Micro Cheat Sheet #2

Micro Cheat Sheet #2 (PASS Videos)

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Spore Formers – Bacillus and Clostridium

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SPORES o o o o

Made of “Ca-dipocholinate” Dormant form of the bacteria CANNOT replicate but CAN release toxin especially when exposed to heat (“GET MAD!”) It is destroyed ONLY by sterilization process  121 degrees C vaporized

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Bacillus o Has poly D-Glutamate membrane (humans have L-amino acids) o B. anthracis  Has a toxin with three factors: lethal factor (kills cells), edema factor, and protective factor (mediates entry)  Two types of Anthrax:  Cutaneous Anthrax: malignant pustule (skin necrosis) o Will not kill pt unless inhales cutaneous form  Pulmonary Anthrax: Wool Sorter’s Disease; (hot desert) mediastinal hemorrhagic lymphadenitis o B. cereus  Fried/reheated rice (hot wok)  Two toxins:  Emetic toxin: from the rice – fast (1-6hrs)  diarrhea, vomiting  Diarrheal toxin: meats, sauces – increases cAMP - 18hrs watery diarrhea

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Clostridium o C. difficile  Gastroenteritis associated with antibiotic use  ALL Antibiotics destroy E.coli  Clindamycin is notorious

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Pseudomembranous colitis – grey membrane with yellow plaques on colon Tx: DOC is metronidazole (promotes production of free radical)  Side Effects: dysguzia (alteration in taste), disulfiram reaction  Most Effective Drug is Vancomycin C. perfringens  Gas Gangrene  Known to attack extremities in diabetics o Dry gangrene – necrotic skin o Wet gangrene – blood to the area (risk of gas emboli) o Tx: Immediate amputation (hyperbaric chamber)  Food poisioning  Gastroenteritis – associated with holiday ham or turkey o Enterotoxin o Immediate symptoms – diarrhea almost instantaneously C. melanogosepticus  Associated with colon cancer (along with S. bovis)  Produces a black pigment C. tetani  Associated with a dirty wound  Give anti-Ig to bind toxin (into the wound)  Toxin:  Inhibits release of glycine (inhibitory) in the spinal cord – increasing contraction respiratory failure  Lock jaw  Tetanus Immunizations: Td = toxoid; TIG = immunoglobulin

Hx Td dose ≥3 known doses < 3 or >10years since last booster

Clean, Minor: Td NO YES

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Clean Minor: TIG NO NO

Other: Td CLAUSE below YES

Other: TIG NO YES

Clean is considered anywhere inside your house. Dirty is when you step outside. Knife cut in house = clean. Knife cut outside = dirty If more than 3 tetanus shots, you don’t do anything. EXCEPT: when it is a dirty wound and it has been greater than 5 years then give Td

C. botulinum  Toxin – inhibits presynaptic release of Ach – flaccid paralysis (floppy baby)  Muscle will not work – die of respiratory failure  Worse in kids (especially infants) because of excess brown fat  inceased heat  spores hate heat  Children – Honey, molasses

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 Do NOT give children honey until 6mo of age (normal flora will appear) Adults – ingest spores via canned foods Tx: antitoxin first, antibiotic second

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Propionobacterium Acne o Progesterone stimulates propionic acid or sebum o Acne more severe in women and adolescent boys o Refer to a dermatologist when its nodular or nodulocystic o Gram (+) anaerobe; hides in the hair follicles o White comedones: clear vesicles o Black comedones: sebum has been oxidized; turns black o Tx: oxy-5 or oxy-10; benzoyl peroxide or abrasive pads; antibiotics (minocycline, clindamycin, or erythromycin); retinoic acid

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Retinoic Acid o Pre-Vitamin A o Cause proliferation of skin cells, pushing the pathogen to the surface (hypersensitivity) o Main Side effects:  Hyperlipidemia (fat soluble)  Hyperparathyroidism  Retinoic acid is a cofactor  Vit A and Mg are cofactors for PTH  Pseudotumor cerebri  Vit A needed to make CSF  Teratogenic (must do pregnancy test)

