Biofilm-Producing and Specific Antibiotic Resistance Genes in Pseudomonas aeruginosa Isolated from Patients Admitted to a Tertiary Care Hospital, Bangladesh

Abstract

Pseudomonas aeruginosa is one of the organisms well-known for producing biofilm. Biofilms are responsible for persistent infections and antimicrobial resistance. The aim of this was to investigate P. aeruginosa for its ability to form biofilm. Genes that were responsible for the production of biofilms and biofilm-specific antimicrobial resistance were detected. The association between antibiotic resistance and biofilm was investigated. This cross-sectional study was conducted from July 2017 to December 2018. A total of 446 samples (infected burns, surgical wounds, and ETA) were collected from admitted patients at Dhaka Medical College and Hospital, Bangladesh. P. aeruginosa was isolated and identified by biochemical tests and PCR. Biofilm production by the tissue culture plate (TCP) method was followed by the detection of biofilm[1]producing genes (pqsA, pslA, pslD, pslH, pelA, lasR) and biofilm-specific antibiotic resistance genes (ndvB, PA1874, PA1876, PA1877) by PCR. The antibiotic susceptibility test was carried out by the disc diffusion method; for colistin agar dilution, the MIC method was followed. Among 232 (52.02%) positive strains of P. aeruginosa, 24 (10.30%) produced biofilms in TCPM. Among biofilm-producing genes, pqsA was found the highest number of isolates (79.17%), which was followed by pslA and pelA (70.83%). Other were found in lesser extent. Among the biofilm-specific antibiotic resistance genes, 16.67% of the isolates had ndvB, and 8.33% had PA1874 and PA1877. Biofilm-forming strains were significantly resistant to colistin in comparison to non-biofilm-forming ones. In conclusion, detection of biofilm-forming genes may be a good tool for the evaluation of biofilm production, which will help in prompt and better management of chronic or device-associated infections.

Bangladesh J Microbiol, Volume 40, Number 2, December 2023, pp 60-65