Comparison of Supplemented Brucella Agar and Modified Clostridium difficile Agar for Antimicrobial Susceptibility Testing of Clostridium difficile
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Background: Antimicrobial susceptibility testing (AST) of Clostridium difficile is increasingly important because of the rise in resistant strains. The standard medium for the AST of C. difficile is supplemented Brucella agar (sBA), but we found that the growth of C. difficile on sBA was not optimal. Because active growth is critical for reliable AST, we developed a new, modified C. difficile (mCD) agar. C. difficile grew better on mCD agar than on sBA. Methods: C. difficile isolates were collected from patients with healthcare-associated diar- rhea. sBA medium was prepared according to the CLSI guidelines. Homemade mCD agar containing taurocholate, L-cysteine hydrochloride, and 7% horse blood was used. For 171 C. difficile isolates, we compared the agar dilution AST results from mCD agar with those from sBA. Results: No significant differences were observed in the 50% minimal inhibitory concentra- tion (MIC 50 ) and 90% minimal inhibitory concentration (MIC 90 ) of clindamycin (CLI), metro- nidazole (MTZ), moxifloxacin (MXF), piperacillin-tazobactam (PTZ), and rifaximin (RIX), but the values for vancomycin (VAN) were two-fold higher on mCD agar than on sBA. The MICs of CLI, MXF, and RIX were in 100% agreement within two-fold dilutions, but for MTZ, VAN, and PTZ, 13.7%, 0.6%, and 3.1% of the isolates, respectively, were outside the ac- ceptable range. Conclusions: The MIC ranges, MIC 50 and MIC 90 , were acceptable when AST was per- formed on mCD agar. Thus, mCD agar could be used as a substitute medium for the AST of C. difficile.
Abstract
Background: Antimicrobial susceptibility testing (AST) of Clostridium difficile is increasingly important because of the rise in resistant strains. The standard medium for the AST of C. difficile is supplemented Brucella agar (sBA), but we found that the growth of C. difficile on sBA was not optimal. Because active growth is critical for reliable AST, we developed a new, modified C. difficile (mCD) agar. C. difficile grew better on mCD agar than on sBA. Methods: C. difficile isolates were collected from patients with healthcare-associated diar- rhea. sBA medium was prepared according to the CLSI guidelines. Homemade mCD agar containing taurocholate, L-cysteine hydrochloride, and 7% horse blood was used. For 171 C. difficile isolates, we compared the agar dilution AST results from mCD agar with those from sBA. Results: No significant differences were observed in the 50% minimal inhibitory concentra- tion (MIC 50 ) and 90% minimal inhibitory concentration (MIC 90 ) of clindamycin (CLI), metro- nidazole (MTZ), moxifloxacin (MXF), piperacillin-tazobactam (PTZ), and rifaximin (RIX), but the values for vancomycin (VAN) were two-fold higher on mCD agar than on sBA. The MICs of CLI, MXF, and RIX were in 100% agreement within two-fold dilutions, but for MTZ, VAN, and PTZ, 13.7%, 0.6%, and 3.1% of the isolates, respectively, were outside the ac- ceptable range. Conclusions: The MIC ranges, MIC 50 and MIC 90 , were acceptable when AST was per- formed on mCD agar. Thus, mCD agar could be used as a substitute medium for the AST of C. difficile.
