
- Tropical Infectious Diseases Research & Education Centre, University of Malaya, Kuala Lumpur, Malaysia
| | - Sing-Sin Sam
- Tropical Infectious Diseases Research & Education Centre, University of Malaya, Kuala Lumpur, Malaysia
| | - Jing-Jing Khoo
- Tropical Infectious Diseases Research & Education Centre, University of Malaya, Kuala Lumpur, Malaysia
| | - Hai-Yen Lee
- Tropical Infectious Diseases Research & Education Centre, University of Malaya, Kuala Lumpur, Malaysia
| | - Yvonne Ai-Lian Lim
- Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Sazaly Abubakar
- Tropical Infectious Diseases Research & Education Centre, University of Malaya, Kuala Lumpur, Malaysia.,Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
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8
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Lim FS, Khoo JJ, Tan KK, Zainal N, Loong SK, Khor CS, AbuBakar S. Bacterial communities in Haemaphysalis, Dermacentor and Amblyomma ticks collected from wild boar of an Orang Asli Community in Malaysia. Ticks Tick Borne Dis 2019; 11:101352. [PMID: 31866439 DOI: 10.1016/j.ttbdis.2019.101352] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [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: 04/16/2019] [Revised: 11/08/2019] [Accepted: 12/02/2019] [Indexed: 12/11/2022]
Abstract
Ticks are hematophagous vectors of arthropod-borne disease agents globally. In Malaysia, despite seroprevalence studies indicating the presence of tick-borne diseases among the indigenous people, the etiological agents of these diseases are still unclear. These indigenous people, also known as the Orang Asli, still live in forested areas with frequent contact with wildlife. Wild boar are ubiquitously found in the forested areas where the Orang Asli communities are located and are commonly hunted as a food supplement. In this study, we aim to determine the tick species parasitizing wild boar from an Orang Asli community, and explore the tick-associated bacterial communities using 16 s rRNA amplicon sequencing on the Ion Torrent PGM™ platform. A total of 72 ticks were collected from three wild boar and were morphologically identified as Haemaphysalis hystricis (n = 32), Dermacentor compactus (n = 15), Amblyomma testudinarium (n = 13), Dermacentor steini (n = 10) and Dermacentor atrosignatus (n = 2). Across all tick samples, 910 bacterial taxa were identified. Although the bacterial communities were not significantly distinct between tick species in beta-diversity analyses, Coxiella, Rickettsia and Francisella were detected at high relative abundance in H. hystricis, D. compactus and D. steini respectively. Many other bacterial genera, including those that have been described in many different tick species, were also identified, including Pseudomonas, Acinetobacter, Staphylococcus and Corynebacterium. Beta-diversity analyses also showed that the bacterial communities were separated based on the animal host from which the ticks were collected from, suggesting that the bacterial communities here may be influenced by the animal skin microflora, host blood or the environment. PCR screening confirmed the presence of Rickettsia sp. related to spotted fever group Rickettsia in some of the ticks. This study provides baseline knowledge of the microbiome of H. hystricis, D. atrosignatus, D. compactus, D. steini and A. testudinarium parasitizing wild boar in this region. The information gained in this study provides the basis to target our efforts in H. hystricis, D. compactus and D. steini for the future investigation of vector competence and the zoonotic potential for the Coxiella, Rickettsia and Francisella detected here, as well as their implications for the risks of tick-borne diseases among the Orang Asli communities.
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Affiliation(s)
- Fang Shiang Lim
- Tick Cell Biobank Asia Outpost, Tropical Infectious Diseases Research and Education Centre (TIDREC), Universiti Malaya, Kuala Lumpur, 50603 Malaysia; Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, 50603 Malaysia
| | - Jing Jing Khoo
- Tick Cell Biobank Asia Outpost, Tropical Infectious Diseases Research and Education Centre (TIDREC), Universiti Malaya, Kuala Lumpur, 50603 Malaysia.
| | - Kim Kee Tan
- Tick Cell Biobank Asia Outpost, Tropical Infectious Diseases Research and Education Centre (TIDREC), Universiti Malaya, Kuala Lumpur, 50603 Malaysia
| | - Nurhafiza Zainal
- Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, 50603 Malaysia
| | - Shih Keng Loong
- Tick Cell Biobank Asia Outpost, Tropical Infectious Diseases Research and Education Centre (TIDREC), Universiti Malaya, Kuala Lumpur, 50603 Malaysia
| | - Chee Sieng Khor
- Tick Cell Biobank Asia Outpost, Tropical Infectious Diseases Research and Education Centre (TIDREC), Universiti Malaya, Kuala Lumpur, 50603 Malaysia
| | - Sazaly AbuBakar
- Tick Cell Biobank Asia Outpost, Tropical Infectious Diseases Research and Education Centre (TIDREC), Universiti Malaya, Kuala Lumpur, 50603 Malaysia; Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, 50603 Malaysia.
