[Flouroquinolone activity in clinical isolates of Streptococcus pneumoniae with different susceptibility to penicilline: an epidemiological study in five cities of Mexico].
OBJECTIVE
Determine the susceptibility to five fluoroquinolones and cross-resistance of pneumococcusclinical isolates with different penicillin susceptibilities gathered in a community-based study.


METHODS
Cross-sectional survey.


METHODS
Two hundred and thirty one (231) isolates were obtained from respiratory secretions or blood specimens from 231 patients with acquired acute respiratory infection or bacteremia.


METHODS
In vitro susceptibility to penicillin (PEN), ciprofloxacin (CIP), levofloxacin (LEV), gatifioxacin (GAT), moxifloxacin (MOX) and gemifioxacin (GEM) was determined with minimal inhibitory concentration (MIC) using the E test.


RESULTS
42% of the isolates showed decreased susceptibility to PEN. The lowest antibiotic concentration that inhibited 90% of the isolates was 3 microg/ml (for CIP), 1 microg/ml (for LEV), 0.25 microg/ml (for GAT), 0.125 microg/ml (for MOX) and 0.032 microg/ml (for GEM). Median MIC for LEV, GAT, MOX and GEM increased with decreasing susceptibility to CIP. Susceptibility to CIP was similar between penicillin-susceptible and penicillin-resistant pneumococci.


CONCLUSIONS
Third and fourth generation fluoroquinolones showed very high inhibitory activity, higher than that for CIP, for both penicillin-susceptible and penicillin-resistant pneumococci. We noted cross-resistance among fluoroquinolones.
Calva-Mercado
Juan José
JJ
Unidad de Epidemiología Clínica, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, México, DF, Mexico.
Castillo
Gonzalo
G
López-Vidal
Yolanda
Y
D000208:Acute Disease; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001372:Aza Compounds / Q000494:pharmacology; D016470:Bacteremia / Q000382:microbiology; D002939:Ciprofloxacin / Q000494:pharmacology; D003627:Data Interpretation, Statistical; D004351:Drug Resistance; D024841:Fluoroquinolones / Q000494:pharmacology*; D000077734:Gatifloxacin; D000077735:Gemifloxacin; D006801:Humans; D064704:Levofloxacin; D008800:Mexico; D008826:Microbial Sensitivity Tests; D000077266:Moxifloxacin; D009287:Naphthyridines / Q000494:pharmacology; D015242:Ofloxacin / Q000494:pharmacology; D010403:Penicillin Resistance; D010406:Penicillins / Q000494:pharmacology*; D011804:Quinolines / Q000494:pharmacology; D012141:Respiratory Tract Infections / Q000382:microbiology; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000302:isolation & purification
D000900:Anti-Bacterial Agents; D001372:Aza Compounds; D024841:Fluoroquinolones; D009287:Naphthyridines; D010406:Penicillins; D011804:Quinolines; D002939:Ciprofloxacin; D064704:Levofloxacin; D015242:Ofloxacin; D000077734:Gatifloxacin; D000077735:Gemifloxacin; D000077266:Moxifloxacin