Year : 2015  |  Volume : 6  |  Issue : 2  |  Page : 383-387

Phenotypic detection of extended spectrum β-lactamase and Amp-C β-lactamase producing clinical isolates in a Tertiary Care Hospital: A preliminary study

1 Department of Microbiology, Dhanalakshmi Srinivasan Medical College, Perambalur, Tamil Nadu, India
2 Department of Microbiology, Indira Gandhi Medical College and Research Institute (Government of Puducherry Institute), Puducherry, India
3 Department of Microbiology, Sri Manakula Vinayagar Medical College, Puducherry, India
4 Department of Microbiology, Aarupadai Veedu Medical College, Puducherry, India

Correspondence Address:
Dr. A Malini
Department of Microbiology, Indira Gandhi Medical College and Research Institute (Government of Puducherry Institute), Puducherry
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/0976-9668.160014

Rights and Permissions

Background: Production of β-lactamase enzymes by Gram-negative bacteria is the most common mechanism to acquire drug resistance to β-lactam antibiotics. Limitations in detecting extended spectrum β-lactamases (ESBL) and Amp-C β-lactamases have contributed to the uncontrolled spread of bacterial resistance and are of significant clinical concern. Materials and Methods: A total of 148 samples was selected on the basis of resistance against third-generation cephalosporin for screening ESBLs and Amp-C β-lactamases production. These multidrug-resistant strains were phenotypically screened for ESBL production by phenotypic confirmatory disc diffusion test and double disc synergy test. Modified three-dimensional method was used for Amp-C β-lactamases detection. Result: Among the 148 isolates, 82 (55.40%) were ESBL producers, and 115 (77.70%) were Amp-C β-lactamases producers. Co-existence of ESBL and Amp-C was observed in 70 (47.29%) isolates. Escherichia coli was the most common ESBL and Amp-C β-lactamase producer. All ESBL producers were highly resistant to ciprofloxacin (83.10%), cotrimoxazole (95.27%), and gentamicin (89.18%). However, these bacterial strains were sensitive to imipenem 146 (98.64%) and piperacillin/tazobactam 143 (96.62%). Conclusion: Our study showed that ESBL producing organisms were not only resistant to cephalosporins but also to other group of drugs and also that multiple mechanisms play a role in drug resistance among Gram-negative bacteria.

Print this article     Email this article
 Next article
 Previous article
 Table of Contents

 Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
 Citation Manager
 Access Statistics
 Reader Comments
 Email Alert *
 Add to My List *
 * Requires registration (Free)

 Article Access Statistics
    PDF Downloaded346    
    Comments [Add]    

Recommend this journal