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Elbeyioglu F, Roberts SB, Spencer-Smith R, Pulijala M, Zelewska MA, Nebel JC, Snyder LAS. Inversion of Correia repeat enclosed elements in Neisseria gonorrhoeae. Microbiology (Reading) 2017; 163:31-36. [DOI: 10.1099/mic.0.000394] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Firat Elbeyioglu
- School of Life Sciences, Pharmacy and Chemistry, Kingston University, Kingston upon Thames KT1 2EE, UK
| | - Sabrina B. Roberts
- School of Life Sciences, Pharmacy and Chemistry, Kingston University, Kingston upon Thames KT1 2EE, UK
| | - Russell Spencer-Smith
- Present address: University of Illinois at Chicago, Chicago, IL, USA
- School of Life Sciences, Pharmacy and Chemistry, Kingston University, Kingston upon Thames KT1 2EE, UK
| | - Madhuri Pulijala
- School of Life Sciences, Pharmacy and Chemistry, Kingston University, Kingston upon Thames KT1 2EE, UK
| | - Marta A. Zelewska
- School of Life Sciences, Pharmacy and Chemistry, Kingston University, Kingston upon Thames KT1 2EE, UK
| | - Jean-Christophe Nebel
- School of Computer Science and Mathematics, Kingston University, Kingston upon Thames KT1 2EE, UK
| | - Lori A. S. Snyder
- School of Life Sciences, Pharmacy and Chemistry, Kingston University, Kingston upon Thames KT1 2EE, UK
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Diallo K, Trotter C, Timbine Y, Tamboura B, Sow SO, Issaka B, Dano ID, Collard JM, Dieng M, Diallo A, Mihret A, Ali OA, Aseffa A, Quaye SL, Bugri A, Osei I, Gamougam K, Mbainadji L, Daugla DM, Gadzama G, Sambo ZB, Omotara BA, Bennett JS, Rebbetts LS, Watkins ER, Nascimento M, Woukeu A, Manigart O, Borrow R, Stuart JM, Greenwood BM, Maiden MCJ. Pharyngeal carriage of Neisseria species in the African meningitis belt. J Infect 2016; 72:667-677. [PMID: 27018131 PMCID: PMC4879866 DOI: 10.1016/j.jinf.2016.03.010] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 03/14/2016] [Accepted: 03/16/2016] [Indexed: 12/29/2022]
Abstract
Objectives Neisseria meningitidis, together with the non-pathogenic Neisseria species (NPNs), are members of the complex microbiota of the human pharynx. This paper investigates the influence of NPNs on the epidemiology of meningococcal infection. Methods Neisseria isolates were collected during 18 surveys conducted in six countries in the African meningitis belt between 2010 and 2012 and characterized at the rplF locus to determine species and at the variable region of the fetA antigen gene. Prevalence and risk factors for carriage were analyzed. Results A total of 4694 isolates of Neisseria were obtained from 46,034 pharyngeal swabs, a carriage prevalence of 10.2% (95% CI, 9.8–10.5). Five Neisseria species were identified, the most prevalent NPN being Neisseria lactamica. Six hundred and thirty-six combinations of rplF/fetA_VR alleles were identified, each defined as a Neisseria strain type. There was an inverse relationship between carriage of N. meningitidis and of NPNs by age group, gender and season, whereas carriage of both N. meningitidis and NPNs was negatively associated with a recent history of meningococcal vaccination. Conclusion Variations in the prevalence of NPNs by time, place and genetic type may contribute to the particular epidemiology of meningococcal disease in the African meningitis belt. A prevalence of 10.2% of Neisseria infection was observed during the study. Five Neisseria species were identified in nasopharyngeal samples. High level of genetic diversity was observed in carried isolates. Inverse relationship between carriage of Neisseria meningitidis and non-pathogenic Neisseria.
