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Yee WX, Elsener T, Cehovin A, Maiden MCJ, Tang CM. Evolution and exchange of plasmids in pathogenic Neisseria. mSphere 2023; 8:e0044123. [PMID: 37850911 PMCID: PMC10732060 DOI: 10.1128/msphere.00441-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Accepted: 09/07/2023] [Indexed: 10/19/2023] Open
Abstract
IMPORTANCE Horizontal gene transfer (HGT) is a major influence in driving the spread of antimicrobial resistance (AMR) in many bacteria. A conjugative plasmid which is widespread in Neisseria gonorrhoeae, pConj, prevented the use of tetracycline/doxycycline for treating gonococcal infection. Here, we show that pConj evolved in the related pathogen, Neisseria meningitidis, and has been acquired by the gonococcus from the meningococcus on multiple occasions. Following its initial acquisition, pConj spread to different gonococcal lineages; changes in the plasmid's conjugation machinery associated with another transfer event limit spread in the gonococcal populations. Our findings have important implications for the use of doxycycline to prevent bacterial sexually transmitted disease which is likely to exacerbate the spread of AMR through HGT in pathogenic bacteria.
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Affiliation(s)
- Wearn-Xin Yee
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Tabea Elsener
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Ana Cehovin
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | | | - Christoph M. Tang
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
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2
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Yee WX, Yasir M, Turner AK, Baker DJ, Cehovin A, Tang CM. Evolution, persistence, and host adaption of a gonococcal AMR plasmid that emerged in the pre-antibiotic era. PLoS Genet 2023; 19:e1010743. [PMID: 37186602 DOI: 10.1371/journal.pgen.1010743] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 05/25/2023] [Accepted: 04/14/2023] [Indexed: 05/17/2023] Open
Abstract
Plasmids are diverse extrachromosomal elements significantly contributing to interspecies dissemination of antimicrobial resistance (AMR) genes. However, within clinically important bacteria, plasmids can exhibit unexpected narrow host ranges, a phenomenon that has scarcely been examined. Here we show that pConj is largely restricted to the human-specific pathogen, Neisseria gonorrhoeae. pConj can confer tetracycline resistance and is central to the dissemination of other AMR plasmids. We tracked pConj evolution from the pre-antibiotic era 80 years ago to the modern day and demonstrate that, aside from limited gene acquisition and loss events, pConj is remarkably conserved. Notably, pConj has remained prevalent in gonococcal populations despite cessation of tetracycline use, thereby demonstrating pConj adaptation to its host. Equally, pConj imposes no measurable fitness costs and is stably inherited by the gonococcus. Its maintenance depends on the co-operative activity of plasmid-encoded Toxin:Antitoxin (TA) and partitioning systems rather than host factors. An orphan VapD toxin encoded on pConj forms a split TA with antitoxins expressed from an ancestral co-resident plasmid or a horizontally-acquired chromosomal island, potentially explaining pConj's limited distribution. Finally, ciprofloxacin can induce loss of this highly stable plasmid, reflecting epidemiological evidence of transient local falls in pConj prevalence when fluoroquinolones were introduced to treat gonorrhoea.
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Affiliation(s)
- Wearn-Xin Yee
- Sir William Dunn School of Pathology, University of Oxford, OXFORD, United Kingdom
| | | | | | | | - Ana Cehovin
- Sir William Dunn School of Pathology, University of Oxford, OXFORD, United Kingdom
| | - Christoph M Tang
- Sir William Dunn School of Pathology, University of Oxford, OXFORD, United Kingdom
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Jones RA, Yee WX, Mader K, Tang CM, Cehovin A. Markerless gene editing in Neisseria gonorrhoeae. MICROBIOLOGY (READING, ENGLAND) 2022; 168. [PMID: 35763318 DOI: 10.1099/mic.0.001201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Neisseria gonorrhoeae, the gonococcus, is a pathogen of major public health concern, but sophisticated approaches to gene manipulation are limited for this species. For example, there are few methods for generating markerless mutations, which allow the generation of precise point mutations and deletions without introducing additional DNA sequence. Markerless mutations are central to studying pathogenesis, the spread of antimicrobial resistance (AMR) and for vaccine development. Here we describe the use of galK as a counter-selectable marker that can be used for markerless mutagenesis in N. gonorrhoeae. galK encodes galactokinase, an enzyme that metabolizes galactose in bacteria that can utilize it as a sole carbon source. GalK can also phosphorylate a galactose analogue, 2-deoxy-galactose (2-DOG), into a toxic, non-metabolisable intermediate, 2-deoxy-galactose-1-phosphate. We utilized this property of GalK to develop a markerless approach for mutagenesis in N. gonorrhoeae. We successfully deleted both chromosomally and plasmid-encoded genes, that are important for gonococcal vaccine development and studies of AMR spread. We designed a positive-negative selection cassette, based on an antibiotic resistance marker and galK, that efficiently rendered N. gonorrhoeae susceptible to growth on 2-DOG. We then adapted the galK-based counter-selection and the use of 2-DOG for markerless mutagenesis, and applied biochemical and phenotypic analyses to confirm the absence of target genes. We show that our markerless mutagenesis method for N. gonorrhoeae has a high success rate, and should be a valuable gene editing tool in the future.
