Activity of Gallium Meso- and Protoporphyrin IX against Biofilms of Multidrug-Resistant Acinetobacter baumannii Isolates
AbstractAcinetobacter baumannii is a challenging pathogen due to antimicrobial resistance and biofilm development. The role of iron in bacterial physiology has prompted the evaluation of iron-modulation as an antimicrobial strategy. The non-reducible iron analog gallium(III) nitrate, Ga(NO3)3, has been shown to inhibit A. baumannii planktonic growth; however, utilization of heme-iron by clinical isolates has been associated with development of tolerance. These observations prompted the evaluation of iron-heme sources on planktonic and biofilm growth, as well as antimicrobial activities of gallium meso- and protoporphyrin IX (Ga-MPIX and Ga-PPIX), metal heme derivatives against planktonic and biofilm bacteria of multidrug-resistant (MDR) clinical isolates of A. baumannii in vitro. Ga(NO3)3 was moderately effective at reducing planktonic bacteria (64 to 128 µM) with little activity against biofilms (≥512 µM). In contrast, Ga-MPIX and Ga-PPIX were highly active against planktonic bacteria (0.25 to 8 µM). Cytotoxic effects in human fibroblasts were observed following exposure to concentrations exceeding 128 µM of Ga-MPIX and Ga-PPIX. We observed that the gallium metal heme conjugates were more active against planktonic and biofilm bacteria, possibly due to utilization of heme-iron as demonstrated by the enhanced effects on bacterial growth and biofilm formation. View Full-Text
Share & Cite This Article
Chang, D.; Garcia, R.A.; Akers, K.S.; Mende, K.; Murray, C.K.; Wenke, J.C.; Sanchez, C.J. Activity of Gallium Meso- and Protoporphyrin IX against Biofilms of Multidrug-Resistant Acinetobacter baumannii Isolates. Pharmaceuticals 2016, 9, 16.
Chang D, Garcia RA, Akers KS, Mende K, Murray CK, Wenke JC, Sanchez CJ. Activity of Gallium Meso- and Protoporphyrin IX against Biofilms of Multidrug-Resistant Acinetobacter baumannii Isolates. Pharmaceuticals. 2016; 9(1):16.Chicago/Turabian Style
Chang, David; Garcia, Rebecca A.; Akers, Kevin S.; Mende, Katrin; Murray, Clinton K.; Wenke, Joseph C.; Sanchez, Carlos J. 2016. "Activity of Gallium Meso- and Protoporphyrin IX against Biofilms of Multidrug-Resistant Acinetobacter baumannii Isolates." Pharmaceuticals 9, no. 1: 16.
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.