Ubiquitous in nature and often surface associated, biofilms cause numerous chronic human infections. Biofilms are structured multicellular bacterial communities where cells are entrapped in a polymer matrix. Bacteria growing as biofilms are characterized by marked tolerance to many biocides, including oxidants such as hydrogen peroxide. Hydrogen peroxide is both produced by host phagocytic cells, and used as an antimicrobial compound. Understanding biofilm tolerance to hydrogen peroxide is therefore relevant to the persistence of Pseudomonas aeruginosa in human infections (such as chronic Pseudomonas aeruginosa infections in cystic fibrosis airways) as well as in environmental settings (such as water pipes).

This protocol was developed to determine the tolerance of Pseudomonas aeruginosa biofilms to hydrogen peroxide (H₂O₂) killing. The bacteria are grown as colony biofilms on polycarbonate membranes, as previously described in Walters et al. 2003. The protocol may be adapted for other bacterial, with appropriate changes in H₂O₂ concentrations, since different bacterial species may be more or less susceptible to H₂O₂ than Pseudomonas aeruginosa.

Pseudomonas aeruginosa (铜绿假单胞菌)

Biofilms (生物膜)

Oxidative stress (氧化应激)

Hydrogen peroxide (过氧化氢)

Tolerance (容忍)