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.

Antimicrobial susceptibility of Neisseria gonorrhoeae in Barcelona during a five-year period, 2013 to 2017.

IntroductionIncreasing rates of antimicrobial resistance in Neisseria gonorrhoeae cause problems for treating gonorrhoea.AimThis observational study aimed to describe isolates from all patients found infected with N. gonorrhoeae, in Barcelona, Spain, between 2013 and 2017, and with available antimicrobial susceptibility data.MethodsMinimum inhibitory concentrations (MICs) of penicillin (PEN), cefixime (CFM), ceftriaxone (CRO), azithromycin (AZM), ciprofloxacin (CIP), spectinomycin (SPT), fosfomycin (FOF) and gentamicin (GEN) were determined by E-test. Susceptibility was assessed using clinical breakpoints from the European Committee on Antimicrobial Susceptibility Testing. Time trends for PEN, CFM, AZM and CIP were investigated using logistic regression.ResultsOf 1,979 patients with infection (2,036 isolates), 1,888 (95.4%) were men. Patient median age was 32 years. The proportions of isolates resistant to extended-spectrum cephalosporins were low, with 0.3% (5/1,982) resistant to CRO and 4.9% (98/1,985) to CFM. AZM resistance prevalence was 2.7% (52/1,981), including 16 isolates detected in 2016 and 2017, with high-level resistance. For CIP, 51.3% (1,018/1,986) of isolates were resistant, and for PEN, 20.1% (399/1,985). All isolates were susceptible to SPT. MIC50 and MIC90 values of GEN were 4 and 6 mg/L and of FOF 12 and 24 mg/L, respectively. Between 2013 and 2017, PEN and CFM resistance rates each decreased from 28.1% (92/327) to 12.2% (70/572) and from 8.3% (27/327) to 4.4% (25/572) (p ≤ 0.0073). In contrast, AZM resistance prevalence appeared to increase from 1.5% in 2014 (5/340) to 3.0% (17/572) in 2017. No trend was identified for CIP.ConclusionAntimicrobial susceptibility surveillance is important to timely detect new phenotypes and trends.