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.

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

2020 ◽  
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

AbstractObjectivesThe prevalence of azithromycin resistance in Neisseria gonorrhoeae is increasing in numerous populations worldwide. The aim of this study was to characterize the genetic pathways leading to high-level azithromycin resistance.MethodsA 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.ResultsWithin 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-encoded 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.ConclusionsThis 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.

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 New Mutation in 23S rRNA Gene Associated with High Level of Azithromycin Resistance in Neisseria gonorrhoeae

2010 ◽  
Vol 54 (4) ◽  
pp. 1652-1653 ◽  
Author(s):  
Patricia G. Galarza ◽  
Raquel Abad ◽  
Liliana Fernández Canigia ◽  
Luis Buscemi ◽  
Irene Pagano ◽  
...  
Keyword(s):  
Neisseria Gonorrhoeae ◽  
23S Rrna ◽  
Rrna Gene ◽  
New Mutation ◽  
23S Rrna Gene ◽  
High Level ◽  
Azithromycin Resistance

scholarly journals Atypical Mutation in Neisseria gonorrhoeae 23S rRNA Associated with High-Level Azithromycin Resistance.

2020 ◽  
Author(s):  
Cau D. Pham ◽  
Evelyn Nash ◽  
Hsi Liu ◽  
Matthew W. Schmerer ◽  
Samera Sharpe ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Genetic Analysis ◽  
Neisseria Gonorrhoeae ◽  
23S Rrna ◽  
Rrna Gene ◽  
Neisseria Gonorrhoea ◽  
23S Rrna Gene ◽  
High Level ◽  
Azithromycin Resistance

A2059G mutation in the 23S rRNA gene is the only reported mechanism conferring high-level azithromycin resistance (HL-AZMR) in Neisseria gonorrhoea. Through U.S. gonococcal antimicrobial resistance surveillance projects, we identified four HL-AZMR gonococcal isolates lacking this mutational genotype. Genetic analysis revealed an A2058G mutation of 23S rRNA alleles in all four isolates. In vitro selected gonococcal strains with homozygous A2058G recapitulated the HL-AZMR phenotype. Taken together, we postulate that A2058G mutation confers HL-AZMR in N. gonorrhoeae.

Antimicrobial susceptibility and mechanisms of high-level macrolide resistance in clinical isolates of Moraxella nonliquefaciens

2014 ◽  
Vol 63 (2) ◽  
pp. 242-247 ◽  
Author(s):  
Shotaro Nonaka ◽  
Kosuke Matsuzaki ◽  
Tomoya Kazama ◽  
Hiroyuki Nishiyama ◽  
Yoko Ida ◽  
...  
Keyword(s):  
Antimicrobial Susceptibility ◽  
Ribosomal Proteins ◽  
Macrolide Resistance ◽  
Clinical Isolates ◽  
23S Rrna ◽  
Rrna Gene ◽  
Efflux System ◽  
Strong Activity ◽  
23S Rrna Gene ◽  
High Level

We investigated antimicrobial susceptibility and the molecular mechanism involved in conferring high-level macrolide resistance in 47 clinical isolates of Moraxella nonliquefaciens from Japan. Antimicrobial susceptibility was determined using Etest and agar dilution methods. Thirty-two erythromycin-non-susceptible strains were evaluated for the possibility of clonal spreading, using PFGE. To analyse the mechanism related to macrolide resistance, mutations in the 23S rRNA gene and the ribosomal proteins, and the presence of methylase genes were investigated by PCR and sequencing. The efflux system was examined using appropriate inhibitors. Penicillin, ampicillin, amoxicillin, cefixime, levofloxacin and antimicrobials containing β-lactamase inhibitors showed strong activity against 47 M. nonliquefaciens isolates. Thirty-two (68.1 %) of the 47 isolates showed high-level MICs to macrolides (MIC ≥128 mg l−1) and shared the A2058T mutation in the 23S rRNA gene. The geometric mean MIC to macrolides of A2058T-mutated strains was significantly higher than that of WT strains (P<0.0001). Thirty-two isolates with high-level macrolide MICs clustered into 30 patterns on the basis of the PFGE dendrogram, indicating that the macrolide-resistant strains were not clonal. In contrast, no common mutations of the ribosomal proteins or methylase genes, or overproduction of the efflux system were observed in A2058T-mutated strains. Moreover, of the 47 M. nonliquefaciens strains, 43 (91.5 %) were bro-1 and 4 (8.5 %) were bro-2 positive. Our results suggest that most M. nonliquefaciens clinical isolates show high-level macrolide resistance conferred by the A2058T mutation in the 23S rRNA gene. This study represents the first characterization of M. nonliquefaciens.

