Coxiella burnetti

• Coxiella burnetii is a zoonotic disease that is primarily transmitted through occupational exposure to animals such as vets, farmers, slaughterhouse workers, and laboratory workers.
• Coxiella burnetii is categorized as a bioterrorism agent by the CDC due to its ability to cause disability, fever outbreaks, and epidemics of abortion in ruminants.
• Coxiella burnetii is an intracellular bacteria that can survive in the environment for years using a pseudo-spore-like life form known as the small cell variant (SCV).
• The life cycle of Coxiella burnetii includes a hardy form that is inactive when it is outside of the host cell or when conditions are not suitable, and an infectious or transmissible form known as the large cell variant (LCV).
• Coxiella burnetii has a wide host range and can infect all vertebrates and ticks, with cattle, sheep, and goats being the primary reservoirs.
• Coxiella burnetii has been isolated from approximately 40 species of ticks.
• Coxiella burnetii is a zoonotic disease that can infect humans.
• Diagnosis and management of Q fever is important, as it can lead to serious health complications.
• The environment should be cleaned with quaternary ammonium-detergent compound or household bleach to decontaminate surfaces from spore-like form of Coxiella burnetii.
• An N95 respiratory protection mask should be worn during performing Q fever positive/suspected autopsies and/or assisting parturition.
• Chloramphenicol is an alternative treatment for Coxiella burnetii.
• Personal protective equipment (PPE) should be worn during isolation and manipulations of Coxiella burnetii.
• Fluoroquinolones are an alternative treatment for Coxiella burnetii.
• Erythromycin is an alternative treatment for Coxiella burnetii.
• A whole-cell killed vaccine for Coxiella burnetii is licensed in Australia and Europe and is used in cattle to lower the risk of spreading infection and in goats to reduce abortions as well as reduce spreading the infection.
• Tick control is a strategy to protect against Coxiella burnetii infection.
• Trimethoprim-sulfamethoxazole is the safest treatment for Coxiella burnetii.
• Pilus is a Type IV Secretion System for adhesion & invasion.
• Coxiella burnetii has the ability to form different cell variants and maintain an obligate intracellular life.
• In the avirulent phase II (attenuated) of Coxiella burnetii, LPS has lost its O-antigen (rough surface).
• Coxiella burnetii enters cells in its non-replicative SCV form.
• Lipopolysaccharide (LPS) protects Coxiella for its optimal growth in phagocytes, non-phagocytic cells and in cell-free culture media.
• The LCV form of Coxiella burnetii is a replicative intracellular life form and is virulent.
• This ability allows Coxiella burnetii to develop and replicate inside the vacuole and protects it from damage by the phagolysosomes of the host cell.
• Coxiella burnetii has the ability to form vacuole acidification by colliding with cell lysozyme, which results in a pH decline from 5.4 to 4.5.
• The Type 4 secretion system of Coxiella burnetii injects many proteins into phagocytes and endothelial cells.
• At 6 days post-infection, a mixed population of LCVs and SCVs are observed in mature CCVs (stationary phase).
• The SCV form of Coxiella burnetii is a dormant extracellular life form.
• Coxiella burnetii is an intracellular bacterium that can survive inside microbicidal cells like monocytes and macrophages by hijacking several functions of the immune system.
• Exponential bacterial replication occurs over the next 4 days post-infection.
• The non-replicative SCV changes to the replicative LCV form within the first 2 days post-infection (lag phase).
• Among several virulence factors, the lipopolysaccharide (LPS) of Coxiella burnetii is one of the major factors involved in this immune hijacking because of its atypical composition and structure.
• Coxiella burnetii resides in a Coxiella-containing vacuole (CCV).
• Pilus is used for attachment and promoting Coxiella intracellular survival & replication.
• Other antimicrobials are used for treating acute Q fever.
• Doxycycline 200 mg daily for 14 days is the most effective drug for acute Q fever.
• Coxiella burnetii stands as the sole example of an obligate intracellular bacterial pathogen for which a specific axenic culture medium has been developed.
• Nutrient final concentration for the development of Coxiella burnetii in axenic media is Neopeptone 0.1 mg/ml, Fetal bovine serum (FBS) or methyl- β - cyclodextrin 1% , RPMI 1640 1/8x, Citrate 29 mM, Casamino acids 2.5 mg/ml, L-cysteine 1.5 mM.
• Oxytetracycline (20 mg per kg body weight) in the last trimester pregnant animals is used for treating acute Q fever.
• The molecular pathogenesis of Coxiella burnetii involves the use of EEA1 and Rab5.