| 1. |
- Cole, Michelle Jayne, et al.
(author)
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No widespread dissemination of Chlamydia trachomatis diagnostic : escape variants and the impact of Neisseria gonorrhoeae positivity on the Aptima Combo 2 assay
- 2022
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In: Sexually Transmitted Infections. - : BMJ Publishing Group Ltd. - 1368-4973 .- 1472-3263. ; 98:5, s. 366-370
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Journal article (peer-reviewed)abstract
- OBJECTIVES: (NG) with the Hologic Aptima CT (ACT) assay was recommended to identify any CT variants.METHODS: From June to October 2019, specimens with discrepant AC2/ACT CT results were submitted to Public Health England and screened for detectable CT DNA using an inhouse real-time (RT)-PCR. When enough DNA was present, partial CT 23S rRNA gene sequencing was performed. Analysis of available relative light units and interpretative data was performed.RESULTS: A total of 317 discordant AC2/ACT specimens were collected from 315 patients. Three hundred were tested on the RT-PCR; 53.3% (n=160) were negative and 46.7% (n=140) were positive. Due to low DNA load in most specimens, sequencing was successful for only 36 specimens. The CT 23S rRNA wild-type sequence was present in 32 specimens, and two variants with C1514T or G1523A mutation were detected in four specimens from three patients. Of the discordant specimens with NG interpretation, 36.6% of NG-negative/CT-negative AC2 specimens had detectable CT DNA on the inhouse RT-PCR vs 53.3% of NG-positive/CT-negative specimens.CONCLUSIONS: No widespread dissemination of AC2 diagnostic-escape CT variants has occurred in England. We however identified the impact of NG positivity on the discordant AC2/ACT specimens; a proportion appeared due to NG positivity and the associated NG signal, rather than any diagnostic-escape variants or low DNA load. Several patients with gonorrhoea may therefore receive false-negative AC2 CT results. Single diagnostic targets and multiplex diagnostic assays have their limitations such as providing selection pressure for escape mutants and potentially reduced sensitivity, respectively. These limitations must be considered when establishing diagnostic pathways.
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| 2. |
- Hadad, Ronza, 1984-, et al.
(author)
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Evaluation of the SpeeDx ResistancePlus® GC and SpeeDx GC 23S 2611 (beta) molecular assays for prediction of antimicrobial resistance/susceptibility to ciprofloxacin and azithromycin in Neisseria gonorrhoeae
- 2021
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In: Journal of Antimicrobial Chemotherapy. - : Oxford University Press. - 0305-7453 .- 1460-2091. ; 76:1, s. 84-90
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Journal article (peer-reviewed)abstract
- BACKGROUND: Accurate molecular assays for prediction of antimicrobial resistance (AMR)/susceptibility in Neisseria gonorrhoeae (Ng) can offer individualized treatment of gonorrhoea and enhanced AMR surveillance.OBJECTIVES: We evaluated the new ResistancePlus® GC assay and the GC 23S 2611 (beta) assay (SpeeDx), for prediction of resistance/susceptibility to ciprofloxacin and azithromycin, respectively.METHODS: Nine hundred and sixty-seven whole-genome-sequenced Ng isolates from 20 European countries, 143 Ng-positive (37 with paired Ng isolates) and 167 Ng-negative clinical Aptima Combo 2 (AC2) samples, and 143 non-gonococcal Neisseria isolates and closely related species were examined with both SpeeDx assays.RESULTS: The sensitivity and specificity of the ResistancePlus® GC assay to detect Ng in AC2 samples were 98.6% and 100%, respectively. ResistancePlus® GC showed 100% sensitivity and specificity for GyrA S91 WT/S91F detection and 99.8% sensitivity and specificity in predicting phenotypic ciprofloxacin resistance. The sensitivity and specificity of the GC 23S 2611 (beta) assay for Ng detection in AC2 samples were 95.8% and 100%, respectively. GC 23S 2611 (beta) showed 100% sensitivity and 99.9% specificity for 23S rRNA C2611 WT/C2611T detection and 64.3% sensitivity and 99.9% specificity for predicting phenotypic azithromycin resistance. Cross-reactions with non-gonococcal Neisseria species were observed with both assays, but the analysis software solved most cross-reactions.CONCLUSIONS: The new SpeeDx ResistancePlus® GC assay performed well in the detection of Ng and AMR determinants, especially in urogenital samples. The GC 23S 2611 (beta) assay performed relatively well, but its sensitivity, especially for predicting phenotypic azithromycin resistance, was suboptimal and further optimizations are required, including detection of additional macrolide resistance determinant(s).
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| 3. |
- Hernando Rovirola, Cristina, et al.
