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Unemo, Magnus
Publications (10 of 18) Show all publications
Lundbäck, D., Fredlund, H., Berglund, T., Wretlind, B. & Unemo, M. (2006). Molecular epidemiology of Neisseria gonorrhoeae-identification of the first presumed Swedish transmission chain of an azithromycin-resistant strain.. Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS), 114(1), 67-71
Open this publication in new window or tab >>Molecular epidemiology of Neisseria gonorrhoeae-identification of the first presumed Swedish transmission chain of an azithromycin-resistant strain.
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2006 (English)In: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS), ISSN 0903-4641, E-ISSN 1600-0463, Vol. 114, no 1, p. 67-71Article in journal (Refereed) Published
Abstract [en]

In the present study, 10 azithromycin-resistant Neisseria gonorrhoeae isolates from 6 Swedish male patients in 2004, 3 sporadic Swedish azithromycin-resistant N. gonorrhoeae isolates from recent years and one Swedish N. gonorrhoeae isolate from 2003 that was susceptible to azithromycin but assigned the same serological variant (serovar), i.e. IB-37, as the isolates from 2004 were included. The isolates were characterized phenotypically using antibiograms and serovar determination and genetically with pulsed-field gel electrophoresis (PFGE), entire porB gene sequencing and N. gonorrhoeae multiantigen sequence typing (NG-MAST). The epidemiological information and the results of the thorough phenotypic characterisation and genetic characterisation identified the first presumed domestic transmission of one azithromycin-resistant N. gonorrhoeae strain in Sweden in 2004. This stresses the need for continuous surveillance of the antibiotic susceptibility of N. gonorrhoeae in order to identify emergence of new resistance, monitor the changing patterns of the susceptibility, and be able to update treatment recommendations on a regular basis.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-33256 (URN)10.1111/j.1600-0463.2006.apm_332.x (DOI)19255 (Local ID)19255 (Archive number)19255 (OAI)
Available from: 2009-10-09 Created: 2009-10-09 Last updated: 2017-12-13
Jacobsson, S., Thulin, S., Mölling, P., Unemo, M., Comanducci, M., Rappuoli, R. & Olcén, P. (2006). Sequence constancies and variations in genes encoding three new meningococcal vaccine candidate antigens. Vaccine, 24(12), 2161-2168
Open this publication in new window or tab >>Sequence constancies and variations in genes encoding three new meningococcal vaccine candidate antigens
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2006 (English)In: Vaccine, ISSN 0264-410X, E-ISSN 1873-2518, Vol. 24, no 12, p. 2161-2168Article in journal (Refereed) Published
Abstract [en]

By the strategy “reverse vaccinology” a number of new antigens have been identified in Neisseria meningitidis, which are potential candidates for a highly needed broad-spectrum meningococcal vaccine. In the present study we examined the prevalence, sequence constancies and variations of the genes encoding three of these new antigens designated, genome-derived neisserial antigen (GNA) 1870, GNA1946 and GNA2132. All three genes were present in all N. meningitidis isolates tested. Concerning gna1870, three major variants of the gene sequences and deduced amino acid sequences were identified and 56% of the deduced amino acids were conserved in all isolates. In gna1946, 98% of the deduced amino acids were conserved and in gna2132, 54% of the deduced amino acids were conserved. Based on gene prevalence and conservation, all three antigens are promising candidates for an effective meningococcal vaccine against all N. meningitidis irrespective of serogroup.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-33472 (URN)10.1016/j.vaccine.2005.11.006 (DOI)19495 (Local ID)19495 (Archive number)19495 (OAI)
Available from: 2009-10-09 Created: 2009-10-09 Last updated: 2017-12-13Bibliographically approved
Thulin, S., Olcén, P., Fredlund, H. & Unemo, M. (2006). Total variation in the penA gene of Neisseria meningitides: Correlation between susceptibility to beta-lactam antibiotics and penA gene heterogeneity.. Antimicrobial Agents and Chemotherapy, 50(10), 3317-3324
Open this publication in new window or tab >>Total variation in the penA gene of Neisseria meningitides: Correlation between susceptibility to beta-lactam antibiotics and penA gene heterogeneity.
2006 (English)In: Antimicrobial Agents and Chemotherapy, ISSN 0066-4804, E-ISSN 1098-6596, Vol. 50, no 10, p. 3317-3324Article in journal (Refereed) Published
Abstract [en]

