scholarly journals Genomic Epidemiology and Molecular Resistance Mechanisms of Azithromycin-Resistant Neisseria gonorrhoeae in Canada from 1997 to 2014

2016 ◽  
Vol 54 (5) ◽  
pp. 1304-1313 ◽  
Author(s):  
Walter Demczuk ◽  
Irene Martin ◽  
Shelley Peterson ◽  
Amrita Bharat ◽  
Gary Van Domselaar ◽  
...  
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Resistance Mechanisms ◽  
23S Rrna ◽  
Phylogenomic Analysis ◽  
Single Nucleotide ◽  
Content Type ◽  
E Coli ◽  
Genomic Epidemiology ◽  
High Level ◽  
Promoter Mutations

The emergence ofNeisseria gonorrhoeaestrains with decreased susceptibility to cephalosporins and azithromycin (AZM) resistance (AZMr) represents a public health threat of untreatable gonorrhea infections. Genomic epidemiology through whole-genome sequencing was used to describe the emergence, dissemination, and spread of AZMrstrains. The genomes of 213 AZMrand 23 AZM-susceptibleN. gonorrhoeaeisolates collected in Canada from 1989 to 2014 were sequenced. Core single nucleotide polymorphism (SNP) phylogenomic analysis resolved 246 isolates into 13 lineages. High-level AZMr(MICs ≥ 256 μg/ml) was found in 5 phylogenetically diverse isolates, all of which possessed the A2059G mutation (Escherichia colinumbering) in all four 23S rRNA alleles. One isolate with high-level AZMrcollected in 2009 concurrently had decreased susceptibility to ceftriaxone (MIC = 0.125 μg/ml). An increase in the number of 23S rRNA alleles with the C2611T mutations (E. colinumbering) conferred low to moderate levels of AZMr(MICs = 2 to 4 and 8 to 32 μg/ml, respectively). Low-level AZMrwas also associated withmtrRpromoter mutations, including the −35A deletion and the presence ofNeisseria meningitidis-like sequences. Geographic and temporal phylogenetic clustering indicates that emergent AZMrstrains arise independently and can then rapidly expand clonally in a region through local sexual networks.

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

2014 ◽  
Vol 53 (1) ◽  
pp. 191-200 ◽  
Author(s):  
Walter Demczuk ◽  
Tarah Lynch ◽  
Irene Martin ◽  
Gary Van Domselaar ◽  
Morag Graham ◽  
...  
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Large Scale ◽  
Epidemiological Studies ◽  
23S Rrna ◽  
Genome Comparison ◽  
Whole Genome ◽  
Content Type ◽  
Genomic Epidemiology ◽  
High Level ◽  
Sequence Types

A large-scale, whole-genome comparison of CanadianNeisseria gonorrhoeaeisolates 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 someN. gonorrhoeaemultiantigen 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 nonmosaicpenAalleles, followed in 2000/2001 with thepenAmosaic X allele and then in 2007 with ST1407 strains with thepenAmosaic XXXIV allele. Five genetically distinct ESC-DS lineages were associated withpenAmosaic 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.

Emergence and dissemination of three mild outbreaks of Neisseria gonorrhoeae with high-level resistance to azithromycin in Barcelona, 2016–18

2020 ◽  
Author(s):  
P Salmerón ◽  
A Moreno-Mingorance ◽  
J Trejo ◽  
R Amado ◽  
B Viñado ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Neisseria Gonorrhoeae ◽  
23S Rrna ◽  
Phylogenomic Analysis ◽  
Rrna Gene ◽  
Snp Analysis ◽  
Enhanced Resolution ◽  
23S Rrna Gene ◽  
High Level ◽  
Level Resistance

