Usefulness of a Chromogenic Selective Agar for the Identification of Bacillus cereus Isolated from Blood Cultures.
10.3343/kjlm.2010.30.4.394
- Author:
Eun Sun JEONG
1
;
Jong Hee SHIN
;
Myung Geun SHIN
;
Soon Pal SUH
;
Dong Wook RYANG
Author Information
1. Department of Laboratory Medicine, Chonnam National University Medical School, Gwangju, Korea. shinjh@chonnam.ac.kr
- Publication Type:Original Article ; English Abstract ; Research Support, Non-U.S. Gov't
- Keywords:
Bacillus cereus;
Chromogenic agar;
API 50CH/B system;
Identification
- MeSH:
Adolescent;
Adult;
Agar/chemistry;
Aged;
Bacillus cereus/*isolation & purification;
Bacteremia/*diagnosis/microbiology;
Child;
Child, Preschool;
Chromogenic Compounds/*chemistry;
Culture Media;
Female;
Gram-Positive Bacterial Infections/*diagnosis/microbiology;
Humans;
Infant;
Infant, Newborn;
Male;
Middle Aged;
Reagent Kits, Diagnostic;
Sensitivity and Specificity
- From:The Korean Journal of Laboratory Medicine
2010;30(4):394-399
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
BACKGROUND: The incidence of Bacillus cereus bacteremia is increasing, but the identification of Bacillus species remains difficult. Brilliance Bacillus cereus agar (BBC agar; Oxoid, UK) is a new CHROMagar medium that allows selective isolation and identification of B. cereus; however, its clinical usefulness is seldom studied. We evaluated the usefulness of BBC agar to identify B. cereus isolates recovered from blood cultures. METHODS: We analyzed a total of 53 blood isolates that showed a Bacillus-like morphology on Gram staining. All isolates were identified by using both the API Coryne (bioMerieux, France) and API 50CH/B (bioMerieux) systems. They were subsequently subcultured on BBC agar, incubated for 24 hr, and then examined for characteristic blue-green colonies. The clinical characteristics of patients whose isolates were identified as B. cereus were assessed. RESULTS: Of the 53 isolates, 18 were identified as B. cereus by API 50CH/B. With the API 50CH/B system used as gold standard, the sensitivity and specificity for the identification of B. cereus were 100% (18/18) and 100% (35/35), respectively, using BBC agar, and 67% (12/18) and 100% (35/35), respectively, using the API Coryne system. Of the 18 patients with B. cereus bacteremia, 15 showed infectious signs, and 3 had more than 2 blood cultures positive for B. cereus on separate days. CONCLUSIONS: Our study shows, for the first time, that BBC agar, with its good agreement and ease of use, is a valuable alternative to the API 50CH/B system for the presumptive identification of B. cereus isolates from blood cultures.
