Microbiology: Antimicrobial Agents and Bacterial Resistance

Vocabulary practice flashcards focusing on antibacterial classifications, mechanisms of action, and bacterial resistance mechanisms based on the lecture notes.

Antibiotic

Naturally occurring and synthetically derived compounds that selectively inhibit or destroy bacteria.

Bactericidal

Antimicrobial agents that actively kill bacteria; examples include aminoglycosides, beta-lactams, vancomycin, quinolones, rifampin, and metronidazole.

Bacteriostatic

Antimicrobial agents that inhibit the growth and replication of susceptible bacteria rather than killing them immediately, eventually leading to bacterial death.

Selective Toxicity

The essential property of an ideal antibiotic that enables it to inhibit or destroy the pathogen without causing harm to host cells.

$\beta$-Lactams

A major class of cell wall synthesis inhibitors characterized by a beta-lactam core, comprising penicillins, cephalosporins, monobactams, and carbapenems.

Glycopeptides

A class of bacterial cell wall synthesis inhibitors exemplified by vancomycin.

MRSA

Methicillin Resistant Staph. aureus, a resistant bacterial pathogen treated clinically with vancomycin or daptomycin.

Beta-lactamases

Bacterial enzymes capable of inactivating penicillin-family drugs by hydrolyzing the beta-lactam ring, thereby nullifying the antibiotic's clinical effect.

Clavulanic Acid

A beta-lactamase inhibitor engineered to bind bacterial beta-lactamase enzymes and protect co-administered penicillins from enzymatic destruction.

Augmentin

A combination formulation containing the extended-spectrum penicillin amoxicillin paired with the beta-lactamase inhibitor clavulanic acid.

Cephalothin

A first-generation ($1^{\text{st}}\text{ G}$) cephalosporin antibiotic that inhibits cell wall synthesis.

Cefuroxime

A second-generation ($2^{\text{nd}}\text{ G}$) cephalosporin antibiotic.

Cefotaxime

A third-generation ($3^{\text{rd}}\text{ G}$) cephalosporin antibiotic.

Cefipime

A fourth-generation ($4^{\text{th}}\text{ G}$) cephalosporin antibiotic.

Ceftaroline

An advanced, next-generation cephalosporin antibiotic that targets bacterial cell wall synthesis.

Aztreonam

A monobactam antibiotic that functions as a cell wall synthesis inhibitor.

Imipenem

A carbapenem antibiotic that targets bacterial cell wall synthesis.

$50\text{S}$ Ribosomal Subunit Inhibitors

Protein synthesis inhibitors targeting the bacterial $50\text{S}$ ribosomal subunit, such as chloramphenicol (targeting Salmonella) and erythromycin (targeting Gram-positive bacteria).

$30\text{S}$ Ribosomal Subunit Inhibitors

Protein synthesis inhibitors targeting the bacterial $30\text{S}$ ribosomal subunit, including oxytetracycline (Gram-positive coverage) and aminoglycosides such as gentamicin and amikacin (Gram-negative coverage).

Polymyxins

A class of antibiotics that work via alteration and disruption of bacterial cell membrane function.

Daptomycin

An antibiotic that disrupts bacterial cell membrane function and exhibits dedicated activity against MRSA.

Co-trimoxazole (Bactrim)

A synergistic nucleic acid synthesis inhibitor consisting of sulfamethoxazole combined with trimethoprim ($200/40\,\text{mg}$).

Quinolones

A class of antimicrobial agents that exert their bactericidal action by inhibiting bacterial nucleic acid (DNA) synthesis.

Superbugs

Multidrug-resistant bacterial strains that emerge as a direct result of the abuse, overuse, and misuse of antibiotics, leading to life-threatening infections.

Efflux Pump

An active bacterial transport system that pumps antimicrobial agents out of the cell to reduce intracellular drug accumulation and confer resistance.

Plasmid-Mediated Resistance

An extra-chromosomal genetic mechanism of drug resistance in which resistance factors are encoded on autonomous circular DNA plasmids.

Chromosomal Resistance

A genetic form of antibiotic resistance arising from spontaneous mutations localized within the bacterial chromosome.