Rapid detection of Staphylococcus aureus and mecA gene by recombinase aided amplification combined with dual nucleic acid lateral flow strips
- Author:
GUO Qingxin
;
ZHU Zonglin
;
WANG Jiawen
- Publication Type:Journal Article
- Keywords:
Staphylococcus aureus;
recombinase aided amplification;
nucleic acid lateral flow strips;
nuc gene;
mecA gene
- From:
China Tropical Medicine
2024;24(12):1465-
- CountryChina
- Language:Chinese
-
Abstract:
Objective To shorten the detection time of Staphylococcus aureus (SA), this study established a rapid detection method for the thermostable nuclease nuc gene and mecA resistance gene of SA based on recombinase aided amplification (RAA) combined with lateral flow strips (LFS). Methods Efficient RAA primers and probes were designed and screened based on the conserved sequences of the nuc gene in the SA genome and the mecA gene on the staphylococcal SCCmec removable genetic element, and then, the reaction temperature and for the simultaneous detection of nuc and mecA genes by time of RAA-LFS were verified. Sensitivity, specificity, and comparison with quantitative real-time PCR (qPCR) were also assessed. A prospective evaluation was conducted using 52 vials of non-repeat positive blood cultures from two tertiary hospitals. Results The RAA-LFS was able to amplify both nuc and mecA genes under the reaction conditions of 20-45 °C for 15-30 minutes, with a detection limit of 10² CFU/mL. A total of 50 clinically isolated non-SA strains were validated with 100% specificity for both nuc and mecA genes. Of the 30 methicillin-resistant Staphylococcus aureus (MRSA) and 30 methicillin-susceptible Staphylococcus aureus (MSSA) strains preserved in our laboratory, all were positive for the nuc gene, and 30 strains were positive for the mecA gene. The positive and negative concordance rates with qPCR were both 100%, with a consistency test Kappa value of 1. In a prospective analysis of the 52 vials of positive blood cultures, the identification and antibiotic susceptibility test results of 16 strains of MSSA and 6 strains of MRSA showed a 100% concordance rate with the results obtained using the Mérieux VITEK-2 compact microbiological detection system. Conclusions We combined nucleic acid release agents, RAA, and lateral flow strips to develop a simple, rapid, and highly sensitive assay applicable for SA and mecA resistance gene detection in colonies or positive blood culture bottles.
- Full text:20251113151122908466.Rapid detection of Staphylococcus aureus and mecA gene by recombinase aided amplification combined with dual nucleic acid lateral flow strips.pdf
