RESUMO
La Yersinia enterocolitica o la Yersinia pseudotuberculosis pueden tener diferentes formas de presentación entre las que están la enteritis o enterocolitis, la adenitis mesentérica asociada a ileitis distal, la septicemia, infecciones localizadas o manifestaciones extraintestinales. Es responsable de hasta 7 por ciento de los cuadros de gastroenteritis infecciosas y se asocia a una elevada mortalidad post-infección a corto y largo plazo, de 2 a 3 veces mayor. Esta infección bacteriana se adquiere mediante la ingesta oral de productos contaminados y/o inadecuadamente preparados. El aislamiento de Yersinia en las deposiciones es el examen más específico y siempre debe ser solicitado. Debido a su baja sensibilidad los estudios serológicos pueden ser útiles para el diagnóstico, y la reacción de polimerasa en cadena (PCR) puede constituirse próximamente en el examen de elección para el diagnóstico de esta infección. Los antibióticos útiles para su tratamiento son los aminoglicósidos, cefalosporinas de tercera generación, cloranfenicol, quinolonas, tetraciclinas y trimetoprim-sulfametoxazol.
Yersinia enterocolitica or yersinia pseudotuberculosis may have different presentation forms: among those are enteritis or enterocholitis, mesenteric adenitis associated with distal ileitis, septicemia, localized infections or extra-intestinal manifestations. It is responsible for up to 7 percent of infectious gastroenteritis and is associated with high post-infection mortality in the short and long term, which is 2 to 3 times higher. This bacterial infection is acquired through oral consumption of contaminated and/or inappropriately prepared products. Isolation of Yersinia in stool samples is the more specific exam and it should always be performed. Due to its low sensibility, serological studies may be useful for the diagnosis, and the polymerase chain reaction (PCR) may become the elective exam for the diagnosis of this infection in the future. Antibiotics that are useful for its treatment are aminoglycoside, third-generation cephalosporins, chloramphenicol, quinolones, tetracyclines, and Trimetoprim-sulfametoxasol.
Assuntos
Humanos , Gastroenterite/microbiologia , Yersiniose/diagnóstico , Yersiniose/fisiopatologia , Yersiniose/tratamento farmacológico , Antibacterianos/uso terapêutico , Fezes/microbiologia , Testes Sorológicos , Reação em Cadeia da Polimerase , Yersinia enterocolitica/isolamento & purificação , Yersinia enterocolitica/patogenicidade , Yersinia pseudotuberculosis/isolamento & purificação , Yersinia pseudotuberculosis/patogenicidadeRESUMO
Ribotyping and virulence markers has been used to investigate 68 Yersinia pseudotuberculosis strains of serogroups O:1a and O:3. The strains were isolated from clinical material obtained from healthy and sick animals in the Southern region of Brazil. Ribotypes were identified by double digestion of extracted DNA with the restriction endonucleases SmaI and PstI, separation by electrophoresis and hybridization with a digoxigenin-labeled cDNA probe. The presence of the chromosomal virulence marker genes inv, irp1, irp2, psn, ybtE, ybtP-ybtQ, and ybtX-ybtS, of the IS100 insertion sequence, and of the plasmid gene lcrF was detected by polymerase chain reaction. The strains were grouped into four distinct ribotypes, all of them comprising several strains. Ribotypes 1 and 4 presented distinct profiles, with 57.3% genetic similarity, ribotypes 2 and 3 presented 52.5% genetic similarity, and genetic similarity was 45% between these two groups (1/4 and 2/3). All strains possessed the inv, irp1, and irp2 genes. Additionally, strains of serogroup O:1a carried psn, ybtE, ybtP-ybtQ, ybtX-ybtS, and IS100. As expected lcrF was only detected in strains harboring the virulence plasmid. These data demonstrate the presence of Y. pseudotuberculosis strains harboring genotypic virulence markers in the livestock from Southern Brazil and that the dissemination of these bacteria may occur between herds.
