Gram neg/Spirochetes/Mycoplasma Flashcards Preview

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Flashcards in Gram neg/Spirochetes/Mycoplasma Deck (52):

Neisseria meningitides

-Gram - , diplocci (BEAN shaped)
-Encapsulated (LOS** correlates w M and M ~LPS), Maltose and glucose fermenting (meningitides for maltose)
-Vaccine exists (for type A)
-Found in respiratory/oral secretions
--> Meningococcemia, meningitis (2nd most common children-adults, but # 1 in teens), rash on soles and palms (small vessel vasculitis) Waterhouse-Friderichsen syndrome
-IgA Protease +
-Chocolate agar

-tend to happen in outbreaks in close quarters (think College DORMS!)


Waterhouse-Friderichsen syndrome

<-- N. meningitides
-1) Bilateral adrenal hemorrhage
-2) DIC
-3) Shock (hypotension)
-4) Purple rash


Neisseria gonococci

-Facultative intracellular: often see in Neutrophils
Only glucose fermenting
-spread by sexual contact
--> gonorrhea, septic arthritis, neonatal conjunctivitis, PID, Fitz-Hugh-Curtis syndrome (Fibrotic Hepatic Capsule syndrome)
-IgA protease+
-Thayer-martin media (choc. sheep blood + ABX - make sure you get rid of all the other bacteria from the vagina swab) = Prostitutes on Thayer Street
-Rx: IM Ceftriaxone + treatment for chlamydia

Think Gonorrhea when you see asymmetric polyarthritis (knees, elbows) in a sexually active young adult


HaEMOPhilus. influenzae

Gram - coccobacillus
--> Epiglottis* ("cherry red"), Meningitis*, Otitis media (nontypeable strains cause mucosal infxns), Pneumonia*
-IgA protease (type B is encapsulated)
-Chocolate agar w V, X.
-OR Chocolate agar, S. Aureus, X
-Vaccine: Type B capsular polysaccharide + diptheria toxioid/other . Give to infants! produces anti-PRP** antibodies.


Gram Negative Bacilli/rods

Outer membrane inhibits entry of PCN G and Vancomycin! Resistant!
-May be susceptible to derivatives like Ampicillin and Amoxicillin


Lactose fermenters

Test w macConKEES agar, turn PINK
-on EMB agar turn Purple/black (except E. coli has green sheen)

E. coli


Legionella pneumonphila

Gram - rod, Lactase -, Oxidase +
--> Legionnaires' ds: atypical pneumonia, high fever, Diarrhea, and CNS sxs/confusion; all in a smoker!
--> Pontiac fever: mild flu-like sxs
-Use Silver stain
-grown on charcoal yeast w iron and cysteine
-HYPONATREMIA, test for antigen in urine

The Legionnaire wears a silver helmet and sits at a charcoal fire w an iron stoker before he decides to charge the Pontiac. He is no Sissy/Cysteine. But he's chugging a lot of water before he goes so he doesn't get dehydrated (--> Hyponatremic)


PSEUDOmonas aeruginosa

Gram - rod, Oxidase POS, Aerobe. NON-lactose fermenting.
--> Pneumonia (CF), Sepsis (black skin lesions/burn pts), Ecythema gangrenosum (pts w neutropenia), UTI (w indwelling cath), Dermatitis (hot-tube users), Otitis externa (swimmers)/Osteomyelitis (Diabetes, IV drug users)
-Produces Pyocyanin* (blue-green) pigment w grape-like odor.
--> Endotoxin (fever, shock), and Exotoxin A (inactivate EF-2)


E. coli EIEC

Gram - rod, Lactose fermenter, motile
-No toxin produced
-Microbe invades intestinal mucosa --> necrosis, inflammation
~ clinical pic of Shigella
I for INVASIVE, dysentery

Ferments Sorbitol/glucose (vs EHEC) --> gas
Stool: would see many erythrocytes and some leukocytes


