The clinical use of a fast screening test based on technology of capillary zone electrophoresis (CZE) for identification of Escherichia coli infection in biological material

Abstract

Background: Escherichia coli is a Gram-negative bacterium which is a basic, symbiotic element of the physiological flora of the large intestine of humans and warm-blooded animals. However, in specific cases it may become a very dangerous pathogen (eg, diarrhoea, infection of the urinary tract, lungs, and generalized infections). Its early detection, as a cause of infectious disease, helps to achieve optimal treatment results; however, classical microbiological tests require at least 24 hours from sample taking to diagnosis.

Material/methods: We present a unique solution based on CZE technologies enabling identification of E. coli presence in studied sample within half an hour. Altogether, 30 E. coli-infected wounds and ulcerations were examined, comparing the results obtained by classical culture method with the result of capillary zone electrophoresis (CZE) electropherogram.

Results: The method, which does not require any preparation of the sample, achieved 86.7% sensitivity and 85%specificity in the examined clinical material (infections of surgical wounds).

Conclusions: The obtained results enable reliable, very fast testing for E. coli as a pathogen.

Figure 1

Example of an infected wound (appendectomy).

Figure 2

Electropherogram of additional strains in the biological sample, in which conventional method primarily detected only presence of E. coli. The next inoculation showed co-infection of Staphylococcus sp.

Figure 3

Typical electropherograms of biological sample (A, B) and standard (C) with presence of Escherichia coli (arrow).

Figure 4

Selected electropherogram of the biological sample infected with E. coli (+++) and Enterobacter cloacae (+). Clear, pathognomonic signal of E. coli is seen of tm=2.6 minutes.

Figure 5

Spectrum of background (morphotic elements of tissue excretion) – matrix effect.