Otitis Media Pathogens Research Articles

Bacteriological profile, antibiotic susceptibility, and biofilm formation in children with chronic suppurative otitis media.

Chronic suppurative otitis media is predominantly caused by aerobic bacterial infections, complicated by antibiotic-resistant strains and biofilm formation. This study aims to identify the aerobic bacterial pathogens in chronic suppurative otitis media among children and assess their antibiotic susceptibility patterns. The potential link between biofilm formation and antibiotic resistance is also evaluated. A cross-sectional study was conducted on 457 children with chronic suppurative otitis media. Middle ear discharge samples were collected and aerobic bacteria were isolated and identified using standard microbiological methods. Antibiotic susceptibility was determined by the agar dilution method, and biofilm formation was assessed using the microtiter plate assay. Of the 457 cases, 89.72% were monomicrobial infections. The most prevalent Gram-negative bacterium was Pseudomonas aeruginosa (35.71%), while Staphylococcus aureus (26.27%) was the leading Gram-positive pathogen. Pseudomonas aeruginosa demonstrated high resistance, with 96.77% resistant to cefuroxime and 92.26% to amoxicillin/clavulanic acid. Similarly, Staphylococcus aureus showed significant resistance to ampicillin (83.33%) and amoxicillin (78.07%). A strong correlation (p<0.001) was observed between biofilm formation and antibiotic resistance, with Gram-negative bacteria resisting an average of 4.24±1.769 antibiotics and Gram-positive bacteria resisting 5.13±1.535 antibiotics. A high prevalence of antibiotic-resistant pathogens has been observed in children with chronic suppurative otitis media, with a significant association between biofilm formation and antibiotic resistance.

Simplified process for preparing native and depolymerized capsular polysaccharides of Streptococcus pneumoniae

Streptococcus pneumoniae is a major pathogen of bacterial pneumonia, meningitis, sepsis, and otitis media. The pathogenicity of this bacterium is largely attributed to its polysaccharide capsule, a protective layer around bacterial cell that enables bacteria to resist against host defense. Capsular polysaccharides (CPSs) of S. pneumoniae have been used as antigens to develop a variety of pneumococcal vaccines against invasive pneumococcal disease (IPD). These vaccines have been proven to be effective in reducing the incidence of IPD cases that are caused by vaccine-covered serotypes at the global scale. A crucial step in the manufacture of pneumococcal polysaccharide and conjugate vaccines is to purify native and depolymerized CPSs to meet strict quality standards in purity and structural integrity. The major impurities comprise proteins, nucleic acids and cell wall polysaccharides (CWPS). Traditionally, the removal of impurities to obtain purified native CPSs involves a complex process of purification, after which purified CPSs need to be further size-reduced to obtain depolymerized CPSs by multi-step approaches. In this study, we streamlined the process of CPS purification, which involves firstly ultrafiltration, followed by one-step acid precipitation, and finally diafiltration to obtain pure native CPSs. Furthermore, hydrolysis using trifluoroacetic acid (TFA) was integrated into the process to obtain purified depolymerized CPSs. The native and depolymerized CPSs produced by this optimized process were comparable to the materials obtained by the traditional approaches in purity and structural integrity, which would meet the quality standards of CPSs for vaccine production in the current edition of the European Pharmacopeia.