(author)
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Antimicrobial resistance in Neisseria gonorrhoeae isolates from foreign-born population in the European Gonococcal Antimicrobial Surveillance Programme
- 2020
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In: Sexually Transmitted Infections. - : BMJ Publishing Group Ltd. - 1368-4973 .- 1472-3263. ; 96:3, s. 204-210
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Journal article (peer-reviewed)abstract
- OBJECTIVES: infections worldwide. We compared the prevalence of AMR gonococcal isolates among native persons to foreign-born (reporting country different from country of birth) persons, and describe the epidemiological and clinical characteristics of foreign-born patients and their associations to AMR.METHODS: We analysed isolates and patient data reported to the European Gonococcal Antimicrobial Surveillance Programme (Euro-GASP) 2010-2014 (n=9529).RESULTS: Forty-three per cent of isolates had known country of birth and 17.2% of these were from persons born abroad. Almost 50% of foreign-born were from the WHO European Region (13.1% from non-European Union [EU] and the European Economic Area [EEA] countries). Compared with isolates from natives, isolates from foreign-born had a similar level (p>0.05) of azithromycin resistance (7.5% vs 7.2%), ciprofloxacin resistance (50.0% vs 46.3%) and of decreased susceptibility to ceftriaxone (1.9% vs 2.8%); a lower rate of cefixime resistance (5.7% vs 3.6%, p=0.02), and a higher proportion of isolates producing penicillinase (8.4% vs 11.7%, p=0.02). Among isolates from persons born outside EU/EEA, the level of decreased susceptibility to ceftriaxone was higher (1.8% vs 3.5%, p=0.02), particularly in those from the WHO Eastern Mediterranean Region and non-EU/EEA WHO European countries (1.9% vs 9.6% and 8.7%, respectively, p<0.01). In multivariable analysis, foreign-born patients with AMR isolates were more likely to be from non-EU/EEA WHO European countries (adjusted OR [aOR]: 3.2, 95% CI 1.8 to 5.8), WHO Eastern Mediterranean countries (aOR: 1.8, 95% CI 1.1 to 3.3) and heterosexual males (aOR: 1.8, 95% CI 1.2 to 2.7).CONCLUSIONS: Importation of AMR strains remains an important threat in the EU/EEA. Research to improve understanding of sexual networks within foreign born and sexual tourism populations could help to inform effective tailor-made interventions. The Euro-GASP demonstrates the public health value of quality-assured surveillance of gonococcal AMR and the need for strengthened AMR surveillance, particularly in the non-EU/EEA WHO European Region.
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| 4. |
- Pitt, Rachel, et al.
(author)
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Antimicrobial resistance in Mycoplasma genitalium sampled from the British general population
- 2020
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In: Sexually Transmitted Infections. - : BMJ Publishing Group Ltd. - 1368-4973 .- 1472-3263. ; 96:6, s. 464-468
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Journal article (peer-reviewed)abstract
- Background: Mycoplasma genitaliumis a common sexually transmitted infection. Treatment guidelines focus on those with symptoms and sexual contacts, generally with regimens including doxycycline and/or azithromycin as first-line and moxifloxacin as second-line treatment. We investigated the prevalence of antimicrobial resistance (AMR)-conferring mutations inM. genitaliumamong the sexually-active British general population.Methods: The third national survey of sexual attitudes and lifestyles (Natsal-3) is a probability sample survey of 15 162 men and women aged 16-74 years in Britain conducted during 2010-12. Urine test results forM. genitaliumwere available for 4507 participants aged 16-44 years reporting>1 lifetime sexual partner. In this study, we sequenced regions of the 23S rRNA andparCgenes to detect known genotypic determinants for resistance to macrolides and fluoroquinolones respectively.Results: 94% (66/70) of specimens were re-confirmed asM. genitaliumpositive, with successful sequencing in 85% (56/66) for 23S rRNA and 92% (61/66) forparCgenes. Mutations in 23S rRNA gene (position A2058/A2059) were detected in 16.1% (95%CI: 8.6% to 27.8%) and inparC(encodingParCD87N/D87Y) in 3.3% (0.9%-11.2%). Macrolide resistance was more likely in participants reporting STI diagnoses (past 5 years) (44.4% (18.9%-73.3%) vs 10.6% (4.6%-22.6%); p=0.029) or sexual health clinic attendance (past year) (43.8% (23.1%-66.8%) vs 5.0% (1.4%-16.5%); p=0.001). All 11 participants with AMR-conferring mutations had attended sexual health clinics (past 5 years), but none reported recent symptoms.Conclusions: This study highlights challenges inM. genitaliummanagement and control. Macrolide resistance was present in one in six specimens from the general population in 2010-2012, but no participants with AMRM. genitaliumreported symptoms. Given anticipated increases in diagnostic testing, new strategies including novel antimicrobials, AMR-guided therapy, and surveillance of AMR and treatment failure are recommended.
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