Determination of Staphylococcus spp. isolation, identification and antibiotic sensitivity from raw milk

In this study, it was aimed to isolate/identify staphylococci species from raw cow milk sold in Hatay province, to determine the susceptibility of isolates to antibiotics and the mechanisms mediating resistance. For this, 120 raw cow's milk was examined for staphylococcus. In this context, 110 (91,6%) Staphylococcus spp. were isolated from 120 raw cow milk samples. By Polymerase Chain Reaction (PZR) performed with species-specific primers, 54 (49,1%) of isolates were defined Stapylococcus epidermidis, 19 (17,2%) S. sciuri, 17 (15,4%) S. aureus, 6 (5,4%) S. simulans, 6 (5,4%) S. saprophyticus, 4 (3,6%) S. chromogenes, 2 (1,8%) S. xylosis, 1 (0,9%) S. haemolyticus, 1 (0,9%) S. arlettae. While all of the isolates were sensitive to vancomycin; 58,1% (n:64) ampicillin, 56,3% (n:62) penicillin, 23,6% (n:26) cefoxitin, 12,7% (n:14) trimethoprim-sulfamethoxazole, 12,7% (n:14) amoxycillin, 11,8% (n:13) tetracycline, 10% (n:11) gentamicin, 9% (n:10) clindamycin, 4,5% (n:5) erythromycin, 1,8% (n:2) chloramphenicol, 0,9% (n:1) rifampine, 0,9% (n:1) found resistant to ciprofloxacin. The blaZ gene was found in 33 of the penicillin-resistant isolates, and the methicillin-resistance gene mecA was detected in 13 isolates. In erythromycin resistant isolates, ermB+ermC resistance genes were detected for 1 isolate and ermC was detected in 1 isolate. Among the tetracycline resistance genes, tetK was detected in 6 and tetM in 3 isolates. The genes responsible for aminoglycoside resistance were detected ant(4')-la in 1 isolates, aph(3')-IIIa in 1 isolates, aac(6')-aph (2'') in 2 isolates, aac (6')-aph(2'')+ aph(3')-IIIa in 2 isolates and aac(6')-aph(2'')+ aph(3')-IIIa+ ant(4')-la combination in 1 isolate. In this thesis, it has been shown that raw cow milk is an important source of antibiotic resistance genes among staphylococcal isolates. Horizontal transfer of these genes to other bacteria is hazardous for public health. For this, antibiotic resistance surveillance of microorganisms in all kinds of raw milk is important.