URINARY TRACT INFECTIONS - ESSENTIAL APPROACH

1.
Major
number
of
specimens
comes
in
Diagnostic
Bacteriology
to
be
Urine,
for
Bacteriological
Studies
and
establishing
urinary
tract
infections.
Urinary tract infection (UTI) is one of the most common disease, occurring from
the neonate up to geriatric age groups. Forty to 50% of adult women have a
history of at least one UTI. Urinary tract infection is a major cause of Gram-
negative sepsis in hospitalized patients and after renal transplantation.
Preserving Urine specimens after collection, to be a top priority if the delay is
unavoidable in processing the specimens. Laboratories should put efforts to do
Microscopic examination for Pus cells and epithelial cells; the counts are
reported as given per low-power field or high-power field. Results can be also
given per unit volume of urine. At the high magnification (×40) the presence of
1–10 micro-organisms/high-power field is indicative of bacteriuria. The
presence of ≥10 white blood cells/high-power field is indicative of pyuria.
On many occasions we take Kass et al criteria in diagnosis of urinary tract
infection, Traditionally the concept of significant bacteriuria for the diagnosis of
UTI was based on the notion that the quantitative bacterial count allowed
distinction between infection and contamination. The utility and consistency of
the criterion of ≥105 colony-forming units per milliliter (c.f.u. /ml) of clean-
catch urine for the diagnosis of UTI has been validated repeatedly. In children,
rapid and reliable diagnosis of UTI is mandatory and important to prevent renal
damage and other systemic infections. In the changing concept, UTI is defined as
bacterial count ≥104 c.f.u. /ml urine, accompanied by microscopical examination
of the urine to exclude vaginal contamination (because such contamination
frequently results in false-positive culture tests). Studies by Kunin et al. and
Arav-Boger et al. ASM suggested that low-count bacteriuria might be an early
phase of UTI. The majority of patients with bacterial counts between 102 and
104 c.f.u. /ml has microorganisms typical for UTI (E. coli, Staphylococcus
saprophytic us, and enteric Gram-negative bacteria). As the criteria is concerned
not possible to implement by Microbiologists unless a optimal clinical
information is provided. First, it is likely that symptomatic bacteriuria of
<105c.f.u. /ml reflects ongoing UTI, and therefore the microbiological criterion
should be reduced to >102 c.f.u./ml in symptomatic patients. Second, a low
number of bacteria in the urine may be the result of increased urine output due
to high fluid in take we should avoid collecting a specimen when the patient is
wakened and already taken sufficient fluids. Is ideal to take a specimen when the
patient awakened in the early morning. Third, low-count bacteriuria may be
produced by slow growth of some uropathogens such as S. saprophytic us. We
have to use a different discrimination when we are reporting specimens from
males where the chances of contamination are less and significance of low
counts are important for interpretation of low bacterial counts with
uropathogens may be clinically meaningful. For infections with S.
saprophyticus and Candida species, the lower cutoff level of ≥104 c.f.u./ml is
commonly accepted. Contamination is likely if only small numbers of bacteria or
several bacterial species grow in urinary culture; Diptheroids, Corynebacteria
species, Gardnerella, alpha-hemolytic streptococci, and other aerobes are
considered urethral and vaginal contaminants. Even With years of accumulated
experience in bacteriological Culturing and reporting urine specimens, Reporting
continues to be difficult if taken with good spirit. As we, all lack clinical support
in Majority of the institutions in the Developing countries we lack precision is

2. reporting. The reported variations between Microbiologists continue to limit and
bring in uniformity in reporting. However, our reporting will not improve unless
we follow up with clinical progress of the patient. Above all cautious with
specimens collected from Urinary Catheters cause for errors and misreporting.
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