Conformal immunomodulatory hydrogels for the treatment of otitis media

Otitis media (OM), a condition stemming from the proliferation of various bacteria within the tympanic cavity (TC), is commonly addressed through the administration of ofloxacin (OFL), a fluoroquinolone antibiotic. Nevertheless, the escalating issue of antibiotic resistance and the challenge of drug leakage underscore the exploration of an alternative, more effective treatment modality in clinical practice. Here, we introduce a simple and easily implementable fluid-regulated strategy aimed at delivering immunomodulatory hydrogels into the TC, ensuring conformal contact with the irregular anatomical surfaces of the middle ear cavity to more effectively eliminate bacteria and treat OM. This innovative strategy exhibits expedited therapeutic process of antibiotic-resistant, acute and chronic OM rats, and significant reductions in the severity of tympanic membrane (TM) inflammation, residual bacteria within the TC (0.12 *105 CFU), and the thickness of TM/TC mucosa (17.63/32.43 μm), as compared to conventional OFL treatment (3.6, 0.76 *105 CFU, 48.70/151.26 μm). The broad-spectrum antibacterial and antibiofilm properties of this strategy against a spectrum of OM pathogens are demonstrated. The strategy is validated to bolster the host’s innate immune response through the stimulation of antibacterial protein synthesis, macrophage proliferation and activation, thereby accelerating bacterial eradication and inflammation resolution within the TC. This facile, cost-effective and in vivo degradable technology exhibits promising prospects for future clinical implementation.

MOST COMMON PATHOGENS OF OTITIS MEDIA IN PEDIATRICS AND THEIR RESISTANCE TO ANTIMICROBIAL AGENTS

Acute otitis media (AOM) stands as a prevalent child­hood illness, frequently necessitating antibiotic treatment. Its burden is significant, affecting about 80% of children under 3 years old, with approximately 40% experiencing recurrent episodes by age 3. In a study spanning Euro­pean countries, including Lithuania, middle ear otitis occurred at a rate of 160.7 cases per 100,000 children per year. Post-pneumococcal conjugate vaccine (PCV) implementation, causative agents shifted towards non-vaccine pneumococcal types and Haemophilus influen­zae. Antibiotic prescription rates, as noted from surveys of European pediatricians, range up to 78% for otitis media with effusion (OME). Commonly prescribed me­dications include amoxicillin (88.5%), amoxicillin-cla­vulanate (7.8%), cephalosporins (3.4%), and macrolides (0.3%). Despite similar antibiotic prescription frequen­cies in Eastern Europe and the Baltic, prescription practi­ces differ, influenced by active otitis monitoring. In this review article, we care to provide up to date cri­tical review of the literature on AOM prevalence, most common pathogens and antimicrobial resistance. Conclusions and recommendations. The most common pathogens of acute otitis media are Streptococcus pneu­moniae and Haemophilus influenzae, with S. pneumoniae often showing resistance to penicillin and erythromycin, while H. influenzae tends to be resistant primarily to ampicillin and amoxicillin when combined with clavu­lanic acid; however, due to increased PCV vaccination, H. influenzae is becoming more prevalent, especially among patients unresponsive to first-line treatment with amoxicillin, often due to β-lactamase-producing strains.

Lactobacillus acidophilus VB1 co-aggregates and inhibits biofilm formation of chronic otitis media-associated pathogens

This study aims to evaluate the antibacterial activity of Lactobacillus acidophilus, alone and in combination with ciprofloxacin, against otitis media-associated bacteria. L. acidophilus cells were isolated from Vitalactic B (VB), a commercially available probiotic product containing two lactobacilli species, L. acidophilus and Lactiplantibacillus (formerly Lactobacillus) plantarum. The pathogenic bacterial samples were provided by Al-Shams Medical Laboratory (Baqubah, Iraq). Bacterial identification and antibiotic susceptibility testing for 16 antibiotics were performed using the VITEK2 system. The minimum inhibitory concentration of ciprofloxacin was also determined. The antimicrobial activity of L. acidophilus VB1 cell-free supernatant (La-CFS) was evaluated alone and in combination with ciprofloxacin using a checkerboard assay. Our data showed significant differences in the synergistic activity when La-CFS was combined with ciprofloxacin, in comparison to the use of each compound alone, against Pseudomonas aeruginosa SM17 and Proteus mirabilis SM42. However, an antagonistic effect was observed for the combination against Staphylococcus aureus SM23 and Klebsiella pneumoniae SM9. L. acidophilus VB1 was shown to significantly co-aggregate with the pathogenic bacteria, and the highest co-aggregation percentage was observed after 24 h of incubation. The anti-biofilm activities of CFS and biosurfactant (BS) of L. acidophilus VB1 were evaluated, and we found that the minimum biofilm inhibitory concentration that inhibits 50% of bacterial biofilm (MBIC50) of La-CFS was significantly lower than MBIC50 of La-BS against the tested pathogenic bacterial species. Lactobacillus acidophilus, isolated from Vitane Vitalactic B capsules, demonstrated promising antibacterial and anti-biofilm activities against otitis media pathogens, highlighting its potential as an effective complementary/alternative therapeutic strategy to control bacterial ear infections.