Assuntos
Ilhas Genômicas/genética , Plasmídeos/genética , Ribotipagem/métodos , Fatores de Virulência/genética , Yersinia pseudotuberculosis/patogenicidade , Animais , Brasil , DNA Bacteriano/química , DNA Bacteriano/genética , Eletroforese em Gel de Campo Pulsado , Marcadores Genéticos/genética , Reação em Cadeia da Polimerase , Virulência/genética , Fatores de Virulência/química , Yersinia pseudotuberculosis/classificação , Yersinia pseudotuberculosis/genéticaRESUMO
Ribotyping and virulence markers has been used to investigate 68 Yersinia pseudotuberculosis strains of serogroups O:1a and O:3. The strains were isolated from clinical material obtained from healthy and sick animals in the Southern region of Brazil. Ribotypes were identified by double digestion of extracted DNA with the restriction endonucleases SmaI and PstI, separation by electrophoresis and hybridization with a digoxigenin-labeled cDNA probe. The presence of the chromosomal virulence marker genes inv, irp1, irp2, psn, ybtE, ybtP-ybtQ, and ybtX-ybtS, of the IS100 insertion sequence, and of the plasmid gene lcrF was detected by polymerase chain reaction. The strains were grouped into four distinct ribotypes, all of them comprising several strains. Ribotypes 1 and 4 presented distinct profiles, with 57.3 percent genetic similarity, ribotypes 2 and 3 presented 52.5 percent genetic similarity, and genetic similarity was 45 percent between these two groups (1/4 and 2/3). All strains possessed the inv, irp1, and irp2 genes. Additionally, strains of serogroup O:1a carried psn, ybtE, ybtP-ybtQ, ybtX-ybtS, and IS100. As expected lcrF was only detected in strains harboring the virulence plasmid. These data demonstrate the presence of Y. pseudotuberculosis strains harboring genotypic virulence markers in the livestock from Southern Brazil and that the dissemination of these bacteria may occur between herds.
Assuntos
Animais , Ilhas Genômicas/genética , Plasmídeos/genética , Ribotipagem/métodos , Fatores de Virulência/genética , Yersinia pseudotuberculosis/patogenicidade , Brasil , DNA Bacteriano/química , DNA Bacteriano/genética , Eletroforese em Gel de Campo Pulsado , Marcadores Genéticos/genética , Reação em Cadeia da Polimerase , Fatores de Virulência/química , Virulência/genética , Yersinia pseudotuberculosis/classificação , Yersinia pseudotuberculosis/genéticaRESUMO
The course of in vivo infection of five isolates of Yersinia pseudotuberculosis was followed for three weeks in Swiss mice. The strains were isolated from diarrheic and normal feces and mesenteric lymph nodes of healthy and sick stock animals. Four strains of serogroup O:3 and one of serogroup O:1a, with and without the virulence plasmid, were inoculated intragastrically and intravenously in the mice. Groups of five animals were sacrificed at 6 h and 3, 6, 10, 15, and 21 days after inoculation, and organs and tissues were checked for possible macroscopic alterations. Development of infection was monitored at these times by performing viable bacterial counts in homogenates of selected tissues. The animals were checked daily for clinical alterations. The results of the study showed that strains with the virulence plasmid infected organs and tissues at various times and at varying intensity by both routes of infection, the strain of type O:1a being the most invasive. Moreover, clinical and pathological alterations occurred only in animals inoculated with bacteria carrying the virulence plasmid, regardless of the route of infection.
