[Susceptibility of bacteria isolated from the patients with lower respiratory tract infections to antibiotics (1985)].

It has been more than 4 years since third-generation cephems were introduced into clinical practice. The range of our drug selection definitely tends to increase, because we today have more antibiotics with wider spectrum, antibiotics with strong activities only against Gram-negative strains, such as monobactams, and those with tremendously high activities such as quinolone carboxylic acid derivatives, in comparison to those we had in the past. Among isolates obtained mainly from sputa of 567 patients with lower respiratory tract infections at 16 institutions throughout Japan between September of 1985 and March of 1986, 741 strains were determined to be causative organisms. MIC's of various antimicrobial agents were determined against 67 strains of Staphylococcus aureus, 100 strains of Streptococcus pneumoniae, 199 strains of Haemophilus influenzae, 92 strains of non-mucoid Pseudomonas aeruginosa, 40 strains of mucoid P. aeruginosa, 29 strains of Klebsiella pneumoniae, 10 strains of Escherichia coli and for 42 strains of Branhamella catarrhalis out of the above 741 strains to determine their drug sensitivities. As for types of lower respiratory tract infections found in 1981--1983, 57.9--64.5% of the infections were chronic respiratory infections; i.e., chronic bronchitis, chronic bronchiolitis and bronchiectasis. These chronic infections, including diffuse panbronchiolitis (DPB), were found in 63.1% of lower respiratory tract infections in 1984. Their incidence dropped to 54.0% in 1985, even though DPB was included; i.e., the incidence of chronic bronchiolitis was 5.5%, that of DPB was 7.1%, and that of bronchial asthma associated with lower respiratory tract infections in 1985 was 8.8% which was twice as much as that found in 1981--1984. Although bacterial pneumonia was found in 24.8% of all the cases in 1981, its incidence was reduced to 11.0% in 1983, 15.1% in 1984, and 17.6% in 1985. This reduction seemed to have resulted from gradual decreases in the occurrence of bacterial pneumonia among the young population. As with usual years, a high incidence rate in a total lower respiratory tract infections in 1985 was found among older patients; namely, 73.5% was at the age of 50 or over (417/567). Next, we determined relationships between clinical isolates and isolates from respiratory infections, including chronic bronchitis, chronic bronchiolitis, bronchiectasis and DPB. H. influenzae was isolated from 50.5% of patients with these infections in 1981; however, the detection rate decreased by about 20% to 29.7% in 1985. P. aeruginosa was consistently isolated, between 24.1% and 30.4% every year.(ABSTRACT TRUNCATED AT 400 WORDS)