Inhibition of Quorum Sensing-Controlled Virulence Factors and Biofilm Formation inPseudomonas aeruginosaby Culture Extract from Novel Bacterial Species ofPaenibacillusUsing a Rat Model of Chronic Lung Infection

摘要

Quorum sensing (QS) is a key regulator of virulence factors and biofilm formation in Gram-negative bacteria such asPseudomonas aeruginosa. Microorganisms that inhabit soil are of strategic importance in the discovery of compounds with anti-QS properties. The objective of the study was to test the culture extract of a taxonomically novel species ofPaenibacillusstrain 139SI for its inhibitory effects on the QS-controlled virulence factors and biofilm formation ofPseudomonas aeruginosabothin vitroandin vivo. ThePaenibacillussp. culture extract was used to test its anti-QS effects on the LasA protease, LasB elastase, pyoverdin production, and biofilm formation ofP. aeruginosaas well as evaluate its therapeutic effects on lung bacteriology, pathology, hematological profile, and serum antibody responses of experimental animals in a rat model of chronic lung infection. Results showed significant decrease in the activities of QS-controlled LasA protease, LasB elastase pyoverdin, and biofilm formation ofP. aeruginosacaused by the culture extract. Moreover, the extract significantly prolonged the survival times of rats and facilitated the clearance of biofilm infections from infected lungs. In conclusion, the antiquorum sensing effects of culture extract from a novel species ofPaenibacillusprovide new insights to combat biofilm-associated infections.