Yersiniose em Trachinotus marginatus (pampo): diagnóstico histopatológico e imuno-histoquímico / Yersiniosis in Trachinotus marginatus (pampo): histopathological and immunohistochemical diagnostic

Descreveu-se um surto de yersiniose em uma criação de pampo Trachinotus marginatus estudado no Laboratório de Piscicultura Estuarina e Marinha da Universidade Federal do Rio Grande. A enfermidade manifestou-se por transtornos natatórios, exoftalmia com panoftalmite e pela clássica boca vermelha, nome pelo qual se denomina "enfermidade da boca vermelha" (EBV). Na necropsia, foram observados focos de hemorragia peritoneal, esplenomegalia e hepatomegalia. Microscopicamente, foi observada panoftalmite com infiltrados inflamatórios densos que afetavam quase todas as estruturas oculares. Esses infiltrados estavam constituídos por granulócitos, linfócitos, macrófagos e células granulares eosinofílicas. No exsudado, observaram-se estruturas pequenas, pouco coradas, de aspecto bacteriano Gram negativo. O estudo imuno-histoquímico, que se utilizou de um anticorpo monoclonal anti-Yersinia ruckeri, resultou positivo. Este é o primeiro surto conhecido de yersiniose em Trachinotus marginatus no Brasil.

In the "Laboratório de Piscicultura Estuarina e Marinha da Universidade Federal do Rio Grande" the rearing of Trachinotus marginatus (pompano) is studied, and in one of these rearing a yersioniosis outbreak occured. The disease was manifested by swimming disturbances, exophthalmiawith panophthalmitis and the classic red mouth, (red mouth disease (RMD). The necropsies revealed focus of peritoneal hemorrhage, esplenomegalyand hepatomegaly.Microscopically a panophthalmitis with dense inflammatory infiltrates was observed, which affected almost all ocular structures. These infiltrates were constituted by granulocytes, lymphocytes, macrophages and eosinophylicgranular cells (ECG), in the exudatessmall structures less colored with Gram negative bacteria aspect were observed. The immunohistochemical, which used a monoclonal antibody anti- Yersinia ruckeri waspositive. The RMD is caused by enterobacteriaGram negative, which affects both freshwater and saltwater fish, with predominance in salmonids. This is the first known yersiniosis outbreak in Trachinotus marginatus in Brazil and it is necessary to keep this disease in mind at the moment of rearing fish of this species.

Cell adherence--a determinant of virulence in Yersinia enterocolitica.

The adherence of pathogenic bacteria to eukaryotic cells plays a central role in their ability to colonize the mucosal epithelial surfaces. The adherence by Y. enterocolitica to the mucosal surface of the gut is the initiating event leading to penetration of mucosa. Adhesion of 10 probable pathogenic and one non-pathogenic isolate was studied using ileum and colon epithelial cells of mouse for 90 minutes. Adhesion study revealed that isolates of Y. enterocolitica had a good adhesive property while non pathogenic showed negligible adherence. All isolates showed better adherence to colon epithelial cells. The organism continued to be excreted in faeces up to 8-10 days after oral feeding. Adhesion positive isolates were found to be virulent when tested in mice for diarrhoea and death. Adhesion was found to be thermoregulated.

Importância de Yersinia enterocolitica em microbilogia médica / Importance of Yersinia enterocolitica in medical microbiology

Y.enterocolitica é um enteropatógeno invasivo de humanos que provoca uma série de sintomas clínicos intestinais e extra-intestinais que variam desde uma gastrenterite branda a uma linfadenite mesentérica que mimetiza apendicite e em casos raros pode evoluir para uma septicemia.A infecção causada por Y.enterocolitica pode levar a seqüelas imunológicas, incluindo artrite, eritema nodoso e glomerulonefrite.Amostras patogênicas de Y.enterocolitica são associadas a determinados sorogrupos e biotipos e a uma variedade de características fenotípicas relacionadas a virulência.Estudos de genética molecular demonstraram a importância do plasmídio pYV que codifica vários genes de virulência, bem como a importância de vários genes de virulência cromossomais na patogênese dessa bactéria.As infecções intestinais causadas por Y.enterocolitica são normalmente auto-limitadas não havendo usualmente a necessidade de antibioticoterapia.A ocorrência de infecções por Y.enterocolitica no Brasil não é tão freqüente como em países europeus, Japão e Estados Unidos.Essa revisão enfoca as características gerais, a patogênese, os sintomas clínicos, mecanismos de virulência, tratamento e susceptibilidade a antibióticos de amostras de Y.enterocolitica isoladas no Brasil e ao redor do mundo.

