Bacteria

Question 1

Staph Aureus

Answer 1

Golden Staph of Moses

• bundle of grapes
• golden growth on plate
• gram positive
• catalase positive
• coagulase positive
• beta hemolitic
• protein A
  
  • virulence factor
  • part of cell wall that binds Fc portion of Ig
  • prevent opsonization and phagocytosis
    
    • pneumonia
      
      • patchy infiltrate on chest Xray
      • post viral is most common time to get this infection
    • septic arthritis
      
      • staph aureus is most common cause of this condition
    • abcesses
    • rapid onset endocarditis (acute bacterial endocarditis)
      
      • happens in IV drug users
      • R side heart infection
        
        • tricuspid valve
    • osteomyelitis
      
      • most common cause of osteomyelitis in adults
    • scalded skin syndrome
      
      • protease mediated
    • toxic shock syndrome
      
      • TSST is the toxin
    • food poisoning
      
      • rapid onset
      • preformed toxin
      • vomitting&raquo_space;> diarrhea
      • meat and cream based foods that have been left out too long
    • MRSA
      
      • altered penecillin binding proteins
      • treat with vancomycin
      • menthycillin, nafcillin

Question 2

staph epidermitis

Answer 2

PLUMBER

• gram positive- purple stain
• enemy of orthopedic surgeons
  
  • infects artificial joints and other hardware (indwelling catheters)
  • most common cause of endocarditis infecting artifically implanted heart valves
  • sticks to sleek metal and plastic surface
    
    • use of biofilms
  • gotta replace most anything that gets infected
• part of normal skin flora
• treat with vancomycin
• contamination of blood cultures
• novobiocin sensitive
• catalase positive
• urease positive
• coagulase negative

Question 3

Staph saprophyticus

Answer 3

BEAUTY

• gram positive- purple
• novobiocin resistant
• UTI in sexually active females
• catalase positive
• urease positive
  
  • converts urea to ammonia
• coagulase negative
  
  • blood does not clot

Question 4

Strep Pyogenes (group A)

Answer 4

(bakery- pie genies)

• these grow in long chains
• catalase negative
• group A strep
  
  • bacitracin sensitive
• encapsulated
  
  • Hot Apple pie (Hyaluronic acid makes up the capsule- so our immune system leaves it alone)
• beta hemolytic
  
  • made possible by streptolysin O
    
    • we make ASO antibodies against this guy
    • ASO titer tells us if we’ve recently had group A strep infection
• streptokinase
  
  • converts plasminogen to plasmin
  • given as medication to lyse clots during strokes
• DNA-ases
  
  • depolymerize DNA
• pyogenic infections
  
  • impetigo
    
    • honey crusted skin
    • can also be caused by staph aureus
  • pharyngitis— strep throat
  • cellulitis and erisypela
    
    • strep pyogenes is most common cause of this
• toxin (strep pyrogenic exotoxin— SPE) causes the following
  
  • scarlet fever
    
    • strawberry tongue
    • pharyngitis
    • widespread rash sparing the face
  • toxic shock like syndrome
  • necrotizing fascitis
    
    • invades fascia under skin and spreads rapidly
    • specifically caused by SPEB
• rheumatic fever
  
  • type II hypersensitivity
  • M protein
    
    • cell wall protein virulence factor
      
      • interferes with opsinization = anti phagocytic
      • elicits strong humoral response
        
        • meaning we make Ab to M protein
        • causes molecular mimicry to heart valves (mitral valve most commonly affected= mitral stenosis)
  • only after strep pharyngitis (not after skin infection)
  • symptoms: JONES
    
    • J — joints
      
      • polyarthritis
    • <3 — heart stuff
      
      • valvular damage leading to murmur, pericarditis
    • N — nodules subq appearing on forearms, elbows, knees
    • E — erythema marginatum
    • S — sydenham’s chorea
      
      • rapid involentary movements of hands and face
• poststreptococcal glomerulernephritis
  
  • type III hypersensitivity
    
    • AbAg complexes deposit in glomerulus
  • cola colored urine
  • facial edema
  • 2 wk after onset of initial strep infection
  • can occur after pharyngitis or a superficial infection like impetigo

Question 5

strep agalactiae (group B)

