Antimicrobial susceptibility of bifidobacteria.
The antimicrobial susceptibility of 37 strains of bifidobacteria to 18 antimicrobial agents was determined by a macrodilution broth method. Most of the strains used were isolated from commercial yogurts and starters. Tested organisms were usually sensitive to Gram-positive spectrum antibiotics (bacitracin, erythromycin, lincomycin, and vancomycin), and most of the organisms were inhibited by a concentration < 1.56 micrograms/ml. Erythromycin was the most active agent; all strains were inhibited by < .19 microgram/ml. beta-Lactam antibiotics (penicillin G, ampicillin, methicillin, and cephalothin), showing a wide range of minimum inhibitory concentration, were less effective than Gram-positive spectrum antibiotics. Most strains were somewhat resistant to cephalothin, exhibiting inhibition at concentrations of 6.25 to 25.0 micrograms/ml. Test organisms were most resistant to kanamycin, neomycin, paromomycin sulfate, nalidixic acid, and polymyxin B sulfate; inhibition occurred only at > or = 50 micrograms/ml, and strains were somewhat less resistant to gentamicin and streptomycin. Susceptibility to nitrofurantoin and tetracycline was variable; minimum inhibitory concentrations ranged from 1.56 to 50.0 and .39 to 50.0 micrograms/ml, respectively, but chloramphenicol had a narrow range from 1.56 to 6.25 micrograms/ml.
Lim
K S
KS
Laboratory of Biochemistry, Hankuk Yakult Institute, Euiwang-si, Kyunggi-do, Korea.
Huh
C S
CS
Baek
Y J
YJ
D000617:Aminoglycosides; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001644:Bifidobacterium / Q000187:drug effects*; D004352:Drug Resistance, Microbial; D004917:Erythromycin / Q000494:pharmacology; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects; D007769:Lactams; D008826:Microbial Sensitivity Tests
D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D007769:Lactams; D004917:Erythromycin