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Pryce TM, Foti OR, Haygarth EJ, Whiley DM. Maximizing the Neisseria gonorrhoeae confirmatory rate and the genotypic detection of ciprofloxacin resistance for samples screened with cobas CT/NG. J Clin Microbiol 2024; 62:e0103923. [PMID: 38084950 PMCID: PMC10793287 DOI: 10.1128/jcm.01039-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 10/27/2023] [Indexed: 01/18/2024] Open
Abstract
Supplementary nucleic acid amplification testing for Neisseria gonorrhoeae (NG) is widely used to circumvent specificity problems associated with extragenital sites. Here, we compared different supplementary approaches for confirming NG-positive samples from the cobas 4800 CT/NG (c4800) and cobas 6800 CT/NG (c6800) assays using the ResistancePlusGC (RP-GC) assay, which in addition to detecting NG, also predicts ciprofloxacin susceptibility via NG gyrA characterization. Two different nucleic acid extraction techniques were investigated for RP-GC detection; extracts from c4800 (c4800-RP-GC) and MagNA Pure 96 (MP96-RP-GC). NG-positive (n = 300) and -negative (n = 150) samples in cobas PCR media from routine c4800 testing were retrospectively retested with c4800, c6800, c4800-RP-GC, and MP96-RP-GC. Selected samples were also tested with Xpert CT/NG (Xpert) for discrepant analysis. The gyrA status was compared to ETEST ciprofloxacin susceptibility or non-susceptibility for recovered isolates (n = 63). Extragenital confirmatory rates were higher for MP96-RP-GC (131/140; 93.6%) compared to c4800-RP-GC (126/146; 86.3%), albeit not significantly (P = 0.6677). Of 9 samples testing positive by c6800 and negative by MP96-RP-GC, 7/9 (77.8%) were also negative by Xpert. By contrast, the number of samples returning a valid gyrA status was significantly (P = 0.0003) higher for MP96-RP-GC (270/293; 92.2%) compared to c4800-RP-GC (245/298; 82.2%). The overall MP96-RP-GC gyrA status correlated 98.4% (61/62) with the reported ciprofloxacin sensitive (35/36; 97.2%) or non-susceptible (26/26; 100%) phenotype. Improved RP-GC confirmatory rates and reported gyrA status were observed using MP96 nucleic acids compared to c4800 extracts. The data further highlight the ongoing need for NG supplemental testing for oropharyngeal samples.
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Affiliation(s)
- Todd M. Pryce
- Department of Clinical Microbiology, PathWest Laboratory Medicine WA, Fiona Stanley Hospital, Murdoch, Western Australia, Australia
| | - Olivia R. Foti
- Department of Clinical Microbiology, PathWest Laboratory Medicine WA, Fiona Stanley Hospital, Murdoch, Western Australia, Australia
| | - Erin J. Haygarth
- Department of Clinical Microbiology, PathWest Laboratory Medicine WA, Fiona Stanley Hospital, Murdoch, Western Australia, Australia
| | - David M. Whiley
- Centre for Clinical Research, The University of Queensland, Brisbane, Queensland, Australia
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Cornelissen CN. Subversion of nutritional immunity by the pathogenic Neisseriae. Pathog Dis 2018; 76:4553517. [PMID: 29045638 PMCID: PMC6251569 DOI: 10.1093/femspd/ftx112] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 10/12/2017] [Indexed: 12/21/2022] Open
Abstract
The pathogenic Neisseria species, including Neisseria meningitidis and Neisseria gonorrhoeae, are obligate human pathogens that cause significant morbidity and mortality. The success of these pathogens, with regard to causing disease in humans, is inextricably linked to their ability to acquire necessary nutrients in the hostile environment of the host. Humans deploy a significant arsenal of weaponry to defend against bacterial pathogens, not least of which are the metal-sequestering proteins that entrap and withhold transition metals, including iron, zinc and manganese, from invaders. This review will discuss the general strategies that bacteria employ to overcome these metal-sequestering attempts by the host, and then will focus on the relatively uncommon 'metal piracy' approaches utilized by the pathogenic Neisseria for this purpose. Because acquiring metals from the environment is critical to microbial survival, interfering with this process could impede growth and therefore disease initiation or progression. This review will also discuss how interfering with metal uptake by the pathogenic Neisseriae could be deployed in the development of novel or improved preventative or therapeutic measures against these important pathogens.
