Non-tuberculous mycobacteria: clinical and laboratory characterisation (2009 and 2019).

A cross-sectional and retrospective study of patients with Mycobacterium spp. in a Portuguese tertiary hospital, in 2009 and 2019, was performed to understand better the rise in isolations of nontuberculous mycobacteria (NTM). The number of patients with positive samples for Mycobacterium spp. grew from 56 in 2009 to 83 in 2019. The proportion of NTM rose from 39.3% to 49.4% (P = 0.240), with Mycobacterium avium complex being more frequent in 2009 and Mycobacterium gordonae in 2019, and Mycobacterium tuberculosis complex decreased from 60.7% to 50.6%. Higher age was associated with NTM in both years, and pulmonary disease and immunosuppression were associated with NTM in 2019 (P < 0.05), with weak to moderate correlation (V = 0.231-0.343). The overall rise of NTM, allied to their known capacity to resist antimicrobial therapy, alerts clinicians to the importance of recognising potential risk factors for infection and improving future prevention strategies.

Molecular characterization of Klebsiella pneumoniae isolated from renal transplanted patients: virulence markers, extended-spectrum ß-lactamases, and genetic relatedness.

The objective was to characterize virulence markers and ß-lactam resistance in Klebsiella pneumoniae isolates from renal transplant patients and to evaluate their genetic relatedness. Two main genetic lineages were detected: 1 carried bla(CTX-M-15) not associated to IncFIIA plasmid replicon, which was found on the other lineage not expressing CTX-M-type enzyme. PAI III(536) and PAI II(CFT073) were detected for the first time in K. pneumoniae in 1 clone, while the siderophore kfu was carried by the other, with only PAI IV(536). The molecular data indicate colonization before admission and fuel the discussion on implementation of antibiotherapy before surgery.