Gatifloxacin phase IV surveillance trial (TeqCES study) utilizing 5000 primary care physician practices: report of pathogens isolated and susceptibility patterns in community-acquired respiratory tract infections.
Recently FDA-approved fluoroquinolones like gatifloxacin possess enhanced activity against Gram-positive pathogens such as Streptococcus pneumoniae. However, experience with adverse events among previously used fluoroquinolones has led to expanded post-marketing investigations of clinical efficacy and safety. An open-label gatifloxacin trial was initiated in early 2000, using 2795 (>15000 enrolled cases) primary care providers for treatment of community-acquired respiratory tract infections (CARTI) such as community-acquired pneumonia (CAP), acute bacterial exacerbation of chronic bronchitis (ABECB), acute sinusitis. Microbiology specimens and sputum slides were referred to a reference laboratory, pathogens identified and reference antimicrobial susceptibility tests performed. Results were classified by infection site, geographic census region and patient profile/demographics. The most frequent pathogens were: for CAP (n = 384)-S. pneumoniae (37%) > Hemophilus influenzae (31%) > Moraxella catarrhalis (13%); for ABECB (528)-H. influenzae (37%) > M. catarrhalis (26%) > S. pneumoniae (17%); and for sinusitis (2691)-M. catarrhalis (29%) > H. influenzae (24%) > S. pneumoniae (17%). H. parainfluenzae (ABECB) and S. aureus (sinusitis) were also commonly isolated. CAP S. pneumoniae isolates had significantly less high-level resistance (5% at > or =2 micro g/ml) than those isolates from ABECB or sinusitis (13-15%). United States census zone differences in S. pneumoniae resistance were identified (greatest in West or East South Central, South Atlantic). S. pneumoniae macrolide resistance was high (23-33%) and H. influenzae clarithromycin susceptibility was only 56-62%. beta-lactamase rates in H. influenzae and M. catarrhalis were 21-29% and 88-92%, respectively. Only one S. pneumoniae was not susceptible to gatifloxacin, and this new fluoroquinolone was fourfold more potent than levofloxacin (MIC(50,) 0.25 vs. 1 micro g/ml). This Phase IV surveillance trial (TeqCES) confirmed the clinical importance of S. pneumoniae, H. influenzae and M. catarrhalis in CARTI, and high fluoroquinolone potency/spectrum (>97% susceptible). beta-lactams and macrolides continue to be compromised by increasing resistances in pathogens isolated in these monitored primary care settings.
Pfaller
Michael A
MA
CAST Laboratories, University of Iowa College of Medicine, Iowa City, Iowa, USA. michael-pfaller@uiowa.edu
Jones
Ronald N
RN
D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000890:Anti-Infective Agents / Q000494:pharmacology*; D017714:Community-Acquired Infections / Q000188:drug therapy / Q000382:microbiology; D004352:Drug Resistance, Microbial; D005260:Female; D024841:Fluoroquinolones; D000077734:Gatifloxacin; D006090:Gram-Negative Bacteria / Q000187:drug effects* / Q000302:isolation & purification; D006094:Gram-Positive Bacteria / Q000187:drug effects* / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D011159:Population Surveillance; D011320:Primary Health Care; D012141:Respiratory Tract Infections / Q000188:drug therapy / Q000382:microbiology*; D012680:Sensitivity and Specificity
D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D024841:Fluoroquinolones; D000077734:Gatifloxacin