Browsing by Author "D'Costa, Dilecta"

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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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    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.