|PIRAS, CRISTIAN - University Of Milan|
|SOGGIU, ALESSIO - University Of Milan|
|GRECO, VIVIANA - University Of Rome|
|PIERA, ANNA - University Of Milan|
|DEL CHIERICO, FEDERICA - Ospedale Pediatrico Bambino Gesu|
|PUTIGNANI, LORENZA - Ospedale Pediatrico Bambino Gesu|
|URBANI, ANDREA - University Of Rome|
|BONIZZI, LUIGI - University Of Milan|
|RONCADA, PAOLA - University Of Milan|
Submitted to: Journal of Proteomics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/8/2015
Publication Date: 6/9/2015
Citation: Piras, C., Soggiu, A., Greco, V., Piera, A.M., Del Chierico, F., Putignani, L., Urbani, A., Nally, J.E., Bonizzi, L., Roncada, P. 2015. Mechanisms of antibiotic resistance to enrofloxacin in uropathogenic Escherichia coli in dog. Journal of Proteomics. DOI: 10.1016/j.jprot.2015.05.040.
Interpretive Summary: Enrofloxacin is one of the most efficient antibiotics against the bacterial pathogen Escherichia coli. However, there is considerable evidence that E. coli can acquire antibiotic resistance to enrofloxacin. In order to investigate mechanisms of resistance to enrofloxacin, an isolate of E. coli that causes urinary tract infections in dogs was selected for its ability to grow in the presence of 10 µg/ml of enrofloxacin. The tools of proteomics, including 2D DIGE and shotgun mass spectrometry, were used to identify pathways that mediate antibiotic resistance. Pathways identified include one that is involved in the stabilization of the structure of DNA via increased expression of Dsp protein. A second pathway was identified that demonstrated decreased expression of the outer membrane protein W which reduces membrane permeability to enrofloxacin. Differentially expressed proteins that mediate resistance to enrofloxacin are putative targets for the development of new strategies to counteract antibiotic resistance.
Technical Abstract: Escherichia coli (E. coli) urinary tract infections (UTIs) are becoming a serious problem both for pets and humans (zoonosis) due to the close contact and to the increasing resistance to antibiotics. Canine E. coli represents a good experimental model useful to study this pathology. Moreover, as described afterwards, there have been found similarities between canine E. coli infections and human ones, suggesting the possibility that dogs could represent a reservoir for human infection. This study has been performed in order to unravel the mechanism of induced enrofloxacin resistance in E. coli. Proteins that are principally involved in antibiotic resistance are linked to the oxidative stress response, to DNA protection and in membrane permeability. Moreover, since enrofloxacin is an inhibitor of DNA gyrase, the overexpression of DNA starvation/stationary phase protection protein (Dsp) could be a central point to discover the mechanism of this clone to counteract the effects of enrofloxacin. In parallel, the dramatic decrease of the synthesis of the outer membrane protein W, which represents one of the main gates for enrofloxacin entrance, could be explain additional mechanism of E. coli defense against this antibiotic.