Antimicrobial Chemotherapy

Aminoglycoside antibiotic
An antibiotic that contains a cyclohexane ring and amino sugars; this antibiotic binds to the small ribosomal subunit and inhibits protein synthesis
Antimetabolite
A compound that blocks metabolic pathway function by competitively inhibiting a key enzyme’s use of a metabolite because it closely resembles the normal enzyme substrate
Broad-spectrum drugs
Chemotherapeutic agents that are effective against many different kinds of pathogens
Chemotherapeutic agent
Compounds used in the treatment of disease that destroy pathogens or inhibit their growth at concentrations low enough to avoid doing undesirable damage to the host; includes antibiotics and antimicrobials
Antibiotics
Natural microbial chemotherapeutic agents
Antimicrobials
Naturally or chemically synthesized chemotherapeutic agents
Cidal
Having the capacity to cause cell death
Integron
A genetic element with an attachment site for site-specific recombination and an integrase gene; it can capture genes and gene cassettes
Kirby-Bauer method
A disk diffusion test to determine the susceptibility of a microorganism to chemotherapeutic agents
Macrolide antibiotic
An antibiotic containing a macrolide ring, a large lactone ring with multiple keto and hydroxyl groups, linked to one or more sugars; inhibits bacterial growth by binding to the 50S ribosomal subunit, thereby blocking protein synthesis
Minimal inhibitory concentration (MIC)
The lowest concentration of a drug that prevents the growth of a particular microorganism
Minimal lethal concentration (MLC)
The lowest concentration of a drug that kills a particular microorganism
Narrow-spectrum drugs
Chemotherapeutic agents that are effective only against a limited variety of microorganisms
Quinolones
A class of broad-spectrum antibiotics, derived from nalidixic acid, that bind to bacterial DNA gyrase, inhibiting DNA replication; this group of antibiotics is bacteriocidal
R plasmids
Plasmids bearing one or more drug-resistance genes
Selective toxicity
The activity of a drug that kills or inhibits the microbial pathogen while damaging the host as little as possible
Static
Having the capacity to limit microbial growth but not cause microbial death
Tetracyclines
A family of antibiotics with a common four-ring structure; they are isolated from the genus Streptomyces or produced semisynthetically
Therapeutic index
The ratio between the toxic dose and the therapeutic dose of a drug, used as a measure of the drug’s relative safety
Beta-lactam ring
Most crucial feature feature of the penicillin molecule, the target of the enzyme penicillinase produced by penicillin-resistant bacteria
Cephalosporins
Family of antibiotics structurally similar to penicillins; used against Pseudomonas aeruginosa
Vancomycin
Glycopeptide antibiotic produced by Streptomyces orientalis; bactericidal for Staphylococcus and some members of the genera Clostridium, Bacillus, Streptococcus, and Enterococcus; peptide portion blocks transpeptidation reaction of peptidoglycan
Teicoplanin
Glycopeptide antibiotic produced by the actinomycete Actinoplanes; similar in structure and mechanism of action to vancomycin but has fewer side effects
Sulfonamides
Metabolic antagonists that compete with PABA (used in the synthesis of folic acid), causing a decline in folate concentration, which results in cessation of protein synthesis and DNA replication
Trimethoprin
Synthetic antibiotic that interferes with the production of folic acid by binding to dihydrofolate reductase (DHFR); often used to treat respiratory and middle ear infections, urinary tract infections, and traveler’s diarrhea
Amantadine
Used to prevent influenza A infections by blocking the penetration and uncoating of influenza virus particles
Azidothymidine (AZT)
Reverse transcriptase inhibitor
Tamiflu
Antiviral agent that inhibits neuraminidase
Quinine drugs
Used to treat malaria by suppressing reproduction and are effective in eradicating erythrocytic asexual stages
Artemisinin
Chemical found in the wormwoood plant that grows in Africa and Asia; used to treat malaria by forming reactive oxygen intermediates inside infected red blood cells
Metronidazole
Used to treat Entamoeba infections by causing DNA fragmentation
Parenteral routes
Non-oral routes of drug administration
MRSA
S. aureus that has developed resistance to vancomycin
Efflux pumps
Plasma membrane translocases that expel drugs out of pathogenic cells
Drug inactivation
Chemical modification of drugs
Gene cassettes
Genetic elements that may exist as circular, non-replicating DNA when moving from one site to another, but normally are a linear part of a transposon, plasmid, or bacterial chromosome