Synergetic action of atorvastatin and fluconazole against fluconazole-resistant Candida albicans in vitro and in a murine model for intra-abdominal Candidiasis / Ação sinérgica da atorvastatina e fluconazol contra Candida albicans resistente ao fluconazol in vitro e em um modelo murino contra Candidíase intra-abdominal

Introduction: Candida albicans is the most common causative agent of Intra-abdominal Candidiasis (IAC) and it is resistant to most antifungal drugs currently available. Here we investigated atorvastatin in vitro and in vivo antifungal activities against a fluconazole-resistant C. albicans strain as a potential repurposed drug. The following tests were carried out: antifungal susceptibility tests to determine minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC), determination of time-kill curve, biofilm assays, Candida albicans yeast-hyphae transition inhibition assay, murine model of Intra-abdominal candidiasis, survival curve, fungal load quantification, histopathology analysis, quantification of TNF-α and IL-17 cytokines, quantification of N-acetyl-β-D-glucosaminidase. In vitro assays showed the synergetic action of atorvastatin and fluconazole against C. albicans growth and biofilm maturation while the time-kill curve assay revealed their fungicidal effect after 24 h of treatment. When yeast-to-hyphae transition was assessed, the synergetic effect of atorvastatin and fluconazole reduced C. albicans filamentation significantly. In vivo tests showed that one of the most noticeable signs of IAC is the intense systemic inflammation. However, our survival curve test showed that despite being ill, animals exhibited little to no clinical signs of systemic inflammation when treatment included a combination of atorvastatin and fluconazole. Altogether, these findings suggest that atorvastatin could be feasibly used in the treatment fluconazole-resistant C. albicans strains, showing that drug repurposing is an important strategy when considering the limited number of antifungal drugs available for treatment in addition to financial hardship experienced in research and development of new antifungal drugs.

Avaliação €œin vitro€ do efeito antiviral do acetato de bauer-7-en-3b -ILA, o principal constituinte de uma amostra de própolis brasileira, contra o alphaherpesvirus

O crescente interesse na busca por substâncias que apresentem atividade antiviral se deve, entre outros fatores, à dificuldade de tratamento de infecções virais, tanto em virtude da característica de latência viral quanto pelo surgimento de novos vírus. O triterpenóide acetato de bauer-7-en-3b-ila (BA) foi previamente isolado do extrato clorofórmico de uma amostra de própolis coletada em Minas Gerais, região sudeste do Brasil (TEIXEIRA et al., 2006). A atividade antiviral desta substância contra o herpesvírus bovino tipo 1 (BoHV-1) e o herpesvírus suíno tipo 1 (SuHV-1) foi investigada através da infecção de culturas de células de rim bovino (MDBK) e de células de rim de macaco verde africano (VERO). O efeito citotóxico do triterpenóide foi previamente avaliado e as concentrações máximas não tóxicas foram 20µg mL-1 e 15µg mL-1 para células VERO e MDBK, respectivamente. Os resultados mostraram atividade antiviral contra SuHV-1 (p<0,05), porém não contra BoHV-1. Todavia, a forma como o BA interfere na multiplicação do SuHV-1 ainda precisa ser elucidada

Immunopathogenic and Neurological Mechanisms of Canine Distemper Virus

Canine distemper is a highly contagious viral disease caused by the canine distemper virus (CDV), which is a member of the Morbillivirus genus, Paramyxoviridae family. Animals that most commonly suffer from this disease belong to the Canidae family; however, the spectrum of natural hosts for CDV also includes several other families of the order Carnivora. The infectious disease presents worldwide distribution and maintains a high incidence and high levels of lethality, despite the availability of effective vaccines, and no specific treatment. CDV infection in dogs is characterized by the presentation of systemic and/or neurological courses, and viral persistence in some organs, including the central nervous system (CNS) and lymphoid tissues. An elucidation of the pathogenic mechanisms involved in canine distemper disease will lead to a better understanding of the injuries and clinical manifestations caused by CDV. Ultimately, further insight about this disease will enable the improvement of diagnostic methods as well as therapeutic studies

Study of Vaccinia and Cowpox viruses' replication in Rac1-N17 dominant-negative cells

Interfering with cellular signal transduction pathways is a common strategy used by many viruses to create a propitious intracellular environment for an efficient replication. Our group has been studying cellular signalling pathways activated by the orthopoxviruses Vaccinia (VACV) and Cowpox (CPXV) and their significance to viral replication. In the present study our aim was to investigate whether the GTPase Rac1 was an upstream signal that led to the activation of MEK/ERK1/2, JNK1/2 or Akt pathways upon VACV or CPXV' infections. Therefore, we generated stable murine fibroblasts exhibiting negative dominance to Rac1-N17 to evaluate viral growth and the phosphorylation status of ERK1/2, JNK1/2 and Akt. Our results demonstrated that VACV replication, but not CPXV, was affected in dominant-negative (DN) Rac1-N17 cell lines in which viral yield was reduced in about 10-fold. Viral late gene expression, but not early, was also reduced. Furthermore, our data showed that Akt phosphorylation was diminished upon VACV infection in DN Rac1-N17 cells, suggesting that Rac1 participates in the phosphoinositide-3 kinase pathway leading to the activation of Akt. In conclusion, our results indicate that while Rac1 indeed plays a role in VACV biology, perhaps another GTPase may be involved in CPXV replication