Results from an ongoing surveillance study, PROTEKT US (Prospective Resistant Organism Tracking and Epidemiology of the Ketolide Telithromycin - United States) Year 2 (2001-2002), suggest that Ketek (telithromycin) is highly active in vitro against Streptococcus pneumoniae (S. pneumoniae) isolates, including those resistant to other antimicrobial agents.

These data were presented at the 100th International Conference of the American Thoracic Society (ATS). Increasing multi-drug resistance among S. pneumoniae isolates compromises the treatment of community-acquired respiratory tract infections. This study found that nearly 30 per cent (n=2,805) of S. pneumoniae isolates were resistant to several antibacterials, including penicillin, cefuroxime, erythromycin, clindamycin, levofloxacin, tetracycline and co-trimoxazole, while more than 99 per cent (n=9,517) of S. pneumoniae isolates were susceptible to Ketek, irrespective of multi-drug resistance. A total of 242 centers submitted 9,531 S. pneumoniae isolates for the study.

"The increasing incidence of multi-drug resistant S. pneumoniae poses a challenge in the management of community-acquired respiratory tract infections," said Steven Brown, PhD, of the Clinical Microbiology Institute, Wilsonville, Oregon and the lead author of the poster. "As results from Protekt US demonstrate, Ketek is active against these resistant strains of S. pneumoniae in vitro."

Data from Protekt US were analyzed to determine the prevalence of multi-drug resistance (defined as resistant to > or equal to 2 antimicrobials) among S. pneumoniae isolates. A total of 9,531 S. pneumoniae isolates from bronchoalveolar lavage, blood, ear, nasopharyngeal swab/aspirate, sinus and sputum cultures were examined from patients in 242 centers across the United States. Isolates were studied for in vitro resistance to penicillin, cefuroxime, erythromycin, clindamycin, levofloxacin, tetracycline and co-trimoxazole. Study results found that 2,805 of the S. pneumoniae isolates were multi-drug resistant.

Resistance to four antibacterials was the most common type of multi-drug resistance in all culture sources. The most common example of multi-drug resistance was resistance to penicillin, cefuroxime, erythromycin and co-trimoxazole, accounting for 74.6 per cent of four antimicrobial resistance from bronchoalveolar lavage cultures, 85.9 per cent from blood cultures, 73.4 per cent from ear cultures, 76.0 per cent from nasopharyngeal swab/aspirate cultures, 73.8 per cent from sinus cultures and 69.1 per cent from sputum cultures. Overall, 99.9 per cent of the S. pneumoniae isolates were susceptible to Ketek, ranging from 99.4 per cent (bronchoalveolar lavage cultures) to 99.9 per cent (blood and sputum).