[Use of paper strips impregnated with antibiotics in the bacteriological diagnosis of dysentery: the 2-strip method]

The studies provided development of a new method consisting of placing 2 filter paper strips each impregnated with an antibiotic (2 antibiotics are used out of 3: levomycetin, tetracycline and streptomycin) under a layer of Ploskirev's medium with sodium sulfacyl. The antibiotics are chosen proceeding from the predominance in the given area of Shigella resistant to some of the above antibiotics. The method simplifies and makes more economic the tests, provides higher frequency of Shigella isolation as compared to the procedure with the routine Ploskirev's medium or gradient dishes, has almost the same isolation frequency as with the use of 2 plates (with and without antibiotic). The method is recommended for wide use in practice.