Steve Martin's Manic Micro Material Flashcards
Peptidoglycan
Gives rigid support, protects against osmotic pressure
sugar backbone with peptide side chains cross lnked by transpeptidase.
Cell wall/Cell membrane of gram positive bacteria
Major surface antigen
peptidoglycan for support
lipoteichoic acid induces TNF and IL-1
Outer membrane of gram negatives
Site of endotoxin (lipopolysaccharide (LPS))
major surface antigen
Lipid A induces TNF and IL-1
O polysaccharide is the atnigen
Ribosome subunits of bacteria
Have 30s and 50s subunits
Giemsa Stains
Chlamydia, Borrelia, Rickettsiae, Trypanosomes, Plasmodium
clams, ticks, worms, and mosquitos
PAS periodic acid-Schiff
Stains glycogen, mucopolysaccharides: used to diagnose Whipple disease
PAS the Sugar
Ziehl-Neelsen (Carbol Fuchsin)
Acid fast organisms Nocardia and mycobacterium
India Ink
Cryptococcus neformans (mucicarmine can also be used to stain thick polysaccharide capsule red)
Silver Stain
Fungi luke pneyocystis
Legionella
Helicobacter pylori
Culture for H. Influenza
Chocolate agar with factors V (NAD+) and X (hematin)
When you have the flu, you go to the five (V) and dime (X) to buy chocolate
Culture for N. Gonorrhoeae and N meningitidis
Thayer Martin, AKA VPN media
Vanco to inhibit gram +
Polymixin to inhibit gram negative except neisseria
Nystatin inhibits fungi
to connect to neisseria, please use your VPN client
Culture for B pertussis
Bordet-Gengou agar
also Regan-lowe
Culture for C Diptheria
Tellurite agar loffler medium
country tom has a DIP in and he says “I’ll tell you right!”
Culture for M tuberculosis
Lowenstein-Jensen agar
tuberculowenstein-jensen
Culture for M pneumoniae
Eaton agar, requires cholesterol
mycoplasma pneumonia eats away your lungs
Culture for Lactose-fermenting enterics
Pink colonies on MacConkey agar (fermentation produces acid, turning colony pink)
E Coli is grown on eosin-methylene blue (EMB) agar as colonies with green metallic sheen
Citrobacter, Klebsiella,
E. coli, Enterobacter, and Serratia
Culture for Legionaella
Charcoal yeast extract agar buffered with cysteine and iron
A french legionnaire wears a silver helmet, an iron dagger, has a charcoal bonfire and is not a sissy (cysteine)
Culture for fungi
Sabouraud agar
Sab is a fun guy!
Sab is also cryptic when he goes to india……. (india ink used for cryptococcus neoformans)
Obligate Aerobes
Use O2 dependent system to generate ATp
Nocardia, Pseudomonas, MycoBacterium tuberculosis
Know Pseudomonas Must Breath
Obligate anaerobes
Actinomyces, Fusobacterium, Bacteroides, and Clostridium
“Can’t Breath or Act if you are Fused to the Back of the Closet”
Lack catalase and or superoxide dismutase therefore they are susceptible to oxidative damage
Generally foul smelling due to short fatty acids
are difficult to culture
produce gas in tissue (CO2 and H+)
Obligate intracellular bugs
Rickettsia, Chlamydia, Coxiella
Can’t make own ATP
“Rick is Clammy and Cocky inside”
the rick from rick and morty
Facultative intracellular
Salmonella, Neisseria, Brucella, Mycobacterium, Listeria, Francisella, Legionella, Yersinia pestis
“Some Nasty Bugs May Live FacultiveLY”
Encapsulated Bacteria
“SHiNE SKiS”
Strep pneumoniae
Haemophilus influenzae type B, Neisseria meningitidis, Escherichia coli, Salmonella, Klebsiella pneumoniae, and group B Strep
Capsules have antiphagocytic virulence factors
Capsule + protein conjugate serves as an atigen in vaccines
Bugs are opsonized, cleared by spleen
No spleen, big risk of infection
Catalase-Positive Bugs
Catalase degrades H202 before it can be converted to microbicidal products by the enzyme myeloperozidase
People with chronic granulomatous disease (NADPH ozidase deficiency) have recurrent infections with catalase organisms
Pseudomonas, Listeria, Aspergillus, Candida, E. coli, S. Aureus, Serratia
“you need PLACESS for your CATs”
cats can serrate your face
Encapsulated Bacteria Vaccines
Some vaccines have polysaccharide capsule antigens that are conjugated to a carrier protein, enhancing immunogenicity by promoting T-cell activation and subsequent class switching A polysaccharide antigen alone cannot be present to T-Cells so you won't get class switching
Urease-positive bugs
CHuck norris hates PUNKSS
Cryptococcus, H pylori, Proteus, Ureaplasma, Norcardia, Klebsiella, S. epidermidis, S saprophyticus
Pigment producing bacteria
Actinomyces isrelii makes yellow sulfur granules which are composed of filaments of bacteria (israel has yellow sand)
S. aureus makes yellow pigment (aureus latin for gold)
Pseudomonas aeruginosa makes blue green pigment (aerugula is green)
Serrratia marcescens makes a red pigment - after a cat serrates your face you bleed red
Protein A bacterial virulence factor
binds Fc region of IgG
prevents opsonization and phagocytosis
Expressed on S aureus
IgA protease bacterial virulence factor
Enzyme that cleaves IgA
secreted by S. pneumoniae, H. influenza type B, Neisseria in order to colonize respiratory mucosa
SHiN
M protein bacterial virulence factor
Helps prevent phagocytosis
Expressed by group A streptococci
meromysin in heart
Characteristics of Exotoxins
