Study on antibiotic resistance of Streptococcus thermophilus

The antibiotic sensitivity of Streptococcus thermophilus( KLDS3.1012,KLDS3.1014,KLDS- SM,KLDS3.0206,KLDS3.0207) to 15 kinds of antibiotics was tested with agar disc diffusion method.The results showed KLDS3.1014 was resistant to 2 kinds of antibiotics,KLDS3.1012、KLDS- SM、KLDS3.0206 were resistant to 3 kinds of antibiotics respectively,and only KLDS3.0207 was resistant to more than 3 kinds of antibiotics. The genes( tet M,tet K,tet L and tet S) related to tetracycline resistance,genes( erm A,erm B,msr A / B) related to erythromycin resistance and gene( cat) related to chloramphenicol resistance were discussed. However,the genes were not found in the genomic DNA of strains above,besides,all the testing strains had no plasmid. It may preliminarily determined that the testing strains have no transferability of common antibiotic resistance genes.