title: Occurrence and Characteristics of Erythromycin-Resistant Streptococcus pneumoniae Strains Isolated in Three Major Brazilian States.
abstract: We investigated the occurrence and phenotypic and genotypic characteristics of erythromycin-resistant Streptococcus pneumoniae strains isolated in three major states in Brazil, from 1990 to 1999. Of the 931 pneumococcal strains evaluated, 40 (4.3%) were erythromycin-resistant (Ery-R). Among the 40 Ery-R strains, 90.0%, 80.0%, 27.5%, 5.0%, and 2.5% were resistant to tetracycline, trimethoprim-sulfamethoxazole, penicillin, chloramphenicol, and rifampin, respectively. None of the strains were resistant to ofloxacin or to vancomycin. Most [37 (92.5%)] of the 40 Ery-R isolates presented the MLS(B) phenotype and 3 (7.5%) strains showed the M phenotype. PCR testing indicated that all MLS(B) phenotype isolates harbored the erm(B) gene only, whereas the mef(A/E) gene was present in all isolates presenting the M phenotype. The tet(M) gene was the most frequent (86.1%) among Ery-R isolates that were also resistant to tetracycline. Pulsed-field gel electrophoresis (PFGE) analysis after SmaI digestion revealed the occurrence of clonal relationships within groups of strains belonging to serotypes 14, 19A, and 23F. All Ery-R isolates belonging to serotype 14 were susceptible to penicillin and were included in a single clonal group (named Ery(14)-A) related to the England(14-)9 internationally spread clone.
authors.affiliation: Instituto de Microbiologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-590, Brazil.
authors.forename: Cláudia R V
authors.initials: CR
authors.lastname: Mendonça-Souza
authors.forename: Maria Da Glória S
authors.initials: Mda G
authors.lastname: Carvalho
authors.forename: Rosana R
authors.initials: RR
authors.lastname: Barros
authors.forename: Cícero A
authors.initials: CA
authors.lastname: Dias
authors.forename: Jorge Luiz M
authors.initials: JL
authors.lastname: Sampaio
authors.forename: Angela C D
authors.initials: AC
authors.lastname: Castro
authors.forename: Richard R
authors.initials: RR
authors.lastname: Facklam
authors.forename: Lúcia M
authors.initials: LM
authors.lastname: Teixeira
mesh_terms: D001938:Brazil; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D004917:Erythromycin / Q000494:pharmacology*; D006801:Humans; D008826:Microbial Sensitivity Tests; D010802:Phylogeny; D013296:Streptococcus pneumoniae / Q000145:classification / Q000187:drug effects* / Q000235:genetics
chemical_list: D004917:Erythromycin