Displaying publications 1 - 20 of 47 in total

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  1. Could rapid test reader maximize the benefits to the HIV self-tester?
    Balakrishnan P, Girija ASS, Kannan I, Vignesh R, Shankar EM, Sucharitha ST
    Indian J Med Microbiol, 2023;43:49-50.
    PMID: 36280566 DOI: 10.1016/j.ijmmb.2022.10.004
  2. Fulltext The Implementation of HIV Self-Testing in Resource-Limited Settings Where the HIV Disease Burden is High
    Balakrishnan P, Smiline Girija AS, Shanmugam S, Kannan I, Vignesh R, Shankar EM, et al.
    Int J Public Health, 2023;68:1605790.
    PMID: 37266035 DOI: 10.3389/ijph.2023.1605790
    In resource-limited settings, there is growing evidence that HIV testing is lacking among high-risk key populations such as men having sex with men, injection drug users, and transgenders largely due to stigma, discrimination, and lack of confidentiality. Findings from recent studies among high-risk key populations and the general population from various regions including resource-limited settings support the need for wider accessibility of HIV self-testing (HIV-ST) to reach those who may not otherwise have access to testing. Therefore, HIV-ST has untapped potential as a strategy to improve access to HIV testing and to increase testing frequency among key high-risk populations and their partners. Though HIV-ST has emerged as a safe, acceptable, and effective way to reach people, there are several roadblocks to implementing the HIV-ST policy, and fast-track policy implementation needs to be necessitated with newer or modified strategic plans.
  3. Fulltext Recent advances in HIV diagnostics: Point-of-care CD4 + T-cell count & viral load assays
    Balakrishnan P, Saravanan S, Vignesh R, Shankar EM
    Indian J Med Res, 2023 Nov 01;158(5&6):447-450.
    PMID: 38063301 DOI: 10.4103/ijmr.ijmr_1616_23
  4. Chronic hepatitis C virus infection triggers spontaneous differential expression of biosignatures associated with T cell exhaustion and apoptosis signaling in peripheral blood mononucleocytes
    Barathan M, Gopal K, Mohamed R, Ellegård R, Saeidi A, Vadivelu J, et al.
    Apoptosis, 2015 Apr;20(4):466-80.
    PMID: 25577277 DOI: 10.1007/s10495-014-1084-y
    Persistent hepatitis C virus (HCV) infection appears to trigger the onset of immune exhaustion to potentially assist viral persistence in the host, eventually leading to hepatocellular carcinoma. The role of HCV on the spontaneous expression of markers suggestive of immune exhaustion and spontaneous apoptosis in immune cells of chronic HCV (CHC) disease largely remain elusive. We investigated the peripheral blood mononuclear cells of CHC patients to determine the spontaneous recruitment of cellular reactive oxygen species (cROS), immunoregulatory and exhaustion markers relative to healthy controls. Using a commercial QuantiGenePlex(®) 2.0 assay, we determined the spontaneous expression profile of 80 different pro- and anti-apoptotic genes in persistent HCV disease. Onset of spontaneous apoptosis significantly correlated with the up-regulation of cROS, indoleamine 2,3-dioxygenase (IDO), cyclooxygenase-2/prostaglandin H synthase (COX-2/PGHS), Foxp3, Dtx1, Blimp1, Lag3 and Cd160. Besides, spontaneous differential surface protein expression suggestive of T cell inhibition viz., TRAIL, TIM-3, PD-1 and BTLA on CD4+ and CD8+ T cells, and CTLA-4 on CD4+ T cells was also evident. Increased up-regulation of Tnf, Tp73, Casp14, Tnfrsf11b, Bik and Birc8 was observed, whereas FasLG, Fas, Ripk2, Casp3, Dapk1, Tnfrsf21, and Cflar were moderately up-regulated in HCV-infected subjects. Our observation suggests the spontaneous onset of apoptosis signaling and T cell exhaustion in chronic HCV disease.
  5. CD8+ T cells of chronic HCV-infected patients express multiple negative immune checkpoints following stimulation with HCV peptides
    Barathan M, Mohamed R, Vadivelu J, Chang LY, Vignesh R, Krishnan J, et al.
    Cell Immunol, 2017 03;313:1-9.
