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
What is the toxin and mechanism of EIEC? This is similar to which other microbe?
Microbe invades INTESTINAL mucosa and causes NECROSIS and INFLAMMATION
Similar to SHIGELLA
What is the presentation of EIEC?
What is the toxin and mechanism of ETEC?
Produces HEAT-LABILE and HEAT-STABLE ENTERTOXINS
No inflammation or invastion
What is the presentation of ETEC?
Traveler's diarrhea (watery)
What is the toxin and mechanism of EPEC?
NO TOXIN produced
Adheres to apical surface, FLATTENS VILLI--> prevents absorption
What is the presentation of EPEC?
Diarrhea, usually in children (P for pediatrics)
What is the most common serotype of EHEC?
What toxin does EHEC produce? What does this toxin cause? What is the triad of this syndrome
EHEC produces the SLT (Shiga-like toxin)
Causes Hemolytic-Uremic Syndrome (HUS)
HUS: Anemia, thrombocytopenia, and acute renal failure
What is the pathogenesis of hemolysis, decreased renal blood flow, and thrombocytopenia caused by EHEC?
1. Microthrombi form on endothelium damaged by SLT. This causes mechanical hemolysis (schistocytes form) and decreased renal blood flow
2. The microthrombi also consume platelets--> thrombocytopenia
Where does Klebsiella normally reside? What is it known for causing in alcoholics and diabetics?
Causes atypical lobar pneumonia when aspirated
Klebsiella has abundant polysaccharide capsules...what does this cause? What does Klebsiella sputum look like?
Very MUCOID colonies
Red "currant jelly" sputum
Klebsiella is also known to cause what (3) besides pneumonia?
1. Abscess in lungs
2. Abscess in liver
3. Nosocomial UTIs
What are the 4 A's of Klebsiella (one is a stretch)
Abscess in lungs and liver
di-A-betics (told you it was a stretch)
Spread throughout the body?
**Hydrogen sulfide production?
**Antibiotic effects on disease?
Invades where in the body?
MANY animal reservoirs
**PRODUCES hydrogen sulfide
**Antibiotics PROLONG fecal excretion of organism
Invades INTESTINAL mucosa and causes a MONOCYTIC response
CAN cause bloody diarrhea (not often)
**DOES NOT ferment LACTOSE
Spread throughout the body
**Hydrogen sulfide production
**Antibiotic effects on disease Invades where in the body?
NO goddamn flagella
CELL TO CELL transmission;
no hematogenous spread
Only reservoir are HUMANS and PRIMATES
**DOES NOT produce hydrogen sulfide
**Antibiotics SHORTEN fecal excretion of organism
Invades INTESTINAL mucosa and causes a PMN response
OFTEN causes bloody diarrhea
**DOES NOT ferment lactose
E. Coli algorithm findings: gram shape lactose
E. Coli is a gram negative rod FAST fermenter of lactose
Pseudomonas algorithm findings gram shape lactose oxidase
Gram Negative Rod Lactose negative Oxidase positive
Shigella algorithm findings
Gram negative rod Negative lactose Negative oxidase H2S -
Salmonella algorithm findings
Gram negative rod
Salmonella typhi causes what? Found only in which animal?
Salmonella typhi causes Typhoid Fever Only found in humans
Salmonella typhi is characterized by what (4)? symptoms How to become a carrier?
Rose spots on abdomen
Can remain in gallbladder causing a carrier state