Pathogenic characteristics of Escherichia coli strains in cases of asymptomatic bacteriuria and symptomatic urinary tract infections

The aim of this study was to examine if E. coli isolated from asymptomatic bacteriuria differed in pathogenic features from strains isolated from symptomatic infections of urinary tract. In this study 130 strains of E. coli isolated from women having asymptomatic bacteriuria and 112 strains isolated from patients with symptoms of urinary tract infection were examined. It was shown that E. coli isolated from patients with symptomatic urinary tract infection showed the more frequently ability to cause mannose-resistant haemagglutination of human erythrocytes, resistance to bactericidal activity of serum and haemolytic properties than those isolated from asymptomatic bacteriuria. These strains showed also the higher ability to adhere to Vero cells in tissue culture. Among E. coli strains isolated from persons with asymptomatic bacteriuria the pathogenic features were most frequently found in strains from healthy women and the most rarely in isolated from diabetic women.     

Interprotein Disulfide Bonds Formed During Isolation Process Tighten the Structure of the Postsynaptic Density

Postsynaptic densities (PSDs) isolated by biochemical means consist of a complex mixture of proteins that tightly bond to each other. The purpose of this report is to study whether the numerous interprotein disulfides found in the isolated PSDs contribute to the tight structure of the PSDs and whether these interprotein disulfides exist in vivo. PSDs were isolated from pig cerebral cortex by conventional methods except that iodoacetic acid (IAA) was added to all solutions to curtail the formation of disulfides during the isolation process. The PSDs thus isolated were fragmented easily by treatment with chaotropic reagents or ionic detergents, whereas the PSDs isolated in IAA-free solutions were resistant to these treatments. Electron microscopy revealed that the PSDs isolated in IAA-containing solutions were more fragmented than those isolated in IAA-free solutions. Furthermore, the PSD sample isolated in IAA-free solutions contained very large disulfide-linked aggregates that were virtually absent from the PSDs isolated in IAA-containing solutions. Our results suggest that the exceptionally tight structure of the PSDs isolated by conventional methods is due largely to the new disulfides formed during the isolation process and that the PSD proteins under in vivo conditions are held together primarily by noncovalent interactions.     

Isolation rate of enterotoxigenic staphylococci in patients with sepsis, pneumonia and burns

The occurrence of Staphylococcus aureus strains producing enterotoxins of types SEA and SEB, which isolated from patients of different profile and caused the infectious process accompanied by pronounced intoxication without vomiting and enteric disturbances, was determined by means of the indirect hemagglutination test. The collection included 28 strains isolated in sepsis, 38 strains isolated in pneumonia, 57 strains isolated from patients with burns and 23, from the hands and nasopharynx of the medical staff. Among the staphylococcal strains isolated in sepsis, 75.6% synthesized SEA and 5.4%, SEB. The occurrence of SEA- and SEB-positive strains isolated in pneumonia was, respectively, 42.1% and 2.6%. From patients with burns SEA-positive staphylococci were mainly isolated (92.9%). Only 3% of the cultures isolated in wound infections produced SEA. From the medical staff, 13.4% of SEA-positive strains and 17.3% of SEB-positive strains were isolated. The data obtained from this study indicate the expediency of the determination of the enterotoxigenic properties of S. aureus clinical isolates in medical institutions for prophylactic measures with a view to the prevention of the spread of pathogenic clones.     

Preliminary studies on the characterization and distribution of Staphylococcus and Micrococcus species on animal skin.

A total of 221 strains of staphylococci and 98 strains of micrococci isolated from the skins of Eastern gray squirrels, Southern flying squirrels, raccoons, opossums, squirrel monkeys, swine, sheep, horses, cattle, and dogs were characterized in a preliminary attempt to resolve their natural relationships and distribution in nature. Staphylococci demonstrating the widest host range included Staphylococcus xylosus and unnamed Staphylococcus sp. 3. Unnamed Staphylococcus sp. 2 was isolated only from sheep, Staphylococcus sp. 4 only from opossums, Staphylococcus sp. 5 only from squirrel monkeys, and Staphylococcus sp. 6 only from swine. The predominant species isolated from human skin, including S. epidermidis, S. hominis, S. haemolyticus, and S. capitis, were either not isolated or only rarely isolated from animal skin. Micrococcus varians was the predominant Micrococcus species isolated from animal skin. M. luteus was only occasionally isolated. M. lylae, M. sedentarius, M. roseus, M. kristinae, and M. nishinomiyaensis, species occasionally isolated from human skin, were not isolated from animal skin.     

