RESUMO
BACKGROUND: Open facture is easy to induce infection, which is an urgent problem in clinic. Establishing a reliable animal model of open fracture with infection is of great significance for drug and instrument development and application. OBEJCTIVE: To develop an open fracture with infection model in New Zealand white rabbits, and to identify the available number of bacteria that can cause infection. METHODS: The amount of bacteria was determined by establishing open fracture structure and verifying the concentration of bacterial colonies. Thirty New Zealand white rabbits were randomly divided into control group and four experimental groups, and a transverse fracture at the middle part of tibia was established in all rabbits,followed by the injection of 1 mL of normal saline or 1mL of Staphylococcus aureus suspension at the concentrations of 1×105, 1×106, 5×106, and 1×107CFU/mL. Afterwards, the optimal concentration of 1 mL of bacteria liquid causing infection was determined by gross observation, body temperature analysis and body mass measurement, white blood cell and C-reactive protein detection, bacterial culture and pathological observation. RESULTS AND CONCLUSION: Rabbits in the 5×106CFU/mL group were all infected and had higher survival rate. In the 1×105and 1×106CFU/mL groups, some rabbits showed no infection. One rabbit died due to infection in the 1×107CFU/mL group. In summary, the reliable infection model of open fracture can be induced by injected with 1 mL of Staphylococcus aureus at the concentration of 5×106CFU/mL in New Zealand white rabbits, which can be used as an effective model to guide drugs and instruments related anti-infective research.