858例血感染患者病原菌分布及耐药情况

目的:通过对某地区中心医院收集的临床血感染患者感染病原菌的分析,了解该地区血感染患者病原菌构成、分布及耐药特点,为临床治疗提供参考和指导。方法:收集2012年6月至2013年8月期间在某院就诊的858例血感染患者血液标本,采用BACTEC9050全自动血培养仪培养,采用VITEK 2 Compack系统和K-B琼脂纸片扩散法对阳性标本进行菌种鉴定和药敏检测。结果:血培养结果显示,在858份血培养标本中共检出阳性标本109份,每份标本都只检出一种病菌,总检出率为12.7%,革兰阳性菌占64.22%(70/109),革兰阴性菌占33.03%(36/109),真菌占0.35%%(3/109);药物敏感试验结果显示:葡萄球菌对青霉素、红霉素和复方新诺明耐药率40%;肠杆菌科细菌对氨苄西林和氯霉素耐药率40%;非发酵菌科细菌对氨苄西林,头孢他啶,头孢噻肟和氯霉素耐药率40%。结论:目前本地区临床血感染患者革兰阳性菌感染率高,以金黄色葡萄球菌和凝固酶阴性葡萄球菌为主,治疗可以首选糖肽类抗菌药物;革兰阴性菌以大肠杆菌和绿脓杆菌为主,对氨苄西林、氯霉素耐药率高,大肠杆菌对头孢类抗生素的耐受较绿脓杆菌低,两种细菌感染治疗可以考虑选择单环-内酰胺类抗生素。及时准确的血培养结果及药敏试验可为临床合理选择抗菌药物提供重要依据。     

Species identification in the genus Saprolegnia (Oomycetes): Defining DNA-based molecular operational taxonomic units

The lack of a robust taxonomy in the genus Saprolegnia is leading to the presence of incorrectly named isolates in culture collections and of an increasing number of misassigned sequences in DNA databases. Accurate species delimitation is critical for most biological disciplines. A recently proposed approach to solve species delimitation (taxonomic diagnosis system) of difficult organisms is the definition of molecular operational taxonomic units (MOTUs). We have used 961 sequences of nrDNA ITS from culture collections (461 sequences) and GenBank (500 sequences), to perform phylogenetic and clustering optimization analyses. As result, we have identified 29 DNA-based MOTUs in agreement with phylogenetic studies. The resulting molecular clusters support the validity of 18 species of Saprolegnia and identify 11 potential new ones. We have also listed a number of incorrectly named isolates in culture collections, misassigned species names to GenBank sequences, and reference sequences for the species. We conclude that GenBank represents the main source of errors for identifying Saprolegnia species since it possesses sequences with misassigned names and also sequencing errors. The presented taxonomic diagnosis system might help setting the basis for a suitable identification of species in this economically important genus.     

血流感中的病原菌分布及耐药性分析

目的了解血流感染中的病原菌种类、分布及耐药性,为临床合理选用抗菌药物提供依据。方法按照无菌操作方法采集疑为血流感染患者的血液标本进行血培养,采用美国BD公司PHOENIX-100全自动细菌鉴定药敏系统进行细菌鉴定及药敏试验,并对结果进行统计分析。结果共检出1080株病原菌,其中革兰阴性杆菌630株（占58．3％）,革兰阳性球菌428株（占39．6％）,真菌22株（占2．1％）。药敏结果显示：革兰阳性球菌对万古霉素、利奈唑胺敏感率最高,对青霉素、红霉素、头孢菌素等耐药率较高。革兰阴性杆菌对碳青霉烯类、哌拉西林／他唑巴坦、头孢哌酮／舒巴坦敏感率较高,对青霉素类、头孢菌素类和喹诺酮类耐药率较高。结论引起血流感染的病原菌分布复杂,耐药率较高,临床应提高血培养送检率,根据药敏结果合理选用抗菌药物,以减少多重耐药菌的发生和传播。     

系统性红斑狼疮合并感染病原菌与降钙素原的相关性分析

目的探讨降钙素原（PCT）在判断系统性红斑狼疮（SLE）合并感染病原菌中临床价值。方法采用回顾性研究,选取2011年1月至2013年6月住院的SLE合并感染患者98例。研究各种病原菌与PCT浓度的相关性,计算SLE合并感染革兰阴性菌、革兰阳性菌、真菌及支原体、病毒患者的PCT浓度。结果SLE合并感染病原体的PCT浓度：革兰阴性菌组〉革兰阳性菌组〉真菌及支原体组〉病毒组。结论SLE合并感染病原菌与降钙素原水平有一定的相关性,定量检测PCT可辅助诊断SLE合并感染病原菌种。     

阴道卷曲乳酸杆菌对阴道致病菌的体外生物拮抗作用

目的研究阴道卷曲乳酸杆菌对阴道致病菌的体外生物拮抗作用。方法将阴道卷曲乳酸杆菌分别与3株阴道致病菌（金黄色葡萄球菌、大肠埃希菌、粪肠球菌）混合接种于GAM液体培养基中进行厌氧培养,通过平板菌落计数法计算阴道致病菌的菌数。结果经混合培养后阴道致病菌的菌数明显下降。结论阴道卷曲乳酸杆菌A7在体外能明显抑制3株肠道致病菌的生长繁殖。     

