| 1. |
- Demczuk, Walter H.B., et al.
(author)
-
Neisseria gonorrhoeae Sequence Typing for Antimicrobial Resistance : a Novel Antimicrobial Resistance Multilocus Typing Scheme for Tracking Global Dissemination of N. gonorrhoeae Strains
- 2017
-
In: Journal of Clinical Microbiology. - : American Society for Microbiology. - 0095-1137 .- 1098-660X. ; 55:5, s. 1454-1468
-
Journal article (peer-reviewed)abstract
- A curated Web-based user-friendly sequence typing tool based on antimicrobial resistance determinants in Neisseria gonorrhoeae was developed and is publicly accessible (https://ngstar.canada.ca). The N. gonorrhoeae Sequence Typing for Antimicrobial Resistance (NG-STAR) molecular typing scheme uses the DNA sequences of 7 genes (penA, mtrR, porB, ponA, gyrA, parC, and 23S rRNA) associated with resistance to β-lactam antimicrobials, macrolides, or fluoroquinolones. NG-STAR uses the entire penA sequence, combining the historical nomenclature for penA types I to XXXVIII with novel nucleotide sequence designations; the full mtrR sequence and a portion of its promoter region; portions of ponA, porB, gyrA, and parC; and 23S rRNA sequences. NG-STAR grouped 768 isolates into 139 sequence types (STs) (n = 660) consisting of 29 clonal complexes (CCs) having a maximum of a single-locus variation, and 76 NG-STAR STs (n = 109) were identified as unrelated singletons. NG-STAR had a high Simpson's diversity index value of 96.5% (95% confidence interval [CI] = 0.959 to 0.969). The most common STs were NG-STAR ST-90 (n = 100; 13.0%), ST-42 and ST-91 (n = 45; 5.9%), ST-64 (n = 44; 5.72%), and ST-139 (n = 42; 5.5%). Decreased susceptibility to azithromycin was associated with NG-STAR ST-58, ST-61, ST-64, ST-79, ST-91, and ST-139 (n = 156; 92.3%); decreased susceptibility to cephalosporins was associated with NG-STAR ST-90, ST-91, and ST-97 (n = 162; 94.2%); and ciprofloxacin resistance was associated with NG-STAR ST-26, ST-90, ST-91, ST-97, ST-150, and ST-158 (n = 196; 98.0%). All isolates of NG-STAR ST-42, ST-43, ST-63, ST-81, and ST-160 (n = 106) were susceptible to all four antimicrobials. The standardization of nomenclature associated with antimicrobial resistance determinants through an internationally available database will facilitate the monitoring of the global dissemination of antimicrobial-resistant N. gonorrhoeae strains.
|
|
| 2. |
- van Dam, Alje P., et al.
(author)
-
Verified clinical failure with cefotaxime 1g for treatment of gonorrhoea in the Netherlands : a case report
- 2014
-
In: Sexually Transmitted Infections. - : BMJ Publishing Group Ltd. - 1368-4973 .- 1472-3263. ; 90:7, s. 513-514
-
Journal article (peer-reviewed)abstract
- We describe the first case of treatment failure of gonorrhoea with a third generation cephalosporin, cefotaxime 1g intramuscularly, in the Netherlands. The case was from a high-frequency transmitting population (men having sex with men) and was caused by the internationally spreading multidrug-resistant gonococcal NG-MAST ST1407 clone. The patient was clinically cured after treatment with ceftriaxone 500 mg intramuscularly and this is the only third generation cephalosporin that should be used for first-line empiric treatment of gonorrhoea. Increased awareness of failures with third generation cephalosporins, enhanced monitoring and appropriate verification of treatment failures including more frequent test-of-cures, and strict adherence to regularly updated treatment guidelines are essential globally.
|
|
| 3. |
- Wind, Carolien M., et al.
