Plasmid mediated quinolone resistance determinants qnr, aac(6')-Ib-cr, and qep in ESBL-producing Escherichia coli clinical isolates from Egypt

W M Hassan, A Hashim, Raa Domany
Indian Journal of Medical Microbiology 2012, 30 (4): 442-7

PURPOSE: To characterize the prevalence of plasmid-mediated quinolone resistance determinants qnr, aac(6')-Ib-cr and qep in extended-spectrum β-lactamase (ESBL) -producing E. coli and to determine the association of these determinants with CTX-M group in Cairo, Egypt.

MATERIALS AND METHODS: MICs of 15 antimicrobial agents against 70 E. coli clinical isolates were determined using agar dilution technique according to CLSI. Screening for the qnrA, qnrB, qnrS, aac(6')-Ib, qep and CTX-M genes was carried out by PCR amplification and DNA sequencing. Curing was used to confirm whether qnr, aac(6')-Ib, qep or ESBL-encoding genes were located on plasmids.

RESULTS: Out of 70 E. coli clinical isolates, 61 were resistant to at least one antibiotic, 16 (22.8%) were multidrug resistant and 30 (42%) were ESBL producers. Out of 30 ESBL producers E. coli isolates, 8 (26.6%) were positive for qnr genes, and the qnrA1-, qnrB1-and qnrS1-type genes were detected alone or in combination in 5 (16.6%), 7 (23.3%) and 5 (16.6%) isolates, respectively. Seven (23.3%) isolates were positive for aac(6')-Ib-cr and only two (6.6%) isolates were positive for qepA4. Loss of all plasmids upon curing suggested that qnr, aac(6')-Ib-cr , qep A4 and ESBL-encoding genes were always plasmid mediated. Out of 8 Qnr positive isolates 5 were associated with both CTX-M-1 and CTX-M-9 while 2 from 6 aac(6')-Ib-cr positive isolates were associated with both CTX-M-1 and CTX-M-9.

CONCLUSIONS: This study highlights the prevalence of quinolone resistance determinants qnr, aac(6')-Ib-cr , qep A4 associated with CTX-M positive E. coli isolates from Egypt. This is the first report of the plasmid mediated fluoroquinolone efflux pump, Qep A from Egypt.

Full Text Links

Find Full Text Links for this Article


You are not logged in. Sign Up or Log In to join the discussion.

Related Papers

Remove bar
Read by QxMD icon Read

Save your favorite articles in one place with a free QxMD account.


Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"