title: Changes in serotypes and antimicrobial susceptibility of invasive Streptococcus pneumoniae strains in Cleveland: a quarter century of experience.
abstract: The serotypes and susceptibilities to penicillin, macrolides, and clindamycin of 1,655 invasive isolates of Streptococcus pneumoniae recovered between 1979 and 2004 were determined. A precipitous decrease of 61% in the number of isolates was found following 2000, the year of 7-valent protein-conjugated pneumococcal vaccine (PCV7) introduction (139 versus 55 per 2-year period prior to versus after 2000; P < 0.001). This decrease was 84% in children <5 years old (80 versus 13 per 2-year period; P < 0.001) and 18 to 23% in other age groups (P, not significant). PCV7 serotypes decreased by 76% overall (103 versus 25 per 2-year period; P < 0.001) and by 92% in children <5 years old (65 versus 5 per 2-year period; P < 0.001), with significant decreases in six of the seven PCV serotypes. Other serotypes, except for type 19A, decreased from 32 to 22 per 2-year period, while type 19A increased from 4 to 8 per 2-year period, although none of these changes reached significance. Drug resistance emerged slowly, with the first penicillin-intermediate strain isolated in 1980 and the first macrolide/lincosamide-resistant strain isolated in 1984. The first penicillin-resistant strain was isolated in 1993. Resistance increased steadily thereafter until 2003-2004, when 51.1% of isolates were penicillin nonsusceptible and 53.3% were macrolide resistant. Clindamycin resistance remained low until 2003-2004, when 26.7% of strains were resistant; this was associated with the emergence of multidrug-resistant type 19A strains. This study documents the emergence of resistance over a quarter century among invasive pneumococci in the Cleveland area, as well as the reduction in disease caused by PCV7 serotypes following the introduction of PCV7 in 2000.
authors.affiliation: Department of Pathology, University Hospitals Case Medical Center, Case Western Reserve University, 11100 Euclid Avenue, Cleveland, OH 44106, USA. mrj6@cwru.edu
authors.forename: Michael R
authors.initials: MR
authors.lastname: Jacobs
authors.forename: Caryn E
authors.initials: CE
authors.lastname: Good
authors.forename: Bernard
authors.initials: B
authors.lastname: Beall
authors.forename: Saralee
authors.initials: S
authors.lastname: Bajaksouzian
authors.forename: Anne R
authors.initials: AR
authors.lastname: Windau
authors.forename: Cynthia G
authors.initials: CG
authors.lastname: Whitney
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002648:Child; D002675:Child, Preschool; D002981:Clindamycin / Q000494:pharmacology; D024881:Drug Resistance, Bacterial; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D006801:Humans; D015994:Incidence; D018942:Macrolides / Q000494:pharmacology; D022401:Meningococcal Vaccines / Q000008:administration & dosage; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D009820:Ohio / Q000453:epidemiology; D010406:Penicillins / Q000494:pharmacology; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000382:microbiology; D022242:Pneumococcal Vaccines / Q000008:administration & dosage; D011159:Population Surveillance / Q000379:methods; D012703:Serotyping; D013296:Streptococcus pneumoniae / Q000145:classification* / Q000187:drug effects* / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D018942:Macrolides; D022401:Meningococcal Vaccines; D010406:Penicillins; D022242:Pneumococcal Vaccines; D002981:Clindamycin