A case of canine multiple inflammatory colorectal polyps treated by endoscopic polypectomy and argon plasma coagulation

Endoscopic polypectomy and argon plasma coagulation (APC) were performed in a refractory case of inflammatory colorectal polyps in a 7-year-old male Miniature Dachshund. Colonoscopic examination revealed a large sessile polyp and multiple diffuse small polyps, localized to the descending colon and rectum. The case showed a poor therapeutic response to prednisolone and cyclosporine. Under anesthesia, piecemeal resections were performed by polypectomy. APC was carried out to cauterize the polyp remnants. After treatment, reduction of the lesions and the improvement in clinical signs were observed, without recurrence of lesions for at least 10 months. Endoscopic treatment by polypectomy and APC is suggested to be a therapeutic option for refractory cases of inflammatory colorectal polyps in dogs.     

Decreased gallbladder emptying in dogs with biliary sludge or gallbladder mucocele

Biliary sludge in dogs is dismissed commonly as an incidental finding. On the other hand, gallbladder mucocele is reported increasingly in dogs and can lead to biliary obstruction or gallbladder rupture. Cholestasis is suspected to play a role in development of sludge and mucoceles, though there are no data in dogs to support this. We investigated gallbladder emptying, a key factor in biliary flow, in dogs with mobile sludge, immobile sludge, or gallbladder mucocele and in healthy controls. Gallbladder ejection fraction estimated by ultrasonography was used as the index of gallbladder emptying. The ejection fraction at 60 min after eating was significantly decreased in all three abnormal groups. Moreover, all dogs with sludge or a mucocele had gallbladder distension. These changes were the greatest in the mucocele group. Thus, biliary stasis occurs not only in dogs with gallbladder mucocele but also in dogs with biliary sludge. Cholestasis may play a role in the pathogenesis or progression of these diseases in dogs.     

No evidence for adaptation of current egg drop syndrome 1976 viruses to chickens

In order to determine whether the current field strains of egg drop syndrome (EDS) 1976 viruses adapt to chickens, we compared the growth efficiency of three Japanese field strains (PA-1/79, AWI/98, Gifu/01) in chicken and duck embryo liver cells. The growth efficiency in chicken or duck embryo liver cells was almost similar in these strains. The fiber protein may carry the type-specific antigen and the hemagglutination activity, and hexon protein may contain the subgroup-specific antigenic determinants. Therefore, the fiber head and hexon loop 1 DNA domain sequences of the six Japanese field strains UPA-1/79, ME/80, 44/81, Kyoto/91, AWI/98, Gifu/01) were compared, but these DNA domains were identical among the six field strains. Our data suggested that the EDS virus was maintained without discernible changes for the last two decades in the field.     

Invasion and colonization of mature apple fruit by Erwinia amylovora tagged with bioluminescence genes

Invasion and colonization of mature apple fruit by a transformant of Erwinia amylovora tagged with bioluminescence genes from Vibrio fischeri was examined. The transformant was deposited on cut surfaces of fruit stems, wounds on the shoulders and calyces, injured fruit-bearing twigs of harvested apple fruit, and cut fruit flesh. After incubation in closed stainless steel or plastic boxes at 25°C, fruit were periodically observed with a two-dimensional luminometer. The presence of the transformant in luminous areas was confirmed by isolating it on selective media. E. amylovora, when deposited in fruit stems: (1) can invade mature as well as immature apple fruit; (2) vertically and horizontally spreads and colonizes along vascular bundles, increasing its population; (3) reaches the calyx end and the flesh just under the exocarp within 3–4 days after inoculation; (4) when deposited on cut fruit flesh, irrespective of its maturity, can easily increase its population and survive 2–4 weeks or more at 25°C; and (5) even at the time of fruit maturation, can migrate within twigs rapidly and reaches the abscission layers between fruit-bearing twigs and fruit stems.     