Secreted from cell Polypeptide Highly toxic induces high antitoxin antibody response toxoids used as vaccines destroyed rapidly at 60 degrees C examples: tetanus, botulism, diphtheria
Characteristics of Endotoxin
secreted from cell membrane of gram negative cells is a lipopolysaccharide low level of toxicity, poorly antigenic fever, shock (hypotension), DIC Induces TNF, IL-1, IL-6 Stable at 100 degrees C No antitoxin vaccines Example: meningococcoemia, sepsis by gram negative rods
Corynebacterium diphtheriae: toxins
releases diphtheria toxin, inactivating elongation factor EF-2
Causes pharyngitis with pseudomembranes (fibrinous) in throat and severe lymphadenopathy
positive ELEK test
LICK test for blue and red corn chips
Pseudomonas aeruginoase: toxins
realeases Exotoxin A, inactivating elongation factor EF-2
Causes host cell death
Shigella spp: toxins
releases shiga toxin causing inactivation of 60s ribosome by removing adenine from rRNA
causes GI mucosal damage leading to dysentery, also enhances cytokine release causing hemolytic-uremic syndrome
Enterohemorrhagic E coli: toxin
releases Shiga like Toxin causing inactivation of 60s ribosome by removing adenine from rRNA
SLT enhances cytokine release causing hemolytic-uremic syndrome, but does not invade host cells
Enterotoxigenic E. coli: toxin
Heat labile toxin: overactivates cAMP causing increase Cl secretion in gut and efflux
Heat stabile toxin: overactivates cGMP causing decreased reaborption of NaCl and H2O in gut
Both cause watery diarrhea
“Liable in the Air, Stable on the Ground”
Bacillus anthracis: toxin
Edema factor toxin
mimics the cAMP enzyme
likely responsible for characteristic edematous borders of black eschar in cutaneous anthrax
vibrio cholerae: toxin
cholerae toxin
overactivates cAMP by permanently activating Gs leading to increase Cl secretion with H2O following
Voluminous “rice-water” diarrhea
Vibrate the G-Spot
Vibrio Gs
Bordetella pertussis: toxin
Pertussis toxin
overactivates cAMP by disabling Gi, impairing phagocytosis to permit survival of microbe
Whooping cough: child coughs on expiration and whoops on inspiration
Clostridium tetani: toxin
tetanospasmin toxin
protease that cleave SNARE proteins required for neurotransmitter release
Symptoms: spasticity, rusis sardonicus, lockjaw, prevents release of inhibitory neurotransmitters (GABA, glycine) from Renshaw cells in spinal cord
get tetanus from a rusty wrench-saw (Renshaw)
Clostridium botulinum: toxin
Botulinum toxin
Proteases that cleave SNARE proteins required for neurotransmitter release
Flaccid paralysis, floppy baby
toxin prevents release of stimulatory ACh signals at neuromuscular junctions leading to flaccid paralysis
Clostridium perfringens: toxin
Alpha toxin
phospholipase (lecithinase) that degrades tissue and cell membranes
degradation of phospholipids leading to myonecrosis (gas gangrene) and hemolysis (double zone of hemolysis on blood agar)
Streptococcus pyogenes: toxin
streptolysin O
Protein that degrades cell membrane
Lyses RBCs, contributes to Beta-hemolysis, host antibodies against toxin (ASO) used to diagnose rheumatic fever (do not confuse with immune complexes of poststreptococcal glomerulonephritis)
Exotoxin A
bring MHC II and TCR in proximity to outside of antigen binding site to cause overwhelming release of IFN-gamma and IL-2 leading to shock
Toxic shock syndrome: fever, rash, shock
Staphococcus aureus: toxin
Toxic shock syndrome toxin (TSST-1)
bring MHC II and TCR in proximity to outside of antigen binding site to cause overqhelming release of IFN-gamma and IL-2 leading to shock
also protein A binds Fc portion of IgG
Bacterial Transformation
Ability to take up naked DNA (i.e. from cell lysis) from environment (aka competence)
a feature of many bacteria
any DNA can be used
Bacterial transformation: Hfr x F-
High frequency recombination (Hfr)
replication of incorporated plasmid DNA may include flanking chromosomal genes
transfer of plasmid and chromosomal genes
Transposition
segment of DNA (e.g. transposon) that can “jump” from one location to another, can transfer genes from plasmid to chromosome and vice versa
when excision occurs, may include some flanking chromosomal DNA which can be incorporated into a plasmid and transferred to another bacterium
examples include antibiotic resistance genes on R plasmid
Transduction: Generalized
A packaging event
lytic phage infects bacterium, leading to cleavage of bacterial DNA
Parts of bacterial chromosomal DNA may become packaged in viral capsid
phage infects another bacterium, transferring these genes
Transduction: specialized
an excision event lysogenic phage infects bacterium
viral DNA incorporates into bacterial chromosome
when phage DNA is excised, flanking bacterial genes may be excised with it
DNA is packaged into phage viral capsid
phage infects another bacterium, transferring these genes
alpha hemolytic bacteria
Form green ring around colonies on blood agar
Streptococcus pneumoniae
viridans streptococci
Streptococcus pneumoniae: Classification
Capsule Optochin sensitive Bile soluble Catalase negative alpha hemolytic gram positive Cocci diplococci lancet shaped IgA protease natural transformer