    PMID: 28104239 DOI: 10.1016/j.cellimm.2016.12.002
    Hepatitis C virus (HCV)-specific CD4+ and CD8+ T cells are key to successful viral clearance in HCV disease. Accumulation of exhausted HCV-specific T cells during chronic infection results in considerable loss of protective functional immune responses. The role of T-cell exhaustion in chronic HCV disease remains poorly understood. Here, we studied the frequency of HCV peptide-stimulated T cells expressing negative immune checkpoints (PD-1, CTLA-4, TRAIL, TIM-3 and BTLA) by flow cytometry, and measured the levels of Th1/Th2/Th17 cytokines secreted by T cells by a commercial Multi-Analyte ELISArray™ following in vitro stimulation of T cells using HCV peptides and phytohemagglutinin (PHA). HCV peptide-stimulated CD4+ and CD8+ T cells of chronic HCV (CHC) patients showed significant increase of CTLA-4. Furthermore, HCV peptide-stimulated CD4+ T cells of CHC patients also displayed relatively higher levels of PD-1 and TRAIL, whereas TIM-3 was up-regulated on HCV peptide-stimulated CD8+ T cells. Whereas the levels of IL-10 and TGF-β1 were significantly increased, the levels of pro-inflammatory cytokines IL-2, TNF-α, IL-17A and IL-6 were markedly decreased in the T cell cultures of CHC patients. Chronic HCV infection results in functional exhaustion of CD4+ and CD8+ T cells likely contributing to viral persistence.
  6. Fulltext SARS-CoV-2 in Pregnant Women: Consequences of Vertical Transmission
    Chaubey I, Vignesh R, Babu H, Wagoner I, Govindaraj S, Velu V
    Front Cell Infect Microbiol, 2021;11:717104.
    PMID: 34568094 DOI: 10.3389/fcimb.2021.717104
  7. Fulltext Infectious risk assessment of unsafe handling practices and management of clinical solid waste
    Hossain MS, Rahman NN, Balakrishnan V, Puvanesuaran VR, Sarker MZ, Kadir MO
    Int J Environ Res Public Health, 2013 Jan 31;10(2):556-67.
    PMID: 23435587 DOI: 10.3390/ijerph10020556
    The present study was undertaken to determine the bacterial agents present in various clinical solid wastes, general waste and clinical sharp waste. The waste was collected from different wards/units in a healthcare facility in Penang Island, Malaysia. The presence of bacterial agents in clinical and general waste was determined using the conventional bacteria identification methods. Several pathogenic bacteria including opportunistic bacterial agent such as Pseudomonas aeruginosa, Salmonella spp., Klebsiella pneumoniae, Serratia marcescens, Acinetobacter baumannii, Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Streptococcus pyogenes were detected in clinical solid wastes. The presence of specific pathogenic bacterial strains in clinical sharp waste was determined using 16s rDNA analysis. In this study, several nosocomial pathogenic bacteria strains of Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Lysinibacillus sphaericus, Serratia marcescens, and Staphylococcus aureus were detected in clinical sharp waste. The present study suggests that waste generated from healthcare facilities should be sterilized at the point of generation in order to eliminate nosocomial infections from the general waste or either of the clinical wastes.
  8. Fulltext Ertapenem for multiple β-lactamases producing Gram-negative bacteria causing urinary tract infections in HIV patients
    Kumar MRR, Arunagirinathan N, Vignesh R, Balakrishnan P, Solomon S, Sunil SS
    J Res Med Sci, 2017;22:69.
    PMID: 28616056 DOI: 10.4103/jrms.JRMS_884_16
  9. Increase of Plasma TNF-α Is Associated with Decreased Levels of Blood Platelets in Clinical Dengue Infection
    Meena AA, Murugesan A, Sopnajothi S, Yong YK, Ganesh PS, Vimali IJ, et al.
    Viral Immunol, 2019 09 18;33(1):54-60.
    PMID: 31532346 DOI: 10.1089/vim.2019.0100
    Dengue virus (DENV) infection has become an increasingly common concern in tropical and subtropical regions. It has protean manifestations ranging from febrile phase to severe life-threatening illness. In this study, we estimated Th1 and Th2 cytokines and correlated the levels with dengue severity along with certain hematological and biochemical parameters. We also studied the seroprevalence of dengue between October and December 2017 at the Government Theni Medical College, India. Individuals with dengue fever (DF) were positive for either IgM or IgG, or both. The biochemical and hematological parameters along with plasma tumor necrosis factor alpha (TNF-α), interferon-gamma (IFN-γ), granulocyte monocyte-colony stimulating factor (GM-CSF), interleukin (IL)-13, IL-12p70, IL-10, IL-5, IL-4, and IL-2 cytokines were estimated. The prevalence of DF was 42.9% during the study period. IL-2, TNF-α, IL-4, and IL-10 levels were significantly elevated (p 
  10. Broad neutralization response in a subset of HIV-1 subtype C-infected viraemic non-progressors from southern India
    Nandagopal P, Bhattacharya J, Srikrishnan AK, Goyal R, Ravichandran Swathirajan C, Patil S, et al.
