Urinary tract infections

World Journal of Microbiology and Biotechnology -     

Urinary tract infections in adults

Urinary tract infection (UTI) is an exceedingly common problem prompting seven million office visits and one million hospitalizations in the United States each year. Advances in the understanding of both host and bacterial factors involved in UTI have led to many improvements in therapy. While there have also been advances in the realm of antimicrobials, there have been numerous problems with multiple drug resistant organisms. Providing economical care while minimizing drug resistance requires appropriate diagnosis, evaluation, and treatment of urinary tract infections.     

Urinary tract morphometry. An overview

An overview is presented of the application of morphometry to conditions in the urinary tract, with the work of a number of researchers briefly summarized. The data discussed show that morphometric techniques are already being successfully applied in the differential diagnosis and grading of some diseases of the prostate, urinary bladder and kidney. In the prostate, nonneoplastic changes can be differentiated from neoplasms and prostatic carcinomas can be more precisely graded. Both cytologic and histologic preparations of bladder carcinomas can be graded by morphometric techniques. Morphometry has found another application in assisting in the distinction between normal kidneys and those with "minimal-change" disease. The specific criteria pertaining to the use of morphometric methods in each of these situations are also discussed.     

Urinary tract infections; problems in medical management

The lesion principally responsible for chronic, or recurrent, urinary tract infection is a focus in the interstitial tissue of the kidney. Most cursory antimicrobial therapy suppresses the manifestations of lower urinary tract involvement but does not eradicate the renal focus. In order to cure rather than merely suppress the infection, it is imperative that, as early as possible, steps be taken to isolate and identify the etiologic microorganism and to determine its sensitivity to antimicrobial agents. Based on this information sufficient amounts of drug should be given for an adequate period (probably at least two weeks) to eradicate the infection within the renal tissue. Such a program would tend to reduce the number of cases in which irreversible renal failure develops from chronic pyelonephritis.     

Urinary tract infections due to Staphylococcus saprophyticus biotype 3.

Staphylococcus saprophyticus biotype 3 (Micrococcus subgroup 3 or M3) has usually been shown to be the second commonset cause of urinary tract infections in European women who are not in hospital. It generally causes pyuria and symptoms as severe as those caused by Escherichia coli. Unlike S. epidermidis it is seldom found as a contaminant in midstream urine specimens, and almost exclusively infects women in their reproductive years. However, S. saprophyticus is seldom differentiated from S. epidermidis in Canadian clinical laboratories. Urinary isolates of S. saprophyticus were presumptively differentiated from other coagulase-negative Micrococcaceae by their resistance to novobiocin as demonstrated by a simple disc susceptibility test that misidentified the infecting organism in only 3.4% of specimens. These novobiocin-resistant, coagulase-negative organisms caused similar proportions of the urinary tract infections in young women in York, England and Vancouver -- 6.6% and 6.9% respectively. In York these organisms were associated with significantly greater pyuria than novobiocin-sensitive organisms or bile-tolerant streptococci but not S. aureus or Enterobacteriaceae. In both communities novobiocin-sensitive, coagulase-negative Micrococcaceae were appreciably more resistant to penicillin than novobiocin-resistant organisms. Thus, differentiating S. saprophyticus from novobiocin-sensitive, coagulase-negative organisms provides information that is clinically useful, particularly for primary care practitioners working in the community or in outpatient clinics.