Details

Autor(en) / Beteiligte

• Ben Said, Leila
• Jouini, Ahlem
• Klibi, Naouel
• Dziri, Raoudha
• Alonso, Carla Andrea
• Boudabous, Abdellatif
• Ben Slama, Karim
• Torres, Carmen

Titel

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

Ist Teil von

• International journal of food microbiology, 2015-06, Vol.203, p.86-92

Ort / Verlag

Netherlands: Elsevier B.V

Erscheinungsjahr

2015

Link zum Volltext

Quelle

Elsevier ScienceDirect Journals Complete

Beschreibungen/Notizen

• 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. •Detection of ESBL-producing Enterobacteriaceae in 8–16% of vegetables, soil and irrigation water samples of Tunisian farms•ESBL-Enterobacteriaceae were detected in almost 9% of vegetable food samples tested at the market level.•ESBL variants detected correspond to those previously found in animals or humans in Tunisia.•First detection of ESBL-Enterobacteriaceae in the vegetable farms in Tunisia