Zhonghua Minguo wei sheng wu xue za zhi = Chinese journal of microbiology最新文献

A strain of Thermoactinomyces sp., TM9208, isolated from a soil sample in the Taipei area showed antagonistic activity to Gram positive bacteria but not to the Gram negative on the potato extract agar plate by the cross streaking method. The strain showed strong starch hydrolysis, beta type of hemolysis, brownish yellow growth on the potato extract agar and green on the nutrient agar. Its aerial mycelium, white to grayish white, was long and straight with short branches. The spores are single and have smooth surface. It is a good utilizer of starch, maltose and cellobiose as carbon source, but utilizes dulcitol, salicin, sucrose, rhamnose and sorbitol poorly.

Serum and urine were collected from 58 patients with nephrotic syndrome. Immunoglobulins (IgA, IgG and IgM), complement (C3) and transferrin levels were measured by single radial immunodiffusion. The extent of glomerular injury was estimated by determining the selectivity of proteinuria. The relationship between the severity of glomerular damage and serum concentrations of immunoglobulins and complement was assessed. Higher IgM and lower IgG serum concentrations were found in nephrotic patients than in normal controls (157 +/- 108 mg+ vs 127 +/- 38 mg% for IgM, 929 +/- 537 mg% for IgG). The difference was statistically significant (p less than 0.05 for IgM, p less than 0.001 for IgG). No correlation was present between the selectivity of proteinuria and serum levels of IgA, IgM, IgG or C3. The results indicate that abnormalities in humoral components of the immune system are present in nephrotic patients and are probably related to a basic immunological defect in the patients rather than to the severity of glomerular damage.

In the routine bacteriological examination of 8,423 clinical specimens, 906 strains of anaerobic bacteria were isolated at National Taiwan University Hospital between April 1972 and April 1976. Most of the strains were isolated from sites allied to the abdominal cavity and genito-urinary tract. Bacteroides fragilis was the most commonly isolated pathogen. The minimal inhibitory concentrations of 10 different antimicrobial agents to 74 clinical isolates of B. fragilis were determined by an agar dilution method under anaerobic conditions. The percentages of the strains susceptible to clindamycin, carbenicillin, ampicillin, cephalothin, and tetracycline were 98, 92, 75, 41 and 5%, respectively. Rifampin, metronidazole and chloramphenicol also inhibited all isolates in clinically attainable concentrations. All strains were resistant to the aminoglycoside antibiotics, kanamycin and gentamicin.

Cell extracts obtained from KB cells and 5 human lymphoblastoid cell lines including 2 from Burkitt's lymphoma (P3HR-1 and Raji), one each from nasopharyngeal carcinoma (no.223), acute lymphatic leukemia (MOLT-4) and a healthy person (NC-37) were tested for their inhibitory effects on the growth of herpes simplex virus type-1 (HSV-1) in green monkey kidney (GMK) cells by the plaque titration method. The relationship between the production of HSV-1 inhibitors and the degree of Epstein-Barr virus (EBV) genome repression in lymphoblastoid cells were also examined. Among the cell lines used P3HR-1 and no.223 cells produced a few EBV particles, Raji and NC-37 cells contained EBV genomes only, and MOLT-4 as well as KB cells were EBV genome-negative. The results revealed that P3HR-1 cell extract showed a tendency to inhibit HSV-1 growth in GMK cells but the other 4 lymphoblastoid cell lines and KB cells did not produce HSV-1 inhibitors, indicating that EBV genomes governing the formation of EBV structural antigens were not related to the production of HSV-1 growth inhibitors. The extracts from MOLT-4 cells, which are only a T lymphocyte cell line used in this study, stimulated HSV-1 growth in GMK cells significantly.

The F'lac+ episome of Escherichia coli origin was transferred by conjugation with frequencies of 10(-7) to 10(-5) from Erwinia amylovora to 14 out of 15 Salmonella typhimurium trp female parents. The chromosomal trp+ genes were transferred with frequencies of 10(-7) to 10(-6) only to one trpB and 2 trpD female parents, which have a point mutation in the 2nd and fourth structural genes, respectively, of the tryptophan operon. The transferred male trp+ genes became integrated at the selected sites of the S. tryphimurium chromosome. The resulting Trp+ hybrids were phenotypically stable, lacked a cryptic trp allele selected against in the female parent, had high genetic homology values in the tryptophan region, and showed biochemical reactions and pathogenicity typical of S. typhimurium.

For understanding some biological properties of TT-1 cell line established in our laboratory in 1962, its viral susceptibility and the changes in chromosomes related to mycoplasma contamination were studied. TT-1 cells were susceptible to the infection of picorna (Polio type 1, Coxsackie B1 and Echo type 2), measles, Newcastle disease, herpes simplex (type 1), adeno (type 12) and vaccinia viruses. Contamination of TT-1 cells with Mycoplasma hominis was treated successfully with bottromycin A2 (50 microgram/ml). The chromosomes of the cells ranged from 52 to 55 in number and two additional minute chromosomes were found in the cells contaminated with the mycoplasma. However, after treatment with bottromycin, these two minute chromosomes disappeared.