Ella Trembizki1, Christine Doyle2, Cameron Buckley1, Amy Jennison2, Helen Smith2, John Bates2, Theo Sloots1, Michael Nissen1, Monica M Lahra3, David Whiley1. 1. Queensland Paediatric Infectious Diseases Laboratory, Queensland Children's Health Services, Block 28, Royal Children's Hospital, Herston Road, Herston, Qld 4029, Australia. 2. Public Health Microbiology, Queensland Health Forensic and Scientific Services, Archerfield, Qld 4108, Australia. 3. WHO Collaborating Centre for STD, Microbiology Department, South Eastern Area Laboratory Services, Prince of Wales Hospital, Sydney, NSW 2031, Australia.
Abstract
UNLABELLED: Background Mixed gonococcal infections within the one anatomical site have been recognised but questions remain over how often they occur. In this study, the aim was to estimate the prevalence of mixed gonococcal infections using novel real-time polymerase chain reaction (PCR) methods that were developed and validated, targeting the gonococcal porB gene. METHODS: Neisseria gonorrhoeae strains were categorised into three different porB groups, based on sequence data derived from N. gonorrhoeae multi-antigen sequence typing (NG-MAST) analyses of local isolates. Specific PCR methods for each group were then developed and these PCR methods were used to test clinical samples (n=350) that were positive for gonorrhoea as determined by nucleic acid amplification test (NAAT) diagnostic screening. RESULTS: Initial validation using isolates showed the group PCR methods proved 100% sensitive and 100% specific for their respective porB groups. When applied to the clinical specimens, 298/350 (85%) provided positive results by the group PCR methods. Of these, four specimens showed evidence of mixed infections, supported by subsequent DNA sequencing of the PCR products. CONCLUSIONS: The data provide further evidence of mixed gonococcal infections at the same anatomical site, but show that such infections may be relatively infrequent (1.3%; 95% confidence interval 0.01-2.6%) in a general screening population.
UNLABELLED: Background Mixed gonococcal infections within the one anatomical site have been recognised but questions remain over how often they occur. In this study, the aim was to estimate the prevalence of mixed gonococcal infections using novel real-time polymerase chain reaction (PCR) methods that were developed and validated, targeting the gonococcal porB gene. METHODS:Neisseria gonorrhoeae strains were categorised into three different porB groups, based on sequence data derived from N. gonorrhoeae multi-antigen sequence typing (NG-MAST) analyses of local isolates. Specific PCR methods for each group were then developed and these PCR methods were used to test clinical samples (n=350) that were positive for gonorrhoea as determined by nucleic acid amplification test (NAAT) diagnostic screening. RESULTS: Initial validation using isolates showed the group PCR methods proved 100% sensitive and 100% specific for their respective porB groups. When applied to the clinical specimens, 298/350 (85%) provided positive results by the group PCR methods. Of these, four specimens showed evidence of mixed infections, supported by subsequent DNA sequencing of the PCR products. CONCLUSIONS: The data provide further evidence of mixed gonococcal infections at the same anatomical site, but show that such infections may be relatively infrequent (1.3%; 95% confidence interval 0.01-2.6%) in a general screening population.
Authors: Jesse C Thomas; Sandra Seby; A Jeanine Abrams; Jack Cartee; Sean Lucking; Eshaw Vidyaprakash; Matthew Schmerer; Cau D Pham; Jaeyoung Hong; Elizabeth Torrone; Sancta St Cyr; William M Shafer; Kyle Bernstein; Ellen N Kersh; Kim M Gernert Journal: J Infect Dis Date: 2019-06-19 Impact factor: 5.226
Authors: C R Robert George; Rodney P Enriquez; Barrie J Gatus; David M Whiley; Ying-Ru Lo; Naoko Ishikawa; Teodora Wi; Monica M Lahra Journal: PLoS One Date: 2019-04-03 Impact factor: 3.240