Microbiological technique ; Laboratory automation ; Body fluids ; Urine
Abstract
Background: In most clinical microbiology laboratories, inoculation of specimens on plates is performed manually and is a time-consuming process.
The efficiency of this process can be improved by using an automated instrument. Currently, several automated instruments have been introduced
for inoculation of samples. In this study, we have evaluated an automated instrument, PREVI Isola® (Biomerieux, France), used for inoculation
of body fluids and urine specimens.
Methods: Both manual and automated instrument methods were used to inoculate 74 body fluid and 204 urine samples. Precision was evaluated
by testing 3 types of urine samples (A, 6×103 colony-forming units (CFU)/mL; B, 3×104 CFU/mL; and C, >106 CFU/mL) in replicates of 20. Results
of the 2 methods were compared by counting the isolated colonies on agar plates after incubation. The time required for both methods was also compared.
Results: The coefficient of variation (CV) of samples A, B, and C examined using the automated instrument method was 176.1%, 18.1%, and 12.6%, respectively. The sensitivity and specificity of testing body fluid samples were 77% and 100%, respectively, and those of urine samples were 87% each. The time required for testing 15 body fluid specimens and that for inoculation of each specimen was 9.7 min shorter using PREVI Isola® than using the manual method.
Conclusions: The results of body fluid and urine culture by inoculation using the automated instrument, PREVI Isola®, showed relative good agreement with those obtained using the manual method. The use of PREVI Isola® would be expected to reduce the time and labor involved in inoculating
various kinds of specimens.