Abstract Background Neisseria gonorrhoeae (NG) isolates with high-level azithromycin resistance (HL-AziR) have emerged worldwide in recent decades, threatening the sustainability of current dual-antimicrobial therapy. Objectives This study aimed to characterize the first 16 NG isolates with HL-AziR in Barcelona between 2016 and 2018. Methods WGS was used to identify the mechanisms of antimicrobial resistance, to establish the MLST ST, NG multiantigen sequence typing (NG-MAST) ST and NG sequence typing for antimicrobial resistance (NG-STAR) ST and to identify the clonal relatedness of the isolates with other closely related NG previously described in other countries based on a whole-genome SNP analysis approach. The sociodemographic characteristics of the patients included in the study were collected by comprehensive review of their medical records. Results Twelve out of 16 HL-AziR isolates belonged to the MLST ST7823/NG-MAST ST5309 genotype and 4 to MLST ST9363/NG-MAST ST3935. All presented the A2059G mutation in all four alleles of the 23S rRNA gene. MLST ST7823/NG-MAST ST5309 isolates were only identified in men who have sex with women and MLST ST9363/NG-MAST ST3935 were found in MSM. Phylogenomic analysis revealed the presence of three transmission clusters of three different NG strains independently associated with sexual behaviour. Conclusions Our findings support the first appearance of three mild outbreaks of NG with HL-AziR in Spain. These results highlight the continuous capacity of NG to develop antimicrobial resistance and spread among sexual networks. The enhanced resolution of WGS provides valuable information for outbreak investigation, complementing the implementation of public health measures focused on the prevention and dissemination of MDR NG.

scholarly journals Ribosomal Mutations Conferring Macrolide Resistance in Legionella pneumophila

2017 ◽  
Vol 61 (3) ◽  
Author(s):  
Ghislaine Descours ◽  
Christophe Ginevra ◽  
Nathalie Jacotin ◽  
Françoise Forey ◽  
Joëlle Chastang ◽  
...  
Keyword(s):  
Legionella Pneumophila ◽  
Ribosomal Proteins ◽  
Fold Increase ◽  
Resistance Mechanisms ◽  
Macrolide Resistance ◽  
23S Rrna ◽  
Content Type ◽  
First Line Therapy ◽  
High Level ◽  
Domain V

ABSTRACT Monitoring the emergence of antibiotic resistance is a recent issue in the treatment of Legionnaires' disease. Macrolides are recommended as first-line therapy, but resistance mechanisms have not been studied in Legionella species. Our aim was to determine the molecular basis of macrolide resistance in L. pneumophila. Twelve independent lineages from a common susceptible L. pneumophila ancestral strain were propagated under conditions of erythromycin or azithromycin pressure to produce high-level macrolide resistance. Whole-genome sequencing was performed on 12 selected clones, and we investigated mutations common to all lineages. We reconstructed the dynamics of mutation for each lineage and demonstrated their involvement in decreased susceptibility to macrolides. The resistant mutants were produced in a limited number of passages to obtain a 4,096-fold increase in erythromycin MICs. Mutations affected highly conserved 5-amino-acid regions of L4 and L22 ribosomal proteins and of domain V of 23S rRNA (G2057, A2058, A2059, and C2611 nucleotides). The early mechanisms mainly affected L4 and L22 proteins and induced a 32-fold increase in the MICs of the selector drug. Additional mutations related to 23S rRNA mostly occurred later and were responsible for a major increase of macrolide MICs, depending on the mutated nucleotide, the substitution, and the number of mutated genes among the three rrl copies. The major mechanisms of the decreased susceptibility to macrolides in L. pneumophila and their dynamics were determined. The results showed that macrolide resistance could be easily selected in L. pneumophila and warrant further investigations in both clinical and environmental settings.

scholarly journals Is Neisseria gonorrhoeae Initiating a Future Era of Untreatable Gonorrhea?: Detailed Characterization of the First Strain with High-Level Resistance to Ceftriaxone

2011 ◽  
Vol 55 (7) ◽  
pp. 3538-3545 ◽  
Author(s):  
Makoto Ohnishi ◽  
Daniel Golparian ◽  
Ken Shimuta ◽  
Takeshi Saika ◽  
Shinji Hoshina ◽  
...  
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Resistance Mechanisms ◽  
New Drugs ◽  
Public Health Response ◽  
Detailed Characterization ◽  
Content Type ◽  
Resistance Determinants ◽  
Confirmatory Tests ◽  
High Level

