Drug-resistant Streptococcus pneumoniae in the Lebanon: implications for presumptive therapy.
A total of 50 consecutive clinical isolates of Streptococcus pneumoniae, collected between 1996 and 1998, were tested against six antimicrobial agents using the E-test. The percentages of fully resistant (R) and intermediately-R strains, respectively, were: benzyl penicillin 18 and 38%, amoxycillin-clavulanate 6 and 12%, cefuroxime 22 and 16%, ceftriaxone 2 and 16%, and clarithromycin 10%. Fully and or intermediately multidrug-resistance (two or more drugs) was seen in 44% of the isolates, 18% being fully resistant. The MIC breakpoint for cefaclor is not defined by the National Committee for Clinical Laboratory Standards (NCCLS) but MICs showed that: 76% of the isolates had an MIC of < or = 8 mg/l, 4% had an MIC of 16 mg/l and 20% had an MIC of > or = 32 mg/l. There was agreement between the E-test Pen MIC results and the 1 microg oxacillin (oxa) disk diffusion screen test for the 22 susceptible and the nine fully R strains but not for the 19 strains with Pen MICs between 0.1 and 1 mg/l; this shows the importance of MIC determination in such isolates. Penicillin and multiply antibiotic-resistant pneumococci are spreading in Lebanon, emphasizing the necessity to reconsider current treatment regimens in this country.
Araj
G F
GF
Department of Pathology and Laboratory Medicine, American University of Beirut Medical Center, Lebanon. garaj@aub.edu.lb
Bey
H A
HA
Itani
L Y
LY
Kanj
S S
SS
D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use; D002511:Cephalosporins / Q000494:pharmacology* / Q000627:therapeutic use; D004352:Drug Resistance, Microbial; D006801:Humans; D007861:Lebanon / Q000453:epidemiology; D018942:Macrolides; D008826:Microbial Sensitivity Tests; D010406:Penicillins / Q000494:pharmacology* / Q000627:therapeutic use; D013290:Streptococcal Infections / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology*; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000302:isolation & purification
D000900:Anti-Bacterial Agents; D002511:Cephalosporins; D018942:Macrolides; D010406:Penicillins