Block 2 (Santosh's review) Flashcards
Chlamydia trachomia (Harry Potter)
Niche
Strains
ABC
D-K
L1,2,3
Feature
VF
Tests
(“HP’s CUTe CAT PuRs LouD in the morNinG”)
Humans
ABC= Trochoma (a very serious eye infection that can lead to blindness (trichiasis))
D-K = Neonatal conjunctivitis & pneumonia, Adult (cervicitis, urethritis, prostatitis)
L1-3= LGV (lymphoma granulomatous venerum
Feature= It forms HP (Halbertaedter-prowzek) bodies (these store glycogen)
VF= No peptidoglycan wall means its resistant to B-lactam antibiotics (cefuroxime)
Tests= Giema staining shows the HP inclusion bodies
Actinomyces Nocardia:
- Nocardia brasiliensis
- Nocardia ostitidis vaviarum
Causes what infection?
Tests (BAMS)
Treatment?
(“ACT NAtural & Don’t Panic… BAMS!!”)
Causes Actinomycotic mycetoma (chronic + slow progressive granulomatous infection of the skin, connective tissue, & bone forming swollen discharging sinuses (yellow granules)
Tests=
- Modified Brown-Brenn (shows gram-negative & branching)
- Acid-fast (1% sulphuric acid or 3% HCL in 95% ethanol)
- Sabourain agar & Brain heart infusion
Treat= surgically drain sinuses, then use a large dose of penicillin
Actinomyces Israelii
Causes what infection?
Tests (BAMS)
Treatment?
(“ACTIng in MAY then ….BAMS Dead Profession”)
Causes= Actinomycosis (from a tooth abscess/infection in the mandible with yellow-sulphur granules and inflammation)
Tests=
- Brain-heart infusion agar
- Acid-fast staining
- modified Brown-Brenn test shows gram-negative branching organisms)
- Sabouraund’s agar
Treat= drain + penicillin
Legionella
Nich
Causes what infection?
Tests (BAMS)
Treatment?
(“PLEasE WIPe your Loins”)
Gram-negative bacilli
Niche= water + amoebas
Causes=
Legionellosis (Legionnaires disease= L. pneumophila Look for atypical pneumonia + fever, headache, confusion, focal neuro def, scanty non-purulent sputum, hypernatremia)
Mild legionellosis NO PNEUMONIA (Pontiac fever = fever, headache, myalgia)
Tests= Immunofluorescent stain (antisera-direct) & urine ELISA (antigen detection)
Treat= Legionnaires (a high dose of erythromycin or fluoroquinolones as an alternative (Levofloxacin)
&
Pontiac fever = self-limiting
Predispotions= alcoholic liver cirrhosis, smoking, AIDS, & hospitalization
Vibrio cholera
Causes what infection?
Pathogenesis
Tests
Treatment?
(“NOt Good, ViCtory FACes GIrls ToDay”)
Gram-negative motile, oxidase-positive, halophilic, bacilli
Causes= food poisoning (sudden onset of effortless vomiting & profuse watery diarrhea (rice water-stool)
Patho= v. cholera is ingested and multiplies in the small intestine –> releases cholera toxin to increase Adenylate cyclase and increase cAMP production to inhibit G-inhibitory protein and cause more salt and water loss into the bowels (diarrhea)
Tests= alkaline peptone water growth, non-lactose fermenting (pale on MacConkeys), sensitive to TCBS, ferments glucose
Treat= IV rehydration and tetracycline (or cotrimoxazole)
Psittacosis (aka parrot fever) chlamydia
Niche
Causes what?
Tests
Treat
“PArrots Have Great ColourFul Dives”
Niche= birds
IP ~14 days cause atypical pneumonia + hepatitis (headache, fever, chills, myalgia, malaise, non-productive cough, rales
Tests= Giemsa stain (shows cytoplasmic inclusions), serodiagnosis via complement fixation test
Treat= doxycycline
Mycoplasm pneumoniae
Features
Causes what?
