You are here: Home Published Research Peroxiredoxin/glutaredoxin (pdgX) and catalase (htkE) promote resistance of nontypeable Haemophilus influenzae 86-028NP to oxidant and survival within neutrophil extracellular traps.

Richard A Juneau, Bing Pang, Chelsie E Armbruster, Kyle A Murrah, Antonia C Perez, and W. E Swords (2014)

Peroxiredoxin/glutaredoxin (pdgX) and catalase (htkE) promote resistance of nontypeable Haemophilus influenzae 86-028NP to oxidant and survival within neutrophil extracellular traps.

Infection and immunity.

Nontypeable Haemophilus influenzae (NTHi) is a common commensal and opportunistic pathogen of the human airways. For example, NTHi is a leading cause of otitis media and is the most common cause of airway infections associated with chronic obstructive pulmonary disease (COPD). These infections are often chronic/recurrent in nature and involve bacterial persistence within biofilm communities that are highly resistant to host clearance. Our previous work has shown that NTHi within biofilms have increased expression of factors associated with oxidative stress responses. The goal of this study was to define role(s) for catalase (hktE) and a bifunctional peroxiredoxin-glutaredoxin (pdgX) in resistance of NTHi to oxidants and persistence in vivo. Isogenic NTHi 86-028NP mutants lacking hktE and pdgX had increased susceptibility to peroxide. Moreover, these strains had persistence defects in the chinchilla infection model for otitis media, as well as a murine model for COPD. Additional work showed that pdgX and hktE were important determinants of NTHi survival within neutrophil extracellular traps (NETs), which we have shown to be an integral part of NTHi biofilms in vivo. Based on these data, we conclude that catalase and peroxiredoxin-glutaredoxin are determinants of bacterial persistence during chronic/recurrent NTHi infections that promote bacterial survival within NETs.

 
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