3 Parts of LPS
- Lipid A
- O Antigen
- Polysaccharide
Function of lipid A
TNF and IL-1 induction for gram negative sepsis
Function of O antigen
used for typing of Gram Negative species
Branching filaments
Actinomyces
Nocardia
Difference between actinomyces and nocardia
Nocardia is weakly acid fast
Mycoplasma cell membrane/cell wall features
- Sterols in cell membrane
- NO cell wall
Mycobacteria cell membrane/cell wall features
- Contain mycolic acid
- High lipid content
Bugs that do not gram stain well (and why)
- Treponema (too thin)
- Mycobacteria (tons of lipid in cell wall)
- Mycoplasma (no cell wall)
- Legionella (intracellular)
- Rickettsia (intracellular)
- Chlamydia (intracellular; lacks muramic acid in cell wall)
“These Microbes May Lack Real Color”
Bugs that stain with Giemsa stain
Chlamydia Borrelia Rickettsiae Trypanosomes Plasmodium
“Certain Bugs Really Try my Patience”
PAS staining bugs (why)
Tropheryma whipplei (stains glycogen and mucopolysaccharides)
Ziehl-Neelsen staining bugs (and why)
Nocardia
Mycobacteria
(acid fast)
India ink staining bugs
Cryptococcus neoformans
What other than india ink can be used to visualize cryptococcus?
Mucicarmine (stains thick polysaccharide capsule red)
Silver staining bugs
Fungi
Legionella
H. pylori
Isolated on chocolate agar
H. flu (needs X and V)
Isolated on Thayer-Martin Media
Neisseria
What is in Thayer-Martin Media
VPN
Vancomycin (kills GPs)
Polymyxin (kills GNs but neisseria)
Nystatin (kills fungi)
Isolated on Bordet-Gengou agar
Bordetella pertussis
Isolated on tellurite agar or Loffler medium
C. diptheriae
Isolated on Lowenstein-Jensen agar
Tb
Isolated on Eaton agar
M. pneumoniae (needs cholesterol)
Pink on MacConkey agar
Lactose-fermening enterics
Green metallic sheen on EMB agar
E. coli
Isolated on charcoal yeast extract buffered with cysteine and iron
Legionella
Isolated on Sabouraud Agar
fungi
Obligate aerobes
Nocardia Pseudomonas MycoBacterium Tb (apex of lung)
“Nagging Pests Must Breathe”
Obligate anaerobes
Closridium
Bacteroides
Actinomyces
“Can’t Breathe Air”
What do obligate anaerobes lack?
Catalase and/or Superoxide dismutase (so susceptible for oxidative damage)
Obligate intracellular
Chlamydia
Rickettsia
Facultative intracellular
Samonella Neisseria Brucella Mycobacterium Listeria Francisella Legionella Yersinia pestis
“Some Nasty Bugs May Live FacultativeLY”
Encapsulated Bacteria
Salmonella H. Influenza Neisseria meningitidis E. coli Strep pneumo Klebsiella Strep agalactiae (GBS)
SHINE SKiS
Catalase Positive Bugs
Pseudomonas Listeria Aspergillus Candida E. coli S. aureus Serratia
“PLACESS for cats”
Urease Positive Bugs
Cryptococcus H. Pylori Proteus Ureaplasma Nocardia Klebsiella S. epidermidis S. saprophyticus
“CHuck norris hates PUNKSS”
Yellow “sulfur” granules
Actinomyces
Yellow pigment
Staph aureus
Blue-green pigment
Pseudomonas aeruginosa
Red pigment
Serratia marcescens
What produces Protein A?
Staph aureus
Wat does Protein A do?
Binds Fc region of IgG (to prevent opsonizaiton and phagocytosis)
What produces IgA protease?
S. pnumoniae
H. flu
Neisseria
“SHiN”
What does IgA protease do?
cleaves IgA in order to colonize respiratory mucosa
What produces M protein?
Group A Strep
What does M protein do?
helps prevent phagocytosis
Endotoxin or exotoxin: stable at 100 degrees for 1 hr
Endotoxin (exotoxin is destroyed at 60 degrees except staph enterotoxin)
Exotoxin or endotoxin: located on outer cell membrane
Endotoxin (of most gram negative bacteria)
Exotoxin or endotoxxin: high toxicity
Exotoxin
Exotoxin or endotoxin: poorly antigenic
Endotoxin (exotoxin induces high-titer Ab’s called anti-toxins)
Which toxins inactivate elongation factor EF-2 via ADP ribosylation?
Diptheria Exotoxin A (Pseudomonas)
Which toxins inactivate 60S ribosome by removing adenine from rRNA?