VF
Tests
Treat
(“My PEnis FEEls iTChy & AChy”)
Feat= pleomorphic/fried egg colonies
causes= Atypical pneumonia (low fever, chronic onset/recovery), tracheobronchitis, acute pharyngitis
VF= P1 antigen to adhere to a sialylated glycoprotein at the base of ciliated cells or the surface of RBCs (adherence to mucus membranes)
Tests=
- Animal serum (sterol) + yeast extract medium shows mulberry colonies
- Cold agglutination (insensitive/nonspecific)
- Compliment fixation test (high false positives)
- ELISA (IgG+M antibodies)
Treat= erythromycin + tetracylcine
Klebsiella granulomatosis (calymatobacterium) vs Klebsiella pneumoniae
Grams
Cause what?
Tests
Treatment
K. granulomatosis (“KiNG DONOVAN WRIGHT”)
K. Pneumonia (“Kill NyPD”)
Both are gram-negative, capsulated, motile bacilli
K.granulomatosis = Donovanosis (marked beefy red ulcers with rolled edges (painless)) shows Donovan bodies on wright’s stain (intracellularly)
K. peunomiae = pneumonia esp in alcoholics (Friedlander’s disease = upper lobes abscesses with currant jelly sputum)
Tests
MacConkeys + pink lactose fermeters = both
Giemsa stain & Wright’s stain show donovan bodies = k. granulomatosis
Treat doxycycline = both
pseudomonas aruginosa associated with cystic fibrosis
Gram
VF
Pathogenesis
Tests
Treat
“NOt Good, PiCk ANoTher Fruit To Peel”
gram-negative, motile oxidase + catalase positive, strict aerobic bacilli
VF= endo/exo-toxins, enzymes, pyocyanin (damages cilia)
Patho= patients with cystic fibrosis have reduced clearance capacities and are more at risk of p. aruginosa
Tests=
- MacConkeys (pale NLF colonies)
- Oxidase + catalase positive
- TSI (metallic sheen)
- Nutrient agar ( blue/green + fruity smell)
- pyocin + bacteria phage typing
Treat= ticarcillin or piperacillin & an aminoglycoside (gentamycin or ankimycin)
Prevent= keep neutrophil levels above 500 mew/L
Neonatal meningitis
Three organisms in descending order of likely hood s
Treatment
less than a month old
more than a month old
“NEonateS LoVe Alot”
E.coli
S. agalactia
L. monocytogenes
Look for=
Early: lethargy, hypotonia, vomiting
Late: Fontanelle bulging
Treat:
less than a month = ampicillin + aminoglycoside (gentamycin) or a 3rd gen cephalosporin (cefotaxime or ceftazidime (higher risk tho)
&
more than a month= vancomycin + a 3rd gen cephalosporin (cefotaxime or ceftriaxone)
Kid/adults classical triad fever, headache, neck stiffness)
Neonatal diarrhea
Three most common organisms that cause it
“Newborn Diet CauSeS diarrhea”
C. jejuni
Salmonella
Shigella
Mechanism of action for isoxazolyl
“Supports MSsa & Reduces MRsa”
active against MSSA
but
inactive against MRSA
Mechanism of action of ciprofloxacin
“Can I Dick Girls Today?”
It inhibits DNA gyrase and topoisomerase IV
&
its used for:
- gram-negative bacilli that cause (Gi and urinary tract infections
- Some gram-positive pathogens
- N. gonorrhea
- Chlamydia trachomatic
- Ureaplasma urealyticum
- Pseudomonas aruginosa
Mech of action of Clindamycin
“CLIP’s from The 50’s”
it binds the 50s subunit of the bacterial ribosome and prevents peptide translocation thereby blocking elongation and bacteria protein synthesis
Used for
c. perfringes
Bacteroides
strep. a pyogenes
Borrelia
B. recurrentis
B. duttoni
B. hermsii
Cause what?
