Comparison of isotonic and radiometric-hypertonic cultures for the recovery of organisms from cerebrospinal, pleural and synovial fluids.

Two hundred eighteen (218) specimens of body fluids were examined by both isotonic and hypertonic culture methods. The specimens examined included 108 pleural fluids, 43 synovial fluids, and 67 cerebrospinal fluids. Organisms were recovered in 99 instances by means of the isotonic system and in 140 instances by the hypertonic system. The hypertonic system also involved the use of radiometric assay for the detection of positive cultures. In all 140 cases, detection was accomplished within 36 hours after collection of the specimen by the radiometric method, while only 26 specimens showed any visual evidence of bacterial growth. Of the 218 patients involved, 198 were receiving antimicrobial therapy in which the antimicrobial agent attacked the bacterial cell wall.