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Published on: March 4, 2020
Metallo- β - lactamase producing nonfermentative gram-negative bacteria: an increasing clinical threat among
Varsha Gupta1, Shailpreet Sidhu, Jagdish Chander
1Department of Microbiology, Govt. Medical College & Hospital, Chandigarh, India.
Objective:
To detect and evaluate the various methods for metallo- β -lactamases (MBL) production in Pseudomonas aeruginosa (P. aeruginosa) and Acinetobacter species.
Methods:
A total of 109 P. aeruginosa and 85 Acinetobacter species were screened for imipenem resistance by Kirby-Bauer disc diffusion methods. Detection of MBL production was done by imipenem-EDTA combined disc test, double disc synergy test (DDST) and imipenem-EDTA MBL E test.
Results:
A total of 63 (57.8%) strains of P. aeruginosa and 46 (54.1%) strains of Acinetobacter spp. were found to be resistant to imipenem. Of the 63 imipenem resistant P. aeruginosa tested for MBL production, 44 (69.8%) were found to be positive and among 46 imipenem resistant Acinetobacter, 19 (41.3%) were shown to be the MBL producers.
Conclusions:
Imipenem-EDTA combined disc test and MBL E test are equally effective for MBL detection in both P. aeruginosa and Acinetobacter spp., but given the cost-constraints, combined disc can be used as a convenient screening method in the clinical microbiology laboratory.
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