Evaluation of the Etest for antimicrobial spectrum and potency determinations of anaerobes associated with bacterial vaginosis and peritonitis.
One hundred ninety-seven anaerobic organisms (24 Gardnerella vaginalis, 16 Mobiluncus spp., 19 Peptostreptococcus spp., 20 Lactobacillus spp., 20 Prevotella bivia/disiens, 81 Bacteroides fragilis group, 12 Clostridium spp., and five Fusobacterium spp.) were processed by the Etest (AB Biodisk, Solna, Sweden) and a reference (Brucella blood agar) method against 10 antimicrobial agents. For the bacterial vaginosis-associated pathogens, the Etest was more reproducible and correlated acceptably with the reference agar test: within +/- 1 log2 dilution for 74.4% of Mobiluncus spp. to 96.0% for Peptostreptococcus spp. (all organisms, 83.4%). The quantitative correlation +/- 2 log2 dilution steps between test results was 94.3%. Results with B. fragilis group strains demonstrated 97.3% correlation (+/- 2 log2 dilution) with a trend toward slightly lower Etest minimum inhibitory concentrations for ampicillin-sulbactam, cefotaxime, imipenem, and clindamycin. The absolute qualitative interpretive agreement between Etest and the reference agar dilution method results was 94.4%, with only a 0.4% false-susceptible error rate. The Etest appears to be a very practical, quantitatively accurate, alternative procedure for clinical microbiology laboratories routinely testing the susceptibilities of anaerobes and, by these presented data, organisms associated with female tract infections.
Croco
J L
JL
Department of Pathology, University of Iowa College of Medicine, Iowa City 52242.
Erwin
M E
ME
Jennings
J M
JM
Putnam
L R
LR
Jones
R N
RN
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001421:Bacteria, Anaerobic / Q000145:classification / Q000187:drug effects* / Q000302:isolation & purification; D001424:Bacterial Infections / Q000175:diagnosis / Q000382:microbiology*; D001431:Bacteriological Techniques; D005260:Female; D006801:Humans; D008826:Microbial Sensitivity Tests; D010538:Peritonitis / Q000175:diagnosis / Q000382:microbiology*; D012044:Regression Analysis; D012680:Sensitivity and Specificity; D014627:Vaginitis / Q000175:diagnosis / Q000382:microbiology*
D000900:Anti-Bacterial Agents