title: Microevolution of the chromosomal region of acute disease antigen A (adaA) in the query (Q) fever agent Coxiella burnetii.
abstract: The acute disease antigen A (adaA) gene is believed to be associated with Coxiella burnetii strains causing acute Q fever. The detailed analysis of the adaA genomic region of 23 human- and 86 animal-derived C. burnetii isolates presented in this study reveals a much more polymorphic appearance and distribution of the adaA gene, resulting in a classification of C. burnetii strains of better differentiation than previously anticipated. Three different genomic variants of the adaA gene were identified which could be detected in isolates from acute and chronic patients, rendering the association of adaA positive strains with acute Q fever disease disputable. In addition, all adaA positive strains in humans and animals showed the occurrence of the QpH1 plasmid. All adaA positive isolates of acute human patients except one showed a distinct SNP variation at position 431, also predominant in sheep strains, which correlates well with the observation that sheep are a major source of human infection. Furthermore, the phylogenetic analysis of the adaA gene revealed three deletion events and supported the hypothesis that strain Dugway 5J108-111 might be the ancestor of all known C. burnetii strains. Based on our findings, we could confirm the QpDV group and we were able to define a new genotypic cluster. The adaA gene polymorphisms shown here improve molecular typing of Q fever, and give new insights into microevolutionary adaption processes in C. burnetii.
authors.affiliation: Bundeswehr Institute of Microbiology, Munich, Germany. DimitriosFrangoulidis@Bundeswehr.org
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Frangoulidis
authors.forename: Wolf D
authors.initials: WD
authors.lastname: Splettstoesser
authors.forename: Olfert
authors.initials: O
authors.lastname: Landt
authors.forename: Jasmin
authors.initials: J
authors.lastname: Dehnhardt
authors.forename: Klaus
authors.initials: K
authors.lastname: Henning
authors.forename: Angela
authors.initials: A
authors.lastname: Hilbert
authors.forename: Tilman
authors.initials: T
authors.lastname: Bauer
authors.forename: Markus
authors.initials: M
authors.lastname: Antwerpen
authors.forename: Hermann
authors.initials: H
authors.lastname: Meyer
authors.forename: Mathias C
authors.initials: MC
authors.lastname: Walter
authors.forename: Johannes K-M
authors.initials: JK
authors.lastname: Knobloch
mesh_terms: D000942:Antigens, Bacterial / Q000235:genetics* / Q000502:physiology; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins / Q000235:genetics* / Q000502:physiology; D002876:Chromosomes, Bacterial / Q000648:ultrastructure*; D016997:Coxiella burnetii / Q000235:genetics* / Q000378:metabolism*; D017931:DNA Primers / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D019143:Evolution, Molecular; D017353:Gene Deletion; D005819:Genetic Markers; D005838:Genotype; D006801:Humans; D058889:Molecular Typing; D010802:Phylogeny; D011110:Polymorphism, Genetic; D016016:Proportional Hazards Models; D011778:Q Fever / Q000382:microbiology*; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D017931:DNA Primers; D004269:DNA, Bacterial; D005819:Genetic Markers; C582900:acute disease antigen A, Coxiella burnetii