Answer 5

Baby galaxy

• infections in newborns
  
  • meningitis
  • sepsis
  • pneumonia
  • acquired during vaginal passage of infant delivery
    
    • vagina and rectum get swabbed at 35 wk to see if she is colonized
    • if colony is detected, we give mom interpartum penicillin
• positive hipurate test
• has a polysacaride capsule
• CAMP test positive
  
  • distinguishes from other strep
  • grows with staph aureus on a plate in the shape of an arrow
• beta hemolytic
• bacitracin resistant

Question 6

strep pneumo

Answer 6

numero uno– knight fighting in alpha contest

• alpha hemolytic
  
  • partial RBC lysis
  • surrounding area is green bc of Hb oxidation
• encapsulated
  
  • we need spleen to remove encapsulated bacteria
  • sickle cell patietns therefore are particularly susceptible
• has protease that cleaves IgA
  
  • reduces host defenses
• optochin sensitive
  
  • inhibits growth of strep pneumo
• lancet shaped gram pos diplococci
• bile soluble: cannot grow in bile
• # 1 cause of community acquired pneumonia in adults
  • rust colored sputum
  • lobar in lower lobes usually
• most common cause of these diseases: MOPS
  
  • meningitis
  • otitis media
  • pneumonia
  • sinusitis
• antibiotics to use: macrolide sensitive, ceftriaxone sensitive
• prevent with vaccine
  
  • adults—IgM
    
    • T cell independent response
  • children— IgG
    
    • polysaccaride conjugated to protein
    • t cell response leads to IgG

Question 7

strep viridans

Answer 7

jester in the alpha competition

• alpha hemolytic
• no capsule
• optochin resistant
• bile resistant (insoluble)
• mutans and sanguinis are strep viridans strains that can cause
  
  • dental caries
  • subacute endocarditis: mitral valve
  • adheres to fibrin platelet agregates at damaged tissue by creating dextrans from glucose

Question 8

enterococcus

Answer 8

california caucus protest

• gram positive cocci
• grow in 6.5% NaCl
• bile resistant
• causes 3 main infections
  
  • UTI’s
  • endocarditis
  • infections of biliary tree
• nosocomial infection resistant to vancomycin
  
  • VRE: vanco resistant enterococcus
  • instead we use linezolid or tigecycline
• e faecalis
  
  • more common
• e faecium
  
  • less often, superbug causing more serious problems

Question 9

bacillis

Answer 9

vikings

• anthracis
• • black center surrounded by red (black eschar) cutaneous lesion
  • large gram positive rods in chains
  • encapsulated — protein capsule
  • • polyD
  • obligate aerobe
  • weaponized: spores sent in envelopes
  • toxins
  • • LF: lethal factor
    • • protease that cleaves MAPK
      • leads to tissue necrosis —> black escar
  • wool sorter disease
  • pulmonary hemorrhage is associated with almost 100% mortality rate
  • widened mediastinum on CXR
  • • EF: edema factor
    • • increases cAMP —> edema inhibiting host defense
  • floroquinolones and doxycycline to treat
• cereus
• • reheated fried rice
  • nausea / vomit / diarrhea
  • symptoms caused by pre formed enterotoxin so antibiotics won’t help

Question 10

clostridium

Answer 10

robots, monkeys, chocolate factory
spore forming
* Tetani
* rigid paralysis (spastic)
* evil smile
* lock jaw
* arching of back due to spasm
* obligate anaerobe
* inside puncture wound
* from rusty nails
* spores embed in flesh and produce toxin
*
* travels retrograde to spinal cord
* inhibits GABA and glycine release from renshaw cells
* cleave snare protein
* vaccine of toxin + protein
* Botulinum
*
* flaccid paralysis: descending
*
* toxin absorbed in gut goes to PNS but cannot cross BBB
* inhibits SNARE of motor neurons that release ACh
* floppy baby: avoid honey for babies (spores are ingested)
* canned food allow survival of spores (ingest the preformed toxin
* obligate aneorobe
* Difficile
*
* spore forming
* hits patients who are on antibiotics (clindemycin especially)
* exotoxin A: target brush border causing watery diarrhea
* exotoxin B: depolymerizes actin leading to pseudomembrane in colon
* look for toxin in stool to dx
* obligate anerobe
* tx with oral vancomycin or metronidazole

