Identification of carbonylated proteins in a bactericidal process induced by curcumin with blue light irradiation on imipenem‐resistant Acinetobacter baumannii

Abstract

Rationale Antimicrobial photodynamic treatment is potentially an alternative to antibiotics and is also effective against viruses, fungi and some cancers. Our previous studies have shown that blue light combined with curcumin, a chemical from the turmeric plant, exerted effective antimicrobial activity via photodynamic treatment. The study reported in this paper investigates which target proteins are affected after the treatment. Methods We treated imipenem‐resistant Acinetobacter baumannii with blue light and curcumin and used protein carbonylation as a marker for oxidative damage. After treatment, the bacterial proteins were extracted and the protein carbonyls marked using dinitrophenylhydrazide. After enzyme digestion, we used liquid chromatography/nano‐electrospray ionization (LC/nano‐ESI) ion trap mass spectrometry to identify bacterial peptides from a customized database. The functional enrichment analyses of the identified proteins were performed using gene ontology annotation and the STRING protein–protein interaction network. Results The application of curcumin with blue light showed good antibacterial activity against imipenem‐resistant A. baumannii. Using a shotgun proteomics approach, the carbonylated proteins in A. baumannii caused by the photolytic curcumin were identified. The results showed that the proteins related to membrane structures, translation and response to oxidative stress were preferentially modified. Conclusions The photolytic curcumin treatment could be a potential alternative to antibiotics for bacterial infection. In this study, the shotgun proteomics strategy allows us to explore the possible bactericidal mechanisms under this oxidative stress. The result provides a reference for future studies on the enhancement of the action of photolytic curcumin.

Inactivation of Opportunistic Pathogens Acinetobacter baumannii and Stenotrophomonas maltophilia by Antimicrobial Photodynamic Therapy

“…The A. baumannii inactivation efficiency shown for RF-aPDT in our study, is similar to that reported for Aloe emodin, although the former was achieved applying a ten-times higher dye concentration and a twice-higher illumination dose. Chang et al [ 26 ] reported 97.5% inhibition of imipenem-resistant A. baumannii planktonic cells with curcumin-based aPDT. The effect was achieved by applying a 0.2 mM PS concentration and blue light irradiation using a 5.4 J/cm 2 illumination dose (3 mW/cm 2 ).…”

“…However, data on natural PS-based aPDT perspectives in the control of emerging multidrug resistant hospital infection agents and their biofilms remain scarce. For A. baumannii aPDT inactivation, only a few natural PSs [ 25 , 26 , 27 , 28 ] have been analyzed, although none of these studies addressed biofilm inactivation. Furthermore, no research has been performed on S. maltophilia aPDT inactivation, neither with natural nor with other PSs.…”

Natural Photosensitizers in Antimicrobial Photodynamic Therapy

“…in food-related diseases, periodontitis, wound healing, and multidrug resistance. Curcumin concentrations ranging from 0.5 µM to 6.1 mM have been effectively used in APDT studies [ 35 , 77 , 78 , 81 , 82 , 83 , 84 , 86 , 87 , 88 , 89 , 90 ]. In addition, mosquito larvae are controlled by curcumin exposure for 120 min at a light intensity of 220 W/m 2 [ 91 ].…”

Antimicrobial Effect of Phytochemicals from Edible Plants

“…The antimicrobial activity of riboflavin under illumination has been demonstrated against a variety of microorganisms (Table 3). Acinetobacter baumannii [211] Aggregatibacter actinomycetemcomitans [212,213] Escherichia coli [214][215][216][217][218][219][220] Enterococcus faecalis [221][222][223][224][225][226][227] Helicobacter pylori [228] Lactobacillus casei [179] Listeria innocua [216,229] Listeria monocytogenes [230,231] Porphyromonas gingivalis [212] Propionibacterium acnes [224,232] Pseudomonas [233] Pseudomonas aeruginosa [234] Staphylococcus aureus [177,214,215,218,220,[234][235][236][237][238][239][240][241][242][243] Salmonella strains [230] Salmonella typhimurium…”