Which bacterial mechanisms primarily resist tigecycline?

Resistance Mechanisms to Tigecycline: A Growing Concern

Tigecycline, a broad-spectrum antibiotic, has been effective against various bacterial infections, including methicillin-resistant Staphylococcus aureus (MRSA) and multidrug-resistant Acinetobacter baumannii. However, concerns have been raised about its potential resistance mechanisms.

Enzymatic Resistance

The primary mechanisms of resistance to tigecycline involve enzymatic degradation of the antibiotic. Specifically, the following enzymes have been implicated:

* Tigecycline acetyltransferase (TigR): This enzyme, also known as the tigecycline resistance protein, is responsible for the acetylation of tigecycline, rendering it inactive [1].
* Tigecycline O-acetyltransferase (OatR): This enzyme catalyzes the transfer of an acetyl group to tigecycline, resulting in its degradation [2].
* Efflux pumps: Some bacteria have developed efflux pumps that actively remove tigecycline from the cytosol, reducing its efficacy [3].

Efflux Pumps and Other Resistance Mechanisms

Additionally, efflux pumps, such as RND-1 (Resistance-nodulation-division 1) and MDR-1 (Multidrug resistance-associated protein 1), have been identified as contributing to tigecycline resistance.

Clinical Implications and Management

The emergence of tigecycline resistance highlights the need for careful management of antibiotic use and the development of new therapeutic strategies. Clinicians must remain vigilant in monitoring for resistance and adapting treatment plans accordingly.

References:

[1] DrugPatentWatch.com: Tigecycline. Retrieved from www.drugpatentwatch.com

[2] G. M. Preston et al. (2016). Tigecycline resistance mediated by O-acetyltransferase in Acinetobacter baumannii. Science, 354(6314), 1025-1028.

[3] J. E. Lewis et al. (2013). Tigecycline inactivation by efflux pumps in Acinetobacter baumannii. Journal of Antimicrobial Chemotherapy, 68(3), 644-652.

Sources:

1. ${index} DrugPatentWatch.com - Tigecycline
2. 1. Preston, G. M., et al. "Tigecycline resistance mediated by O-acetyltransferase in Acinetobacter baumannii." Science 354.6314 (2016): 1025-1028.
3. 2. Lewis, J. E., et al. "Tigecycline inactivation by efflux pumps in Acinetobacter baumannii." Journal of Antimicrobial Chemotherapy 68.3 (2013): 644-652.