Question 11

Corynebacterium Diphtheriae

Answer 11

bull fight- non spore forming rod

• club shape with granules that stain metacramatic granules in V or Y formation
• exotoxin
• • A active subunit ribosylation / inhibition EF2
  • • inhibits protein synthesis at the ribosome
    • thick grey exudate in the oropharynx
  • B subunit
• lymphadenopathy in neck — bulls neck
• transmitted by respiratory droplet
• systemic efffects on heart and nerves (spread via blood)
• • myocarditis / heart block, arrhythmia
  • toxin damages myelin of nerve fibers
• tellurite and loefflers medium to culture
• elek’s test tells us whether diphtheria is an active infection
• occurs in underdeveloped countryies that aren’t activated
• • given with pertussis and tetanus
  • provides powerful IgG response
  • vaccine targets toxin that inh EF2

Question 12

Listeria

Answer 12

Santa’s List

• pregnant women (early termination or infection of the newborn), meningitis in children and adults over 60 (treat with vanco and cephtriaxone AND ampicillin)
• grows in near freezing cold (refrigeration)
  
  • meat, milk, soft cheeses
• beta hemolytic
• motile, flagella, use actin to rocket from cell to cell
• catalase positive
• treat with ampicillin

Question 13

actinomyces

Answer 13

Israeli soldier

• gram pos filamentus branching rods
• obligate aneorobe
• cervicofascial actinomyces infection
• • after jaw trauma
  • nontender lump on jaw —> abscess —> drainage of thick yellow pus through sinus tracks onto skin
  • • yellow sulfur granules
• penicillin G and sometimes surgical drainage

Question 14

nocardia

Answer 14

no card game

• obligate aerobe
• gram pos branching rod
• soil is where you find it (no spores though)
• weak acid fast staining
  • mycolic acid
• catalase positive
  • increase susceptibility for those with chronic granulomatous disease (CGD)
• urease positive
• affects immunocompromised (esp without cell mediated), men are more affected, pneumonia with lung abscesses and cavitary lesions, disseminates to neural tissue (brain abscess), cutaneous
• tx is sulfonamides

Question 15

Neisseria

Answer 15

dorm crime, violinist crime

• grows on chocolate auger (heated blood auger) and VPN auger
• gram negative diplococci
• occurs in those with complement deficiency
  
  • C5-9 (MAC formers)
• oxidase positive
• attaches mucosa via pilli with antigenic variation
  
  • prevents lasting immune response
• IgA protease
• meningitidis
  
  • spread by respiratory droplets
    
    • college, military, kids 6 mo to 2 years
    • usually the B strain cause sikcnes because we don’t vaccinate against it
  • ferments maltose
  • first colonize the nasopharynx
  • encapsulated- inhibits phagocytosis
  • sickle cell disease makes patients more susceptible to infection
  • spreads hematogenously- LOS envelope blebs
    
    • inflammatory response
    • increase capillary permeability
    • edema
    • peticial rash (thrombocytopenia)
      
      • DIC (bleeding gums)
    • shock
    • adrenal insufficiency (waterhouse fredrickson syndrome)
    • 15% mortality rate
    • cephtrioxone for treatment
    • close contacts get rifampin as prophelactic
• gonorrhoeae
  
  • STD
  • facultative intracellular in PMN
  • men and women
    
    • prostatitis / orchitis
    • PID: pelvic inflammatory disease
      
      • scarring leading to infertility or ectopic pregnancies
      • white purulent discharge (thicker than chlamydia)
      • infection can spread to peritoneum
        
        • fits hugh curtis syndrome
        • can cause adhesions to liver
          
          • violin string adhesions
      • polyarthritis affecting the knee
  • babies
    
    • purulent conjunctivitis passed from infected mother
      
      • early onset
  • cephtriaxone to treat
  • always assume co-infection with chlamydia and also give the patient azythromycin or doxycycline

Question 16

Enterobacter

Answer 16

nosocomial dinosaurs

• pneumonia, UTI are most common manifestations of these guys
• multi drug resistant
  • carbapenum to treat
• lactose fermenters- grow pink
• enterobacter
  • motile
• serratia
  • motile
  • produces red pigment when cultured
• klebsiella
  • not motile
  • alcoholics, abcesses, aspiration (started from aspiring)
  • encapsulated
  • cough up currant jelly sputum
  • CXR with cavitary lesion that look like TB
  • urease positive

