Term
| 5 types of Antimicrobials |
|
Definition
1) antibacterials
2) antivirals
3) antifungal
4) antiprotozoals
5) antihelminths |
|
|
Term
|
Definition
| to exploit differences in structure and metabolism of pathogens and host cells (to kill organisms not man) |
|
|
Term
| Ways of classifying antibacterials |
|
Definition
1) by Origin
2) whether bactericidal or bacteriostatic
3) by target site or activity |
|
|
Term
|
Definition
| natural products of fungi ex. penicillins, cephalosporins, tetracyclines |
|
|
Term
| ex. of synthetic compounds |
|
Definition
|
|
Term
|
Definition
| prevents organism from increasing. host-defense can cope with a static population |
|
|
Term
|
Definition
|
|
Term
| Cell wall synthesis (mammalian cells lack a cell wall) |
|
Definition
Block synthesis and repair:
Penicillin
Fosfomycin
Vancomycin
Bacitracin
Monobactams
Cephalosporins
Cycloserine |
|
|
Term
| Bacterial Protein synthesis (ribosome) |
|
Definition
| Site of action: 50S Ribosome Chloramphenicol Erythromycin Clindamycin Oxalolidinones Site of action: 30S Subunit Aminoglycosides Tetracyclines Streptomycin Amikacin |
|
|
Term
| Nucleic Acid Synthesis of bacteria |
|
Definition
Antibacterial target the DNA
- inhibit replication and transcription
-inhibit gyrase (unwinding enzymes)
Quinolones (ciprofloxacin)
-Inhibit RNA polymerase (Rifampin) |
|
|
Term
| Cell membrane function of bacteria |
|
Definition
Antibacterial target the
Cell membrane - polymyxins
Cytoplasm - inhibit folic acid metabolism (sulfanamides - sulfa drugs) Trimethoprim |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
used to treat C. difficile (Gram positive rod)
Vancomycin is nephrotoxic |
|
|
Term
|
Definition
Penicillin-binding proteins
-enzymes involved in cross-linking bacterial cell wall components |
|
|
Term
|
Definition
| bind to and inhibit enzymes which catalyse NAG-NAM link |
|
|
Term
|
Definition
Beta-lactamase inhibitors
-used with amoxycillin (Augmentin)
-used with ticarcillin (Timentin) |
|
|
Term
|
Definition
Beta-lactamase inhibitor
- used with ampicillin (unavailable in UK) |
|
|
Term
|
Definition
Beta-lacatamase inhibitor
-used with pipercillin (Tazocin) |
|
|
Term
| Aminoglycosides protein synthesis inhibition |
|
Definition
goes inside 30s subunit (3 triangles) and mRNA is blocked and protein is incorrect.
Bactericidal but most antibiotics are bacteriostatic |
|
|
Term
| Chloramphenicol protein synthesis inhibition |
|
Definition
formation of peptide bond is blocked (rectangle inside 50S subunit)
-bacteriostatic against G+ and many G- not P.aerugisa |
|
|
Term
| Oxalolidinones protein synthesis inhibition |
|
Definition
prevent initiation of protein synthesis
(inside 50S; rhombus in the first AA) |
|
|
Term
| Tetracyclines protein synthesis inhibition |
|
Definition
tRNA is blocked; no protein synthesis
(inside 30S kite shaped blocking the 2nd AA in P site)
-bind to newly synthesized bone and discolor teeth.
-(doxycycline) can cause a photosensitizing skin rash |
|
|
Term
| Erythromycin protein synthesis inhibition |
|
Definition
Ribosome is prevented from translocation
(spherical shape blocking in between 50s and 30s with mRNA in the middle) |
|
|
Term
| Streptomycin (Aminoglycosides) |
|
Definition
Oldest aminoglycoside - now used to treat TB
causes vestibular ototocity, but not nephrotoxic |
|
|
Term
| Amikacin (aminoglycoside) |
|
Definition
| Semi-synthetic derivative of kanamycin, active against gentamicin-resistant Gram negative rod |
|
|
Term
|
Definition
G - First broad spectrum aminoglycoside
T - similar spectrum to G |
|
|
Term
| Azithromycin - Macrolides |
|
Definition
-active against many respiratory tract pathogens, including pneumococci, Haemophilus, Moraxella, Mycoplasma
-expensive
-used to prevent MAC in AIDS
GI complications mostly with erythromycin |
|
|
Term
| Trimethoprim (DNA synthesis) |
|
Definition
inhibits folate required for the synthesis of purines and pyramidines by enzyme inhibition
Sulphonamides - also inhibit synthesis |
|
|
Term
|
Definition
-broad spectrum activity
-principal use is for treatment of UTIs
-useful in treatment of PCP, Nocardia and toxoplasma gondii |
|
|
Term
|
Definition
ex. ciprofloxacin
-large family of synthetic agents that affect DNA gyrase |
|
|
Term
| Polymyxin B (cell membrane antibiotic) |
|
Definition
| used topically due to toxicity |
|
|
Term
|
Definition
| topical antifungal agent, also oral for intestinal candidiasis |
|
|
Term
|
Definition
| antifungal agent used IV in spite of considerable toxicity, esp renal, bec. few or no alt. for the treatment of many fungi |
|
|
Term
|
Definition
| a phosphoric acid effective as alternate treatment for UTIs, inhibit cell wall synthesis and decreases the adherence of bacteria to epithelial cells of the urinary tract |
|
|
Term
|
Definition
effective against Staphylococcus Enterococcus that cause endocarditis & surgical infection
-inhibits protein synthesis |
|
|
Term
|
Definition
a synthetic antibiotic belonging to a new class of antimicrobial called oxalolidinones
-used for Vancomycin-resistant Enterococcus faecium |
|
|
Term
| Mechanism of drug resistance |
|
Definition
1) Drug inactivation ex penicillinase
2) Decreased permeability - the receptor that transport the drug is altered
3) Activation of drug pumps - specialized membrane protein are activated and continually pump the drug out of the cell.
4. Use of metabolic pathways - the microbe circumvents the blocked path(blocked by the drug). |
|
|
Term
|
Definition
jumping genes
-extrachromosomal elements which sponsor transfer of small lengths of genetic material
-resistance genes in transposons can move bet plasmids and chromosomes and from one plasmid to another. |
|
|
Term
|
Definition
jumping genes
-extrachromosomal elements which sponsor transfer of small lengths of genetic material
-resistance genes in transposons can move bet plasmids and chromosomes and from one plasmid to another. |
|
|
Term
| MIC (minimum inhibitory concentration) |
|
Definition
| smallest concentration of drug that visibly inhibits growth |
|
|
Term
|
Definition
| the ratio of the dose of the drug that is toxic to humans as compared to its minimum effective dose |
|
|
