A Clinical Isolate of Neisseria gonorrhoeae With In Vitro Resistance to Erythromycin and Decreased Susceptibility to Azithromycin

Ehret, Josephine M.; Nims, L J; Judson, Franklyn N.

doi:10.1097/00007435-199607000-00004

Cited by 40 publications

(20 citation statements)

References 15 publications

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“…The characteristics of each group are summarized in Table 1. 10 The quinolone-resistant group had a higher proportion of men (p < 0.001) and patients over 30 years of age (p < 0.001). Among the men, the proportion who have sex with men was similar in the quinolone-resistant and quinolone-susceptible groups (p = 0.63).…”

Section: Resultsmentioning

confidence: 94%

Prevalence of and risk factors for quinolone-resistant Neisseria gonorrhoeae infection in Ontario

Ota¹,

Fisman²,

Jones³

et al. 2009

Canadian Medical Association Journal

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Section: Resultsmentioning

confidence: 94%

Prevalence of and risk factors for quinolone-resistant Neisseria gonorrhoeae infection in Ontario

Ota¹,

Fisman²,

Jones³

et al. 2009

Canadian Medical Association Journal

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“…Antimicrobial susceptibilities of N. gonorrhoeae to spectinomycin, ceftriaxone, erythromycin, penicillin, tetracycline, azithromycin, cefixime (Sigma-Aldrich Canada Ltd., Oakville, Ontario, Canada), and ciprofloxacin (generously provided by Bayer, Etobicoke, Ontario, Canada) were determined using the agar dilution method as previously described (37). Interpretation of the MIC was based on established criteria (38,39); cefixime decreased susceptibility MIC of Ն0.25 g/ml, ceftriaxone decreased susceptibility MIC of Ն0.125 g/ml (2), and azithromycin resistance MIC of Ն2.0 g/ml (40). N. gonorrhoeae ATCC 49226, WHO-B, WHO-C, WHO-D, WHO-F, WHO-G, WHO-K, and WHO-P reference cultures were used as controls (41).…”

Section: Methodsmentioning

confidence: 99%

Whole-Genome Phylogenomic Heterogeneity of Neisseria gonorrhoeae Isolates with Decreased Cephalosporin Susceptibility Collected in Canada between 1989 and 2013

et al. 2015

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A large-scale, whole-genome comparison of Canadian Neisseria gonorrhoeae isolates with high-level cephalosporin MICs was used to demonstrate a genomic epidemiology approach to investigate strain relatedness and dynamics. Although current typing methods have been very successful in tracing short-chain transmission of gonorrheal disease, investigating the temporal evolutionary relationships and geographical dissemination of highly clonal lineages requires enhanced resolution only available through whole-genome sequencing (WGS). Phylogenomic cluster analysis grouped 169 Canadian strains into 12 distinct clades. While some N. gonorrhoeae multiantigen sequence types (NG-MAST) agreed with specific phylogenomic clades or subclades, other sequence types (ST) and closely related groups of ST were widely distributed among clades. Decreased susceptibility to extended-spectrum cephalosporins (ESC-DS) emerged among a group of diverse strains in Canada during the 1990s with a variety of nonmosaic penA alleles, followed in 2000/2001 with the penA mosaic X allele and then in 2007 with ST1407 strains with the penA mosaic XXXIV allele. Five genetically distinct ESC-DS lineages were associated with penA mosaic X, XXXV, and XXXIV alleles and nonmosaic XII and XIII alleles. ESC-DS with coresistance to azithromycin was observed in 5 strains with 23S rRNA C2599T or A2143G mutations. As the costs associated with WGS decline and analysis tools are streamlined, WGS can provide a more thorough understanding of strain dynamics, facilitate epidemiological studies to better resolve social networks, and improve surveillance to optimize treatment for gonorrheal infections. N eisseria gonorrhoeae is a Gram-negative diplococcus bacterium that causes gonorrhea infections. Gonorrhea is the second most reported bacterial sexually transmitted infection (STI) in Canada, with reported cases increasing from 15.5 per 100,000 in 1997 to 36.2 per 100,000 in 2012 (1), and approximately 106 million cases are estimated annually worldwide (2). N. gonorrhoeae bacteria have developed resistance against sulfonamides, penicillins, tetracyclines, and fluoroquinolones (3, 4), and current treatment options now include third-generation extended-spectrum cephalosporins (ESC), namely, cefixime (CFM) and ceftriaxone (CRO) (5). MIC creep has seen the modal MIC values rise between 2001 and 2010 in Canada from 0.016 g/ml to 0.125 g/ml and 0.063 g/ml for CFM and CRO, respectively (6). These results coincide with recent clinical reports of treatment failures to primarily CFM monotherapy in Canada (7,8) and additional global reports of high-level CRO MICs in isolates from Japan and Europe (9-13). Furthermore, isolates with decreased susceptibility to cephalosporins and coresistance to azithromycin (AZM), a recommended cotherapy (5), have recently been identified in Canada (14).Decreased susceptibility to extended-spectrum cephalosporins (ESC-DS) and resistance to AZM have been attributed to several molecular mechanisms. The primary mechanism for ESC-DS is modification of the ...

