جستجوی مقالات مرتبط با کلیدواژه "yersiniosis" در نشریات گروه "دامپزشکی"

Yersiniosis is known as one of the most prevalent bacterial diseases in fish, which causes high mortality and economic losses in cultured fish farms every year.

The present study was conducted to investigate the changes in hematological indices and gut histopathology in Caspian roach (Rutilus caspicus) exposed to Yersinia ruckeri.

60 Caspian roach broodstock with an average weight of 63.4 ± 2.1 g were divided into three groups (with two replicates for each group), including one treatment, one positive control, and one negative control groups. The treatment group was intraperitoneally injected with Yersinia ruckeri bacterium at a dosage of 3.8 × 107 cell/fish. The positive group just received normal saline (0.9 % NaCl) via intraperitoneal injection. No injection was performed in the negative control group.

Symptoms appeared on the fourth day after exposure and 20 % of the fish in the treatment group died 5 days after the challenge. Cumulative mortality reached 53 % on day 9 after the challenge.  According to hematological analysis, the challenge with Yersinia ruckeri led to a significant increase in white blood cell counts (WBC) compared to the control groups. Moreover, 10 days following exposure, the treatment group experienced hypochromic macrocytic anemia. Gut histopathology was characterized with necrosis and detachment of intestinal epithelial cell and inflammatory cells infiltration in the treatment group.

Based on the obtained results herein, Yersinia rackeri can cause acute disease in Caspian roach; therefore, preventing and controlling this disease is essential for these fish in infected regions.

Currently, global use of prebiotic compounds has increased considerably. This study aims to analyse the effect of complementing the rations of rainbow trout with different concentrations of Celmanax® prebiotic, which contains Saccharomyces cerevisia associated compounds with Mannan-oligosaccharide on gill and liver histology during the growing period and experimental challenge with yersiniosis. Four concentration levels of prebiotic (0, 0.1, 0.5 and 1%) were mixed into fish feed pellets. The fish (with mean body weight of 19.08±1.45 gr) were fed a supplemented commercial diet for 60-days.On day 60 of the study, experimental yersiniosis was induced in all treatment groups by intraperitoneal injection of bacterial suspension. Tissue samples were taken on days 0, 30 and 60 and also after induction of experimental yersiniosis. The results showed that complementing rainbow trout rations with different concentrations of Celmanax® improved the gill and liver injuries on days 30 and 60 of the study. The best tissue effects in the growing period were observed in treatment groups which received 0.1% and 0.5% of the prebiotic respectively, and after experimental challenge with yersiniosis, the lowest lesions of liver and gill pathology were seen in the treatment group fed with 0.1% prebiotic which was significantly different (p<0.05) from all other treatments. According to the results of this study, adding Celmanax® to rainbow trout diet at 0.1% concentration improves tissue parameters during breeding period and decreases tissue lesions when faced with yersiniosis.

Yersiniosis is one of the most important fish bacterial diseases cause by of Yersinia ruckeri. Isolation, characterization and of protein profile of Yersinia ruckeri were studied in some affected rainbow trout farms in Iran. The kidney and spleen samples from 16 fish farms in Charmahal-va-Baakhteyiari, Mazandaran and Qazvin provinces were cultured on blood agar at 220C for 48 hours and the grown bacteria were characterized by phonotypical and molecular studies. Biochemical and molecular works resulted in identification of six isolates of Yersinia ruckeri. The whole proteins of the six recovered isolates of Yersinia ruckeri subjected to sodium dodecyl sulphat - poly acrylamide gel electrophoresis (SDS-PAGE) showed that the protein profiles of 5 isolates were highly similar to each other and only one isolates showed 5% difference with other isolates. Therefore, these results show that some farmed trout in Iran are affected by Yersinia ruckeri isolates of high homology. Also, such results could be useful for protection aims such as immunization.

Yersinia ruckeri is the causative agent of yersiniosis, one of the most serious bacterial diseases in rainbow trout culture industry with high economic losses. Outbreaks of clinical forms of the disease have been considerable in Iranian rainbow trout farms. This study was aimed to evaluate the molecular epidemiology of yersiniosis caused by Y. ruckeri, affected farmed trout in Mazandaran (22 farms), Tehran (18 farms), Lorestan (6 farms) and Zanjan (6 farms) provinces during 2011to 2013. Furthermore, biotyping and sequencing of the recovered Iranian isolates was performed. Totally, 34 Y. ruckeri isolates were identified in Mazandaran (14 farms), Tehran (17 farms) and Zanjan (3 farms). All isolates were strongly positive in latex bacterial agglutination using monoclonal antibody to Y. ruckeri. Also, all isolates were identified as biotype 1 showing motility and having lipase activity. In addition, all isolates showed high sequencing similarity (99%). These biochemical, serological and molecular studies all together confirmed the increasing distribution of yersiniosis casued by Y. ruckeri biotype 1 in farmed trout in Iran and so require preventive measures.

Yersiniosis or Enteric Red Mouth Disease (ERM) is an infectious bacterial disease that causes mortality and alsoeconomical loss in Salmonid aquaculture industries. In recent years, the yersiniosis has been expended in differentpart of Iran and there are reports about it in most of the Rainbow trout farms in Iran. Mazandaran Province hasthe second grade of Rainbow trout production in Iran and the most production of Mazandaran is in Haraz Zone(East of Mazandaran). There for, because of the importance of Yersiniosis and also high production of Rainbowtrout in this part of Mazandaran, factors influencing on yersiniosis incidence was evaluated. Samplings were donefrom July 2011 to August 2012 and in 10 rainbow trout farms. Overall, liverand kidney of 1200 fsh with clinicalsigns (410 samples) either without clinical signs (790 samples) were Cultured in TSA agar (Merck Co. Germany).Then Microbial cultures were transformed to laboratory (Ecology of Caspian Sea Institute, Health and Aquaticanimal’s Disease branch) and Bacteria were identifed using gram staining and biochemical tests. In addition, thewater of farms was sampled for calculating Bacterial total count and also measuring some of the physicochemicalparameters (Temperature, DO, pH, Nitrate, Nitrite, NH4+ and TDS) of water. Result showed that decrease oftemperature and increase of pH had the most effects on incidence of yersiniosis . Also, it was demonstrated thatfrom 410 diseased fsh and 790 fsh without clinical signs, 20% and 10% suffered from yersiniosis respectively.