目的 探讨我国南方地区鲍曼不动杆菌流行株ST457毒力进化方向。方法 收集南方地区5家大型三甲医院2012年—2015年血和/或痰标本来源的鲍曼不动杆菌菌株,运用不同毒力实验,比较ST457与其他CC92流行克隆株与非流行克隆株的毒力差异。结果 ST457感染患者早期死亡率高;ST457菌株平均产生物膜能力低于ST195和ST208;83.3%的鲍曼不动杆菌临床分离菌株在血清的存活率大于60%,其中43.3%的菌株可在血清内快速繁殖,不同ST型组间、菌血症组和非菌血症组间无差异;不同ST型菌株竞争后,ST457未展现出竞争优势。结论 与传统CC92流行株相比,ST457毒力表型与传统的CC92流行株类似,提示CC92克隆株共进化能力。部分流行株短时间内在血清中快速繁殖,提示其条件致病后潜在的血流感染的能力。

Objective To investigate the virulence of the prevalent clone ST457 of Acinetobacter baumannii in Southern China. Methods Isolates from sputum and/or blood samples from 2012 to 2015 in 5 large differences between clonal complex 92(CC92) and non-CC92 were estimated by biofilm assay, competition assay and serum assay. Results Patients with ST457 infection had high early mortality. The average biofilm production of ST457 was significantly lower than that of ST195 and ST208. In serum assay, 83.3% isolates survived in the serum with over 60% survival rate, of which 43.3% strains reproduced in the serum, with no difference between STs or between bacteremia and non-bacteremia group. After competing with different ST strains, ST457 shows no competitive advantage. Conclusions ST457 had a similar virulence phenotype with the traditional prevalent CC92 clone, suggesting the co-evolutionary ability for CC92 clone. Some clinical isolates were survived in human serum, suggesting the potential capacity of bloodstream infection.

目的 探讨血必净注射液对SAP大鼠TLR4信号通路介导肠黏膜屏障功能障碍的影响。方法 24只SD大鼠随机分成空白组(n=8)、对照组(n=8)和治疗组(n=8)。对照组和治疗组用4.5%牛磺胆酸钠溶液胆胰管逆行注射制备SAP模型,空白组采用等量生理盐水逆行注射。治疗组在造模3 h后经鼠尾静脉注射血必净注射液(3 mL/kg)。三组大鼠造模后观察24 h,然后处死取胰腺和小肠组织送病理检查,采用荧光RT-PCR技术检测TLR4和NF-κB表达水平,采用ELSIA法检测血清TNF-α、IL-6、淀粉酶(AMS)及二胺氧化酶(DAO)水平,比较三组大鼠各项指标。结果 对照组和治疗组小肠组织TLR4和NF-κB表达以及血清TNF-α、IL-6、AMS及DAO水平均高于空白组(P>0.05),治疗组小肠组织TLR4和NF-κB表达以及血清TNF-α、IL-6、AMS及DAO水平低于对照组(P＜0.05)。结论 血必净注射液通过干预SAP大鼠TLR4信号通路,降低小肠组织TLR4和NF-κB的表达,减轻小肠组织的炎症反应,对肠黏膜屏障具有一定的保护作用。

Objective To investigate the effect on intestinal mucosal barrier dysfunction (IBF) of Xuebijing injection mediated by Toll-like receptor 4 (TLR4) signal pathway in rats of severe acute pancreatitis (SAP). Methods 24 Sprague Dawley (SD) rats were randomly divided into Sham group (n=8), control group (n=8) and treatment group (n=8). The SAP model was established by retrograde injection of 4.5% sodium taurocholate into the biliopancreatic duct in control group and treatment group, while control group was injected with the same amount of saline. In treatment group, Xuebijing injection (3 mL/kg) was injected via tail vein after 3h of modeling. All rats were monitored and sacrificed after 24 hours of modeling. Samples of pancreas and intestine were collected for pathologic determination. A fluorescent RT-PCR was used to determine the expression of TLR4 and NF-κB of small intestine. The serum levels of TNF-α, IL-6, amylase (AMS) and diamine oxidase (DAO) were measured by using ELISA. All parameters of three groups were compared. Results The expression of TLR4 and NF-κB of small intestine in control group and treatment group were higher than it in control group (P<0.05), as well as the serum levels of TNF-α, IL-6, AMS and DAO (P<0.05). The expression of TLR4 and NF-κB of small intestine in treatment group were lower than it in control group (P<0.05), as well as the serum levels of TNF-α, IL-6, AMS and DAO (P<0.05). Conclusion Xuebijing injection may not only reduce the expression of TLR4 and NF-κB of small intestine, but also alleviate the inflammation reaction of small intestine by interfering with TLR4 signal pathway, which may have a protective effect on intestinal mucosal barrier in SAP rats.