Evaluation of commercial systems VITEK 2 and API 20NE for identification of Burkholderia cepacia complex bacteria from clinical samples

Abstract

Species belonging to the Burkholderia cepacia complex (BCC) are capable of causing chronic respiratory tract infections in patients suffering from cystic fibrosis as well as in immunocompromised individuals. Most of these species are highly resistant to antibiotic therapy, generating the need for their rapid and accurate detection for the proper treatment and clinical management of these patients. In this work, the polymerase chain reaction (PCR) technique based on the amplification of the recA gene (PCR-recA) was applied for an accurate identification of bacteria belonging to the BCC. Sensitivity (S) and specificity (E) of two biochemically-based commercial automated systems, API 20NE and VITEK 2 (bioMérieux®), and of the most representative biochemical manual tests for the identification of the Burkholderia cepacia complex were herein evaluated. The commercial systems VITEK 2 and API 20NE showed the following sensitivity and specificity vaues for identification to the species level, S: 71.1 %, E: 100 %, S: 69.7 %, E: 90.2 %, respectively. More complex results were observed for phenotypic manual tests, since BCC bacteria can undergo selective pressure to survive in chronic patients causing the loss of their typical phenotypic characteristics. The PCR-recA technique was easy to implement even in medium-complexity clinical diagnostic laboratories.