Recovery of microorganisms from synovial and pleural fluids of animals using hyperosmolar media

L-phase (CWD) broth and plate media were used in parallel with conventional microbiological media during a 3-year period for culturing synovial and pleural fluids of animals. Two kinds of recoveries were obtained where parallel conventional methods were negative: (1) parent or normal bacteria, in very low numbers; and (2) Type B CWD variants in equally low numbers. Organisms in group 1 were: Streptococcus zooepidemicus from horses (2X); β-hemolytic streptococci, Lancefield Gp. G (2X); Staphylococcus aureus; Actinobacillus, and Actinomyces viscosus. Group 2 consisted of Bacteroides sp., Propionibacterium acnes, and three “Nocardia-like” sp. Catalase + Actinomyces was not recovered equally well on CWD plates as on conventional media with fluids obtained during ampicillin treatment. This occurred in spite of the fact that the CWD media was shown to support growth and reversion of laboratory induced L-phase variants of Nocardia caviae and N. asteroides, and had facilitated recovery of a Bacteroides L-phase variant from a pleural fluid. The nature of this fault in the media is under investigation in this laboratory.