Isolation of Salmonella enterica in opossum (Didelphis aurita and Didelphis albiventris) of the São Paulo State, Brazil

No Brasil, não há relato de estudos de Salmonella em gambás, sendo assim, este trabalho tem por objetivo determinar a frequência de isolamento de Salmonella enterica em gambás (D. aurita e D. albiventris) no Estado de São Paulo. No período de janeiro de 2005 a dezembro de 2006, foram necropsiados 106 D. aurita e 40 D. albiventris e colhidos fragmentos de intestinos delgado, grosso e suabe da cloaca. As amostras foram plaqueadas diretamente em ágar Mac Conkey, paralelamente suspendidas nos caldos Rappaport-Vassiliadis e Tetrationato e posteriormente plaqueados em ágar XLT4. As colônias sugestivas de Salmonella foram confirmadas através de provas bioquímicas e sorotipagem. Encontrou-se Salmonella enterica em 17,0% (18/106) dos D. aurita. Destes, 50% apresentaram positividade no intestino delgado (ID), 88,9% no intestino grosso (IG) e 66,7% na cloaca. Da espécie S. enterica, as subespécies encontradas foram: diarizonae (11,1%) houtenae e enterica (5,5% cada um); enquanto da subespécie S. enterica enterica os sorotipos foram Newport (83,3%), Typhimurium e Cerro (5,5% cada um). Nos D. albiventris, 17,5% (7/40) eram positivos, sendo que se encontraram 42,8% no ID, 85,7% no IG e 71,4% na cloaca. O sorotipo mais prevalente também foi Newport (71,4%), seguido por Typhimurium, Bareilly e Thompson (14,3% cada um). Através dos resultados obtidos neste estudo pode-se comprovar a presença de Salmonella enterica no trato intestinal de gambás no Brasil.In Brazil there is not report of Salmonella in opossum, so then, the objective of this study is to determine the isolation frequency of Salmonella enterica in opossum in São Paulo State, Brazil. From January 2005 to December 2006, 106 D. aurita and 40 D. albiventris were necropsied and samples from small and large intestine and cloacal swab were collected. These samples were submitted to direct plating in Mac Conkey agar and parallel suspension in Rappaport-Vassiliadis and Tetrationate broths with posterior streaking in XLT4 agar. The characterization of the isolates was done through biochemical tests and serotyping. Salmonella enterica was found in 17.0% (18/106) of the D. aurita; 50% presented the bacteria in the small intestine (SI), 88.9% in the large intestine (LI) and 66.7% in the cloaca. Of the S. enterica were found the subspecies: diarizonae (11.1%), enterica and houtenae (5.5% each); and the serotypes of the S. enterica enterica were Newport (83.3%), Typhimurium and Cerro (5.5% each). In the D. albiventris 17.5% (7/40) were positive; 42.8% in the SI, 85.7% in the LI and 71.4% in the cloaca. Newport (71.4%) was also the most frequent serotype and the second were Typhimurium, Bareilly and Thompson (14.3% each). The presence of Salmonella enterica in the intestines of opossums in Brazil was proved

Sirtuin E deacetylase is required for full virulence of Aspergillus fumigatus

Aspergillus fumigatus represents a public health problem due to the high mortality rate in immunosuppressed patients and the emergence of antifungal-resistant isolates. Protein acetylation is a crucial post-translational modification that controls gene expression and biological processes. The strategic manipulation of enzymes involved in protein acetylation has emerged as a promising therapeutic approach for addressing fungal infections. Sirtuins, NAD+-dependent lysine deacetylases, regulate protein acetylation and gene expression in eukaryotes. However, their role in the human pathogenic fungus A. fumigatus remains unclear. This study constructs six single knockout strains of A. fumigatus and a strain lacking all predicted sirtuins (SIRTKO). The mutant strains are viable under laboratory conditions, indicating that sirtuins are not essential genes. Phenotypic assays suggest sirtuins’ involvement in cell wall integrity, secondary metabolite production, thermotolerance, and virulence. Deletion of sirE attenuates virulence in murine and Galleria mellonella infection models. The absence of SirE alters the acetylation status of proteins, including histones and non-histones, and triggers significant changes in the expression of genes associated with secondary metabolism, cell wall biosynthesis, and virulence factors. These findings encourage testing sirtuin inhibitors as potential therapeutic strategies to combat A. fumigatus infections or in combination therapy with available antifungals