Document Detail


Wide dispersal and possible multiple origins of low-copy-number plasmids in rickettsia species associated with blood-feeding arthropods.
MedLine Citation:
PMID:  20097813     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Plasmids are mobile genetic elements of bacteria that can impart important adaptive traits, such as increased virulence or antibiotic resistance. We report the existence of plasmids in Rickettsia (Rickettsiales; Rickettsiaceae) species, including Rickettsia akari, "Candidatus Rickettsia amblyommii," R. bellii, R. rhipicephali, and REIS, the rickettsial endosymbiont of Ixodes scapularis. All of the rickettsiae were isolated from humans or North and South American ticks. R. parkeri isolates from both continents did not possess plasmids. We have now demonstrated plasmids in nearly all Rickettsia species that we have surveyed from three continents, which represent three of the four major proposed phylogenetic groups associated with blood-feeding arthropods. Gel-based evidence consistent with the existence of multiple plasmids in some species was confirmed by cloning plasmids with very different sequences from each of two "Ca. Rickettsia amblyommii" isolates. Phylogenetic analysis of rickettsial ParA plasmid partitioning proteins indicated multiple parA gene origins and plasmid incompatibility groups, consistent with possible multiple plasmid origins. Phylogenetic analysis of potentially host-adaptive rickettsial small heat shock proteins showed that hsp2 genes were plasmid specific and that hsp1 genes, found only on plasmids of "Ca. Rickettsia amblyommii," R. felis, R. monacensis, and R. peacockii, were probably acquired independently of the hsp2 genes. Plasmid copy numbers in seven Rickettsia species ranged from 2.4 to 9.2 per chromosomal equivalent, as determined by real-time quantitative PCR. Plasmids may be of significance in rickettsial evolution and epidemiology by conferring genetic plasticity and host-adaptive traits via horizontal gene transfer that counteracts the reductive genome evolution typical of obligate intracellular bacteria.
Authors:
Gerald D Baldridge; Nicole Y Burkhardt; Marcelo B Labruna; Richard C Pacheco; Christopher D Paddock; Philip C Williamson; Peggy M Billingsley; Roderick F Felsheim; Timothy J Kurtti; Ulrike G Munderloh
Related Documents :
3294423 - Unexpected divergence and molecular coevolution in yeast plasmids.
7961433 - Plasmids bearing hfq and the hns-like gene stpa complement hns mutants in modulating ar...
9733063 - The follicle-stimulating hormone beta-subunit gene of the common brushtail possum (tric...
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural     Date:  2010-01-22
Journal Detail:
Title:  Applied and environmental microbiology     Volume:  76     ISSN:  1098-5336     ISO Abbreviation:  Appl. Environ. Microbiol.     Publication Date:  2010 Mar 
Date Detail:
Created Date:  2010-03-05     Completed Date:  2010-05-18     Revised Date:  2010-09-02    
Medline Journal Info:
Nlm Unique ID:  7605801     Medline TA:  Appl Environ Microbiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1718-31     Citation Subset:  IM    
Affiliation:
Department of Entomology, University of Minnesota, 1980 Folwell Ave., St. Paul, MN 55108, USA. baldr001@umn.edu
Data Bank Information
Bank Name/Acc. No.:
GENBANK/GU180086;  GU180087;  GU180088;  GU322807;  GU322808
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Animals
Bacterial Proteins / genetics
Cluster Analysis
DNA, Bacterial / chemistry,  genetics*
Heat-Shock Proteins / genetics
Humans
Molecular Sequence Data
Phylogeny
Plasmids / genetics*
Rickettsia / genetics*,  isolation & purification
Rickettsia Infections / microbiology*
Sequence Analysis, DNA
Sequence Homology
Ticks / microbiology*
Grant Support
ID/Acronym/Agency:
R01 AI49424/AI/NIAID NIH HHS
Chemical
Reg. No./Substance:
0/Bacterial Proteins; 0/DNA, Bacterial; 0/Heat-Shock Proteins; 0/chromosome partition proteins, bacterial

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Membrane topology of the outer membrane protein AlgE which is required for alginate production in Ps...
Next Document:  Discrimination of Bacillus cereus T-strain Spores Grown on Different Media using Fatty Acid Methyl E...