Prevalence of latent Mycobacterium tuberculosis infection in hematopoietic stem cell transplantation comparing tuberculin skin test and interferon-gamma release assay.

The aim of this study was to evaluate the prevalence of latent Mycobacterium tuberculosis infection in hematopoietic stem cell transplantation candidates, using tuberculin skin test and QuantiFERON-TB Gold-Plus, in a high-burden tuberculosis country. Adult candidates for hematopoietic stem cell transplantation performed both tests before and those submitted to transplantation were followed up for 12 months. The prevalence of latent Mycobacterium tuberculosis infection was 17.1% and a moderate agreement between QuantiFERON-TB Gold-Plus and tuberculin skin test was observed in this population. Previous tuberculosis exposure was a risk factor for latent Mycobacterium tuberculosis infection. No cases of tuberculosis were diagnosed during follow-up period.

Invasive Aspergillosis in Patients with Acute Leukemia: Comparison Between Acute Myeloid and Acute Lymphoid Leukemia.

BACKGROUND: The epidemiology of invasive aspergillosis (IA) in patients with acute lymphoid leukemia (ALL) has not been well characterized. OBJECTIVES: To identify potential peculiarities in the natural history, treatment response and outcome of IA diagnosed in patients with ALL and AML. METHODS: This is a retrospective cohort study conducted in seven tertiary-care hospitals between 2009 and 2017 of all consecutive episodes of IA occurring in adult patients with acute leukemia. Demographic characteristics, underlying disease and recent treatment, antifungal prophylaxis, neutropenia, receipt of corticosteroids, clinical and radiological findings, mycological results, antifungal therapy, and 6-week and 12-week survival were recorded. RESULTS: We identified 77 cases of IA in 54 patients with AML and 23 patients with ALL. The majority of patients developed IA in the context of induction chemotherapy for newly diagnosed (48.0%) or relapsed (41.6%) leukemia, with no differences between ALL and AML. Lung involvement was more frequent in AML (96.3% vs. 82.6%, p = 0.06) and rhinosinusitis was more common in ALL (43.5% vs. 24.1%, p = 0.09). Galactomannan was the microbiologic documentation of IA in 76.6%, with similar patterns of positivity in AML and ALL. The 6-week survival of IA in patients with AML and ALL was 63.0% and 56.5%, respectively (p = 0.60). CONCLUSIONS: The epidemiology, clinical presentation, diagnosis and outcome of IA in ALL patients are similar to patients with AML.

Carbapenem-resistant Pseudomonas aeruginosa carrying blaVIM-36 assigned to ST308: Indicated non-virulence in a Galleria mellonella model.

OBJECTIVES: Based on pulsed-field gel electrophoresis (PFGE) profile, whole-genome sequencing (WGS) of eight carbapenem-resistant Pseudomonas aeruginosa isolates from a bone marrow transplant unit in São Paulo, Brazil, was performed to investigate the presence of resistance and virulence genes as well as to determine the sequence type (ST) by multilocus sequence typing (MLST). METHODS: The initial phenotypic susceptibility pattern of the isolates was determined by VITEK®2. Minimum inhibitory concentrations (MICs) were determined by the broth microdilution method for amikacin, meropenem and colistin. WGS was performed using an Illumina MiSeq system. A Galleria mellonella infection model was used to evaluate the virulence of the strains. RESULTS: WGS demonstrated that mutations in genes encoding outer membrane proteins and efflux pumps in an isolate harbouring blaVIM-36 (ST308) differed from those in isolates harbouring blaSPM (ST277). The mexT gene harboured a mutation resulting in a frameshift in all isolates; in addition, the oprD gene of the blaVIM-36-carrying isolate had an insertion leading to a frameshift. Virulence genes did not differ between ST277 and ST308 strains. Moreover, only two isolates harbouring blaSPM showed virulence in the G. mellonella model, killing 100% of larvae after 18-24h. CONCLUSIONS: P. aeruginosa carrying blaVIM-36 belonging to ST308 was identified for the first time in our hospital. Although the virulence gene profiles were similar in isolates carrying blaSPM and the isolate carrying blaVIM-36, only two isolates harbouring blaSPM showed virulence in the G. mellonella model.