(author)
-
Successful Combination of Nucleic Acid Amplification Test Diagnostics and Targeted Deferred Neisseria gonorrhoeae Culture
- 2015
-
In: Journal of Clinical Microbiology. - 0095-1137 .- 1098-660X. ; 53:6, s. 1884-1890
-
Journal article (peer-reviewed)abstract
- Nucleic acid amplification tests (NAATs) are recommended for the diagnosis of N. gonorrhoeae infections because of their superior sensitivity. Increasing NAAT use causes a decline in crucial antimicrobial resistance (AMR) surveillance data, which rely on culture. We analyzed the suitability of the ESwab system for NAAT diagnostics and deferred targeted N. gonorrhoeae culture to allow selective and efficient culture based on NAAT results. We included patients visiting the STI Clinic Amsterdam, The Netherlands, in 2013. Patient characteristics and urogenital and rectal samples for direct N. gonorrhoeae culture, standard NAAT, and ESwab were collected. Standard NAAT and NAAT on ESwab samples were performed using the Aptima Combo 2 assay for N. gonorrhoeae and C. trachomatis. Two deferred N. gonorrhoeae cultures were performed on NAAT-positive ESwab samples after storage at 4 degrees C for 1 to 3 days. We included 2,452 samples from 1,893 patients. In the standard NAAT, 107 samples were N. gonorrhoeae positive and 284 were C. trachomatis positive. The sensitivities of NAAT on ESwab samples were 83% (95% confidence interval [CI], 75 to 90%) and 87% (95% CI, 82 to 90%), respectively. ESwab samples were available for 98 of the gonorrhea-positive samples. Of these, 82% were positive in direct culture and 69% and 56% were positive in the 1st and 2nd deferred cultures, respectively (median storage times, 27 and 48 h, respectively). Deferred culture was more often successful in urogenital samples or when the patient had symptoms at the sampling site. Deferred N. gonorrhoeae culture of stored ESwab samples is feasible and enables AMR surveillance. To limit the loss in NAAT sensitivity, we recommend obtaining separate samples for NAAT and deferred culture.
|
|
| 4. |
- Wind, Carolien M., et al.
(author)
-
Test of cure for anogenital gonorrhoea using modern RNA-based and DNA-based nucleic acid amplification tests : a prospective cohort study
- 2016
-
In: Clinical Infectious Diseases. - Cary, United Kingdom : Oxford University Press. - 1058-4838 .- 1537-6591. ; 62:11, s. 1348-1355
-
Journal article (peer-reviewed)abstract
- Background: The use of nucleic acid amplification tests (NAATs) to diagnose Neisseria gonorrhoeae infections complicates the performance of a test of cure (TOC) to monitor treatment failure, if this is indicated. As evidence for the timing of TOC using modern NAATs is limited, we performed a prospective cohort study to assess time to clearance when using modern RNA- and DNA-based NAATs.Methods: We included patients with anogenital gonorrhoea visiting the STI Clinic Amsterdam from March through October 2014. After treatment with ceftriaxone mono- or dual therapy (with azithromycin or doxycycline) anal, vaginal or urine samples were self-collected during 28 consecutive days, and analysed using an RNA-based NAAT (Aptima Combo 2) and a DNA-based NAAT (Cobas 4800). Clearance was defined as three consecutive negative results, and blips as isolated positive results following clearance.Results: We included 77 patients; five self-cleared gonorrhoea before treatment and ten were lost to follow-up. Clearance rate of the remaining 62 patients was 100%. Median time to clearance was two days, with a range of 1-7 days for RNA-based NAAT, and 1-15 days for DNA-based NAAT. The risk of finding a blip after clearance was 0.8% and 1.4%, respectively. One patient had a reinfection.Conclusions: If indicated, we recommend to perform a TOC for anogenital gonorrhoea at least 7 or 14 days after administering therapy, when using modern RNA- or DNA-based NAATs, respectively. When interpreting TOC results for possible treatment failure, both the occurrence of blips and a possible reinfection need to be taken into account.
|
|
| 5. |
- Wind, Carolien M., et al.
(author)
-
Time to clearance of Chlamydia trachomatis RNA and DNA after treatment in patients coinfected with Neisseria gonorrhoeae : a prospective cohort study
- 2016
-
In: BMC Infectious Diseases. - London, United Kingdom : BioMed Central. - 1471-2334. ; 16:1
-
Journal article (peer-reviewed)abstract
- Background: Performing a test of cure (TOC) could demonstrate success or failure of antimicrobial treatment of Chlamydia trachomatis infection, but recommendations for the timing of a TOC using nucleic acid amplification tests (NAATs) are inconsistent. We assessed time to clearance of C. trachomatis after treatment, using modern RNA- and DNA-based NAATs.Methods We analysed data from patients with a C. trachomatis and Neisseria gonorrhoeae coinfection who visited the STI Clinic Amsterdam, The Netherlands, from March through October 2014. After treatment with ceftriaxone plus either azithromycin or doxycycline, patients self-collected anal, vaginal or urine samples during 28 consecutive days. Samples were analysed using an RNA-based NAAT (Aptima Combo 2) and a DNA-based NAAT (Cobas 4800 CT/NG). We defined clearance as three consecutive negative results, and defined "blips" as isolated positive results following clearance.Results: We included 23 patients with C. trachomatis and N. gonorrhoeae coinfection. All patients cleared C. trachomatis during follow-up, and we observed no reinfections. The median time to clearance (range) was 7 days (1-13) for RNA, and 6 days (1-15) for DNA. Ninety-five per cent of patients cleared RNA at day 13, and DNA at day 14. The risk of a blip after clearance was 4.4 % (RNA) and 1.7 % (DNA).Conclusions: If a TOC for anogenital chlamydia is indicated, we recommend performing it at least 14 days after initiation of treatment, when using modern RNA- and DNA-based assays. A positive result shortly after 14 days probably indicates a blip, rather than a treatment failure or a reinfection.
|
|
| 6. |
- Heymans, Raymond, et al.
