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Culture-Independent Genotyping Improves Surveillance of Neisseria gonorrhoeae, Especially in Oropharyngeal Samples, the Netherlands, 2017 to 2018. Pathogens 2022; 11:pathogens11111344. [DOI: 10.3390/pathogens11111344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 10/28/2022] [Accepted: 11/10/2022] [Indexed: 11/16/2022] Open
Abstract
It is important i to monitor the transmission and antimicrobial resistance of Neisseria gonorrhoeae (NG). Current surveillance relies on culturing, which frequently fails. Previously, a culture-independent genotyping method was developed based on NG multi-antigen sequence typing (NG-MAST). To determine whether crucial sequence types (STs) are missed during culture-dependent surveillance, NG-positive NAAT samples were genotyped, and the results of the culture-positive and culture-negative samples were compared. In total, 196 NG-positive NAAT samples, from January 2017 until August 2018, which were also routinely cultured, were retrospectively included. Genotyping was successful in 152 NAAT samples (77.0%), 33 NAAT samples failed, and 11 NAAT samples showed possible mixed strain infections. Oropharyngeal samples (n = 16) showed the largest increase in typing rate from 6.3% (1/16) success in culture-dependent genotyping to 81.3% (13/16) in culture-independent genotyping. Nine genogroups (n ≥ 5 samples) were found; all included both culture-positive and culture-negative NG. However, culture-independent surveillance revealed 14 additional STs in the culture-negative samples. Overall, culture-dependent surveillance could detect all genogroups, indicating that major trends could be identified with culture-dependent surveillance. However, culture-independent surveillance provides more STs, mixed infections and more oropharyngeal samples, giving a more detailed view and could result in an earlier detection of outbreaks and transmission.
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Carter E, Davis SA, Hill DJ. Rapid Detection of Neisseria gonorrhoeae Genomic DNA Using Gold Nanoprobes Which Target the Gonococcal DNA Uptake Sequence. Front Cell Infect Microbiol 2022; 12:920447. [PMID: 35873173 PMCID: PMC9304934 DOI: 10.3389/fcimb.2022.920447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 06/10/2022] [Indexed: 11/13/2022] Open
Abstract
The rapid spread of antimicrobial resistant Neisseria gonorrhoeae continues to pose a serious threat to global health. To successfully treat and control gonococcal infections, rapid diagnosis is critical. Currently, nucleic acid amplification tests are the recommended diagnostic, however, these are both technically demanding and time consuming, making them unsuitable for resource-poor clinics. Consequently, there is a substantial need for an affordable, point-of-care diagnostic to use in these settings. In this study, DNA-functionalised gold nanoparticles (gold nanoprobes), with the ability to specifically detect the DNA Uptake Sequence (DUS) of Neisseria gonorrhoeae, were prepared. Using complementary annealing, the gold nanoprobes were shown to hybridise to genomic gonococcal DNA, causing a significant shift in their salt stability. By exploiting the shift in nanoprobe stability under the presence of target DNA, a solution-based colorimetric diagnostic for gonococcal DNA was prepared. Detection of purified genomic DNA was achieved in under 30 minutes, with a detection limit of 15.0 ng. Significantly, testing with DNA extracted from an off-target control organism suggested specificity for Neisseria. These results highlight the potential of DUS-specific gold nanoprobes in the rapid point-of-care diagnosis of gonococcal infections.
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Affiliation(s)
- Ella Carter
- School of Chemistry, University of Bristol, Bristol, United Kingdom
- Bristol Centre for Functional Nanomaterials, University of Bristol, Bristol, United Kingdom
| | - Sean A. Davis
- School of Chemistry, University of Bristol, Bristol, United Kingdom
- *Correspondence: Darryl Hill, ; Sean Davis,
| | - Darryl J. Hill
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, United Kingdom
- *Correspondence: Darryl Hill, ; Sean Davis,
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In Vitro Analysis of Matched Isolates from Localized and Disseminated Gonococcal Infections Suggests That Opa Expression Impacts Clinical Outcome. Pathogens 2022; 11:pathogens11020217. [PMID: 35215160 PMCID: PMC8880309 DOI: 10.3390/pathogens11020217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 02/04/2022] [Accepted: 02/05/2022] [Indexed: 12/04/2022] Open
Abstract
Gonorrhea is the second most common sexually transmitted infection, which is primarily localized but can be disseminated systemically. The mechanisms by which a localized infection becomes a disseminated infection are unknown. We used five pairs of Neisseria gonorrhoeae isolates from the cervix/urethra (localized) and the blood (disseminated) of patients with disseminated gonococcal infection to examine the mechanisms that confine gonococci to the genital tract or enable them to disseminate to the blood. Multilocus sequence analysis found that the local and disseminated isolates from the same patients were isogenic. When culturing in vitro, disseminated isolates aggregated significantly less and transmigrated across a polarized epithelial monolayer more efficiently than localized isolates. While localized cervical isolates transmigrated across epithelial monolayers inefficiently, those transmigrated bacteria self-aggregated less and transmigrated more than cervical isolates but comparably to disseminating isolates. The local cervical isolates recruited the host receptors of gonococcal Opa proteins carcinoembryonic antigen-related cell adhesion molecules (CEACAMs) on epithelial cells. However, the transmigrated cervical isolate and the disseminated blood isolates recruit CEACAMs significantly less often. Our results collectively suggest that switching off the expression of CEACAM-binding Opa(s), which reduces self-aggregation, promotes gonococcal dissemination.
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The Frequency of Discordant Gyrase A Genotypes Among Cases of Multiple Neisseria gonorrhoeae Infections at Different Anatomic Sites. Sex Transm Dis 2020; 46:e3-e4. [PMID: 30216232 DOI: 10.1097/olq.0000000000000912] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Gyrase A genotyping reliably predicts Neisseria gonorrhoeae susceptibility to ciprofloxacin. It is unknown whether concurrent infections at different anatomic sites harbor different susceptibility profiles. We found a 3.2% frequency of discordant gyrase A genotypes among concurrent but anatomically separate N. gonorrhoeae infections diagnosed at 2 laboratories in Los Angeles.
