1. Spores are DEPOSITED in skin, respiratory or GI mucosa 2. Spores then GERMINATE in tissues 3. Bacteria MULTIPLY and PRODUCE TOXINS 4. Toxins cause TISSUE NECROSIS 5. Anthrax toxins DISSEMINATE through bloodstream and lymphatics 6. Anthrax causes systemic toxicity and DEATH
What toxins are produced by anthrax?
1. Lethal toxin 2. Edema toxin
CAPSULE blocks phagocytosis and toxins inhibit neutrophil function (oxidative burst) & induce cytotoxic effects
How does Cutaneous Anthrax manifest clinically?
Pruritic papules on exposed skin -Enlarges over several days, progressing to an ulcer with/without surround vesicles -CENTER is BLACK and NECROTIC -EDEMA surrounds the lesion -Often painless, regional lymphadenopathy
After germination and transport via the lymphatics, where do the Respiratory anthrax spores go to?
Hilar/mediastinal lymph nodes
What do antrax toxins do to the mediastinum?
Cause necrosis and hemorrhage
What do Chest XRay and CT findings show with respiratory anthrax?
What are the symptoms of respiratory anthrax?
Substernal pain and cough Signs of stridor (noisy breathing) on exam Neck and mediastinal edema
What does necrosis in the pleura from anthrax lead to?
How does respiratory anthrax spread?
How many phases are there to respiratory anthrax? What are they?
1. Initial phase (1-3 days) Malaise, fever, dry cough, sub-sternal pain 2. Secondary Phase Sudden onset, rapid progression to death in 1-2 DAYS!! Dyspnea, stridor, high fever, diaphoresis Mortality high, over 90% (difficult to diagnose!)
How is respiratory anthrax diagnosed?
Chest X-ray with Widened mediastinum! -Bloody pleural tap -Culture blood, pleural fluid or CSF for Gram Positive Rods
How does a human contract GI anthrax?
Human consumes meat from an infected animal
Where do INGESTED spores germinate?
How does Gastrointestinal Anthrax present?
One of TWO forms: 1. Oropharyngeal Anthrax (hard palate, postpharynx) 2. Abdominal Anthrax (Large bowel, cecal lesions)
How do you diagnose someone with Anthrax?
High Clinical Suspicion -Must be able to recognize clinical syndromes
How do you treat anthrax?
IV Penicillin G, doxycycline, ciprofloxacin
What is used for prophylaxis measures for anthrax?
Doxycycline or quinolone (cipro), up to 6wk
How do you control antrax disease?
Must control the ANIMAL disease
What types of infections do Bacillus cereus cause?
-Food poisoning -Traumatic ocular infections
Bacillus cereus pathogenesis
1. Enzymes destroy tissue 2. Toxins cause diarrhea/emesis 3. Anti-microbial agents produced by bacteria help the bacteria to compete
What are the two types of food poisoning?
1. Emetic form vomiting predominate feature 2. Diarrhea form cramps, nausea, watery stools
What is an example of a food that causes emesis?
What are examples of foods that cause the diarrheal form of food poisoning?
Contaminated MEATS (turkey) or VEGETABLES
How long does it take for Bacillus cereus to incubate in the emetic form?
How long does it take for Bacillus cereus to incubate in the diarrheal form?
10-12 hours, improved in 24
What is the virulence factor that is responsible for Bacillus cereus food poisoning?
How do you diagnose Bacillus cereus?
Clinical syndrome -Culture the FOOD
How do you treat food-poisoning?
Self-limited, so no antibiotic therapy is need
What bacillus species is responsible for ocular infections?
How are bacillus ocular infections usually caused?
-Trauma (soil exposure) -Foreign body (particles of dust, soil or shrapnel) -IV drug abuse
How do Bacillus ocular infections manifest?
-Panopthalmitis -Ocular abscess
How long does it take for Bacillus cereus to cause damage to the eye
RAPID: 12-48 hours -pain, redness, visual changes
What are important Corynebacterial Infections?
1. C. diphtheriae 2. C. jeikeium 3. Arcanobacterium haemolyticum 4. Rhodococcus equi
What organism causes diptheria?
What does C. jeikeium cause?
Bacteremia in IMMUNOCOMPROMISED PATIENTS/NEUTROPENIA, HOSPITAL ACQUIRED INFECTIONS (IV CATHETERS)
How does C. diptheriae appear on a gram stain?
What is C. diptheriae's virulence factor?
What does C. diptheriae's virulence factor do?
-Inhibits protein synthesis -Extremely potent -Responsible fo tonsilar/pharyngeal exudate that characteristics of diptheri
What is a protective factor to diptheria?
Having antibodies to the diptheria exotoxin
What is the reservoir for diptheria?
What percentage of diptheria remains as an asymptomatic carrier state on the skin and pharynx?
How is diptheria transmitted?
Transmission through bacteria in AIRBORNE droplets or CONTACT with secretions/exudate
When is diptheria usually around?
What conditions make diptheria more prominent?
Who is at risk for diptheria today?
Children <15 yo if unvaccinated Unimmunized or unboosted adolescents/adults (urban poor, those with no access to health care, IV drug users)
What does the diptheria exudate consist of?
Necrotic collection of cells, fibrin, dead respiratory epithelial cells, RBCs, WBCs and bacteria
What can the diptheria exudate cause?
-OBSTRUCTION of the airway -BULL NECK
How can DEATH be caused by diphteria?
Aspiration of the membrane?
Besides the exudate, how does someone with diptheria usually present in the clinic?
-Fever, sore throat and membrane development (tonsils, posterior pharynx) -Cervical lymph nodes common -Systemic effects on tissues at distant sites -Cardiac toxicity (myocarditis) -Neurological toxicity Paralysis of palate, hoarseness or stridor
What is special about Listeria Monocytogenes?
25C TUMBLING MOTILITY
Is listeria pathogenesis extra or intracellular?
Listeria risk of disease?
Rare cause of disease but risk to select population
What kind of diseases is Listeria responsible for?
Food borne disease
What bacterium is zoonotic?
How is Listeria moncytogenes transmitted among humans?
Vertical transmission ONLY
What general foods can harbor Listeria monocytogenes?
Raw vegetables, raw milk , raw fish, meants and poultry
What are specific examples of foods that can harbor Listeria monocytogenes?
-Coleslaw -Unpasteurized soft cheeses -Ready-to-eat products/meats -Smoked fish
Who is most at risk for Listeria monocytogenes?
-Neonates and elderly -Pregnant women -Impaired cell-mediated immunity, immunosuppressed -HIV+
How long is the incubation time for Listeria monocytogenes?
How does Listeria monocytogenes infection usually begin?
Ingestion of contaminated food
What promotes Listeria monocytogenes infection?
-Gastric surgery -H2 blockers (stomach pH increased)
Where does Listeria monocytogenes like to stay in the body?
What is the pathogenesis of Listeria monocytogenes?
-Binds epithelial cells -Escapes host's ability to kill the organism -Survives intracellularly
What are the clinical diseases caused by Listeria?