Download rickettsiaceae

DR VIDYA PAI
 Gram
negative bacilli
 Obligate intracellular parasitism
 Primarily infect arthropods
 Transmitted to humans by vectors
 In humans infect vascular endothelium
 Howard Taylor Ricketts 1906
 Genera- Rickettsia, Orientia, Ehrlichia
 (Coxiella, Rochalimaea)
 Pleomorphic
coccobacilli
 0.3-0.6X0.8-2 micron in size
 Gram stain not very useful, stain light(G –ve)
 Giemsa, Casteneda- bluish purple
 Machiavello, Giminez- deep red
 Do not grow in culture media.
 Yolk sac of chick embryo, HeLa and Hep-2 cell linesprimary isolation
 Animal inoculation- Guinea pigs, Mice
 Genus
Rickettsia - 2 groups of diseases :
TUPHUS FEVER, SPOTTED FEVER
 Genus Orientia – Scrub typhus
 Genus Ehrlichia - Ehrlichiosis
GROUP
SPECIES
DISEASE
VECTOR
VERTEBRAT DISTRIBUTIO
E
N
RESERVOIR
TYPHUS
R.
prowazekii
Epidemic
typhus
Louse
Humans
Worldwide
R. typhi
Endemic
typhus
Rat flea
Rats
Worldwide
R. rickettsii
Rocky
Mountain
Spotted
Fever
Tick
Rodents
North
America
R. conori
(R. siberica,
R. japonca)
Indian Tick
Typhus
Tick
Rodents
India
R.akari
Rickettsial
pox
Mite
Rodents
USA, Russia
SPOTTED
FEVER
DISEASES
RICKETTSIAL
AGENT
INSECT
VECTOR
MAMMALIAN
RESERVOIR
a) Q fever
C. burnetti Nil
Cattle,
sheep,goats
b) Trench
fever
Rochalima Louse
ea
quintana
Human
 The
lice that almost defeated socialism
Posted under Lenin, odd animals, socialism |
Tags:civil war, fuel, grain, lice, reading
Lenin, war communism |
Comrades, we must concentrate everything on
this problem. Either the lice will defeat
socialism, or socialism will defeat the lice!
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Worldwide but common in Russia
and East Europe.
1917-1922- Napolean retreat
25 million cases & 3 mil.deaths
Socialism Vs Louse
Von Prowazek
Humansthe
only
natural
vertebrate host
Vector- Pediculus humanus corporis
Incubation period: 5-15 days
Clinical features: fever with chills,
skin rash 4th- 5th day(trunk-limbs
sparing face, palm, soles); 2nd wkstupor, delirium.
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Source of infection: Infected patient
Mode of infection: Body louse feces rubbed onto abrasions on
skin.
Louse feeds on infected patient
Rickettsiae multiply in GIT of the insect & appear in feces in
3-5 days.
Louse may be transferred to another person
Lice defecate while feeding and when louse feces is rubbed
through minute abrasions caused by scratching.( aerosol
inhalation/ conjunctiva- dried louse feces)
Rickettsemia.
TYPHUS= dhupa (Sanskrit)/ typhos(cloud).
CFR= 40%
Recovery-? Latency in lymphoid tissue ----Recrudescent
typhus
 Reactivation
 Rickettsiae
reservoir.
of latent/dormant R. prowazekii
can remain without louse as
Fleaborne typhus
 Vector-Xenopsylla cheopis
 Humans acquire through - Bite of infected flea
 Mild disease
 No man to man transmission
 Worldwide- KASHMIR in India.
 Neill Mooser reaction- Tunica reaction to differentiate
epidemic from endemic typhus.
Male guinea pigs – intraperitoneal inoculation with
blood from rickettsemic patient- inflammatory
adhesions between the layers of tunica vaginalis- testes
cannot be pushed into the abdomen.
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Rocky mountain spotted fever
Siberian tick typhus
Indian tick typhus
R. rickettsii- the first insect
transmitted bacterial pathogen
to be recognised
Transovarially transmitted in
ticks(reservoirs)
RMSF- Dermacentor andersoni,
Most serious spotted fever
North and South America
Boutonneuse fever in the
mediterranean - Conor
India - Himalayas – Megaw 1917
Ripicephalus sanguineus
 Orientia
tsutsugamushi
 East Asia, Korea to
Indonesia, Australia
 Mite larvae
(chiggers)
 Zoonotic tetrad
(Agent. Chiggers,
rats, vegetation )
 Tsutsuga= dangerous
 Mushi= mite
 Affinity
to blood
cells
 Mulberry like
clusters ( morula )
inside the infected
cell
 Anaplasma/ Cowdria
 Tick borne
infections of cattle
and sheep
 E.
sennetsu – Sennetsu fever ( lymphoid
hyperplasia
 E. chaffeensis – Human monocytic
ehrlichiosis
 E. equi - Human granulocytic ehrlichiosis
Microscopy
Serological Tests (Weil-Felix reaction, ELISA, IF,
– Paired sera to be tested.
Molecular methods – PCR.
