Rapid Detection of Pathogens and Resistance Genes Grown in Blood Cultures with Two Multiplex Tandem Real-Time PCR Kits.

Abstract

Objective: In this study, two multiplex tandem real-time PCR kits were used to rapidly diagnose common Gram-positive cocci and Gram-negative bacilli, detect their commonly seen antibiotic resistance genes, and evaluate the two kits' performance.

Materials and methods: Gram-positive 12 (GP-12) kit (AusDiagnostics, Australia) and Gram-negative 12 (GN-12) kit (AusDiagnostics, Australia) were used in the study. Seventy-eight Gram-negative bacilli and 54 Gram-positive cocci grown in blood culture vials were applied to GN-12 and GP-12 panels. At the same time, the passages of the samples were made and incubated. After that, identification and antibiograms were made in the Phoenix™ automated system (Becton, Dickinson and Company, USA) and VITEK 2 Compact automated system (bioMérieux, France).

Results: Twenty-one Staphylococcus aureus, twelve coagulase-negative staphylococci (CoNS), two Streptococcus pneumoniae, two Enterococcus faecium, and three Enterococcus faecalis were found to match the results from the automated GP-12 Kit. Pathogens present in the panel were successfully identified using the GN-12 kit. Both panels were found to be more effective in diagnosing polymicrobial infections.

Conclusion: These evaluated kits were rapid (approximately three hours) and valuable in identifying common sepsis pathogens and resistance genes. Thus, these tests can easily be used in the diagnosis of sepsis.