Antibiotics Mechanism of Action Quiz

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Questions and Answers

What is the mechanism of action for Cephalosporins?

Disrupt RNA polymerase function

Inhibit DNA gyrase

Bind to penicillin binding proteins to inhibit cell wall synthesis (correct)

Inhibit folate production

Which of the following drugs works by disrupting bacteria through nitro reductases?

Cefazolin

Tetracyclines

Metronidazole (correct)

Rifampin

What is a defining characteristic of fluoroquinolones?

They inhibit protein synthesis by binding to the 50s ribosome

They are bacteriostatic

They cause extreme deadly diarrhea

They inhibit DNA gyrase and are bactericidal (correct)

What distinguishes Glycopeptides from β-lactams?

They bind to precursor sites different from β-lactams (B) Signup and view all the answers

Which of the following best describes the action of Chloramphenicol?

It reversibly binds to the 50s ribosome (A) Signup and view all the answers

What is the grading system for a heart murmur that is loud and has a palpable thrill audible with a stethoscope held away from the chest wall?

Grade 6 (B) Signup and view all the answers

Which of the following is NOT an indication for performing an ECG?

Signs of good performance (D) Signup and view all the answers

Which lead placement corresponds to the left fifth intercostal space at the level of the olecranon?

Black lead (D) Signup and view all the answers

What effect does atrial fibrillation have on cardiac output?

Decreases it by 20-30% (A) Signup and view all the answers

What is the primary treatment step for atrial fibrillation once underlying pathology has been ruled out?

Transvenous electrical cardioversion (D) Signup and view all the answers

In which of the following scenarios is a horse advised NOT to be ridden or driven?

Signs of congestive heart failure (A) Signup and view all the answers

Which drug is commonly used for the cardioversion of atrial fibrillation?

Quinidine sulfate (C) Signup and view all the answers

What are the primary factors leading to Equine Pastern Dermatitis?

Environmental, infectious, and parasitic factors (C) Signup and view all the answers

What are the clinical signs of the exudative form of Equine Pastern Dermatitis?

Erythema, alopecia, and serous to purulent crust (C) Signup and view all the answers

Which diagnostic method is NOT typically used for Equine Pastern Dermatitis?

Radiography (B) Signup and view all the answers

Which of the following forms of Equine Pastern Dermatitis is characterized by excessive granulation tissue?

Chronic proliferative form (D) Signup and view all the answers

How is Chronic Progressive Lymphedema most commonly diagnosed?

History and clinical presentation (B) Signup and view all the answers

What does Chronic Progressive Lymphedema primarily affect?

Lymphatic structures in all four limbs (D) Signup and view all the answers

Which UV wavelength range is associated with photosensitivity in horses?

320-400 nm (C) Signup and view all the answers

What is a common clinical sign of Chronic Progressive Lymphedema?

Swelling and thickened skin folds (B) Signup and view all the answers

Which type of dermatitis is characterized by scalp lesions and epidermal hyperplasia?

Mild dermatitis (D) Signup and view all the answers

What is a common complication associated with cryotherapy?

Hyperemia (C) Signup and view all the answers

How does topical Fluorouracil function in cancer treatment?

Inhibits DNA and RNA synthesis (B) Signup and view all the answers

Which of the following antibiotics should be avoided for general use?

Vancomycin (D) Signup and view all the answers

What classification of photosensitivity is characterized by hepatotoxic plants?

Hepatogenous photosensitivity (D) Signup and view all the answers

Which clinical sign is NOT typically associated with photosensitivity?

Hirsutism (D) Signup and view all the answers

What defines time dependent antibiotics?

Need to remain above MIC for a portion of the time (A) Signup and view all the answers

What is a key difference between Cisplatin injections and Cisplatin beads used for chemotherapy?

Injections require more frequent dosing than beads (C) Signup and view all the answers

What is the main cause of Pituitary Pars Intermedia Dysfunction (PPID)?

Loss of dopaminergic inhibition (B) Signup and view all the answers

Which of the following is a common clinical sign of PPID in horses?

Excessive shedding (B) Signup and view all the answers

What provides the mechanism of action for aminoglycosides?

Binding to ribosomal subunits (B) Signup and view all the answers

What is the treatment method for periocular sarcoids?

Excision, laser, and chemotherapy (A) Signup and view all the answers

What is a key component of the ACTH production process in the normal pars intermedia?

PC2 cleaving pro-opiomelanocortin (B) Signup and view all the answers

Which testing method is NOT recommended for diagnosing PPID?

Urine test for toxins (A) Signup and view all the answers

Which of the following is NOT a consideration when choosing antibiotics?

Comprehensive chemistry analysis of the drug (A) Signup and view all the answers

What would be an appropriate step to take before conducting a TRH stimulation test?

Ensure the horse has not eaten grain within the last 12 hours (D) Signup and view all the answers

What process does surgical excision aim to avoid during the treatment of sarcoids?

