Notes on the microbiology of cholesteatoma: clinical findings and treatment.

Anomalous proliferation of the cholesteatoma epithelium is caused by extrinsic factors such as toxins or bacterial antigens combined with lytic enzymes, lymphokines and cytokines released from the inflammatory infiltrate. This could explain the close relationship between the aggressiveness of cholesteatoma and repeated bacterial superinfection, therefore it is very important to know the bacteria involved in order to control the regrowth of skin following surgery, reduce the aggressive potential of the cholesteatoma and limit the incidence of complications. This study focused on 70 females and 80 males aged between 15 and 65 years, affected by cholesteatomatous otitis media; all underwent bacteriological examination of the auricular secretion. The floral bacteria which proved to play the most important role (60.3%) were the aerobic type and the highest levels were those of Pseudomonas aeruginosa (31.1%) followed by Staphylococcus aureus (19.1%), Proteus mirabilis (7.7%), Escherichia coli (1.4%) and Klebsiella pneumoniae (1%). Anaerobic floral bacteria were found in a fairly high percentage of cases (38.2%); in particular, anaerobic gram-positive cocci (Peptococcus 12.4% and Peptostreptococcus in 4.8% of cases), Bacteroides (12.4%), Clostridium (3.8%), Fusobacterium (2.9%) and Propionobacterium (1.9%) were isolated. In 3 cases of mycetes (1.4%) only Aspergillus, in association with Pseudomonas and Staphylococcus, was identified. The study showed, then, how effective second generation fluoroquinolones and third generation cephalosporins are (the latter being used in pre-adolescent children), the reason being that these antibiotics work not only on Pseudomonas and Staphylococcus, but also on the anaerobic bacteria.