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Molecular Antimicrobial Resistance of Neisseria gonorrhoeae in a Moroccan Area. Infect Dis Obstet Gynecol 2018; 2018:7263849. [PMID: 30584266 PMCID: PMC6280242 DOI: 10.1155/2018/7263849] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 10/24/2018] [Accepted: 11/11/2018] [Indexed: 12/02/2022] Open
Abstract
Objectives To identify the prevalence and the types of Neisseria gonorrhoeae (NG) resistance plasmids-mediated penicillin (PPNG) and tetracycline (TRNG), the ciprofloxacin resistance (CRNG), and related risk factors of each types of resistance. Methods The beta-lactamase-producing plasmid types (Africa, Asia, and Toronto), tetM tetracycline resistance plasmid types (America and Dutch), and the determination of the Ser-91 mutation of GyrA were detected by specifics PCRs on 149 diagnosed NG positives samples followed by Hinf1 digestion for tetM and gyrA mutation. Results 135 (90.1%) samples showed a profile of molecular resistance to at least one antibiotic with predominance of ciprofloxacin resistance. In fact, 36 (24.2%) and 69 (46.3%) cases harbored PPNG and TRNG, respectively, and 116 (77.9%) cases showed the mutation Ser-91 of GyrA (CRNG). From a total of 36 PPNG isolates, the Toronto, Asian, and Toronto/Asian types were detected in 13 (36.1%), 10 (27.8%), and 13 (36.1%) cases, respectively, whereas the African type was not detected. In addition, the American type of TRNG was detected in 92.8% (64/69) of cases, while the Dutch type was detected in 7.2% (5/69) of cases. The association of demographics and clinical variables with NG resistance to ciprofloxacin, penicillin, and tetracycline was studied and the risk factors have been determined. Conclusion Resistance to penicillin, tetracycline, and ciprofloxacin among NG samples positives remained at high levels in Morocco as determined by molecular profile. So, the use of molecular tools for NG antimicrobial resistance detection can help in the management and spread limitation of this infection.
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Mortimer TD, Grad YH. Applications of genomics to slow the spread of multidrug-resistant Neisseria gonorrhoeae. Ann N Y Acad Sci 2018; 1435:93-109. [PMID: 29876934 DOI: 10.1111/nyas.13871] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 05/07/2018] [Indexed: 01/05/2023]
Abstract
Infections with Neisseria gonorrhoeae, a sexually transmitted pathogen that causes urethritis, cervicitis, and more severe complications, are increasing. Gonorrhea is typically treated with antibiotics; however, N. gonorrhoeae has rapidly acquired resistance to many antibiotic classes, and lineages with reduced susceptibility to the currently recommended therapies are emerging worldwide. In this review, we discuss the contributions of whole genome sequencing (WGS) to our understanding of resistant N. gonorrhoeae. Genomics has illuminated the evolutionary origins and population structure of N. gonorrhoeae and the magnitude of horizontal gene transfer within and between Neisseria species. WGS can be used to predict the susceptibility of N. gonorrhoeae based on known resistance determinants, track the spread of these determinants throughout the N. gonorrhoeae population, and identify novel loci contributing to resistance. WGS has also allowed more detailed epidemiological analysis of transmission of N. gonorrhoeae between individuals and populations than previously used typing methods. Ongoing N. gonorrhoeae genomics will complement other laboratory techniques to understand the biology and evolution of the pathogen, improve diagnostics and treatment in the clinic, and inform public health policies to limit the impact of antibiotic resistance.
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Affiliation(s)
- Tatum D Mortimer
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, Massachusetts
| | - Yonatan H Grad
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, Massachusetts.,Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
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Hui BB, Whiley DM, Donovan B, Law MG, Regan DG. Identifying factors that lead to the persistence of imported gonorrhoeae strains: a modelling study. Sex Transm Infect 2016; 93:221-225. [PMID: 28432206 DOI: 10.1136/sextrans-2016-052738] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 09/15/2016] [Accepted: 09/29/2016] [Indexed: 11/03/2022] Open
Abstract
OBJECTIVE The importation of Neisseria gonorrhoeae (NG) strains from overseas is believed to be the main source of antimicrobial resistance in Australia. With recent sporadic cases of ceftriaxone-resistant gonorrhoea reported in Australia and elsewhere, we sought to model the potential for imported NG strains to persist in the men who have sex with men (MSM) population in Australia. METHODS We developed an individual-based model to simulate the transmission of NG in a population of urban MSM, and used this model to investigate factors contributing to the probability that an imported NG strain will persist. RESULTS The probability of the imported NG strain persisting as the result of a single importation event is less than 1%, but the probability increases to 1% if the imported NG strain is resistant to treatment, and further increases to 3.1% if the imported NG strain can also form mixed infections with the local NG strain. The probability of the imported NG strain persisting increases to 4.4% if there are at least three importation events per month within a 1-year period. CONCLUSION The imported NG strain is unlikely to persist as a result of a single importation event. However, the probability of persistence increases if the imported NG strain is resistant to treatment, can form mixed infections with the local NG strain or there are frequent importation events. Identification of the factors that determine the likelihood of persistence of an imported NG strain could contribute to our capacity to respond appropriately and in a timely fashion.
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Affiliation(s)
- Ben B Hui
- The Kirby Institute, UNSW Australia, Sydney, New South Wales, Australia
| | - David M Whiley
- University of Queensland Centre for Clinical Research, University of Queensland, Brisbane, Queensland, Australia
| | - Basil Donovan
- The Kirby Institute, UNSW Australia, Sydney, New South Wales, Australia.,Sydney Sexual Health Centre, Sydney Hospital, Sydney, New South Wales, Australia
| | - Matthew G Law
- The Kirby Institute, UNSW Australia, Sydney, New South Wales, Australia
| | - David G Regan
- The Kirby Institute, UNSW Australia, Sydney, New South Wales, Australia
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Goire N, Kundu R, Trembizki E, Buckley C, Hogan TR, Lewis DA, Branley JM, Whiley DM, Lahra MM. Mixed gonococcal infections in a high-risk population, Sydney, Australia 2015: implications for antimicrobial resistance surveillance? J Antimicrob Chemother 2016; 72:407-409. [PMID: 27707989 DOI: 10.1093/jac/dkw406] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 08/24/2016] [Accepted: 08/26/2016] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES Previous studies have shown that mixed-strain gonococcal infections can occur. However, it remains unclear whether such infections impact upon the reliability of Neisseria gonorrhoeae antimicrobial resistance (AMR) surveillance. In this study, we aimed to resolve this question by intensively sampling isolates from gonorrhoea-positive specimens in a high-risk population in Sydney, Australia. METHODS A total of 615 N. gonorrhoeae isolates, originating from 63 clinical samples (31 rectal swabs and 32 throat swabs), were characterized. All isolates were subject to N. gonorrhoeae identification, antimicrobial susceptibility testing and genotyping by SNP-based MLST. RESULTS Only 2 of the 63 (3.2%) samples provided evidence of mixed-strain infections. These comprised two rectal swabs that harboured isolates of different SNP-based MLST genotypes; however, the AMR susceptibility profiles of the different genotypes from these samples were indistinguishable. Within-sample differences in the AMR susceptibility profiles were observed for a further seven samples; however, the differences were not considered significant; MIC values were typically within a 2-fold difference or were close to test breakpoints. CONCLUSIONS Results of this study provide further evidence that mixed-strain gonococcal infections do occur, although at low prevalence. Our data indicate that at a population level such infections are unlikely to impact significantly upon N. gonorrhoeae AMR surveillance.
