PcrV antibody protects multi-drug resistant Pseudomonas aeruginosa induced acute lung injury

• We analyzed the expression level of TTSS in clinically isolated multi-drug resistant Pseudomonas aeruginsoa strains and compared it with susceptible strains.
• We investigated the effect of PcrV antibody on multi-drug resistant Pseudomonas aeruginosa induced acute lung injury.
• The TTSS is comparatively conservative without correlation with antimicrobial resistance.
• PcrV antibody could protect multi-drug resistant Pseudomonas aeruginosa induced acute lung injury.

Blocking PcrV, an essential component of the Type III secretion system (TTSS), has demonstrated efficacy against Pseudomonas aeruginosa infections. However, most of the results came from laboratory strains. Whether it is applicable to clinically isolated multi-drug resistant (MDR) strains is unknown. In this study we investigated the expression level of TTSS in clinically isolated MDR P. aeruginosa strains and the effects of anti-PcrV antibody on MDR isolate induced acute lung injury (ALI). The expression level of TTSS was quantified in 53 isolates including 25 MDR strains and 28 susceptible strains. We investigated the effect of anti-PcrV antibody through a murine model induced by instillation of a MDR strain into the left lung through trachea. Our results showed that the expression level of TTSS in MDR strains is comparable to susceptible strains. Anti-PcrV ensured the survival of challenged mice, reduced the bacteria numbers and attenuated lung inflammation and injury. This study proved that anti-PcrV may be a potentially effective strategy against MDR P. aeruginosa induced ALI.