title: High incidence of erythromycin-resistant Streptococcus pyogenes in Monza (North Italy) in untreated children with symptoms of acute pharyngo-tonsillitis: an epidemiological and molecular study.
abstract: A retrospective analysis of susceptibility data available for Group A streptococcal isolates collected between January 1990 and January 1996 at the Hospital Microbiology Laboratory of Monza (North Italy), showed a sharp rise in the erythromycin resistance rates during the last 3 years. Streptococcus pyogenes resistant to erythromycin accounted for approximately 1% of strains isolated between 1990 and 1992; the percentage then rose from 5% in 1993 to almost 39% in 1995. In January 1996, the resistance rates peaked to 81%. A prospective controlled study performed between March and May of 1996 to determine the percentage of erythromycin-resistant Group A streptococci isolated in Monza from untreated children with acute pharyngo-tonsillitis, gave further confirmation of a high rate of erythromycin resistance (47%) in this area. Molecular characterization by T-serotyping and pulse-field gel electrophoresis analysis of 25 erythromycin-resistant Group A streptococcal isolates, showed a relatively high degree of heterogeneity among these strains, demonstrating that the increased resistance is not caused by the spread of a single clone.
authors.affiliation: Istituto di Microbiologia Medica, Università di Milano, Italy.
authors.forename: C E
authors.initials: CE
authors.lastname: Cocuzza
authors.forename: R
authors.initials: R
authors.lastname: Mattina
authors.forename: A
authors.initials: A
authors.lastname: Mazzariol
authors.forename: G
authors.initials: G
authors.lastname: Orefici
authors.forename: R
authors.initials: R
authors.lastname: Rescaldani
authors.forename: A
authors.initials: A
authors.lastname: Primavera
authors.forename: S
authors.initials: S
authors.lastname: Bramati
authors.forename: G
authors.initials: G
authors.lastname: Masera
authors.forename: F
authors.initials: F
authors.lastname: Parizzi
authors.forename: G
authors.initials: G
authors.lastname: Cornaglia
authors.forename: R
authors.initials: R
authors.lastname: Fontana
mesh_terms: D000208:Acute Disease; D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D004352:Drug Resistance, Microbial; D004591:Electrophoresis, Polyacrylamide Gel; D004917:Erythromycin / Q000494:pharmacology* / Q000627:therapeutic use; D005260:Female; D005798:Genes, Bacterial / Q000235:genetics; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D008826:Microbial Sensitivity Tests; D010612:Pharyngitis / Q000453:epidemiology* / Q000382:microbiology*; D012189:Retrospective Studies; D013290:Streptococcal Infections / Q000453:epidemiology* / Q000382:microbiology*; D013297:Streptococcus pyogenes / Q000187:drug effects* / Q000235:genetics; D014069:Tonsillitis / Q000453:epidemiology* / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents; D004917:Erythromycin