Molecular cloning, nucleotide sequence, and expression of genes encoding a polycyclic aromatic ring dioxygenase from Mycobacterium sp. strain PYR-1.

Mycobacterium sp. strain PYR-1 degrades high-molecular-weight polycyclic hydrocarbons (PAHs) primarily through the introduction of both atoms of molecular oxygen by a dioxygenase. To clone the dioxygenase genes involved in PAH degradation, two-dimensional (2D) gel electrophoresis of PAH-induced proteins from cultures of Mycobacterium sp.

Cloning, expression, and characterization of the katG gene, encoding catalase-peroxidase, from the polycyclic aromatic hydrocarbon-degrading bacterium Mycobacterium sp. strain PYR-1.

A 81-kDa protein from Mycobacterium sp. strain PYR-1 was expressed in response to exposure of the strain to the polycyclic aromatic hydrocarbon pyrene and recovered by two-dimensional gel electrophoresis. The N-terminal sequence of the protein indicated that it was similar to catalase-peroxidase.

The potential oncogenic activity of influenza A virus in lungs of mice.

Adult male CD1 mice were inoculated with chicken egg-propagated influenza type A/PR8/34 virus. Fully developed pulmonary pneumonia was found 7 d after the infection. In addition to the pneumatic condition, pronounced thickening of the bronchiolar epithelium denoting hyperplastic and dysplastic transformation of the epithelial cells were also observed.

Lethal synergism induced in mice by influenza type A virus and type Ia group B streptococci.

Intranasal inoculation of CD-1 or BALB/c mice with low doses of influenza A/PR8/34 (HON1) virus followed 48 h later by intranasal inoculation of low doses of type Ia group B streptococci effected a lethal synergism. At a constant input dose of virus, a direct relationship between input dose of bacteria and percent mortality was observed; the converse was also true. An inverse relationship between input dose of group B streptococci, but not input dose of virus, and mean time to death was observed in CD-1 but not in BALB/c mice.

Group B streptococcal type Ia sepsis in mice after intranasal inoculation and the effect of infection on lungs.

The intranasal inoculation of adult mice with saline suspensions of virulent group B streptococci serotype Ia resulted in septicemia which was lethal. Decreasing the inoculation dose of streptotocci increased the time required for their appearance in the blood and the mean time to death of the mice. Before the appearance of septicemia, the number of organisms in the lungs decreased to about 1% of the inoculation dose, and the majority could be recovered by lavage of the lungs through the trachea.

Adult mice as a model for early onset group B streptococcal disease.

The intravenous inoculation of adult mice with virulent group B streptococci serotype Ia resulted in fulminating sepsis with extensive colonization of the lungs and kidneys. The time course of the infection lasting 24 to 40 h, extensive pulmonary colonization, and resistance of the type Ia organism to phagocytosis in the absence of specific antibody suggest that mice are an appropriate model for the study of early onset streptococcal infection of human neonates.

The effect of two isomeric octadecenoic acids on the lipid metabolism and growth of Novikoff hepatoma cells.

The origin and metabolism of octadecenoic acid (18 : 1) was examined in intact Novikoff rat hepatoma cells by using labeled precursors and two isomeric octadecenoic acids which differed in their abilities to stimulate cell growth in a serum-free medium. The isomers (ci-6-18 : 1 and cis-9-18 : 1) were measured in the cellular lipid by ozonolysis and reduction of the ozonides. The results indicate that the 18 : 1 fatty acid accumulated in the cell lipid by uptake of the preformed acid from the medium.