INCEDENCE of THERMODURIC ANTIMICROBIAL-RESISTANT Bacillus and Enterococcus SPECIES in SOME DAIRY PRODUCTS

Abstract

Thermoduric bacteria can survive pasteurization and subsequently grow in pasteurized or in contaminated products. Hazards associated with these organisms vary from health to spoil-age issues. This study aimed to determine the microbial load, species identification, and antimi-crobial resistance profile of some thermoduric bacillus and enterococcus isolates. Samples of raw, pasteurized and UHT milk, Ras cheese, and dairy desserts were collected and tested for the presence of antimicrobial-resistant Bacillus and Enterococcus species, which were identified us-ing the Vitek 2 system. The most predominated strains were B. subtilis and E. faecium (100%, each). Different antimicrobial resistance patterns were observed. Antimicrobial resistance rate of B. subtilis was 100% to cefepime, ampicillins, oxacillin, amoxicillin/Clavulanic acid, vancomycin and chloramphenicol. Antimicrobial resistance of E. faecium was 100% to clindamycin. Multi-drug-resistance (MDR) was observed in B. subtilis (25%) and E. faecium (12%) isolates. The most common antibiotic resistance patterns observed in B. subtilis isolates were AMP/CLI/AMC/VAN and FEP/OXA/CHL (12.25% each), while the most common antimicrobial resistance patterns ob-served in E. faecium isolates were GHL/CLI/DOX and SHL/CLI/TET (6% each). Accordingly, strict hygienic measures should be applied and followed during manufacture of heat treated dairy products to avoid contamination with those antimicrobial-resistant potential pathogens.