Topographic distribution of biofilm-producing bacteria in adenoid subsites of children with chronic or recurrent middle ear infections

Biofilm Production and Its Implications in Pediatrics

Biofilms, aggregates of bacteria enclosed in a self-produced matrix, have been implicated in various pediatric respiratory infections, including acute otitis media (AOM), otitis media with effusion (OME), adenoiditis, protracted bacterial bronchitis, and pulmonary exacerbations in cystic fibrosis. These infections are prevalent in children and often associated with biofilm-producing pathogens, leading to recurrent and chronic conditions. Biofilms reduce antibiotic efficacy, contributing to treatment failure and disease persistence. This narrative review discusses biofilm production by respiratory pathogens such as Streptococcus pneumoniae, non-typeable Haemophilus influenzae, Pseudomonas aeruginosa, and Staphylococcus aureus. It examines their mechanisms of biofilm formation, antibiotic resistance, and the challenges they present in clinical treatment. Various antibiofilm strategies have shown promise in vitro and in animal studies, including the use of N-acetylcysteine, enzymes like dispersin B, and agents disrupting quorum sensing and biofilm matrix components. However, their clinical application, particularly in children, remains limited. Traditional treatments for biofilm-associated diseases have not significantly evolved, even with biofilm detection. The transition from experimental findings to clinical practice is complex and requires robust clinical trials and standardized biofilm detection protocols. Addressing biofilms in pediatric respiratory infections is crucial for improving treatment outcomes and managing recurrent and chronic diseases effectively.

Topical administration of S. salivarius 24SMB-S. oralis 89a in children with adenoidal disease: a double-blind controlled trial

Chronic adenoiditis (CA) is generally sustained by some infectious foci mainly located within the nasopharynx or in the deep adenoidal pads and it is characterized by a complex interplay between bacterial species. The aim of this study was to assess the efficacy and safety of the topical nasal administration of a probiotic compound based on S. salivarius 24SMB and S. oralis 89a in children with CA in terms of reduction in: the number of acute adenoidal infections (primary outcome), and in the blockage of the nasopharynx space by hypertrophic adenoids (secondary outcome). A prospective, double-blind, 1:1 randomized controlled study was performed to test the effectiveness of a 90-day treatment with Rinogermina spray (DMD ITALIA s.r.l, Rome), 1 puff each nostril twice a day for 90 days, to nasal spray placebo in children with CA (in terms of number of acute exacerbations and blockage of nasopharynx space assessed after 90 days of treatment- T1, and 90 days later- T2). The final analysis was based on 152 children (males = 48.0%; mean age = 49.2 ± 14.1 months). Compared to the baseline, no significant differences in terms of number of acute exacerbations at T1 and T2 follow-up visits were detected in both groups. After treatment, a significant reduction in the blockage of nasopharynx space by hypertrophic adenoids (0.002 < p-value < 0.007) compared to the baseline was attested in the study group at T1 and T2, but not in the control group.

CONCLUSIONS

Our findings document a positive effect of Rinogermina spray in achieving reduction in the blockage of nasopharynx space by hypertrophic adenoids, thus suggesting that its use into the integrated therapeutic management of children with CA could be of a certain utility.

WHAT IS KNOWN

• Chronic adenoiditis in children results from an imablance in baterial homeostasis at the nasophaynx, with impairment in respiratory microbiota. • The modulatory effect of target transnasal bacteriotheray by means of S. salivarius has been considered in children with chronic adenoiditis in children with recurrent acute otitis media with preliminary positive results.

WHAT IS NEW

• This randomized controlled study, specifically designed on a cohrt of children with chronic adenoiditis, documents a certain effectiveness of the probiotic treatment in achieving a reduction in the grade of adenoidal hypertropy, compared to placebo.