“BaRF OnTo Every Desk”
B. Burgdorferi
causes what?
pathogenesis
Tests
Treat
Co-infections
“BURGers In LighT BARbacue sauceD”
Relapsing fever via ornithodorus tick bites (rodent born)
Look for IP 14 days fever, headache, myalgia, arthralgias, photophobia
Sometimes has hypotension and shock, which are fatal
B. burgdorferi
causes Lyme disease via ixodid ticks
Patho=
Stage1: gradual spreading rash + sometimes a bull’s eye (rash =erythema migrans)
Stage2: dissemination into the blood (weeks/months later) multiple skin lesions, neurological symptoms (cranial neuritis/meningitis), cardiac symptoms )myocardial, AV block)
Stage 3: post-infection (months/years later) monoarthritis in the knees
Tests=
- ELISA (1st test)
- Western blot (confirmatory test)
- Barbour Stoenner-kelly medium
- PCR (to detect borrelia antigens in the joint fluid)
Treat= doxycycline or ceftriaxone via IV if symptoms reoccur
Co-infections
- Babesiosis (severe in asplenic patients)
- Human granulocytic anoplasmosis
R. Rickettsia
causes what?
Niche
VF
Test
Treatment
Causes= Rocky Mountain fever (fever, severe headache, chills, aches, nausea and then 2-6 days later a developing maculopapular rash (1st on palms and soles then the chest)
Niche= ticks that bite rodents or dogs
VF= Induced phagocytosis & recruit actin for intracellular spreading
Test=
- Giemsa stain or direct immuno fluorescent antibody test
-Serology weil-felic reaction (r.rickettsia reacts with p. vulgaris OX2,19)
Treat= chloramphenicol or tetracycline
if untreated it invades the blood and causes death
Leptospira interrogans
Niche?
Features:
Causes what?
Tests?
Treat
Niche= rat pee
Feat= spirochete with hook-shaped ends
Causes=
Mild (anicteric) Leptospirosis = fever, myalgia, headaches, conjunctival hemorrhages, rash, photophobia, diarrhea + vomiting
&
Severe Leptospirosis (Weil disease) = Fever, hepatitis (jaundice/acute liver failure), nephritis, anemia, high risk of hemorrhaging, & cardia issues (myocarditis, arrhythmia, pericarditis etc.)
Test= microscopy
Treat= benzyl penicillin (or doxycycline incase of allergy)
Coxiella burnetii
Niche?
Causes what?
Test
Feature
Treat
“COws BRinG us DQ”
Niche Sheep, goats, and cattle (inhaled via aerosols)
Causes Q fever:
Acute= 2-6 weeks post-infection, the sudden onset of fever, chills, headache, & atypical pneumonia
&
Chronic= months-years post-infection causes low-grade fever & endocarditis
Test
- Indirect fluorescent antibody test
- Giemsa stain (shows gram-negative obligate intracellular parasites)
FEAT= Resistant to lysosomal enzymes
Treat=
acute -doxycycline
chronic doxycycline + hydroxychloroquine (interferes with parasite lysosome interaction)
Treponema pallidum
Niche
Caused what?
Pathology
Tests
Treat
“TraP Some CRiCkets in sticky BanDs”
niche= mucus membranes (mouth/genitals)
Causes= Syphilis
Patho=
- Primary stage: painless chancre on the genitals (resolves spontaneously at 3-6 weeks)
- Secondary stage: Disseminated progression (moves into the blood) Pleomorphic-maculopapular rash (on the palms/soles which spread) & condylomata (painless wart-like lesion white-ish
- Latent stage: No symptoms, but serology is positive for syphilis
- Tertiary stage (some patients progress): causes
—> Cardiovascular syphilis (~10yrs later, the treponema causes chronic inflammation of aortic vessels supplying the heart, causing necrosis and ultimately aortic dissection/aortic aneurysm)
ANTIBIOTICS DON’T WORK FOR THIS VARIANT---> Gumma (chronic, very destructive granulomatous lesions with a necrotic center that ulcerate (skin/bones) (fucks up the face pretty badly)
Others include neuro and congenital syphilis (not covered in B2 … hopefully)
Tests=
- Grows super slow (months to years for progression)
- Darkfield Direct microscopy of chancre discharge
- serological tests (non & specific tests for antibodies)
- immunofluorescence
- Treponema hemagglutination assay
Treat= benzathine penicillin, or if allergic, use doxycycline (only the primary/secondary stage)
When treating a patient with syphilis (treponema palladium), what adverse reaction might occur?
“JuSTin Picked Selener”
Jarisch-Herheimer reaction
Pathogenesis= happens after being treated with penicillin because of the bacterial endotoxins released after antibiotic therapy
Its SELF-LIMITING (fever, chills, myalgia, headache)
Note it they develop hypertension or tachycardia they risk death
Clostridium perfringes (Non enteric infection)
Gram’s report
Causes what?
