Evaluation of preservative fluid for urine collected for culture.
Author(s): Lauer BA, Reller LB, Mirrett S
Publication: J Clin Microbiol, 1979, Vol. 10, Page 42-5
PubMed ID: 500793 PubMed Review Paper? No
Purpose of Paper
This paper investigated the effects of storing urine at room temperature in BD tubes rather than refrigerated in the collection cup on urine culture results in 1000 specimens from pregnant women and patients suspected to have a urinary tract infection (UTI).
Conclusion of Paper
Of the 88 specimens that were positive in the initial culture, 82 were positive when cultured after 18-24 h of storage in the refrigerated collection container and in BD tubes at room temperature and only one initially negative specimen cultured positive after 24 h of refrigerated storage. Most of the discrepant cases were due to growth of gram positive urogenital tract contaminants in addition to the pathogen.
Studies
-
Study Purpose
This study investigated the effects of storing urine in BD tubes at room temperature rather than refrigerating in the collection cup on urine culture results in 1000 specimens from pregnant women and patients suspected to have a UTI. Urine was collected by the clean-catch midstream method (785 specimens), single-catheterization (82 specimens), indwelling catheter (77 specimens), or by an unspecified method (56 specimens). Specimens were refrigerated (4-10˚C) until initial culture and then a portion of each was poured into a BD urine tube for room temperature storage and the remainder was returned to the refrigerator. Specimens were cultured again after 18-24 h of storage. Positive cultures were defined as having >105 cfu/mL of a pure pathogen. Mixed cultures were considered to be negative.
Summary of Findings:
Of the 88 specimens that were positive in the initial culture, 82 were positive when cultured after 18-24 h of storage in the refrigerated collection container and in BD tubes at room temperature. Most of the discrepant cases were due to growth of gram positive urogenital tract contaminants in addition to the pathogen. Of the 912 cultures that were negative, one was considered a false positive after 24 h of refrigerated storage. Importantly, bacterial counts in 98% of specimens refrigerated or stored in BD tubes were within 10-fold of initial levels.
Biospecimens
Preservative Types
- Other Preservative
- None (Fresh)
Diagnoses:
- Pregnant
- Not specified
- Other diagnoses
Platform:
Analyte Technology Platform Cell count/volume Microbiological assay Pre-analytical Factors:
Classification Pre-analytical Factor Value(s) Biospecimen Preservation Type of fixation/preservation None (fresh)
Boric acid
Glycerol
Sodium formate
Refrigeration
Storage Storage duration 0 h
18-24 h
Storage Storage temperature Room temperature
4-10˚C
Storage Type of storage container BD tube
Collection container