Granulation tissue formation (A) Signup and view all the answers

Which of the following conditions is most commonly associated with older horses?

Pituitary Pars Intermedia Dysfunction (B) Signup and view all the answers

Radiation therapy is considered for which of the following conditions?

Sarcoids (C) Signup and view all the answers

Which method is part of the basic procedure for baseline ACTH testing?

Centrifuge to separate plasma after collection (C) Signup and view all the answers

What is the primary role of dopamine in the normal functioning of the pars intermedia?

To inhibit secretion of hormones from the pars intermedia (A) Signup and view all the answers

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Study Notes

Horse Ophthalmology

Horse's field of vision is large, 350 degrees, with narrow blind spots. Rod cells (light/motion) make up 90% of the retina, and cone cells (color) make up 10%
Epiphora is tearing.
Blepharospasm is squinting.
Common ocular problems in horses include epiphora, blepharospasm, vision loss, behavioral changes, conjunctivitis, and discharge.
Important aspects of an ophthalmic exam include assessing vision (ambient and dim light), menace response, obstacle course (with one eye blindfolded), and cranial nerve function (CN 2, 3, 5, 7).
The menace response in foals is learned and not evident until after 2-3 weeks of age.
Cranial nerves checked during an exam include 2, 3, 5, and 7. Specifically, the ophthalmic exam checks the following cranial nerves: CN2 (optic nerve), CN3 (oculomotor nerve), CN5 (trigeminal nerve), and CN7 (facial nerve).
An equine ophthalmic exam involves evaluation of the orbit, eyelids, nictitating membrane, conjunctiva, anterior segment (tears, cornea, iris, lens, ciliary body), and posterior segment (vitreous, retina, choroid, optic nerve).
Typical sedation/blocking protocol for equine ophthalmic exams include xylazine (150-250 mg for a 1,000 pound horse) for 10 minutes, followed by an auriculopalpebral block for motor and supraorbital block for sensory.
Fluorescein stain is a diagnostic test for all horses.
Schirmer tear test measures tear production. A value of less than 10 mm/minute is considered abnormal. Alpha 2 agonists can cause increased lacrimation, so it's important to perform the test prior to any medications and sedation.
Intraocular pressure (IOP) is normal in horses at 16-30 mmHg. Normal IOP is 16-28 mmHg. High IOP indicates glaucoma, and low IOP indicates inflammation or uveitis.
Rose Bengal staining helps visualize tear film deficiencies, and is especially useful for chronically affected horses.
A Nasolacrimal flush can be used to treat blockages of the tear duct.
Tropicamide is a mydriatic (pupil dilating) drug, commonly used for thorough retinal examination.
Corneal ulcers are a common condition in horses, and are diagnosed using corneal cultures and scrapes prior to medication.
Ultrasounds are used to view the different structures in the eye such as cornea, lens, retina, iris, ciliary body, optic nerve and vitreous.

Other Horse Eye Conditions

Corneal ulcers, keratitis, and stromal abscesses are common eye problems in horses.
Corneal ulcerations necessitate aggressive treatment to prevent complications like globe rupture and blindness.
Uncomplicated corneal ulcer healing time is typically 7-10 days.
Blood vessel formation in corneal ulcers takes approximately 3-5 days.

Additional treatments for eye problems

Topical and systemic medications are used to reduce inflammation and treat infections.
Fungal corneal ulcers require specific antifungal medications.
Corneal lacerations/perforations may require surgical intervention or plugs.
Viral keratitis treatment usually involves topical NSAIDs and antivirals.
Eosinophilic keratoconjunctivitis is treated with topical steroids and cetirizine.
Immune-mediated keratitis (IMMK) is managed with cyclosporine and topical NSAIDs.
Treatments for stromal abscesses include aggressive medical/surgical therapy.

Other Equine Eye Conditions

Equine recurrent uveitis (ERU), is a common inflammatory condition, and is managed with corticosteroids, NSAIDs, and cyclosporine.
Cataracts are lens opacities that may be congenital or secondary to other conditions, including uveitis.
Glaucoma is an elevated Intraocular blood pressure, it is treated with topical carbonic anhydrase inhibitors, miotics, and beta blockers.
Exophthalmos is a forward displacement of the eye. Buphthalmos is a bulging of both eyes,
Chorioretinitis is an inflammation of the choroid/retina, and can be caused by infection, immune-mediated diseases, or trauma.
Corneal ulcers and abrasions/perforations frequently require aggressive treatment.
Alopecia areata, is an immune-mediated inflammatory skin disease.
Dermatophilosis, causes a scaling/crusting dermatitis due to a facultative anaerobic, gram-positive bacterium.
Pemphigus foliaceus: is an autoimmune skin disease characterized by scaling, crusting lesions.

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Description

Test your knowledge on the mechanisms of various antibiotics, including Cephalosporins, fluoroquinolones, and Glycopeptides. Determine how these drugs disrupt bacterial function and what sets them apart from each other. This quiz will help you reinforce your understanding of antibiotic pharmacology.