Abstract
Clostridium ramosum, C. innocuum, and C. clostridioforme are frequently isolated from clinical specimens including blood. Because of Gram stain variability, a lack of spores, and atypical colonial morphology, identification of these species is often difficult. Three anaerobe identification kits were evaluated for their abilities to identify these species. For comparison, 11 strains of C. perfringens were evaluated in parallel. By using profile numbers and codebooks, the correct genus and species were identified, as follows: with the RapID ANA II kit, 100% (20 of 20) of C. ramosum isolates, 24% (5 of 21) of C. innocuum isolates, and 50% (10 of 20) of C. clostridioforme isolates; with the AnIDent kit, 60% (12 of 20) of C. ramosum isolates, 28% (6 of 21) of C. innocuum isolates, and 90% (18 of 20) of C. clostridioforme isolates; with the ATB32A kit, 70% (14 of 20) of C. ramosum isolates, 0% (0 of 21) of C. innocuum isolates, and 40% (8 of 20) of C. clostridioforme isolates. Profile numbers that overlapped several species were obtained as follows: with the RapID ANA II kit, 0% of C. ramosum isolates, 76% of C. innocuum isolates, and 40% of C. clostridioforme isolates; with the AnIDent kit 40% of C. ramosum isolates, 62% of C. innocuum isolates, and 5% of C. clostridioforme isolates; with the ATB32A kit, 15% of C. ramosum isolates, 52% of C. innocuum isolates, and 25% of C. clostridioforme isolates. One strain of C. innocuum was misidentified by the AnIDent kit, and the remainder yielded profile numbers that were not listed in the codebooks. The MICs of 11 antimicrobial agents including penicillin G, metronidazole, clindamycin, cefoxitin, cefotetan, imipenem, meropenem, amoxicillin-clavulanate, ampicillin-sulbactam, piperacillin-tazobactam, and vancomycin were determined by the agar dilution method. All C. perfringens strains were susceptible to all antimicrobial agents tested. Various levels of resistance to cefoxitin, cefotetan, and penicillin G were noted with C. ramosum, C. clostridioforme, and C. innocuum. In addition, resistance to clindamycin was noted with C. ramosum (5%) and C. innocuum (10%). Most strains of C. innocuum were only moderately susceptible to vancomycin (MIC at which 90% of strains are inhibited, 4 micrograms/ml).
Full Text
The Full Text of this article is available as a PDF (203.0 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Appelbaum P. C., Kaufmann C. S., Depenbusch J. W. Accuracy and reproducibility of a four-hour method for anaerobe identification. J Clin Microbiol. 1985 Jun;21(6):894–898. doi: 10.1128/jcm.21.6.894-898.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bourgault A. M., Harding G. K., Smith J. A., Horsman G. B., Marrie T. J., Lamothe F. Survey of anaerobic susceptibility patterns in Canada. Antimicrob Agents Chemother. 1986 Nov;30(5):798–801. doi: 10.1128/aac.30.5.798. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Burlage R. S., Ellner P. D. Comparison of the PRAS II, AN-Ident, and RapID-ANA systems for identification of anaerobic bacteria. J Clin Microbiol. 1985 Jul;22(1):32–35. doi: 10.1128/jcm.22.1.32-35.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Celig D. M., Schreckenberger P. C. Clinical evaluation of the RapID-ANA II panel for identification of anaerobic bacteria. J Clin Microbiol. 1991 Mar;29(3):457–462. doi: 10.1128/jcm.29.3.457-462.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Goldstein E. J., Citron D. M., Cherubin C. E., Hillier S. L. Comparative susceptibility of the Bacteroides fragilis group species and other anaerobic bacteria to meropenem, imipenem, piperacillin, cefoxitin, ampicillin/sulbactam, clindamycin and metronidazole. J Antimicrob Chemother. 1993 Mar;31(3):363–372. doi: 10.1093/jac/31.3.363. [DOI] [PubMed] [Google Scholar]
- Kitch T. T., Appelbaum P. C. Accuracy and reproducibility of the 4-hour ATB 32A method for anaerobe identification. J Clin Microbiol. 1989 Nov;27(11):2509–2513. doi: 10.1128/jcm.27.11.2509-2513.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Looney W. J., Gallusser A. J., Modde H. K. Evaluation of the ATB 32 A system for identification of anaerobic bacteria isolated from clinical specimens. J Clin Microbiol. 1990 Jul;28(7):1519–1524. doi: 10.1128/jcm.28.7.1519-1524.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Marler L. M., Siders J. A., Wolters L. C., Pettigrew Y., Skitt B. L., Allen S. D. Evaluation of the new RapID-ANA II system for the identification of clinical anaerobic isolates. J Clin Microbiol. 1991 May;29(5):874–878. doi: 10.1128/jcm.29.5.874-878.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rotimi V. O., Faulkner J., Duerden B. I. Rapid methods for identification of clinical isolates of Gram-negative anaerobic bacilli. Med Lab Sci. 1980 Oct;37(4):331–339. [PubMed] [Google Scholar]
- Spangler S. K., Jacobs M. R., Appelbaum P. C. Activity of WY-49605 compared with those of amoxicillin, amoxicillin-clavulanate, imipenem, ciprofloxacin, cefaclor, cefpodoxime, cefuroxime, clindamycin, and metronidazole against 384 anaerobic bacteria. Antimicrob Agents Chemother. 1994 Nov;38(11):2599–2604. doi: 10.1128/aac.38.11.2599. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sutter V. L., Finegold S. M. Susceptibility of anaerobic bacteria to 23 antimicrobial agents. Antimicrob Agents Chemother. 1976 Oct;10(4):736–752. doi: 10.1128/aac.10.4.736. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Zabransky R. J., Birk R. J. Comparative activity of several beta-lactam antibiotics against anaerobes determined by two methods. Clin Ther. 1987;10(1):107–125. [PubMed] [Google Scholar]