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DOI: 10.1055/s-0036-1584294
Treatment Challenges of Group A Beta-hemolytic Streptococcal Pharyngo-Tonsillitis
Publication History
06 February 2016
12 April 2016
Publication Date:
03 June 2016 (online)
![](https://www.thieme-connect.de/media/10.1055-s-00025477/201703/lookinside/thumbnails/10-1055-s-0036-1584294_0434sr-1.jpg)
Abstract
Introduction Despite its in vitro efficacy, penicillin often fails to eradicate Group A β-hemolytic streptococci (GABHS) from patients with acute and relapsing pharyngo-tonsillitis (PT).
Objective This review of the literature details the causes of penicillin failure to eradicate GABHS PT and the therapeutic modalities to reduce and overcome antimicrobial failure.
Data Synthesis The causes of penicillin failure in eradicating GABHS PT include the presence of β lactamase producing bacteria (BLPB) that “protect” GABHS from any penicillin; the absence of bacteria that interfere with the growth of GABHS; co-aggregation between GABHS and Moraxella catarrhalis; and the poor penetration of penicillin into the tonsillar tissues and the tonsillo-pharyngeal cells, which allows intracellular GABHS and Staphylococcus aureus to survive. The inadequate intracellular penetration of penicillin can allow intracellular GABHS and S. aureus to persist. In the treatment of acute tonsillitis, the use of cephalosporin can overcome these interactions by eradicating aerobic BLPB (including M. catarrhalis), while preserving the potentially interfering organisms and eliminating GABHS.
Conclusion In treatment of recurrent and chronic PT, the administration of clindamycin, or amoxicillin-clavulanic acid, can eradicate both aerobic and anaerobic BLPB, as well as GABHS. The superior intracellular penetration of cephalosporin and clindamycin also enhances their efficacy against intracellular GABHS and S. aureus.
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References
- 1 Kaplan EL, Chhatwal GS, Rohde M. Reduced ability of penicillin to eradicate ingested group A streptococci from epithelial cells: clinical and pathogenetic implications. Clin Infect Dis 2006; 43 (11) 1398-1406
- 2 Brook I, Gober AE. Persistence of group A beta-hemolytic streptococci in toothbrushes and removable orthodontic appliances following treatment of pharyngotonsillitis. Arch Otolaryngol Head Neck Surg 1998; 124 (09) 993-995
- 3 Gerber MA. Antibiotic resistance in group A streptococci. Pediatr Clin North Am 1995; 42 (03) 539-551
- 4 Hagman MM, Dale JB, Stevens DL. Comparison of adherence to and penetration of a human laryngeal epithelial cell line by group A streptococci of various M protein types. FEMS Immunol Med Microbiol 1999; 23: 195-204
- 5 Neeman R, Keller N, Barzilai A, Korenman Z, Sela S. Prevalence of internalisation-associated gene, prtF1, among persisting group-A streptococcus strains isolated from asymptomatic carriers. Lancet 1998; 352 (9145): 1974-1977
- 6 Brook I. The role of beta-lactamase-producing bacteria in the persistence of streptococcal tonsillar infection. Rev Infect Dis 1984; 6 (05) 601-607
- 7 Lafontaine ER, Wall D, Vanlerberg SL, Donabedian H, Sledjeski DD. Moraxella catarrhalis coaggregates with Streptococcus pyogenes and modulates interactions of S. pyogenes with human epithelial cells. Infect Immun 2004; 72 (11) 6689-6693
- 8 Grahn E, Holm SE. Bacterial interference in the throat flora during a pharyngo- tonsillitis outbreak in an apartment house area. Zentralbl Bakteriol Mikrobiol Hyg A 1983; 256: 72-79
- 9 Brook I. Emergence and persistence of beta-lactamase-producing bacteria in the oropharynx following penicillin treatment. Arch Otolaryngol Head Neck Surg 1988; 114 (06) 667-670
- 10 Podbielski A, Beckert S, Schattke R. , et al. Epidemiology and virulence gene expression of intracellular group A streptococci in tonsils of recurrently infected adults. Int J Med Microbiol 2003; 293 (2–3): 179-190
