Characterization of Pseudomonas Aeruginosa Isolated from Intensive Care Units in Shahid Gangalal National Heart Center

Abstract

Pseudomonas aeruginosa is a gram negative bacterium responsible for several nosocomial infections in highly immunocompromised and catheterized patients in Intensive Care Unit (ICU). In order to characterize and determine the prevalence of P. aeruginosa in the ICUs of Shahid Gangalal National Heart Center, a six month cross sectional microbial study was undertaken. A total of 700 clinical specimens and 360 surface swab samples from ICU were collected and analyzed for bacteriological profile. The bacterial isolates were identified by biochemical testing. Antibiotic susceptibility testing of isolated bacteria was performed by Kirby Bauer disc diffusion technique. In all clinical samples analyzed, P. aeruginosa was detected in 66 (9.43%) samples while in all surface swab samples analyzed, P. aeruginosa was detected in 60 (16.67%) samples. 48 (72.7%) of clinical samples yielded mucoid strains while it was only 24 (40%) for surface swab samples. Among clinical samples, 61 (92.4%) were pigment producing strains while 5 (7.6%) were non-pigmented strains. Likewise, among the surface swab samples, 45 (75.0%) were pigment producing strains of P. aeruginosa while 15 (25.0%) were non-pigmented strains. Antibiotic Susceptibility Test demonstrated that among clinical isolates 56 (84.8%) were sensitive to cefoparazone-sulbactam followed by 42 (63.6%) to polymixin-B and 36 (54.5%) to piperacillin-tazobactam, while among surface swab sample isolates more than 90% isolates were sensitive to most of the common antibiotics used. 59 (89.4%) Multi-drug Resistant P. aeruginosa (MDRPA) were isolated from clinical samples while it was only 7 (11.7%) from surface swab samples. This study signified that P. aeruginosa was an important cause of infection in patients admitted in the ICUs and it could be present in the inanimate surfaces of ICUs posing threat to the ICU patients. Regular monitoring of antimicrobial susceptibility and rational use of antibiotics would be the essential steps to eliminate possible outbreaks of MDRPA in the ICUs.