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Effect of atmosphere and duration of incubation on primary isolation of group A streptococci from throat cultures.

Publication ,  Journal Article
Lauer, BA; Reller, LB; Mirrett, S
Published in: J Clin Microbiol
February 1983

The optimal incubation conditions for isolation of group A streptococci from throat cultures are controversial. Therefore, we compared the effects of aerobic and anaerobic incubations after 24 and 48 h on the recovery of group A streptococci. Throat swabs submitted to the clinical laboratory were inoculated onto duplicate 5% sheep blood agar plates, incubated aerobically or anaerobically (GasPak jar) at 35 degrees C, and examined semiquantitatively after 24 and 48 h. Group A streptococci were identified by the fluorescent-antibody technique. Of 1,040 specimens, 506 (48.6%) grew beta-hemolytic streptococci, including 200 (19.2%) group A streptococci. Group A streptococci were recovered significantly more often with anaerobic incubation than with aerobic incubation after 24 h (182 versus 138; P less than 0.001) and after 48 h (193 versus 174; P less than 0.05). Non-group A beta-hemolytic streptococci also were recovered significantly more often with anaerobic incubation after 24 and 48 h (P less than 0.001). Colony counts were not affected by the incubation atmosphere. We conclude that incubation of throat cultures in an anaerobic atmosphere is superior to incubation in air for detection of group A streptococci. The greater sensitivity of anaerobic incubation, however, may not justify the extra laboratory effort and cost required to differentiate group A streptococci from the non-group A streptococci detected as a result of anaerobic incubation. Throat cultures should be examined after 24 and 48 h, especially if plates are incubated aerobically.

Duke Scholars

Published In

J Clin Microbiol

DOI

ISSN

0095-1137

Publication Date

February 1983

Volume

17

Issue

2

Start / End Page

338 / 340

Location

United States

Related Subject Headings

  • Streptococcus pyogenes
  • Streptococcus
  • Pharynx
  • Pharyngitis
  • Microbiology
  • Humans
  • Child, Preschool
  • Child
  • Anaerobiosis
  • Adult
 

Citation

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Lauer, B. A., Reller, L. B., & Mirrett, S. (1983). Effect of atmosphere and duration of incubation on primary isolation of group A streptococci from throat cultures. J Clin Microbiol, 17(2), 338–340. https://doi.org/10.1128/jcm.17.2.338-340.1983
Lauer, B. A., L. B. Reller, and S. Mirrett. “Effect of atmosphere and duration of incubation on primary isolation of group A streptococci from throat cultures.J Clin Microbiol 17, no. 2 (February 1983): 338–40. https://doi.org/10.1128/jcm.17.2.338-340.1983.
Lauer, B. A., et al. “Effect of atmosphere and duration of incubation on primary isolation of group A streptococci from throat cultures.J Clin Microbiol, vol. 17, no. 2, Feb. 1983, pp. 338–40. Pubmed, doi:10.1128/jcm.17.2.338-340.1983.
Lauer BA, Reller LB, Mirrett S. Effect of atmosphere and duration of incubation on primary isolation of group A streptococci from throat cultures. J Clin Microbiol. 1983 Feb;17(2):338–340.

Published In

J Clin Microbiol

DOI

ISSN

0095-1137

Publication Date

February 1983

Volume

17

Issue

2

Start / End Page

338 / 340

Location

United States

Related Subject Headings

  • Streptococcus pyogenes
  • Streptococcus
  • Pharynx
  • Pharyngitis
  • Microbiology
  • Humans
  • Child, Preschool
  • Child
  • Anaerobiosis
  • Adult