Efficacy of tympanostomy tube placement with adjuvant adenoidectomy in children less than 4 years of age

OBJECTIVE

About 8.6 % of children in the United States undergo tympanostomy tube (TT) placement every year. Of these, 24.1 % require a second set of tubes. Adjuvant adenoidectomy in children over 4 years is thought to improve the efficacy of TT. The goal of this study is to characterize the efficacy of adjuvant adenoidectomy at the time of TT placement in children under 4 years, to further improve middle ear function.

METHODS

All patients undergoing TT placement alone or TT placement with adenoidectomy from 2014 to 2016 were reviewed. The primary outcome was need for subsequent tube placement.

RESULTS

A total of 409 patients were included in the study (60.6 % male, 39.4 % female). Median age at initial TT placement was 18 months (range 5-48 months); extreme outliers for age were removed from further analysis. Patients were followed for 1-8 years. 250 patients received TT alone while 159 received TT with adenoidectomy. 120 required a second set of tubes. There was a statistically significant benefit to those undergoing adjuvant adenoidectomy with TT placement: 33.6 % of those receiving TT alone required subsequent tubes, whereas only 22.6 % of patients who underwent TT with adjuvant adenoidectomy required reinsertion (X2 = 5.630, p = 0.018). Adjuvant adenoidectomy in patients 0-48 months was associated with decreased likelihood of requiring subsequent tube placement (OR = 0.578, p = 0.018). There was an increased likelihood of experiencing otorrhea in those receiving TT alone compared to the TT with adenoidectomy group (X2 = 4.353, df = 1, p = 0.0369).

CONCLUSION

Adjuvant adenoidectomy at the time of initial TT placement may have a role in the management of chronic middle ear disease in patients younger than 4 years. However, further studies and prospective randomized studies are needed to explore if this benefit can also be seen in children without chronic rhinosinusitis or nasal obstruction. The benefit-risk ratio from adenoidectomy and modifications in anesthesia technique in the case of adjuvant adenoidectomy should also be further explored.

Modulation of hyaluronan signaling as a therapeutic target in human disease

The extracellular matrix is an active participant, modulator and mediator of the cell, tissue, organ and organismal response to injury. Recent research has highlighted the role of hyaluronan, an abundant glycosaminoglycan constituent of the extracellular matrix, in many fundamental biological processes underpinning homeostasis and disease development. From this basis, emerging studies have demonstrated the therapeutic potential of strategies which target hyaluronan synthesis, biology and signaling, with significant promise as therapeutics for a variety of inflammatory and immune diseases. This review summarizes the state of the art in this field and discusses challenges and opportunities in what could emerge as a new class of therapeutic agents, that we term "matrix biologics".

Biofilm formation and molecular analysis of intercellular adhesion gene cluster (icaABCD) among Staphylococcus aureus strains isolated from children with adenoiditis

Background and Objectives:

It is well known that Staphylococcus aureus biofilm plays an important role in adenoiditis and biofilm resistance frequently results in failure of therapy. The goal of this study was to evaluate the biofilm production of S. aureus isolates obtained from adenoid specimens and assess the relationship between biofilm formation ability and ica operon genes.

Materials and Methods:

A total of 112 adenoid samples were obtained from patients under 15 years old with adenoid hypertrophy. All S. aureus isolates were initially identified by standard microbiological tests and amplification of nuc by polymerase chain reaction (PCR) technique. Biofilm formation of S. aureus isolates was evaluated and icaADBC genes were detected by PCR technique.

Results:

There were 46 isolates (41%) identified as S. aureus. The ability to produce biofilm was detected among total S. aureus isolates. Molecular study of ica operon revealed that 2 (6.3%) and 19 (59.4%) isolates carried icaA and icaD, respectively. The prevalence of icaA + icaD was seen among 11 (34.4%) S. aureus isolates, while icaC and icaB were not detected.

Conclusion:

Our findings indicated that icaABCD operon are associated with biofilm formation in S. aureus isolates, however the absence of these genes may not necessarily exclude this property.

