Aim: To compare the resistance amongst Gram negative bacteria against imipenem and meropenem. Study Design: Prospective, non-randomized, descriptive study. Place and Duration of Study: Department of Microbiology, Mughal Laboratories, Lahore from 1stJuly 2019 to 31stDecember 2019. Methodology: One hundred culture samples received, bacteria isolated and their susceptibilities to imipenem and meropenem were compared. Organisms were recognized by the microbiological techniques according to the current standards and susceptibility testing was done according to the guidelines of Clinical and Laboratory Standards Institute (CLSI) 2020by using Kirby Bauer Disc diffusion method.

Results: Salmonella typhi, Citrobacter species and Proteus species were 100% sensitive to imipenem. The rest of bacterial isolates had sensitivities to E. coli 88%, Acinetobacter 80%, Klebsiella species 67% and Peudomonas species 64%. The meropenem is highly resistant in all the bacteria as compared to imipenem.

Conclusion: Increasing the trend of carbapenem resistance amongst Gram negative bacteria excluding Salmonella typhi was recorded.

Key words: Gram negative rods, Resistance, Spectrum