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Affiliation(s)
- Kanny Diallo
- Centre pour les Vaccins en Développement, Bamako, Mali; Department of Zoology, University of Oxford, Oxford, UK.
| | - Caroline Trotter
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | | | | | - Samba O Sow
- Centre pour les Vaccins en Développement, Bamako, Mali
| | - Bassira Issaka
- Centre de Recherche Médicale et Sanitaire, Niamey, Niger
| | - Ibrahim D Dano
- Centre de Recherche Médicale et Sanitaire, Niamey, Niger
| | | | - Marietou Dieng
- Institut de Recherche pour le Développement, Dakar, Senegal
| | | | - Adane Mihret
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Oumer A Ali
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Abraham Aseffa
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | | | | | - Isaac Osei
- Navrongo Health Research Centre, Navrongo, Ghana
| | | | | | | | | | | | | | | | | | | | | | - Arouna Woukeu
- London School of Hygiene & Tropical Medicine, London, UK
| | | | - Ray Borrow
- Vaccine Evaluation Unit, Public Health England, Manchester, UK
| | - James M Stuart
- London School of Hygiene & Tropical Medicine, London, UK
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Tsang RSW, Hoang L, Tyrrell G, Horsman G, Wylie J, Jamieson FB, Lefebvre B, Taha MK. Genetic and antigenic characterization of Canadian invasive Neisseria meningitidis serogroup C (MenC) case isolates in the post-MenC conjugate vaccine era, 2009–2013. J Med Microbiol 2015. [DOI: 10.1099/jmm.0.000006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Affiliation(s)
- Raymond S. W. Tsang
- Vaccine Preventable Bacterial Diseases, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Linda Hoang
- BC Public Health Microbiology and Reference Laboratory, Vancouver, British Columbia, Canada
| | - Gregory Tyrrell
- Provincial Laboratory for Public Health, Edmonton, Alberta, Canada
| | - Greg Horsman
- Saskatchewan Disease Control Laboratory, Regina, Saskatchewan, Canada
| | - John Wylie
- Cadham Provincial Public Health Laboratory, Winnipeg, Manitoba, Canada
| | - Frances B. Jamieson
- Faculty of Medicine, University of Toronto, Ontario, Canada
- Public Health Ontario Laboratory, Public Health Ontario, Ontario, Canada
| | - Brigitte Lefebvre
- Laboratoire de Santé Publique du Québec, Institut National de Santé Publique du Québec, Sainte-Anne-de-Bellevue, Québec, Canada
| | - Muhamed-Kheir Taha
- Institut Pasteur, Invasive Bacterial Infections Unit and National Reference Centre for Meningococci, Paris, France
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Abstract
Bacterial genomes are remarkably stable from one generation to the next but are plastic on an evolutionary time scale, substantially shaped by horizontal gene transfer, genome rearrangement, and the activities of mobile DNA elements. This implies the existence of a delicate balance between the maintenance of genome stability and the tolerance of genome instability. In this review, we describe the specialized genetic elements and the endogenous processes that contribute to genome instability. We then discuss the consequences of genome instability at the physiological level, where cells have harnessed instability to mediate phase and antigenic variation, and at the evolutionary level, where horizontal gene transfer has played an important role. Indeed, this ability to share DNA sequences has played a major part in the evolution of life on Earth. The evolutionary plasticity of bacterial genomes, coupled with the vast numbers of bacteria on the planet, substantially limits our ability to control disease.
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5
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Anderson AS, Jansen KU, Eiden J. New frontiers in meningococcal vaccines. Expert Rev Vaccines 2014; 10:617-34. [DOI: 10.1586/erv.11.50] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Oldfield NJ, Matar S, Bidmos FA, Alamro M, Neal KR, Turner DPJ, Bayliss CD, Ala’Aldeen DAA. Prevalence and phase variable expression status of two autotransporters, NalP and MspA, in carriage and disease isolates of Neisseria meningitidis. PLoS One 2013; 8:e69746. [PMID: 23936091 PMCID: PMC3723659 DOI: 10.1371/journal.pone.0069746] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Accepted: 06/12/2013] [Indexed: 01/24/2023] Open
Abstract
Neisseria meningitidis is a human nasopharyngeal commensal capable of causing life-threatening septicemia and meningitis. Many meningococcal surface structures, including the autotransporter proteins NalP and MspA, are subject to phase variation (PV) due to the presence of homopolymeric tracts within their coding sequences. The functions of MspA are unknown. NalP proteolytically cleaves several surface-located virulence factors including the 4CMenB antigen NhbA. Therefore, NalP is a phase-variable regulator of the meningococcal outer membrane and secretome whose expression may reduce isolate susceptibility to 4CMenB-induced immune responses. To improve our understanding of the contributions of MspA and NalP to meningococcal-host interactions, their distribution and phase-variable expression status was studied in epidemiologically relevant samples, including 127 carriage and 514 invasive isolates representative of multiple clonal complexes and serogroups. Prevalence estimates of >98% and >88% were obtained for mspA and nalP, respectively, with no significant differences in their frequencies in disease versus carriage isolates. 16% of serogroup B (MenB) invasive isolates, predominately from clonal complexes ST-269 and ST-461, lacked nalP. Deletion of nalP often resulted from recombination events between flanking repetitive elements. PolyC tract lengths ranged from 6–15 bp in nalP and 6–14 bp in mspA. In an examination of PV status, 58.8% of carriage, and 40.1% of invasive nalP-positive MenB isolates were nalP phase ON. The frequency of this phenotype was not significantly different in serogroup Y (MenY) carriage strains, but was significantly higher in invasive MenY strains (86.3%; p<0.0001). Approximately 90% of MenB carriage and invasive isolates were mspA phase ON; significantly more than MenY carriage (32.7%) or invasive (13.7%) isolates. This differential expression resulted from different mode mspA tract lengths between the serogroups. Our data indicates a differential requirement for NalP and MspA expression in MenB and MenY strains and is a step towards understanding the contributions of phase-variable loci to meningococcal biology.