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Affiliation(s)
- Rebekah A Jones
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, UK
| | - Wearn Xin Yee
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, UK
| | - Kahlio Mader
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, UK
| | - Christoph M Tang
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, UK
| | - Ana Cehovin
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, UK
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Cehovin A, Jolley KA, Maiden MCJ, Harrison OB, Tang CM. Association of Neisseria gonorrhoeae Plasmids With Distinct Lineages and The Economic Status of Their Country of Origin. J Infect Dis 2020; 222:1826-1836. [PMID: 32163577 PMCID: PMC7653084 DOI: 10.1093/infdis/jiaa003] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2019] [Accepted: 01/09/2020] [Indexed: 12/29/2022] Open
Abstract
Plasmids are vehicles for horizontal gene transfer between bacteria, and in Neisseria gonorrhoeae plasmids can mediate high-level antimicrobial resistance (AMR). Using genomic and phylogenetic analyses, we show that plasmids are widespread in a collection of 3724 gonococcal isolates from 56 countries, and characterized the conjugative, β-lactamase and cryptic plasmids. We found that variants of the conjugative plasmid (which can mediate tetracycline resistance) and the β-lactamase plasmid expressing TEM-135 are associated with distinct gonococcal lineages. Furthermore, AMR plasmids are significantly more prevalent in gonococci from less wealthy countries, highlighting the need for further studies. More than 94% of gonococci possess the cryptic plasmid, with its absence correlated with the presence of a novel chromosomal type IV secretion system. Our results reveal the extent of plasmid-mediated AMR in the gonococcus, particularly in less wealthy countries, where diagnostic and therapeutic options can be limited, and highlight the risk of their global spread.
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Affiliation(s)
- Ana Cehovin
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Keith A Jolley
- Department of Zoology, University of Oxford, Oxford, United Kingdom
| | | | - Odile B Harrison
- Department of Zoology, University of Oxford, Oxford, United Kingdom
| | - Christoph M Tang
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
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5
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Bai X, Borrow R, Bukovski S, Caugant DA, Culic D, Delic S, Dinleyici EC, Eloshvili M, Erdősi T, Galajeva J, Křížová P, Lucidarme J, Mironov K, Nurmatov Z, Pana M, Rahimov E, Savrasova L, Skoczyńska A, Smith V, Taha MK, Titov L, Vázquez J, Yeraliyeva L. Prevention and control of meningococcal disease: Updates from the Global Meningococcal Initiative in Eastern Europe. J Infect 2019; 79:528-541. [PMID: 31682877 DOI: 10.1016/j.jinf.2019.10.018] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 10/23/2019] [Accepted: 10/26/2019] [Indexed: 12/20/2022]
Abstract
The Global Meningococcal Initiative (GMI) aims to prevent invasive meningococcal disease (IMD) worldwide through education, research and cooperation. In March 2019, a GMI meeting was held with a multidisciplinary group of experts and representatives from countries within Eastern Europe. Across the countries represented, IMD surveillance is largely in place, with incidence declining in recent decades and now generally at <1 case per 100,000 persons per year. Predominating serogroups are B and C, followed by A, and cases attributable to serogroups W, X and Y are emerging. Available vaccines differ between countries, are generally not included in immunization programs and provided to high-risk groups only. Available vaccines include both conjugate and polysaccharide vaccines; however, current data and GMI recommendations advocate the use of conjugate vaccines, where possible, due to the ability to interrupt the acquisition of carriage. Ongoing carriage studies are expected to inform vaccine effectiveness and immunization schedules. Additionally, IMD prevention and control should be guided by monitoring outbreak progression and the emergence and international spread of strains and antibiotic resistance through use of genomic analyses and implementation of World Health Organization initiatives. Protection of high-risk groups (such as those with complement deficiencies, laboratory workers, migrants and refugees) is recommended.
