Micro Chlamydia, Rickettsia, And Friends

Front 1

Chlamydia trachomatis serovars A - C?

Back 1

Leading cause of blindness worldwide.

Chronic infection of conjunctiva leads to follicles of inflammatory cells; fibrosis of eyelid causes lashes to turn inward and abrade cornea.

Front 2

What is the life cycle of Chlamydia trachomatis?

Back 2

Elementary bodies (EBs) attach to the host cell, which are columnar epi cells of the cervix. Internalized EBs remain within a host-derived vacuole called cytoplasmic inclusion (seen on Giemsa), where they differentiate to larger metabolically active reticulate bodies (RB), which replicate via binary fission. After several rounds of replication, the reticulate bodies reorganize into EBs (large cytoplasmic inclusion) and release to infect more cells.

Front 3

What category does Chlamydia and Rickettsia fall into?

Back 3

They are Gram -- bacteria, who are obligate intracellular parasites.

Front 4

Primary genital lesions of chlamydial occur by?

Back 4

Columnar epi cell destruction that releases proinflammatory cytokines that are chemotactic for neutrophils and mononuclear cells.

Front 5

What kind of parasites are Chlamydia and Rickettsia?

Back 5

Energy parasites: they steal ATP from the host and spit out an ADP--they both have an ATP/ADP translocator.

Front 6

Ascending extension of chlamydiae from the endocervix t the endometrium and endosalpinx is dependent on many endogenous or exogenous factors, such as?

Back 6

Estrogen-dominated (thin) cervical mucus, attachment to sperm that migrate upward, bacterial vaginosis, IUD.

Front 7

Can Chlamydia and Rickettsia both grow on nonliving artificial media?

Back 7

Nope, since they are Obligate intracellular parasites.

Front 8

Although they are similar to viruses in the since they are small and obligate intracellular parasites, but how do Chlamydia and Rickettsia differ from viruses?

Back 8

They have both RNA and DNA, and they can synthesize their own proteins and are sensitive to antibiotics.

Front 9

How do Chlamydia and Rickettsia differ in transmission?

Back 9

Chlamydia through person-to-person, and Rickettsia through an arthropod vector (except for Q fever).

Front 10

How does Chlamydia differ from other Gram -- bacteria?

Back 10

It does not have a peptidoglycan layer or muramic acid.

Front 11

What type of cells do Chlamydia enjoy infecting?

Back 11

Columnar epithelium, which lines mucous mm. Therefore, Chlamydia causes conjunctivitis, cervicitis, and pneumonia.

Front 12

What is the life cycle of Chlamydia?

Back 12

Elementary body (metabolically inert--doesn't divide--infectious particle); and Initial body AKA reticulate body (inhibits phagosome-lysosome fusion, RNA content increases, binary fission occurs, and synthesis of DNA, RNA, and proteins)

Front 13

What are the three strains of Chlamydia, and what do they cause?

Back 13

C. trachomatis (infects eyes, genitals, and lungs), C. psittaci and pneumonia (both affect the lungs)

Front 14

C. trachomatis serovars D - K causes?

Back 14

Inclusion conjunctivitis (neonatal conjunctivits), neonatal pneumonia (interstitial pneumonia), PID, urethritis

D to K are considered the world's most common STD bacterial pathogen (exudative genital infection), and following vertical transmission: neonatal conjunctivitis and pneumonia.

Front 15

Urethritis caused by Chlamydia trachomatis, is clinically indistinguishable from?

Back 15

Neisseria gonorrhoeae. You can treat N. gonorrhoeae with penicillins; however you can't with S. trachomatis since it has no peptidoglycan layer, the target for penicillin. Therefore, with urethritis, antibiotics cover N. gonorrhoeae, C. trachomatis, and Ureaplasma urealyticum.

Front 16

Many PTs with nongonoccoal urethritis (NGU) are asymptomatic; however, if there are symptoms, what are they?

Back 16

Dysuria, thin to thick mucoid discharge from urethra.

Front 17

What two organisms can cause PID?

Back 17

C. trachomatis and N. gonorrhoeae

Front 18

What does an infection from C. trachomatis of the cervix look like?

Back 18

Inflamed, red, swollen, yellow mucopurulent endocervical discharge. Infection can spread to uterus, fallopian tubes, and ovaries.

Front 19

Women with PID develop?

Back 19

vaginal discharge or uterine bleeding, pain with sex (dyspareunia), nausea, vomiting, and fever. Most common symptom is lower abdominal pain. Inflamed cervix, uterus, tubes, and ovaries are very painful. PID shuffle (small, widebase steps to minimize shaking of abdomen) and Chandelier sign (cervical motion tenderness so severe the PT leaps to the chandelier)

Front 20

What are compliations from C. trachomatis infection?

Back 20

Reiter's syndrome: arthritis of large joints, usually men between 20 - 40; uveitis and conjunctivitis and urethritis can also occur

Fitz-Hugh-Curtis syndrome: infection of liver capsule with upper right quadrant pain). Both syndromes can occur with other agents. Gonoccal infection also with Fitz.