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Affiliation(s)
- Neil J. Oldfield
- Molecular Bacteriology and Immunology Group, School of Molecular Medical Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Suzan Matar
- Molecular Bacteriology and Immunology Group, School of Molecular Medical Sciences, University of Nottingham, Nottingham, United Kingdom
- Department of Biological Sciences and Medical Analysis, University of Jordan, Amman, Jordan
| | - Fadil A. Bidmos
- Department of Genetics, University of Leicester, Leicester, United Kingdom
| | - Mohammed Alamro
- Department of Genetics, University of Leicester, Leicester, United Kingdom
| | - Keith R. Neal
- School of Community Health Sciences, University of Nottingham, Nottingham, United Kingdom
| | - David P. J. Turner
- Molecular Bacteriology and Immunology Group, School of Molecular Medical Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Christopher D. Bayliss
- School of Community Health Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Dlawer A. A. Ala’Aldeen
- Molecular Bacteriology and Immunology Group, School of Molecular Medical Sciences, University of Nottingham, Nottingham, United Kingdom
- * E-mail:
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Genetic distribution of noncapsular meningococcal group B vaccine antigens in Neisseria lactamica. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2013; 20:1360-9. [PMID: 23803905 DOI: 10.1128/cvi.00090-13] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The poor immunogenicity of the meningococcal serogroup B (MenB) capsule has led to the development of vaccines targeting subcapsular antigens, in particular the immunodominant and diverse outer membrane porin, PorA. These vaccines are largely strain specific; however, they offer limited protection against the diverse MenB-associated diseases observed in many industrialized nations. To broaden the scope of its protection, the multicomponent vaccine (4CMenB) incorporates a PorA-containing outer membrane vesicle (OMV) alongside relatively conserved recombinant protein components, including factor H-binding protein (fHbp), Neisseria adhesin A (NadA), and neisserial heparin-binding antigen (NHBA). The expression of PorA is unique to meningococci (Neisseria meningitidis); however, many subcapsular antigens are shared with nonpathogenic members of the genus Neisseria that also inhabit the nasopharynx. These organisms may elicit cross-protective immunity against meningococci and/or occupy a niche that might otherwise accommodate pathogens. The potential for 4CMenB responses to impact such species (and vice versa) was investigated by determining the genetic distribution of the primary 4CMenB antigens among diverse members of the common childhood commensal, Neisseria lactamica. All the isolates possessed nhba but were devoid of fhbp and nadA. The nhba alleles were mainly distinct from but closely related to those observed among a representative panel of invasive MenB isolates from the same broad geographic region. We made similar findings for the immunogenic typing antigen, FetA, which constitutes a major part of the 4CMenB OMV. Thus, 4CMenB vaccine responses may impact or be impacted by nasopharyngeal carriage of commensal neisseriae. This highlights an area for further research and surveillance should the vaccine be routinely implemented.
