Eighteen Bifidobacterium strains were tested for their susceptibility to a
range of antimicrobial agents. All the strains tested, including the refere
nce culture Lactobacillus acidophilus CH2, were susceptible to several grou
ps of antimicrobial agents, they were cephalosporin (cefamandole, cefazolin
, cefaperazone, cefoxitin), polypeptide (bacitracin), macrolide (erythromyc
in), penicillin (amoxicillin), phenicol (chloramphenicol) and beta-lactam (
imipenem). Fourteen strains were resistant to more than 10 antibiotics. The
reference culture was resistant to only three antibiotics. The results sho
wed that bifidobacteria are resistant to a wide range of antimicrobial agen
ts.