Characterization of virulence plasmid types in Rhodococcus equi isolates from foals,pigs, humans and soil in Hungary

Rhodococcus equi isolates (204) obtained from foals (lung abscesses, lymph nodes, nasal discharge, rectal swabs) bred in 15 studs located throughout Hungary, isolates from soil samples, lymph nodes of pigs and from lesions of human patients were examined to determine genotypic diversity of virulence-associated plasmids. Isolates were tested for the presence of 15-17 kDa virulence-associated protein antigen (VapA) and 20k Da (VapB) genes by polymerase chain reaction (PCR). Plasmid DNAs were isolated and analysed by digestion with restriction endonucleases for estimation of size and comparison of polymorphisms. Of 146 clinical isolates from foals in 15 studs, 129 (88.3%) gave positive results for the VapA gene, showing a 564 bp product of the expected size in the PCR amplification. Of the 129 clinical isolates from foals, 123 contained an 85 kb type I plasmid and the remaining six contained an 87 kb type I plasmid. Of 48 soil isolates from two horse studs, 26 (54.2%) were positive for VapA gene and contained an 85 kb type I plasmid. Of three pig isolates, one was positive for VapA gene and contained an 85 kb type I plasmid, and the remaining two were positive for the VapB gene, showing a 827 bp product of the expected size in the PCR amplification and were R. equi of intermediate virulence which contained a 95 kb type S5 plasmid. Of the seven human isolates, five were positive for VapB gene by PCR, these were R. equi of intermediate virulence, which contained a 95 kb type S5 plasmid. These results revealed that virulent R. equi strains harbouring a virulence plasmid of 85 kb type I or 87 kb type I, which have been found in clinical isolates from Europe and North and South America, are widespread in Hungary. Furthermore, same intermediately virulence plasmid type was found in both human and pig isolates.     

Gonadosomatic index and testis morphology of common carp (Cyprinus carpio) in rivers contaminated with estrogenic chemicals

To study the effect of estrogenic chemicals on fish, the gonadosomatic index (GSI = [testis weight/body weight] x 100) and testis histology of mature common carp (Cyprinus carpio) from 2 contaminated sites (Ishizu and Wada rivers, Osaka) and a control site were examined between June 1998 and March 2001. The concentration of nonylphenol, bisphenol A and 17beta-estradiol in the Ishizu river was 3-4 times higher than in the Wada river. In the pre-breeding and breeding seasons, there were no significant differences in body weight among carp from the 3 sites, the body weight of Ishizu river carp being significantly lower (p<0.05) than that of Wada river fish only in the post-breeding season. The GSI and testis weight in fish from the Ishizu river were significantly lower (p<0.05) than in control fish during all phases of gonadal cycle and lower than in Wada river fish in the pre-breeding and post-breeding season. No histological abnormalities were found in the testes of the males examined. Histological observation of the testes revealed a delay in the onset of spermatogenesis in fish from the Ishizu river compared with those from the other sites. These results clearly imply that the estrogenic chemicals in the Ishizu river adversely affect the testis development of the fish.     

Long-term excretion of Shiga toxin-producing Escherichia coli (STEC) and experimental infection of a sheep with O157

To investigate a long-term shedding of Shiga toxin (Stx)-producing Escherichia coli (STEC) from sheep, a fifteen-month study for STEC isolation from a sheep, which had yielded STEC before, was attempted. The sheep continued to shed STEC and 39 STEC were isolated. The number of STEC in the feces was estimated at 1.7 x 10(3) per gram. In addition, although Stx1-negative O157 and stx2-encoding bacteriophage were experimentally infected to the sheep, Stx-positive O157 or Stx2- producing bacterial cells were not detected. The genetical and biochemical characterization of those 39 STEC strains showed that all STEC strains produced Shiga toxin 1 (Stx1) and were divided into three classes (I to III). From phylogenetic analysis of their amino acid sequences, class-I STEC was classified as group 1 comprising mainly human STEC, and classes II/III were as group 2 comprising sheep STEC. Our results suggest that STEC easily colonized in sheep and that the sheep continued to shed STEC, showing that sheep might be an important reservoir for human STEC infection.