社区获得性肺炎并发革兰阴性菌感染的病原菌分布及危险因素分析

目的:探讨社区获得性肺炎(CAP)并发革兰阴性菌感染的病原菌分布及危险因素,以降低感染率。方法:选择2013年6月到2015年6月我院确诊CAP患者80例,收集所有患者的临床资料,分析CAP并发革兰阴性菌感染的病原菌分布及危险因素。结果:CAP并发革兰阴性菌感染的病原菌以肺炎克雷伯菌株数最多,13株(占30.23%),其次为大肠埃希菌8株(占18.60%)和鲍曼不动杆菌7株(占16.28%)。感染阳性组入院治疗前使用抗生素、白细胞水平异常、PORT≥3级以及血尿素氮水平7.1 mmol/L的比例较感染阴性组显著更高,差异均有统计学意义(均P0.05)。由Logistic回归分析可知,入院治疗前使用抗生素、白细胞水平异常、PORT≥3级以及血尿素氮水平7.1 mmol/L均为影响CAP患者发生革兰阴性菌感染的危险因素。结论:CAP并发革兰阴性菌感染的病原菌主要以肺炎克雷伯菌,大肠埃希菌和鲍曼不动杆菌为主,临床上应重视CAP并发革兰阴性菌感染危险因素,以降低感染率。     

407例老年肺癌下呼吸道感染患者病原菌分布及耐药分析

目的 分析老年肺癌下呼吸道感染患者痰培养物的病原菌分布及耐药状况.方法 回顾性分析407例老年肺癌下呼吸道感染患者痰标本细菌培养、鉴定及药敏结果.结果 共分离出病原菌238株,革兰阴性菌163株,占68.49％;革兰阳性菌33株,占13.87％;真菌42株,占17.65％.主要病原菌为肺炎克雷伯菌、大肠埃希菌、铜绿假单胞菌、鲍曼不动杆菌、表皮葡萄球菌和金黄色葡萄球菌.其中,肺炎克雷伯菌和大肠埃希菌ESBLs阳性菌株的比例分别为36.73％、28.85％.结论 老年肺癌患者因长期使用抗生素,呼吸道菌群失调,不同病原菌对抗菌药耐药率均较高,以革兰阴性菌感染为主,肺炎克雷伯菌和大肠埃希菌产ESBLs的菌株有较高比例,二重感染比例较高;革兰阳性菌均对万古霉素敏感,未发现耐药菌株.因此临床医生根据药敏结果合理选用抗生素,对于改善患者肺部微生态失衡,延长生存时间具有重要指导意义.     

梗阻性黄疸患者经内镜逆行胰胆管造影术后胆道感染的病原菌分布、耐药性及影响因素分析

目的:探讨梗阻性黄疸患者经内镜逆行胰胆管造影(ERCP)术后胆道感染病原菌分布、耐药性以及导致术后胆道感染的影响因素。方法:选择2016年3月至2019年10月我院收治的310例行ERCP治疗的梗阻性黄疸患者,根据ERCP术后是否发生胆道感染将其分为感染组(50例)和未感染组(260例)。检测胆道感染患者病原菌种类及其耐药性,多元Logistic回归分析影响梗阻性黄疸患者ERCP术后胆道感染的影响因素。结果:ERCP术后胆道感染发生率为16.13%,大肠埃希菌、铜绿假单胞菌、粪肠球菌、屎肠球菌是主要致病菌,检出率分别为40.79%、13.16%、9.21%、6.58%。大肠埃希菌、铜绿假单胞菌对头孢类、氨基糖苷类抗生素耐药率高,粪肠球菌、屎肠球菌对利福平、喹诺酮类抗生素耐药率高,大肠埃希菌、铜绿假单胞菌、粪肠球菌、屎肠球菌均对利奈唑胺、亚胺培南敏感。多元Logistic回归分析结果显示,恶性病变、ERCP2次及以上、胆胰管汇流异常、术后胆管引流不畅是梗阻性黄疸患者ERCP术后胆道感染的危险因素(P0.05),术后预防性使用抗生素是保护因素(P0.05)。结论:梗阻性黄疸患者ERCP术后存在一定胆道感染风险,革兰氏阴性菌是主要致病菌,临床应注重对高危因素预防,有必要术后选择敏感抗生素预防性治疗。     