Nasopharyngeal Microbiota Analysis in Healthy and Otitis-prone Children: Focus on History of Spontaneous Tympanic Membrane Perforation

BACKGROUND

Recurrent acute otitis media (RAOM) is common in children, and it may result in spontaneous tympanic membrane perforation (STMP), management of which is often challenging. In the upper respiratory tract (URT), resident microorganisms play a pivotal role in otitis media pathogenesis and prevention, as they are able to inhibit the colonization process and otopathogens growth. In particular, Dolosigranulum spp. and Corynebacterium spp. have been associated with respiratory health in several studies. This study aims at comparing both nasopharyngeal microbiota of children with RAOM versus matched controls and nasopharyngeal microbiota of children with a history of RAOM with STMP.

METHOD

Nasopharyngeal swabs were collected from 132 children, median age 3.51 (2.13-4.72), including 36 healthy children, 50 with RAOM without STMP, and 46 with RAOM with STMP. Bacterial DNA was subsequently extracted and 16S rRNA gene V3-V4 regions were polymerase chain reaction amplified and sequenced using Illumina MiSeq technology.

RESULTS

A higher relative abundance of Dolosigranulum and Corynebacterium genera was detected in the nasopharynx of healthy children (16.5% and 9.3%, respectively) in comparison with RAOM without STMP (8.9% and 4.3%, respectively) and RAOM with STMP (5.2% and 2.8%, respectively). A decreasing pattern in relative abundance of these 2 pivotal genera through disease severity was detected. In all groups, the most abundant genera were Moraxella, Streptococcus and Haemophilus, followed by Dolosigranulum and Corynebacterium.

CONCLUSIONS

Our study provides a characterization of the URT microbiota in otitis-prone children with and without history of recurrent STMP, suggesting that the role of Dolosigranulum and Corynebacterium in regulating the healthy URT microbiota should be further studied.

Role of Biofilms in Children with Chronic Adenoiditis and Middle Ear Disease

Chronic adenoiditis occurs frequently in children, and it is complicated by the subsequent development of recurrent or chronic middle ear diseases, such as recurrent acute otitis media, persistent otitis media with effusion and chronic otitis media, which may predispose a child to long-term functional sequalae and auditory impairment. Children with chronic adenoidal disease who fail to respond to traditional antibiotic therapy are usually candidates for surgery under general anaesthesia. It has been suggested that the ineffectiveness of antibiotic therapy in children with chronic adenoiditis is partially related to nasopharyngeal bacterial biofilms, which play a role in the development of chronic nasopharyngeal inflammation due to chronic adenoiditis, which is possibly associated with chronic or recurrent middle ear disease. This paper reviews the current evidence concerning the involvement of bacterial biofilms in the development of chronic adenoiditis and related middle ear infections in children.

Biofilm Formations in Pediatric Respiratory Tract Infection : Part 1: Biofilm Structure, Role of Innate Immunity in Protection Against and Response to Biofilm, Methods of Biofilm Detection, Pediatric Respiratory Tract Diseases Associated with Mucosal Biofilm Formation

PURPOSE OF REVIEW

Biofilm represents an organized structure of microorganisms within an extracellular matrix attached to a surface. While the importance of biofilm in prosthetic heart valve and catheter-related infections has been known since the 1980s, the role of mucosal biofilm in human disease pathogenesis has only recently been elucidated. It is now clear that mucosal biofilm is present in both healthy and pathologic states. The purpose of this review is to examine the role of mucosal biofilm in pediatric respiratory infections.

