Colonization by Haemophilus influenzae and group A streptococci in recurrent acute tonsillitis and in tonsillar hypertrophy

Molecular mapping to species level of the tonsillar crypt microbiota associated with health and recurrent tonsillitis

The human palatine tonsils, which belong to the central antigen handling sites of the mucosal immune system, are frequently affected by acute and recurrent infections. This study compared the microbiota of the tonsillar crypts in children and adults affected by recurrent tonsillitis with that of healthy adults and children with tonsillar hyperplasia. An in-depth 16S rRNA gene based pyrosequencing approach combined with a novel strategy that included phylogenetic analysis and detection of species-specific sequence signatures enabled identification of the major part of the microbiota to species level. A complex microbiota consisting of between 42 and 110 taxa was demonstrated in both children and adults. This included a core microbiome of 12 abundant genera found in all samples regardless of age and health status. Yet, Haemophilus influenzae, Neisseria species, and Streptococcus pneumoniae were almost exclusively detected in children. In contrast, Streptococcus pseudopneumoniae was present in all samples. Obligate anaerobes like Porphyromonas, Prevotella, and Fusobacterium were abundantly present in children, but the species diversity of Porphyromonas and Prevotella was larger in adults and included species that are considered putative pathogens in periodontal diseases, i.e. Porphyromonas gingivalis, Porphyromonas endodontalis, and Tannerella forsythia. Unifrac analysis showed that recurrent tonsillitis is associated with a shift in the microbiota of the tonsillar crypts. Fusobacterium necrophorum, Streptococcus intermedius and Prevotella melaninogenica/histicola were associated with recurrent tonsillitis in adults, whereas species traditionally associated with acute tonsillitis like pyogenic streptococci and Staphylococcus aureus were scarce. The findings suggest that recurrent tonsillitis is a polymicrobial infection in which interactions within consortia of taxa play an etiologic role. The study contributes to the human microbiome data, to the understanding of the etiology of infections affecting the tonsils, and forms a basis for further insight into the consequences of the intense microbe-host interactions that take place in the tonsils.

The effect of radiofrequency ablation on microbiology of the tonsils

OBJECTIVE

To investigate the effect of tonsil size reduction using temperature controlled radiofrequency on the number of pathogenic bacteria in the tonsil tissue.

MATERIALS AND METHODS

This study was performed on 25 patients who had undergone tonsillectomy under general anesthesia at our clinic. Immediately after the cold knife tonsillectomy both tonsils were removed, one was included in the control and the other one was included in the study group. In vitro radiofrequency was applied to the tonsil in the study group at eight distinct points, each lasting 15s. Biopsy materials were taken under sterile conditions from the center of each tonsil for further culturing.

RESULTS

The difference in bacterial number was investigated between the two groups. The bacterial number following radiofrequency administration was found to be significantly very lower compared to the control group (p<0.01). Radiofrequency administration significantly reduced growth of all types of bacteria.

CONCLUSION

The radiofrequency tonsil ablation technique, which is used safely and effectively in the management of obstructive tonsil hypertrophy, currently has no indication for the treatment of patients with chronic and recurrent tonsillitis. However, when the right conditions are provided, the radiofrequency tonsil ablation technique may be applied to patients with chronic and recurrent tonsillitis and further studies investigating the differences in the frequency of patients' tonsillitis episodes should be undertaken.

Detection of group A Streptococcus in tonsils from pediatric patients reveals high rate of asymptomatic streptococcal carriage

Background

Group A Streptococcus (GAS) causes acute tonsillopharyngitis in children, and approximately 20% of this population are chronic carriers of GAS. Antibacterial therapy has previously been shown to be insufficient at clearing GAS carriage. Bacterial biofilms are a surface-attached bacterial community that is encased in a matrix of extracellular polymeric substances. Biofilms have been shown to provide a protective niche against the immune response and antibiotic treatments, and are often associated with recurrent or chronic bacterial infections. The objective of this study was to test the hypothesis that GAS is present within tonsil tissue at the time of tonsillectomy.

Methods

Blinded immunofluorescent and histological methods were employed to evaluate palatine tonsils from children undergoing routine tonsillectomy for adenotonsillar hypertrophy or recurrent GAS tonsillopharyngitis.

