Metallo- β - lactamase producing nonfermentative gram-negative bacteria: an increasing clinical threat among hospitalized patients.
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.
Department of Microbiology, Govt. Medical College & Hospital, Chandigarh, India.
Varsha
V
Gupta
Shailpreet
S
Sidhu
Jagdish
J
Chander
D000150:Acinetobacter / Q000378:metabolism*; D000151:Acinetobacter Infections / Q000382:microbiology*; D000900:Anti-Bacterial Agents; D003428:Cross Infection / Q000188:drug therapy; D052978:Disk Diffusion Antimicrobial Tests; D006801:Humans; D015378:Imipenem; D011552:Pseudomonas Infections / Q000382:microbiology*; D011550:Pseudomonas aeruginosa / Q000378:metabolism*; D018440:beta-Lactam Resistance / Q000502:physiology*; D001618:beta-Lactamases / Q000096:biosynthesis*
D000900:Anti-Bacterial Agents; D015378:Imipenem; C409201:beta-lactamase IMP-1; D001618:beta-Lactamases