RECENT FINDINGS

Mucosal biofilm has been implicated in relationship to several pediatric respiratory infections, including tonsillitis, adenoiditis, otitis media with effusion, chronic rhinosinusitis, persistent endobronchial infection, and bronchiectasis. In these conditions, core pathogens are detected in the biofilm, biofilm organisms are often detected by molecular techniques when conventional cultures are negative, and biofilm presence is more extensive in relation to disease than in healthy tissues. In chronic rhinosinusitis, the presence of polymicrobial biofilm is also a predictor of poorer outcome following sinus surgery. Biofilm in the tonsillar and adenoidal compartments plays a distinct role in contributing to disease in the middle ear and sinuses. Key observations regarding the relevance of biofilm to pediatric respiratory infections include (1) the association between the presence of biofilm and persistent/recurrent and more severe disease in these tissues despite antibiotic treatment, (2) linkage between biofilm core pathogens and acute infections, and (3) interrelationship between biofilm presence in one tissue and persistent or recurrent infection in an adjacent tissue. A greater understanding of the significance of mucosal biofilm will undoubtedly emerge with the development of effective means of eradicating mucosal biofilm.

Supervised Nasal Saline Irrigations in Otitis-Prone Children

Objectives: To retrospectively investigate the impact of supervised daily nasal saline irrigations (NSI) with 0. 9% saline solution in children with a history of recurrent acute otitis media (RAOM). Methods: A retrospective pilot study was planned to evaluate the possible effect of supervised NSI in reducing the number of acute otitis media (AOM) episodes in otitis-prone children aged 1-5 years, compared to children not instructed to correct NSI performance. Results: Analysis was based on the data contained in 173 charts (57.3% males, mean age of 30.9 ± 7.3 months). 52.0% of children had not been instructed to perform NSI, while the remaining (48.0%) patients had received supervised NSI. At the 4-months follow-up visit a significant reduced number of AOM episodes (1.03 ± 0.14 vs. 2.08 ± 0.16; p < 0.001) as well as antibiotic treatments (1.48 ± 0.17 vs. 2.59 ± 0.18; p < 0.001) was documented in children receiving supervised NSI compared to those not instructed for NSI performance. Conclusions: These data suggest that NSI should be considered in the therapeutic management of children with RAOM, and should be routinely prescribed as a daily adjunctive treatment to reduce acute infectious exacerbations in otitis-prone patients. Accurate parents training is crucial in order to improve children compliance and treatment effectiveness.

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.

Phenotype Profiling and Allergy in Otitis-Prone Children

Background: Otitis-prone children can present some distinctive clinical patterns and although a number of known risk factors for recurrent acute otitis media (RAOM) are known, no dedicated epidemiological models have been developed to explain clinical heterogeneity. Methods: A preliminary retrospective pilot study was planned to evaluate the possible effect of allergic disease in the development of different disease phenotypes in otitis-prone children aged 3-10 years, particularly the absence (simple RAOM), or presence of episodes of otitis media with effusion between acute infections (RAOM with OME). Results: Analysis was based on the data contained in 153 charts (55.6% males, mean age of 59.4 ± 16.4 months). 75.8% of children had a simple RAOM and 24.2% a RAOM with OME. Atopy or allergy were documented in respectively 47.7 and 41.3% of children considered as a whole. The prevalence of atopy or allergy was significantly higher in the children with a RAOM with OME (atopy: 73.0 vs. 39.5%, p < 0.001; allergy: 60.0 vs. 36.1%, p = 0.049), who also more frequently showed adenoidal hypertrophy (p = 0.016), chronic adenoiditis (p = 0.007), conductive hearing loss (p = 0.004), and impaired tympanometry (p < 0.001). Conclusions: These data suggest that children with a RAOM with OME are clinically different from children with simple RAOM, as they have a more complex clinical presentation that includes not only adenoidal disease and audiological impairment, but also an underlying allergy or atopy. The possibility that the factors mentioned above may be differently involved in the heterogeneous clinical manifestations occurring in otitis-prone children needs to be further investigated in ad hoc epidemiological studies.