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“…The MICs of all antibiotics except azithromycin and erythromycin (for which there are no NCCLS MIC breakpoints) were interpreted according to the NCCLS guidelines (15). For the purposes of this study, the azithromycin and erythromycin MICs at which strains exhibited resistance were defined as Ն2.0 g/ml (4,21). N. gonorrhoeae reference cultures ATCC 49226, WHO III, WHO V, and WHO VII were used as quality control strains.…”

Section: Methodsmentioning

confidence: 99%

Mutation in 23S rRNA Associated with Macrolide Resistance in Neisseria gonorrhoeae

Martín

Liu

et al. 2002

Antimicrob Agents Chemother

158

132

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Fifty-six azithromycin-resistant (MICs, 2.0 to 4.0 g/ml) Neisseria gonorrhoeae strains with cross-resistance to erythromycin (MICs, 2.0 to 64.0 g/ml), isolated in Canada between 1997 and 1999, were characterized, and their mechanisms of azithromycin resistance were determined. Most (58.9%) of them belonged to auxotype-serotype class NR/IB-03, with a 2.6-mDa plasmid. Based on resistance to crystal violet (MICs > 1 g/ml), 96.4% of these macrolide-resistant strains appeared to have increased efflux. Nine of the eleven strains selected for further characterization were found to have a promoter region mtrR mutation, a single-base-pair (A) deletion in the 13-bp inverted repeat, which is believed to cause overexpression of the mtrCDE-encoded efflux pump. The two remaining macrolide-resistant strains (erythromycin MIC, 64.0 g/ml; azithromycin MIC, 4.0 g/ml), which did not have the mutation in the mtrR promoter region, were found to have a C2611T mutation (Escherichia coli numbering) in the peptidyltransferase loop in domain V of the 23S rRNA alleles. Although mutations in domain V of 23S rRNA alleles had been reported in other bacteria, including E. coli, Streptococcus pneumoniae, and Helicobacter pylori, this is the first observation of these mutations associated with macrolide resistance in N. gonorrhoeae.

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A Clinical Isolate of Neisseria gonorrhoeae With In Vitro Resistance to Erythromycin and Decreased Susceptibility to Azithromycin

Abstract: Continued national monitoring is needed to detect the appearance and early dissemination of new types of gonococcal resistance.

Cited by 40 publications

References 15 publications

Prevalence of and risk factors for quinolone-resistant Neisseria gonorrhoeae infection in Ontario

Prevalence of and risk factors for quinolone-resistant Neisseria gonorrhoeae infection in Ontario

Whole-Genome Phylogenomic Heterogeneity of Neisseria gonorrhoeae Isolates with Decreased Cephalosporin Susceptibility Collected in Canada between 1989 and 2013

Mutation in 23S rRNA Associated with Macrolide Resistance in Neisseria gonorrhoeae

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