Organic Acids and Anaerobic Microorganisms in the Contents of the Cholesteatoma SAC

Abstract

Organic acids in the contents of the cholesteatoma sac from 28 cases were studied by gas chromatographic technique. Five volatile fatty acids (acetate, propionate, isobutyrate, butyrate and isovalerate) and lactate were detected in large amounts, which may lower the pH of the cholesteatoma content. These acids were considered to be derived from products of anaerobic microorganisms. Therefore, the contents from 12 cases were cultured anaerobically in a glove box. Obligate microorganisms were identified in 92% of the cases and Peptococcus, Bacteroides, and Clostridium species were frequently isolated. In vitro, such obligate anaerobes produced various organic acids from the cholesteatoma content. Facultatives such as Staphylococcus aureus and Proteus mirabilis produced acetate in the content under aerobic and anaerobic conditions, whereas no organic acid was produced by Pseudomonas aeruginosa. Organic acids in the cholesteatoma content could be fermentative products made by the microorganisms, anaerobes and facultatives, which use the content as a substrate for acid production.

Increased permeability of the epithelium of middle ear cholesteatoma

“…However, this theory was not well grounded at the time and was only a speculation based on their clinical observations. In the 1980s, Iino et al . detected abundant organic acids, including lactate and short‐chain fatty acids, in the keratin debris of cholesteatoma.…”

“…However, this theory was not well grounded at the time and was only a speculation based on their clinical observations. In the 1980s, Iino et al 47 detected abundant organic acids, including lactate and short-chain fatty acids, in the keratin debris of cholesteatoma. Moreover, Kaneko et al 40 and Suzuki et al 17 discovered that bone destruction is observed in the vicinity of the ruptured cholesteatoma epithelium, where keratin debris escapes through the epithelial break towards the subepithelial layer.…”

The role of anaerobic bacteria in upper respiratory tract and other head and neck infections

“…Anaerobes were isolated from about 50% of the patients with chronic suppurative otitis media [4,6,19,20] and those with infected cholesteatoma [21,22]. The variability in the rate of recovery of anaerobes in various studies may be attributed to differences in geographic locations and laboratory methodologies.…”

“…Anaerobes are often isolated from infected cholesteatomas [21,22]. The cholesteatoma can induce bone absorption, which is enhanced by the organic acids produced by anaerobic bacteria [22].…”

“…The cholesteatoma can induce bone absorption, which is enhanced by the organic acids produced by anaerobic bacteria [22]. Because cholesteatoma associated with chronic suppurative otitis media harbors organisms similar to those isolated from chronically infected ears, the cholesteatoma may serve as a nidus of the chronic infection.…”