Yeongchun Park; Jin Sang Yoon; Jimyung Kim; Gye Cheol Kwon; Sun Hoe Koo

doi:10.3343/lmo.2016.6.1.36

Journal List > Lab Med Online > v.6(1) > 1057328

Go to TopGo to Top Go to BottomGo to Bottom

TOOLS

Park, Yoon, Kim, Kwon, and Koo: Evaluation of Automated Specimen Inoculation for Blood Culture Samples by Use of the Previ Isola® System Compared with the Manual Method

Original Article

Clinical Microbiology

Laboratory Medicine Online 2016; 6(1): 36-40.

Published online: 1 January 2016

DOI: https://doi.org/10.3343/lmo.2016.6.1.36

Evaluation of Automated Specimen Inoculation for Blood Culture Samples by Use of the Previ Isola® System Compared with the Manual Method

Yeongchun Park, M.D., Jin Sang Yoon, M.T., Jimyung Kim, M.D., Gye Cheol Kwon, M.D., Sun Hoe Koo, M.D.

Department of Laboratory Medicine, College of Medicine, Chungnam National University, Daejeon, Korea.

Corresponding author: Sun Hoe Koo. Department of Laboratory Medicine, Chungnam National University Hospital, 282 Munhwa-ro, Jung-gu, Daejeon 35015, Korea. Tel: +82-42-280-7798, Fax: +82-42-257-5365, shkoo@cnu.ac.kr

Received 5 December 2014 Revised 12 June 2015 Accepted 12 June 2015

(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

Recently, a new automated inoculating instrument, Previ Isola® (bioMérieux, France) was introduced. Although there are many evaluation reports about the inoculation of urine and body fluid samples using Previ Isola®, no evaluation has been reported for blood samples. The objectives of this study were to evaluate this instrument for the inoculation of blood samples and to compare the microbiological results with the manual loop-to-plate method.

Methods

From March 2014 to July 2014, a total of 296 non-duplicate blood samples showing positive signals on the BacT/Alert 3D system were obtained, and both manual and automated methods were used for sample inoculation. Results of the two methods were compared according to five aspects: the culture result, number of single colonies, morphology of colonies, number of re-inoculations, and time required for inoculation.

Results

The sensitivity and specificity of Previ Isola® were 98.9% and 96.6%, respectively. The positive and negative predictive values were 99.6% and 90.3%, respectively, and the total concordance rate was 98.6%. For Previ Isola® and the manual methods, the number of average usable single colonies per plate was 25 and 16, the number of re-inoculations was 60 and 62, and the inoculation time for 15 blood samples was 30 min and 75 min, respectively. The morphology of colonies showed no differences between the two methods.

Conclusions

The automated inoculation instrument, Previ Isola®, showed relative good concordance with manual method, with high sensitivity and high specificity for blood sample inoculation. Previ Isola® may be useful for inoculating specimens including blood samples.

Keywords: Previ Isola®, Automation, Inoculation, Blood culture

Figures and Tables

Table 1

Results of isolated bacteria species

Gram stain		Number	Species
Gram (+)	Cocci	139	Coagulase-negative staphylococci, Staphylococcus aureus, Enterocaoccus faecium, Enterococcus faecalis, Streptococcus pyogenes, Staphylococcus saprophyticus, Alloiococcus otitis, Gemella sanguinis
	Bacilli	18	Bacillus spp.,Corynebacterium jeikeium,Corynebacterium striatum,Corynebacterium amycolatum,Weissella confusa (formerly Lactobacillus confusa)
Gram (-)	Bacilli	112	Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter cloacae, Klebsiella oxytoca, Morganella morganii, Stenotrophomonas maltophilia, Salmonella group D
Yeast	Cocci	16	Candida albicans,Candida tropicalis,Candida glabrata, Candida parapsilosis

Table 2

Comparison of Previ Isola® with the manual method

		Automated method (Previ Isola®)^*
		Growth	No growth	Total
Manual method	Growth	264	1	265
	No growth	3	28	31
	Total	267	29	296

^*Automated method: sensitivity, 98.9%; specificity, 96.6%; positive predictive value, 99.6%; negative predictive value, 90.3%; concordance rate, 98.6%.

Table 3

Reasons for re-inoculation with Previ Isola®

Reasons	Number	Species
Mixture	18	Enterococcus faecium & Escherichia coli, Staphylococcus epidermidis & Pseudomonas aeruginosa, E. coli & Klebsiella pneumoniae, Staphylococcus capitis & K. pneumoniae, E. coli & E. faecium, Stenotrophomonas maltophilia & E. faecium, etc.
Tiny colony	19	Streptococcus, Bacillus spp., Actinomyces, Corynebacterium spp., Streptococcus parasanguinis, Aerococcus, Gemella sanguinis, etc.
Yeast	13	Candida albicans, Candida tropicalis, Candida glabrata, Candida parapsilosis
No single colony	5	Bacillus spp., K. pneumoniae, etc.
Inoculation failure	5	E.faecium, S.epidermidis, Bacillus spp., Streptococcus sanguis, Weissella confusa (formerly Lactobacillus confusa)

Notes

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

References

1. Chong Y, Lee K, et al. Diagnostic microbiology. 4th ed. Seoul: Seoheung Publishing Company;2009. p. 58–113.

2. Glasson JH, Guthrie LH, Nielsen DJ, Bethell FA. Evaluation of an automated instrument for inoculating and spreading samples onto agar plates. J Clin Microbiol. 2008; 46:1281–1284.

3. Greub G, Prod'hom G. Automation in clinical bacteriology: what system to choose. Clin Microbiol Infect. 2011; 17:655–660.

4. Mischnik A, Mieth M, Busch CJ, Hofer S, Zimmermann S. First evaluation of automated specimen inoculation for wound swab samples by use of the Previ Isola system compared to manual inoculation in a routine laboratory: finding a cost-effective and accurate approach. J Clin Microbiol. 2012; 50:2732–2736.

5. Uh Y, Jang IH, Park SD, Kim KS, Seo DM, Yoon KJ, et al. Factors influencing the false positive signals of continuous monitoring blood culture system. Ann Clin Microbiol. 2014; 17:58–64.

6. Nebbad-Lechani B, Emirian A, Maillebuau F, Mahjoub N, Fihman V, Legrand P, et al. New procedure to reduce the time and cost of broncho-pulmonary specimen management using the Previ Isola® automated inoculation system. J Microbiol Methods. 2013; 95:384–388.

7. Kim Y, Yoon S, Sohn YS, Lee Y, Chung HS, Lee W, et al. Evaluation of an automated instrument, PREVI Isola® for inoculation of body fluids and urine samples onto agar plates. Lab Med Online. 2011; 1:105–109.

TOOLS

Similar articles