Determination of SCCmec types in methicilline resistant staphylococci isolated from cows and farm workers

This study was conducted to determine staphylococcal cassette chromosome mec (SCCmec) types of methicilline resistance staphylococci isolated from cattle and humans. In the study, staphylococci from the milk (n=90) and nasal samples (n=56) of cows with subclinic mastitis, and from nasal samples (n=35) of veterinarians and farm workers were used. By using cefoxitin disc diffusion test, methicilline resistance was detected in 23.3%, 32.1% and 57.1% of milk, bovine nasal and human nasal strains, respectively. Phenotypical characteristics of these strains were confirmed by triplex PCR by means of mecA, nuc and 16S rRNA genes. Ten Staphylococcus spp. (18 S. haemolyticus, 17 S. epidermidis, 12 S. aureus, 4 S. xylosus, 3 S. cohnii, 1 S. equorum, 1 S. sciuri, 1 S. succinus, 1 S. pseudointermedius ve 1 S. saprophyticus) among 59 methicilline resistant staphylococci were identified by 16S rRNA sequence analysis. SCCmec types of these strains were investigated by multipleks PCR, for mec and ccr genes, associated IS element and plasmids. SCCmec Type II was found in 2, Type III in 38, Type IV in 18 and Type V in 1 methicilline resistant stapyhlococci. While 40 strains including Type II and III were defined as hospital-acquired, 19 strains including Type IV and V as community-acquired. SCCmec Type III and IV were found in 66.6% and 28.2% of bovine strains respectively, and in 60.0% and 35.0% of human strains. Almost all strains of S. haemolyticus and S. aureus strains carried hospital-acquired type SCCmec. The similarity of SCCmec types harboured by staphylococcus strains from cattle and human and higher prevalence of hospital-acquired SCCmec types in cattle suggested that humans may be source of methicilline resistant strains of cattle.