    J Gen Virol, 2018 Mar;99(3):379-392.
    PMID: 29458681 DOI: 10.1099/jgv.0.001016
    Broadly neutralizing antibodies (bnAbs) have been considered to be potent therapeutic tools and potential vaccine candidates to enable protection against various clades of human immunodeficiency virus (HIV). The generation of bnAbs has been associated with enhanced exposure to antigen, high viral load and low CD4+ T cell counts, among other factors. However, only limited data are available on the generation of bnAbs in viraemic non-progressors that demonstrate moderate to high viraemia. Further, since HIV-1 subtype C viruses account for more than 50 % of global HIV infections, the identification of bnAbs with novel specificities is crucial to enable the development of potent tools to aid in HIV therapy and prevention. In the present study, we analysed and compared the neutralization potential of responses in 70 plasma samples isolated from ART-naïve HIV-1 subtype C-infected individuals with various disease progression profiles against a panel of 30 pseudoviruses. Among the seven samples that exhibited a neutralization breadth of ≥70 %, four were identified as 'elite neutralizers', and three of these were from viraemic non-progressors while the fourth was from a typical progressor. Analysis of the neutralization specificities revealed that none of the four elite neutralizers were reactive to epitopes in the membrane proximal external region (MPER), CD4-binding site and V1V2 or V3 glycan. However, two of the four elite neutralizers exhibited enhanced sensitivity towards viruses lacking N332 glycan, indicating high neutralization potency. Overall, our findings indicate that the identification of potent neutralization responses with distinct epitope specificities is possible from the as yet unexplored Indian population, which has a high prevalence of HIV-1 subtype C infection.
  11. Fulltext Updates on Dengue Vaccine and Antiviral: Where Are We Heading?
    Norshidah H, Vignesh R, Lai NS
    Molecules, 2021 Nov 09;26(22).
    PMID: 34833860 DOI: 10.3390/molecules26226768
    Approximately 100-400 million people from more than 100 countries in the tropical and subtropical world are affected by dengue infections. Recent scientific breakthroughs have brought new insights into novel strategies for the production of dengue antivirals and vaccines. The search for specific dengue inhibitors is expanding, and the mechanisms for evaluating the efficacy of novel drugs are currently established, allowing for expedited translation into human trials. Furthermore, in the aftermath of the only FDA-approved vaccine, Dengvaxia, a safer and more effective dengue vaccine candidate is making its way through the clinical trials. Until an effective antiviral therapy and licensed vaccine are available, disease monitoring and vector population control will be the mainstays of dengue prevention. In this article, we highlighted recent advances made in the perspectives of efforts made recently, in dengue vaccine development and dengue antiviral drug.
  12. Fulltext Assessing the potential of NS2B/NS3 protease inhibitors biomarker in curbing dengue virus infections: In silico vs. In vitro approach
    Norshidah H, Leow CH, Ezleen KE, Wahab HA, Vignesh R, Rasul A, et al.
    Front Cell Infect Microbiol, 2023;13:1061937.
    PMID: 36864886 DOI: 10.3389/fcimb.2023.1061937
    An increase in the occurrence of viral infectious diseases is a global concern for human health. According to a WHO report, dengue virus (DENV) is one of the most common viral diseases affecting approximately 400 million people annually, with worsening symptoms in nearly 1% of cases. Both academic and industrial researchers have conducted numerous studies on viral epidemiology, virus structure and function, source and route of infection, treatment targets, vaccines, and drugs. The development of CYD-TDV or Dengvaxia® vaccine has been a major milestone in dengue treatment. However, evidence has shown that vaccines have some drawbacks and limitations. Therefore, researchers are developing dengue antivirals to curb infections. DENV NS2B/NS3 protease is a DENV enzyme essential for replication and virus assembly, making it an interesting antiviral target. For faster hit and lead recognition of DENV targets, methods to screen large number of molecules at lower costs are essential. Similarly, an integrated and multidisciplinary approach involving in silico screening and confirmation of biological activity is required. In this review, we discuss recent strategies for searching for novel DENV NS2B/NS3 protease inhibitors from the in silico and in vitro perspectives, either by applying one of the approaches or by integrating both. Therefore, we hope that our review will encourage researchers to integrate the best strategies and encourage further developments in this area.