119例胆道感染患者胆汁病原菌分布及耐药性分析

目的探讨胆道感染患者胆汁培养的病原菌的分布及耐药性,为临床医师有针对性的选择抗菌药物治疗胆道感染提供依据。方法对2010年6月至2012年6月119例胆道感染患者胆汁中分离得到的菌株进行回顾性分析。结果 119例胆道感染患者的胆汁标本中共分离出病原菌80株,阳性检出率为67.2%。其中,检出的革兰阴性杆菌57株,占71.3%;革兰阳性球菌14株,占17.5%,真菌9株,占11.2%。排名病原菌前3位的分别为大肠埃希菌(36.3%)、粪肠球菌(13.8%)、肺炎克雷伯杆菌(12.5%);大肠埃希菌及肺炎克雷伯杆菌对美罗培南的耐药率分别为3.4%和0.0%、哌拉西林/他唑巴坦及阿米卡星的耐药率均是6.9%和10.0%。肺炎克雷伯杆菌对左氧氟沙星的敏感率明显高于大肠埃希菌,分别为64.4%与38.4%。头孢菌素类药物中头孢噻肟的耐药率最高,分别是72.4%和60.0%。粪肠球菌除对糖肽类万古霉素及替考拉宁的敏感率为100.0%外,对其他抗菌药物均有一定的耐药性。在检测出的39株大肠埃希菌和肺炎克雷伯杆菌中分离到产ESBLs细菌17株,阳性检出率为43.6%。结论摒弃经验性用药、避免预防性用药、增加标本送检率、结合药敏结果合理选择抗菌药物以及规范手术操作,才能达到提高治疗胆道感染成功率的目的。     

235例泌尿系统感染的病原菌分布及药敏分析

目的:了解本地区泌尿系统感染的病原菌分布情况,指导临床合理使用抗生素.方法:细菌鉴定及药敏试验采用VITEK-60全自动细菌鉴定仪.结果:革兰阴性菌是本地区泌尿系统感染的主要致病菌70.64%(166/235),其中大肠埃希菌占革兰阴性菌的66.87%(111/166),其次为克雷伯菌属10.84%(18/166).主要致病革兰阳性菌以葡萄球菌为主38.7%(24/62).革兰阴性菌对环丙沙星、左氧氟沙星和甲氧苄啶/磺胺甲恶唑耐药率高,革兰阳性菌对氨苄西林/舒巴坦、环丙沙星和甲氧苄啶/磺胺甲恶唑等 8种抗生素耐药率均偏高.治疗首选万古霉素、呋哺类、利福平等抗生素.结论:大肠埃希菌是本地区泌尿系统感染的主要病原菌.细菌对多种抗生素耐药,建议临床根据药敏结果使用抗生素.     

泌尿外科住院患者泌尿系感染病原菌分布及其耐药性分析

了解泌尿外科住院患者泌尿系感染病原菌的分布及其对常用抗菌药物的耐药情况。对泌尿外科泌尿系感染住院患者的消毒中段尿培养结果进行回顾性分析,尿培养菌株的鉴定、药敏分析和统计分析采用VITEK2全自动微生物仪。3 a中泌尿外科泌尿系感染住院患者共分离到细菌1 233株,其中革兰阴性杆菌772株,占62.61%,革兰阳性球菌353株,占28.63%,真菌82株,占6.65%。菌株数居前5位的细菌依次为:大肠埃希菌、肠球菌属、洋葱伯克霍尔德菌、假丝酵母菌属和变形杆菌。分离大肠埃希菌产ESBLs率为66.18%,粪肠球菌中未发现VRE菌株,屎肠球菌VRE为0.8%。未发现对美洛培南耐药的大肠埃希菌,对肠埃希菌耐药率在10%以下的有亚胺培南、阿米卡星、哌拉西林/他唑巴坦和呋喃妥因。洋葱伯克霍尔德菌和铜绿假单胞菌对所监测的抗菌药物均有不同程度的耐药。未发现对万古霉素、替考拉宁及氨苄西林耐药的粪肠球菌。泌尿系感染的病原菌以大肠埃希菌和肠球菌为主,非发酵革兰阴性杆菌及假丝酵母菌所占比例超过20%,不容忽视,病原菌的耐药率较高,临床医生应根据尿培养和药敏试验结果合理使用抗菌药物。     