In recent decades, the prevalence of Neisseria meningitidis isolates with reduced susceptibility to penicillins has increased. The intermediate resistance to penicillin (Peni) for most strains is due mainly to mosaic structures in the penA gene, encoding penicillin-binding protein 2. In this study, susceptibility to ß-lactam antibiotics was determined for 60 Swedish clinical N. meningitidis isolates and 19 reference strains. The penA gene was sequenced and compared to 237 penA sequences from GenBank in order to explore the total identified variation of penA. The divergent mosaic alleles differed by 3% to 24% compared to those of the designated wild-type penA gene. By studying the final 1,143 to 1,149 bp of penA in a sequence alignment, 130 sequence variants were identified. In a 402-bp alignment of the most variable regions, 84 variants were recognized. Good correlation between elevated MICs and the presence of penA mosaic structures was found especially for penicillin G and ampicillin. The Peni isolates comprised an MIC of >0.094 µg/ml for penicillin G and an MIC of >0.064 µg/ml for ampicillin. Ampicillin was the best antibiotic for precise categorization as Pens or Peni. In comparison with the wild-type penA sequence, two specific Peni sites were altered in all except two mosaic penA sequences, which were published in GenBank and no MICs of the corresponding isolates were described. In conclusion, monitoring the relationship between penA sequences and MICs to penicillins is crucial for developing fast and objective methods for susceptibility determination. By studying the penA gene, genotypical determination of susceptibility in culture-negative cases can also be accomplished.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-37340 (URN)10.1128/AAC.00353-06 (DOI)34682 (Local ID)34682 (Archive number)34682 (OAI)
Available from: 2009-10-10 Created: 2009-10-10 Last updated: 2017-12-13
Fjeldsoe-Nielsen, H., Unemo, M., Fredlund, H., Hjorth, S., Berthelsen, L., Palmer, H. & Friis-Möller, A. (2005). Phenotypic and genotypic characterization of prolyliminopeptidase-negative Neisseria gonorrhoeae isolates in Denmark.. European Journal of Clinical Microbiology and Infectious Diseases, 24(4), 280-283
Open this publication in new window or tab >>Phenotypic and genotypic characterization of prolyliminopeptidase-negative Neisseria gonorrhoeae isolates in Denmark.
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2005 (English)In: European Journal of Clinical Microbiology and Infectious Diseases, ISSN 0934-9723, E-ISSN 1435-4373, Vol. 24, no 4, p. 280-283Article in journal (Refereed) Published
Abstract [en]

In the study presented here 26 recent Danish clinical isolates of prolyliminopeptidase (PIP)-negative Neisseria gonorrhoeae were phenotypically and genotypically characterized to investigate whether one or more PIP-negative strains are circulating in the Danish community. The profiles of these isolates were compared with those of three isolates from a recent outbreak of PIP-negative N. gonorrhoeae infection in the UK. Twenty-five of the Danish isolates and all three UK isolates had similar antibiograms and were designated serovar IB-4. Genotypic characterization by pulsed-field gel electrophoresis, porB1b gene sequencing, and opa-typing revealed that these isolates were indistinguishable or closely related. The results indicate that at least one PIP-negative N. gonorrhoeae strain is currently circulating in the Danish community, and this strain is indistinguishable from the one that caused an outbreak in the UK.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-32357 (URN)10.1007/s10096-005-1319-5 (DOI)18252 (Local ID)18252 (Archive number)18252 (OAI)
Available from: 2009-10-09 Created: 2009-10-09 Last updated: 2017-12-13
Unemo, M., Norlén, O. & Fredlund, H. (2005). The por A pseudogene of Neisseria gonorrhoeae - low level of genetic polymorphism and a few, mainly identical, inactivating mutations.. Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS), 113(6), 410-419
Open this publication in new window or tab >>The por A pseudogene of Neisseria gonorrhoeae - low level of genetic polymorphism and a few, mainly identical, inactivating mutations.
2005 (English)In: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS), ISSN 0903-4641, E-ISSN 1600-0463, Vol. 113, no 6, p. 410-419Article in journal (Refereed) Published
Abstract [en]