ABSTRACTRecently, the firstNeisseria gonorrhoeaestrain (H041) that is highly resistant to the extended-spectrum cephalosporin (ESC) ceftriaxone, the last remaining option for empirical first-line treatment, was isolated. We performed a detailed characterization of H041, phenotypically and genetically, to confirm the finding, examine its antimicrobial resistance (AMR), and elucidate the resistance mechanisms. H041 was examined using seven species-confirmatory tests, antibiograms (30 antimicrobials),porBsequencing,N. gonorrhoeaemultiantigen sequence typing (NG-MAST), multilocus sequence typing (MLST), and sequencing of ESC resistance determinants (penA,mtrR,penB,ponA, andpilQ). Transformation, using appropriate recipient strains, was performed to confirm the ESC resistance determinants. H041 was assigned to serovar Bpyust, MLST sequence type (ST) ST7363, and the new NG-MAST ST4220. H041 proved highly resistant to ceftriaxone (2 to 4 μg/ml, which is 4- to 8-fold higher than any previously described isolate) and all other cephalosporins, as well as most other antimicrobials tested. A newpenAmosaic allele caused the ceftriaxone resistance. In conclusion,N. gonorrhoeaehas now shown its ability to also develop ceftriaxone resistance. Although the biological fitness of ceftriaxone resistance inN. gonorrhoeaeremains unknown,N. gonorrhoeaemay soon become a true superbug, causing untreatable gonorrhea. A reduction in the global gonorrhea burden by enhanced disease control activities, combined with wider strategies for general AMR control and enhanced understanding of the mechanisms of emergence and spread of AMR, which need to be monitored globally, and public health response plans for global (and national) perspectives are important. Ultimately, the development of new drugs for efficacious gonorrhea treatment is necessary.

scholarly journals Emergence and Spread of Neisseria gonorrhoeae Strains with High-Level Resistance to Azithromycin in Taiwan from 2001 to 2018

2019 ◽  
Vol 63 (9) ◽  
Author(s):  
Yen-Hung Liu ◽  
Ya-Hui Wang ◽  
Chun-Hsing Liao ◽  
Po-Ren Hsueh
Keyword(s):  
Neisseria Gonorrhoeae ◽  
23S Rrna ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Coding Region ◽  
Content Type ◽  
First Choice ◽  
Agar Dilution ◽  
High Level ◽  
Level Resistance

ABSTRACT A total of 598 Neisseria gonorrhoeae isolates obtained from patients in Taiwan from 2001 to 2018 were evaluated. The MICs of ceftriaxone (CRO) and azithromycin (AZM) against the isolates were determined by the agar dilution method. N. gonorrhoeae isolates with AZM MICs of ≥1 μg/ml were identified and characterized by the presence of AZM resistance determinants. For high-level AZM-resistant (AZM-HLR) isolates (MIC ≥ 256 μg/ml), genotyping was performed using multilocus sequence typing (MLST) and N. gonorrhoeae multiantigen sequence typing (NG-MAST). Among the N. gonorrhoeae isolates studied, 8.7% (52/598) exhibited AZM MICs of ≥1 μg/ml. Thirteen of the 52 isolates contained A2059G (23S rRNA NG-STAR type 1) or C2611T (23S rRNA NG-STAR type 2) mutations. The prevalence of the A2059G mutation was higher in AZM-HLR isolates (P < 0.001). The −35A deletion in the promoter region of the mtrR gene did not differ between AZM-HLR isolates (100%, 10/10) and the isolates with AZM MICs of 1 μg/ml to 64 μg/ml (95.2%, 40/42) (P = 1.000). The presence of mutations in the mtrR coding region was significantly different between these two groups at 90% (9/10) and 26.2% (11/42), respectively (P < 0.001). The AZM-HLR isolates, all carrying four mutated A2059G alleles, a −35A deletion, and G45D, were classified as MLST 12039/10899 and NG-MAST 1866/16497. In conclusion, Taiwan is among the countries reporting gonococci with high-level resistance to AZM so that a single dose of 1 g ceftriaxone intramuscularly as the first choice for management of N. gonorrhoeae infection should be evaluated.

scholarly journals Increasing Resistance to Azithromycin inNeisseria gonorrhoeaein Eastern Chinese Cities: Resistance Mechanisms and Genetic Diversity among Isolates from Nanjing

2018 ◽  
Vol 62 (5) ◽  
Author(s):  
Chuan Wan ◽  
Yang Li ◽  
Wen-Jing Le ◽  
Yu-Rong Liu ◽  
Sai Li ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Resistance Mechanisms ◽  
23S Rrna ◽  
Molecular Characteristics ◽  
Chinese Cities ◽  
Content Type ◽  
Public Health Challenge ◽  
High Level ◽  
Level Resistance