- 11 Stjernquist-Desatnik A, Samuelsson P, Walder M. Penetration of penicillin V to tonsillar surface fluid in healthy individuals and in patients with acute tonsillitis. J Laryngol Otol 1993; 107 (04) 309-312
- 12 Marouni MJ, Barzilai A, Keller N, Rubinstein E, Sela S. Intracellular survival of persistent group A streptococci in cultured epithelial cells. Int J Med Microbiol 2004; 294 (01) 27-33
- 13 Orrling A, Kamme C, Stjernquist-Desatnik A. Penicillin V, loracarbef and clindamycin in tonsillar surface fluid during acute group A streptococcal pharyngotonsillitis. Scand J Infect Dis 2005; 37 (6–7): 429-435
- 14 Brook I, Gober AE. Interference by aerobic and anaerobic bacteria in children with recurrent group A beta-hemolytic streptococcal tonsillitis. Arch Otolaryngol Head Neck Surg 1999; 125 (05) 552-554
- 15 Brook I, Gober AE. Role of bacterial interference and beta-lactamase-producing bacteria in the failure of penicillin to eradicate group A streptococcal pharyngotonsillitis. Arch Otolaryngol Head Neck Surg 1995; 121 (12) 1405-1409
- 16 Roos K, Holm SE, Grahn E. , et al. Alpha-streptococci as supplementary treatment of recurrent streptococcal tonsillitis: a randomized placebo-controlled study. Scand J Infect Dis 1993; 25: 31-35
- 17 Roos K, Holm SE, Grahn-Håkansson E, Lagergren L. Recolonization with selected alpha-streptococci for prophylaxis of recurrent streptococcal pharyngotonsillitis—a randomized placebo-controlled multicentre study. Scand J Infect Dis 1996; 28 (05) 459-462
- 18 Falck G, Grahn-Håkansson E, Holm SE, Roos K, Lagergren L. Tolerance and efficacy of interfering alpha-streptococci in recurrence of streptococcal pharyngotonsillitis: a placebo-controlled study. Acta Otolaryngol 1999; 119 (08) 944-948
- 19 Brook I, Gober AE. Long-term effects on the nasopharyngeal flora of children following antimicrobial therapy of acute otitis media with cefdinir or amoxycillin-clavulanate. J Med Microbiol 2005; 54 (Pt 6): 553-556
- 20 Brook I, Gilmore JD. Evaluation of bacterial interference and beta-lactamase production in management of experimental infection with group A beta-hemolytic streptococci. Antimicrob Agents Chemother 1993; 37 (07) 1452-1455
- 21 Brook I, Gober AE. Prophylaxis with amoxicillin or sulfisoxazole for otitis media: effect on the recovery of penicillin-resistant bacteria from children. Clin Infect Dis 1996; 22 (01) 143-145
- 22 Brook I, Gober AE. Emergence of beta-lactamase-producing aerobic and anaerobic bacteria in the oropharynx of children following penicillin chemotherapy. Clin Pediatr (Phila) 1984; 23 (06) 338-341
- 23 Brook I. Role of beta-lactamase-producing bacteria in the failure of penicillin to eradicate group A streptococci. Pediatr Infect Dis 1985; 4: 491-495
- 24 Brook I, Yocum P, Friedman EM. Aerobic and anaerobic bacteria in tonsils of children with recurrent tonsillitis. Ann Otol Rhinol Laryngol 1981; 90 (3 Pt 1): 261-263
- 25 Reilly S, Timmis P, Beeden AG, Willis AT. Possible role of the anaerobe in tonsillitis. J Clin Pathol 1981; 34 (05) 542-547
- 26 Tunér K, Nord CE. beta-Lactamase-producing anaerobic bacteria in recurrent tonsillitis. J Antimicrob Chemother 1982; 10 (Suppl A): 153-156
- 27 Chagollan J, Macias JR, Gil JS. Flora indigena de las amigdales. Invest Med Int 1984; 11: 36-39
- 28 Kielmovitch IH, Keleti G, Bluestone CD, Wald ER, Gonzalez C. Microbiology of obstructive tonsillar hypertrophy and recurrent tonsillitis. Arch Otolaryngol Head Neck Surg 1989; 115 (06) 721-724
- 29 Brook I, Yocum P, Foote Jr PA. Changes in the core tonsillar bacteriology of recurrent tonsillitis: 1977-1993. Clin Infect Dis 1995; 21 (01) 171-176
