Nosocomial infection of urinary tract: changing pathogens, changing patterns.

Risk factors for the development of nosocomial infection, i.e., diabetes, immunosuppressive therapy, etc., are reviewed. In most cases, the patient's own fecal flora is the primary reservoir for potentially infecting pathogens, such as Escherichia coli, Pseudomonas, Klebsiella, Enterobacter, Proteus, Serratia, and enterococcus. Hospitalized patients are likely to have antibiotic-related changes in fecal flora. Abnormal urethral flora in men, as well as high rates of vaginal and urethral colonization in women, increase the risk of infection associated with urinary catheterization or instrumentation. The costs of nosocomial urinary tract infections, both in economic and health terms, are briefly discussed. After a review of the causes and consequences of bacterial resistance to antibiotics, the issue of perioperative prophylaxis is addressed. It is concluded that the most important aspects of effective perioperative prophylaxis are achievement of suitable drug-tissue levels at the time of surgery and a limited period of postoperative antibiotic administration. The problem and probable causes of cross contamination are described. Recommendations for reducing nosocomial infections are offered.