贵阳地区儿童重症社区获得性肺炎肺泡灌洗液病原及药敏分析

目的分析贵阳地区儿童重症社区获得性肺炎支气管肺泡灌洗液（BALF）病原学分布及耐药特点。方法收集989例重症社区获得性肺炎患儿临床资料，将支气管肺泡灌液采用支气管镜取出进行细菌培养、病毒以及肺炎支原体(MP)检测。结果（1）989例重症社区获得性肺炎患儿病原检出阳性716例，阳性率72.40%，细菌、病毒、支原体检出率分别33.27% （329例）、22.45%（222例）、31.45%（311例）。（2）细菌感染中的肺炎链球菌、金黄色葡萄球菌为最为常见的革兰阳性菌株(G+)；而肺炎克雷伯菌、大肠埃希菌为最为常见的革兰阴性菌株(G-)。培养菌株对青霉素类、红霉素、第1、2、3代头孢类抗生素有较高的耐药性，对头孢吡肟、拉氧头孢、哌拉西林、左氧氟沙星有较高的敏感性，对亚胺培南、万古霉素、利奈唑烷均无耐药发生。（3）病毒感染检出222例，其中呼吸道合胞病毒131例，腺病毒检测49例，流感病毒6例（A型2例，B型4例），副流感病毒36例（1型3例、2型4例、3型29例），病毒检出率以0～12月龄组最高，RSV、ADV感染主要集中在冬春季节。（4）肺炎支原体检出阳性率31.45%（311例），肺炎支原体检出率以3～5岁组最高。结论贵阳地区重症肺炎中肺炎克雷伯杆菌、肺炎链球菌、大肠埃希菌、金黄色葡萄球菌为重要的细菌病原。重要病毒为腺病毒和呼吸道病毒为主，1～12月龄组的病毒感染检出率比较高。     

The effect of interleukin 6 deficiency on myocardial signal transduction pathways activation induced by bacterial lipopolysaccharide in young and old mice

PurposeExaggerated release of proinflammatory mediators during sepsis contributes to inadequate vasodilatation and depressed myocardial contractility, which lead to development of shock and circulatory collapse. The aim of the study was to evaluate the effect of IL-6 and aging on activation of intracellular signaling pathways in the myocardium induced by bacterial lipopolysaccharide (LPS) administration.Material/methodsLPS was injected intraperitoneally to male 3- and 24-month old mice with systemic IL-6 gene knock-out (IL-6KO) and the reference strain (WT). LPS was given intraperitoneally in single low (0.1 mg/kg) or high (10 mg/kg) dose, or in two doses (0.1 + 10 mg/kg) with 24-h delay. The expression and phosphorylation of STAT3, ERK1/2, Akt1/2/3 proteins in the left ventricular myocardium was evaluated after 24 h using Western blotting.ResultsLow LPS dose induced higher STAT3 phosphorylation only in old IL-6KO mice, not affecting ERK1/2 and Akt1/2/3 phosphorylation in any group. High LPS dose upregulated STAT3 phosphorylation similarly in all groups, reduced ERK1/2 expression in young WT mice and upregulated Akt1/2/3 expression and phosphorylation in young IL-6KO mice. Pretreatment with low LPS dose attenuated phosphorylation of STAT3 in both old groups and phosphorylation of Akt1/2/3 in young IL-6KO group. Two-dose approach also significantly potentiated ERK1/2 phosphorylation in both old groups.ConclusionsObtained results show that IL-6 deficiency alters the activity of intracellular signaling pathways: JAK/STAT in old and Akt in young LPS-treated mice. This may indicate that lack of IL-6 attenuates Akt-related cytoprotective effect of pretreatment with low LPS dose in young but not in aged animals.     