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Affiliation(s)
- Xilian Bai
- Meningococcal Reference Unit, Public Health England, Manchester Royal Infirmary, Manchester M13 9WZ, UK.
| | - Ray Borrow
- Meningococcal Reference Unit, Public Health England, Manchester Royal Infirmary, Manchester M13 9WZ, UK.
| | - Suzana Bukovski
- University Hospital for Infectious Diseases, Zagreb, Croatia.
| | | | - Davor Culic
- Institute for Public Health, Sombor, Serbia.
| | | | | | - Medeia Eloshvili
- National Center for Disease Control & Public Health, Tbilisi, Georgia.
| | - Tímea Erdősi
- National Public Health Center, Budapest, Hungary.
| | | | - Pavla Křížová
- National Institute of Public Health, Prague, Czechia.
| | - Jay Lucidarme
- Meningococcal Reference Unit, Public Health England, Manchester Royal Infirmary, Manchester M13 9WZ, UK.
| | | | - Zuridin Nurmatov
- Scientific and Production Association "Preventive Medicine", Bishkek, Kyrgyzstan.
| | - Marina Pana
- Cantacuzino National Medico Military Institute for Research Development, Bucharest, Romania
| | | | - Larisa Savrasova
- The Centre for Disease Prevention and Control of Latvia, Riga, Latvia.
| | - Anna Skoczyńska
- National Reference Centre for Bacterial Meningitis, National Medicines Institute, Warsaw, Poland.
| | - Vinny Smith
- Meningitis Research Foundation, Bristol, UK.
| | - Muhamed-Kheir Taha
- National Reference Centre for Meningococci, Institute Pasteur, Paris, France.
| | - Leonid Titov
- Republican Research & Practical Center for Epidemiology & Microbiology, Minsk, Belarus.
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Resistance of Neisseria gonorrhoeae isolates to beta-lactam antibiotics (benzylpenicillin and ceftriaxone) in Russia, 2015-2017. PLoS One 2019; 14:e0220339. [PMID: 31344102 PMCID: PMC6657886 DOI: 10.1371/journal.pone.0220339] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 07/12/2019] [Indexed: 12/22/2022] Open
Abstract
The goal of this work was to study the phenotypic susceptibility and resistance determinants of N. gonorrhoeae isolates to beta-lactam antimicrobials (benzylpenicillin and ceftriaxone). A total of 522 clinical isolates collected in Russia in 2015–2017 were analysed for susceptibility using the agar dilution method. DNA loci involved in antimicrobial resistance were identified using DNA microarray analysis and sequencing. Resistance to benzylpenicillin remained high, with 7.7% of isolates resistant (MICpen > 1 mg/L) and 47.5% of isolates showing intermediate susceptibility (MICpen = 0.12–1 mg/L). The most frequent resistance determinant (72.4% isolates) was the Asp345 insertion in penA, both as a single mutation and in combination with other mutations, particularly with the substitution Leu421Pro in ponA (39.0%). Mutations affecting the influx and efflux of drugs were also found, including amino acid substitutions in PorB (26.8% isolates) and delA in the promoter region of mtrR (22.8%). The accumulation of mutations in chromosomal genes (penA, pon, porA, and mtrR) led to a stepwise increase in MICpen to values characteristic of intermediate resistance. The presence of blaTEM plasmids was found in 25 isolates (4.8%), resulting in a strong increase in resistance to penicillin (MICpen > 16 mg/L) compared with the chromosomal mutations; 23 plasmids were of the African type with TEM-1 beta-lactamase, and two plasmids were of the Toronto/Rio type with TEM-135 beta-lactamase. Only three isolates were found with reduced susceptibility to ceftriaxone, with MICcef = 0.12–0.25 mg/L. Sequencing of penA did not reveal mutations associated with resistance to third-generation cephalosporins, and the gene structure was non-mosaic. The majority of isolates (21 of 25) carrying the blaTEM plasmid also contained the conjugative plasmid with tetM (resistance to tetracyclines), consistent with previously reported data that the presence of the conjugative plasmid facilitates the transfer of other plasmids associated with antimicrobial resistance.
