Carbapenem-resistant Klebsiella pneumoniae bloodstream infections in haematological malignances and hematopoietic stem cell transplantation: Clinical impact of combination therapy in a 10-year Brazilian cohort.

Bacterial bloodstream infections (BSI) are a common threat among patients with haematological malignancies (HM) and hematopoietic stem cell transplant recipients (HSCT). The purpose of this research was to describe clinical and microbiological aspects of BSI caused by carbapenem-resistant Klebsiella pneumoniae (CRKp) and assess risk factors associated with 30-day mortality in a 10-year cohort of haematological patients. A total of 65 CRKp-BSI episodes occurring in HM patients and HSCT recipients and CRKp-BSI between January 2010 and December 2019 were retrospectively studied. Acute leukemias were the most frequently observed underlying disease (87.7%) and 18 patients (27.7%) received HSCT. Mucosal barrier injury in the gastrointestinal tract was the primary cause of bacteremia (86.1%). Also, 14 individuals (21.6%) had an Invasive Fungal Disease (IFD) throughout the episode. Regarding treatment, in 31 patients (47.7%) empirical therapy was deemed appropriate, whereas 33 (50.8%) patients received a combination therapy. Microbiological data revealed that the majority of isolates (53-58%) had the Polymyxin B co-resistance phenotype, while amikacin resistance was less common (16 samples, or 24.7%). The mortality rates at 14 and 30 days were 32.3% and 36.9%, respectively. In a multivariate Cox regression analysis, prompt appropriate antibiotic administration within three days was associated with a better outcome (Adjusted Hazard Ratio [aHR]: 0.33; 95% Confidence Interval [CI]: 0.14-0.76; p = 0.01), whereas hypotension at presentation (aHR: 3.88; 95% CI: 1.40-10.74; p = 0.01) and concurrent IFD (aHR: 2.97; 95% CI: 1.20-7.37; p = 0.02) were independently associated with death within 30 days. Additionally, a favorable correlation between combination therapy and overall survival was found (aHR: 0.18; 95%CI: 0.06-0.56; p = 0.002). In conclusion, 30-day mortality CRKp-BSI was elevated and most of the isolates were polymyxin B resistant. Early appropriate antimicrobial treatment and the use of combination therapy were linked to a better outcome.

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.

Epidemiology of Invasive Fungal Diseases in Patients with Hematologic Malignancies and Hematopoietic Cell Transplantation Recipients Managed with an Antifungal Diagnostic Driven Approach.

Patients with hematologic malignancies and hematopoietic cell transplant recipients (HCT) are at high risk for invasive fungal disease (IFD). The practice of antifungal prophylaxis with mold-active azoles has been challenged recently because of drug-drug interactions with novel targeted therapies. This is a retrospective, single-center cohort study of consecutive cases of proven or probable IFD, diagnosed between 2009 and 2019, in adult hematologic patients and HCT recipients managed with fluconazole prophylaxis and an antifungal diagnostic-driven approach for mold infection. During the study period, 94 cases of IFD occurred among 664 hematologic patients and 316 HCT recipients. The frequency among patients with allogeneic HCT, autologous HCT, acute leukemia and other hematologic malignancies was 8.9%, 1.6%, 17.3%, and 6.4%, respectively. Aspergillosis was the leading IFD (53.2%), followed by fusariosis (18.1%), candidiasis (10.6%), and cryptococcosis (8.5%). The overall 6-week mortality rate was 37.2%, and varied according to the host and the etiology of IFD, from 28% in aspergillosis to 52.9% in fusariosis. Although IFD occurred frequently in our cohort of patients managed with an antifungal diagnostic driven approach, mortality rates were comparable to other studies. In the face of challenges posed by the use of anti-mold prophylaxis, this strategy remains a reasonable alternative.

Triazole Resistance Is Still Not Emerging in Aspergillus fumigatus Isolates Causing Invasive Aspergillosis in Brazilian Patients.

Aspergillus fumigatus azole resistance has emerged as a global health problem. We evaluated the in vitro antifungal susceptibility of 221 clinical A. fumigatus isolates according to CLSI guidelines. Sixty-one isolates exhibiting MICs at the epidemiological cutoff value (ECV) for itraconazole or above the ECV for any triazole were checked for CYP51A mutations. No mutations were documented, even for the isolates (1.8%) with high voriconazole MICs, indicating that triazoles may be used safely to treat aspergillosis in Brazil.

Successful use of gentamycin as an antibiotic prophylaxis regimen to reduce the rate of healthcare-associated infections after renal transplantation.

At our institution, we observed an increase in the incidence of healthcare-associated infections (HAI) due to Gram-negative bacilli, including three cases of carbapenem-resistant Klebsiella pneumoniae, among patients who underwent renal transplantation. In addition to strengthening infection control measures, we chose to add gentamycin to the antibiotic prophylaxis regimen of patients undergoing renal transplantation. We assessed the number of HAI occurring within 30 days of renal transplantation during two time periods: (1) the pre-intervention period, between September 2009 and June 2010, and (2) the post-intervention period, between July 2010 and April 2011. The intervention consisted of the addition of gentamycin to the surgical antibiotic prophylaxis regimen. The percentage of patients with HAIs was 31% lower during the post-intervention period (p=0.03), with the greatest reductions observed for urinary tract infections (p=0.024). Carbapenem-resistant K. pneumoniae was not isolated during this period. The investigated patients did not exhibit worsening renal function. Further studies are needed to assess antibiotic prophylaxis in renal transplantation patients at institutions where there is a high prevalence of multidrug-resistant Gram-negative bacteria.