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9
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Abstract
Zika virus (ZIKV) infection is a serious public health concern. ZIKV infection has been associated with increased occurrences of microcephaly among newborns and incidences of Guillain-Barré syndrome among adults. No specific therapeutics or vaccines are currently available to treat and protect against ZIKV infection. Here, a plant-secreted phytoalexin, resveratrol (RES), was investigated for its ability to inhibit ZIKV replication in vitro. Several RES treatment regimens were used. The ZIKV titers of mock- and RES-treated infected cell cultures were determined using the focus-forming assay and the Zika mRNA copy number as determined using qRT-PCR. Our results suggested that RES treatment reduced ZIKV titers in a dose-dependent manner. A reduction of >90% of virus titer and ZIKV mRNA copy number was achieved when infected cells were treated with 80 µM of RES post-infection. Pre-incubation of the virus with 80 µM RES showed >30% reduction in ZIKV titers and ZIKV mRNA copy number, implying potential direct virucidal effects of RES against the virus. The RES treatment reduced >70% virus titer in the anti-adsorption assay, suggesting the possibility that RES also interferes with ZIKV binding. However, there was no significant decrease in ZIKV titer when a short-period of RES treatment was applied to cells before ZIKV infection (pre-infection) and after the virus bound to the cells (virus internalization inhibition), implying that RES acts through its continuous presence in the cell cultures after virus infection. Overall, our results suggested that RES exhibited direct virucidal activity against ZIKV and possessed anti-ZIKV replication properties, highlighting the need for further exploration of RES as a potential antiviral molecule against ZIKV infection.
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Affiliation(s)
- Azirah Mohd
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, Kuala Lumpur, Malaysia.,Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Nurhafiza Zainal
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, Kuala Lumpur, Malaysia.,Department of Medical Microbiology, University of Malaya, Kuala Lumpur, Malaysia.,Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Kim-Kee Tan
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, Kuala Lumpur, Malaysia.,Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Sazaly AbuBakar
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, Kuala Lumpur, Malaysia. .,Department of Medical Microbiology, University of Malaya, Kuala Lumpur, Malaysia. .,Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
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10
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Zainal N, Tan KK, Johari J, Hussein H, Wan Musa WR, Hassan J, Lin YS, AbuBakar S. Sera of patients with systemic lupus erythematosus cross-neutralizes dengue viruses. Microbiol Immunol 2018; 62:659-672. [PMID: 30259549 DOI: 10.1111/1348-0421.12652] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 07/16/2018] [Accepted: 09/10/2018] [Indexed: 11/28/2022]
Abstract
Dengue is the most prevalent mosquito-borne disease in Southeast Asia, where the incidence of systemic lupus erythematosus (SLE) is approximately 30 to 53 per 100,000. Severe dengue, however, is rarely reported among individuals with SLE. Here, whether sera of patients with SLE cross-neutralize dengue virus (DENV) was investigated. Serum samples were obtained from individuals with SLE who were dengue IgG and IgM serology negative. Neutralization assays were performed against the three major DENV serotypes. Of the dengue serology negative sera of individuals with SLE, 60%, 61% and 52% of the sera at 1/320 dilution showed more than 50% inhibition against dengue type-1 virus (DENV-1), DENV-2 and DENV-3, respectively. The neutralizing capacity of the sera was significantly greater against DENV-1 (P < 0.001) and DENV-3 (P < 0.01) than against DENV-2 (P < 0.05). Neutralization against the DENV correlated with dengue-specific IgG serum titers below the cut-off point for dengue positivity. Depletion of total IgG from the sera of patients with SLE resulted in significant decreases of up to 80% in DENV inhibition, suggesting that IgG plays an important role. However, some of the SLE sera was still able to neutralize DENV, even with IgG titers <0.1 OD absorbance. Our findings suggest that sera of patients with SLE contain IgG, and possibly other type of antibodies, that can cross-neutralize DENV, which may explain the rarity of severe dengue in individuals with SLE. Further studies, are needed to further substantiate this finding and to elucidate the specific neutralizing epitopes recognized by the sera of individuals with SLE.
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Affiliation(s)
- Nurhafiza Zainal
- Institute of Graduate Studies, University of Malaya, Kuala Lumpur, Malaysia.,Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.,Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Kim-Kee Tan
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.,Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, Kuala Lumpur, Malaysia
| | - Jefree Johari
- Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, Kuala Lumpur, Malaysia
| | | | | | - Jamiyah Hassan
- Department of Obstetrics and Gynaecology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Yee-Shin Lin
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Centre of Infectious Disease and Signalling Research, National Cheng Kung University, Tainan, Taiwan
| | - Sazaly AbuBakar
- Institute of Graduate Studies, University of Malaya, Kuala Lumpur, Malaysia.,Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.,Tropical Infectious Diseases Research and Education Centre (TIDREC), University of Malaya, Kuala Lumpur, Malaysia
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11
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Abstract
Kocuria marina has recently emerged as a cause for catheter-related bloodstream infections in patients with underlying health complications. One K. marina strain was recently isolated from the lung tissues of a wild urban rat (Rattus rattus diardii) caught during rodent surveillance. Here, we present the draft genome of the first K. marina animal isolate, K. marina TRE150902.