Front 21

C. trachomatis serovars L1 - L3 cause?

Back 21

Lymphogranuloma venerum (STD, painless papule or ulceration on genitals that heal spontaneously. Bacteria spreads to inguinal lymph nodes, which enlarges and become painful. Nodes become tender, and may break open.

In homosexual males, can cause granulomatous proctitis that resemble Crohn disease.

Front 22

How do you treat C. trachomatis?

Back 22

DOC: doxycycline for adults (according to Nath), and a single dose of azithromycin for non compliant PTs.

(+ ceftriazone for concurrent N. gonorrhea); oral erythromycin for neonates (topical doesn't work), prophylactic erythromycin eye drops for neonates.

Front 23

What causes Psittacosis?

Back 23

C. psittaci

Front 24

C. psittaci infects? Therefore, who is at risk?

Back 24

130 species of birds, even parrots. Therefore, Pet shop owners and veterinarians are at a high risk.

Front 25

Psittacosis is what type of pneumonia?

Back 25

Atypical (dry cough, fever, less sick, sore throat)

Front 26

C. pneumoniae causes?

Back 26

Atypical pneumonia, acquired by person-to-person (community acquired).

Front 27

How is Rickettsia different from Chlamydia?

Back 27

Rickettsia requires an arthropod vector (expect for Q fever); Rickettsia replicates in the cytoplasm while Chlamydia replicates in endosomes (inclusions); Rickettsia has a tropism for endothelial cells that line blood vessels while Chlamydia likes columnar epithelium

Front 28

What does the Weil-Felix reaction perform?

Back 28

A test that uses cross-reacting Proteus vulgaris antigens to help confirm a diagnosis of a rickettsial infection.

Note: Proteus vulgaris and ricketssial sharing the same antigens is purely coincidental. These antigens are: OX-2, OX-19, and OX-K. Felix test is neither sensitive nor specific, leading most experts to recommend against its use.

Front 29

How do you treat and diagnose Rickettsia?

Back 29

Doxycycline (a drug that can enter in the cell) or chloramphenicol (for children young than 8 or pregnant women); Weil-Felix and serology

Note: 3 - 5% of PTs will die from infection.

Front 30

What causes Rocky Mountain Spotted Fever?

Back 30

Rickettsia rickettsii

Front 31

What is the vector that causes Rocky Mountain Spotted Fever?

Back 31

Wood tick, Dermacentor andersoni, or the dog tick Dermacentor variabilis

Commonly transmitted from a dog.

Front 32

What is the clinical presentation Rocky Mountain Spotted Fever?

Back 32

Fever, conjunctival redness, severe headache, and rash that appears first on the wrist, ankles, soles, and palms that spreads to the trunk.

The organisms proliferate in the endothelial lining of small blood vessels and capillaries, causing small hemorrhages, thrombi, and spotted (petechial) rash.

Note: Rickettsiae spread from cell to cell and effects small- to medium sized blood vessels. With each cellular burst after a cycle of growth leads to rupture of vascular endothelial lining, causing vascular damage.

Front 33

The maculopapular rash that appears with Rickettsia rickettsii spreads how?

Back 33

Spreads from the arms to the trunk.

Front 34

Rocky Mountain Spotted fever mainly appears in what location?

Back 34

Southeastern U.S., not so much the Rocky Mountain region.

Front 35

What causes the rickettsialpox, and what is the vector?

Back 35

Rickettsia akari; mites that live on house mice.

Front 36

What two agents cause typhus, and how are they similar and different.

Back 36

Both Rickettsia prowazekii (epidemic form) and typhi (endemic form) cause typhus. They have different reservoirs and vectors; however, they have a similar disease, and infection with one confers immunity to the other.

Front 37

Rickettsia prowazekii, is carried and transmitted by?

Back 37

Is carried by flying squirrels, and the vectors are lice and fleas

Front 38

In contrast to Rocky Mountain Spotted Fever, what is the clinical presentation of epidemic typhus?

Back 38

The rash spares the palms, soles, and face. There is a sudden headache and fever. Increase risk of blood clotting leads to gangrene of the feet or hands.

Front 39

If a PT goes without treatment with an antibiotic, who had been infected with Rickettsia prowazekii, what may happen?

Back 39

They may develop Brill-Zinsser disease: the pathogen is retain in a latent state but develops to produce a milder form of typhus, without a skin rash Diagnosis is from a early rise in IgG titter (Not with an IgM, which occurs in primary infection).

Front 40

What causes cat scratch fever? (I do not know why this bacteria is in this category--DO NOT stereotype this bacteria with the others!)

Back 40

Bartonella henselae

Front 41

How is Coxiella burnetii similar to Clostridium and Bacillus?

Back 41

It is a gram + spore former, and has an endospore. It is resistant to heat and drying (therefore, present in contaminated milk); extracellular existence (steals ATP); non-arthropod transmission (grows in ticks and cattle, sheep, and goats while remaining viable in dried feces)

Front 42

What causes Q fever?

Back 42

Coxiella burnetii

Front 43

What is Q fever?

Back 43

An atypical pneumonia with fever, soaking sweats. There is no rash with Q fever. It may lead to hepatitis, and chronic endocarditis.