Recurrences in chronic tonsillitis substained by tonsillar biofilm-producing bacteria in children. Relationship with the grade of tonsillar hyperplasy

Analysis of Tonsil Tissues from Patients Diagnosed with Chronic Tonsillitis-Microbiological Profile, Biofilm-Forming Capacity and Histology

Chronic tonsillitis (CT) is a global health issue which can impair patient's quality of life and has an important socioeconomic impact due to the nonrational use of antibiotics, increased antimicrobial resistance and frequent need for surgical treatment. In order to isolate and identify the causing agents of CT, a total of 79 postoperative palatine and adenoid tissue samples were obtained from the ENT Clinic, KBC Zvezdara, Belgrade, Serbia. Culture identification was performed by MALDI-TOF MS and the Staphylococcus aureus isolates were tested for biofilm forming capability and antibiotic susceptibility. Additionally, a histological examination of palatine and adenoid tissue was performed in order to detect the presence of CT-causing bacteria. The slight majority of participants were females with median age of 28 years for adult patients (group I) and 6 years for children (group II). Analysis of the incidence of bacteria isolated from tissue samples in both groups showed the highest prevalence of S. aureus, Streptococcus oralis and Streptococcus parasanquinis. In addition to interfollicular hyperplasia, colonies of species S. aureus were detected in histological material. The presence of biofilm might be the reason for the recurrence of infection. Therefore, searching for a new treatment of CT is of great importance.

Electrochemical monitoring of bronchial inflammation in pediatric athletes: A prospective study

The assessment of inflammation by accessible, reproducible and especially non-invasive methods is one of the main goals for numerous medical specialties. One variable for assessment is the fraction of nitric oxide in exhaled air (FeNO), which correlates with the inflammatory syndrome of the airways. The objective of the present study was the biochemical evaluation of FeNO in children practicing sports in Oltenia, Romania. Between January and December 2018, children practicing sports (football, track and field, judo, fencing, handball, volleyball and basketball) were enrolled in the study. The FeNO values were compared with the asthma history and with the spirometric evaluation. A total of 23 children without a previous asthma diagnosis exhibited positive spirometry results. The prevalence of the disease was 3.6% in the cohort, and FeNO dosing showed higher values in the group at risk in children diagnosed with asthma, compared with that in children without this diagnosis. The children who performed outdoor sports (soccer, and track and field) had higher electrochemical levels of nitric oxide compared with those who performed indoor sports (mean, 29.70 vs. 20.56; P<0.0005), which led to the hypothesis that these children had an increased risk of developing bronchospasm. FeNO dosing can thus be a useful and easy-to-use tool in practice for assessing bronchial inflammation in children practicing various types of sports. The spirometric data of undiagnosed asthma patients from the present study may indicate that the disease is still underdiagnosed within Romania.

Hyaluronic acid in otology: Its uses, advantages and drawbacks - A review

OBJECTIVES

Review of the literature for studies involving the use of hyaluronic acid (HA) in otology.

METHODS

Pubmed and OvidMedline were searched using a combination of the following words in different variations: hyaluronic acid, hyaluronate, otolaryngology, otology, ear, tympanic membrane, perforation, tympanostomy, tympanoplasty, myringoplasty, packing, middle ear, cochlea, gene delivery, gene therapy, cochlear implant, hearing loss, meniere, vertigo, otitis and cholesteatoma.

RESULTS

The papers relevant for this review were triaged based on abstracts and titles and were then categorized based on topic/disease entity/procedure. The papers were read and summarized in order to use their findings in this review.

CONCLUSIONS

HA is being recently used as adjuvant therapy for multiple inflammatory conditions and in tissue repair. These immunomodulatory properties and biocompatibility have interested researchers specially in the field of otology for repair, gene delivery, immunomodulation etc. Recent data in the field show optimistic results for the use of HA in several conditions especially tympanic membrane perforations and gene delivery. It also establishes the role of HA as ancillary treatment in many other otologic pathologies. This review presents the most recent findings on the use of HA in otology. The results could be used to guide clinical practice and incite further research based on the presented results of the literature.

Staphylococcus aureus in tonsils of patients with recurrent tonsillitis: prevalence, susceptibility profile, and genotypic characterization

Introduction

Bacterial tonsillitis is an upper respiratory tract infection that occurs primarily in children and adolescents. Staphylococcus aureus is one of the most frequent pathogens in the etiology of tonsillitis and its relevance is due to its antimicrobial resistance and persistence in the internal tissues of the tonsils. Tonsillectomy is indicated in cases of recurrent tonsillitis after several failures of antibiotic therapy.

