Colonies grown on MacConkey agar are which color?
Which bacteria (5) grow on MacConkey's agar? Which one is weak fermenter? "maConKEE'S agar"
Citrobacter Klebsiella E. coli Enterobacter Serratia (weakly)
How does E. coli ferment lactose?
E. coli produced B-galactosidase which breaks down lactose into galactose and glucose...FUN!!
Which bacteria are resistant to penicillin G? How do we kill these bugs? How are these bugs resistant?
Gram negative bacilli are resistant to PCN G.
Gram negative bacilli MAY be resistant to PCN derivatives such as ampicillin and amoxicillin.
The outer membrane of gram negative bacilli bugs inhibits enter of PCN G and vancomycin
Neisseria comes in two forms Algorithm findings: gram and shape
N. Gonococci and N. meningococci
Both are GRAM NEGATIVE DIPLOCOCCI
Both ferment GLUCOSE
Both produce IgA protease
How to tell Neisseria species apart?
"MeninGococci ferment Maltose and Glucose" "Gonococci ferments Glucose only"
Gonococci: Capsule Maltose fermentation Vaccine Transmission Causes (5) Prophylaxis (2) Treatment (1 + ?)
NO polysacchardie capsule
NO maltose fermentation
NO vaccine (due to rapid antigenic variation of pilus proteins)
Gonorrhea, septic arthritis, neonatal conjunctivitis, PID, and Fitz-Hugh-Curtis Syndrome
Condoms for sex and erythromycin ointment prevents neonatal transmission
Treatment: CEFTRIAXONE + (azithromycin or doxycycline to cross cover for chlamydia)
Meningococci: Capsule Maltose fermentation Vaccine Transmission Causes (3) Prophylaxis (3) Treatment (2)
Maltose and glucose fermentation
Vaccine (none for type B)
Respiratory and oral transmission
Causes meningococcemia, meningitis, and Waterhouse-Friderichsen syndrome
Rifampin, cipro, or ceftriaxone prophylaxis
Treatment: CEFTRIAXONE or PCN G
Lab findings of haemophilus influenzae (size, gram, shape)
Which strain is most invasive?
What do non-invasive strains cause?
Produces which protease?
Small, gram negative rod
Mucosal infections: otitis media, conjunctivitis, bronchitis
IgA protease (invades mucosal surfaces)
H. influenza grows on which agar? What requirements (2)
Chocolate agar Factor V (NAD+) and X (hematin)
H. influenza causes which disease states? "haEMOPhilus"
Epiglottitis (children) Meningitis Otitis media Pneumonia
How to treat H. influenza mucosal infections
Amoxicillin (+/- clavulanatic acid)
How to treat H. influenza meningitis? Prophylaxis?
Ceftriaxone for treatment
Rifampin for prophylaxis
Describe the HiB vaccine. When to give the HiB vaccine?
Type B capsular polysaccharide conjugated to diphtheria toxoid. Given between 2-18 months
Legionella staining and shape
Gram NEGATIVE ROD....doesn't stain well Use SILVER STAIN
How is legionella cultured?
Grown on CHARCOAL yeast extract culture with IRON and CYSTEINE
How is legionella detected clinically?
Antigen in urine
Aerosol transmission from environmental water source: air conditioning, hot water tanks, hot tubs NOT FROM PERSON TO PERSON
macrolide or quinolone
Legionnaires' disease symptoms:
What is Pontiac Fever?
Mild, acute, flu-like syndrome caused by a Legionella species
What will labs show with Legionella?
Pseudomonas aeruginosa algorithm:
Stain and shape?
Aerobic, Gram NEGATIVE ROD
Pseudomonas appearance and smell
Pyocyanin (blue-green) pigment Smells likes grapes apparently
Some type of water source...usually a hot tub
Which toxins (2) does Pseudomonas produce
Endotoxin --> fever and shock
Exotoxin A --> inactivated EF-2
"PSEUDOmonas" is associated with... (8)
**There are two more outside of PSEUDO that you must know.
Burn and wound infections
Pneumonia (especially in cystic fibrosis)
External otitis (swimmer's ear)
Hot tub folliculitis
An immunocompromised patient has rapidly progressive, necrotic cutaneous lesions caused by Pseudomonas bacteremia...what does he have?
Aminoglycoside plus extended spectrum PCN (piperacillin, ticaracillin, cefipime, imipenem, meropenem)
E. coli has 3 virulence factors...what are they and what do they do
1. Fimbriae--cystitis and pyelonephritis (urinary)
2. K capsule--pneumonia, neonatal meningitis
3. LPS endotoxin--septic shock