Browsing by Author "Kalekar, Sushanta"

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    Characterization of Listeria monocytogenes isolated from human clinical cases
    (International Journal of Medical and Health Sciences (IJMHS), 2015) Kalekar, Sushanta; Doijad, Swapnil; Poharkar, Krupali V.; Rodriguez, Savio; Kalorey, D R; Kurkure, Nitin V; Rawool, Deepak B; D'Costa, Dilecta; Bhosle, Saroj; Barbuddhe, S B
    Introduction: Listeria monocytogenes is an emerging foodborne pathogen and causative agent of listeriosis. It is one of the cause of spontaneous abortions and meningitis. The objective of the study was to determine the incidences of L. monocytogenes from human cases of spontaneous abortions or having a history of spontaneous abortions and meningitis. Materials and Methods: A total of 481 samples from humans having a history of spontaneous abortions and meningitis were analyzed. Isolation of the pathogen was attempted employing two step enrichment followed by plating on selective media. Characterization of the isolates was based on biochemical tests, haemolysis on blood agar, CAMP test, phosphatidyl inositol-speciï¬ c phospholipase C assay, multiplex PCR to detect virulence-associated genes (hlyA, actA and iap) and serotyping by conventional and PCR based method. Results: Of the 481 samples analysed, 7 (1.45%) samples from abortion cases were found positive, while no CSF sample from meningitis cases was positive for L. monocytogenes. All the isolates showed in-vitro virulence characteristics such as hemolysis on 5% sheep blood agar, positive CAMP test and showed hallow formation on ALOA medium. All the isolates showed the presence of the hly, actA and iap genes. Conventional serotyping as well as PCR based serotyping revealed the isolates to be of 4b, 1/2b and 4e serotypes. Antibiotic sensitivity assay showed that the isolates were sensitive to trimethoprim, however, the isolates were least sensitive to meropenem. Conclusions: The study highlights the incidence of L. monocytogenes in humans with spontaneous abortions. KEYWORDS: Listeria monocytogenes, Serotypes, Isolation, PCR, human.
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    Genotypic characterization of Listeria monocytogenes isolated from humans in India
    (Taylor & Francis, 2011) Kalekar, Sushanta; Rodrigues, Jenney; D'Costa, Dilecta; Doijad, Swapnil; Ashok Kumar, J; Malik, S. V. S; Kalorey, D. R; Hain, T; Chakraborty, T; Barbuddhe, Sukhadeo B.
    Listeria monocytogenes is a foodborne pathogen associated with severe diseases in humans and animals. The genotypic analysis of 17 L. monocytogenes isolates recovered from humans in India during 2006–2009 using multiplex serotyping PCR allowing serovar predictions, conventional serology and by pulsed field gel electrophoresis (PFGE) is presented. The isolates were recovered from patients exhibiting various clinical conditions. A multiplex-PCR based serotyping assay revealed 88·24% (15/17) of the strains belonging to the serovar group 4b, 4d, 4e and 11·76% (2/17) to the serovar group 1/2b, 3b. Conventional serology indicated that 13 (76·47%) L. monocytogenes isolates to be of serotype 4b, 2 (11·76%) serotype 4d, and 2 (11·76%) serotype 1/2b. Ten ApaI and nine AscI pulsotypes were recognized among the 17 human isolates. PFGE analysis allowed discrimination among isolates of the same serotype and among isolates from the same sampling areas or those isolated from different areas. Thus, PFGE together with multiplex-PCR serotyping allows rapid discrimination of L. monocytogenes strains. In addition, the predominance of L. monocytogenes serotype 4b is of concern, as this serotype has been most frequently associated with human listeriosis outbreaks.
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    Incidence and genetic variability of Listeria species from three milk processing plants
    (Elsevier, 2011) Doijad, Swapnil; Barbuddhe, S. B.; Garg, Sandeep; Kalekar, Sushanta; Rodrigues, Jenney; D’Costa, Dilecta; Bhosle, S.; Chakraborty, Trinad
    The presence of Listeria in three milk processing environments as a potential source of milk contamination was assessed. Swab samples (n = 210) taken from milk processing plants were examined. Sample sites included the milk processing equipment, besides areas handling raw and pasteurized milk. The USDA Listeria-selective enrichment procedure was used to process the samples. Forty one (19.52%) Listeria isolates were recovered. The isolates were further subjected to biochemical and genotypic characterization. Out of 41 isolates, 16 (7.62%) were confirmed as Listeria monocytogenes, 2 (0.95%) as L. ivanovii, 19 (9.05%) as L. innocua. 1 (0.48%) as L. seeligeri and 3 (1.43%) as L. grayi. All the L. monocytogenes isolates were positive for the hlyA gene. PCR based serotyping revealed all L. monocytogenes to be of 1/2a, 1/2c, 3a and 3c serovar group. AscI and ApaI restriction analysis yielded four PFGE clusters for 16 L. monocytogenes isolates obtained from raw milk collector, milk silos, buttermilk mixer, cheese and other milk product processor. No predominant PFGE cluster was observed among these L. monocytogenes isolates. The main sources of L. monocytogenes were found to be raw milk collector and milk silos. In the present study L. monocytogenes was isolated from milk and milk products processing plants which could cross-contaminate the processed products and may possess a potential threat to public health.
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    Prevalence and characterisation of Listeria spp. from seafood
    (Indian Council of Agricultural Research, 2015) Rodrigues, Jenney; Kalekar, Sushanta; Doijad, Swapnil; Poharkar, Krupali; D'Costa, Dilecta; Barbuddhe, Sukhadeo B.
    Listeria monocytogenes, the causative organism of listeriosis, is primarily transmitted to humans through contaminated food. We examined the prevalence of L. monocytogenes isolates from fishery products marketed in Goa, India. A total of 221 raw seafood samples were examined for the presence of Listeria species following ISO 11290 protocol. Thirty seven (16.74%) samples were positive for Listeria species. Out of these, isolates from 4 (1.8%) samples were confirmed asL. monocytogenes, the remaining 33 isolates were Listeria innocua. All the isolates were subjected to PCR for the hlyAgene, which was detected in all the L. monocytogenes isolates. The isolates were also found to express phosphatidyl-inositol specific phospholipase C activity on ALOA agar. Multiplex PCR-based clonal typing revealed three L. monocytogenesisolates to be of serovar group 1/2a, 1/2c, 3a, 3c while the remaining isolates belonged to serovar group 1/2b, 3b 4b, 4d and 4e. The isolates were grouped into two AscI and ApaI PFGE (pulsed field gel electrophoresis) profiles. Prevalence ofL. monocytogenes in fresh seafood is of significance as it may contaminate and persist in the processing environment.