老年慢性阻塞性肺疾病急性加重合并肺部感染的病原菌分布及高危因素分析

目的探讨老年慢性阻塞性肺疾病(COPD)急性加重合并肺部感染的病原菌分布及高危因素。方法老年COPD急性加重患者260例按照其肺部感染发生情况分为感染组与非感染组,记录所有患者的临床资料,并对感染组患者进行病原菌分布及高危因素分析。结果 260例老年COPD急性加重患者中共发现30例肺部感染,感染率为11.5%,在感染组30例患者中,共检出病原菌45株,其中革兰阴性菌25株,革兰阳性菌18株,念珠菌2株,排名前4位的病原菌为铜绿假单胞菌、肺炎克雷伯菌、粪肠球菌、金黄色葡萄球菌等。铜绿假单胞菌、肺炎克雷伯菌对红霉素、庆大霉素有比较高的耐药率,而粪肠球菌、金黄色葡萄球菌对左氧氟沙星、美罗培南都比较高的耐药率。单因素回归分析发现感染组与非感染患者的糖尿病史、吸烟、长期使用抗菌药物、长期使用激素、长期卧床等比较差异具有统计学意义(P0.05);多因素非条件Logistic回归分析结果显示糖尿病史(OR=10.593,P=0.000)、吸烟(OR=6.194,P=0.008)、长期使用抗菌药物(OR=3.255,P=0.014)为导致肺部感染的高危因素(P0.05)。结论老年慢性阻塞性肺疾病急性加重合并肺部感染比较常见,病原菌中主要为革兰阴性菌,对多种抗菌药物有耐药性,发病高危因素主要为糖尿病、吸烟与长期使用抗菌药物。     

胸外科患者术后医院感染的病原菌与危险因素分析

目的:分析胸外科患者术后医院感染的病原菌分布及危险因素,为防控医院感染提供数据支持。方法:选择2014年1月至2015年5月医院接受胸外科手术治疗的患者284例进行研究。回顾性分析284例患者的临床病历数据资料以及细菌培养与鉴定的结果,分析医院感染的主要部位及病原菌分布,以及产生医院感染的危险因素。结果:284例患者共有82例发生医院感染,感染率是28.87%,感染部位以呼吸系统为主,占56.10%;检出病原菌88株,革兰阴性菌71株,占80.68%,以铜绿假单胞菌为主,占30.68%。革兰阳性菌17株,占19.32%,以金葡菌为主,占9.09%。单因素分析发现,胸外科术后医院感染与年龄、手术时间、住院时间及糖尿病史有关,差异有统计学意义(P0.05);Logistic回归分析显示,年龄≥60岁、手术时间2 h、住院时间15 d以及有糖尿病史是胸外科术后医院感染的危险因素。结论:胸外科患者术后医院感染的病原菌分布以铜绿假单胞菌与金葡菌为主,应重点防范影响感染的危险因素,以降低感染率。     

