7: Gram Negative Bacteria Flashcards
Specific plate and agar for growing Neisseria
“Chocolate agar” (heated blood), on Thayer-Martin agar (VCN Abx modified)
Two Neisseria meningitis vaccines and what groups they target
- MenACWY: preteens and teens
2. MenB: 16-18 year olds
PID
Pelvic inflammatory disease; infection of uterus, Fallopian tubes, and ovaries - can cause sterility
Enterics
Gram negative bacteria that are part of the normal GI flora or cause GI disease
Three bacterial mechanisms that cause different types of diarrhea
- Lack of invasion -> watery diarrhea
- Epithelial invasion -> blood diarrhea, fever, cramps
- LN and blood stream invasion -> diarrhea +/- blood, fever, abdominal pain -> sepsis
Agar used to see if bacteria ferments lactose and what color it changes
MacConkey agar -> turns pink
What do ETEC, EIEC, EHEC, and HUS stand for?
- ETEC: Enterotoxigenic E. coli
- EIEC: enteroinvasive E. Coli
- EHEC: enterohemorrhagic
- HUS: hemolytic uremic syndrome
Most common cause of UTIs
E. coli
Most common species of Shigella in the US
Shigella sonnei
Explain Typhoid Mary
Typhoid fever can have a asymptomatic chronic carrier state - Typhoid Mary was an asymptomatic cook in the 1900’s
What does urease do?
Breaks down urea -> CO2 + ammonia
Susceptible individuals to pseudomonas aeruginosa
CF, burn victims, hospitalized pts, diabetics
Reiter’s Syndomre: describe
A post-infectious immune mediated reaction, AKA reactive arthritis
Gene associated with Reiter’s syndrome
HLA-B27
Classic triad of Sx in Reiter’s syndrome
Conjunctivitis, urethritis, arthritis
What type of bacteria triggers Retier’s syndrome and name examples
Enteric bacteria: salmonella, shigella, c. Jejuni, yersinia enterocolitica, c. Diff
Hib vaccine
Against Haemophilus influenzae, given in first 1.5 yrs of life
Three zoonotic bacilli that are intracellular organisms
Yersinia pestis, francisella tularensis, brucella
Size of chlamydia sp
Very small, on the order of viruses
How many women are asymptomatic with chlamydia
About 3/4 of women
Weil-Felix test positive
Shows agglutination by OX Abs
Which species are mostly Weil-Felix positive?
Rickettsia
Two types of screening for syphilis
VDRL, RPR
What does it mean if a bacterium is acid fast?
Has a waxy cell wall with mycolic acids which retain stain after treatment, so they look gram negative but are actually gram positive
