A real-time PCR assay for direct characterization of the Neisseria gonorrhoeae GyrA 91 locus associated with ciprofloxacin susceptibility

Buckley, Cameron, Trembizki, Ella, Donovan, Basil, Chen, Marcus, Freeman, Kevin, Guy, Rebecca, Kundu, Ratan, Lahra, Monica M., Regan, David G., Smith, Helen and Whiley, David M. (2015) A real-time PCR assay for direct characterization of the Neisseria gonorrhoeae GyrA 91 locus associated with ciprofloxacin susceptibility. Journal of Antimicrobial Chemotherapy, 71 2: 353-356. doi:10.1093/jac/dkv366


Author Buckley, Cameron
Trembizki, Ella
Donovan, Basil
Chen, Marcus
Freeman, Kevin
Guy, Rebecca
Kundu, Ratan
Lahra, Monica M.
Regan, David G.
Smith, Helen
Whiley, David M.
Title A real-time PCR assay for direct characterization of the Neisseria gonorrhoeae GyrA 91 locus associated with ciprofloxacin susceptibility
Journal name Journal of Antimicrobial Chemotherapy   Check publisher's open access policy
ISSN 1460-2091
0305-7453
Publication date 2015-11-03
Year available 2015
Sub-type Article (original research)
DOI 10.1093/jac/dkv366
Open Access Status Not yet assessed
Volume 71
Issue 2
Start page 353
End page 356
Total pages 4
Place of publication Oxford, United Kingdom
Publisher Oxford University Press
Collection year 2016
Language eng
Formatted abstract
Objectives: The objective of this study was to develop a real-time PCR method for specific detection of the gonococcal GyrA amino acid 91 locus directly in clinical samples so as to predict Neisseria gonorrhoeae ciprofloxacin susceptibility.

Methods: The real-time PCR assay, GyrA91-PCR, was designed using two probes, one for detection of the WT S91 sequence and the other for detection of the S91F alteration. The performance of the assay was initially assessed using characterized N. gonorrhoeae isolates (n = 70), a panel of commensal Neisseria and Moraxella species (n = 55 isolates) and clinical samples providing negative results by a commercial N. gonorrhoeae nucleic acid amplification test (NAAT) method (n = 171). The GyrA91-PCR was then applied directly to N. gonorrhoeae NAAT-positive clinical samples (n = 210) from the year 2014 for which corresponding N. gonorrhoeae isolates with susceptibility results were also available.

Results: The GyrA91-PCR accurately characterized the GyrA 91 locus of all 70 N. gonorrhoeae isolates (sensitivity = 100%, 95% CI = 94.9%–100%), whereas all non-gonococcal isolates and N. gonorrhoeae NAAT-negative clinical samples gave negative results by the GyrA91-PCR (specificity = 100%, 95% CI = 98.4%–100%). When applied to the 210 N. gonorrhoeae NAAT-positive clinical samples, the GyrA91-PCR successfully characterized 195 samples (92.9%, 95% CI = 88.5%–95.9%). When compared with the corresponding bacterial culture results, positivity by the GyrA91-PCR WT probe correctly predicted N. gonorrhoeae susceptibility to ciprofloxacin in 161 of 162 (99.4%, 95% CI = 96.6%–99.9%) samples.

Conclusions: The use of a PCR assay for detection of mutation in gyrA applied directly to clinical samples can predict ciprofloxacin susceptibility in N. gonorrhoeae.
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: UQ Centre for Clinical Research Publications
Official 2016 Collection
Child Health Research Centre Publications
 
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Citation counts: TR Web of Science Citation Count  Cited 2 times in Thomson Reuters Web of Science Article | Citations
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Created: Tue, 17 Nov 2015, 14:36:42 EST by Ella Trembizki on behalf of UQ Centre for Clinical Research