title: IncI1/ST3 and IncN/ST1 plasmids drive the spread of blaTEM-52 and blaCTX-M-1/-32 in diverse Escherichia coli clones from different piggeries.
abstract: OBJECTIVE
  The spread of ESBL-producing Enterobacteriaceae among food animals/products has raised concerns about their possible transmission through the food chain. We aimed to characterize piggeries (pigs, piggery environments) as reservoirs of TEM-52- and CTX-M-encoding plasmids and clones.
  
  
  METHODS
  Forty-three samples from five Portuguese intensive production farms were studied (2006-07). Twenty-two ESBL-producing (13 TEM-52, 6 CTX-M-32, 3 CTX-M-1) Escherichia coli isolates from healthy pigs, feed and liquid manure were further characterized. Standard methods were used for clonal (PFGE, MLST) and plasmid (S1-PFGE, replicon typing, pMLST, RFLP) analysis. PCR and sequencing were used for analysis of blaCTX-M genetic context and plasmid-mediated quinolone resistance genes.
  
  
  RESULTS
  TEM-52 (n = 13/22; 59%), CTX-M-32 (n = 6/22; 27%) and CTX-M-1 (n = 3/22; 14%) were identified in feed (36%), swine faeces (36%), swine hide (9%) and liquid manure (18%) at different farms. Diverse phylogenetic groups and clones were identified among TEM-52 (7 A, 3 B1, 2 B2, 1 D; 8 clones)-producing, CTX-M-1 (1 A, 1 B1, 1 D; 3 clones)-producing and CTX-M-32 (4 A, 2 B1; 4 clones)-producing isolates. However, the ST10 clonal complex was frequent among TEM-52 (n = 6) and CTX-M-32 (n = 3) producers. blaTEM-52 and blaCTX-M-1/-32 genes were identified within epidemic IncI1/ST3 and IncN/ST1 plasmid variants, respectively.
  
  
  CONCLUSIONS
  We report for the first time a piggery reservoir for blaTEM-52. The spread of blaTEM-52 and blaCTX-M-1/-32 within and/or between different piggeries was mostly associated with epidemic plasmids and clones previously identified in humans and other animal hosts in different EU countries, highlighting possible distribution along the food chain.
authors.affiliation: REQUIMTE, Laboratório de Microbiologia, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal.
authors.forename: Carla
authors.initials: C
authors.lastname: Rodrigues
authors.forename: Elisabete
authors.initials: E
authors.lastname: Machado
authors.forename: Luísa
authors.initials: L
authors.lastname: Peixe
authors.forename: Angela
authors.initials: A
authors.lastname: Novais
mesh_terms: D000818:Animals; D016521:Electrophoresis, Gel, Pulsed-Field; D004783:Environmental Microbiology; D004926:Escherichia coli / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000382:microbiology / Q000662:veterinary*; D022761:Gene Transfer, Horizontal; D005838:Genotype; D058885:Multilocus Sequence Typing; D010957:Plasmids; D012150:Polymorphism, Restriction Fragment Length; D011174:Portugal; D013552:Swine; D018440:beta-Lactam Resistance; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: C445691:TEM-52 beta-lactamase; C055184:beta-lactamase TEM-3; D001618:beta-Lactamases; C487656:beta-lactamase CTX-M-32, E coli
keywords: CTX-M; ESBLs; TEM-52; epidemic plasmids; food chain; pMLST; swine