Breaking the vicious cycle of antibiotic killing and regrowth of biofilm-residing Pseudomonas aeruginosa.

Breaking the vicious cycle of antibiotic killing and regrowth of biofilm-residing Pseudomonas aeruginosa. Antimicrob Agents Chemother. 2018 Oct 08;: Authors: Müsken M, Pawar V, Schwebs T, Bähre H, Felgner S, Weiss S, Häussler S Abstract Biofilm-residing bacteria embedded in an extracellular matrix are protected from diverse physico-chemical insults. In addition to the general recalcitrance of biofilm-bacteria, high bacterial loads in biofilm-associated infections significantly diminishes the efficacy of antimicrobials due to a low per-cell antibiotic concentration. Accordingly, present antimicrobial treatment protocols, that have been established to serve the eradication of acute infections, fail to clear biofilm-associated chronic infections. In the present study, we applied automated confocal microscopy on Pseudomonas aeruginosa to monitor dynamic killing of biofilm-grown bacteria by tobramycin and colistin in real-time. We revealed that the time required for surviving bacteria to repopulate the biofilm could be taken as measure for effectiveness of the antimicrobial treatment. It depends on the: i) nature and concentration of the antibiotic, ii) duration of antibiotic treatment; iii) application as mono or combination therapy and iv) time intervals of drug administration. The vicious cycle of killing and repopulation of biofilm bacteria could also be broken in an in vivo model system by applying successive antibiotic dosages wi...
Source: Antimicrobial Agents and Chemotherapy - Category: Microbiology Authors: Tags: Antimicrob Agents Chemother Source Type: research