Riederer K, Barczak J, Ramanathan J, Khatib R; American Society for Microbiology. General Meeting.
Abstr Gen Meet Am Soc Microbiol. 1999 May 30-Jun 3; 99: 320 (abstract no. F-120).
St. John Hospital, Detroit, MI.
Electrophoretic karyotyping (EK) is a useful tool for typing C. Albicans (CA). PCR based methods such as Random Amplified Polymorphic DNA (RAPD) are nowadays frequently used because of a quicker turn around time. The optimal typing method remains undetermined due to the lack of a gold standard. We elected to perform a direct comparison of these two methods to determine the ability to distinguish genetically diverse CA strains from different patients as well as potentially genetically related intra-patient strains. 162 colonies of CA, consisting of 9 colonies from each of the 18 inpatient stools cultured on Inhibitory Mold Agar, were included in the study. EK was done using CHEF Genomic EDNA Plug Kits and the CHEF-DRIII (BioRad). For RAPD, DNA was extracted using the QIAamp Tissue Kit (WIAGEN) then analyzed with Ready-To- Go RAPD Analysis Beads utilizing 76 primers (Amersham Pharmacia Biotech). Inter-patient analysis of the predominant strain showed that EK disclosed 9 karyotypes whereas RAPD detected 17 composites. Intra-patient strain differences were detected by EK and RAPD in 25/162 and 22/162 instances respectively, and by both methods in 11/162 instances. Concordant results were noted consistently when patient colonies were genetically identical and when differ- ences in band patterns were major (> or = 3 bands). Discordant results were found only in subtle strain differences (< or = 2 bands). These results show that RAPD, utilizing the 6 primers, yielded more unique patterns among genetically unrelated strains when compared to EK (16 vs 5 of the 18 patients, p<0.001) and that both methods were comparable in detecting intra-patient genetic differences. EK remains a suitable method for typing CA. However, RAPD has the advantage of producing a larger array of band patterns and the ability to form composite types by using multiple primers, resulting in greater genetic discrimina- tion between patient samples as well as a faster turn around time.
Publication Types:
Keywords:
- Candida albicans
- DNA Fingerprinting
- Genetic Screening
- Humans
- Karyotyping
- Polymerase Chain Reaction
- Random Amplified Polymorphic DNA Technique
- genetics
- methods
Other ID:
UI: 102195713
From Meeting Abstracts