N. meningitidis is the only Neisseria species known to express two outer membrane porins, PorA and PorB. However, a porA pseudogene has been identified in N. gonorrhoeae. The present study investigated the prevalence and genetic polymorphism of this porA pseudogene in 87 different N. gonorrhoeae strains. The porA pseudogene was identified in all isolates. The pseudogene comprised 12 (5.5%), of which 10 were located in the promoter spacer, and 11 (1.0%) polymorphic nucleotide sites in the upstream segment containing the promoter region, i.e. the putative -10 and -35 sequences and the promoter spacer in-between, and the hypothetical PorA coding sequence, respectively. A phylogenetic analysis of the upstream segment and the hypothetical coding sequence identified 36 sequence variants, of which 30 were not previously described. All strains comprised at least two identical confirmed inactivating deletions, of which one was located in the promoter region and one in the hypothetical PorA coding sequence. In conclusion, the porA pseudogene and its few inactivating mutations are widespread in the N. gonorrhoeae population and the homology with the N. meningitidis porA gene reflects their common evolutionary origin. The highly conserved N. gonorrhoeae porA pseudogene may reflect an evolutionary neutral molecular clock and may be a suitable genetic target for diagnosis of N. gonorrhoeae.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-32358 (URN)10.1111/j.1600-0463.2005.apm_206.x (DOI)18253 (Local ID)18253 (Archive number)18253 (OAI)
Available from: 2009-10-09 Created: 2009-10-09 Last updated: 2017-12-13
Unemo, M., Olcén, P., Jonasson, J. & Fredlund, H. (2004). Molecular typing of Neisseria gonorrhoeae isolates by pyrosequencing of highly polymorphic segments of the porB gene. Journal of Clinical Microbiology, 42(7), 2926-2934
Open this publication in new window or tab >>Molecular typing of Neisseria gonorrhoeae isolates by pyrosequencing of highly polymorphic segments of the porB gene
2004 (English)In: Journal of Clinical Microbiology, ISSN 0095-1137, E-ISSN 1098-660X, Vol. 42, no 7, p. 2926-2934Article in journal (Refereed) Published
Abstract [en]

For prevention and control of gonorrhea, an objective, highly discriminating, and reproducible molecular epidemiological characterization of Neisseria gonorrhoeae is essential. In the present study, in pursuance of providing such qualities, pyrosequencing technology, a fast real-time DNA sequence analysis, was applied to six short, highly polymorphic porB gene segments, with subsequent genetic variant (genovar) determination of the bacterial isolates. The sequencing templates were obtained by real-time PCR amplification, which also included fluorescence melting curve analysis of the entire porB gene in order to determine the genogroup (porB1a or porB1b allele) prior to pyrosequencing analysis. The PSQ 96 MA system used allowed rapid (in approximately 1.5 h) determination of 96 sequences of 20 to 65 correct nucleotides each. The results were reproducible and mostly in concordance with the results of conventional Sanger dideoxy sequencing, with the exception of shorter read lengths and some uncertainty in determining the correct number of identical nucleotides in homopolymeric segments. The number of sequence variants identified in each of the six highly polymorphic segments of the porB1a and porB1b alleles (encoding surface-exposed amino acid loops of the mature PorB protein) ranged from 5 to 11 and from 8 to 39, respectively. Among porB1a isolates (n = 22) and porB1b isolates (n = 65), 22 and 64 unique genovars, respectively, were identified. All isolates were typeable. The present results provide evidence of a high discriminatory ability, practically the same as that for sequencing of the entire porB gene. In conclusion, the fast and high-throughput pyrosequencing technology can be used for molecular epidemiological characterization of N. gonorrhoeae.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-22299 (URN)10.1128/JCM.42.7.2926-2934.2004 (DOI)1488 (Local ID)1488 (Archive number)1488 (OAI)
Available from: 2009-10-07 Created: 2009-10-07 Last updated: 2017-12-13
Clarke, S. C., Diggle, M. A., Mölling, P., Unemo, M. & Olcén, P. (2003). Analysis of PorA variable region 3 in meningococci: implications for vaccine policy?. Vaccine, 21(19-20), 2468-2473
Open this publication in new window or tab >>Analysis of PorA variable region 3 in meningococci: implications for vaccine policy?
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2003 (English)In: Vaccine, ISSN 0264-410X, E-ISSN 1873-2518, Vol. 21, no 19-20, p. 2468-2473Article in journal (Refereed) Published
Abstract [en]