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Lysteria o L. monocytogenes  The ONLY gram + with endotoxin (kills quickly)  Causes monocytosis – granulomatous inflammation  Syphilis  TB  EBV – Epstein-barr virus STELS  Lysteria Monocytogenes  Salmonella typhi  Attack placenta causing abortions  Requires iron to grow; high incidence in pt with hemochromatosis

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Causes:  Neonatal sepsis  Gastroenteritis associated with migrant workers, raw cabbage, spoiled milk, hot dogs  Curved rod, tumbling motility  Intracellular, cold growth  Tx: Ampicillin, macrolide, vancomycin L. meningitis  MCC of meningitis in Renal Transplant pt and Adults with cancer

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Gram Negatives

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Hemophilus o o o o o o

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Gram (-) pleomorphic rod Has IgA protease Part of normal flora for the posterior pharynx 80% are NOT encapsulated and therefore cause noninvasive respiratory diseases (nontypeable) 20% are encapsulated (poly D-glutamic acid) causes the systemic form (H. influenza B) H. Influenza  2nd MCC of sinusitis, otitis media, bronchitis, and pneumonia  S. pneumonia is #1 H. Influenza type B  MCC for epiglottitis  Symptoms: Thumb print sign, drooling, fever, stridor (upper airway; both inspiration and expiration)  Tx: intubate immediately H. aegyptus  Pink eye (not viral conjunctivitis which is a little redness in the eye) H. ducreyi  MCC of chancroid  Most common painful genital lesion (unilateral lymph node)  Tx: ceftriaxone

Painful genital Lesions o Chancroid (H. ducreyi) – most common ulceration with central necrotic area  Tx: Ceftriaxone

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Herpes (Herpes Simplex II) – small vesicular rash  Acyclovir – 5x day  Pancyclovir – 3x day  Valcyclovir (valtrex) – 2x day (more compliant) ***Remember: does NOT sure – decreases symptomatic days, viral shedding and recurrence 

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Pregnancy – symptomatic within 2 weeks of planned deliver – must do a C section Lymphogranuloma venereum  Chlamydia trachomatis – ulcerative LN drain (bilateral)  Tx: Doxycycline Granuloma Inguinale  Calymmatobacterium donovini – donovini bodies (macrophages with the bug in it)  Tx: Arithromycin, tetracycline

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HiB Vaccine o Has cut HiB infections down by 90% o Given at 2m, 4m, 6m, 18m o Last dose at 5y; no longer needed after that

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Nisseriae o The ONLY gram negative diplococcic o Has IgA protease o Part of throat flora o Encapsulated (has the largest capsule) o The ONLY gram (-) that releases endotoxin during the “log” phase o N. meningitis  Ferments maltose and glucose  Presents with DIC (uses up clotting factors) – D-dimer and fibrin split products  Waterhouse-Fredrickson syndrome – hemorrhage into adrenal gland  Increased ACTH levels  MCC of meningitis from 10-21y/o  Tx: dexamethasone BEFORE antibiotic to prevent hearing loss from inflammatory neurological damage ; give rifampin to close contacts (>25hrs/wk) o N. gonorrhea  Ferments glucose  Has pili that naturally transform each year (phase variation)

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MCC for purulent STDs #2 cause of STDs (Chlamydia is #1)  In men: 90% of cases are symptomatic  In women: 50% are symptomatic  Uses pili to walk up the uroepithelium to gain access to the blood  Fitz-Hugh-Curtis Syndrome: Abscess right underneath the liver  Gonococcal arthritis: ligaments (i.e. tenosynovitis)  Starts at Wrist and ankles  When cultures positive, cover for Chlamydia as well (but not vice-versa)  Azithromycin: 1gm or 2gm – for both GC and Chlamydia  Ceftriaxone: 250mg IM  Cefixime: 400mg PO  Cefoxitin: 250mg IM  Ciprofloxacin: 500mg PO for just N. gonorrhea  Gatifloxacin: 400mg PO  Ofloxacin: 400mg PO N. caterrhalis  Does NOT ferment sugar  Most common strain in the back of the throat  Loves mucus  #3 for respiratory tract infections (sinusitis, otitis media, bronchitis, pneumonia)

