Occurrence of Multidrug-Resistant Salmonella spp. in Raw Meat Retailed in Wet Markets in Chattogram City, Bangladesh.

Abstract

Background: Antimicrobial resistance (AMR) in foodborne pathogens has become a global public health issue. Salmonella is one of the most widespread foodborne pathogens worldwide, causing foodborne-related hospitalizations and deaths. Multidrug resistance (MDR) in Salmonella makes foodborne salmonellosis challenging to treat and control. Foodborne salmonellosis often follows the consumption of contaminated animal products, typically resulting from the use of infected animals in food production or contamination of carcasses or edible organs. Therefore, screening raw meats for MDR in Salmonella spp. can help identify the extent of exposure to antimicrobial resistance through food. This study aimed to determine the prevalence and molecular identification of the isolates, as well as to screen them for the presence of three antimicrobial resistance genes: blaTEM, sul1, and sul2.

Methods: A total of 200 raw meat samples (beef, n = 50; goat, n = 50; buffalo, n = 50; and chicken, n = 50) were collected from five local wet markets in Chattogram city, Bangladesh. Salmonella spp. was phenotypically detected following ISO-6579-1 guidelines and biochemical tests. For molecular identification, polymerase chain reaction (PCR) was performed using Salmonella-specific paired primers (ST11 and ST15). The antimicrobial susceptibility profiles of PCR-positive Salmonella isolates were determined by the disk diffusion method. The isolates were also screened for three antimicrobial resistance genes: blaTEM, sul1, and sul2.

Results: The overall prevalence of Salmonella spp. in raw meat was 13.5% (95% CI 9.03-19.03), with the highest detection rate in poultry meat. All 27 phenotypically positive isolates were confirmed as Salmonella in the molecular screening of PCR. All the Salmonella isolates were found to be MDR with the highest resistance to sulfamethoxazole-trimethoprim (100%), amoxicillin (92.6%), and ampicillin (92.6%). The most prevalent resistance genotype was blaTEM (81.5%), whereas 11.1% and 18.5% of the Salmonella isolates were of the sul1 and sul2 genotypes, respectively.

Conclusion: The present study revealed that a substantial proportion of Salmonella isolates from raw meat showed resistance to multiple antibiotics, posing potential public health concerns in Chattogram city, Bangladesh. One Health interventions are necessary to mitigate the spread of MDR Salmonella.