A new animal model for the purpose of studying superficial infections is presented. In this model an infection is established by disruption of the skin barrier by partial removal of the epidermal layer by tape stripping and subsequent application of the pathogens Staphylococcus aureus and Streptococcus pyogenes. The infection and the infection route are purely topical, in contrast to those used in previously described animal models in mice, such as the skin suture-wound model, where the infection is introduced into the deeper layers of the skin. Thus, the present model is considered more biologically relevant for the study of superficial skin infections in mice and humans. Established topical antibiotic treatments are shown to be effective. The procedures involved in the model are simple, a feature that increases throughput and reproducibility. This new model should be applicable to the evaluation of novel antimicrobial treatments of superficial infections caused by S. aureus and S. pyogenes.An important stage in testing the potential of chemicals as antimicrobial drug candidates is establishment of their effectiveness in an animal model system (12,30). A useful animal model system should be clinically relevant, experimentally robust, ethically acceptable, and convenient to perform and should provide reliable and reproducible results. We report here on a new model in mice that fulfills these criteria. The tape-stripping model has been developed to test the effectiveness of topical antibiotic treatments of superficial skin infections caused by Staphylococcus aureus or Streptococcus pyogenes. S. aureus and S. pyogenes are the most common causative agents of primary skin infections in humans (11,17).The existing mouse models for topical treatment of skin infections are the burnt skin model (1, 32, 36) and the skin suture-wound model (5,14). Either the bacteria are introduced into the skin by injection in a traumatized skin area, as in the burnt skin model, or a bacterium-impregnated nylon suture is implanted into an artificial wound (a scalpel incision through all skin layers), which is then sewn or stapled shut, as in the skin suture-wound model. The area of infection in these models is usually dorsally located to hinder grooming or cleaning by the animal itself. Antibiotics dissolved in cream or ointment can be applied to the wound during the course of the experiment. At the experimental end point, the animal is killed, the infected area of the skin is cut out, and the number of bacteria in the sample is assayed (1,5,14,32,36). These mouse models for skin infections have some disadvantages in relation to superficial infections. The burnt skin model has been developed for studying issues related to infections in burn patients and is ethically unacceptable from an animal welfare perspective for the study of localized skin infections, such as impetigo and erysipelas. The skin suture-wound model involves cutting into the deeper layers of the skin and is thus not clinically relevant to purely topical conditions. Here ...

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Novel photoaffinity labeled fusidic acid analogues were obtained by a synthetic sequence employing a Wittig reaction between a fusidic acid aldehyde and benzyl bromides in the key step. Three commonly used photoreactive groups, benzophenone, trifluoromethyldiazirine, and aryl azide, were used. The photoaffinity labeled fusidic acid analogues demonstrated a potent antibacterial activity (MIC 0.016-4 microg/mL) and therefore represent a potential tool for the elucidation of the interactions between fusidic acid and its receptor EF-G.