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Clonal analysis of Neisseria meningitidis serogroup B strains in South Africa, 2002 to 2006: emergence of new clone ST-4240/6688. J Clin Microbiol 2012; 50:3678-86. [PMID: 22972827 DOI: 10.1128/jcm.01079-12] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
From August 1999 through July 2002, hyperinvasive Neisseria meningitidis serogroup B (MenB) clonal complexes (CCs), namely, ST-32/ET-5 (CC32) and ST-41/44/lineage 3 (CC41/44), were predominant in the Western Cape Province of South Africa. This study analyzed MenB invasive isolates from a national laboratory-based surveillance system that were collected from January 2002 through December 2006. Isolates were characterized by pulsed-field gel electrophoresis (PFGE) (n = 302), and multilocus sequence typing (MLST) and PorA and FetA typing were performed on randomly selected isolates (34/302, 11%). In total, 2,400 cases were reported, with the highest numbers from Gauteng Province (1,307/2,400, 54%) and Western Cape Province (393/2,400, 16%); 67% (1,617/2,400) had viable isolates and 19% (307/1,617) were identified as serogroup B. MenB incidence remained stable over time (P = 0.77) (average incidence, 0.13/100,000 population [range, 0.10 to 0.16/100,000 population]). PFGE (302/307, 98%) divided isolates (206/302, 68%) into 13 clusters and 96 outliers. The largest cluster, B1, accounted for 25% of isolates (76/302) over the study period; its prevalence decreased from 43% (20/47) in 2002 to 13% (8/62) in 2006 (P < 0.001), and it was common in the Western Cape (58/76, 76%). Clusters B2 and B3 accounted for 10% (31/302) and 6% (19/302), respectively, and showed no significant change over time and were predominant in Gauteng. Randomly selected isolates from clusters B1, B2, and B3 belonged to CC32, CC41/44, and the new CC4240/6688, respectively. Overall, 15 PorA and 12 FetA types were identified. MenB isolates were mostly diverse with no single dominant clone; however, CC32 and CC41/44 accounted for 35% and the new CC4240/6688 was the third most prevalent clone.
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9
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Klena JD, Wasfy MO, Nada RA, Ahmed SF, Maksoud MA, Marfin A, Pimentel G. Characterization of Neisseria meningitidis isolates from Egypt using multilocus sequence typing. Trans R Soc Trop Med Hyg 2012; 106:309-14. [PMID: 22405492 DOI: 10.1016/j.trstmh.2012.01.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2011] [Revised: 01/23/2012] [Accepted: 01/23/2012] [Indexed: 10/28/2022] Open
Abstract
To characterize Neisseria meningitidis isolates collected from cerebrospinal fluid of meningitis cases in Egypt (1998-2003) as part of surveillance studies, 67 isolates were serogrouped, tested for antibiotic sensitivity and analyzed using multilocus sequence typing (MLST). Results show that isolates expressing serogroup B (50.7%) and serogroup A (34.3%) antigens were predominant in Egypt during the surveillance period, possibly due to suppression of other serogroups by meningococcal vaccines in current use. Intermediate resistance to penicillin was observed in 71% of the isolates, suggesting a need for physicians to shift to third-generation cephalosporins during the empirical treatment of infection. Recurrent lineages of N. meningitidis in Egypt appear to originate from Europe and other Middle Eastern countries. Of 19 sequence types detected, five were unique to Africa and 10 were not observed previously in the MLST database. The information obtained illustrates the changing dynamics of meningitis after vaccine introduction in Egypt.
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Affiliation(s)
- John D Klena
- US Naval Medical Research Unit No. 3, Cairo, Egypt.
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10
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Characterization of Neisseria meningitidis isolates that do not express the virulence factor and vaccine antigen factor H binding protein. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2011; 18:1002-14. [PMID: 21508163 DOI: 10.1128/cvi.00055-11] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Neisseria meningitidis remains a leading cause of bacterial sepsis and meningitis. Complement is a key component of natural immunity against this important human pathogen, which has evolved multiple mechanisms to evade complement-mediated lysis. One approach adopted by the meningococcus is to recruit a human negative regulator of the complement system, factor H (fH), to its surface via a lipoprotein, factor H binding protein (fHbp). Additionally, fHbp is a key antigen in vaccines currently being evaluated in clinical trials. Here we characterize strains of N. meningitidis from several distinct clonal complexes which do not express fHbp; all strains were recovered from patients with disseminated meningococcal disease. We demonstrate that these strains have either a frameshift mutation in the fHbp open reading frame or have entirely lost fHbp and some flanking sequences. No fH binding was detected to other ligands among the fHbp-negative strains. The implications of these findings for meningococcal pathogenesis and prevention are discussed.