Viridans Streptococci: Classification
No capsule optochin resistant bile insoluble alpha hemolytic Gram positive cocci Catalase negative
Strep pyogenes: classification
Group A Bacitracin sensitive Beta hemolytic catalase negative gram positive cocci
Strep agalactiae: classification
Group B Bacitracin resistant gram positive cocci in chains Beta hemolytic catalase negative CAMP test positive
Enterococcus: classification
Group D gram positive cocci Catalase negative gamma hemolytic Growth in bile and NaCl
Staph saprophyticus: classification
novobiocin resistant
Gram positive cocci
catalase positive
coagulase negative
Staph epidermidis: classification
Novobiocin sensitive Gram positive cocci catalase negative coagulase negative Makes biofilm(which is why it can adhere to medical implants and cause infections)
Staph aureus: classification
gram positive cocci
catalase positive
coagulase positive
beta-hemolytic
Gram positive rods: classification
Clostridium corynebacterium listeria bacillus mycobacterium
actinomyces: classification
Gram positive branching filaments
anaerobe
not acid fast
nocardia classification
Gram positive
branching filaments
aerobe
mildly acid fast
Staphylococcus aureus: Virulence factor, what does the infection cause
Protein A- binds Fc-IgG
Inflammatory disease
Toxin-mediated disease- toxic shock syndrome (TSST-1), scalded skin syndrome (exfoliative toxin), rapid onset food poisoning (enterotoxins)
MRSA- altered penicillin-binding protein makes it resistant
Streptococcus pneumoniae: causes what
MOPS meningitis Otitis media in kids Pneumonia Sinusitis Rusty sputum (alpha hemolytic) causes sepsis in sickle cell anemia and splenectomy
S. pneumoniae MOPS are Most OPtochin
Sensitive.
What bacteria is likely to be the cause of dental carries
Streptococci mutans
What bacteria is likely to cause infection of damaged heart valves
Streptococci sanguinis
sanguis=blood
makes dextrans which bind to fibrin-platelet aggregates on damaged heart valves
Streptococcus pyognenes (group a strep): causes what
release pyrogenic exotoxin in scarlet fever rheumatic fever (antibodies against M protein, type II hypersensitivity) acute glomerulonephritis (type III hypersensitivity)
Strep agalactiae: causes, prevention
B is for babies (group B), shortly after birth babies get symptoms
causes pneumonia, meningitis, and sepsis
Colonizes vagina
Produces CAMP factor which enlarges area of hemolysis cause by strep aureus)
Hippurate test positive
screen pregnant women and give positive ones intrapartum penicillin prophylaxis
Enterococci: causes, facts
normal colonic flora that are penicillin G resistant
cause UTI, biliary infections, subacute endocarditis following GI/GU procedures
VRE= Vanco resistant enterococci
Streptococcus bovis: causes
Colonizes the gut
can cause bacteremia and subacute endocarditis in COLON CANCER
Corynebacterium diphtheriae: causes
causes diphtheria via exotoxin encoded by beta prophage
Potent exotoxin inhibits protein synthesis via ADP-ribosylation of EF-2
lab diagnosed
Bacterial Spores
Spores are highly resistant to heat and chemicals
Need to autoclave to kill
Have dipicolinic acid in their core
If you DIP your COLON in
ACID, only the spores will be left (like clostridium)
Clostridia botulinum
preformed heat labile toxin that inhibits ACh release at the neuromuscular junction causing botuism
Adults ingest the toxin
babies ingest the spores in honey causing floppy baby syndrome
Clostridia perfringens
produce alpha toxin
lecithinase which is a phospholipase
can cause myonecrosis (gas gangrene) and hemolysis
Clostridia difficle
Produces 2 toxins
Toxin A, enterotoxin, binds brush border of gut
Toxin B, cytotoxin, cases cytoskeletal disruption via actin depolymerization causing pseudomembranous colitis leading to diarrhea
usually secondary to antibiotic use. especially clindmycin or ampicillin
diagnose by detecting one of the toxins in stool
Anthrax
caused by bacillus anthracis
gram positive spore forming rod
only bacterium with a polypeptide capsule
(contains D-glutamate)
Cutaneous anthrax
boil-like lesion
ulcer with black eschar (painless and necrotic)
uncommon for it to progress to bacteremia and death
Pulmonary anthrax
inhalation of spores
flu-like symptoms that progress to fever, pulmonary hemorrhage, mediastinitis and shock
Woolsorters’ disease
inhalation of anthrax spores from contaminated wool……weird
Bacillus cereus
causes food poisoning
spores survive cooking rice, keeping rice warm results in germination and enterotoxin formation
emetic type usually seen with rice and pasta (nausea and vomiting within 1 to 5 hrs, caused by cerculide, a preformed toxin)
Diarrheal type causes watery, nonbloody diarrhea and GI pain within 8 to 18 hrs
Cereus - cereal
Rice - warm rice krispies cereal
Listeria monocytogenes
Facultative intracellular microbe
ingestion of unpasteurized dairy products, deli meats, transplacental transmission, or vaginal during birth
form “rocket tails” from actin polymerization, help it move, tumbling motility
Only gram positive to produce LPS
can cause amnionitis, septicemia, spontaneous abortion, neonatal meningitis
goes away in adults usually
