RESUMO
In this study, to better our understanding of the current state of conservation of Cardisoma guanhumi and its habitats, we evaluated the potential spatio-temporal genomic damage of this species across five estuaries in Brazil. The experiment was performed over two consecutive years, and the sampling was performed in the winter and summer seasons. Two genetic tests - micronucleus test and comet assay - were used to quantify the DNA damage. Unlike in the summers and in the winter of 2013, in the winter of 2012 a significant increase was noted in the frequency of micronucleated cells and genomic damage index. The occurrence of genomic damage coincided with the arrival of the harsh winter of 2012 as the water sourced from the coastal rivers significantly affected the estuarine species under study. Our results confirmed that this species was resilient to the atypical climatic conditions, which facilitated the generation of excessive waste.
Assuntos
Braquiúros , Estuários , Animais , Brasil , Ensaio Cometa , Monitoramento Ambiental , Rios , Estações do AnoRESUMO
AIMS: Crotalicidin (Ctn), a cathelicidin-related antimicrobial peptide from the South American rattlesnake venom gland, and its C-terminal Ctn[15-34] fragment, have exhibited important activities against micro-organisms, trypanosomatid protozoa and certain lines of tumour cells. Herein, the activity against clinical strains of fluconazole-resistant Candida albicans and of amphotericin B and fluconazole-resistant Cryptococcus neoformans was investigated. METHODS AND RESULTS: Microdilution and luminescent cell viability tests were used to evaluate and compare the susceptibility of pathogenic yeasts to these peptides. The time-kill curves of the most active Ctn[15-34] alone or in combination with fluconazole against drug-resistant yeasts were determined. Concomitantly, the fungicidal and/or fungistatic effects of Ctn[15-34] were visualized by the spotting test. The peptides were active against all strains, including those resistant to antifungal agents. The association of fluconazole with both Ctn and Ctn[15-34], although not synergic, was additive. In contrast, such pattern was not observed for C. neoformans. CONCLUSIONS: Overall, Ctn and Ctn[15-34] are potential antifungal leads displaying anti-yeast activities against clinical isolates endowed with drug resistance mechanisms. SIGNIFICANCE AND IMPACT OF THE STUDY: The effective peptide activity against resistant strains of pathogenic yeasts demonstrates that crotalicidin-derived peptides are promising templates to develop new antifungal pharmaceuticals.
Assuntos
Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Cryptococcus neoformans/efeitos dos fármacos , Fragmentos de Peptídeos/farmacologia , Anfotericina B/farmacologia , Candida albicans/crescimento & desenvolvimento , Cryptococcus neoformans/crescimento & desenvolvimento , Fluconazol/farmacologia , Testes de Sensibilidade Microbiana , Triazóis/farmacologiaRESUMO
The shrimp farming has been converted into a mature aquaculture industry dealing with over millions of metric tonnes of processed commodities. Nevertheless, the global shrimp productions are constantly threatened by disease outbreaks, mainly triggered by rapidly disseminating viruses. Infectious myonecrosis virus (IMNV) is one of these epizootic agents affecting shrimp production in Brazil, of which no treatment exists. Herein, the antiviral activity against IMNV of an eicosapeptide, named Ctn[15-34], derived from a member of the cathelicidin family of antimicrobial peptides, was demonstrated. Cultures of hemocytes from Litopenaeus vannamei were established that support IMNV replication and infectivity titration. The cytotoxic effect of IMNV in culture and the in vitro anti-IMNV activity of Ctn[15-34] were assessed using a high-sensitive fluorescent-based method in combination with quantitative PCR. The Ctn[15-34] (<12.5 µM) neutralized the toxic effects of IMNV at loads sufficient to kill 50% of shrimp hemocytes. This study reported for the first time the replication of IMNV in vitro and the employment of a straightforward methodology to assess cell viability and viral/antiviral activities. In addition, it provided the basis for the development of the anti-infective multi-effector Ctn[15-34] eicosapeptide and analogs as components of antiviral formulations against shrimp viral diseases.
Assuntos
Peptídeos Catiônicos Antimicrobianos/farmacologia , Antivirais/farmacologia , Hemócitos/virologia , Penaeidae/virologia , Totiviridae/efeitos dos fármacos , Animais , Peptídeos Catiônicos Antimicrobianos/química , Antivirais/química , Brasil , Células Cultivadas , Hemócitos/efeitos dos fármacos , Totiviridae/genética , Totiviridae/fisiologia , Replicação Viral/efeitos dos fármacos , CatelicidinasRESUMO
As encefalopatias espongiformes transmissíveis (EETs), ou doenças priônicas, são um grupo de doenças infecciosas neurodegenerativas que conduzem seus portadores à morte. Ainda sem cura e formas de prevenção, as EETs ganham cada vez mais importância à medida que novos estudos têm mostrado sua abrangente disseminação mundial e a grande quantidade de grupos animais susceptíveis ao desenvolvimento das doenças. As EETs mais popularmente conhecidas são a doença de Creutzfeldt-Jacob em humanos, a Encefalopatia Espongiforme Bovina (BSE) e o scrapie em ovinos. Outra forma de encefalopatia menos conhecida, mas não menos importante, é a Doença da Debilidade Crônica (CWD) que acomete espécies da família Cervidae. A CWD diferencia-se das demais EETs por ser a única forma conhecida da doença que ataca animais selvagens. Estudos nos EUA, Canadá e Coréia do Sul têm mostrado um padrão bastante preciso do desenvolvimento da CWD associado a polimorfismos específicos no gene Prnp. Apesar de ser considerada uma epidemia nos Estados Unidos, e diversos programas de vigilâ