title: Faecal Escherichia coli isolates from healthy dogs harbour CTX-M-15 and CMY-2 β-lactamases.
abstract: The presence of extended spectrum β-lactamase (ESBL) and plasmid-mediated AmpC β-lactamase (pAmpC) producing Escherichia coli, along with the mechanisms of antimicrobial resistance and the molecular types of isolates, was investigated in faecal samples from 53 healthy dogs in Mexico. Samples were inoculated on Levine agar plates with 2 µg/mL cefotaxime for recovery of cefotaxime-resistant (CTX(R)) E. coli. CTX(R)E. coli isolates were recovered from 9/53 (17%) samples; one isolate was characterised from each positive sample. ESBL producing E. coli isolates were detected in 3/53 (6%) samples; these isolates carried the blaCTX-M-15 gene and one isolate also carried blaSHV-2. These three ESBL-positive E. coli isolates belonged to phylogroup A and sequence types ST617, ST410 or ST3944. The remaining 6/53 (11%) samples contained pAmpC positive isolates; these isolates carried the blaCMY-2 gene, which encodes CMY-2 β-lactamase. These six isolates belonged to phylogroups A (n = 2), B1 (n = 1) and D (n = 3), and sequences types ST1431, ST57, ST93 and ST4565. One CMY-2 β-lactamase positive E. coli isolate of lineage ST93 had the -32 mutation in the chromosomal ampC promoter/attenuator region. Five ESBL/pAmpC positive E. coli isolates carried class 1 integrons (dfrA17-aadA5, aadA and aadA/aadB arrays were detected in three isolates) and one isolate carried a class 2 integron (dfrA12-sat2-aadA1). The aac(6')Ib-cr, aac(3)-II, qnrB19, tet(A), tet(B), cmlA, and sul3 genes were also detected. All studied isolates showed unrelated PFGE-patterns. To our knowledge, this is the first description of ESBL-producing E. coli and the second of pAmpC-producing E. coli from healthy dogs in America. Our results suggest the potential zoonotic role of dogs in the transmission to humans of ESBL and pAmpC E. coli in the household environment.
authors.affiliation: Posgrado en Microbiología, Centro de Investigaciones en Ciencias Microbiológicas, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, San Manuel, 72570 Puebla, Mexico.
authors.forename: R C
authors.initials: RC
authors.lastname: Rocha-Gracia
authors.affiliation: Posgrado en Microbiología, Centro de Investigaciones en Ciencias Microbiológicas, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, San Manuel, 72570 Puebla, Mexico.
authors.forename: G
authors.initials: G
authors.lastname: Cortés-Cortés
authors.affiliation: Posgrado en Microbiología, Centro de Investigaciones en Ciencias Microbiológicas, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, San Manuel, 72570 Puebla, Mexico.
authors.forename: P
authors.initials: P
authors.lastname: Lozano-Zarain
authors.affiliation: Escuela de Biología, Benemérita Universidad Autónoma de Puebla, San Manuel, 72570 Puebla, Mexico.
authors.forename: F
authors.initials: F
authors.lastname: Bello
authors.affiliation: Posgrado en Microbiología, Centro de Investigaciones en Ciencias Microbiológicas, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, San Manuel, 72570 Puebla, Mexico.
authors.forename: Y
authors.initials: Y
authors.lastname: Martínez-Laguna
authors.affiliation: Área Bioquímica y Biología Molecular, Universidad de La Rioja, Madre de Dios 51, Logroño 26006, Spain. Electronic address: carmen.torres@unirioja.es.
authors.forename: C
authors.initials: C
authors.lastname: Torres
mesh_terms: D000818:Animals; D004283:Dog Diseases / Q000235:genetics* / Q000382:microbiology; D004285:Dogs; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D004927:Escherichia coli Infections / Q000235:genetics / Q000382:microbiology / Q000662:veterinary*; D005243:Feces / Q000382:microbiology; D008800:Mexico; D001618:beta-Lactamases / Q000235:genetics* / Q000378:metabolism
chemical_list: C103022:beta-lactamase CMY-2; C473109:beta-lactamase CTX-M-15; C062760:beta-lactamase SHV-2; D001618:beta-Lactamases
keywords: Canine; Escherichia coli; Extended spectrum β-lactamases