自上世纪90 年代以来, 多耐药非发酵革兰阴性杆菌开始成为医院感染的重要病原菌, 并迅速增加, 其中不动杆菌( Acinetobacter) 尤其令人关注。鲍曼不动杆菌( Acinetobacter baumannii) 或称鲍曼-醋酸钙不动杆菌复合群, 占不动杆菌的80% ~90% , 是不动杆菌中引起人类感染的主要菌群, 具有极强的环境适应能力、获得外源性耐药基因的能力及播散性, 因而被称为21 世纪革兰阴性菌中的“耐甲氧西林金黄色葡萄球菌( MRSA) ”, 值得引起临床医生的重视。
抗生素的降阶梯治疗(de-escalation therapy)是近年来提出的用于治疗重症肺部感染的一个策略,在临床研究和实践中能够有效地提高重症感染治疗的成功率,降低病死率,同时降低住院时间和费用,是感染治疗策略的一大进展。本文就这一策略的概念演变和应用时机作一介绍
随着免疫抑制人群的增多、检测技术的发展, 深部真菌感染日益受到人们的关注。真菌中的曲霉属成了这些免疫功能低下患者致病性感染的重要原因, 而烟曲霉在侵袭性曲霉病例中最常见。侵袭力是烟曲霉菌极为重要的致病原因;病原菌侵入上皮、内皮细胞等组织细胞后才导致了可怕的侵袭性感染。从上世纪90 年代来, 对于侵袭的研究已逐步深入, 为探讨复杂的致病机制打下了基础。侵袭性烟曲霉病一般的致病过程认为是烟曲霉孢子被宿主吸入下呼吸道, 侵入呼吸道上皮细胞后发育成菌丝, 菌丝进一步生长, 可侵入血管、进入血液, 造成全身播散[ 1] 。因此曲霉与宿主细胞( 上皮细胞、内皮细胞等) 的相互作用成了致病过程的重要环节。目前对病原体与宿主细胞作用的研究取得了一些进展, 对阐明致病机制、研究治疗靶点等有重要意义。
In recent years, with the wide application of metagenomics next-generation sequencing, more and more rare pathogens have been detected in our clinical work, including non-tuberculous Mycobacterium, Corynebacterium, Fusarium, Cryptococcus pneumoniae, human herpes virus, torque teno virus, parvovirus, Tropheryma whipplei, Bartonella, Chlamydia psittaci, etc. It is difficult to determine whether these rare pathogens are clinically significant and need treatment. This article puts forward some suggestions and discussions on the diagnosis and treatment of pulmonary infections with some rare pathogens.
Objective To investigate changes of TLR2 mRNA expression in lung of a mouse model of Chlamydia Pneumoniae pneumonitis, and to explore the possible mechanism of signal transduction. Methods Ninety-six male C3H/HeJ mice were randomly divided into four groups as follows: a control group, a model group, a SB203580 intervened group, and a pyrrolidine dithiocarbamate( PDTC) intervened group. Chlamydia Pneumoniae pneumonitis was induced by intranasally inoculated with 4. 0 ×106 IFU/mL of C. Pneumoniae per mouse in the model group and two intervened groups. Then the intervened groups were intraperitoneally injected with the p38MAPK inhibitor SB203580 and nuclear factor kappa B ( NF-κB)inhibitor PDTC, respectively. Six mice in each group were randomly killed in 1st, 4th, 7th and 14th day. The expressional changes of TLR2 mRNA in the mice lung tissue were measured by semi-quantitative RT-PCR. The concentrations of TNF-α in the lung homogenate were measured by ELISA. Results TLR2 mRNA expression in the lung tissue significantly increased after C. Pneumoniae infection, peaking at 4th and 7th days, then decreased after 14th day. Tumor necrosis factor-α( TNF-α) was also elevated in the lung tissue after C. Pneumoniae challenging. Both SB203580 and PDTC treatment effectively inhibited TNF-αand TLR2 mRNA expressions in lung. The inhibitory effect was more obvious by SB203580 treatment. Conclusion C. Pneumoniae can upregulate the expressions of TLR2 and TNF-α in lung, and TLR2/MAPK and TLR2 /NF-κB signal pathways may be involved in Chlamydia Pneumoniae pneumonitis.