The Landscape Ecology and Microbiota of the Human Nose, Mouth, and Throat

Landscape ecology examines the relationships between the spatial arrangement of different landforms and the processes that give rise to spatial and temporal patterns in local community structure. The spatial ecology of the microbial communities that inhabit the human body-in particular, those of the nose, mouth, and throat-deserves greater attention. Important questions include what defines the size of a population (i.e., "patch") in a given body site, what defines the boundaries of distinct patches within a single body site, and where and over what spatial scales within a body site are gradients detected. This Review looks at the landscape ecology of the upper respiratory tract and mouth and seeks greater clarity about the physiological factors-whether immunological, chemical, or physical-that govern microbial community composition and function and the ecological traits that underlie health and disease.

Potential impact of a Moraxella catarrhalis vaccine in COPD

Moraxella catarrhalis is the second most common cause of exacerbations in adults with COPD, resulting in enormous morbidity and mortality in this clinical setting. Vaccine development for M. catarrhalis has lagged behind the other two important causes of exacerbations in COPD, nontypeable Haemophilus influenzae and Streptococcus pneumoniae. While no licensed vaccine is currently available for M. catarrhalis, several promising candidate vaccine antigens have been identified and characterized and are close to entering clinical trials. Key steps that are required to advance vaccines for M. catarrhalis along the translational pipeline include standardization of assay systems to assess candidate antigens, identification of a reliable correlate of protection and expansion of partnerships between industry, academia and government to overcome regulatory hurdles. A vaccine to prevent M. catarrhalis infections in COPD would have a major impact in reducing morbidity, mortality and healthcare costs in COPD.

Paediatric nasopharyngeal cytology: a new diagnostic opportunity?

The purpose of this investigation was to describe the first application of nasopharyngeal cytology (NPC), a new cytological technique to collect cellular material from the nasopharyngeal surface non-invasively in children with chronic adenoiditis associated with recurrent acute otitis media and/or otitis media with effusion. Cellular material was collected transorally using an extra-thin flexible wire nasopharyngeal swab and then examined under a light microscope. The diagnostic accuracy of NPC in detecting the presence of allergy and pathogens (compared to microbiological evaluation of nasopharyngeal aspirates, NPAs) was assessed. NPC was performed on 121 children (mean age 69.4 ± 15.5 months). Inflammatory cells and pathogens were detected in 61.1 % and 44.2 % of patients, respectively. The specificity of nasopharyngeal eosinophils in detecting allergy was good (91.9 %), as was the specificity of mast cells, but the sensitivities were less. The NPAs revealed bacterial colonisation in 84.7 % of the patients, and Streptococcus pneumoniae was the most frequently isolated (60.0 %). NPC revealed the presence of bacteria in 94.9 % of patients, including bacillary species in 33.9 %. NPC was highly sensitive in detecting pathogens (96.0 %). Its specificity in detecting bacillary species was fairly good (75.0 %), but the corresponding values of the specificity of NPC in detecting pathogens and its sensitivity in detecting bacillary species were poor. Our findings suggest the need for more structured studies that can test the real effectiveness and usefulness of NPC in defining nasopharyngeal cytological patterns in children with chronic nasopharyngeal diseases by comparing it with established diagnostic techniques.

Endoscopic Adenoidectomy in Children With Otitis Media With Effusion and Mild Hearing Loss

Objectives

Surgical management of children with chronic otitis media with effusion (OME) includes tympanostomy tube insertion or adenoidectomy, alone or with myringotomy and tube insertion. The aim of this study was to compare the effectiveness of transoral microdebrider endoscopic-assisted adenoidectomy (TOMEA) and traditional adenoidectomy in the management of children with mild hearing loss due to OME and chronic adenoiditis.

Methods

This prospective, double-blind and controlled study involved 120 consecutive patients aged 4–12 years, who were randomised 1:1 to undergo TOMEA or traditional adenoidectomy under general anesthesia. All the patients underwent a complete otolaryngological examination, including nasopharyngeal fibre endoscopy (NFE), pneumatic otoscopy, otomicroscopy, tympanometry and supraliminar tonal audiometry, upon enrolment, and three and nine months postoperatively.