Outer membrane protein (OMP) vaccines are being developed against Neisseria meningitidis serogroup B which may provide protection against common circulating serotypes and serosubtypes in some countries. However, limited data is available in Europe from genosubtyping meningococci. We therefore undertook a retrospective analysis of the three main variable regions, VR1, VR2 as well as VR3, of the porA gene from N. meningitidis isolated from different countries, mainly from Scotland and Sweden. Analysis of this gene showed that, amongst 226 strains studied, there were a total of 78 different strains. No new VR1 or VR2 alleles were found but five new VR3 alleles are described. Our data indicates the importance of analysing the VR3 region of PorA in addition to VR1 and VR2 and also highlights, in general terms, the need for genosubtyping meningococci. Such analyses have major implications for the design of new meningococcal vaccines.

Keywords
Neisseria meningitidis, Meningococci, porA, Sequence typing, Vaccine
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-26554 (URN)10.1016/S0264-410X(03)00033-1 (DOI)11116 (Local ID)11116 (Archive number)11116 (OAI)
Available from: 2009-10-08 Created: 2009-10-08 Last updated: 2017-12-13Bibliographically approved
Unemo, M., Olcén, P., Albert, J. & Fredlund, H. (2003). Comparison of serologic and genetic porB-based typing of Neisseria gonorrhoeae: consequences for future characterization. Journal of Clinical Microbiology, 41(9), 4141-4147
Open this publication in new window or tab >>Comparison of serologic and genetic porB-based typing of Neisseria gonorrhoeae: consequences for future characterization
2003 (English)In: Journal of Clinical Microbiology, ISSN 0095-1137, E-ISSN 1098-660X, Vol. 41, no 9, p. 4141-4147Article in journal (Refereed) Published
Abstract [en]

Due to temporal changes in the epidemiology of gonorrhea, a precise characterization of Neisseria gonorrhoeae is essential. In the present study genetic heterogeneity in the porB genes of N. gonorrhoeae was examined, and serovar determination was compared to porB gene sequencing. Among 108 N. gonorrhoeae isolates, phylogenetic analysis of the entire porB alleles (924 to 993 bp) identified 87 unique sequences. By analyzing only the four to six most heterogeneous porB gene regions (174 to 363 bp), 86 out of these 87 genetic variants were identified. Consequently, analysis of shorter highly variable regions of the porB gene generates high-level discriminatory ability as well as fast, objective, reproducible, and portable data for epidemiological characterization of N. gonorrhoeae. Regarding putative antigenic epitopes of PorB for Genetic Systems monoclonal antibodies (MAbs), some of the previous findings were confirmed, but new findings were also observed. For several of the MAbs, however, the precise amino acid residues of PorB critical for single-MAb reactivity were difficult to identify. In addition, repeated serovar determination of 108 N. gonorrhoeae isolates revealed discrepancies for 34 isolates, mostly due to nonreproducible reactivity with single MAbs. Thus, the prospects of a genetic typing system with congruent translation of the serovar determination seem to be limited. In conclusion, analysis of short highly variable regions of the porB gene could form the basis for a fast molecular epidemiological tool for the examination of emergence and transmission of N. gonorrhoeae strains within the community.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-26458 (URN)10.1128/​JCM.41.9.4141-4147.2003 (DOI)11006 (Local ID)11006 (Archive number)11006 (OAI)
Available from: 2009-10-08 Created: 2009-10-08 Last updated: 2017-12-13Bibliographically approved
Unemo, M. (2003). Genotypic and phenotypic characterisation of Neisseria gonorrhoeae. (Doctoral dissertation). Linköping: Linköpings universitet
Open this publication in new window or tab >>Genotypic and phenotypic characterisation of Neisseria gonorrhoeae
2003 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The bacterium Neisseria gonorrhoeae (the gonococcus) is the aetiological agent of gonorrhoea, which remains a major sexually transmitted infection/disease (STI/STD) worldwide. The incidence of gonorrhoea was previously high in many countries, Sweden included. The incidence in Sweden culminated in 1970 with 487 cases per 100,000 inhabitants. After that, the incidence declined almost every year until an all-time low of 2.4 was observed in 1996. ln 1997 the incidence of gonorrhoea began to significantly increase in Sweden, due mainly to a larger number of domestic cases of young heterosexuals of both sexes and homosexual men. This observation, in combination with the widespread use of suboptimal methods for characterisation and, in some countries, for diagnosis of the bacterium, as well as the rapid increase of resistance to several antibiotics, has intensified the research in the field of N. gonorrhoeae.

