Micro Final Notes

Micro Final Notes - 1 Bacillus anthracis Anthrax ­...

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Unformatted text preview: 1 Bacillus anthracis Anthrax ­ zoonotic disease that effects herbivores Humans are infected through infected animal tissues or can be used as biological warfare spore former found in soil (Malachite green ­special spore stain used) has a capsule which allows it to avoid phagocytosis 3 different toxins (2 must combine for toxicity): Protective factor ­ (aka protective antigen) initiate pore formation, most immunogenic of the toxins Edema factor ­ binds to PA to complete pore formation, increases intracellular CAMP causing edema Lethal factor ­ binds to PA to complete pore formation & forms lethal toxin(cleaves MAP kinase causing cell death) Forms of Anthrax: Cutaneuos: most common form, characterized by an Eschar ­ black necrotic ulcer Gastrointestinal: due to ingestion of spores, Rare but high mortality rate Inhalation: aka Wool ­sorters disease, latent period then sudden onset leading to possible death in 72 hours Bacillus cereus opportunist associated with rice 2 enterotoxins: 1) Heat stable 2)Heat labile Listeria monocytogenes Gram + Grows in a wide range of temperatures and in high salt concentrations facultative intracellular pathogen that thrives inside macrophages and epithelial cells infection starts in Peyer’s patches can grow in foods that have been refrigerated for a long period of time Gardnerella vaginalis Normal flora in most women associated with bacterial vaginosis ­ not an infection, an imbalance of flora(due to increased pH); fishy smelly vaginal discharge Potentially could cause Pelvic Inflammatory Disease ­ could lead to premature delivery or low birth weight Clue cells are the cause of the foul odor Douche and alkaline soups should be avoided due to adverse affects on normal flora and pH 2 Corynebacterium spp. Diptheria toxin ­ symptoms due to exotoxin released by lysogenized forms of the bacteria; toxin shuts off RNA process toxin is responsible for issues not the organism itself Transmitted by respiratory aerosols Pathological conditions: Diptheria (“leathery”) ­ Causes production of a pseudomembrane in throat; gives “bull ­neck” appearance Skin lesions: ulcerative lesions on skin; pseudomembrane also forms Myobacterium spp. Overview Tuberculosis and Leprosy (Hansens’s disease) Complex cell walls growth rate is very slow Myobacterium tuberculosis transmitted by aerosols Tuberculosis(Consumption): infection in lungs; Initial infection of alveolar macrophages; lesion is called Ghon’s focus Pott’s disease: TB infection of the vertebral column Manifestation of disease is typically due to the host response to the infection Pathological issues due to the result of the Cell immediate immune response Milk is pasteurized due to Bovine (cow) form of TB (M. bovis) Myobacterium leprae Causes leprosy (Hansens’s disease) Only non ­human source is armadillo Immune compromise is required for disease to occur produces a chronic infection of the skin and peripheral nerves 3 types: Lepromatous, Granulomatous, and Tuberculoid (Neural) Leprosy Lepromatous ­ effects skin cells, causes hypesthesia (numbness) of the skin 3 Clostridium spp.Overview Endospores ­ allow organism to live outside of the body; allows it to live in harsh conditions Found in soil, water and sewage produces toxins which cause pathologies Clostridium perfringens Toxin lyses RBC’S and WBC’S Toxin can cause: muscle tissue destruction, hepatic toxicity, and myocardial dysfunction Enterotoxin: heat labile (can be killed by heat) Clinical conditions: Gas gangrene (myonecrosis) ­ gas bubbles in tissue Clostridium difficile Results when antibodies have been taken for a long time; destroys flora of intestinal tract (Antibiotic ­associated colitis) Treatment: Fecal transfer ­ stool from healthy individual is injected into intestinal tract of compromised individual Food Poisoning: due to inadequate heating; produces abdominal cramps & diarrhea Clostidium botulinum Most potent biological toxin known; a potential bioterrorism weapon Use to be due to canning; not an issue in acidic foods Targets cholinergic nerves and prevents the release of acetylcholine; results in flaccid paralysis Regeneration of nerve endings is required for recovery Causes: Infant Botulism ­ “floppy baby”, poor muscle tone, failure to thrive Wound Botulism Do not feed infants honey because they don’t have flora to deal with the botulism bacteria Clostridium tetani Causes tetanus Spores survive in soil Can get from barb wire, splinters, animal/insect bites, self piercing or self tattooing full blown cases are usually a result or indoor injuries not outdoor injuries 2 most potent biological toxin nd 4 Blocks release of neurotransmitters causing Spastic Paralysis (causes back spasms= opisthotonos) Can cause: trismus or lockjaw; characterized by sardonic smile or risus sardonicus Vaccination (dpT and dT) targets to neutralize the