Estimation of antimicrobial resistance of Mycoplasma genitalium, Belgium, 2022.

BackgroundAntimicrobial resistance (AMR) of Mycoplasma genitalium (MG) is a growing concern worldwide and surveillance is needed. In Belgium, samples are sent to the National Reference Centre of Sexually Transmitted Infections (NRC-STI) on a voluntary basis and representative or robust national AMR data are lacking.AimWe aimed to estimate the occurrence of resistant MG in Belgium.MethodsBetween July and November 2022, frozen remnants of MG-positive samples from 21 Belgian laboratories were analysed at the NRC-STI. Macrolide and fluoroquinolone resistance-associated mutations (RAMs) were assessed using Sanger sequencing of the 23SrRNA and parC gene. Differences in resistance patterns were correlated with surveillance methodology, socio-demographic and behavioural variables via Fisher's exact test and logistic regression analysis.ResultsOf the 244 MG-positive samples received, 232 could be sequenced for macrolide and fluoroquinolone RAMs. Over half of the sequenced samples (55.2%) were resistant to macrolides. All sequenced samples from men who have sex with men (MSM) (24/24) were macrolide-resistant. Fluoroquinolone RAMs were found in 25.9% of the samples and occurrence did not differ between socio-demographic and sexual behaviour characteristics.ConclusionAlthough limited in sample size, our data suggest no additional benefit of testing MG retrieved from MSM for macrolide resistance in Belgium, when making treatment decisions. The lower occurrence of macrolide resistance in other population groups, combined with emergence of fluoroquinolone RAMs support macrolide-resistance testing in these groups. Continued surveillance of resistance in MG in different population groups will be crucial to confirm our findings and to guide national testing and treatment strategies.

Analytical Performance Verification of the Beckman Coulter AU5800 Clinical Chemistry Analyser Against Recognized Quality Specifications Reveals Relevance of Method Harmonization.

BACKGROUND: Analytical performance of 24 Beckman-Coulter AU 5800 methods was verified against recognized quality goals and manufacturer's expected imprecision and bias. METHODS: AU5800 method imprecision, bias, agreement with a comparative method, and linearity were studied using CLSI protocols, commercial control material, patient samples, and linearity test kit solutions. Repeat patient testing and IQC were also used for imprecision. Commutability of control material was tested. Total analytical error (TAE) was estimated for each method and between the tested and the comparative method, the Beckman-Coulter Unicel DxC800. RESULTS: CLSI EP15 total imprecision CV (TCV) < 3.2%. Duplicate patient imprecision CV < 2.8%. IQC imprecision CV < 5.1%, except for low level ALP (CV = 7.4%). Sodium and urate IQC imprecision were higher than manufacturer's specifications. TAE for all methods met accepted quality goals. Correlation between methods was > 0.975, except for Cl (0.971), TP (0.964), and Na (0.948). Average bias versus Unicel DxC800 is high for ALP (17.3%), GGT (37%), LD (20%), TBIL (-23%), and TP (8%) and was confirmed in other laboratories. TAE between methods met allowable total error for 21 analytes. For GGT, between method TAE (23 to 51%) was predictable from expected bias and combined method imprecision. For LD and TP several between method differences were outside boundaries describing expected bias. Linearity was excellent with R2 > 0.997 and deviations met accepted goals. CONCLUSIONS: The Beckman-Coulter AU 5800 demonstrates good linearity, low imprecision, and good correlation with previous methods. Observed between method differences suggest ALP, GGT, LD, TBIL, and TP harmonization should be considered.