ampicillin in kids, immunocompromised, elderly
Actinomyces
gram positive anaerobe
long, branching filaments resembling fungi
not acid fast
normal oral flora
causes oral/facial abscesses that drain through sinus tracts, forms yellow sulfur granules
treat with penicillin
Nocardia
Gram positive aerobe
weakly acid fast
long, branching filaments resembling fungi
found in soil
causes pulmonary infections in immune compromised and cutaneous infections after trauma in normal patients
treat with sulfonamides
Primary TB infection
Ghon complex
usually in mid zone of lung
Secondary TB infection
what is it called when it invades the vertebral body
fibrocaseous cavitary lesion usually in upper lobe
pott disease when in the vertibrae
Mycobacteria
acid fast
M. tuberculosis
M. kansasii (pulmonary TB-like symptoms)
M. avium (intracellular, causes disseminated non-TB disease in AIDS patients), prophylactic treatment with azithromycin
TB symptoms, and virulence
fever, night sweats, weight loss, hemoptysis
cord factor in virulent strains inhibits macrophage maturation and induces release of TNF-alpha. sulfatides inhibit phagolysosomal fusion
Leprosy
Caused by mycobacterium leprae
2 forms
lepromatous and tuberculoid
mycobacterium leprae
causes leprosy
acid fast bacillus
likes cool temperatures (infects skin, superficial nerves)
can’t be grown in vitro
reservoir in US is in armadillos
dapsone, rifampin and clofazimine for 2 to 5 years
Lepromatous leprosy
presents diffusely over skin with leonine facies, no granulomas,
communicable
low cell-mediated immunity with humor Th2 response
Tuberculoid leprosy
limited to a few hypoesthetic, hairless skin plaques, go after superficial surface and nerves, slow growth
high cell-mediated immunity with Th1 type immune response, will see granulomas on biopsy
dapsone and rifampin treats in 6 months
M. Tuberculosis
Acid fast bacillus
produces niacin
mycolic acids make it resistant to gram staining
Auramine- rhodamine stain of sputum will be positive
Campylobacter jejuni: classification
Gram negative oxidase positive comma shaped grows at 42 degrees polar flagella microaerophilic
Vibrio cholerae: classification
Gram negative
oxidase positive
comma shaped
grows in alkaline media
Helicobacter pylori: classification
Gram negative
oxidase positive
comma shaped
produces urease
Haemophilus influenzae: classification
gram negative
coccoid rod
require factors V and X
Pasteurella
gram negative rod
coccoid rods
from animal bites
Brucella
Gram negative
coccoid rod
causes brucellosis
Bordetella pertussis: classification
gram negative
coccoid rod
N. meningitidis: classification
gram negative
diplococci
maltose fermenter
N. gonorrhoeae
gram negative diplococci maltose nonfermenter Can be grown on chocolate agar, but not on blood agar Pili are its pathogenic feature
Klebsiella: classification
gram negative rod
fast lactose fermenter
E. coli: classification
gram negative rod
fast lactose fermenter
produces beta galactosidase which breaks down lactose into glucose and galactose
Enterobacter: classification
gram negative rod
fast lactose fermenter
Citrobacter: classification
gram negative rod
slow lactose fermenter
Serratia: classification
gram negative rod
slow lactose fermenter
Shigella: classification
Gram negative rod
lactose non fermenter
oxidase negative
Salmonella: classification
Gram negative rod
lactose non fermenter
oxidase negative
Proteus: classification
Gram negative rod
lactose non fermenter
oxidase negative
Yersinia: classification
Gram negative rod
lactose non fermenter
oxidase negative
Pseudomonas: classification
Gram negative rod
non fermenter
Oxidase positive
Lactose fermenting enteric bacteria
Lactose is KEE
Test with macConKEE’S agar, turns pink from acid
Citrobacter, Klebsiella, E. coli, Enterobacter, and Serratia
EMB agar- lactose fermenters grow as purple/black colonies
E. coli grows purple with green sheen
Penicillin and gram negative bugs
gram negative bacilli are resistant to penicillin G but may be susceptible to penicillin derivatives such as ampicillin or amoxicillin
gram negative outer membrane blocks penicillin and vanco entry
Neisseria Gonococci
Gram negative diplococci (only circular gram negative)
ferments glucose
Produces IgA proteases
Has pili
Mostly found intracellularly in neutrophils but not an intracellular organism
No capsule
No maltose fermentation
No vaccine due to rapid antigenic variation of pilus proteins
Sexually transmitted
Causes gonorrhea, septic arthritis, neonatal conjunctivitis, pelvic inflammatory disease, Fitz-hugh curtis syndrome
Condoms prevent transmission
treat with ceftriaxone (add azithromycin or doxy for possible chlamydia co infection)
Capsule is immunogenic
Neisseria Meningococci
Gram negative diplococci ferments glucose Produces IgA proteases Polysaccharide capsule maltose fermentation Vaccine but not for type B Transmitted by respiratory and oral secretions Causes meningiococcemia and meningitis, waterhouse-Friderichsen syndrome prophylaxis with rifampin, ciprofloxacin, or ceftriaxone Treat with ceftriaxone or penicillin G Type B capsule is not immunogenic GIVE AWAY MENINGITIS IS PETECHIAL RASH!
