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Fig. 1 | Antimicrobial Resistance & Infection Control

Fig. 1

From: Comparative evaluation of the effect of different growth media on in vitro sensitivity to azithromycin in multi-drug resistant Pseudomonas aeruginosa isolated from cystic fibrosis patients

Fig. 1

Evaluation of azithromycin MICs against P. aeruginosa strain PAO1 and MDR P. aeruginosa CF isolates in different media. a P. aeruginosa strain PAO1was inoculated in the indicated media and increase in bacterial growth was continuously evaluated over 24 h by measuring backscattered light intensity using Cell Growth Quantifier system. CA-MHB: cation-adjusted Mueller Hinton Broth; RPMI: Roswell Park Memorial Institute 1640 medium; FCS: fetal calf serum; SCFM: synthetic cystic fibrosis sputum medium. Data indicate mean (solid lines) +/− SD (dotted lines) from three independent experiments. b, c MICs of azithromycin were determined by broth microdilution in P. aeruginosa strain PAO1 (b) and in multidrug resistant (MDR) clinical P. aeruginosa isolates derived from cystic fibrosis patients (c) using CA-MHB, SCFM and RPMI 1640 supplemented with 30% FCS as test medium. Bars indicate mean +/− SD from three independent experiments (b) or median values (c). For MDR isolates, n = 29 for CA-MHB and RPMI/FCS and n = 27 for SCFM (Two isolates failed to grow in SCFM and were therefore excluded from analysis). Statistical analysis was performed using a Kruskal-Wallis test and Dunn’s test for multiple comparison. (**) p < 0.01; (***) p < 0.001; ns: not significant (d) MIC distribution in RPMI/FCS for strains that showed either wildtype (wt) or mutant (mut) sequence in 23S rRNA (pos. 2045, 2046 and 2598)

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