The aim of the study was to investigate the presence of various genes encoding resistance against tetracyclines, erythromycin, chloramphenicol and aminoglycoside antibiotics in 50 samples of raw milk from Slovenian vending machines. By using PCR method we analysed the presence of genes encoding resistance to tetracyclines (tet(A), tet(B), tet(C), tet(M), tet(O), tet(W)), erythromycin (erm(A), erm(B), erm(C)), aminoglycoside antibiotics (aac(6')-aph(2''), ant(6)-la, aph(3')-llla) and chloramphenicol (cat). The most commonly determined antibiotic resistance gene was aac(6')-aph(2''), presented in 21 samples of raw milk, followed by the remaining aminoglycoside genes, tetracyclines and erythromycin genes. However, the gene encoding resistance to chloramphenicol was not detected. In addition, we found that in PCR method, selected antibiotic resistance genes had different limits of detection and were in range between 2 x 103 to 1 x 108 CFU/mL of milk. In conclusion, raw milk from Slovenian milk vending machines contains various antibiotic resistance genes, although the prevalence is lower compared to reports from other countries in Europe and world.
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