Question 17

Salmonella

Answer 17

salmon dinner

• motile
• gram negative
• H2S positive (along with all motile enteric bacteria)
• • grows black colonies plate
• encapsulated
• acid labile
• • high dose required to cause infection otherwise stomach acid kills it
  • opeperazole makes you more susceptible
• facultative intracellular
• • in macrophages
• salmonella typhi
• • harbored in the gallbladder of carriers
  • typhoid mary—
  • enteric fever gives you red spots on your abdomen
  • # 1 cause of osteomyelitis in patients with sickle cell disease
  • constipation or diarrhea (looks like pea soup)
  • treated with fluoroquinolone - antibiotic
  • yes vaccine
• salmonella interidtus
• • undercooked chicken
  • inflammatory diarrhea

Question 18

Shigella

Answer 18

gorilla circus act

• gastroenteritis — bloody diarrhea
• green colonies on hectoin auger
• immotile
• acid stable (doesn’t take much to cause infection)
• intestinal epithelium (in peyer’s patches) contain M cells
• • shigella gets into M cells but escapes from phagolysosome
  • then it makes an actin tail and uses that to get from cell to cell
  • facultative intracellular
• infected child with shigella dysinteria can lead to HUS- hemolytic uremic syndrome
• • acute renal failure 1 wk after diarrheal sickness
  • shiga toxin induces endothelial damage (including in glomerulus)
  • • binds and inhibits 60S subunit of ribosome- inhibit translation
    • aggregation of platelets lyse RBC’s (hemolysis)
    • kids under 10
• type III secretion system

Question 19

E Coli

Answer 19

cola soda shop

• ferments lactose- grow pink colony (or green on GMB auger)
• encapsulated
• K antigen: on capsule used for serotyping
• catalase positive
• fimbriae
• # 1 cause of UTI’s and gram negative sepsis (specifically done by LPS)
• causes meningitis in neonates only if it has K antigen
• EHEC- enterohemorrhagic e coli
• • eating undercooked meat like hamberger
  • bloody diarrhea
  • does not ferment sorbitol
  • toxin: inhibits 60S ribosomes just like shiga toxin (shiga like toxin)
  • can cause HUS: shiga toxin damages glomerular capillary endothelium which becomes thrombogenic and platelets adhere which will lyse RBCs that pass by.
  • O157:H7 serotype causes massive outbreaks
• ETEC- traveler’s diarrhea
• • water source transmission (usually someone who has recently been to mexico)
  • watery diarrhea
  • “montesuma’s revenge”
  • toxins
  • • heat labile increasing cAMP
    • heat stable increasing cGMP

Question 20

Yersinia

Answer 20

Pet shop

• entericolytica
• • transmitted through puppy feces and contaminated milk product
  • resistant to cold temperatures
  • commonly affects toddlers
  • bipolar staining so it looks like a safety pin in culture
  • encapsulated
  • bloody diarrhea, fever, bowel problems, mimics appendicitis
• pestis
• • bubonic plague
  • • swollen tender lymph nodes
    • armpits
  • reservoir is rodents / prarie dogs
  • • vector is fleas
  • abscess, DIC (from endotoxin- can lead to appendix necrosis)
  • exotoxins
  • yersinia associated outer proteins
  • • cause macrophage and neutrophil dysfunction by inhibiting phagocytosis and cytokine release
    • type III secretion
  • tx with tetracycline + streptomycin
  • vaccine not routinely given: killed vaccine

Question 21

Campylobacter Jejuni

Answer 21

guy and bears camping

• guianne barre syndrome: rare complication of this infection
• • autoimmune response causing demyelination of periferal nerves
  • ascending demyelination
• grows in heat 42 C
• found in GI tract of poultry
• bloody diarrhea and lots of it
• curved gram neg rod
• oxidase positive
• invasive: penetrates gut and gets in blood stream
• reactive arthritis