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Bertrand S, Van Meervenne E, De Baere T, Vanhoof R, Collard JM, Ruckly C, Taha M, Carion F. Detection of a geographical and endemic cluster of hyper-invasive meningococcal strains. Microbes Infect 2011; 13:684-90. [PMID: 21376133 DOI: 10.1016/j.micinf.2011.02.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2010] [Revised: 02/01/2011] [Accepted: 02/17/2011] [Indexed: 01/10/2023]
Abstract
From 2006 to December 2009, 45 out of the 513 strains isolated from patients with invasive meningococcal disease in Belgium, were identified as Neisseria meningitidis serogroup B, non-serotypeable, subtype P1.14 (B:NT:P1.14). Most cases were geographically clustered in the northern part of the country. Multilocus Sequence Typing and antigen gene sequencing combined with Pulsed-Field Gel electrophoresis were used to investigate this cluster. Molecular typing showed that 39 out of these 45 N. meningitidis strains belonged to the clonal complex cc-269. The presence of the same PorA Variable Regions (VR1-VR2: 22, 14), the FetA allele (F5-1) and the highly similar Pulsed-Field Gel Electrophoresis profiles, supported genetic relatedness for 38 out of these 39 isolates. Retrospective analysis of B:NT:P1.22,14 isolates from 1999 onwards suggested that these strains belonging to the cc-269 complex, first emerged in the Belgian province of West-Flanders in 2004. This study showed that the combination of molecular tools with classical methods enabled reliable outbreak detection as well as a cluster identification.
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Affiliation(s)
- Sophie Bertrand
- National Reference Centre for Neisseria meningitidis, Bacterial Diseases Division, Communicable and Infectious Diseases, Scientific Institute of Public Health, J. Wytsman Street, 14-16, B-1050 Brussels, Belgium.
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Mothibeli KM, du Plessis M, von Gottberg A, Murphy E, Hoiseth SK, Zlotnick G, Klugman KP. Distribution of factor H binding protein beyond serogroup B: Variation among five serogroups of invasive Neisseria meningitidis in South Africa. Vaccine 2011; 29:2187-92. [PMID: 21144918 DOI: 10.1016/j.vaccine.2010.11.072] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2010] [Revised: 11/11/2010] [Accepted: 11/20/2010] [Indexed: 10/18/2022]
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13
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Harrison LH, Shutt KA, Schmink SE, Marsh JW, Harcourt BH, Wang X, Whitney AM, Stephens DS, Cohn AA, Messonnier NE, Mayer LW. Population structure and capsular switching of invasive Neisseria meningitidis isolates in the pre-meningococcal conjugate vaccine era--United States, 2000-2005. J Infect Dis 2010; 201:1208-24. [PMID: 20199241 DOI: 10.1086/651505] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND A quadrivalent meningococcal conjugate vaccine (MCV4) was licensed in the United States in 2005; no serogroup B vaccine is available. Neisseria meningitidis changes its capsular phenotype through capsular switching, which has implications for vaccines that do not protect against all serogroups. METHODS Meningococcal isolates from 10 Active Bacterial Core surveillance sites from 2000 through 2005 were analyzed to identify changes occurring after MCV4 licensure. Isolates were characterized by multilocus sequence typing (MLST) and outer membrane protein gene sequencing. Isolates expressing capsular polysaccharide different from that associated with the MLST lineage were considered to demonstrate capsular switching. RESULTS Among 1160 isolates, the most common genetic lineages were the sequence type (ST)-23, ST-32, ST-11, and ST-41/44 clonal complexes. Of serogroup B and Y isolates, 8 (1.5%) and 3 (0.9%), respectively, demonstrated capsular switching, compared with 36 (12.9%) for serogroup C (P < .001); most serogroup C switches were from virulent serogroup B and/or serogroup Y lineages. CONCLUSIONS A limited number of genetic lineages caused the majority of invasive meningococcal infections. A substantial proportion of isolates had evidence of capsular switching. The high prevalence of capsular switching requires surveillance to detect changes in the meningococcal population structure that may affect the effectiveness of meningococcal vaccines.
