RESUMO
Dahl salt-sensitive (Dahl-S) rats, serving as a model of hereditary hypertension, were used to examine the effect of mannooligosaccharides (MOS) on blood pressure. Dahl-S rats were induced to develop hypertension by administering them with a 1.25% salt solution ad libitum. In a 10-wk experimental period, the Dahl-S control and MOS groups developed and maintained significantly higher blood pressure than the Dahl salt-resistant normal control group. The MOS group showed a significantly lower blood pressure than the Dahl-S control group after 5-wk of treatment (p<0.05). In addition, the serum aldosterone level of the MOS group significantly decreased (p<0.05). The findings of this study using a model of hypertensive rats suggest that MOS are able to suppress an elevation in blood pressure.
Assuntos
Pressão Sanguínea/efeitos dos fármacos , Café/química , Hipertensão/prevenção & controle , Mananas/farmacologia , Oligossacarídeos/farmacologia , Aldosterona/sangue , Animais , Peso Corporal/efeitos dos fármacos , Dieta/métodos , Modelos Animais de Doenças , Hipertensão/induzido quimicamente , Hipertensão/tratamento farmacológico , Masculino , Mananas/administração & dosagem , Oligossacarídeos/administração & dosagem , Ratos , Ratos Endogâmicos Dahl , Cloreto de Sódio/administração & dosagem , Fatores de TempoRESUMO
To determine virulence-related genes in uropathogenic Escherichia coli (UPEC) showing invasiveness to T-24 bladder cancer cells, genomic subtractive hybridization was performed between a highly invasive and a less invasive strain. Forty-nine DNA fragments were isolated from the invasive strain. One of them showed homology with Salmonella invA gene. By chromosomal walking of the strain, a type III secretion system that has been described in E. coli O157:H7 was identified on the genome of the invasive strains. Three strains out of 100 UPEC isolates had a type III secretion system inserted at 64 min of the chromosome, corresponding to E. coli K-12 MG1655. This finding suggested that the type III secretion system could play a part in uropathogenicity of UPEC.
Assuntos
Secreções Corporais/fisiologia , Infecções por Escherichia coli/microbiologia , Escherichia coli/genética , Escherichia coli/patogenicidade , Infecções Urinárias/microbiologia , Cromatóforos Bacterianos , Proteínas de Bactérias/genética , Pré-Escolar , Mapeamento Cromossômico , Cistite/epidemiologia , Cistite/microbiologia , Escherichia coli/metabolismo , Infecções por Escherichia coli/epidemiologia , Feminino , Genoma Bacteriano , Humanos , Pessoa de Meia-Idade , Hibridização de Ácido Nucleico , Prevalência , Pielonefrite/epidemiologia , Pielonefrite/microbiologia , Células Tumorais Cultivadas , Neoplasias da Bexiga Urinária , Infecções Urinárias/epidemiologia , VirulênciaRESUMO
This study involved 82 Salmonella enterica serovar Oranienburg isolates from patients with gastroenteritis and/or focal infections, healthy carriers, and cuttlefish chips which were epidemiologically linked to a major outbreak that had affected 1,505 people in Japan between 1998 and 1999. We concurrently investigated four different molecular subtyping methods using human salmonellosis-associated Salmonella serovars and their applicability in detection of serovar Oranienburg in an outbreak. Pulsed-field gel electrophoresis (PFGE), enterobacterial repetitive intergenic sequence PCR (ERIC2-PCR), or 16S/23S rRNA ribotyping provided a high degree of interserovar discrimination for most of the serovars, with PFGE being the most discriminatory. For intraserovar typing of serovar Oranienburg, ERIC2-PCR was found to be the most sensitive. Native plasmid profiling, however, revealed nine different subgroups among epidemiologically and genetically related outbreak strains. Using these methods, a link was confirmed between food (cuttlefish chips) and patients in the serovar Oranienburg outbreak. This study underscores the limitations of chromosome-based and plasmid-based typing methods.
Assuntos
Técnicas de Tipagem Bacteriana , Surtos de Doenças , Gastroenterite/epidemiologia , Intoxicação Alimentar por Salmonella/epidemiologia , Salmonella enterica/classificação , Salmonella enterica/genética , Animais , Impressões Digitais de DNA , Eletroforese em Gel de Campo Pulsado , Fezes/microbiologia , Peixes/microbiologia , Gastroenterite/microbiologia , Humanos , Japão/epidemiologia , Reação em Cadeia da Polimerase , Ribotipagem , Intoxicação Alimentar por Salmonella/microbiologia , Infecções por Salmonella/epidemiologia , Infecções por Salmonella/microbiologia , Salmonella enterica/isolamento & purificaçãoRESUMO
Fimbrial (type 1, P, and S) and afimbrial adhesins, the unique virulence traits of uropathogenic Escherichia coli (UPEC), are well recognized for their role in the initial step of uropathogenesis. In this study, we investigated whether these adhesins are dispensable for UPEC in adherence and invasion of uroepithelial cells by using E. coli isolates (n=40) from cystitis patients and T-24 cells, the bladder carcinoma cell line. We found all isolates adherent to T-24 cells within 15 min of infection. In invasion assay, all isolates could invade T-24 cells to a variable degree; 22.5% of them were found highly invasive. About 33% of isolates that do not have any recognized adhesins were as invasive as other isolates. The amplitude of invasiveness was also independent of the adhesins. In conclusion, this study demonstrates that type 1 fimbriae, P fimbriae, S fimbriae, and afimbrial adhesin I are not required for UPEC to adhere to and invade uroepithelial cells.
