(LE4) Bacterial Pathogens Flashcards
What virulence factor is shared with all S. aureus strains?
Coagulase
- form a blood clot around bacteria
- important for furuncle and carbuncle
What complication is shown?
Scalded Skin Syndrome
- lysogenized exotoxin only found in one type of Staph as a result of transduction with a bacteriophage
- most common in newborns and infants
What is TSST-1
Can cause toxic shock syndrome
S/S: - sunburn-like rash
- relatively high fever
- Shock
What is enterotoxin?
Cause food-borne illness
What disease is shown here? What causes this disease? Describe the mode of transmission, signs/symptoms, prevention and treatment, and interesting facts
Disease: staph infection
Pathogen: S. aureus
MOT: direct contact on skin
S/S: different forms based on entry points and virulence factors
- Furuncle (boil) inflammation filled with pus. Can move subcutaneously and become carbuncle
- Endocarditis: if it enters the bloodstream
Tx: Antibiotics
ETC: Food poisoning (heat stabile toxins, Staph is a halophile)
Describe different Streptococcus virulence factors
Dependent on portal of entry
- Hyularonidase and Collagenase: breaks down CT
- Protease: protein breakdown
- Pyrogen: Fever inducer
- Leukocidins: WBC breakdown
- Hemolysins: RBC breakdown
- Erythrogenic toxin: causes scarlet fever
- H protein: super antigen that creates immune complexes
What disease is shown here? What causes this disease? Describe the mode of transmission, signs/symptoms, prevention and treatment, and interesting facts
Disease: strep throat
Pathogens: Streptococcus pyogenes (group A beta-hemolytic Strep)
MOT: Droplet (PoE: Upper respiratory tract)
S/S: sore throat, fever, dysphagia
Tx: antibiotics
What complication is pictured?
Scarlet fever
erythrogenic toxin
S/S: - sunburn-like rash, fever, strawberry tongue
- skin doesn’t blanche
What complications can occur post-Strep infections with M protein?
Rheumatic fever
- Ag-Ab complexes settle in joints and heart valves
- arthritic-like symptoms
Glomerulonephritis
- Ag-Ab complexes settle in kidney
- Inflamed kidneys
- may require dialysis or kidney transplant
What disease is shown?
Erysipelas - cutaneous strep infection
S/S: fever and rash with well-defined edges
Portal of Entry: hair follicle
What disease is shown?
Necrotizing Fasciitis - “flesh-eating” Streptococcus
Portal of Entry: minor cut/abrasion
S/S: Begins with furuncle and spread quickly (few days)
- Systemic infection: DIC
Tx: - Localized: surgery, amputation, antibiotics
Describe bacterial meningitis
Pathogen: Multiple
Portal of entry: Respiratory -> blood -> CSF. may be part of normal flora for some
S/S: - headache, stiff neck, high fever, ringing in ears
Tx: Broad-spectrum antibiotics
ETC: - occur in sporadic outbreaks
Dx: Lumbar puncture
- more severe than fungal or viral meningitis
What bacteria cause meningitis?
Streptococcus pneumoniae (G+C)
- most common in children and elderly
Neisseria meningitidis (G-C)
- most common in adolescents and young adults
- outbreaks
Haemophilus influenzae b (G-B)
- most common in 6mo-4yr
What disease is shown?
Disease: Tetanus
Pathogen: Clostridium tetani
Portal of Entry: Deep wound (anaerobic tissue) (spore in soil)
S/S: Spastic paralysis, fatal: diaphragm
Tx: vaccine, antitoxin, and antibiotics
ETC: - tetanus toxin inhibits ACh re-uptake (for muscle relaxation) at NMJ
What disease is shown?
Disease: Botulism
Pathogen: Clostridium botulinum
Portal of Entry: canned foods or needles (IV drug use)
S/S: Flaccid paralysis, fatal: diaphragm
Tx: Antitoxin
ETC: - botulism toxin inhibits ACh release at NMJ
What disease is shown here? What causes this disease? Describe the mode of transmission, signs/symptoms, prevention and treatment, and interesting facts
Disease: Gas gangrene
Pathogen: Clostridium perfringens (soil-dwelling spore former)
PoE: Deep wounds
S/S: Gas bubble formation, Necrosis
Tx: Amputation, antibiotics (best early with wound)
ETC: before antibiotics, maggot therapy was used
What disease is shown here? What causes this disease? Describe the mode of transmission, signs/symptoms, prevention and treatment, and interesting facts
Disease: Anthrax “woolsorter’s disease”
Pathogen: Bacillus anthracis (spore former)
Cutaneous: - PoE: wound
- S/S: Dark localized sore, potential septicemia (10-20% fatality)
Inhalation: - PoE: respiratory tract
- S/S: rapid onset pneumonia (100% fatal)
Tx: antibiotics
What disease is shown here? What causes this disease? Describe the mode of transmission, signs/symptoms, prevention and treatment, and interesting facts
Disease: Septicemia
Pathogen: most often G- bacteria growing in blood
PoE: nosocomial infection
S/S: preceded by lymphangitis, broad symptoms, elevated WBCs, shock
Tx: antibiotics, anti-inflammatories
ETC: fast-moving, treatment difficult for G- bacteria
What disease is shown here? What causes this disease?
