[Skip to Content]
[Skip to Content Landing]
June 1978

Mycobacterium marinum Infections

Arch Dermatol. 1978;114(6):966. doi:10.1001/archderm.1978.01640180096038

To the Editor.—  I read with interest the article "Mycobacterium marinum Infections Treated With Tetracycline" (113:1067-1068, 1977). The authors state that "based on our correlated in vitro antimicrobial studies, we believe that this [clinical effectiveness] is a direct antimicrobial effect." The five isolates in their study demonstrated in vitro sensitivity to tetracycline at the 25 to 50 μg/ml level. On their suggested oral treatment regimen of 2 g of tetracycline daily, peak blood levels of 3 to 6 μg/ml are achieved.1,2 This would only be 5% to 10% of the quantity of tetracycline necessary for the in vitro inhibition of M marinum. Although tetracycline concentrates in certain tissue sites, I am unaware of data showing tenfold to 20-fold concentration in skin or soft tissues, as compared with serum levels.I agree with Izumi et al that "the results of chemotherapy have been difficult to evaluate because of the natural