Gram - Bacteria Flashcards
Neisseria gonorrhoeae
ferment glucose
produce IgA protease
Gram - diplococci
hematogenous spread –> septic arthritis
Infant –> conjunctivitis
No polysaccharide capsule
Maltose non-fermenter
Tx:
Ceftriaxone
azithromycin
Neisseria meningitidis
ferment glucose
produce IgA protease
Gram - diplococci
polysaccharide capsule
maltose fermenter
transmitted by respiratory secretions
meningitis - kids, young adults
-10-15% death
Blood stream infection –> DIC, purpura fulminans, shock
–> Waterhouse Friderichsen Syn - b/l adrenal hemorrhage
Vaccine available
Prophylaxis:
Rifampin
Ciprofloxacin
Cetriaxone
Tx: immediate and empric: Cefotaxime, Ceftriaxone
Haemophilus Influenzae
Culture on chocolate agars - factors V and X needed
Coccobacillus
Epiglottis: sniffing dog position - plan to secure airway, crying –> lose airway and die
Meningitis - decreased since HIB vaccine
IgA protease
Nontypable strains:
no capsules
sinusitis, otitis, pneumonia
Haemophilus ducreyi
STI –> chancroid
1 or more PAINFUL genital ulcers
inflamed inguinal LN
Pseudomonase aeruginosa
Gram - rod Lactose non-fermenter oxidase + Blue-green pigment fruity sweet smell
Ventilator associated pneumonia
colonizes airways of CF patients
woulds of burn patients
Hot tube folliculitis
Exotoxin A: inactivates EF2 –> necrosis
Tx: MDR risk! Fluoroquinolone Ticarcillin Pipercillin Carbapenens - imipenem, meropenenm Cefepime Ceftazidime
Legionella Pneumophilia
Legionnaire’s disease:
- severe atypical pneumonia
- fever
- GI sx: D
Pontiac fever: mild flu like, resolves w/o tx
Culture on buffered charcoal yeast extract agar
-requires iron and cysteine
Gram - rod, stains poorly
May be visible on silver stain
Dx: urine antigen (serotype 1)
Transmission: aerosols from water sources
Tx: macrolide or flurorquinolone
Helicobacter pylori
Urease + Urea breat test urease test on bx serology stool antigen
Gastritis
duodenal/gastric ulcers
gastric adenocarcinoma
gastric mucosa assoc lymphoma (GALToma)
Tx:
Triple: PPI, clarithromycin, amox or metronidazole
Quad: PPI, bismuth, metronidazole, tetracycline
Draw out Gram - algorithm
printed (page 324)
Shigella
bloody D, mucoid D, fever, cramping, tenesmus
- invades colonic mucosa –> inflammation and necrosis –> travel to adjacent cells
- shiga toxin –> vascular inflamamtion of colon
nonmotile, non-lactose fermenting, gram -
person to perosn or contaminated food/water
sx 7 days
Tx: supportive in immunocompetent elderly and adult immunosuppressed: fluoroquinolones TMP-SMX azithromycin Avoid antimotility drugs
food handlers should NOT work while stool +
Assoc w/ reactive arthritis
Salmonella
gram -, lactose non-fermenter, motile - flagella
Typhoid fever:
fecal contaminated food/water
fever, sepsis
salmon-colored spots on abdomen and trunk
Gastroenteritis: exposure to chicken, eggs, handling reptiles 1-3 d incubation period Dx: stool cx Tx: healthy-supportive severe or high fever- fluoroquinolones
Hematogenous spread --> endocarditis mycotic aneurysms **osteomyelitis in sickle cell pts reactive arthritis
Campylobacter jejuni
birds and pigs
gram -, s-shaped rod, oxidase +
grows at 42 C - “hot camp fire”
inflammatory/bloody D
poultry
2-5 d incubation
Tx:
severe/high risk: fluoroquinolones, azithromycin
Assoc: reactive arthritis and Guillian Barre sn
Yersinia enterocolitica
gram - bacillis
contaminated food/pets - pork undercooked
4-6 day incubation
bloody D
Pseudoappendicitis - mesenteric adenitis
-RLQ pain
Tx: mild: supportive
Fluoroquinolone or TMP-SMX
Vibrio cholerae
Gram -, oxidase +, comma shaped
grows in alkaline media
motile - flagellin
Cholera: profuse, secretory D “rice water”
–> hypovolemic shock in 24 hrs
heat labile toxin –> increased cAMP –> Cl- secretion –> loss of electrolytes and H2O –> severe dehydration –> high mortality
Tx: aggressive oral rehydration
10^8 to innoculate in every mL of stool
Enterotoxigenic E coli (ETEC)
10^8 to infect
Watery D d/t heat-labile (increases cAMP) and heat stable (increased cGMP) enterotoxins –> increased Cl- secretion and H2O loss
-no fever, no bloody D
Does not infect the intestinal wall
MC type of traveler’s diarrhea
Enterohemorrhagic E coli (EHEC)
10-100 bacteria to infect
Bloody D and severe illness from contaminated meat - ground beef
MC: O157:H7 - cattle reservoir
Produces shiga toxin –> vascular damage –> bloody D, HUS
HUS: microangiopathic hemolytic anemia, thrombocytopenia, acute renal failure
Tx: supportive
