[Studies of isolated organisms from otorhinolaryngological infections and their susceptibilities to macrolide antibiotics].

To study current situation of pathogenic bacteria and their drug resistance to macrolide antibiotics in the otorhinolaryngological infections, 609 strains diagnosed as pathogen derived from 463 patients were collected from cohospitals or institutions during the period of 1980-1983. The results obtained were as follows: Gram-positive cocci (GPC) was dominant (410 strains) and major species were S. aureus (135 strains), S. pneumoniae (81 strains), S. epidermidis (68 strains) and S. pyogenes (65 strains). In Gram-negative bacteria giving 147 strains and 43 strains, of anaerobes prevailing species were H. influenzae, P. aeruginosa and Peptostreptococcus spp. Representative species in the diseases were S. aureus (26.6%), S. epidermidis (24.5%), and P. aeruginosa (12.8%) in acute otitis media, S. aureus (34.4%), S. epidermidis (17.7%) and P. aeruginosa (14.6%) in acute exacerbation of chronic otitis media, S. epidermidis (17.0%), S. aureus (16.1%) and H. influenzae (13.4%) in acute paranasal sinusitis, S. pyogenes (29.1%), S. pneumoniae (19.6%) and S. aureus (15.1%) in acute tonsillitis. Although most of isolates were susceptible to macrolides, 62 resistant strains to macrolides were found in 501 strains and the resistant rates were 26.7% in S. aureus, 23.1% in S. epidermidis and 6.5% in S. pyogenes. The resistant pattern was somewhat different against each macrolides, resistant strains giving over 100 micrograms/ml in MIC were 55/62 in erythromycin, 35/62 in josamycin and midecamycin and 7/62 in TMS-19-Q, a new macrolide.