This document discusses Rickettsia, which are small, Gram-negative bacteria that cause diseases transmitted by arthropod vectors like ticks and fleas. It outlines several Rickettsia species and the diseases they cause including typhus, Rocky Mountain spotted fever, and Q fever. It describes the characteristics of Rickettsia as obligate intracellular parasites that infect endothelial cells. Symptoms and treatment options for various Rickettsial diseases are also summarized.

1. Shivajirao S. Jondhale college
of pharmacy, Asangaon.

3. Introduction
 Rickettsia are small,Gram-negativea bacilli which have properties in between bacteria and
viruses.
 They are primarily parasites of arthropods such as fleas, lice, mites and ticks .
 The family Rickettsiaceae is named after Howard Taylor Ricketts who discovered the spotted
fever rickettsia in 1909.
 He died of laboratory infection from these highly infectious organisms during his studies.

4. Genus Species
Rickettsia Rickettsia prowazekii
Rickettsia akari
Rickettsia australis
Rickettsia sibirica
Rickettsia conorii
Rickettsia rickettsi
Rickettsia typhi
Orientia Orientia tsutsugamushi
Coxiella Coxiella burnettai
Ehrlichia Ehrlichia sennestu
Ehrlichia chaffeensis
Ehrlichia phagocytophila

5.  The organisms of Rickettsiae are small coccobacilli visible under a light microscope
and are held back by bacterial filters.
 They are obligate intracellular parasites.
 They multiply by binary fission.
 They posses both DNA and RNA.
 They are sensitive to lysozyme and antibiotics
 They contains muramic acid in the cell wall.
 They do not multiply outside the cell. However, they grow readily on the yolk of chick
sac embryo.
 They produce only endotoxin and no exotoxin.
 They require an arthopod vector as a part of their natural cycle and are transmitted to
humans by blood sucking arthopods.
 They posses a trilaminar cytoplasmic membrane.

6.  Need cell culture lines.
 Grows in the cytoplasm.
 Grows at 32 to 35 degree c. .
 Grows in yolk sac of developing chick embryo.
 Grows in mouse fibroblasts, Hela, Hep2, Detroit 6.

7.  Rickettsiae infect endothelial cells in small blood vessels
- Induced phagocytosis
 Lysis of phagosome and entry into cytoplasm
- Phospholipase
 Replication
 Release – Primary lesions is vasculitis

9. THYPHUS FEVER GROUP
Disease Causative agent Vector Reservoir
a. Epidemic
typhus
Rickettsia
prowazekii
Human body
louse,
Flying squirrel
Human body
b. Brill-zinsser
disease
(Racrudescent
typhus)
Rickettsia
prowazekii
Louse Human body
C. Endemic
typhus
(murine / fleaborn
typhus)
Rickettsia typhi Flea Rodents

10. Disease Causative agent Vector Reservoir
a. Rocky Mountain
spotted fever
Ricketssia rickettsii Tick Small mammals
Eg. Dog
b. Other tick- borne
disease
1.Boutonneuse
fever
2.Australian tick
typhus
3.Siberian tick
typhus
R. Conorii
R.Australis
R.sibirica
Tick
Tick
Tick
Dog, rodents
Bus rodents
Wild animals, cattle,
birds
C. Rickettsial pox Ricketssia okari Mite House mice, wild
rodent

11. Disease Causative agent Vector Reservoir
Q-fever Rickettssia burnetii
,
Coxiella burnetii
Infected milk,
faeces of infected
animals, infected
straw, infected
cloth
Rodents, cattle,
sheep

12. Disease Causative agent Vector Reservoir
Trench fever Rochalimaea
quintana ,
Human body louse Unknown

13. Disease Causative agent Vector Reservoir
Scrub typhus Rickettssia
tsutsugamushi
Mites Rodents, birds

14.  Headache.
 Fever.
 Vommiting.
 Cough.
 Chills.
 Myalgia.
 Malaise.

15.  Doxycycline.
 Chloramphenicol.
 Tetracycline.
 Azithromycin.

17.  Chlamydia, or more specifically a chlamydia infection, is a sexually transmitted
infection caused by the bacterium Chlamydia trachomatis.
 Chlamydia is one of the most common sexually transmitted infections, affecting
about 4.2% of women and 2.7% of men worldwide.
 Infections are most common among those between the ages of 15 and 25 and
are more common in women than men.
 Repeated infections of the eyes that go without treatment can result in trachoma
common cause of blindness in the developing world.

