Antibiotic susceptibility profile of probiotic bacillus subtilis species

Abstract

The study aims to determine the antibiotic tolerance patterns of Bacillus subtilis isolates extracted from local broiler chicken intestines and determine their suitability as probiotics. A study isolated Bacillus subtilis from broiler chickens' intestinal walls following organic food consumption. The identification process included morphological evaluation and biochemical tests for strain recognition, while antibiotic susceptibility testing was done through the disk diffusion method. The bacterial species were identified through PCR testing of the bsub and RecA genes, and sequence confirmation was followed by amplification. The Bacillus subtilis isolate showed susceptibility against multiple antibiotics, including trimethoprim-sulfa, kanamycin, ciprofloxacin, gentamycin, penicillin, and erythromycin. The bacterial strain demonstrated resistance to oxytetracycline, colistin sulfate, cefotaxime with clavulanic acid and ampicillin. The analysis of RecA genetic material led to the identification of Bacillus subtilis at a molecular level.