Results

Immunofluorescence analysis using anti-GAS antibody was positive in 11/30 (37%) children who had tonsillectomy for adenotonsillar hypertrophy and in 10/30 (33%) children who had tonsillectomy for recurrent GAS pharyngitis. Fluorescent microscopy with anti-GAS and anti-cytokeratin 8 & 18 antibodies revealed GAS was localized to the tonsillar reticulated crypts. Scanning electron microscopy identified 3-dimensional communities of cocci similar in size and morphology to GAS. The characteristics of these communities are similar to GAS biofilms from in vivo animal models.

Conclusion

Our study revealed the presence of GAS within the tonsillar reticulated crypts of approximately one-third of children who underwent tonsillectomy for either adenotonsillar hypertrophy or recurrent GAS tonsillopharyngitis at the Wake Forest School of Medicine.

Trial Registration

The tissue collected was normally discarded tissue and no patient identifiers were collected. Thus, no subjects were formally enrolled.

Increased recovery of Moraxella catarrhalis and Haemophilus influenzae in association with group A beta-haemolytic streptococci in healthy children and those with pharyngo-tonsillitis

The inflamed tonsils harbour numerous types of bacteria, alone or in combination with group A beta-haemolytic streptococci (GABHS). The cohabitation of the tonsils by GABHS and certain other bacterial species may contribute to the inflammatory process and the failure of penicillin therapy. This study evaluated the recovery of Moraxella catarrhalis, Haemophilus influenzae, Staphylococcus aureus and Streptococcus pneumoniae in association with GABHS in healthy children and those with acute pharyngo-tonsillitis (APT). Pharyngo-tonsillar cultures were obtained from 548 children with APT and 866 healthy children. GABHS was recovered from 112 (20.4%) children with APT. Of the 114 H. influenzae isolates, 32 were recovered in association with GABHS (29% of all patients who had GABHS) and 82 were isolated without GABHS (19%) (P=0.0267). Of the 69 M. catarrhalis isolates, 25 were recovered in association with GABHS (22% of all patients who had GABHS) and 44 were isolated without GABHS (10%) (P=0.0012). In contrast, there was no association between the isolation of GABHS and the recovery of Staph. aureus or Strep. pneumoniae. GABHS was recovered from 104 (12%) healthy children. Of the 69 M. catarrhalis isolates, 24 were recovered in association with GABHS (23% of all patients who had GABHS) and 80 were isolated without GABHS (10%) (P=0.006). There was no association between the isolation of GABHS and the recovery of H. influenzae, Staph. aureus or Strep. pneumoniae. This study demonstrates an association between the recovery of GABHS and H. influenzae and M. catarrhalis from pharyngo-tonsillar cultures of patients with APT and M. catarrhalis from pharyngo-tonsillar cultures of healthy children.

Situación actual de las resistencias a antibióticos en infecciones amigdalares

OBJECTIVE

To obtain the main responsible organisms, its sensitivity and resistances to antibiotics in tonsillitis.

MATERIAL AND METHODS

We have studied the post-surgical tonsils, carrying out a microbiologic study, its culture and sensitivity.

RESULTS

The most frequent isolated organisms were Staphylococcus aureus (29.3%), followed by Streptococcus pyogenes (23.4%), and Haemophilus influenzae (12.1%). The highest resistances were for the S. aureus (penicillin 91%, erythromycin 18% and 5% to the rest of the beta-lactams), followed by H. influenzae (50% clarithromycin, 30% amoxyciIlin and 2% cephalosporins) and S. pyogenes (28% erytromycin, 10% clindamycin and 3% penicillin).

CONCLUSIONS

We noticed the minimal resistance found to cephalosporins, and for this reason they appear to be the safest option, except in children under five years old, in which amoxicillin is still the first line treatment, because the causative agent is S. pyogenes, sensitive to that antibiotic.

