INTRODUCTION

Infection due to Gram-negative bacteria (GNB) has become an ever increasing problem in recent years [1]. Gram-negative bacteria are common causes of intraabdominal infections (IAIs), urinary tract infections (UTIs), nosocomial pneumonia, and bacteremia.The most common organisms responsible for these infections are multidrug resistant Gram negative bacilli particularly members of the family Enterobacteriaceae and nonfermenting gram negative rods.

Antimicrobial resistance among GNB is increasing worldwide. This is a major public health problem and a cause for both substantial morbidity and mortality among hospitalized patients [2].

The development of antibiotic resistance limits the choice of antibiotics to be used. Widespread irrational antibiotic usage is leading to a greater trend towards antibiotic resistance. Lack of local antibiotic policy in most of the settings is further exerting a selective antibiotic pressure selecting out resistant strains [3].