RESUMO
La infección por Clostridioides difficile es una de las principales causas de diarrea nosocomial en hospitales del mundo, asociada a antibióticos de amplio espectro. Estudio descriptivo, retrospectivo, de corte transverso, de tipo censal. Se estudiaron 281 muestras de pacientes hospitalizados con la infección, se analizaron características socio-demográficas, clínicas y se caracterizó molecularmente al patógeno. Como resultado, se obtuvieron pacientes con la infección con una mediana de edad de 64 años siendo el 61,5 % del sexo masculino. El promedio de presentación del cuadro diarreico fue de 5 días, con tratamiento antimicrobiano de 8 días e internación de 15 días. El 94% tuvo tratamiento antimicrobiano previo, y el 6% estuvo expuesto a algún factor de riesgo. Los antimicrobianos más utilizados solos o en combinación fueron betalactámicos, fluoroquinolonas, vancomicina y carbapenémicos. Las áreas de internación con mayor frecuencia de presentación de la infección fueron las unidades de Clínica Médica, Traumatología, Geriatría y Unidad de Terapia Intensiva. La prevalencia de C. difficile toxigénico fue de 14%, y de esta frecuencia el 100% presentó toxinas TcdA y TcdB, con ausencia de toxinas binarias y deleción del gen tcdC. Se constató la presencia grupos clonales en la misma unidad de internación y misma institución de salud. El 100% de las cepas resultaron susceptibles a los antibióticos de elección para la infección. La prevalencia de la infección y presencia de perfiles clonales detectadas revelan la necesidad de un mejoramiento en el sistema de control de infecciones, así como del fortalecimiento y vigilancia de la resistencia antimicrobiana.
Clostridioides difficile infection is one of the main causes of nosocomial diarrhea in hospitals worldwide, associated with broad-spectrum antibiotics. Descriptive, retrospective, cross-sectional, census-type study. Two hundred eighty-one samples from patients hospitalized with the infection were studied, sociodemographic and clinical characteristics were analyzed and the pathogen was characterized molecularly. As a result, patients with the infection had a median age of 64 years and 61.5% male. The average presentation of diarrhea was 5 days, antimicrobial treatment 8 days and hospitalization 15 days. Ninety four percent had previous antimicrobial treatment, and 6% were exposed to some risk factor. The most commonly used antimicrobials alone or in combination were beta-lactams, fluoroquinolones, vancomycin, and carbapenems. The hospitalization areas with the highest frequency of presentation of the infection were the Clinical Medicine, Traumatology, Geriatrics and Intensive Care Unit units. The prevalence of toxigenic C. difficile was 14%, and of this frequency, 100% presented TcdA and TcdB toxins, with the absence of binary toxins and deletion of the tcdC gene. The presence of clonal groups was verified in the same hospitalization unit and the same health institution. All the strains were susceptible to the antibiotics of choice for the infection. The prevalence of infection and the presence of clonal profiles detected reveal the need for improvement of the infection control system, as well as of the strengthening and surveillance of antimicrobial resistance.
RESUMO
Toxoplasma gondii Nicolle et Manceaux, 1909, the etiologic agent of toxoplasmosis, was considered a clonal population with three distinct genetic lineages (I, II and III); however, sequence analysis of different strains has revealed distinct atypical genotypes. Macrophages are essential for immunity against toxoplasmosis and differential cell regulation may affect the course of the disease. In this context, our study aims to investigate the infection by TgChBrUD2, a highly virulent atypical Brazilian strain of T. gondii, on the activation and polarisation of human macrophages. Human macrophage-like cells obtained from THP-1 cells were infected with TgChBrUD2, RH or ME49 strains of T. gondii to evaluate the impact of parasite infection on macrophage polarisation. Our results indicate that the TgChBrUD2 and ME49 strains of T. gondii induced a classic activation of human macrophages, which was confirmed by the high rate of spindle-shaped macrophages, low amount of urea and increase in the levels of nitrite, as well as the down-regulation of M2-markers. In contrast, RH strain promoted an alternative activation of macrophages. The polarisation of human macrophages towards an M1 subtype mediated by TgChBrUD2 and ME49 strains resulted in a low parasite burden, with high levels of IL-6 and MIF. Finally, the M2 subtype triggered by the RH strain culminated in a lower intracellular proliferation index. We concluded that the atypical (TgChBrUD2) and clonal (ME49) strains are able to elicit an M1 subtype, which results in parasitism control, partially explained by the high levels of IL-6 and MIF produced during the infection by these genotypes. In contrast, the clonal (RH) strain promoted a macrophage polarisation towards an M2 subtype, marked by a high parasite burden, with a weak modulation of pro-inflammatory cytokines. Thus, atypical strains can present different mechanisms of pathogenicity and transmissibility compared to clonal strains, as well as they can use distinct strategies to evade the host's immune response and ensure their survival.