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Affiliation(s)
- Lee H Harrison
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA.
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Abad R, Agudelo CI, Brandileone MC, Chanto G, Gabastou JM, Hormazabal JC, O Gorla MC, Maldonado A, Moreno J, Muros-Le Rouzic E, Lersch R, Regueira M, Salcedo C, Sorhouet C, Vázquez JA. Molecular characterization of invasive serogroup Y Neisseria meningitidis strains isolated in the Latin America region. J Infect 2009; 59:104-14. [PMID: 19576638 DOI: 10.1016/j.jinf.2009.06.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2009] [Revised: 06/02/2009] [Accepted: 06/02/2009] [Indexed: 11/16/2022]
Abstract
OBJECTIVES To improve the understanding of serogroup Y invasive meningococcal disease (IMD) in Latin America, particularly IMD molecular epidemiology; 166 Y serogroup isolates received at the National Reference Laboratories of Argentina, Brazil, Chile, Colombia, and Costa Rica during 2000-2006 were characterized by their molecular markers. METHODS This analysis included serological assays to determine serogroup/serotype/serosubtype, DNA sequencing and genotyping of the porB and/or porA genes, multilocus sequence typing (MLST) and fetA allele determination. RESULTS Sixteen different antigenic combinations were observed. Sixty-two (37.3%) isolates were NT:P1.5 and 36 (21.7%) isolates were 14:NST. Thirty-two different STs appeared, but 3 STs (ST-1624, ST-23, and ST-5770) accounted for 69.9% (116) of the strains. Most of the IMD isolates belonged to the ST-23, ST-167 clonal complexes or the group composed by ST-5770 and related STs. CONCLUSIONS Isolates obtained in Colombia and Costa Rica were similar to that of the United States, in that most sequence types belonged to the ST-23 clonal complex. IMD isolates found in Argentina appear to be the result of an independent event and did not spread from nearby countries, being the sequence type ST-1624 (ST-167 clonal complex) the most frequently found. We were unable to correlate an antigenic shift of outer membrane proteins with an increase of serogroup Y meningococcal cases in our collection of isolates.
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Affiliation(s)
- Raquel Abad
- Reference Laboratory for Meningococci, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Ctra Majadahonda-Pozuelo, Km2, 28220 Majadahonda, Madrid, Spain
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Comparative analysis of two Neisseria gonorrhoeae genome sequences reveals evidence of mobilization of Correia Repeat Enclosed Elements and their role in regulation. BMC Genomics 2009; 10:70. [PMID: 19203353 PMCID: PMC2649163 DOI: 10.1186/1471-2164-10-70] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2008] [Accepted: 02/09/2009] [Indexed: 11/22/2022] Open
Abstract
Background The Correia Repeat Enclosed Element (CREE) of the Neisseria spp., with its inverted repeat and conserved core structure, can generate a promoter sequence at either or both ends, can bind IHF, and can bind RNase III and either be cleaved by it or protected by it. As such, the presence of this element can directly control the expression of adjacent genes. Previous work has shown differences in regulation of gene expression between neisserial strains and species due to the presence of a CREE. These interruptions perhaps remove the expression of CREE-associated genes from ancestral neisserial regulatory networks. Results Analysis of the chromosomal locations of the CREE in Neisseria gonorrhoeae strain FA1090 and N. gonorrhoeae strain NCCP11945 has revealed that most of the over 120 copies of the element are conserved in location between these genome sequences. However, there are some notable exceptions, including differences in the presence and sequence of CREE 5' of copies of the opacity protein gene opa, differences in the potential to bind IHF, and differences in the potential to be cleaved by RNase III. Conclusion The presence of CREE insertions in one strain relative to the other, CREE within a prophage region, and CREE disrupting coding sequences, provide strong evidence of mobility of this element in N. gonorrhoeae. Due to the previously demonstrated role of these elements in altering transcriptional control and the findings from comparing the two gonococcal genome sequences, it is suggested that regulatory differences orchestrated by CREE contribute to the differences between strains and also between the closely related yet clinically distinct species N. gonorrhoeae, Neisseria meningitidis, and Neisseria lactamica.
