Improvement of bacterial estimation in urinalysis by iQ®200 ELITE®: capture image principle urine microscopic system

Kridsada Sirisabhabhorn1 Anurak Choeymang2 Supaporn Pumpa1 Krim Kamyod1 and Palakorn Puttaruk1

1Department of Medical Technology Laboratory, Thammasat University hospital, Pathumthani, Thailand 2Pharmacology and Toxicology Unit, Faculty of Allied Health Sciences, Thammasat University, Pathumthani, Thailand

The iQ®200 urine microscopic automate analyzer system, principle in capture urine particles images has been introduced for reduction job work load unit. However, low specificity of bacteria images is problem for estimated bacteria by semi-quantitative estimation. Also, the ASP (All Small Particles) parameter and bacterial images background were used for estimated bacterial grading but interferences of some urine sediment and less experience effect to inaccurately and difficultly bacterial estimation. The objective of this study was to estimate bacteria classification by semi quantitative grading in urinalysis which using ASP parameter of iQ®200 compared with urine sediment centrifugation and microscopic examination. All 372 cases were estimated bacterial grading from principle of capture image and sediment centrifuge examination immediately. Descriptive statistic was analyzed bacterial classified groups to semi quantitative as few moderate and numerous using median of ASP values. The results demonstrated that frequency bacterial estimation of iQ®200 presented as few, moderate and numerous were 96.5, 2.7 and 0.8 % respectively and microscopic examination were 40.59, 37.6 and 21.8% respectively, obviously uncorrelated classification. The classification of semi quantitative bacterial study consider combine with ASP values of iQ®200 were illustrated ASP’s median values to few, moderate and numerous as 1,911, 3,851 and 12,845 particles/µL respectively. Conclusion, preliminary classification of bacterial estimation with ASP particles of iQ®200 to rare, few, moderate and numerous as interval as <1,000, 1,000-3,000, 3,000-8,000 and >8,000 particles/µL respectively. Benefit from the study is helpful for rapid diagnosis of bacterial estimation by iQ®200 system urine microscopic automate analyzer system in routine urinalysis.

Abstract

Key words: automate analyzer, bacteria, microscopic, urinalysis

Introduction

Materials and Methods

Results

Conclusion and discussion

Bacteria

Frequency

cases

Percent

(%)

few 151 40.60

moderate 140 37.63

numerous 81 21.77

Total 372 100.0

Urine 10 ml

Removed supernatant

Bacteria

Frequency

cases

Percent

(%)

few 359 96.51

moderate 10 2.69

numerous 3 0.81

Total 372 100.0

At the present urine sediment system analyzer can help to short work flow in urinalysis. The iQ®200 urine microscopic automate analyzer system, principle capture images of urine elements which introduce instead of conventional urinalysis, centrifugation and observation sediments under light microscope process. However, iQ®200 was presented low specific bacteria feature which sometime made difficultly estimated bacteria volume. Many interference sediments like shape bacteria such as mucous, amorphous, sperm, budding yeast and pseudohyphae provided false positive/negative volume of bacteria. Thus bacterial estimation was applied combine with background of elements image and ASP (All Small Particles) values follow as recommend by product specialist. However lack of experience skill for bacteria identification induce to confuse in decision. Aim of this study was to design groups of semi-quantitative bacteria which related with ASP values from iQ®200ELITE® system and compare with bacteria estimation available from conventional method. The study benefit to created easily guideline model for bacterial grading that result from iQ®200ELITE® in particular laboratory.

iQ®200 urine microscopic automate analyzer system Conventional method

Table 1 illustrated frequency of quantitative bacteria derived from iQ®200

Table 2 illustrated frequency of quantitative bacteria available from light microscope

ASP (All Small Particles) values were classified by descriptive statistic

Semi-quantitative bacteria

Median (particles/µl)

Std. Error of Mean(particles/µl)

few 1,191.00 230.48

moderate 3,851.50 702.61

numerous 12,845.00 4,461.66

Table 3. Illustrated Median (particles/µl) and Std. Error of Mean (particles/µl) of ASP values derived

from iQ®200 system in bacteria grading.

ASP values guideline for bacterial grading

Semi-quantitative bacteria Median (particles/µl)

rare <1,000

few 1,000-3,000

moderate 3,000-8,000

numerous >8,000

In table 1 and 2 were demonstrated non-relation of frequency cases in bacterial decision from iQ®200 system and bacteria particles under microscope. Further study in ASP values each groups of semi-quantitative bacteria estimations as few, moderate and numerous were illustrated ASP’s median and standard error of mean according table 3. Conclusion, in brief result of semi-quantitative bacteria estimation were designed ASP’s values of rare, few, moderate and numerous within range of <1,000, 1,000-3,000, 3,000-8,000 and >8,000 particles/µl respectively. The benefit in this study can apply combination with ASP’s values in semi quantitative bacterial estimation which responsible easy decision and reduced turn around time per case. Furthermore this study can be used as guide line for bacteria semi-quantitative grading which perform by iQ®200 analyzer system in urinalysis. Nevertheless, if be uncertain in difficult bacterial estimation must be confirm with microscope investigation. Finally, updating of guideline and false positive result need to investigated in further study. Unforgettable, quality control assurance are necessary with recommend by medical technologist always. This study declared no conflict of interest.

References

Table 4. Design interval range guideline of semi-quantitative bacteria grading by Median (particles/µl)

derived from iQ®200 microscopic system

Linko S, Kouri TT, Toivonen E, Ranta PH, Chapoulaud E, Lalla M. Analytical performance of the Iris iQ 200 automated urine microscopy analyzer. Clinica Chimica Acta, 2006, 372 : 54-64. Sarvary E, Lee D, Varadi J, Varga M, Gaal I, Chmel R et al, The iQ200 Microscopic Analyzer is valuable tool for evaluation of urinary sediment at transplanted patients. Intervention Medicine & Applied Science, 2010, 2: 22-6.

Discrepancy of bacteria detection result with iQ®200

0

10

20

30

40

50

60

70

80

90

100

few moderate numerous

96.51

2.69 0.81

40.6 37.63

21.77

Microscope iQ200®analyzer

Centrifuge at 1,500 rpm 5 min

Loading to iQ200 Choosing image

Observation image

All 372 urine specimens were used in study. Firstly, prepare 10 ml of urine loaded to iQ200® then perform manual method with together. Two methods’ result were analyzed by discriptive statistic.

Graph 1. Comparison of cases were investigated bacteria with 2 methods, conventional method and iQ200®.

(%)

fre

qu

en

cy c

ase

s

Observed urine sediment under light microscope

Materials and Methods