Evaluation of Beta-lactamase Activity and Microbial Interference in Treatment Failures of Acute Streptococcal Tonsillitis

Roos, Kristian; Grahn, Eva; Holm, Stig E.

doi:10.3109/00365548609032342

Cited by 80 publications

(38 citation statements)

References 24 publications

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“…Mechanisms that may explain penicillin treatment failure have been explored extensively. These mechanisms include elimination of commensal organisms (6,13,28), viral copathogenicity (16), internalization of GAS in epithelial cells (21,23), and bacterial copathogenicity (6,7,28,34). To date, none of these mechanisms, either individually or in combination, completely explains the occurrence of penicillin treatment failure observed in clinical practice.…”

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confidence: 99%

Biofilm Formation by Group A Streptococci: Is There a Relationship with Treatment Failure?

Conley¹,

Olson²,

Cook³

et al. 2003

J Clin Microbiol

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Group A streptococcus (GAS) is the primary cause of bacterial pharyngitis in children and adults. Up to one-third of patients treated for GAS pharyngitis fail to respond to antibiotic therapy. The objective of this cohort study was to evaluate GAS biofilm formation as a mechanism for antibiotic treatment failure using previously collected GAS isolates and penicillin treatment outcome data. The minimum biofilm eradication concentration (MBEC) assay device was used to determine the biofilm-forming capabilities, efficiencies, and antibiotic susceptibilities of GAS isolates. The MBECs and MICs of several antibiotics for GAS were determined. All 99 GAS isolates available for this study formed biofilms, with various efficiencies. Antibiotic MBECs were consistently higher than MICs for all of the GAS isolates. MBECs indicated penicillin insensitivity in 60% of GAS isolates, producing the first report of in vitro GAS insensitivity to penicillin. Using MBECs to predict penicillin treatment failure had better sensitivity (56%) but lower specificity (36%) than the sensitivity (0%) and specificity (100%) when MICs were used. However, the positive predictive value of the MBEC was superior to that of the MIC (56 versus 0%), while the negative predictive values (42 and 47%) were similar. More studies are needed to understand the roles of biofilms and the MBEC assay in predicting GAS treatment failure. In addition, further investigations are necessary to determine if non-biofilm-forming strains of GAS exist and the roles of in vivo monospecies and multispecies biofilms in streptococcal pharyngitis treatment failure.

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confidence: 99%

Biofilm Formation by Group A Streptococci: Is There a Relationship with Treatment Failure?

Conley¹,

Olson²,

Cook³

et al. 2003

J Clin Microbiol

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“…This led to the hypothesis that bacteriocin production may result from a selective pressure exerted by GABHS and also that these substances might actually inhibit colonization of the upper respiratory tract and/or aid in the eradication of GABHS. Roos and col-leagues (20) demonstrated that both production of ,B-lactamase by the normal oropharyngeal flora and the lack of colonization of the pharynx with inhibiting AHS correlated with the failure of penicillin to cure GABHS tonsillitis. Although only a single strain of each organism was used in the present study, the isolates that we used represent typical isolates of each bacterial species.…”

Section: Discussionmentioning

confidence: 99%

Evaluation of bacterial interference and beta-lactamase production in management of experimental infection with group A beta-hemolytic streptococci

Brook

Gilmore

1993

Antimicrob Agents Chemother

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The in vivo effects of penicillin and cefprozil therapy on the interaction between organisms commonly recovered from inflamed tonsils were studied by using a subcutaneous abscess model in mice. These organisms were group A beta-hemolytic streptococci (GABHS), Streptococcus salivarius (which is capable of interfering with GABHS), and Staphylococcus aureus. In mice infected with GABHS and S. salivarius alone or in combination, penicillin eliminated both organisms and cefprozil eliminated GABHS and S. aureus but not S. salivarius. Penicillin did not, however, reduce the number of GABHS or S. salivarius in the presence of S.aureus. The present study demonstrated the ability of 1-lactamase-producing S. aureus to protect GABHS from penicillin. However, no such protection was present following the administration of cefprozil. Furthermore, the preservation of S. salivarius that interferes with GABHS growth may provide protection from reinfection with GABHS. This study supports and provides an explanation for the increased efficacies of cephalosporins administered orally over that of penicillin when treating patients with acute GABHS pharyngitis or tonsillitis.