Análisis de una cepa de Yersinia enterocolitica aislada de heces diarreicas humanas en Argentina / Analysis of a Yersinia enterocoliticaisolated from human diarreic feces in Argentina

Algunos serotipos de Yersinia enterocolitica ocasionan desde diarreas hasta infecciones invasivas. El objetivo del trabajo fue analizar factores de virulencia y marcadores asociados en una cepa de Y. enterocolitica aislada de heces diarreicas humanas. El aislamiento deY. enterocolitica analizado fue incluído dentro del sub-grupo 1A.La determinación de resistencia al suero humano normal e hidrofobicidad de superficie, así como la búsqueda de los genes vir F y ail, resultaron negativos. Se demostró sin embargo producción de enterotoxina a 20 °C y también a 37 °C en condiciones de osmolaridad y pH similares a las del intestino humano. La enterotoxina, presentó reactividadpor la prueba del ratón lactante, aunque no se pudo comprobarpor PCR la presencia del gen yst. Los resultados obtenidos por nosotros, coincidentes con los de otros investigadores, indican que ciertos aislamientos clínicos de Y. enterocolitica del biotipo 1A (“avirulentas”), son capaces de causar enfermedad, probablemente a través de otros mecanismos, distintos a los caracterizados en especies de Yersinia enteropatógenas.

Some serotypes of Yersinia enterocoliticamight causediarrheas and/or invasive infections. The aim of this work was to analyze virulence factors and associated markers in a strain of Y. enterocolitica isolated from human diarrheic feces. The strain analyzed was included in the biotype 1A. The virulence markers determinationas well as the search of the genes vir F and ail,were negatives. However, it was demonstratedenterotoxin production at 20 °C, andat 37 °C in osmolarity conditions and pH similar to the human intestine. The enterotoxin presented reactivity for the infant mouse test, although it could not be proven the presence of yst gene by PCR. The results obtained by us, coincident with those of other investigators,indicated that certain clinical isolates of Y. enterocolitica of the biotype 1A (“avirulent”), could be the etiological agent of the illness trhough other mechanisms of virulence, that would differ from those previously characterized in species of enteropathogenic Yersinia.

Association between polyclonal B cell activation and the presence of autoantibodies in mice infected with Yersina enterocolitica O:3

Eight-week old conventional female Swiss mice were inoculated intravenously with Yersinia enterocolitica O:3. A second group of normal mice was used as control. Five mice from eaeh group were bled by heart puncture and their spleens were removed for spleen cell collection on the 3rd, 5th, 7th, 1Oth, l4th and 21st day after infection. Immunoglobulin-secreting spleen cells were detected by the isotypespecific protein A plaque assay. Total immunoglobulin levels were determined in mouse serum by single radial immunodiffusion and the presence of autoantibodies was determined by ELISA. We observed a marked increase in the total number of cells secreting immunoglobulins of all isotypes as early as on the 3rd day post-infection and the peak of secretion occurred on the 7th day. At the peak of the immunoglobulin response, the total number of secreting cells was 19 times higher than that of control mice and most immunoglobulin-secreting cells were of the IgG2a isotype. On the 10th day post-infection, total serum immunoglobulin values were 2 times higher in infected animals when compared to the control group, and continued at this level up to the 2lst day post-infection. Serum absorption with viable Y. enterocolitica cells had little effect on antibody levels detected by single radial immunodiffusion. Analysis of serum autoantibody levels revealed that Y. enterocolitica infection induced an increase of antimyosin and anti-myelin immunoglobulins. The sera did not react with collagen. The present study demonstrates that Y. enterocolitica O:3 infection induces polyclonal activation of murine B cells which is correlated with the activation of some autoreactive lymphocyte clones.

