Lecture 3 highlights: Bacteria Flashcards
only stuff he discussed in class
1) Pyrogens act on body’s thermostat in the ______________, raising body temperature
2) Name 3 medications that can induce fever
1) hypothalamus
2) Beta-lactams, nitrofurantoin, sulfonamides
Most infections result in elevated levels of what?
WBCs (leukocytosis)
1) What make up 70% of WBCs?
2) Basophils are involved in what?
3) What are eosinophils involved in?
1) Neutrophils
2) Allergic rxn
3) Parasitic rxns and allergic rxns
What WBC would be elevated with viral illnesses or unusual bacterial infections?
Basophils
What are cytokines?
Messengers
1) What does an antibiogram tell you?
2) What does “formulary” mean when considering which empiric therapy to choose?
1) Rates
2) What medications are likely in stock
True or false: A component of antimicrobial stewardship is switching from IV to PO antibiotics in a timely manner
True
Who sets the susceptibility breakpoint?
Clinical & Laboratory Standards Institute (CLSI)
1) How many sets of blood cultures should you order?
2) What do you need to tell pts about collecting urine for a culture?
1) 2 or more
2) Midstream catch
What are the 3 results of gram staining?
Positive, negative, and atypical
Bacteria:
1) What are rods?
2) What are spheres?
1) Bacilli
2) Cocci
1) What are the two shapes of gram positive bacteria?
2) What are the two types of G+ cocci?
1) Cocci and bacilli
2) Catalase positive (staphylococcus) and negative (streptococcus)
1) What are the two types of catalase positive (G+) cocci?
2) What are the 3 main types of G- bacteria?
1) Coagulase + (S.a) or coagulase -
2) Cocci, bacilli, and coccobacilli
What are the 3 main types of streptococcus?
1) Beta-hemolytic (clear)
2) y-hemolytic (enterococcus)
3) alpha-hemolytic (green)
1) Name some infections caused by S. aureus (a species of staphylococci)
2) What type is either nosocomial or community acquired, and is treated with vancomycin? What does it produce?
1) Skin/ soft tissue infections, TTS
2) Methicillin-resistant staphylococcus aureus (MRSA). PBP2’ .
Name a strain of staph. aureus besides Methicillin-resistant staphylococcus aureus (MRSA)
Vancomycin-resistant staphylococcus aureus (VRSA)
-alter peptide chain structure of peptidoglycan subunit
1) Is staphylococcus epidermidis more or less virulent than S. aureus?
2) What type of infections does it usually result from?
3) What are most strains resistant to?
1) Less virulent
2) Foreign objects (catheters, prosthetic joints, etc)
3) Methicillin resistant (MRSE)
Name a type of diplococcus that’s α-hemolytic and commonly causes pneumonia and meningitis
Pneumococci (S. pneumoniae)
Viridans group streptococci:
1) What hemolysis pattern?
2) Name one of the places it commonly colonizes
3) Name 3 infections it causes
4) Is it very virulent?
α-hemolytic (incomplete hemolysis)
2) Mouth
3) Infective endocarditis, dental caries, and neutropenic pt infections
4) No; low virulence
1) Group A (S. pyogenes) strep does what kind of hemolysis?
2) Name a condition it often causes
3) It has immune-mediated post-infection sequelae; what does this mean?
1) Beta
2) Pharyngitis
3) It can come back if full course of antibiotics not taken; can come back as Rheumatic fever or acute glomerulonephritis
Group B (S. agalactiae) strep:
1) What type of hemolysis?
2) Who is most commonly infected?
1) Beta-hemolysis (complete)
2) Neonates and infants
1) Enterococci were formerly known as what?
2) What are two types? Which is more common? Which is more resistant?
3) What are they normal flora of?
1) Streptococcus
2) E.faecalis is more common, E. faecium has more resistance
3) GI tract
1) Name 2 infections Enterococci can cause.
2) Why are they intrinsically resistant to so many drugs?
