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Beh CC, Zulkufli NS, Loh LM, Cheng KW, Choo LM, Cheah MW, Siow KW, Yon R. SARS-CoV-2 seroprevalence and antibody trends in vaccinated, multi-ethnic healthcare employees. Trop Biomed 2021; 38:552-560. [PMID: 35001921 DOI: 10.47665/tb.38.4.098] [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
Understanding of antibody kinetics against SARS-CoV-2 and its vaccines is rapidly evolving. This study aims to (1) determine post-vaccination seroprevalence; (2) compare antibody levels between vaccine types and various clinical/demographic determinants; and (3) determine post-vaccination antibody concentrations against time. This is a retrospective cross-sectional study involving 148 healthcare employees all over Malaysia. IgG Spike (RBD), IgM Spike and IgG Nucleocapsid concentration medians were compared using Mann-Whitney U or Kruskal-Wallis tests. Chi Square and Spearman correlation coefficient tests were performed to identify variables associated with antibody titers. A scatter plot of IgG Spike (RBD) against time from last vaccine dose was also plotted. At 1-month post-vaccination, all employees successfully seroconverted regardless of vaccine type, health status and COVID- 19 history. Comirnaty, convalescent, female or Malay vaccinees had significantly higher IgG Spike (RBD) titers compared to their respective counterparts. No correlation was found between age and IgG Spike (RBD) levels. Concentration of all three antibodies waned with time post-vaccination, with IgM Spike and IgG Nucleocapsid waning faster than IgG Spike (RBD).
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Affiliation(s)
- C C Beh
- BP Clinical Lab Sdn Bhd, Temasya@Glenmarie, Lot 2, Jalan Pendaftar U1/54, Section U1, 40150 Shah Alam, Selangor, Malaysia
| | - N S Zulkufli
- BP Clinical Lab Sdn Bhd, Temasya@Glenmarie, Lot 2, Jalan Pendaftar U1/54, Section U1, 40150 Shah Alam, Selangor, Malaysia
| | - L M Loh
- BP Clinical Lab Sdn Bhd, Temasya@Glenmarie, Lot 2, Jalan Pendaftar U1/54, Section U1, 40150 Shah Alam, Selangor, Malaysia
| | - K W Cheng
- BP Clinical Lab Sdn Bhd, Temasya@Glenmarie, Lot 2, Jalan Pendaftar U1/54, Section U1, 40150 Shah Alam, Selangor, Malaysia
| | - L M Choo
- BP Clinical Lab Sdn Bhd, Temasya@Glenmarie, Lot 2, Jalan Pendaftar U1/54, Section U1, 40150 Shah Alam, Selangor, Malaysia
| | - M W Cheah
- BP Clinical Lab Sdn Bhd, Temasya@Glenmarie, Lot 2, Jalan Pendaftar U1/54, Section U1, 40150 Shah Alam, Selangor, Malaysia
| | - K W Siow
- BP Clinical Lab Sdn Bhd, Temasya@Glenmarie, Lot 2, Jalan Pendaftar U1/54, Section U1, 40150 Shah Alam, Selangor, Malaysia
| | - R Yon
- BP Clinical Lab Sdn Bhd, Temasya@Glenmarie, Lot 2, Jalan Pendaftar U1/54, Section U1, 40150 Shah Alam, Selangor, Malaysia
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Alsayed SSR, Beh CC, Foster NR, Payne AD, Yu Y, Gunosewoyo H. Kinase Targets for Mycolic Acid Biosynthesis in Mycobacterium tuberculosis. Curr Mol Pharmacol 2019; 12:27-49. [PMID: 30360731 DOI: 10.2174/1874467211666181025141114] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [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: 08/08/2018] [Revised: 10/11/2018] [Accepted: 10/11/2018] [Indexed: 12/12/2022]
Abstract
BACKGROUND Mycolic acids (MAs) are the characteristic, integral building blocks for the mycomembrane belonging to the insidious bacterial pathogen Mycobacterium tuberculosis (M.tb). These C60-C90 long α-alkyl-β-hydroxylated fatty acids provide protection to the tubercle bacilli against the outside threats, thus allowing its survival, virulence and resistance to the current antibacterial agents. In the post-genomic era, progress has been made towards understanding the crucial enzymatic machineries involved in the biosynthesis of MAs in M.tb. However, gaps still remain in the exact role of the phosphorylation and dephosphorylation of regulatory mechanisms within these systems. To date, a total of 11 serine-threonine protein kinases (STPKs) are found in M.tb. Most enzymes implicated in the MAs synthesis were found to be phosphorylated in vitro and/or in vivo. For instance, phosphorylation of KasA, KasB, mtFabH, InhA, MabA, and FadD32 downregulated their enzymatic activity, while phosphorylation of VirS increased its enzymatic activity. These observations suggest that the kinases and phosphatases system could play a role in M.tb adaptive responses and survival mechanisms in the human host. As the mycobacterial STPKs do not share a high sequence homology to the human's, there have been some early drug discovery efforts towards developing potent and selective inhibitors. OBJECTIVE Recent updates to the kinases and phosphatases involved in the regulation of MAs biosynthesis will be presented in this mini-review, including their known small molecule inhibitors. CONCLUSION Mycobacterial kinases and phosphatases involved in the MAs regulation may serve as a useful avenue for antitubercular therapy.
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Affiliation(s)
- Shahinda S R Alsayed
- School of Pharmacy and Biomedical Sciences, Faculty of Health Sciences, Curtin University, Perth, WA 6102, Australia
| | - Chau C Beh
- Western Australia School of Mines: Minerals, Energy and Chemical Engineering, Curtin University, Bentley 6102 WA, Australia.,David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02142, United States
| | - Neil R Foster
- Western Australia School of Mines: Minerals, Energy and Chemical Engineering, Curtin University, Bentley 6102 WA, Australia
| | - Alan D Payne
- School of Molecular and Life Sciences, Curtin University, Perth, WA 6102, Australia
| | - Yu Yu
- School of Pharmacy and Biomedical Sciences, Faculty of Health Sciences, Curtin University, Perth, WA 6102, Australia
| | - Hendra Gunosewoyo
- School of Pharmacy and Biomedical Sciences, Faculty of Health Sciences, Curtin University, Perth, WA 6102, Australia
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