Antimicrobial effectiveness of wild-type Bacillus spp compared to Bacillus subtilis ATCC 6051 against Escherichia coli isolated from bovine mastitis

Bovine mastitis, a condition significantly impacting dairy production, represents a significant source of spread for antimicrobial-resistant bacterial agents. This study evaluated the antimicrobial effectiveness of two strains of Bacillus, Bacillus subtilis ATCC 6051 and wild-type Bacillus spp., against Escherichia coli, the causative agent of bovine mastitis. Using the agar well diffusion method and considering variables such as the type of Bacillus and the pathogenic bacteria, the results indicated that Bacillus subtilis ATCC 6051, through direct diffusion, exhibited an average inhibition zone of 16.60 mm against E. coli, surpassing the filtrate diffusion method. In comparison, wild-type Bacillus spp. showed lower inhibition measures. The growth curve revealed that Bacillus subtilis ATCC 6051 has a more significant growth capacity in the exponential phase, attributable to differences in metabolic capacity. In conclusion, Bacillus subtilis ATCC 6051 demonstrated remarkable antimicrobial capacity against the studied pathogen, suggesting its potential application in bovine mastitis control.