title: Microbiology of peritonsillar abscesses.
abstract: OBJECTIVE
  The objective of the present study was to analyze the microbiology of peritonsillar abscesses.
  
  
  METHODS
  Thirty patients, mean age 24,2 years, with peritonsillar abscesses underwent aspiration of at least 3 mL of pus, which was cultured for aerobes and anaerobes.
  
  
  RESULTS
  87% samples showed positive cultures. Aerobic or facultative aerobic bacteria were isolated from 23% aspirates, mixed aerobic and anaerobic bacteria from 60%, and anaerobic bacteria from only 3% aspirate. A total of 69 bacterial isolates (34 aerobic and 35 anaerobic) were recovered. The most common aerobic isolate was Streptococcus sp, with Streptococcus pyogenes being identified in 23% of aspirates. The predominant anaerobic isolates were Prevotella sp and Peptostreptococcus sp. Patients had received previous antimicrobial therapy in 63% cases. In this group, 1.8 isolates per specimen were recovered, a lower number than in the untreated group (3.0 per specimen). No significant difference in the species isolated was observed between these two groups.
  
  
  CONCLUSIONS
  Peritonsillar abscess is usually a polymicrobial infection, with predominance of anaerobic bacteria. The number of agents isolated was larger in patients not previously treated with antibiotics, but the use of antimicrobial drugs did not interfere with the type of bacterium isolated.
authors.affiliation: University Hospital, USP, Brazil. sakaeflavio@yahoo.com.br
authors.forename: Flavio Akira
authors.initials: FA
authors.lastname: Sakae
authors.forename: Rui
authors.initials: R
authors.lastname: Imamura
authors.forename: Luiz Ubirajara
authors.initials: LU
authors.lastname: Sennes
authors.forename: Bernardo Cunha
authors.initials: BC
authors.lastname: Araújo Filho
authors.forename: Domingos Hiroshi
authors.initials: DH
authors.lastname: Tsuji
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D005260:Female; D006090:Gram-Negative Bacteria / Q000145:classification / Q000302:isolation & purification*; D006094:Gram-Positive Bacteria / Q000145:classification / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D008875:Middle Aged; D000039:Peritonsillar Abscess / Q000382:microbiology*; D011446:Prospective Studies