Epidemiology and virulence gene expression of intracellular group A streptococci in tonsils of recurrently infected adults

Intracellularly persistent group A streptococci (GAS, Streptococcus pyogenes) have been associated with recurrent tonsillopharyngitis and antibiotic treatment failure. As a supplementation of the published in vitro data, conventional bacteriology and molecular epidemiology was performed on material from 29 adult patients of a German army hospital with anamnestic signs of recurrent tonsillopharyngitis. Pre-surgery tonsil swabs and the surgically removed tonsils were examined with respect to growth of aerobic bacteria in absence and presence of antibiotics with exclusively extracellular activity. Under such antibiotic selection, Staphylococcus aureus and GAS were cultured from specimens of 13 and 3 patients, respectively. In every material GAS-positive by culture methods, the intracellular location of the penicillin-susceptible GAS isolates was confirmed by immunohistologic examination of tonsillar sections using a GAS-specific IgG antibody. The three intracellular GAS isolates were typed by emm gene sequencing and could be associated to types M6 and M49 (two isolates). The bacteria were serially passaged on sheep blood agar, and semiquantitative mRNA analysis from virulence genes was performed using bacteria of the 4th and 25th passage after isolation. An M-type-specific pattern of virulence gene expression and different gene expression levels in relation to the passage number were observed.

The prevalence of potential pathogenic bacteria in nasopharyngeal samples from individuals with a respiratory tract infection and a sore throat--implications for the diagnosis of pharyngotonsillitis

BACKGROUND

Treatment failure in patients with pharyngotonsillitis after a traditional course of penicillin V is a common finding. Several factors have been proposed to explain the failure rate, but the presence of aetiological agents other than group A beta-haemolytic streptococci has attracted little attention.

OBJECTIVES

The aim of the present study was to investigate if a nasopharyngeal sample could suggest the aetiology of a sore throat in patients with a respiratory tract infection.

METHODS

The prevalence of potentially pathogenic bacteria (Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis) in nasopharyngeal samples from 618 healthy individuals was compared with that from 108 patients with a respiratory tract infection and a sore throat.

RESULTS

The prevalence of H.influenzae was higher in patients with a sore throat than in healthy individuals of the same age. For the adult patients with a sore throat, the prevalence was 27.5% compared with 2.7% for the healthy carriers (P < 10(-7)). The corresponding figures for schoolchildren were 31.3% versus 6.1% (P = 0.004) and for pre-school children 37.8% versus 13.2% (P = 0.0003).

CONCLUSIONS

If H.influenzae is found in a nasopharyngeal sample from a patient with a respiratory tract infection and a sore throat, it might be the aetiological agent.

Do systemic corticosteroids effectively treat obstructive sleep apnea secondary to adenotonsillar hypertrophy?

To determine if pediatric obstructive sleep apnea syndrome (OSAS) caused by adenotonsillar hypertrophy (ATH) could be treated by a short course of systemic corticosteroids, we conducted an open-label pilot study in which standardized assessments of symptomatology, OSAS severity, and adenotonsillar size were performed before and after a 5-day course of oral prednisone, 1.1+/-0.1 (+/-SE) mg/kg per day. Outcome measures included symptom severity, adenotonsillar size, and polysomnographic measures of OSAS. Selection criteria included age from 1 to 12 years, ATH, symptomatology suggesting OSAS, an apnea/hypopnea index (AHI) > or = 3/hour, and intent to perform adenotonsillectomy. Only one of nine children showed enough improvement to avoid adenotonsillectomy. Symptomatology did not improve after corticosteroid treatment but did after removal of tonsils and adenoids. Polysomnographic indices of OSAS severity did not improve after corticosteroid treatment. After corticosteroids, tonsillar size decreased in only two patients, adenoidal size was only marginally reduced, and the size of the nasopharyngeal airway was not significantly increased. These results suggest that a short course of prednisone is ineffective in treating pediatric OSAS caused by ATH.

Adherence of non-typeable Haemophilus influenzae promotes reorganization of the actin cytoskeleton in human or chinchilla epithelial cells in vitro

Non-typeable Haemophilus influenzae (NTHi) are opportunistic mucosal pathogens which adhere to epithelial cells via a variety of non-specific and specific interactions. Several adhesins have been identified and while the complimentary receptor(s) for each of these adhesins has not yet been fully characterized, it is widely accepted that adherence is an absolute prerequisite for disease. Several reports have indicated that NTHi can also be internalized and reside intracellularly. For this to occur, NTHi must be taken up by mucosal epithelial cells lining the respiratory tract. We have noted, by TEM, that adherent NTHi overlie an electron dense area in the cell membrane of human epithelial cells which is associated with a localized complex assembly of cytoskeletal fibers in the eukaryotic cytoplasm. We thus examined the potential involvement of cytoskeletal actin in this phenomenon via FITC-phalloidin labeling of respiratory tract epithelial cells which had been incubated with several clinical isolates of NTHi. Strong punctate fluorescence was coincident with adherent NTHi to both human oropharyngeal and chinchilla middle ear epithelial cells. This reactivity was similar to the discrete fluorescent spots observed with enteropathogenic Escherichia coli which were adhered to HeLa cells. In contrast, none of the NTHi isolates tested induced actin polymerization in cells of endothelial origin. While the exact mechanisms involved are yet to be elucidated, our data indicated that actin nucleation was coincident with NTHi adherence.