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“…The recovery of aerobic and anaerobic BLPB in over threequarters of patients with recurrent GABHS tonsillitis (1,7,13), the ability to measure ␤-lactamase activity in the tonsillar core (2), and the response of patients with recurrent GABHS tonsillitis to antimicrobials effective against BLPB (1,5,7,13) support this explanation.…”

mentioning

confidence: 92%

“…One explanation of this phenomenon is that ␤-lactamase-producing bacteria (BLPB) protect GABHS by inactivating penicillin (1). Another explanation is that the preservation of alpha-hemolytic streptococci (AHS) that possess interfering capabilities against GABHS contribute to the eradication of this organism (13).…”

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confidence: 99%

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Efficacy of Penicillin versus Cefdinir in Eradication of Group A Streptococci and Tonsillar Flora

Brook

Foote

2005

Antimicrob Agents Chemother

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Core tonsillar cultures were obtained from 40 children with recurrent tonsillitis treated with either penicillin or cefdinir. Group A beta-hemolytic streptococci were isolated from 11 penicillin-and 3 cefdinir-treated (P < 0.001) patients. ␤-Lactamase producers were recovered from 17 penicillin-and 3 cefdinir-treated (P < 0.01) patients. Inhibiting alpha-hemolytic streptococci were isolated less often from penicillin-treated patients than from cefdinir-treated patients.Penicillin failure to eradicate group A beta-hemolytic streptococci (GABHS) from inflamed tonsils is of great concern (8). One explanation of this phenomenon is that ␤-lactamase-producing bacteria (BLPB) protect GABHS by inactivating penicillin (1). Another explanation is that the preservation of alpha-hemolytic streptococci (AHS) that possess interfering capabilities against GABHS contribute to the eradication of this organism (13).Several classes of antimicrobials that are active against GABHS and BLPB are more effective than penicillin in eradicating GABHS from recurrently inflamed tonsils (1, 5, 7). A possible explanation for the improved efficacy of cephalosporins over penicillin is the activity of cephalosporins against BLPB and their relative inactivity against AHS.This study investigated the effects of penicillin and cefdinir therapies on the core tonsillar aerobic bacterial flora of children with recurrent tonsillitis.Patients consecutively scheduled for elective tonsillectomies because of recurrent GABHS tonsillitis were included. Criteria for inclusion were a history of recurrent GABHS pharyngotonsillitis (at least six episodes within the preceding 2 years, with at least four by GABHS) and an age of Ͼ4 years. Excluded were subjects who received antimicrobials or had any infection during the previous month. The study was performed between June 1998 and June 2002 and was approved by the Institutional Review Board. Each subject had general physical and otolaryngological examinations, a complete blood cell count, and urinalysis.Following a tonsillectomy, one tonsil was cauterized with a heated scalpel, and an incision was made through the area. The tonsillar core was swabbed with a sterile, cotton-tipped applicator that was placed onto an anaerobic transport medium (Port-A-Cul; BBL, Cockeysville, Md.) and inoculated within 24 h onto sheep's blood (5%), chocolate, and MacConkey agar plates (all media from BBL, Becton Dickinson Co., Cockeysville, Md.). The plates were incubated aerobically at 37°C (MacConkey) and under 5% CO 2 and were examined at 24 and 48 h (11). ␤-Lactamase activity was determined on five colonies of each morphological feature of all isolates by using a Cefinaz disk (BBL, Cockeysville, Md.).Inhibitory activities of five separate colonies of AHS from each patient were tested against one strain of a recent clinical isolate of GABHS. Minidrops of log-phase broth cultures of the isolates were transferred with a Steers steel pin replicator to vitamin K1-enriched Brucella blood agar plates and allowed to dry for 15 min. A log-ph...

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Evaluation of Beta-lactamase Activity and Microbial Interference in Treatment Failures of Acute Streptococcal Tonsillitis

Cited by 80 publications

References 24 publications

Biofilm Formation by Group A Streptococci: Is There a Relationship with Treatment Failure?

Biofilm Formation by Group A Streptococci: Is There a Relationship with Treatment Failure?

Evaluation of bacterial interference and beta-lactamase production in management of experimental infection with group A beta-hemolytic streptococci

Efficacy of Penicillin versus Cefdinir in Eradication of Group A Streptococci and Tonsillar Flora

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