Abstract
The methods for performing anaerobic bacterial isolation and identification continue to change and improve. Anaerobic susceptibility testing has become controversial, and method-dependent variability has been noted. To assess the status of clinical anaerobic bacteriology in the United States, we surveyed, by means of a questionnaire, 120 hospitals, selected at random, with bed capacities of 200 to 1,000, and we received responses from 88 (73%). All hospitals performed cultures for anaerobes. The media and methods used for transport, initial processing, incubation, and identification varies between the different regions in the United States. Thirty percent of laboratories did not perform susceptibility studies, 16% used a reference laboratory, and 54% performed them in house. For half the laboratories, susceptibility testing was performed on isolates depending on the source; in this case, blood cultures were tested by 97% of the laboratories, serious infections were tested by 60%, sterile body sites were tested by 73%, pure cultures were tested by 47%, and tests were done by physician request by 39%. For laboratories doing testing, the broth disk method, no longer sanctioned by the National Committee for Clinical Laboratory Standards, was used most often (56%), followed by microdilution (33%), beta-lactamase testing (25%), macrotube dilution (2%), and agar dilution (2%). The antimicrobial agents tested were as follows: penicillin-ampicillin, 94%; clindamycin, 94%, metronidazole, 90%; chloramphenicol, 80%; cefoxitin, 76%; tetracyclines, 51%; and erythromycin, 45%. All other agents were tested by less than or equal to 25% of laboratories; the methods used could be improved to make the results more timely and consequently more clinically relevant.
Full text
PDF





Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Aldridge K. E., Wexler H. M., Sanders C. V., Finegold S. M. Comparison of in vitro antibiograms of Bacteroides fragilis group isolates: differences in resistance rates in two institutions because of differences in susceptibility testing methodology. Antimicrob Agents Chemother. 1990 Jan;34(1):179–181. doi: 10.1128/aac.34.1.179. [DOI] [PMC free article] [PubMed] [Google Scholar]
 - Appleman M. D., Heseltine P. N., Cherubin C. E. Epidemiology, antimicrobial susceptibility, pathogenicity, and significance of Bacteroides fragilis group organisms isolated at Los Angeles County-University of Southern California Medical Center. Rev Infect Dis. 1991 Jan-Feb;13(1):12–18. doi: 10.1093/clinids/13.1.12. [DOI] [PubMed] [Google Scholar]
 - Bourgault A. M., Harkness J. L., Rosenblatt J. E. Clinical usefulness of susceptibility testing of anaerobes. Arch Intern Med. 1978 Dec;138(12):1825–1827. [PubMed] [Google Scholar]
 - Brook I. Anaerobic bacterial bacteremia: 12-year experience in two military hospitals. J Infect Dis. 1989 Dec;160(6):1071–1075. doi: 10.1093/infdis/160.6.1071. [DOI] [PubMed] [Google Scholar]
 - Brown E. M. Lack of standardization of in-vitro susceptibility testing of the Bacteroides fragilis group to amoxycillin-clavulanic acid. J Antimicrob Chemother. 1991 Jul;28(1):147–149. doi: 10.1093/jac/28.1.147. [DOI] [PubMed] [Google Scholar]
 - Buskila D., Gladman D. Musculoskeletal manifestations of infection with human immunodeficiency virus. Rev Infect Dis. 1990 Mar-Apr;12(2):223–235. doi: 10.1093/clinids/12.2.223. [DOI] [PubMed] [Google Scholar]
 - Citron D. M., Baron E. J., Finegold S. M., Goldstein E. J. Short prereduced anaerobically sterilized (PRAS) biochemical scheme for identification of clinical isolates of bile-resistant Bacteroides species. J Clin Microbiol. 1990 Oct;28(10):2220–2223. doi: 10.1128/jcm.28.10.2220-2223.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
