Manual versus automated streaking system in clinical microbiology laboratory: Performance evaluation of Previ Isola for blood culture and body fluid samples.

BACKGROUND

The process of plate streaking has been automated to improve routine workflow of clinical microbiology laboratories. Although there were many evaluation reports about the inoculation of various body fluid samples, few evaluations have been reported for blood. In this study, we evaluated the performance of automated inoculating system, Previ Isola for various routine clinical samples including blood.

METHODS

Blood culture, body fluid, and urine samples were collected. All samples were inoculated on both sheep blood agar plate (BAP) and MacConkey agar plate (MCK) using Previ Isola and manual method. We compared two methods in aspect of quality and quantity of cultures, and sample processing time. To ensure objective colony counting, an enumeration reading reference was made through a preliminary experiment.

RESULTS

A total of 377 nonduplicate samples (102 blood culture, 203 urine, 72 body fluid) were collected and inoculated. The concordance rate of quality was 100%, 97.0%, and 98.6% in blood, urine, and other body fluids, respectively. In quantitative aspect, it was 98.0%, 97.0%, and 95.8%, respectively. The Previ Isola took a little longer to inoculate the specimen than manual method, but the hands-on time decreased dramatically. The shortened hands-on time using Previ Isola was about 6 minutes per 10 samples.

CONCLUSION

We demonstrated that the Previ Isola showed high concordance with the manual method in the inoculation of various body fluids, especially in blood culture sample. The use of Previ Isola in clinical microbiology laboratories is expected to save considerable time and human resources.