Increasing resistance of Streptococcus pneumoniae to fluoroquinolones: results of a Hong Kong multicentre study in 2000

Abstract

The MICs of 13 antimicrobial agents including seven fluoroquinolones (ciprofloxacin, levofloxacin, sparfloxacin, grepafloxacin, gatifloxacin, moxifloxacin and clinafloxacin) for Streptococcus pneumoniae isolates obtained from all regions of Hong Kong in the year 2000 were determined by the Etest. Overall, 39.4% of 180 isolates were susceptible to penicillin, 11.7% were intermediate and 48.9% were resistant. The overall prevalence of fluoroquinolone non-susceptibility (levofloxacin MIC > or = 4 mg/L) was 13.3% but increased to 27.3% among the penicillin-resistant isolates. For the fluoroquinolone non-susceptible isolates, within-class cross-resistance was common. For the fluoroquinolone non-susceptible isolates, the median MICs of clinafloxacin, gatifloxacin, moxifloxacin, sparfloxacin and grepafloxacin were, respectively, six-, 24-, 32- 84- and 128-fold higher than those for the susceptible isolates. All fluoroquinolone non-susceptible strains were derived from adults. The prevalence of fluoroquinolone resistance was higher in isolates from older patients (17.1% among those > or = 65 years of age versus 9.1% among those 18-64 years of age, P < 0.001) and from adults with chronic obstructive pulmonary disease (24.6% versus 9.3%, P = 0.01). All fluoroquinolone non-susceptible strains were non-susceptible to penicillin (MIC range 2-4 mg/L), cefotaxime (MIC range 1-4 mg/L) and erythromycin (MIC range 4- > or = 256 mg/L). The fluoroquinolone non-susceptible isolates were genetically related to the Spain(23F)-1 clone when analysed by pulse-field gel electrophoresis and multilocus sequence typing. In conclusion, a rapid increase in the prevalence of fluoroquinolone resistance among S. pneumoniae was found in Hong Kong. Typing analysis suggests that this is due to the pan-regional dissemination of a fluoroquinolone-resistant variant (designated Hong Kong(23F)-1) of the globally distributed Spain(23)F-1 clone.

Efficacy and safety of levofloxacin in the context of other contemporary fluoroquinolones: a review

“…Fluoroquinolone resistance among S pneumoniae is appearing in some areas of the world, notably Hong Kong 16 and Spain 17 and, to a lesser extent, North America. 18 Some evidence shows that bacterial resistance may lead to treatment failure.…”

“…Most rapid emergence of resistance has been due to the selection and dissemination of Ն1 single clone, as in Hong Kong. 16 It is unclear whether levofloxacin (which permits single-step resistance emergence) is more likely to select resistant strains than agents that require both topoisomerase and gyrase mutations, such as 8-methoxyquinolones. Although resistance-selection frequencies of levofloxacin are higher than those for moxifloxacin, 22 1 study 23 that attempted to assess potential for resistance selection in S pneumoniae while simulating human dosing and kinetics demonstrated that, despite lower MICs seen with moxifloxacin, the overall selection of resistance with levofloxacin did not differ significantly from that seen with moxifloxacin.…”

Susceptibility of Streptococcus pneumoniae to Fluoroquinolones in Canada

“…Ciprofloxacin, the first fluoroquinolone to be used to treat lower respiratory tract infections (LRTIs) (29), demonstrates poor potency against S. pneumoniae, and its introduction has been associated with the rapid emergence of resistance in pneumococci (5,6,9,16,26,29).…”

Antimicrobial Activities of Garenoxacin (BMS 284756) against Asia-Pacific Region Clinical Isolates from the SENTRY Program, 1999 to 2001

“…Similar high levels of resistance have been reported for ORSA from other countries in the region, 66% for Korea (22), 97% for Taiwan (12% in oxacillinsusceptible S. aureus [OSSA]) (23), and Ͼ50% for Japan (36). Resistance to fluoroquinolones has been reported for S. pneumoniae with 13.3% (27.3% for non-penicillin-susceptible isolates) resistance to levofloxacin in a recent study in Hong Kong (15) and up to 12% resistance in Korea (22). It is therefore important to determine the comparative activities of the newer fluoroquinolones, including garenoxacin, against recent clinical isolates in the Asia-Pacific region.…”