无创呼吸机相关性肺炎患者多重耐药菌感染的病原菌和耐药性及危险因素分析CSCD

目的探讨无创呼吸机相关性肺炎患者多重耐药(MDR)菌感染的病原菌分布、耐药性及危险因素。方法选择2017年6月至2022年6月我院的80例无创呼吸机相关性肺炎患者为研究对象进行回顾性分析,统计患者的临床资料和病原菌分布情况,并对病原菌的耐药性进行分析。采用单因素分析和多因素Logistic分析研究MDR感染的危险因素。结果80例患者中MDR感染37例,感染率为46.25%,以鲍曼不动杆菌(43.97%)、肺炎克雷伯菌(20.57%)、铜绿假单胞菌(15.60%)为常见病原菌。药敏试验结果显示,主要革兰阴性菌对哌拉西林/他唑巴坦、庆大霉素、氨苄西林、阿米卡星、头孢呋辛的耐药率较高,对美罗培南、米诺环素、亚胺培南敏感性较高;主要革兰阳性菌对青霉素、环丙沙星、头孢他啶、克林霉素等药物耐药率较高,对万古霉素、利奈唑胺、复方新诺明、利福平敏感性较高。单因素和多因素Logistic回归分析显示,晚发型感染(OR=6.785)、近90 d接受3代头孢菌素治疗以及使用含酶抑制剂的复合制剂或碳青霉烯类抗菌药物(OR=6.781)、经胃鼻管(OR=8.579)、APACHE评分≥15分(OR=8.871)、机械通气时间≥48 h(OR=11.695)是MDR感染的独立危险因(均P<0.05)。结论无创呼吸机相关性肺炎患者MDR感染的主要病原菌有铜绿假单胞菌、鲍曼不动杆菌等,MDR感染的独立危险因素包括晚发型感染、近90 d接受3代头孢菌素治疗等,临床可对具有上述特征的患者进行针对性治疗,从而降低无创呼吸机相关性肺炎患者MDR感染的风险。     

创面分泌物病原菌的分布及危险因素分析

目的分析烧伤外科患者创面分泌物病原菌的分布及感染危险因素,为临床防控提供理论依据。方法采用回顾性分析方法,收集2012年至2014年期间本院烧伤外科住院患者的临床细菌学资料,分析创面病原菌的分布。根据创面分泌物细菌培养结果分为病原菌阴性组和阳性组,对比两组患者临床资料,分析创面分泌物病原菌阳性的相关危险因素,并采用非条件Logistic回归法分析独立危险因素。结果创面分泌物培养401次,阳性结果302次(75.31%)。分离出315株病原菌,其中革兰阳性菌148株(46.98%),革兰阴性菌167株(53.02%)。常见病原菌为:金黄色葡萄球菌(37.46%)、铜绿假单胞菌(23.81%)、大肠埃希菌(8.89%)、粪肠球菌(5.08%)、肺炎克雷伯杆菌(5.08%)。255例患者纳入研究,其中创面分泌物病原菌阴性组92例(36.08%),阳性组163例(63.92%)。单因素分析显示:住院史、危重症、创面深度、难愈性创面、血红蛋白、近期导管植入、近期输液、近期手术、近期抗菌药物治疗是创面分泌物病原菌阳性的相关危险因素(P0.05)。多因素Logistic回归分析显示:难愈性创面和近期抗菌药物治疗是创面分泌物病原菌阳性的独立危险因素(P0.05)。结论创面分泌物病原菌分布广泛,金黄色葡萄球菌和铜绿假单胞菌是常见菌。难愈性创面和近期抗菌药物治疗与创面分泌物病原菌阳性有关。     

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。     

急性呼吸窘迫综合征合并肺部感染患者病原菌构成、耐药性特点及死亡的影响因素分析

摘要 目的：探讨急性呼吸窘迫综合征（ARDS）合并肺部感染患者病原菌构成、耐药性特点及死亡的影响因素。方法：将我院从2017年1月～2020年1月收治的98例ARDS合并肺部感染患者纳入研究。所有患者均开展痰分离培养,并对分离获取的病原菌实施药物敏感试验。此外,统计入院后28 d内死亡患者例数,单因素及多因素Logistic回归分析ARDS合并肺部感染患者死亡的影响因素。结果：98例ARDS合并肺部感染患者共分离出病原菌163株,占比从高到低分别为革兰阴性菌123株占75.46%、革兰阳性菌33株占20.25%、真菌7株占4.29%。其中革兰阴性菌又以铜绿假单胞菌（50株占30.67%）、鲍氏不动杆菌（32株占19.63%）以及肺炎克雷伯菌（21株占12.88%）较为多见。铜绿假单胞菌、鲍氏不动杆菌、金黄色葡萄球菌及溶血葡萄球菌对常见抗菌药物均有不同程度的耐药性,而肺炎克雷伯菌对头孢哌酮/舒巴坦、头孢吡肟、哌拉西林/他唑巴坦及左氧氟沙星的耐药率均为0.00%。多因素Logistic回归分析结果显示：年龄≥60岁、C反应蛋白（CRP）水平升高、降钙素原（PCT）水平升高、急性生理功能和慢性健康状况评分系统Ⅱ（APACHEⅡ）评分≥25分、氧合指数＜80 mmHg、入住内科重症监护室（MICU）时长≥10 d以及机械通气时间≥6 d均是ARDS合并肺部感染患者死亡的危险因素（均OR＞1,P＜0.05）。结论：ARDS合并肺部感染患者病原菌以革兰阴性菌为主,其中肺炎克雷伯菌对头孢哌酮/舒巴坦、头孢吡肟、哌拉西林/他唑巴坦及左氧氟沙星具有较好的敏感性,年龄、CRP、PCT、APACHEⅡ评分、氧合指数、入住MICU时长以及机械通气时间是此类患者死亡的影响因素。     