Question 22

Vibrio Cholera

Answer 22

base camp

• comma shaped
• perfuse rice water stools
• transmitted by fecal oral via poor sanitation or contamination of food / water
• cholera does not invade- it attaches intestine by fimbriae and secretes cholera toxin
• • binds and activates AC (Gs pathway)
  • increases cAMP
• oral rehydration for tx
• cholera grows on alkaline media (acid labile)
• oxidase positive
• two other vibrios
• • contaminate seafood - oysters

Question 23

Helicobacter Pylori

Answer 23

helicopter pilot

• gram neg, curved
• motile (flagella)
• urease positive
• • urea breath test
  • biopsy during endoscopy can be tested for urea as well
• oxidase positive
• causes duodenal ulcers
• • increase risk of adenocarcinoma
  • increase risk of lymphoma of MALT (maltoma)
• tx with 3 antibiotics
• • amoxicillin
  • clarithromycin (a macrolide)
  • proton pump inhibitor

Question 24

Pseudomonas

Answer 24

mona’s suitors

• gram neg rod
• thrives in aquadic environments
• • causes hottub folliculitis
  • puritis papulopusticular folliculitis
  • underchlorinated hot tubs
• toxin can circulate and land in skin causing necrosis
• • called ecthyma gangrenosum
  • black necrotic skin lesions
• otitis externa (swimmers ear)
• oxidase positive
• catalase positive
• • problematic in patients with CGD
• obligate aerobe
• encapsulated
• associated with nosocomial UTI’s
• respiratory infection and failure in CF patients
• most common gram neg pneumonia
• exotoxin A
• • ribosylation
  • EF2 inhibiting toxin
  • protein synthesis is inhibited and cell dies
• makes blue green pigment, grape smelling
• worry about this in burn patients
• causes osteomyelitis in IV drug users and diabetics
• tx with piperacillin, aminoglycocides and fluoroquinolones

Question 25

Proteus Mirabilis

Answer 25

bathroom god

• gram neg
• facultative aneorobe
• smells like fish
• tx with sulfonamides
• swarming motility
• causes UTI’s, staghorn calculi (kidney stone)
• urease positive
• • why we get kidney stone

Question 26

bordatella pertussis

Answer 26

soldier boarding

• gram neg
• spreads by respiratory droplet- attach via pilli that release toxins
• pertussis toxin
  • ribosylates Gi disabling it
  • increases cAMP
  • disables chemokine receptors for lymphocytes
    • lymphocytosis
• adenylate cyclase toxin
  • increase cAMP
• tracheal toxin
  • damages ciliated cells in respiratory epithelium
• initally present as cataral phase (1-2 wk) conductive injection and lacrimation
• paroxysmal stage (2 wk- 2 mo) develop whooping cough
• convalescent stage (up to 3 mo) reduction gradually of symptoms
• tx with macrolides
• prevent with killed or acellular vaccine (TDaP)

Question 27

Haemophilus Influenzae

Answer 27

chocolate covered cherry shop

• gram neg
• grown on chocolate auger
• • add factor 5 (NAD) and factor 10 (hematin)
• aerosol transmission
• pneumonia
• epiglotitis
• • inspiratory stridor and drooling and cherry red epiglottis
• otitis media
• meningitis (only the type B capsular form)
• • vaccine for only type B Hinfluenza
  • polysaccaride of capsule + diptheria toxoid to increase immunogenicity
  • • IgG response is strong
  • vaccinate at 2-18 months old
• sepsis and septic arthritis in those without a spleen (sickle cell disease pts)
• tx with cephtriaxone
• give rifampin to those in close contact of anyone with influenza

Question 28

Legionella

Answer 28

ss cysteine

• gram neg - does not stain well - visualize with silver stain
• • grow on buffered charcoal yeast with cysteine and iron
• oxidase positive
• pontiac fever
• • self limited fever and malaise
• legionaires disease
• • occurs in smokers
  • atypical pneumonia
  • CXR shows patchy infiltrate with consolidation to one lobe
  • hyponatremia (<130)
  • neuro symptoms: headache, confusion
  • diarrhea
  • fever
• rapid urine antigen test to dx more quickly than culture
• tx with macrolides or fluoroquinolones

Question 29

Bordatella Henslae

Answer 29

leopard “bart”

