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Seasonal variations in detecting Borrelia burgdorferi sensu lato in rodents from north eastern Austria.
Austria is well known as an endemic area of Lyme borreliosis. To assess the annual variation of rodent populations that may host agents of Lyme borreliosis we collected rodents in northeastern Austria. Life traps were set out every six weeks during a year consecutively in one each of the three different zones (Hohenau, Ernstbrunn, Vienna Woods) that cover the main habitat characteristics of small mammals in northeastern Austria. Rodents were collected and identified. Samples of heart, urine bladder and brain were removed under aseptic conditions for cultivation of borrelia. Samples of heart muscle were additionally used for molecular detection of borrelia by Real-Time polymerase chain reaction. PCR was performed with borrelia universal primers and with species-specific primers. 938 mice were caught, most frequently Apodemus flavicollis (44%), followed by Clethrionomys glareolus (35%), Microtus arvalis (9%), A. sylvaticus (7%) and Mus musculus (6%). Significant differences were seen in the total number of catch per area (Hohenau, Ernstbrunn, Vienna Woods equal 10:9:2) and in the distribution of the various rodent species in the respective areas. Borrelia strains were grown from only 65 (7%) animals, and more frequently isolated from bladder wall than from heart muscle, and only once from brain. Heart specimens of 223 animals were positive by borrelia PCR (24%), most frequently of the rodent species A. flavicollis (43%) and C. glareolus (38%).
Isn't there a discrepancy ? only 7% were grown, but 24% were found in the heart?
Posts: 109 | Registered: Aug 2005
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lymie tony z
Frequent Contributor (1K+ posts)
Member # 5130
posted
This is basically telling you that Bb prefers the bladder(kidney system) and the heart(cardio vascular) system from the specimens they found.
I may well be different in humans...
zman
-------------------- I am not a doctor...opinions expressed are from personal experiences only and should never be viewed as coming from a healthcare provider. zman Posts: 2527 | From safety harbor florida(origin Cleve., Ohio | Registered: Jan 2004
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Borrelia strains were grown from only 65 (7%) animals, and more frequently isolated from bladder wall than from heart muscle, and only once from brain. Heart specimens of 223 animals were positive by borrelia PCR (24%), most frequently of the rodent species A. flavicollis (43%) and C. glareolus (38%).
the take home message I got is that PCR is the way to detect Borellia, as opposed to cultuing. PCR (Polymerase chain reaction) detects the presence of Borellia's DNA (genetic material), while culturing is an attempt to grow the actual Borellias.
The sensitivity of PCR can be, technically, as low as one DNA molecule per test tube. To give an idea about sensitivity, they can PCR amplify DNA from bones of Neanderthal fossils.
Posts: 59 | From CA | Registered: Dec 2006
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david1097
Frequent Contributor (1K+ posts)
Member # 3662
posted
I agree with Nimzo.. culture and PCR are diferent detection techniques. PCR is often questioned in terms of reliability as even the most microscopic level of contamination can result in a "positive" result. Contamination with culture is possible but is not as sensitive but is also not as suseptable to contamination.
This being said, Culture is not the easiest thing to do and its yeild is somewhat poor, partiuclalry if you do not start with a high enough number of organisms. Even worse, there are various reports floating around of differences in the viability of culture for different strains of the organism. Still if it grows in culture it is pretty hard to be refuted by anyone so they were right to include this in their protocol.
My question to the authors would be why did they only atempt PCR on the heart tissue? It would have been interesting to see what the comparison between PCR and culture would have been, or perhaps that is for their next paper in the series....
In this bussiness (I am assuming university life), it is publish papers or die, the more milage (Ie publications) you can get out of one project the better.
[ 26. December 2006, 12:27 AM: Message edited by: david1097 ]
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