Study of Colistin Sensitivity Pattern of Pseudomonas Aeruginosa in a Tertiary Care Hospital

ABSTRACT

Introduction: Pseudomonas is an invasive organism thatcauses severe Hospital Acquired Infections in immunecompromised hosts and it exhibits a high degree of resistanceto broad spectrum antibiotics. In recent years Colistin is thedrug of choice for use against MDR strains. The aim wasto study the antibiotic susceptibility and Colistin sensitivitypattern of Pseudomonas isolates from various samples.Material and methods: 100 Pseudomonas aeruginosaisolates from various samples (exudates, bloods and urines)were included and other isolates were excluded in the study.The samples were collected under aseptic precautions.Isolation and identification of the isolates was done as per thestandard guidelines in the lab and AST was done by KirbyBauer disc diffusion method and interpretation was done asper CLSI guidelines.Results: Out of 100 isolates, 36 were from the surgicalwards;30, 20 and 14 were from medical wards, OBG andGHCCD respectively. 83%of isolates were sensitive toColistin and 17% were resistant. MDR strains (both ESBL’sand MBL’s) were detected in 33% and out of these 15.2%were also resistant to Colistin.Conclusion: Colistin is one of the first antibiotics withsignificant activity against MDR Gram negative pathogensand its usefulness has been documented that it will be the “lastline” therapeutic drug in the 21st century. In the present studyit is showing that resistance to Colistin is also increasing,recommending regular monitoring of AST for propermanagement and to limit its use routinely