  13. Fulltext Genotyping of Toxoplasma gondii isolates from wild boars in Peninsular Malaysia
    Puvanesuaran VR, Noordin R, Balakrishnan V
    PLoS One, 2013;8(4):e61730.
    PMID: 23613920 DOI: 10.1371/journal.pone.0061730
    Toxoplasma gondii is a parasitic protozoan that infects nearly one-third of the world population. The present study was done to isolate and genotype T. gondii from wild boar from forests of Pahang, Malaysia. A total of 30 wild boars' blood, heads and hearts were obtained for this study and 30 (100.0%) were found to be seropositive when assayed with modified agglutination test (MAT ≥ 6). The positive samples were inoculated into mice and T. gondii was only isolated from samples that had strong seropositivity (MAT ≥ 1:24).The isolates were subjected to PCR-RFLP analysis and all the Peninsular Malaysia isolates of T. gondii are of clonal type I.
  14. Isolation and genotyping of Toxoplasma gondii from free-range ducks in Malaysia
    Puvanesuaran VR, Noordin R, Balakrishnan V
    Avian Dis, 2013 Mar;57(1):128-32.
    PMID: 23678741
    Toxoplasma gondii is a parasitic protozoan that infects nearly one-third of humans. The present study was performed to isolate and genotype T. gondii from free-range ducks in Malaysia. Sera, heads, and hearts from 205 ducks were obtained from four states in Peninsular Malaysia, and 30 (14.63%) sera were found to be seropositive when assayed with the modified agglutination test (MAT > or = 1:6). All the positive samples were inoculated into mice, and T. gondii was successfully isolated from four individual duck samples (1.95%), which were initially found to be strongly seropositive (MAT > or = 1:24). The isolates were subjected to PCR-RFLP analysis, and two T. gondii strains were identified: type I and type II. This is the first reported study on the genetic characterization of T. gondii isolates from free-range farm animals in Southeast Asia.
  15. Dissemination of Trimethoprim-Sulfamethoxazole Drug Resistance Genes Associated with Class 1 and Class 2 Integrons Among Gram-Negative Bacteria from HIV Patients in South India
    Ramesh Kumar MR, Arunagirinathan N, Srivani S, Dhanasezhian A, Vijaykanth N, Manikandan N, et al.
    Microb Drug Resist, 2017 Jul;23(5):602-608.
    PMID: 27854149 DOI: 10.1089/mdr.2016.0034
    The antibiotic, trimethoprim-sulfamethoxazole (TMP-SMX), is generally used for prophylaxis in HIV individuals to protect them from Pneumocystis jiroveci infection. Long-term use of TMP-SMX develops drug resistance among bacteria in HIV patients. The study was aimed to detect the TMP-SMX resistance genes among gram-negative bacteria from HIV patients. TMP-SMX-resistant isolates were detected by the Kirby-Bauer disc diffusion method. While TMP resistance genes such as dfrA1, dfrA5, dfrA7, and dfrA17 and SMX resistance genes such as sul1 and sul2 were detected by multiplex PCR, class 1 and class 2 integrons were detected by standard monoplex PCR. Of the 151 TMP-SMX-resistant bacterial isolates, 3 were positive for sul1 alone, 48 for sul2 alone, 11 for dfrA7 alone, 21 for sul1 and sul2, 1 for sul1 and dfrA7, 23 for sul2 and dfrA7, 2 for sul2 and dfrA5, 41 for sul1, sul2, and dfrA7, and 1 for sul2, dfrA5, and dfrA7. Of 60 TMP-SMX-resistant isolates positive for integrons, 44 had class 1 and 16 had class 2 integrons. It was found that the prevalence of sul genes (n = 202; p 
  16. Occurrence of extended-spectrum β-lactamase, AmpC, and carbapenemase-producing genes in gram-negative bacterial isolates from human immunodeficiency virus infected patients
    Rameshkumar MR, Arunagirinathan N, Senthamilselvan B, Swathirajan CR, Solomon SS, Vignesh R, et al.
    J Infect Public Health, 2021 Nov 10.