Results

There were no statistically significant differences in age or gender distribution between the TOMEA group (mean age, 4.9±1.1 years; 53.3% males) and the traditional adenoidectomy group (mean age, 5.3±0.9 years; 56.7% males). Both procedures led to a significant improvement in choanal patency (P<0.01) and all of the otological and audiological parameters (P<0.01) 3 and 9 months postoperatively, although postoperative NFE showed that the mean percentage of residual choanal obstruction was significantly less in the TOMEA group (P=0.02). There was no significant between-group difference in the percentage of children with tympanic membrane changes, but the postoperative prevalence of children with a type B tympanogram was significantly lower in the TOMEA group after 3 (15.0% vs. 31.7%, P=0.05) and 9 months (18.3% vs. 38.3%, P=0.02), as was the percentage of children with mild conductive hearing loss (3.3% vs. 23.3%, P<0.01; and 8.3% vs. 28.3%, P<0.01).

Conclusion

Although both TOMEA and traditional adenoidectomy are effective in treating children with mild hearing loss due to adenoidal hypertrophy and OME, the former achieves the greater reduction in residual adenoidal hypertrophy and better audiological outcomes.

The role of hyaluronan in the pathobiology and treatment of respiratory disease

Hyaluronan, a ubiquitous naturally occurring glycosaminoglycan, is a major component of the extracellular matrix, where it participates in biological processes that include water homeostasis, cell-matrix signaling, tissue healing, inflammation, angiogenesis, and cell proliferation and migration. There are emerging data that hyaluronan and its degradation products have an important role in the pathobiology of the respiratory tract. We review the role of hyaluronan in respiratory diseases and present evidence from published literature and from clinical practice supporting hyaluronan as a novel treatment for respiratory diseases. Preliminary data show that aerosolized exogenous hyaluronan has beneficial activity against airway inflammation, protects against bronchial hyperreactivity and remodeling, and disrupts the biofilm associated with chronic infection. This suggests a role in airway diseases with a predominant inflammatory component such as rhinosinusitis, asthma, chronic obstructive pulmonary disease, cystic fibrosis, and primary ciliary dyskinesia. The potential for hyaluronan to complement conventional therapy will become clearer when data are available from controlled trials in larger patient populations.

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.

Detection of Bacterial Biofilms in Chronic Pharyngitis Resistant to Medical Treatment

OBJECTIVE

To evaluate the role played by adenoids as a reservoir for infection in children assigned for adenoidectomy.

METHODOLOGY

The study included 35 children with adenoid hypertrophy. All patients underwent clinical examination and adenoidectomy, adenotonsillectomy, or myringotomy with insertion of aeration tube according to indications. Surgical specimens were processed for conventional bacterial culture examination and to assay for biofilm formation. The obtained adherence values using spectrophotometer at 595 nm (OD595) was used to classify isolates according to its biofilm forming capacity.

RESULTS

We did adenotonsillectomy and myringotomy with insertion of aeration tube in 5 patients having adenotonsillitis with otitis media with effusion. We did adenotonsillectomy in 12 patients having adenotonsillitis and adenoidectomy in 18 patients having adenoid hypertrophy. Thirty-one surgical specimens showed bacterial growth on conventional media, while 4 specimens failed to give growth. The predominant organism was H influenzae then Staph aureus and Strept pneumoniae. Thirty-two specimens showed biofilm forming capacity (BFC) of variable extent, while others showed no BFC.

CONCLUSION

Adenoids act as a bacterial reservoir secondary to bacterial biofilm formation so could induce chronicity and initiate development of complications. Determination of BFC using the proposed protocol is feasible, inexpensive, and available and spares the need for sophisticated instruments or approaches.

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.

