Pathology - Zoonotic Bacteria Pt. 2

Front 1

chlamydiae
1. morphology
2. tissue infected
3. body response

Back 1

1. obligate intracelluar parasite G- bacT; Chlamys - cloak (under membrane)
2. mucosal infections (difficult to grow in cultures)
3. humoral (Abs) & cellular

Front 2

chlamydiae:
--diagnostics
-- abx sensitivity

Back 2

type specific chlamydial Abs in serum & secretions - immunofluorescence

***cytoplasmic inclusions***

-- large spectrum; NOT PCN

Front 3

chlamydiae
-- pathophy (3 steps)

Back 3

1. elementary body - 0.3 micron: infxous form released from infected host cell (protective envelop), enters cells via endocytosis
2. reticulate [initial] body - 1 micron: replicates w/in host cell vacuoles
3. intra-cytoplasmic inclusions in epithelial cells

Front 4

3 species of chlamydiae

Back 4

1. C. pneumoniae - infxs only humans; atypical pneumonia - transmitted by aerosols
2. C. psittaci - avian reservoir; atyp. PNA - aerosols (parakeets/parrots)
3. C. trachomatis

Front 5

3 categories of C. trachomatis

Back 5

1. Type A, B, C trachoma - follicular kerato-conjunctivitis
2. Type D-K - urethritis, neonatal PNA, inclusion conjunctivitis
3. Type L1, L2, L3 - lymphogranuloma venereum

Front 6

C. psittaci
1. aka
2. transmission
3. incubation period

Back 6

1. ornithosis aka psittacosis
2. aerosols (dust-borne) through inhalation of dried excreta (parakeets, parrots, other birds); BITE of BIRD & DIRECT contact w/ pt
3. 1-3 wks

Front 7

C. psittaci
1. clinical forms

Back 7

1. asymptomatic infxn
2. transient flu-like illness - ie viral pneumonitis: fever, malaise, sore throat, cough, dyspnea
3. fatal PNA

Front 8

C. psittaci
1. gross
2. microscopy
3. lethal disease
4. dx

Back 8

1. pneumonitis, lung abscesses
2. alveolar damage, consolidations, pulm. edema, pneumocytes may contain INTRA-CYTOPLASMATIC bodies
3. **focal necroses, mononuclear infiltrates in liver,spleen,kidneys,heart
4. rise in specific Abs; culture difficult

Front 9

Chlamydial urethritis & cervicitis
1. up to 10 % of ppl carry bacT where?
2. 70% of women have...?
3. what is increased by 8-10%/year
4. rank in list of STDs in US
5. What serotypes are 50% of the cases of C. trachomatis due to?

Back 9

1. repro tract (higher in promiscuous)
2. asymptomatic carriage on cervix
3. prevalence among young, sexually active teens
4. MC STD in US
5. serotyes D-K

Front 10

Chlamydial urethritis & cervicitis
1. what is seen in infants born by infx'd mothers
2. clinical findings in females
3. in males
4. complications of ds

Back 10

1. inclusion conjunctivitis & neonatal PNA
2. cervicitis, salpingitis, PID - pelvic inflamm. ds, proctitis
3. prostatitis, epididymitis
4. long term repro damage; ectopic pregnancy, sterility

Front 11

Chlamydial inclusion conujunctivitis
1. general classification
2. how are newborns infx'd
3. adults?
4. histology

Back 11

1. suppurative, beningn, self-limiting
2. from mothers
3. directly, or from swimming pools
4. chlamydial inclusions in exudate & lymphcytic infiltration in tissue

Front 12

C. trachomatis serotypes A, B, C
1. define trachoma
2. significant in global manifestions
3. mostly occurs to whom/where
4. transmission

Back 12

1. follicular kerato-conjunctivitis
2. leading global cuase of blindness through scarring
3. poor ppl in dry/sandy regions
4. direct contact, flies, fomites (objects)