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Bennett JS, Thompson EAL, Kriz P, Jolley KA, Maiden MCJ. A common gene pool for the Neisseria FetA antigen. Int J Med Microbiol 2009; 299:133-9. [PMID: 18718812 PMCID: PMC3968273 DOI: 10.1016/j.ijmm.2008.06.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2007] [Revised: 04/10/2008] [Accepted: 06/24/2008] [Indexed: 11/25/2022] Open
Abstract
Meningococcal FetA is an iron-regulated, immunogenic outer membrane protein and vaccine component. The most diverse region of this protein is a previously defined variable region (VR) that has been shown to be immunodominant. In this analysis, a total of 275 Neisseria lactamica isolates, collected during studies of nasopharyngeal bacterial carriage in infants, were examined for the presence of a fetA gene. The fetA VR nucleotide sequence was determined for 217 of these isolates, with fetA apparently absent from 58 isolates, the majority of which belonged to the ST-624 clonal complex. The VR in N. lactamica was compared to the same region in N. meningitidis, N. gonorrhoeae, and a number of other commensal Neisseria. Identical fetA variable region sequences were identified among commensal and pathogenic Neisseria, suggesting a common gene pool, differing from other antigens in this respect. Carriage of commensal Neisseria species, such as N. lactamica, that express FetA may be involved in the development of natural immunity to meningococcal disease.
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Affiliation(s)
- Julia S Bennett
- Department of Zoology, The Peter Medawar Building for Pathogen Research, University of Oxford, Oxford, UK.
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Caugant DA. Genetics and evolution of Neisseria meningitidis: importance for the epidemiology of meningococcal disease. INFECTION GENETICS AND EVOLUTION 2008; 8:558-65. [PMID: 18479979 DOI: 10.1016/j.meegid.2008.04.002] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2008] [Revised: 04/01/2008] [Accepted: 04/02/2008] [Indexed: 11/30/2022]
Abstract
Meningococcal disease is a life-threatening illness occurring worldwide with incidence rates varying from 1 to 1000 cases per 100,000. The causative organism, Neisseria meningitidis, is a normal commensal of humans. While strains associated with asymptomatic carriage are highly diverse, a few hyper-invasive genetic clones of the species may spread rapidly through human populations, resulting in countrywide epidemics of meningococcal meningitis. N. meningitidis fitness for spread and colonization is directly linked to the capability of the bacterium to change its genome and adapt to its environment, by means of a variety of genetic mechanisms. This review addresses some of the impacts of the evolutionary potential of N. meningitidis on the occurrence of meningococcal disease.
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Affiliation(s)
- Dominique A Caugant
- WHO Collaborating Centre for Reference and Research on Meningococci, Department of Bacteriology and Immunology, Norwegian Institute of Public Health, P.O. Box 4404 Nydalen, NO-0403 Oslo, Norway.
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Whole-genome comparison of disease and carriage strains provides insights into virulence evolution in Neisseria meningitidis. Proc Natl Acad Sci U S A 2008; 105:3473-8. [PMID: 18305155 DOI: 10.1073/pnas.0800151105] [Citation(s) in RCA: 135] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Neisseria meningitidis is a leading cause of infectious childhood mortality worldwide. Most research efforts have hitherto focused on disease isolates belonging to only a few hypervirulent clonal lineages. However, up to 10% of the healthy human population is temporarily colonized by genetically diverse strains mostly with little or no pathogenic potential. Currently, little is known about the biology of carriage strains and their evolutionary relationship with disease isolates. The expression of a polysaccharide capsule is the only trait that has been convincingly linked to the pathogenic potential of N. meningitidis. To gain insight into the evolution of virulence traits in this species, whole-genome sequences of three meningococcal carriage isolates were obtained. Gene content comparisons with the available genome sequences from three disease isolates indicate that there is no core pathogenome in N. meningitidis. A comparison of the chromosome structure suggests that a filamentous prophage has mediated large chromosomal rearrangements and the translocation of some candidate virulence genes. Interspecific comparison of the available Neisseria genome sequences and dot blot hybridizations further indicate that the insertion sequence IS1655 is restricted only to N. meningitidis; its low sequence diversity is an indicator of an evolutionarily recent population bottleneck. A genome-based phylogenetic reconstruction provides evidence that N. meningitidis has emerged as an unencapsulated human commensal from a common ancestor with Neisseria gonorrhoeae and Neisseria lactamica and consecutively acquired the genes responsible for capsule synthesis via horizontal gene transfer.
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