医院血流感染病原菌分布及耐药性分析

目的了解医院血流感染病原菌的分布及其耐药性,为临床治疗提供参考。方法收集2013年1月至12月浙江中医药大学附属第一医院患者血培养标本,采用WHONET 5.6软件对所分离的病原菌及药敏结果进行统计分析。结果 2 017份血培养标本共检出病原菌370株,阳性率为18.34%,其中革兰阳性菌142株占38.38%,革兰阴性菌213株占57.57%,真菌15株,占4.05%。排名前5位病原菌依次是凝固酶阴性葡萄球菌、大肠埃希菌、肺炎克雷伯菌、肠球菌属和金黄色葡萄球菌,分别占19.73%、17.03%、13.51%、6.22%和4.59%。除哌拉西林/他唑巴坦对大肠埃希菌和铜绿假单胞菌仍保持较高的抗菌活性外,革兰阴性菌尤其是肺炎克雷伯菌对多种药物均产生了严重耐药性,其中产ESBLs大肠埃希菌和肺炎克雷伯菌分别占46.80%和20.00%。革兰阳性菌对利奈唑胺100%敏感,检出耐甲氧西林金黄色葡萄球菌(MRSA)4株,占25.00%,耐甲氧西林凝固酶阴性葡萄球菌(MRCNs)占92.00%,耐万古霉素的表皮葡萄球菌1株和耐万古霉素的粪肠球菌3株。结论血流感染病原菌分布复杂,以革兰阴性菌为主,耐药率高,且已出现耐万古霉素的表皮葡萄球菌和粪肠球菌,因此,进行早期监测和耐药性分析非常必要,对控制感染、指导合理使用抗菌药物,减缓耐药菌株的出现具有重要的临床意义。     

脊柱外科术后病原菌感染分析

目的研究并分析脊柱外科术后病原感染情况以及干预措施。方法选取我院2015-2020年接受脊柱外科手术治疗并发生术后感染的患者183例为研究对象,使用生理盐水对患者手术切口进行擦拭,收集患者血液、分泌物、穿刺液并送检,并对病原菌进行培养与鉴别并进行药敏试验。根据试验结果选择合适的药物进行干预。结果183例患者发生感染的主要类型是切口感染(105例,57.4%),共分离出143株病原菌。其中:75株革兰阳性菌,占52.4%;60株革兰阴性菌,占42.0%;8株真菌,占5.6%。革兰阳性菌对万古霉素(VA)无耐药性,肺炎克雷伯菌对环丙沙星(CIP)、亚胺培南(IPM)和头孢哌酮/舒巴坦(SCF)无耐药性,大肠埃希菌对亚胺培南(IPM)无耐药性。结论脊柱外科术后感染中切口是感染主要部位,金黄色葡萄球菌和肺炎克雷伯菌是主要病原菌,可以使用VA治疗金黄色葡萄球菌感染,使用CIP、IPM、SCF治疗肺炎克雷伯菌感染。     

老年女性泌尿系统感染患者的病原菌分布及耐药情况研究

目的通过对老年女性泌尿系统感染患者病原菌类型和耐药情况进行研究,为临床合理、安全、有效使用抗菌药物提供依据。方法收集2014年9月至2017年7月在我院进行诊治的661例老年女性泌尿系统感染患者,对其清晨清洁中段尿进行细菌培养并进行耐药试验。结果 661例样本中共分离出病原菌255株,其中革兰阴性菌165株,占64.7%,以大肠埃希菌为主,构成比为45.5%;革兰阳性菌77株,占30.2%,以屎肠球菌为主,构成比为10.2%;真菌13株,占5.1%。G-菌中检出率排在前三的依次是大肠埃希菌、肺炎克雷伯菌、奇异变形杆菌。大肠埃希菌、肺炎克雷伯菌对氨苄西林、复方新诺明耐药性较高,奇异变形杆菌对头孢唑啉耐药性较高,三者均对亚胺培南敏感性较高。G+菌中检出率排在前三的依次是屎肠球菌、表皮葡萄球菌、粪肠球菌。三种病原菌对青霉素、氨苄西林、环丙沙星耐药性较高,对万古霉素、替考拉宁敏感性较高。结论老年女性泌尿系统感染患者的病原菌多数为革兰阴性菌,且以大肠埃希菌为主,病原菌培养和耐药试验对于临床合理有效地使用抗菌药物具有重要的指导意义。     

