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ASU MIC 205 - Exam 2 Review- Book of Bad Bugs

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Exam 2 Review- Book of Bad Bugs Diseases/microbes---- THIS EXAM COVERS THE CLOSTRIDIA AS WELL AS STREPTOCOCCI, LISTERIA, AND DIPTHERIA BAD BUGS LECTURES, INCLUDING WHAT WAS MENTIONED ORALLY AND ON THE WHITEBOARD.** Be able to identify the causative pathogen and/or disease by being given a description of the symptoms. Some will overlap, that is fine. Specific antibiotics that were emphasized during lecture are required. Do they have exotoxins? Endotoxins? Form endospores, capsules, fimbriae? Gram +, negative? Aerobe/Anaerobe? What is the “hallmark” symptom for the disease? What properties of the bacteria (when given) make them especially pathogenic? Is the disease common or not (don’t need to memorize numbers of cases per year). What leads to the disease (how is it usually contracted?). What are the treatments (when mentioned in class)? What is the treatment (antibiotics, surgery, debridement, hyperbarics, antitoxin, anti-anxiety meds, etc)?Clostridia Infections Clostridia - Gram +, spore forming anaerobes. EXOTOXINS, ANAEROBE- migrate to places with little oxygen. - Clostridia are known to produce a variety of toxins some of which are fatal.- They excrete powerful exotoxins and enzymes and produce endospores. - Clostrdium tetani - C. botulinum- C. perfingens - C. difficile Exotoxins: are proteins produced inside pathogenic bacteria, most commonly gram + bacteria, as part oftheir growth and metabolism. The exotoxins are then secreted or released into the surrounding mediumfollowing lysis. Endotoxins: are the lipid portions of lipopolysaccharides (LPS) that are part of the outer membrane of the cell wall of gram – bacteria (lipid A): The endotoxins are liberated when the bacteria die, and the cellwall breaks apart. Botulism- Botulism in not an infection, but rather a poisoning caused by the bacterium Clostridium botulinum.There are about 100 species of Clostridium and the species botulinum is responsible for Botulism poisoning. There are 7 types of botulism toxin designated by the letters A through G: only types A, B, E and F cause illness in humans. Clostridium Botulinum- EXTREMELY LETHAL NEUROTOXIN - RAPIDLY FATAL FOOD POISONING - Adult Botulism: smoked fish, home-canned veggies (toxin in food) Ingestion of preformed toxin, open wounds (release of toxin in open wound), GI surgery (rare)- Symptoms: No fever, double vision, general muscle weakness, sudden respiratory paralysis, death. - Infant Botulism: Ingestion of food contaminated with spores, botulism toxin releasedin intestinal tract, constipation for 2-3 days, difficulty swallowing, muscle weakness. - High correlation of infants that consume honey or corn syrup that has been contaminated with the spores, move through stomach acid and sporulate within the gut and produce the toxin which react with epithelial cells which cause constipation, takes about 2-3 days for constipation to ramp up then signs will be the same as adults. Look out for floppy baby syndrome. - Ingestion of spores, they grow and release the toxin. - HALLMARK: There is NO fever in intoxication Manifestations of Botulism1.) Foodborne: follows ingestion of toxin produced in food by C. botulinum. The most frequent source is home canned foods. (canned veggies) (dented cans) Alaska-smoked fish2.) Infant: Occurs when C. botulinum spores germinate and produce toxin in the gastrointestinal tract of infants. (honey, or corn syrup) Weak microbiome?3.) Wound: Occurs when C. botulinum spores germinate within wounds (drug addicts) Symptoms 18-36 hours after consumed, up to 10 days. Adult: Double vision, blurred vision, drooping eyelids, slurred speech, difficulty swallowing, dry mouth, muscle weakness, muscle paralysis Infant: Lethargy, poor feeding, constipation, a weak cry, poor muscle tone, respiratory (25% mortality rate) * Symptoms generally being 18 to 36 hours after eating contaminated food. As late as 10 days0.9 micrograms are lethal. Diagnosis Botox works by blocking ACH from being released Test- Positive serum- Selective culture (CBI agar, C. botulinum isolation agar)- Gastric contents- selective culture- Stool- Selective culture - Suspected food- selective culture - Positive mouse inoculation test- Mouse dies if +- Myasthenia Gravis (autoimmune)- Because the clinical presentation is similar to stroke, Guillain-Barre and Eaton-Lambert syndromes, neural imaging and spinal fluid analysis are generally performed; results are negative in botulism Treatment - Hospitalization (ventilator assist)- Trivalent antitoxin (ABE), an antitoxin made from horses, should be administered via IV or IM early in patients suspected of having botulism - Early usage decreases mortality and morbidity associated with illness- Physical therapy for strength recovery Infant treatment of Botulism - Given antitoxin but not antibiotics.- Treatment consequence of giving antibiotics to infants: can cause sudden release of more toxin (harmful and unfavorable)- Medicines that cause vomiting or enemas (to remove undigested food from the gut - Wound treatment: surgery used to remove contaminated tissue Clostridium Tetani - Puncture wound with rusty nail - Any skin trauma by an object contaminated with spores- Common in soil and animal feces - Exotoxin: (tetanospasmin) (encoded on a plasmid)- Sustained contraction of skeletal muscles - Tetany, Rigid, severe muscle spasms, lock jaw, - Clinically: Present with severe muscle spasms; lockjaw, grotesque grinning expression(Risus Sardonicus) 1.) Another booster shot2.) Booster, antibiotics to tetanus toxin (TIG) 3.) Clear toxin - May result in respiratory failure Treatment:- Antibiotics: Penicillin G (not given in late stage of tetanus) , any benzos for sedation such as Ativan/ Diazepam (IM), additional treatment would include a tetanus booster- tIg/antibody - Most common cause of death; same from botulism= respiratory failure - Time frame of 8 days after infection, combo of intoxication and infection- Puncture wound- bacteria or spore got into wound and starts to replicate and becomes a living cell, not as potent as botulism, requires more to be produced, haveto have more bacteria producing toxin which is why 8 days is enough time for bacteria to produce toxin.Clostridium Perfringens More of an infection - Causative agent for Gas Gangrene (Dishwater Pus) - Caused by a traumatic experience (GSW, stab wound) - In WWI soldiers died from gas gangrene - When spore gets into muscle, part of their metabolism is


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