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Affiliation(s)
- Namraj Goire
- WHO Collaborating Centre for Sexually Transmitted Diseases, Sydney, Department of Microbiology, South Eastern Area Laboratory Services, Prince of Wales Hospital, Randwick, New South Wales 2031, Australia .,Sydney Medical School Nepean, The University of Sydney, Nepean Hospital, Penrith, New South Wales 2747, Australia
| | - Ratan Kundu
- WHO Collaborating Centre for Sexually Transmitted Diseases, Sydney, Department of Microbiology, South Eastern Area Laboratory Services, Prince of Wales Hospital, Randwick, New South Wales 2031, Australia
| | - Ella Trembizki
- The University of Queensland Centre for Clinical Research, Royal Brisbane and Women's Hospital Campus, Herston, Queensland 4029, Australia
| | - Cameron Buckley
- The University of Queensland Centre for Clinical Research, Royal Brisbane and Women's Hospital Campus, Herston, Queensland 4029, Australia
| | - Tiffany R Hogan
- WHO Collaborating Centre for Sexually Transmitted Diseases, Sydney, Department of Microbiology, South Eastern Area Laboratory Services, Prince of Wales Hospital, Randwick, New South Wales 2031, Australia
| | - David A Lewis
- Western Sydney Sexual Health Centre, Parramatta, New South Wales 2150, Australia.,Marie Bashir Institute for Infectious Diseases and Biosecurity & Sydney Medical School-Westmead, University of Sydney, New South Wales 2006, Australia
| | - James M Branley
- Sydney Medical School Nepean, The University of Sydney, Nepean Hospital, Penrith, New South Wales 2747, Australia
| | - David M Whiley
- The University of Queensland Centre for Clinical Research, Royal Brisbane and Women's Hospital Campus, Herston, Queensland 4029, Australia.,Pathology Queensland Central Laboratory, Brisbane, Queensland 4029, Australia
| | - Monica M Lahra
- WHO Collaborating Centre for Sexually Transmitted Diseases, Sydney, Department of Microbiology, South Eastern Area Laboratory Services, Prince of Wales Hospital, Randwick, New South Wales 2031, Australia.,School of Medical Sciences, Faculty of Medicine, The University of New South Wales, Kensington, New South Wales 2033, Australia
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Fingerhuth SM, Bonhoeffer S, Low N, Althaus CL. Antibiotic-Resistant Neisseria gonorrhoeae Spread Faster with More Treatment, Not More Sexual Partners. PLoS Pathog 2016; 12:e1005611. [PMID: 27196299 PMCID: PMC4872991 DOI: 10.1371/journal.ppat.1005611] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 04/12/2016] [Indexed: 11/18/2022] Open
Abstract
The sexually transmitted bacterium Neisseria gonorrhoeae has developed resistance to all antibiotic classes that have been used for treatment and strains resistant to multiple antibiotic classes have evolved. In many countries, there is only one antibiotic remaining for empirical N. gonorrhoeae treatment, and antibiotic management to counteract resistance spread is urgently needed. Understanding dynamics and drivers of resistance spread can provide an improved rationale for antibiotic management. In our study, we first used antibiotic resistance surveillance data to estimate the rates at which antibiotic-resistant N. gonorrhoeae spread in two host populations, heterosexual men (HetM) and men who have sex with men (MSM). We found higher rates of spread for MSM (0.86 to 2.38 y−1, mean doubling time: 6 months) compared to HetM (0.24 to 0.86 y−1, mean doubling time: 16 months). We then developed a dynamic transmission model to reproduce the observed dynamics of N. gonorrhoeae transmission in populations of heterosexual men and women (HMW) and MSM. We parameterized the model using sexual behavior data and calibrated it to N. gonorrhoeae prevalence and incidence data. In the model, antibiotic-resistant N. gonorrhoeae spread with a median rate of 0.88 y−1 in HMW and 3.12 y−1 in MSM. These rates correspond to median doubling times of 9 (HMW) and 3 (MSM) months. Assuming no fitness costs, the model shows the difference in the host population’s treatment rate rather than the difference in the number of sexual partners explains the differential spread of resistance. As higher treatment rates result in faster spread of antibiotic resistance, treatment recommendations for N. gonorrhoeae should carefully balance prevention of infection and avoidance of resistance spread. More and more infectious disease treatments fail because the causative pathogens are resistant to the drugs used for treatment. For the treatment of Neisseria gonorrhoeae, a sexually transmitted bacterium, drug resistance is a particularly big problem: there is only a single antibiotic left that is recommended for treatment. We aimed to understand how antibiotic-resistant N. gonorrhoeae spread in a sexually active host population and how the spread of resistance can be slowed. From antibiotic resistance surveillance data, we first estimated the rate at which antibiotic-resistant N. gonorrhoeae spread. Second, we reproduced the observed dynamics in a mathematical model describing the transmission between hosts. We found that antibiotic-resistant N. gonorrhoeae spread faster in host populations of men who have sex with men than in host populations of heterosexuals. We could attribute the faster spread of resistant pathogens to higher treatment rates. This finding implies that promoting screening to control antibiotic-resistant N. gonorrhoeae could in fact accelerate their spread.