Efficacy of 5-day cefpodoxime proxetil for recurrent pharyngitis in adults. A comparative study with 10-day penicillin V or amoxycillin---clavulanate

OBJECTIVE: To compare the clinical and bacteriologic efficacy of a 5-day course of cefpodoxime proxetil (CPD) with that of a 10-day course of penicillin V (PNV) or amoxycillin---clavulanate (AMC) in recurrent pharyngitis in adults. A cost-effectiveness study (reported elsewhere) was carried out at the same time. METHODS: This multicenter, randomized, open label trial involved 580 adult patients consulting general practitioners for clinical recurrent pharyngitis (greater-than-or-equal3 episodes within the last 12 months) regardless of the bacterial etiology. Patients were treated for 5 days with CPD, 100 mg twice daily, or for 10 days with PNV, 1x106 IU three times a day, or for 10 days with AMC, 500 mg (amoxycillin) three times a day. Clinical and bacteriologic outcomes were noted at the end of treatment, and cases of clinical recurrence were recorded during a 6-month follow-up period. RESULTS: At the end of treatment, clinical response was satisfactory in 157 of 170 (92.3%) patients on CPD, 147 of 166 (88.5%) patients on PNV, and 168 of 177 (94.9%) patients on AMC. Group A beta-hemolytic streptococci (GABHS) were eradicated in 22 of 23 (95.65%) patients on CPD, 16 of 16 (100%) patients on PNV, and 19 of 20 (95%) patients on AMC. The rates of clinical success and GABHS eradication were not significantly different between the groups. Compliance (p<0.001) and tolerance (p<0.001) were significantly better in the CPD group than in the other two groups. Among the 389 patients evaluable 6 months after the end of treatment, the recurrence rate of acute pharyngitis (due to any bacterium) was significantly lower in the CPD group (p=0.01 versus PNV; p<0.01 versus AMC). A Kaplan---Meier analysis (469 patients over 6 months) of the rate of non-recurrence, with comparison by the log-rank test, also showed a significant difference in favor of CPD. CONCLUSIONS: A 5-day treatment of recurrent pharyngitis with CPD was as effective and better tolerated than a 10-day treatment with PNV or AMC. The risk of recurrence was lower with CPD.

Immune responses against Streptococcus pyogenes in human palatine tonsils

We investigated cellular immunity against Streptococcus pyogenes in human tonsils by measuring antigen-specific immunoglobulin-secreting cells and the production of cytokines from CD4+ T cells in response to M proteins. The incidence of S pyogenes in tonsils was significantly higher in patients with recurrent tonsillitis (RT) than in patients with tonsillar hypertrophy (TH). M protein-specific immunoglobulin A (IgA) and immunoglobulin G spot-forming cells were increased in patients with RT compared with patients with TH. In RT the number of M protein-specific IgA spot-forming cells was significantly greater in the S pyogenes-negative subjects than in the S pyogenes-positive subjects. Proliferation of CD4+ T cells and production of interferon-gamma (IFN-gamma) and interleukins -2, -4, -5, and -6 (IL-2, IL-4, IL-5, and IL-6) from those T cells were observed in response to M protein. The concentrations of IFN-gamma and IL-4 were higher in RT than in TH. These findings suggest that S pyogenes is associated with the pathogenesis of RT and that immune responses against M protein may play an important role in preventing the colonization of this bacteria in tonsils.