ABSTRACTAzithromycin resistance (AZM-R) ofNeisseria gonorrhoeaeis emerging as a clinical and public health challenge. We determined molecular characteristics of recent AZM-R Nanjing gonococcal isolates and tracked the emergence of AZM-R isolates in eastern Chinese cities in recent years. A total of 384N. gonorrhoeaeisolates from Nanjing collected from 2013 to 2014 were tested for susceptibility to AZM and six additional antibiotics; all AZM-R strains were characterized genetically for resistance determinants by sequencing and were genotyped usingN. gonorrhoeaemultiantigen sequence typing (NG-MAST). Among the 384 isolates, 124 (32.3%) were AZM-R. High-level resistance (MIC, ≥256 mg/liter) was present in 10.4% (40/384) of isolates, all of which possessed the A2143G mutation in all four 23S rRNA alleles. Low- to mid-level resistance (MIC, 1 to 64 mg/liter) was present in 21.9% (84/384) of isolates, 59.5% of which possessed the C2599T mutation in all four 23S rRNA alleles. The 124 AZM-R isolates were distributed in 71 different NG-MAST sequence types (STs). ST1866 was the most prevalent type in high-level AZM-R (HL-AZM-R) isolates (45% [18/40]). This study, together with previous reports, revealed that the prevalence of AZM-R inN. gonorrhoeaeisolates in certain eastern Chinese cities has risen >4-fold (7% to 32%) from 2008 to 2014. The principal mechanisms of AZM resistance in recent Nanjing isolates were A2143G mutations (high-level resistance) and C2599T mutations (low- to mid-level resistance) in the 23S rRNA alleles. Characterization of NG-MAST STs and phylogenetic analysis indicated the genetic diversity ofN. gonorrhoeaein Nanjing; however, ST1866 was the dominant genotype associated with HL-AZM-R isolates.

scholarly journals Emergence of Neisseria gonorrhoeae Strains Harboring a Novel Combination of Azithromycin-Attenuating Mutations

2019 ◽  
Vol 63 (4) ◽  
Author(s):  
Cau D. Pham ◽  
Samera Sharpe ◽  
Karen Schlanger ◽  
Sancta St. Cyr ◽  
Justin Holderman ◽  
...  
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Genetic Material ◽  
23S Rrna ◽  
Inhibitory Effects ◽  
Antibiotic Resistant ◽  
Exogenous Dna ◽  
Content Type ◽  
Genomic Plasticity ◽  
High Level ◽  
Azithromycin Resistance

ABSTRACT The nimbleness of Neisseria gonorrhoeae to evade the effect of antibiotics has perpetuated the fight against antibiotic-resistant gonorrhea for more than 80 years. The ability to develop resistance to antibiotics is attributable to its indiscriminate nature in accepting and integrating exogenous DNA into its genome. Here, we provide data demonstrating a novel combination of the 23S rRNA A2059G mutation with a mosaic-multiple transferable resistance (mosaic-mtr) locus haplotype in 14 N. gonorrhoeae isolates with high-level azithromycin MICs (≥256 μg/ml), a combination that may confer more fitness than in previously identified isolates with high-level azithromycin resistance. To our knowledge, this is the first description of N. gonorrhoeae strains harboring this novel combination of resistance determinants. These strains were isolated at two independent jurisdictions participating in the Gonococcal Isolate Surveillance Project (GISP) and in the Strengthening the U.S. Response to Resistant Gonorrhea (SURRG) project. The data suggest that the genome of N. gonorrhoeae continues to shuffle its genetic material. These findings further illuminate the genomic plasticity of N. gonorrhoeae, which allows this pathogen to develop mutations to escape the inhibitory effects of antibiotics.

scholarly journals Plasmid-Mediated OqxAB Is an Important Mechanism for Nitrofurantoin Resistance in Escherichia coli

2015 ◽  
Vol 60 (1) ◽  
pp. 537-543 ◽  
Author(s):  
Pak-Leung Ho ◽  
Ka-Ying Ng ◽  
Wai-U Lo ◽  
Pierra Y. Law ◽  
Eileen Ling-Yi Lai ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Efflux Pump ◽  
Geometric Mean ◽  
Resistance Mechanism ◽  
Multidrug Resistant ◽  
Resistance Mechanisms ◽  
Content Type ◽  
E Coli ◽  
High Level ◽  
Tract Infections