3) Name an antibiotics they’re resistant to
1) UTIs, endocarditis
2) Almost all drugs are bacteriostatic
3) Vancomycin resistant enterococci (VRE)
1) Name 2 species of coccobacilli
2) What are all gram negative cocci? Give 2 examples.
3) Klebsiella, E. coli, and Enterobacter are all examples of what?
1) H. influenzae and L. pneumophila
2) Neisseria spp; N. meningiditis and N. gonorrhoeae
3) Lactose + bacilli that are fast fermenters
What are the 3 types of lactose negative G- organisms? Give examples of 2 of the types
1) Oxidase + (P. aeruginosa)
2) Oxidase-
3) Strict anaerobes (B. fragilis)
P. mirabilis is an example of what?
A urase +, oxidase -, G- bacteria
Enterobacteriaceae (G-):
1) Give 3 examples in this category
2) Why do these 3 examples have resistance? To what?
1) E. coli, Proteus, Klebsiella
2) Extended-spectrum beta-lactamase (ESBL):
Degrade all beta-lactams except carbapenems and sometimes β-lactam/β-lactamase inhibitors
1) Klebsiella often causes infections in pts with what?
2) What gives it resistance, and to what?
3) What bacteria almost exclusively cause UTIs?
1) Alcoholism
2) Cabapenemase (KPC); to all beta-lactams
3) Proteus
Serratia, Citrobacter, Enterobacter, Morganella are all more examples of what? What’s the mnemonic to remember this category?
Enterobacteriaceae; SPACE-M
1) Serratia, Citrobacter, Enterobacter, Morganella all have what resistance mechanism?
2) What 3 things does this give them resistance to?
1) AmpC-type β-lactamase
2) PCN, ampicillin/amoxicillin, 1st generation cephalosporins
Give 2 examples of non-fermenters
Acinetobacter baumanii and Stenotrophomonas maltophilia
Stenotrophomonas maltophilia: community or nosocomial? Does it have resistance?
Nosocomial pathogen with intrinsic resistance
What bacteria has many virulence factors that contribute to tissue damage and help with motility and adherence?
P. aeruginosa
1) P. aeruginosa is a frequent cause of what kind of infections?
2) What increases the risk of these?
1) Nosocomial infections
2) Loss of anatomical/physiological barrier, recent antibiotic
What is are the two main groups of Haemophilus influenzae
Typable and non-typable
1) What is Haemophilus influenzae type B?
2) Is there a vaccine? If so, does it work? If not, why?
3) What kind of infection is caused by non-typable Haemophilus influenzae?
1) Type b: invasive infections
2) HIB vaccine: highly effective
<1% colonization in vaccinated patients
3) Mucosal infections (mild)
1) Neisseria meningitidis usually causes meningitis and sepsis in what 3 groups?
2) How is Neisseria gonorrhoeae spread?
1) Young children, college freshman, and military recruits
2) Sexually transmitted disease
1) What are the two main types of chlamydia? List each species.
2) Why can it be described as “sneaky”?
3) What type of bacteria is it?
1) STD (C. trachomatis) OR pneumonia and bronchitis (C. pneumoniae)
2) Obligate intracellular organism
3) Atypical [gram stain]
1) What atypical organism lacks a cell wall?
2) What does Legionella inhabit and what can it cause?
1) Mycoplasma
2) Waterways; Legionnaires’ disease
1) Is Clostridium G+ or -? How else can it be identified?
2) Name 4 things it can cause
3) Why is it unique?
1) Gram-positive, spore-forming
2) Tetanus, botulism, gangrene, C.diff
3) Very few anaerobic bacteria cause infections
What non-spore forming anerobic bacteria rarely causes infections alone? What’s it’s shape?
Peptostreptococcus; cocci
1) What class of G- bacteria is anerobic? What species does this include?
2) Name 2 characteristics of this species
1) Bacteroides, B. fragilis
2) More virulence factors; Beta-lactamase production
