Persistence of Salmonella and Campylobacter on Whole Chicken Carcasses under the Different Chlorine Concentrations Used in the Chill Tank of Processing Plants in Sri Lanka

The persistence of non-typhoidal Salmonella and Campylobacter in chicken meat is a considerable public health risk and a future challenge. This study aimed to determine the prevalence of Salmonella and Campylobacter in poultry processing lines where different chlorine concentrations were used in the chill tank. The samples were collected from four types of processing plants in Sri Lanka, considering the chlorine concentration used in the chill tank, which ranged from 2 ppm to 50 ppm. Salmonella and Campylobacter were isolated from whole carcass washings, neck skin, and cecal samples. Subsequently, an antimicrobial susceptibility test was performed for the isolates. The results revealed the overall prevalence of Salmonella and Campylobacter was 78.25% and 63.5%, respectively. Positive percentages of Salmonella and Campylobacter were high in the carcasses compared to the neck skin and ceca. The Campylobacter counts on the whole carcasses were significantly low (p < 0.001), at higher chlorine concentrations ranging from 20 to 30 ppm and 40 to 50 ppm. The pathogen prevalence in the whole carcasses was 84.7% Campylobacter coli, 39.1% Campylobacter jejuni, 71.1% Salmonella Typhimurium, and 28.8% Salmonella Infantis. The highest resistance was observed for tetracycline (63.8%) in Salmonella, while it was for gentamicin (87.8%) in Campylobacter. The prevalence percentage of multidrug-resistant Campylobacter was 51.2%, while it was 2.12% for Salmonella. The persistence of multidrug-resistant Salmonella and Campylobacter on the post-chill carcasses was highlighted in the present study as a significant public health threat that has to be addressed urgently.

Salmonella spp. in Chicken: Prevalence, Antimicrobial Resistance, and Detection Methods

Multidrug-resistant Salmonella spp. is one of the leading causes of worldwide foodborne disease outbreaks. Animal-derived foods, particularly chicken and poultry products, are the most likely source of Salmonella transmission to humans. The increasing demand for chicken meat has raised a global food safety issue. This review aims to determine the prevalence and antimicrobial resistance of Salmonella spp. in chickens from various countries in Asia. The methods for detecting Salmonella will also be discussed in this review. The prevalence of Salmonella spp. in chicken and poultry products is lower in developed countries than in developing countries. In addition, the incidence of Salmonella spp. in chicken and poultry products from fresh markets is higher than those from supermarkets. Furthermore, this review also reported the presence of multidrug-resistant Salmonella strains in various Asian countries. Rapid Salmonella detection based on immunological assays, molecular-based assays, and biosensors can provide more accurate results with high sensitivity and specificity. These methods also require a shorter time than the cultural-based Salmonella detection method. The use of suitable detection methods to determine the presence of Salmonella spp. in chicken and poultry products is important to ensure food safety.

Serovar diversity of Salmonella among poultry

Background & objectives

Salmonellosis due to the consumption of contaminated poultry products is a well-known public health concern, and assessing the distribution of Salmonella serovars among poultry becomes important for better prevention and control. The objective of the present study was to assess the distribution of Salmonella serovars among poultry.

Methods

The isolates received at National Salmonella and Escherichia Centre during 2011-2016 were subjected to biochemical identification, followed by serological characterization to identify the Salmonella serovars, and the data were presented to exhibit the distribution of Salmonella serovars among poultry.

Results

Salmonella was found to be present in poultry in all the regions included in the study. Salmonella Typhimurium, S. Gallinarum and S. Enteritidis were the most prevalent serovars accounting for 96.2 per cent of isolates. Salmonella was identified in poultry from all major egg-producing and egg-consuming States. Other serovars which were scantly identified included S. Infantis (2.7%), S. Montevideo (0.64%), S. Newport (0.26%) and S. Pullorum (0.13%).

Interpretation & conclusions

Diverse distribution of Salmonella serovars in poultry in India, with known potential to infect human population and/or other poultry flocks, requires urgent nationwide stringent control measures.

Isolation, conventional and molecular characterization of Salmonella spp. from newly hatched broiler chicks

Salmonella is an important pathogen for poultry production as well as for human due to zoonotic importance. It has more than 2600 identified serovars despite of this identification and classification of Salmonella isolates into different serovars is critical for study of incidence and surveillance. This study investigates the epidemiology and molecular characterization of Salmonella isolates in broiler chicks during 1st week of life. A total of (n = 1000) samples including liver, intestine, yolk sac, spleen and heart blood were collected from El-Gharbia, El-Behera, Kafr-Elshikh, Alexandria, Marsamatroh Provinces in Egypt and tested through bacteriological, biochemical, serological and molecular examinations. Incidence of Salmonella was demonstrated on 75 positive samples from 1000 samples and the predominance of Salmonella that isolated from internal organs of newly hatched chicks was highest from yolk sacs (10%), liver and intestines (9%) followed by the spleen (7.5%) then heart blood (2%). Serotyping of the isolated strains using slide agglutination test revealed that 24 isolates belonging to S. enteritidis (1,9,12 g.m 1,7), while, 14 isolates belonging to S. virchow (6,7 r 1,2), in addition to, 12 isolates belonging to S. typhimurium (1,4,5,12.i.1,2) and 8 isolates belonging to S. kentucky (6,8.I,z). Enterobacterial Repetitive Intergenic Consensus (ERIC) PCR revealed that two S. enteriditis isolates were identical and one isolate differ by 40%, while two S. typhimurium isolates were identical by 80% and one isolate was similar by 20% to the other two isolates, in addition, two S. virchow isolates were identical by 80% and the two S. kentucky isolates were different.