Isolated trees support lower bird taxonomic richness than trees within habitat patches but similar functional diversity

Large isolated trees are keystone structures that can help maintain biodiversity in fragmented landscapes, with evidence that open areas with isolated trees may support similar levels of taxonomic diversity to nearby patches of habitat. However, it is not clear if isolated trees can support the same diversity of ecological functions as trees in habitat patches. We compared species richness, community composition, and functional diversity of birds in trees at forest edges and isolated trees. Twenty isolated trees and ten edge trees of American muskwood (Guarea guidonia) were selected, and sampled on 11 occasions, each of 20 min, over four months. All individual birds that landed at trees were recorded using a standardized protocol. Species richness was, on average, almost twice as high at edge trees than at isolated trees. Taxonomic composition differed between edge and isolated trees, with many forest‐dependent birds restricted to edge trees, and some open‐area birds restricted to isolated trees. Overall functional diversity was similar at edge and isolated trees, but some ecological functions (e.g., frugivory) were less frequent, while others (e.g., granivory) were more frequent at isolated compared with edge trees. Isolated trees are important for supporting many ecological functions in modified areas. However, the maintenance of forest patches is essential to complement the provision of such functions in modified landscapes. Abstract in Portuguese is available with online material.     

三江平原孤立湿地景观空间结构

受人类活动的影响,近几十年来三江平原大片连续湿地逐渐破碎化,形成了大量孤立湿地。湿地景观格局分析已成为湿地生态和全球变化研究领域的热点,因此以三江平原遥感影像为数据源,利用GIS技术和景观指数模型,在60m分析粒度下,对三江平原孤立湿地景观空间结构进行分析。结果表明:1研究区的中南部孤立湿地的斑块数量较多,而中东部孤立湿地的斑块面积较大,且孤立湿地斑块之间的邻近程度和连接度较高,三江、洪河自然保护区及研究区西部孤立湿地斑块的形状较复杂;2随着湿地斑块数量的递减,非孤立湿地在景观连接中起到的作用逐渐增加,孤立湿地在景观连接中起到的作用逐渐减小,但面积相对较大的孤立湿地斑块重要值一直处于较高水平,在景观连接中起着重要作用;3三江平原孤立湿地景观空间结构是地形地貌、农业开发活动、国家政策等因子综合作用的结果,应加强对孤立湿地的保护。     

2006年广州登革热病原体的分离鉴定及其生物学性质的观察

目的：对2006年广州流行登革热病原进行分离鉴定及生物学性质研究。方法：采用传代蚊细胞微量培养方法对2006年广州登革热病原进行分离,并通过脑内途径观察其对乳鼠的致病性;经间接免疫荧光和RT-PCR技术,对患者血清标本中的病毒特异抗体及新分离的病原体进行检测和鉴定;将此次分离的病原体与1980年分离的同型毒株进行生物学性质比较。结果：从57份患者血清标本中分离出10株病毒,在传代蚊细胞中可产生稳定的细胞病变并对乳鼠致病;其基因组为登革1型病毒特异的RNA分子,经鉴定为登革1型病毒;此次分离的登革1型病毒与1980年分离的同型毒株在致细胞产生病变的时间和严重程度,蚀斑的大小、形态以及致乳鼠发病的时间等生物学性质上有所不同。结论：2006年广州流行登革热病原为登革1型病毒,且与1980年分离的同型毒株在生物学性质方面存在明显差异。     

A possible bio-assay for chromosome movement in isolated mitotic apparatus

We isolated mitotic apparatus (MA) from sea urchin zygotes using several methods. The isolated MA were injected into nucleated frog eggs or into enucleated frog eggs, and 24 h later we determined whether or not the eggs had undergone normal cleavage. Normal cleavage occurred in about 50% of the cases when MA isolated in glycerol-dimethyl sulphoxide were injected into either nucleated or enucleated frog eggs. Likewise for MA isolated initially in hexylene glycol and transferred immediately into glycerol-dimethyl sulphoxide. No cleavage occurred when MA isolated in hexylene glycol (and stored in hexylene glycol) were injected into frog eggs. We discuss two possible interpretations of the results. In one interpretation cleavage of the frog eggs is a bioassay, measuring the ability of the isolated MA to support chromosome movement. In the other interpretation the isolated MA contribute only nuclear material and cleavage initiation factors, and there is no chromosome movement in the isolated MA per se.     

Five new Candida species

Summary The following five new yeast species are described:Candida beechii isolated from cider,C. blankii isolated from a mink,C. cacaoi isolated from fermenting cacao,C. freyschussii isolated from wood pulp andC. melibiosica isolated from sputum.     

Delayed development of aggressive behavior in castrate isolated male mice

Male mice were castrated at 21–22 days of age. Intact and castrated mice were isolated to induce aggressive behavior. The incidence of fighting between paired nonisolated and isolated mice was measured at 3, 6, 12, and 23 weeks to determine the effect of time of isolation on aggressive behavior. After 3 weeks isolation, 90% of the intact isolated mice fought, but none of the castrate isolated mice fought. Aggressive behavior equivalent to that of intact isolated mice developed in the castrate mice after 23 weeks of isolation. These results suggest that the presence of gonadal androgen is important in expediting the onset of aggressive behavior in isolated mice, but its absence does not preclude its eventual development.     

