[Microbiologic findings in nephrology].

Infections of the urinary tract belong to the most frequently encountered bacterial diseases of man. Up to 20% of urinary tract infections take a chronic course and thus give rise for complications. Culture and identification of microorganisms as well as susceptibility testing are an essential part of the diagnostic procedures and give a basis for specific treatment. Bacteriological reports have an increasing importance also for the physician in private practice, since therapy failures and complications can only be avoided if the resistance patterns of the causative organisms are known. Appropriate collection and transport of specimens are an important prerequisite for clinically relevant reports. In most cases properly collected mid-stream urine is sufficient for microbiology. Catheterization and other collection methods are less frequently applied. The urine sample should reach the laboratory as fast as possible and should be stored refrigerated until processing. As an alternative dip-slide cultures can also be used. Dip-slides, however, yield much less information than urine specimens. Bacterial counts of 10(5)/ml or greater are usually considered as significant bacteriuria. Under certain conditions lower counts can be clinically relevant. The most frequent causes of urinary tract infections are still Escherichia coli and other enterobacteriaceae. Hemodialysis patients and kidney transplant recipients are highly infection-prone. In hemodialysis infections of the vascular shunt are frequently seen. These infections are mainly caused by Staphylococcus aureus. About one third of all complications after kidney transplantation are related infectious conditions. Thus early detection and surveillance of infections to preserve the transplant function are a great concern for clinical microbiology.