TY - JOUR
T1 - In vitro activity of colistin against biofilm by Pseudomonas aeruginosa is significantly improved under "cystic fibrosis-like" physicochemical conditions
AU - Pompilio, Arianna
AU - Crocetta, Valentina
AU - Pomponio, Stefano
AU - Fiscarelli, Ersilia
AU - Di Bonaventura, Giovanni
PY - 2015/8/1
Y1 - 2015/8/1
N2 - The impact of physicochemical conditions observed in cystic fibrosis (CF) lung on colistin activity against both planktonic and biofilm P. aeruginosa cells was evaluated. MIC, minimum bactericidal concentration (MBC), and minimum biofilm eradication concentration (MBEC) values were assessed against 12 CF strains both under "CF-like" (anaerobiosis, pH6.4) and "standard" (aerobiosis, pH7.4) conditions. The activity of colistin was significantly higher under "CF-like" conditions compared to "standard" ones, both against planktonic (MIC90: 1 and 4μg/mL, respectively) and biofilm (MBEC90: 512 and 1.024μg/mL, respectively) cells, as confirmed by scanning electron microscopy. Improved activity was not related to biofilm matrix amount. It may be necessary to adequately "rethink" the protocols used for in vitro assessment of colistin activity, by considering physicochemical and microbiological features in the CF lung at the site of infection. This could provide a more favorable therapeutic index, rationale for administration of lower doses, probably resulting in reduced toxicity and emergence of resistant clones.
AB - The impact of physicochemical conditions observed in cystic fibrosis (CF) lung on colistin activity against both planktonic and biofilm P. aeruginosa cells was evaluated. MIC, minimum bactericidal concentration (MBC), and minimum biofilm eradication concentration (MBEC) values were assessed against 12 CF strains both under "CF-like" (anaerobiosis, pH6.4) and "standard" (aerobiosis, pH7.4) conditions. The activity of colistin was significantly higher under "CF-like" conditions compared to "standard" ones, both against planktonic (MIC90: 1 and 4μg/mL, respectively) and biofilm (MBEC90: 512 and 1.024μg/mL, respectively) cells, as confirmed by scanning electron microscopy. Improved activity was not related to biofilm matrix amount. It may be necessary to adequately "rethink" the protocols used for in vitro assessment of colistin activity, by considering physicochemical and microbiological features in the CF lung at the site of infection. This could provide a more favorable therapeutic index, rationale for administration of lower doses, probably resulting in reduced toxicity and emergence of resistant clones.
KW - Biofilm
KW - Colistin
KW - Cystic fibrosis
KW - In vitro antimicrobial susceptibility assay
KW - Lung infection
KW - Pseudomonas aeruginosa
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UR - http://www.scopus.com/inward/citedby.url?scp=84930576537&partnerID=8YFLogxK
U2 - 10.1016/j.diagmicrobio.2015.01.006
DO - 10.1016/j.diagmicrobio.2015.01.006
M3 - Article
C2 - 26004353
AN - SCOPUS:84930576537
VL - 82
SP - 318
EP - 325
JO - Diagnostic Microbiology and Infectious Disease
JF - Diagnostic Microbiology and Infectious Disease
SN - 0732-8893
IS - 4
ER -