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Affiliation(s)
- Cynthia Nau Cornelissen
- Department of Microbiology and Immunology, Virginia Commonwealth University School of Medicine, Box 980678, Richmond, VA 23298-0678, USA
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Kandler JL, Acevedo RV, Dickinson MK, Cash DR, Shafer WM, Cornelissen CN. The genes that encode the gonococcal transferrin binding proteins, TbpB and TbpA, are differentially regulated by MisR under iron-replete and iron-depleted conditions. Mol Microbiol 2016; 102:137-51. [PMID: 27353397 DOI: 10.1111/mmi.13450] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 06/20/2016] [Accepted: 06/22/2016] [Indexed: 01/01/2023]
Abstract
Neisseria gonorrhoeae produces two transferrin binding proteins, TbpA and TbpB, which together enable efficient iron transport from human transferrin. We demonstrate that expression of the tbp genes is controlled by MisR, a response regulator in the two-component regulatory system that also includes the sensor kinase MisS. The tbp genes were up-regulated in the misR mutant under iron-replete conditions but were conversely down-regulated in the misR mutant under iron-depleted conditions. The misR mutant was capable of transferrin-iron uptake at only 50% of wild-type levels, consistent with decreased tbp expression. We demonstrate that phosphorylated MisR specifically binds to the tbpBA promoter and that MisR interacts with five regions upstream of the tbpB start codon. These analyses confirm that MisR directly regulates tbpBA expression. The MisR binding sites in the gonococcus are only partially conserved in Neisseria meningitidis, which may explain why tbpBA was not MisR-regulated in previous studies using this related pathogen. This is the first report of a trans-acting protein factor other than Fur that can directly contribute to gonococcal tbpBA regulation.
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Affiliation(s)
- Justin L Kandler
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia
| | - Rosuany Vélez Acevedo
- Department of Microbiology and Immunology, Virginia Commonwealth University Health System, Richmond, Virginia
| | - Mary Kathryne Dickinson
- Department of Microbiology and Immunology, Virginia Commonwealth University Health System, Richmond, Virginia
| | - Devin R Cash
- Department of Microbiology and Immunology, Virginia Commonwealth University Health System, Richmond, Virginia
| | - William M Shafer
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia.,Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, Georgia.,Department of Veterans Affairs Medical Center, Laboratories of Microbial Pathogenesis, Decatur, Georgia
| | - Cynthia Nau Cornelissen
- Department of Microbiology and Immunology, Virginia Commonwealth University Health System, Richmond, Virginia.
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Pond MJ, Hall CL, Miari VF, Cole M, Laing KG, Jagatia H, Harding-Esch E, Monahan IM, Planche T, Hinds J, Ison CA, Chisholm S, Butcher PD, Sadiq ST. Accurate detection of Neisseria gonorrhoeae ciprofloxacin susceptibility directly from genital and extragenital clinical samples: towards genotype-guided antimicrobial therapy. J Antimicrob Chemother 2016; 71:897-902. [PMID: 26817487 PMCID: PMC4790619 DOI: 10.1093/jac/dkv432] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Accepted: 11/12/2015] [Indexed: 11/13/2022] Open
Abstract
INTRODUCTION Increasing use of nucleic acid amplification tests (NAATs) as the primary means of diagnosing gonococcal infection has resulted in diminished availability of Neisseria gonorrhoeae antimicrobial susceptibility data. We conducted a prospective diagnostic assessment of a real-time PCR assay (NGSNP) enabling direct detection of gonococcal ciprofloxacin susceptibility from a range of clinical sample types. METHODS NGSNP, designed to discriminate an SNP associated with ciprofloxacin resistance within the N. gonorrhoeae genome, was validated using a characterized panel of geographically diverse isolates (n = 90) and evaluated to predict ciprofloxacin susceptibility directly on N. gonorrhoeae-positive NAAT lysates derived from genital (n = 174) and non-genital (n = 116) samples (n = 290), from 222 culture-confirmed clinical episodes of gonococcal infection. RESULTS NGSNP correctly genotyped all phenotypically susceptible (n = 49) and resistant (n = 41) panel isolates. Ciprofloxacin-resistant N. gonorrhoeae was responsible for infection in 29.7% (n = 66) of clinical episodes evaluated. Compared with phenotypic susceptibility testing, NGSNP demonstrated sensitivity and specificity of 95.8% (95% CI 91.5%-98.3%) and 100% (95% CI 94.7%-100%), respectively, for detecting ciprofloxacin-susceptible N. gonorrhoeae, with a positive predictive value of 100% (95% CI 97.7%-100%). Applied to urogenital (n = 164), rectal (n = 40) and pharyngeal samples alone (n = 30), positive predictive values were 100% (95% CI 96.8%-100%), 100% (95% CI 87.2%-100%) and 100% (95% CI 82.4%-100%), respectively. CONCLUSIONS Genotypic prediction of N. gonorrhoeae ciprofloxacin susceptibility directly from clinical samples was highly accurate and, in the absence of culture, will facilitate use of tailored therapy for gonococcal infection, sparing use of current empirical treatment regimens and enhancing acquisition of susceptibility data for surveillance.