- 30 Brook I, Yocum P. Quantitative measurement of beta lactamase in tonsils of children with recurrent tonsillitis. Acta Otolaryngol 1984; 98 (5–6): 556-559
- 31 Brook I. Beta-lactamase-producing bacteria and their role in infection. Rev Med Microbiol 2005; 16: 91-99
- 32 Brook I, Hirokawa R. Treatment of patients with a history of recurrent tonsillitis due to group A beta-hemolytic streptococci. A prospective randomized study comparing penicillin, erythromycin, and clindamycin. Clin Pediatr (Phila) 1985; 24 (06) 331-336
- 33 Brook I. Treatment of patients with acute recurrent tonsillitis due to group A beta-haemolytic streptococci: a prospective randomized study comparing penicillin and amoxycillin/clavulanate potassium. J Antimicrob Chemother 1989; 24 (02) 227-233
- 34 Kaplan EL, Johnson DR. Eradication of group A streptococci from the upper respiratory tract by amoxicillin with clavulanate after oral penicillin V treatment failure. J Pediatr 1988; 113 (02) 400-403
- 35 Holm S, Henning C, Grahn E, Lomberg H, Staley H. ; The Swedish Study Group. Is penicillin the appropriate treatment for recurrent tonsillopharyngitis? Results from a comparative randomized blind study of cefuroxime axetil and phenoxymethylpenicillin in children. Scand J Infect Dis 1995; 27 (03) 221-228
- 36 Holm SE, Roos K, Strömberg A. A randomized study of treatment of streptococcal pharyngotonsillitis with cefadroxil or phenoxymethylpenicillin (penicillin V). Pediatr Infect Dis J 1991; 10 (10, Suppl) S68-S71
- 37 Brook I, Gober AE. Failure to eradicate streptococci and beta-lactamase producing bacteria. Acta Paediatr 2008; 97 (02) 193-195
- 38 Brook I, Foote Jr PA. Isolation of methicillin resistant Staphylococcus aureus from the surface and core of tonsils in children. Int J Pediatr Otorhinolaryngol 2006; 70 (12) 2099-2102
- 39 Brook I, Gober AE. Recovery of interfering and beta-lactamase-producing bacteria from group A beta-haemolytic streptococci carriers and non-carriers. J Med Microbiol 2006; 55 (Pt 12): 1741-1744
- 40 Woo JH, Kim ST, Kang IG, Lee JH, Cha HE, Kim DY. Comparison of tonsillar biofilms between patients with recurrent tonsillitis and a control group. Acta Otolaryngol 2012; 132 (10) 1115-1120
- 41 Brook I. The role of anaerobic bacteria in tonsillitis. Int J Pediatr Otorhinolaryngol 2005; 69 (01) 9-19
- 42 Brook I, Gillmore JD. Enhancement of growth of group A beta-hemolytic streptococci in mixed infections with aerobic and anaerobic bacteria. Clin Microbiol Infect 1996; 1 (03) 179-182
- 43 Brook I, Gober AE. Increased recovery of Moraxella catarrhalis and Haemophilus influenzae in association with group A beta-haemolytic streptococci in healthy children and those with pharyngo-tonsillitis. J Med Microbiol 2006; 55 (Pt 8): 989-992
- 44 Casey JR, Pichichero ME. The evidence base for cephalosporin superiority over penicillin in streptococcal pharyngitis. Diagn Microbiol Infect Dis 2007; 57 (3, Suppl): 39S-45S
- 45 Casey JR, Pichichero ME. Meta-analysis of cephalosporins versus penicillin for treatment of group A streptococcal tonsillopharyngitis in adults. Clin Infect Dis 2004; 38 (11) 1526-1534
- 46 Coonan KM, Kaplan EL. In vitro susceptibility of recent North American group A streptococcal isolates to eleven oral antibiotics. Pediatr Infect Dis J 1994; 13 (07) 630-635
- 47 Macris MH, Hartman N, Murray B. , et al. Studies of the continuing susceptibility of group A streptococcal strains to penicillin during eight decades. Pediatr Infect Dis J 1998; 17 (05) 377-381
- 48 van Asselt GJ, Mouton RP, van Boven CP. Penicillin tolerance and treatment failure in group A streptococcal pharyngotonsillitis. Eur J Clin Microbiol Infect Dis 1996; 15 (02) 107-115
- 49 Shulman ST, Bisno AL, Clegg HW. , et al; Infectious Diseases Society of America. Clinical practice guideline for the diagnosis and management of group A streptococcal pharyngitis: 2012 update by the Infectious Diseases Society of America. Clin Infect Dis 2012; 55 (10) e86-e102
