Environmental Surveillance of Pseudomonas aeruginosa: Virulence Determinants and Antibiotic Resistance Patterns in Hospital Settings

Abstract

Pseudomonas aeruginosa is an opportunistic pathogen mainly responsible for many nosocomial infections. The pathogen has the ability to produce a diverse range of virulence factors to establish infection in the host. Keeping these points in mind, the present study aims to isolate P. aeruginosa from the hospital environment to characterise its virulence and determine its antibiotic susceptibility pattern. The study selectively isolated P. aeruginosa using cetrimide agar and conducted phenotypic, biochemical, and virulence characterisation along with antibiotic susceptibility pattern testing. P. aeruginosa was found to be prevalent in the hospital environment. Approximately 92% of the isolates recovered exhibited a mucoid phenotype often associated with biofilm formation and persistence in P. aeruginosa, suggesting a pathogenic nature. The degree of siderophore production varied amongst the isolates, ranging from a 1.5-12 mm zone diameter. For phospholipase C production, 20% of isolates were strong producers, followed by 30% were moderate producers, and 50% were weak producers. All isolates recovered from the air sample in the outpatient Department (OPD) and water sample from the hospital canteen tested positive for hemolysin production. In contrast, isolates recovered from air samples at the hospital main gate and the Hospital Canteen did not produce hemolysin. All isolates exhibited cell-surface hydrophobicity ranging from 20% to 80%. Additionally, 70% of the isolates were resistant to ampicillin. Norfloxacin, imipenem, and gentamicin were effective against all isolates. The isolates showed variable susceptibility to ciprofloxacin and chloramphenicol. The current study revealed that P. aeruginosa possesses a diverse array of virulence factors, enabling it to cause a wide range of infections even after exposure to multiple antimicrobial agents.