1.0 INTRODUCTION/LITERATURE REVIEW
1.1 INTRODUCTION
The emergence of antibiotic-resistant Salmonella strains has become a major public health concern. Salmonella species are widely distributed in the environment that causes a diverse spectrum of diseases in human and animals. Non typhoidal Salmonella species are among the foremost bacterial pathogens implicated in food-borne gastroenteritis worldwide (Foley et al., 2006). The World Health Organization (WHO) has estimated that annually 1.3 billion cases of acute gastroenteritis or diarrhea due to non typhoid salmonellosis causing 3 million deaths. In India an estimated 4,00,000 children below 5 years age die each year due to diarrhoea (Sudershan et al., 2009). Salmonella is most often transmitted to humans through the food chain, with over 95% of salmonellosis cases attributable to the consumption of undercooked or mishandled beef, chicken and eggs etc., (Foley et al., 2006). A variety of antimicrobial agents have been used to treat the salmonellosis. An increasing rate of antimicrobial resistance in Salmonella has been reported in many developing and developed countries (Threlfall et al., 1993). Briggs and Fratamsco (1999) reported that the frequency of resistance is presumably due to extensive use of antimicrobial agents in human and veterinary medicine. Furthermore, resistance to combinations of several classes of antimicrobials has led to the emergence of Multi-Drug Resistant (MDR) strains that may pass from food animals to humans (White et al., 2001). The genes involved in resistance in Salmonella are often plasmid-born and therefore potentially transmissible to other pathogenic enteric microorganism with genetic factors which control antibiotic resistance. Spread of antibiotic resistance plasmids in Salmonella from chickens to human handlers (White et al., 2001) or of antibiotic-resistant microorganisms from poultry to humans in various countries (Poppe et al., 2002) has been reported.
Poultry in India started as a backyard activity and in the past three decades it has gone through a revolutionary change. Today India ranks 8th in broiler production in the world. Statistics of 2002 show that India produced 1.2 billion kg of broiler meat per annum which gave an annual per capita consumption of 1.2 kg (Asha, 2004). Chicken is considered to be the most widely produced in Namakkal (Latitude:11°.13’ 48” N; Longitude: 78° 10’ 12” E). Thus, the poultry industry is one of the major sources of economy. There are mass production centres in various parts of the country especially in Southern states, Tamil Nadu, Karnaka and Andhra Pradesh. Though the consumption has been promoted, no effective steps are taken to monitor the quality of chicken meat and no guidelines have been prescribed for the meat processing in retail markets. The present study has been taken up primarily to assess the level of Salmonella contamination in meat with special reference to S. enteritidis. The export of poultry product from this region is increasingly on the rise. The possibility for transfer of antibiotic resistance genes among humans, animals and the environment is a direct threat to public health. The incidence of antibiotic-resistant Salmonella may pose health risk to many populations in world.
AIM AND OBJECTIVES
The aim of this study is to evaluate the plasmid profile of salmonella species isolated and its objectives is as stated