Multiple-Strain Infections of B. afzelii

Topics with information and discussion about published studies related to Lyme disease and other tick-borne diseases.
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RitaA
Posts: 2768
Joined: Thu 1 Jul 2010 8:33

Multiple-Strain Infections of B. afzelii

Post by RitaA » Sat 30 Mar 2013 5:50

http://www.ncbi.nlm.nih.gov/pubmed/23535618
Am Nat. 2013 Apr;181(4):545-54. doi: 10.1086/669905. Epub 2013 Mar 8.

Multiple-Strain Infections of Borrelia afzelii: A Role for Within-Host Interactions in the Maintenance of Antigenic Diversity?

Andersson M, Scherman K, Råberg L.

Source

Molecular Ecology and Evolution Lab, Department of Biology, Lund University, Sölvegatan 37, 223 62 Lund, Sweden.

Abstract

Abstract Genetically diverse infections are common but little is known about what effects coinfecting strains have on each other in natural host-parasite systems. To explore the nature and consequences of interactions in the wild, we studied the tick-transmitted bacterium Borrelia afzelii in one of its main reservoir hosts, the bank vole Myodes glareolus. We measured overall infection intensity with quantitative polymerase chain reaction (PCR) and resolved the composition of multiple infections using strain-specific PCR assays targeting the ospC gene (which encodes an immunodominant surface protein). We found seven different strains, as defined by ospC genotype. There was little evidence for interactions affecting infection intensities, but strains were highly aggregated (i.e., there were more multiple infections than expected from random co-occurrence). Moreover, there was a positive correlation between the difference at the amino acid level between two OspC types and their degree of association. Overall, the observed patterns suggest that facilitation is more important than competition in this system and that more diverse infections have an advantage in establishing and/or maintaining infection. We propose that this advantage is one of the factors that favors antigenic diversity.

PMID: 23535618 [PubMed - in process]

RitaA
Posts: 2768
Joined: Thu 1 Jul 2010 8:33

Re: Multiple-Strain Infections of B. afzelii

Post by RitaA » Sat 30 Mar 2013 6:00

http://www.amnat.org/an/newpapers/AprAndersson.html
“Multiple-strain infections of Borrelia afzelii – a role for within-host interactions in the maintenance of antigenic diversity?”

Posted on February 20, 2013 by Owen

Martin Andersson, Kristin Scherman and Lars Råberg

[snip]

Their results suggest instead that different strains in a vole had a positive effect on each other. Moreover, genetically diverse strains were more often found together, and the authors therefore suggest that positive interactions between strains might help maintain strain diversity within Borrelia. These results have implications for vaccine design and the understanding of Lyme disease epidemiology.

A free article preview of the article is available here, and the full article can be purchased for $19 USD:

http://www.jstor.org/discover/10.1086/6 ... 2061700637

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