Material and methods

In this study we evaluated 123 surgically removed tonsils from patients who had history of recurrent tonsillitis. The tonsils were submitted to microbiological analysis for detection of S. aureus. The isolates were identified by PCR for femA gene. Antimicrobial susceptibility of the isolates was determined by disk diffusion tests. All isolates were submitted to PCR to detect mecA and Panton-Valentine leucocidin (PVL) genes. The genetic similarity among all isolates was determined by pulsed field gel electrophoresis.

Results

Sixty-one S. aureus isolates were obtained from 50 patients (40.7%) with mean age of 11.7 years. The isolates showed high level resistance to penicillin (83.6%), 9.8% had inducible MLSb phenotype, and 18.0% were considered multidrug resistant (MDR). mecA gene was detected in two isolates and the gene coding for PVL was identified in one isolate. The genetic similarity analysis showed high diversity among the isolates. More than one genetically different isolate was identified from the same patient, and identical isolates were obtained from different patients.

Conclusions

MDR isolates colonizing tonsils even without infection, demonstrate persistence of the bacterium and possibility of antimicrobial resistance dissemination and recurrence of infection. A specific clone in patients colonized by S. aureus was not demonstrated.

The Relationship between Colonization by Moraxella catarrhalis and Tonsillar Hypertrophy

We sought to investigate the prevalence of potentially pathogenic bacteria in secretions and tonsillar tissues of children with chronic adenotonsillitis hypertrophy compared to controls. Prospective case-control study comparing patients between 2 and 12 years old who underwent adenotonsillectomy due to chronic adenotonsillar hypertrophy to children without disease. We compared detection of Streptococcus pneumoniae, Haemophilus influenzae, Staphylococcus aureus, Pseudomonas aeruginosa, and Moraxella catarrhalis by real-time PCR in palatine tonsils, adenoids, and nasopharyngeal washes obtained from 37 children with and 14 without adenotonsillar hypertrophy. We found high frequency (>50%) of Haemophilus influenzae, Streptococcus pneumoniae, Moraxella catarrhalis, and Pseudomonas aeruginosa in both groups of patients. Although different sampling sites can be infected with more than one bacterium and some bacteria can be detected in different tissues in the same patient, adenoids, palatine tonsils, and nasopharyngeal washes were not uniformly infected by the same bacteria. Adenoids and palatine tonsils of patients with severe adenotonsillar hypertrophy had higher rates of bacterial coinfection. There was good correlation of detection of Moraxella catarrhalis in different sampling sites in patients with more severe tonsillar hypertrophy, suggesting that Moraxella catarrhalis may be associated with the development of more severe hypertrophy, that inflammatory conditions favor colonization by this agent. Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae, and Moraxella catarrhalis are frequently detected in palatine tonsils, adenoids, and nasopharyngeal washes in children. Simultaneous detection of Moraxella catarrhalis in adenoids, palatine tonsils, and nasopharyngeal washes was correlated with more severe tonsillar hypertrophy.

Chronic tonsillitis and biofilms: a brief overview of treatment modalities

Recurrent tonsillitis is described as when an individual suffers from several attacks of tonsillitis per year. Chronic and recurrent tonsillitis both cause repeated occurrences of inflamed tonsils which have a significant impact on a patient's quality of life. Numerous children suffer from recurrent tonsillitis and sore throats, and these illnesses become part of their life. Antimicrobials can provide temporary relief, but in many cases, tonsillitis recurs. The cause of such recurrent infections have been identified as microorganisms which often create biofilms and a repository of infection in the wet and warm folds of the tonsils. This review discusses different treatment modalities, their advantages and disadvantages, and new treatment options focusing on biofilms. All treatment options should be selected based on evidence and individual need.

In reply to "Commentary to: Endoscopic and clinical benefits of hyaluronic acid in children with chronic adenoiditis and middle ear disease", by Zhengcai Lou

Some considerations will be expressed in consideration of the commentary previously published. In particular, we underline that no other medications were administered to the patients during the study period and any clinical evaluation was postponed in case of acute upper respiratory tract infection in the previous 14 days. We strongly advocate antibiotic treatment during any acute otitis media episode, and we agree that topically administered hyaluronic acid should be considered as a supporting treatment, "complementary to traditional therapies" in children with recurrent disease.

