title: Atypical epidemiology of CTX-M-15 among Enterobacteriaceae from a high diversity of non-clinical niches in Angola.
abstract: OBJECTIVE
  The objective of this study was to investigate the distribution and molecular epidemiology of ESBLs, acquired AmpCs and carbapenemases in Enterobacteriaceae from non-clinical niches in Angola, an under-researched sub-Saharan country.
  
  
  METHODS
  Eighty-one samples were recovered from healthy persons (n = 18), healthy animals (n = 33) and their environments (n = 10) or aquatic settings (n = 20) in south Angola (2013). Samples were plated onto CHROMagar™ Orientation with/without antibiotics. Standard methods were used for bacterial identification, characterization of bla genes, antibiotic susceptibility testing and conjugation assays. Clonal analysis (XbaI-PFGE, MLST and Escherichia coli phylogroups), location of bla and plasmid characterization (S1-PFGE, I-CeuI-PFGE, replicon typing and hybridization) were also performed.
  
  
  RESULTS
  ESBLs (almost exclusively CTX-M-15, 98%) were detected in 21% (45/216) of the isolates, recovered from diverse non-clinical niches and belonging to different Enterobacteriaceae species (mainly E. coli). Acquired AmpCs or carbapenemases were not found. The pandemic B2-ST131 E. coli clone was not identified, but some widespread clonal complexes (CCs) from A (CC10 and CC168), B1 (CC156) or D (CC38) phylogroups were detected. blaCTX-M-15 was variably identified on typeable (29%; 100-335 kb; IncFII, IncFIIK6, IncHI2 and IncY) or non-typeable (16%; 70-330 kb) plasmids or on the chromosome (14%), while for 41% of the isolates its specific location was not determined.
  
  
  CONCLUSIONS
  This study reports, for the first time in Angola, an unexpected high occurrence of CTX-M-15 in diverse non-clinical niches and Enterobacteriaceae species, and uncovers novel plasmid replicons in under-researched geographical regions. The diffusion of blaCTX-M-15 through such a high diversity of genetic backgrounds (clones, typeable/non-typeable plasmids and genetic environments) unveils an extraordinary ability for blaCTX-M-15 acquisition and mobilization favoured by unrecognized ecological factors.
authors.affiliation: UCIBIO/REQUIMTE, Laboratório de Microbiologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal.
authors.forename: T G
authors.initials: TG
authors.lastname: Ribeiro
authors.affiliation: UCIBIO/REQUIMTE, Laboratório de Microbiologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal.
authors.forename: Â
authors.initials: Â
authors.lastname: Novais
authors.affiliation: UCIBIO/REQUIMTE, Laboratório de Microbiologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal.
authors.forename: L
authors.initials: L
authors.lastname: Peixe
authors.affiliation: UCIBIO/REQUIMTE, Laboratório de Microbiologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal FP-ENAS/CEBIMED, Faculdade de Ciências da Saúde, Universidade Fernando Pessoa, Porto, Portugal emachado@ufp.edu.pt elisabetemac@gmail.com.
authors.forename: E
authors.initials: E
authors.lastname: Machado
mesh_terms: D000810:Angola; D000818:Animals; D003227:Conjugation, Genetic; D016521:Electrophoresis, Gel, Pulsed-Field; D004755:Enterobacteriaceae / Q000145:classification / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification*; D004783:Environmental Microbiology; D022761:Gene Transfer, Horizontal; D005838:Genotype; D064368:Healthy Volunteers; D006801:Humans; D008826:Microbial Sensitivity Tests; D058885:Multilocus Sequence Typing; D010957:Plasmids / Q000032:analysis; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: C473109:beta-lactamase CTX-M-15; D001618:beta-Lactamases