 - Citron D. M., Ostovari M. I., Karlsson A., Goldstein E. J. Evaluation of the E test for susceptibility testing of anaerobic bacteria. J Clin Microbiol. 1991 Oct;29(10):2197–2203. doi: 10.1128/jcm.29.10.2197-2203.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
 - Goldstein E. J., Citron D. M. Annual incidence, epidemiology, and comparative in vitro susceptibilities to cefoxitin, cefotetan, cefmetazole, and ceftizoxime of recent community-acquired isolates of the Bacteroides fragilis group. J Clin Microbiol. 1988 Nov;26(11):2361–2366. doi: 10.1128/jcm.26.11.2361-2366.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
 - Goldstein E. J., Citron D. M. Susceptibility testing of anaerobes--fact, fancy, and wishful thinking. Clin Ther. 1989 Nov-Dec;11(6):710–723. [PubMed] [Google Scholar]
 - Hanson C. W., Martin W. J. Evaluation of enrichment, storage, and age of blood agar medium in relation to its ability to support growth of anaerobic bacteria. J Clin Microbiol. 1976 Nov;4(5):394–399. doi: 10.1128/jcm.4.5.394-399.1976. [DOI] [PMC free article] [PubMed] [Google Scholar]
 - Heseltine P. N., Yellin A. E., Appleman M. D., Gill M. A., Chenella F. C., Kern J. W., Berne T. V. Perforated and gangrenous appendicitis: an analysis of antibiotic failures. J Infect Dis. 1983 Aug;148(2):322–329. doi: 10.1093/infdis/148.2.322. [DOI] [PubMed] [Google Scholar]
 - Jacobs M. R., Spangler S. K., Appelbaum P. C. Beta-lactamase production, beta-lactam sensitivity and resistance to synergy with clavulanate of 737 Bacteroides fragilis group organisms from thirty-three US centres. J Antimicrob Chemother. 1990 Sep;26(3):361–370. doi: 10.1093/jac/26.3.361. [DOI] [PubMed] [Google Scholar]
 - Mangels J. I., Douglas B. P. Comparison of four commercial brucella agar media for growth of anaerobic organisms. J Clin Microbiol. 1989 Oct;27(10):2268–2271. doi: 10.1128/jcm.27.10.2268-2271.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
 - Murray P. R. Growth of clinical isolates of anaerobic bacteria on agar media: effects of media composition, storage conditions, and reduction under anaerobic conditions. J Clin Microbiol. 1978 Dec;8(6):708–714. doi: 10.1128/jcm.8.6.708-714.1978. [DOI] [PMC free article] [PubMed] [Google Scholar]
 - Narikawa S., Suzuki T., Yamamoto M., Nakamura M. Lactate dehydrogenase activity as a cause of metronidazole resistance in Bacteroides fragilis NCTC 11295. J Antimicrob Chemother. 1991 Jul;28(1):47–53. doi: 10.1093/jac/28.1.47. [DOI] [PubMed] [Google Scholar]
 - Rosenblatt J. E., Fallon A., Finegold S. M. Comparison of methods for isolation of anaerobic bacteria from clinical specimens. Appl Microbiol. 1973 Jan;25(1):77–85. doi: 10.1128/am.25.1.77-85.1973. [DOI] [PMC free article] [PubMed] [Google Scholar]
 - Sheppard A., Cammarata C., Martin D. H. Comparison of different medium bases for the semiquantitative isolation of anaerobes from vaginal secretions. J Clin Microbiol. 1990 Mar;28(3):455–457. doi: 10.1128/jcm.28.3.455-457.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
 - Sondag J. E., Ali M., Murray P. R. Relative recovery of anaerobes on different isolation media. J Clin Microbiol. 1979 Nov;10(5):756–757. doi: 10.1128/jcm.10.5.756-757.1979. [DOI] [PMC free article] [PubMed] [Google Scholar]
 - Swenson R. M. Rationale for identification and susceptibility testing of anaerobic bacteria. Rev Infect Dis. 1986 Sep-Oct;8(5):809–813. doi: 10.1093/clinids/8.5.809. [DOI] [PubMed] [Google Scholar]
 - Wexler H. M., Finegold S. M. Antimicrobial resistance in Bacteroides. J Antimicrob Chemother. 1987 Feb;19(2):143–146. doi: 10.1093/jac/19.2.143. [DOI] [PubMed] [Google Scholar]
 - Wexler H. M. Susceptibility testing of anaerobic bacteria: myth, magic, or method? Clin Microbiol Rev. 1991 Oct;4(4):470–484. doi: 10.1128/cmr.4.4.470. [DOI] [PMC free article] [PubMed] [Google Scholar]
 
