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RND Efflux Systems Contribute to Resistance and Virulence of Aliarcobacter butzleri

Authors :
Cristiana Mateus
Ana Rita Nunes
Mónica Oleastro
Fernanda Domingues
Susana Ferreira
Source :
Antibiotics, Vol 10, Iss 7, p 823 (2021)
Publication Year :
2021
Publisher :
MDPI AG, 2021.

Abstract

Aliarcobacter butzleri is an emergent enteropathogen that can be found in a range of environments. This bacterium presents a vast repertoire of efflux pumps, such as the ones belonging to the resistance nodulation cell division family, which may be associated with bacterial resistance, as well as virulence. Thus, this work aimed to evaluate the contribution of three RND efflux systems, AreABC, AreDEF and AreGHI, in the resistance and virulence of A. butzleri. Mutant strains were constructed by inactivation of the gene that encodes the inner membrane protein of these systems. The bacterial resistance profile of parental and mutant strains to several antimicrobials was assessed, as was the intracellular accumulation of the ethidium bromide dye. Regarding bacterial virulence, the role of these three efflux pumps on growth, strain fitness, motility, biofilm formation ability, survival in adverse conditions (oxidative stress and bile salts) and human serum and in vitro adhesion and invasion to Caco-2 cells was evaluated. We observed that the mutants from the three efflux pumps were more susceptible to several classes of antimicrobials than the parental strain and presented an increase in the accumulation of ethidium bromide, indicating a potential role of the efflux pumps in the extrusion of antimicrobials. The mutant strains had no bacterial growth defects; nonetheless, they presented a reduction in relative fitness. For the three mutants, an increase in the susceptibility to oxidative stress was observed, while only the mutant for AreGHI efflux pump showed a relevant role in bile stress survival. All the mutant strains showed an impairment in biofilm formation ability, were more susceptible to human serum and were less adherent to intestinal epithelial cells. Overall, the results support the contribution of the efflux pumps AreABC, AreDEF and AreGHI of A. butzleri to antimicrobial resistance, as well as to bacterial virulence.

Details

Language :
English
ISSN :
20796382
Volume :
10
Issue :
7
Database :
Directory of Open Access Journals
Journal :
Antibiotics
Publication Type :
Academic Journal
Accession number :
edsdoj.1735209ba653474cb51d9c05447fa847
Document Type :
article
Full Text :
https://doi.org/10.3390/antibiotics10070823