Transcript Q-Fever (Coxiella burnetii)

By
R.Teja sri
Introduction
 Coxiella
burnetti is the causative agent of
‘Q-fever’
 Obligate
intracellular, gram negative
bacterium
 Distributed
 Found
globally
in many species of animals
Morphology:obligate intracellular pathogen .
 gram negative .
 Pleomorphic .
 size : rods:- 0.2 – 0.4 x 0.4 – 1.0 mc
spheres :- 0.3 – 0.4 mc
 filterable .
 better stained with GIMINEZ and other
rickettsiael stains .

C. burnetii
i
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Culture
 Grows
well in yolk sac of chick embryos
and in various cell cultures .
Ag structure
 shows phase variation .
phase – I ,II .
 phase – I :- autoagglutinable
more immunogenic
activity due to periodate sensitive trichloracetic
acid-soluble surface carbohydrate .
o Phase – II :- more suitable for CFT .
o both phase I ,II elicit good Ab response .

Resistance
Resistant to physical and chemical agents
 In pasteurization flash method is effective
 Can survive in dust and aerosols
 Inactivated by 2% formaldehyde
5% H2O2
1% Lysol .

Contd….

Resistant to heat, drying and disinfectants

Air samples test positive for 2+ weeks

Soil samples test positive for 150+ days

Spore formation
PATHOGENESIS
History
Q
stands for Query or Queensland
 Origin

of disease unknown
First reported cases were in
Queensland, Australia
 Differentiating
features :
1. Having smaller size
2. Resistance to heat and drying
3. Major route of transmission isinhalation/ingestion
Primary Reservoir
Goats
Cattle
Sheep
* All eukaryotes can be infected
Bacteria is excreted in:
Feces
Urine
Milk
of infected animals
Release Into Environment:
During birthing the organisms are shed in high
numbers in amniotic fluids and the placenta

109 bacteria per gram of placenta
Do not touch!
Transmission
 Most
common route is inhalation of
aerosols
 Contaminated dust, manure,
birthing products
 Tick bites (rare)
 Human to human also very rare
gsbs.utmb.edu
Contd…..
 Who’s
at risk?
 Farmers,
veterinarians, researchers,
abattoir (slaughterhouse) workers etc.
 People
who breed animals
 Immunocompromised
Acute or Chronic Q fever
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*Bacteria spread through blood
Symptoms
Acute Q fever
 Self-limiting, flu-like disease
 Fever, nausea, headaches, vomiting, chest/abdominal
pain
 Pneumonia & granulomatous hepatitis

 Chronic
Q fever (> 6 months)
 Endocarditis & meningoencephalitis
 Pre-existing disease
Host interaction
 Entry
via inhalation
 Alveolar macrophages encounter bacteria
 C. burnetii phagocytosed
Macrophage
C. burnetii
R Heinzen, NIAID
Host interaction
 Replication
 Low
within phagolysosme
pH needed for metabolism
 No
cellular damage unless lyses
occurs
 Can
invade deeper tissue and cause
complications
Phagocytosis
 Binding/entry
into macrophages via:
 Integrin Associated Protein (IAP)
 Leukocyte Response Integrin (LRI)
macrophage
bacteria
Binding & Entry
Phagocytosis
Phagocytic vesicle
Lysis of phagolysosome and
macrophage
Phago-lysosome
fusion: bacteria
survive and
multiplies
LAB DIAGNOSIS
Hard to diagnose because:

Asymptomatic in most cases

Looks like other disease (Flu or cold)

Serology continues to be best method

PCR, ELISA and other methods

WEIL – FELIX test is negative .
Contd…..
Bio safety level 3 (BSL-3) facility
 Very infectious (one organism causes infection)
 Listed by the CDC as a potential bioterrorism
agent.
 Isolated in cell cultures or embryonated eggs

Treatment
Once infected, humans can have life-long
immunity
 Acute Q fever treated with:
doxycycline,
chloramphenicol,
erythromycin or
fluoroquinolones


Chronic Q fever treated with:
Vaccines : prepared from formalin killed whole
cells
attenuated strains
trichloroacetic acid extracts

Prophylaxis:Pasteurization and sterilization of milk and other
dairy products
 Disinfect utensils, machines used in farm areas
for birthing
 Regular testing of animals and those who work
closely with them
 Protective Personal Equipment

BARTONELLA
INTRODUCTION

Family Bartonellaceae contain two genera
Bartonella
Grahamella

Grahamella does not infect humans

Bartonella contain 3 species:
B.bacilliformis
B.quintana
B.henselae
BARTONELLA BACILLEFORMIS


Carrions disease
Causes OROYA fever

MORPHOLOGY:
Gram negative
Pleomorphic
strict aerobe
motile, small bacillu0.3-0.5x0.2-0.5mc
found inside erytrocyte infected persons
Opt. temp 25-28 c

CULTURE;
Grow in semisolid nutrient agar with
10% rabbit serum
0.5%Hb
Growth is slow takes about 10 days
PATHOGENISIS:
Causes OROYA fever

Transmitted by SAND flies

INCUBATION PERIOD;
3 weeks to 3 months
CLINICAL FEATURES:




Fever
Headache
Chills
Severe anemia
Several weeks after recovery pt. develop
nodular lesions on the body
Secondarily infect produce ulcers –
VERUGA PERUANA
Lab diagnosis:Demonstrated in blood smear by GIEMSA
stain
 Seen in cytoplasm and adhere to cell surface
 Grown on NA agar contain rabbit serum,
Hb
 Guinea pig inoculation leads to
VERUGA PERUANA

TRETMENT:
Susceptible to penicillin
streptomycin
Tetracycline
Chloramphenicol
PREVENTION

Insecticides such as DDT should be used
to eliminate sand flies
BARTONELLA QUINTANA

MORPHOLOGY:small gram negative bacillus
0.3-0.5 mc to1.0-1.7 mc
Does not posses flagella
show twitching movments by fimbriae
CULTURE: Grows on rabbit /sheep blood agar
 opt. temp -35 c in 5% CO2
 colonies appear after 14 days primary
inoculation

PATHOGENESIS:Formerly called Rochalimaea quintana
Causes TRENCH fever
also called FIVE DAY fever



Transmission; by body louse
vertical transmission does not occur in lice
Lice after acquiring infection remain
infectious through out life
CLINICAL FEATURES:
Mild symptoms

leads to chronic rickttesiaemia

Relapse have been observed even after 20
years primary disease
Lab diagnosis:
Detected in the gut of infected lice

Isolate from pt. blood by cultur
sheep blood agar

Weil-felix test negative

PCR- detect organism in tissues
BARTONELLA
HENSELAE

MORPHOLOGY:Gram negative
Slightly curved
Show twitching movments

CULTURE:Grows on chocolate agar
columbia agar with 5%sheep blood
tryptic-soy agar
opt.temp-35-37 c in 5% CO2

COLONY MORPHOLOGY:-
white, dry, cauliflower like and
embedded in the agar
PATHOGENESIS:

Causes CAT-SCRATCH disease
Occur by contact with scratch / bite of
an infected cat
Resolution
in weeks to
months
1 - 3 weeks
Cat contact
(scratch, bite,
? cat flea bite)
Dissemination
in immunocompromised
hosts
CLINICAL FEATURES:



Regional lymphadenopathy
Fever
Endocarditis
In AIDS pt. leads to;
bacillary angiomatosis
Lab diagnosis:

lymph node biopsy – stained with
WARTIN-STARRY SILVER
IMPREGNATION –clusters of bacillus
Grow on chocolate agar/ columbia agar
TREATMENT:
Self limiting

No specific treatment required