Beta-Lactam and Cephalosporin Antibiotics

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Questions and Answers

Which beta-lactam antibiotic is known for having broad-spectrum coverage, including against Gram-negative bacteria?

Methicillin

Penicillin G

Cephalexin

Carbapenems (correct)

What is the primary mechanism of action of aminoglycosides?

Inhibit DNA gyrase

Inhibit cell wall synthesis

Inhibit folic acid synthesis

Bind to 30S ribosomal subunit (correct)

Which antibiotic is specifically indicated for treating MRSA infections?

Ceftaroline (correct)

Cefepime

Penicillin V

Vancomycin

What is the consequence of using chloramphenicol in infants?

Grey baby syndrome Signup and view all the answers

Which of the following antibiotics is an effective treatment for UTI while targeting multiple cellular processes?

Nitrofurantoin Signup and view all the answers

What is the main side effect associated with tetracyclines?

Discoloration of teeth Signup and view all the answers

Which of the following agents does NOT have an effect on DNA synthesis?

Trimethoprim Signup and view all the answers

Which antimicrobial resistance testing method is used for vancomycin-resistant strains?

van A PCR Signup and view all the answers

What commonly used medication inhibits the synthesis of mycolic acid, making it effective against Mycobacterium?

Isoniazid Signup and view all the answers

Which antifungal agent is primarily used for severe systemic fungal infections but has a risk of nephrotoxicity?

Amphotericin B Signup and view all the answers

Match the following beta-lactam antibiotics with their characteristics:

Penicillin G/V = Treats streptococcal infections, Gram-positive Methicillin/Oxacillin = Resistance to beta-lactamase, Gram-positive Carbapenems = Broadest spectrum for severe infections Cephalosporins 5th Generation = Covers MRSA Signup and view all the answers

Match the following protein synthesis inhibitors with their unique features:

Aminoglycosides = Broad-spectrum, binds 30S Macrolides = Used for penicillin-allergic patients Chloramphenicol = Reserved for serious infections Tetracyclines = Deposits in teeth Signup and view all the answers

Match the following antifungal agents with their specific uses:

Amphotericin B = Drug of choice for severe fungal infections 5-Fluorocytosine = Effective against Cryptococcus Caspofungin = Effective against Candida and Aspergillus Azoles = Inhibits sterol synthesis Signup and view all the answers

Match the following medications with their corresponding actions:

Isoniazid = Inhibits mycolic acid synthesis Fluoroquinolones = Inhibits DNA gyrase, stops replication Trimethoprim/Sulfamethoxazole = Inhibits folic acid synthesis Rifampin = Inhibits DNA polymerase Signup and view all the answers

Match the following antimycobacterial agents with their side effects:

Ethambutol = Can cause optic neuritis Isoniazid = Can cause hepatitis Pyrazinamide = Causes GI upset Rifampin = Can alter body fluids color Signup and view all the answers

Match the following cell membrane disruptors with their targets:

Bacitracin = Inhibits peptidoglycan addition, Gram-positive Polymyxins = Disrupts outer membrane, Gram-negative Vancomycin = Interferes with cross-linking of peptidoglycan Ampicillin = Broad-spectrum, affects cell wall Signup and view all the answers

Match the following antiviral agents with their specific targets:

Acyclovir = Effective against Herpes Ribavirin = Effective against Respiratory Syncytial Virus Neuraminidase inhibitors = Inhibits Influenza A and B M2 Inhibitor = Inhibits Influenza A Signup and view all the answers

Match the following antimicrobial resistance testing methods with their targets:

MRSA testing = mecA gene produces altered PBP2a VRSA testing = Test with Etest ESBL testing = Test with and without clavulanic acid Glycopeptide testing = van A PCR Signup and view all the answers

Match the following agents with their mechanisms of action:

Chloramphenicol = 50S binding, risk of 'grey baby syndrome' Macrolides = Binds 50S, used for streptococcal infections Polymyxins = Disrupts outer membrane integrity Nitrofurantoin = Targets multiple cellular processes Signup and view all the answers

Match the following generations of cephalosporins with their properties:

1st Generation = Cephalexin, Gram-positive spectrum 2nd Generation = Cefuroxime, extended spectrum for Gram-negative 4th Generation = Cefepime, coverage for third-generation resistant bacteria 3rd Generation = Ceftriaxone, used for central-nervous system infections Signup and view all the answers

