PREVALENCE AND ANTIBIOTIC RESISTANCE OF BACILLUS STRAINS ISOLATED FROM VARIOUS FOOD STUFFS.

Abstract

The present study was aimed to explore the prevalence of Bacillus spp. in some commonly offered foodstuffs and to assess the antibiotic resistance and susceptibility profile of these isolated bacterial contaminants. A total of fifty-seven food samples were collected comprising of different types of foods from street vendors, restaurants, kitchens, ready-to-eat packed foods and mid-day meals from different locations of NCR and Delhi, India. These samples were subjected to the isolation of Bacillus strains. Various biochemical analysis were done for the identification of Bacillus spp. Out of fifty-seven samples evaluated, twenty-six morphologically distinct isolates were obtained.  All the bacterial isolates were then evaluated for their antibiotic resistance and sensitivity against twenty commonly prescribed and commercially available antibiotics. A greater degree of variability was observed in resistance profile of isolated Bacillus strains. Some of the isolates were found to be 100% susceptible against a few of antibiotics such as ciprofloxacin, gentamycin, meropenem, doxycycline, leavofloxacin and gatifloxacin. Out of the selected antibiotics, some of them were observed to have moderate-to-severe antibacterial effectiveness against the isolated Bacillus strains. Only one species of Bacillus was found to have maximum MAR value i.e. 0.55; however, the least resistance was found in two isolates. Other organisms were found to be fragile within the range of 0.15 to 0.45 showing the variable sensitivities against the antibiotics used in the study.

KEYWORDS: Foodstuffs, Bacillus, Antibiotic, Resistance, Susceptibility, MAR Index