Investigation of Virulence Factors and Antibiotic Resistance of Pseudomonas aeruginosa Isolated from A Range of Clinical Samples

Abstract

Objective: Pseudomonas aeruginosa is an opportunistic pathogen, is one of the leading nosocomial infection-causing agents and over time has developed multidrug resistance. One of the most common patient groups affected by P. aeruginosa are on the intensive care unit (ICU), an optimal environment for the development of antibiotic resistance. The aim of this study was to investigate virulence factors and antibiotic resistance profiles of P. aeruginosa isolated from hospitalized patients in Turkey. Methods: Samples from the general wards and ICU-hospitalized patients were included. A nutrient agar-elastin method was used for the biochemical activity of elastase. For las B assessment PCR was used while special production medium was used to assay pyoverdine and pyocyanin. Isolate biofilm production was tested with the crystal violet method. Standard broth microdilution was used for antibiotic susceptibility. Results: A total of 208 samples were assessed. The virulence factor frequencies in ICU and ward isolates, were: pyocyanin 86.2% and 86.7%, pyoverdine 90.1%, and 89.6%, elastase 68.6% and 67.9%, las B 93.1% and 89.6%, and biofilm production 51.9% and 48.1%, respectively. Antibiotic resistance rates in ICU and ward were: meropenem 41.1% and 28.9%, colistin 11.7% and 13.2%, ceftazidime 43.1%,and 41.1%, and cefepime 52.9% and 48.5%. Conclusion: Virulence factors were present in most of the hospitalized patient samples. However, antibiotic resistance rates were below 50%, except for cefepime. In addition, low rates of colistin resistance suggest that colistin resistance is not yet widespread in our hospital.