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7
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Abstract
Neisseria gonorrhoeae, the causative agent of the sexually transmitted disease gonorrhoeae, possesses several mobile genetic elements (MGEs). The MGEs such as transposable elements mediate intrachromosomal rearrangements, while plasmids and the gonococcal genetic island are involved in interchromosomal gene transfer. Additionally, gonococcal MGEs serve as hotspots for recombination and integration of other genetic elements such as bacteriophages, contribute to gene regulation or spread genes through gonococcal populations by horizontal gene transfer. In this review, we summarise the literature on the structure and biology of MGEs and discuss how these genetic elements may play a role in the pathogenesis and spread of antimicrobial resistance in N. gonorrhoeae. Although an abundance of information about gonococcal MGEs exists (mainly from whole genome sequencing and bioinformatic analysis), there are still many open questions on how MGEs influence the biology of N. gonorrhoeae.
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Affiliation(s)
- Ana Cehovin
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Steven B Lewis
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
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Unemo M, Shafer WM. Antibiotic resistance in Neisseria gonorrhoeae: origin, evolution, and lessons learned for the future. Ann N Y Acad Sci 2012; 1230:E19-28. [PMID: 22239555 DOI: 10.1111/j.1749-6632.2011.06215.x] [Citation(s) in RCA: 147] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The strict human pathogen Neisseria gonorrhoeae has caused gonorrhea for thousands of years, and currently gonorrhea is the second most prevalent bacterial sexually transmitted infection worldwide. Given the ancient nature of N. gonorrhoeae and its unique obligate relationship with humankind over the millennia, its remarkable ability to adapt to the host immune system and cause repeated infections, and its propensity to develop resistance to all clinically useful antibiotics, the gonococcus is an ideal pathogen on which to study the evolution of bacterial pathogenesis, including antimicrobial resistance, over the long term and within the host during infection. Recently, the first gonococcus displaying high-level resistance to ceftriaxone, identified in Japan, was characterized in detail. Ceftriaxone is the last remaining option for empirical first-line treatment, and N. gonorrhoeae now seems to be evolving into a true "superbug." In the near future, gonorrhea may become untreatable in certain circumstances. Herein, the history of antibiotics used for treatment of gonorrhea, the evolution of resistance emergence in N. gonorrhoeae, the linkage between resistance and biological fitness of N. gonorrhoeae, lessons learned, and future perspectives are reviewed and discussed.
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Affiliation(s)
- Magnus Unemo
- National Reference Laboratory for Pathogenic Neisseria, Department of Laboratory Medicine, Microbiology, Örebro University Hospital, Örebro, Sweden.
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9
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Scharbaai-Vázquez R, González-Caraballo AL, Torres-Bauzá LJ. Four different integrative recombination events involved in the mobilization of the gonococcal 5.2 kb beta-lactamase plasmid pSJ5.2 in Escherichia coli. Plasmid 2008; 60:200-11. [PMID: 18778732 DOI: 10.1016/j.plasmid.2008.07.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2008] [Revised: 07/16/2008] [Accepted: 07/17/2008] [Indexed: 10/21/2022]
Abstract
We identified and characterized four different recombination mechanisms involved in the cointegrative transfer of the Neisseria gonorrhoeae beta-lactamase plasmid pSJ5.2 by the gonococcal 41 kb tet(M) and the Gram negative self-transmissible plasmids N3 and R64 drd-33 using an Escherichia colirecA-background. Mobilization of pSJ5.2 by the tet(M) plasmid occurred by cointegration through a replicative transposition of two IS1 elements inserted upstream from the beta-lactamase gene of pSJ5.2 and creating a IS1::beta-lactamase hybrid promoter. Two types of recombinational events occurred within the 1.8 kb BamH1-HindIII fragment of pSJ5.2 with the N3 and R64 plasmids. A non-homologous recombination was found at coordinates 1817 and 2849 of pSJ5.2 with sequences from R64. A non-homologous recombination combined with an IS26-mediated one-ended transposition was found at coordinates 1817 and 3010 of pSJ5.2 with N3. In both recombinational events, a deletion of over 1 kb of pSJ5.2 occurred. The fourth recombination event was detected in the 1.0 kb BamH1-HindIII fragment of pSJ5.2 by homologous recombination between DNA from the truncated Tn3 resolvase gene of pSJ5.2 and the resolvase sequences from R64 and N3.
