Anthelmintic activity of nanoencapsulated carvacryl acetate against gastrointestinal nematodes of sheep and its toxicity in rodents.

The objective of this study was to evaluate the efficacy of carvacryl acetate (CVA) and nanoencapsulated CVA (nCVA) on gastrointestinal nematodes of sheep. The CVA was nanoencapsulated with chitosan/gum arabic and the efficacy of nanoencapsulation (EE), yield, zeta potential, nanoparticle morphology and release kinetics at pH 3 and 8 were analyzed. Acute and subchronic toxicity were evaluated in rodents and reduction of egg counts in the faeces (FECRT) of sheep. The sheep were divided into four groups (n = 10): G1, 250 mg/kg CVA; G2, 250 mg/kg nCVA; G3, polymer matrix and G4: 2.5 mg/kg monepantel. EE and nCVA yield were 65% and 57%, respectively. The morphology of the nanoparticles was spherical, size (810.6±286.7 nm), zeta potential in pH 3.2 (+18.3 mV) and the 50% release of CVA at pHs 3 and 8 occurred at 200 and 10 h, respectively. nCVA showed LD50 of 2,609 mg/kg. CVA, nCVA and monepantel reduced the number of eggs per gram of faeces (epg) by 57.7%, 51.1% and 97.7%, respectively. The epg of sheep treated with CVA and nCVA did not differ from the negative control (P>0.05). Nanoencapsulation reduced the toxicity of CVA; however, nCVA and CVA presented similar results in the FECRT.

Anthelmintic activity of nanoencapsulated carvacryl acetate against gastrointestinal nematodes of sheep and its toxicity in rodents / Atividade anti-helmíntica do acetato de carvacrila nanoencapsulado sobre nematoides gastrintestinais de ovinos e toxicidade em roedores

Abstract The objective of this study was to evaluate the efficacy of carvacryl acetate (CVA) and nanoencapsulated CVA (nCVA) on gastrointestinal nematodes of sheep. The CVA was nanoencapsulated with chitosan/gum arabic and the efficacy of nanoencapsulation (EE), yield, zeta potential, nanoparticle morphology and release kinetics at pH 3 and 8 were analyzed. Acute and subchronic toxicity were evaluated in rodents and reduction of egg counts in the faeces (FECRT) of sheep. The sheep were divided into four groups (n = 10): G1, 250 mg/kg CVA; G2, 250 mg/kg nCVA; G3, polymer matrix and G4: 2.5 mg/kg monepantel. EE and nCVA yield were 65% and 57%, respectively. The morphology of the nanoparticles was spherical, size (810.6±286.7 nm), zeta potential in pH 3.2 (+18.3 mV) and the 50% release of CVA at pHs 3 and 8 occurred at 200 and 10 h, respectively. nCVA showed LD50 of 2,609 mg/kg. CVA, nCVA and monepantel reduced the number of eggs per gram of faeces (epg) by 57.7%, 51.1% and 97.7%, respectively. The epg of sheep treated with CVA and nCVA did not differ from the negative control (P>0.05). Nanoencapsulation reduced the toxicity of CVA; however, nCVA and CVA presented similar results in the FECRT.

Resumo O objetivo deste trabalho foi avaliar a eficácia do acetato de carvacrila (ACV) e do ACV nanoencapsulado (nACV) sobre nematóides gastrintestinais de ovinos. O ACV foi nanoencapsulado com quitosana/goma arábica e foi analisada a eficácia de nanoencapsulamento (EE), o rendimento, potencial zeta, morfologia das nanopartículas e cinética de liberação em pH 3 e 8. Foram avaliadas as toxicidades aguda e subcrônica em roedores e a redução da contagem de ovos nas fezes (RCOF) de ovinos. Os ovinos foram divididos em quatro grupos (n = 10): G1, 250 mg/kg ACV; G2, 250 mg/kg de nACV; G3, matriz polimérica e G4: 2,5 mg/kg de monepantel. A EE e o rendimento de nACV foram de 65% e 57%, respectivamente. A morfologia das nanopartículas foi esférica, tamanho (810,6±286,7 nm), potencial zeta no pH 3,2 (+18,3 mV) e a liberação de 50% de CVA nos pHs 3 e 8 ocorreu às 200 e 10 h, respectivamente. nACV apresentou DL50 de 2.609 mg/kg. ACV, nACV e o monepantel reduziram a contagem de ovos por grama de fezes (opg) em 57,7%, 51,1% e 97,7%, respectivamente. A contagem de opg de ovelhas tratadas com ACV e nCVA não diferiu do controle negativo (P>0,05). O nanoencapsulamento reduziu a toxicidade do AVC; no entanto, nACV e ACV apresentaram resultados semelhantes na RCOF.

Potassium iodide and miltefosine inhibit biofilms of Sporothrix schenckii species complex in yeast and filamentous forms.

