MICROB 2800: EXAM 2
113 Cards in this Set
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metabolism
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All chemical reac3ons and physical workings of the cell to either gain or use energy
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anabolism
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also called biosynthesis- any process that results in synthesis of cell molecules and structures (usually requires energy input)
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catabolism
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the breakdown of bonds of larger molecules into smaller molecules (often release energy)
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bacterial metabolism
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1. identification: Certain bacteria can be ID’d by what they use/refuse-some only use glucose
2. Control: Knowledge about metabolism can be useful to inhibit microbes
3. Similarity: What things we use/do, they do also
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enzymes
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Protein biological catalysts that increase the rate of a chemical reac6on without becoming part of the products or being consumed in the reaction
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simple enzymes
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consist of protein alone
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conjugated enzymes
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contain protein and non protein molecules(cofactors)
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competitive inhibition
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substrates that mimic the original substrate
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non-competitive inhibition
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regulatory sites are changed; stop cofactors
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sterilization
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complete removal/destruction of all viable microorganisms, including ‘non-active’ forms
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disinfection
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reduction in number of majority growing/active microbes, but not all
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Aseptic/Antisepsis/Degerming
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reducing number of total organisms, best referred to as:“as cleanly as possible”
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autoclaving
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heat+steam+pressure used in sterilization
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probiotics
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live microorganisms, which when administered in adequate amounts, confer a health benefit on the host
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bactericidal antibiotics
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kills bacteria; used when host function is compromised
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bacteriostatic antibiotic
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inhibits bacteria; used when host function is good
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allergy
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Immune system recognizing an antibiotic as “foreign” and stimulates a
response against it
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Red Man Syndrome
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-caused by vancomycin; release large amounts of histamine; itch with rash
---SIDE EFFECT
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Steven Johns Syndrome
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immune system response that attacks own body and leads to rash
-rare,serious disorder in which skin and mucous membranes react severely to a medication
-Most associated with Non steroidal anti-inflammatory drugs (NSAIDs), and B-lactams
***Painful red or purplish rash that spreads and b…
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Minimum inhibitory concentration (MIC)
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Lowest concentration of antibiotic to slow bacterial growth
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Minimum bacteriocidal concentration (MBC)
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Lowest concentration of antibiotic to kill bacteria
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therapeutic index
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Ratio of Max. safe antibiotic amount to MIC
-High ratios = Good, Low ratios = Bad
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cross-reaction
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target looks almost identical to your processes
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accumulation
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levels that result in compromise of normal host cellular fcn/process
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4 ways antibiotics inhibit the bacteria
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Inhibition at cell wall level (PPG)
Inhibition of protein synthesis
Inhibition of metabolic synthesis (antimetabolites)
Inhibition of nucleic acid structure and function
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beta-lactam antibiotics
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cell wall inhibition
-"cillin" compounds
-garage + house
-basic mechanism: inhibit PPG synthesis
-no effect on plant or animal cells
-effective only when bacteria are growing
-effective primarily against Gram+
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vancomycin
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-interferes with alanine-alanine bridges in PPG
-SpoA-against Gram+ but NOT Gram-
-big gun antibiotic, very powerful and effective
-side effect: Red Man Syndrome
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Imipenem
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same mechanism as PEN, but resistent to beta-lactam
-Carbepenem” family, very broad spectrum, often the “β-lac of choice” for G(-)’s
-carbepenem is highly resistant to the β-lactamase enzymes produced by many multiple drug-resistant Gram-negative bacteria
-no longer unbreakable
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Isoniazid and ethambutol
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for gram not-applicables
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cephalosporin
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-still has beta-lactam functional group
2 sided R-group house + basement
-“Generations” allow for specialization of treatment -Each generation active against different organism classes
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cephalosporin Hen PEcK
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1st gen: cephalexin
2nd gen: cefuroxime (Zinacef)
3rd gen:Ceftazidime, Ceftriaxone
4th gen:Cefepime (Maxipime)
-higher generations attack more Gram-
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Bacitracin + Polymyxin B (+ neomycin)
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not classic PPG attackers, but still attack membrane
-pore formers inside bacteria (triple antibiotic)
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daptomycin
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-lipopeptide binds to the membrane, causes rapid depolarization, and loss
of membrane potential
In turn, inhibition of metabolism (protein, DNA and RNA) processes, which results in bacterial cell death.
