Resistencia a los azoles en cepas de Aspergilus fumigatus sensu stricto aislados de muestras clínicas respiratorias

Introducción. La aspergilosis invasiva presenta alta mortalidad en pacientes con enfermedades crónicas e inmunocomprometidos. Aspergillus fumigatus sensu stricto (AFSS) es el principal agente etiológico y su tipificación requiere de métodos moleculares. La incidencia incrementada de AI resistentes a los antifúngicos demanda un diagnóstico certero y oportuno. Métodos. Se estudiaron 20 cepas de la micoteca del Instituto de Medicina Tropical - Universidad Nacional Mayor de San Marcos, aisladas de muestras respiratorias e identificadas como Aspergillus fumigatus sensu lato mediante el estudio macroscópico y microscópico. Las cepas fueron referidas a la Universidad Nacional del Litoral para su tipificación mediante una PCR screening para AFSS basada en secuencias del gen CYP51A y el estudio de sensibilidad antifúngica para voriconazol (VOR), itraconazol (ITC), posaconazol (POS), isavuconazol (ISA), anidulafungina (ANF), caspofungina (CSF) y anfotericina B (AMB) obteniendo la concentración inhibitoria mínima (CIM) mediante el protocolo de CLSI M38M51S-Ed3. Resultados. Las 20 cepas fueron identificadas como AFSS. Ninguna de las cepas tuvo una CIM por encima del punto de corte clínico (VOR), ni epidemiológico (ITC, ISA, AMB y CSF). POS fue la droga más potente frente a la colección de cepas evaluadas (media geométrica (GM) de CIM de 0,042 µg/ml). Conclusiones. Todos los aislamientos fueron tipificados como AFSS sensibles a los azoles según los puntos de corte clínico, posaconazol tuvo la mayor actividad antifúngica. Nuestros hallazgos aportan a incrementar la escasa información sobre la etiología y sensibilidad a los antifúngicos de uso clínico de las aspergilosis invasiva en nuestro país.

Introduction. Invasive Aspergillosis (IA) poses a significant threat to patients with chronic diseases and compromised immune systems, with Aspergillus fumigatus sensu stricto (AFSS) being the primary etiological agent. Accurate and timely diagnosis is crucial, particularly given the rising incidence of IA strains resistant to antifungals, necessitating molecular methods for typing. Methods. Twenty strains from Instituto de Medicina Tropical - Universidad Nacional Mayor de San Marcos, mycological collection, previously identified as Aspergillus fumigatus sensu lato through macroscopic and microscopic analysis, were studied. These strains were forwarded to the Universidad Nacional del Litoral for AFSS typing using a PCR screening based on CYP51A gene sequences. Antifungal susceptibility testing was performed for Voriconazole (VOR), Itraconazole (ITC), Posaconazole (POS), Isavuconazole (ISA), Anidulafungin (ANF), Caspofungin (CSF), and Amphotericin B (AMB), obtaining Minimum Inhibitory Concentrations (MICs) according to CLSI M38M51S-Ed3. Results. All 20 strains were identified as AFSS. None of the strains exhibited MICs above the clinical breakpoint (VOR) or the epidemiological cutoffs (ITC, ISA, AMB, and CSF). POS demonstrated the highest potency against the strain collection, with a geometric mean MIC of 0,042 µg/ml. Conclusions. All isolates were classified as azole-sensitive Aspergillus fumigatus sensu stricto (AFSS) based on clinical cutoff points, particularly posaconazole, which exhibited superior antifungal activity. Our findings contribute to augmenting the limited information on the etiology and clinical antifungal sensitivity of IA in our country.

Active cancer as the main predictor of mortality for COVID-19 in oncology patients in a specialized center.