Haemophilus influenzae
Small gram negative coccobacillary rod
aerosol transmission
Produces IgA proteases
culture on chocolate agar with Nad (V) and hematin (X) or with staph aureus which provides factor X
haEMOPhilus causes: Epiglottitis, Meningitis, Otitis media, Pneumonia
Treat mucosal with amoxicillin +/- clavulanate
treat meningitis with ceftriaxone
rifampin for prophylaxis
X-ray of H. influenzae epiglottitis
thumbprint sign- thickening of epiglottis on lateral neck radiograph
Legionella pneumophila
Gram negative rod, stains poorly-use silver stain Grow on charcoal yeast extract with iron and cysteine clinically detected by antigen in urine aerosol transmission from water no person to person transmission treat with macrolide or quinolone labs show hyponatremia pontiac fever= mild flu like symptoms
Legionnaires disease
severe pneumonia
fever
GI
CNS symptoms
Pseudomonas aeruginosa
Aerobic gram negative rod
non lactose fermenting oxidase positive
produces pyocyanin (blue green pigment)
grape like odor
from a water source
produces endotoxin (fever, shock) and exotoxin A (inactivates EF-2)
PSEUDOmonas is associated with burn infections, Pneumonia (especially cystic fibrosis), Sepsis, External otitis, UTI, Drug use, and Diabetic Osteomyelitis, and hot tub folliculitis
treat with aminoglycosides plus extended spectrum penicillin (piperacillin, ticarcillin, cefepime, imipenen, meropenum)
Ecthyma gangrenosum
rapidly progressive necrotic cutaneous lesions caused by pseudomonas bacteremia
usually in immune compromised patients
treat with aminoglycosides plus extended spectrum penicillin (piperacillin, ticarcillin, cefepime, imipenen, meropenum)
E coli
Gram negativem oxidase negative lactose fermenting rod
grows pink on MacConkey agar
virulence factors: fimbriae- cystitis and pyelonephritis, K capsule- pneumonia, neonatal meningitis, LPS endotoxin- septic shock
Strain EIEC of E coli
Microbe invades intestinal mucosa and causes necrosis and inflammation
clinically similar to shigella
Invasive; dysentery
Strain ETEC of E coli
produces heat-labile and heat-stabile enterToxins. no inflammation or invasion
Travelers’ diarrhea (watery)
Strain EPEC of E coli
no toxin produced
adheres to apical surface,
flattens villi, prevents absorption
Diarrhea usually in Peds patients
strain EHEC of E coli
O157:H7 is the most common serotype
produces Shiga-like toxin causing hemolytic-uremic syndorme (triad of anemia, thrombocyopenia, acute renal failure)
also called STEC (shiga toxin producing E coli)
Microthrombi form on endothelium damaged by toxin leading to mechanical hemolysis (schistocytes) and decreased renal blood flow; microthrombi consume platelets leading to thrombocytopenia
Dysentery (toxin alone causes necrosis and inflammation)
Does not ferment sorbitol (which other E coli do)
Klebsiella
Gram negative, oxidase negative, bacillus,
fast lactose fermenting, urease positive
MacConkeys agar
an intestinal flora that causes lobar pneumonia in alcoholics and diabetics when aspirated
very mucoid, abundant polysaccharide capsules
red currant jelly sputum, x ray shows lobar cavitation
nosocomial UTIs
4 A’s
Aspiration pneumonia, Abscess in lungs and liver, Alcoholics, di-A-betics
treat with 3rd gen cephalosporin +/- aminoglycoside
Salmonella
has flagella can disseminate hematogenously have animal reservoirs produces hydrogen sulfide antibiotics may prolong fecal excretion of organism invades intestinal mucosa and causes a monocytic response can cause blood diarrhea does not ferment lactose
Shigella
no flagella
cell to cell transmission no hematogenous spread
only reservoirs are humans and primates
does not produce hydrogen sulfide
antibiotics shorten duration of fecal excretion of organism
invades intestinal mucosa and causes PMN infiltration
often causes blood diarrhea
does not ferment lactose
Salmonella typhi
Causes typhoid fever
found only in humans
characterized by rose spots on the abdomen, fever, headache, and diarrhea
can remain in gallbladder and cause a carrier state
Neonates with meningitis: what bugs are you thinking
Group B strep (agalactae)
E coli
Listeria monocytogenes
Campylobacter jejuni
major cause of bloody diarrhea, especially in kids
fecal oral transmission through foods (pork, meat, unpasteurized milk)
Comma or S shaped
oxidase positive, grows at 42 Celcius
Look for RBCs and WBCs in stool (invasive bug causing immune response and bleeding)
common antecedent to Guillain-Barre syndrome and reactive arthritis
Vibrio cholerae
produces profuse rice-water diarrhea via enterotoxin that permanently activates Gs, increasing cAMP
comma shaped, oxidase positive, grown in alkaline media
endemic to developing countries
oral rehydration necessary
Yersinia enterocoliticia
Usually transmitted from pet feces, contaminated milk, or pork
causes mesenteric adenitis that can MIMIC Crohns disease or appendicitis (find micro abscesses in lymph nodes when they think they have appendicitis
Helicobacter pylori
Causes gastritis and peptic ulcers (especially duodenal)
risk factor or peptic ulcer, gastric adenocarcinoma, lymphoma
curved gram negative rod
catalase positive, oxidase positive, urease positive
Use urea breath test or urine antigen test to diagnose
creates alkaline environment
most common initial treatment is triple therapy: proton pump inhibitor, clarithromycin, and amoxicillin or metronidazole
