Detection of ESBL among ampc producing enterobacteriaceae using inhibitor-based method

  • Sasirekha Bakthavatchalu
  • Uma Shakthivel
  • Tannu Mishra

Abstract

Introduction: The occurrence of multiple β-lactamases among bacteria only limits the therapeutic options but also poses a challenge. A study using boronic acid (BA), an AmpC enzyme inhibitor, was designed to detect the combined expression of AmpC β-lactamases and extendedspectrum β-lactamases (ESBLs) in bacterial isolates further different phenotypic methods are compared to detect ESBL and AmpC. Methods: A total of 259 clinical isolates of Enterobacteriaceae were isolated and screened for ESBL production by (i) CLSI double-disk diffusion method (ii) cefepime- clavulanic acid method (iii) boronic disk potentiation method. AmpC production was detected using cefoxitin alone and in combination with boronic acid and confirmation was done by three dimensional disk methods. Isolates were also subjected to detailed antibiotic susceptibility test. Results: Among 259 isolates, 20.46% were coproducers of ESBL and AmpC, 26.45% were ESBL and 5.40% were AmpC. All of the 53 AmpC and ESBL coproducers were accurately detected by boronic acid disk potentiation method. Conclusion: The BA disk test using Clinical and Laboratory Standards Institute methodology is simple and very efficient method that accurately detects the isolates that harbor both AmpCs and ESBLs.

Pan African Medical Journal 2013 14:28

Author Biographies

Sasirekha Bakthavatchalu
Department of Microbiology, Centre for Post Graduate Studies, Jain University, Bangalore, Karnataka- 560 011, India
Uma Shakthivel
Department of Microbiology, Centre for Post Graduate Studies, Jain University, Bangalore, Karnataka- 560 011, India
Tannu Mishra
Department of Microbiology, Centre for Post Graduate Studies, Jain University, Bangalore, Karnataka- 560 011, India
Published
2013-05-01
Section
Articles

Journal Identifiers


eISSN: 1937-8688