Abstract
AIMS: To compare CCFA (cycloserine, cefoxitin fructose agar) with a new selective medium CDMN (containing cysteine hydrochloride, norfloxacin, and moxalactam) for the isolation of Clostridium difficile after direct faecal culture. METHODS: The minimum inhibitory concentration (MIC) of norfloxacin was determined for 64 strains of C difficile, 17 strains of other Clostridium sp, and 66 various isolates of faecal origin, together with MIC determinations of moxalactam against the 81 strains of Clostridium sp and 15 isolates of Bacteroides sp. Using C difficile agar base with 0.5 g/l of cysteine hydrochloride, norfloxacin and moxalactam were incorporated into the medium and compared with CCFA for the isolation of C difficile after direct faecal culture. RESULTS: Norfloxacin (12 mg/l) inhibited the growth of enterobacteriaceae and faecal streptococci; moxalactam (32 mg/l) inhibited the growth of most strains of Bacteroides sp tested, together with Clostridium sp other than C difficile. Using the antibiotics in combination (CDMN), the growth and colonial morphology of 64 strains of C difficile were unaffected. When CDMN medium was compared with CCFA for the isolation of C difficile from 832 faeces from inpatients with diarrhoea, the CDMN agar isolated 20% more strains and reduced the number of contaminating colonies by 30%. CONCLUSIONS: CDMN both improves the isolation rate of C difficile from faecal specimens and reduces the growth of other organisms compared with CCFA.
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Selected References
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- Finegold S. M. Anaerobic infections and Clostridium difficile colitis emerging during antibacterial therapy. Scand J Infect Dis Suppl. 1986;49:160–164. [PubMed] [Google Scholar]
- George W. L., Rolfe R. D., Finegold S. M. Clostridium difficile and its cytotoxin in feces of patients with antimicrobial agent-associated diarrhea and miscellaneous conditions. J Clin Microbiol. 1982 Jun;15(6):1049–1053. doi: 10.1128/jcm.15.6.1049-1053.1982. [DOI] [PMC free article] [PubMed] [Google Scholar]
- George W. L., Sutter V. L., Citron D., Finegold S. M. Selective and differential medium for isolation of Clostridium difficile. J Clin Microbiol. 1979 Feb;9(2):214–219. doi: 10.1128/jcm.9.2.214-219.1979. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Head C. B., Ratnam S. Comparison of API ZYM system with API AN-Ident, API 20A, Minitek Anaerobe II, and RapID-ANA systems for identification of Clostridium difficile. J Clin Microbiol. 1988 Jan;26(1):144–146. doi: 10.1128/jcm.26.1.144-146.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Levett P. N. Effect of antibiotic concentration in a selective medium on the isolation of Clostridium difficile from faecal specimens. J Clin Pathol. 1985 Feb;38(2):233–234. doi: 10.1136/jcp.38.2.233. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Levett P. N. Identification of Clostridium difficile using the API ZYM system. Eur J Clin Microbiol. 1985 Oct;4(5):505–507. doi: 10.1007/BF02014434. [DOI] [PubMed] [Google Scholar]
- Lyerly D. M., Krivan H. C., Wilkins T. D. Clostridium difficile: its disease and toxins. Clin Microbiol Rev. 1988 Jan;1(1):1–18. doi: 10.1128/cmr.1.1.1. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Phillips K. D., Rogers P. A. Rapid detection and presumptive identification of Clostridium difficile by p-cresol production on a selective medium. J Clin Pathol. 1981 Jun;34(6):642–644. doi: 10.1136/jcp.34.6.642. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Willey S. H., Bartlett J. G. Cultures for Clostridium difficile in stools containing a cytotoxin neutralized by Clostridium sordellii antitoxin. J Clin Microbiol. 1979 Dec;10(6):880–884. doi: 10.1128/jcm.10.6.880-884.1979. [DOI] [PMC free article] [PubMed] [Google Scholar]