Detection of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae in vegetables, soil and water of the farm environment in Tunisia

  1. Ben Said, L. 2
  2. Jouini, A. 3
  3. Klibi, N. 2
  4. Dziri, R. 2
  5. Alonso, C.A. 1
  6. Boudabous, A. 2
  7. Ben Slama, K. 2
  8. Torres, C. 1
  1. 1 Universidad de La Rioja
    info

    Universidad de La Rioja

    Logroño, España

    ROR https://ror.org/0553yr311

  2. 2 Université de Tunis El Manar
    info

    Université de Tunis El Manar

    Túnez, Túnez

    ROR https://ror.org/029cgt552

  3. 3 Institut Pasteur de Tunis
    info

    Institut Pasteur de Tunis

    Túnez, Túnez

    ROR https://ror.org/04pwyer06

Revista:
International Journal of Food Microbiology

ISSN: 0168-1605

Año de publicación: 2015

Volumen: 203

Páginas: 86-92

Tipo: Artículo

DOI: 10.1016/J.IJFOODMICRO.2015.02.023 SCOPUS: 2-s2.0-84924976303 WoS: WOS:000354588700013 GOOGLE SCHOLAR

Otras publicaciones en: International Journal of Food Microbiology

Resumen

One-hundred-nine samples of 18 different farms (49 of food-vegetables, 41 of soil and 19 of irrigation water) and 45 vegetable food samples of 13 markets were collected in Tunisia. These samples were inoculated in MacConkey agar plates supplemented with cefotaxime (2μg/ml). ESBL-producing Enterobacteriaceae (ESBL-Eb) were detected in 10 of the 109 farm samples (vegetables, 8.2%; soil, 7.3%; water, 15.8%), and in 4 of 45 vegetables of markets (8.9%), recovering 15 ESBL-Eb. Isolates and ESBL genes detected were: Escherichia coli (n=8: 5 blaCTX-M-1, 2 blaCTX-M-15 and one blaCTX-M-14), Citrobacter freundii (n=4: 3 blaCTX-M-15 and one blaSHV-12), Enterobacter hormaechei (n=2: 2 blaCTX-M-15) and Klebsiella pneumoniae (n=1, blaCTX-M-15). The ISEcp1 sequence was found upstream of blaCTX-M genes in 13 of 14 strains (in three cases truncated by IS5), and orf477 or IS903 downstream. Class 1 integrons were detected in five strains and contained two gene cassette arrangements (dfrA17-aadA5 and aadA1). Most isolates tested showed a multiresistant phenotype. All blaCTX-M-15-positive strains carried the aac(6')-1b-cr gene, that affects to amikacin-tobramycin-kanamycin-ciprofloxacin. Five ESBL-Eb strains carried genes of the qnr family. The 8 ESBL-positive E. coli isolates were typed as: ST58/B1 (n=3) and ST117/D, ST131/B2, ST10/A, ST23/A, and the new ST3496/D (one strain, each). From 1-2 plasmids were detected in all ESBL-positive E. coli isolates (63-179kb). The ESBL genes were transferred by conjugation in 4 blaCTX-M-1-positive E. coli strains, and transconjugants acquired a 97kb IncI1 plasmid. ESBL-Eb isolates are frequently disseminated in vegetable farms and potentially could be transmitted to humans through the food chain. © 2015 Elsevier B.V.