Virulence of Yersinia spp. strains isolated from non-human sources

1. Strains of Yearsinia enterocolitica, Y. intermedia, Y frederiksenii and Y. kristensenii from non-human sources were examined for virulence factors. Four of these strains were positive for autoagglutination, three were calcium dependent at 37-C, three produced lipase, five had the ability to bind Congo red, six had pyrazinamidase activity, and two had a 42 MDa plasmid. 2. One strain (Y. enterocolitica 0:5) was lethal for mice and had the ability to invade guinea pig eyes and HeLa cells. After inoculation of mice by the intravenous route, this strain was isolated from the cecum. The spleen, liver, kidneys and lymph nodes presented necrosis. After intragastric inoculation, the strain was isolated from all of the organs and tissues examined. 3. Three of the remaining strains invaded HeLa cells but none caused guinea pig conjunctivitis. 4. After intragastric inoculation, all the strains were isolated from the cecum but disappeared between dys 3 and 6. After intravenous infection, three strains produced necrosis of the spleen and were more invasive, eliciting infection in various organs. The remaining strains caused hypertrophy and hyperplasua of Peyer's patches and/or lymph nodes. 5. These results indicate that Y. enterocolitica 0:5 can be considered as virulent as typical European Y. enterocolitica strains. The remaining strains perphaps induce a weak immune response independent of virulence factors

Primer aislamiento y caracterización de Yersinia enterocolitica en heces humanas en Argentina / First isolation and characterization of Yersinia enterocolitica from human feces in Argentina

Por primera vez en Argentina se informa el aislamiento de Yersinia enterocolitica en un caso de diarrea aguda. La cepa fue clasificada como perteneciente al biotipo 4 de Wauters, serotipo O:3, lisotipo VIII. Las pruebas de autoaglutinación, dependencia de Calcio y producción de toxina termoestable resultaron positivas, mientras que no se demostró letalidad por vía oral para el ratón adulto, ni invasividad mediante la prueba de Serény en ratón. Se detectó la presencia de un plásmido de aproximadamente 40 Mdal. La DL50 en ratón lactante fue de 4,1 x 10**6. Estos resultados coinciden con lo observado para la mayoría de las cepas de Yersinia enterocolitica pertenecientes a este sorotipo

Período de infectividade de animais inoculados experimentalmente com Yersinia sp / Period of infectivity of animals challenged by Yersinia sp

Lotes de camundongos suiços convencionais foram inoculados tanto por via intragástrica (IG) quanto por via intravenosa (IV) com Yersinia enterocolitica dos sorotipos 0:3, 0:8 e 0:9 e com amostras de yersinias atípicas. Foi mantido um lote de animais näo inoculados como controle. Verificou-se qual o período de permanência dessas bactérias no intestino dos animais inoculados. Yesinia enterocolitica dos sorotipos 0:3, 0:8 e 0:9, considerados adaptados ao homem, permaneceram no intestino dos animais inoculados por um período muito maior do que as amostras de Yersinia näo adaptadas, quer inoculadas por via intragástrica, quer por via intravenosa

Yersinia pseudotuberculosis Septicemia Report of a Case

Yersinia pseudotuberculosis is known to cause septicemia, mesenteric lymphadenitis enteritis and erythema nodosum. Most of the infections were found in European countries, but none in Korea ti11 now. For the first time in Korea Y. pseudotuberculosis was isolated form a 51-year-old ma1e with liver cirrhosis. The patient showed chills, abdominal pain and diarrhea followed by a comatose state. The organism was isolated from both blood and peritoneal fluid. The isolation and identification were difficult as the organism grew slowly and many of the characteristics were similar to other enteric bacilli. The isolate was susceptible to all antibiotics tested in vitro, but our chemotherapy with ampicillin and kanamycin did not save the patient's life.