Inverse relationship between toxic shock syndrome toxin-1 antibodies and interferon-γ and interleukin-6 in peripheral blood mononuclear cells from patients with pediatric tonsillitis caused by Staphylococcus aureus

INTRODUCTION

Pediatric tonsillitis is frequently caused by Staphylococcus aureus, which is the most common pathogen that causes serious pyogenic infections in humans and endangers human health. S. aureus produces numerous potent virulence factors that play a critical role in the pathogenesis of the infection caused by this bacterium, and one of the most important toxins produced by S. aureus is toxic shock syndrome toxin-1 (TSST-1). The aim of this study is to investigate the first time the levels of IFN-γ and interleukin IL-6 in TSST-1-stimulated PBMCs from pediatric tonsillitis patients and the correlation of these cytokine levels with TSST-1-specific IgG in serum.

METHODS

TSST-1 gene of S. aureus was cloned and expressed in a prokaryotic expression system, and purified recombinant TSST-1 protein was used for measuring TSST-1-specific antibodies in the serum of patients with pediatric tonsillitis caused by S. aureus. Moreover, the levels of interferon (IFN)-γ and interleukin (IL)-6 in TSST-1-stimulated peripheral blood mononuclear cells (PBMCs) from pediatric tonsillitis patients were investigated.

RESULTS

In patients with pediatric tonsillitis caused by S. aureus, significantly higher levels of serum TSST-1-specific IgG (P < 0.05) and IgG1 (P < 0.05) were detected than in healthy children. Moreover, PBMCs from the patients exhibited higher IFN-γ (P < 0.05) production in response to TSST-1 than did PBMCs from healthy children. In patients with pediatric tonsillitis caused by S. aureus, the positive rate of TSST-1-specific IgG was 70%, and the patients who tested negative for TSST-1-specific IgG exhibited significantly higher levels of IFN-γ (P < 0.05) and IL-6 (P < 0.05) than did the IgG-positive patients, in accord, the levels of TSST-1-specific IgG correlated inversely with the levels of IFN-γ and IL-6 in patients PBMCs stimulated with TSST-1.

CONCLUSIONS

TSST-1 induces humoral and cellular immunity in pediatric tonsillitis caused by S. aureus, which suggests that TSST-1 may play an important role in the pathogenesis of pediatric tonsillitis.

Hyperplasia and the degree and activity of inflammation in chronic recurrent tonsillitis: a histopathological study

Postoperative haemorrhage following tonsillectomy occurs in 5.98% of all cases with up to 10 deaths reported annually in Germany. When comparing tonsillectomy (TE) and tonsillotomy (TT), the same long-term frequency of ENT infections is displayed in children and young adults. However, taking postoperative haemorrhaging into account, TT is more favourable. Chronic tonsillitis is one of the most common indications for TE in the adult population; however, a histopathological characterization may reveal objective criteria and provide a foundation for routinely performing TT in adults too. Three essential parameters hyperplasia (HP), grade of inflammation (GOI) and activity of inflammation (AOI), which are responsible for, and associated with a clinically relevant disease were histopathologically examined in the tonsils of 100 adult patients with chronic recurrent tonsillitis. The parameters were analysed and compared separately in the pharyngeal and basal parts of the tonsils as well as in three sections (upper and lower pole of the tonsil, middle part) as this may influence the indication for TT. The comparison of the basal and pharyngeal portions displayed a significant difference in the GOI and the HP in all three sections: grade 2 HP as well as GOI were more commonly found in the basal than pharyngeal portions (p > 0.001). AOI (grade 2) displayed the same properties in the middle section (p < 0.002), but did not reach statistical significance in the cranial and caudal sections (p = 0.107 and p = 0.186). An overabundance of grade 1 GOI, AOI, and HP was seen in the pharyngeal sections. The results show that two out of three relevant parameters that demonstrate histopathological changes in recurrent inflamed tonsils have a significantly stronger presence in the basal section of the tonsil as opposed to the pharyngeal section. The processes initiated by inflammation next to the surface responsible for a clinically relevant recurrent tonsillitis seem to cause stronger reactions in the deep follicular portion of the tonsils.

