title: Mobile insertion cassette elements found in small non-transmissible plasmids in Proteeae may explain qnrD mobilization.
abstract: qnrD is a plasmid mediated quinolone resistance gene from unknown origin, recently described in Enterobacteriaceae. It encodes a pentapeptide repeat protein 36-60% different from the other Qnr (A, B, C, S and VC). Since most qnrD-positive strains were described as strains belonging to Proteus or Providencia genera, we hypothesized that qnrD originated in Proteeae before disseminating to other enterobacterial species. We screened 317 strains of Proteeae for qnrD and its genetic support by PCR. For all the seven qnrD-positive strains (4 Proteus mirabilis, 1 Proteus vulgaris and 2 Providencia rettgeri) the gene was carried onto a small non-transmissible plasmid, contrarily to other qnr genes that are usually carried onto large multi-resistant plasmids. Nucleotide sequences of the qnrD-bearing plasmids were 96% identical. Plasmids contained 3 ORFs apart from qnrD and belonged to an undescribed incompatibility group. Only one plasmid, in P. vulgaris, was slightly different with a 1,568-bp insertion between qnrD and its promoter, leading to absence of quinolone resistance. We sought for similar plasmids in 15 reference strains of Proteeae, but which were tested negative for qnrD, and found a 48% identical plasmid (pVERM) in Providencia vermicola. In order to explain how qnrD could have been inserted into such native plasmid, we sought for gene mobilization structures. qnrD was found to be located within a mobile insertion cassette (mic) element which sequences are similar to one mic also found in pVERM. Our conclusions are that (i) the small non-transmissible qnrD-plasmids described here may result from the recombination between an as-yet-unknown progenitor of qnrD and pVERM, (ii) these plasmids are maintained in Proteeae being a qnrD reservoir (iii) the mic element may explain qnrD mobilization from non-transmissible plasmids to mobilizable or conjugative plasmids from other Enterobacteriaceae, (iv) they can recombined with larger multiresistant plasmids conjugated in Proteeae.
authors: EA 4687, UFR Médecine SFR CAP-Santé Université de Reims Champagne-Ardenne, Reims, France ; EA3964, PRES Sorbonne Paris Cité Université Paris Diderot-Paris 7, Paris, France ; Laboratoire de Bactériologie-Virologie-Hygiène, CHU Reims - Hôpital Robert Debré, Reims, France.
authors: Thomas
authors: T
authors: Guillard
authors: Laboratoire de Bactériologie-Virologie-Hygiène, CHU Reims - Hôpital Robert Debré, Reims, France.
authors: Antoine
authors: A
authors: Grillon
authors: EA 4687, UFR Médecine SFR CAP-Santé Université de Reims Champagne-Ardenne, Reims, France ; Laboratoire de Bactériologie-Virologie-Hygiène, CHU Reims - Hôpital Robert Debré, Reims, France.
authors: Christophe
authors: C
authors: de Champs
authors: Laboratoire de Bactériologie-Virologie-Hygiène, CHU Reims - Hôpital Robert Debré, Reims, France.
authors: Céline
authors: C
authors: Cartier
authors: Laboratoire de Bactériologie-Virologie-Hygiène, CHU Reims - Hôpital Robert Debré, Reims, France.
authors: Janick
authors: J
authors: Madoux
authors: EA3964, PRES Sorbonne Paris Cité Université Paris Diderot-Paris 7, Paris, France ; Laboratoire de Bactériologie, AP-HP Groupe Hospitalier Lariboisière - Saint Louis, Paris, France.
authors: Béatrice
authors: B
authors: Berçot
authors: EA 4687, UFR Médecine SFR CAP-Santé Université de Reims Champagne-Ardenne, Reims, France.
authors: Anne-Laure
authors: AL
authors: Lebreil
authors: Laboratoire de Bactériologie, CHU Nancy - Hôpital Central, Nancy, France.
authors: Alain
authors: A
authors: Lozniewski
authors: Laboratoire de Bactériologie, AP-HP Groupe Hospitalier Lariboisière - Saint Louis, Paris, France.
authors: Jacques
authors: J
authors: Riahi
authors: EA 4687, UFR Médecine SFR CAP-Santé Université de Reims Champagne-Ardenne, Reims, France ; Laboratoire de Bactériologie-Virologie-Hygiène, CHU Reims - Hôpital Robert Debré, Reims, France.
authors: Véronique
authors: V
authors: Vernet-Garnier
authors: EA3964, PRES Sorbonne Paris Cité Université Paris Diderot-Paris 7, Paris, France ; Laboratoire de Bactériologie, AP-HP Groupe Hospitalier Lariboisière - Saint Louis, Paris, France.
authors: Emmanuelle
authors: E
authors: Cambau
mesh_terms: D001483:Base Sequence; D004251:DNA Transposable Elements; D024881:Drug Resistance, Bacterial / Q000235:genetics; D004755:Enterobacteriaceae / Q000187:drug effects / Q000235:genetics*; D023061:Gene Order; D005798:Genes, Bacterial; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D010957:Plasmids / Q000737:chemistry / Q000235:genetics*
chemical_list: D004251:DNA Transposable Elements