Front 13

C. trachomatis serotypes A, B, C
- morphology

Back 13

- suppuration - deeper tissue inflitration w/ lymphocytes & plasma cells
- formation of lymphoid cell follicles = follicular conjunctivitis
- ulceration of conjuncvtiva, vascular invasion [pannus formation], fibroblast ingrowths
- eventually scarring -> blindness

Front 14

Chlamydia trachomatis serotypes L1,2,3
1. causes
2. incubation
3. primary lesion

Back 14

1. lymphogranuloma venereum - STD aka Nicolas Favre disease
2. 4-21 days
3. at site of infxn: penis, labia, vag, cervis, lips, tongue, fingers, anorectal

Front 15

Chlamydia trachomatis serotypes L1,2,3
3 stages of progression

Back 15

1. stage I
- small ulcer, at inoculation site, w/ neutrophil infil. & granuloma at base
- chlamydial inclusions in cells
2. Stage II
- suppurative granulomatous lympadenitis
- matted nodes
- stellate abscesses
- fistulae discharging pus
3. Stage III
- chronic inflamm infiltrate
- dense fibrosis
- late stage: rectal stenosis & chronic genital lymphedema [vulvular elephantiasis]

Front 16

Rickettsiae
1. micro - morphology
2. natural vectors
3. transmission

Back 16

1. small pleomorphic [rod shape to coccoid] obligate intracellular G- bacT
2. ticks, mites, fleas, lice
3. arthropod bite/contact w/ aerosols from animal excreta

Front 17

Rickettsiae
1. pathogenesis
2. host defense

Back 17

1. enters host cells by induced endocytosis -> multiply in several cells types [endothelial]; do NOT generate toxins
2. immune response: cytolytic T lympocyte dependent; gamma-interferon
--Abs can convey passive protection

Front 18

Rickettsiae
- various vectors & target cells (8!)

Back 18

1. R. prowazeki - endothelial cells (epidemic typhus - human body lice)
2. R. rickettsii - endothelial cells (RMSF - ticks)
3. R. mooseri - endothelial cells of rodents & humans (Murine typhus - fleas [mus,muris - mouse])
4. E. chaffensis - monocytes & granulocytes (non-specific febrile illness - ticks)
5. Coxiella burnetti - macrophages (Q fever [Queensland] - inhaled aerosols)
6. Bartonella [Rochalimaea] - peri-cellular infxn - lice
7. B. quintana - trench fever
8. B. henselae - endocarditis in homeless, septicemia; in immunocompetent - cat scratch fever - inoculated benign lympho-reticulosis

Front 19

Rickettsiae
1. dx
2. morphology
a. macroscopic
b. microscopy

Back 19

1. skin biopsy & immunoflorescent staining; specific serum Ab titers; direct culture
2.
a. skin rash, skin eschar [in spotted fever group]
b. mononuclear inflamm infiltrate, focal vas inflammation, micro-thrombi, ischemia or hemorrhage [rash-associated]

Front 20

What is an eschar

Back 20

well circumscribed nodular [swollen], dark encrusted lesion

Front 21

Louse-borne epidemic typhus
1. cause (R. ______)
2. cycle
3. epidemics

Back 21

1. R. prowazeki
2. man-louse-man
3. poor sanitation, crowding, famine, war

Front 22

Louse-borne epidemic typhus
1. transmission/pathology

Back 22

1. contaminated louse feces penetrates skin abrasions [SCRATCH!!]
2. inhalation of air-borne Rickettsia
3. multiplication in human endothelial cells
4. rupture of endothelial cells releases R. p. in circulation
5. rickettsemia
6. louse taking blood meal from infected human becomes infected w/ rickettsiae
7. obligate intra-cellular G- bacT enters epithelial cells of louse's midgut
8. rickettsia released in lumen of louse intestine contaminating the feces
9. feces deposited on non-infected human skin

Front 23

what is rickettsemia

Back 23

human blood circulating rickettsiae

Front 24

Louse-borne epidemic typhus
1. incubation
2. clinical aspects (triad/severe cases)

