ABSTRACT
The use of PCR assays with degenerate primers has suggested the existence of numerous as yet uncharacterized bovine papillomaviruses (BPV). Despite the endemic nature of BPV infections, the identification of BPV types in Brazilian cattle is still only sporadic. However, in a recent analysis of a partial segment of the L1 gene, we observed notable diversity among the BPV types detected. The aim of this study was to determine the phylogenetic position of the previously identified wild strain BPV/BR-UEL2 detected in the state of Paraná in Brazil. Since previous analysis of the partial L1 sequence had shown that this strain was most closely related to BPV type 4, genus-specific primers were designed. Phylogenetic analysis using complete L1 ORF sequences revealed that BPV/BR-UEL2 was related to BPV types classified in the genus Xipapillomavirus and shared the highest L1 nucleotide sequence similarity with BPV type 4 (78 percent). This finding suggests that BPV/BR-UEL2 should be classified as a potential new type of BPV in the genus Xipapillomavirus.
ABSTRACT
The common occurrence of multiple papillomavirus infections has been shown in several studies involving the human host. However, investigations with the aim of identifying mixed papillomavirus infections in cattle have been conducted only recently. In the current work we describe a co-infection with two different bovine papillomavirus (BPV) types that was identified in a bovine teat papilloma. The skin wart was obtained from a cow belonging to a Brazilian beef herd. A PCR assay was carried out with the FAP primer pair, which amplifies a partial segment of the L1 gene (approximately 478 bp), and the amplicon was submitted to direct sequencing. Because nucleotide sequences with satisfactory quality scores were not obtained, the amplicon was cloned and further sequencing, involving ten selected clones, was performed. The sequence analysis of the cloned inserts revealed the presence of two different BPV types. BPV-1 (Deltapapillomavirus genus) was detected in six clones, while BPV-6 (Xipapillomavirus genus) was detected in four clones. This finding confirms the presence of BPV co-infection associated with cutaneous papillomatosis in cattle.
Em seres humanos, as infecções múltiplas pelo papilomavírus têm sido demonstradas em vários estudos. Em bovinos, somente recentemente foram conduzidas investigações com o objetivo de avaliar infecções mistas pelo papilomavírus. O presente trabalho teve como objetivo descrever a co-infecção por dois tipos de papilomavírus bovino (BPV) em um papiloma de teto. A amostra clínica foi obtida de uma vaca pertencente a um rebanho de corte localizado na região norte do estado do Paraná, Brasil. Inicialmente, a técnica de PCR foi realizada com o par de oligonucleotídeos iniciadores FAP, que amplificam um segmento do gene L1, sendo que o amplicon gerado foi submetido ao sequenciamento direto. Entretanto, como as sequências obtidas não apresentaram qualidade aceitável, o amplicon foi clonado e dez clones foram selecionados para um novo sequenciamento. A análise das sequências dos insertos revelou a presença de dois diferentes tipos de BPV. O BPV-1 (gênero Deltapapillomavirus) foi detectado em seis clones, enquanto o BPV-6 (gênero Xipapillomavirus) foi detectado em quatro clones. Esse resultado confirma a ocorrência da co-infecção pelo BPV associada a papilomas cutâneos em bovinos.
ABSTRACT
Bovine papillomavirus type 8 (BPV-8) was first detected and described in teat warts as well as in healthy teat skin from cattle raised in Japan. The entire viral genome was sequenced in 2007. Additionally, a variant of BPV-8, BPV-8-EB, was also identified from papillomatous lesions of a European bison in Slovakia. In Brazil, despite the relatively common occurrence of BPV infections, the identification and determination of viral types present in cattle is still sporadic. The aim of this study is to report the occurrence of the recently described BPV-8 in Brazil. The virus was identified in a skin warts obtained from a beef cattle herd located in Parana state, southern Brazil. The papilloma had a macular, non-verrucous gross aspect and was located on the dorsal thorax of a cow. Polymerase chain reaction (PCR) was performed using generic primers for partial amplification of L1 gene. The obtained amplicon (480bp) was cloned and two selected clones were sequenced. The nucleotide sequence was compared to existing papillomaviral genomic sequences, identifying the virus as BPV type 8. This study represents the first report of BPV-8 occurrence in Brazil, what suggests its presence among Brazilian cattle.
A primeira descrição do papilomavírus bovino tipo 8 (BPV-8) foi realizada em amostras de papilomas de teto e de pele saudável de tetos de bovinos no Japão. Em 2007, a seqüência genômica completa do BPV-8 foi determinada. Ainda em 2007, uma variante do BPV-8 (BPV-8-EB) foi identificada em lesões papilomatosas de um bisão europeu na Eslováquia. No Brasil, apesar da infecção pelo BPV ser comumente observada em bovinos, a determinação dos tipos virais associados com a infecção ainda é esporádica. Este estudo tem o objetivo de relatar a ocorrência do BPV-8 no país. A amostra clínica foi obtida em um rebanho de corte do estado do Paraná, região sul do Brasil. O papiloma cutâneo, de aspecto macular e não-verrucoso, estava localizado na região dorsal torácica do animal. A identificação do vírus foi realizada pela reação em cadeia da polimerase (PCR) utilizando primers genéricos para a amplificação parcial do gene L1. O produto amplificado, com aproximadamente 480 pb, foi clonado e os fragmentos presentes em dois clones foram seqüenciados. A comparação da seqüência de nucleotídeos com a de outros papilomavírus demonstrou 100 por cento de identidade com o BPV-8. Assim, esta é a primeira descrição da ocorrência do BPV-8 no Brasil, o que sugere a sua presença nos rebanhos bovinos brasileiros.