胫腓骨开放性骨折术后并发感染的病原菌分布、耐药性及影响因素分析

目的:研究胫腓骨开放性骨折术后并发感染患者的病原菌分布、耐药性及影响因素。方法:回顾性分析2014年1月到2018年1月于华北石油管理局总医院接受治疗的267例单侧胫腓骨开放性骨折患者的临床资料,统计术后感染病例,分析胫腓骨开放性骨折术后感染患者的病原菌分布情况,分析主要革兰阳性菌和主要革兰阴性菌的耐药性,采用单因素和多因素Logistic回归分析术后患者发生感染的危险因素。结果:267例患者发生术后感染68例,感染率为25.47%;68例患者共分离出病原菌82株,其中革兰阳性菌占64.63%,革兰阴性菌占28.05%,真菌占7.32%;金黄色葡萄球菌、表皮葡萄球菌、粪肠球菌对青霉素、哌拉西林/他唑巴坦耐药性较高,对万古霉素、亚胺培南比较敏感;大肠埃希菌、阴沟肠杆菌、铜绿假单胞菌、鲍氏不动杆菌对头孢唑林耐药性较高,对亚胺培南和头孢哌酮/舒巴坦比较敏感;单因素分析显示:受伤原因、骨折部位、有无合并糖尿病、受伤至手术时间、清创情况、止血情况、引流情况、术后有无使用抗菌药物均是导致胫腓骨开放性骨折术后发生感染的相关因素(P0.05);多因素Logistic回归分析显示:受伤至手术时间6 h、清创不彻底、止血不彻底、引流不通畅、术后未使用抗菌药物均是导致胫腓骨开放性骨折术后发生感染的危险因素(P0.05)。结论:胫腓骨开放性骨折患者术后感染以革兰阳性菌为主,其对青霉素、哌拉西林/他唑巴坦敏感性较低,临床上应针对危险因素采取有效预防措施,并根据药敏试验选择有效药物治疗。     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.     

Composition and diversity of bird communities in Swedish farmland–forest mosaic landscapes

CapsuleThe amount of forest (at local and landscape scales) and occurrence of residual habitats at the local scale are shown to be the major factors influencing bird community composition in farmland–forest landscapes in central Sweden.

Aims To investigate the importance of local habitat and landscape structure for breeding birds in farmland–forest landscapes in central Sweden.

Methods Breeding birds were censused at 292 points. A detailed habitat mapping was made within 300 m of the points. Within a 300–600 m radius only two major habitats (forests and arable fields) were identified.

Results Cluster analyses of bird communities identified three site types that also differed in habitat composition: (i) partially forested sites in forested landscapes; (ii) heterogeneous sites with residual habitats in mosaic landscapes; and (iii) field-dominated farmland sites in open landscapes. A total of 19 of 25 farmland bird species (restricted to farmland or using both farmland and forest) had the highest abundance in farmland sites with mosaics of forest and farmland, while only six farmland species had the highest abundance in field-dominated sites. The bird community changed from being dominated by farmland species to being dominated by forest species (common in forest landscapes without farmland) at small proportions (10–20%) of forest at the local scale. A major difference in habitat composition between heterogeneous and field-dominated sites was the occurrence of different residual habitats (e.g. shrubby areas and seminatural grasslands). These habitats seemed to influence bird community composition more than land-use, despite covering <10% of the area. Seminatural grasslands were important for bird community composition and species-richness, but grazing seemed to be less important. Among different land-use types, cereal crops were the least preferred fields. Set-asides with tall vegetation and short rotation coppices were positively associated with species-richness of farmland birds.

Conclusion In general, the composition of the landscape was important for bird community composition, although amount and distribution of forests, occurrence of residual habitats and land-use of fields at the local scale had the strongest influence on bird community composition. The possible implications of these patterns for managing farmland–forest landscapes are discussed.     

Chemical constituents from the fruits of Rhus typhina L. and their chemotaxonomic significance

This work describes the isolation and characterization of twenty-nine compounds from the fruits of Rhus typhina L., including eleven flavonoids (1–11), eleven phenols (12–22), two pentacyclic triterpenes (23–24), two organic acids (25–26), one lumichrome (27), one courmarin (28) and one pyrimidine (29) on the basis of their spectroscopic data. Compounds apigenin (1), daidzein (4), orobol (5), 3′, 5, 5′, 7-tetrahydroxyflavanone (6), naringenin (7), butein (8), (-)-catechin (9), quercetin-3-O-α-L-(3″-O-galloyl)-rhamnoside (11), 2-hydroxybenzoic acid (13), 4-hydroxybenzaldehyde (14), vanillin (15), methyl 3,4-dihydroxybenzoate (16), 3,5-dihydroxybenzamide (18), tyrosol (19), caffeic acid (20), 3-(2,4,6-trihydroxyphenyl)-1-(4-hydroxyphenyl)-propan-1-one (21), phlorizin (22), friedelin (23), oleanolic acid (24), 4,4-dimethyl-heptanedioic acid (25), anthranilic acid (26), lumichrome (27), scoparone (28) and uracil (29) have not been recorded before in this plant. This is the first report on the occurrence of compounds 4–7, 9, 11, 13–14, 16, 18–21, 25–29 from the genus Rhus. Moreover, the chemotaxonomic significance of these isolated compounds was also summarized.