Back 24

1. 8-15 d
2.
triad: fever, h/a, maculopapular rash, apathy, stupor, coma (CNS involved)
severe cases: interstitial PNA, nephritis, myocarditis, encephalitis, shock, gangrene [arteritis]

Front 25

Louse-borne epidemic typhus
1. microscopy
2. sporadic thyphus- Brill-Zinsser disease
3. dx

Back 25

1. typhus nodule
2. actual encountered clinical form of typhus: reinfection typhus w/ rickettsiae dormant in spleen
3. detection of rickettsiae - immunofluorescence, abs & Weil-Felix reaction (cross reaction w/ proteus Ags)

Front 26

What is a typhus nodule

Back 26

small vessel lesion in brain & other organs, focal infiltration w/ leukocytes, microglial proliferation

Front 27

R. rickettsii
1. causes
2. transmission
3. incidence in US

Back 27

1. RMSF - prototype of spotted fever group
2. bite of blood sucking ticks; the salivary glands of the tick, Dermacentor, contain Ricketttsiae. Ticks are both the vectors & the reservoir
3. 200-1100 cases/year

Front 28

R. rickettsii
1. incubation2. clinical aspect

Back 28

1. 2-12 d
2. fever, h/a, mm pain
**rash including palms & soles** - beings maculopapular & becomes petechial & purpuric [hemorrhagic], spreads centripetally, from distal extremities to trunk; **eschar at bite site**, absent in mild infections
- necrotic skin foci - fingers, toes, elbows, ears, scrotum

Front 29

R. rickettsii
1. severe cases
2. microscopy
3. dx

Back 29

1. micro-infarcts in brain; pneumonitis & secondary bacterial infection
death - shock, renal failure, CNS damage
2. endothelial lesions underlying rash cause arteritis & thrombosis, generatin necrosis
3. urgernt - immunofluorescence demonstrating R. rickettsii in skin biopsy

Front 30

Mycoplasma
1. aka
2. micro - morphology
3. infects what tissue

Back 30

1. eaton agent
2. tiny, pleomorphic bacT that lack cell wall, called PPLOs (PNA, pleuritis like organisms]; commonly causes ds of fowl & cattle
3. parasitize membrane cells, binding to epithelial linings of RT & GU tract

Front 31

Mycoplasma
1. mycoplasma urethritis
2. effects on pregos

Back 31

1. acute purulent "non-gonococcal" urethritis --> chronic PID
2. may produce chorio-amnionitis which means infxn of placenta, dreadful conditions for pregnancy & life of pregos

Front 32

M. pneumoniae PNA
1. transmission
2. pathogenesis

Back 32

1. by aerosol & droplets; only 1-3% exposed become infected; most in close living quarters [barracks, dorms, boarding schools, huge ships]
2. M. pneumoniae bacT disrupt cilia & damages resp epithelium; produces cold agglutinins & complement fixing Abs; these Abs may cause false-positive serologic tests for syphilis

Front 33

M. pneumoniae PNA
1. microscopy

Back 33

1. interstitial PNA, alveolar air spaces empty [no inflamm cells], thickened alveolar walls = intra-septal inflamm w/ mononuclear [lymphocytes & plasma cells] infilitrate

Front 34

M. pneumoniae PNA
1. clinical

Back 34

- similar to viral PNA;
- 10-30% of comm. acquired atypical PNAs
- low mortality
- walking PNA
- fever, h/a, malaise, sore throat & unprod cough, nasal sxs, chest pain & earache

Front 35

M. pneumoniae PNA
1. complications
2. Stevens Johnson syndrome
3. DONEZO

Back 35

1. myocarditis, miringitis [eardrum infxn], transverse myelitis [spine inflamm w/ tetraplegia]
2. peri-orificial [perioral, perianal, periorbital] ecto-dermitis, formed by uncerated papule which can be bacterial super-infected
3. if you're going in order...otherwise, keep on trucking!