Assessing the pathogenic potential of less common Salmonella enterica serotypes circulating in the Thai pork production chain

Abstract

Salmonella is a frequent zoonotic foodborne pathogen, with swine and pork meats the most common source of human infection. In Chiang Mai and Lamphun Province in northern Thailand, there has been a high prevalence of salmonellosis for over a decade. Infection is usually with several dominant S. enterica serotypes, including serotypes Rissen and Monophasic Typhimurium. However, several less common serotypes also contribute to disease. Whole genome sequencing of 43 of these less common S. enterica serotypes isolated from the pork production chain through 2011-2014 were used to evaluate their genetic diversity and virulence potential. Salmonella contamination at local retail markets represented cross-contamination from multiple sources, including decontaminated foodstuff. Previous studies have highlighted the importance of host cell adhesion, invasion and intracellular survival for the development of clinical salmonellosis. We screened our dataset for known virulence genes and antimicrobial resistance genes, identifying at least 10 antimicrobial resistance genes in all isolates. These results indicate that these less common S. enterica serotypes also pose a significant public health risk. Our findings support the need for appropriate surveillance of food products going to market to reduce public exposure to highly pathogenic, multi-drug resistant Salmonella. Surveillance throughout the pork production chain would motivate stakeholders to reinforce sanitation standards and help reduce the risk of salmonellosis in humans.

Antibiotic resistance mechanism and diagnosis of common foodborne pathogens based on genotypic and phenotypic biomarkers

“…Generally, the mechanism of target protection requires sustained or repeated direct interactions between the resistant protein and the target to develop antibiotic resistance, and no permanent changes are caused to the properties of the target. Common resistant proteins include tetracycline ribosomal protective protein (TRPPs; e.g., TetM, TetO), quinolone resistance protein (e.g., Qnr), antibiotic resistance (ARE) ABC-F protein (e.g., Msr, Vga, Lsa, Sal, Vml), FusB-type proteins, and cis-acting peptides (Eiamsam-ang et al, 2022;Ero et al, 2021;Slettemeås et al, 2019). TRPPs mediate the target protection against the tetracycline via the binding to the 30S ribosome subunit to obstruct the transmission of incoming aminoyl-TrNA through the extension factor Tu (EF-TU) during the extension phase of protein synthesis, which inhibits the bacterial translation (Ero et al, 2021;Founou et al, 2019).…”