title: Detection of Escherichia coli ST131 clonal complex (ST705) and Klebsiella pneumoniae ST15 among faecal carriage of extended-spectrum β-lactamase- and carbapenemase-producing Enterobacteriaceae.
abstract: OBJECTIVE
  The objective of the present study was to evaluate the prevalence of intestinal colonization with extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae (ESBL-E) and carbapenemase-producing Enterobacteriaceae (CPE) in non-selected hospitalized and non-hospitalized patients from the same geographic area of Madrid.
  
  
  METHODS
  A total of 501 fecal samples were screened. Diluted samples in saline were cultured in MacConkey agar plates with ceftazidime, cefotaxime, imipenem and meropenem disks. Colonies growing within the inhibition zone of either disk were selected. Characterization of ESBLs and CPEs were performed by PCR and sequencing. The Wider system was used for the bacterial identification. In addition, clonal analysis was carried out for species predominant among the fecal carriage.
  
  
  RESULTS
  Among the 501 patients enrolled, 43 (8.6 %) carried ESBL-E and 8 (1.6 %) patients exhibited CPE. The main intestinal colonizer among ESBL-E was CTX-M-producing Escherichia coli isolates in both settings (community and hospital). ST131 clonal complex was the most common among faecal ESBL-producing E. coli. All gut carriers of CPE were hospitalized patients, Klebsiella pneumoniae being the most prevalent species. Two OXA-48-producing K. pneumoniae isolates belonging to ST15 were detected.
  
  
  CONCLUSIONS
  Present study reveals that faecal carriage of ESBL is common among inpatients and outpatients, whereas carbapenemase producers are only present in the hospital setting. Therefore, active surveillance will be useful for reducing transmission of antimicrobial-resistant bacteria and preventing infection.
authors.affiliation: Microbiology Department, Hospital Clínico San Carlos, c/Martín Lagos s/n, Madrid 28040, Spain.
authors.forename: Esther
authors.initials: E
authors.lastname: Ríos
authors.affiliation: Microbiology Department, Hospital Clínico San Carlos, c/Martín Lagos s/n, Madrid 28040, Spain.
authors.forename: María Carmen
authors.initials: MC
authors.lastname: López
authors.affiliation: Microbiology Department, Hospital Clínico San Carlos, c/Martín Lagos s/n, Madrid 28040, Spain.
authors.forename: Iciar
authors.initials: I
authors.lastname: Rodríguez-Avial
authors.affiliation: Microbiology Department, Hospital Clínico San Carlos, c/Martín Lagos s/n, Madrid 28040, Spain.
authors.forename: Esther
authors.initials: E
authors.lastname: Culebras
authors.affiliation: Microbiology Department, Hospital Clínico San Carlos, c/Martín Lagos s/n, Madrid 28040, Spain.
authors.forename: Juan José
authors.initials: JJ
authors.lastname: Picazo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001426:Bacterial Proteins / Q000235:genetics*; D002353:Carrier State / Q000382:microbiology*; D002439:Cefotaxime / Q000494:pharmacology; D002442:Ceftazidime / Q000494:pharmacology; D002648:Child; D002675:Child, Preschool; D003428:Cross Infection / Q000175:diagnosis / Q000382:microbiology; D003470:Culture Media / Q000737:chemistry; D024901:Drug Resistance, Multiple, Bacterial; D004926:Escherichia coli / Q000145:classification / Q000201:enzymology / Q000302:isolation & purification*; D005243:Feces / Q000382:microbiology*; D005260:Female; D000069196:Gastrointestinal Microbiome; D006760:Hospitalization; D006801:Humans; D015378:Imipenem / Q000494:pharmacology; D007223:Infant; D007422:Intestines / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000145:classification / Q000201:enzymology / Q000302:isolation & purification*; D008297:Male; D000077731:Meropenem; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D013030:Spain; D013845:Thienamycins / Q000494:pharmacology; D055815:Young Adult; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D003470:Culture Media; D013845:Thienamycins; D015378:Imipenem; D002442:Ceftazidime; D001618:beta-Lactamases; C063912:carbapenemase; D000077731:Meropenem; D002439:Cefotaxime