Sepsis due to Yersinia enterocolitica in an aborted equine fetus: case report / Sepse por Yersinia enterocolitica em um feto equino abortado: relato de caso

Yersinia enterocolitica is a bacterium with zoonotic potential and there are no previous records of this bacteria being isolated from aborted foals. This report aims to describe a case of sepsis due to Y. enterocolitica in a seven month old aborted equine. The fequinoetus was submitted to necropsy and samples of all the organs were collected for the histological exam. Samples of liver, lung, placenta, and stomach contents were collected for bacterial culture. Macroscopically, the liver was enlarged with yellowish heterogeneous color, heart with pale myocardial areas; lungs not collapsed, heavy and shiny, thickened umbilical cord covered with fibrin and pus. Histopathologically, there was moderate multifocal necrosuppurative myocarditis and thrombosis, moderate diffuse suppurative bronchopneumonia, mild multifocal fibrinonecrotic hepatitis, and moderate diffuse necrosuppurative omphalitis with intralesional bacterial myriads and thrombosis. Mild multifocal suppurative placentitis, nephritis, myositis, cystitis, and dermatitis were also observed, in addition to mild diffuse lymphoid rarefaction. The microbiological evaluation identified Y. enterocolitica in the liver, lung, and stomach fluid. This is the first report of sepsis due to Y. enterocolitica causing an abortion in a horse. This bacterium has zoonotic importance; therefore, it should be investigated in abortion in this species, serving as a differential diagnosis in reproductive disorders.(AU)

Yersinia enterocolitica é uma bactéria com potencial zoonótico, e não há informações desse agente como causa de abortamento em equinos. O objetivo deste relato é descrever um caso de sepse por Y. enterocolitica em um feto equino abortado aos sete meses. O feto foi submetido à necropsia, e amostras de todos os órgãos foram processadas para histopatologia. Para microbiologia, foram coletadas amostras de fígado, pulmão, placenta e conteúdo estomacal. Macroscopicamente, observou-se fígado aumentado com coloração amarelada heterogênea; coração com áreas pálidas no miocárdio; pulmões não colabados, pesados e brilhantes; e cordão umbilical espessado e recoberto por fibrina e pus. Na análise histopatológica, havia miocardite necrossupurativa multifocal moderada e trombose, broncopneumonia supurativa difusa moderada, hepatite fibrinonecrótica multifocal discreta e onfalite necrossupurativa difusa moderada com miríades bacterianas intralesionais e trombose. Observou-se também placentite, nefrite, miosite, cistite e dermatite supurativa multifocal discreta, além de rarefação linfoide difusa discreta. A avaliação microbiológica identificou Y. enterocolitica no fígado, no pulmão e no líquido estomacal. Este é o primeiro relato de sepse por Y. enterocolitica causando abortamento na espécie equina. Essa bactéria tem importância zoonótica, portanto deve ser investigada em casos de abortamento nessa espécie, servindo como diagnóstico diferencial em tal distúrbio reprodutivo.(AU)

Study of efficacy of vaccination against yersinosis in rainbow trout using local strains of Yersinia ruckeri

Outbreak and development of yersiniosis in rainbow trout farms in Iran has caused a serious problem over the last years. The purpose of this study was to evaluate the efficacy of immersion vaccination with Yersinia ruckeri in rainbow trout. Prior to antigen preparation, the phenotypic, molecular and serological features of a number of Yersinia ruckeri isolates obtained from affected trout farms were studied. The virulent of these isolates were then evaluated using intra peritoneal injection route. Trout were vaccinated by immersion route [3 min at 12 °C] using Yersinia ruckeri bacterin of the virulent strains. The efficacy of vaccine antibody titer within 2, 4, 6, 8 and 10 weeks post vaccination were evaluated using relative percent survival. The phenotyping, serological and molecular studies have led to identification of 8 isolates of Yersinia ruckeri and all the isolates produced bands 409 bp, which is indicative of Yersinia ruckeri. In pathogenicity test 3 isolates caused above 50% mortality, while 5 isolates reached 16%. The RPS of vaccinated fish reached 72.7, 80, 80, 82.2 and 83.3% within 2, 4, 6, 8 and 10 weeks post vaccination, respectively. In the other words, the mortality level in vaccinated groups was in range of 10-20% within 10 weeks post vaccination, while those of control group was in range 56.7 - 73.3% [p<0.05] .The lowest and the highest antibody titers in immunized groups were 32 +/- 4.50 and 164.57 +/- 9.37 respectively, obtained after 4 and 10 weeks of immunization, whereas the control group had no measurable titer of antibody. The results of this study clearly show that this vaccine can remarkably protect the trout from yersiniosis outbreaks inside Iran

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.

Studies on enteric red mouth disease [ERM] among freshwater fish

Six isolates of Yersinia ruckeri [Y. ruckeri], the aetiological agent of Enteric Red Mouth [ERM] disease were recovered from healthy and septicaemic Oreochromis niloticus [O.niloticus] fish collected from River Nile at Giza Governorate. The isolate No. 2 was the most pathogenic strain of the six isolates, causing high mortality percent among the experimentally infected fish under different stress conditions, namely overcrowdness, external parasitism and transportation with mortality rates of 83%, 70% and 60% in O. niloticus respectively. The mortality rate was 100% in intraperitoneally inoculated O. niloticus and Clarias lazera [C. lazera], while it was 40% in subcutaneously inoculated C. lazera. The main recorded clinical signs in experimentally infected fishes were general septicemia and redness of the eyes. The in-vitro antibiotic sensitivity test for Y. ruckeri isolates revealed their high sensitivity to oxytetracycline