- 50 Bisno AL, Gerber MA, Gwaltney Jr JM, Kaplan EL, Schwartz RH. ; Infectious Diseases Society of America. Practice guidelines for the diagnosis and management of group A streptococcal pharyngitis. Clin Infect Dis 2002; 35 (02) 113-125
- 51 Still GJ. Management of pediatric patients with group A beta-hemolytic Streptococcus pharyngitis: treatment options. Pediatr Infect Dis J 1995; 14 (Suppl3A): 57-61
- 52 McCarty J, Hedrick JA, Gooch WM. Clarithromycin suspension vs penicillin V suspension in children with streptococcal pharyngitis. Adv Ther 2000; 17 (01) 14-26
- 53 Mehra S, van Moerkerke M, Welck J. , et al. Short course therapy with cefuroxime axetil for group A streptococcal tonsillopharyngitis in children. Pediatr Infect Dis J 1998; 17 (06) 452-457
- 54 Adam D, Hostalek U, Tröster K. ; Cefixime Study Group. [5-day therapy of bacterial pharyngitis and tonsillitis with cefixime. Comparison with 10 day treatment with penicillin V]. Klin Padiatr 1996; 208 (05) 310-313
- 55 Boccazzi A, Tonelli P, De'Angelis M, Bellussi L, Passali D, Careddu P. Short course therapy with cefitbuten versus azithromycin in pediatric streptococcal pharyngitis. Pediatr Infect Dis J 2000; 19 (10) 963-967
- 56 Tack KJ, Henry DC, Gooch WM, Brink DN, Keyserling CH. ; Cefdinir Pharyngitis Study Group. Five-day cefdinir treatment for streptococcal pharyngitis. Antimicrob Agents Chemother 1998; 42 (05) 1073-1075
- 57 Howie VM, Ploussard JH. Treatment of group A streptococcal pharyngitis in children. Comparison of lincomycin and penicillin G given orally and benzathine penicillin G given intramuscularly. Am J Dis Child 1971; 121 (06) 477-480
- 58 Lennon DR, Farrell E, Martin DR, Stewart JM. Once-daily amoxicillin versus twice-daily penicillin V in group A beta-haemolytic streptococcal pharyngitis. Arch Dis Child 2008; 93 (06) 474-478
- 59 Gerber MA, Randolph MF, DeMeo K, Feder Jr HM, Kaplan EL. Failure of once-daily penicillin V therapy for streptococcal pharyngitis. Am J Dis Child 1989; 143 (02) 153-155
- 60 Hooton TM. A comparison of azithromycin and penicillin V for the treatment of streptococcal pharyngitis. Am J Med 1991; 91 (3A, Suppl3A) 23S-26S
- 61 Pichichero ME, Disney FA, Aronovitz GH, Talpey WB, Green JL, Francis AB. Randomized, single-blind evaluation of cefadroxil and phenoxymethyl penicillin in the treatment of streptococcal pharyngitis. Antimicrob Agents Chemother 1987; 31 (06) 903-906
- 62 Block SL, Hedrick JA, Tyler RD. Comparative study of the effectiveness of cefixime and penicillin V for the treatment of streptococcal pharyngitis in children and adolescents. Pediatr Infect Dis J 1992; 11 (11) 919-925
- 63 Pichichero ME, Mclinn SE, Gooch III WM, Rodriguez W, Goldfarb J, Reidenberg BE. ; Members of the Ceftibuten Pharyngitis International Study Group. Ceftibuten vs. penicillin V in group A beta-hemolytic streptococcal pharyngitis. Pediatr Infect Dis J 1995; 14 (7, Suppl) S102-S107
- 64 Pichichero ME, Gooch WM, Rodriguez W. , et al. Effective short-course treatment of acute group A beta-hemolytic streptococcal tonsillopharyngitis. Ten days of penicillin V vs 5 days or 10 days of cefpodoxime therapy in children. Arch Pediatr Adolesc Med 1994; 148 (10) 1053-1060
- 65 McCarty JM. Comparative efficacy and safety of cefprozil versus penicillin, cefaclor and erythromycin in the treatment of streptococcal pharyngitis and tonsillitis. Eur J Clin Microbiol Infect Dis 1994; 13 (10) 846-850
- 66 Nemeth MA, Gooch III WM, Hedrick J, Slosberg E, Keyserling CH, Tack KJ. Comparison of cefdinir and penicillin for the treatment of pediatric streptococcal pharyngitis. Clin Ther 1999; 21 (09) 1525-1532