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Affiliation(s)
- Shih Keng Loong
- University of Malaya, Faculty of Medicine, Tropical Infectious
Diseases Research & Education Centre, Kuala Lumpur, Malaysia
| | - Kim-Kee Tan
- University of Malaya, Faculty of Medicine, Tropical Infectious
Diseases Research & Education Centre, Kuala Lumpur, Malaysia
- University of Malaya, Faculty of Medicine, Department of Medical
Microbiology, Kuala Lumpur, Malaysia
| | - Nurhafiza Zainal
- University of Malaya, Faculty of Medicine, Tropical Infectious
Diseases Research & Education Centre, Kuala Lumpur, Malaysia
- University of Malaya, Faculty of Medicine, Department of Medical
Microbiology, Kuala Lumpur, Malaysia
| | - Wai Hong Phoon
- University of Malaya, Faculty of Medicine, Tropical Infectious
Diseases Research & Education Centre, Kuala Lumpur, Malaysia
- University of Malaya, Faculty of Medicine, Department of Medical
Microbiology, Kuala Lumpur, Malaysia
| | - Siti Nursheena Mohd Zain
- University of Malaya, Faculty of Science, Institute of
Biological Sciences, Kuala Lumpur, Malaysia
| | - Sazaly AbuBakar
- University of Malaya, Faculty of Medicine, Tropical Infectious
Diseases Research & Education Centre, Kuala Lumpur, Malaysia
- University of Malaya, Faculty of Medicine, Department of Medical
Microbiology, Kuala Lumpur, Malaysia
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12
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Zainal N, Yaacob S, Kaur A, Pendek R. P01-314 - Prevalence of depression and anxiety disorders among thyroid disorder patients in a teaching hospital in Malaysia. Eur Psychiatry 2010. [DOI: 10.1016/s0924-9338(10)70522-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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14
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Abstract
We report a case of meningitis and one of fatal septicaemia in neonates due to Burkholderia pseudomallei and review the literature on neonatal melioidosis. Pneumonia was the primary presentation and was complicated by shock in the latter case. The epidemiological findings suggest that the cases reported from Malaysia were community-acquired in contrast with those from the USA and Thailand.
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Affiliation(s)
- D Halder
- Department of Paediatrics, Hospital Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia.
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15
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Jackson N, Mohammad S, Zainal N, Jamaluddin N, Hishamuddin M. Autosomal dominant thrombocytopenia with microthrombocytes: a family study. Med J Malaysia 1995; 50:421-4. [PMID: 8668069] [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: 02/01/2023]
Abstract
A family demonstrating autosomal dominant thrombocytopenia is described. A 28-year-old Malay housewife was found to have a platelet count of 40 x 10(9)/l with a low mean platelet volume (6.8 fl) while being investigated prior to ovarian cystectomy. The bone marrow was consistent with immune thrombocytopenia but she failed to respond to appropriate therapy. Five siblings, one parent and one nephew have easy bruising and platelet counts of 39-82 x 10(9)/l. Platelet aggregation studies excluded a major functional defect. Survival of homologous platelets in the circulation was normal. Familial thrombocytopenias are rare but important to differentiate from the common acquired thrombocytopenias in order to spare the patient unnecessary treatments.
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Affiliation(s)
- N Jackson
- Department of Medicine, Universiti Sains Malaysia, Kubang Kerian, Kelantan
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Zainal N, Carmichael DJ, Griffiths JW, Besterman EM, Kidner PH, Gillham AD, Summers GD. Oral disopyramide for the prevention of arrhythmias in patients with acute myocardial infarction admitted to open wards. Lancet 1977; 2:887-9. [PMID: 72237 DOI: 10.1016/s0140-6736(77)90829-7] [Citation(s) in RCA: 63] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Patients with acute myocardial infarction admitted to open wards of three hospitals were given either oral disopyramide (100 mg four times daily) or matching placebo, prophylactically, for seven days. The drug was associated with a significant reduction in mortality (p = 0-0025) and in incidence of extension of infarction (p = 0-01), ventricular fibrillation (p = 0-05), and ventricular tachycardia (p = 0-01). Disopyramide was not associated with any particular complication or side-effect. Unitl information is available to the contrary, oral disopyramide should be given for the first seven days after myocardial infarction to all patients not managed in an intensive-care unit.
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