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Affiliation(s)
- Stephanie M. Fingerhuth
- Institute of Integrative Biology, ETH Zurich, Zurich, Switzerland
- Institute of Social and Preventive Medicine (ISPM), University of Bern, Bern, Switzerland
- * E-mail:
| | | | - Nicola Low
- Institute of Social and Preventive Medicine (ISPM), University of Bern, Bern, Switzerland
| | - Christian L. Althaus
- Institute of Social and Preventive Medicine (ISPM), University of Bern, Bern, Switzerland
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10
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Abstract
The genus Neisseria contains two pathogenic species of prominant public health concern: Neisseria gonorrhoeae and Neisseria meningitidis. These pathogens display a notable ability to undergo frequent programmed recombination events. The recombination-mediated pathways of transformation and pilin antigenic variation in the Neisseria are well-studied systems that are critical for pathogenesis. Here we will detail the conserved and unique aspects of transformation and antigenic variation in the Neisseria. Transformation will be followed from initial DNA binding through recombination into the genome with consideration to the factors necessary at each step. Additional focus is paid to the unique type IV secretion system that mediates donation of transforming DNA in the pathogenic Neisseria. The pilin antigenic variation system uses programmed recombinations to alter a major surface determinant, which allows immune avoidance and promotes infection. We discuss the trans- and cis- acting factors which facilitate pilin antigenic variation and present the current understanding of the mechanisms involved in the process.
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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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12
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Exploring the Benefits of Molecular Testing for Gonorrhoea Antibiotic Resistance Surveillance in Remote Settings. PLoS One 2015; 10:e0133202. [PMID: 26181042 PMCID: PMC4504484 DOI: 10.1371/journal.pone.0133202] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Accepted: 06/24/2015] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Surveillance for gonorrhoea antimicrobial resistance (AMR) is compromised by a move away from culture-based testing in favour of more convenient nucleic acid amplification test (NAAT) tests. We assessed the potential benefit of a molecular resistance test in terms of the timeliness of detection of gonorrhoea AMR. METHODS AND FINDINGS An individual-based mathematical model was developed to describe the transmission of gonorrhoea in a remote Indigenous population in Australia. We estimated the impact of the molecular test on the time delay between first importation and the first confirmation that the prevalence of gonorrhoea AMR (resistance proportion) has breached the WHO-recommended 5% threshold (when a change in antibiotic should occur). In the remote setting evaluated in this study, the model predicts that when culture is the only available means of testing for AMR, the breach will only be detected when the actual prevalence of AMR in the population has already reached 8 - 18%, with an associated delay of ~43 - 69 months between first importation and detection. With the addition of a molecular resistance test, the number of samples for which AMR can be determined increases facilitating earlier detection at a lower resistance proportion. For the best case scenario, where AMR can be determined for all diagnostic samples, the alert would be triggered at least 8 months earlier than using culture alone and the resistance proportion will have only slightly exceeded the 5% notification threshold. CONCLUSIONS Molecular tests have the potential to provide more timely warning of the emergence of gonorrhoea AMR. This in turn will facilitate earlier treatment switching and more targeted treatment, which has the potential to reduce the population impact of gonorrhoea AMR.
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Capturing the cloud of diversity reveals complexity and heterogeneity of MRSA carriage, infection and transmission. Nat Commun 2015; 6:6560. [PMID: 25814293 PMCID: PMC4389252 DOI: 10.1038/ncomms7560] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 02/06/2015] [Indexed: 12/18/2022] Open
Abstract
Genome sequencing is revolutionizing clinical microbiology and our understanding of infectious diseases. Previous studies have largely relied on the sequencing of a single isolate from each individual. However, it is not clear what degree of bacterial diversity exists within, and is transmitted between individuals. Understanding this ‘cloud of diversity’ is key to accurate identification of transmission pathways. Here, we report the deep sequencing of methicillin-resistant Staphylococcus aureus among staff and animal patients involved in a transmission network at a veterinary hospital. We demonstrate considerable within-host diversity and that within-host diversity may rise and fall over time. Isolates from invasive disease contained multiple mutations in the same genes, including inactivation of a global regulator of virulence and changes in phage copy number. This study highlights the need for sequencing of multiple isolates from individuals to gain an accurate picture of transmission networks and to further understand the basis of pathogenesis. Populations of bacterial pathogens can be diverse within colonized individuals. Here, the authors sequence the genomes of methicillin-resistant Staphylococcus aureus isolated from staff and animal patients at a veterinary hospital and show considerable within-host diversity that can rise and fall over time.
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14
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Trembizki E, Doyle C, Buckley C, Jennison A, Smith H, Bates J, Sloots T, Nissen M, Lahra MM, Whiley D. Estimating the prevalence of mixed-type gonococcal infections in Queensland, Australia. Sex Health 2015; 12:439-44. [PMID: 26145099 DOI: 10.1071/sh15009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 05/07/2015] [Indexed: 11/23/2022]
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.
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Affiliation(s)
- Ella Trembizki
- Queensland Paediatric Infectious Diseases Laboratory, Queensland Children's Health Services, Block 28, Royal Children's Hospital, Herston Road, Herston, Qld 4029, Australia
| | - Christine Doyle
- Public Health Microbiology, Queensland Health Forensic and Scientific Services, Archerfield, Qld 4108, Australia
| | - Cameron Buckley
- Queensland Paediatric Infectious Diseases Laboratory, Queensland Children's Health Services, Block 28, Royal Children's Hospital, Herston Road, Herston, Qld 4029, Australia
| | - Amy Jennison
- Public Health Microbiology, Queensland Health Forensic and Scientific Services, Archerfield, Qld 4108, Australia
| | - Helen Smith
- Public Health Microbiology, Queensland Health Forensic and Scientific Services, Archerfield, Qld 4108, Australia
| | - John Bates
- Public Health Microbiology, Queensland Health Forensic and Scientific Services, Archerfield, Qld 4108, Australia
| | - Theo Sloots
- Queensland Paediatric Infectious Diseases Laboratory, Queensland Children's Health Services, Block 28, Royal Children's Hospital, Herston Road, Herston, Qld 4029, Australia
| | - Michael Nissen
- Queensland Paediatric Infectious Diseases Laboratory, Queensland Children's Health Services, Block 28, Royal Children's Hospital, Herston Road, Herston, Qld 4029, Australia
| | - Monica M Lahra
- WHO Collaborating Centre for STD, Microbiology Department, South Eastern Area Laboratory Services, Prince of Wales Hospital, Sydney, NSW 2031, Australia
| | - David Whiley
- Queensland Paediatric Infectious Diseases Laboratory, Queensland Children's Health Services, Block 28, Royal Children's Hospital, Herston Road, Herston, Qld 4029, Australia
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Multiplex bead suspension array for screening Neisseria gonorrhoeae antibiotic resistance genetic determinants in noncultured clinical samples. J Mol Diagn 2012; 15:116-29. [PMID: 23159594 DOI: 10.1016/j.jmoldx.2012.08.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Revised: 08/15/2012] [Accepted: 08/24/2012] [Indexed: 11/22/2022] Open
Abstract
The increasing threat of antibiotic-resistant Neisseria gonorrhoeae highlights the need for new diagnostic options. A high-throughput multiplex bead suspension array assay was developed for profiling 29 N. gonorrhoeae genomic mutations and 2 plasmid genes conferring resistance to 6 antimicrobial agents: penicillin, ciprofloxacin, cefixime, tetracycline, azithromycin, and spectinomycin. The three steps of this assay include amplification of 12 N. gonorrhoeae chromosomal and plasmid loci, multiplex allele-specific primer extension reaction, and multiplex bead suspension array detection. Antibiotic resistance genetic determinants were identified successfully in 239 cervicovaginal N. gonorrhoeae-positive noncultured swab samples. This molecular assay can be used for detection of gonococci in clinical specimens, molecular typing, mutation profiling, and predictive assessment of N. gonorrhoeae susceptibility to antibiotics without the need for culture.
