Activity of quinupristin-dalfopristin in invasive isolates of Streptococcus pneumoniae from Italy.
Eighty-five recent isolates of Streptococcus pneumoniae from patients with invasive disease were examined for their susceptibility to erythromycin, clindamycin, penicillin and quinupristin-dalfopristin by E test. A novel duplex PCR assay was used to detect the presence of the erm(B) or mef(A) genes in all of the erythromycin-resistant isolates. All of the strains tested were susceptible to the combination quinupristin-dalfopristin, regardless of their susceptibility to penicillin or to erythromycin. By duplex PCR, two-thirds of the erythromycin-resistant strains harbored erm, and one-third harbored mef. The activity of quinupristin-dalfopristin was not influenced by the genetic determinant of erythromycin resistance. The in vitro susceptibility of S. pneumoniae to quinupristin-dalfopristin is promising for future use; however, it is important to monitor the possible emergence of resistance.
Pantosti
A
A
Laboratory of Bacteriology and Medical Mycology, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy. pantosti@iss.it
D'Ambrosio
F
F
Bordi
E
E
Scotto D'Abusco
A
A
Del Grosso
M
M
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002981:Clindamycin / Q000494:pharmacology; D024881:Drug Resistance, Bacterial; D004359:Drug Therapy, Combination / Q000494:pharmacology*; D004587:Electrophoresis, Agar Gel; D004917:Erythromycin / Q000494:pharmacology; D006801:Humans; D007558:Italy; D008826:Microbial Sensitivity Tests; D010403:Penicillin Resistance; D010406:Penicillins / Q000494:pharmacology; D011008:Pneumococcal Infections / Q000188:drug therapy* / Q000382:microbiology; D016133:Polymerase Chain Reaction; D013296:Streptococcus pneumoniae / Q000145:classification / Q000187:drug effects* / Q000235:genetics; D014769:Virginiamycin / Q000494:pharmacology*
D000900:Anti-Bacterial Agents; D010406:Penicillins; D014769:Virginiamycin; C062940:quinupristin-dalfopristin; D002981:Clindamycin; D004917:Erythromycin