Yoonjung Kim; Seoyoung Yoon; Young Sook Sohn; Yangsoon Lee; Hae-Sun Chung; Woonhyoung Lee; Dongeun Yong; Seok Hoon Jeong; Kyungwon Lee; Yunsop Chong

doi:10.3343/lmo.2011.1.2.7

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Kim, Yoon, Sohn, Lee, Chung, Lee, Yong, Jeong, Lee, and Chong: Evaluation of an Automated Instrument, PREVI Isola® for Inoculation of Body Fluids and Urine Samples onto Agar Plates

Original Article

Clinical Microbiology

Laboratory Medicine Online

Laboratory Medicine Online 2011; 1(2): 105-109.

Published online: 1 April 2011

DOI: https://doi.org/10.3343/lmo.2011.1.2.7

Evaluation of an Automated Instrument, PREVI Isola® for Inoculation of Body Fluids and Urine Samples onto Agar Plates

Yoonjung Kim¹, Seoyoung Yoon¹, Young Sook Sohn^1,², Yangsoon Lee^1,², Hae-Sun Chung^1,², Woonhyoung Lee¹, Dongeun Yong^1,², Seok Hoon Jeong^1,², Kyungwon Lee^1,², Yunsop Chong^1,²

¹Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, Korea.

²Research Institute of Bacterial Resistance, Yonsei University College of Medicine, Seoul, Korea.

Corresponding author: Dongeun Yong. Department of Laboratory Medicine, Research Institute of Bacterial Resistance, Yonsei University College of Medicine, 134 Sinchon-dong, Seodaemun-gu, Seoul 120-752, Korea. Tel: +82-2-2228-2442; Fax: +82-2-364-1583, deyong@yuhs.ac

Received 9 August 2010 Revised 13 September 2010 Accepted 20 September 2010

(open-access):

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

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.

Keywords: Microbiological technique, Laboratory automation, Body fluids, Urine

Figures and Tables

Fig. 1

The colony morphology on plate by PREVI Isola®. The agar plate is divided in 8 sections (quadrant 1-quadrant 4 and outer/inner zone).

Table 1

Precision of colony count on plates prepared with PREVI Isola®

Abbreviation: CFU, colony-forming units.

Table 2

Comparison of PREVI Isola® with manual body fluid counts

2a-d: quadrants 1-4.

Table 3

Comparison of PREVI Isola® with manual urine counts

Cut off was >10⁵ colonies in manual method and >30 colonies in Q3 in PREVI Isola® preparation. Sensitivity (87%, 64 positive samples using PREVI-Isola® divided by 74 positive samples using manual method) and specificity (87%, 91 negative samples using PREVI-Isola® divided by 105 negative samples using manual method) were calculated.

Abbreviation: CFU, colony-forming units.

Table 4

Spending time measurement for both methods from inoculation to incubation

Notes

This article is available from http://www.labmedonline.org

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