Prevalence and Antimicrobial Susceptibility of Escherichia coli Isolated from Goats in the Mekong Delta, Vietnam

Escherichia coli is one of the severe pathogens causing severe diarrhea and resistance to antibiotics in domestic animals, including goats. From April to June 2023, 122 fresh feces of hybrid Boer goats of different ages and genders were collected randomly in the small-scale farms in the Mekong Delta, Vietnam, to clarify the prevalence and antibiotic resistance of E. coli isolated from those feces. By the traditional culture method, of 122 samples, 87 fecal samples were positive for E. coli (71.31%). There were no statistically significant differences in the prevalence of E. coli among male or female goats and ages (< 6 months and ≥ 6 months). E. coli was detected in goats over 6 months and under 6 months at 76.56% and 65.52%, respectively, while 88.20% and 85.42% in male and female goats. The antimicrobial susceptibility of E. coli strains to 7 examined antibiotics was conducted using the Kirby-Bauer disk diffusion method. The results indicated that E. coli was sensitive 100% to colistin (10 μg), amoxicillin/clavulanic acid (20/10 μg), cefuroxime (30 μg), doxycycline (30 μg), ciprofloxacin (5 μg), and 87.50% to ampicillin (10 μg) and bactrim (trimethoprim/sulfamethoxazole, 1.25/23.75 μg), respectively. However, those E. coli strains were highly resistant to streptomycin (93.75%), and 93.67% of E. coli strains were resistant to one to three antibiotics. Among them, the resistant pattern of Ge+Sm (gentamycin + streptomycin) was the most frequent detection (43.75%). The prevalence rate of antibiotic resistance genes (blaampC, tetA, qnrA, strA, and sulII) in E. coli strains isolated from goat feces was detected by PCR. Among them, gene blaampC was the most predominant (96.88%), followed by qnrA (68.75%). Furthermore, 81.25% of E. coli strains harbored two to five antibiotic-resistance genes, and the gene pattern of blaampC + tetA + qnrA was the most popular (21.88 %). The antibiotic resistance and harbored antibiotic resistance genes in E. coli strains isolated from goat feces increase animal and public health concerns.