Comparison of in vitro activities of tigecycline with other antimicrobial agents against Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis in two university hospitals in Istanbul, Turkey.
BACKGROUND
We compared the in vitro activities of tigecycline with those of other agents against 97 Streptococcus pneumoniae, 140 Haemophilus influenzae and 54 Moraxella catarrhalis strains isolated in two large university hospitals in Istanbul.


METHODS
For analysis, the agar dilution method was used.


RESULTS
For S. pneumoniae isolates, 32% were not susceptible to penicillin (28.9% intermediate and 3.1% resistant). Cefotaxime, telithromycin, moxifloxacin and linezolid were fully active. Tigecycline had a 90% minimum inhibitory concentration (MIC(90)) of 0.12 microg/ml. For H. influenzae, 8.57% were not susceptible to ampicillin, among which 8 possessed beta-lactamase (5.7%). Four (2.87%) H. influenzae isolates with beta-lactamase-negative and ampicillin-resistant phenotype were found. All isolates were susceptible to ceftriaxone, azithromycin, ciprofloxacin, levofloxacin and moxifloxacin. MIC(90) for tigecycline was 0.5 microg/ml. Of 54 M. catarrhalis isolates, 88.9% possessed beta-lactamase. Tigecycline and fluoroquinolones were highly active (MIC(90) < or =0.12 microg/ml).


CONCLUSIONS
Linezolid, telithromycin, newer fluoroquinolones and tigecycline all have excellent in vitro activities against the 3 respiratory pathogens.
Gonullu
Nevriye
N
Department of Microbiology and Clinical Microbiology, Cerrahpasa Faculty of Medicine, University of Istanbul, Istanbul, Turkey. nevriegonullu@yahoo.com
Catal
Fadimana
F
Kucukbasmaci
Omer
O
Ozdemir
Sinem
S
Torun
Muzeyyen Mamal
MM
Berkiten
Rahmiye
R
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D024901:Drug Resistance, Multiple, Bacterial; D006193:Haemophilus influenzae / Q000187:drug effects* / Q000302:isolation & purification; D006785:Hospitals, University; D006801:Humans; D008826:Microbial Sensitivity Tests; D008911:Minocycline / Q000031:analogs & derivatives* / Q000494:pharmacology; D001936:Moraxella catarrhalis / Q000187:drug effects* / Q000302:isolation & purification; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000302:isolation & purification; D000078304:Tigecycline; D014421:Turkey
D000900:Anti-Bacterial Agents; D000078304:Tigecycline; D008911:Minocycline