Terbinafine Resistance in and : A Literature Review.

BACKGROUND/OBJECTIVES: Terbinafine has been the gold standard for the management of superficial fungal infections. The etiological agent generally is (); however, there has been increased reporting of a new terbinafine-resistant strain of the ( ITS genotype VIII otherwise known as ). Here, we review the epidemiology, clinical features, diagnosis, and treatment of and infections.

METHODS

We conducted a systematic literature search using PubMed, Embase (Ovid), and Web of Science, resulting in 83 qualified studies with data summarized for clinical features, antifungal susceptibility, and terbinafine resistance mechanisms and mutations.

RESULTS

Dermatophytosis is most commonly caused by ; however, in certain parts of the world, especially in the Indian subcontinent, infections have been reported more frequently. The majority of isolates remain susceptible to terbinafine (over 60% of isolates show MIC and MIC < 0.5 µg/mL). In contrast, for , 30% of isolates exhibit MIC ≥ 0.5 µg/mL and 80% exhibit MIC ≥ 0.5 µg/mL. Frequently detected squalene epoxidase () mutations in are Phe397Leu/Ile (41.6%) and Leu393Phe (20.8%); in , these include Phe397Leu (33.0%) and Ala448Thr (24.5%). Other potential terbinafine resistance mechanisms in and are discussed.

CONCLUSIONS

generally remain susceptible in vitro to terbinafine in contrast to . The essential components of an effective antifungal stewardship emphasize accurate clinical and laboratory diagnosis, susceptibility testing, and appropriate antifungal therapy selection with a multidisciplinary approach.