Human antimicrobial proteins in ear wax

The role of the microbiome in allergic dermatitis-related otitis externa: a multi-species comparative review

The external ear canal, characterized by species-specific structural and physiological differences, maintains a hostile environment that prevents microbial overgrowth and foreign body entry, supported by factors such as temperature, pH, humidity, and cerumen with antimicrobial properties. This review combines several studies on the healthy ear canal's structure and physiology with a critical approach to the potential existence of an ear microbiome. We use a comparative multi-species approach to explore how allergic conditions alter the ear canal microenvironment and cerumen in different mammalian species, promoting pathogen colonization. We propose a pathogenetic model in which allergic conditions disrupt the antimicrobial environment of the EEC, creating circumstances favorable for facultative pathogenic micro-organisms like Staphylococcus and Malassezia species, leading to otitis externa (OE). A better understanding of the underpinning mechanisms may lead to innovative approaches to disease mitigation.

Isolation, culture, and identification of ceruminous gland cells

External auditory canal (EAC) stenosis or atresia usually requires a skin graft to repair, but due to the lack of a graft containing functional glands, postoperative complications such as infection and eczema are common. The aim of this study was to isolate and characterize seed cells for the construction of tissue engineered EAC skin containing ceruminous gland by isolating and cultivating cells of ceruminous gland. In this study, EAC skin samples were harvested from adult goats for ceruminous gland cell isolation. Cell morphology and proliferation rates, expression of CK7, CK8, CK18, and CK19 (glandular cell specific-markers), and secretion of β-defensin-1, lysozyme, and polysaccharides were evaluated at different passages to verify the presence of ceruminous gland cells and determine whether function and proliferation potential were maintained. Ceruminous glands were successfully isolated and extracted from goat EAC skin. Furthermore, the isolated glandular cells maintained robust proliferation potential, exhibited high expression of CK7, CK8, CK18, and CK19, and vigorously secreted β-defensin-1, lysozyme, and polysaccharides in this culture system. However, expression of glandular cell specific-markers and secretory function gradually declined with increasing passage number, indicating dedifferentiation of the subcultured ceruminous gland cells after five passages. In conclusion, ceruminous glands were successfully isolated, cultured, and expanded from goat EAC skin using the serumcontaining culture system. Importantly, the isolated glandular cells retained robust proliferation potential and maintained their phenotype and function in early passages (P1-P3), indicating the method's potential application for ceruminous gland regeneration.

Targeting bacteria causing otitis media using nanosystems containing nonspherical gold nanoparticles and ceragenins

Aim: To evaluate the antibacterial and antibiofilm activity of ceragenin-conjugated nonspherical gold nanoparticles against the most common agents of otitis media. Methods: Minimal inhibitory and bactericidal concentrations and colony-counting assays, as well as colorimetric and fluorimetric methods, were used to estimate the antibacterial activity of compounds in phosphate-buffered saline and human cerumen. The nanosystems' biocompatibility and ability to decrease IL-8 release was tested using keratinocyte cells. Results: The tested compounds demonstrated strong antimicrobial activity against planktonic and biofilm cultures at nontoxic doses due to the induction of oxidative stress followed by the damage of bacterial membranes. Conclusion: This study indicates that ceragenin-conjugated nonspherical gold nanoparticles have potential as new treatment methods for eradicating biofilm-forming pathogens associated with otitis media.

Sports audiology: Ear hygiene practices of gym users who wear earphones

BACKGROUND

Technological advancements have facilitated the demand for electronic systems to track and measure progress during exercise activities. Electronic devices with music applications, such as iPods and smartphones, are popular during gym sessions as they support the ambiance to one's exercise programme. Earphones are the popular choice for the transmission of music to the gym user's ear. There is a direct correlation between the cardiovascular health and the aural health because of the effect of increased blood supply to the auditory system. Therefore, this research study explores the ear hygiene of gym users.

OBJECTIVES

This study aimed at determining the ear hygiene and middle-ear status of gym users who wore earphones whilst exercising.

METHOD

A purposive sampling method was adopted. Data were collected in two phases: phase 1 via a questionnaire and phase 2 included an otoscopic examination and tympanometry. Qualitative and quantitative data were analysed.

RESULTS

Fifty-four participants were included. Ear hygiene was not a priority for all gym users. The results revealed that 87% of the participants randomly cleaned their ears; however, 59% were cleaning their earphones. The middle ear assessment indicated that 17% of the participants presented with pathological indicators. Participants requested for the implementation of educational programmes pertaining to infection control measures for proper ear hygiene.

CONCLUSION

There is a dearth of health and wellness educational programmes that include ear hygiene practices, necessitating the development of prevention and promotion programmes for this niche area in audiology. The need for guidelines pertaining to ear hygiene practices amongst gym users is vital to ensure that the auditory system is monitored and protected when individuals participate in exercise sessions.