Spirochetes
spiral shaped bacteria with axial filaments
includes Borrelia (big size), Leptospira, Treponema
only borrelia can be visualized using aniline dyes (wright or Giemsa stain) in light microscopy
Treponema is visualized by dark-field microscopy
Leptospira interrogans
Found in water contaminated with animal urine, causes leptospirosis: fly like symptoms, jaundice, photophobia with conjuctival suffusion (erythema w/o exudate)
prevalent among surfers and in tropics (i.e. Hawaii)
Weil Disease
Icterohemorrhagic leptospirosis
severe form of leptospirosis
jaundice, azotemia from liver and kidney dysfunction, fever, hemorrhage, anemia
Lyme Disease
Cause by Borrelia burgdorferi, from tick Ixodes
Natural reservoir is mice
Common in Northeastern US
Initial symptoms- erythema chromicum migrans, flu like, +/- facial palsy (bell palsy)
Later symptoms- monoarthritis (knee, hips) due to type III hypersensitivity, migratory polyarthritis, AV nodal block, encephalopathy, facial nerve palsy, polyneuropathy
treat: doxy, ceftriaxone
Ixodes tick transmits
Lymes, Babesia, Anaplasmosis
Syphilis: caused by, treatment
spirochete Treponema pallidum
treat: penicillin G
Primary syphilis
Localized disease with painless chancre
use dark field microscopy to visualize treponemes in fluid from chancre
Secondary syphilis
secondary=systemic
bronze colored maculopapular rash (palms and soles);
condylomata lata: gray to white flat wart like lesions of the mouth and perineal area;
constitutional symptoms
serologic testing: VDRL/RPR (nonspecific), confirm diagnosis with FTA-ABS (fluorescent treponenal antibody absorption test)
latent syphilis follows (no symptoms, but still positive tests)
Tertiary syphilis
gumma (chronic granulomas), aortitis (vasa vasorum destruction), neurosyphilis (tabes dorsalis), argyll robertson pupils
broad-based ataxia, romberg, charcot joint, stroke without hypertension
for neurosyphilis test spinal fluid with VDRL or RPR
Congenital syphilis
saber shins, saddle nose, CN VIII deafness, Hutchinson teeth, mulberry molars
to prevent, treat mom early, placental transmission usually occurs after first trimester
Argyll Robertson pupil
Pupil constricts with accommodation but is not reactive to light
associated with tertiary syphilis
“prostitute pupil” accommodates but does not react
VDRL false positives
VDRL detects nonspecific antibody that reacts with beef cardiolipin
inexpensive, widely available test for syphilis
sensitive, not specific
many false positives due to VDRL: Viruses, Drugs Rheumatic Fever, Lupus/Leprosy
Jarisch-Herxheimer reaction
Flu-like symptoms after antibiotics are started
due to killed bacteria releasing pyrogens
Anaplamsa spp.
causes Anaplasmosis,
transmitted via Ixodes ticks (live on deer and mice)
Bartonella spp.
causes Cat scratch disease, bacillary angiomatosis
get from cat scratches
Borrelia burgdorferi
causes lyme disease
Transmitted via ixodes tick (live on deer and mice)
Borrelia recurrentis
causes relapsing fever
transmitted via Louse
recurrent due to variable surface antigens
Brucella spp.
causes Brucellosis/undulant fever
from unpasteurized dairy
faculative intracellular
Campylobacter
causes bloody diarrhea
from puppies, livestock (fecal oral, or uncooked meat)
Chlamydophila psittaci
cause psittacosis
from parrots, other birds
Coxiella burnetii
causes Q fever
from Aerosols of cattle/sheep amniotic fluid
BURN the cattle and sheep on the bbQ
Ehrlichia chaffeensis
causes Ehrlichiosis
from lone star ticks
you get ehrlich from the lone star tick
Francisella tularensis
gram negative coccobacillus, slow growing, aerobic, require cystine to grow
involvement of regional lymph nodes
rupture of pustules causes ulcers
causes Tularemia
from ticks, rabbits, deer fly, dermacentor tick, (think mid western hunter)
Leptospira spp.
causes leptospirosis
get it from animal urine
surfers in the leper colony in hawaii surf on a spiral of urine
Mycobacterium leprae
causes leprosy
from humans with lepromatous leprosy or armadillos which are the reservoir in the US
(lepromaTWOs is a Th2 response) (tubercuLLOYD christmas - all that ONE in a million talk is Th1)
Pasteurella multocida
causes cellulitis and osteomyelitis
get it form animal bites, cats, dogs
animals in a pasture chewing on skin and bones
Rickettsia prowazekii
causes epidemic typhus
get it from Louse
epidemic typhus is on the PROWL
Rickettsia rickettsii
causes rocky mountain spotted fever
from dermacentor ticks
obligate intracellular (endothelial cells) organisms that need CoA and NAD because they cannot synthesize ATP
Rickettsia typhi
causes Endemic typhus
from fleas
Yersinia pestis
causes plague from fleas (rats and prairie dogs are reservoirs)
Babesia microti
causes babesiosis from the ixodes tick protozoan parasite, intraerythrocytic fever headache and chills splenectomy patients get severe hemolytic anemia
Gardnerella vaginalis
pleomorphic gram variable rod
causes vaginosis
Presents as a gray vaginal discharge with a fishy smell, nonpainful (vs. vaginitis)
associated with sexual activity, but not sexually transmitted
Clue cells or vaginal epithelial cells covered with Gardnerella bacteria are visible under the microscope
Treat with metronidazole or clindamycin if anaerobic vaginosis (other gram negative bacteria can cause vaginosis)
I don’t have a clue why I smell fish in the vagina
garden!
