Abstract: The present invention provides methods of treating mycobacterial infections or mycobacterial diseases by administering a tetracycline compound, e.g., omadacycline, or a pharmaceutically acceptable salt thereof.

Abstract: The disclosure provides compounds of the formula I and the pharmaceutically acceptable salts thereof. The variables, e.g. R1, R2, R3, R4, A, B, J, V, W, M, J and Ar are defined herein. The disclosure also provides pharmaceutical compositions comprising a compound or salt of formula I and a pharmaceutically acceptable carrier, methods of inhibiting dihydrofolate reductase (DHFR) in vitro or in vivo with a compound or salt of formula I, and methods of treating a bacterial infections, fungal infections, and protozoal infections with a compound or salt of formula I. A compound or salt of formula I can be the first and only active ingredient used in a pharmaceutical composition or method of this disclosure or may be combined with one or more additional active ingredients that are not compounds or salts of formula I.

Abstract: Compounds of formula II ##STR1## wherein R.sup.1 is a hydrocarbon, halogenated hydrocarbon, polyether, substituted phenyl, substituted benzyl or alkylamine; and R.sup.2, R.sup.3 and R.sup.4 are hydrogen, lower alkyl, halogen, haloalkyl, alkoxy and similar substituents are disclosed. The compounds are useful in the treatment of M. avium. Methods and compositions utilizing novel as well as known compounds are disclosed.