Prevalence -lactam resistant Pseudomonas aeruginosa strains isolated from chronic supportive otitis media infections: A single center survey in Eastern India

Abstract

is a pernicious opportunistic bacterium causing several human infections due to its ubiquitous presence and adaptability to various environmental conditions. Primarily, β-lactamase producing strains are the most prevalent ones, especially chronic suppurative otitis media (CSOM) infections. This research was conducted to find the pervasiveness of β-lactam producing strains in CSOM patients attending a multispeciality hospital in Eastern India.The 100 swabs were collected from CSOM patients, of which 76 were males (mean age 46) and 24 were females (mean age 41); strains were isolated and identified using routine microbiological methods. Kirby-Bauer method was employed to determine the antibiotic sensitivity of the isolated strains. Virulence tests like the swarming mortality test, biofilm formation assay, haemolysis assay, protease and pyocyanin production assay were conducted to detect the presence of various inherent virulence characters qualitatively. Both phenotypic and genotypic determination of β-lactamase-producing strains were confirmed by disc diffusion test and PCR methods.Out of 100 samples, 67 strains were isolated, and all were motile. All strains tested positive for pyocyanin and haemolysis enzymes. Most strains had the biofilm formation capacity and release of protease enzyme. Most strains were multidrug-resistant, particularly to the β-lactam group of antibiotics. Nearly 80% of strains harboured all four classes of β-lactamase genes, producing enzymes like ESBLs, MBLs, AmpC and carbapenemase. The β-lactamase genes and the inherent virulence factors that increase the infectiousness and adaptability of strains are significantly correlated. Immediate modified antibiotic policy should be employed to overcome this issue of multidrug resistance.