Study Notes

Beta-Lactam Antibiotics

Inhibit cell wall synthesis by targeting peptidoglycan
Penicillin G and V: Active against gram-positive bacteria, used to treat streptococcal infections.
Methicillin/Oxacillin: Active against gram-positive bacteria, resistant to beta-lactamases.
Ampicillin/Carbenicillin: Broad-spectrum, effective against a wider range of bacteria.
Carbapenems: Broadest spectrum, used for severe infections.
Vancomycin: Glycopeptide, interferes with cross-linking, has a narrow therapeutic index (requires careful monitoring).

Cephalosporins

First Generation (Cephalexin/Cephalothin): Active against gram-positive bacteria.
Second Generation (Cefuroxime): Extended spectrum, effective against gram-negative bacteria.
Third Generation (Ceftriaxone/Cefotaxime): Used for central nervous system infections.
Fourth Generation (Cefepime): Effective against some third-generation resistant bacteria.
Fifth Generation (Ceftaroline): Effective against methicillin-resistant Staphylococcus aureus (MRSA).

Cell Membrane Disruptors

Bacitracin: Active against gram-positive bacteria, inhibits peptidoglycan addition.
Polymyxins: Active against gram-negative bacteria, disrupt the outer membrane.

Protein Synthesis Inhibitors

Aminoglycosides: Broad-spectrum, bind to 30S ribosomes; have a narrow therapeutic index (require careful monitoring).
- Tobramycin/Gentamicin: Example aminoglycosides needing close monitoring for toxicity.
Tetracyclines: Broad-spectrum, bind to 30S ribosomes; can deposit in teeth.
Macrolides: Bind to 50S ribosomes, used for patients allergic to penicillins.
- Erythromycin: Example macrolide used to treat streptococcal infections.
Chloramphenicol: Binds to 50S ribosomes, reserved for serious infections; associated with "grey baby syndrome".

Folic Acid Inhibitors

Trimethoprim/Sulfamethoxazole: Treats chronic urinary tract infections (UTIs), inhibit folic acid synthesis.

DNA Synthesis Inhibitors

Nalidixic Acid: Treats UTIs, inhibits DNA synthesis.
Fluoroquinolones: Inhibit DNA gyrase, stopping DNA replication.
Nitrofurantoin: UTI treatment, targets multiple cellular processes.
Rifampin: Inhibits DNA polymerase; effective against Mycobacterium species.
Metronidazole: Causes DNA breaks under anaerobic conditions; produces a metallic taste as a side effect.

Antimycobacterial Agents

Isoniazid: Inhibits mycolic acid synthesis; can cause hepatitis.
Ethambutol: Inhibits cell wall formation; can cause optic neuritis.
Pyrazinamide: Lowers pH; can cause gastrointestinal upset.

Antifungal Agents

Amphotericin B: Drug of choice for severe fungal infections; has nephrotoxicity (kidney damage) risk.
Azoles: Inhibit sterol synthesis.
5-Fluorocytosine: Effective against Cryptococcus species; can depress bone marrow.
Caspofungin: Effective against Candida and Aspergillus; not effective against Cryptococcus.

Antiviral Agents

Acyclovir: Effective against herpes viruses.
Ribavirin: Effective against respiratory syncytial viruses.
M2 Inhibitor: Inhibits influenza A virus.
Neuraminidase Inhibitors: Inhibit influenza A and B viruses.

Antimicrobial Resistance Testing

MRSA: mecA gene produces an altered penicillin-binding protein (PBP2a).
VRSA: Tested using an Etest.
ESBL: Tested using a method involving clavulanic acid.
Clindamycin Resistance (Erm gene): Tested for the presence of the Erm gene.
Carbapenemase: Modified Hodge Test.
Glycopeptides (Vancomycin resistance): van A PCR.
Oxacillin Resistance: Cefoxitin Disk test.
Penicillin Resistance (Beta-lactamase): Tested for the presence of beta-lactamase.

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Description

This quiz focuses on the mechanisms and classifications of beta-lactam antibiotics and cephalosporins. You'll learn about their action against different types of bacteria and the specific antibiotics used for various infections. Test your knowledge on these crucial medications and their clinical applications.