Insights into cerumen and application in diagnostics: past, present and future prospective

Cerumen or earwax is an emerging bio-fluid in clinical diagnosis that has been very little exploited during the past decades in spite of its high diagnostic potential. It is highly abundant in diagnostic biomarkers such as genetic material, lipids, proteins, chemical elements, internal and external metabolites (e.g. hormones, volatile organic compounds, amino acids, xenobiotics etc.) reaching earwax from the blood circulation. Thus, it is able to reflect not only physiology, pathophysiology of the human body but can also detect recent and long term exposure to environmental pollutants, without the need of invasive blood tests and in the same time overcoming many disadvantages faced by using other diagnostic biological fluids. This review discusses the biology, functions, chemistry of earwax, past and current approaches for the study of its chemical composition, emphasizing how a detected variation in its composition can offer information of high clinical value, which can be useful in diagnosis of many diseases such as metabolic disorders and tumours as well as in forensic applications. It also presents details about techniques of sample collection, storage, and analysis. Moreover, it highlights concerns about the use of earwax for diagnostic purposes, which should be addressed to make earwax diagnostics a reality in the future.

Ultrastructure and immunohistochemical characterization of proteins concerned with the secretory machinery in goat ceruminous glands

The expression of soluble N-ethylmaleimide sensitive fusion attachment protein receptor (SNARE) proteins in apocrine glands has not been fully elucidated. In addition to performing ultrastructural observation of the ceruminous glands in goats, our study focuses on the demonstration of β-defensins, SNARE proteins and Rab3D in these glands with the use of immunohistochemical methods. The secretory cells were equipped with two types of vesicles, Golgi apparatus and abundant rough endoplasmic reticulum (ER). Additionally, in some of them, the characteristic concentric structures composed of rough ER were observed in their circum- and infranuclear parts. The expression of phosphorylated inositol requiring enzyme 1rrwas also detected. These findings may indicate their ability to produce numerous secretory proteins and the maintenance of homeostasis in the glandular cells. Furthermore, β-defensins were demonstrated as products of the ceruminous glands. The present investigation also revealed the presence of SNARE proteins and Rab3D. It is suggested that these proteins are concerned with the secretory machinery of this gland type.

Earwax Impaction: Symptoms, Predisposing Factors and Perception among Nigerians

Background and Aim:

Earwax impaction is a common ear disorder with presentation worldwide. This study aimed at determining the clinical presentation, patients’ perception of earwax, and its predisposing factors among Nigerians.

Materials and Methods:

This prospective study was conducted on consented patients with diagnosis of earwax impaction at the Ear, Nose, and Throat Clinic of the University Teaching Hospital, Ado Ekiti, Ekiti state, south west, Nigeria. The research was carried out over a period of one year (April 2008 and March 2009). All consented patients were told about the aim and scope of the study and their biodata were taken. Detailed history of the presenting complaints and otological complaints were taken and all data entered into structured questionnaires. Full-ear examination and otoscopy were performed and our findings were documented. From all these exercise, data obtained were collated and statistically analyzed.

Results:

A total of 437 patients were diagnosed with earwax impaction and prevalence of 20.1% was found. There was 52.2% male preponderance with male to female ratio of 1:1. Bimodal peak age distribution of patients was found at the extreme ages of life. Most common sources of our patients referrals were 39.6% general medical practitioners with least from 6.2% self-reporting. Common presentations were 277 (63.3%) hearing loss, 268 (61.3%) earache (otalgia), and 234 (53.5%) tiinitus. Unilateral earwax impaction, 75.1% was more common than bilateral earwax impaction. Right ear was more affected than left ear. Recurrent earwax impaction of 66.1% was found in our study. About 382 (87.4%) believed earwax was due to dirt or dust. Most common predisposing factors among our patients were self-ear cleaning.

Conclusion:

Common predisposing factor of this high recurrent earwax impaction were wrong perception and preventable self-ear cleaning with indiscriminate objects including cotton tip swab. This condition could be reduced by health education of the community.

Identification of volatile organic compounds in human cerumen

We report here the initial examination of volatile organic compounds (VOCs) emanating from human earwax (cerumen). Recent studies link a single nucleotide polymorphism (SNP) in the adenosine triphosphate (ATP) binding cassette, sub-family C, member 11 gene (ABCC11) to the production of different types of axillary odorants and cerumen. ABCC11 encodes an ATP-driven efflux pump protein that plays an important function in ceruminous apocrine glands of the auditory canal and the secretion of axillary odor precursors. The type of cerumen and underarm odor produced by East Asians differ markedly from that produced by non-Asians. In this initial report we find that both groups emit many of the same VOCs but differ significantly in the amounts produced. The principal odorants are volatile organic C2-to-C6 acids. The physical appearance of cerumen from the two groups also matches previously reported ethnic differences, viz., cerumen from East Asians appears dry and white while that from non-Asians is typically wet and yellowish-brown.

Lactoferrin: an alternative view of its role in human biological fluids

Lactoferrin is a major component of biologically important mucosal fluids and of the specific granules of neutrophils. Understanding its biological function is essential for understanding neutrophil- and mucosal-mediated immunity. In this review, we reevaluate the in vivo functions of human lactoferrin (hLF) emphasizing in vivo studies and in vitro studies performed in biologically relevant fluids. We discuss the evidence in the literature that supports (or does not support) proposed roles for hLF in mucosal immunity and in neutrophil function. We argue that the current literature supports a microbiostatic role, but not a microbicidal role, for hLF in vivo. The literature also supports a role for hLF in inhibiting colonization and infection of epithelial surfaces by microorganisms and in protecting tissues from neutrophil-mediated damage. Using this information, we briefly discuss hLF in the context of the complex biological fluids in which it is found.