Neisseria gonorrhoeae antimicrobial resistance in Spain: a prospective multicentre study

Impact of time of culture specimen collection on the recovery of Neisseria gonorrhoeae after a positive nucleic acid amplification test

OBJECTIVES

Culture of Neisseria gonorrhoeae remains essential for antimicrobial resistance (AMR) surveillance. We evaluated the effect of time of specimen collection on culture yield following a positive nucleic acid amplification test (NAAT).

METHODS

We retrospectively assessed N. gonorrhoeae culture yield among asymptomatic individuals (largely men who have sex with men) who attended for sexual health screening and had a positive NAAT. Participants underwent either same-day testing and notification (Drassanes Exprés) or standard screening with deferred testing.

RESULTS

Among 10 423 screened individuals, 809 (7.7%) tested positive for N. gonorrhoeae. A total of 995 different anatomical sites of infection culture was performed in 583 of 995 (58.6%) of anatomical sites (Drassanes Exprés 278 of 347, 80.1%; standard screening 305 of 648, 47.1%; p<0.001). Recovery was highest when culture specimens were collected within 3-7 days of screening with only a slight drop in recovery when the interval extended to 7 days . Recovery from pharynx was 38 of 149 (25.5%) within 3 days, 19 of 81 (23.4%) after 4-7 days (p=0.7245), 11 of 102 (10.7%) after 8-14 days (p<0.0036) and 1 of 22 (4.5%) with longer delays (p=0.00287). Recovery from rectum was 49 of 75 (65.3%) within 3 days, 28 of 45 (62.2%) after 4-7 days (p=0.7318), 41 of 69 (59.4%) after 8-14 days (p=0.4651) and 6 of 18 (33.3%) with longer delays (p=0.0131). Median culture specimen collection time was 1 day within Drassanes Exprés vs 8 days within standard screening. Consequently, the overall culture yield was slightly higher within Drassanes Exprés (102/278, 36.6% vs 99/305, 32.5%; p=0.2934).

CONCLUSION

Reducing the interval between screening and collection of culture specimens increased N. gonorrhoeae recovery in extragenital samples. Implementing a same-day testing and notification programme increased collection of culture samples and culture yield in our setting, which may help AMR surveillance.

Genome-based epidemiology and antimicrobial resistance of Neisseria gonorrhoeae in Spain: A prospective multicentre study

BACKGROUND

Whole-genome sequencing (WGS) of Neisseria gonorrhoeae isolates combined with epidemiological and phenotypic data provides better understanding of population dynamics.

AIM

The objective of this study was to investigate the molecular epidemiology of N. gonorrhoeae isolates from three centres in Spain and determine associations of antimicrobial resistance.

METHODS

Genetic characterization was performed in 170 N. gonorrhoeae isolates. WGS was carried out with the HiSeq platform (Illumina). Genome assemblies were submitted to the PubMLST Neisseria database website to determine NG-MAST, MLST and NG-STAR. Antimicrobial resistance genes and point mutations were identified with PubMLST. Phylogenomic comparison was based on whole-genome single nucleotide polymorphism analysis.

RESULTS

Twenty-six MLST, 49 NG-MAST and 41 NG-STAR sequence types were detected, the most prevalent being MLST-ST9363 (27.1%), NG-MAST ST569 (12.4%) and NG-STAR ST193 (14.7%). Phylogenetic analysis identified 13 clusters comprising 69% of the isolates, with two of note: one involved cefixime-resistant isolates from Barcelona presenting a mosaic penA X and belonging to MLST-ST7363 and the other involved azithromycin-resistant isolates from Mallorca that possessed the C2611T mutation in the four 23S rRNA alleles belonging to MLST-ST1901.

CONCLUSION

The population of N. gonorrhoeae is quite heterogeneous in Spain. Our results agree with previous data published in Europe, albeit with some differences in distribution between regions. This study describes the circulation of two gonococcal populations with a specific resistance profile and sequence type in a specific geographic area. WGS is an effective tool for epidemiological surveillance of gonococcal infection and detection of resistance genes.

Markedly decreasing azithromycin susceptibility of Neisseria gonorrhoeae, Germany, 2014 to 2021

We monitored antimicrobial susceptibility developments of Neisseria gonorrhoeae in Germany from January 2014 to May 2021. The proportion of isolates with azithromycin minimum inhibitory concentrations above the epidemiological cut-off increased substantially, from 1.3% in 2014 to 12.2% in 2020. Preliminary data from 2021 showed a further rise (January to May: 20.7%). Therefore, azithromycin as part of the recommended dual therapy in Germany for non-adherent patients is challenged. Antimicrobial susceptibility testing in clinical practice is crucial and continuous susceptibility surveillance indispensable.