Francisella tularensis is a pathogenic species of Gram-negative coccobacillus, an aerobic bacterium. It is nonspore-forming, nonmotile, and the causative agent of tularemia, the pneumonic form of which is often lethal without treatment.

1. COXIELLA BURNETII
SN.FAIZSUL RAGHUMAN
II B.SC. MICROBIOLOGY
PG & RESEARCH DEPARTMENT OF BIOTECHNOLOGY AND MICROBIOLOGY
NATIONAL COLLAGE (AUTONOMOUS)
TIRUCHIRAPPALLI, TAMIL NADU – 620001, INDIA
Inside the vacuoles of Vero cells : Coxiella burnetii

2. INTRODUCTION
 Coxiella burnetii is an obligate intracellular bacterial pathogen, and is the
causative agent of Q fever. The genus Coxiella is morphologically similar
to Rickettsia, but with a variety of genetic and physiological differences.
 It is highly resistant to environmental stresses such as high temperature,
osmotic pressure, and ultraviolet light
 Phylum: Probacteria
Class: Gamabacteria
Family: Coxiellaccea
Order: Legionellales
 Found in many species of animals

3. HISTORY
 In 1937 in Queensland Australia, Derrick described a febrile disease, which
he called ‘query fever’, in 20 of 800 workers of a meat factory in Brisbane. He
used the word ‘query’ because of the inexplicable nature of the disease.
 The pathogenic agent was isolated from the blood and urine of the patients in
Australia by Burnet and Freeman and was called Rickettsia (R. burnetii).
 At the same time, the pathogen was isolated from ticks in Montana, USA, by
Davis and Cox and called R. diaporica, and, later on, renamed to Coxiella
burnetii to honor both research groups.
 The World Health Organization (WHO), the United Nations, and the
Australian Group have classified C. burnetii as dangerous pathogenic agent.

4. MORPHOLOGY
 rod-shaped bacterium belonging to
the family Of coxiellaccae
 It is gram negative
 Pleomorphic
 It is obligate intracellular pathogne
 Size of rods:- 0.2 – 0.4 x 0.4 – 1.0 m
 It is stained with ricketssial stain

5. TRANSMISSION
 C. burnetii has a worldwide geographical distribution and can be transmitted
to humans as zoonotic pathogenic agent.
 According to the current state of knowledge, sheep, goats, and cattle are the
main source of infection for humans.
 In addition, cats, dogs, rabbits, wild animals, and ducks, as well as ticks and
the feces of ticks, have been identified as sources of infection.
 The pathogen causes acute and chronic infections and is transmitted by
contact or inhalation of dust aerosols and droplets, but can also be
transmitted by consumption of raw milk and raw milk products

6. MODE OF TRANSMISSION

7. SYMPTOMS
 Many people infected with Q fever never show symptoms. If you do have symptoms,
you'll probably notice them between three and 30 days after exposure to the
bacteria. Signs and symptoms may include:
 High fever, up to 105 F (41 C)
 Severe headache
 Fatigue
 Chills
 Cough
 Nausea
 Vomiting
 Diarrhea
 Sensitivity to light

8. RISK FACTORS
 Occupation: At-risk occupations include veterinary
medicine, meat processing, livestock farming and animal
research.
 Risk factors for chronic Q fever
 The risk of eventually developing the more deadly form of Q
fever is increased in people who have:
Heart valve disease
Blood vessel abnormalities
Weakened immune systems
Impaired kidney function

9. COMPLICATIONS
 A Q fever recurrence can affect your heart, liver, lungs and brain,
giving rise to serious complications, such as:
 Endocarditis: An inflammation of the membrane inside your heart,
endocarditis can severely damage your heart valves.
 Endocarditis is the most deadly of Q fever's complications.
 Lung issues. Some people who have Q fever develop pneumonia.
This can lead to acute respiratory distress, a medical emergency in
which you're not getting enough oxygen.
 Pregnancy problems. Chronic Q fever increases the risk of
miscarriage, low birth weight, premature birth and stillbirth.

10.  Liver damage. Some people who have Q fever develop
hepatitis, an inflammation of the liver that interferes with its
function.
 Meningitis. Q fever can cause meningitis, an inflammation of
the membrane surrounding your brain and spinal cord.
Granulomatous
hepatitis caused
by Q fever

11. GENOME
 At least five completely sequenced genomes of Coxiella
burnetii exist, which contain about 2.1 Mbp of DNA
each and encode around 2,100 open reading frames;
746 (or about 35%) of these genes have no known
function.
 In bacteria small regulatory RNAs are activated during
stress and virulence conditions.
 Coxiella burnetii small RNAs (CbSRs 1, 11, 12, and 14)
are encoded within intergenic region (IGR).
 CbSRs 2, 3, 4 and 9 are located antisense to
identified ORFs.
 The CbSRs are up-regulated during intracellular
growth in host cells

12. CULTURE
 CULTURE FROM Q- FEVER PATIENT BLOOD: Case study
 Q fever, a worldwide zoonosis caused by Coxiella burnetii, may present as either an acute or a chronic
disease.
 C. burnetii was isolated from 17% of untreated patients with acute Q fever and from 53% of untreated
patients with chronic Q fever.
 C. burnetii was not isolated from patients who were receiving antibiotics active against C. burnetii.
 For seven culture-positive patients with acute Q fever, serology was negative when C. burnetii was
isolated.
 One patient with acute Q fever had a positive blood culture 25 days after the discontinuation of
specific antibiotic therapy, and another had a positive blood culture after the resolution of symptoms.
 In one case of chronic Q fever, a positive blood culture resulted from noncompliance with treatment.
 The culture method described in this report is suitable for all laboratories with cell culture facilities.
 Our findings suggest that blood samples must be collected prior to the initiation of an antibiotic
regimen if C. burnetii is to be successfully isolated.
C. burnetti grows well inside chick
embryo

13. DIAGNOSIS AND TREATMENT
 The best treatment is a combination of doxycycline and hydroxychlorquine.
 Hydroxychloroquine has no activity against C. burnetii, but it alkalinizes the
phagolysosome, thereby rendering doxycylince bactericidal against C. burnetii.
 Hydroxychloroquine is administered in a dose of 400-600 mg per day to achieve a serum
level of 1 mg.
 Once infected, humans can have life-long immunity
 The symptoms of Q fever are similar to many other diseases, often making diagnosis
difficult.
 See your healthcare provider if you develop symptoms after spending time with or near
animals—particularly sheep, goats, and cattle—or in areas where these animals may have
been.
 Your healthcare provider may order blood tests to look for Q fever or for other diseases.
 Laboratory testing and reporting of results can take several weeks, so your healthcare
provider may start antibiotic treatment before results are available