An infant mouse model of influenza-driven nontypeable Haemophilus influenzae colonization and acute otitis media suitable for preclinical testing of novel therapies.

Nontypeable Haemophilus influenzae (NTHi) is a major otitis media (OM) pathogen, with colonization a prerequisite for disease development. Most acute OM is in children <5 years old, with recurrent and chronic OM impacting hearing and learning. Therapies to prevent NTHi colonization and/or disease are needed, especially for young children. Respiratory viruses are implicated in driving the development of bacterial OM in children. We have developed an infant mouse model of influenza-driven NTHi OM, as a preclinical tool for the evaluation of safety and efficacy of clinical therapies to prevent NTHi colonization and the development of OM. In this model, 100% of infant BALB/cARC mice were colonized with NTHi, and all developed NTHi OM. Influenza A virus (IAV) facilitated the establishment of dense (1 × 105 CFU/mL) and long-lasting (6 days) NTHi colonization. IAV was essential for the development of NTHi OM, with 100% of mice in the IAV/NTHi group developing NTHi OM compared with 8% of mice in the NTHi only group. Histological analysis and cytokine measurements revealed that the inflammation observed in the middle ear of the infant mice with OM reflected inflammation observed in children with OM. We have developed the first infant mouse model of NTHi colonization and OM. This ascension model uses influenza-driven establishment of OM and reflects the clinical pathology of bacterial OM developing after a respiratory virus infection. This model provides a valuable tool for testing therapies to prevent or treat NTHi colonization and disease in young children.

Chronic Suppurative Otitis Media: A Prospective Descriptive Study of the Microbiology and Antimicrobial Susceptibility Patterns.

This study aims to identify dominant causative pathogens of chronic suppurative otitis media (CSOM) and their antimicrobial susceptibility patterns. The secondary objective is to assess the cholesteatoma concurrence among this population. A prospective descriptive study. Port Elizabeth Provincial Hospital, Eastern Cape, South Africa. Aural swabs of purulent otorrhoea were collected from patients with CSOM attending the otorhinolaryngology outpatient department between April 2022 and June 2023. Samples were analyzed to determine the microbiological spectrum and evaluate antimicrobial sensitivities. Patient files were reviewed to identify cases with cholesteatoma. The study population size of 169 enabled representative results for a confidence interval of 90%. Patients were divided into 2 age categories: children (0-12 years) and adults (>12 years). Adults represented the majority of cases (76.9%) and females (58.6%) were affected more than males. Fungal isolates, Candida species and Aspergillus species, were the most common (20.8%). This was followed by Pseudomonas aeruginosa (12.4%) and Staphylococcus aureus (11.8%). 3.6% of cases cultured Mycobacterial tuberculosis which was high compared to global estimates. Susceptibility patterns showed 94.3% sensitivity of fungal cultures to fluconazole. Pseudomonas aeruginosa was 100% susceptible to piperacillin-tazobactam and cefepime, but only 76.2% sensitive to ciprofloxacin. Cholesteatoma concurrence was identified in 17.8%. CSOM remains a public health challenge. This study highlights the need to consider fungal etiology in instances where standard antibiotic treatments prove ineffective. Given the variety of cultured organisms and their susceptibility patterns, incorporating culture-directed therapy should be considered standard practice for chronic otorrhoea patients.