Isolation of Rickettsiae – HeLa, Vero cell lines,
Chick embryo
Disease
Antigen
OX19
OX2
OXK
Epidemic typhus
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+
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Brill Zinsser
disease
+
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+
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Endemic typhus
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+
-
_
Spotted fever
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++
_
Scrub typhus
_
-
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 Coxiella
burnetti is the causative agent of
‘Q-fever’
 Obligate
intracellular, gram negative
bacterium
 Distributed
 Found
globally
in many species of animals
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 .
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 Grows
well in yolk sac of chick embryos
and in various cell cultures .
 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 .
 Resistant
 Air
to heat, drying and disinfectants
samples test positive for 2+ weeks
 Soil
samples test positive for 150+ days
A ZOONOTIC DISEASE
Q
stands for Query or Queensland
Origin
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of disease unknown
First reported cases were in
Queensland, Australia
 Differentiating
features from
Rickettsiae:
1. Having smaller size
2. Resistance to heat and drying
3. Major route of transmission isinhalation/ingestion
Primary Reservoir -?
Bandicoots
Goats
Cattle
Sheep
* All eukaryotes can be infected
TICKS
Feces
Urine
Milk
of infected animals
 During
birthing the organisms are shed in high
numbers in amniotic fluids and the placenta
 109
bacteria per gram of placenta
Do not touch!
Most
common route is inhalation of
aerosols
Consumption of raw
Contaminated dust, manure,
birthing products
Tick bites (rare)
Human to human also very rare
gsbs.utmb.edu
 Person-to-person
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(rare)
Transplacental (congenital)
Blood transfusions
Bone marrow transplants
Intradermal inoculation
Possibly sexually transmitted
Center for Food Security and Public Health Iowa State
University - 2004
Farmers,
veterinarians, researchers,
abattoir (slaughterhouse) workers etc.
People
who breed animals
Immunocompromised
Acute or Chronic Q fever
gsbs.utmb.edu
*Bacteria spread through blood
Symptoms :
 Asymptomatic
 Self-limiting, flu-like disease
 Fever, nausea, headaches, vomiting,
chest/abdominal pain
 Pneumonia & granulomatous hepatitis
Chronic Q fever (> 6 months)
 Endocarditis & meningoencephalitis
 Hepatitis
 Spontaneous
recovery
Bacteria may remain latent in tissues for 2-3
years
 Hepatitis
 Endocarditis
 Cirrhosis
Entry
via inhalation
Alveolar macrophages encounter bacteria
C. burnetii phagocytosed
Macrophage
C.
burnetii
R Heinzen, NIAID
Replication
Low
within phagolysosme
pH needed for metabolism
No
cellular damage unless lysis
occurs
Can
invade deeper tissue and cause
complications
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
 Asymptomatic
 Looks
like other disease (Flu or cold)
 Serology
 PCR,
in most cases
continues to be best method
ELISA and other methods
 WEIL –
FELIX test is negative .
 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
Once infected, humans can have life-long immunity
 Acute Q fever treated with:
doxycycline,
chloramphenicol,
erythromycin or
fluoroquinolones
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Chronic Q fever treated with:
More than one antibiotic
tetracycline and cotrimoxazole for 2 years
Vaccines : prepared from formalin killed whole
cells
attenuated strains
trichloroacetic acid
extracts
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NOT FOR GENERAL USE.
 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
 Family
Bartonellaceae
contain two genera
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Bartonella contain 3
species:
Bartonella
B.bacilliformis
Grahamella
B.quintana
Grahamella does not
infect humans
B.henselae
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Carrions disease
Daniel Carrion – Peru
OROYA fever
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Causes OROYA fever
Transmitted by SAND flies
 Infects RBCs
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INCUBATION PERIOD;
3 weeks to 3 months
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Fever
Headache
Chills
Severe anemia
Several weeks after recovery pt. develop
nodular lesions on the body
Secondarily infect produce ulcers –
VERUGA PERUANA
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
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Susceptible to penicillin
streptomycin
Tetracycline
Chloramphenicol
 Insecticides such as DDT should be used
to eliminate sand flies
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Formerly called Rochalimaea quintana
Causes TRENCH fever
also called FIVE DAY fever
 Transmission;
by body louse
 No animal reservoir
 vertical transmission does not occur in lice
 Lice after acquiring infection remain infectious
through out life
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Mild symptoms
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leads to chronic bacteremia
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Relapse have been observed even after 20 years
primary disease
 Rick
quintana
 Rochalimaea quintana ( da Rocha Lima )
 Bartonella quintana
 Detected
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in the gut of infected lice
Isolate from pt. blood by culture
sheep blood agar
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Weil-felix test negative
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PCR- detect organism in tissues
 World
wars
 Recently Tunisia and Mexico
 USA
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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
Regional lymphadenopathy
 Fever
 Endocarditis
 In AIDS pt. leads to;
bacillary angiomatosis (vascular
nodules/tumours appear on skin, mucosa etc )
bacillary peliosis( liver and spleen)
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lymph node biopsy – stained with
WARTIN-STARRY SILVER IMPREGNATION
–clusters of bacillus
Grow on chocolate agar/ columbia agar
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Self limiting
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No specific treatment required