In the present thesis (paper 1), a high prevalence of decreased susceptibility or resistance to several of the traditionally used gonorrhoea antibiotics was identified and correlated to the geographic area of exposure, especially Asia. Nevertheless, effective antibiotics for treating gonorrhoea are at hand. A substantial genetic heterogeneity within identical serological variants (serovars), i.e. intraserovar, as well as interserovar of N. gonorrhoeae strains circulating within the community was revealed, emphasising the importance of using highly discriminative (DNA-based) epidemiological characterisation methods for the bacteria (papers II-V). Effective DNA-based characterisation methods, i.e. pulsed-field gel electrophmesis (PFGE) of genomic DNA digested with rarely cutting restriction endonucleases and porB gene sequencing, were adapted, optimised and evaluated against conventional phenotypic methods, as epidemiological tools on Swedish N. gonorrhoeae isolates. These molecular techniques showed a significantly higher discriminatory ability, reproducibility, and objectivity than the serovar determinations using the Genetic Systems (OS) or the Pharmacia panel (Ph) ofmonoclonal antibodies (MAbs) (papers II & III). According to a comparison of serologic and genetic parB-based typing of N. gonorrhoeae, the precise amino acid residues of porB, critical for the reactivity of several of the GS MAbs, were difficult to identity (paper IV). In papers IV & V, a determination of genetic group (genogroup) and genetic variant (genovar) was developed based on real-time PCR of the entire porB gene with subsequent sequence analysis in real-time by synthesis, i.e. pyrosequencing technology, of short, highly polymorphic porB gene segments. This method provides a rapid, high-throughput, objective, highly discriminative, typeable, portable for interlaboratory comparisons, and reproducible molecular characterisation for N. gonorrhoeae. Genogroup and genovar determination can complement or even replace the internationally established serovar determination in routine use for following the transmission of individual strains in the community and confirming presumed epidemiological connections or discriminating isolates of suspected clusters of gonorrhoea cases.

Abstract [sv]

Bakterien Neisseria gonorrhoeae (gonokocken) orsakar den sexuellt överförbara infektionen gonorré som med eller utan allvarliga komplikationer, som exempelvis infertilitet och utomkvedshavandeskap, är ett globalt folkhälsoproblem. Infektionen var tidigare mycket vanlig i flertalet länder, så även i Sverige där incidensen kulminerade år 1970 varefter den sjönk i stort sett varje år fram till och med år 1996. Från och med 1997 började infektionens incidens öka igen i Sverige, vilket också kunde noteras i flera andra länder. Framförallt orsakades den svenska ökningen av en ökad inhemsk smittspridning bland yngre heterosexuella kvinnor och män samt homosexuella män. En ökad resistens hos bakterien mot flertalet antibiotika är ett känt problem sedan decennier. De senaste åren har en nationell och internationell intensifiering skett av forskningen. Fokus ligger på effektiva diagnostiska tekniker, optimala karakteriseringsmetoder, epidemiologiska studier samt identifiering och övervakning av begynnande eller ökande antibiotikaresistens. Även patogenes, virulens och vaccinutveckling studeras.