toxin Gram Negative Bacteria (All have endotoxin) Neisseria spp. overview Gram negative diplococcic Neisseria gonorrhoeae aka Gonococcus, “Clap”,”Drip” reinfection is common Porin protein protects bacteria by interfering with neutrophil killing invades mucus membranes or skin lesions, once in system it can go anywhere Gonorrhea in men ­ purulent discharge, complications include epididymitis, prostatitis Gonorrhea in women ­ targets cervix Disseminated infection: gonococcemia (DGI) characterized by skin septicemia and infection of skin and joints primary cause of septic arthritis in sexually active adults Purulent conjunctivitis ­ can lead to blindness in adults and newborns (ophthalmia neonatorum) Virulence factor ­ IgA protease breaks down IgA Neisseria meningitides aka Meningococcus typically colonizes in the oropharynx of healthy individuals College students at risk, signs of infection are similar to a hangover Enterobacteriaceae overview side note: we test drinking water for choliforms which indicates fecal contamination that can be due to viruses and pathogens, not necessarily worried about E. coli Largest group of medically important bacteria, includes normal flora Culture: ferments glucose, catalase positive, oxidase negative Surface antigens O,K, H: these are how enterobacteria are named K & H antigens undergo antigenic and phase variation, 5 All fimbrial antigens undergo phase variation: which makes antibodies ineffective against antigens (this is why we can get infections when we go to new places because we haven’t made antibodies to the specific bacteria) Escherichia coli Virulence factors: Adhesins ­ allow bacteria to adhere to urinary and gastrointestinal tract Exotoxins ­ Shiga like toxins, heat stable, heat labile, hemolytic toxins Clinical conditions: Traveler’s diarrhea #1 cause of community & hospital acquired UTI’s Enterohemorrhagic E.coli ­ caused by strain 0157:H7, associated with hemorrhagic colitis Salmonella spp. Spread via Fecal ­oral route via 5 F’s= fingers, food, feces, fomites, and flies requires a large inoculums (large amount of bacteria), unless it is due to Salmonella typhi (strongest) Clinical conditions: Enteritis: Most common form of salmonellosis (caused by bacterial infection not toxin) Septicemia Enteric fever: aka Typhoid fever (caused by S. typhi), infection goes to reticuloenothelial system where they replicate in the liver, spleen and bone marrow; bacteria can re ­enter the bowel and a “rose spot” rash can develop on the abdomen; perforation of the intestine is the most common cause of death due to typhoid fever Treatment: prevention is best: if traveling only drink bottled water, For people who are carriers the bacteria is being shed on a continual basis; Typhoid Mary was a carrier Shigella spp. Most common cause of shigellosis( aka bacillary dysentery): primarily a pediatric disease obtained in daycare centers transmission is thru fecal ­oral route Bacillary dysentery: caused by toxin, symptoms include watery diarrhea, fever, pus and bloddy stool Yersinia pestis causes plague, aka Black Death vector: Rat fleas from rodents, Do not handle tame wild animals or recently deceased animals due to fleas 6 Clinical conditions: Bubonic plague: accumulates in local draining lymph nodes, not contagious Pneumonic plague: gets in lungs & becomes highly contagious Septicemia plague: multiplies in blood, not contagious Side note: CCR5 receptor and CD ­4 (MHC ­II) is what HIV binds to in order to enter cell, Yersinea uses the same two receptors to get in. Survivors of the black plague are missing CCR5 receptor, bacteria couldn’t enter cell due to a deletion of 32 base pairs Klebsiella pneumoniae has a capsule, 5 % of the bacterial pneumonias (high fatality) Proteus spp. 2nd most common cause of UTI’s Characteristics: urease production, increase urine alkalinity, foul odor, renal stones Serratia marcescens Strains produce red pigment grows on wet surfaces and considered harmless use to be used to test ventilation systems and air currents Vibrio cholera transmitted by fecal oral route Causes Cholera; characterized by Severe whatery diarrhea (“ rice water stools”) Campylobacter jejuni get from raw chicken and pets transmission: fecal ­oral route clinical conditions: decreased gastric acidity gastroenteritis with grossly bloody stools Guillaine ­Barre syndrome: a demylenating disorder 7 Heliobacter pylori Most common cause of ulcers Urease neutralizes stomach acid Pseudomonas produce blue ­green pigments Has a “Musty grapes” smell extremely resistant to most antibiotics and to many disinfectants opportunist with a biofilm that causes death in Cystic Fibrosis patients and Burn victims Can be an issue in hot tubs and swimming pools, can get Swimmer’s ear (otitis externa) or Hot tub folliculitis Haemophilus influenza (type b) (Hib) Encapsulated strains responsible for meningitis in children less than 1yr old Unencapsulated strains responsible for otitis media and lower respiratory tract