Further environmental factors affecting the antigenicity of Trichophyton rubrum

Biochemical determinations performed on ammonium sulfate soluble and insoluble fractions of crude mycelial extracts ofTrichophyton rubrum indicated that these antigens were either carbohydrates or carbohydrates with peptide side chains. The antigens contained considerable amounts of galactose and mannose.Gel filtration techniques proved to be effective in separating these antigens. One antigen had a molecular weight greater than or equal to 2.0 × 10⁶. A smaller, more reactive antigen was also found; however, the elution time of this antigen varied with the concentration of dextrose in the medium.Quantitative precipitation tests used to differentiate the serological reactivity of crude antigens, recovered from mycelia grown on media containing variable concentrations of dextrose, indicated that the serological reactivity of the crude antigen was inversely proportional to the concentration of the carbohydrate source, with an optimum reactivity occurring with antigens prepared from mycelia grown in low dextrose concentrations.Nitrogen and carbohydrate concentrations performed on whole mycelia and cell free extracts demonstrated that the total nitrogen, soluble nitrogen, total carbohydrate and soluble carbohydrate concentrations were influenced by the concentration of the carbohydrate source. The optimum carbohydrate concentration necessary for the maximum ratio of protein and carbohydrates per gram of mycelium was 15.0 g/l. This is less than the amount used in most Sabouraud's dextrose media formulations. The effect of these environmental factors on the serological reactivity was discussed.Supported in part by NIH Environmental Health Tranining Grant ES00081-02. The help of Mrs. Gary Swecker is gratefully acknowledged for preparing the graphs.     

Antibacterial Action of Essential Oils of Artemisia as an Ecological Factor: II. Antibacterial Action of the Volatile Oils of Artemisia tridentata (Big Sagebrush) on Bacteria from the Rumen of Mule Deer

Rumen microorganisms of wild and captive deer were subjected to increasing amounts of volatile oils. The oils had a marked antibacterial effect on the rumen bacteria when the concentration reached approximately 16 muliters of oil per 10 ml of rumen fluid nutrient broth. The gross reactions of rumen bacteria obtained from wild, as well as captive, deer to the volatile oils seemed to be of the same magnitude; thus no adaptation by the bacteria to the oils was apparent.     

Dry Heat or Gaseous Chemical Resistance of Bacillus subtilis var. niger Spores Included Within Water-soluble Crystals

Inclusion of spores of Bacillus subtilis var. niger in water-soluble crystals increased the resistance of the spores to dry heat and to a gaseous mixture of methyl bromide and ethylene oxide. Resistance of spores in glycine crystals to dry heat at 125 C was increased 5 to 24 times compared to unprotected spores. There appeared to be a positive correlation between the size of the crystal and the degree of resistance. The resistance to dry heat of spores included in sodium chloride crystals was about six times greater than unprotected spores. A gaseous mixture of methyl bromide (964 mg/liter) and ethylene oxide (642 mg/liter) at 37% relative humidity was ineffective in sterilizing spores enclosed within these water-soluble crystals, as was ethylene oxide alone. However, if the relative humidity was sufficiently high to dissolve the crystals during exposure to the vapor, viable-spore counts were drastically reduced or were negative. The surfaces of crystals grossly contaminated with dry spores were sterilized by exposure to gaseous ethylene oxide. Sterilization of heat-labile or moisture-labile materials with a critical requirement for sterility, as in planetary probes or drugs, may be complicated by the presence of spores in naturally occurring water-soluble crystals. This phenomenon is similar to the protection afforded spores entrapped in solid plastics.     

Serological Studies of the T and Tumor Antigens of the Oncogenic Simian Adenoviruses

Tumor-specific antigens and antisera were prepared for eight of the oncogenic simian adenoviruses. Complement-fixation tests revealed three distinct serological subgroups. This grouping was maintained in studies of virus-infected cells (T antigens) although high titered preparations were obtained for only the major subgroup I. The current grouping is as follows: (I) SV1, SV11, SV25, SV33, SV34, SV38; (II) SV20, SV23; (III) SA 7. Antigens from each subgroup were rapidly inactivated at 56 C, and group II and III antigens were also markedly inactivated at 37 C. One of the tumors (SV1) also contained SV40 T antigen, suggesting origin from a simian adenovirus-SV40 "hybrid."     

Sporicidal Activity of Sodium Hypochlorite at Subzero Temperatures

Sodium hypochlorite was an excellent disinfectant at low temperatures. With the addition of ethylene glycol to prevent freezing, hypochlorite solutions at low free available chlorine concentrations, were effective against Bacillus subtilis var. niger spores from 0 to -40 C. The effectiveness of this decontaminant was influenced by temperature, pH, and concentration, with pH 7.2 the optimum for decontamination at all temperatures and concentrations.     

Mortality of Altitude-exposed Mice Infected with Pasturella tularensis

The influence of reduced barometric pressure equivalent to an altitude of 18,000 ft (5,486 m) on the susceptibility of mice to tularemia was investigated by exposing groups of animals to the test environment before, after, or before and after intraperitoneal inoculation of 225 colony-forming units of Pasteurella tularensis. Similarly infected control animals were not exposed to the experimental environment. Two measurements of mortality were employed: (i) the day on which 50% of the mice were dead; and (ii) the number of dead mice on the 8th day. Continuous altitude exposure for 14 days prior to infection had no effect on host susceptibility but exposure after infection significantly increased mortality (P < 0.001).