참고문헌 (25)
- Marler LM, "Comparison of five cultural procedures for isolation of Clostridium difficile from stools", J Clin Microbiol, 30, pp.514~516 (1992)
- Arroyo LG, "Use of a selective enrichment broth to recover Clostridium difficile from stool swabs stored under different conditions", J Clin Microbiol, 43, pp.5341~5343 (2005)
- Kelly CP, "Clostridium difficile —more difficult than ever", N Engl J Med, 359, pp.1932~1940 (2008)
- Pépin J, "Mortality attributable to nosocomial Clostridium difficile-associated disease during an epidemic caused by a hypervirulent strain in Quebec", CMAJ, 173, pp.1037~1042 (2005)
- McDonald LC, "An epidemic, toxin gene–variant strain of Clostridium difficile", N Engl J Med, 353, pp.2433~2441 (2005)
- Peláez T, "Reassessment of Clostridium difficile susceptibility to metronidazole and vancomycin", Antimicrob Agents Chemother, 46, pp.1647~1650 (2002)
- Huang H, "Antimicrobial resistance in Clostridium difficile", Int J Antimicrob Agents, 34, pp.516~522 (2009)
- Clinical and Laboratory Standards Institute, "Standards Institute.Methods for animicrobialsusceptibilitytesting of anaerobic bacteria; Approved Standard. 7th ed. M11-A7", Clinical and Laboratory Standards Institute, ~ (2007)
- Bliss DZ, "Comparison of cycloserine-cefoxitin-fructose agar (CCFA) and taurocholate-CCFA for recovery of Clostridium difficile during surveillance of hospitalized patients", Diagn Microbiol Infect Dis, 29, pp.1~4 (1997)
- Aspinall ST, "New selective medium for isolating Clostridium difficile from faeces", J Clin Pathol, 45, pp.812~814 (1992)
- Erikstrup LT, "Antimicrobial susceptibility testing of Clostridium difficile using EUCAST epidemiological cut-off values and disk diffusion correlates", Clin Microbiol Infect, 18, pp.266~272 (2012)
- Bland JM, "Statistics notes-Transforming data", Br Med J, 312, pp.770~ (1996)
- Davies BI, "The importance of the geometric mean MIC", J Antimicrob Chemother, 25, pp.471~472 (1990)
- Reynolds R, "BSACWorking Parties on Resistance Surveillance. Survey, laboratory and statistical methods for the BSAC Resistance Surveillance Programmes", J Antimicrob Chemother, 62(2), pp.15~28 (2008)
- 김희정, "Investigation of Toxin Gene Diversity, Molecular Epidemiology, and Antimicrobial Resistance of Clostridium difficile Isolated from 12 Hospitals in South Korea", Annals of Laboratory Medicine, 30(5), pp.491~497 (2010), 대한진단검사의학회
- Huang H, "Clostridium difficile infections in a Shanghai hospital: antimicrobial resistance, toxin profiles and ribotypes", Int J Antimicrob Agents, 33, pp.339~342 (2009)
- Hecht DW, "In vitro activities of 15 antimicrobial agents against 110 toxigenic Clostridium difficile clinical isolates collected from 1983 to 2004", Antimicrob Agents Chemother, 51, pp.2716~2719 (2007)
- European Committee on Antimicrobial Susceptibility, "Breakpoint tables for interpretation of MICs and zone diameters. Version 3.0" (2013), EUCAST
- Huang H, "Antimicrobial susceptibility and heteroresistance in Chinese Clostridium difficile strains", Anaerobe, 16, pp.633~635 (2010)
- Chen J, "Effect of temperature on the metronidazole–BSA interaction: Multi-spectroscopic method", J Mol Struct, 876, pp.121~126 (2008)
- Zietsman S, "Formulation development and stability studies of aqueous metronidazole benzoate suspensions containing various suspending agents", Drug Dev Ind Pharm, 33, pp.191~197 (2007)
- Wang DP, "Degradation kinetics of metronidazole in solution", J Pharm Sci, 82, pp.95~98 (1993)
- 강정옥, "실용적인 Helicobacter pylori 항균제감수성검사법의 확립을 위한 네 가지 검사법의 비교", Annals of Clinical Microbiology, 8(1), pp.82~89 (2005), 대한임상미생물학회
- Baines SD, "Emergence of reduced susceptibility to metronidazole in Clostridium difficile", J Antimicrob Chemother, 62, pp.1046~1052 (2008)
- Jiang ZD, "In vitro susceptibility of Clostridium difficile to rifaximin and rifampin in 359 consecutive isolates at a university hospital in Houston, Texas", J Clin Pathol, 63, pp.355~358 (2010)