Molecular Epidemiology of
            <i>Neisseria gonorrhoeae</i>
            : Sequence Analysis of the
            <i>porB</i>
            Gene Confirms Presence of Two Circulating Strains

Unemo, Magnus; Olcén, Per; Berglund, Torsten; Albert, Jan; Fredlund, Hans

doi:10.1128/jcm.40.10.3741-3749.2002

Cited by 49 publications

(83 citation statements)

References 32 publications

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“…Overall, the results of the sequencing of the entire porB gene, NG-MAST, and PFGE showed congruence but not complete identity, which is in concordance with previous studies (10,(35)(36)(37). All these genetic methods exhibited a high discriminatory ability and excellent typeability, which also agree with previous studies (8)(9)(10)28,(34)(35)(36)(37)(38).…”

Section: Discussionsupporting

confidence: 81%

“…All these genetic methods exhibited a high discriminatory ability and excellent typeability, which also agree with previous studies (8)(9)(10)28,(34)(35)(36)(37)(38). However, when characterizing N. gonorrhoeae for epidemiological purposes, a sequence-based genetic typing seems to be the best single choice of method.…”

Section: Discussionsupporting

confidence: 80%

“…No restriction sites for the PFGE enzymes SpeI and BglII existed in the porB1b genes or the tbpB genes of the examined isolates. Thus, the results of the present study as well as numerous previous studies (8)(9)(10)12,28,(34)(35)(36)(37)(38) emphasize that a highly discriminative, reproducible, and objective characterization of N. gonorrhoeae is crucial for understanding gonorrhoea epidemiology. A precise method, i.e.…”

Section: Discussionmentioning

confidence: 66%

“…1) gonorrhoeae IB-10 isolates that circulated in the Swedish society in 2003 were included for comparison. All isolates were preserved at −70°C and cultured as previously described (10).…”

Section: Bacterial Isolates and Culture Conditionsmentioning

confidence: 99%

“…According to previous studies (8,10,12), the transmission of single strains in Swedish society may result in large domestic core groups of gonorrhoea cases and it is possible to identify these strains with a precise genetic characterization of the bacterial isolates. Since the mid-1990s, the prevalence of isolates resistant to ciprofloxacin, previously the drug of first choice for treatment of uncomplicated gonorrhoea, has been increasing in Sweden and in many other countries (SWEDRES 2004 http://www.strama.se (2)(3)(4)(5)13)).…”

mentioning

confidence: 99%

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Molecular characterization of Neisseria gonorrhoeae identifies transmission and resistance of one ciprofloxacin‐resistant strain

Unemo

Sjöstrand

Akhras

et al. 2007

APMIS

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A highly discriminative and objective genetic characterization of N. gonorrhoeae, which increases our knowledge of strain populations in different geographic areas, is crucial for the development of improved control measures. In the present study, conventional phenotypic characterization and genetic characterization by means of pulsed-field gel electrophoresis (PFGE), sequencing of the entire porB gene, N. gonorrhoeae multiantigen sequence typing (NG-MAST), and pyrosequencing of a quinolone resistance determining region (QRDR) of the gyrA gene of Swedish ciprofloxacinresistant N. gonorrhoeae serovar IB-10 isolates (n=45) were performed. The genetic characterization identified one widely spread ciprofloxacin-resistant N. gonorrhoeae ST147 strain. In addition, isolates with slightly different genetic characteristics, which presumably reflect the ongoing evolution only, were also identified. All the isolates contained single nucleotide polymorphisms in QRDR of the gyrA gene that are highly correlated with ciprofloxacin resistance. Consequently, comprehensive characterization identified the first confirmed large domestic transmission, mainly among young heterosexuals, of one ciprofloxacin-resistant N. gonorrhoeae strain in Swedish society during [2002][2003]. In conclusion, a precise, i.e. genetic, characterization for identification of individual strains is a very valuable support to the crucial active surveillance of the epidemiological characteristics and the antibiotic susceptibility of N. gonorrhoeae in the effective treatment of gonorrhoea. KeywordsNeisseria gonorrhoeae; ciprofloxacin resistance; molecular epidemiology; porB gene; NG-MAST Gonorrhoea remains a major sexually transmitted infection (STI) in many countries (1,2). The mainstay in its prevention is based on the availability of effective diagnostics and antibiotic treatment, as well as regional, national, and international surveillance of the epidemiological characteristics and the antibiotic susceptibility of the etiological agent, i.e. Neisseria gonorrhoeae. Nowadays, a high level of decreased susceptibility or resistance to most traditional antibiotics used for treatment of gonorrhoea has been identified in most countries [2][3][4][5]). In addition, the characteristics of circulating N. gonorrhoeae strains fluctuate over time and a highly discriminative and objective characterization, i.e. genetic typing, of the bacteria, is crucial. This genetic typing may identify the transmission of more virulent and/or antibiotic-resistant strains, information that is important for the development of improved control measures. Conventional phenotypic characterization of N. gonorrhoeae strains has several limitations (6-10) and many genetic methods have been developed to overcome these shortcomings (11).Since 1997 the incidence of gonorrhoea in Sweden has increased almost annually (Gonorrhoea/ year and month statistics per county http://gis.smittskyddsinstitutet.se/mapapp/build/intro_eng.html (3,8)). According to previous studies (8,10,12), the transmi...

