[Rapid and accurate detection of resistant bacteria for respiratory tract infection--present situation and future]

Abstract

Respiratory tract infection (RTI) is a common and potentially life-threatening illness that continues to be a major medical problem. The rapid detection system such as Gram staining or urinary antigen detection for respiratory infection is useful. However, the genetic diagnosis for resistant pathogens has been expected because they have been prevalent. We evaluated the RQ-mPCR (real-time quantitative PCR combined with multiplex PCR) assay for drug resistant S. pneumonia infection. The RQ-mPCR method developed here had high sensitivity and specificity for pneumococci and could detect drug resistance in both clinical S. pneumoniae strains and in sputum samples. Furthermore, the results can be obtained directly from clinical samples within 3h. This method may be helpful for the rapid screening of resistance in pneumococcal isolates, and should allow the administration of earlier, more focused and effective treatment of drug-resistant S. pneumonia. We also established the rapid quantitative detection of metallo-beta-lactamase-producing P. aeruginosa in clinical isolates and samples using real-time PCR targeting gyrB (identification of P. aeruginosa) and blaIMP (identification of metallo-beta-lactamase). The present PCR assay was thus easily and quickly performed, and accurately detected Pseudomonas aeruginosa and metallo-beta-lactamase, and it should be helpful in the diagnosis and control of nosocomial infection. We expect that the genetic diagnosis will be an adjunct to, or a replacement of, conventional culture methods and susceptibility tests.