RESUMO
Escherichia albertii is a recently discovered species with a limited number of well characterized strains. The aim of this study was to characterize four of the E. albertii strains, which were among 41 identified Escherichia strains isolated from the feces of living animals on James Ross Island, Antarctica, and Isla Magdalena, Patagonia. Sequencing of 16S rDNA, automated ribotyping, and rep-PCR were used to identify the four E. albertii isolates. Phylogenetic analyses based on multi-locus sequence typing showed these isolates to be genetically most similar to the members of E. albertii phylogroup G3. These isolates encoded several virulence factors including those, which are characteristic of E. albertii (cytolethal distending toxin and intimin) as well as bacteriocin determinants that typically have a very low prevalence in E. coli strains (D, E7). Moreover, E. albertii protein extracts caused cell cycle arrest in human cell line A375, probably because of cytolethal distending toxin activity.
Assuntos
Escherichia/metabolismo , Animais , Regiões Antárticas , Charadriiformes/microbiologia , Chile , Eletroforese em Gel de Campo Pulsado/veterinária , Escherichia/genética , Escherichia/isolamento & purificação , Fezes/microbiologia , Tipagem de Sequências Multilocus/veterinária , Reação em Cadeia da Polimerase/veterinária , RNA Ribossômico 16S/genética , Ribotipagem/veterinária , Focas Verdadeiras/microbiologia , Spheniscidae/microbiologiaRESUMO
Eight coagulase-negative, oxidase-negative and novobiocin-susceptible staphylococcal strains were isolated from the gastrointestinal tracts of South American squirrel monkeys (Saimiri sciureus L.). These strains were differentiated from known staphylococcal species on the basis of 16S rRNA gene and hsp60 gene sequencing, and from the most closely related species by using DNA-DNA hybridization, ribotyping, whole-cell protein profiles and biotyping. Phylogenetic analysis based on 16S rRNA gene sequences confirmed that these strains are members of the Staphylococcus aureus species group (99% similarity) but are biochemically similar to Staphylococcus piscifermentans, from which they can be phenotypically distinguished by resistance to polymyxin B, acid production from D-mannitol, the inability to hydrolyse aesculin and DNA and the absence of alpha-glucosidase. On the basis of these analyses, a novel species of the genus Staphylococcus is described, for which the name Staphylococcus simiae sp. nov. is proposed, with CCM 7213(T) (=LMG 22723(T)) as the type strain.