Increase in the activity of third-generation cephalosporins in combination with clavulanic acid and Sulbactam against Bacteroides fragilis.
We studied the sensitivity of 160 strains of Bacteroides fragilis (74 beta-lactamase-positive and 86 beta-lactamase-negative) to four third-generation cephalosporins, alone as well as in combination with clavulanic acid and Sulbactam. For susceptibility testing we used a dilution method in agar. Detection of beta-lactamase production by this micro-organism was performed using chromogenic cephalosporin (Nitrocefin). There was a substantial improvement in cephalosporin activity with both positive and negative strains when they were combined with the inhibitors, although this was more significant in beta-lactamase-producing organisms. Generally, the results achieved in combination with clavulanic acid were better than those with Sulbactam, the highest increase in activity being obtained with Ceftizoxime in combination with any one of the inhibitors.
Department of Microbiology, University School of Medicine and Dentistry, Granada, Spain.
M A
MA
Martín
A M
AM
Castillo
J
J
Liebana
P
P
Mesa
G
G
Piedrola
J
J
Gutierrez
D001441:Bacteroides fragilis / Q000187:drug effects*; D002511:Cephalosporins / Q000008:administration & dosage*; D002969:Clavulanic Acids / Q000008:administration & dosage*; D004359:Drug Therapy, Combination / Q000008:administration & dosage; D008826:Microbial Sensitivity Tests; D013407:Sulbactam / Q000008:administration & dosage*
D002511:Cephalosporins; D002969:Clavulanic Acids; D013407:Sulbactam