Antibiotic Resistance Pattern of Escherichia coli Isolated from Layer Chicken in Bali-Indonesia

Antibiotics have been used as growth promoters in the poultry industry worldwide, which might lead to the emergence of anti-microbial resistant bacterial strains. Theoretically, older animals should have been exposed to antibiotics and anti-microbial resistant (AMR) strains for longer periods, which may result in the discovery of more resistant strains. The present study aimed to evaluate the antibiotic resistance of Escherichia coli isolated from fecal samples of layer chicken that showed signs of watery diarrhea. In the current study, 134 fecal samples were taken from the layer chicken farms in Penebel village, Tabanan District, Bali, Indonesia. The chickens were classified into three groups including Group 1 under 7 days of age, group 2 aged 7-30 days, and Group 3 chickens older than one month. The samples were cultured in Eosin Methylene Blue agar. The suspected colonies were stained, and subjected to biochemical tests. Escherichia coli-positive colonies were subjected to a bacteria sensitivity test using multiple antibiotic discs. The result demonstrated multi-drug resistance (MDR) of Escherichia coli, while the isolated Escherichia coli was resistant to the most common antibiotics in layer farms in the study area including kanamycin, enrofloxacin, sulfamethoxazole-trimethoprim, streptomycin, and enrofloxacin. In addition, the present study confirmed that although all sample groups were sensitive to bacitracin, oxytetracycline, and clindamycin, they were resistant to sulfamethoxazole-trimethoprim, kanamycin, and ampicillin.