Micro: Gram - Bacterial Infections Flashcards
Gram negatives can be grouped based on shape into:
Gram - rods (majority of gram negs) and gram - cocci
Mostly, the gram - rods are found in these locations:
GI/GU tract and respiratory tract
List the two genus/species that are characteristic of gram - cocci.
Family Neisseriaciae
Moraxella catarrhalis
Gram - rods, a major component of normal GI flora can cause these two diseases in uncontrolled.
gastroenteritis & enterocolitis
Inflammatory diarrhea also called dysentery is characterized by having:
blood. WBCs/RBCs seen in stool
What part of the GI tract is commonly involved in inflammatory diarrhea?
Colon
What part of the GI tract is commonly involved in noninflammatory diarrhea?
small intestine
90% of gastroenteritis is caused by:
viruses
Name the two types of E. coli that cause gastroenteritis.
Enterohemmorhagic E. coli (EHEC)
Enterotoxigenic E. coli (ETEC)
What subgroup of E. coli is implicated in hemorrhagic colitis caused by eating undercooked meats?
EHEC
EHEC’s disease of hemorrhagic colitis is _____-mediated.
Toxin mediated (inhibits protein synthesis)
This particular strain of EHEC can lead to hemolytic uremic syndrome, a feared serious complication causing anemia, thrombocytopenia, and renal failure.
EHEC 0157:H7
True or false: treating EHEC 0157:H7 with abx can precipitate hemolytic uremic syndrome, and is therefore contraindicated.
True.
People acquire ETEC by:
Ingesting contaminated food/water
ETEC’s disease is _______-mediated. (think about this one…)
Toxin-mediated! woooooooooooooooot
This is a major cause of “traveler’s diarrhea”.
ETEC
This pathogen causes 90% of UTIs. #1 cause
E. coli
Can people become bacterimic from their own normal flora of E. coli?
Hell yeah they can!
Which species of Salmonella is implicated in gastroenteritis caused by eating contaminated poultry and eggs and also from touching Watson and Crick and not washing your hands?
S. enteritidis
Which species of Salmonella is implicated in Typhoid fever?
S. enterica serotype Typhimurium
What is one of the most common causes of bloody diarrhea/dysentery?
Shigella sonnei (most common in US), dysenteriae (more common world-wide)
How does one, say, acquire Shigella infection?
Eating shit. Or touching shit that has touched shit and putting that shit covered shit in your mouth. Nasty ass kids.
What terrible disease associated with EHEC can Shigella also cause?
Hemolytic uremic syndrome
What microscopic morphology is characteristic of Campylobacter sp?
this, spiral, or S-shaped gram - rods.
What is the most common enteric bacterial infection in developed countries?
Campylobacter
What disease characterizes Campylobacter?
Watery diarrhea that progresses to bloody
The Vibrio genus of bacteria is characterized by what microscopic morphology?
curved rods
Vibrio cholerae causes what disease?
Cholera; caused by fecal contamination from water
Vibrio cholerae showes its ugly face under these conditions:
poor sanitation, malnutrition, natural disasters
Vibrio cholerae is _____-mediated. (be careful on this one, it’s tricky)
Toxin-mediated. man, you’re catching on…
Vibrio cholerae is characterized by disease presenting as:
Massive watery diarrhea “rice water stools”. Can lead to dehydration and death
What is the treatment for Vibrio cholerae?
Oral rehydration salts
Vibrio parahaemolyticus is caused by:
ingesting raw/undercooked seafood/shellfish (esp. oysters)
Vibrio parahaemolyticus’s disease is characterized by:
watery diarrhea. can also cause wound infections
Vibrio vulnificus is cause by:
eating raw shellfish
Vibrio vulnificus’s disease is characterized as.
Diarrhea/severe soft tissue infections. Can cause sepsis and death in those with underlying liver disease.
List the 3 respiratory tract infection causing gram - rods and the two that are considered opportunistic pathogens
Haemophilus influenzae
Bordetella pertussis
Legionella pneumophila
Opportunistics:
Pseudomonas aeruginosa
Klebsiella pneumoniae
H. influenzae causes:
Meningitis (less commonly now that there is a vaccine for it) Otitis media and sinusitis Epiglottitis Pneumonia- elderly COPD exacerbations
Describe the micro morph of H. influenzae
Coccobacillus
Describe the micro morph of Bordetella pertussis
Encapsulated coccobacillus
B. pertussis causes this disease, surprise!
Pertussis- whooping cough
T/F: there is a vaccine that prevents pertussis.
True.
This bacterium causes an atypical pneumonia and can be transmitted through contaminated fountains, whirlpool baths, air conditioners, etc.
Legionella pneumophila
Pseudomonas aeruginosa is susceptible to most abx on the market, T/F.
False, it is multi-drug resistant
P. aeruginosa causes these infections:
Hospital-acquired pneumonia
Sepsis
Skin infections in burn pts
UTIs, esp. hospital-acquired
Where is P. aeruginosa found?
water, soil, GI tract
Klebsiella pneumoniae is found:
Water, soil, GI tract
K. pneumoniae causes this disease:
Hospital-acquired Pneumonia
T/F: resistance among strains of K. pneumoniae is uncommon.
False, resistance is common; some strains are resistant to most abx
List the two sp. of Neisseria we need to know.
N. gonorrheae
N. meningitidis
Describe the micro morph of Neisseria
Gram neg doplococci, “kissing kidney beans”
N. meningitidis causes:
Meningitis.
Is there a vaccine for N. meningitidis?
Yes, does not cover all serotypes.
N. gonorrheae is an STI that causes:
Purulent urethritis or cervicitis. can also cause pharyngitis and proctitis
Describe the micro morph of Moraxella catarrhalis.
Diplococcus
Where is Moraxella catarrhalis found?
Part of normal throat flora
What diseases does Moraxella catarrhalis cause?
Sinusitis Otitis media Bronchitis Pneumonia Acute COPD exacerbations
____________ (genus/species) is associate with pneumonia and production of a currant jelly sputum in alcoholics and the malnourished.
Klebsiella pneumoniae