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Affiliation(s)
- Ramón Scharbaai-Vázquez
- Department of Microbiology, San Juan Bautista School of Medicine, P.O. Box 4968, Caguas, PR 00726-4968, USA
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Scharbaai‐Vázquez R, Candelas T, Torres‐Bauzá LJ. Mobilization of the gonococcal 5.2 kb beta-lactamase plasmid pSJ5.2 into Escherichia coli by cointegration with several gram-conjugative plasmids. Plasmid 2006; 57:156-64. [PMID: 17027960 PMCID: PMC1973139 DOI: 10.1016/j.plasmid.2006.07.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2006] [Revised: 07/07/2006] [Accepted: 07/24/2006] [Indexed: 10/24/2022]
Abstract
We report the mobilization by cointegration of the gonococcal 5.2 kb beta-lactamase plasmid pSJ5.2 in an Escherichia coli background. Transfer of pSJ5.2 was measured by filter mating assays with five different conjugative plasmids from Enterobacteriaceae and the gonococcal 41 kb tet(M). Plasmid pSJ5.2 was mobilized to E. coli at frequencies of 1.7x10(-6), 9.3x10(-8) and 2.7x10(-5) by the tet(M), R64 drd-33 and N3 conjugative plasmids, respectively. Mobilization of pSJ5.2 by the 41 kb tet(M) conjugative plasmid resulted in stable Amp(R) E. coli transconjugants consisting of pSJ5.2 plasmid with an insertion located in the 2.4 kb BamHI-BamHI fragment. Mobilization of pSJ5.2 by R64drd-33 and N3 conjugative plasmids involved stable cointegrates as detected by Southern Blot with a DIG-labelled PstI-digested pSJ5.2 probe. Restriction analysis of the R64::pSJ5.2 and N3::pSJ5.2 cointegrates and Southern Blot with the pSJ5.2 probe showed that cointegrates formed by deletion of DNA regions within the 1.8 kb BamHI-HindIII fragment of pSJ5.2. The plasmid thus appears to use multiple recombination mechanisms for cointegration with different conjugative plasmids. The complete nucleotide sequence of pSJ5.2 was determined, and will be a useful tool to further investigate the molecular mechanisms leading to its cointegrative transfer.
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Affiliation(s)
- R. Scharbaai‐Vázquez
- Department of Microbiology and Medical Zoology, P.O. Box 365067, Medical Sciences Campus, University of Puerto Rico, San Juan, P.R. 00936
| | - T. Candelas
- Department of General Sciences, University of Puerto Rico, Río Piedras Campus
| | - L. J. Torres‐Bauzá
- Department of Microbiology and Medical Zoology, P.O. Box 365067, Medical Sciences Campus, University of Puerto Rico, San Juan, P.R. 00936
- Corresponding Author: Tel. 787‐758‐2525, x. 2905, 1708, Fax: 787‐758‐4808, E‐mail address: (L.J. Torres‐Bauzá)
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Rossi-Fedele G, Scott W, Spratt D, Gulabivala K, Roberts AP. Incidence and behaviour of Tn916-like elements within tetracycline-resistant bacteria isolated from root canals. ACTA ACUST UNITED AC 2006; 21:218-22. [PMID: 16842505 DOI: 10.1111/j.1399-302x.2006.00279.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
INTRODUCTION Tetracycline resistance is commonly found in endodontic bacteria. One of the most common tetracycline-resistance genes is tet(M), which is often encoded on the broad-host-range conjugative transposon Tn916. This study aimed to determine whether tet(M) was present in bacteria isolated from endodontic patients at the Eastman Dental Institute and whether this gene was carried on the transferable conjugative transposon Tn916. METHODS The cultivable microflora isolated from 15 endodontic patients was screened for resistance to tetracycline. Polymerase chain reactions for tet(M) and for unique regions of Tn916 were carried out on the DNA of all tetracycline-resistant bacteria. Filter-mating experiments were used to see if transfer of any Tn916-like elements could occur. RESULTS Eight out of 15 tetracycline-resistant bacteria isolated were shown to possess tet(M). Furthermore, four of these eight were shown to possess the Tn916-unique regions linked to the tet(M) gene. Transfer experiments demonstrated that a Neisseria sp. donor could transfer an extremely unstable Tn916-like element to Enterococcus faecalis. CONCLUSIONS The tet(M) gene is present in the majority of tetracycline-resistant bacteria isolated in this study and the conjugative transposon Tn916 has been shown to be responsible for the support and transfer of this gene in some of the bacteria isolated.
