Fig. 1.

Vancomycin and colistin in Gram-negative reference and MDR isolates. In vitro evaluation of the bactericidal activity of colistin combinations at 0.5× MIC against A. baumannii ATCC 19606 (a), K. pneumoniae ATCC 700603 (b), P. aeruginosa ATCC 27853 (c), ABm1 [COL MIC = 8] (d), KPm1 [COL MIC = 32] (e), and PAm1 [COL MIC = 8] (f). Filled circle growth control, open circle colistin plus vancomycin, inverted filled triangle colistin plus trimethoprim, open triangle colistin plus trimethoprim–sulfamethoxazole. ATCC American type culture collection, COL combination with colistin, MDR multidrug resistant, MIC minimum inhibitory concentration. Reproduced with permission from Antimicrobial Agents and Chemotherapy [29]