RESUMO
We analyzed the usefulness of rpoA, recA, and pyrH gene sequences for the identification of vibrios. We sequenced fragments of these loci from a collection of 208 representative strains, including 192 well-documented Vibrionaceae strains and 16 presumptive Vibrio isolates associated with coral bleaching. In order to determine the intraspecies variation among the three loci, we included several representative strains per species. The phylogenetic trees constructed with the different genetic loci were roughly in agreement with former polyphasic taxonomic studies, including the 16S rRNA-based phylogeny of vibrios. The families Vibrionaceae, Photobacteriaceae, Enterovibrionaceae, and Salinivibrionaceae were all differentiated on the basis of each genetic locus. Each species clearly formed separated clusters with at least 98, 94, and 94% rpoA, recA, and pyrH gene sequence similarity, respectively. The genus Vibrio was heterogeneous and polyphyletic, with Vibrio fischeri, V. logei, and V. wodanis grouping closer to the Photobacterium genus. V. halioticoli-, V. harveyi-, V. splendidus-, and V. tubiashii-related species formed groups within the genus Vibrio. Overall, the three genetic loci were more discriminatory among species than were 16S rRNA sequences. In some cases, e.g., within the V. splendidus and V. tubiashii group, rpoA gene sequences were slightly less discriminatory than recA and pyrH sequences. In these cases, the combination of several loci will yield the most robust identification. We can conclude that strains of the same species will have at least 98, 94, and 94% rpoA, recA, and pyrH gene sequence similarity, respectively.
Assuntos
Proteínas de Bactérias/genética , Técnicas de Tipagem Bacteriana , Filogenia , Análise de Sequência de DNA , Vibrio/classificação , Animais , Antozoários/microbiologia , RNA Polimerases Dirigidas por DNA/genética , Proteínas de Escherichia coli/genética , Genes Supressores , Recombinases Rec A/genética , Especificidade da Espécie , Transferases/genética , Vibrio/genética , Vibrionaceae/classificação , Vibrionaceae/genéticaRESUMO
Six new Vibrio-like isolates originating from different species of bleached and healthy corals around Magnetic Island (Australia) were investigated using a polyphasic approach. Phylogenetic analyses based on 16S rRNA, recA and rpoA gene sequences split the isolates in two new groups. Strains LMG 22223(T), LMG 22224, LMG 22225, LMG 22226 and LMG 22227 were phylogenetic neighbours of Photobacterium leiognathi LMG 4228(T) (95.6 % 16S rRNA gene sequence similarity), whereas strain LMG 22228(T) was related to Enterovibrio norvegicus LMG 19839(T) (95.5 % 16S rRNA gene sequence similarity). The two new groups can be distinguished from closely related species on the basis of several phenotypic features, including fermentation of d-mannitol, melibiose and sucrose, and utilization of different compounds as carbon sources, arginine dihydrolase activity, nitrate reduction, resistance to the vibriostatic agent O/129 and the presence of fatty acids 15 : 0 iso and 17 : 0 iso. The names Photobacterium rosenbergii sp. nov. (type strain LMG 22223(T)=CBMAI 622(T)=CC1(T)) and Enterovibrio coralii sp. nov. (type strain LMG 22228(T)=CBMAI 623(T)=CC17(T)) are proposed to accommodate these new isolates. The G+C contents of the DNA of the two type strains are respectively 47.6 and 48.2 mol%.
Assuntos
Antozoários/metabolismo , Antozoários/microbiologia , Photobacterium/classificação , Vibrionaceae/classificação , Animais , Técnicas de Tipagem Bacteriana , DNA Bacteriano/análise , DNA Ribossômico/análise , RNA Polimerases Dirigidas por DNA/genética , Genes de RNAr , Dados de Sequência Molecular , Fenótipo , Photobacterium/genética , Photobacterium/metabolismo , Filogenia , RNA Ribossômico 16S/genética , Recombinases Rec A/genética , Análise de Sequência de DNA , Especificidade da Espécie , Vibrionaceae/genética , Vibrionaceae/metabolismoRESUMO
Thirty-eight free-ranging dusky-headed parakeets (Aratinga weddellii) and 13 tui parakeets (Brotogeris sanctithomae) were caught and released in Parque Nacional del Manu in southeastern Peru from 19 July to 5 August 1993. Blood and fecal samples were collected and sera were evaluated for titers to Pacheco's disease herpesvirus, psittacine polyomavirus, paramyxovirus-1, and Chlamydia psittaci. Fecal samples were examined for evidence of ascarid or coccidial infection by fecal flotation, and blood smears were examined for hemoparasites. Five (50%) of 10 A. weddellii serum samples tested by complement fixation (CF) for psittacine polyomavirus antibodies were positive, and three (19%) of 16 A. weddellii samples tested by virus neutralization (VN) for psittacine polyomavirus antibodies were positive, yielding a total of 8 (38%) of the 21 A. weddellii samples positive for psittacine polyomavirus. Based on CF for herpesvirus, four (11%) of 38 A. weddellii samples had antibodies against herpesvirus. All B. sanctithomae were negative for psittacine polyomavirus and psittacine herpesvirus. Thirty-five of the A. weddellii tested were negative for Chlamydia psittaci by CF, latex agglutination, and elementary body agglutination, and all B. sanctithomae were negative for Chlamydia psittaci by the CF test. Nine A. weddellii and eight B. sanctithomae evaluated for paramyxovirus-1 titers by the hemagglutination inhibition test were negative. All fecal samples were negative for ascarids or coccidia by fecal flotation, and all blood smears were negative for hemoparasites by direct microscopic examination. This is the first known description of psittacine polyomavirus and psittacine herpesvirus in free-ranging parrots. Serologic evidence of Pacheco's disease herpesvirus in wild A. weddellii is interesting in light of the fact that Aratinga spp. are considered to be possible carriers of this virus in captivity.