机械通气患者肺部感染病原菌分布及其影响因素

目的分析机械通气患者肺部感染病原菌分布情况及其感染影响因素,为后续研究提供参考。方法选取2017年2月至2019年2月我院收治的接受机械通气时间大于48 h的115例患者为研究对象,回顾性分析引起肺部感染的病原菌分布和感染相关危险因素。结果 115例患者中,18例经确诊出现肺部感染,占15.65%。感染者中7例死亡,病死率为38.89%。18例肺部感染患者中检出35株病原菌,主要包括6株肺炎克雷伯菌,6株铜绿假单胞菌,5株恶臭假单胞菌,病原菌以革兰阴性菌为主。发生与未发生肺部感染患者的糖尿病史、低白蛋白血症、慢性阻塞性肺疾病史、机械通气时间、插管方式、鼻饲方法、抗生素使用情况、气管切开、定时吸痰和APACHEII评分情况差异有统计学意义(均P0.05)。糖尿病史,低白蛋白血症,慢性阻塞性肺疾病史,机械通气时间,插管方式,鼻饲方法,抗生素使用≥2种,气管切开,定时吸痰,APACHEII评分为影响肺部感染的独立影响因素。结论机械通气患者肺部感染病原菌主要为革兰阴性菌,其次为革兰阳性菌。影响机械通气患者肺部感染的因素较多,应根据患者病史、病情及危险因素采取防护措施。     

肿瘤患者经外周放置中心静脉导管相关性感染的病原菌分布、耐药性及影响因素分析

目的:研究肿瘤患者经外周放置中心静脉导管(PICC)相关性感染的病原菌分布、耐药性,并分析其影响因素。方法:以2016年1月～2019年3月于我院行PICC置管的肿瘤化疗患者450例为研究对象,分析其PICC相关性感染发生情况。采集感染患者标本进行病原学检查,并分析感染病原菌种类、分布情况以及耐药性。同时对PICC相关性感染的影响因素进行分析。结果:450例患者发生PICC相关性感染的人数为40例,占比8.89%。共检出病原菌40株,其中革兰阳性球菌12株,革兰阴性杆菌28株。革兰阳性球菌对万古霉素、利奈唑胺和呋喃妥因均不耐药(0.00%),而对青霉素耐药率最高(100.00%)。鲍曼不动杆菌、铜绿假单胞菌对头孢吡肟、四环素的耐药率最高(100.00%),而鲍曼不动杆菌、铜绿假单胞菌和洋葱伯克霍尔德菌对呋喃妥因、头孢唑林的耐药率最低(0.00%)。经单因素分析发现:穿刺次数、导管留置时间、免疫功能、化疗次数以及是否合并糖尿病均与肿瘤患者PICC相关性感染有关(均P0.05)。经多因素Logistic回归分析显示:穿刺次数≥2次、免疫功能低下、化疗次数≥5次以及合并糖尿病均是肿瘤患者PICC相关性感染的独立危险因素(均P0.05)。结论:PICC相关性感染病原菌分布主要包括革兰阳性球菌与革兰阴性杆菌,临床应针对各病原菌的耐药性合理选择抗菌药物,同时加强对危险因素的干预,以降低PICC相关性感染的发生率。     

