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Veterinary bacteriology: information about important bacteria
Veterinary bacteriology

Species/Subspecies: Coxiella burnetii
Category: Zoonotic
Etymology: Genus name: named after Harold R. Cox, who first isolated the organism in U.S.A.
Species epithet: named after Frank MacFarlane Burnet, who first studied the characteristics of this bacterium.
Significance:The clinical significance of C. burnetii on ruminants in Sweden has not been established. However, one case with connection to reproduction problems in cattle has recently (2010) been described (see References).
Type Strain: ATCC VR 615.
Macromorphology (smell): Cannot be cultivated on cell free substrates (e.g. agar plates).
Micromorphology: Small nonmotile and pleomorphic rods (0.2-0.4 x 0.4-1.0 µm)
Gram +/Gram -:G-
Metabolism: Aerobic
Spec. Char.: C. burnetii is highly resistant to chemicals and high temperature. The bacterium can form an endospore-like body.
Special Media:
Vector: Flies (mechanical vectors)
HostsDiseaseClinical picture
HumansQ-feverWide clinical spectrum, can manifest as an acute influenza-like disease, abortion, fever, pneumonia, and hepatitis or as a chronic disease mainly endocarditis
RuminantsQ-feverMostly asymptomatic, cases of reproductive disorders and abortion have been observed
Virulence Factors: The bacterium possess a type IV secretion system named icm/dot (intracellular multiplication / defect in organelle trafficking genes) to inject effector proteins (so-called Ank proteins) into the host cell. These effectors increase the ability of to the bacteria to survive inside the host cell.
Genome Sequence:
Acc-noStrainSize (bp)Genome
NC_002971 RSA 493 1 995 281 1c + 1c 
Five strains have been sequenced and 0-1 plasmid has been found in these strains.

16S rRNA Seq.:
Acc-noStrainNumber of NTOperon
AE016828 RSA 493 1457 

Coxiella burnetii  
Only one species has been described within the genus Coxiella, which is related to to genus Legionella (although not that close).
Legislation: C. burnetii belongs to category B as a potential bioterrorism agent according to NIAID.
Comment:Strictly intracellular. Grows in phagolysosomes, which is formed when lysosomes fuse with phagosomes. Extremely infectious and zoonotic. A single aerosol associated organism may cause Q fever. Farmers, slaughterhouse workers, veterinarians and others may contract the disease.
Reference(s): No. 102, 103, 104

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