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Chloramphenicol
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ribosomal inhibitor
-VERY broad spectrum antibacterial, but high side effects
-RESTRICTED to life-threatening infection w no alternatives
-Adverse effects: bone marrow suppression, aplastic anemia, grey baby syndrome, leukemia
-attacks 50S
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Lincomycin and derivative CLindamycin
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-ribosomal inhibitor
-50S
-used for anaerobic and severe aerobic infections (toxic shock syndrome)
effects: c. diff
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Erythromycin
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-ribosomal inhibitor
-50s
-SPoA- Gram+ and Gram NA
-good choice for PEN
effects: diarrhea, nausea
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tetracycline
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-ribosomal inhibitor
-30s
-very broad spectrum Gram +/-/NA
-high adverse effects
-teratogen in fetus
-inactivated by Ca+
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Aminoglycoside antibiotics
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-mostly for serious Gram- in severe cases
-high toxicity
-NOT usable against anaerobic organisms
effects: Nephrotoxicity, hearing loss
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Synercid
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synthetic
-attacks 50S
-Effective against Staphylococcus and Enterococus species and against resistant strains of Streptococcus
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oxazolidones
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-inhibit 50S
-brand name: zyvox
Used to treat infections caused by two of the most difficult clinical pathogens: methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE)
– “Last line” for Gram(+), almost no activity in Gram(-)
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antimetaboliteantibiotics
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often act as:
1. mimics natural compound (competitive inhibition)
2. shuts down natural processes (non-competitive inhibition)
-Exploited when differences exist between metabolic processes of host and pathogen
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Sulfonamides
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-sulfa drugs-very first modern antimicrobials
-Mimic of PABA, necessary for making folate
-Folate → nucleotides → DNA replication
-SpOA=Gram -Entericbacteria, Shigellosis, acute urinary tract infections
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Trimethoprim
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-inhibits an enzymatic step immediately after the step inhibited by sulfonamides in the synthesis of folic acid
-SpOA = otitis media, urinary tract infections
**synergist given in combination with sulfa and trimeth
-septra, bactrim
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Mechanism IV- Antibiotic inhibitors of bacterial nucleic acid synthesis
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Quinolones/Fluoroquinolones-inhibit prokaryotic DNA gyrase, stop replication
-Rifampin- inhibit action of bacterial RNA polymerase during transcription
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Quinolones/Fluoroquinolones
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-flox antibiotics
1. cipro: SpoA-prophlaxis-preventative treatment
2. norfloxacin-SpoA- Gram(+/-), Pseudomonas, UTIs • Quickly cleared in urine...
3. Levofloxacin-SpoA-Many STD organisms, skin infections, systemic infections
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Rifampin
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inhibit action of bacterial RNA polymerase during transcription
-SpoA- gram +/- mycobacterium tuberculosis
-Used in treatment of pneumonia, UTI, gastroenteritis and atypical pneumonia
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superinfection
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infection occurring after or on top of an earlier infection, especially following treatment with broad-spectrum antibiotics.
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Modes that antivirals attack
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Slowing/Blocking the transcription and translation of new viral molecules
(usually at level of DNA/RNA synthesis)
Host polymerases are not “killed”, but slowed (have proofreading)
– Viral polymerases have to “start over” when they incorporate these “dead-end” molecules
-mimic …
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DNA polymerase antivirals
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acyclovir
-valacyclovir (valtrex)
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Retrovirus antivirals-RDDP
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AZT
-Lamivudine
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RNA polymerase antivirals RDRP
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ribavirin
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entry/exit blocker antivirals
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1. Zanamivir (Relenza)- Act as a competitive inhibitor to host sialic acid or binds neuraminidase, preventing/entry spread of
2. tamiflu (no longer in use)
3. interferons- naturally produced; signal infected cells to switch to non-corruptible pathways; hepatitis
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synthetic -azole
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-broad spectrum anti-fungals that targets ergosterol
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Clotrimazole/Miconazole
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mainly topical ointments for infections in the skin, mouth, and vagina
(Monistat, Micatin, etc)
-simplest and safest form given
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Ketoconazole
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anti-fungal
-oral and topically for cutaneous mycoses, vaginal and oral candidiasis, and some
systemic mycoses
-2nd antifungal
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Fluconazole:
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antifungal
-used in selected patients for AIDS-related mycoses, gets to CSF
-3rd option
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Amphotericin B
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attack ergosterol and form pores
-cross-reactivity: can attack human cholesterol; must monitor
-high toxicity
-highest powered
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terbinafine
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brand name lamisil
-anti-fungal
-topical ointment for skin
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nystatin
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oral antifungal that is usually used in dental procedures
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anti-parisitic
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Quinine & Derivatives as anti-malarials
-came from the bark of tree
-slows parasitic growth
-replaced by synthesized quinolines (chloroquine and primaquine) -- less toxic to humans
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Metronidazole (Flagyl)
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Usually for protozoan infections, causes DNA and protein damage
Amoebicide ,Giardialamblia and Trichomonasvaginalis !