慢性下肢静脉曲张性溃疡的病原菌分布及耐药性分析

目的观察绍兴市人民医院血管外科慢性下肢静脉曲张性溃疡（CLU）患者的病原菌分布以及耐药特点,为临床合理用药提供依据。方法对该院血管外科2012年1月至2013年12月的CLU患者,其溃疡面渗出物培养出的病原菌及耐药性进行回顾性分析。结果病原菌分布较广泛,以铜绿假单胞菌和金黄色葡萄球菌为主。金黄色葡萄球菌对青霉素G的耐药率最高,达到97.37%,对红霉素和克林霉素的耐药率分别为60.53%和55.26%,对利奈唑烷和万古霉素全部敏感。铜绿假单胞菌对抗生素的敏感性较好。结论 CLU患者感染的病原菌分布广泛,且易多重感染,临床在采用外科治疗的同时,宜合理使用抗生素,针对不同患者采取个体化、系统化治疗方案,以提高治愈率,降低复发率。     

胸腹水培养中的病原菌分布及耐药性分析

目的了解胸腹水培养中病原菌的分布和耐药情况,为临床合理用药提供依据。方法通过回顾性分析中山市第二人民医院住院部自2011年1月至2013年11月送检的胸腹水标本细菌培养及药敏资料。结果在494份胸腹水标本中共检出47株病原菌,总阳性率为9.5%;其中326例胸水分离出病原菌28例,阳性率为8.59%,胸水培养中革兰阳性菌占67.86%,革兰阴性菌占32.12%,菌种较为分散;168例腹水分离出病原菌19例,阳性率为11.31%,腹水培养中革兰阴性菌占73.68%,革兰阳性菌占26.32%。检出革兰阴性病原菌对氨苄西林和四环素耐药率较高,对阿米卡星、美罗培南和亚胺培南敏感。检出革兰阳性病原菌对氨苄西林、头孢西丁和红霉素耐药率高,对万古霉素、替考拉宁和吗啉噁酮敏感。结论应重视胸腹水标本的细菌学检查,依据药敏试验合理使用抗菌药物,减少细菌的耐药率。     

Tracking algorithms chase down pathogens

Understanding subcellular dynamic processes governing pathogenic mechanisms is a necessary step towards the development of new drugs and strategies against infectious diseases. Subcellular pathogenic mechanisms, such as viral invasion processes involve highly dynamic nanometric-scale objects and rapid molecular interactions that require the study of individual particle paths. Single-particle tracking methods allow visualizing and characterizing the dynamics of biological objects, and provide a straightforward and accurate means to understand subcellular processes. This review describes a number of particle-tracking methods in time-lapse microscopy sequences and provides examples of using such techniques to investigate mechanisms of host-pathogen interactions.     

Chitosan Treatment: An Emerging Strategy for Enhancing Resistance of Greenhouse Tomato Plants to Infection by Fusarium oxysporum f.sp. radicis-lycopersici

The potential of chitosan, a non-toxic and biodegradable polymer of beta -1,4-glucosamine, for controlling fusarium crown and root rot of greenhouse-grown tomato caused by Fusarium oxysporum f.sp. radicis-lycopersici (FORL) was investigated. The amendment of plant growth substratum with chitosan at concentrations of 12.5 or 37.5 mg l-1 significantly reduced plant mortality, root rot symptoms and yield loss attributed to FORL. Maximum disease control was achieved with chitosan at 37.5 mg l-1, when plant mortality was reduced by more than 90% and fruit yield was comparable with that of non-infected plants. In the absence of FORL, chitosan did not adversely affect plant growth and fruit yield. Cytological observations on root samples from FORL-inoculated plants revealed that the beneficial effect of chitosan in reducing disease was associated with increased plant resistance to fungal colonization. In chitosan-treated plants, fungal growth was restricted to the epidermis and the cortex. Invading hyphae showed marked cellular disorganization, characterized by increased vacuolation and even complete loss of the protoplast. The main host reactions included the formation of structural barriers at sites of attempted fungal penetration, the deposition of an opaque material (probably enriched with phenolics according to its electron density) in intercellular spaces and the occlusion of xylem vessels with tyloses, polymorphic bubbles and osmiophilic substances. Although chitosan may also have antifungal properties, the ultrastructural observations provide evidence that chitosan sensitizes tomato plants to respond more rapidly and efficiently to FORL attack. Chitosan has the potential to become a useful agent for controlling greenhouse diseases caused by soil-borne pathogens.     

急性化脓性骨髓炎患者病原菌分布及耐药性分析

目的:分析急性化脓性骨髓炎患者病原菌的分布特点及耐药情况。方法:取急性化脓性骨髓炎患者窦道深部分泌物或病灶组织做细菌培养及药敏试验。结果:80例患者共培养出病原菌18种110株:其中7例同时培养出3种细菌,15例同时培养出2种细菌,58例培养出1种细菌。110株细菌中,革兰氏阳性(G+)菌55株,占50.0%,主要为金黄色葡萄球菌14株,占25.5%;革兰氏阴性(G-)菌52株,占47.3%,主要为铜绿假单胞菌13株,占25.0%。真菌3株,占2.7%。金黄色葡萄球菌对抗菌药物万古霉素最敏感,耐药率为7.1%,对青霉素耐药率最高,耐药率为92.9%;铜绿假单胞菌对抗菌药物头孢哌酮最敏感,耐药率为7.7%,对亚胺培南的耐药率最高,为92.3%。结论:化脓性骨髓炎的致病菌中革兰氏阳性菌和革兰氏阴性菌的的占比基本持平,大多数病原菌对常用的抗菌药物均具有耐药性。