Detection of unrelated Escherichia coli strains harbouring genes of CTX-M-15, OXA-1, and AAC(6')-Ib-cr enzymes in a Tunisian Hospital and characterization of their integrons and virulence factors.

  1. Jouini, A. 14
  2. Ben Slama, K. 4
  3. Vinué, L. 1
  4. Ruiz, E. 1
  5. Sáenz, Y. 2
  6. Somalo, S. 1
  7. Klibi, N. 4
  8. Zarazaga, M. 12
  9. Ben Moussa, M. 3
  10. Boudabous, A. 4
  11. Torres, C. 12
  1. 1 Universidad de La Rioja
    info

    Universidad de La Rioja

    Logroño, España

    ROR https://ror.org/0553yr311

  2. 2 Centro de Investigación Biomédica de La Rioja
    info

    Centro de Investigación Biomédica de La Rioja

    Logroño, España

    ROR https://ror.org/03vfjzd38

  3. 3 Military Hospital of Tunis
    info

    Military Hospital of Tunis

    Túnez, Túnez

    ROR https://ror.org/04n4f3r80

  4. 4 Université de Tunis El Manar
    info

    Université de Tunis El Manar

    Túnez, Túnez

    ROR https://ror.org/029cgt552

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Revista:
Journal of Chemotherapy

ISSN: 1120-009X

Año de publicación: 2010

Volumen: 22

Número: 5

Páginas: 318-323

Tipo: Artículo

PMID: 21123154 SCOPUS: 2-s2.0-78651403084 WoS: WOS:000285703400005 GOOGLE SCHOLAR

Otras publicaciones en: Journal of Chemotherapy

Resumen

Beta-lactamase characterization was carried out in a collection of 18 extended-spectrum beta-lactamase (ESBL)-positive Escherichia coli isolates from blood (n=8) and urine (n=10) obtained in 2007 in a Tunisian Hospital. All isolates were clonally unrelated according to PFGE analysis. Seventeen strains presented the bla CTX-M-15 gene associated with bla OXA-1 and four of these strains with the bla TEM-1b gene. The remaining ESBL-positive strain contained the bla CTX-M-9 gene associated with the bla OXA-1 and bla TEM-1b genes. The orf477 sequence was identified downstream of the bla CTX-M-15 gene in all 17 bla CTX-M-15-positive strains, and ISEcp1 upstream in 15 of them (in eight cases truncated by IS26). The presence of a class 1 integron was demonstrated in 4 of the 18 ESBL-positive strains (22.2%), with dfrA17 + aadA5 (3 strains) and dfrA12 + orfF + aadA2 (1 strain) being the gene cassettes identified. The variant aac(6′)-Ib-cr was found in 15 bla CTX-M-15-containing strains. All 18 ESBL-positive strains were typed as phylogroup B2 and contained at least three of the eight tested virulence genes (fimA, papGIII, hlyA, cnf1, papC, aer, eae and bfp). Six bla CTX-M-15-positive strains were included in the serotype O25b and one of them was typed as ST131. Another bla CTX-M-15-positive strain serotype-O25 was typed as ST638. The bla CTX-M-15, aac(6′)-Ib-cr, and aac(3)-II genes were co-transferred by conjugation from 7 donor strains to E. coli CSH26 recipient strain. The bla CTX-M-15 gene is prevalent among ESBL-positive E. coli strains in the studied hospital, that is frequently found together with aac(6′)-Ib-cr, and aac(3)-II genes. The detection of the clone O25b-ST131 in a bla CTX-M-15 strain corroborates its worldwide dissemination. © E.S.I.F.T. srl - Firenze.