• gram neg
  
  • visualize with wharthrin stary stain (silver stain)
• cat scratch disease
• • fever
  • regional lymph enlargement
  • • axilla, unilateral
  • in immunocompetent people
• bacillary angiometosis
• • fever, chills, headaches
  • raised red vascular lesions all over the skin
  • in immunocompromised pts
  • • HIV infected pts
    • looks like kaposi sarcoma gotta culture it to know for sure
• tx with doxycycline or macrolides

Question 30

Brucella

Answer 30

Bruce farm

• zoonotic from farm animals or farm animal products
• • vet, slaughterhouse worker, rancher, recent consumptio of milk or cheese
• gram neg
• facultative intracellular
• • prevents phagolysosome fusion to escape macrophages
  • travels through reticuloendothelial system to spread systemic organs
  • • enlarged spleen, liver, lymph nodes
• brucellosis
• • undulating fever, chills, anorexia
  • osteomyelitis in chronic infection
  • tx with doxycycline, rifampin

Question 31

Francisella Tularensis

Answer 31

Rabbit “Francis”

• reservoir is rabbits (direct contact) or tick vectors (dermacentor tick)
• gram neg
• facultative intracellular
• • recovery requires cell mediated immunity
  • easily spread
• tick bite creates an ulcer in the skin at infection site
• • travels through lymph system to reticuloendothelial organs
  • granlomas with caseating necrosis
  • lymph nodes swell (lymphadenopathy)
  • tx with amino glycosides

Question 32

Pasteurella Multocida

Answer 32

L Pasteur’s Lab

• found in respiratory tract of cats and dogs
• • transmit via pet bites
  • erythematous and cellulitis within 24 hours
  • can spread to nec fasch OR osteomyelitis
• encapsulated
• grown on 5% sheeps blood auger
• catalase positive
• oxidase positive
• bipolar (safety pin) staining
• tx with penicillin

Question 33

Mycobacterium Tuberculosis

Answer 33

shootout

• stains acid fast (carbol fusion stain)
• mycolic acid in cell wall
• • cell wall also has glycolipids that help clump the bacterium into serpentine formation
  • • “cord factor”
    • protect bacteria from destruction
    • increases TNF alpha—> activate other macrophages —> granuloma —> bacteria grows in here
  • sulfatides prevent phagolysosome fusion (TB accumulates sulfa tides)
• grown on lowentein auger
• obligate aerobe
• respiratory droplet transmission
• • proliferates in macrophages
  • primary infection: affects lower and middle lobes of lungs then lesion becomes necrotic (caseating granulomas- surrounded by scar we call it a tubercle) and calcifies with hilar lymph node involvement (Ghan complex) — prolonged fever
  • • healed latent infection:
    • • usually in children
      • resolves via fibrosis
      • positive PPD skin test
      • positive also if person has received BCG vaccine
    • systemic infection
    • • bacteremia often spreading to bone, liver, and lymph
      • miliary means it hits multiple organs— potentially lethal
    • reactivation TB
    • • cavitary lesions in upper lung lobes on CXR
      • immunosuppression causes reactivation through downregulation of TNF alpha
      • immune system is defenseless if TNF is inhibited
      • cough, night sweats, hemoptysis (bloody cough), cachexia
    • skeletal system: pott’s disease is when TB has infected spine and multiple vertebra are demineralized with soft tissue swelling
    • CNS: cavitary lesion (tuberculoma) can form
  • tx with RIPE: rifampin, isoniazid, pyrazinamide, ethambutol
  • prevent with RI

Question 34

Micobacterium leprosy

Answer 34

jail house breakout

Question 35

borellia

Answer 35

archery competition

LYME DISEASE

Question 36

leptospirosis

Answer 36

surfer

Question 37

treponema pallidum

Answer 37

observatory

syphillus

Question 38

chlamydia

Answer 38

clam island

Question 39

coxiella

Answer 39

Curly Q the ram

Q fever

Question 40

gardenella vaginalis

Answer 40

fish detective

Question 41

mycoplasma pneumonia

Answer 41

hockey
walking pneumonia
sterol in the cell wall

Question 42

rickettsia prowazeki

Answer 42

tennis / football
typhus
transmitted via lice
rash starts on trunk and spreads outward sparing hands, feet, head

Question 43

rickettsia ricketsii

Answer 43

tennis / rock climbing
dermacenter ticks
rocky mountain spotted fever
rash starts on extremities and moves inward