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Affiliation(s)
- G Rossi-Fedele
- Endodontic Unit, Eastman Dental Institute, University College London, University of London, London, UK
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12
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Snyder LAS, Davies JK, Ryan CS, Saunders NJ. Comparative overview of the genomic and genetic differences between the pathogenic Neisseria strains and species. Plasmid 2005; 54:191-218. [PMID: 16024078 DOI: 10.1016/j.plasmid.2005.04.005] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2005] [Revised: 04/18/2005] [Accepted: 04/21/2005] [Indexed: 01/19/2023]
Abstract
The availability of complete genome sequences from multiple pathogenic Neisseria strains and species has enabled a comprehensive survey of the genomic and genetic differences occurring within these species. In this review, we describe the chromosomal rearrangements that have occurred, and the genomic islands and prophages that have been identified in the various genomes. We also describe instances where specific genes are present or absent, other instances where specific genes have been inactivated, and situations where there is variation in the version of a gene that is present. We also provide an overview of mosaic genes present in these genomes, and describe the variation systems that allow the expression of particular genes to be switched ON or OFF. We have also described the presence and location of mobile non-coding elements in the various genomes. Finally, we have reviewed the incidence and properties of various extra-chromosomal elements found within these species. The overall impression is one of genomic variability and instability, resulting in increased functional flexibility within these species.
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Affiliation(s)
- Lori A S Snyder
- Bacterial Pathogenesis and Functional Genomics Group, Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK.
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13
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Abstract
During periods of endemic disease, about 10 % of the general population harbour Neisseria meningitidis in the nasopharynx. Since N. meningitidis is a strict human pathogen and most patients have not been in contact with other cases, asymptomatic carriers are presumably the major source of the pathogenic strains. Most carrier isolates are shown to lack capsule production. The capsule deficient state of meningococcal strains in the nasopharynx may aid evasion of the human immune defence and hence be selected to survive nasopharyngeal colonization. Carriage itself can be an immunizing process resulting in systemic protective antibody responses. Frequent nasopharyngeal colonization with related bacteria like Neisseria lactamica improves natural immunity to meningococci by the formation of cross-reacting antibodies. While most meningococcal strains recovered from patients belong to a limited number of clonal groups worldwide, strains isolated from carriers comprise numerous genotypes, with only a small proportion of the strains representing invasive clones. During the carriage state, co-colonization with other pathogenic and non-pathogenic bacteria may lead to genetic exchange, which may result in the emergence of new meningococcal clones. The high diversity of meningococcal carrier strains, compared with hypervirulent strains, supports the idea that transmissibility, not invasion, is essential in the life cycle of N. meningitidis.
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Affiliation(s)
- Siamak P Yazdankhah
- Department of Airborne Infections, Division of Infectious Disease Control, Norwegian Institute of Public Health, PO Box 4404 Nydalen, NO-0403 Oslo, Norway 2Department of Oral Biology, University of Oslo, Oslo, Norway
| | - Dominique A Caugant
- Department of Airborne Infections, Division of Infectious Disease Control, Norwegian Institute of Public Health, PO Box 4404 Nydalen, NO-0403 Oslo, Norway 2Department of Oral Biology, University of Oslo, Oslo, Norway
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14
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Bäckman A, Orvelid P, Vazquez JA, Sköld O, Olcén P. Complete sequence of a beta-lactamase-encoding plasmid in Neisseria meningitidis. Antimicrob Agents Chemother 2000; 44:210-2. [PMID: 10602753 PMCID: PMC89658 DOI: 10.1128/aac.44.1.210-212.2000] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Identical beta-lactamase-encoding (TEM-1) plasmids were found in two different clinical Neisseria meningitidis strains. They were completely sequenced (5,597 bp) and designated pAB6. The plasmid is almost identical to Neisseria gonorrhoeae plasmid pJD5 (5,599 kb) and may have been picked up from a gonococcus in vivo.
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Affiliation(s)
- A Bäckman
- Department of Clinical Microbiology and Immunology, Orebro Medical Center Hospital, SE-701 85 Orebro, Sweden.
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15
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Roberts MC, Chung WO, Roe D, Xia M, Marquez C, Borthagaray G, Whittington WL, Holmes KK. Erythromycin-resistant Neisseria gonorrhoeae and oral commensal Neisseria spp. carry known rRNA methylase genes. Antimicrob Agents Chemother 1999; 43:1367-72. [PMID: 10348754 PMCID: PMC89280 DOI: 10.1128/aac.43.6.1367] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Two Neisseria gonorrhoeae isolates from Seattle and two isolates from Uruguay were resistant to erythromycin (MIC, 4 to 16 microg/ml) and had reduced susceptibility to azithromycin (MIC, 1 to 4 microg/ml) due to the presence of the self-mobile rRNA methylase gene(s) ermF or ermB and ermF. The two Seattle isolates and one isolate from Uruguay were multiresistant, carrying either the 25.2-MDa tetM-containing plasmid (Seattle) or a beta-lactamase plasmid (Uruguay). Sixteen commensal Neisseria isolates (10 Neisseria perflava-N. sicca, 2 N. flava, and 4 N. mucosa) for which erythromycin MICs were 4 to 16 microg/ml were shown to carry one or more known rRNA methylase genes, including ermB, ermC, and/or ermF. Many of these isolates also were multiresistant and carried the tetM gene. This is the first time that a complete transposon or a complete conjugative transposon carrying an antibiotic resistance gene has been described for the genus Neisseria.
