Zoonotic Bacterial Flashcards
1
Q
Yersinia Pestis (“Black Death”)
A
- Gram (-) rod-Bipolar staining “safety pin”
-
Reservoir: Urban plague Rats-Vector: Rat flea
- Xensopsylla cheopsis-<u>recgurgitates bacteria into human</u>
- _Sylvatic plague-_squirrles, field rats, rabbits
- <u><strong>Vector</strong></u>-Flea
- USA is endemic<strong> (regional outbreak)-Southwestern (Nevada & Arizona)</strong>
-
Transmission: Flea bite or direct contact w/sick animal
- Via Resp droplets <strong>(Pneumonic plague)</strong>
- High Risk: Campers, Hikers, Hunters
2
Q
Yersinia Pestis (Virulence)
A
- @ 37C different virulence factors expressed
-
Major factor is resisting phagocytic killing
- <u>Capsule (F1)-</u>Antiphago & Adhesion
- Low conc needed for infection=<em><strong>1 bite enough</strong></em>
- Plasminogen activator-Protease gene:
- Degrades comp C3b & C5a (prevents opsonization/phego cell migration)
- Degrades fibrin cots-Promote dissemmination
- Yops (yersinia outer proteins)-
- Destructive enzymatic activity on host cells
- Injected in host cells via Type 3
- Inside cell=Disrupt intracellular function (signaling system)
- STOPS phagocytosis, destroy cytoskeleton, blocks cytokine release
- Endotoxin-LPS
3
Q
Yersinia Pestis (Disease)
A
- Bubonic plague (direct bite): multiplication in regional lymph w/seeding of pathogen in blood, lung
- IP: 2-7 days
-
Symptoms: Rapid onset fever-PAINFUL swollen lymph nodes (BUBOES)-groin or axilia (Hemorrhagic supprative lymphadenitis)
- W/o treatment 50-75% progress to bacteremia=Death of septic shock w/in hrs-days
- 5% develop to pneumonic plague (Epidemic spread human2human)
- Pneumonic plague: Necrotizing hemorr
- IP 1-4 days w/mortality 100%
- Symptoms: Rapid onset fever, productive cough, DIC, meningitis
- Terminal cyanosis-Blackening of skin (“Black death”)
4
Q
Yersinia Pestis (Clinical)
A
- Diagnosis: Geimsa stain of aspirates from Buboes
- Bipolar staining=“Safety pin”
- Culture is hazardous and done in specialized labs
- Treat: Streptomycin, Tetracycline/Gentamicin
- _Prevention: _
- Sylvatic (US): Avoid contact w/dead animals
- Prophaylatic antibios-Tetra/doxy
- Infection leads to life long immunity
- Quarintine is advised
5
Q
Borrelia Burgdorferi (general)
A
- “Lyme Disease”-Common
- Spirochete (weak gram stain) gram (-) w/axial filaments
- Reserviors: White foot mouse, White tail deer-Tick(vector)-Ixodes sp
- Transmission depends on tick stage (larva or adult)
- Infected “Nymph & Adults” tick infects humans
- HIgh risk: Campers & Hikers
- Diagnosis:
-
Microscopy-early stage w/skin lesion (Rash)
- <strong>Cannot isolate Spirochete in Tertiary state</strong>
- Serology-Detect IgM or _4x increase IgG _
- Cross rxn w/RA-CONFIRM w/Western Blot
6
Q
Borrelia Burgdorferi (Disease)
A
- Co-infection w/Babesia (same vector)
- Lyme disease-IP 3-30 days w/3 stages:
-
Primary-Rash @ site of bite “Chronicum Migrans”
- “Bull’s eye rash” (5-30cm)
- Red macule w/clear center, pain less w/FLU
-
Secondary-systemic stage presents years later
- Spirochetes move into skin, nervous system, heart & joints
- Neurologic-CN Bell’s palsy (CN7)
-
Tertiary-Months to years arthritis of LARGE joints
- Chronic progressive CNS disease
- Shooting pains in face around <em><strong>Trigeminal nerve</strong></em> (CN5)
- Numbness/tingling in hands or feet
- Concentration & short term memory issues
- Treat: @ early stages doxy or Amoxicillin (not effective @ late)
7
Q
Borrelia Spp (general)
A
- “Relapsing Fever”- 2 types
-
Endemic-Tick borne in animals
- 15 different Borrelia species-Ticks are vetors
- Rodents are reservoirs
-
Epidemic fever-Louse borne (severe)
- Cause=Borrelia recurrentis
- Transmitted by Pediculus humanus (human lice)
- Human is ONLY host
- Gram(-) spirochete w/Antigenic variation (30)=Relasping
- HIGH risk: Hunters, campers <strong>(endemic)</strong> & Poor (epidemic)
- Found in seasonal spring/summer
8
Q
Borrelia Spp (Pathogenesis)
A
- IP: 2-18 days
- Fever w/chills, Splenomegaly & Hepatomegaly