Prevention of early episodes of otitis media by pneumococcal vaccines might reduce progression to complex disease

Otitis media is a common childhood infection of the middle ear and a major cause of morbidity. This multifactorial disease manifests as a spectrum of clinical syndromes from uncomplicated acute otitis media to more complex recurrent and chronic cases (frequently polymicrobial), with the major pathogens involved being Streptococcus pneumoniae and non-typeable Haemophilus influenzae. Pneumococcal conjugate vaccines (PCVs) target only a few serotypes that cause otitis media; however, results from studies suggest that existing PCVs can prevent early episodes of disease associated with vaccine serotypes, resulting in a reduction of subsequent complex cases caused by non-vaccine serotypes and other otopathogens, which contribute considerably to the disease burden. In this Review, we discuss the role of pneumococcus in the disease continuum and assess clinical evidence showing the effect of prevention of early episodes on the complex interplay between bacterial species implicated in otitis media.

Nasopharyngeal and Adenoid Colonization by Haemophilus influenzae and Haemophilus parainfluenzae in Children Undergoing Adenoidectomy and the Ability of Bacterial Isolates to Biofilm Production

Haemophili are pathogenic or opportunistic bacteria often colonizing the upper respiratory tract mucosa. The prevalence of Haemophilus influenzae (with serotypes distribution), and H. parainfluenzae in the nasopharynx and/or the adenoid core in children with recurrent pharyngotonsillitis undergoing adenoidectomy was assessed. Haemophili isolates were investigated for their ability to biofilm production.Nasopharyngeal swabs and the adenoid core were collected from 164 children who underwent adenoidectomy (2-5 years old). Bacteria were identified by the standard methods. Serotyping of H. influenzae was performed using polyclonal and monoclonal antisera. Biofilm formation was detected spectrophotometrically using 96-well microplates and 0.1% crystal violet.Ninety seven percent (159/164) children who underwent adenoidectomy were colonized by Haemophilus spp. The adenoid core was colonized in 99.4% (158/159) children, whereas the nasopharynx in 47.2% (75/159) children (P < 0.0001). In 32% (51/159) children only encapsulated (typeable) isolates of H. influenzae were identified, in 22.6% (36/159) children only (nonencapsulated) H. influenzae NTHi (nonencapsulated) isolates were present, whereas 7.5% (12/159) children were colonized by both types. 14.5% (23/159) children were colonized by untypeable (rough) H. influenzae. In 22% (35/159) children H. influenzae serotype d was isolated. Totally, 192 isolates of H. influenzae, 96 isolates of H. parainfluenzae and 14 isolates of other Haemophilus spp. were selected. In 20.1% (32/159) children 2 or 3 phenotypically different isolates of the same species (H. influenzae or H. parainfluenzae) or serotypes (H. influenzae) were identified in 1 child. 67.2% (129/192) isolates of H. influenzae, 56.3% (54/96) isolates of H. parainfluenzae and 85.7% (12/14) isolates of other Haemophilus spp. were positive for biofilm production. Statistically significant differences (P = 0.0029) among H. parainfluenzae biofilm producers and nonproducers in the adenoid core and the nasopharynx were detected.H. influenzae and H. parainfluenzae carriage rate was comparatively higher in the adenoid core than that in the nasopharynx in children undergoing adenoidectomy, suggesting that their involvement in chronic adenoiditis. The growth in the biofilm seems to be an important feature of haemophili colonizing the upper respiratory tract responsible for their persistence.

The presence of biofilm-producing bacteria on tonsils is associated with increased exhaled nitric oxide levels: preliminary data in children who experience recurrent exacerbations of chronic tonsillitis

BACKGROUND

It has been suggested that bacterial biofilms may be a causative factor in the aetiopathogenesis of chronic tonsillitis. Involvement of exhaled nitric oxide has been previously considered, with conflicting findings.

OBJECTIVE

A pilot study was performed to investigate the relationship between exhaled nitric oxide levels and the presence of tonsillar biofilm-producing bacteria in children with chronic tonsillitis.

METHOD

Tonsillar biofilm-producing bacteria on bioptic specimens taken during tonsillectomy were assessed by means of spectrophotometry.

RESULTS

Analysis was based on 24 children aged 5-10 years (median, 7.5 years). Biofilm-producing bacteria were found in 40.9 per cent of specimens. The median exhaled nitric oxide level was 11.6 ppb (range, 3.2-22.3 ppb). There was a significant relationship between the presence of biofilm-producing bacteria and increased exhaled nitric oxide levels (p = 0.03). Children with exhaled nitric oxide levels of more than 8 ppb were at three times greater risk of developing tonsillar biofilm-producing bacteria than those with lower levels.

CONCLUSION

Our findings suggest the possibility of discriminating children with chronic biofilm-sustained tonsillar infections on the basis of exhaled nitric oxide levels.

