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Flashcards in Gram Negative Bugs Deck (43):
1

HaEMOPhilus Causes

Epiglottitis (cherry red in children), Meningitis, Otitis Media (Nontypeable strains), and Pneumonia

2

Most invasive disease caused by capsular type B, it is a small gram-neg (coccobacillary) rod that produces IgA protease and is transmitted by aerosols.

Haemophilus Influenza

3

What type of agar do you culture H. Flu on?

- Chocolate agar with factors V(NAD+) and X (hematin).
- Can also be grown with Staph Aureus which will lyse the cells giving H. flu access to V and X.

4

H. Flu vaccine contains what?

Type B capsular polysaccharide (polyribosylribitol phosphate) conjugated to dphtheria toxoid or other protein.

5

Treat meningitis with? Give what as prophylaxis to close contacts?

Treat with ceftriaxone and give Rifampin to close contacts.

6

Pt presents as a child that has to hunch over in order to breathe and drools like a zombie, what do they have and what is the cause?

Epiglottitis and most often Strep Pneumo but if the kid is not vaccinated then it would be H. Flu.

7

Gram neg diplococci that ferments glucose, produces IgA proteases and is Oxidase Positive.

Neisseria (Gonococci and Meningococci)

8

What does N. Meningococci Ferment?

Maltose and Glucose

9

What does N. Gonococci Ferment?

Glucose

10

What's so special about N. Meningococci?

- Polysaccharide capsule
- Maltose fermentation
- Vaccine (none for type B)
- Respiratory and Oral Secretions.
- Causes meningococcemia, meningitis, and Waterhouse-Friderichsen syndrome.

11

What's so special about N. Gonococci?

- No capsule, no maltose fermentation, No vaccine (due to antigenic variation)
- Sexually Transmitted
- Causes gonorrhea, septic arthritis, neonatal conjuntivitis, PID, and Fitz-Hugh-Curtis Syndrome.

12

- Presents with Severe Pneumonia, Fever, GI issues (diarrhea), and CNS symptoms (Mental Confusion)
- Typically in smokers >55 yrs with high alcohol intake or in immunosuppressed.

- Legionnaires' Disease (Legionella Pneumophila)
- Think of a French Legionnaire with his silver helmet, sitting around a campfire (charcoal) with his iron dagger - he is no sissy (cysteine).

13

Mild flu-like syndrome with no fatalities. Related to Legionnaires'.

Pontiac Fever

14

- Gram neg rod that stains poorly, use a silver stain.
- Transmitted by Aerosol WATER DROPLETS FROM ENVIRONMENTAL WATER SOURCE HABITAT. (Could come from a lake, river, shower, drinking fountain, misters at the store, etc).
- NO PERSON TO PERSON SPREAD.

Legionella Pneumophila (Legionnaires' Disease)

15

- Grows on charcoal yeast extract with iron and cysteine.
- Diagnosed by presence of antigen in urine.
- Facultative Intracellular = Granulomas.
- Treat with macrolide or quinolone.

Legionnaires' Disease

16

- Associated with wound/burn infections, Pneumonia (especially in cystic fibrosis), sepsis (black lesions on skin), External Otitis (swimmer's ear), UTI, Drug use, Diabetic Osteomyelitis, and hot tub folliculitis (healthy pts)
- Also Malignant otitis externa in diabetics, eye ulcers from prolonged contact lens wear, and erythema gangrenosum.

Pseudomonas Aeruginosa

17

Aerobic, encapsulated gram-neg rod, non-lactose fermenting, oxidase positive (granulomas), and produces pyocyanin (blue-green) pigment that has a grape-like odor.

Pseudomonas Aeruginosa

18

- Produces endotoxin (fever, shock) and exotoxin A (ribosylates EF-2 to inactivate it)

Pseudomonas Aeruginosa

19

Treat Pseudomonas Aeruginosa with....

