The mouse peritonitis model: present and future use.

The mouse peritonitis model was the first experimental animal model to be used in antibiotic research in 1935, where it proved the effect of Prontosil and derivative sulphonamides against Streptococcus pyogenes in vivo. Since then the mouse peritonitis model has been a natural step in testing antibiotics in vivo before moving to larger animals or humans. Only a few bacteria are naturally virulent to mice, e.g. Streptococcus pneumoniae, but the mice can be rendered susceptible to most human pathogens by inhibition of one or more parts of the natural defence of the animals. For measuring the effect of antibiotics two parameters are usually considered: bacterial counts in fluids or tissues, or death/survival of the animal. Both parameters have flaws, but death is usually used, owing to the ease of observation and quantification by calculation of the 50% effective (protective or curative) doses. With these parameters a number of significant factors of importance for antibiotic effect have been detected or proven in this model. Together with the recent insight into the correlation of pharmacokinetic behaviour between these small animals and man, it is predicted that the mouse peritonitis model will continue to be an important means of studying the effect of antibiotics in vivo.