Pathology
Tests
Treatment
Predispositions
“No GoodS when CamPinG ArouNd GaS PrOpane fires”
Gram-negative, obligate anaerobe, spore-forming double zone of hemolysis (boxcar-shaped) bacilli
Causes: Gas gangrene (aka clostridial myonecrosis)
Pathology:
1. C.perfringes infiltrates a wound & multiplies (anaerobic conditions).
- It secretes exotoxins i.e alpha-toxin (phospholipase lecithinase), to degrade phospholipids in the tissue causing myonecrosis, inhibiting leukocytes and making gas (seen via CT)
- the gas spreads to healthy tissue to colonize and fuck shit up
Early symptoms= sudden onset of SEVERE/UNRELENTING pain, followed by edema and tenderness
Later symtoms=
- massive edema with discolouration (bronze–> red-purple —> black) & bullae
- Serosanguinous discharge is usually dark and stinky
- crepitus (cracking skin from the gas)
Systemic toxicity symptoms (uh oh, double fuck)
- early (fever + tachycardia)
- late (shock + multiorgan failure) dead
Tests=
- Blood agar (double-zone/target hemolysis inner =Beta)
- Nagier’s reaction (positive = alpha-toxin)
- Robertson’s cooked meat medium (pink =acid saccharolytic & black = necrotic)
- Litmus milk fermentation (positive shows red colonies)
Treat= surgery (usually amputation), penicillin G, & a hyperbaric O2 chamber
Predispositions= ischemic vascular disease or peripheral arteriosclerosis
Clostridium perfringes (Enteric infection)
Causes
Pathology
Tests
Complications & treatment & predispositions
“CamPing in Dirt is Wet And Problematic, I Prefer SoftNess”
Causes= Food poisoning
Patho= c. perfringes type A release enterotoxin (heat resistant toxins) which become pre-formed in food (SELF-LIMITING), causing abdominal pain and watery diarrhea within 24hrs of eating
Tests= stool cultures
Complication= Clostridial necrotizing enteritis (affects the small intestine via the beta toxin (from type C c.perfringes) to cause severe abdominal pain, vomiting, and bloody stool
Treat= Piperacillin, tetracycline, & clindamycin
Predispositions=
- protein-calorie deficiency
- starchy diet (lots of sweet potatoes)
- nematode infection
Campylobacter jejuni
Gram stain
Growth conditions/transmission
Causes what?
Complications
Test
Treat
“NO Good CaJun Dishes aRe RouGh on Every Person’s tummy”
Gram-negative, oxidase-positive, microaerophilic polar flagellated bacilli
Grows at 37-42 degrees Celsius & transmitted via the fecal-oral route
Causes= Gastroenteritis (IP~3 days with watery/bloody diarrhea, fever, & abdominal cramps)
Complations=
- Guillain-Barre synd (ascending flaccid paralysis)
- Reactive arthritis (arthritis, conjunctivitis, & urethritis)
- Reiter’s syndrome
Test= Presence of pus cells (sensitive to nalidixic acid)
Treat= Erythromycin or ciprofloxacin
Clostridium difficile
Gram’s report
Niche
Causes what?
Pathology
VF
Test
Treat
“Positively GoodS APles Picked At Breakfast Mmmm!”
Gram-positive, obligate anaerobe, spore-forming, bacilli
Niche= Gi tract
Causes= Antibiotic-Associated diarrhea + pseudomembranous colitis (watery diarrhea, cramping/pain, abdominal tenderness, fever)
Patho=
—> When a patient is treated with a large dose of antibiotics (esp clindamycin), it wipes out most gut flora, but the resistant c. difficile can take over
—> 1st response is short/sluggish, allowing c.difficile to multiple
—> 2nd response (anamnestic) is prompt/powerful/prolonged with IgG’s against the toxin A leading to pseudomembranous colitis
VF= Toxin A (enterotoxin= diarrhea) & Toxin B (cytotoxin = pore forming)
Test= Stool toxin test (PCR + Enzyme immuno assay to detect toxins)
Treat=
- Metronidazole
- oral vancomycin
- fidaxomicin
