Buckley, Cameron

Trembizki, Ella

Donovan, Basil

Chen, Marcus

Freeman, Kevin

Guy, Rebecca

Lahra, Monica M

Kundu, Ratan L

Regan, David G

Smith, Helen V

Whiley, David M

2016-11-01

The objective of this study was to develop a real-time PCR assay targeting the gonococcal porB gene (PorB-PCR) for predicting susceptibility of Neisseria gonorrhoeae to penicillin. This complements a previously described PCR assay for detecting penicillinase-producing N. gonorrhoeae (PPNG) developed by our laboratory (PPNG-PCR). The PorB-PCR assay was designed using six probes to characterize various combinations of amino acids at positions 101 and 102 of the PorB1b class protein, including the WT G101/A102 and mutant G101K/A102D, G101K/A102N and G101K/A102G sequences, as well as the PorB1a sequence. The ability of these sequences to predict penicillin susceptibility was initially assessed using 2307 N. gonorrhoeae isolates from throughout Australia for which phenotypic susceptibility data were available. The assay was then applied to N. gonorrhoeae-positive clinical specimens (n = 70). Specificity was assessed by testing commensal Neisseria strains (n = 75) and N. gonorrhoeae-negative clinical specimens (n = 171). Testing of the 2307 N. gonorrhoeae isolates using PorB-PCR to detect G101/A102 and PorB1a sequences identified a total of 78.4% (61.2% and 17.2%, respectively) of penicillin-susceptible isolates with specificities of 97.4% and 99.3% and positive predictive values of 98.8% and 98.9%, where PPNG strains were simultaneously identified and excluded. Similar performance data were obtained when the PorB-PCR assay was applied to the N. gonorrhoeae-positive clinical specimens. No false-positive results were observed for the N. gonorrhoeae-negative samples and no cross-reactions were observed with the non-gonococcal species. When used in parallel with the previously described PPNG-PCR, the PorB-PCR approach has the potential to facilitate individualized treatment of gonorrhoea using penicillin.

J Antimicrob Chemother . 2016 Nov;71(11):3090-3095. doi: 10.1093/jac/dkw291. Epub 2016 Jul 25.

https://pubmed.ncbi.nlm.nih.gov/27494921/?otool=iaurydwlib

https://hdl.handle.net/10137/5335

Anti-Bacterial Agents

Australia

Genotyping Techniques

Humans

Microbial Sensitivity Tests

Neisseria gonorrhoeae

Oligonucleotide Probes

Penicillins

Porins

Predictive Value of Tests

Real-Time Polymerase Chain Reaction

Sensitivity and Specificity

Real-time PCR detection of Neisseria gonorrhoeae susceptibility to penicillin.

Journal Article

Publication