E. coli ETEC

Gram - rod, lactose fermenter, motile
-T for Traveler's diarrhea
LT/ST toxins. No inflammation or invasion

Ferments Sorbitol/glucose (vs EHEC) --> gas


E. Coli EPEC

Gram - rod, lactose fermenter, motile
-P for Pediatrics (diarrhea in children)
-No toxin
-Adheres to apical surface, flattens villi, prevents absorption

Ferments Sorbitol/glucose (vs EHEC) --> gas


E. coli EHEC

Gram - rod, lactose fermenter, motile
-H for Hemorrhagic diarrhea (does not invade the cells*, toxin alone causes necrosis/inflmtn)
-O157:H7 most common type --> SLT --> HUS (TAU - thrombycotpenia, Anemia, Uremia)
(endothelium swells and narrows lumen --> microangiopathic anemia and reduced renal flow. Damaged endothelium consumes plts).
*Does NOT ferment sorbitol or produce glucuronidase.
-Stool: erythrocytes w/o pus (bc not invasive)

FAT RN in kids who ate hamburgers


E. Coli Virulence factors

-Fimbriae --> UTI (#1), cystitis, pyelonephritis
-K capsule (prevents phagocytosis) -->, neonatal meningitis (#2) and neonatal pneumonia (#2) (#1 in both is group b strep)
-LPS endotoxin --> septic shock



Gram - rod, Lactose fermenter
-A: Aspiration pneumonia (DM/ETOHpts)
-B: Burning urine/nosocomial UTI
-C: (red) currant jelly sputum
-D: Donovan bodies (STI called "granuloma inguinale")


Salmonella typhi
(or paratyphi)

Gram - rod, Lactose -, Oxidase -
-Flagellate organism, can dissem hematogenously**, animal reservoirs, invades intestinal mucosa --> monocytic response, produce H2S on triple sugar iron (TSI) agar--> black
-antibiotics may prolong sxs*/fecal excretion of bacteria
-multiples in mesenteric LN's and is phagocytosed by macrophages, lives inside them (facultative intracellular)
--> Typhoid Fever. Only in humans. ROSE spots on abdomen, fever, HA, diarrhea, abdml pain, HEPATOSPLENOMEGALY --> hemorrhagic enteritis w possible bowel perf. Can remain in GALLBLADDER = carrier state

(common OUTSIDE the States - think of it when someone travels and gets a rash peri-umbilically)

Salmonella and Shigella are SOL: no oxidase OR lactose fermenting


Shigella dysenteriae

Gram - rod, Lactose - , Oxidase -
-Invades intestinal mucosa via M cells and causes PMN infiltration
-->severe bloody diarrhea (Shiga-Toxin)
-Stool: many erythrocytes and some leukocytes
-Not* carried by animals. Fecal-oral route - daycare center, food contaminated etc
-as few as 10 cells of any shigella spp can cause infection**

Salmonella and Shigella are SOL: no oxidase OR lactose fermenting


Campylobacter jejuni

Gram - , Comma shaped, Oxidase +
-likes the HOT CAMPfire. grows at 42C
--> diarrhea (activate adenylate cyclase; initially watery --> bloody)
-Fecal oral route by poultry, milk, domestic animals (cattle, sheep, puppies!)
--> Guillain Barre, Reactive arthritis
-has a filament so it moves in a "corkscrew" fashion
-Most common cause of acute gastroenteritis of children and adults in industrialized countries*


Vibrio cholerae

Gram -, Comma shaped, Oxidase +
-Grows in ALKALINE media
--> Rice water diarrhea by permanantly activating Gs to incr cAMP


Yersinia enterocolitica

gram - rod, Oxidase -, Lactose -
-transmitted by Puppy Poop and unpasteurized Milk
~ETEC/ST in that it activates guanylate cyclease and incr cGMP
--> Pediatric diarrhea, Mesenteric Adenitis = abdl pain (~ CD or appendicitis)


