Detection of Pathogenicity Islands and Antimicrobial-Resistant Genes in Serovars Enteritidis and Typhimurium Isolated from Broiler Chickens.

Rapid growth in commercial poultry production is one of the major sources of infections that leads to human salmonellosis. The two main serovars associated with human salmonellosis are enteritidis and typhimurium. The aim of this study was to determine the prevalence of serovars Enteritidis and Typhimurium as well as their pathogenicity islands (SPI) and antibiotic resistance profiles in broiler chicken feces from slaughterhouses. A total of 480 fecal samples from broiler chickens that were grouped into 96 pooled samples were identified to have spp. using the gene, whilst the and genes were used to screen for the presence of Enteritidis and Typhimurium serovars, respectively, by polymerase chain reaction (PCR) assays. The isolates were also screened for the presence of pathogenicity islands (SPIs) using PCR. The disc diffusion assay was performed to determine the antibiotic resistance profiles of the isolates. A total of 36 isolates were confirmed as spp. through amplification of the gene. Out of 36 confirmed spp. a total of 22 isolates were classified as . Enteritidis (n = 8) and were Typhimurium (n = 14) serovars. All (n = 22) Enteritidis and Typhimurium isolates possessed the (SPI-1), (SPI-2) and (SPI-11) pathogenicity islands genes. Amongst these serovars, 50% of the isolates (n = 11/22) were resistant to tetracycline and nalidixic acid. Only 22% of the isolates, Typhimurium (13.6%) and Enteritidis (9.1%) demonstrated resistance against three or more antibiotic classes. The most detected antibiotic resistance genes were (), , and with 13 (59.1%), 9 (40.9%), 9 (40.9%) and 7 (31.8%), respectively. The findings of this study revealed that Typhimurium is the most prevalent serotype detected in chicken feces. To reduce the risk to human health posed by salmonellosis, a stringent public health and food safety policy is required.