Molecular mechanisms of moraxella catarrhalis-induced otitis media

Moraxella catarrhalis is a Gram-negative bacterium, exclusively present in humans and a leading causative agent of otitis media (OM) in children. Most children (80 %) experience at least one episode of OM by their third birthday and half suffer multiple episodes of infection. Over the last 10 years, increased evidence suggests that M. cat possesses multiple virulence factors which can be carried through biologically active outer membrane vesicles (OMVs) that are themselves able to activate host-immune responses. It has also been noted that multiple toll-like receptors are responsible for M. cat recognition. This review is intended to summarize the key findings and progress in recent years of the molecular mechanisms of M. cat-induced otitis media with particular emphasis on adhesion, invasion, and activation of the host immune system, biofilm formation, and vaccine development.

Moraxella catarrhalis uses a twin-arginine translocation system to secrete the β-lactamase BRO-2

Background

Moraxella catarrhalis is a human-specific gram-negative bacterium readily isolated from the respiratory tract of healthy individuals. The organism also causes significant health problems, including 15-20% of otitis media cases in children and ~10% of respiratory infections in adults with chronic obstructive pulmonary disease. The lack of an efficacious vaccine, the rapid emergence of antibiotic resistance in clinical isolates, and high carriage rates reported in children are cause for concern. Virtually all Moraxella catarrhalis isolates are resistant to β-lactam antibiotics, which are generally the first antibiotics prescribed to treat otitis media in children. The enzymes responsible for this resistance, BRO-1 and BRO-2, are lipoproteins and the mechanism by which they are secreted to the periplasm of M. catarrhalis cells has not been described.

Results

Comparative genomic analyses identified M. catarrhalis gene products resembling the TatA, TatB, and TatC proteins of the well-characterized Twin Arginine Translocation (TAT) secretory apparatus. Mutations in the M. catarrhalis tatA, tatB and tatC genes revealed that the proteins are necessary for optimal growth and resistance to β-lactams. Site-directed mutagenesis was used to replace highly-conserved twin arginine residues in the predicted signal sequence of M. catarrhalis strain O35E BRO-2, which abolished resistance to the β-lactam antibiotic carbanecillin.

Conclusions

Moraxella catarrhalis possesses a TAT secretory apparatus, which plays a key role in growth of the organism and is necessary for secretion of BRO-2 into the periplasm where the enzyme can protect the peptidoglycan cell wall from the antimicrobial activity of β-lactam antibiotics.

Nasopharyngeal fiberendoscopy in children: a diagnostic challenge in current clinical practice: how we do it

OBJECTIVE

Nasopharyngeal fiberendoscopy (NFE) is the gold standard diagnostic procedure in children with suspected adenoidal disease, but it is not always easily feasible in younger children, and there is no consensus on the optimal technical approach according to children's age or disease. This paper aims to report our experience with NFE performed during routine paediatric clinical examination, also with regards to tolerability and patients' satisfaction.

METHODS

NFE was performed in paediatric patients with suspected adenoidal obstruction by means of a 2.7 mm-diameter flexible endoscope with the child seated in a chair or on parent's knees under outpatients basis and without administering local decongestants, anaesthetic agents, or sedatives. Relationship between possible confounders and patients' satisfaction, NFE tolerability, or needing for restraining was evaluated.

RESULTS

NFE was successfully performed in all but one syndromic 2-year old patient. Analysis was conducted on 191 children (mean age = 5.58; standard error, SE = 2.52 years). Restraining was required more frequently (p < 0.001) in younger children; NFE tolerability was good, as documented by mean visual analogue scale (VAS) values of 2.06 (SE = 1.58), and a better NFE tolerance was reported more frequently (p < 0.001) in older children. No significant relationship was found between needing for restraining or VAS and gender. No major or minor adverse events occurred.

CONCLUSIONS

Our results support the feasibility and tolerability of flexible NFE performed by a skilled ENT specialist for nasopharyngeal evaluation in children aged more than 2 years with suspected adenoidal disease.