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Affiliation(s)
- M C Roberts
- Department of Pathobiology, University of Washington, Seattle, Washington 98195, USA.
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Nicolas P, Cavallo JD, Fabre R, Martet G. [Standardization of the Neisseria meningitidis antibiogram. Detection of strains relatively resistant to penicillin]. Bull World Health Organ 1998; 76:393-400. [PMID: 9803590 PMCID: PMC2305766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023] Open
Abstract
Studying the susceptibility of 189 Neisseria meningitidis strains to penicillin, amoxicillin, cefotaxime, ceftriaxone, chloramphenicol and rifampicin by determination of minimum inhibitory concentrations (MICs) by agar dilution (reference method), E-test and disc diffusion method on Mueller-Hinton agar at 37 degrees C with 5% CO2 enabled us to standardize the antibiograms. While MIC determination by agar dilution is still the reference method, it is possible to obtain exact or approximate MIC values using the E-test. For laboratories that cannot determine penicillin MICs, it is impossible to detect strains that are relatively resistant to penicillin (RRP strains: 0.1 < or = MIC < or = 1 mg/l) using a 10-U penicillin disc. A 1 microgram-oxacillin disc allows MIC to be determined in most cases when the oxacillin inhibition zone is < or = 10 mm. Such strains must be sent to a reference laboratory for exact MIC determination. Based on our results and literature data on pharmacokinetics, we propose critical concentrations for these various antibiotics as well as critical diameters for chloramphenicol and rifampicin discs.
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Affiliation(s)
- P Nicolas
- Institut de Médecine tropicale du Service de Santé des Armées, France
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Kupsch EM, Aubel D, Gibbs CP, Kahrs AF, Rudel T, Meyer TF. Construction of Hermes shuttle vectors: a versatile system useful for genetic complementation of transformable and non-transformable Neisseria mutants. MOLECULAR & GENERAL GENETICS : MGG 1996; 250:558-69. [PMID: 8676859 DOI: 10.1007/bf02174444] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
A versatile shuttle system has been developed for genetic complementation with cloned genes of transformable and non-transformable Neisseria mutants. By random insertion of a selectable marker into the conjugative Neisseria plasmid ptetM25.2, a site within this plasmid was identified that is compatible with plasmid replication and with conjugative transfer of plasmid. Regions flanking the permissive insertion site of ptetM25.2 were cloned in Escherichia coli and served as a basis for the construction of the Hermes vectors. Hermes vectors are composed of an E. coli replicon that does not support autonomous replication in Neisseria, e.g. ColE1, p15A, or ori(fd), fused with a shuttle consisting of a selectable marker and a multiple cloning site flanked by the integration region of ptetM25.2. Complementation of a non-transformable Neisseria strain involves a three-step process: (i) insertion of the desired gene into a +Hermes vector; (ii) transformation of Hermes into a Neisseria strain containing ptetM25.2 to create a hybrid ptetM25.2 via gene replacement by the Hermes shuttle cassette; and (iii) conjugative transfer of the hybrid ptetM25.2 into the final Neisseria recipient. Several applications for the genetic manipulation of pathogenic Neisseriae are described.