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Vazquez F, Otero L, Melón S, de Oña M. Overview of molecular biological methods for the detection of pathogens causing sexually transmitted infections. Methods Mol Biol 2012; 903:1-20. [PMID: 22782808 DOI: 10.1007/978-1-61779-937-2_1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We review here different state-of-the-art molecular methods currently used in the diagnosis of sexually transmitted infections.
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Affiliation(s)
- Fernando Vazquez
- Servicio de Microbiología, Hospital Monte Naranco, Oviedo, Spain.
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17
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Review and international recommendation of methods for typing neisseria gonorrhoeae isolates and their implications for improved knowledge of gonococcal epidemiology, treatment, and biology. Clin Microbiol Rev 2011; 24:447-58. [PMID: 21734242 DOI: 10.1128/cmr.00040-10] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Gonorrhea, which may become untreatable due to multiple resistance to available antibiotics, remains a public health problem worldwide. Precise methods for typing Neisseria gonorrhoeae, together with epidemiological information, are crucial for an enhanced understanding regarding issues involving epidemiology, test of cure and contact tracing, identifying core groups and risk behaviors, and recommending effective antimicrobial treatment, control, and preventive measures. This review evaluates methods for typing N. gonorrhoeae isolates and recommends various methods for different situations. Phenotypic typing methods, as well as some now-outdated DNA-based methods, have limited usefulness in differentiating between strains of N. gonorrhoeae. Genotypic methods based on DNA sequencing are preferred, and the selection of the appropriate genotypic method should be guided by its performance characteristics and whether short-term epidemiology (microepidemiology) or long-term and/or global epidemiology (macroepidemiology) matters are being investigated. Currently, for microepidemiological questions, the best methods for fast, objective, portable, highly discriminatory, reproducible, typeable, and high-throughput characterization are N. gonorrhoeae multiantigen sequence typing (NG-MAST) or full- or extended-length porB gene sequencing. However, pulsed-field gel electrophoresis (PFGE) and Opa typing can be valuable in specific situations, i.e., extreme microepidemiology, despite their limitations. For macroepidemiological studies and phylogenetic studies, DNA sequencing of chromosomal housekeeping genes, such as multilocus sequence typing (MLST), provides a more nuanced understanding.
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18
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Prevalence and implications of multiple-strain infections. THE LANCET. INFECTIOUS DISEASES 2011; 11:868-78. [DOI: 10.1016/s1473-3099(11)70241-9] [Citation(s) in RCA: 166] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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19
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Sun A, Fan X, Gu Y, Du P, Tang R, Mao Y, Lin X, Yan J. Predominant porB1A and porB1B genotypes and correlation of gene mutations with drug resistance in Neisseria gonorrhoeae isolates in Eastern China. BMC Infect Dis 2010; 10:323. [PMID: 21067570 PMCID: PMC2992536 DOI: 10.1186/1471-2334-10-323] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2010] [Accepted: 11/10/2010] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Variations of porB1A and porB1B genes and their serotypes exist in Neisseria gonorrhoeae isolates from different geographical areas, and some site mutations in the porB1B gene correlate with drug resistance. METHODS The β-lactamase production of N. gonorrhoeae isolates was determined by paper acidometric test and nitrocefin discs. The porB1A and porB1B genes of 315 non-penicillinase-producting N. gonorrhoeae (non-PPNG) strains were amplified by PCR for sequencing to determine serotypes and site mutations. A duplex PCR was designed to simultaneously detect both porB1A and porB1B genes. Penicillin and tetracycline resistance was assessed by an in vitro drug sensitivity test. RESULTS Of the N. gonorrhoeae isolates, 31.1% tested positive for porB1A and 68.9% for porB1B genes. All the 98 porB1A+ isolates belonging to IA6 serotype with either no mutation at the 120 and 121 sites (88.8%) or a D120G (11.2%) mutation and were no resistance to both penicillin and tetracycline. Among the 217 porB1B+ isolates, 26.7%, 22.6% and 11.5% belonged to IB3, IB3/6 and IB4 serotypes, respectively. Particularly, two novel chimeric serotypes, IB3/6-IB2 and IB2-IB4-IB2, were found in 77 and 8 porB1B+ isolates. Two hundred and twelve (97.7%) of the porB1B+ isolates were presented G120 and/or A121 mutations with 163 (76.9%) at both sites. Interestingly, within the 77 porB1B+ isolates belonging to IB3/6-IB2 serotype, 15 were discovered to possess novel deletions at both A121 and N122 sites. All the replacement mutations at these sites in PorB1B were correlated with resistance and the deletion mutation showed the highest resistance. CONCLUSION N. gonorrhoeae isolates circulating in Eastern China include a sole PorB1A serotype (IA6) and five PorB1B serotypes. Multiple mutations in porB1B genes, including novel A121 and N122 deletions, are correlated with high levels of penicillin and tetracycline resistance.