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Helicobacter o H. pylori  Curved rod, urease positive  Silver stain – GI tissue  1 of 3 with silver stain  CLO test  Associated with duodenal ulcers (95%) and gastric ulcers (70%)  Treat ALL positive gastric cultures  Hydrogen breath test is most diagnostic, if available, for eradication  Tx: Amoxicillin, Bismuth, H-2 blocker or PPI  Need to have a PPI and an antibiotic combo  Bismuth – suffocates  3 drugs for 2 weeks (98% eradication)  MCC – bad water (sewer system)

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E. coli

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Makes up 95% of small intestinal flora Small Intestinal infections:  Acute cholecystitis - +Murphy sign, colic pain  Ascending cholangitis – increased alkaline phosphatase  Common bile duct is affected  Acute appendicitis  Most common cause is fecal matter stuck there  Abdominal abscess  Acute spontaneous bacterial peritonitis Makes:  90% of vitamin K  Clotting factors 2,7, 9, 10  Biotin  Folate  Cofactor for rapidly dividing cells  Panthotenic acid Helps absorb:  Vit. B12  Dorsal column o How do we know have dorsal column problems? Vibration and position sense  Cortical spinal tract o Responsible for motor function  USA – pernicious anemia o Knocks out intrinsic factor, therefore cannot absorb b12  Antiparietal cell Ab ETEC (enterotoxogenic)  Major cause of diarrhea in developing areas  Traveler’s Diarrhea (rice water)  Severe watery diarrhea (>20L per day) EPEC (enteropathogenic)  Young children and infants  Causes loss of microvilli  E/A  Diarrhea from malabsorption  Results in calcium oxalate stones in kidney o Malabsorption  no calcium absorption by calcium binding proteins calcium binds to fat (saponification). Oxalate breaking down from proteins in stomach is now going to get reabsorbed  bind with Ca in the blood  gets filtered into the kidney

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 To check if microvili problem, give D-xylose EIEC (enteroinvasive)  Plasmid shared by shigella  Invades intestinal mucosa  Provides shiga-like toxins (verotoxin)  Can cause seizures  Bloody, purulent diarrhea EHEC (enterohemorrhagic)  O157:H7 (outbreak – epidemic)  Cattle, sheep, goats  Ingestion of contaminated food  Bloody diarrhea, endemic HUS renal failure  Anemia, thrombocytopenia, renal failure

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Proteus o P. mirabilis  #2 MCC for UTI’s  #1 is E.coli  Urease positive  Associated with high urine pH, struvite stones (must be surgically removed), staghorn calculus, high ammonia in the urine  Tx: Quinolones

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Klebsiella o K. pneumoniae  #3 for UTI’s  Likes to attack alcoholics and homeless people  In lungs: currant (blood mixed with mucus) jelly sputum; likes to attack fissures  Encapsulated

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Likes Immunocompromised people o Serratia marscesens  Produces a red pigment o Citrobacter  Produces citric acid  Encapsulated  Likes to attack 0-2mo babies  Causes multiple cerebral abscesses

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Pseudonomas auregenosa  Same enzymes as S.aureus  Likes to attack diabetics, burn pt (2nd week; 1st week is S.aureus), neutropenics, and cystic fibrosis  Gold pigment like S.aureus  Also produces a green pigment  Has a fruity grape smell when plated  Likes plastic (endotracheal tubes, bladder catheters)  Causes:  Whirlpool folliculitis  Tennis Shoe folliculitis – nail through shoe  Malignant otitis externa – mastoid (coagulase)  MCC of death in 2nd week after burn  Recurrent pulmonary infections in CF  Ichthyma gangrenosum – blood form (black bulla on the skin)