Yersnia Pestis

Gram-, Lactose-, Oxidase-
Bubonic Plague (swollen LNs)
-sepsis in SouthWestern Rancher exposed to fleas or terrorist attack
-Fleas get it from rats and prairie dogs


Proteus mirabilis

Gram - rod, Lactase -, Oxidase -
-DO have flagella and make H2S (like salmonella) -->black on TSI agar
-Urease Positive (like H. pylori) but prefers GU tract
--> Staghorn calculi (Struvite Kidney Stones)


H. Pylori

Gram - , comma-shaped.
-Urease+ in GI tract --> Alkaline environment
-RX: PPI, Clarithryomycin, Amoxocillin



-Borrelia (BIG!) - visualized w aniline dye (Wright's or Giemsa) in LM
-Treponema - visualized by dark-field micro


Mycoplasma pneumoniae

-No cell wall, sterols in plasma membrane (they can get all of us 25 yr olds! and they're like us: we don't have cell walls, and we do have cholesterol in our membranes)
--> atypical "walking" pneumonia (insidious onset, HA, nonproductive cough, diffuse interstital infiltrate), transient anemia
-High titer of COLD AGGLUTININS (IgM) --> agglutinate or lyse rbcs (may see anemia)
-Grows on Eaton's agar
-most common pneumonia adults 18-40 (everyone older Strep pneumo)


Cold agglutinins (IgM) assoc w.

Mycoplasma pneumoniae
Epstein Barr Virus
hemolytic malignancies


E. coli EAEC

-Cause "Stacked-brick" intestinal adhesions


Leptospira Interrogans

-Found in : animal/RAT urine. See in SURFERS/tropics/Hawaii
--> Leptospirosis (mild): flu-like sxs, jaundice, photophobia w conjunctivitiis (meningitis-like)
--> Weil's ds (Bad). Icterohemorrhagic ds: severe jaundice, azotemia from LIVER/KIDNEY dysfxn, fever, hemorrhage, edema


Borrelia burgdorferi

-In mice and deer, transmitted by tick Ixodes
-Think CAMPERS in the North East
-"Ticks Find Folds Amongst inAppropriate NE Clothes"
RX: doxycycline (tetracycline), ceftriaxone (3-cephalosporin)


Stages of Lyme ds <-- Borrelia burgdorferi

-1) Erythema migrans, flu-like sxs
-2) Neuro/Facial n palsy, Cardiac/AV block
-3) MS (arthritis, esp knees), neuro (encephalopathy/polyneuropathy), cutaneous manifestations

Ticks Find Folds Amongst inAppropiate NE Clothes

Target Flu-like sxs, Facial n palsy AV block, Arthritis Neuro/enceophalopathy Cutaneous manifestations


Treponema pallidum
Primary Syphillus

--> (P)rimary for (P)ainless* chancre (treponemes present in the chancre)
-Screen w VDRL and confirm dx w FTA-ABS (fluorescent treponemal antibodies - Absorption)


VDRL; False positives

Used to test for syphillis/Treponemal pallidum
-check for ABs against beef Cardiolipin

False positives: VDRL
-Viruses (mono, hepatitis - also mycoplasma pneumoniae*)
-Rheumatic Fever
-Lupus, leprosy (anti-cardiolipin/phosphlipid abs)


Treponema pallidum
Secondary syphillis

-(S)econdary for (S)ystemic and (S)ole/palm rash
--> Disseminated: constitutional sxs, maculopapular rash (palms, soles), Condyloma Lata (treponemes present in it)
-Screen w VDRL and dx w FTA-ABS


Treponema pallidum
Tertiary Syphillis

-(T)ertiary for Tabes Dorsalis --> sensory ataxia
--> Gumma (chromic GRANULOMAS) in liver/bone/skin, Aortitis (vasa vasorum destruction), Neurosyphillis (tabes dorsalis), Argyll Robertons pupil (Prostitutes pupil)
-Signs: Broad-based ataxia, Rhomberg+, Charcot joint (degeneration of joint/no pain/deform), stroke w/o HTN
-Test CSF w VDRL


