Urease-producing species of intestinal anaerobes and their activities.

Urease activities of anaerobic bacteria that constituted predominant gut flora were examined. It was demonstrated that some strains of Eubacterium aerofaciens, E. lentum, and Peptostreptococcus products produced urease. They were the most numerous species in human feces. All strains of Bifidobacterium infantis and some strains of Bacteroides multiacidus, B. bifidum, Clostridium symbiosum, Fusobacterium necrophorum, F. varium, Lactobacillus fermentum, Peptococcus asaccharolyticus, and P. prevotii produced urease. The optimum pH of the Lactobacillus urease was found to be 4.0, whereas the pH value of B. multiacidus urease was 8.0.     

Histochemical characteristics of glycoproteins in the bile duct system of mice immunized with swine serum

The bile duct system of BALB/c and DDY mice, which were immunized with swine serum (SS) or not, was examined histochemically. Biliary epithelial cells of the SS-treated BALB/c mice, which were positively stained with periodic acid-Schiff (PAS) and had binding sites of Dolichos biflorus (DBA), were thought to secrete neutral glycoproteins with terminal N-acetyl-D-galactosamine residues. Those of the SS-treated DDY mice were however negatively or weakly stained with any histochemical stainings. On the other hand, glandular epithelial cells of the SS-treated mice of both strains, which were positively stained with high iron diamine-alcian blue (HID-AB) and had binding sites of DBA, Griffonia simplicifolia-II (GS-II), Ulex europaeus-I (UEA-I), and Triticum vulgaris (WGA), were thought to secrete glycoproteins with terminal sialic acid residues. Biliary and glandular epithelial cells of the normal mice contained only a small amount of glycoproteins showing similar histochemical characteristics to those in the SS-treated BALB/c mice. BALB/c mice immunized with SS were thought to be very useful for the investigation of production and secretion of glycoproteins in the bile duct system as well as being good model of bile duct disease.     

Development of spontaneous tongue calcification and polypoid lesions in DBA/2NCrj mice

Calcified tongue lesions were observed in 4- to 8-week-old DBA/2NCrj mice, the highest frequency being reached at 6 weeks of age. Calcification was initially observed in the superficial longitudinal muscles and these lesions were distributed segmentally under the dorsolateral mucous epithelium in the middle portion of the lingual body. After calcification, marked inflammation was observed in the same lesion. Finally, the swollen tissue elevated the covering mucous epithelium and produced polypoid lesions.     

MutMap+: Genetic Mapping and Mutant Identification without Crossing in Rice

Advances in genome sequencing technologies have enabled researchers and breeders to rapidly associate phenotypic variation to genome sequence differences. We recently took advantage of next-generation sequencing technology to develop MutMap, a method that allows rapid identification of causal nucleotide changes of rice mutants by whole genome resequencing of pooled DNA of mutant F2 progeny derived from crosses made between candidate mutants and the parental line. Here we describe MutMap+, a versatile extension of MutMap, that identifies causal mutations by comparing SNP frequencies of bulked DNA of mutant and wild-type progeny of M3 generation derived from selfing of an M2 heterozygous individual. Notably, MutMap+ does not necessitate artificial crossing between mutants and the wild-type parental line. This method is therefore suitable for identifying mutations that cause early development lethality, sterility, or generally hamper crossing. Furthermore, MutMap+ is potentially useful for gene isolation in crops that are recalcitrant to artificial crosses.     

Staphylococcus schleiferi subsp. coagulans subsp. nov., isolated from the external auditory meatus of dogs with external ear otitis

A new subspecies, Staphylococcus schleiferi subsp. coagulans, was isolated from the external auditory meatus of dogs suffering from external ear otitis and is described on the basis of studies of 21 strains. Phenotypic studies showed that these strains are more closely related to Staphylococcus intermedius than to other staphylococci, but DNA hybridization studies indicated that they are closely related to Staphylococcus schleiferi N850274T. On the basis of biochemical distinctiveness (positive test tube coagulase test and different carbohydrate reactions) and the etiological importance (frequent isolation from otitis specimens from dogs) of these strains, we propose to classify them as a subspecies of S. schleiferi. The strains of this new subspecies are coagulase tube test, beta-hemolysin, and heat-stable nuclease positive but clumping factor negative. A simple scheme for the differentiation of S. schleiferi subsp. coagulans from the other coagulase-positive staphylococci is presented. The type strain is GA211 (= JCM 7470).     

Effect of Corn Fiber on Fecal Flora,Properties of Feces, β-Glucuronidase,and Levels of Serum Lipid in Healthy Men

The effects of corn fiber intake (6 and 12 g/day for 10 days) on the fecal weight, moisture, neutral detergent fiber (NDF), pH, microflora and β-glucuronidase activity, and on the serum lipids were investigated in five healthy men. Fecal weight and NDF increased depending on the fiber dose, whereas fecal moisture decreased. No remarkable change in fecal microflora was observed. Fecal β-glucuronidase activities (per gram of wet feces and daily output) were dose-dependently decreased by corn fiber intake. The levels of serum lipids did not change. These results show that corn fiber intake yielded an increase of fecal weight and a reduction of fecal β-glucuronidase activity.     

Isolation of Clostridium difficile from various colonies of laboratory mice

An attempt was made to isolate Clostridium difficile from a total of 565 mice from nine different conventional mouse colonies and six different specified-pathogen-free mouse colonies. C. difficile was isolated from all the conventional colonies but from none of the specified-pathogen-free colonies. Ampicillin injected intraperitoneally increased the isolation rate of C. difficile from mouse faeces to 63.6% compared with 19.4% from untreated mice.