Ranjana Deshmukh

Humoral immune responses and protective efficacy of sequential B- and T-cell epitopes of V antigen of Yersinia pestis by intranasal immunization in microparticles

Capsular F1 and secretory V antigen are the putative vaccine candidates for plague, caused by Yersinia pestis. Contemplating this, we studied the immunogenicity and protective efficacy of collinearly synthesized B- and T-cell epitopes (B-T constructs) of V antigen entrapped in poly (dl-lactide-co-glycolide) microparticles immunized intranasally using single dose immunization schedule in outbred, H-2b and H-2d mice. High antibody levels were observed in terms of IgG, IgA and SIgA peak titers in sera and mucosal washes to different B-T constructs. The constructs ai, bi and fi especially showed high peak antibody titers ranging from 51,200 to 204,000, which were maintained till day 120 post immunization. IgG/IgA Specific activity in sera and washes correlated well with the peak antibody titers. Moreover, all the B-T constructs showed mixed IgG1 and IgG2a/2b response, variable immunoreactivity as well as memory response with V antigen. B-T constructs, viz ai, ak, bi, fi, di and ik showed comparatively high isotype levels. These constructs showed high immunoreactivity, and good recall response with V antigen. Finally, in vivo protective study in BALB/c mice demonstrated the protective efficacy of three B-T constructs (ai, bi and fi) against lethal doses of Yersinia pestis till day 20 post challenge, while construct ‘id’ showed partial protection.

Prevalence of leptospirosis among dogs and rodents and their possible role in human leptospirosis from Mumbai, India

A total of 100 blood and 18 urine samples of rodents and suspected dogs were collected from Mumbai, India during 2006-2008. In order to determine the role of animals in transmission of the disease to humans, all the samples were screened retrospectively by real-time polymerase chain reaction for leptospiral DNA and antibodies were detected using microscopic agglutination test. Leptopsiral DNA was detected from two blood and five urine samples from rodents. Of a total of 71 rodent and dog samples investigated for anti-Leptospira antibodies, 14 (19.7%) were positive. Pyrogenes was the predominant serovar found in 100.0% (7/7) and 85.7% (6/7) from suspected canine cases and rodents, respectively; followed by Icterohemorrhagiae, which was found in one rodent sample 14.28% (1/7). The study proves that there is high prevalence of leptospirosis in rodents and dogs in this region, which proves possible role of these animals in transmission of leptospires to humans. Hence it is imperative to necessary control measures to prevent human leptospirosis.

Evaluation of anti-viral activity of Jatropha curcas leaf extracts against potentially drug-resistant HIV isolates

Methods In vitro micro-co-culture was employed for virus isolation followed by drug susceptibility assays to determine resistance to Azidothymidine (AZT) and Lamivudine (3TC). Jatropha curcasleaves were extracted using Soxhlet apparatus. Methanolic (ME) and aqueous (AE) extracts were chosen for further study. Secondary metabolites were detected by High-Performance Thin Laye rChromatography and in vitro cytotoxicity established by MTT assay. Anti-viral activity was evaluated by p24 inhibitionin postand pre-infection interaction studies.

Prevalence of influenza virus among the paediatric population in Mumbai during 2007-2009

PURPOSE Influenza has a major impact on public heath, annually affecting 15-20% of the global population. Information on the activity of influenza virus in Mumbai is limited. The present study was carried out to determine the prevalence of influenza viruses causing acute respiratory infections in children by molecular methods. OBJECTIVE To study the prevalence of influenza viruses among the paediatric population in Mumbai by real-time reverse-transcriptase polymerase chain reaction (rRT-PCR). MATERIALS AND METHODS From July 2007 to July 2009, 100 respiratory samples (nasal and throat swabs) were collected from paediatric patients with acute respiratory symptoms. attending out patients department, and admitted to the paediatric wards of B. J. Wadia Hospital for Children, Mumbai. The samples were collected and processed as per World Health Organization (WHO) guidelines. Viral RNA was extracted and one-step rRT-PCR was performed to detect influenza type A (H1 and H3) and influenza type B virus. RESULTS Out of 100 samples processed by rRT-PCR, a total of 11 samples (11%) were positive for influenza virus. The typing for influenza A subtypes showed 1% (1) positivity for H1 and 5% (5) positivity for H3 subtypes and 5% (5) samples tested positive for influenza type B virus. CONCLUSION It was observed that both influenza type A and B viruses were prevalent in Mumbai during the study period. Such surveillance data are important in the early detection of any antigenic variants that may be helpful in global influenza vaccine preparation and for any pandemic preparedness activity.