Disease: Endocarditis
Pathogen: Staphylococcus (acute; days-weeks), Streptococcus (Subacute; weeks-months)
PoE: Nosocomial bacteremia, dental work, poor nursing care
ETC: Most common with damaged heart valve (Rheumatic fever, congenital defect, other infections)
What disease is shown here? What causes this disease? Describe the mode of transmission, signs/symptoms, prevention and treatment, and interesting facts
Disease: Plague
Pathogen: Yersinia pestis
Reservoir: rats, rodents. - Vector: Fleas
Bubonic plague: -S/S: buboes, high fever, sepsis, hemorrhaging
- ETC: 50% fatality (untreated). Veterinary problem
Pneumonic plague: - S/S: Rapid onset pneumonia
- Acute, 100% fatal
- Inhalation from bubonic patient
Tx: antibiotics
What disease is shown here? What causes this disease? Describe the mode of transmission, signs/symptoms, prevention and treatment, and interesting facts
Disease: Lyme disease
Pathogen: Borrelia burgdorferi
Reservoir: mice, Vector - Deer tick
S/S: Bullseye rash at bite site, systemic granulomas, arthritis, neurological symptoms
Tx: antibiotics if caught early, vaccine (not very effective)
What disease is shown here? What causes this disease? Describe the mode of transmission, signs/symptoms, prevention and treatment, and interesting facts
Disease: Diphtheria
Pathogen: Corynebacterium diptheriae (G+ uneven bacillus)
MOT: Droplet transmission (very contagious)
S/S: Gray pseudomembrane -> dyspnea
Tx: Antibiotics, antitoxin, DTaP vaccine
ETC: Lysogenized exotoxin: inhibits protein synthesis
What disease is shown here? What causes this disease? Describe the mode of transmission, signs/symptoms, prevention and treatment, and interesting facts
Disease: Whooping cough (pertussis)
Pathogen: Bordetella pertussis
MOT: Droplet transmission (very contagious)
S/S: Chronic cough (1-6 weeks), can be fatal in young infants
Tx: antibiotics.
Vaccines: Old: inactivated, effective, side effects. New: TDaP, acellular, safe, less effective, frequent boosters
ETC: Exotoxin kills cilia in throat (cough to move mucus, difficult to inhale when coughing)
What disease is shown here? What causes this disease? Describe the mode of transmission, signs/symptoms, prevention and treatment, and interesting facts
Disease: Hansen’s Disease (Leprosy)
Pathogen: Mycobacterium leprae (slow to grow/die. prefers cooler areas of body like skin and limbs)
PoE: Respiratory
Tuberculoid form: -milder
- S/S: raised lesions, loss of skin pigment, loss of sensation
- Good immune system
Lepromatous form: - more serious
- S/S: granulomas in skin and limbs, disfigurement, “lions face”(disfigurement of philtrum)
- immunocompromised
Tx: Years of antibiotics
ETC: Chronic condition (incubation period is 4-8 years)
Not infectious after 24 hours receiving treatment.
What disease is shown here? What causes this disease? Describe the mode of transmission, prevention and treatment, and interesting facts
Disease: Tuberculosis
Pathogen: Mycobacterium tuberculosis (slow to grow and die)
MOT: Droplet transmission (not very contagious, needs prolonged exposure to make it to alveoli)
Non-progressive TB: - grows inside alveolar macrophage, granulomas form, granuloma calcify to form tubercle. Tubercle contained without underlying disease. No symptoms, not contagious
Progressive TB: With underlying conditions (COPD, immunocompromization), tubercles break open and spread bacteria. Lung and BV damage -> bloody cough. Contagious
Disseminated TB: bacteria spreads to at least one other organ, “consumption”
Tx: 6 mo-2yrs Isoniazid compliance, BCG vaccine (minimal protection)
ETC: Multi-drug resistance
TB Skin test: type 4 immune reaction, if exposed Tc cells will swell area. Not specific if recent or previous exposure, or vaccine
What disease is shown here? What causes this disease? Describe the mode of transmission, signs/symptoms, prevention and treatment, and interesting facts
Disease: Syphilis
Pathogen: Treponema pallidum (G- spirochete)
Primary stage: Chancre
Tx: antibiotics
Secondary stage: Rash
Tx: antibiotics
Tertiary stage: Can cross placenta, Neurosyphillis, Ocular syphilis (blindness), Otosyphilis (deafness)
Tx: none