Rocky Mountain spotted fever
Rickettsia rickettsii (lives in endothelial cells), vector is Dermacentor ticks
Rash usually at wrists and ankles, spreads to trunk, palm, and soles
Classic triad are headache, fever, rash (vasculitis)
Typhus
Endemic (fleas)- R. typhi
Epidemic (human body Louse) R. prowazekii
rash starts centrally and spreads out, sparing palms and soles
Rickettsii on the wRists, Typhys on the Trunk
Ehrlichiosis
Ehrlichia: vector is tick
monocytes with morulae (berry like inclusions) in cytoplasm
ehrlich is from the lone star tick
Anaplasmosis
Anaplasma, vector is tick, granulocytes with morulae (berry like clusters) in cytoplasm (intracellular):
Leukopenia, thrombocytopenia, increased transaminases.
Q fever
Coxiella burnetti
no arthropod vector
tick feces and cattle placenta release spores that are inhaled as aerosols. presents as pneumonia
Q fever is Queer: no rash, no vector, causative organism can survive outside in its endospore form
Chlamydiae
Chlamydie in obligate intracellular organism that causes mucosal infections; non gram staining
Elementary body (small, dense) is infectious and enters cell via endocytosis; transforms into reticulate body (what you would culture)
Reticulate body replicates in cell by fission; reorganizes into elementary body
Diagnose in lab: cytoplasmic inclusions seen on Giemsa iodine, or fluorescent antibody- stained smear
cell wall lacks muramic acid
treat with azithromycin (one time treatment) or doxy
reiter’s = arthreitis
Chlamydia trachomatis causes
reactive arthritis (reiter syndrome) follicular conjuctivitis, nongonococcal urethritis and PID treat with azithromycin (one time treatment) or doxy
Chlamydia pneumoniae and C. psittaci cause
cause atypical pneumonia; transmitted via aerosol
treat with azithromycin (one time treatment) or doxy
Chlamydia trachomatis serotypes: A, B, C
Chronic infection, causes blindness due to follicular conjunctivitis in africa
ABC= Africa/Blindness/Chronic infection
Chlamydia trachomatis serotypes: D-K
Urethritis/PID, ectopic pregnancy, neonatal pneumonia (staccate cough, neonatal infection
D-K=everything else
neonatal disease can be acquired passing through infected birth canal: why we give erythromycin eye drops
Chlamydia trachomatis serotypes: L1, L2, L3
Lymphogranuloma Venereum: small painful ulcers on genitals leading to swollen, painful inguinal lymph nodes that ulcerate (“buboes”) and drain through the skin. treat with doxy
Mycoplasma pneumoniae
not seen on gram stain, no cell wall
membrane has sterols for stability
young people in close quarters
Causes atypical “walking” pneumonia
insidious onset, headache, nonproductive cough, patchy or diffuse interstitial infiltrate
X ray looks worse than patient
higher titer of cold agglutinins (IgM)
grown on Eaton agar
treatment: macrolide, doxy, or fluoroquinolone
penicillin does not work because it has no cell wall
Cold agglutinins
IgM: IgM isohemagglutinins that agglutinate autologous erythrocytes at 4 degrees C
Strep MG agglutinins: agglutinates streptococcus salivaries termed MG
Treatment of mycoses
local infection: fluconazole or intraconazole
systemic infection: amphotericin B
Histoplasmosis
Looked for a macrophage filled with histoplasms (the histoplasma is smaller than RBC, 2-5 micrometers) thin capsule, no true cell wall Mississippi and ohio river valleys causes pneumonia *Birds or bat droppings*
Blastomycosis
States east of Mississippi river and central US
Causes inflammatory lung disease
can disseminate to bones and skin, joints, and genitourinary
forms granulomatous nodules
Broad based budding (same size as RBCs)
Blasto Buds Broadly
a dog rolling around in a rotting wood pile
Coccidiomycosis
Southwestern US, California, Desert areas
Causes pneumonia and meningitis
can disseminate to bone and skin
increased cases after earthquakes (spores go into air, become spherules in lungs)
Spherule is much larger than an RBC, filled with endospores
Valley fever, desert humps (erythema nodosum), Desert rheumatism (arthralgias)
Paracoccidioidomycosis
Latin America
Budding yeast with captians wheel formation
way bigger than RBC
Paracoccidio parasails with the captian’s wheel all the way to latin america
paraguay is in south america, and you can sail there with your captain wheel
Tinea Versicolor
caused by malassezia furfur
degradation of lipids produces acids that damage melanocytes and cause hypopigmented and or hyperpigmented patches
occurs in hot humid weather
treat: topical miconazole, selenium sulfide,
spaghetti and meatball appearance
Furry meatballs look green under a woods lamp
Trichophytan rubrum
KOH the skin scraping, detects arthroconida and hyphae
Candida albicans
alba=white
systemic or superficial infections
Oral and esophageal in immunocompromised or steroid asthma user who doesn’t wash out mouth
Vulvovaginits, diaper rash, endocarditis in IV drug user, disseminates to any organ, chronic mucocutaneous candidiasis
treat: topical azole for vagina, fluconazole or caspofungin for oral/esophageal; systemic is fluconazole, amphotericin B, or caspofungin
Diagnosed by gram tube test, budding yeast with short true hyphae
catalase positive
Aspergillis fumigatus
Invasive aspergillosis, especially in immunocompromised or chronic granulomatous disease
Allergic bronchopulmonary aspergillosis (ABPA): associated with asthma and cystic fibrosis, may cause bronchiectasis and eosinophilia
Aspergillomas in lung cavities, especially after TB infection
Some species produce aflatoxins which are associated with hepatocellular carcinoma
think A’s for Acute Angles in Aspergillus. not dimorphic
the aflac duck eats liver and asparagus (aflatoxin of aspergillus causes hepatocellular carcinoma)
fumigatus = fumes = lungs
Catalase positive
Cryptococcus Neoformans
Cryptococcal meningitis, cryptococcus
Heavily encapsulated yeast
not dimorphic
found in soil, pigeon droppings
get it from inhalation with hematogenous spread to meninges
culture on Sabouraud agar, stain with india ink and mucicarmine
latex agglutination test detects polysaccharide capsular antigen and is most specific
“Soap Bubble” legions in brain
Most common cause of meningitis in AIDS patients in US
Sab is a cryptic guy when he visits india because he has a latex soap bubble fetish fetish, he also raises pigeons
Mucor and Rhizopus spp.