**Also very good for anaerobic bacterial infections (C.diff!)
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anti-helminth (worms)
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de-energize worms and leads to paralysis
-must poop out or throw up the worms
-*pyranted pamoate
*piperzine
*Mebendazole & Thiabendazole
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one of the most common infections in humans
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oral infections
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Tooth and Gum Infections
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Mixed, synergystic infections involving multiple species of normal flora
CC: Steptococcus mutans - Gram(+)
vf: Biofilms
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gingivitis
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(swelling, loss of normal contour, patches of redness, and increased bleeding of the gingival) -- can progress to periodontitis
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Necrotizing Ulcerative Gingivitis (NUG)
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severe pain, bleeding, and necrosis
-"Trench Mouth"
-oral swishing antibiotics
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Gastritis and Gastric Ulcers
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CC: Helicobacter pylori
VF: Urease enzyme
Gastritic: sharp/burning pain emanating from abdomen
Ulcers: lesions in mucosa of stomach
-Urease detections as ID factor, "Ammonia breath test"
-urease breaks down mucus and chews the stomach lining, which can lead to broken blood vessels
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ribavirin
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boosts immune response when given
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enterocytes
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cells with villi (increase surface area), primary cells involved in
adsorption
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crypt cells
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produce new enterocytes (renewal & maintenance)
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goblet cells
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secrete/make mucous
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M-cells/ Peyer's Patches
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intestinal immune lineages & ‘outposts’ for immune cells
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foodborne infections
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-live cells delivered by food
-MULTIPLY in host once consumed
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Intoxications
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are illnesses in which bacterial toxins are ingested with food and water
-may NOT have live organisms
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Reiter's Syndrome
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urethritis, conjunctivitis,
arthritis
– “Can’t see, can’t pee, can’t climb a tree”
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Guillaine-Barre Syndrom
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neuropathy, paralysis caused from diarrhea
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salmonella
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-fecal, oral spread, but HIGH ID50-Ampicillin/bactrim
-#2 most common cause for diarrhea: dairy or raw meat products; Gram - rod-S. TYPHI=MOST SEVERE
VF: Invasive-hides and replicates in cells after "membrane ruffling"
-can enter blood to cause shock or osteomylitis
complication: Typh…
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Shigella
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intense pain with bloody stools (dysentery)
-complication: HUS-kidney failure if TOXIN enters blood
cc: higella sonnei, Shigella flexneri, Shigella dysenteriae
vf: shiga toxin-inhibiton of protein synthesis
invasive: replicates inside intestinal wall
-fecal-oral spread-very low 1D50 …
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Enterohemorrhagic (EHEC)
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E.coli O157:H7 or E. coli O104:H4
-bloody diarrhea
HUS, HEMORRHAGE, HAMBURGER
VF: shiga toxin
dx: cannot use sorbital for metabolism
-NO ANTIBIOTICS
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Enteroinvasive (EIEC)
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-bloody diarrhea with PUS
-vf: invasive-leads to cell destruction
dx: cannot use lactose for metabolism
