耐甲氧西林金黄色葡萄球菌皮肤脓肿小鼠感染模型的建立与评估

Establishment and Evaluation of a Mouse Model of Skin Abscess by Infection with an Isolated Methicillin-Resistant Staphylococcus aureus(MRSA) Strain

目的建立耐甲氧西林金黄葡萄球菌(methicillin-resistant Staphylococcus aureus,MRSA)小鼠皮肤脓肿感染模型,观察脓肿形成动态变化及药物对脓肿愈合的影响。方法 45只SPF级裸鼠随机分为PBS对照组、感染组及给药组,用临床分离鉴定的ST-239型MRSA菌株皮下注射感染裸鼠,对脓肿的形成过程进行时相性观察,测定脓肿体积的变化,并通过H.E染色观察皮肤的组织病理学改变。结果 PBS处理组小鼠皮肤无脓肿形成,显微镜下皮肤各层结构清楚;感染组和给药组可见到典型的脓肿,临床症状的时相性过程明显,感染组小鼠皮肤真皮层的胶原纤维消失,可见大量炎性细胞浸润,给药组小鼠的脓肿体积在整个实验周期内低于感染组,且在第5天时与感染组相比有差异。结论成功建立MRSA小鼠皮肤脓肿感染模型,该模型的建立可为进一步研究来源于临床MRSA菌株的病原特性、发病机制、治疗方法等提供可靠的动物模型。

Objective To establish a skin abscess model in nude mice by infection of a clinically isolated methicillin-resistant Staphylococcus aureus（MRSA） strain,and evaluate the dynamics of abscess formation and drug effect.Methods Forty-five specific pathogen free nude mice were randomly divided into three groups： the PBS,MRSA-infected and durg-treated infected groups.All the mice were inoculated by subcutaneous injection of MRSA suspension and the kinetics of abscess formation was monitored.The clinical changes and abscess volume were examined during the whole experimental period.Finally,the abscesses in different groups were examined and compared by histopathological observation using HE staining.Results There were no skin abscess formed in the PBS group during the experimental period.Skin abscesses were observed in the MRSA-infected and drug-treated MRSA-infected groups.The volume of skin abscess was higher in the MRSA-infected mice than that in the drug-treated MRSA-infected animals.Moreover,severe histopathologic changes were observed in the MRSA-infected mice.Conclusion A nude mouse model of skin abscess has been successfully established by MRSA-infection.This model will provide a useful tool for studies on the pathogenic characteristics and pathogenesis of skin abscess caused by MRSA infection,and promote the development of effectivetherapeutic approaches in the future.