Improved method of isolating bacteria from joint fluids by the use of blood culture bottles.

An analysis of 47 episodes of bacterial arthritis showed that applying a blood culture procedure to the culture of joint fluids gave positive results in 10 cases (21%) that were negative by conventional methods. When follow up samples taken during antibiotic treatment were considered the proportion of false negatives eliminated rose to 40%. The respective advantages of using a large volume of inoculum and a large volume of medium are that very low numbers of viable bacteria in infected fluid can be detected, and that growth inhibitors are diluted.