NAPLEX Practice Test 2026 – Complete Prep Resource

Tigecycline is a broad-spectrum antibiotic that belongs to the glycylcycline class, and it is effective against a variety of Gram-positive and Gram-negative bacteria, as well as anaerobes. However, it has some limitations in its spectrum of activity.

The reason Staphylococcus is the correct answer is that while Tigecycline is effective against various strains of Staphylococcus, including certain MRSA strains, it is not the drug of choice for treating infections caused by Staphylococcus aureus. This is due to the concern for resistance mechanisms and the potential for treatment failures, especially in severe infections. In contrast, Proteus, Pseudomonas, and Providencia are not covered by Tigecycline at all; it does not effectively treat infections caused by these bacteria.

Understanding the specific coverage of Tigecycline helps guide appropriate antibiotic use and treatment selection, especially in complex infections where resistant organisms may be involved. The limitations in coverage, particularly against organisms like Staphylococcus, emphasize the need to consider susceptibility testing and the choice of alternative antibiotics when treating infections related to this bacterium.