Chapter 7: Controlling microbial growth IN VIVO Flashcards
use of any chemical or drug to treat any disease or condition
chemotherapy
any drug used to treat any condition or disease
chemotherapeutic agent
any chemical or drug used to treat an INFECTIOUS disease caused by microbes, by inhibiting (stopping the growth) or killing the pathogens in vivo
antimicrobial agent
drugs used to treat bacterial diseases
antibacterial agents
drugs used to treat fungal disease (mycoses)
antifungal agents
drugs used to treat protozoal diseases
antiprotozoal agents
drugs used to treat viral diseases
antiviral agents
substance produced by a microorganism that kills or inhibits the growth of other microorganisms
antibiotic
antibiotic that came from one organism and will inhibit other microorganisms
natural antibiotics
antibiotics that have been chemically modified to kill a wider variety of pathogens or reduce side effects
semisynthetic antibiotics
discovered penicillin from Penicillium notatum (mould)
Alexander Fleming
inhibits the growth of bacteria
bacteriostatic drugs
kills bacteria
bactericidal drugs
a bacteriostatic drug that inhibit the production of folic acid needed by bacteria that require p-aminobenzoic acid to synthesize folic acid (without folic acid bacteria can’t produce certain nutrients and will die)
sulfonamide drugs
drug that interferes with the synthesis of peptidoglycan (usually in gram+ bacteria) and destroys the bacteria
penicillin
antibiotics with limited effects
ex. colistin and nalidixic acid which destroys only gram - bacteria
narrow-spectrum antibiotics
destructive to both gram + and -
ex. ampicillin, tetracycline
broad-spectrum antibiotics
combining one antibiotics to another
multidrug therapy
two antimicrobial agents are used together to produce a degree of pathogen killing that is greater than that achieved by either drug alone
synergism
when two drugs actually work against each other
antagonism
ex. of bactericidal and interferes with cell wall synthesis
penicillins and cephalosporins
bacteriostatic; inhibit protein synthesis
tetracyclines
bactericidal; inhibit protein synthesis
aminoglycosides
bacteriostatic at lower doses; bactericidal at higher doses; inhibit protein synthesis
macrolides
bactericidal; inhibit DNA synthesis
fluoroquinolones
the newest weapons in antimicrobial methodology.
- Difficult to develop these agents because viruses are produced within host cells.
antiviral agents
several antiviral drugs that are administered all at the same time
cocktails
microbes (mainly bacteria) that have become resistant to one or more antimicrobial agents.
- these bacteria produce beta-lactamase which destroys antibiotics instead of
antibiotics destroying bacteria
superbugs
hospital-acquired infection
nosocomial infection
Some bacteria are naturally resistant because they lack the specific target site for the drug T OR F
true
naturally resistant because they lack the specific target site for the drug or the drug is unable to cross the organism’s cell wall or cell membrane and, thus, cannot reach its site of action
intrinsic resistance
bacteria that were once susceptible to a particular drug become resistant
- able to adapt to drastic environment bc of antibiotics na tinigil i-take
acquired resistance
Before a drug enters a bacterial cell, it must first bind to proteins on the surface of the cell
drug-binding sites
Many bacteria have become resistant to penicillin because they have acquired the gene for penicillinase production during conjugation T OR F
true
a plasmid that contains multiple genes for drug resistance
- can transfer to other bacteria through conjugation bc of pili
resistance factor (R-factor)
enables the cell to pump drugs out before they can damage or kill the cell
multidrug-resistance pump (MDR pump)
Every penicillin and cephalosporin molecule contains a double-ringed structure known as the β-lactam ring; bacteria produces enzymes (b-lactamases) that destroys the ring (once destroyed, drug no longer works) t or f
true
two types of b-lactamases
penicillinases
cephalosporinases
when drug therapy is initiated before laboratory results are available
empiric therapy
Organisms susceptible to the agent will die, but resistant ones will survive
selecting for resistant organisms
a broad-spectrum antibiotic may destroy the normal flora, resulting in an overgrowth of bacteria
superinfection
