Antibiotic-resistant Escherichia coli and Salmonella spp. associated with dairy cattle and farm environment having public health significance

Abstract

Aim: The present study was carried out to determine load of total bacteria, Escherichia coli and Salmonella spp. in dairy farm and its environmental components. In addition, the antibiogram profile of the isolated bacteria having public health impact was also determined along with identification of virulence and resistance genes by polymerase chain reaction (PCR) under a one-health approach. Materials and Methods: A total of 240 samples of six types (cow dung - 15, milk - 10, milkers' hand wash - 10, soil - 10 water - 5, and vegetables - 10) were collected from four dairy farms. For enumeration, the samples were cultured onto plate count agar, eosin methylene blue, and xylose-lysine deoxycholate agar and the isolation and identification of the E. coli and Salmonella spp. were performed based on morphology, cultural, staining, and biochemical properties followed by PCR. The pathogenic strains of E. coli stx1, stx2, and rfbO157 were also identified through PCR. The isolates were subjected to antimicrobial susceptibility test against 12 commonly used antibiotics by disk diffusion method. Detection of antibiotic resistance genes ereA, tetA, tetB, and SHV were performed by PCR. Results: The mean total bacterial count, E. coli and Salmonella spp. count in the samples ranged from 4.54±0.05 to 8.65±0.06, 3.62±0.07 to 7.04±0.48, and 2.52±0.08 to 5.87±0.05 log colony-forming unit/g or ml, respectively. Out of 240 samples, 180 (75%) isolates of E. coli and 136 (56.67%) isolates of Salmonella spp. were recovered through cultural and molecular tests. Among the 180 E. coli isolates, 47 (26.11%) were found positive for the presence of all the three virulent genes, of which stx1 was the most prevalent (13.33%). Only three isolates were identified as enterohemorrhagic E. coli. Antibiotic sensitivity test revealed that both E. coli and Salmonella spp. were found highly resistant to azithromycin, tetracycline, erythromycin, oxytetracycline, and ertapenem and susceptible to gentamycin, ciprofloxacin, and imipenem. Among the four antibiotic resistance genes, the most observable was tetA (80.51-84.74%) in E. coli and Salmonella spp. and SHV genes were the lowest one (22.06-25%). Conclusion: Dairy farm and their environmental components carry antibiotic-resistant pathogenic E. coli and Salmonella spp. that are potential threat for human health which requires a one-health approach to combat the threat.

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

“…From each farm, 10 cloacal swabs, 7 litter samples and 3 feed samples were collected. Isolation and identification of Salmonella from the collected samples were based on culture on selective media (XLD) (Hi Media, India), Gram staining and biochemical test as was previously described [29].…”

“…However, resistance genes were detected in Escherichia coli isolated from cloacal swabs of boiler chicks in Bangladesh [27,28]. Moreover, a study in Bangladesh, detected resistance genes in E. coli and Salmonella from dairy farms [29]. Another study detected integrons in Salmonella from chicken feces [30].…”

Pastoral community practices, microbial quality and associated health risks of raw milk in the milk value chain of Nakasongola District, Uganda

“…Whereas consumers' quest for wholesome quality milk is paramount, attaining raw milk of acceptable quality remains a challenge for the informal milk value chain. Contamination of milk is associated with the transmission of resistant bacteria to consumers, causing severe milk-borne illnesses that are hard to treat with the available antibiotic drugs (Krahulcová et al 2018;Sobur et al 2019). Therefore, this study assessed the milk handling practices, the bacterial quality and public health risks of raw milk in the informal milk value chain in Nakasongola district.…”

Prevalence and antibiotic resistance of <Salmonella> spp. in South Punjab-Pakistan

“…Investigators further recorded susceptibility pattern as ciprofloxacin (100.0%), chloramphenicol (91.0%), ceftriaxone (91.0%), tetracycline (86.0%) and ampicillin (86.0%) attributing the increased emergence of resistance to imprudent and indiscreet exploitation of antimicrobials to treat animals against infectious diseases in dairy farms in Ghana and Uruguay [32,40]. Lately, Sobur et al [41] delineated an upsurge in resistance among Salmonella spp. against a number of antibiotics including oxytetracycline, tetracycline, erythromycin, azithromycin, and ertapenem.…”