Unexpected distribution of the fluoroquinolone-resistance gene qnrB in Escherichia coli isolates from different human and poultry origins in Ecuador

• Paulina I. Armas-Freire ^[1] ; Gabriel Trueba ^[1] ; Carolina Proaño-Bolaños ^[1] ; Karen Levy ^[2] ; Lixin Zhang ^[5] ; Carl F. Marrs ^[3] ; William Cevallos ^[4] ; Joseph N.S. Eisenberg ^[3]
  1. [1] Universidad San Francisco de Quito

     Universidad San Francisco de Quito

     Quito, Ecuador

     
  2. [2] Emory University

     Emory University

     Estados Unidos

     
  3. [3] University of Michigan–Ann Arbor

     University of Michigan–Ann Arbor

     City of Ann Arbor, Estados Unidos

     
  4. [4] Universidad Central del Ecuador

     Universidad Central del Ecuador

     Quito, Ecuador

     
  5. [5] 1.Department of Epidemiology, University of Michigan, Ann Arbor. USA 2.Department of Epidemiology and Biostatistics, Michigan State University, East Lansing, USA.

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• Localización: International microbiology: official journal of the Spanish Society for Microbiology, ISSN 1139-6709, Vol. 18, Nº. 2, 2015, págs. 85-90
• Idioma: inglés
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  • Fluoroquinolone resistance can be conferred through chromosomal mutations or by the acquisition of plasmids carrying genes such as the quinolone resistance gene (qnr). In this study, 3,309 strains of commensal Escherichia coli were isolated in Ecuador from: (i) humans and chickens in a rural northern coastal area (n = 2368, 71.5%) and (ii) chickens from an industrial poultry operation (n = 827, 25%). In addition, 114 fluoroquinolone-resistant strains from patients with urinary tract infections who were treated at three urban hospitals in Quito, Ecuador were analyzed. All of the isolates were subjected to antibiotic susceptibility screening. Fluoroquinolone-resistant isolates (FRIs) were then screened for the presence of qnrB genes. A significantly higher phenotypic resistance to fluoroquinolones was determined in E. coli strains from chickens in both the rural area (22%) and the industrial operation (10%) than in strains isolated from humans in the rural communities (3%). However, the rates of qnrB genes in E. coli isolates from healthy humans in the rural communities (11 of 35 isolates, 31%) was higher than in chickens from either the industrial operations (3 of 81 isolates, 6%) or the rural communities (7 of 251 isolates, 2.8%). The occurrence of qnrB genes in human FRIs obtained from urban hospitals was low (1 of 114 isolates, 0.9%). These results suggested that the qnrB gene is more widely distributed in rural settings, where antibiotic usage is low, than in urban hospitals and industrial poultry operations. The role of qnrB in clinical resistance to fluoroquinolones is thus far unknown. [Int Microbiol 2015; 18(2):85-90]Keywords: Escherichia coli · gene qnrB · quinolone resistance · urban hospitals · industral poultry operations