MICROB 3200: EXAM 1
52 Cards in this Set
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Gram +
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Simple, thick peptidoglycan, has teichoic acids
**NO OUTER MEMBRANE OR LPS**
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Gram-
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More complex than gram+, thin peptidoglycan layer, no teichoic acid
**Has an outer membrane and LPS (responsible for toxicity)
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Peptidoglycan made up of..
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Alternating NAG & NAM, as well as cross-linking transpeptides
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Peptidoglycan functions: (3)
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Shape
Protection Diffusion
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LPS made of
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Lipid A --responsible for toxicity
Core oligosaccharide O polysaccharide antigen
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Ribosomes
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Site of protein synth
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Inclusion
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reserve energy molecules
contain phosphate, polysaccharide, ipid, sulfer etc. Most are energy reserves Helpful in diagnosis
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Corynebacterium diptheriae
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Metachromatic phosphate containing granules (INCLUSIONS)
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Catabolism
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The process of substrate breakdown
GENERATES ATP
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Anabolism
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the process of synthesis of cellular elements
**REQUIRES ATP**
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3 Important electron carriers
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NAD
NADP FAD
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Coenzymes
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organic by nature
many are synth from vitamins --NAD is made from niacin
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Cofactors
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Inorganic by nature
Improve fit Ions of Mg, Zn, Mn
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Factors that influence rate of enzymatic reactions (4)
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Temp
pH enzyme and substrate concentrations presence of inhibitors
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Competitive inhibitors
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similar in structure to substrate
competes for active site
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Noncompetitive inhibition
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bind to a site other than active site
pushes on it which changes the shape of the active site
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Feedback inhibition
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end product of reaction binds to and inactivates enzyme
reversible noncompetitive
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Neisseria meningitidis *Is it aerobic or anaerobic?/What does it utilize
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obligate aerobe
utilizes glucose/maltose
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Escherichia coli *Aerobic or anaerobic/what does it utilize?
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faculative anaerobes
utilizes glucose & lactose
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Clostridium Tetani *Aerobic or anaerobic
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obligate anaerobe,
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Neisseria gonorrhoeae utilizes__
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glucose
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Shigella sonnei utilizes__
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glucose
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S. Aureus utilizes__
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mannitol
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Clostridium perfringens utilizes__
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glucose
produces butyric acid which causes tissue damage
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Lipid catabolism
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bacteria produce lipase that breaks down fats
produces fatty acids cause inflammation & redness **cause of acne**
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Major sites of antibiotic targeting (5)
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cell wall
cell membrane ribosomes metabolic pathway DNA
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bactericidal
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kill bacteria
used when host defense mechanisms are impaired required in endocarditis, kidney infections
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bacteriostatic
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inhibit bacteria
used when hosts defense mech are intact
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Vancomycin
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interferes with aline-aline bridges in gram + bacteria
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Penicillin
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effective primarily against gram + organisms
beta lactam antibiotic
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Ampicillin & Amoxicillin
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effective against both gram + and -
Used in UTI, salmonella, mono & strep A Adverse effects : allergic rxns, anaphalactic shock
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1st gen cephalosporin
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cephalexin
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2nd gen cephalosporin
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cefuroxime
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3rd gen cephalosporin
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ceftazidime
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4th gen cephalosporin
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cefepime
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Amphotericin B
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attaches to ergosterol in fungal membranes
**ANTIFUNGAL MED** humans somewhat susceptible b/c cholesterol is similar to ergosterol -- leads to nephrotoxicity
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Chloramphenicol 4 adverse effects
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INHIBITS 50s SUBUNIT RIBOSOME
crosses blood brain barrier 1st choice in brain abscess caused by staph aureus Adverse effects: bone marrow supression, aplastic anemia, grey baby syndrome, leukemia
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Lincomycin
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INHIBITS 50S
used in anaerobic and severe aerobic infections Adverse effect: pseudomembranous colitis (clostridium difficile
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Erythromycin
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effective against gram + bacteria, mycoplasma pneumoniae, Legionella pneumophilia
adverse effects: GI disturbances
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Tetracycline
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INHIBITS 30S
used to treat acne vulgaris, rocky mtn spotted fever, lyme disease, non-gonococcal urethritis is a broad spectrum antibiotic adverse effects: stains teeth, inactivated by calcium, photosensitivity, drug induced lupus and hepatitis
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Amnioglycosides
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INHIBITS 30S
used to treat severe gram - infections and TB adverse effects: nephrotoxicity &ototoxicity
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Lopinavir & Ritonavir
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inhibit HIV specific protease
*type of drug used in inhibition of metabolic pathways
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Trimethoprim/Sulfamethoxazole
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used to treat otitis media, UTI
adverse effects: rash, stevens-johnson syndrome, toxic epidermal necrolysis
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Acyclovir, AZT, Lamivudine
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inhibits viral nucleic acid synth
also effective against rapidly dividing cancer cells
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Quinolones & Floroquinolones
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inhibit prokaryotic DNA gyrase
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Rifampin
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inhibit action of RNA polymerase during transcription
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Quinolones used for: (4 adverse effects)
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treatment of pneumonia, UTI, gastroenteritis, atypical pneumonia
adverse effects = peripheral neuropathy, stevens johnson syndrome, pseudomembranous colitis(c. difficile), seizures
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Chromosome mediated genetic resistance
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spontaneous mutation in target molecule or in drug uptake system
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Plasmid mediated resistance
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common in gram - rods
transferred via conjugation thru pilli *cause of multi drug resistance
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Pathogenicity
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ability of a microorganism to cause disease
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virulence
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degree of pathogenicity
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virulence factors: (4)
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adhesion factors, extracellular enzymes, toxins, antiphagocytic factors
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MICROB 3200: EXAM 1