Antibiotic Susceptibility Profiling, Molecular Characterization, and16S rRNA-Based Phylogenetic Analysis of Pseudomonas Aeruginosa Isolates from Musculoskeletal Infections

Authors

Abstract

Objective: The primary goal of this research was to describe antibiotic resistance and identification of virulence genes in Pseudomonas aeruginosa.

Methods

The study was cross-sectional, featuring a randomized selection of samples. Conducted from January to December 2023, the study encompassed a sample size of 320 including blood, pus, and wound swabs [Male:169(52.8%), Female 151(47.1%)]. Age-based categories were ascertained, G1:13-20 years, G2:21-40 years, G3:41-60 years, G4:61-80 years. Identification tests for Pseudomonas aeruginosa included API20NE (bioMérieux®, France). Antimicrobial susceptibility testing was following the CLSI,2020 for the Disc Diffusion Test.DNA extraction and purification were carried out through a Genome Jet DNA Purification kit and 16S rRNA primers for the identification of resistance genes exoA and oprL. Phylogenetic and taxonomic identification was conducted via ribosomal RNA sequencing of PCR amplified products(BIO-RAD T100TM Thermocycler) and sequencing with an automated sequencer (Illumina MiniSeqTM). Phylogenetic tree was constructed by MEGA11.p-value<0.05 was statistically significant.

Results

 Prevalence of Pseudomonas aeruginosa was 22%. Positivity was recorded from pus (152/320:47.5%),blood(124/320-38.75%) and wound swabs(44/320-1 3.75%).G4 showed maximum positive isolates(91.25%).Maximum resistance was exhibited against Meropenem(76%) and Imipenem(70%).PCR identified the presence of resistance genes,exoA gene(125 bp), and oprL(105 bp). The phylogenetic tree was constructed through ribosomal RNA.The gene bank accession number for 16S rRNA gene of P. aeruginosa is PQ269824.

Conclusion

 Antimicrobial susceptibility testing helps improve the treatment alternatives for stubborn strains. The presence of resistance genes highlights how research at the molecular level enhances treatment approaches for managing multi-drug resistant pathogens.

Keywords:

Pseudomonas aeruginosa, antibiotic susceptibility, musculoskeletal infections, phylogenetic tree.

Published

2025/06/05