Brook I, Gober AE. Persistence of Group A β-Hemolytic Streptococci in Toothbrushes and Removable Orthodontic Appliances Following Treatment of Pharyngotonsillitis. Arch Otolaryngol Head Neck Surg. 1998;124(9):993-995. doi:10.1001/archotol.124.9.993
To investigate the persistence of group A β-hemolytic streptococci (GABHS) in toothbrushes and removable orthodontic appliances (ROAs) in children who suffer from acute GABHS pharyngotonsillitis and the association with penicillin treatment failure.
Private practice setting.
Patients and Methods
Pharyngotonsillar and toothbrush cultures were obtained from 104 children with acute GABHS pharyngotonsillitis before and after 10 days of penicillin V potassium therapy. Cultures of ROAs were also obtained from 21 children. The persistence of GABHS in 10 daily rinsed and 10 nonrinsed toothbrushes was studied in vitro.
Group A β-hemolytic streptococci were isolated from 11 (11%) of the toothbrushes and 18 (17%) of the patients after the completion of penicillin therapy. Toothbrushes of 5 (28%) of the 18 children who harbored GABHS were colonized with the organism. Group A β-hemolytic streptococci were also isolated from 4 (19%) of 21 ROAs after therapy. In vitro studies illustrated the persistence of GABHS in nonrinsed toothbrushes for up to 15 days. In contrast, the organism was not isolated from rinsed toothbrushes beyond day 3.
Toothbrushes and ROAs that harbor GABHS may contribute to the persistence of GABHS in the oropharynx and may account for the failure of penicillin therapy in some cases of pharyngotonsillitis.
INFECTIONS CAUSED by group A β-hemolytic streptococci (GABHS) continue to present an important clinical problem. Failure to eradicate the streptococci from patients with pharyngitis or tonsillitis can lead to recurrent infections and septic and nonseptic complications, such as rheumatic fever.1 The frequently reported inability of penicillin therapy to eradicate GABHS is therefore of great concern.2 Various theories have been offered to explain the failure of penicillin therapy to eradicate GABHS.3 However, to our knowledge, the role of reinfection by the patient's own toothbrush or removable orthodontic appliances (ROAs) (retainers) has not been previously studied.
This study was designed to investigate whether (1) GABHS can persist in toothbrushes in vitro, (2) GABHS can be recovered from the toothbrushes or ROAs of children with acute GABHS pharyngotonsillitis, and (3) the persistence of GABHS on these fomites can contribute to the failure of penicillin therapy to eradicate GABHS.
Children who were seen consecutively for acute GABHS tonsillitis between October 10, 1996, and May 21, 1997, in a suburban private practice clinic participated in the study. They presented with a sore throat and at least 1 of the following: anterior cervical adenitis, a temperature higher than 38.3°C (101°F), pharyngeal or tonsillar exudate, or pharyngeal injection. The diagnosis of acute GABHS pharyngotonsillitis was established by recovery of the organisms from pharyngotonsillar cultures.
Penicillin V potassium was administered orally in 3 divided doses a day for 10 days at a dosage of 40 to 50 mg/d for children weighing less than 50 kg and 15 mg/d for those weighing more than 50 kg. The children were then asked to return for reexamination 2 to 4 days after the completion of therapy and to bring along their own toothbrush and ROA (if they had one) in a clean plastic bag. At that time, cultures were obtained from the patient's throat, personal toothbrush, and ROA. The first 104 children who complied with these directions and with the antimicrobial therapy were included in the study. Compliance was assessed by a dosage card and inspection of the unused medicine after the completion of therapy. The mean age of the patients was 8 years 5 months (age range, 5-14 years), and 59 were boys.
Pharyngotonsillar cultures for aerobic bacteria were obtained before and after therapy using a sterile cotton swab system (Culturette, Marion Scientific Corp, Rockford, Ill) that was placed in a modified Stuart bacterial transport system. A sheep blood agar (5%) plate was inoculated and then incubated at 37°C under 5% carbon dioxide and examined at 24 and 48 hours. The GABHS were identified using conventional methods4 and characterized by bacitracin sensitivity and serologic grouping.
A recently isolated clinical strain of GABHS recovered from a child with acute tonsillitis was inoculated onto sheep blood agar (5%) medium at 37°C under 5% carbon dioxide for 48 hours. The plate was wiped with a sterile swab, and a suspension of 105 colony-forming units per milliliter of the organism was prepared in sterile saline tubes. Twenty newly acquired sterilized unused toothbrushes were dipped into these tubes for 2 minutes, and then placed in a sterile container that was left at room temperature (21°C-25°C). Ten of these toothbrushes were rinsed with sterile water at room temperature once a day for 21 days.
The surface of the toothbrushes and ROAs was thoroughly swabbed once a day for 21 days with a sterile cotton swab, and the material was transferrred onto sheep blood agar (5%) plates. The plates were incubated at 37°C under 5% carbon dioxide and examined at 24 and 48 hours.
Group A β-hemolytic streptococci were isolated from 11 (11%) of the toothbrushes and from the pharyngotonsillar cultures obtained from 18 (17%) patients 2 to 4 days after the completion of therapy. Seven of these patients were symptomatic with tonsillitis. The toothbrushes of 5 (28%) of these 18 children also harbored GABHS, and 3 of the 5 children were symptomatic. In contrast, 6 (7%) of the 86 children who were successfully treated had positive toothbrush cultures (P<.02).
Cultures of ROAs were obtained in 21 instances, and GABHS were isolated in 4 (19%) of them; the toothbrushes of 2 of the 4 children involved also harbored these organisms. Two of the 4 children experienced treatment failure as well.
Group A β-hemolytic streptococci persisted in nonrinsed toothbrushes for up to 15 days (Table 1). The number of positive cultures decreased gradually, until no organisms were recovered beyond day 15. In contrast, GABHS were not isolated from rinsed toothbrushes beyond day 3.
This study illustrates the recovery of GABHS in the toothbrushes and ROAs of 11% and 19%, respectively, of children who had received 10 days of treatment of penicillin for pharyngotonsillitis. The persistence of GABHS in these fomites may account for the recovery of the organisms in the pharynx of some of the patients and for the recurrence of GABHS tonsillitis. It is difficult, however, to know whether the recovery of GABHS in toothbrushes and ROAs of these patients with positive pharyngotonsillar cultures may be the cause, or the result, of the pharyngotonsillar presence of GABHS. However, the persistence of GABHS in vitro in nonrinsed toothbrushes and in toothbrushes and ROAs of nonsymptomatic patients at the end of therapy suggests that these fomites can continue to harbor GABHS and serve as a potential source of reinoculation of the patient and possibly other household members.
The persistence of GABHS in fomites has been previously reported.5 Toothbrushes and ROAs, especially when not rinsed or cleaned, may enhance the survival of GABHS. Toothbrushes can harbor microorganisms,6 and may serve as a potential for transmission of pathogens.7 The moisture and food debris that they may contain can contribute to this phenomenon. In contrast, cleansing of toothbrushes, even with water, may facilitate the eradication of these organisms from the objects.
Our data suggest that toothbrushes and ROAs that are not thoroughly cleaned daily may contribute to the persistence of GABHS in the oropharynx of children. Further studies are warranted to elucidate the contribution of this phenomenon to the failure of penicillin therapy in the treatment of GABHS pharyngotonsillitis and to find out the best method to cleanse oral fomites and to prevent the persistence of GABHS.
Corresponding author: Itzhak Brook, MD, MSc, PO Box 70412, Chevy Chase, MD 20813-0412.
Accepted for publication June 15, 1998.