Effect of antibiotic use on bacterial flora of tonsil core in patients with recurrent tonsillitis

The aim of this study was to investigate the effects of commonly used antibiotics on bacterial flora of the tonsil core. Patients who underwent tonsillectomy for recurrent chronic tonsillitis were included in the study. Three groups were formed: group 1 was treated for 10 days preoperatively with amoxicillin/clavulanic acid; group 2 was treated for 10 days preoperatively with clarithromycin; and group 3 included patients who underwent tonsillectomy without preoperative antibiotic use. The removed palatine tonsils were sent to our microbiology department in sterile tubes for bacteriological analysis. Seventy-three patients (group 1 = 19, group 2 = 20, group 3 = 34 patients) aged 3-18 years (mean 7 years) were included in the study. At least one bacterium was isolated from all tonsils, except for two cases in group 1; the difference in single bacterial growth among groups was not significant (p = 0.06). On the other hand, the numbers of patients with pathogenic bacterial growth was significantly lower in group 2 (n = 2) compared with group 1 (n = 10) and group 3 (n = 27) (p < 0.001). The bacterium isolated most frequently from the tonsils was Streptococcus viridans. Pseudomonas aeruginosa was the only pathogenic bacterium that grew in all three groups. Clarithromycin was more effective than amoxicillin/clavulanic acid in eradicating pathogenic bacteria in the tonsil core. Pseudomonas aeruginosa might be responsible for resistant or recurrent tonsil infections. To prevent endocarditis, antibiotic prophylaxis toward S. viridians, which is the most prevalent bacterium in the tonsil core, should be kept in mind for patients with heart valve damage.

Tonsillitis and sore throat in children

Surgery of the tonsils is still one of the most frequent procedures during childhood. Due to a series of fatal outcomes after hemorrhage in children in Austria in 2006, the standards and indications for tonsillectomy have slowly changed in Germany. However, no national guidelines exist and the frequency of tonsil surgery varies across the country. In some districts eight times more children were tonsillectomized than in others. A tonsillectomy in children under six years should only be done if the child suffers from recurrent acute bacterially tonsillitis. In all other cases (i.e. hyperplasia of the tonsils) the low risk partial tonsillectomy should be the first line therapy. Postoperative pain and the risk of hemorrhage are much lower in partial tonsillectomy (=tonsillotomy). No matter whether the tonsillotomy is done by laser, radiofrequency, shaver, coblation, bipolar scissor or Colorado needle, as long as the crypts are kept open and some tonsil tissue is left behind. Total extracapsular tonsillectomy is still indicated in severely affected children with recurrent infections of the tonsils, allergy to antibiotics, PFAPA syndrome (periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis) and peritonsillar abscess. With regard to the frequency and seriousness of the recurrent tonsillitis the indication for tonsillectomy in children is justified if 7 or more well-documented, clinically important, adequately treated episodes of throat infection occur in the preceding year, or 5 or more of such episodes occur in each of the 2 preceding years (according to the paradise criteria). Diagnosis of acute tonsillitis is clinical, but sometimes it is hard to distinguish viral from bacterial infections. Rapid antigen testing has a very low sensitivity in the diagnosis of bacterial tonsillitis and swabs are highly sensitive but take a long time. In all microbiological tests the treating physician has to keep in mind, that most of the bacterials, viruses and fungi belong to the healthy flora and do no harm. Ten percent of healthy children even bear strepptococcus pyogenes all the time in the tonsils with no clinical signs. In these children decolonization is not necessary. Therefore, microbiological screening tests in children without symptoms are senseless and do not justify an antibiotic treatment (which is sometimes postulated by the kindergartens). The acute tonsillitis should be treated with steroids (e.g. dexamethasone), NSAIDs (e.g. ibuprofene) and betalactam antibiotics (e.g. penicillin or cefuroxime). With respect to the symptom reduction and primary healing the short-term late-generation antibiotic therapy (azithromycin, clarithromycin or cephalosporine for three to five days) is comparable to the long-term penicilline therapy. There is no difference in the course of healing, recurrence or microbiological resistance between the short-term penicilline therapy and the standard ten days therapy. On the other hand, only the ten days antibiotic therapy has proven to be effective in the prevention of rheumatic fever and glomerulonephritic diseases. The incidence of rheumatic heart disease is currently 0.5 per 100,000 children of school age. The main morbidity after tonsillectomy is pain and the late haemorrhage. Posttonsillectomy bleeding can occur till the whole wound is completely healed, which is normally after three weeks. Life-threatening haemorrhages occur often after smaller bleedings, which can spontaneously cease. That is why every haemorrhage, even the smallest, has to be treated properly and in ward. Patients and parents have to be informed about the correct behaviour in case of haemorrhage with a written consent before the surgery. The handout should contain important addresses, phone numbers and contact persons. Almost all cases of fatal outcome after tonsillectomy were due to false management of haemorrhage. Haemorrhage in small children can be especially life-threatening because of the lower blood volume and the danger of aspiration with asphyxia. A massive haemorrhage is an extreme challenge for every paramedic or emergency doctor because of the difficult airway management. Intubation is only possible with appropriate inflexible suction tubes. All different surgical techniques have the risk of haemorrhage and even the best surgeon will experience a postoperative haemorrhage. The lowest risk of haemorrhage is after cold dissection with ligature or suturing. All "hot" techniques with laser, radiofrequency, coblation, mono- or bipolar forceps have a higher risk of late haemorrhage. Children with a hereditary coagulopathy have a higher risk of haemorrhage. It is possible, that these children were not identified before surgery. Therefore it is recommended by the Society of paediatrics, anaesthesia and ENT, that a standardised questionnaire should be answered by the parents before tonsillectomy and adenoidectomy. This 17-point-checklist questionnaire is more sensitive and easier to perform than a screening with blood tests (e.g. INR and PTT). Unfortunately, a lot of surgeons still screen the children preoperatively by coagulative blood tests, although these tests are inappropriate and incapable of detecting the von Willebrand disease, which is the most frequent coagulopathy in Europe. The preoperative information about the surgery should be done with the child and the parents in a calm and objective atmosphere with a written consent. A copy of the consent with the signature of the surgeon and both custodial parents has to be handed out to the parents.

