O gênero Babesia compreende protozoários causadores de enfermidades denominadas babesioses. Cães geralmente são acometidos por Babesia canis ou Babesia gibsoni, sendo a primeira classificada em subespécies Babesia canis canis, Babesia canis vogeli e Babesia canis rossi. Entre essas, Babesia canis vogeli predomina no Brasil. O objetivo desse trabalho foi realizar estudo filogenético de amostras de Babesia em cães, em Goiânia, Goiás. Amostras de sangue foram obtidas de 890 cães atendidos no Hospital Veterinário de Goiás, apresentando sinais clínicos de babesiose. Somente amostras com presença de parasitos intraeritrocitários típicos foram utilizadas. Estas foram submetidas a extração de DNA e amplificação de fragmento do gene 18S rRNA pela PCR. Os produtos de PCR foram purificados e sequenciados. Foram sequenciadas 35 amostras, das quais apenas 17 foram mantidas após avaliação de qualidade. A análise de similaridade fornecida pelo BLASTn demonstrou que as 17 sequências deste estudo eram correspondentes a Babesia canis vogeli. Pela utilização do programa Mega4, foi possível verificar que as amostras de Babesia canis vogeli, provenientes de cães da cidade de Goiânia, apresentam, alto grau de similaridade molecular (99,2 a 100%) com isolados de referência de outras regiões do Brasil e do mundo, depositados em GenBank.

The genus Babesia comprises protozoa that cause diseases known as babesiosis. Dogs are commonly affected by Babesia canis or Babesia gibsoni. Babesia canis is divided into the subspecies Babesia canis canis, Babesia canis vogeli and Babesia canis rossi. Among these, Babesia canis vogeli predominates in Brazil. The objective of this study was to conduct a phylogenetic analysis on Babesia isolates from dogs in Goiânia, Goiás. Blood samples were obtained from 890 dogs presenting clinical signs suggestive of canine babesiosis that were attended at a veterinary hospital of Goiás. Only samples presenting typical intraerythrocytic parasites were used in the study. These were subjected to DNA extraction and amplification of a fragment of the 18S rRNA, by means of PCR. The PCR products were purified and sequenced. Sequences were obtained from 35 samples but only 17 of these were kept after quality assessment. Similarity analysis using BLASTn demonstrated that all 17 sequences corresponded to B. canis vogeli. Analysis using the Mega4 software showed that the isolates of B. canis vogeli from dogs in Goiânia present a high degree of molecular similarity (99.2 to 100%) in comparison with other reference isolates from other regions of Brazil and worldwide, deposited in GenBank.

Paracoccidioides brasiliensis causes infection through inhalation by the host of airborne propagules from the mycelium phase of the fungus. This fungus reaches the lungs, differentiates into the yeast form and is then disseminated to virtually all parts of the body. Here we review the identification of differentially-expressed genes in host-interaction conditions. These genes were identified by analyzing expressed sequence tags (ESTs) from P. brasiliensis cDNA libraries. The P. brasiliensis was recovered from infected mouse liver as well as from fungal yeast cells incubated in human blood and plasma, mimicking fungal dissemination to organs and tissues and sites of infection with inflammation, respectively. In addition, ESTs from a cDNA library of P. brasiliensis mycelium undergoing the transition to yeast were previously analyzed. Together, these studies reveal significant changes in the expression of a number of genes of potential importance in the host-fungus interaction. In addition, the unique and divergent representation of transcripts when the cDNA libraries are compared suggests differential gene expression in response to specific niches in the host. This analysis of gene expression patterns provides details about host-pathogen interactions and peculiarities of sites within the host.

Hepatitis A virus (HAV) infection is a public health problem worldwide and the virus has been classified into six genotypes. In Brazil, the only genotype that has been found is genotype I, predominately from subgenotype IA. Here, the HAV genotypes were analyzed of 18 isolates circulating between 1996-2001 in Goiânia, state of Goiás, Brazil. Viral RNA was extracted from 18 serum samples and amplified (RT-PCR/nested-PCR), followed by the genomic sequencing of the VP1/2A junction region of the HAV genome. Sequences of 168 nucleotides were compared and analyzed using the BLAST N, Clustal X and PAUP v. 4.10b programs. All samples were classified as genotype I, with 10 belonging to subgenotype IA and eight to subgenotype IB. The subgenotype IA isolates showed greater diversity than the subgenotype IB isolates at the nucleotide level. Elevated identity values were found between isolates obtained in this study and those from other regions of the world, including Brazil, highlighting the high conservation among different isolates of this virus. However, changes in the HAV subgenotype circulation could also be observed during the evaluated period.

Nonstructural protein 4 (NSP4), encoded by group A rotavirus genome segment 10, is a multifunctional protein and the first recognized virus-encoded enterotoxin. The NSP4 gene has been sequenced, and five distinct genetic groups have been described: genotypes A-E. NSP4 genotypes A, B, and C have been detected in humans. In this study, the NSP4-encoding gene of human rotavirus strains of different G and P genotypes collected from children between 1987 and 2003 in three cities of West Central region of Brazil was characterized. NSP4 gene of 153 rotavirus-positive fecal samples was amplified by reverse transcriptase-polymerase chain reaction and then sequenced. For phylogenetic analysis, NSP4 nucleotide sequences of these samples were compared to nucleotide sequences of reference strains available in GenBank. Two distinct NSP4 genotypes could be identified: 141 (92.2%) sequences clustered with NSP4 genotype B, and 12 sequences (7.8%) clustered with NSP4 genotype A. These results reinforce that further investigations are needed to assess the validity of NSP4 as a suitable target for epidemiologic surveillance of rotavirus infections and vaccine development.

Mycoplasmas are the smallest known prokaryotes with self-replication ability. They are obligate parasites, taking up many molecules of their hosts and acting as pathogens in men, animals, birds and plants. Mycoplasma hyopneumoniae is the infective agent of swine mycoplasmosis and Mycoplasma synoviae is responsible for subclinical upper respiratory infections that may result in airsacculitis and synovitis in chickens and turkeys. These highly infectious organisms present a worldwide distribution and are responsible for major economic problems. Proteins of the GTPase superfamily occur in all domains of life, regulating functions such as protein synthesis, cell cycle and differentiation. Despite their functional diversity, all GTPases are believed to have evolved from a single common ancestor. In this work we have identified mycoplasma GTPases by searching the complete genome databases of Mycoplasma synoviae and Mycoplasma hyopneumoniae, J (non-pathogenic) and 7448 (pathogenic) strains. Fifteen ORFs encoding predicted GTPases were found in M. synoviae and in the two strains of M. hyopneumoniae. Searches for conserved G domains in GTPases were performed and the sequences were classified into families. The GTPase phylogenetic analysis showed that the subfamilies were well resolved into clades. The presence of GTPases in the three strains suggests the importance of GTPases in 'minimalist' genomes.

Mycoplasma synoviae and Mycoplasma hyopneumoniae are wall-less eubacteria belonging to the class of Mollicutes. These prokaryotes have a reduced genome size and reduced biosynthetic machinery. They cause great losses in animal production. M. synoviae is responsible for an upper respiratory tract disease of chickens and turkeys. M. hyopneumoniae is the causative agent of enzootic pneumonia in pigs. The complete genomes of these organisms showed 17 ORFs encoding kinases in M. synoviae and 15 in each of the M. hyopneumoniae strain. Four kinase genes were restricted to the avian pathogen while three were specific to the pig pathogen when compared to each other. All deduced kinases found in the non pathogenic strain (J[ATCC25934]) were also found in the pathogenic M. hyopneumoniae strain. The enzymes were classified in nine families composing five fold groups.