Shiga toxin
Shiga-like toxin (EHEC)
Which toxins overactivate adenylate cyclase to increase cAMP and Cl- secretion in the gut (and H2O efflux)?
LT toxin (ETEC) Cholera toxin (permanent activaiton of Gs)
Which toxin mimics cholera toxin in the skin?
Edema factor (Bacillus anthracis)
Which toxin overactivates adenylate cyclase by disabling Gi (impairing phagocytosis)?
Pertussis toxin
Which toxin overactivates guanylate cyclase to incrase cGMP and decreases resorption of NaCl and H2O in the gut?
ST toxin (ETEC)
Which toxin prevents release of inhibitory neutotransmitters from Renshaw cells in spinal cord?
Tetanospasmin (cleave SNARE proteins)
Which toxin prevents release of stimulatory signals at the NMJ?
Botulinum toxin (cleave SNARE proteins)
Which toxin acts by degrading phospholipids?
Alpha toxin (lecithinase) of clostridium perfringens
What is the result of alpha toxin in clostridium perfringens?
- Myonecrosis (gas gangrene)
- “Double zone” of hemolysis on blood agar
Which toxin is a protein that degrades cell membranes?
Streptolysin O (strep pyogenes)
Which toxins bring MHC II and TCR together at outside of Ag binding iste to cause release of IL-1, TNF-alpha and IL-2?
- TSST-1 (staph aureus)
- Exotoxin A (strep pyogenes)
What things are released with endotoxins?
ENDOTOXIN
- edema (C3a)
- NO
- dic/death
- outer membrane
- TNF-ALPHA
- o-antigen
- extremely heat stable
- IL-1
- neutrophil chemotaxis (C5a)
Which bacteria are specialized at transformation (taking up DNA from environment)?
- S. pneumo
- H. flu
- Neisseria
“SHiN”
List the 5 bacterial toxins encoded on a lysogenic phage.
1) shigA-like toxin
2) Botulinum toxin
3) Cholera toxin
4) Diptheria toxin
5) Erythrogenic toxin of strep. pyogenes
Catalase positive
Staph
Novobiocin resistant
Staph Saprophyticus
Novobiocin sensitive
Staph Epidermidis
Optochin Sensitive
Strep pneumoniae
Optochin resistant
Strep viridans
Bacitracin sensitive
GAS
Bacitracin resistant
GBS
Alpha hemolytic
Strep pneumo
Viridans strep
Alpha-hemolytic bug that is bile soluble
Strep pneumo
Beta hemolytic
GBS and GAS
Gamma hemolytic
Enterococcus (GDS)
Strep. bovis
Gamma hemolytic with growth in bile and 6.5% NaCl
Enterococcus
Gram positive rods with metachromatic (blue and red) granules
Corynebacterium diptheriae
If see subacute endocarditis suspect colon cancer?
Strep bovis
Food poisoning with 2-6 hour incubation
Staph Aureus (enterotoxin)
Rusty sputum
Strep pneumo
Substance made by Strep sanguinis that binds to fibrin-platelet aggregates on damaged heart valves.
Dextrans
Sand-paper like rash and strawberry tongue
Scarlet fever (GAS)
What precedes rheumatic fever?
strep pharyngitis
What precedes PSGS?
impetigo > strep pharyngitis
Produces CAMP factor (enlarges area of hemolysis caused by Staph aureus).
GBS
Pregnant women positive for GBS treatment
Intrapartum penicillin prophylaxis for mom
What is Lancefield grouping based on?
differences in C carbohydrate in bacterial cell wall
Spore forming GP bacteria in soil.
Bacillus anthracis
Clostridium perfringens
C. tetani
Spore forming GP bacteria (not in soil)
B. cereus
C. botulinum
Coxiella burnetii
What is present in core of spore?
dipicolinic acid
How do you kill spores?
autoclaving (121 degrees for 15 minutes)
Toxin A of C-diff
Enterotoxin that binds to brush border of gut
Toxin B of C-diff
Cytotoxin that causes cytoskeletal disruption via actin depolymerization
Only bacteria with polypeptide capsule
Bacillus anthracis (D-glutamate)
Food poisoning with 1-5 hours til N/V and 8-18 hours til Diarrhea
B. cerues
Only gram positive bacteria to make endotoxin
Listeria monocytogenes
Branching filaments treated with penicillin
actinomyces
Branching filaments treated with sulfonamides
Nocardia
Which GP branching filament is an anaerobe?
Actinomyces
Which GP branching filament is part of normal oral flora?
Actinomyces (nocardia is in soil)
Which GP branching filament causes pulmonary infection in immunocompromised or cutaneous infection in immunocompetent with trauma?