Mucormycosis
Disease mostly in ketoacidotic diabetic and leukemic patients
fungi proliferate in blood vessel walls when there is excess ketone and glucose
penetrate cribriform plate and enter brain
rhinocerebral, frontal lobe abscesses
Symptoms: headache, facial pain, black necrotic eschar on face, may have CN involvement
treat: amphotericin B
Ribbon form hypae branching at 90 degrees
Pneumocystic jirovecii
Causes Pneumocystis pneumonia, diffuse interstitial pneumonia (increased surfactant due to activation of type II pneumocytes leading to death by asphyxiation)
Yeast
Inhaled
Get this if immunosuppressed (AIDS, newborn)
X ray shows diffuse bilateral CXR appearance
Lung biopsy or lavage confirms
Disc shaped yeast forms on methenamine silver stain
TMP-SMX to treat
atovaquone, dapsone to prevent when CD4 count less than 200
pneumodiscus
Sporothrix schenckii
Sporotrichosis
Dimorphic cigar shaped budding yeast that lives on vegetation
thorn prick introduces yeast to skin
causes local pustule or ulcer with nodules along draining lymphatics
little systemic illness
treat with itraconazole or potassium iodide
ITRy to plant a Rose in a Pot, pot=potassium
ITRaconazome
Giardia lamblia
Giardiasis: blotting, flatulence, foul-smelling, fatty diarrhea
often seen in campers/hikers and may be in water supply
think fat-rich Ghirardelli chocolates for fatty stools of Giardia, may be asymptomatic
comes from cysts in water
Look for trophozoites or cysts in stool to diagnose
Treat with metronidazole
Entamoeba histolytica
Amebiasis: bloody diarrhea (dysentery), liver abscess (anchovy paste exudate), abdominal abscesses before liver affected RUQ pain (histology shows flask like ulcer if submucosal abscess of colon ruptures comes from cysts in water diagnose by doing serology and or trophozoites (with RBCs in cytoplams) or cysts in stool treat with metronidazole or iodoquinol for asymptomatic cyst passers
Cryptosporidium
Causes severe diarrhea in AIDS
Mild disease with watery diarrhea in healthy people
get it from Oocysts in water
Diagnose by seeing oocysts on acid fast stain
treat by prevention (city water filters), nitazoxanide in healthy people
Diarrhea caused by bug lysing brush boarder cells (bug replicates in brush border cells)
Nita is Sabs cryptic sister who has oocytes and does so much butt stuff that she has severe diarrhea with her AIDS
Toxoplasma gondii
brain abscess in HIV (ring enhancing lesions on CT/MRI)
Congenital Toxoplasmosis= triad of chorioretinitis, hydrocephalus, and intracranial calcifications
“bright periphery and dark core” due to necrosis
Transmitted as cysts in meat, uncooked pork, or oocytes in cat feces, cross placenta (pregnant stay away form cats)
diagnose by serology
treat with sulfadiazine and pyrimethamine
15-20% of population is infected but immune system makes it go dormant until immune compromised then they get the infection
Most common brain infection in HIV patients causing seizures, altered mental status, focal neurologic defects
Naegleria fowleri
Rapidly fatal meningoencephalitis
flagellated trophozoite
Get it from swimming in freshwater lakes (Naegleria-Nalgene)
enters body via cribiform plate forming necrotic lesions spreading from olfactory lobes
Diagnose by amoebas in spinal fluid
Treat: amphotericin B, but most still die
Trypanosoma brucei
African sleeping sickness: enlarged lymph nodes, recurring fever ( due to antigenic variation), somnolence, coma
two subtypes: rhodesiense and gambiense
get it from Tsetse fly that has a painful bite
diagnose by blood smear
Suramin for blood borne disease or melarsoprol for CNS penetration
(“it sure is nice to go to sleep”; melatonin helps with sleep)
Plasmodium
Causes malaria: headache, fever, anemia, splenomegaly
vivax and ovale-get 48 hour cycle (tertian; fever on first and third day, thus fevers are 48 hours apart)
dormant in liver
Falciparum-sever; irregular fever pattern; parasites in RBCs occlude capillaries in brain (cerebral malaria), kidney, lungs
malariae- 72 hour cycle (quartan)
transmitted via misquito (anopheles)
diagnosed by blood smear showing trophoziote ring from within RBC, schizont containing merozoites
Treatment of plasmodium
AKA treatment of malaria
Begin with chlorquine, which blocks plasmodium heme polymerase; if resistant use mefloquine or atovaquone/proguanil
If life threatening use IV quinidine (test for G6PD deficiency)
if Vivax/ovale add primaquine for hypnozoite (test for G6PD deficiency)
Babesia
Babesiosis: fever and hemolytic anemia; predominantly in Northeastern US,
if asplenic you get increase risk of severe disease
Transmitted via ixodes tick (same as borrelia burgdorferi of Lymes, so many are co infected)
Diagnose via blood smear, see ring form “maltese cross’ or PCR
Treat with atovaquone + azithromycin