Investigation of the Presence of Biofilms in Chronic Suppurative Otitis Media, Nonsuppurative Otitis Media, and Chronic Otitis Media with Cholesteatoma by Scanning Electron Microscopy

Abstract

Objective. Biofilms have been shown to play a major role in the pathogenesis of otolaryngologic infections. However, very limited studies have been undertaken to demonstrate the presence of biofilms in tissues from patients with chronic otitis media (COM) with or without cholesteatoma. Our objective is to study the presence of biofilms in humans with chronic suppurative and nonsuppurative otitis media and cholesteatoma. Study Design. In all, 102 tissue specimens (middle ear, mastoid tissue, and ossicle samples) were collected during surgery from 34 patients. Methods. The samples were processed for the investigation of biofilms by scanning electron microscopy (SEM). Results. Our research supports the hypothesis in which biofilms are involved in chronic suppurative otitis media, cholesteatoma, and, to a lesser degree, chronic nonsuppurative otitis media. There were higher rates in hypertrophic and granulated tissue samples than in normal mucosa. In addition, the presence of biofilms was significantly higher in the middle ear mucosa compared with the mastoid and ossicle samples. Conclusion. In the clinic, the careful use of topical or systemic antimicrobials is essential, and, during surgery, hypertrophic tissue must be carefully removed from normal tissue.

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“…This was lower compared to prior studies in which it ranged from 60-70 per cent [6,21,22]. Staphylococcus aureus was the predominant biofilm former with 47.36 per cent of the isolates testing positive for biofilm formation.…”

“…Recently, biofilms have been found to play a pivotal role in the pathogenesis of CSOM with an incidence of about 60-65% [6]. Biofilms are complex bacterial communities that adhere to the surface of implanted biomaterial or mucosa, embedded in a slimelike extracellular matrix composed of proteins, polysaccharides, and nucleic acids known as extracellular polymeric substances and are very difficult to treat and eradicate [7,8].…”

Current concepts in the pathogenesis and treatment of chronic suppurative otitis media

“…In addition, biofilms attach firmly to damaged tissue, such as exposed osteitic bone and ulcerated middle ear mucosa, or to otological implants such as tympanostomy tubes, further aggravating the problem of eradication (Wang et al, 2014). Although biofilms have been demonstrated in the middle ear of CSOM patients, their precise role in the pathophysiology of the disease is yet to be determined (Saunders et al, 2011;Lampikoski et al, 2012;Kaya et al, 2013;Gu et al, 2014;Khosravi et al, 2014). Furthermore, the molecular mechanisms leading to biofilm formation in the middle ear during CSOM are also poorly understood.…”

Chronic otitis media

“…Common causative bacteria found in active COM are pseudomonas species, proteus species and staphylococcus aureus [6,7]. Complex bacterial communities, known as biofilms, have also been identified in the middle ear mucosa of COM patients [8]. Mucosal COM may remain active despite topic treatment if the organisms involved have antibiotic resistance or there is a suppressed immune response.…”