Transtympanic delivery of V2O5 nanowires with a tympanic-membrane penetrating peptide.

Otitis media is a prevalent pediatric condition. Local delivery of antimicrobial agents to treat otitis media is hindered by the low permeability of the stratum corneum layer in the tympanic membrane. While nanozymes, often inorganic nanoparticles, have been developed to cure otitis media in an antibiotic-free manner in a chinchilla animal model, the tympanic membrane creates an impenetrable barrier that prevents the local and non-invasive delivery of nanozymes. Here, we use a newly developed vanadium pentoxide (V2O5) nanowire as an example, which catalyzes the metabolic products of an otitis media pathogen (Streptococcus pneumoniae) into antiseptics, to explore the transtympanic delivery strategies for antimicrobial nanozymes. V2O5 nanowires with smaller dimensions (<300 nm in length) were synthesized by optimizing the synthesis conditions. To enhance penetrations across intact tympanic membranes, the nanowire was mixed or surface-modified with a trans-tympanic peptide, TMT3. The peptide-modified nanowires were characterized for their physical properties, catalytic activities, and antimicrobial activities. The cytotoxicity profile and permeation across ex vivo tympanic membrane samples were analyzed for the mixed and surface-modified nanozyme formulations.

The Unneglectable Disease Burden of Otitis Media Among Children in China: A Systematic Review and Meta-analysis.

Otitis media (OM) is one of the most commonly diagnosed infections among children yet with obscure disease burden. The literature published from 1980 to 2022 was retrieved in PubMed, Ovid-EMBASE, Web of Science, CNKI, Wanfang and VIP. Literature screening, quality assessment and data extraction were conducted by 2 independent reviewers. Heterogeneity and publication bias were detected by I2 , Egger's and Begg's tests. The data were pooled using the random-effects model. The number of OM cases was estimated by the multiplied model based on pooled results and the 2020 China census data. A total of 28,378 literatures were identified with 67 finally included for data analysis. The OM incidence among children was 7.89% [95% confidence interval (CI): 5.43%-11.33%] and the prevalence of OM was 5.13% (95% CI: 3.49%-7.49%). The most common pathogen of the OM cases was Streptococcus pneumoniae ( S. pneumoniae ), with a positive rate of 33.52% (95% CI: 26.55%-41.29%). The most common serotypes of S. pneumoniae isolated from OM cases were serotypes 19F, 19A, 6B, 23F and 3, with 85.8% covered by the PCV13. We estimated that there were 8,950,797 (95% CI: 6,080,533-12,928,051) OM cases among under-fives in China in 2020, of which 3,374,451 (95% CI: 1,698,901-6,277,862) cases of OM were caused by S. pneumoniae . The burden of OM in China was considerable yet neglected. To date, S. pneumoniae was the most frequently detected bacterial pathogen of OM. Vaccination may be effective to protect young children from OM.

Bacteriostatic effect of Ag@TiO2-Poly(p-dioxanone)-coated gauzes in vitro and in vivo on otitis media pathogens