住院患者发生院内感染的病原学监测及耐药性分析

目的:探讨住院患者院内感染的危险因素、病原学和耐药性,为加强院内感染控制提供依据。方法:回顾性收集2015年1月至2016年7月我院住院患者5665例,根据患者是否发生院内感染将患者分为感染组(n=238)和非感染组(n=5427),分析院内感染患者临床特征、危险因素、病原菌和病原菌的耐药性。结果:共238例患者发生院内感染,培养出病原菌294株。与非感染组比较,感染组患者糖尿病及慢性阻塞性肺疾病发生率显著升高,身体体重指数显著增加,血红蛋白、红细胞显著降低,深静脉置管显著增加,APPACHEⅡ评分≥5分显著增加,住院时间及长期卧床率显著增加(P0.05)。单因素和多因素logistic回归分析显示糖尿病、深静脉置管、住院时间延长和长期卧床是院内感染的危险因素(P0.05)。院内感染以革兰阴性菌较为常见,占62.93%。最常见的革兰阴性菌为铜绿假单胞菌,占13.61%。最常见的革兰阳性菌为金黄色葡萄球菌,占4.08%。金黄色葡萄球菌对氨苄西林、链霉素和青霉素耐药率均为100%,表皮葡萄球菌对氨苄西林、链霉素、青霉素和阿莫西林/棒酸耐药率均为100%。铜绿假单胞菌对氯霉素、头孢曲松和亚胺培南耐药率分别为100.00%、70.00%和65.00%。结论:我院院内感染的危险因素是糖尿病、深静脉置管、住院时间延长和长期卧床,以革兰阴性菌常见,耐药率较高。     

血液透析患者导管相关性血流感染的病原菌、耐药性以及影响因素分析

目的:研究血液透析患者导管相关性血流感染(CRBSI)的病原菌、耐药性以及影响因素。方法:将我院从2018年1月～2019年1月收治的100例CRBSI血液透析患者纳入研究,记作感染组。通过细菌培养分析病原菌分布情况,以药敏试验观察主要病原菌对常见抗菌药物的耐药性。另取同期于我院接受血液透析未发生CRBSI的患者100例作为无感染组,比较两组临床病理资料,并对血液透析患者CRBSI发生的影响因素进行多因素Logistic回归分析。结果:100例CRBSI患者共分离获取病原菌118株,按照占比从高到低的顺序依次是金黄色葡萄球菌、表皮葡萄球菌、大肠埃希菌、粪肠球菌、鲍氏不动杆菌、铜绿假单胞菌、肺炎克雷伯菌、其它病原菌,占比依次为25.42%、16.95%、15.25%、12.71%、9.32%、8.47%、7.63%、4.24%。金黄色葡萄球菌以及表皮葡萄球菌对万古霉素、替加环素的耐药率均为0.00%,且金黄色葡萄球菌对莫西沙星、庆大霉素的耐药率亦为0.00%。感染组合并基础疾病、导管留置时间≥2周以及股静脉插管人数占比高于无感染组(P0.05)。经多因素Logistic回归分析可得:合并基础疾病以及插管部位为股静脉均是血液透析患者CRBSI的独立危险因素(OR=2.006、1.390,P0.05)。结论:血液透析患者CRBSI病原菌主要为金黄色葡萄球菌、表皮葡萄球菌,上述两种病原菌对万古霉素、替加环素较为敏感,其中金黄色葡萄球菌对莫西沙星以及庆大霉素亦较为敏感。合并基础疾病,股静脉插管均会增加CRBSI发生的风险,值得临床重点关注。     

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.