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Affiliation(s)
- Aihua Sun
- Division of Basic Medical Microbiology, State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, the First Affiliated Hospital of Zhejiang University, Zhejiang 310003, Hangzhou, China
- Faculty of Basic Medicine, Zhejiang Medical College, 310053 Zhejiang Hangzhou, China
- Department of Medical Microbiology and Parasitology, College of Medicine, Zhejiang University, Zhejiang 310058, Hangzhou, China
| | - Xingli Fan
- Faculty of Basic Medicine, Zhejiang Medical College, 310053 Zhejiang Hangzhou, China
| | - Ye Gu
- College of Foreign Languages, Zhejiang Chinese Medicine University, Zhejiang 310053, Hangzhou, China
| | - Peng Du
- Division of Basic Medical Microbiology, State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, the First Affiliated Hospital of Zhejiang University, Zhejiang 310003, Hangzhou, China
- Faculty of Basic Medicine, Zhejiang Medical College, 310053 Zhejiang Hangzhou, China
- Department of Medical Microbiology and Parasitology, College of Medicine, Zhejiang University, Zhejiang 310058, Hangzhou, China
| | - Renxian Tang
- Department of Medical Microbiology and Parasitology, Xuzhou Medical College, Jiangsu 221009, Xuzhou, China
| | - Yafei Mao
- Division of Basic Medical Microbiology, State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, the First Affiliated Hospital of Zhejiang University, Zhejiang 310003, Hangzhou, China
- Department of Medical Microbiology and Parasitology, College of Medicine, Zhejiang University, Zhejiang 310058, Hangzhou, China
| | - Xuai Lin
- Division of Basic Medical Microbiology, State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, the First Affiliated Hospital of Zhejiang University, Zhejiang 310003, Hangzhou, China
- Department of Medical Microbiology and Parasitology, College of Medicine, Zhejiang University, Zhejiang 310058, Hangzhou, China
| | - Jie Yan
- Division of Basic Medical Microbiology, State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, the First Affiliated Hospital of Zhejiang University, Zhejiang 310003, Hangzhou, China
- Department of Medical Microbiology and Parasitology, College of Medicine, Zhejiang University, Zhejiang 310058, Hangzhou, China
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20
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Molecular surveillance of clinical Neisseria gonorrhoeae isolates in Russia. J Clin Microbiol 2010; 48:3681-9. [PMID: 20660213 DOI: 10.1128/jcm.00565-10] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The choice of adequate methods for epidemiological purposes remains a challenging problem in Neisseria gonorrhoeae molecular monitoring. In this study, the collection of geographically unrelated gonococci (n = 103) isolated in Russian clinics was comparably tested by (i) a traditional serotyping scheme, (ii) por typing, (iii) Neisseria gonorrhoeae multiantigen sequence typing (NG-MAST), and (iv) multilocus sequence typing (MLST). It is shown that, according to sequencing data, a third of the strains carried new porB1 alleles, as well as tbpB ones, and more than half of the samples had new sequence types (STs) as determined by NG-MAST or MLST. The discriminatory power for each typing method was calculated by using the Hunter-Gaston discriminatory index, D. Commonly, modern nucleic acid-based typing methods (por typing, NG-MAST, and MLST) appeared to be more efficient than the classical serotyping scheme. While the traditional serotyping gave a D value of 0.82, the por typing, NG-MAST, and MLST approaches yielded D values of 0.97, 0.98, and 0.91, respectively. Each typing technique revealed the distribution of gonococci slightly correlated with their geographical sources. However, only the MLST method STs were highly associated with certain phenotypes. Although ST1594, ST1892, and ST6720 were typical for susceptible gonococci, ST1901 and ST6716 were undoubtedly associated with a multidrug-resistant phenotype. We conclude that every tested nucleic acid-based typing method is suitable for N. gonorrhoeae molecular surveillance. However, the MLST method seems to serve large-scale epidemiological purposes, whereas the NG-MAST and por typing approaches are more appropriate for the investigation of local outbreaks.
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Spread of a chromosomal cefixime-resistant penA gene among different Neisseria gonorrhoeae lineages. Antimicrob Agents Chemother 2009; 54:1060-7. [PMID: 20028823 DOI: 10.1128/aac.01010-09] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In Neisseria gonorrhoeae, the mosaic type of penA, which encodes penicillin-binding protein 2 (PBP 2), is associated with reduced susceptibility to oral cephalosporins. To investigate the relatedness of N. gonorrhoeae clinical isolates with reduced susceptibility, we sequenced the penA genes of 32 isolates. Five different amino acid sequence types of PBP 2 were identified, but all seemed to be derivatives of pattern X of PBP 2 (PBP 2-X). However, multilocus sequence typing of the isolates showed that the isolates belonged to six different sequence types. As PBP 2-X was identified in three different sequence types, horizontal transfer of the penA allele encoding PBP2-X was suggested. We demonstrated that the penA gene could be transferred from an isolate with reduced susceptibility to a sensitive isolate by natural transformation. Comparison of the sequence of the penA-flanking regions of 12 transformants with those of the donor and the recipient suggested that at least a 4-kb DNA segment, including the penA gene, was transferred. During horizontal transfer, some of the penA alleles also acquired variations due to point mutations and genetic exchange within the allele. Our results provide evidence that the capacity for natural transformation in N. gonorrhoeae plays a role in the spread of chromosomal antibiotic resistance genes and the generation of diversity in such genes.
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22
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Vernel-Pauillac F, Nandi S, Nicholas RA, Goarant C. Genotyping as a tool for antibiotic resistance surveillance of Neisseria gonorrhoeae in New Caledonia: evidence of a novel genotype associated with reduced penicillin susceptibility. Antimicrob Agents Chemother 2008; 52:3293-300. [PMID: 18591264 PMCID: PMC2533457 DOI: 10.1128/aac.00020-08] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2008] [Revised: 02/04/2008] [Accepted: 06/11/2008] [Indexed: 11/20/2022] Open
Abstract
Antibiotic resistance in Neisseria gonorrhoeae continues to be a major concern in public health. Resistance of N. gonorrhoeae bacteria to penicillin G is widespread in most developed countries, which has necessitated a change to newer drugs for treatment of gonococcal infections. Recent reports indicate that resistance to these newer drugs is increasing, highlighting the need for accurate therapeutic recommendations. In some countries or communities, however, N. gonorrhoeae isolates are still susceptible to penicillin, so the use of this antibiotic for single-dose treatments of medically under-resourced patients is beneficial. In order to evaluate the adequacy and sustainability of this treatment approach, we explored the presence and prevalence of chromosomally mediated resistance determinants in N. gonorrhoeae isolates collected from 2005 to 2007 in New Caledonia. We developed two new real-time PCR assays targeting the penB and mtrR determinants, to be used together with a previously described duplex assay targeting the penA and ponA determinants. The results of this study provided evidence that neither the most-common mtrR determinants nor the most-resistance-associated penB alleles are currently circulating in New Caledonia, suggesting that penicillin should still be considered a valuable treatment strategy. Additionally, using our genotyping assay, we observed an unexpected penB genotype at a relatively high frequency that was associated with a decreased susceptibility to penicillin (average MIC, 0.15 mug/ml). Sequencing revealed that this genotype corresponded to an A102S mutation in the penB gene. The molecular tools developed in this study can be used successfully for prospective epidemiological monitoring and surveillance of penicillin susceptibility.
