RESUMO
The transcriptional changes that occurred in Salmonella enterica serovar Enteritidis during colonization of the alimentary tract of newly hatched chickens were studied. A whole genome oligonucleotide microarray was used to compare the expression pattern with that from bacteria cultured in nutrient broth in vitro. Amongst other changes Salmonella Pathogenicity Island (SPI)-1, SPI-2 and SPI-5 genes were up-regulated in vivo suggesting a close association with the mucosa during colonization. Particular attention was paid to genes associated with metabolism of dicarboxylic acids and to responses to high osmolarity. Association between the colonization phenotype and gene mutations indicated that the latter was more important as a contribution to the colonization phenotype.
Assuntos
Mucosa Intestinal/microbiologia , Doenças das Aves Domésticas/microbiologia , Salmonelose Animal/microbiologia , Salmonella enteritidis/genética , Salmonella enteritidis/metabolismo , Animais , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Galinhas/genética , Galinhas/metabolismo , Galinhas/microbiologia , Perfilação da Expressão Gênica , Ilhas Genômicas , Mutação , Salmonella enteritidis/patogenicidadeAssuntos
Hipertensão/epidemiologia , Hipertensão/fisiopatologia , Apneia Obstrutiva do Sono/epidemiologia , Apneia Obstrutiva do Sono/fisiopatologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Polissonografia , Prevalência , Estudos Retrospectivos , Arábia Saudita/epidemiologia , Estatísticas não ParamétricasRESUMO
AIMS: The aim of the study was to characterize a spirochaete isolated from the lesions of a cow with digital dermatitis (DD). METHODS AND RESULTS: The characterization was on the basis of its light and electron microscopic appearance, enzymic profile and DNA sequence analysis of its flagellin and 16S rRNA genes. The spirochaete was 6-8-microm long and 0.2-0.3 microm in diameter, and possessed seven to eight periplasmic flagella, with three to five helical turns. The enzymic profile of the bacterium resembles, but is not identical to that of Treponema brennaborense. Its flagellin gene sequence was identical to that of Treponema phagedenis but distinct from that of an ovine spirochaete. Analysis of a 1477-bp region of the 16S rRNA genes indicated that this is a Treponema species and that it is indistinguishable from some isolates made from cases of bovine DD in the United States. Finally, electron microscopy revealed the presence of myovirus-like bacteriophage particles in all cultures of the treponeme examined. CONCLUSIONS: The spirochaete isolate was identified as a Treponema species closely related to some isolates from the United States (by 16S rDNA) and to T. phagedenis (by flagellin gene sequence) and is associated with bacteriophage particles. SIGNIFICANCE AND IMPACT OF THE STUDY: The fact that the isolates with the same or very similar 16S rDNA sequences have been obtained from cases of bovine DD in cattle in different countries at different times, lends further support to the hypothesis that treponemes play a role in the pathogenesis of this disease.
Assuntos
Doenças dos Bovinos/microbiologia , Dermatoses do Pé/microbiologia , Dermatoses do Pé/veterinária , Treponema/isolamento & purificação , Infecções por Treponema/microbiologia , Infecções por Treponema/veterinária , Animais , Bacteriófagos/ultraestrutura , Sequência de Bases , Bovinos , Biologia Computacional , Flagelos/ultraestrutura , Pododermatite Necrótica dos Ovinos/microbiologia , Microscopia Eletrônica , Dados de Sequência Molecular , Filogenia , Ribotipagem , Análise de Sequência de DNA , Ovinos , Doenças dos Ovinos/microbiologia , Treponema/genética , Treponema/ultraestrutura , Reino Unido , Estados UnidosRESUMO
A potential pathological role for spirochaetes in bovine digital dermatitis (bovine DD) and severe virulent ovine foot rot (SVOFR) has been considered and a treponeme isolate obtained from each disease in the UK. In this work, we have investigated the hypothesis that the two diseases may have a shared (common) spirochaetal aetiology. Experiments were designed to identify serological similarities and differences between the two spirochaetes; an enzyme-linked immunosorbent assay (ELISA) was developed to detect anti-treponeme antibodies in the sera of cows and sheep against the two-treponeme isolates. Sera were further tested for antigen reactivity by Western blotting. Cattle and sheep with bovine DD and SVOFR, respectively, had increased seropositivity rates to both treponeme isolates, with different patterns of reactivity between farms. In some cattle herds, significant correlations were shown between antibodies to bovine DD treponemes and SVOFR treponemes (P<0.001). In other herds, there was no apparent cross reaction, suggesting the presence of more than one treponeme in bovine DD on some farms. There was no significant correlation between the two treponeme isolates when ELISA-tested against 58 sheep sera from SVOFR cases (P>0.05); sheep showed strong evidence of reactivity to one or the other treponeme antigens, but never to both. Western blotting against both treponeme antigens showed that they frequently displayed different antigen epitopes, although some minor bands were common to both organisms. The data suggest that there are a number of spirochaetes in UK farms, which could be involved in the pathogenesis of either bovine DD or SVOFR.