Detection of tumors with fluoromarker-releasing bacteria

Combining the specificity of tumor-targeting bacteria with the sensitivity of biomarker detection would create a screening method able to detect small tumors and metastases. To create this system, we genetically modified an attenuated strain of Salmonella enterica to release a recombinant fluorescent biomarker (or fluoromarker). Salmonella expressing ZsGreen were intravenously administered to tumor-bearing mice and fluoromarker production was induced after 48 hr. The quantities and locations of bacteria and ZsGreen were measured in tumors, livers and spleens by immunofluorescence, and the plasma concentration of ZsGreen was measured using single-layer ELISA. In the plasma, the ZsGreen concentration was in the range of 0.5–1.5 ng/ml and was dependent on tumor mass (with a proportion of 0.81 ± 0.32 ng·ml⁻¹·g⁻¹). No adverse reaction to ZsGreen or bacteria was observed in any mice. ZsGreen was released at an average rate of 4.3 fg·CFU⁻¹·hr⁻¹ and cleared from the plasma with a rate constant of 0.259 hr⁻¹. ZsGreen production was highest in viable tissue (7.6 fg·CFU⁻¹·hr⁻¹) and lowest in necrotic tissue (0.47 fg·CFU⁻¹·hr⁻¹). The mass transfer rate constant from tumor to blood was 0.0125 hr⁻¹. Based on these measurements, this system has the capability to detect tumors as small as 0.12 g. These results demonstrate four essential mechanisms of this method: (i) preferential tumor colonization by bacteria, (ii) fluoromarker release in vivo, (iii) fluoromarker transport through tumor tissue and (iv) slow enough systemic clearance to enable measurement. This bacteria-based blood test would be minimally invasive and has the potential to identify previously undetectable microscopic tumors.     

龙胆泻肝汤对阴道加德纳菌的体外抑制作用

目的研究龙胆泻肝汤对阴道加德纳菌(GV)的体外抑制作用。方法利用稀释法检测龙胆泻肝汤对GV增殖的影响,并测定药物的最低抑菌浓度,通过革兰氏染色法观察龙胆泻肝汤对GV黏附人宫颈癌Hela细胞的影响,MTT法检测龙胆泻肝汤对GV细胞毒性的影响,96孔微量板法检测龙胆泻肝汤对GV生物膜形成的影响,qRT-PCR法检测龙胆泻肝汤对GV BAP、sialidase mRNA表达的影响。结果龙胆泻肝汤水提物、70%醇提物和90%醇提物对GV的最低抑菌浓度分别为(62.5±3.6)、(15.6±1.5)、(125.0±2.8) mg/mL。龙胆泻肝汤70%醇提物(1.56、15.6 mg/mL)能降低GV对Hela细胞的黏附,抑制GV生物膜的形成(P<0.01),下调BAP、sialidase mRNA表达(P<0.05,P<0.01),龙胆泻肝汤70%醇提物(15.6 mg/mL)抑制GV对Hela细胞的毒性作用(P<0.01)。结论龙胆泻肝汤70%乙醇提物能显著抑制GV增殖,并能抑制GV细胞毒性、粘附能力和生物膜形成。     

Antimycobacterial action of a new glycolipid‐peptide complex obtained from extracellular metabolites of Raoultella ornithinolytica

In this paper, an antimycobacterial component of extracellular metabolites of a gut bacterium Raoultella ornithinolytica from D. veneta earthworms was isolated and its antimycobacterial action was tested using Mycobacterium smegmatis. After incubation with the complex obtained, formation of pores and furrows in cell walls was observed using microscopic techniques. The cells lost their shape, stuck together and formed clusters. Surface‐enhanced Raman spectroscopy analysis showed that, after incubation, the complex was attached to the cell walls of the Mycobacterium. Analyses of the component performed with Fourier transform infrared spectroscopy demonstrated high similarity to a bacteriocin nisin, but energy dispersive X‐ray spectroscopy analysis revealed differences in the elemental composition of this antimicrobial peptide. The component with antimycobacterial activity was identified using mass spectrometry techniques as a glycolipid–peptide complex. As it exhibits no cytotoxicity on normal human fibroblasts, the glycolipid–peptide complex appears to be a promising compound for investigations of its activity against pathogenic mycobacteria.     

Actinomycotic Endocarditis of the Eustachian Valve: A Rare Case and a Review of the Literature

Eustachian valve endocarditis caused by Actinomyces species is extremely rare. A literature review revealed only one reported case—caused by Actinomyces israelii in an intravenous drug abuser.Our patient, a 30-year-old woman who at first appeared to be in good health, presented with fever, a large mobile mass on the eustachian valve, and extensive intra-abdominal and pelvic masses that looked malignant. Histopathologic examination of tissue found in association with an intrauterine contraceptive device revealed filamentous, branching microorganisms consistent with Actinomyces turicensis. This patient was treated successfully with antibiotic agents.In addition to presenting a new case of a rare condition, we discuss cardiac actinomycotic infections in general and eustachian valve endocarditis in particular: its predisposing factors, clinical course, sequelae, and our approaches to its management.