    PMID: 34810142 DOI: 10.1016/j.jiph.2021.11.008
    BACKGROUND: Progressive decline of immune response in HIV patients makes them susceptible to frequent bacterial infections. High usage of antibiotics influences the emergence of multidrug-resistant bacteria and worsens the clinical outcomes. In this study, the occurrence of drug-resistant genes in Gram-negative bacterial isolates from HIV patients in South India was analyzed.

    METHODS: A total of 173 Gram-negative bacterial (GNB) isolates from HIV patients were screened for antibiotic susceptibility profile using the Kirby-Bauer diskdiffusion method. Positivity of drug-resistant genes was analyzed using polymerase chain reaction method.

    RESULTS: In this study, 72.8% of bacterial isolates were obtained from urine specimens, and Escherichia coli (47.4%) was the predominantly isolated bacterium. Overall, 87.3% and 83.2% of GNB were resistant to 3rd generation cephalosporin antibiotics such as cefotaxime and ceftazidime, respectively, 56.6% were resistant to cephamycin (cefoxitin) and 43% to carbapenem (imipenem) antibiotics. Extended-spectrum β-lactamases (ESBL) production was noted among 79.5% of GNB isolates, followed by AmpC (57.1%) and Metallo β-lactamases (37.3%). Molecular analysis revealed that ESBL genes such as blaTEM (94.1%), blaCTX-M (89.2%), and blaSHV (24.2%) were detected at higher levels among GNB isolates. Carbapenemase-producing genes such as blaOXA-48 (20%), blaOXA-23 (2.6%), and both blaOXA-23 and blaOXA-51 like genes (2.6%) and AmpC producing genes such as blaCIT (26.7%), blaDHA (3.6%), and blaACC (1.8%) were detected at low-level.

    CONCLUSIONS: This study concludes that ESBL producing genes are detected at high level among gram-negative bacterial isolates from HIV patients in South India.

  17. Fulltext Do the clonally different Escherichia coli isolates causing different infections in a HIV positive patient affect the selection of antibiotics for their treatment?
    Rameshkumar MR, Arunagirinathan N, Swathirajan CR, Vignesh R, Balakrishnan P, Solomon SS
    Indian J Med Res, 2018 09;148(3):341-344.
    PMID: 30425226 DOI: 10.4103/ijmr.IJMR_730_17
  18. Fulltext Chromogenic agar medium for rapid detection of extended-spectrum β-lactamases and Klebsiella pneumoniae carbapenemases producing bacteria from human immunodeficiency virus patients
    Rameshkumar MR, Vignesh R, Swathirajan CR, Balakrishnan P, Arunagirinathan N
    J Res Med Sci, 2015 Dec;20(12):1219-20.
    PMID: 26958061 DOI: 10.4103/1735-1995.172994
  19. Fulltext Detection of blaNDM-1 and blaNDM-5 genes among Gram-negative bacteria isolated from human immunodeficiency virus patients in South India
    Rameshkumar MR, Arunagirinathan N, Indu P, Swathirajan CR, Solomon SS, Vignesh R, et al.
    J Res Med Sci, 2018;23:112.
    PMID: 30774691 DOI: 10.4103/jrms.JRMS_627_18
  20. Occult hepatitis B virus infection and current perspectives on global WHO 2030 eradication
    Saravanan S, Shankar EM, Vignesh R, Ganesh PS, Sankar S, Velu V, et al.
    J Viral Hepat, 2024 Apr 05.
    PMID: 38578122 DOI: 10.1111/jvh.13928
    The current World Health Organization (WHO) Hepatitis Elimination Strategy suffers from lack of a target for diagnosing or expunging occult HBV infection. A sizable segment of the global population has an undetected HBV infection, particularly the high-risk populations and those residing in countries like India with intermediate endemicity. There is growing proof that people with hidden HBV infection can infect others, and that these infections are linked to serious chronic hepatic complications, especially hepatocellular carcinoma. Given the current diagnostic infrastructure in low-resource settings, the WHO 2030 objective of obliterating hepatitis B appears to be undeniably challenging to accomplish. Given the molecular basis of occult HBV infection strongly linked to intrahepatic persistence, patients may inexplicably harbour HBV genomes for a prolonged duration without displaying any pronounced clinical or biochemical signs of liver disease, and present histological signs of moderate degree necro-inflammation, diffuse fibrosis, and hence the international strategy to eradicate viral hepatitis warrants inclusion of occult HBV infection.
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