Introduction: The role of the type, stage and status of cancer in the outcome of COVID-19 remains unclear. Moreover, the characteristic pathological changes of severe COVID-19 reveled by laboratory and radiological findings are similar to those due to the development of cancer itself and antineoplastic therapies. Objective: To identify potential predictors of mortality of COVID-19 in cancer patients. Materials and methods: A retrospective and cross-sectional study was carried out in patients with clinical suspicion of COVID-19 who were confirmed for COVID-19 diagnosis by RT-PCR testing at the National Institute of Neoplastic Diseases between April and December 2020. Demographic, clinical, laboratory and radiological data were analyzed. Statistical analyses included area under the curve and univariate and multivariate logistic regression analyses. Results: A total of 226 patients had clinical suspicion of COVID-19, the diagnosis was confirmed in 177 (78.3%), and 70/177 (39.5%) died. Age, active cancer, leukocyte count ≥12.8 × 109/L, urea ≥7.4 mmol/L, ferritin ≥1,640, lactate ≥2.0 mmol/L, and lung involvement ≥35% were found to be independent predictors of COVID-19 mortality. Conclusion: Active cancer represents the main prognosis factor of death, while the role of cancer stage and type is unclear. Chest CT is a useful tool in the prognosis of death from COVID-19 in cancer patients. It is a challenge to establish the prognostic utility of laboratory markers as their altered values it could have either oncological or pandemic origins.

First Isolates of OXA-48-Like Carbapenemase-Producing Enterobacteriaceae in A Specialized Cancer Center.

BACKGROUND: OXA-48-like carbapenemases have been found in a growing and varied number of carbapenemase-producing Enterobacteriaceae (CPE) isolates, and they are spreading to several countries. Although this oxacillinase leads to weak resistance to carbapenems without affecting broad-spectrum cephalosporin activity, when they are associated with other resistance mechanisms, the level of resistance to these antibiotics may be significantly higher. This weak resistance against carbapenems and cephalosporins, along with the absence of other resistance mechanisms, could render OXA-48-like harboring isolates undetected in the laboratory routine. In addition, the lack of a specific screening test for this enzyme complicates the detection of these isolates. This report characterizes the first isolates of OXA-48-like CPE detected in our laboratory. MATERIALS AND METHODS: The study was carried out at the Instituto Nacional de Enfermedades Neoplasicas, Lima - Peru, between March and December 2021. OXA-48-like CPE isolates were detected as part of the routine microbiological study, and clinical data were obtained by reviewing medical records. The automated microbiological system provides the bacterial identification and antimicrobial susceptibility profile by the dilution method. Additionally, the column chromatography test is used to detect carbapenemase enzymes, including OXA-48-like. Finally, the molecular identification of the OXA-48-like enzyme was carried out by Polymerase Chain Reaction PCR amplification for the blaOXA-48-like. RESULTS: Seven OXA-48-like CPE strains were isolated. Notably, in all cases, the automated system issued a minimum inhibitory concentration (MIC) of ≥1 ug/mL for ertapenem and a MIC of >64/4 ug/mL for piperacillin/tazobactam. In addition, resistance category to imipenem and meropenem was found (2/7), at least one indeterminate category for any of these carbapenems (5/7), and other serine ß-lactamases such as Extended-spectrum beta-lactamases (3/7) and AmpC (3/7). The immunochromatographic study confirmed the presence of the OXA-48-like enzyme in all isolates, while class A and class B were ruled out for them. Finally, the multiplex PCR, for the five isolates that could be recovered, showed amplification for carbapenemase OXA-48-like, while none of the other carpabemases was amplified for class A or class B carbapenemase genes. CONCLUSION: We confirm the emergence of OXA-48-like CPE isolates in our cancer center and highlight the need to implement surveillance and detection measures of these strains, for controlling their dissemination. We found practical and inexpensive methodologies for the detection of OXA-48-like CPE: (1) the finding of resistance to ertapenem and piperacillin/tazobactam in the antibiogram in the absence of class A and B carbapenemases, for screening and (2) immunochromatographic study, for confirmation.