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Affiliation(s)
- Frédérique Vernel-Pauillac
- Institut Pasteur de Nouvelle-Calédonie, Laboratoire de Recherche en Bactériologie, Nouméa Cedex, New Caledonia
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23
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Warner DM, Shafer WM, Jerse AE. Clinically relevant mutations that cause derepression of the Neisseria gonorrhoeae MtrC-MtrD-MtrE Efflux pump system confer different levels of antimicrobial resistance and in vivo fitness. Mol Microbiol 2008; 70:462-78. [PMID: 18761689 DOI: 10.1111/j.1365-2958.2008.06424.x] [Citation(s) in RCA: 147] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The MtrC-MtrD-MtrE efflux pump system confers resistance to macrolide antibiotics and antimicrobial substances of the host innate defence. Clinical isolates with increased resistance to erythromycin and azithromycin frequently harbour mutations in the mtrR structural gene, which encodes a repressor of the mtrCDE operon, or the mtrR promoter region. The MtrC-MtrD-MtrE system is important for gonococcal survival in the murine genital tract, and derepression of the mtrCDE operon via deletion of mtrR confers increased fitness in vivo. Here we compared isogenic strains with naturally occurring mtrR locus mutations for differences in mtrCDE expression and pump-related phenotypes. Mutations upstream of mtrC, including those within the MtrR binding region and a novel mutation that increases mtrC RNA stability conferred the highest levels of derepression as measured by mtrCDE transcription and resistance to antibiotics, progesterone and antimicrobial peptides. In contrast, mutations within the mtrR coding sequence conferred low to intermediate levels of derepression. In vivo, the mtr mutants were more fit than the wild-type strain, the degree to which paralleled in vitro resistance gradients. These studies establish a hierarchy of mtrR locus mutations with regard to regulation of pump efflux, and suggest selection for more derepressed mutants may occur during mixed infections.
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Affiliation(s)
- Douglas M Warner
- Department of Microbiology and Immunology, F. Edward Hèbert School of Medicine, Uniformed Services University, Bethesda, MD, USA
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24
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Phenotypic and genotypic analyses of Neisseria gonorrhoeae isolates that express frequently recovered PorB PIA variable region types suggest that certain P1a porin sequences confer a selective advantage for urogenital tract infection. Infect Immun 2008; 76:3700-9. [PMID: 18541655 DOI: 10.1128/iai.00265-08] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Typing of the porB variable region (VR) is an epidemiological tool that classifies gonococcal strains based on sequence differences in regions of the porB gene that encode surface-exposed loops. The frequent isolation of certain porB VR types suggests that some porin sequences confer a selective advantage during infection and/or transmission. Alternatively, certain porin types may be markers of strains that are successful due to factors unrelated to porin. In support of the first hypothesis, here we show urogenital tract isolates representing the most common PIA VR types identified in an urban clinic in Baltimore, MD, over a 10-year period belonged to several different clonal types, as determined by pulsed-field gel electrophoresis (PFGE). Serum resistance, which was confirmed by factor H and C4b-binding protein binding studies, was more often associated with gonococcal the most common VR types. In contrast, three porin-independent phenotypes, namely, lactoferrin utilization, beta-lactamase production, and multiple transferable resistance (Mtr), were segregated with the PFGE cluster and not with the VR type. Data combined with another PIA strain collection showed a strong correlation between serum resistance and the most common VR types. A comparison of VR typing hybridization patterns and nucleotide sequences of 12 porB1a genes suggests that certain porin loop 1, 3, 6, and/or 7 sequences may play a role in the serum resistance phenotype. We conclude that some PorB PIA sequences confer a survival or transmission advantage in the urogenital tract, perhaps via increased resistance to complement-mediated killing. The capacity of some porin types to evade a porin-specific adaptive immune response must also be considered.
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25
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Liao M, Bell K, Gu WM, Yang Y, Eng NF, Fu W, Wu L, Zhang CG, Chen Y, Jolly AM, Dillon JAR. Clusters of circulating Neisseria gonorrhoeae strains and association with antimicrobial resistance in Shanghai. J Antimicrob Chemother 2008; 61:478-87. [PMID: 18227091 DOI: 10.1093/jac/dkm544] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVES (i) To distinguish Neisseria gonorrhoeae isolates in Shanghai by porB typing; (ii) to ascertain the congruence of porB DNA sequence typing with cases linked epidemiologically; (iii) to determine the association of specific PorB mutations with antimicrobial resistance to penicillin or tetracycline. METHODS porB DNA sequences of 174 N. gonorrhoeae isolates, collected from 143 male patients and 31 female sexual partners in Shanghai were determined. Phylogenetic analysis was used to determine sequence associations and concordance with epidemiologically linked cases. PorB protein sequences were compared with the wild-type sequence to identify mutations associated with antimicrobial resistance to penicillin and tetracycline. RESULTS porB1a genotypes comprised 27.0% of the isolates and included 15 distinct DNA sequences, while 73.0% of the isolates carried porB1b genotypes with 63 distinct DNA sequences. porB DNA sequence typing was congruent with patient-reported sexual contacts. In addition, porB DNA sequence analysis revealed a number of strains with identical DNA sequences not identified through traditional epidemiological methods. The porB1b isolates had a significantly higher percentage of chromosomally mediated resistance to tetracycline and higher MIC50s to penicillin and ciprofloxacin. G120K/A121D mutations were observed in 71.1% of PIB isolates and were associated with resistance to penicillin and/or tetracycline. The majority of the PIA isolates (82.1%) also carried G120D/A121G double mutations. The index of discrimination for porB DNA sequence analysis was 95%. CONCLUSIONS The porB1b genotype was found to be predominant in Shanghai. porB DNA sequence typing was sufficiently discriminatory for differentiating N. gonorrhoeae isolates and was congruent with epidemiological linkages. Novel porB sequences of N. gonorrhoeae and novel mutations of PorB proteins were identified.
