[Susceptibility of bacteria isolated from lower respiratory tract infections to antibiotics (1983)].

Bacterial isolates from the patients with pulmonary infections have been collected over these 3 years, in collaboration with investigators at 13 hospitals in various parts of Japan for the study on frequency of isolation of pathogens among the patients and their drug susceptibilities. Possible causative pathogens mainly isolated from sputum in patients with lower respiratory tract infections during period from September 1983 to March 1984, were collected. The frequency of bacterial isolates from the sputum and their drug susceptibility on H. influenzae among the various pathogens are discussed. The kinds of bacterial species isolated from the patients with respiratory tract infections associated with chronic bronchitis, chronic capillary bronchitis or bronchiectasis and their relative frequency of isolation were as follows; Total numbers of bacterial isolates collected from various hospitals were 220 strains in 1981, 168 strains 1982 and 258 strains in 1983. H. influenzae was always isolated with highest frequency of 50.5% in 1981, 45.8% in 1982 and 40.7% in 1983, and followed by P. aeruginosa (24.1%), S. aureus (8.2%), S. pneumoniae (7.3%) and K. pneumoniae (5.9%) and E. coli (4.1%) in 1981; P. aeruginosa (30.4%), S. pneumoniae (11.9%), S. aureus (4.8%), K. pneumoniae (3.0%) and E. coli (1.8%) in 1982; P. aeruginosa (26.7%), S. pneumoniae (10.1%), S. aureus (7.8%), K. pneumoniae (3.5%) and E. coli (3.5%) in 1983. The drug susceptibility test of H. influenzae to ampicillin (ABPC), piperacillin (PIPC), mezlocillin (MZPC), sulbenicillin (SBPC), gentamicin (GM), amikacin (AMK), cefotiam (CTM), cefmetazole (CMZ), cefoperazone (CPZ), cefotaxime (CTX), ceftizoxime (CZX), cefmenoxime (CMX) and latamoxef (LMOX) was done by using agar micro-broth dilution methods. H. influenzae was most markedly susceptible to cephems of the third generation, especially to CMX, CZX and CTX by which about 95% of H. influenzae tested were inhibited the growth under the concentration with less than or equal to 0.10 microgram/ml of the drugs. Furthermore, annual changes in susceptibility of H. influenzae to various antibiotics was analyzed over the period from 1981 to 1983. The frequency of S. pneumoniae isolated from patients with chronic bronchitis or bronchiectasis was about 10% in this survey. However, in the case of respiratory infections associated with bacterial pneumonia, the frequencies were as follows; 24.8% (77 cases/311 cases) in 1981, 17.7% (44 cases/248 cases) in 1982, and 11.0% (39 cases/355 cases) in 1983. The frequency of isolation of S. pneumoniae decreased every year.(ABSTRACT TRUNCATED AT 400 WORDS)