Bacterial Infections and Antibacterial Therapy Flashcards

Vocabulary flashcards covering bacterial infection definitions, classifications, mechanisms of action, and major prototype drug profiles based on Pathopharmacology II notes.

Pathogenicity

The ability of an organism to cause infection.

Virulence

The ability of an organism to produce disease when present in very small numbers.

Colonization

A condition where microbes are present in or on the body without host interaction.

Infection

A state in which the host interacts with the microbe and mounts an immune response.

Infectious Disease

A state in which an infection produces a decline in host wellness.

Cocci

Bacteria that are classified visually by their round shape.

Bacilli

Bacteria that are classified visually by their rod shape.

Spirochetes

Bacteria that are classified visually by their spiral or corkscrew shape.

Bactericidal Antibiotics

Antibacterial medications that directly kill bacteria (e.g., Penicillin G, gentamicin, and ciprofloxacin).

Bacteriostatic Antibiotics

Antibacterial medications that stop bacterial growth and multiplication, allowing the host's immune defenses to clear the infection (e.g., tetracycline and TMP-SMZ).

Culture and Sensitivity (C&S)

Diagnostic testing where a culture identifies the specific microorganism causing an infection and sensitivity identifies which antimicrobials are likely to be effective.

Empiric Therapy

Antibiotic treatment started before final culture and sensitivity results are returned when treatment cannot wait.

Superinfection

A secondary infection occurring when antibiotics destroy protective normal flora, leading to conditions such as Clostridioides difficile diarrhea, oral thrush, or vaginal yeast infections.

Penicillin G Potassium

A bactericidal beta-lactam prototype that blocks cell wall synthesis; requires a $1$\,hour wait before IV administration of aminoglycosides in the same line and reduces oral contraceptive effectiveness.

Cephalexin

A first-generation bactericidal cephalosporin prototype that interferes with cell-wall synthesis; contraindications include penicillin allergies, and it carries a risk of a disulfiram-like reaction with alcohol (ETOH).

Tetracycline

A broad-spectrum bacteriostatic protein-synthesis inhibitor; contraindicated in pregnancy (Category D) and children ages $\le 8$ years due to tooth and bone effects, and its absorption is impaired by dairy, calcium, iron, magnesium, and antacids.

Erythromycin

A macrolide protein-synthesis inhibitor that can cause ototoxicity, cardiotoxicity (dysrhythmias with high-dose IV), and GI upset, and must not be administered with grapefruit juice.

Aminoglycoside Toxicity

Major toxic effects associated with aminoglycoside antibiotics, specifically ototoxicity and nephrotoxicity.

Gentamicin

An aminoglycoside bactericidal antibiotic that inhibits protein synthesis and carries Black Box Warnings for ototoxicity, nephrotoxicity, neurotoxicity, and neuromuscular blockade, requiring peak and trough monitoring due to a narrow therapeutic window.

Ciprofloxacin

A bactericidal fluoroquinolone prototype that inhibits bacterial DNA synthesis and carries a Black Box Warning for tendonitis and tendon rupture.

Trimethoprim-Sulfamethoxazole (TMP-SMZ)

A bacteriostatic sulfonamide combination drug that inhibits bacterial folic acid metabolism; adverse effects include Stevens-Johnson syndrome, photosensitivity, hyperkalemia, and crystalluria/acute kidney injury.

Nitrofurantoin

A urinary antibacterial/antiseptic used for lower UTIs and UTI prophylaxis that causes a harmless rust-yellow or brown urine discoloration.

Imipenem-cilastatin

A very broad-spectrum bactericidal carbapenem beta-lactam that destroys bacterial cell walls and reduces valproic acid levels, increasing the risk for breakthrough seizures.

Vancomycin

A glycopeptide bactericidal antibiotic that inhibits cell wall synthesis by binding to D-Ala-D-Ala; used for severe Gram-positive infections like MRSA and C. difficile (given orally), with risks of Red Man Syndrome, nephrotoxicity, and ototoxicity.

Fosfomycin

An oral antibacterial administered as a single dose specifically for drug-resistant urinary tract infections (UTIs).