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Affiliation(s)
- Mingmin Liao
- Vaccine and Infectious Disease Organization, University of Saskatchewan, 120 Veterinary Road, Saskatoon, Saskatchewan, Canada S7N 5E3
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26
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Ling A, Bash M, Lynn F, Lister N, Zhu P, Garland S, Fairley C, Tabrizi S. Evaluation of PorB variable region typing of Neisseria gonorrhoeae using PCR-ELISA in samples collected from men who have sex with men. J Clin Lab Anal 2007; 21:237-43. [PMID: 17621363 PMCID: PMC6649155 DOI: 10.1002/jcla.20173] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
A polymerase chain reaction (PCR)-based enzyme-linked immunosorbent assay (ELISA) methodology was developed to characterize Neisseria gonorrhoeae porB gene variable regions (VR); the methodology was evaluated in comparison to porB VR typing by checkerboard hybridization. Clinical noncultured samples from 35 men who have sex with men (MSM), positive by nucleic amplification assays for N. gonorrhoeae, were typed using a panel of 40 oligonucleotide probes to porB VRs and compared to checkerboard hybridization. Complete concordance was observed between the two methods at PIB VRs 1, 3, and 7. At the more degenerate VRs 5 and 6, PCR ELISA resulted in obtaining more typeable VRs than checkerboard hybridization due to single nucleotide mismatches. By PCR ELISA, two predominant PIB porB types were identified in 58% of the samples and the remaining 16 samples had one of six other porB types. Both PCR ELISA and checkerboard hybridization methods of porB VR typing allowed characterization of N. gonorrhoeae from noncultured clinical samples including throat and rectal swabs and discriminated N. gonorrhoeae from N. meningitidis present in some of the samples. PCR ELISA is a rapid, relatively inexpensive and alternative molecular typing method for N. gonorrhoeae, suitable for use in conjunction with molecular diagnostic tests.
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Affiliation(s)
- A.E. Ling
- Department of Microbiology and Infectious Diseases, The Royal Women's Hospital, Melbourne, Australia
| | - M.C. Bash
- Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, Maryland
| | - F. Lynn
- Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, Maryland
| | - N.A. Lister
- Melbourne Sexual Health Centre, Melbourne, Australia
| | - P. Zhu
- Creatv MicroTech, Inc., Potomac, Maryland
| | - S.M. Garland
- Department of Microbiology and Infectious Diseases, The Royal Women's Hospital, Melbourne, Australia
- Department of Obstetrics and Gynaecology, University of Melbourne, Melbourne, Australia
| | - C.K. Fairley
- Melbourne Sexual Health Centre, Melbourne, Australia
- School of Population Health, University of Melbourne, Melbourne, Australia
| | - S.N. Tabrizi
- Department of Microbiology and Infectious Diseases, The Royal Women's Hospital, Melbourne, Australia
- Department of Obstetrics and Gynaecology, University of Melbourne, Melbourne, Australia
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Kolader ME, Dukers NHTM, van der Bij AK, Dierdorp M, Fennema JSA, Coutinho RA, Bruisten SM. Molecular epidemiology of Neisseria gonorrhoeae in Amsterdam, The Netherlands, shows distinct heterosexual and homosexual networks. J Clin Microbiol 2006; 44:2689-97. [PMID: 16891479 PMCID: PMC1594601 DOI: 10.1128/jcm.02311-05] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Molecular typing, added to epidemiological data, can better identify transmission patterns of gonorrhea in Western countries, where the incidence has recently been rising. From September 2002 to September 2003, patients with a laboratory-confirmed diagnosis of gonorrhea at the Clinic for Sexually Transmitted Infections in Amsterdam, The Netherlands, were subjected to a questionnaire pertaining to sexual risk behavior and sexual partners in the 6 months prior to the diagnosis. The Neisseria gonorrhoeae isolates were all genotyped using PCR-restriction fragment length polymorphism of the porin and opacity genes. All patients with a completed questionnaire and genotyped isolates were included in the study. We obtained 885 N. gonorrhoeae isolates from 696 patients that revealed 88 clusters and 46 unique genotypes. Patients infected at multiple anatomical sites with one or more strains and patients infected several times during the study period were shown to pursue high-risk sexual behavior and were considered core groups. There were 11 clusters of > or =20 patients; in seven clusters, 81% to 100% of patients were men who have sex with men (MSM), three clusters contained 87 to 100% heterosexual men and women, and one cluster was formed by equal proportions of MSM and heterosexual male and female patients. However, the various clusters differed in characteristics such as types of coinfections, numbers of sexual partners, Internet use to seek sexual partners, and locations of sexual encounters. Molecular epidemiology of gonococcal isolates in Amsterdam revealed core groups and clusters of MSM and heterosexual patients that probably indicate distinct transmission networks.
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Affiliation(s)
- Marion-Eliëtte Kolader
- STI Clinic, Cluster of Infectious Diseases, Health Service of Amsterdam, Amsterdam, The Netherlands
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Zhan L, Wang D, Zhang C, Wen H, Xu X, Pei X. Expression of the Neisseria gonorrhoeae major outer membrane protein PI in Escherichia coli. World J Microbiol Biotechnol 2006. [DOI: 10.1007/s11274-005-9092-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Bash MC, Zhu P, Gulati S, McKnew D, Rice PA, Lynn F. por Variable-region typing by DNA probe hybridization is broadly applicable to epidemiologic studies of Neisseria gonorrhoeae. J Clin Microbiol 2005; 43:1522-30. [PMID: 15814961 PMCID: PMC1081315 DOI: 10.1128/jcm.43.4.1522-1530.2005] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The porin gene (porB) of Neisseria gonorrhoeae encodes the major outer membrane protein identified as PI or Por. To examine the utility of por variable-region (VR) typing, porB from 206 isolates was characterized by using oligonucleotide probes in a checkerboard hybridization assay that identifies the sequence types of five VRs of both PIA and PIB porB alleles. The strains represented temporally and geographically distinct isolates, isolates from a large cluster, epidemiologically linked partner isolates, and a collection of strains from disseminated gonococcal infections. By using rigorous epidemiologic criteria for transmission of infection between sex partners, por VR typing was more discriminatory than serovar typing in classifying isolates from both members of 43 epidemiologically linked pairs: 39 of 43 pairs were classified as coinciding by por VR typing compared to 43 of 43 by serovar determination (P = 0.058). porB sequence data confirmed the accuracy of the por VR method. Relationships between VR type and serovar typing monoclonal antibodies were observed for all six PIB and three of six PIA antibodies. por VR typing is a molecular tool that appears to have broad applicability. This method can be adapted to a wide range of technologies from simple hybridization to microarray and may allow for typing from noncultured clinical specimens.
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Affiliation(s)
- Margaret C Bash
- Division of Bacterial, Parasitic and Allergenic Products, HFM-428, Center for Biologics Evaluation and Research, 1401 Rockville Pike, Rockville, MD 20852, USA.
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