19.  Chlamydiae are obligate intracellular bacterial parasites of humans, animals and
birds with tropism for squamous epithelial cells and macrophages of the
respiratory anf gastrointestinal tracts.
 Chlamydiae occur in two forms - elementary body and the reticulate body.
 The elementary body is the extracellular, infective form which is a spherical
particle, 200-300 nm in diameter with an electron dense nucleiod.
 The reticulate body is the intracellular growing and replicative form, 500-1000nm
in size having a fragile cell wall leading to pleomorphism.
 They possess both DNA and RNA like bacteria and multiply by binay fission.
 They are susceptible to antibiotics and chemotherapeutic agents.

20.  Infection is initiated by attachment of the elementary body to the surface of a susceptible epithelial
cell followed by its endocytosis.
 Inside the host cell, the elementary body lies within the endosome, being separated from the host cell
cytoplasm by the endosome membrane throughout its active growth cycle.
 By about 8 hours elementary bodies are reorganized into reticulate body, which begins to divide by
binary fission by 12 hours.
 By 20-24 hours, the pleomorphic progent are converted to elementary bodies and the binary fission
continues till about 40 hours.
 The developing chlamydia is called as inclusion body. The mature inclusion body contains 100-500
elementary bodies which are released from host cells within 24 hour of lysis.
 The mature inclusion appears to be exocytosed in 72-96 hours, the host cell is being left with scar.

23. Chlamydia trachomatis is a leading cause of ocular and genital infections
worldwide.
 Trachoma
 Inclusion conjuctivitis
 Infant pneumonia
 Genital infections

24.  It is a chronic keratoconjunctivitis characterized by follicular hypertropy, hyperplaisa,
pannus formatuon and in the late stages, cicatrisation.
 At first, trachoma may cause mild itching and irritation of your eyes and eyelids. Then you
may notice swollen eyelids and pus draining from the eyes. Untreated trachoma can lead
to blindness.
 Trachoma spreads through contact with discharge from the eyes or nose of an infected
person. Hands, clothing, towels and insects can all be routes for transmission.
 No trachoma vaccine is available, but prevention is possible through “Safe strategy”
S: Surgery for Trichiasis
A: Antibiotics for C. trachomatis infection
F: Facial cleanliness
E: Environmental change to improve

25.  Inclusion conjunctivitis is an inflammation of the conjunctiva, or white of the eye.
 Symptoms: acute or subacute in onset and include ocular irritation, foreign body
sensation, watering, mucopurulent discharge and sticking of the lids
 Neonatal inclusion conjunctivitis develops within five to 12 days after birth and is
contracted as the child passes through the mother's cervix. Two-thirds of those
females with a chlamydial infection pass the infection on to the child
during childbirth.
 Doxycycline, tetracycline, ocufloxacin, and erythromycin are sometimes
prescribed. Tetracycline is not given to children under eight years of age, and
ocufloxacin is not given to those under 18 years of age.

26.  If child's pneumonia is caused by bacteria, they will be prescribed antibiotics.
 Children with bacterial pneumonia usually improve within 48 hours of starting antibiotics.
 It is very important to complete the whole course of antibiotics, even if your child seems
much better. Treatment will continue for 3 to 7 days.
 The child may continue to cough for up to three weeks after treatment, but this is nothing
to worry about if they are otherwise getting better.

27.  You can get chlamydia during oral, vaginal, or anal sex with someone who has the
infection. A woman can also pass chlamydia to her baby during childbirth.
 Symptoms in women include-
Abnormal vaginal discharge, which may have a strong smell.
A burning sensation when urinating.
Pain during intercourse.
 Symptoms in men include-
Discharge from your penis
A burning sensation when urinating
Burning or itching around the opening of your penis
Pain and swelling in one or both testicles.

28.  Chlamydia psittaci is a lethal intracellular bacteria species that may
cause chlamydiosis, epizootic outbreaks in mammals, and
respiratory psittacosis in humans.
 Potential hosts include feral birds and domesticated poultry, as well
as cattle, pigs, sheep, and horses.
 C. psittaci is transmitted by inhalation, contact, or ingestion among birds and to
mammals.
 Many strains remain quiescent in birds until activated by stress.
 In addition to symptoms and CHX,complement fixation, micro immunofluorescence,
and polymerase chain reaction tests can be used confirm the diagnosis.

29.  Azithromycin
 Doxycycline
 Erythromycin
 Ofloxacin

30. Reference - professor Chandrakant kokare “Pharmaceutical
Microbiology Concepts and Application”. J.P.
Euzéby. "Chlamydia". List of Prokaryotic names with Standing
in Nomenclature. Retrieved 2008-09-11.