'Granulomatous amoebic encephalitis (GAE) is a usually fatal disease caused by the free-living amoebae Balamuthia mandrillaris and Acanthamoeba spp. The intent of this study was to determine if the polymerase chain reaction (PCR) could be used retrospectively to detect amoeba mitochondrial 16S rRNA gene DNA in confirmed archival tissue sections from GAE cases stored in our laboratories for 1 to 34 years,' scientists in the United States report (see also DNA Research).
'The DNA was extracted from deparaffinized sections, and appropriate primer sets for each of the two amoebae were used for amoeba DNA detection. Indirect immunofluorescent (IIF) staining of tissue sections was used as the standard for identification of amoebae against which the PCR results were compared. Sixty slides from a total of 56 cases were processed by PCR for amoeba 16S DNA. In 28 slides (47%), there was agreement between the IIF and PCR results. In 41 of the slides (52%), no amoeba DNA was detected after PCR. In one slide (1%), the PCR and IIF results did not agree. While PCR supported IIF findings in about half of the slides, there are significant limitations in amoeba DNA identifications in formalin-fixed brain tissues,' wrote S. Yagi and colleagues.
The researchers concluded: 'Degradation of amoeba DNA caused by formalin fixation was probably a factor in limiting valid results.'
Yagi and colleagues published their study in Parasitology Research (Demonstration of Balamuthia and Acanthamoeba mitochondrial DNA in sectioned archival brain and other tissues by the polymerase chain reaction. Parasitology Research, 2008;102(3):491-497).
For more information, contact F.L. Schuster, California Dept. of Public Health, Viral & Rickettsial Diseases Laboratory, 850 Marina Bay Pkwy, Richmond, CA 94804, USA.
Publisher contact information for the journal Parasitology Research is: Springer, 233 Spring Street, New York, NY 10013, USA.
Keywords: United States, Richmond, Central Nervous System Disease, DNA Detection, DNA Research, Deoxyribonucleic Acid, Diagnosis, Diagnostics, Encephalitis, Enzyme Research, Parasitology, Polymerase, Proteomics.
This article was prepared by Health & Medicine Week editors from staff and other reports. Copyright 2008, Health & Medicine Week via NewsRx.com.
