Juliana Almeida Leite

Passatempo Virus, a Vaccinia Virus Strain, Brazil

Passatempo virus was isolated during a zoonotic outbreak. Biologic features and molecular characterization of hemagglutinin, thymidine kinase, and vaccinia growth factor genes suggested a vaccinia virus infection, which strengthens the idea of the reemergence and circulation of vaccinia virus in Brazil. Molecular polymorphisms indicated that Passatempo virus is a different isolate.

Zoonotic Vaccinia Virus Infection in Brazil: Clinical Description and Implications for Health Professionals

ABSTRACT Bovine vaccinia virus outbreaks have been occurring in different regions of Brazil. We report here the time course of natural human infection by vaccinia virus and describe important clinical and epidemiological aspects of this zoonotic infection. The diagnosis of vaccinia virus infection was based on clinical, serological, and molecular procedures.

Brazilian Vaccinia virus strains are genetically divergent and differ from the Lister vaccine strain.

Vaccinia virus is responsible for an important zoonotic disease affecting dairy cattle and humans in Brazil, but little is known about the origin, epidemiology and evolution of these Brazilian Vaccinia virus strains. In this work, seven Brazilian Vaccinia virus strains and the Lister-derived Brazilian vaccine strain, named Lister-Butantan, were compared based on the sequences of ten host range and virulence related genes. Comparison of Brazilian Vaccinia virus strains with Lister-Butantan revealed several differences. Phylogenetic analyses confirmed the existence of genetically distinct Brazilian Vaccinia virus groups and has not thus far demonstrated a close relationship between Brazilian strains and Lister-Butantan. In this study, the BeAn58058 and SPAn232 strains were grouped together with the Belo Horizonte and Guarani P1 strains. Additionally, genetic polymorphisms in host range and virulence genes as well as differences in the deduced amino acid sequences were detected among Brazilian Vaccinia virus. This genetic diversity may result in a plethora of different biological properties presented by Brazilian Vaccinia virus, including differences in adaptation to the host as well as pathogenic properties. Furthermore, co-circulation of these divergent strains could increase the possibility of recombination events in nature, leading to the formation of new variants with unpredictable pathogenic potential.

Brazilian Vaccinia virus strains show genetic polymorphism at the ati gene

Nucleotide sequence comparison of the internal region of the ati gene of members of the Orthopoxvirus genera revealed that this gene is variable among different species, although within members of the same species it is considered to be well conserved. Previous studies indicated that there is genetic variability in the ati gene among some Brazilian Vaccinia virus strains. To further investigate this variability, we performed molecular analysis of the internal region of the ati gene of eight Brazilian Vaccinia virus strains. While the internal region of this gene in one strain was similar to the Western Reserve strain, four strains presented two blocks of deletions in the analyzed region, and the ati gene was almost entirely deleted from three other strains. These findings demonstrate that there is genetic polymorphism within the ati gene among different Brazilian Vaccinia virus strains.

A-type inclusion bodies: a factor influencing cowpox virus lesion pathogenesis

The family Poxviridae comprises the most complex animal DNA viruses. During some poxvirus infections, A-type inclusion bodies (ATIs), codified by the ati gene, are produced. Although some studies have compared poxviruses that encode these inclusion bodies with those that do not, the biological function of ATIs is poorly understood. A recombinant ati-deleted cowpox virus was constructed and compared with the wild-type virus in in vitro experiments including electron microscopy and plaque and viral growth assays. No significant differences were observed in vitro. This reinforces the conclusion that the inclusion body is not essential for in vitro viral replication and morphogenesis. Additionally, different lesion progressions in vivo were observed by macroscopic and histological analysis, suggesting that the presence or absence of ATIs could result in different healing dynamics. This is the first time that the role of ATIs during viral replication has been studied based solely on one variable, the presence or absence of ATIs.