Campylobacter fetus utilizes paracrystalline surface (S-) layer proteins that confer complement resistance and that undergo antigenic variation to facilitate persistent mucosal colonization in ungulates. C. fetus possesses multiple homologues of sapA, each of which encode full-length S-layer proteins. Disruption of sapA by a gene targeting method (insertion of kanamycin (km) resistance) caused the loss of C. fetus cells bearing full-length S-layer proteins and their replacement by cells bearing a 50 kDa truncated protein that was not exported to the cell surface. After incubation of the mutants with serum, the survival rate was approximately 2 x 10(-2). Immunoblots of survivors showed that phenotypic reversion involving high-level production of full-length (98, 127 or 149 kDa) S-layer proteins had occurred. Revertants were serum resistant but caused approximately 10-fold less bacteraemia in orally challenged mice than did the wild-type strain. Southern hybridizations of the revertants showed rearrangement of sapA homologues and retention of the km marker. These results indicate that there exists high-frequency generation of C. fetus sapA antigenic variants, and that intracellular mechanisms acting at the level of DNA reciprocal recombination play key roles in this phenomenon.
This research output has an Altmetric Attention Score of 6. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 12 October 2004.
All research outputs
#6,682,255
of 30,878,141 outputs
Outputs from Molecular Microbiology
#1,705
of 7,403 outputs
Outputs of similar age
#20,777
of 103,885 outputs
Outputs of similar age from Molecular Microbiology
#246
of 1,307 outputs
Altmetric has tracked 30,878,141 research outputs across all sources so far. This one has received more attention than most of these and is in the 74th percentile.
So far Altmetric has tracked 7,403 research outputs from this source. They typically receive a little more attention than average, with a mean Attention Score of 5.2. This one has gotten more attention than average, scoring higher than 64% of its peers.
Older research outputs will score higher simply because they've had more time to accumulate mentions. To account for age we can compare this Altmetric Attention Score to the 103,885 tracked outputs that were published within six weeks on either side of this one in any source. This one has gotten more attention than average, scoring higher than 68% of its contemporaries.
We're also able to compare this research output to 1,307 others from the same source and published within six weeks on either side of this one. This one has gotten more attention than average, scoring higher than 56% of its contemporaries.