scholarly journals A T2504A mutation in the 23S rRNA gene responsible for high-level resistance to linezolid of Staphylococcus epidermidis

2009 ◽  
Vol 64 (1) ◽  
pp. 206-207 ◽  
Author(s):  
A. Liakopoulos ◽  
C. Neocleous ◽  
D. Klapsa ◽  
M. Kanellopoulou ◽  
I. Spiliopoulou ◽  
...  
Keyword(s):  
Staphylococcus Epidermidis ◽  
23S Rrna ◽  
Rrna Gene ◽  
23S Rrna Gene ◽  
High Level ◽  
Level Resistance

scholarly journals Molecular characterization of a ceftriaxone-resistant Neisseria gonorrhoeae strain found in Switzerland: a case report

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Konrad Egli ◽  
Anna Roditscheff ◽  
Ursula Flückiger ◽  
Martin Risch ◽  
Lorenz Risch ◽  
...  
Keyword(s):  
Neisseria Gonorrhoeae ◽  
23S Rrna ◽  
Rrna Gene ◽  
Limited Information ◽  
Specific Pcr ◽  
Appropriate Treatment ◽  
23S Rrna Gene ◽  
Allele Type ◽  
Ciprofloxacin Resistance

Abstract Background The resistance of Neisseria gonorrhoeae to ceftriaxone is unusual in Switzerland. The underlying genotype responsible for resistance is suspected to be novel. Generally, resistance in Neisseria gonorrhoeae (Ng) involves a comprehensive set of genes with many different mutations leading to resistance to different β-lactams and fluoroquinolones. Case presentation A patient had a positive result from specific PCR for Ng. We routinely culture all clinical specimens with a positive NG-PCR. In this particular case, we isolated a strain with resistance to ceftriaxone in Switzerland. A total of seven different genes (penA, ponA, porinB, mtr, gyrA, parC, 23S rRNA gene) in this strain were partially sequenced for comparison with phenotypic susceptibility testing. Interestingly, two different mutations in the porinB gene were observed, and data on this gene are limited. Information on the identified allele type of the penA gene is very limited as well. Three different mutations of parC and gyrA that correlate with ciprofloxacin resistance were found. The combination of ceftriaxone and ciprofloxacin resistance makes an appropriate treatment difficult to obtain due to multidrug resistance. Conclusion The combined results for all genes show the appearance of new mutations in central Europe either due to worldwide spread or the emergence of new genetic combinations of mutations.

scholarly journals Molecular Basis of Macrolide Resistance inCampylobacterStrains Isolated from Poultry in South Korea

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Bai Wei ◽  
Min Kang
Keyword(s):  
Molecular Mechanisms ◽  
Macrolide Resistance ◽  
23S Rrna ◽  
Rrna Gene ◽  
Campylobacter Coli ◽  
Erythromycin Resistance ◽  
23S Rrna Gene ◽  
Ribosomal Protein L22 ◽  
Resistant Strains ◽  
Azithromycin Resistance

We investigated the molecular mechanisms underlying macrolide resistance in 38 strains ofCampylobacterisolated from poultry. Twenty-seven strains were resistant to azithromycin and erythromycin, five showed intermediate azithromycin resistance and erythromycin susceptibility, and six showed azithromycin resistance and erythromycin susceptibility. FourCampylobacter jejuniand sixCampylobacter colistrains had azithromycin MICs which were 8–16 and 2–8-fold greater than those of erythromycin, respectively. The A2075G mutation in the 23S rRNA gene was detected in 11 resistant strains with MICs ranging from 64 to ≥ 512μg/mL. Mutations including V137A, V137S, and a six-amino acid insertion (114-VAKKAP-115) in ribosomal protein L22 were detected in theC. jejunistrains. Erythromycin ribosome methylase B-erm(B) was not detected in any strain. All strains except three showed increased susceptibility to erythromycin with twofold to 256-fold MIC change in the presence of phenylalanine arginine ß-naphthylamide (PAßN); the effects of PAßN on azithromycin MICs were limited in comparison to those on erythromycin MICs, and 13 strains showed no azithromycin MIC change in the presence of PAßN. Differences between azithromycin and erythromycin resistance and macrolide resistance phenotypes and genotypes were observed even in highly resistant strains. Further studies are required to better understand macrolide resistance inCampylobacter.