Clinico-epidemiological observations of human leptospirosis from Mumbai, India.

In this Journal, Allwood and his colleagues (2014) ad described environmental risk factors associted with leptospirosis cases from Jamaica [1]. ere, we describe multi-year retrospective study f suspected cases of leptospirosis along with the linical characteristics, environmental factors and ocio-economic behavior associated with this disase from Mumbai, India. Leptospirosis has been recognized as an imporant emerging global public health problem because f its epidemic proportions and increasing incience in both developing and developed countries. ince the original identification of leptospirois by Dr. Weil, outbreaks of leptospirosis have ccurred sporadically throughout world [2,3]. Sevral epidemics of leptospirosis have been reported orldwide during the past century, whereas in ndia, leptospirosis is endemic in most of the rban areas in Southern and Western India, where utbreaks usually occur after flooding caused by eavy seasonal rainfall [4—6]. Epidemiological studes indicate that infection is commonly associated ith certain occupational workers such as farmers, ewage workers, veterinarians, and animal hanlers. Leptospirosis can also be transmitted during

Estimation of mRNA levels of interleukin (IL)-10, tumor necrosis factor (TNF)-α, IL-4 and interferon (IFN)-γ in HIV infected children in Mumbai.

Cytokines, viral load and opportunistic infections play an important role in HIV-disease progression. Hundred children vertically infected with HIV were enrolled to determine mRNA levels of TNF-α, IL-10, IL-4 and IFN-γ. These levels were estimated by amplifying cytokine mRNA from peripheral blood mononuclear cells. Severity of HIV was staged by the reduction in CD4+ T cells and the onset of opportunistic infections. IL-10 mRNA levels were observed to increase with the severity. Despite the rising IL-10 mRNA levels, TNF-α mRNA levels increased with severity of HIV and decrease in CD4+ T cell counts. IL-4 mRNA levels increased with the reduction in CD4+ T cell numbers. Depleting mRNA levels of IFN-γ contributed to the worsening of HIV disease. Increase in TNF-α and IL-4 levels appended to the disease severity by upregulation of the viral replication. Increased IL-10 levels and decreased IFN-γ levels predisposed the children to HIV associated opportunistic infections, which in return contributed to cytokine disarray.

Seroprevalence of Measles, Mumps, and Rubella Antibodies in College Students in Mumbai, India

Measles, Mumps, and Rubella (MMR) are vaccine preventable viral infections, which cause significant mortality and morbidity globally. Increased incidence rates of these infectious diseases are observed in young adults. Information on seroprevalence data on MMR in India is limited. The objective of this study was to determine the prevalence of IgG antibodies against MMR among young adults. This was a descriptive cross-sectional study involving 192 healthy college students from Maharshi Dayanand College, Mumbai. The project was approved by the Institutional Ethics Committee of Haffkine Institute. Between December 2012 and September 2013, blood samples were collected from individuals of age 18-23 years after obtaining written informed consent from them. The quantitative determination of IgG antibodies in serum specimens against MMR was determined using enzyme linked immunosorbent assay. Data on history of vaccination were also collected from participants. Among 192 healthy college students (age 18-23 years), MMR seroprevalence was 91%, 97%, and 88%, respectively. The overall seropositivity of MMR was 79%. The highest level of seronegativity was seen with regards to rubella-specific antibodies in 12% of cases. About 96% of the participants did not know about their vaccination history while none of the participants knew about their history of MMR infections. Despite unknown vaccination status, a majority of college students in our study were found seropositive for all three infections, which indicate natural boosting. However, the proportion of seronegativity for measles and rubella was relatively higher. Especially since the study population belonged to reproductive age group, there is a concern of congenital rubella syndrome in the offspring. Although a larger multicentric study is required to confirm the findings, the results indicate that a dose of measles-rubella (MR) vaccine should be offered to these college students.

