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

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.

Prevalence and associated factors of cigarette smoking among medical students at King Fahad Medical City in Riyadh of Saudi Arabia

To determine the prevalence of smoking among medical students at the medical college at King Fahad Medical City in Riyadh, and assess the association between smoking and socio-demographical factors, smoking contacts, reasons for smoking and attempts to quit. Cross-sectional survey in which anonymous, self-administered questionnaire was used to survey the cigarette smoking habits of the first-and second-year medical students in the Faculty of Medicine, King Fahad Medical City in June 2009. Overall 39.8% of the investigated students [153] had smoked before, and 17.6% were current smokers. The mean age of initiating smoking was 15.8 +/- 3.3]. There were significantly more males than females. The most important reasons for smoking were leisure, imitation of other people and a means of relieving psychological pressure. Reasons for not smoking were mostly health and religion-based. Smokers tended to have friends who smoked. Cigarettes smoking is highly prevalent among medical students in the Faculty of Medicine, King Fahad Medical City. Contact with smokers particularly friends are the major risk factors for the initiation of the habit. Health and religious considerations are important motives for not smoking, quitting or attempting to quit. These findings can be of help in designing future intervention strategies