title: Fluoroquinolone efflux in Streptococcus suis is mediated by SatAB and not by SmrA.
abstract: Streptococcus suis is an emerging zoonotic pathogen. With the lack of an effective vaccine, antibiotics remain the main tool to fight infections caused by this pathogen. We have previously observed a reserpine-sensitive fluoroquinolone (FQ) efflux phenotype in this species. Here, SatAB and SmrA, two pumps belonging to the ATP binding cassette (ABC) and the major facilitator superfamily (MFS), respectively, have been analyzed in the fluoroquinolone-resistant clinical isolate BB1013. Genes encoding these pumps were overexpressed either constitutively or in the presence of ciprofloxacin in this strain. These genes could not be cloned in plasmids in Escherichia coli despite strong expression repression. Finally, site-directed insertion of smrA and satAB in the amy locus of the Bacillus subtilis chromosome using ligated PCR amplicons allowed for the functional expression and study of both pumps. Results showed that SatAB is a narrow-spectrum fluoroquinolone exporter (norfloxacin and ciprofloxacin), susceptible to reserpine, whereas SmrA was not involved in fluoroquinolone resistance. Chromosomal integration in Bacillus is a novel method for studying efflux pumps from Gram-positive bacteria, which enabled us to demonstrate the possible role of SatAB, and not SmrA, in fluoroquinolone efflux in S. suis.
authors.affiliation: Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid, Spain.
authors.forename: Jose Antonio
authors.initials: JA
authors.lastname: Escudero
authors.forename: Alvaro
authors.initials: A
authors.lastname: San Millan
authors.forename: Belen
authors.initials: B
authors.lastname: Gutierrez
authors.forename: Laura
authors.initials: L
authors.lastname: Hidalgo
authors.forename: Roberto M
authors.initials: RM
authors.lastname: La Ragione
authors.forename: Manal
authors.initials: M
authors.lastname: AbuOun
authors.forename: Marc
authors.initials: M
authors.lastname: Galimand
authors.forename: María José
authors.initials: MJ
authors.lastname: Ferrándiz
authors.forename: Lucas
authors.initials: L
authors.lastname: Domínguez
authors.forename: Adela G
authors.initials: AG
authors.lastname: de la Campa
authors.forename: Bruno
authors.initials: B
authors.lastname: Gonzalez-Zorn
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D000890:Anti-Infective Agents / Q000378:metabolism* / Q000494:pharmacology; D001412:Bacillus subtilis / Q000235:genetics; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D024881:Drug Resistance, Bacterial; D024841:Fluoroquinolones / Q000378:metabolism* / Q000494:pharmacology; D006801:Humans; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D020411:Oligonucleotide Array Sequence Analysis; D010641:Phenotype; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D017011:Streptococcus suis / Q000187:drug effects* / Q000378:metabolism
chemical_list: D018528:ATP-Binding Cassette Transporters; D000890:Anti-Infective Agents; D001426:Bacterial Proteins; D024841:Fluoroquinolones