Assuntos
Yersiniose/microbiologia , Yersinia pseudotuberculosis/patogenicidade , Animais , Biomarcadores , Modelos Animais de Doenças , Feminino , Fígado/microbiologia , Linfonodos/microbiologia , Camundongos , Nódulos Linfáticos Agregados/microbiologia , Baço/microbiologia , Fatores de TempoRESUMO
An essential key to pathogenicity in Yersinia is the presence of a 70 kb plasmid (pYV) which encodes a type-III secretion system and several virulence outer proteins whose main function is to enable the bacteria to survive in the host. Thus, a specific immune response is needed in which cytokines are engaged. The aim of this study was to assess the influence of Yersinia outer proteins (Yops) released by Yersinia pseudotuberculosis on the production of the proinflammatory cytokines, interleukin-12 (IL-12), and tumor necrosis factor alpha (TNF-alpha), and nitric oxide (NO) by murine peritoneal macrophages. To this end, female Swiss mice were infected intravenously with wild-type Y. pseudotuberculosis or with mutant strains unable to secrete specific Yops (YopE, YopH, YopJ, YopM, and YpkA). On the 7th, 14th, 21st, and 28th days after infection, the animals were sacrificed and the cytokines and NO were assayed in the peritoneal macrophages culture supernatants. A fall in NO production was observed during the course of infection with all the strains tested, though during the infection with the strains that did not secrete YopE and YopH, the suppression occurred later. There was, in general, an unchanged or sometimes increased production of TNF-alpha between the 7th and the 21st day after infection, compared to the control group, followed by an abrupt decrease on the last day of infection. The IL-12 production was also suppressed during the infection, with most of the strains tested, except with those that did not secrete YopJ and YopE. The results suggest that Yops may suppress IL-12, TNF-alpha, and NO production and that the most important proteins involved in this suppression are YopE and YopH.
Assuntos
Proteínas da Membrana Bacteriana Externa/fisiologia , Citocinas/biossíntese , Macrófagos Peritoneais/imunologia , Óxido Nítrico/biossíntese , Infecções por Yersinia pseudotuberculosis/imunologia , Infecções por Yersinia pseudotuberculosis/microbiologia , Yersinia pseudotuberculosis/patogenicidade , Animais , Proteínas da Membrana Bacteriana Externa/genética , Feminino , Interleucina-12/biossíntese , Macrófagos Peritoneais/química , Macrófagos Peritoneais/microbiologia , Camundongos , Camundongos Endogâmicos , Óxido Nítrico/análise , Fator de Necrose Tumoral alfa/biossíntese , Yersinia pseudotuberculosis/metabolismo , Infecções por Yersinia pseudotuberculosis/metabolismoAssuntos
Infecções por Yersinia pseudotuberculosis/genética , Yersinia pseudotuberculosis/patogenicidade , Animais , Brasil/epidemiologia , Búfalos/microbiologia , Bovinos/microbiologia , Marcadores Genéticos , Humanos , Valores de Referência , Suínos/microbiologia , Virulência/genética , Yersinia pseudotuberculosis/genética , Yersinia pseudotuberculosis/isolamento & purificação , Infecções por Yersinia pseudotuberculosis/epidemiologia , Infecções por Yersinia pseudotuberculosis/veterinária , ZoonosesRESUMO
Strains (105) of Yersinia pseudotuberculosis isolated in Brazil between 1982 and 1990 were bio-serotyped. They were also studied for plasmid profile, autoagglutination and calcium dependence at 37 degrees C, Congo red uptake, pyrazinamidase activity, esculin hydrolysis, salicin fermentation and drug sensitivity: 95.24% were biotype 2, serogroup O:3; 2.86% were biotype 1, serogroup O:1; and 1.90% were biotype 2, non-agglutinable. Plasmids were found in 77.14% of the strains (one in each strain). There was total correlation between the presence of the virulence plasmid and autoagglutination, calcium dependence at 37 degrees C and Congo red uptake. The esculin, salicin and pyrazinamidase tests were not efficient in differentiating pathogenic from non-pathogenic Y. pseudotuberculosis isolates. All strains were highly sensitive to the drugs used. These results indicate that Y. pseudotuberculosis is a potential pathogen for humans in Brazil, especially because the bio-serogroups detected among animals are those most frequently associated with human diseases.