author(s)
Shubhangi Warke, Ingle VC and UM Tumlam

abstract
A total of 625 samples comprising of animal clinical cases (n=256), milk (n=238) and farm environment (n=131), were screened to determine the prevalence of Listeria monocytogenes in different parts of Nagpur region, India. The isolates were further characterized using phenotypic assays (Hemolysis test, Christie Atkins Munch-Petersen test (CAMP) and growth on Agar Listeria acc. to Ottaviani and Agosti (ALOA) and genotypic assays. Out of these, 14 (5.46%) samples from animal clinical cases, 12 (5.04%) from milk and 12 (9.16%) from environment were found positive for Listeria monocytogenes. Overall virulence pattern indicated presence of five genes present in three strains, plcA, actA, hlyA, iap in one strain, actA, hly A, iap, prfA in twelve strains, act A, hlyA, iap in nine strains, hlyA, iap, prfA in five strains, hlyA, iap in three strains and hlyA in five strains. Serotyping revealed out of total 38 L. monocytogenes isolates tested majority of isolates (n=34) represented the group corresponding to serovars 1/2b, 3b, 4b, 4d, 4e and three isolates represented serogroup corresponding to serovars 4b, 4d and 4e while one isolate was grouped as serogroup 1/2a, 1/2c, 3a and 3c. In vitro antibiotic sensitivity pattern of L. monocytogenes indicated sensitivity to erythromycin, nitrofurantin and chloramphinicol and resistance to colistin, cloxacillin, nalidixic acid and sulfonamide. Present study showed that farm environment acts as potential reservoir for transmitting L. monocytogenes to animals.