Antibiotic Resistance and Plasmid DNA Contents of Streptococcus thermophilus Strains Isolated from Turkish Yogurts

Authors : Belma ASLIM, Yavuz BEYATLI

Pages : 257-263

View : 18 | Download : 7

Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :Thirty-four Streptococcus thermophilus strains were isolated from yogurt samples obtained from various villages in different regions of Turkey. These strains were examined for their antibiotic resistance patterns and plasmid carriage. The susceptibility of the isolates to 8 antibiotics insert ignore into journalissuearticles values(vancomycin, tetracycline, chloramphenicol, erythromycin, cephalothin, ampicillin-sulbactam, gentamicin and penicillin G); was determined by the disk diffusion method. Most strains of S. thermophilus were resistant to gentamicin insert ignore into journalissuearticles values(79%); and penicillin G insert ignore into journalissuearticles values(64%); and susceptible to chloramphenicol insert ignore into journalissuearticles values(94%); and tetracycline insert ignore into journalissuearticles values(88%);. In plasmid DNA analyses, it was determined that 7 strains did not contain any plasmid DNA, while other strains included plasmid DNA ranging from 1 to 5. The molecular weights of these plasmids were found to be in various sizes from 1.88 to 19.89 kb. An interaction was observed between the resistance to antibiotics and the occurrence of plasmids in some S. thermophilus strains; for instance, some strains carrying only one or no plasmid were observed to be susceptible to most antibiotics. The resistance to most antibiotics was determined in 3 strains insert ignore into journalissuearticles values(B55.S, B56.S, B58.S); containing 5 plasmid DNAs. However, no correlation was observed between the resistance to antibiotics and the occurrence of plasmids in some strains.
Keywords : Streptococcus thermophilus, plasmid DNA, antibiotic resistance