The application of packing agents affects the final surgical outcomes in treating otitis media (OM) and introduces the risk of infection. To decrease the infectious risks of packing agents and even introduce positive bacteriostatic functions, a kind of PPDO-grafted Ag-incorporated TiO2 nanoparticles (Ag@TiO2-PPDO NP)-coated gauzes were prepared by a solution immersion method. Morphologies and in vitro Ag+ releasing of Ag@TiO2-PPDO NP coated gauzes were determined by scanning electron microscope (SEM) and inductively coupled plasma-mass spectrum (ICP-Ms). Ag@TiO2-PPDO NP could respond to visible light, which might make Ag@TiO2-PPDO NP inhibit the proliferation of bacteria continually and positively with irradiation of visible light. Then the bacteriostatic effects of these gauzes on OM pathogens were investigated in vitro and in vivo. These gauzes could inhibit the proliferation of pathogenic Staphylococcus aureus (S. aureus) and Streptococcus pneumoniae (S. pneumoniae) in vitro and rat subcutaneous infection models. Specifically, the bacteriostatic effect of these gauzes on S. aureus and S. pneumoniae could be enhanced with irradiation by visible light in vitro. Further, the rat external auditory canal infection model verified the enhanced bacteriostatic effect of Ag@TiO2-PPDO-coated gauzes on S. aureus with irradiation by visible light. The Ag@TiO2-PPDO-coated gauzes are promising for packing materials after OM surgery and could reduce postoperative antibiotic requirements.

Prevalence and Antibiotic-Resistance Indices of Bacterial Pathogens of Otitis Media among Patients Attending a Tertiary Hospital in Calabar, Nigeria

Background: Otitis media is linked to middle ear inflammation and sequelae, frequently occurring in infants and early childhood dealing with the accumulation of fluid behind the eardrum. It is often associated with the absence of timely and appropriate antibacterial interventions.&#x0D; Aim: To investigate the identity and antibiogram of bacterial agents of otitis media among patients attending a tertiary health facility in Calabar, Nigeria.&#x0D; Methods: Ear specimens collected from a total of 70 subjects were processed by conventional bacteriological methods for isolation and identification of pathogens. Antibiotic susceptibility testing was carried out on all the isolates using the Kirby-Bauer disk diffusion method. Multiple antibiotic resistance (MAR) indices of the isolates were evaluated.&#x0D; Results: The prevalence of bacterial otitis media was 72.9% in the study population. A total of 51 bacterial isolates including Pseudomonas aeruginaosa (26), Staphylococcus aureus (17), Proteus mirabilis (6), and Klebsiella pneumoniae (2) were found. Isolates of P. aeruginosa and S. aureus showed high susceptibility to amoxicillin-clavulanate (92.3%) and ciprofloxacin (88.3%), respectively. The prevalence of multidrug resistant (MDR) isolates was 25.4%. MDR percentages such as 100%, 33.3%, 30.7% and 29.4% were reported for isolates of K. pneumoniae, P. mirabilis, P. aeruginosa and S. aureus respectively. MAR indexing revealed high values ranging from 0.4 to 0.87 for all the isolates.&#x0D; Conclusion: High susceptibility of the predominant isolates to amoxicillin-clavulanate and ciprofloxacin may underscore the drugs’ potential as antibiotics of choice for prompt treatment of otitis media in the population. However, the overall high drug-resistance indices of the isolates would suggest dire implications for empiric antibacterial therapy in the population. Choice of antibiotics for treatment of bacterial infections in this population should be driven by results of microbiological drug-susceptibility tests.

Evaluation of the Current Bacterial Pathogens and Antibiogram of Chronic Suppurative Otitis Media in Adults.

To determine the bacterial pathogens in chronic suppurative otitis media (CSOM) & the antibiotic susceptibility patterns of isolates among patients. A total of 400 patients clinically diagnosed with CSOM were interviewed &middle-ear effusion samples were collected using sterile swabs. All bacterial isolates were identified by conventional microbiological methods. Antibiotic susceptibility patterns of the isolates were determined by Kirby-Bauer disc diffusion. Pseudomonas aeruginosa (30.25%) were the most prevalent bacteria isolated, followed by S. aureus (MSSA) (18.5%) & MRSA (8.25%). The most effective antibiotic for treatment of bacterial CSOM was amikacin & ciprofloxacin. Statistical analysis showed no significant difference in bacterial infestations among CSOM patients & the antimicrobial susceptibility patterns of the bacterial isolates based on age (p > 0.05). The importance of a continuous & annual evaluation of bacteriological profile & antibiotic susceptibility patterns in CSOM patients is highlighted in our study.

