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ABSTRACT: Objectives: Candida tropicalis is one of the three most frequent species causing candidaemia in Latin America. Despite the high prevalence of C. tropicalis in candidaemia cases in Brazil, little is known about the trends in fluconazole susceptibility over time. The objective of this study was to evaluate temporal trends in azole resistance rates among C. tropicalis bloodstream isolates from patients treated in six Brazilian medical centres over a 12-year period. Methods: We selected 200 C. tropicalis bloodstream isolates from six medical centres in Brazil collected between 2007 and 2018. Species identification was confirmed by MALDI-TOF/MS. Antifungal susceptibility testing for four antifungal agents was performed by the Clinical and Laboratory Standards Institute (CLSI) microbroth method. Results: Overall, rates of non-susceptibility were 4% and 3.5% to fluconazole and voriconazole, respectively. All isolates were susceptible to amphotericin B and only one isolate was resistant to echinocandins. Conclusion: Although we failed to demonstrate statistical differences in the rates of azole resistance documented during the period of analysis, trends towards lower susceptibility to fluconazole and voriconazole were shown.

During the past decade, studies on the composition of human microbiota and its relation to the host became one of the most explored subjects of the medical literature. The development of high-throughput molecular technologies allowed a deeper characterization of human microbiota and a better understanding of its relationship with health and disease. Changes in human habits including wide use of antimicrobials can result in dysregulation of host–microbiome homeostasis, with multiple consequences. The purpose of this review is to highlight the most important evidence in the literature of host–microbiome interactions and illustrate how these intriguing relations may lead to new treatment and prevention strategies. Keywords: Gastrintestinal microbiome, Human

Problems with resistance to antifungal drugs have emerged due to an increase in the incidence of systemic fungal infections and widespread use of antifungal agents. Accordingly, efforts have been made to develop adequate fungal susceptibility tests. The ideal test should have high intra and inter-laboratory reproducibility, good correlation with the clinical outcome, and should be easy to perform. While no such test has yet been developed, advances have been made. Over the past decade, many reports of fungal resistance have been published, most of them in AIDS patients. Though the frequency of resistant strains is still low in neutropenic cancer patients, and is mostly limited to Candida glabrata and Candida krusei, resistance to Candida albicans has also been reported.

The increasing magnitude of antifungal resistance as well as the advent of new antifungal drugs has generated a renewed interest in fungal susceptibility testing. We used a previously described disk diffusion method to evaluate the susceptibility profile of a large collection of recent clinical Candida spp. isolates against fluconazole. A total of 1,784 yeast isolates were tested, including the following species: Candida albicans (1,036), C. tropicalis (279), C. parapsilosis (202), C. glabrata (119), C. guilliermondii (90), C. krusei (32), C. lusitaniae (7), Candida spp. (14) and other yeasts (5). Susceptibility ranking to fluconazole obtained with all yeasts tested was: C. parapsilosis @ C. tropicalis @ C. guilliermondii > C. glabrata > C. krusei. The majority (94%) of all yeast isolates tested were susceptible to fluconazole. Isolates of C. glabrata and C. krusei exhibited the highest rate of DDS/resistance among all isolates tested but they represented only 9% of all yeasts routinely sent to our lab. Careful periodical surveillance is needed in order to identify any changes in the susceptibility patterns of fluconazole with the increased use of this antifungal agent in Brazilian tertiary care hospitals.

Introdução: ICSs causadas por leveduras do gênero Candida ocorrem com alta frequência em nossos hospitais (0,33-6,51 casos por 1.000 admissões) e associam-se a altas taxas de morbidade e mortalidade. Nos últimos anos, notou-se um aumento global na prevalência de espécies raras de Candida (ERC) associadas a ICS, principalmente em pacientes hospitalizados submetidos a procedimentos invasivos, uso antimicrobianos e imunocomprometidos. Tais espécies apresentam peculiaridades de história natural, dificuldades em sua identificação e susceptibilidade a antifúngicos. A prevalência de ERC em episódios de ICSs e seu impacto clínico no Brasil tem sido pouco investigado. Objetivo: Caracterizar a prevalência de leveduras raras em ICS documentadas em um laboratório de referência em Micologia Médica durante 2007-2023. Método: Realizamos o levantamento de prevalência de ERC entre isolados de hemocultura encaminhados para o Laboratório Especial de Micologia, Universidade Federal de São Paulo, entre 2007-2023. Tendências históricas na prevalência de ERC foram avaliadas considerando todas as amostras de leveduras coletadas entre: 2007-2015 (P1) versus 2016-2023 (P2). Taxas de prevalência (P1vs.P2) foram comparadas por qui-quadrado. Valor de p < 0,05 foi considerado. As espécies foram selecionadas com base na identificação realizada por meios cromogênicos, sistemas comerciais ou MALDI-TOF MS. Resultados: Ao todo, 2265 isolados (excluídos amostras repetidas) de diferentes episódios de ICS foram considerados, provenientes de 43 centros médicos de 14 unidades federativas. Como resultado, 188 isolados (8,3%) representativos de ERC foram associados a diferentes episódios de ICSs. Durante o período avaliado, houve uma manutenção nas taxas de prevalência entre os períodos considerados (P1 = 85 raras de 1062 totais, 8%; P2 = 103 raras de 1569 totais, 6,5%; p > 0,05). Ao final, encontramos isolados representantes de 20 ERC com destaque para:Candida (n = 77,40%), Meyerozyma (n = 73,38%), Clavispora (n = 20,10%). Conclusão: Neste estudo preliminar identificamos uma taxa de prevalência de 8,3% de ERC causando episódios de ICS, taxa esta considerada superior àquelas documentadas na Ásia e Oceania.Observou-se tendência de estabilidade nas taxas nos centros médicos avaliados. No entanto, análises futuras serão realizadas. Esses dados ressaltam a relevância de estudos epidemiológicos nacionais para um melhor entendimento sobre a epidemiologia de infecções invasivas por ERC e seu impacto na prática clínica.