-fecal-oral spread and use supportive treatment
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Enterotoxigenic (ETEC)
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-causes watery "traveler's diarrhea"
-can be transmitted via fomites-glassware
VF: 2 Toxins- heat stable toxin (st) and heat labile toxin (lt)
-self limiting
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Enteropathogenic (EPEC)
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-profuse watery diarrhea
-common in infants
VF: forms pedestals, where actin on vili become depolarized
-rehydration
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Enteroaggregative (EAEC)
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slow developing, chronic diarrhea (14+) days
VF: biofilms, clustering
-"ballooning", leading to disruption of mucous cells
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Campylobacter jejuni
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-#1 cause of diarrhea
-frequent, watery, yellowish stools with chunks
-wants to be very deep
-cooked poultry
VF: 2 toxins: enterotoxin (cAMP) and cytotoxin (PS)
-Spirochete
-higher chance of Guillain-Barre syndrome
-erythromycin
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Clostridium difficile
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G+, NF, spore-former
-superinfection, especially in broad-spectrum antibiotics
VF: 2 enterotoxins- A&B that lead to necrosis and form yellow plaques-pseudomembranous colitis (destruction/perf of intestinal wall)
-discontinue antibiotic and switch to FLAGYL
"FFRT"
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vibrio cholerae
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G-, comma shaped that lives in water
-PROFUSE watery diarrhea "rice water"
VF: cholera toxin, classic A-B toxin cAMP regulator
-NO abdominal pain, just dehydration
**little brother in USA is Vibrio parahaemolyticus - extreme watery diarrhea, linked to shellfish consumption (invasive…
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staph. aureus exotoxin
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Often associated with “white” foods such as custards, sauces, cream pastries, processed meats, mayonnaise, or “X salad”, that have been contaminated and then left unrefrigerated for a few hours
– VF: Staph enterotoxin A (SEA)-not properly heating the food correctly, rapid recovery
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Bacillus cereus
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wo exotoxins: one causes diarrheal-type disease,the other cause an emetic disease-SPORE FORMER
Emetic form frequently linked to fried rice, especially when cooked and kept warm for long periods of time
Diarrheal form associated with cookmats or vegetables that are held at a warm…
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Cryptosporidium parvum
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-parasitic
-Waterborne (fecal-oral) usually from animal wastes in water
*resistant to to chlorination
-ID50 is very low: 10-30 oocytes
-severe in immunocompromised
dx: acid-fast staining-find oocytes in sample "O&P"
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Giardia lamblia
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Diarrhea of long duration, abdominal pain, and flatulence, with Greasy, malodorous stools
-PARASITIC
-Fecal-Oral transmission via water
-“Backpacker’s disease,” “Boy Scout Diarrhea,” “Beaver fever”
– Easily recognized in stool -- parasite with TWO eyespots (“monkey head, lion …
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Entamoeba histolytica
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Bloody diarrhea, abdominal pain, fever, diarrhea, weight loss
– “Non-bacillary dysentery”
VF: Secretes enzymes that dissolve tissues
Fecal-oral transmission of cysts (found in pt samples), then replicates as trophozoites
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Cyclosporiasis
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-watery diarrhea with BLOATING
-does NOT spread person-to-person
-found in salads, imported raspberries
CC: Cyclospora cayetanensis (protozoan) – VF:parasitic,invasive
• Fecal-oral transmission of oocysts, then invasive as sporozoites
• Dx w standard O&P (acid-fast staining)
T…
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rotavirus
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-vomitting, watery diarrhea with sudden onset, short incubation 8hr-2days
-600,000 pediatric deaths-attacks infants
CC: Rotavirus (11 segments of dsRNA capable of re-assortment!!)
