A survey of 303 urban and 156 rural children showed nasopharyngeal carriage of relatively resistant Streptococcus pneumoniae organisms in 14.2% and 19.2% of children, respectively. These organisms have minimum inhibitory concentrations for penicillin in the range of 0.12-1 microgram/ml. An analysis of 40 relatively resistant S. pneumoniae strains showed resistance to co-trimoxazole in 47.5%, tr...

The work carried on under the auspices of the Medical Commission for the Investigation of Acute Respiratory Diseases, at the Bacteriological Laboratory of the College of Physicians and Surgeons, Columbia University, has consisted principally of a comparative study of the morphology, growth characters, fermentative activities, and agglutination reactions of pneumococci and allied organisms isola...

Eighty-four pneumococci with various MICs of penicillin (38 with MICs of less than or equal to 0.06 micrograms/ml [susceptible], 35 with MICs of 0.12 to 1.0 micrograms/ml [relatively resistant], and 11 with MICs of greater than 1.0 micrograms/ml [resistant] ) were screened by a disk diffusion test using oxacillin and methicillin to see how well they distinguished penicillin-susceptible strains ...

Solutions of all of the C. P. sucrose reagents of American manufacture that were tested gave reactions with Type II antipneumococcus serum. The capacity of that antiserum to react with sucrose solutions was removed by absorption with the homologous pneumococci or with Leuconostoc mesenteroides. The serological reactivity was due not to sucrose itself but to accompanying substances that could be...

Mice vaccinated with yeast were protected against subsequent infection with Type II pneumococci, but not against Types I or III. While the protection was not universal, as high a percentage of mice acquired active anti-Type II immunity, as was obtained by vaccination of another group of mice with Type II pneumococci themselves. This specific protection of mice by active immunization with the ye...