Novel external quality assurance scheme for drug susceptibility testing of non-tuberculous mycobacteria: a multicentre pilot study

Comparative analysis of phenotypic and genotypic antibiotic susceptibility patterns in Mycobacterium avium complex

“…To a lesser extent, this applies to doxycycline and rifabutin: a loss of biological activity equaling only one dilution step could be observed. As the visual reading of MICs in the broth microdilution method is usually subjective and somewhat difficult to reproduce between different readers and centers (Nikolayevskyy et al, 2019), this loss of concentration may be of low practical importance but should be kept in mind.…”

“…This study has several limitations. First, the pDST is error-prone due to the subjective nature of visual reading, and a variation of one dilution step might already result in a different susceptibility category according to CLSI criteria (Nikolayevskyy et al, 2019). We tried to minimize this factor by independent plate reading by two different observers.…”

“…The use of pDST, however, poses several problems: First, in slow-growing mycobacteria (SGM), it is very time-consuming. Second, interpretation of results remains highly subjective, as a recent comparison between MIC reading of different European reference centers has shown (Nikolayevskyy et al, 2019). Automated analysis is not ready yet for standard utilization in the clinical context (Rockland et al, 2018).…”

International Society of Cardiovascular Infectious Diseases Guidelines for the Diagnosis, Treatment and Prevention of Disseminated Mycobacterium chimaera Infection Following Cardiac Surgery with Cardiopulmonary Bypass

“…Breakpoints for antimicrobials used in the treatment of NTM infections were redefined in the M24Ed3 [90] and M62Ed1 [91] CLSI documents, respectively. To ensure optimal results, AST of M. chimaera isolates should be performed by experienced reference laboratories [92]. Baseline macrolide AST should be performed for clarithromycin, as the solubility at high concentrations is increased as compared to that of azithromycin [79,93,94].…”

“…Additionally, NTM can grow over a very wide temperature range (15e45 C) and survive at 55e60 C [65]. Since decontamination measures often fail [41,91,92] and since intensified cleaning and disinfection might lead to device damage [36,106], facilities can either use other HCDs or they are strongly advised to separate HCDs from the OR room air volume by: (i) placing HCDs in dedicated utility rooms adjacent to the operating room (OR) [33,102,107,108] or (ii) placing them in encasings with controlled air extraction via a duct to the theatre exhaust conduit [41]. However, products such as encasings that are engineered and built by hospitals may alter the function of the HCD and the potential for such changes in function should be taken into consideration when implementing such interventions.…”