Coliform Infection of the Urinary Tract

The differentiation of Enterobacteriaceae infecting the urinary tract: A study in male paraplegics

Methods adopted in a routine bacteriology laboratory for the rapid identification of Enterobacteriaceae isolated from urine are described. The incidence of various bacteria causing infection in paraplegics after catheterization of the bladder is recorded, Klebsiella accounting for the majority of infections caused by lactose fermenters and Providence for the majority of ;paracolon' infections. The importance of these bacteria in cross-infection is discussed.

Interpretation of multiple isolate urine cultures in adult male patients

A retrospective analytical study examined the records of 220 adult males (mean age 64.9 years) to determine the relative probability that multiple urine culture isolates (MUI) represent urinary tract infection (UTI) versus contamination or colonization. Nonculture laboratory data were used to determine the likelihood of UTI. Patients were classified into three categories: group 1 (those with single isolate cultures; n = 110), group 2 (those with MUI and either symptomatic UTI or an underlying pathologic condition; n = 71) and group 3 (those with MUI and either surgically altered urinary passages or absence of UTI symptoms; n = 39). Nonculture laboratory data suggested UTI in 48.2% of patients in group 1, 46.5% in group 2, and 23.1% in group 3. Patients in groups 1 or 2 with cultures yielding isolate counts of 10(5) colony forming units/mL were 6.2 times more likely to be classified as having a UTI (by nonculture laboratory data) compared with patients having only one or more of these two criteria. This study proposes a more objective approach to interpretation of MUI cultures using the results of nonculture laboratory data, clinical profiles, and colony counts.

Frequency of E. coli K antigens in urinary-tract infections in children

The somatic (O) and casular (K) antigens of Escherichia coli from the urine of patients with acute pyelonephritis, acute cystitis, and asymptomatic bacteriuria, and in the faeces of healthy schoolchildren have been investigated. Typing antisera for sixteen capsular acidic polysaccharide K antigens were used, and five (numbers 1, 2, 3, 12, and 13) accounted for 70% of isolates from patients with acute pyelonephritis. These five K antigens were found to a lesser extent in the three other study groups. Thus, only a few K polysaccharides are associated with virulent properties of E. coli for the upper urinary tract. This finding is similar to the association of only some capsular types of pneumococci, meningococci, and Haemophilus influenzae with invasiveness. The identification of virulence markers for E. coli associated with upper-urinary-tract disease may permit more successful control with reference to preventive immunisation.

Polymicrobic bacteriuria: significant association with bacteremia

Current clinical practice states that a urine culture yielding three or more isolates must be considered a contaminated specimen and discarded. The validity of this practice was tested by reviewing all patients at the West Haven Veterans Administration Hospital with positive blood cultures for 1 year to determine how many were associated with polymicrobic bacteriuria (two or more urine isolates each present at greater than 10(5) colonies/ml). During 1973 there were 18 patients who had bacteremia associated with a urinary tract infection in which the same organism with the identical antibiogram was found in both the blood and the urine of these 18 patients with monomicrobic bacteremia 11(61%) had polymicrobic bacteriuria, with a mean of an additional 1.75 urinary pathogens present in significant quantities. In these patients with polymicrobic bacteriuria, an indwelling bladder catheter was present for a mean period of 4.4 months before the episode of bacteremia. Only 5 of the 11 patients with polymicrobic bacteriuria had temporally associated urinary tract manipulation. Monomicrobic bacteriuria occurred in seven patients (39%). The mean indwelling bladder catheter time was 0.9 days, and urinary tract manipulation near the time of bacteremia occurred in all seven patients. Prospectively, nine other patients with polymicrobic bacteriuria were recultured by one of us to be certain that appropriate collection and transportation methods were used; the presence of polymicrobic bacteriuria was repeatedly demonstrated in 7(78%). This study illustrates the clinical importance of polymicrobic bacteriuria.