scholarly journals Overexpression of the MtrC-MtrD-MtrE Efflux Pump Due to an mtrR Mutation Is Required for Chromosomally Mediated Penicillin Resistance in Neisseria gonorrhoeae

2002 ◽  
Vol 184 (20) ◽  
pp. 5619-5624 ◽  
Author(s):  
Wendy L. Veal ◽  
Robert A. Nicholas ◽  
William M. Shafer
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Base Pair ◽  
Efflux Pump ◽  
Penicillin Resistance ◽  
Single Base ◽  
Base Pair Deletion ◽  
Resistance To Penicillin ◽  
Single Base Pair ◽  
High Level ◽  
Level Resistance

ABSTRACT The importance of the mtrCDE-encoded efflux pump in conferring chromosomally mediated penicillin resistance on certain strains of Neisseria gonorrhoeae was determined by using genetic derivatives of penicillin-sensitive strain FA19 bearing defined mutations (mtrR, penA, and penB) donated by a clinical isolate (FA6140) expressing high-level resistance to penicillin and antimicrobial hydrophobic agents (HAs). When introduced into strain FA19 by transformation, a single base pair deletion in the mtrR promoter sequence from strain FA6140 was sufficient to provide high-level resistance to HAs (e.g., erythromycin and Triton X-100) but only a twofold increase in resistance to penicillin. When subsequent mutations in penA and porIB were introduced from strain FA6140 into strain WV30 (FA19 mtrR) by transformation, resistance to penicillin increased incrementally up to a MIC of 1.0 μg/ml. Insertional inactivation of the gene (mtrD) encoding the membrane transporter component of the Mtr efflux pump in these transformant strains and in strain FA6140 decreased the MIC of penicillin by 16-fold. Genetic analyses revealed that mtrR mutations, such as the single base pair deletion in its promoter, are needed for phenotypic expression of penicillin and tetracycline resistance afforded by the penB mutation. As penB represents amino acid substitutions within the third loop of the outer membrane PorIB protein that modulate entry of penicillin and tetracycline, the results presented herein suggest that PorIB and the MtrC-MtrD-MtrE efflux pump act synergistically to confer resistance to these antibiotics.

scholarly journals Natural Transformation-Mediated Transfer of Erythromycin Resistance in Campylobacter coli Strains from Turkeys and Swine

2006 ◽  
Vol 72 (2) ◽  
pp. 1316-1321 ◽  
Author(s):  
Joo-Sung Kim ◽  
Donna K. Carver ◽  
Sophia Kathariou
Keyword(s):  
Point Mutation ◽  
Natural Transformation ◽  
23S Rrna ◽  
Rrna Gene ◽  
Campylobacter Coli ◽  
Erythromycin Resistance ◽  
23S Rrna Gene ◽  
High Level ◽  
Human Infections ◽  
Spontaneous Mutants

ABSTRACT Erythromycin resistance in Campylobacter coli from meat animals is frequently encountered and could represent a substantial barrier to antibiotic treatment of human infections. Erythromycin resistance in this organism has been associated with a point mutation (A2075G) in the 23S rRNA gene. However, the mechanisms responsible for possible dissemination of erythromycin resistance in C. coli remain poorly understood. In this study, we investigated transformation-mediated acquisition of erythromycin resistance by genotypically diverse C. coli strains from turkeys and swine, with total genomic DNA from erythromycin-resistant C. coli of either turkey or swine origin used as a donor. Overall, transformation to erythromycin resistance was significantly more frequent in C. coli strains from turkeys than in swine-derived strains (P < 0.01). The frequency of transformation to erythromycin resistance was 10−5 to 10−6 for turkey-derived strains but 10−7 or less for C. coli from swine. Transformants harbored the point mutation A2075G in the 23S rRNA gene, as did the erythromycin-resistant strains used as DNA donors. Erythromycin resistance was stable in transformants following serial transfers in the absence of the antibiotic, and most transformants had high MICs (>256 μg/ml), as did the C. coli donor strains. In contrast to the results obtained with transformation, spontaneous mutants had relatively low erythromycin MICs (32 to 64 μg/ml) and lacked the A2075G mutation in the 23S rRNA gene. These findings suggest that natural transformation has the potential to contribute to the dissemination of high-level resistance to erythromycin among C. coli strains colonizing meat animals.

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