Drug and Heat Resistance of Escherichia Coli and Staphylococcus Aureus Isolated from Dairy Products from Lebanon

Abstract

With the ongoing economical-political crisis that Lebanon has been going through and the reflecting effect on the food security and safety sectors on one hand, and with the expansion of heat and drug-resistant bacteria worldwide on the other hand, this study aimed to examine the behavior of microorganisms isolated from Lebanese dairy products towards heat treatments and antibiotics. A sampling of various dairy products of which Halloum, Akkawi, Kashta, Karishe, and raw milk and more were gathered from different Lebanese areas to be screened for microbial contamination. Microorganisms such as Escherichia coli, Staphylococcus aureus, Salmonella were isolated from the samples, of which 38.33% were found contaminated. The isolates were tested for their heat tolerance. Salmonella isolate was sensitive to heat, however, E. coli and S. aureus isolates showed resistance with a prevalence of 68.4% and 50% respectively at 65C/30 min and 47.4% and 25% respectively at 75C/15s. Meanwhile eight E.coli and one S. aureus isolates tolerated both heating methods of 75C for 15 seconds and 65C for 30 minutes. A variety of antimicrobial agents of Amikacin (AKN30), Cefepime (FEP30), Cefuroxime, (CXM 30), Chloramphenicol (CHL30), Fosfomycin (FOS200), Gentamicin (GMN10), Levofloxacin (LVX5), Meropenem (MEM10), Nutrofurantoin (FTN300), Piperacillin + Tazobactam (TZP110), Streptomycin (SMN10), Tetracycline (TET30), Trimethoprim + sulfamethoxazole (SXT25), Amoxicillin + Clavulanic Acid (AMC30), Ciprofloxacin (CIP5), Clindamycin (CMN2), Erythromycin (ERY15) and Penicillin (PEN6) were used to test the resistance of the isolates. 52.6% of the E.coli isolates exhibited resistance to one or more antimicrobials and 21% were multidrug resistant while only one S. aureus was resistant to PEN6 and none was multidrug resistant.