Reduced Time to Positive Culture Utilizing a Novel Incubation Technique: A Retrospective Cohort Study.

INTRODUCTION

() is a common pathogen in postoperative shoulder infections. The purpose of this study was to evaluate the time to positive cultures for and compare our experience before and after implementation of a regulated anaerobic chamber system. We hypothesized that this would reduce the time to identify positive cultures.

METHODS

This was a retrospective review of 34 patients with cultures obtained from the shoulder that were positive for . The time until positive result was evaluated before and after implementation of a regulated anaerobic incubation chamber.

RESULTS

Following implementation of the regulated anaerobic incubation chamber, the time until culture growth significantly decreased from 6.5 days (range 3-10 days) to 4.9 days (range 2.75-10 days) (mean difference: 1.6 days, 95% confidence interval: 1.06-2.66 days;  = .002). True infections had a significantly shorter time to positive culture compared to contaminants (5.5 vs 6.8 days, respectively,  = .003). Increased number of positive culture specimens correlated with a shorter time to positivity (Spearman rank = -0.58,  = .007).

CONCLUSION

Improved anaerobic culture protocols and techniques may lead to greater accuracy and earlier diagnosis and initiation of treatment of postoperative shoulder infections.