Nocardia (actinomyces causes oral/facial abscesses that drain through sinus tracts)
Tumbling motility
Listeria
Mycobacterium leprae that has humoral Th2 response
Lepromatous leprosy
Mycobacterium leprae that has largery Th1 type immune response
Tuberculoid
Comma shaped oxidase positive GN
Campylobacter jejuni
Vibrio cholerae
H. pylori
Oxiadase positive GN rod
Pseudomonas
GN gros in 42 degrees
Campylobacter jejuni
GN Rod lacose nonfermenter
Shigella Salmonella Proteus Yersinia Pseudomonas
GN Rod lactose fermenter
Klebsiella (fast) E. coli (fast) Enterobacter (fast) Citrobacter (slow) Serratia (slow)
“macConKEES agar used to test!”
GN “coccobacilli”
- H. flu
- Pasteurella
- Brucella
- Bordetella pertussus
GN diplococci
Neisseria
Which neisseria ferments maltose?
Neisseria meningitidis
Bug that makes beta-galactosidase
E. coli (breaks lactose into glucose and galactose)
Which neisseria has a capsule?
Meningococci
Whcih neisseria can cause Fitz-Hugh-Curtis syndrome?
Gonococci
Which neisseria is treated with cegtriaxone or penicillin G?
Meningococci (gonococci is treated with ceftriaxone + azithromycin or doxy for chlamydia co-infection)
Treatment of H. flu mucosal infection.
Amoxicillin +/- clavulanate
Treatment of H. flu close contacts.
Rifampin
Treatment of H. flu meningitis
Ceftriaxone
WHen do you give HiB vaccine?
Between 2-18 months
Detect pulmonary infection by antigen in urine?
legionella
What lab oddity is seen in Legionella infection?
hyponatremia
DOC for legionella
Macrolide
Quinolone
DOC for Pseudomonas
Aminoglycoside + piperacillin, ticarcillin, cefepime, imipenem, meropenem
E. coli that adheres to apical surface, prevents absorption, flattens villi
EPEC (affects children)
E. coli that invades intestinal mucosa and mimics shigella in manifestations
EIEC
4 A’s of Klebsiella
Aspiration pneumonia
Abscess in lungs/liver
Alcoholics
di-A-betics
Salmonella or shigella: flagella
salmonella
Salmonella or shigella: PMN infiltrate
shigella
Salmonella or shigella: hematogenous spread
salmonella
Salmonella or shigella: hydrogen sulfide production
salmonella
Salmonella or shigella: antibiotics prolong fecal excretion of organism
salmonella
Salmonella or shigella: OFTEN causes bloody diarrhea
shigella (salmonella can cause)
What bug has K1 capsular polysaccharide?
E. coli
What is the function of K1 capsular polysaccharide?
Prevents phagocytosis and complement mediated lysis (causes neonatal meningitis)
What bug has P fimbriae?
E. coli
What is the function of P fimbriae?
allows adhesion to uroepithelium for UTIs
Comma shaped, oxidase +, GN that grows in alkaline media
Vibrio cholera
Transmitted by puppy poop and pork
Yersinia enterocolitica
H pylori treatment
PPI + Clarithromycin + Amoxicillin or metronidazole
Spirochetes
Borrelia (big)
Leptospira
Treponema
Surfers in Hawaii or animal urine
Leptospira interrogans
Symptoms of Leptospirosis
Flu-like
Jaundice
Photophobia
COnjunctival suffusion
Weil disease
Leptospira interrogans (icterohemorrhagic leptospirosis)
Ixodes tick
Borrelia burgdorferi
Babesia
Anaplasma
VDRL false positives
Viruses (mono, hepatitis)
Drugs
Rheumatic fever
Lupus/Leprosy
Flu-like syndrome after syphilis treatment
Jarisch-Herxheimer reaction
Monocytes with morulae in cytoplasm
ehrlichiosis
Granulocytes with morulae in cytoplasm
Anaplasmosis
Cat scratch, bacillary angiomatosis
Bartonella
Louse
- Borrelia recurrentis (relapsing fever due to variable surface antigens)
- Rickettsia prowazekii (epidemic typhus)
Unpasteurized dairy
Brucella (undulant fever)
Puppies, livestock then bloody diarrhea
Campylobacter
Parrots
Chlamydophila psittaci
Aerosols of cattle/sheep amniotic fluid
Coxiella burnetii (Q fever)
Lone star tics
Ehrlichia chaffeensis
Dermacentor tics
Rickettsia rickettsii
Ticks, rabbits, deer fly
Francisella tularensis
Armadillo
Mycobacterium leprae
