title: Re-identification of Aeromonas isolates from rainbow trout and incidence of class 1 integron and β-lactamase genes.
abstract: Forty-eight Aeromonas isolates from rainbow trout previously identified by the 16S rDNA-RFLP technique were re-identified using 2 housekeeping genes (gyrB and rpoD). After sequencing the prevalences of the species were A. veronii (29.2%), A. bestiarum (20.8%), A. hydrophila (16.7%), A. sobria (10.4%), A. media (8.3%), A. popoffii (6.2%), A. allosaccharophila (2.1%), A. caviae (2.1%), A. salmonicida (2.1%) and one isolate (2.1%) belongs to a candidate new species "Aeromonas lusitana". Coincident identification results to the 16S rDNA-RFLP technique were only obtained for 68.8% of the isolates. PCR amplification of the enterobacterial repetitive intergenic consensus (ERIC-PCR) indicated that the 48 isolates belonged to 33 different ERIC genotypes. Several genotypes were isolated from different farms and organs in the same fish, indicating a systemic dissemination of the bacteria. The presence of genes (blaIMP, blaCphA/IMIS, blaTEM, blaSHV and intI1) that encode extended-spectrum beta-lactamases (ESBLs), metallo-beta-lactamases (MBLs) and class 1 integrons were studied by PCR. Only 39.6% (19/48) of the strains showed the presence of one or more resistance genes. The gene blaCphA/IMIS was detected in 29.2% of the isolates, followed by the intI1 (6.2%) and blaSHV (4.2%) genes. The variable region of class 1 integrons of the 3 positive isolates was sequenced revealing the presence of the gene cassette aadA1 (aminoglycoside transferase) that plays a role in streptomycin/spectinomycin resistance.
authors.affiliation: Centro de Investigación y Estudios Avanzados en Salud Animal, Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma del Estado de México, Toluca, Mexico.
authors.forename: Vicente
authors.initials: V
authors.lastname: Vega-Sánchez
authors.affiliation: Unitat de Microbiologia, Departament de Ciènces Médiques Bàsiques, Facultat de Medicina i Ciències de la Salut, IISPV, Universitat Rovira i Virgili, Reus, Spain.
authors.forename: Fadua
authors.initials: F
authors.lastname: Latif-Eugenín
authors.affiliation: Centro de Investigación y Estudios Avanzados en Salud Animal, Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma del Estado de México, Toluca, Mexico.
authors.forename: Edgardo
authors.initials: E
authors.lastname: Soriano-Vargas
authors.affiliation: Unitat de Microbiologia, Departament de Ciènces Médiques Bàsiques, Facultat de Medicina i Ciències de la Salut, IISPV, Universitat Rovira i Virgili, Reus, Spain.
authors.forename: Roxana
authors.initials: R
authors.lastname: Beaz-Hidalgo
authors.affiliation: Unitat de Microbiologia, Departament de Ciènces Médiques Bàsiques, Facultat de Medicina i Ciències de la Salut, IISPV, Universitat Rovira i Virgili, Reus, Spain. Electronic address: mariajose.figueras@urv.cat.
authors.forename: María José
authors.initials: MJ
authors.lastname: Figueras
authors.affiliation: Laboratorio de Bacteriología Médica, Escuela Nacional de Ciencias Biológicas (ENCB), Instituto Politécnico Nacional (IPN), Mexico.
authors.forename: Ma Guadalupe
authors.initials: MG
authors.lastname: Aguilera-Arreola
authors.affiliation: Laboratorio de Bacteriología Médica, Escuela Nacional de Ciencias Biológicas (ENCB), Instituto Politécnico Nacional (IPN), Mexico. Electronic address: chelacastro@hotmail.com.
authors.forename: Graciela
authors.initials: G
authors.lastname: Castro-Escarpulli
mesh_terms: D000333:Aeromonas / Q000235:genetics / Q000302:isolation & purification*; D000818:Animals; D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D005393:Fish Diseases / Q000382:microbiology*; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D016905:Gram-Negative Bacterial Infections / Q000382:microbiology / Q000662:veterinary*; D015994:Incidence; D032023:Integrons / Q000235:genetics*; D017686:Oncorhynchus mykiss; D001618:beta-Lactamases / Q000235:genetics / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D001618:beta-Lactamases
keywords: Aeromonas; ESBLs; Integrons; Rainbow trout; gyrB; rpoD