infections Hib vaccine is for this bacteria Haemophilus ducreyi STD characterized by a chancroid or soft chancre, which is PAINFUL, bleeds easily and has a soft raised border Bordetella pertussis Whooping cough (pertussis) (100 day cough) 3 stages plus a recovery period that can take over three months Complications include pneumonia, seizures, encephalopathy or death infants are at the highest risk of mortality due to the fact that they don’t have muscles developed yet to expel mucus DPT was the original vaccine ­ whole cell vaccine that eliminated the organism DTaP is the current vaccine ­ acellular vaccine that doesn’t eliminate organism but deals with toxin Brucella abortus Causes Brucellosis or “undulant fever” 8 Legionella pneumophila Occurred at the American Legionnaire’s convention in Philadelphia lives within amoeba Causes: Legionnaires Disease (Legionellosis), Legionnaire’s Pneumonia, Pontiac Fever recently was an issue at a hotel due to shower heads that removed the chlorine out of the water supply prevention: minimize growth of amoeba in water (chlorinate chlorinate chlorinate) Bartonella henselae Cat ­scratch disease Spirochetes: Treponema, Borrelia & Leptospira spp.(“Teflon bacteria”) Treponema pallidum pallidum spiral shaped bacteria that is not Gram negative or positive Infection requires direct person to person contact Clinical conditions: Primary syphilis: characterized by a PAINLESS, circular, purplish chancre with a FIRM raised margin Secondary syphilis: copper colored rash on body especially on palms and soles (“pockmarks”), this stage often gives syphilis the name “The Great Pox”, Condylomata lata ­ knobby wartlike growth that grows in warm moist areas of the body Tertiary syphilis: untreated it can lead to irreversible complications, characterized by gummas, granulomatous lesions on mucous membranes or Argyll Robertson pupils, can lead to blindness hearing impairment, arteritis, dementia or death Congenital syphilis: Characterized by Hutchinson’s triad Treponema pallidum pertenue Produces Yaws or frambesia (red raspberry lesions) Mother yaw forms at the site of the infections Leptospira interrogans Due to contact dog or rodent urine Causes: Leptospirosis ­ typically a urinary tract disease symptoms: Weil’s disease 9 Borrelia recurrentis Causes two forms of relapsing fever: Tick ­borne (endemic relapsing fever)& Louse ­borne (epidemic relapsing fever) Borrelia burgdorferi Lyme disease, named for a cluster of cases of Juvenile Arthritis in Lyme, Connecticut Willy Burgdorfer first isolated the spirochete from the gut of a tick Lyme disease is the most reported tick borne disease in the USA Transmitted by Ixodes tick (deer tick) Stage 1 Early Lyme disease: characterized by a ring called erythema migrans with a clear center “bulls ­eye lesion” Stage 2 Disseminated Lyme disease: misdiagnosed as chronic fatigue syndrome or fibromyalgia, can cause Bell’s palsy Stage 3 Chronic Lyme disease: Characteristic symptom is migratory arthritis, other symptoms include Destructive arthritis due to autoimmune reactivity (molecular mimicry) which attacks synovial tissues Prevention: using a repellent with DEET, inspect entire body after being outdoors Mycoplasma and Ureaplasma intro No cell wall Intracellular bacteria smallest free living bacterium not susceptible to penicillin due to the fact that it does not have a cell wall Mycoplasma pneumonia membrane parasite that appears worm ­like clinical considerations: Walking pneumonia Rickettsia spp. and Orientia Obligate intracellular parasites Clinical considerations: Rocky Mountain Spotted Fever due to Rickettsia rickettssi Rickettsial pox due to Rickettsia akari Epidemic typhus due to Rickettsia prowazekii Brill Zinsser Disease due to Rickettsia prowazekii Endemic typhus due to Rickettsia typhi (vector is the rat flea) Scrub typhus due to Orientia tsutsugamushi ( vector is the larval form (chigger) of a mite) 10 Coxiella burnetti Transmitted to cows by ticks can be in milk can also be in straw Current pasteurization temperatures are set to target this organism Chlamydiae overview “Energy Parasites” ­ these cannot make ATP Stains as Gram negative but have no peptidoglycan Chlamydia trachomatis Clinical conditions: Trachoma: causes keratoconjunctivitis, World’s leading cause of preventable blindness Chlamydia: dual infection with Neisseria gonorrhea, may result in Reiter’s syndrome Adult Inclusion Conjunctivitis (aka swimming pool conjunctivitis) Chlamydophila psittaci Causes psittacosis, parrot fever due to inhalation of dried bird feces Chlamydophila pneumonia (she really didn’t mention anything but the name) produces bronchitis, pneumonia, sinusitis has been recently associated with an increase risk of atherosclerosis ...
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This note was uploaded on 05/03/2011 for the course BIO 1 taught by Professor Paul during the Spring '11 term at Palmer Chiropractic.

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