Spreading of West Nile virus infection in Croatia

West Nile virus (WNV) is an emerging zoonotic pathogen with rapid global expansion. The virus circulation is confirmed in many countries of Mediterranean Basin and Southern and Central Europe. In our study detection of specific WNV antibodies was performed in horses and cattle sera samples collected from October 2010 to April 2011. Serum samples were randomly taken from different parts of Croatia and tested by IgG and IgM ELISA. Positive serological results were confirmed by virus neutralization assay (VN-assay) and plaque reduction neutralization test (PRNT). Results showed that WNV antibodies were present in 72 out of 2098 horse sera (3.43%) and 3 of 2695 cattle sera (0.11%). The highest seroprevalence was found in Eastern Croatia in counties next to Hungarian, Serbian and Bosnia and Herzegovinian state borders. In Adriatic part of Croatia positive animals were found only in the westernmost county, near Slovenian and Italian borders. Geographic distribution and number of positive horses indicated that WNV is highly present in Croatia and spreading from East to West. However, positive horses in westernmost part of country indicate possible second origin of spreading. Location of serological positive cattle supports the hypothesis that seropositive cattle could be indicators of high WNV activity in the respective geographic regions.     

Mycobacterial infection in goats: Diagnosis and pathogenicity of the organism

Counterimmunoelectrophoresis of serum samples and intradermal tuberculin testing were compared with cultural results for the diagnosis of mycobacterial infection in a goat herd. Only eight of 47 culture-positive animals were not identified by a combination of the other two methods.Typical isolates resembled Mycobacterium paratuberculosis in cultural characteristics and mycobactin dependence but serologically resembled Mycobacterium avium. One isolate was inoculated into guinea-pigs, mice, chickens and calves and, although the infection in guinea-pigs, mice and chickens resembled that of M. paratuberculosis, it did not cause Johne's-like disease in calves.     

猪塞内卡病毒感染的最新研究进展(续1)

主要介绍2015年及以后猪群塞内卡病毒感染情况以及塞内卡病毒感染的流行病学特征。     

Experimental rotavirus infection in three-week-old pigs

Thirteen 3-week-old pigs that had been allowed to nurse for the first 16 to 18 hours after birth were orally inoculated with 1 x 10(6.5) TCID50 of porcine rotavirus. All developed diarrhea, anorexia, and vomiting by postinoculation (PI) hour 30. These signs had abated by PI day 6. Villus blunting in the small intestine was most severe in the jejunum and ileum of pigs euthanatized between PI days 3 and 5. Villi had returned to nearly normal length by PI day 6, although fused villi were seen in a few locations in the distal portion of the jejunum and in the ileum. Virus was detected in the feces of inoculated pigs by isolation in cell cultures and by electron microscopy during the 7-day course of the experiment. There was 1 extraintestinal virus isolation from the lung of 1 pig at PI day 2. Infection and disease developed in the presence of serum-neutralizing antibody obtained by nursing seropositive sows. There was no significant change in neutralizing antibody titers in the 3-week-old pigs over the course of the experiment. In this experimental work, a model to study rotavirus infection in 3-week-old pigs has been developed.     

Experimental Brucella abortus infection in pigs

Sixteen pigs inoculated by the intra-conjunctival, intravenous or subcutaneous routes with Brucella abortus Strain 544 developed a short-lived infection usually accompanied by conjunctival and vaginal excretion of the organism for up to 99 days post-inoculation. Serological tests performed by the agglutination, complement fixation, Rose Bengal plate, antiglobulin, immunodiffusion or ELISA procedures with B. abortus antigens disclosed wide variations in the antibody responses of individual animals. In some cases the serological tests were negative even though the animal was shown to be excreting B. abortus. The intradermal test for delayed hypersensitivity to Brucella antigens gave more consistent results, especially when supported by histological evaluation of the skin reactions.     

Enteric adenovirus infection in pigs.

Intranuclear adenovirus inclusion bodies were identified in intestinal epithelium by histological, electron microscopical or cytological examination of 43 conventionally raised pigs submitted for diagnostic evaluation from 38 farms between August 1981 and January 1983. The affected pigs were usually less than three weeks old, but ranged from five days to 24 weeks of age. The inclusion bodies occurred in the epithelium of ordinary intestinal villi, or more commonly, in the epithelium covering the blunt villi located over Peyer's patches in the ileum. Fifty-three percent of these adenovirus infected pigs had diarrhea. In most of these pigs with diarrhea (19 of 23) however, agents previously established as causes of porcine enteric disease were also identified. Of the pigs with enterocyte inclusion bodies but without diarrhea, the adenovirus infection appeared incidental to the major disease processes in the pigs. These findings suggest that this adenovirus is an asymptomatic and probably incidental infection in conventional farm-raised pigs.     

猪塞内卡病毒感染的最新研究进展(续2)

主要介绍塞内卡病毒的致病性证据、免疫应答和诊断等。     

Actinobacillus suis infection in pigs in Australia

This is the first report of the isolation of Actinobacillus suis in association with significant disease among preweaned pigs in Australia. Sudden deaths occurred in preweaned piglets at one facility and enlarged joints, particularly the stifles and tarsi, occurred at another. Isolates with the biochemical phenotype and apx genotype profile of A suis were cultured from affected piglets. Both facilities were of high health status and one had undergone a recent depopulation, disinfection and sow repopulation process. Reviewing initial reports of A suis disease overseas, it is apparent that outbreaks occurred sporadically in various locations, with disease occurring among the herds involved for some months only, before development of immunity. A suis disease is now considered an emerging disease on high health status farms.