Molecular Epidemiology of Nontyphoidal Salmonella in Poultry and Poultry Products in India: Implications for Human Health

Abstract

Human infections with non-typhoidal Salmonella (NTS) serovars are increasingly becoming a threat to human health globally. While all motile Salmonellae have zoonotic potential, Salmonella Enteritidis and Salmonella Typhimurium are most commonly associated with human disease, for which poultry are a major source. Despite the increasing number of human NTS infections, the epidemiology of NTS in poultry in India has not been fully understood. Hence, as a first step, we carried out epidemiological analysis to establish the incidence of NTS in poultry to evaluate the risk to human health. A total of 1215 samples (including poultry meat, tissues, egg and environmental samples) were collected from 154 commercial layer farms from southern India and screened for NTS. Following identification by cultural and biochemical methods, Salmonella isolates were further characterized by multiplex PCR, allele-specific PCR, enterobacterial repetitive intergenic consensus (ERIC) PCR and pulse field gel electrophoresis (PFGE). In the present study, 21/1215 (1.73 %) samples tested positive for NTS. We found 12/392 (3.06 %) of tissue samples, 7/460 (1.52 %) of poultry products, and 2/363 (0.55 %) of environmental samples tested positive for NTS. All the Salmonella isolates were resistant to oxytetracycline, which is routinely used as poultry feed additive. The multiplex PCR results allowed 16/21 isolates to be classified as S. Typhimurium, and five isolates as S. Enteritidis. Of the five S. Enteritidis isolates, four were identified as group D Salmonella by allele-specific PCR. All of the isolates produced different banding patterns in ERIC PCR. Of the thirteen macro restriction profiles (MRPs) obtained by PFGE, MRP 6 was predominant which included 6 (21 %) isolates. In conclusion, the findings of the study revealed higher incidence of contamination of NTS Salmonella in poultry tissue and animal protein sources used for poultry. The results of the study warrants further investigation on different type of animal feed sources, food market chains, processing plants, live bird markets etc., to evaluate the risk factors, transmission and effective control measures of human Salmonella infection from poultry products.

Molecular Detection of Multidrug Resistant Salmonella Species Isolated from Broiler Farm in Bangladesh

“…The WHO recognized Salmonella as one of the pathogens having severe impacts on human health [48]. Poultry and poultry products have been frequently reported to be involved in the outbreaks of salmonellosis [49]. Alarmingly, all the Salmonella isolated in the present study were found to be MDR including fluroquinolone-resistant Salmonella.…”

Antimicrobial resistance profiles of <em>Salmonella</em> serovars isolated from dressed chicken meat at slaughter in Kaduna, Nigeria

“…Antimicrobial-resistant Salmonella spp. have been isolated from different foods of animal origin around the world (Garedew et al, 2015;Löfström et al, 2015;Saravanan et al, 2015). Extensive use of antimicrobial agents in animal production is common and selects for multidrug resistant (MDR) pathogens (Marshall and Levy, 2011;Oluwasile et al, 2014).…”

Antimicrobial drug resistant non-typhoidal Salmonella enterica in commercial poultry value chain in Chitwan, Nepal

“…Similar to our ndings, the Vietnamese studies detected high percentages of NTS isolates resistant to tetracycline varying from 40% (20) to 78% (21) and low resistance to cipro oxacin. Other studies of poultry and poultry farms from India found 100% of the NTS isolates to be tetracycline resistant (18,19); and one of these the routine use of oxytetracycline as a feed additive. In Myanmar, 54% and 9% of NTS isolates from retail chicken samples were resistant to tetracycline and cipro oxacin, respectively (22).…”