Evaluation of the automated system Vitek2 for identification and antimicrobial susceptibility testing of Brazilian Gram-positive cocci strains

Brazilian Journal of Infectious Diseases

Pedro Alves D'azevedo²  Itacy Siquiera¹  Juliana Gugel¹  Ana Lúcia Souza Antunes²  Carina Secchi²  Jacyr Pasternak¹  Marinês Dalla Vale Martino¹ 

[1] ,Clinical Medical School of Porto Alegre Department of Microbiology and Parasitology Porto Alegre RS

关键词: Automated system;    Vitek2;    Gram-positive cocci;    identification;    antimicrobial susceptibility testing;   

DOI  :  10.1590/S1413-86702009000200007

来源: SciELO

【 摘 要 】

Automated instruments offer many advantages for clinical laboratories. Nevertheless, they can have problems identifying and determining susceptibilities of some pathogens. Vitek® 2 (bioMérieux) is an automated system that was recently introduced to Brazil. We evaluated the performance of this equipment for Brazilian isolates that had been characterized using reference identification and antimicrobial susceptibility testing methods. Ninety-nine strains of Gram-positive cocci from a local reference center collection were analyzed, consisting of 50 coagulasenegative Staphylococcus (CoNS) and 49 Enterococcus and related species. Vitek® 2 correctly identified 79.8% (79/99) of the isolates. Oxacillin resistance was detected in 76% (19/25) of resistant S. epidermidis strains and in 88% (22/25) of other resistant CoNS species strains. Vancomycin resistance was detected in 100% (20/20) of resistant Enterococcus and related species strains. Vitek® 2 performed very well for the identification of S. epidermidis and non-epidermidis staphylococci, and for the detection of vancomycin resistance in Enterococcus and related species. However, the system needs improvement in order to provide reliable results for the characterization of some CoNS species, identification of Enterococcus and related species and for detecting oxacillin resistance in CoNS.

【 授权许可】

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