Objective: To analyze the antimicrobial susceptibility of lactic acid bacteria (LAB) from yogurt, and to provide references for evaluating the safety of LAB and screening safe strains.
Methods: The sensitivity of 43 LAB strains, including 14 strains of Streptococcus thermophilus, 12 strains of Lactobacillus acidophilus, 9 strains of Lactobacillus bulgaricus and 8 strains of Bifidobacterium, to 22 antibiotics were tested by agar plate dilution method.
Results: All 43 LAB strains were resistant to trimethoprim, nalidixic acid, ciprofloxacin, lomefloxacin, danofloxacin and polymyxin E. Their resistances to kanamycin, tetracycline, clindamycin, doxycycline and cephalothin were varied. The sensitivity to other antibiotics were sensitive or moderate. All isolates were multidrug-resistant.
Conclusion: The antimicrobial resistance of tested LAB strains was comparatively serious, and continuously monitoring their antimicrobial resistance and evaluating their safety should be strengthened.