Role of biofilm in children with recurrent upper respiratory tract infections

Recurrent respiratory tract infections (RRTIs) are very common in children and a major challenge for pediatricians. In the last few years, bacterial biofilms have been linked to RRTIs and antibiotic resistance, and have raised serious concerns regarding the therapeutic management of recurrent middle ear diseases, chronic rhinosinusitis, and recurrent pharyngotonsillitis. This paper aims to review the new insights into biofilm-related upper respiratory tract infections in children and possible therapeutic strategies. It focuses on the clinical implications for recurrent disease and on studies in pediatric patients. Analysis of the literature showed that the involvement of bacterial biofilm in recurrent upper airway tract infections is an emerging problem that may lead to serious concerns about infection control. Despite the large amount of research within this field, detailed insight into the complex structure of bacterial biofilms and the ultrastructural and biochemical mechanisms responsible for its evasion of the immune system and resistance to treatments is currently lacking. In the future, additional emphasis should be placed on biofilm management as a component of therapeutic strategies. This goal can be attained by finding feasible methods for detecting biofilms in vivo and identifying effective methods for administering treatments that eradicate preexisting bacterial biofilms or hinder bacterial adhesion to respiratory cells.

Carriage of antibiotic-resistant Haemophilus influenzae strains in children undergoing adenotonsillectomy

Haemophilus influenzae is one of the major pathogenic bacteria in upper respiratory tract of children. In this study, the presence of various H. influenzae genotypes were followed-up for at least 13 weeks, starting from one week before surgery. Forty-one children with chronic adenoid hypertrophy were prospectively enrolled to the study. The consecutive swabs of adenoid and tonsils, two before adenotonsillectomy and two after the surgery together with homogenates of adenotonsillar tissues and lysates of the CD14(+) cells fraction were acquired from 34 children undergoing adenotonsillectomy. Up to ten isolates from each patient at each collection period were genotyped using a PFGE method and their capsular type and antibiotic susceptibility was determined. Of the 1001 isolates examined, we identified 325 isolates grouped into 16 persistent genotypes, which colonized throats for more than seven weeks and were not eliminated by the surgery. The other 506 isolates grouped into 48 transient genotypes that had been eliminated by the surgery. The resistance to ampicillin were found in 23.8% of the transient strains, and 4.7% of the newly acquired strains following the surgical intervention. In contrast, none of the persistent strains were resistant to ampicillin; however, these strains showed apparently higher level of resistance to co-trimoxazole when compared to transient strains. The transient and persistent strains did not significantly differ in bacterial viability in the biofilms formed in vitro. Some of the strains were identified in two or three different patients and were considered as the strains circulating in the region between 2010 and 2012.