A cascade nanozyme with antimicrobial effects against nontypeable Haemophilus influenzae.

Otitis media (OM) is the main cause of pediatric antibiotic prescriptions. Nontypeable Haemophilus influenzae (NTHi) is a major OM pathogen, which forms a biofilm that resists conventional antimicrobials and immune clearance. Thus, novel treatments that are effective against NTHi and its biofilm are urgently required. Nanozymes (often inorganic nanoparticles) mimic natural enzymes' catalytic activities to generate strong antimicrobials at the site of infection, and thus represent one of the emerging solutions to the crisis of antimicrobial resistance. They mimic natural enzymes' activities, such as generating strong antimicrobials catalytically at the site of infection, to minimize overexposure. However, that in situ generation often relies on Reactive Oxygen Species (ROS) as precursors, a prerequisite that limits the broad deployment of nanozymes. To address this challenge, we designed a cascade nanozyme that generates an antiseptic, HOBr, from a ubiquitous non-ROS, i.e., O2, which successfully eradicates NTHi. The cascade nanozyme simultaneously exhibits glucose oxidase (GOx)-like activity from gold nanoparticles (AuNPs) and haloperoxidase (HPO)-mimicking activity from vanadium pentoxide nanowires (V2O5 NWs) connected using dopamine (DPA). The cascade nanozyme demonstrated strong antimicrobial efficacy against NTHi and its biofilm, while showing improved biocompatibility compared to the nanozyme of V2O5 NWs alone. The cascade nanozyme thus points to a material-oriented infectious disease treatment strategy, where small-molecule antimicrobials are generated in real time at the site of infection for the benefit of autonomous dosing. This strategy potentially mitigates the development of antimicrobial resistance and reduces side effects.

On-demand synthesis of antiseptics at the site of infection for treatment of otitis media

Otitis media (OM) is the main reason for pediatric antibiotic prescriptions. The current treatment mandates a rigorous regimen of multidose antibiotics over 5–10 days. The systemic antibiotic exposure and often prematurely terminated treatment due to the challenge of drug administration to young patients are believed to breed antibiotic resistance. To address these challenges, we designed a local treatment that converted a metabolic product (H2O2) of an OM pathogen (Streptococcus pneumoniae) into a potent antiseptic (HOBr), a reaction catalyzed by locally administered vanadium pentoxide nanowires. The therapeutic, HOBr, was only synthesized in the presence of the pathogen, enabling on-demand generation of therapeutics for OM treatment. Hypohalous acids are broad-spectrum and have a long history in general disinfection applications without breeding substantial drug resistance. A single dose of the nanowire formulation eradicated OM in a standard chinchilla model in 7 days with no observable tissue toxicity or negative impact on hearing sensitivity.

АНАЛИЗ РЕЗУЛЬТАТОВ АНКЕТИРОВАНИЯ СТУДЕНТОВ СТАРШИХ КУРСОВ МЕДИЦИНСКОГО УНИВЕРСИТЕТА ПО ВОПРОСАМ РАЦИОНАЛЬНОЙ АНТИБИОТИКОТЕРАПИИ ИНФЕКЦИЙ ВЕРХНИХ ДЫХАТЕЛЬНЫХ ПУТЕЙ И ЛОР-ОРГАНОВ У ДЕТЕЙ

