muramidase and Otitis-Media--Suppurative

Streptococcus pneumoniae is an important bacterial pathogen in the pathophysiology of otitis media. To elucidate the inflammatory responses that occur during pneumococcal otitis media, the kinetics of the biochemical and cytologic middle ear responses to heat-killed encapsulated and nonencapsulated pneumococci were studied in the chinchilla model. Inoculation of the middle ear cavity with at least 10(6) S pneumoniae cells induced an early, brief vascular response with leakage of small (albumin) followed by larger (alpha 2-macroglobulin) proteins, followed by sustained influx of acute inflammatory cells and lysozyme. The threshold for a sustained lysozyme response was 1,000 times lower for nonencapsulated than for encapsulated pneumococci. These results indicate that nonviable S pneumoniae organisms with an intact envelope initiate the middle ear inflammatory response. Therefore, interventions that enhance the clearance of pneumococcal cells from the middle ear may reduce the inflammatory response and prevent chronic middle ear inflammation.

Topics: Albumins; alpha-Macroglobulins; Animals; Chinchilla; Muramidase; Neutrophils; Otitis Media; Otitis Media, Suppurative; Streptococcal Infections

The sequential cytologic and biochemical events of middle ear effusion (MEE) were studied in experimental models of serous otitis media (SOM) and purulent otitis media (POM) in chinchilla. In the SOM model, the initial appearance of neutrophils was followed by macrophages. In the POM model, neutrophils were the predominant cells in MEE and the number of neutrophils was about 100-fold higher than in the SOM model. The activity of lysozyme in MEE was higher in POM than in SOM and correlated with the number of neutrophils and mononuclear phagocytes. The results of the present study suggest that neutrophils and mononuclear phagocytes are one of the main sources for lysozyme levels in MEE during otitis media.

Topics: Animals; Chinchilla; Muramidase; Otitis Media; Otitis Media with Effusion; Otitis Media, Suppurative; Pneumococcal Infections; Time Factors

Topics: Animals; Child; Child, Preschool; Chinchilla; Exudates and Transudates; Female; Humans; Infant; L-Lactate Dehydrogenase; Male; Muramidase; Otitis Media; Otitis Media with Effusion; Otitis Media, Suppurative; Penicillins

Topics: Animals; Exudates and Transudates; Humans; L-Lactate Dehydrogenase; Muramidase; Otitis Media; Otitis Media, Suppurative

147 samples of punctured middle ear effusion fluid from cases of otitis media with effusion and 150 samples from patients with acute purulent otitis media were tested for lysozyme activity. In otitis media with effusion the concentration was 182.0 U/ml, in acute otitis 433.8 U/ml. The lysozyme concentration in otitis media with effusion depended upon the nature of the effusion. Serous fluid showed an activity of 124.8 U/ml and mucoid 311.6 U/ml, respectively. In culture-positive cases of acute otitis media the lysozyme level was 423.4 U/ml. Culture-negative cases showed about the same concentration, 438.3 U/ml. The possible role of lysozyme in defence systems of the middle ear is discussed.

Topics: Adolescent; Adult; Aged; Albumins; Child; Child, Preschool; Humans; Immunoglobulins; Infant; Middle Aged; Muramidase; Otitis Media; Otitis Media, Suppurative