What is the effectiveness of beta-glucan for treatment of acute otitis media?

INTRODUCTION

As a supplement, beta-glucan has various therapeutic healing effects generated by the immune cells. It has been scientifically approved and proven to be a biological defense modifier. The aim of this study was to investigate the effects of beta-glucan on treatments administered in an acute otitis media model OBJECTIVES: This study investigated the effect of beta-glucan on the treatment of acute otitis media in an acute otitis media -induced animal model. Efficacy was evaluated both immunologically and histologically.

METHODS

The study sample comprised 35 adult rats, randomly separated into 5 groups of 7: Group 1 (control), Group 2 (acute otitis media, no treatment), Group 3 (acute otitis media+antibiotic), Group 4 (acute otitis media+beta-glucan) and Group 5 (acute otitis media+beta-glucan+antibiotic). Analyses were made of the histopathology and immunology examination results in respect of thickening of the tympanic membrane, epithelium damage, inflammation, and sclerosis. In all groups the serum levels of TNF-α, IL-4, IL-6 and IL-1β were evaluated.

RESULTS

All serum cytokine levels were significantly lower in the beta-glucan and antibiotic-treated groups compared to the acute otitis media Group. Significant differences in tympanic membrane thickness, inflammation, epithelium damage, and sclerosis values were observed between the acute otitis media+antibiotic and acute otitis media+beta-glucan Groups. According to these parameters, the values in aute otitis media+antibiotic+beta-glucan Group were markedly lower than those of the other groups. There was a significant difference in the acute otitis media+antibiotic+beta-glucan Groups compared to acute otitis media Group (p < 0.001).

CONCLUSIONS

Both antibiotic and beta-glucan treatment reduced acute otitis media signs of inflammations in an acute otitis media-induced rat model, decreasing histological damage and cytokine levels. Co-administration of antibiotic and beta-glucan led to a significant reduction in tympanic membrane thickness, inflammation, and epithelium damage. Antibiotic+beta-glucan treatment resulted in a greater decrease in tympanic membrane thickness, inflammation, and epithelium damage than in the other groups. From these results, it can be suggested that beta-glucan, in combination with antibiotics may provide an alternative for the treatment of acute otitis media.

Efficacy of injectable trivalent virosomal-adjuvanted inactivated influenza vaccine in preventing acute otitis media in children with recurrent complicated or noncomplicated acute otitis media

BACKGROUND

Most cases of acute otitis media (AOM) follow an upper respiratory infection due to viruses, including influenza viruses. As effective and safe influenza vaccines are available, their use has been considered among the possible measures of AOM prophylaxis.

OBJECTIVES

To evaluate the efficacy of an inactivated virosomal-adjuvanted influenza vaccine in preventing AOM in children with a history of noncomplicated recurrent AOM (rAOM) or rAOM complicated by spontaneous perforation.

METHODS

In this prospective, randomized, single-blinded, placebo-controlled study, 180 children aged 1 to 5 years with a history of rAOM and previously unvaccinated against influenza were randomized to receive the inactivated virosomal-adjuvanted subunit influenza vaccine (n = 90) or no treatment (n = 90), and AOM-related morbidity was monitored every 4 to 6 weeks for 6 months.

RESULTS

The number of children experiencing at least 1 AOM episode was significantly smaller in the vaccinated group (P < 0.001), as was the mean number of AOM episodes (P = 0.03), the mean number of AOM episodes without perforation (P < 0.001), and the mean number of antibiotic courses (P < 0.001); the mean duration of bilateral OME was significantly shorter (P = 0.03). The only factor that seemed to be associated with the significantly greater efficacy of influenza vaccine in preventing AOM was the absence of a history of recurrent perforation (crude odds ratio, P = 0.01; adjusted odds ratio, P = 0.006).

CONCLUSIONS

The intramuscular administration of injectable trivalent inactivated virosomal-adjuvanted influenza vaccine in children with a history of rAOM significantly reduces AOM-related morbidity. However, the efficacy of this preventive measure seems to be reduced in children with rAOM associated with repeated tympanic membrane perforation.

