Differentiation of Coxiella burnetii isolates by analysis of restriction-endonuclease-digested DNA separated by SDS-PAGE

Abstract

Thirty-two isolates of Coxiella burnetii collected from various hosts ranging from arthropods to man were compared by restriction endonuclease (RE) digestion patterns of chromosomal DNA using SDS-PAGE. SDS-PAGE provided better DNA fragment separation than agarose gel electrophoresis and enabled the differentiation of these isolates into six distinct groups on the basis of DNA restriction fingerprints. Two groups of chronic disease isolates could be distinguished, each having unique RE digestion patterns of chromosomal DNA. Three similar but distinct RE digestion patterns were seen among the group of acute disease isolates. Three additional isolates included in this study exhibited a unique RE digestion pattern and also had a unique plasmid type, designated QpDG. DNA-DNA hybridization on selected isolates quantified the relatedness between several groups and supported the classification of these groups as distinct strains.

Coxiella burnetiiIsolates Cause Genogroup-Specific Virulence in Mouse and Guinea Pig Models of Acute Q Fever

“…They found that vaccines from NM and Priscilla afforded a higher degree of protection than S and Luga vaccines and that whole-cell vaccines were more effective than soluble vaccines (28). In the guinea pig challenge study presented here, killed whole-cell vaccines made from isolates differing in LPS banding pattern (16), plasmid type (44), and genomic group (20), specifically isolates from groups I and V, conferred heterologous protection against virulent high-dose challenge in accordance with previous studies (28). This suggests that although the manifestations of disease and genomic contents differ among various isolate groups, the antigenic properties of whole-cell vaccines are shared enough that crossprotection is possible.…”

“…Unique sequence differences between genomic groups are correlated with the clinical expression of Q fever (44). Biochemical markers have grouped C. burnetii isolates from chronic-disease patients separately from acute-disease/arthropod/domestic animal isolates, but whether these groupings predict virulence potential and acute/chronicdisease outcomes has not yet been fully resolved (20). Samuel et al were the first to separate these isolates and their resulting diseases based on plasmid patterns (44).…”

“…Hackstadt used variations in lipopolysaccharide (LPS) banding patterns to divide isolates of C. burnetii into three groups, and group distinction was noted in correlation with acute or chronic disease (16). Hendrix et al separated C. burnetii isolates into six genomic groups (20). Group I to III isolates have a QpH1 plasmid and have been isolated from ticks, acute human Q fever cases, cow's milk, and livestock abortions.…”

Is Q Fever an emerging or re-emerging zoonosis?

“…There are 21 copies of a unique IS110-related isotype, named IS1111, 5 IS30 and 3 ISAs1 family elements, and 3 degenerate transposase genes of unknown lineage [63]. Among the strains, four plasmid types designated QpH1, QpRS, QpDV and one plasmid without designation derived from a chinese C. burnetii isolate have been described [60,70,88,112,163,172]. Plasmidless C. burnetii strains carry large plasmid-homologous sequences integrated into the chromosome [181].…”

Differentiation of Coxiella burnetii by Sequence Analysis of the Gene (com1) Encoding a 27‐kDa Outer Membrane Protein

“…The differentiation of C. burnetii isolates is very important for the diagnosis and treatment of the various manifestations of Q fever and for epidemiological investigations. C. burnetii isolates have been differentiated by their plasmid types (11,15,21,24), lipopolysaccharide (LPS) profiles (2) and chromosomal DNA restriction endonuclease fragment patterns (3,6,20,22). These studies of phenotypic and biochemical characteristics suggested that isolates involved in chronic endocarditis differed genetically from those causing acute infections (3,6,15,21).…”