I denna avhandlings arbete I identifierades, bland svenska N. gonorrhoeae isolat, en hög prevalens av nedsatt känslighet eller resistens mot flertalet av de traditionella antibiotika för behandling av gonorré. En korrelation mellan nedsatt känslighet/resistens och geografisk smittort, framförallt Asien, kunde fastställas. Flera olika antibiotika för effektiv behandling finns dock fortfarande tillgängliga. I arbete I-V identifierades en stor genetisk heterogenitet inom och mellan olika serologiska varianter (serovarer) av N. gonorrhoeae stammar. Detta belyser behovet av att använda högdiskriminerande (DNA-baserade) metoder för epidemiologisk karakterisering av bakterien. Effektiva DNA-baserade molekylärgenetiska tekniker, som pulsfältgelelektrofores (PFGE) av genomiskt DNA efter klyvning med restriktionsenzym och sekvenseling av porB genen, adapterades, optimerades och evaluerades mot traditionella fenatypiska metoder, som epidemiologiska verktyg för svenska N. gonorrhoeae isolat. Båda metoderna visade en signifikant högre diskriminemnde förmåga, reproducerbarhet och objektivitet än traditionell karakterisering (arbete II & III). En jämförelse mellan serologisk och genetisk porB-baserad typning av N. gonorrhoeae visade på stora svårigheter att komplett identifiera de använda monoklonala antikropparnas antigena epitoper hos porB (arbete IV). I arbete IV & V utvecklades en bestämning av genetisk grupp (genogrupp) och genetisk variant (genovar) baserad på realtids-PCR av hela porB genen med efterföljande sekvensering i realtidsformat, med hjälp av pyrosequencing teknologi, av korta högvariabla segment av porB genen. Metoden är mycket snabb, högdiskriminerande, reproducerbar, objektiv samt har en hög kapacitet. Metoden skulle kunna ersätta alternativt komplettera den bristfalliga men internationellt etablerade och rutinmässigt använda serovarbestämningen av N. gonorrhoeae för att identifiera spridningen av individuella stammar i samhället, karakterisera isolat i misstänkta kluster av gonorréfall och för rutinmässig partnerspårning.

Place, publisher, year, edition, pages
Linköping: Linköpings universitet, 2003. p. 104
Series
Linköping University Medical Dissertations, ISSN 0345-0082 ; 828
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-26673 (URN)11240 (Local ID)91-7373-517-5 (ISBN)11240 (Archive number)11240 (OAI)
Public defence
2003-12-19, Wilandersalen, Universitetssjukhuset, Örebro, 13:00 (Swedish)
Opponent
Available from: 2009-10-08 Created: 2009-10-08 Last updated: 2023-03-03Bibliographically approved
Jacobsson, S., Issa, M., Unemo, M., Bäckman, A., Mölling, P., Sulaiman, N. & Olcén, P. (2003). Molecular characterisation of group A Neisseria meningitidis isolated in Sudan 1985–2001. Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS), 111(11), 1060-1066
Open this publication in new window or tab >>Molecular characterisation of group A Neisseria meningitidis isolated in Sudan 1985–2001
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2003 (English)In: Acta Pathologica, Microbiologica et Immunologica Scandinavica (APMIS), ISSN 0903-4641, E-ISSN 1600-0463, Vol. 111, no 11, p. 1060-1066Article in journal (Refereed) Published
Abstract [en]

A total of 33 group A Neisseria meningitidis (Mc) isolates, collected in Sudan between 1985 and 2001, were studied in order to describe the changes over time in a country within the meningitis belt of Africa. The isolates were characterised by traditional phenotypic methods (serogrouping, serotyping, serosubtyping and antibiogram) and molecular techniques (genosubtyping, pulsed-field gel electrophoresis [PFGE] with restriction endonucleases SpeI and NheI, and multilocus sequence typing [MLST]). Three clones of group A Mc were identified: one before 1988 (sulphadiazine sensitive, serotype 4, genosubtype P1.7,13-1,35-1, sequence type 4 [ST-4]); another during and after the 1988 epidemic (sulphadiazine resistant, serotype 4, genosubtype P1.20,9,35-1, ST-5); and a third causing the 1999 epidemic (sulphadiazine resistant, serotype 4, genosubtype P1.20,9,35-1, ST-7). The first clone showed major differences compared to the other two. The second and third clones had many similarities with differences in only a single gene (pgm) in the MLST (47 of the 450 bp) but significant other differences according to the PFGE patterns. Within the clones, genosubtyping and MLST gave identical information (except one base substitution in the aroE gene in one isolate). However, the PFGE patterns showed changes over time within the clones, where SpeI revealed somewhat more diversity than NheI.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-26556 (URN)10.1111/j.1600-0463.2003.apm1111108.x (DOI)11118 (Local ID)11118 (Archive number)11118 (OAI)
Available from: 2009-10-08 Created: 2009-10-08 Last updated: 2017-12-13Bibliographically approved
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