Immunization with outer membrane protein P6 from nontypeable Haemophilus influenzae induces bactericidal antibody and affords protection in the chinchilla model of otitis media

The role of nontypeable Haemophilus influenzae (NTHi) outer membrane protein (OMP) P6 in the pathogenesis of otitis media (OM) has not been defined. OMPs, fimbriae, pili, and lipooligosaccharide are several types of surface antigens of NTHi that are currently being evaluated as potential vaccine candidates. P6 is antigenically conserved among both nontypeable and type b H. influenzae strains and elicits bactericidal as well as protective antibodies; however, initial evaluation of a vaccine mixture of P6 combined with other NTHi OMPs failed to induce bactericidal antibody or protection in the chinchilla model of OM. We undertook an assessment of the ability of immunization with isolated P6 lipoprotein alone to confer protection. Chinchillas were immunized with P6 and challenged 10 days after the final immunization with either 3 x 10(3) CFU of NTHi delivered directly into the middle ear to induce OM or 5 x 10(8) CFU of NTHi delivered intranasally to establish nasopharyngeal colonization. All immunized animals responded with elevated serum titers of anti-P6 antibody, which also demonstrated bactericidal activity against homologous as well as a heterologous NTHi isolate. By 14 days post-transbullar challenge, the number of chinchillas with middle ear fluid and the incidence of NTHi culture-positive middle ear fluids were reduced 48 and 51%, respectively, in the P6-immunized chinchillas relative to the sham-immunized cohort. Nasopharyngeal colonization levels were comparable in the two cohorts. These data demonstrate that active immunization with P6 results in the production of NTHi-specific bactericidal antibody in the chinchilla and also affords a reduction in the incidence of NTHi-induced OM; however, parenteral immunization does not appear to affect the extent or duration of nasopharyngeal colonization by NTHi.

Expression of antigens associated with the individual stages of the inflammatory response in child and adult as a possible distinctive method for recurrent and chronic tonsillitis

Monoclonal antibodies (MoAbs) specific for the antigens associated with each stage of an inflammatory response were assayed with tonsillar mononuclear cells (TMNG). MoAbs BMA 27 E 10 and BMA 4 D 10 were used as markers for the early stages, BMA RM 3/1 for the intermediate stage, BMA 25 F 9 for the late stage, and BMA G 16/1 for the chronic stage. TMNC were obtained from patients operated for (1) recurrent tonsillitis with hypertrophy caused by common flora (children); (2) an indication for surgery for chronic tonsillitis in adults; (3) patients who were 'warm' tonsillectomized for a second peri-tonsillar phlegmon. Our results are presented and discussed in the light of their possible clinical significance. Our findings indicate that clinical chronic tonsillitis in the adult really is such. In the adults studied there was a high expression of antigens which is associated with the chronic stages, while the low expression of antigens is associated with the intermediate stage and an even lower antigen expression indicates the acute stage. In children what is considered to be chronic tonsillitis may perhaps be more correctly regarded as an expression of recurrent inflammation.

High recovery of Haemophilus influenzae and group A streptococci in recurrent tonsillar infection or hypertrophy as compared with normal tonsils

One hundred and twenty-six patients who underwent tonsillectomy because of recurrent acute tonsillitis, tonsillar hypertrophy or sleep apnoea were evaluated by tonsillar core culturing. The sleep apnoea patients served as controls, since none of them had tonsillar hypertrophy at ENT examination or any history of recurrent acute tonsillitis, and thus their tonsillar core flora could be regarded as normal. The isolation rate of H. influenzae was much lower among sleep apnoea controls (2.7 per cent) than among either the patients with recurrent acute tonsillitis (20.3 per cent) or those with tonsillar hypertrophy (36.7 per cent) (p less than 0.05), as was that of group A streptococci, 5.4 per cent versus 16.9 and 20 per cent, respectively (though the latter differences were not statistically significant). The isolation frequencies of B. catarrhalis, pneumococci, group C and G streptococci did not differ between the three groups. The high tonsillar core recovery rates of H. influenzae and group A streptococci both in patients with recurrent acute tonsillitis and in those with tonsillar hypertrophy, as compared with normal controls, suggests the possible involvement of these bacteria in both conditions.

Immunological investigations on tonsillar and peripheral blood lymphocytes after adeno-tonsillectomy. Possible suggestions for phenotypical and functional differences

The phenotypical and functional aspects of tonsillar (TMNC) and peripheral blood mononuclear cells (PBMNC) obtained from 40 patients who had undergone adeno-tonsillectomy for different tonsillar diseases were investigated. TMNC and PBMC were separately tested at the time of surgery; then a further investigation on the peripheral blood lymphocytes was performed three months after surgery. The most interesting findings are presented and discussed with particular attention to their clinical implications.