The Qnr gene product inhibits quinolones binding to target Ipatasertib datasheet proteins [13]. Other horizontally acquired quinolone resistance genes include aac(6 ‘ )-Ib, encoding a fluroquinolone acetylating enzyme, as well as qepA and oqxAB, which encode horizontally transmitted efflux pumps [14–16]. Resistance to the quinolones often emerges at low-levels by acquisition of an initial resistance-conferring mutation or gene. Acquisition of subsequent mutations leads to higher levels of resistance to the first-generation quinolone, nalidixic acid and a BB-94 datasheet broadening of the resistance spectrum to include second-generation quinolones (first-generation fluoroquinolones) such as ciprofloxacin, followed by newer second- and third-generation fluoroquinolones

[17]. Although multiple mechanisms of quinolone resistance have been reported from other continents, there are few data from sub-Saharan Africa on the molecular basis for quinolone resistance. We performed antimicrobial susceptibility testing on fecal E. coli isolates from Accra, Ghana in 2006, 2007 and 2008. We identified isolates that were resistant to nalidixic acid and screened these strains for mutations in the QRDR of gyrA and parC as well as horizontally-acquired quinolone-resistance genes. In order to gain some insight into resistance dissemination, we also studied inter-strain relatedness among quinolone-resistant E. coli isolates by multilocus

sequence typing. Results Resistance to commonly used antimicrobials is high and resistance Cyclic nucleotide phosphodiesterase to the quinolones was detected In 2006, 2007 and 2008 respectively, 156, 78 and 101 stool specimens were collected. A total of 293 Escherichia coli isolates were Selleck VX-680 recovered from culture

of the 335 stool specimens. Consistent with the results of recent studies from West African countries, including Ghana [1, 7, 8], 50-90% of the E. coli isolates were resistant to the broad-spectrum antimicrobials ampicillin, streptomycin, sulphonamides, tetracycline and trimethoprim (Figure 1). Resistance to chloramphenicol was less common but was seen in 30-41% of the isolates. The proportions of isolates resistant to most agents were comparable between 2006 and 2007. However, the proportion of isolates resistant to each antimicrobial in 2008 was significantly greater than those seen in 2006, for all agents (p < 0.05) (Figure 1). Figure 1 Proportion of E. coli isolates resistant to each of eight broad-spectrum antibacterials in 2006, 2007 and 2008. As illustrated in Figure 1 in 2006 and 2007, we recorded resistance rates to nalidixic acid of 12.3% but by 2008, 15 (18.2%) of isolates were nalidixic acid resistant. Ciprofloxacin-resistant isolates represented 7 (5.4%) and 6 (7.7%) of the total number of isolates in 2006 and 2007 respectively. In 2008, 10 (9.9%) of the isolates were fluoroquinolone resistant. Thus, in 2006 and 2007, 13 (52%) quinolone-resistant E. coli isolates were ciprofloxacin resistant but in 2008, 10 (67%) of the quinolone-resistant E.