title: Changing patterns of fluoroquinolone resistance among Bacteroides fragilis group organisms over a 6-year period (1997-2002).
abstract: The evolution of susceptibility to the newer fluoroquinolones, moxifloxacin and trovafloxacin, of Bacteroides fragilis group organisms isolated in our hospital from 1997 to 2002 was studied. A total of 927 strains were included in the study. Trovafloxacin was more active than moxifloxacin against the various species of the group. During the study period, an increase in resistance to both quinolones was observed. Rates of resistance to moxifloxacin at a breakpoint of 8 microg/mL remained stable at around 6% during the period 1997-1998 and increased to 11.4% in 2000 and to 16.5% in 2001-2002 (P<0.005). Resistance to trovafloxacin rose significantly from 0.6% in 1998 to 6.8% in 1999 (P<0.05) and did not change appreciably over the last 3 years studied. This study confirms the increasing resistance of B. fragilis group organisms to trovafloxacin and moxifloxacin and emphasizes the need to perform periodic antimicrobial susceptibility tests to guide the selection of appropriate antimicrobial therapy.
authors.affiliation: Department of Clinical Microbiology, Hospital Clínico San Carlos, 28040 Madrid, Spain. cbetriu@efd.net
authors.forename: Carmen
authors.initials: C
authors.lastname: Betriu
authors.forename: Iciar
authors.initials: I
authors.lastname: Rodríguez-Avial
authors.forename: María
authors.initials: M
authors.lastname: Gómez
authors.forename: Esther
authors.initials: E
authors.lastname: Culebras
authors.forename: Juan J
authors.initials: JJ
authors.lastname: Picazo
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology*; D001372:Aza Compounds / Q000494:pharmacology*; D001441:Bacteroides fragilis / Q000145:classification / Q000187:drug effects* / Q000302:isolation & purification; D024881:Drug Resistance, Bacterial; D024841:Fluoroquinolones / Q000494:pharmacology*; D006801:Humans; D008826:Microbial Sensitivity Tests; D000077266:Moxifloxacin; D009287:Naphthyridines / Q000494:pharmacology*; D011804:Quinolines / Q000494:pharmacology*
chemical_list: D000890:Anti-Infective Agents; D001372:Aza Compounds; D024841:Fluoroquinolones; D009287:Naphthyridines; D011804:Quinolines; C080163:trovafloxacin; D000077266:Moxifloxacin