Nasal nocardiosis in a calf.

Nasal nocardiosis was found in a female Japanese Black calf, 11 months of age. Macroscopically, the posterior half of the left nasal passage was completely obstructed by yellowish brown caseous substance and the mucosa was irregularly thickened. In the brain, a few soft brown foci were present in the olfactory bulb and frontal lobe. Microscopically, there were closely packed granulomas in the nasal cavity and brain. The lesions were characterized by a center of cellular debris surrounded by epithelioid macrophages, neutrophils, lymphocytes and multinucleated giant cells of the Langhans type. Special stains revealed the presence of a large number of filamentous branching gram-positive, partially acid-fast organisms in these epithelioid cells and giant cells, and in cellular debris.

Characteristics of Staphylococcus aureus isolated from peracute, acute and chronic bovine mastitis.

Fifty-eight Staphylococcus aureus strains isolated from bovine mastitic milk at 27 dairy farms in Japan during the period from November 1988 to May 1989 were examined for their productivity of virulence associated factors. The positive rates of the total isolates for various virulence factors were as follows: toxic shock syndrome toxin-1 (TSST-1, 27.6%), staphylococcal enterotoxins (SEs, 34.5%), alpha-haemolysin (74.1%), beta-haemolysin (65.5%), delta-haemolysin (12.1%), DNase (100%), egg-yolk factor (25.9%), clumping factor (70.7%) and protein A (58.6%). All of S. aureus isolates from peracute mastitis produced TSST-1, SEC, alpha-haemolysin and beta-haemolysin. While none of clumping factor and protein A were detected among peracute isolates, these factors were produced at a relatively high frequency by isolates from chronic mastitis. In coagulase typing, the most predominant type was VI (36.2%), and types IV, V and VIII were not observed. TSST-1 positive isolates showed interesting characteristics which all of the isolates produce both SEC and coagulase type VI but lack egg-yolk factor, clumping factor and protein A except for one isolate. We could infer that TSST-1 and SEC contribute to bovine mastitis, especially to peracute mastitis from the present study.

4'-galactooligosaccharide affects sodium and potassium metabolism in rats.

The effect of different levels (0, 10 and 20%) of O-beta-D-galactopyranosyl-(1-4)-O-beta-D-galactopyranosyl-(1-4)-D- glucose (4'-GL) on the bioavailability of sodium and potassium was studied in 18 male rats. Three 3-d metabolic balance studies were conducted during the 62-d feeding trial. These were between d 30 and 32 (first period), 45 and 47 (second period) and 60 and 62 (third period). Growth and food intake were not significantly different (P less than 0.05) between the control group and the 4'-GL-fed groups. In rats fed 10 and 20% 4'-GL diet, the fecal sodium excretion was significantly greater (P less than 0.05) in all three balance periods. Fecal potassium excretion was significantly greater (P less than 0.05) in the 10% 4'-GL-fed group in the second balance period and the 20% 4'-GL-fed group in all balance periods relative to the control group. Although not statistically significant, rats in the 4'-GL-fed groups exhibited a tendency for lower sodium retention and higher potassium retention compared with the control group. The cecal weight of rats in both 4'-GL-fed groups was significantly heavier (P less than 0.05) than that of the control group at the end of study. Sodium concentration in the cecum was significantly lower (P less than 0.05) in the 20% 4'-GL-fed group relative to the other groups.

[The effect of cellulose and glucomannan on the absorption of lead in rats].

The effect of two different fibers on lead (Pb) absorption was investigated during two 3-day balance-study periods (day 15th to 17th and 30th to 32nd) of a 32-day feeding course in young rats. Young rats were fed for 32 days diets containing Pb (200 mg/kg diet), with or without the addition of 10% cellulose or glucomannan. The following results were obtained: 1) The total fecal Pb content was significantly increased (p less than 0.05) in the Pb + cellulose group than in the Pb alone group during both balance-study periods. However, there was no significant difference between the Pb alone group and the Pb + glucomannan group. 2) Lead retention was significantly lower (p less than 0.05) in the Pb + cellulose group than in the Pb alone group during both balance-study periods. However, there was no significant difference observed between the Pb alone group and the Pb + glucomannan group. 3) Rats fed on the Pb + glucomannan diet had a significantly heavier (p less than 0.05) cecum and large intestine than rats fed on the other two diets. 4) The concentration of Pb in the cecum was significantly lower (p less than 0.05) in the Pb + cellulose group than in the other two groups. These results indicate that cellulose supplementation reduced the retention of Pb, while glucomannan supplementation had no significant effect on the retention of Pb.

[Effects of sodium chloride on destruction of microorganisms by microwave heating in potatoes].

To assess the destructive effect of different sodium chloride concentrations (0, 0.3, 1.5, and 3%) on microorganisms with microwave heating, strains of Vibrio parahaemolyticus, Staphylococcus aureus, Salmonella enteritidis, Escherichia coli and Bacillus cereus were used to inoculate a mashed potato preparation. After microwave heating for 1 min at 800 W, resulted in temperatures and rate of destruction of bacteria significantly higher (p less than 0.05) in the core than on the surface of mashed potato when no salt was added. Except for B. cereus, microorganisms inoculated into mashed potato, with no added salt, could be completely destroyed by 2 min of microwave heating. Core temperatures and rate of destruction of microorganisms in the mashed potato decreased significantly (p less than 0.05) with increase in concentration of added salt. The results also indicate that bacterial species differ in their susceptibility to microwave inactivation. In particular, S. aureus, which exhibited a level of survival that was greater than that of any other species tested here, seemed notably resistant to microwave treatment for 2 min while V. parahaemolyticus was highly susceptible.