(author)
-
Clonally Related Neisseria gonorrhoeae Isolates with Decreased Susceptibility to the Extended-Spectrum Cephalosporin Cefotaxime in Amsterdam, the Netherlands
- 2012
-
In: Antimicrobial Agents and Chemotherapy. - : American Society for Microbiology. - 0066-4804 .- 1098-6596. ; 56:3, s. 1516-1522
-
Journal article (peer-reviewed)abstract
- From 2006 to 2008, Neisseria gonorrhoeae isolates were identified with decreased susceptibility to the extended-spectrum cephalosporin (ESC) cefotaxime among visitors of the Amsterdam sexually transmitted infections (STI) clinic, the Netherlands. Spread, clonality, and characteristics of 202 isolates were examined using antibiograms, conventional penA mosaic gene PCR, and N. gonorrhoeae multiple-locus variable-number tandem repeat analysis (NG-MLVA). A strictly defined subset was further characterized by N. gonorrhoeae multiantigen sequence typing (NG-MAST) and sequencing of ESC resistance determinants (penA, mtrR, and porB1b). Seventy-four N. gonorrhoeae isolates with a cefotaxime MIC of >0.125 mu g/ml (group A), 54 with a cefotaxime MIC of 0.125 mu g/ml (group B), and a control group of 74 with a cefotaxime MIC of <0.125 mu g/ml (group C) were included. Fifty-three clonally related penA mosaic-positive isolates (penicillin-binding protein 2 type XXXIV) were identified in group A (n = 47 isolates; 64%) and B (n = 6 isolates; 11%). The 53 penA mosaic-positive isolates were predominantly NG-MAST ST1407 (87%) and contained an mtrR promoter A deletion (98%) and porB1b alterations G101K/A102N. All were assigned to the same NG-MLVA cluster that comprised in total 56 isolates. A correlation was found between decreased cefotaxime susceptibility and ST1407 that was highly prevalent among visitors of the Amsterdam STI clinic. The rapid spread of this strain, which also has been identified in many other countries, might be facilitated by high-risk sexual behavior and should be monitored closely to identify potential treatment failure. Quality-assured surveillance of ESC susceptibility on the national and international levels and exploration of new drugs and/or strategies for treatment of gonorrhea are crucial.
|
|
| 7. |
- Jacobsson, Susanne, 1974-, et al.
(author)
-
WGS analysis and molecular resistance mechanisms of azithromycin-resistant (MIC >2 mg/L) Neisseria gonorrhoeae isolates in Europe from 2009 to 2014
- 2016
-
In: Journal of Antimicrobial Chemotherapy. - Oxford, United Kingdom : Oxford University Press. - 0305-7453 .- 1460-2091. ; 71:11, s. 3109-3116
-
Journal article (peer-reviewed)abstract
- Objectives: To elucidate the genome-based epidemiology and phylogenomics of azithromycin-resistant (MIC >2 mg/L) Neisseria gonorrhoeae strains collected in 2009-14 in Europe and clarify the azithromycin resistance mechanisms.Methods: Seventy-five azithromycin-resistant (MIC 4 to >256 mg/L) N. gonorrhoeae isolates collected in 17 European countries during 2009-14 were examined using antimicrobial susceptibility testing and WGS.Results: Thirty-six N. gonorrhoeae multi-antigen sequence typing STs and five phylogenomic clades, including 4-22 isolates from several countries per clade, were identified. The azithromycin target mutation A2059G (Escherichia coli numbering) was found in all four alleles of the 23S rRNA gene in all isolates with high-level azithromycin resistance (n = 4; MIC ≥256 mg/L). The C2611T mutation was identified in two to four alleles of the 23S rRNA gene in the remaining 71 isolates. Mutations in mtrR and its promoter were identified in 43 isolates, comprising isolates within the whole azithromycin MIC range. No mutations associated with azithromycin resistance were found in the rplD gene or the rplV gene and none of the macrolide resistance-associated genes [mef(A/E), ere(A), ere(B), erm(A), erm(B), erm(C) and erm(F)] were identified in any isolate.Conclusions: Clonal spread of relatively few N. gonorrhoeae strains accounts for the majority of the azithromycin resistance (MIC >2 mg/L) in Europe. The four isolates with high-level resistance to azithromycin (MIC ≥256 mg/L) were widely separated in the phylogenomic tree and did not belong to any of the main clades. The main azithromycin resistance mechanisms were the A2059G mutation (high-level resistance) and the C2611T mutation (low- and moderate-level resistance) in the 23S rRNA gene.
|
|
