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Page No. : 33-39

ABSTRACT

The present study was conducted to isolate Listeria spp. from women and buffaloes with a history of reproductive disorders. For this, a total of 204 different samples from 51 cases of spontaneous abortions in pregnant women and 248 samples from 62 buffaloes were analyzed. All the isolates were subjected to in-vitro pathogenicity tests like haemolysis on sheep blood agar, CAMP test and phosphatidylinositol phospholipase C (PI-PLC) activity and PCR for virulence-associated genes (plcA, actA and hlyA). Out of 204 women clinical samples analyzed, 6 (2.94%) samples (5 placental and 1 vaginal swab samples) were found positive for Listeria spp. Amongst all the Listeria spp. positive, 5 (2.45%) samples (four of placenta and one vaginal swab) and 1 (0.49%) sample (placenta) showed presence of Listeria monocytogenes and Listeria ivanovii, respectively. However, patient-wise prevalence of L. monocytogenes and Listeria spp. was found to be 7.84% and 9.80%, respectively. In 248 buffalo clinical samples analyzed, 19 (7.66%) Listeria isolates were observed, of which 14 (5.64%), 2 (0.80%), 1 (0.40%) and 2 (0.80%) isolates belonged to L. monocytogenes, L. seeligeri, L. innocua and L. ivanovii, respectively. Thus, overall animal-wise prevalence of L. monocytogenes (8 of 62 animals) and Listeria spp. (11 of 62 animals) was found to be 12.90% and 20.96%, respectively. PCR assay standardized for serotyping and detection of three different virulence associated genes of Listeria spp. was found to be simple, rapid, reliable and sensitive technique for confirming the isolates of Listeria spp. from clinical samples. The PCR results obtained from the study proves that there is genetic variation in L. monocytogenes for their virulence markers, which plays important role in their pathogenicity.

Keywords: Buffaloes, isolation, Listeria spp., prevalence, multiplex-PCR assay, women.