Drug susceptibility of influenza A/H3N2 strains co-circulating during 2009 influenza pandemic: First report from Mumbai

OBJECTIVE From its first instance in 1977, resistance to amantadine, a matrix (M2) inhibitor has been increasing among influenza A/H3N2, thus propelling the use of oseltamivir, a neuraminidase (NA) inhibitor as a next line drug. Information on drug susceptibility to amantadine and neuraminidase inhibitors for influenza A/H3N2 viruses in India is limited with no published data from Mumbai. This study aimed at examining the sensitivity to M2 and NA inhibitors of influenza A/H3N2 strains isolated from 2009 to 2011 in Mumbai. METHODS Nasopharyngeal swabs positive for influenza A/H3N2 virus were inoculated on Madin-Darby canine kidney (MDCK) cell line for virus isolation. Molecular analysis of NA and M2 genes was used to detect known mutations contributing to resistance. Resistance to neuraminidase was assayed using a commercially available chemiluminescence based NA-Star assay kit. RESULTS Genotypically, all isolates were observed to harbor mutations known to confer resistance to amantadine. However, no know mutations conferring resistance to NA inhibitors were detected. The mean IC50 value for oseltamivir was 0.25 nM. One strain with reduced susceptibility to the neuraminidase inhibitor (IC₅₀=4.08 nM) was isolated from a patient who had received oseltamivir treatment. Phylogenetic analysis postulate the emergence of amantadine resistance in Mumbai may be due to genetic reassortment with the strains circulating in Asia and North America. CONCLUSIONS Surveillance of drug susceptibility helped us to identify an isolate with reduced sensitivity to oseltamivir. Therefore, we infer that such surveillance would help in understanding possible trends underlying the emergence of resistant variants in humans.

Characterization of influenza virus among influenza like illness cases in Mumbai, India

The present study was carried out to monitor influenza viruses by identifying the virus and studying the seasonal variation during 2007–2009 in Mumbai. A total of 193 clinical respiratory samples (nasal and throat swab) were collected from patients having influenza like illness in Mumbai region. One-step real-time reverse-transcriptase PCR (rRTPCR) was used to detect Influenza type A (H1 and H3) and Influenza type B virus. Isolation of the virus was carried out using in vitro system which was further confirmed and typed by hemagglutination assay and hemagglutination inhibition assay. Out of 193 samples 24 (12.4 3%) samples tested positive for influenza virus, of which 13 (6.73 %) were influenza type A virus and 10 (5.18 %) were influenza type B virus, while 1 sample (0.51 %) was positive for both. By culture methods, 3 (1.55 %) viral isolates were obtained. All the three isolates were found to be Influenza type B/Malaysia (Victoria lineage) by Hemagglutination Inhibition Assay. The data generated from the present study reveals that both Influenza type A and B are prevalent in Mumbai with considerable activity. The peak activity was observed during monsoon season.

Genetic Characterization of Influenza A (H1N1) Pandemic 2009 Virus Isolates from Mumbai.

Pandemic influenza A (H1N1) 2009 virus was first detected in India in May 2009 which subsequently became endemic in many parts of the country. Influenza A viruses have the ability to evade the immune response through its ability of antigenic variations. The study aims to characterize influenza A (H1N1) pdm 09 viruses circulating in Mumbai during the pandemic and post-pandemic period. Nasopharyngeal swabs positive for influenza A (H1N1) pdm 09 viruses were inoculated on Madin–Darby canine kidney cell line for virus isolation. Molecular and phylogenetic analysis of influenza A (H1N1) pdm 09 isolates was conducted to understand the evolution and genetic diversity of the strains. Nucleotide and amino acid sequences of the HA gene of Mumbai isolates when compared to A/California/07/2009-vaccine strain revealed 14 specific amino acid differences located at the antigenic sites. Amino acid variations in HA and NA gene resulted in changes in the N-linked glycosylation motif which may lead to immune evasion. Phylogenetic analysis of the isolates revealed their evolutionary position with vaccine strain A/California/07/2009 but had undergone changes gradually. The findings in the present study confirm genetic variability of influenza viruses and highlight the importance of continuous surveillance during influenza outbreaks.