This study aimed to evaluate the yeast biofilm growth kinetics and ultrastructure of Sporothrix schenckii complex and assess their mature biofilm susceptibility in filamentous and yeast forms to potassium iodide (KI) and miltefosine (MIL). Yeast biofilms were evaluated by crystal violet staining, XTT reduction assay and microscopic techniques. Susceptibility of planktonic and sessile cells was analyzed by broth microdilution. S. schenckii complex in yeast form produced biofilms, with an optimum maturation at 96 h, showing multilayered blastoconidia embedded in extracellular matrix. KI and MIL minimum inhibitory concentration (MIC) ranges against planktonic cells were 62,500-250,000 µg/ml and 0.125-4 µg/ml, respectively. KI and MIL reduced biofilm metabolic activity by 75.4% and 67.7% for filamentous form and 55.1% and 51.6% for yeast form, respectively. This study demonstrated that S. schenckii complex forms biofilms in vitro, and potassium iodide and miltefosine inhibit Sporothrix spp. biofilms in both filamentous and yeast forms.

Leishmanicidal and fungicidal activity of lipases obtained from endophytic fungi extracts.

This work describes the production of lipases from endophytic fungi: Vermisporium-like, Emericella nidulans, Dichotomophtora portulacae and D. boerhaaviae and the biological activity against the dermatophyte fungi Malassezia sp and Microsporum canis and the parasite Leishmania amazonensis. All fungal enzymes extract showed lipolysis action in the media that contains long carbon chain lipids. The proteomic analysis of lipases exhibits several molecules mostly ranging in size from 220 to 20 kDa, with clear differences in protein profile's yield. All fungal enzymes were competent to eliminate promastigote forms of Leishmania amazonensis at 5 mg.mL-1. The antileishmanial activity of lipases from Vermisporium-like, E. nidulans, D. portulacae and D. boerhaaviae in amastigote forms, promoted the reduction in viability of 78.88, 39.65, 63.17 and 98.13%, with selectivity index of 19.56, 30.68, 18.09 and 20.99. In relation to antifungal activity, Dichothomophtora enzymes demonstrate best action with MFC of 14.65 µg.mL-1 against Malassezia sp and Microsporum canis, respectively. These results allow us to infer that lipases from entophytic fungi displays activity against dermatophyte fungi (Malassezia sp. and Microsporum canis) as well as Leishmania.

Feral pigeons (Columba livia) as potential reservoirs of Salmonella sp. and Escherichia coli / Pombos de vida livre (Columba livia) e seu potencial como reservatórios de Salmonella sp. e Escherichia coli

This study aimed to review the scientific literature for information about free-living pigeons (Columba livia) as potential reservoirs of Salmonella sp. and Escherichia coli. Rock doves are currently adapted to the urban environment and distributed all over the world. These birds carry microorganisms that are pathogenic for man and other animals, such as bacteria, viruses, fungi and parasites. Among these microorganisms, Salmonella is a pathogenic genus that cause severe economic losses and it is zoonotic, causing foodborne infections in humans. In addition, Escherichia coli is an worrisome species involved in the poultry industry. However, this micro-organism is also a risk to the public health, considering pathotypes that are known to cause diseases in man have been isolated from feral pigeons. The infections caused by these bacteria depend on virulence factors that provide the necessary tools to develop the disease. These factors are encoded by genes that may be found in pathogenicity islands inside the bacterial genome. In addition, pigeons may harbor antimicrobial-resistant bacteria, which may pass this characteristic to other strains, and present a risk to the public health as well. In conclusion, pigeons are reservoirs of strains of Salmonella sp. and Escherichia coli that may present high levels of resistance to antibiotics.(AU)

O objetivo deste estudo foi revisar na literatura científica informações sobre os pombos de vida livre (Columba livia) e seu potencial como reservatórios de Salmonella sp. e Escherichia coli. Os pombos, atualmente adaptados ao meio urbano, encontram-se distribuídos por todo o mundo e carreiam micro-organismos patogênicos ao homem e a outros animais, podendo ser um dos responsáveis pela disseminação de bactérias, fungos, vírus e parasitas. Entre esses micro-organismos, a Salmonella é um patógeno que gera grande preocupação para a economia e para a saúde pública mundial, uma vez que cria transtornos para a indústria avícola quando ocorrem a contaminação dos plantéis e, consequentemente, o risco para a saúde humana por conta de surtos de toxi-infecções alimentares causados por essa bactéria. Outra bactéria preocupante para a indústria avícola e para a saúde pública é a Escherichia coli, uma vez que alguns patotipos patogênicos para o homem já foram isolados de pombos de vida livre. O desenvolvimento de infecções por essas bactérias depende de fatores que são codificados por genes de virulência que podem ser encontrados nas ilhas de patogenicidade de cepas patogênicas. Os pombos podem também albergar cepas com carga genética resistente a antibióticos, passíveis de serem transmitidas a outras bactérias e, portanto, de trazer riscos para a saúde pública. Dessa forma, com base nessas informações, conclui-se que os pombos são reservatórios de cepas de Salmonella sp. e Escherichia coli, que podem apresentar elevado potencial de virulência, com altos níveis de resistência antimicrobiana.(AU)