The invention provides novel quinoline sulfonamide compounds of Formula I : (Formula (I)) and their use for the treatment or prevention of bacterial infections caused by both Gram positive and Gram negative bacteria such as, for example, infections caused by one or more bacteria from the Enterobactericeae, Staphylococcaceae, or Streptococcaceae families. The compounds described and claimed herein may be formulated in one or more pharmaceutical or veterinary compositions for use in animal husbandry, and in particular in relation to the treatment of mastitis by directly targeting mastitis causing bacteria in a bovine herd. In certain embodiments described herein the pharmaceutical or veterinary compositions are formulated as a spray for direct administration to the udder of the bovine animal such as a cow.