title: Surveillance of Extended-Spectrum Beta-Lactamase-Producing Escherichia coli in Dairy Cattle Farms in the Nile Delta, Egypt.
abstract: BACKGROUND
  Industrial livestock farming is a possible source of multi-resistant Gram-negative bacteria, including producers of extended spectrum beta-lactamases (ESBLs) conferring resistance to 3rd generation cephalosporins. Limited information is currently available on the situation of ESBL producers in livestock farming outside of Western Europe. A surveillance study was conducted from January to May in 2014 in four dairy cattle farms in different areas of the Nile delta, Egypt.
  
  
  METHODS
  In total, 266 samples were collected from 4 dairy farms including rectal swabs from clinically healthy cattle (n = 210), and environmental samples from the stalls (n = 56). After 24 h pre-enrichment in buffered peptone water, all samples were screened for 3rd generation cephalosporin-resistant Escherichia coli using Brilliance™ ESBL agar. Suspected colonies of putatively ESBL-producing E. coli were sub-cultured and subsequently genotypically and phenotypically characterized. Susceptibility testing using the VITEK-2 system was performed. All suspect isolates were genotypically analyzed using two DNA-microarray based assays: CarbDetect AS-1 and E. coli PanType AS-2 kit (ALERE). These tests allow detection of a multitude of genes and their alleles associated with resistance toward carbapenems, cephalosporins, and other frequently used antibiotics. Serotypes were determined using the E. coli SeroGenotyping AS-1 kit (ALERE).
  
  
  RESULTS
  Out of 266 samples tested, 114 (42.8%) ESBL-producing E. coli were geno- and phenotypically identified. 113 of 114 phenotypically 3rd generation cephalosporin-resistant isolates harbored at least one of the ESBL resistance genes covered by the applied assays [blaCTX-M15 (n = 105), blaCTX-M9 (n = 1), blaTEM (n = 90), blaSHV (n = 1)]. Alarmingly, the carbapenemase genes blaOXA-48 (n = 5) and blaOXA-181 (n = 1) were found in isolates that also were phenotypically resistant to imipenem and meropenem. Using the array-based serogenotyping method, 66 of the 118 isolates (55%) could be genotypically assigned to O-types.
  
  
  CONCLUSIONS
  This study is considered to be a first report of the high prevalence of ESBL-producing E. coli in dairy farms in Egypt. ESBL-producing E. coli isolates with different underlying resistance mechanisms are common in investigated dairy cattle farms in Egypt. The global rise of ESBL- and carbapenemase-producing Gram-negative bacteria is a big concern, and demands intensified surveillance.
authors.affiliation: Alere Technologies GmbHJena, Germany; InfectoGnostics Research CampusJena, Germany.
authors.forename: Sascha D
authors.initials: SD
authors.lastname: Braun
authors.affiliation: Department of Animal Hygiene and Zoonoses, Faculty of Veterinary Medicine, Mansoura University Mansoura, Egypt.
authors.forename: Marwa F E
authors.initials: MF
authors.lastname: Ahmed
authors.affiliation: Institute of Bacterial Infections and Zoonoses, Friedrich-Loeffler-InstitutJena, Germany; Department of Poultry Disease, Faculty of Veterinary Medicine, Kafrelsheikh UniversityKafr El-Sheikh, Egypt.
authors.forename: Hosny
authors.initials: H
authors.lastname: El-Adawy
authors.affiliation: Institute of Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institut Jena, Germany.
authors.forename: Helmut
authors.initials: H
authors.lastname: Hotzel
authors.affiliation: Alere Technologies GmbHJena, Germany; InfectoGnostics Research CampusJena, Germany.
authors.forename: Ines
authors.initials: I
authors.lastname: Engelmann
authors.affiliation: Alere Technologies GmbHJena, Germany; InfectoGnostics Research CampusJena, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Weiß
authors.affiliation: Alere Technologies GmbHJena, Germany; InfectoGnostics Research CampusJena, Germany; Institute for Medical Microbiology and Hygiene, Technical University of DresdenDresden, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Monecke
authors.affiliation: Alere Technologies GmbHJena, Germany; InfectoGnostics Research CampusJena, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Ehricht
keywords: CRE; ESBL; Egypt; Escherichia coli; carbapenemases; dairy cattle; genotype; microarray