Antibiotic Resistance Screening in Ureaplasma and Mycoplasma

Analysis of putative resistant isolates was conducted in accordance with CLSI M43A(21) using a previously published methodology for breakpoint analysis for Ureaplasma spp. isolates [22 (link)]. The method was modified to include additional antibiotics, alongside utilising MHSM for the breakpoint screening of M. hominis isolates. Isolates were screened against the CLSI guideline concentrations of antibiotic. Isolates were only screened against antibiotics if they had shown supposed resistance to that antibiotic on the MYCO WELL D-ONE assay. All antibiotics were purchased from Sigma-Aldrich (Dorset, UK) and supplied as or reconstituted to 1 mg/mL stock solutions, prior to further dilution in the appropriate media (USM/MHSM) to achieve CLSI-compliant concentrations for AST.