BACKGROUND: In view of the widespread use of penicillin for >50 years for the treatment of group A streptococcal infections, we examined the question of whether there has been a change in susceptibility to penicillin in group A streptococcal strains collected during a span of 80 years (1917 to 1997). METHODS: One hundred thirty-three group A streptococcal strains collected during 80 years were tested for changes in penicillin susceptibility. Three tests were used: (1) the microtiter broth minimal inhibitory concentration (MIC); (2) the minimal bactericidal concentration (MBC); and (3) the penicillin E strip MIC. RESULTS: The results indicate there has been no change in the susceptibility to penicillin in these group A streptococci during the past 80 years. The microtiter broth MIC90 for the oldest strains (0.032 microg/ml) was not significantly different from those collected most recently (0.032 microg/ml); there is no statistical difference between the raw MIC data for the four collection periods (P=0.468, analysis of variance on ranks). CONCLUSIONS: There has been no change in the susceptibility of group A streptococci during this time in spite of well-documented cases of penicillin resistance in other Gram-positive organisms and despite recognized resistance of group A streptococci to other antibiotics.
BACKGROUND: In view of the widespread use of penicillin for >50 years for the treatment of group A streptococcal infections, we examined the question of whether there has been a change in susceptibility to penicillin in group A streptococcal strains collected during a span of 80 years (1917 to 1997). METHODS: One hundred thirty-three group A streptococcal strains collected during 80 years were tested for changes in penicillin susceptibility. Three tests were used: (1) the microtiter broth minimal inhibitory concentration (MIC); (2) the minimal bactericidal concentration (MBC); and (3) the penicillin E strip MIC. RESULTS: The results indicate there has been no change in the susceptibility to penicillin in these group A streptococci during the past 80 years. The microtiter broth MIC90 for the oldest strains (0.032 microg/ml) was not significantly different from those collected most recently (0.032 microg/ml); there is no statistical difference between the raw MIC data for the four collection periods (P=0.468, analysis of variance on ranks). CONCLUSIONS: There has been no change in the susceptibility of group A streptococci during this time in spite of well-documented cases of penicillin resistance in other Gram-positive organisms and despite recognized resistance of group A streptococci to other antibiotics.
Authors: Randall J Olsen; Luchang Zhu; Regan E Mangham; Ahmad Faili; Samer Kayal; Stephen B Beres; James M Musser Journal: Am J Pathol Date: 2022-07-15 Impact factor: 5.770
Authors: Mark J Walker; Timothy C Barnett; Jason D McArthur; Jason N Cole; Christine M Gillen; Anna Henningham; K S Sriprakash; Martina L Sanderson-Smith; Victor Nizet Journal: Clin Microbiol Rev Date: 2014-04 Impact factor: 26.132
Authors: David Metzgar; Darcie Baynes; Christian J Hansen; Erin A McDonough; Daisy R Cabrera; Melody M Ellorin; Patrick J Blair; Kevin L Russell; Dennis J Faix Journal: PLoS One Date: 2009-09-04 Impact factor: 3.240