New Vaccine: RotaTeq (5 strains)
***ROTA=Wheel round shape
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norovirus
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-Projectile vomiting & watery diarrhea
Highly contagious including airborne transmission
-50% of all foodborne epidemics
CC: Norovirus (+) ssRNA, Caliciviridae family
•VF: CPE seen in both intestinal cell types
“Calici” = “Cup” -- small round virus with cup/goblet shape in …
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hepatitis
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inflammation of the livers, typically viral
jaundice: yellowing (bilirubin)
-tea colored urine
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hepatitis A
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transmitted fecal-oral
-CC: (+) ssRNA genome, Picornaviridae family virus
-highest in day-care settings, military, unsanitary areas
-same as Hep E
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hepatitis B
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May cause chronic hepatitis leading to cirrhosis and/or cancer
-Transmission via exchange of body fluids
-CC: Partially dsDNA virus in Hepadnaviridae family
The ONLY Hepatitis virus in the Hep family! (“Balls & Sticks” appearance)
HBsAg & HBeAg
-episomal latency; not integr…
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phases of immune tolerance in Hep B
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1. tolerance: high amounts of both HBeAg, and HBsAg
2.clearance: high amounts of HBeAg
3. infection: High amounts of HBsAg
**can use this information to tell how far along infection is and how to treat it
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hepatitis C
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More likely to cause chronic hepatitis than HBV, but less prevalent in the population
-transmitted via body fluid, usually blood
-hepatitis core protein: HCcaAg-immune suppression
-ssRNA, flavivirdae
High risk groups -- IV drug users, transfusion and organ transplant recipient…
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nterobius vermicularis (“Pinworm”)
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-butthole worm
-crawl in a out of anus to lay eggs on anal folds, then newborns crawl back up
-"In-Out-In life cycle
-Passage thru linens, toys, clothing, etc -- often infecting whole families
Causes perianal itching,“squirming” -- feels better if scratched, but continues infectious c…
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Ascaris lumbricoides
(“Roundworms”)
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-fecal oral that hatch in small intestine to roundworms
-Migrate thru liver & intestines upwards towards lungs -- cough up larvae/eggs to reswallow.
-causes distended belly, intestinal blockage, no nutrients, death
-"In-Up cycle"
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Necator americanus
(“Hookworm”)
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-uses teeth to latch onto skin and chew through your skin, causing GROUND ITCH
-most common in soil
-starts in intestines, and can lead to CYSTS
Causes fatigue, anemia, severe nutrient depletion, and “failure to thrive”
-"BLOOD SUCKING WORM"
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Trichinella spiralis
(“Hunter’s worm”)
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-found in wild game such as boars, deer that are not cooked properly
-forms cysts in muscle, brain
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Taenia saginata
(“Beef tapeworm”)
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hatch in intestines
-scolex with suckers only
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Taenia solium
(“Pork tapeworm”)
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-more dangerous than beef tapeworm due to auto-infectious cycle
-Cystircercosis: Causes cysts (brain & muscle)
-likes to move and can reproduce much more RAPIDLY
-recognized by scolex with suckers AND teeth
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eosinophilia
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immune response cells that target only worms
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candida albicans (vaginitis)
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-inflammation of the vagina with burning, itching, and WHITE discharge
-common cause of yeast infections-NF
1. oral thrush-White coating or patches on mouth/tongue
2.diaper rash-Red rash in wet, moist areas
3.Nosocomial infections -- found everywhere
DX: by white colonies on on s…
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Gardnerella vaginalis
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itching and vaginal discharge with a FISHY smell
-grey or yellow discharge-not inflammation
-G-
-Dx: vaginal smears heavy w bacteria + “CLUE CELLS”
-associated with multiple sex partners
-NOT a true STI, but rather a disruption of NF
-"vaginosis"
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Trichomonas vaginalis
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-Causes greenish-white, frothy, foul-smelling vaginal discharge – -“Strawberry cervix” appearance w inspection
-PARASITIC
ID -- Easily recognized in smears as parasite with ONE eyespot +
lophotrichous flagella (“whiskers”)
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Prostatitis
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-pain in the pelvic area, painful urination
-cc: unknown, but likely introduction of GI FLORA into urinary tract
treatment: very broad spectrum, long-term antibiotics
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Ureaplasma urealyticum
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-if it burns and we can't find NGU or NCU, we assume UU
-mimics chlamydia with light discharge
vf: urease enzymes
NO CELL WALL, so we use tetracycline or erythromycin
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Treponema pallidum
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-bacteria replicate slowly and in STAGES
-enters through abrasions in skin
-SPIROCHETE
VF: Teflon pathogens where antibiotics cannot stick
VF: highly MOTILE
ID: DARKFIELD MICROSCOPY, where organism is fluorescent
ID: Giemsa stain
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Chancroid
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cc: H. Ducreyi
-PAINFUL chancres
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MICROB 2800: EXAM 1