- Self limiting 3-4 days-cleared by immune system
-
Antigenic variation changes in course of SINGLE infection
- Relaspe in a weeks time will be less severe
- 10+ relapses occur in endemic (fewer in epidemic)
- High mortality rate in epidemic-Human lice
- Death due to: cardiac failure, hepatic necrosis, or cerebral hemorrhage
- Diagnose: Giemsa/Wright stain=Spirochetes
- Treat: Tetracycline, penicillin, erythromycin
9
Q
Lestospira Interogans (Weil’s)
A
- Gram (-) thin coiled spirochetes W/hooked ends
- Resevoir: Rodents, dogs, farm animals
- Transmission: Exposure to contaminated water (fresh water) w/animal urine or infected tissue
- Entry via skin abrasions or conjuctiva
- High risk: Farmers, vets, hunters, meat handlers, water sports, sewer workers
- Diagnose: Dark field or giemsa stain
- Serology: Preferred test-Sensitive (isolated in bacteria phase)
- Treat: Doxy
10
Q
Lestospira Interogans (Pathogenesis)
A
- From skin/eye migrates to blood/CNS-(liver/kidney)
- Infects endo cells damages BV:
- Extensive vasculitis in many organs
- Meninges, liver, kidney, lung, hemorrhages
- Leptospirosis: IP 1-2 weeks
- Initial phasedue tobacteria-Mild-flu w/muscle pain
-
Secondary due _immune complex deposition _
- Aseptic meningitis, Jaundice
- Conjunctival suffusion (redding of eye
-
Weil’s disease-Most severe form w/Hepatic & renal dysfunction
- Renal failure, myocarditis, & vascular collaspe
- Cong form spread through breast feeding
11
Q
Brucella Spp (general)
A
- Very small Gram(-) coccobacilli-Strict aerobe
- Faculative intracellular of epi/phago cells <strong>(resist killing)</strong>
- Reservoir: Cattle (B.Abortus), Goats/sheep (B.melitensis), Pigs (B. suis), Dogs (B. Canis)
- Transmission: Consumption of contaminated dairy products/meat OR placenta
- High risk: Slaughter house, farmers, vets
- Abortion of cattle=High conc of erythriol (GF for Brucella)
- Serology: 4X increase in paired sera
- Treat: 3-6 weeks w/doxy + rifampin/gentamicin
12
Q
Brucella Spp (Pathogenesis)
A
- Penetrates skin or mucous membrane
- Faculative intracellular pathogen (inhibits phago formation)
- Inhibits apoptosis=prolongs life in infected cells
- Engulfed by PMNs-enter lymph-Blood
- Localizes in reticuloendothelial-Lymph, spleen, liver and BM
- Small granulomas/abscesses
- Periodic release=recurrent chills/fever
-
IP=1-3 weeks w/non-specific symptoms
- Chills & fever anorexia, weight loss
- Fever occurs daily (rising & falling)** onset<span></span>weeks to years**
- B. Meltitensis <strong>(goats/sheep)</strong>-fever & drenching sweats late afternoon or evening
13
Q
Francisella Tularensis (Tularemia)
A
- Very small gram(-) rod-Strict aerobe grows SLOWLY
- Faculative intracellular-Inhibits phagosome-lyso formation
- Inside mactophages of reticuloendothelial system
- Formation of granulomas-Symptoms=Cell HS
- Requires cysteine & buffered charcoal yeast extract
- Reservoir: Rabbits, deer & rodents
-
Transmission: Direct contact (rabbits & beavers), ingestion of meat, inhalation & VECTORS
- Low infectious dose (10-50)=Inhaled or wound
- High risk: Outdoorsman, hunters, trappers
14
Q
Francisella Tularensis (Disease)
A
-
_Tularemia-“Rabbit fever” _
- Different symptoms depending on site of entry
- Acute onset of fever, chills, malaise
- Ulceraoglandular(<strong>common)</strong>-Insect bite/skin
- Cuteneous ulcer @ bite w/swollen lymph-Papule ulcartes w/nectoric center & raised border
- Oculoglandular: Eye & swollen lymph (loss of jaw angle)
- Orophryngeal/GI-Eating meat (high conc needed)
- Pneumonic: Aerosol <strong>(low conc)</strong> high mortality
- Typhoidal: Prolonged illness (Typhoid fever)
- Any of the above can cause **Systemic sepsis **
15
Q
Francisella Tularensis (Clinical)
A
- High risk-Lab acquired infections
- To small to stain
- Culture: Cysteine supplements media
- Cysteine + Chocolate agar OR BCYE (slow growth)
- Treat: Streptomycin or Gentamicin
- _Prevention: _
- Live attenuated vaccine for high risk
- lab personnel contact w/animals