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Section: Discussionsupporting

confidence: 81%

Section: Discussionsupporting

confidence: 80%

Section: Discussionmentioning

confidence: 66%

Section: Bacterial Isolates and Culture Conditionsmentioning

confidence: 99%

mentioning

confidence: 99%

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Molecular characterization of Neisseria gonorrhoeae identifies transmission and resistance of one ciprofloxacin‐resistant strain

Unemo

Sjöstrand

Akhras

et al. 2007

APMIS

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Phenotypic and genotypic characterization of prolyliminopeptidase-negative Neisseria gonorrhoeae isolates in Denmark

Fjeldsøe-Nielsen

Unemo

Fredlund

et al. 2005

Eur J Clin Microbiol Infect Dis

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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.

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Neisseria gonorrhoeae antimicrobial susceptibility in Barcelona: penA, ponA, mtrR, and porB mutations and NG-MAST sequence types associated with decreased susceptibility to cephalosporins

Serra-Pladevall

Barberà

Rodríguez

et al. 2016

Eur J Clin Microbiol Infect Dis

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The aims of this study were to determine the antimicrobial susceptibility of Neisseria gonorrhoeae (NG) in our area, to analyze the molecular mechanisms involved in cephalosporins resistance, and to undertake molecular typing of our NG strains. Antimicrobial susceptibility was determined using the Etest. The genes penA, mtrR, penB, and ponA were studied. Molecular typing was performed by N. gonorrhoeae multiantigen sequence typing. Of 329 strains analyzed in 2013, none showed high-level cephalosporin resistance, but 8.2 % had resistance to cefixime [minimum inhibitory concentration (MIC) > 0.125 μg/mL] and 0.6 % to ceftriaxone (MIC > 0.125 μg/mL). Azithromycin resistance was documented in 4.3 % and ciprofloxacin resistance in 49.2 %. Among 48 strains with an MIC ≥ 0.125 μg/mL to cefixime, 58.3 % showed the penA mosaic pattern XXXIV, 98 % a Leu → Pro substitution at position 421 of the ponA gene, 100 % amino acid changes at positions 101 and 102 of the PorB1b porin, and 87.5 % of strains an adenine deletion in the promoter region of the MtrC-D-E efflux pump. A significant difference between strains with and without decreased cephalosporin susceptibility (MIC ≥ 0.125 μg/mL) was observed for these four genes. Of the 48 strains with an MIC ≥ 0.125 μg/mL to cefixime, 43.8 % belonged to the genogroup G1407 and 27.1 % belonged to the genogroup G2400. A significant association of G1407 with decreased susceptibility (MIC ≥ 0.125 μg/mL) and G2992 with susceptibility was found, and also between G1407 and mosaic pattern XXXIV and between G2400 and A501T substitution in penA. The NG resistance rate in our area is higher than the median of Europe. We have detected the emergence of G2400, which may be a source of antimicrobial resistance.

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Molecular Epidemiology of Neisseria gonorrhoeae : Sequence Analysis of the porB Gene Confirms Presence of Two Circulating Strains

Cited by 49 publications

References 32 publications

Molecular characterization of Neisseria gonorrhoeae identifies transmission and resistance of one ciprofloxacin‐resistant strain

Molecular characterization of Neisseria gonorrhoeae identifies transmission and resistance of one ciprofloxacin‐resistant strain

Phenotypic and genotypic characterization of prolyliminopeptidase-negative Neisseria gonorrhoeae isolates in Denmark

Neisseria gonorrhoeae antimicrobial susceptibility in Barcelona: penA, ponA, mtrR, and porB mutations and NG-MAST sequence types associated with decreased susceptibility to cephalosporins

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