Bacteria Flashcards
Staph Aureus
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»_space;> diarrhea
- meat and cream based foods that have been left out too long
- MRSA
- altered penecillin binding proteins
- treat with vancomycin
- menthycillin, nafcillin
- pneumonia
staph epidermitis
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
Staph saprophyticus
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
Strep Pyogenes (group A)
(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
- made possible by streptolysin O
- 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
- impetigo
- 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
- scarlet fever
- 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)
- cell wall protein virulence factor
- 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
- J — joints
- 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
- type III hypersensitivity
strep agalactiae (group B)
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
strep pneumo
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
- adults—IgM
strep viridans
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
enterococcus
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
bacillis
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
clostridium
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
Corynebacterium Diphtheriae
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
Listeria
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
actinomyces
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
nocardia
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
Neisseria
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
- spread by respiratory droplets
- 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
- purulent conjunctivitis passed from infected mother
- cephtriaxone to treat
- always assume co-infection with chlamydia and also give the patient azythromycin or doxycycline
Enterobacter
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
Salmonella
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