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Affiliation(s)
- Marcus J Pond
- Institute for Infection and Immunity, St George's, University of London, London, UK
| | - Catherine L Hall
- Institute for Infection and Immunity, St George's, University of London, London, UK
| | - Victoria F Miari
- Institute for Infection and Immunity, St George's, University of London, London, UK
| | - Michelle Cole
- Sexually Transmitted Bacteria Reference Unit, Public Health England, Colindale, London, UK
| | - Ken G Laing
- Institute for Infection and Immunity, St George's, University of London, London, UK
| | - Heena Jagatia
- Institute for Infection and Immunity, St George's, University of London, London, UK
| | - Emma Harding-Esch
- Institute for Infection and Immunity, St George's, University of London, London, UK Department of STI/HIV, Public Health England, Colindale, London, UK
| | - Irene M Monahan
- Institute for Infection and Immunity, St George's, University of London, London, UK
| | - Timothy Planche
- Institute for Infection and Immunity, St George's, University of London, London, UK Medical Microbiology, South West London Pathology, St George's University Hospitals NHS Foundation Trust, London, UK
| | - Jason Hinds
- Institute for Infection and Immunity, St George's, University of London, London, UK
| | - Catherine A Ison
- Sexually Transmitted Bacteria Reference Unit, Public Health England, Colindale, London, UK
| | - Stephanie Chisholm
- Sexually Transmitted Bacteria Reference Unit, Public Health England, Colindale, London, UK
| | - Philip D Butcher
- Institute for Infection and Immunity, St George's, University of London, London, UK
| | - Syed Tariq Sadiq
- Institute for Infection and Immunity, St George's, University of London, London, UK Department of Genitourinary & HIV Medicine, St George's University Hospitals NHS Foundation Trust, London, UK Department of STI/HIV, Public Health England, Colindale, London, UK
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Unemo M, Golparian D, Shafer WM. Challenges with gonorrhea in the era of multi-drug and extensively drug resistance - are we on the right track? Expert Rev Anti Infect Ther 2014; 12:653-6. [PMID: 24702589 DOI: 10.1586/14787210.2014.906902] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Neisseria gonorrhoeae has retained antimicrobial resistance to drugs previously recommended for first-line empiric treatment of gonorrhea, and resistance to ceftriaxone, the last option for monotherapy, is evolving. Crucial actions to combat this developing situation include implementing response plans; considering use of dual antimicrobial regimens; enhancing surveillance of gonorrhea, gonococcal antimicrobial resistance, treatment failures and antimicrobial use/misuse and improving prevention, early diagnosis, contact tracing and treatment. The ways forward also include an intensified research to identify novel antimicrobial resistance determinants and develop and evaluate appropriate use of molecular antimicrobial resistance testing, ideally point-of-care and with simultaneous detection of gonococci, to supplement culture-based methods and ideally guide tailored treatment. It is crucial with an enhanced understanding of the dynamics of the national and international emergence, transmission and evolution of antimicrobial-resistant gonococcal strains. Genome sequencing combined with epidemiological metadata will detail these issues and might also revolutionize the molecular antimicrobial resistance testing. Ultimately, novel antimicrobials are essential and some antimicrobials in development have shown potent in vitro activity against gonococci. Several of these antimicrobials deserve further attention for potential future treatment of gonorrhea.
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Affiliation(s)
- Magnus Unemo
- WHO Collaborating Centre for Gonorrhoea and other Sexually Transmitted Infections, National Reference Laboratory for Pathogenic Neisseria, Department of Laboratory Medicine, Microbiology, Örebro University Hospital, Örebro, Sweden
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