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Affiliation(s)
- E M Kupsch
- Max-Planck-Institut für Biologie, Abteilung Infektionsbiologie, Tübingen, Germany
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Bäckman M, Jacobson K, Ringertz S. The virgin population of Neisseria gonorrhoeae in Stockholm has decreased and antimicrobial resistance is increasing. Genitourin Med 1995; 71:234-8. [PMID: 7590715 PMCID: PMC1195520 DOI: 10.1136/sti.71.4.234] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
AIMS To investigate the evolution of chromosomal and plasmid mediated resistance for ampicillin and tetracycline of N gonorrhoeae strains in Stockholm during 1982-1993. METHODS A total of 404 gonococcal strains isolated in 1982, 1987, 1990, 1992, 1993 were analysed for minimal inhibitory concentrations (MIC) of ampicillin and tetracycline and for plasmid content. MIC values were determined by the agar dilution method and plasmid preparations were performed using alkaline lysis. To detect additional gonococcal strains with tet(M) plasmids all strains isolated in 1988-1989 and 1991, in all 234 isolates, were analysed retrospectively for MIC values of tetracycline. If an MIC value of > or = 4.0 mg/l was recorded plasmid analysis was performed. RESULTS Increased proportions of chromosomally mediated resistance to tetracycline (p < 0.001) as well as plasmid mediated resistance to both ampicillin (p < 0.02) and tetracycline were found in the later part of the study. In 1991 the first gonococcus with tet(M) plasmid was isolated in Sweden. The proportion of strains with chromosomally mediated resistance for ampicillin did not change during the study period. The proportion of gonococcal strains with the 39 kb conjugative plasmid was increased in the later part of the study. CONCLUSIONS The increased proportion of N gonorrhoeae strains with resistance to ampicillin and tetracycline is most likely due to importation of strains from areas with high prevalence of antibiotic resistant gonococci. The proportion of N gonorrhoeae strains with tet(M) plasmids is low in Sweden, but might increase in the same way as the proportion of PPNG strains has increased during 1982-1993.
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Affiliation(s)
- M Bäckman
- Department of Microbiology, Stockholm Söder Hospital, Sweden
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Abstract
Haemophilus ducreyi is a fastidious gram-negative bacillus that causes the sexually transmitted infection chancroid. Chancroid is a major genital ulcerative disease in Africa, Southeast Asia, the Caribbean, and Latin America and is of increasing concern in the United States. Genital ulcerative disease and chancroid in particular have been associated with facilitating the transmission of human immunodeficiency virus. The diagnosis of chancroid based on the clinical appearance of the genital lesion or on the isolation of H. ducreyi on selective medium is relatively insensitive. However, recent advances in nonculture diagnostic tests have enhanced our ability to diagnose chancroid. There has been renewed interest in understanding the pathogenesis of H. ducreyi. In vitro and in vivo models have been developed to help identify important virulence determinants. Through the use of biochemical and molecular techniques, macromolecular components that may be important in virulence have been identified.
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Affiliation(s)
- D L Trees
- Division of Sexually Transmitted Disease, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA
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Winterscheid KK, Whittington WL, Roberts MC, Schwebke JR, Holmes KK. Decreased susceptibility to penicillin G and Tet M plasmids in genital and anorectal isolates of Neisseria meningitidis. Antimicrob Agents Chemother 1994; 38:1661-3. [PMID: 7979304 PMCID: PMC284612 DOI: 10.1128/aac.38.7.1661] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Genital and anorectal isolates of Neisseria meningitidis were characterized, and their antimicrobial susceptibilities were determined. Twelve of 43 isolates demonstrated moderate susceptibility to penicillin G (MIC range, 0.125 to 0.5 microgram/ml). Two isolates were resistant to tetracycline (MIC, > or = 8 micrograms/ml) and contained plasmids of 25.2 MDa.
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Roberts MC. Characterization of the Tet M determinants in urogenital and respiratory bacteria. Antimicrob Agents Chemother 1990; 34:476-8. [PMID: 2159259 PMCID: PMC171619 DOI: 10.1128/aac.34.3.476] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Tetracycline-resistant Fusobacterium nucleatum, Haemophilus ducreyi, Mycoplasma hominis, Peptostreptococcus spp., Ureaplasma urealyticum, and Veillonella parvula had DNA sequences which showed homology throughout the length of the Tet M transposon, Tn916. In contrast, Gardnerella vaginalis, commensal Neisseria spp., and the 25.2-megadalton plasmid family lacked the complete transposon.
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Affiliation(s)
- M C Roberts
- Department of Pathobiology, School of Public Health and Community Medicine, University of Washington, Seattle 98195
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Abstract
A tetracycline-resistant Haemophilus ducreyi strain isolated in the United States was shown to carry a 34-megadalton plasmid which hybridized with the 1.8-kilobase KpnI-HindIII Tet M probe. The complete Tn916 transposon hybridized with five different bands from this plasmid, suggesting homology throughout the length of the transposon.
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Affiliation(s)
- M C Roberts
- Department of Pathobiology, School of Public Health and Community Medicine, University of Washington, Seattle 98195
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Affiliation(s)
- M C Roberts
- Department of Pathobiology, University of Washington, Seattle 98195
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