Characteristics of Staphylococcus intermedius isolates from diseased and healthy dogs

Staphylococcus intermedius isolates from diseased and healthy dogs were examined for production of extracellular enzymes and toxins, and phage patterns. There were no significant differences between the two groups of isolates in the production rates of DNase, protease, lipase, gelatinase, hyaluronidase, hemolysins, protein A, and TSST-1, or in phage patterns. But the production rate of enterotoxins in isolates from diseased dogs was significantly higher than that in isolates from healthy dogs. PFGE analysis was performed with isolates from different body sites in individual dogs. In 3 of 6 healthy dogs, identical PFGE patterns were seen in isolates from the nares, external auditory meatus or skin. The remaining 3 dogs yielded isolates of different patterns. In 4 of 6 diseased dogs, identical patterns were seen in isolates from lesions as well as from the other normal sites.     

Gizzard spirurid nematode Acuaria skrjabini in Japanese tree sparrows and a gray starling from Tokyo

Gastrointestinal helminths were collected from 49 Japanese tree sparrows (Passer montanus saturatus) in Tokyo, Japan. In 16 sparrows, 1-9 (average, 3.5) gizzard spirurid nematodes (Acuaria skrjabini Ozerskaya, 1926) were found embedded in the mucosa of the gizzard. In addition, Capillaria sp., Platynosomum passeri Yamashita et Tsumura, 1962, and a hymenolepidid cestode were collected from 1, 2, and 1 sparrows, respectively. A sexually mature A. skrjabini female and 3 males were found also in a young gray starling (Sturnus cineraceus) that was found dead in the same area after failure to leave the nest. Starlings are a new host record for this spirurid species. Until this study, this gizzard spirurid species has not been recorded in this country or the Far East region.     

Taenia taeniaeformis larval product induces gastric mucosal hyperplasia in SCID mice

The effects of intraperitoneal implantation of Taenia taeniaeformis larvae and inoculation of in vitro larval products on gastric mucosa of SCID mice were investigated in this study. Mice surgically implanted with T. taeniaeformis larvae developed slight and moderate gastric hyperplasia. When in vitro cultured T. taeniaeformis larval excretory-secretory (TtLES) products containing 1 mg of protein were injected daily into mice, they caused gastropathy after 5-7 days. Mice injected daily with 0.5 mg of TtLES products also showed slight gastric hyperplasia after day 14 and 28. The gastropathy was characterized by reduction of both parietal and zymogenic cell number and increased number of alcian blue-periodic acid Schiff (AB-PAS)-positive cells and by two-fold extension of proliferative zone of gastric units. Larval implantation demonstrated a more potent effect in inducing gastropathy than did in vitro larval culture products. Significant decrease in number of parietal cells with concomitant increase of proliferative zone and AB-PAS-positive cell number indicated their important roles in inducing the hyperplastic lesion. Similarities with other gastropathies indicated that there is a common fundamental regulatory mechanism involved, and that the host response may not be specific to parasites. Present study validated the induction of gastric mucosal hyperplasia by larval ES products of T. taeniaeformis. This proved the hypothesis of previous studies suggesting the role of larvae-derived products in inducing gastric mucosal hyperplasia in T. taeniaeformis-infected rats.     

Effect of different methods for conserving rice grain on in situ ruminal degradation and in vivo nutrient digestion and rumen fermentation in steers

We investigated the effects of different rice conservation techniques on in situ ruminal degradation and in vivo nutrient digestibility and rumen fermentation in steers. Raw rice grain was dried before crushing (DRY), ensiled after crushing (ENS‐A), or ensiled before crushing (ENS‐B). Six ruminally cannulated steers were used in a replicated 3 × 3 Latin square design with three dietary treatments: diets containing DRY, ENS‐A, or ENS‐B at 36% of the dietary dry matter. The in situ rapidly degradable fraction and effective ruminal degradability were higher for ensiled rice than for DRY, and higher for ENS‐A than for ENS‐B. The ruminal pH was lower and the lactic acid and total volatile acid concentrations were higher for the steers fed ensiled rice than those fed the DRY diet, but a treatment effect was not observed in the comparison between ENS‐A and ENS‐B. The whole‐tract digestibility of crude protein and ether extract was improved when the rice grain was ensiled, but there were no differences in nutrient digestibility between ensiling methods. These results show that ensiling treatment can be a strategy to improve the nutrient value of rice grain, but the ensiling method has little impact on in vivo digestion.     

Genetic and pathobiological characterization of bovine viral diarrhea viruses recently isolated from cattle in Japan

The 475 strains of bovine viral diarrhea virus (BVDV) isolated from cattle in 12 prefectures of Japan in the last 7 years were phylogenetically classified as BVDV-1 or BVDV-2 on the basis of the nucleotide sequence of the 5'-untranslated region. BVDV-1 strains were further subtyped as 1a (101 strains), 1b (163), 1c (128), 1j (3), and So CP/75-like (1), and all of the 79 BVDV-2 strains belonged to subtype 2a. These 2a BVDVs contain two isolates that had high nucleotide identities with those of highly pathogenic BVDV-2 strains reported in North America (Pellerin et al., 1994). However, acute infection with severe mortality like North American outbreak was not observed and most of the present BVDV-2 strains were isolated from persistently infected (PI) cattle showing mild or no clinical sign. Moreover, it was revealed that 61.5% of the 39 PI cattle with cytopathogenic BVDVs did not show typical mucosal disease and 54.6% of the 405 PI animals only with non-cytopathogenic BVDVs were apparently healthy. The present results indicate that the prevention of the infection with an appropriate vaccine and active surveillance covering healthy cattle are required for the control of BVD.