Despite the availability of clinical guidelines, the issues of choosing the optimal first-line antibiotic therapy in the treatment of infections of the upper respiratory tract and ENT organs in children still remain relevant. Knowledge of the etiology of infections and the rational apply of systemic antibiotics are formed in senior medical students. Therefore, the purpose of this study is to analyze the knowledge of 6th year students of a medical university on the etiology and antibiotic therapy of upper respiratory tract infections and ENT organs in children, as well as comparing the results with knowledge on these issues of pediatricians. The article presents the results of a survey among the 350 volunteer students of the 6th year of the pediatric faculty on the etiology and antibacterial treatment of upper respiratory tract infections and ENT organs in children. These data have been compaired with the results of the large-scale multicenter study «PATRIOT» (2011-2013) among the pediatricians from 18 cities of Russia. It was revealed that most students overestimate the role of Staphylococcus aureus as the main pathogen in acute otitis media and acute tonsillopharyngitis (tonsillitis) in children. The main group of empirical antibiotic therapy were called aminopenicillins, often inhibitor-protected, whereas the role of natural penicillins in streptococcal tonsillopharyngitis and amoxicillin in acute otitis media and acute sinusitis was underestimated. Among district pediatricians, the frequency of correct answers to questions regarding the etiology and antibiotic therapy of these diseases was significantly higher than among students. It was found that only 9.4% of students and 6.1% of doctors would prescribe antibiotics for uncomplicated acute respiratory infection (ARI), but in real clinical practice they were prescribed in 59.6% of cases. These data indicate a different level of knowledge between students and doctors, as well as the difference in approaches to rational antibiotic therapy in theory and in real practice.

Essential Role of the Innate Immune Adaptor RIP2 in the Response to Otitis Media.

Intracellular nucleotide binding and oligomerization domain (NOD) and Toll-like (TLR) receptors have emerged as pivotal sensors of infection. Both Nod1 and Nod2 contain a caspase activation and recruitment domain (CARD) that interacts with the adaptor protein RIP2 (receptor-interaction protein-2). This leads to ubiquitination of RIP2 and in turn to the activation of NFκB and MAPK transcription factors, to command the host defensive response against pathogenic infections. RIP2 is also activated by TLRs 2 and 4, although the mechanism of this activation is less. The role of RIP2 in otitis media (OM) pathogenesis has yet to be examined. Herein, we used in vivo animal models including C57BL/6 wild-type (WT) and RIP2−/− knockout mice inoculated in the middle ear (ME) with non-typeable Haemophilus influenzae (NTHi), a common human OM pathogen, to evaluate the expression of RIP2 and its signaling genes at the cellular level to determine the role of RIP2 in OM pathogenesis and recovery. The Nod1, Nod2, and Ripk2 genes are minimally expressed in the normal ME. However, they are strongly upregulated during acute OM, as are many genes related to RIP2 signaling. However, while signaling genes were expressed by various ME cell types, only mucosal epithelial and stromal cells expressed the NODs, RIP2, and signaling genes required for the activation of the host defensive response. Whereas WT mice clear ME bacteria and recover from OM within 5 days after infection, RIP2-deficient mice show persistent ME bacterial carriage and inflammation to at least 15 days. This includes significantly prolonged mucosal hyperplasia and ME leukocytic infiltration. Recruitment of macrophages is also delayed in comparison to WT mice. Thus, RIP2 is required to elicit a robust innate immune response that promotes bacterial clearance and increases host innate resistance. The results also identify the structural cells of the ME mucosa, as opposed to leukocytes, as the primary sites of NOD/RIP2 activity in the infected ME.

Bacterial Agents Causing Chronic Suppurative Otitis Media

Background: Otitis media which is an acute or chronic inflammatory state of the middle ear may be classified as suppurative or non—suppurative.&#x0D; Methods: A total of 100 ear swabs from cases of chronic otitis media were variously collected from patients attending the ENT Clinic. Specimens were immediately transported in a transport medium to the base laboratory of the Department of Microbiology.&#x0D; Results: Out of a total number of 100 cases of chronic otitis media screened for the isolation of bacterial aetiologic agents, 8 different genera comprising 13 bacterial species were isolated. These included S. aureus (39%), Pseudomonas aeruginosa (25%), Proteus mirabilis (16%), Alcaligenes faecalis (5%) and Klebsiella aerogenes (1%). Escherichia coli, Proteus rettgeri, Staphylococcus epidermidis, and Klebsiella pneumoniae, constituted (3%), (3%), (3%) and 1% of isolates in that respective order. From the number of cases screened, it was observed that 54 (54% and 46(46%) were males and females respectively.&#x0D; Conclusion: We conclude that higher prevalence of otitis media among males than females and S. aureus has been identified as the leading pathogen in chronic otitis media.&#x0D; Keywords: Bacterial Infections, Etiology, Otitis Externa.

