Submitted: 27 Jan 2022
Revision: 08 Mar 2022
Accepted: 16 Mar 2022
ePublished: 29 Mar 2022
EndNote EndNote

(Enw Format - Win & Mac)

BibTeX BibTeX

(Bib Format - Win & Mac)

Bookends Bookends

(Ris Format - Mac only)

EasyBib EasyBib

(Ris Format - Win & Mac)

Medlars Medlars

(Txt Format - Win & Mac)

Mendeley Web Mendeley Web
Mendeley Mendeley

(Ris Format - Win & Mac)

Papers Papers

(Ris Format - Win & Mac)

ProCite ProCite

(Ris Format - Win & Mac)

Reference Manager Reference Manager

(Ris Format - Win only)

Refworks Refworks

(Refworks Format - Win & Mac)

Zotero Zotero

(Ris Format - Firefox Plugin)

Avicenna J Clin Microbiol Infect. 2022;9(1): 1-7.
doi: 10.34172/ajcmi.2022.01
  Abstract View: 279
  PDF Download: 184

Original Article

The Diagnostic Capacity of Three Phenotypic Techniques of Extended-Spectrum β-Lactamase Detection

Abera Abdeta 1* ORCID logo, Adane Bitew 2, Surafel Fentaw 1, Estifanos Tsige 1, Dawit Assefa 1, Eyasu Tigabu 3, Tadesse Lejisa 4, Yordanos Kefyalew 5, Ebisa Fekede 1

1 National Clinical Bacteriology and Mycology Reference Laboratory, Ethiopian Public Health Institute, Addis Ababa, Ethiopia
2 Department of Medical Laboratory Sciences, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
3 Global One Health Initiative, The Ohio State University, East African Regional Office, Addis Ababa, Ethiopia
4 National Clinical Chemistry Reference Laboratory, Ethiopian Public Health Institute, Addis Ababa, Ethiopia
5 Department of Applied Biology, School of Applied Natural Science, Adama Science and Technology University, Adama, Ethiopia
*Corresponding Author: *Corresponding author: Abera Abdeta (MSc), P.O. Box: 1242 or 5654, Tel : +251911566420, Email: , Email: aberaabdeta4@gmail.com


Background: Early detection of extended-spectrum β-lactamases (ESBLs) producing bacteria is critical for infection prevention and control. Numerous phenotypic approaches and automated systems have been developed for detecting ESBL bacteria. However, there is a scarcity of data in Ethiopia regarding the most reliable, simple, and cost-effective methods for detecting ESBL-producing bacteria. This study, therefore, aimed to evaluate the diagnostic performance of three phenotypic approaches for detecting ESBL-producing bacteria.

Methods: In this study, 117 isolates of Klebsiella pneumoniae, Escherichia coli, Klebsiella oxytoca, and Proteus mirabilis were examined. Cefotaxime (30 µg) and ceftazidime (30 µg) were used for screening ESBL enzymes. A screening breakpoints of≤27 mm and≤22 mm were used for cefotaxime (30 µg) and ceftazidime (30 µg), respectively, as per the Clinical and Laboratory Standards Institute (CLSI) guidelines. All 117 strains were further confirmed by the Vitek 2 compact, double disk synergy, ESBL Epsilometer test, and combined disk method. The combined disk method was adopted as the reference method.

Results: Out of 117 isolates, 90 (86%) had zone diameters of≤27 mm and≤22 mm for cefotaxime (30 µg) and ceftazidime (30 µg), respectively. The reference method detected 76 (65%) ESBL isolates out of 117 ones. From among the three techniques (i.e., double disk synergy, Vitek 2 compact, and ESBL Epsilometer test), the double disk synergy method demonstrated overall sensitivity and specificity of 97.4% and 97.6%, respectively. Vitek-2, cefotaxime, and ceftazidime Epsilometer test indicated indeterminate results of 6.8%, 6.8%, and 5.1% respectively.

Conclusion: Double disk synergy was found to have the highest sensitivity and specificity for detecting ESBL isolates with no indeterminate results.

Please cite this article as follows: Abdeta A, Bitew A, Fentaw S, Tsige E, Assefa D, Tigabu E, et al. The diagnostic capacity of three phenotypic techniques of extended-spectrum β-lactamase detection. Avicenna J Clin Microbiol Infect. 2022; 9(1):1-7. doi:10.34172/ajcmi.2022.01
First Name
Last Name
Email Address
Security code

Abstract View: 279

Your browser does not support the canvas element.

PDF Download: 184

Your browser does not support the canvas element.