Genetic requirement for pneumococcal ear infection

Background

Ear infection or otitis media (OM) accounts for most bacterial respiratory infections in children in both developed and developing nations. Streptococcus pneumoniae, nontypeable Haemophilus influenzae, and Moraxella catarrhalis are the major OM pathogens. However, little is known about the genetic basis of bacterial OM largely due to practical difficulties in conducting research in ear infection models and genetically manipulating clinical isolates. Here, we report the first genome-scale in vivo screen for bacterial genes required for ear infection in a chinchilla model by signature tagged mutagenesis (STM), a high throughput mutant screen technique.

Methodology/Principal Findings

STM strains were constructed with a multi-drug resistant OM isolate ST556 (serotype 19F) and screened in a chinchilla OM model. Out of 5,280 mutants tested, 248 mutants were substantially underrepresented in the mutant pools recovered from the middle ear fluids of the infected chinchillas, indicating the impaired ability to survive and replicate in the middle ears due to genetic disruptions in the chromosome of strain ST556. Further DNA sequencing analysis mapped the mutations to 169 pneumococcal genes. Surprisingly, only 52 of these genes were required for pneumococcal nasopharyngeal colonization in a murine model. This infection site-specific gene requirement was verified by targeted mutagenesis in the selected genes.

Conclusions/Significance

These findings suggest that there are a subset of pneumococcal genes required for ear infection and that these may be distinct from those required for nasal colonization. Our data thus provide comprehensive gene targets for mechanistic understanding of pneumococcal ear infection. Finally, this study has also developed a model for future genome-scale search for virulence determinants in other pathogens associated with ear infections.

Nasopharyngeal colonization: a target for pneumococcal vaccination

The pneumococcal conjugate vaccine (PCV), licensed in 2000, is highly efficient in preventing serious disease caused by serotypes in the vaccine and also prevents symptomless colonization of the nasopharynx. Prevention of this first step in the infection cycle has important consequences: it reduces chances of spread of the infection and indirectly protects from disease. Through these indirect effects, the protection afforded by the vaccine extends to the whole population, including those not vaccinated (herd immunity). Already now, after 5 years of wide use of PCV for infant immunization in the USA, more cases are prevented through the indirect effects than by vaccine-induced immunity in those vaccinated. The extended protection increases the cost-effectiveness of PCV and should clearly encourage its use in poorly resourced countries. However, the accumulated experience also shows that the herd immunity, due to PCV, is partly offset by replacement of the vaccine serotypes by other, nonvaccine serotypes. Owing to the general reduced virulence of the latter, this has only had a modest effect on disease, but the possibility of more virulent nonvaccine serotypes arising cannot be ignored and should be the focus of continued surveillance.

The role of immunomodulatory oligonucleotides in prevention of OVA-induced Eustachian tube dysfunction

OBJECTIVE

To evaluate the potential role of immunomodulatory oligonucleotides (IMO) in the prevention of OVA-induced Eustachian tube dysfunction (ETD) in a rat model.

METHODS

Brown-Norway rats were sensitized to ovalbumin (OVA) and randomized to receive pre-treatment with IMO or phosphate buffered saline (PBS). After systemic sensitization, subjects received a transtympanic OVA challenge followed by evaluation of the Eustachian tube's dynamic function.

RESULTS

Pre-treatment of OVA sensitized animals with IMO normalized passive opening and closing Eustachian tube pressures, improved active clearance of negative pressure in the middle ear, and resulted in reduced mean mucociliary transit times compared to untreated OVA-sensitized animals (P<0.001).

CONCLUSION

These data demonstrate that pre-treatment with IMO prevent OVA-induced ETD in the rat. IMO treatment in the future may offer considerable promise in the management of OME in children.

Mouse models of induced otitis media

The mouse has seen limited use as a model for experimental otitis media, due primarily to the small size of its middle ear. However, the genetic resources of this species offer substantial potential benefits. These include detailed genomic information, a wealth of genetic models, and gene arrays that represent virtually all mouse genes. This has led to the development of methods for inducing otitis in mice. These include surgical approaches to the middle ear, documentation of the murine middle ear response to various pathogens and inflammatory factors, as well as characterization of induced otitis media in several mouse strains. The results indicate that induced otitis media in the normal mouse is in most respects comparable to that observed in other animal models and in humans. They further suggest that the considerable genetic resources of this species can be harnessed to increase our understanding of this disease.