Selection of Specific Peptides for Coccidioides spp. Obtained from Antigenic Fractions through SDS-PAGE and Western Blot Methods by the Recognition of Sera from Patients with Coccidioidomycosis.

Antigenic fractions of 100, 50, 37, and 28 kDa obtained through the SDS-PAGE method that were more frequently recognized by anti-Coccidioides antibodies in the sera of coccidioidomycosis patients were selected using western blotting. Subsequently, these bands were sequenced, and the obtained proteins were analysed by BLAST to choose peptides specific for Coccidioides spp. from among the shared aligned sequences of related fungi. A peptide specific for C. immitis was selected from the "GPI anchored serine-threonine rich protein OS C. immitis", while from the "uncharacterized protein of C. immitis", we selected a peptide for C. immitis and C. posadasii. These proteins arose from the 100 kDa antigenic fraction. From the protein "fatty acid amide hydrolase 1 of C. posadasii" that was identified from the 50 kDa antigenic fraction, a peptide was selected that recognized C. immitis and C. posadasii. In addition, the analysis of all the peptides (353) of each of the assembled proteins showed that only 35 had 100% identity with proteins of C. immitis and C. posadasii, one had 100% identity with only C. immitis, and one had 100% identity with only C. posadasii. These peptides can be used as diagnostic reagents, vaccines, and antifungals.

Proteolytic activity of extracellular products from Arthrobotrys musiformis and their effect in vitro against Haemonchus contortus infective larvae.

Arthrobotrys musiformis is a nematophagous fungus with potential for the biological control of Haemonchus contortus larvae. This study aimed to identify and demonstrate the proteolytic activity of extracellular products from A musiformis cultured in a liquid medium against H contortus infective larvae. A musiformis was cultured on a solid medium and further grown in a liquid medium, which was then processed through ion exchange and hydrophobic interaction chromatography. The proteolytic activity of the purified fraction was assayed with either gelatin or bovine serum albumin as substrate. Optimum proteolytic activity was observed at pH 8 and a temperature of 37°C. Results obtained with specific inhibitors suggest the enzyme belongs to the serine-dependent protease family. The purified fraction concentrate from A musiformis was tested against H contortus infective larvae. A time-dependent effect was observed with 77 per cent immobility after 48 hours incubation, with alteration of the sheath. It is concluded that A musiformis is a potential candidate for biological control because of its resistant structures and also because of its excretion of extracellular products such as proteases. The present study contributes to the identification of one of the in vitro mechanisms of action of A musiformis, namely the extracellular production of proteases against H contortus infective larvae. More investigations should be undertaken into how these products could be used to decrease the nematode population in sheep flocks under field conditions, thereby improving animal health while simultaneously diminishing the human and environmental impact of chemical-based drugs.