Nghiên cứu xác định gen độc lực và gen kháng thuốc của vi khuẩn Escherichia coli và Salmonella đồng nhiễm ở gà và lợn có triệu chứng tiêu chảy tại một số địa phương
A study in 2025 aimed to identify reservoir of Escherichia coli and Salmonella bacteria carrying virulence and resistance genes in diarrheal chickens and pigs in Thai Binh and Hanoi. A total of 262 farms with diarrheal chickens and pigs were identified. Of these, 4 farms were identified containing chickens and/or pigs co-infected with both bacteria, and 33 bacterial strains (12 Salmonella strains and 21 E. coli strains) carrying multiple virulence genes were collected. Among these, Salmonella strains carried species-specific virulence genes such as invA, stn, sopB, and sipB. E. coli strains isolated from chickens carried virulence gene combinations iss, iutA, iroN, ompT, and hlyF characteristic of the avian pathogenic group (APEC). Pathogenic strains contained important resistance genes (mcr-1, mcr-3, blaTEM, blaCTX-M, qnrB, and qnrS). Furthermore, the resistance threshold to colistin in bacteria isolated from pigs and chickens was high (8-16 µg/ml). This co-infection increases the risk of synergistic interactions, promoting the horizontal transmission of drug-resistant plasmids across biofilms, and some strains with high resistance thresholds may form silent outbreaks that are difficult to control. The research results provide scientific evidence to affirm the necessity of implementing intervention programs to thoroughly eradicate virulent, multidrug-resistant bacterial strains to ensure effective livestock production and protect public health.
