Molecular Detection of Multidrug Resistant Salmonella Species Isolated from Broiler Farm in Bangladesh

Abstract

Multidrug resistant (MDR) Salmonella are a leading cause of foodborne diseases and serious human health concerns worldwide. In this study we detected MDR Salmonella in broiler chicken along with the resistance genes and class 1 integron gene intl1. A total of 100 samples were collected from broiler farms comprising 50 cloacal swabs, 35 litter and 15 feed samples. Overall prevalence of Salmonella was 35% with the highest detected in cloacal swabs. Among the Salmonella, 30 isolates were confirmed as S. enterica serovar Typhimurium using molecular methods of PCR. Disk diffusion susceptibility test revealed that all the Salmonella were classified as MDR with the highest resistance to tetracycline (97.14%), chloramphenicol (94.28%), ampicillin (82.85%) and streptomycin (77.14%). The most prevalent resistance genotypes were tetA (97.14%), floR (94.28%), blaTEM-1 (82.85%) and aadA1 (77.14%). In addition, among the MDR Salmonella, 20% were positive for class 1 integron gene (intl1). As far as we know, this is the first study describing the molecular basis of antibiotic resistance in MDR Salmonella from broiler farms in Bangladesh. In addition to tetA, floR, blaTEM-1, aadA1 and intl1 were also detected in the isolated MDR Salmonella. The detection of MDR Salmonella in broiler chicken carrying intl1 is of serious public health concern because of their zoonotic nature and possibilities to enter into the food chain.

Isolation and Characterization of Multidrug-Resistant Escherichia coli and Salmonella spp. from Healthy and Diseased Turkeys

“…were found to be resistant to levofloxacin, erythromycin, ciprofloxacin, meropenem, and tetracycline. This antibiotic resistance profile can be due to the frequent use of antibiotics in poultry for therapeutic and growth promotion purposes [32,33]. The presence of antibiotic-resistant E. coli and Salmonella spp.…”

“…Several studies detected the tetA gene in E. coli and Salmonella spp. from dairy farms, boiler farms, house flies, and aquatic environments [31,33,[50][51][52]. However, there were no studies on the detection of the tetA gene in E. coli and Salmonella from turkeys.…”

“…This overuse typically occurs without consulting any veterinarians and without any previous testing of the animals. The development of MDR bacteria in poultry has been previously reported in previous studies [22,[33][34][35]. Poultry farmers have been using different types of poultry in recent years including broilers, layers, and turkeys.…”

“…In addition, the indiscriminate use of antibiotics in livestock is one of the main causes of AMR [25,26]. The overuse of antibiotics by farm owners in poultry farms, a common practice in developing countries, is a major reason for the development of MDR bacteria [32,33]. This overuse typically occurs without consulting any veterinarians and without any previous testing of the animals.…”

Antibiotics in Food Chain: The Consequences for Antibiotic Resistance

“… Sepsis, urinary tract Aminoglycosides ampicillin vancomycin Food-producing animals (poultry); People exposed to hospital care, food animals Tuf , VanC-1, VanC-2-VanC-3, pbp5 [ 41 , 42 , 43 , 44 , 45 ] 3 E. coli Gastrointestinal, urinary tract, diarrhoea Quinolones sulphonamides trimethoprim Childcare facilities Bla, qnrS, frdD [ 46 , 47 , 48 ] 4 Salmonella spp. (non-typhoidal) Gastrointestinal, diarrhoea Cephalosporins quinolones tetracyclines Food-producing animals (pigs, cows, poultry) IntI1, qnrA [ 49 , 50 , 51 , 52 ] 5 S. pneumoniae Otitis media, pneumonia, sinusitis, meningitis Penicillin, macrolides, cephalosporins, tetracyclines Childcare facilities, paediatric populations erm(B), mef [ 53 , 54 , 55 , 56 ] 6 S. pyogenes Pharyngitis, impetigo, cellulitis Macrolides, tetracyclines …”