RESUMO
Although often considered a strict human pathogen, Streptococcus pneumoniae has been reported to infect and cause pneumonia in horses, although the pathology appears restricted compared to that of human infections. Here we report on the molecular characterization of a group of S. pneumoniae isolates obtained from horses in England and Ireland. Despite being obtained from geographically distinct locations, the isolates were found to represent a tight clonal group, virtually identical to each other but genetically distinguishable from more than 120 divergent isolates of human S. pneumoniae. A comprehensive analysis of known pneumococcal virulence determinants was undertaken in an attempt to understand the pathogenicity of equine pneumococci. Surprisingly, equine isolates appear to lack activities associated with both the hemolytic cytotoxin pneumolysin, often considered a major virulence factor of pneumococci, and the major autolysin gene lytA, also considered an important virulence factor. In support of phenotypic data, molecular studies demonstrated a deletion of parts of the coding sequences of both lytA and ply genes in equine pneumococci. The implications of these findings for the evolution and pathogenicity of equine S. pneumoniae are discussed.
Assuntos
Genes Bacterianos , Doenças dos Cavalos/microbiologia , N-Acetil-Muramil-L-Alanina Amidase/genética , Infecções Pneumocócicas/veterinária , Streptococcus pneumoniae/genética , Estreptolisinas/genética , Animais , Fusão Gênica Artificial , Proteínas de Bactérias , Sequência de Bases , DNA Bacteriano , Enzimas/genética , Cavalos , Humanos , Dados de Sequência Molecular , Infecções Pneumocócicas/microbiologia , Streptococcus pneumoniae/classificação , Streptococcus pneumoniae/isolamento & purificação , Streptococcus pneumoniae/patogenicidade , VirulênciaRESUMO
The majority of condylomata acuminata (anogenital warts) are caused by infection with Human Papilloma Virus type 6 (HPV-6). We have sequenced the HPV-6 early genes, E1-E4, E6 and E7 from wart biopsy DNA samples sourced from the UK and USA and derived a consensus sequence for these genes and the proteins they encode. When compared to the prototype HPV-6b sequence, published over 12 years ago, the E1-E4 consensus sequence showed 3/91 (3.3%) amino acid changes, the E6 consensus sequence showed 1/150 (0.7%) changes and the E7 consensus sequence showed 1/98 (1.0%) changes. Since many of the early gene sequences from biopsy material were more similar to the HPV-6a subtype than HPV-6b, this data supports the use of HPV-6a as the HPV-6 prototype.