NOSOCOMIAL STREPTOCOCCAL BLOOD-STREAM INFECTIONS IN THE SCOPE PROGRAM- SPECIES OCCURRENCE AND ANTIMICROBIAL RESISTANCE

Nosocomial blood stream infections due to streptococci represent an in creasingly important problem, particularly among neutropenic cancer pa tients. This problem is compounded by the emerging resistance to antim icrobial agents commonly used For empiric or prophylactic treatment of hospitalized patients. In this study, we examined the species distrib ution and antimicrobial susceptibility profile of 295 streptococcal no socomial blood stream isolates from more than 30 U.S. medical centers (SCOPE National Surveillance Program). Streptococci accounted for 5.4% of all nosocomial blood stream isolates reported. The viridans group streptococci (VGS) were the most frequently isolated streptococci (50. 8%), followed by the beta-haemolytic streptococci (31.9%) and pneumoco cci (13.2%). The beta-haemolytic streptococci were dominated by serogr oup B strains (63%), followed by serogroups A and G. Of these organism s, 193 strains were referred for subsequent monitor susceptibility tes ting. Approximately 14% of S. pneumoniae, 9.2% of VGS, and 0% of beta- haemolytic streptococci were resistant to penicillin. Ceftriaxone was highly active against virtually all isolates (93-100% susceptible) exc ept the VGS (77% susceptible). The rank order for activity of the four agents tested against the 193 isolates was vancomycin > ceftriaxone > penicillin > erythromycin. Importantly, 69% of the penicillin interme diate and resistant strains of VGS were also resistant to at least one additional antimicrobial (31% resistant to ceftriaxone, 51% resistant to erythromycin, 15% resistant to both ceftriaxone and erythromycin). The relatively poor activity of erythromycin against virtually all st reptococci and the frequent association of macrolide resistance with p enicillin resistance among the VGS suggests that both macrolides and p -lactam agents might have limited value as prophylactic agents For den tal procedures and in empiric or prophylactic use in neutropenic patie nts. (C) 1997 Elsevier Science Inc.