ABSTRACTIncreasing consumption of nitrofurantoin (NIT) for treatment of acute uncomplicated urinary tract infections (UTI) highlights the need to monitor emerging NIT resistance mechanisms. This study investigated the molecular epidemiology of the multidrug-resistant efflux geneoqxABand its contribution to nitrofurantoin resistance by usingEscherichia coliisolates originating from patients with UTI (n= 205; collected in 2004 to 2013) and food-producing animals (n= 136; collected in 2012 to 2013) in Hong Kong. TheoqxABgene was highly prevalent among NIT-intermediate (11.5% to 45.5%) and -resistant (39.2% to 65.5%) isolates but rare (0% to 1.7%) among NIT-susceptible (NIT-S) isolates. In our isolates, theoqxABgene was associated with IS26and was carried by plasmids of diverse replicon types. Multilocus sequence typing revealed that the clones ofoqxAB-positiveE. coliwere diverse. The combination ofoqxABandnfsAmutations was found to be sufficient for high-level NIT resistance. Curing ofoqxAB-carrying plasmids from 20 NIT-intermediate/resistant UTI isolates markedly reduced the geometric mean MIC of NIT from 168.9 μg/ml to 34.3 μg/ml. In the plasmid-cured variants, 20% (1/5) of isolates withnfsAmutations were NIT-S, while 80% (12/15) of isolates withoutnfsAmutations were NIT-S (P= 0.015). The presence of plasmid-basedoqxABincreased the mutation prevention concentration of NIT from 128 μg/ml to 256 μg/ml and facilitated the development of clinically important levels of nitrofurantoin resistance. In conclusion, plasmid-mediatedoqxABis an important nitrofurantoin resistance mechanism. There is a great need to monitor the dissemination of this transferable multidrug-resistant efflux pump.

scholarly journals Genomic Characterization of Neisseria gonorrhoeae Strains from 2016 U.S. Sentinel Surveillance Displaying Reduced Susceptibility to Azithromycin

2020 ◽  
Vol 64 (5) ◽  
Author(s):  
Matthew W. Schmerer ◽  
A. Jeanine Abrams ◽  
Sandra Seby ◽  
Jesse C. Thomas ◽  
John Cartee ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Neisseria Gonorrhoeae ◽  
Resistance Mechanisms ◽  
Sentinel Surveillance ◽  
23S Rrna ◽  
Molecular Surveillance ◽  
Content Type ◽  
Genomic Characterization

ABSTRACT In 2016, the proportion of Neisseria gonorrhoeae isolates with reduced susceptibility to azithromycin rose to 3.6%. A phylogenetic analysis of 334 N. gonorrhoeae isolates collected in 2016 revealed a single, geographically diverse lineage of isolates with MICs of 2 to 16 μg/ml that carried a mosaic-like mtr locus, whereas the majority of isolates with MICs of ≥16 μg/ml appeared sporadically and carried 23S rRNA mutations. Continued molecular surveillance of N. gonorrhoeae isolates will identify new resistance mechanisms.

scholarly journals Molecular pathways to high-level azithromycin resistance in Neisseria gonorrhoeae

2021 ◽  
Author(s):  
J G E Laumen ◽  
S S Manoharan-Basil ◽  
E Verhoeven ◽  
S Abdellati ◽  
I De Baetselier ◽  
...  
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Ribosomal Proteins ◽  
Efflux Pump ◽  
23S Rrna ◽  
Rrna Gene ◽  
23S Rrna Gene ◽  
Evolution Of Resistance ◽  
High Level ◽  
Azithromycin Resistance ◽  
Level Resistance

Abstract Background The prevalence of azithromycin resistance in Neisseria gonorrhoeae is increasing in numerous populations worldwide. Objectives To characterize the genetic pathways leading to high-level azithromycin resistance. Methods A customized morbidostat was used to subject two N. gonorrhoeae reference strains (WHO-F and WHO-X) to dynamically sustained azithromycin pressure. We tracked stepwise evolution of resistance by whole genome sequencing. Results Within 26 days, all cultures evolved high-level azithromycin resistance. Typically, the first step towards resistance was found in transitory mutations in genes rplD, rplV and rpmH (encoding the ribosomal proteins L4, L22 and L34 respectively), followed by mutations in the MtrCDE-encoded efflux pump and the 23S rRNA gene. Low- to high-level resistance was associated with mutations in the ribosomal proteins and MtrCDE efflux pump. However, high-level resistance was consistently associated with mutations in the 23S ribosomal RNA, mainly the well-known A2059G and C2611T mutations, but also at position A2058G. Conclusions This study enabled us to track previously reported mutations and identify novel mutations in ribosomal proteins (L4, L22 and L34) that may play a role in the genesis of azithromycin resistance in N. gonorrhoeae.

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