Animal bite
Pasteurella multocida
Fleas
- Rickettsia typhi (endemic typhus)
- Yersinia pestis (on rats and prarie dogs)
Whiff test, Clue cells
Gardnerella vaginalis
Palms and soles rash
Coxsackievirus A (HF&M disease)
RMSF (starts on wrists)
Secondary syphilis
Rash that starts centrally, spreads out and spares palms/soles (from fleas/louse)
Endemic or Epidemic Typhus
Stages of chlamydia life cycle
Elementary body can live outside cells (gets endocytosed); Reticular body forms from EB and replicated by binary fission; RB transforms into EB
Lymphogranuloma venerum
Chlamydia trachomatis types L1-L3
Chlamydia induced blindness
Types A, B, C
Cold agglutinins (IgM)
Mycoplasma pneumoniae
MIssissippi and OH river valleys (caves)
HIstoplasmosis (macrophage filled with Histoplasma)
East of Mississippi and Central America
Blastomycosis (broad based buds)
Southwestern USA (California after earthquake)
Coccidioidomycosis (spherules filled with endospores)
Latin America
Paracoccidioidomycosis (looks like captin’s wheel)
Spaghetti and meatballs
Malassezia furfur (tinea versicolor)
Treatment of versicolor
Topical miconazole
Selenium sulfide
Pseudohyphae at 20; germ tubes at 37
Candida albicans (opportunistic)
Septate hyphae at 45; Conidiophore with radiating chains
Aspergillus fumigatus (opportunistic)
Opportunistic fungi that causes meningitis
Cryptococcus neoformans
Diabetic ketoacidosis and leukemic patients
Mucormycosis
Latex agglutination test to detech polysaccharide capsular antigen
Cryptococcus
Fungal infection that increases risk of HCC
Aspergillus (produces aflatoxins)
Pigeon droppings
Cryptococcus
Treatment for pneumocystic jirovecci
TMP-SMX (prophylaxis with dapsone or atovaquone at CD4 <200)
Nodules along draining lymphatics
Sporothrix schenckii (from rose prick)
Treatment for sporothrix schenckii
Potassium iodide or itraconazole
Oocysts in water transmission
Cryptosporidium
Cysts in water transmission
Giardia lamblia
Entamoeba histolytica
Bloody diarrhea; Flask shaped ulcer; liver abscess with anchovy paste exudate
Entamoeba histolytica
Bloating, flatulence, fatty diarrhea
Giardia lamblia
Severe diarrhea in AIDS
Cryptosporidium
Trophozoites (with RBCs in cytoplasm) or Cysts (with up to 4 nuclei)
Entamoeba histolytica
Cryptosporidium treatment
Nitazoxanide
Transmitted by cysts in meat or oocysts in cat feces
Toxoplasma gondii
Transmitted by Tsetse fly (painful bite)
Trypanosoma brucei (African sleeping sickness)
Transmitted when freshwater lake swimming and enters cribriform plate
Naegleria fowleri
Causes ring-enhancing grain lesions and chorioretinitis, hydrocephalus and intracranial calcifications
Toxoplasmosis
Rapidly fatal meningoencephalitis with amoebas in spinal fluid
Naegleria fowleri
Treatment for Trypanosoma infection
Suramin (blood borne disease)
Melarsoprol (CNS penetration)
Maltese cross on blood smear
Babesia
Reduviid bug
Trypanosoma cruzi
Sandfly
Leishmania donovani
Sexual protozoa
Trichomonas vaginalis (treat partner with metronidazole)
Blackfly bite
Onchocerca volvulus (causes hyperpigmentation and river blindness)
Ingested nematodes
Enterobius (pinworm)
Ascaris (fiant roundworm)
Toxocara canis (causes visceral larva migrans)
Nematodes that penetrate skin
Strongyloides (worm ball)
Ancylostoma (hookworm)
Necator (hookworm)
Nematodes that enter via bites
Loa Loa (worm in conjunctiva) Onchocerca volvulus (River blindness) Wuchereria bancrofti (elephantitis)
Biliary tract disease, cholangiocarcinoma
Clonorchis sinensis (from undercooked fish)
Brain cysts, seizures
Taenia solium (cysticercosis fromeating eggs)
Hematuria, bladder cancer
Schistosoma haematobium
Liver (hyadatid) cysts
Echinococcus granulosus
Microcytic anemia
Ancyostoma
Necator
Perianal pruritis
Enterobius
Portal HTN
Schistosoma mansoni
Schistosoma japonicum
Vitamin B12 deficiency
Diphyllobothrium latum