Marjorie Bohnhoff

Effect of Streptomycin on Susceptibility of Intestinal Tract to Experimental Salmonella Infection.

Summary 1. Preliminary treatment by mouth with a large dose (50 mg) of streptomycin increased the susceptibility of mice to infection following oral inoculation with a streptomycin-resistant strain of Salmonella enteritidis. In mice treated with streptomycin 24 hours before inoculation, <3 Salmonella sufficed to initiate infection in 50% as compared with approximately 105 in untreated controls. 2. This effect of streptomycin decreased as the interval between treatment and inoculation was lengthened but was still detectable on the 5 th day. Smaller doses of streptomycin (5-10 mg) resulted in smaller increases in susceptibility. 1 mg was ineffective. 3. Representative numbers of mice killed for culture showed the spleen to be infected in 90% and hearts blood in 72% of those with positive fecal cultures at the time of autopsy. 4. It is believed that this increase in susceptibility following streptomycin treatment resulted from a disturbance of the normal intestinal microflora caused by the antibacterial action of the drug. 5. It is suggested that this method may be applicable to the experimental study of other enteric infections.

Studies on the Action of Penicillin. IV. Development of Penicillin Resistance by Gonococcus.

Summary Penicillin-fastness developed most rapidly in gonococci under conditions which permitted the greatest number of viable microorganisms to be transferred to a higher concentration of penicillin at each transfer. One strain of gonococcus acquired the ability to prow on media containing 21 units per ml. So appreciable increase in penicillin tolerance resulted from repeated exposure to bacteriostatic concentrations of penicillin.

Studies on Action of Penicillin. V. Virulence of Penicillin Resistant Strains of Meningococcus.

Summary The antibody response of swine to formolized swine influenza virus adsorbed on alum is essentially the same as that to the vaccine dispersed in saline solution. The chief influence of the alum is a brief delay in the peak response. The higher concentrations of alum lessen the primary antibody response, but the subsequent antibody levels and the rates of diminution in titers are nearly identical with the two sorts of vaccine.

Effect of streptomycin therapy on the bacterial flora of the throat

Abstract Specimens from the throats of patients receiving streptomycin were cultured onto streptomycin media in order to detect the presence of streptomycin-resistant and streptomycin-dependent bacteria. Streptomycin-resistant bacteria in large numbers were cultured from the throats of 98.4 per cent of sixty-one patients who were receiving 1 to 4 Gm. of streptomycin per day. They began to appear during the first thirteen days of treatment in the twenty-four patients who were followed from the beginning of streptomycin therapy. Results of a single survey of another series of patients receiving small doses of streptomycin (0.5 to 0.75 Gm. per day) suggested that resistant flora appeared more slowly. These streptomycin-resistant bacteria all belonged to species normally inhabiting the human throat. Yeast-like forms (Monilia) were found in unusually high incidence. Streptomycin-dependent bacteria were found in two-fifths of the patients receiving large doses of streptomycin, i.e., 1 Gm. or more per day. Streptomycin-resistant bacteria in small numbers were recovered from only 4 per cent of 157 members of the hospital staff, student body and clerical personnel and from 10 per cent of untreated patients. The highest incidence of positive cultures in the control series, 21 per cent, occurred in the nursing and ward personnel. Strongly positive cultures were found in four nurses who were caring for patients receiving streptomycin. Streptomycin-dependent micro-organisms were recovered from the pharynx and large bowel of mice and rabbits after one week of treatment with large doses of streptomycin.

Pathological changes in adrenal cortex of mouse during experimental meningococcal infection.

Summary Employing a technic which minimized the production of artifacts, a histological study was made of the adrenal glands of mice infected with meningococcus and also of appropriate controls. Depletion of fat, engorgement and inflammatory cell infiltration were demonstrated during the course of the infection. After successful treatment with penicillin the adrenal cortex showed a progressive recovery as manifested by reaccumulation of fat and reduction of hyperemia and inflammatory reaction.

A Method for Production of a Localized Gonococcal Infection in the Rabbit's Eye.

Summary A method is described for the production of a localized gonococcal infection in the rabbits eye by inoculating gonococci into the anterior chamber. Gonococci were found to invade the tissues of the eye, to multiply there and to produce severe inflammatory reaction. In approximately ⅓ of the animals the infection became chronic and viable gonococci persisted as long as 14 weeks, the maximum period of observation.