Evaluating the minimum active concentrations of penicillin G and V and of retard forms in clinical conditions.

Following several signals indicating the inefficiency of the clinical treatment with various penicillin preparations in some cases, we decided to study the seric penicillin concentrations in the patients hospitalized in the "V. Babes" Hospital of Infectious Diseases, after administration of the various Romanian made forms of penicillin currently used in the therapy of streptococcal infections and in the prophylaxis of the sequelae of these infections. The data obtained on groups exceeding 30 persons by using two methods of determining the penicillin concentrations the dilutions and the diffusimetric methods revealed protective penicillin seric levels satisfactory for penicillin G and Efitard, according to the present treatment schemes.

Characteristics of Neisseria meningitidis strains isolated in Romania between 1986 and 1989.

499 N. meningitidis strains were studied, 454 being isolated from CSF and blood and 45 from nasopharynx. Meningococcal serogroup A was prevalent in 1986-1988, having a decreasing tendency from 84.

Restriction and modification of typing phages by an R factor in S. typhi.

We have investigated the qualities of one R factor 552 discovered on a strain of S. typhi resistant to A, C, S, T, nontypable, isolated from stool cultures; from the same patient, before starting the treatment we isolated, from his blood sample, the strain S. typhi 221, sensitive to A, C, T, degraded phage-type Vi A.