Novel antimicrobial compositions comprise at least a form of a fosfomycin (or suitable analogs, or derivatives thereof), and at least one sulfonamide (or suitable analogs, or derivatives thereof), and/or at least one diaminopyridine (or suitable analogs, or derivatives thereof). Said antimicrobial compositions generally include two or more of said components as a novel combination, provided in a single combination or formulation, or provided independently with overlapping exposures of the two or more components. These novel compositions, when provided as the two or more components, are effective against susceptible microorganisms, and are effective against susceptible drug-resistant microorganisms (e.g., bacteria, parasites), including multi-drug resistant bacteria. These novel compositions are also effective against microorganisms or strains thereof now susceptible to the combination even though said microorganisms or strains thereof were previously found or were considered resistant or intolerant to at least one of the components of the novel composition, when the at least one component was used alone at what was considered an effective dosing amount or concentration.La présente invention concerne de nouvelles compositions antimicrobiennes comprenant au moins une forme d'une fosfomycine (ou des analogues appropriés ou des dérivés associés), et au moins un sulfonamide (ou des analogues appropriés ou des dérivés associés), et/ou au moins une diaminopyridine (ou des analogues appropriés ou des dérivés associés). Lesdites compositions antimicrobiennes comprennent d'une manière générale au moins deux desdits constituants en tant que nouvelle association, fournis sous la forme d'une association ou d'une formulation unique, ou fournis séparément avec des expositions en chevauchement desdits au moins deux constituants. Lorsqu'elles sont fournies sous la forme desdits deux constituants, ces nouvelles compositions sont efficaces contre des microorganismes sensibles, et sont
