title: Group C streptococci isolated from throat swabs: a laboratory and clinical study.
abstract: OBJECTIVE
  To determine the prevalence of beta haemolytic, Lancefield group C streptococci in throat swabs taken in routine clinical practice, and correlate the species identified with presenting clinical features.
  
  
  METHODS
  One year, laboratory based prospective study, using a questionnaire to elicit clinical information.
  
  
  RESULTS
  4.4% of throat swabs yielded group C streptococci, of which 38% belonged to S equisimilis and 53% to S anginosus-milleri group (SAM). Pyrexia was more common in patients with S equisimilis, but other clinical features did not differ significantly between the two groups. No S zooepidemicus was isolated.
  
  
  CONCLUSIONS
  Species identification of group C streptococci from throat swabs does not appear to be clinically useful in this patient population. However, the prevalence and spectrum of organisms is similar to that reported in N America, where studies suggest a possible role in some cases of severe pharyngitis. Observational studies such as this lack power to resolve the issue of pathogenicity, for which a placebo controlled trial of antibiotic treatment is ideally required.
authors.affiliation: Microbiology Department, Victoria Infirmary, Glasgow, UK.
authors.forename: R F
authors.initials: RF
authors.lastname: Lewis
authors.forename: A E
authors.initials: AE
authors.lastname: Balfour
mesh_terms: D000293:Adolescent; D000328:Adult; D016009:Chi-Square Distribution; D005334:Fever / Q000382:microbiology; D006801:Humans; D010612:Pharyngitis / Q000382:microbiology*; D010614:Pharynx / Q000382:microbiology*; D015995:Prevalence; D011446:Prospective Studies; D013291:Streptococcus / Q000302:isolation & purification* / Q000472:pathogenicity