Browsing by Author "Francisco, M."
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- Aspergillus nosocomial infections Do cryptic species found in hospital environment matter?Publication . Sabino, Raquel; Viegas, C.; Francisco, M.; Martins, Carlos; Clemons, Karl; Stevens, DavidPurpose: Aspergillus is a major threat causing nosocomial infections in immunocompromised patients. Advances in molecular methods allowed species identification through sequencing of specific genes, allowing high discrimination amongst isolates. Different Aspergillus species have different susceptibilities to antifungals and several cryptic species have been described as less susceptible to specific antifungals. Therefore, we addressed the possible influence of hospital environmental isolates in the overall situation of Aspergillus antifungal resistance. Methods: During one year, 101 air and 99 surface samples were collected from the environment of a Portuguese central hospital of Lisbon. Aspergillus isolates were identified morphologically and by molecular methods. Genomic DNA was prepared from each isolate and then sequenced to achieve the correct species identification. Determination of the antifungal susceptibility of selected isolates was performed by microdilution (CLSI M38-A2). The antifungal agents studied were deoxycholate amphotericin B, itraconazole, voriconazole, and posaconazole. Results: From the 200 samples collected, 75 isolates of Aspergillus were obtained and identified to section by ITS sequence; cryptic species were identified by β-tubulin and calmodulin sequencing. Ten different sections within the Aspergillus genus were identified: Versicolores (N=20), Nigri (N=11), Flavi (N=10), Circumdati (N=10), Fumigati (N=8), Usti (N=4), Terrei (N=4), Nidulantes (N=4), Aspergilli (N=3) and Cremei (N=1). From these, 25 different Aspergillus species were identified by β-tubulin and calmodulin sequencing, and a high percentage of cryptic species (not sensu stricto) was found (59%). Sections Usti, Versicolores and Circumdati harbored the highest proportion of cryptic species [100% (4/4), 95% (19/20) and 90% (9/10), respectively]. From the 75 isolates, 22 were tested for their antifungal susceptibility. Of the 8 Fumigati isolates, there was 1 cryptic species. The Circumdati, Versicolores and Nigri complexes contained isolates of cryptic species with reduced susceptibility to some of the antifungals used in clinical therapeutics. In the Circumdati complex, 3/5 isolates hadMIC to amphotericin B >8μg/ml and 1/5MIC >8μg/ml to itraconazole; 1/6 isolates fromVersicolores complex hadMIC to itraconazole >8 μg/ml; all 4 isolates fromNigri complex hadMIC to itraconazole=4 μg/ml. Conclusion: Since Aspergillus infections aremainly nosocomial, knowledge of themolecular epidemiology and determinationof the susceptibility profile of environmental isolateswould suggestmeasures need to be considered.
- Fungos e ambiente hospitalar: preocupações relevantes e riscos para o doentePublication . Sabino, Raquel; Francisco, M.; Viegas, C.; Martins, C.; Verissimo, CristinaO número de infeções fúngicas nosocomiais tem vindo a aumentar drasticamente sendo causa, cada vez mais comum, de elevada morbilidade e mortalidade em doentes hospitalizados. O grau de contaminação fúngica ambiental é considerado um fator de extrema importância na incidência e epidemiologia destas infeções. Em contexto hospitalar, a infeção fúngica poderá ocorrer por contacto direto ou indireto com superfícies ou objetos contaminados, através das mãos de profissionais de saúde e por ingestão ou inalação de partículas ou bioaerossóis contaminados. As espécies de Aspergillus e Candida são responsáveis pela maioria das infeções fúngicas em pacientes imunocomprometidos e são frequentemente isolados em ambiente hospitalar. Descrevem-se neste trabalho dois case-study em Hospitais da região de Lisboa onde para além da caracterização do ambiente hospitalar quanto às espécies fúngicas predominantes, foram efetuadas pesquisas dirigidas aos géneros Aspergillus e Candida. Verificou-se que o controlo das infeções nosocomiais requer um conhecimento aprofundado da espécie/estirpe infetante, bem como do seu padrão de suscetibilidade aos antifúngicos, determinando assim o risco de infeção tanto para doentes como para os profissionais de saúde.