In - Vitro Characterization Of Listeria monocytogenes Isolates By Haemolysis, Camp, Piplc Assay With Protein Profiling And Antibiotic Resistance Recovered From Nagpur Region

摘要

Listeria monocytogenes is one of the most virulent foodborne zoonotic pathogen with 20 to 30% of clinical infections resulting in death. The L. monocytogenes is ubiquitous in the nature and has been isolated from a variety of foods and environmental sources infecting human and animals revealing the pathogenicity of organism. Reports are very few regarding the pathogenesis of organism in Nagpur region, Maharashtra, India. So the present study was proposed to evaluate the pathogenicity of 12 L.monocytogenes isolates recovered from foods of animal origin (Chevon, pork, beef and carabeef) collected in and around Nagpur city. In vitro expression of pathogenisity was carried out by using viz., Haemolysis on Sheep blood agar (SBA), Christie Atkins Munch Petersen (CAMP) Test, Phosphatidylinositol–specific phospholipase–C (PI– PLC) assay along with protein profiling and subsequently studied for their pattern of antibiotic resistance. All 12 isolates of L. monocytogenes were found haemolytic in nature and showed PIPLC activity with variation in degree of production which designated them as pathogenic one. The protein profiles of all isolates exhibited minimum 25 to maximum 29 bands where protein bands of molecular weight from 56.237 kDa to 60.33 kDa and 29.226 kDa to 33.48 kDa shared by all isolates can be correlated with the haemolytic LLO (Listerolysin–O) and PI–PLC activity respectively. In antibiotic assay, most isolates showed multidrug resistance, besides no resistance was recorded towards Gentamycin, Norfloxacin, Ampicilin and Cefotaxime. The study revealed a high virulence nature of isolates of L. monocytogenes among food animals in and around Nagpur region. Haemolysin on SBA, PI–PLC activity along with exhibition of polypeptide in the range for these activities can be suggestive of protein profiling as technique for determination of pathogenicity.