Lecture 18: Bacterial Human Disease I Flashcards
1
Q
Bacterial pathogens- respiratory system
A
- Most airborne bacterial diseases infect the respiratory system
- cause disease of sinuses , throat, bronchus, or lungs
- some can disseminate into the bloodstream
2
Q
Pneumonia Symptoms
A
- common symptoms are fever, cough, sore throat, hoarseness, and pain on swallowing
3
Q
Chlamydophila Pneumoniae (Bacterial pneumonia agents)
A
- treated with macrolides
4
Q
Steptococcus pnemoniae (Bacterial pneumonia agents)
A
- treated with tetracyclines or macrolides
5
Q
Mycoplasma pneumoniae (Bacterial pneumonia agents)
A
- “Atypical”, most common in kids, resistant to B- lactams
6
Q
Haemophilus influenza (Bacterial pneumonia agents)
A
- treated with macrolides
7
Q
Diptheria
A
- airborne transmission
- Caused by Corynebacterium diptheriae (G+)
- toxin mediated disease: carries prophage to cause disease
- destroys cardiac, kidney and nervous tissues by inhibiting protein synthesis
- Vaccine- preventable (TDaP)
8
Q
Legionnaire’s disease
A
- airborne, common in HVAC systems
- caused by Legionella pneumophila
- aerobic, Gram -
- outbreaks traced to contaminated water
- fever, cough, headache, neuralgia and diarrhea
- treated with Z-pak or fluoroquinolones
9
Q
pertussis
A
- whooping cough
- caused by Bordetella pertussis (gram -)
- highly contagious
- Fever, malaise, cyanosis (bluing of extremities due to lack of oxygen)
- Vaccine preventable (TDaP), macrolides for treatment
10
Q
Meningitis
A
- inflammation of the brain or spinal cord meninges
- Transmitted by respiratory droplets
- vomiting, headache, lethargy, confusion, sensitivity to light or stiffness in neck
- vancomycin
11
Q
Mycobacterial infections
A
- in soil, water and house dust
- causes human infections difficult to treat
- Mycolic acid in cell wall makes mycobacteria acid-fast
- respiratory and gastrointestinal tracts have been proposed as portals on entry
12
Q
Tuberculosis
A
- caused by mycobacterium tuberculosis (Mtb)
- spread by droplets and aerosols
- fever, fatigue, night sweats, weight loss and cough
- common among homeless, malnourished, alcoholic males and immigrant population
13
Q
leprosy
A
- skin infection
- caused by Mycobacterium leprae
- spread in nasal secretions
- humans and armadillos are only significant reservoirs
14
Q
Steptococcal disease
A
- lancefield “group A” strep
- Caused by step, gram + bacteria
- streptococcus pyogenes: B-hemolytic streptococci
15
Q
Streptococcal diseases (Virulence Factors)
A
- extracellular enzymes: break down host molecules
- Streptokinases: dissolve clots
- Streptolysin: kill host leukocytes
- Capsules& M protein: limit phagocytosis
16
Q
Streptococcal Pharyngitis
A
- strep throat
- spread by droplets of saliva or nasal secretions
- pharyngitis or tonsils (tonsillitis)
- redness, lymph node enlargement in throat
17
Q
Post-streptococcal disease
A
- glomerulonephritis (bright’s disease): inflammatory disease of the kidney; may require kidney transplant or lifelong dialysis
- Rheumatic fever: autoimmune disease affecting the heart valves, joints, subcutaneous tissues and central nervous system
18
Q
Anthropod vectored diseases
A
- direct transmission
- plague
- lyme disease
19
Q
Lyme disease
A
- vector: ticks
- most common tick borne zoonosis
- caused by Borrelia burgdorferi
- rodents are natural hosts
- complex illness
- three stages of disease: initial, disseminated, late stage
20
Q
Localized stage (Lyme disease)
A
- develops 7 to 10 days after infectious bite
- Expanding, ring shaped skin lesion
- flulike symptoms
- docxycline effective in early stages
21
Q
Disseminated stage (lyme disease)
A
- occurs weeks or months after infection
- neurological abnormalities, heart inflammation and arthritis
22
Q
late stage (lyme disease)
A
- occurs years later
- demyelination of neurons with symptoms similar Alzheimer’s disease and multiple sclerosis
23
Q
Rocky Mountain spotted fever
A
- Vector: ticks
- caused by Rickettsia rickettsii
- severe headache, high fever,chills, skin rash
- can destroy blood vessels in heart, lungs, or kidneys, leading to death
24
Q
Bubonic Plague
A
- Vector: Rodents& Fleas
- yersinia pestis- gram negative
- multiply in lymph nodes and disable an effective immune response
- hemorrhages, fever, chills, headache, extreme exhaustion and enlarged lymph nodes (buboes)
- treated with streptomycin
25
Y. pestis virulence (bubonic plague)
- type III secretion system: delivers effective proteins to targeted host cells
- phagocytosed by immune cells and can survive
- A potential bioterrorism agent
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Gas Gangrene
- necrotic diseases
- Caused by Clostridum perfringens; gram +, endospore forming rod
- infection of skeletal muscle
- clostridial myonecrosis
- secretes toxin and tissue damaging enzymes
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Group B streptococcal diseases
- caused by Gram + streptococcus agalactiae or group b steptococcus
- causes sepsis, pneumonia, and skin bone infections
- transmitted maternally to newborns
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Peptic Ulcers and Gastritis
- caused by gram - Helicobacter pylori
- colonizes gastric mucus secreting cells
- produced urease: acts to increase pH
- increase inflammation
- though to cause later stomach cancer
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Chlamydia
- STD
- due to asymptomatic cases
- Chlamydia trachomats; most frequently isolated
- transmitted thru sex
- transmitted from mother to child during vaginal childbirth
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Gonorrhea
- STD
- caused by Neisseria gonorrhoeae
- Gram -, diplococcus
- cefriaxone injection to treat
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Gonorrhea in neonates
- opthalmia neonatorum ( conjunctivitis of the newborn)
- newborn eyes infected as they pass through an infected birth canal
- prevention is by erythomycin on eyes of all newborns
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Syphilis
- STD
- caused by treponeuma pallidum
- congenital syphilis: when disease is transmitted in utero to child
- treatment: benzathine, penicillin or doxycycline
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