Differential antibiotic resistance in biofilm forming Pseudomonas aeruginosa strains

Abstract

The Pseudomonas aeruginosa strains have ability to form biofilm a complex community, the
differential antibiotic resistance is mainly due to unique biofilm composition and its extent of
biofilm formation. In this study, five isolates of Ps. aeruginosa have been isolated from clinical
environment of Government Medical College & Hospital, Nanded on cetrimide agar plate. The
identification of Ps. aeruginosa strains were carried out on basis of morphological features and
16S rRNA gene sequencing. The biofilm formation ability of Ps. aeruginosa strains were
evaluated by using congo-red agar plate and micro-titer plate assay. The resistance of biofilm
forming Ps. aeruginosa strains to 20 antibiotics from diverse class had determined. The
identified Ps. aeruginosa strains using 16S rRNA gene sequencing showed 98-100% nucleotide
homology with biofilm forming and multi drug resistance Ps. aeruginosa strains on NCBI
nucleotide database. The Ps. aeruginosa strains isolated in present investigation showed strong,
moderate and weak biofilm formation ability. The strong biofilm forming strain PA5 showed
resistance to 13 antibiotics, moderate biofilm forming Ps. aeruginosa strains PA2 and PA3
showed resistance to 10 antibiotics and week biofilm forming Ps. aeruginosa strains PA6 and
PA7 showed resistance to 7 antibiotics. The biofilm, forming Ps. aeruginosa strains have
differential resistance to diverse class of antibiotics due to extent of biofilm formation