Aminoglycoside with extended spectrum penicillin (piperacillin/ticarcillin)

20

Virulence Factors:
- Fibriae: cystitis and pyelonephritis
- K capsule: pneumonia, neonatal meningitis
- LPS endotoxin: septic shock

E. coli

21

- Mech: Invades intestinal mucosa and causes necrosis and inflammation (clinically like Shigella) but NO toxin produced.
- Presents as Invasive, dysentery

EIEC

22

Mech: Labile toxin/stable toxin. No inflammation or invasion.
- Presents as Traveler's diarrhea (watery)

ETEC

23

Mech: No toxin produced. Adheres to apical surface, flattens villi, prevents absorption.
- Presents as diarrhea usually in children.

EPEC

24

Mech: Produces Shiga-like toxin and Hemolytic-uremic syndrome (triad of anemia, thrombocytopenia, and acute renal failure).
- Endothelium swells and narrows lumen, leading to mechanical hemolysis and reduced renal blood flow; damaged endothelium consumes platelets.

EHEC

25

Most common serotype of EHEC

O157:H7

26

Presents as Dysentery (toxin alone causes necrosis and inflammation).
- Does not ferment sorbitol (distinguishes it from other E. coli.

EHEC

27

- Intestinal flora that causes lobar pneumonia in alcoholics and diabetics when aspirated.
- Very mucoid colonies caused by abundant polysaccharide capsule --> Red "currant" jelly sputum.
- Also cause of nosocomial infections.

Klebsiella

28

4 A's of Klebsiella

- Aspiration pneumonia
- Abscess in lungs and liver
- Alcoholics
- di-A-betics

29

- No flagella, cell to cell transmission with NO heme spread.
- Humans and primates are only reservoirs.
- Does NOT produce hydrogen sulfide and Antibiotics prolong excretion in feces.

Shigella

30

- Has flagella, can disseminate hematogenously, and has many animal reservoirs.
- Produces hydrogen sulfide and antibiotics may prolong symptoms.

Salmonella

31

- Invades intestinal mucosa and causes a monocytic response --> can cause bloody diarrhea.
- No lactose fermenting.

Salmonella

32

- Invades intestinal mucosa and causes PMN infiltration --> OFTEN causes bloody diarrhea but does not ferment lactose.

Shigella

33

- Found only in humans, characterized by rose spots on abs, fever, headache, and diarrhea.
- Can remain in gallbladder and cause a carrier state.

Salmonella Typhi (Typhoid Fever!)

34

- Major cause of bloody diarrhea, esp in children.
- Fecal/oral through foods like poultry, meat, unpasteurized milk.

Campylobacter Jejuni

35

Comma or S-shaped, oxidase positive, grows at 42 degrees C and is common antecedent to Guillain-Barre syndrome and reactive arthritis.

Campylobacter Jejuni (Campylobacter likes the hot CAMPfire)

36

- Produces profuse rice-water diarrhea via toxin that permanently activates Gs, increases cAMP.
- Comma shaped, oxidase pos, grows in alkaline media. Endemic to developing countries.
- Prompt oral rehydration necessary.

Vibrio Cholera

37

- Usually transmitted from pet feces, contaminated milk, or pork. Causes mesenteric adenines that can mimi Crohn's or appendicitis.
- Gram neg w/ toxins called Yops.

Yersinia Enterocolitica

38

- Transmitted by rodents by aerosols or flea bites.
- Gram neg causes Buboes: massive lymph node enlargement, pneumonia and sepsis.

Yersinia Pestis (Black Plague)

39

- Curved, gram neg rod that causes gastritis and up to 90% of duodenal ulcers.
- Urease positive, creates alkaline environment.

H. pylori

40

What do you treat H. pylori with?

Triple Therapy: Proton Pump Inhibitor, Clarithromycin, and amoxicillin or metronidazole.

41

Found in water contaminated with animal urine.
- Causes flu-like symptoms, jaundice, and photophobia with conjunctivitis. Prevalent among surfers and in tropics.

Leptospira Interrogans (Leptospirosis)

42

Severe form of jaundice and azotemia from liver and kidney dysfunction; fever, hemorrhage, and anemia.

Weil's Disease

43

What is Lyme Disease caused by?

Borrelia Burgdorferi