Prevalence of Listeria spp. in Animals and Associated Environment

Abstract

A total of 215 samples, comprising of both clinical (n=182) and farm environment (n=33), were screened to determine the prevalence of Listeria spp. in different parts of Konkan region, India. Out of these, 27 (12.55%) samples were found positive for Listeria spp. The isolates were further characterized using phenotypic assays (Hemolysis test, Christie Atkins Munch-Petersen test (CAMP) and growth on Agar Listeria acc. to Ottaviani & Agosti (ALOA)) and genotypic assays. The isolates were confirmed as Listeria monocytogenes 12(5.11%), L. ivanovii 2(0.93%), L. innocua 11(5.11%), L. seeligeri 2(0.93%) and L. welshimeri 1(0.46%). The L. monocytogenes isolates were recovered from clinical cases in sheep, goat and pig while one isolate was obtained from pig rearing environment. Serotyping of L. monocytogenes revealed 5 isolates to be of serotype 4b and 6 of serotype 1/2b. L. monocytogenes isolates were sensitive to ampicillin, doxycycline, ciprofloxacin, vancomycin and intermediate resistance towards chloramphenicol, penicillin and gentamicin. The study shows the prevalence of the L. monocytogenes in the clinical cases and associated farm environment of the Konkan region. However, further study is necessary to determine whether farm environment acts as potential reservoir transferring L. monocytogenes to animals.