- 67 Rubio-López V, Valdezate S, Alvarez D. , et al. Molecular epidemiology, antimicrobial susceptibilities and resistance mechanisms of Streptococcus pyogenes isolates resistant to erythromycin and tetracycline in Spain (1994-2006). BMC Microbiol 2012; 12: 215
- 68 Richter SS, Heilmann KP, Beekmann SE. , et al. Macrolide-resistant Streptococcus pyogenes in the United States, 2002-2003. Clin Infect Dis 2005; 41 (05) 599-608
- 69 Tanz RR, Shulman ST, Shortridge VD. , et al; North American Streptococcal Pharyngitis Surveillance Group. Community-based surveillance in the united states of macrolide-resistant pediatric pharyngeal group A streptococci during 3 respiratory disease seasons. Clin Infect Dis 2004; 39 (12) 1794-1801
- 70 Tanz RR, Shulman ST, Sroka PA, Marubio S, Brook I, Yogev R. Lack of influence of beta-lactamase-producing flora on recovery of group A streptococci after treatment of acute pharyngitis. J Pediatr 1990; 117 (06) 859-863
- 71 Brook I, Gober AE. Bacterial interference in the nasopharynx following antimicrobial therapy of acute otitis media. J Antimicrob Chemother 1998; 41 (04) 489-492
- 72 Jain A, Shukla VK, Tiwari V, Kumar R. Antibiotic resistance pattern of group-a beta-hemolytic streptococci isolated from north Indian children. Indian J Med Sci 2008; 62 (10) 392-396
- 73 Casey JR, Pichichero ME. Metaanalysis of short course antibiotic treatment for group a streptococcal tonsillopharyngitis. Pediatr Infect Dis J 2005; 24 (10) 909-917
- 74 Gerber MA, Baltimore RS, Eaton CB. , et al. Prevention of rheumatic fever and diagnosis and treatment of acute Streptococcal pharyngitis: a scientific statement from the American Heart Association Rheumatic Fever, Endocarditis, and Kawasaki Disease Committee of the Council on Cardiovascular Disease in the Young, the Interdisciplinary Council on Functional Genomics and Translational Biology, and the Interdisciplinary Council on Quality of Care and Outcomes Research: endorsed by the American Academy of Pediatrics. Circulation 2009; 119 (11) 1541-1551
- 75 Breese BB, Disney FA, Talpey WB. Beta-hemolytic streptococcal illness. Comparison of lincomycin, ampicillin, and potassium penicillin G in treatment. Am J Dis Child 1966; 112 (01) 21-27
- 76 Breese BB, Disney FA, Talpey WB, Green J. Beta-hemolytic streptococcal infection. Comparison of penicillin and lincomycin in the treatment of recurrent infections or the carrier state. Am J Dis Child 1969; 117 (02) 147-152
- 77 Randolph MF, DeHaan RM. A comparison of lincomycin and penicillin in the treatment of group A streptococcal infections: speculation on the “L” form as a mechanism of recurrence. Del Med J 1969; 41 (02) 51-62
- 78 Randolph MF, Redys JJ, Hibbard EW. Streptococcal pharyngitis. 3. Streptococcal recurrence rates following therapy with penicillin or with clindamycin(7-chlorolincomycin). Del Med J 1970; 42 (04) 87-92
- 79 Brook I, Leyva F. The treatment of the carrier state of group A beta-hemolytic streptococci with clindamycin. Chemotherapy 1981; 27 (05) 360-367
- 80 Stillerman M, Isenberg HD, Facklam RR. Streptococcal pharyngitis therapy: comparison of clindamycin palmitate and potassium phenoxymethyl penicillin. Antimicrob Agents Chemother 1973; 4 (05) 514-520
- 81 Chaudhary S, Bilinsky SA, Hennessy JL. , et al. Penicillin V and rifampin for the treatment of group A streptococcal pharyngitis: a randomized trial of 10 days penicillin vs 10 days penicillin with rifampin during the final 4 days of therapy. J Pediatr 1985; 106 (03) 481-486
- 82 Massell BF. Prophylaxis of streptococcal infections and rheumatic fever: a comparison of orally administered clindamycin and penicillin. JAMA 1979; 241 (15) 1589-1594
- 83 Tanz RR, Shulman ST, Barthel MJ, Willert C, Yogev R. Penicillin plus rifampin eradicates pharyngeal carriage of group A streptococci. J Pediatr 1985; 106 (06) 876-880
