Travel-associated faecal colonization with ESBL-producing Enterobacteriaceae: incidence and risk factors

J Antimicrob Chemother. 2013 Sep;68(9):2144-53. doi: 10.1093/jac/dkt167. Epub 2013 May 14.


Objectives: To study the acquisition of extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-PE) among the faecal flora during travel, with a focus on risk factors, antibiotic susceptibility and ESBL-encoding genes.

Methods: An observational prospective multicentre cohort study of individuals attending vaccination clinics in south-east Sweden was performed, in which the submission of faecal samples and questionnaires before and after travelling outside Scandinavia was requested. Faecal samples were screened for ESBL-PE by culturing on ChromID ESBL and an in-house method. ESBL-PE was confirmed by phenotypic and genotypic methods. Susceptibility testing was performed with the Etest. Individuals who acquired ESBL-PE during travel (travel-associated carriers) were compared with non-carriers regarding risk factors, and unadjusted and adjusted ORs after manual stepwise elimination were calculated using logistic regression.

Results: Of 262 enrolled individuals, 2.4% were colonized before travel. Among 226 evaluable participants, ESBL-PE was detected in the post-travel samples from 68 (30%) travellers. The most important risk factor in the final model was the geographic area visited: Indian subcontinent (OR 24.8, P < 0.001), Asia (OR 8.63, P < 0.001) and Africa north of the equator (OR 4.94, P = 0.002). Age and gastrointestinal symptoms also affected the risk significantly. Multiresistance was seen in 77 (66%) of the ESBL-PE isolates, predominantly a combination of reduced susceptibility to third-generation cephalosporins, trimethoprim/sulfamethoxazole and aminoglycosides. The most common species and ESBL-encoding gene were Escherichia coli (90%) and CTX-M (73%), respectively.

Conclusion: Acquisition of multiresistant ESBL-PE among the faecal flora during international travel is common. The geographical area visited has the highest impact on ESBL-PE acquisition.

Keywords: CTX-M; antibiotic resistance; travel medicine.

Publication types

  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Cohort Studies
  • Enterobacteriaceae / enzymology*
  • Enterobacteriaceae / genetics
  • Enterobacteriaceae / isolation & purification
  • Enterobacteriaceae Infections / epidemiology*
  • Enterobacteriaceae Infections / microbiology*
  • Feces / microbiology
  • Female
  • Genotype
  • Humans
  • Incidence
  • Male
  • Microbial Sensitivity Tests
  • Middle Aged
  • Phenotype
  • Prospective Studies
  • Risk Factors
  • Surveys and Questionnaires
  • Sweden / epidemiology
  • Travel*
  • Young Adult
  • beta-Lactamases / genetics
  • beta-Lactamases / metabolism*


  • beta-Lactamases