Bactericidal effects of high-energy visible light on common otitis media pathogens.

This study assessed the use of high-energy, visible light on the survival rates of three bacteria commonly found in middle ear infections (i.e. otitis media; Streptococcus pneumoniae, Moraxella catarrhalis and Haemophilus influenzae). Bacteria were cultured and then subjected to a single, 4-h treatment of 405nm wavelength light at two different intensities. All three bacteria species were susceptible to the light at clinically significant rates (>99.9% reduction). Bacteria were susceptible to the high-energy visible (HEV) light in a dose-dependent manner (lower survival rates with increased intensity and duration of exposure). The results suggest that HEV light may provide a non-surgical, non-pharmaceutical approach to the therapeutic treatment of otitis media. Given the growing concerns surrounding antibiotic resistance, this study demonstrates a rapid, alternative method for effective inactivation of bacterial pathogens partly responsible for instances of otitis media.

Gene Expression Regulation in Airway Pathogens: Importance for Otitis Media.

Otitis media (OM) is an inflammatory disorder in the middle ear. It is mainly caused by viruses or bacteria associated with the airways. Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis are the three main pathogens in infection-related OM, especially in younger children. In this review, we will focus upon the multifaceted gene regulation mechanisms that are well-orchestrated in S. pneumoniae, H. influenzae, and M. catarrhalis during the course of infection in the middle ear either in experimental OM or in clinical settings. The sophisticated findings from the past 10 years on how the othopathogens govern their virulence phenotypes for survival and host adaptation via phase variation- and quorum sensing-dependent gene regulation, will be systematically discussed. Comprehensive understanding of gene expression regulation mechanisms employed by pathogens during the onset of OM may provide new insights for the design of a new generation of antimicrobial agents in the fight against bacterial pathogens while combating the serious emergence of antimicrobial resistance.

Clonal Distribution, Antimicrobial Resistance, and Pilus Islets in S. pneumoniae Isolates from PCV10-Vaccinated Children with Suppurative AOM in Bulgaria (2015‒2020).

Streptococcus pneumoniae is still a leading bacterial pathogen of acute otitis media (AOM), despite the availability of pneumococcal conjugate vaccines (PCVs). We conducted a study on the population structure, antibiotic nonsusceptibility, serotype distribution, and presence of pilus in middle ear fluids ‒ S. pneumoniae isolates recovered from PCV10-vaccinated children with suppurative АОМ in Bulgaria. Non-susceptibility was observed in 68.75% (n = 33) of the isolates, and multidrug resistance (MDR) was detected in 60.4% of the patients. The dual macrolide resistance mechanism was predominant. The most common serotypes were non-PCV10 serotypes 3 (27.1%, n = 13), 19A (25.0%, n = 12), and VT 19F (23.0%, n = 11). Overall, 64.6% were non-PCV10-serotypes. The presence of Pilus type I was observed mostly in the PCV10-serotypes. We found a strong association between clonal complexes (CCs), serotypes, and antimicrobial resistance. Multilocus sequence typing revealed the presence of four CCs: CC320 (39.6%), CC505 (12.5%), CC1377 8.3%), and CC230 (8.3%). The most abundant CC320 comprised MDR 19A and 19F isolates. CC230 clustered MDR isolates from serotypes 19A, 6C, and 14. CC505 and CC1377 were serotype 3 susceptible isolates. The vaccine-induced changes and trends in antimicrobial resistance and clonality must be the focus of systematic investigations.