Treponema Pallidum
Congenital syphillis

-plancental transmission: 1st trimester
-Saber shins, Saddle noes, CN8 deafness, Hutchinson's teeth (small/wide spaced/notches), mulberry molars (rounded enamel cusps on permanent first molars)


Jarisch-Herxheimer Rxn

-Flu-like syndrome when give someone AB's bc of all the cell's lysing - release pyrogens
-May seem like you get worse when you start treatment


Gardenella Vaginalis

-Gram VARIABLE rod.
I don't have a CLUE (cell) why I smell FISH in the VAGINA GARDEN!
--> Bacterial vaginosis: gray fishy discharge
-not an STD
-Rx: Metronidazole


Rickettsia Rickettsi

-Obligate intracellular organism, needs CoA and NAD+
-> Rocky Mtn spotted fever: throughout US.
-Triad: FEVER, HA, RASH (wrists/ankles --> trunk/palms/soes)
+Weil-Felix rxn (anti-rickettsial IgM cross-reacts w Proteus antigen)

Rickettsi on the wRists, Typhus on the Trunk


Rickettsia Typhus

-Fleas --> Endemic Typhus
-RASH on the TRUNK
+Weil-Felix rxn

Rickettsi on the wRists, Typhus on the Trunk


Rickettsia Prowazekii

-human louse --> Epidemic Typhus
-RASH on trunk --> spread outward but SPARES the Palms and Soles.

Rickettsi on the wRists, Typhus on the Trunk


Palm and sole rash, seen in:

Coxsackievirus A
Rocky Mtn Spotted Fever
Secondary Syphillis
**and N. meningitides --> small vessel vasculitis

Monkeys drive CARS w their PALMS and SOLES


Ehrlichia Chaffeensis
(Rickettsial spp)

Lone star tick --> Ehrlichiosis
-No rash. See Monocytes w Morula (berry-like inclusions) in your cytoplasm
+Weil-Felix rxn

The lone star sheriff could er LICK your butt. But first he needs to have his monocyte cereal breakfast w berries w his coffee/Chaffeen


(Rickettsial spp)

Tick --> Anaplasmosis
-No rash. See Granulocytes w Morula in cytoplasm


Coxiella Burnetti

tick feces/cattle placenta --> Q fever
--> Pneumonia
-No Rash or Vector, organism can survive outside in its endospore form.
NEGATIVE Weil-Felix rxn

Honora wants to be an ob gyn for cows and sheep, Q fever



-obligate intracellular, cell wall lacks muramic acid
-1) Elementary body (small,dense) is "Enfectious"and Enters cell via Endocytosis -->
-2) Reticulate body Replicates in cell by fission - seen on tissue culture --> Elementary bodies + Reticulate bodies --> Released
-Rx: Azithromycin or Doxycycline


Chlamydiae trachomatis

--> Reactive arthritis, conjunctivitis, nongonococcal urethritis, and PID

Reiters + PID


Chlamydiae pneumoniae

Atypical pnuemonia, aerosol spread

(Along w mycoplasma and legionella)


Warm agglutins seen in

--> AI Hemolytic Anemia


Chlamydia type A,B,C

all cause:
African/Blindness/Chronic infxn
-Blindiness from follicular conjunctivitis


Chlamydia type D-K

STI (co-treat w gonorrhea) --> PID
-Neonatal pneumonia (staccato cough)
-neonatal conjuncitivits


Chlamydia types L!, L2, L3

lymphogranuloma venereum (Inguinal lymphadenopathy)


Salmonella enteriditis

Causes invasive diarrhea most frequently without hemorrhage
-stool: Neutrophils predominate


H. influenza capsule

Polyribitol ribose phosphate (PRP)
the vaccine provides anti-PRP antibodies. Esp Protective against Epiglottis, Meningitis
-Epiglottis caused almost exclusively by H. influenza.
-The vaccine: PRP combined w tetanus or diptheria toxoid.