Detecting bacterial pathogens in urine is an important criterion for diagnosing urinary tract infections (UTIs). In a study conducted at the Department of Clinical Laboratory at Renmin Hospital of Wuhan University in China,1 using fluorescence in-situ hybridization (FISH) with rRNA-targeted, fluorescently labeled oligonucleotide probes idenitified bacterial pathogens present in urine samples within three to four hours. In this study, three probes specific for E. coli, E. faecalis and Staphylococcus aureus were designed based on the conserved 16S RNA sequences, whereas probe Eub338 broadly recognizes all bacteria.
Collecting a total of 1,000 urine samples, 325 of the samples tested positive for a UTI via traditional culturing techniques; additionally, all 325 of the samples tested positive with the Eub338 probe in FISH analysis. FISH analyses with species-specific probes were performed in parallel to the test the ability to differentiate among several pathogenic bacteria. The samples for these experiments included 76 E. coli-infected samples, 32 E. faecalis-infected samples and nine S. aureus-infected samples.
Compared to conventional methods of bacterial identification, the FISH method produced positive results for >90% of the samples tested; therefore, FISH has the potential to become an extremely useful diagnostic tool for UTIs because it has a quick turnaround time and high accuracy.
1. Q. Wu et al. J Microbiol Methods., doi: 10.1016/j.mimet.2010.08.015 (2010)
Posted by Lee Mather
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