title: Analysis of plasmid-mediated quinolone resistance genes in clinical isolates of the tribe Proteeae from Argentina: First report of qnrD in the Americas.
abstract: To analyse the occurrence and prevalence of plasmid-mediated quinolone resistance (PMQR) genes in the tribe Proteeae, 81 isolates (65 Proteus spp., 12 Morganella morganii and 4 Providencia stuartii) consecutively collected in 66 hospitals belonging to the WHONET-Argentina Resistance Surveillance Network were studied. Of the 81 isolates, 50 (62%) were susceptible to quinolones [43/65 (66%) Proteus spp. and 7/12 (58%) M. morganii). The remaining 31 isolates (22 Proteus spp., 5 M. morganii and all P. stuartii) showed high-level resistance to nalidixic acid (NAL) and decreased susceptibility or resistance to ciprofloxacin. All NAL-resistant isolates harboured mutations associated with quinolone resistance (MAQRs) in both gyrA (S83I/R) and parC (S80I/R), and some also had MAQRs in gyrB (S464Y/F). The unique PMQR gene detected was qnrD, which was found in 2/81 isolates (Proteus mirabilis Q1084 and Proteus vulgaris Q5169), giving a prevalence of 2.5% in Proteeae. These two isolates were from different geographical regions and both harboured MAQRs in gyrA and parC. The qnrD genes were located on the related plasmids pEAD1-1 (2683bp) and pEAD1-2 (2669bp). Plasmid pEAD1-1 was 100% identical to pCGH15 and differed in only three nucleotides from pDIJ09-518a, which were previously found in clinical isolates of P. mirabilis (China) and Providencia rettgeri (France), respectively, whilst pEAD1-2 was not previously described. The extended-spectrum β-lactamase CTX-M-2 was found in 27% (22/81) of the isolates and was significantly associated with quinolone resistance but not with qnrD (only P. mirabilis Q1084 expressed CTX-M-2). This is the first report of qnrD in the Americas.
authors.affiliation: Servicio Antimicrobianos, Departamento de Bacteriología, Instituto Nacional de Enfermedades Infecciosas-ANLIS 'Dr Carlos G. Malbrán', Av. Vélez Sarsfield 563 (C1282AFF), Ciudad Autónoma de Buenos Aires, Argentina.
authors.forename: Ezequiel
authors.initials: E
authors.lastname: Albornoz
authors.affiliation: Servicio Antimicrobianos, Departamento de Bacteriología, Instituto Nacional de Enfermedades Infecciosas-ANLIS 'Dr Carlos G. Malbrán', Av. Vélez Sarsfield 563 (C1282AFF), Ciudad Autónoma de Buenos Aires, Argentina.
authors.forename: Celeste
authors.initials: C
authors.lastname: Lucero
authors.affiliation: Servicio Antimicrobianos, Departamento de Bacteriología, Instituto Nacional de Enfermedades Infecciosas-ANLIS 'Dr Carlos G. Malbrán', Av. Vélez Sarsfield 563 (C1282AFF), Ciudad Autónoma de Buenos Aires, Argentina.
authors.forename: Genara
authors.initials: G
authors.lastname: Romero
authors.affiliation: Servicio Antimicrobianos, Departamento de Bacteriología, Instituto Nacional de Enfermedades Infecciosas-ANLIS 'Dr Carlos G. Malbrán', Av. Vélez Sarsfield 563 (C1282AFF), Ciudad Autónoma de Buenos Aires, Argentina.
authors.forename: Melina
authors.initials: M
authors.lastname: Rapoport
authors.affiliation: Servicio Antimicrobianos, Departamento de Bacteriología, Instituto Nacional de Enfermedades Infecciosas-ANLIS 'Dr Carlos G. Malbrán', Av. Vélez Sarsfield 563 (C1282AFF), Ciudad Autónoma de Buenos Aires, Argentina.
authors.forename: Leonor
authors.initials: L
authors.lastname: Guerriero
authors.affiliation: Servicio Antimicrobianos, Departamento de Bacteriología, Instituto Nacional de Enfermedades Infecciosas-ANLIS 'Dr Carlos G. Malbrán', Av. Vélez Sarsfield 563 (C1282AFF), Ciudad Autónoma de Buenos Aires, Argentina.
authors.forename: Patricia
authors.initials: P
authors.lastname: Andres
authors.affiliation: Servicio Antimicrobianos, Departamento de Bacteriología, Instituto Nacional de Enfermedades Infecciosas-ANLIS 'Dr Carlos G. Malbrán', Av. Vélez Sarsfield 563 (C1282AFF), Ciudad Autónoma de Buenos Aires, Argentina.
authors.affiliation: Servicio Antimicrobianos, Departamento de Bacteriología, Instituto Nacional de Enfermedades Infecciosas-ANLIS 'Dr Carlos G. Malbrán', Av. Vélez Sarsfield 563 (C1282AFF), Ciudad Autónoma de Buenos Aires, Argentina.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Galas
authors.affiliation: Servicio Antimicrobianos, Departamento de Bacteriología, Instituto Nacional de Enfermedades Infecciosas-ANLIS 'Dr Carlos G. Malbrán', Av. Vélez Sarsfield 563 (C1282AFF), Ciudad Autónoma de Buenos Aires, Argentina.
authors.forename: Alejandra
authors.initials: A
authors.lastname: Corso
authors.affiliation: Servicio Antimicrobianos, Departamento de Bacteriología, Instituto Nacional de Enfermedades Infecciosas-ANLIS 'Dr Carlos G. Malbrán', Av. Vélez Sarsfield 563 (C1282AFF), Ciudad Autónoma de Buenos Aires, Argentina. Electronic address: apetroni@anlis.gov.ar.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Petroni
keywords: Plasmid-mediated quinolone resistance; Quinolone; gyrA; gyrB; parC; qnrD