Molecular diagnosis of Hepatozoon canis in symptomatic dogs in the city of Goiania, Goiás, Brazil / Diagnóstico molecular de Hepatozoon canis em cães sintomáticos do município de Goiânia, Goiás, Brasil

More than 300 species have been described in the genus Hepatozoon, occurring in different vertebrates. Among these, only Hepatozoon canis and Hepatozoon americanum are seen in dogs. Different methods may be used for laboratory diagnosis. The most common of these is direct parasitological examination of parasite stages in blood smears. The aim of this investigation was to conduct a phylogenetic study on Hepatozoon isolates from symptomatic dogs in the city of Goiânia, Goiás, Brazil. Blood samples were obtained from 40 symptomatic dogs that had been referred to the Veterinary Hospital of the Federal University of Goiás. Among these, only two samples were positive for Hepatozoon spp. using the direct parasitological method. These samples were then subjected to a DNA extraction process and amplification of a fragment of the 18S rRNA by means of PCR. Subsequently, the PCR products from each sample were purified and sequenced. The sequences obtained were then analyzed using the BLASTn algorithm, which identified both sequences of this study as Hepatozoon canis. By applying the Mega4 software, it was confirmed that these isolates of H. canis from dogs in Goiânia are similar to other reference isolates of the same species from other regions of Brazil and worldwide.(AU)

São descritas mais de 300 espécies do gênero Hepatozoon que acometem diferentes vertebrados. Entre estas, apenas Hepatozoon canis e Hepatozoon americanum são descritas em cães. Diferentes métodos podem ser utilizados para o diagnóstico laboratorial. O mais empregado é o exame parasitológico direto do parasito em esfregaços sanguíneos. O objetivo deste trabalho foi realizar um estudo filogenético em Hepatozoon isolados de cães sintomáticos de Goiânia, Goiás. As amostras de sangue foram obtidas de 40 cães sintomáticos encaminhados ao Hospital Veterinário da Universidade Federal de Goiás. Entre essas, duas únicas amostras foram positivas para Hepatozoon spp. pelo método parasitológico direto. Estas amostras foram, então, submetidas ao processo de extração de DNA e de amplificação de um fragmento de 18S rRNA por PCR. Ambas as amostras foram positivas na PCR. Posteriormente, os produtos de PCR de cada amostra foram purificados e sequenciados. As sequências obtidas foram analisadas pelo algoritmo BLASTn, sendo identificadas como Hepatozoon canis. Por meio do software Mega4 foi confirmado que estes isolados de H. canis de cães de Goiânia são semelhantes a outros isolados de referência da mesma espécie de outras regiões do Brasil e do mundo.(AU)

Transcriptome overview of Paracoccidioides brasiliensis proteases

Proteases perform a wide variety of functions inside and outside cells, regulating many biological processes. Infectious microorganisms use proteases, either secreted or attached to their cell surface to weaken and invade their hosts. Therefore, proteases are targets for drugs against a diverse set of diseases. Paracoccidioides brasiliensis is the most prevalent fungal pathogen causing systemic mycosis in Latin America. The development of paracoccidioidomycosis depends on interactions between fungal and host components and proteases have been described as important factors implicated in the mechanism of host colonization by fungi. The primary goal for this study is to present an overview of the transcriptome sequences--identified cDNAs that encode proteases. We obtained a total of 53 cDNAs encoding proteases; 15 were classified as ATP-independent, 12 as ATP-dependent, 22 as proteasome subunits, and 4 as deubiquitinating proteases. The mechanisms and biological activity of these proteases differ in substrate specificity and in catalytic mechanisms.

Chemotaxis and flagellar genes of Chromobacterium violaceum

The availability of the complete genome of the Gram-negative beta-proteobacterium Chromobacterium violaceum has increasingly impacted our understanding of this microorganism. This review focuses on the genomic organization and structural analysis of the deduced proteins of the chemosensory adaptation system of C. violaceum. C. violaceum has multiple homologues of most chemotaxis genes, organized mostly in clusters in the bacterial genome. We found at least 67 genes, distributed in 10 gene clusters, involved in the chemotaxis of C. violaceum. A close examination of the chemoreceptors methyl-accepting chemotaxis proteins (MCPs), and the deduced sequences of the members of the two-component signaling system revealed canonical motifs, described as essential for the function of the deduced proteins. The chemoreceptors found in C. violaceum include the complete repertoire of such genes described in bacteria, designated as tsr, tar, trg, and tap; 41 MCP loci were found in the C. violaceum genome. Also, the C. violaceum genome includes a large repertoire of the proteins of the chemosensory transducer system. Multiple homologues of bacterial chemotaxis genes, including CheA, CheB, CheD, CheR, CheV, CheY, CheZ, and CheW, were found in the C. violaceum genome