Detection of bla KPC and bla NDM genes by duplex PCR with lateral flow dipsticks from sterile body fluid samples

Duplex polymerase chain reaction with lateral flow dipsticks (duplex PCR-LFD) was developed for the simultaneous detection of beta-lactamase Klebsiella pneumoniae carbapenemase (bla ) and beta-lactamase New Dehli metallo-beta-lactamase (bla ) genes in body fluid samples. This method was validated using well-characterized isolates. The assessment of the specificity of duplex PCR-LFD showed that there was no cross-reactivity with other targets. The detection limit of the duplex PCR-LFD assay was 20 CFU per ml for bla and bla . Among 177 sterile body fluid samples tested by the duplex PCR-LFD assay, 40 were bla -positive and five were bla -positive. The results obtained from 122 corresponding Gram-negative bacteria which were isolated from these clinical samples and tested by duplex PCR-LFD assay showed that there were 37 strains carrying bla genes in 40 bla -positive samples and three strains carrying bla genes in five bla -positive samples. Statistical analysis indicated that there was no significant difference between the direct detection of bla and bla genes in clinical sterile body fluid samples and their corresponding clinical isolates. Therefore, duplex PCR-LFD can be effective for the simultaneous detection of bla and bla in clinical isolates and directly from clinical samples, which may be helpful for the administration of appropriate antimicrobial treatment.