- 84 Smith TD, Huskins WC, Kim KS, Kaplan EL. Efficacy of beta-lactamase-resistant penicillin and influence of penicillin tolerance in eradicating streptococci from the pharynx after failure of penicillin therapy for group A streptococcal pharyngitis. J Pediatr 1987; 110 (05) 777-782
- 85 Casey JR, Kahn R, Gmoser D. , et al. Frequency of symptomatic relapses of group A beta-hemolytic streptococcal tonsillopharyngitis in children from 4 pediatric practices following penicillin, amoxicillin, and cephalosporin antibiotic treatment. Clin Pediatr (Phila) 2008; 47 (06) 549-554
- 86 Mahakit P, Vicente JG, Butt DI, Angeli G, Bansal S, Zambrano D. Oral clindamycin 300 mg BID compared with oral amoxicillin/clavulanic acid 1 g BID in the outpatient treatment of acute recurrent pharyngotonsillitis caused by group a beta-hemolytic streptococci: an international, multicenter, randomized, investigator-blinded, prospective trial in patients between the ages of 12 and 60 years. Clin Ther 2006; 28 (01) 99-109
- 87 Tanz RR, Poncher JR, Corydon KE, Kabat K, Yogev R, Shulman ST. Clindamycin treatment of chronic pharyngeal carriage of group A streptococci. J Pediatr 1991; 119 (1 Pt 1): 123-128
- 88 American Academy of Pediatrics, Committee on Infectious Diseases Red Book. Report of the Committee on Infectious Diseases. 30th ed. 2015. Elk Grove Village: Ill American Academy of Pediatrics;
- 89 de Jongh E, Opstelten W. ; Werkgroep NHG-Standaard Acute keelpijn. [Revision of the Dutch College of General Practitioners practice guideline ‘Acute sore throat’]. Ned Tijdschr Geneeskd 2015; 159: A9456
- 90 Snow V, Mottur-Pilson C, Cooper JR. ; American Academy of Family Physicians; American College of Physicians-American Society of Internal Medicine; Centers for Disease Control. Principles of appropriate antibiotic use pharyngitis in adults. Ann Intern Med 2001; 134: 506-508
- 91 Stelter K. Tonsillitis and sore throat in children. GMS Curr Top Otorhinolaryngol Head Neck Surg 2014; 13: Doc07 10.3205/cto000110
- 92 Agence Française de Sécurité Sanitaire des Produits de Santé. Systemic antibiotic treatment in upper and lower respiratory tract infections: official French guidelines. Clin Microbiol Infect 2003; 9 (12) 1162-1178
- 93 Motta G, Motta S, Cassano P. , et al. Effects of guidelines on adeno-tonsillar surgery on the clinical behaviour of otorhinolaryngologists in Italy. BMC Ear Nose Throat Disord 2013; 13: 1
- 94 Piñeiro Pérez R, Hijano Bandera F, Alvez González F. , et al. [Consensus document on the diagnosis and treatment of acute tonsillopharyngitis]. An Pediatr (Barc) 2011; 75 (05) 342.e1-342.e13
- 95 Chiappini E, Regoli M, Bonsignori F. , et al. Analysis of different recommendations from international guidelines for the management of acute pharyngitis in adults and children. Clin Ther 2011; 33 (01) 48-58
- 96 Starreveld JS, Zwart S, Boukes FS, Wiersma T, Goudswaard AN. [Summary of the practice guideline ‘Sore throat’ (second revision) from the Dutch College of General Practitioners]. Ned Tijdschr Geneeskd 2008; 152 (08) 431-435
- 97 Matthys J, De Meyere M, van Driel ML, De Sutter A. Differences among international pharyngitis guidelines: not just academic. Ann Fam Med 2007; 5 (05) 436-443
- 98 Casey JR, Kahn R, Gmoser D. , et al. Frequency of symptomatic relapses of group A beta-hemolytic streptococcal tonsillopharyngitis in children from 4 pediatric practices following penicillin, amoxicillin, and cephalosporin antibiotic treatment. Clin Pediatr (Phila) 2008; 47 (06) 549-554
- 99 Brook I, Gober AE. Rate of eradication of group A beta-hemolytic streptococci in children with pharyngo-tonsillitis by amoxicillin and cefdinir. Int J Pediatr Otorhinolaryngol 2009; 73 (05) 757-759
- 100 Brook I, Foote PA. Efficacy of penicillin versus cefdinir in eradication of group A streptococci and tonsillar flora. Antimicrob Agents Chemother 2005; 49: 4787-4788