Abstract

Carbapenams are one of the ß-lactamase antibiotic resistances to penicillin that were introduced in 1980 to the medical world. Imipenem- a semi-synthetic derivative of thienamycin- is one of the most important broad spectrum ß-lactamase in carbapenems. The irregular usage of drugs, especially in these types of gram-negative bacteria will lead to a serious problem in the treatment of pathogenic bacteria. Comparison of in vitro activity of imipenem productions is the aim of this study. 135 strains of various gram positive and gram negative bacteria collected from Hashemi Nejad Hospital in Tehran were studied. Initially strains were identified by phenotypic methods; then Disk Diffusion and MIC methods based on instructions of Forum France Microbiology were used. From 135 samples, urine samples (36%) were the most and trachea (4%) was the lowest. Among gram-negative bacteria isolated, both E. coli and Pseudomonas (37%) had most common and Enterobacter (1%) was the lowest. By disk diffusion method, Supranem, Taynam and Mast pharmaceutical products, showed similar result, but the results related to internal company disks were different. 20% of the total bacteria studied had MIC over 8 mg (resistant). Due to results of this study using standard dicks and antibiotic powder (Imipenem/Cilastatin sodium) (Supranem) or (Tienam) is recommended.

Key words: ß-lactamase, antibiogram, imipenem.