Comparative studies of antimicrobial agents against causative organisms isolated from urinary tract infections (1984): II. Background of patients

Groups of bacteria were isolated from patients with infections of urinary tracts, and backgrounds of these isolates and patients have been studied in terms of the sexual distribution, and distributions of sexes versus age of the patients relationships between bacterial types and sexual and age distribution of the patients from whom the isolates were obtained correlation between ages of patients and types of infections, the association of certain types of bacteria with certain infections and the effect of antibacterial treatments on these types of bacteria, approximately 20% of simple infections of urinary tracts occurred in males and approximately 80% in females on average from 1981 to 1984. This ratio showed hardly any changes during this period. Likewise, male patients comprised approximately 60–70% of all the cases with complicated infections of urinary tracts regardless of indwelling or without indwelling of catheters. In terms of age, the ratio of urinary tract infections was almost universally observed, e.g., for patients in 40's: 10.0% in 1981, 11.0% in 1984, while in those in 70's: 25.5% and 21.2%, respectively. Consequently, background factors of the cases with infections of urinary tracts, such as sexes, age, or simple or complicated, remained almost stable, whereas bacteria involved showed considerable variations. In 1982 and 1983, the frequency of isolations of Enterococcus spp. was approximately 8% in both males and females. However, in 1984, the frequency of isolation of Enterococcus spp. was 22.5% in the males 17.9% in the females. The frequency of isolation of Enterococcus spp. increased in all age groups, but the frequency was not particularly high among the aged. A study on variations and isolation frequencies of bacteria before the administration of antibiotic agents revealed that isolation frequencies of Enterococcus spp. sharply increased in 1983, and this high frequency remained in 1984. The frequency of isolation of E. coli tended to decrease year after year. This finding represents that the frequency of isolations of E. coli from materials of cases with simple infections of urinary tracts has decreased, showing that pathogenic bacteria from simple infections of urinary tracts were becoming similar to that of the complicated infections of urinary tracts. These findings seem to be worth mentioning here. In cases receiving administrations of antibacterial and antibiotic agents for more than 8 days. Frequencies of isolation from cases without catheter retention and from those with catheter retention were similar. Also in these cases, the frequency of isolations of Enterococcus spp. was approximately 34–38%, followed by that of P. aeruginosa and Serratia spp. It was seemed also to be noteworthy that S. aureus was isolated at a frequency of 4.8% from those with retention of catheter. In 1982, the isolation of S. aureus was 4 strains (4/781), while it was 12 strains (12/724) and 17 strains (17/989) in 1983 and 1984, respectively, showing a steady increase. Furthermore, E. coli used to be approximately 90% of all the pathogenic bacteria in cases with simple urinary tract infections, but decreased to 50%, showing yearly decrease, and, in its stead, pathogenic bacteria found in complicated infections of urinary tracts increased, and urinary tract infections are becoming more complicated.