Evaluation on the capability of CHROMagar orientation medium combined with simple biochemical tests for identificaction of common oxidase-negtive gram-negative bacilli
10.3760/cma.j.issn.0254-5101.2013.07.008
- VernacularTitle:显色培养基联合简单生化试验鉴定常见氧化酶阴性革兰阴性杆菌的能力验证
- Author:
Shengyuan ZHAO
;
Yiwen CHEN
;
Linhui LI
;
Chenlu XIAO
;
Jie LI
;
Chenrong MI
;
Lizhong HAN
;
Yuxing NI
- Publication Type:Journal Article
- Keywords:
CHROMagar orientation medium;
Biochemical test;
Gram-negative bacilli;
Bacterial identification;
Proficiency testing
- From:
Chinese Journal of Microbiology and Immunology
2013;(7):525-530
- CountryChina
- Language:Chinese
-
Abstract:
Objective To evaluate the practicability of CHROMagar orientation medium combined with simple biochemical tests for identification of common oxidase-negtive gram-negative bacilli.Methods The CHROMagar orientation medium was used together with biochemical tests including indole test , ornithine decarboxylase test and lysine decarboxylase test for identification of common oxidase -negtive gram-negative bacilli.The sensitivity, specificity, likelihood ratio, Youden index and Kappa value of the diagnostic assays were evaluated .McNemar test was performed to evaluate facticity, accuracy and cost of the method in com-parison with the Vitek-2 system as reference method .Results The identification of oxidase-negtive gram-negative bacilli from 318 bacterial strains showed that the sensitivities and specificities of CHROMagar orien-tation mediumm in combination with simple biochemical tests to Serratia marcescens, Stenotrophomonas mal-tophilia and Acinetobacter baumannii reached 100%, and for Escherichia coli, Enterobacter aerogenes and Klebsiella pneumoiae were above 90%.The specificities for identification of Enterobacter cloacae, Klebsiella oxytoca, Citrobacter freundii and Proteus mirabilis were all above 90%, but the sensitivities were around 75%-90%.Kappa values of the assays were above 0.85, howerer, which was only 0.5947 for Citrobacter freundii.McNemar test showed that all P values were above 0.05, and cost of the assays was reduced by 90%.Conclusion CHROMagar orientation medium in combination with simple biochemical tests is a cost-effective assay for identification of common oxidase-negtive gram-negative bacilli .