鸡贫血病毒哈尔滨分离株全基因克隆和序列分析

通过PCR方法克隆了从哈尔滨分离的一株鸡贫血病毒(CAV)的全基因,并对其进行了测序,该病毒基因组为环状,全长2298bp,含有三个互相重叠的开放读码框和一个调控区。将克隆的基因与GenBank收录的CAV基因比较,同源性至少为97%,未发现与本次克隆的CAV基因完全一致的分离株。与德国分离株Cuxla、26p4和马来西亚分离株分别有42、42和72个核苷酸不同,同源性分别为98.2%、98.2%和96.9%。与德国分离株Cux1b相比,除在调控区内少一个类似增强子的重复序列外,尚有39处核苷酸不同。它与分离于欧洲的几株CAV的亲源性要比来自亚洲的马来西亚株近。对CAV哈尔滨分离株、26p4、Cux1b、Cux1a和马来西亚株的VP1、VP2和VP3蛋白比较,VP2的保守性最高。     

鹅源鸭疫里默氏杆菌的分离、鉴定与生物学特性研究

【目的】从疑似鸭疫里默氏杆菌病的病死雏鹅分离病原菌进行鉴定。【方法】根据细菌培养特性、生化特性、动物试验、血清型鉴定及分子生物学特性对分离菌株进行鉴定。【结果】分离菌株为革兰氏阴性菌,不发酵糖类和醇类,尿素酶试验和氧化酶还原试验为阳性,致病,不同分离株的16S rRNA基因经多重序列比对分析,结果显示鹅源分离株与鸭源鸭疫里默氏杆菌处于同一进化支上,与鸡源鸭疫里默氏杆菌进化关系稍远,血清型鉴定为1型。【结论】分离菌株为血清1型的鸭疫里默氏杆菌,对鸭和鹅均有高致病性,自家疫苗能够较好地保护雏鹅。     

Differences in the initial events of infection of Botrytis cinerea strains isolated from tomato and grape

Various stages of the infection process among B. cinerea strains isolated from tomatoes or grapes, belonging to different genetic groups, were compared. It was found that strains of B. cinerea isolated from either grapes or tomatoes showed differences in adhesion patterns and in the percentage of germination on tomato cutin. In strains isolated from tomato the first stage of adhesion occurred faster than in strains isolated from grape. At the same time strains isolated from tomato showed a higher percentage of germination on tomato cutin than the other strains after 9 h of incubation. The production and isoenzymatic patterns of polygalacturonases, pectin methyl esterases, pectin lyases, p-nitrophenylbutyrate esterases and laccases by B. cinerea in solid-state fermentation also were analyzed. Correlation between the production of these enzymes and the origin of the strains was not found. On the other hand all strains produced different isoenzymes and a common pattern between the strains was not observed. The ability of B. cinerea strains to colonize tomato leaves also differs between the isolated strains obtained from grapes and tomato. Strains isolated from tomato were more virulent on tomato leaves than strains isolated from grapes.     

Agricultural animals as a source of yersiniosis

The role of agricultural animals as the sources of infection was studied. 8 Yersinia strains were isolated from 83 samples taken from cattle. Yersinia were isolated from feces, udder washings and milk. In the examination of 63 samples obtained from sheep the infective agent was isolated from feces in 6 cases. 6 Yersinia strains were isolated from 92 fecal samples taken from pigs. Y. enterocolitica were isolated from sick animals. The isolated strains were classified with serovars 03, 058, 08 and 09. In the foci of animal infection thus revealed antibodies to various Yersinia strains were detected in the blood sera of the animal-tending personnel, which indicates the professional character of the spread of this infection among humans. The infection is probably transferred by the contact and alimentary routes.     

In vivo conformation of mitochondrial DNA revealed by pulsed-field gel electrophoresis in the true slime mold, Physarum polycephalum.

Pulsed-field gel electrophoresis (PFGE) was used to examine the in vivo and in vitro conformations of Physarum polycephalum mitochondrial DNA (mtDNA). We used plugs containing isolated mitochondria, isolated mitochondrial nucleoids (mt-nuclei), and isolated mtDNA, in addition to whole cells. The mtDNA contained in the myxamoebae, plasmodia, isolated mitochondria, and isolated mt-nuclei was circular, but most of the isolated mtDNA had been site-specifically fragmented and linearized during DNA preparation and storage under low ionic strength conditions. Restriction mapping of Physarum mtDNA by the direct digestion of the isolated mt-nuclei from two different strains, DP89 x AI16 and KM88 x AI16, resulted in the circular form. A linear mitochondrial plasmid, mF, is known to promote mitochondrial fusion and integration of itself into the mtDNA in Physarum. Linearization of mtDNA by the integration of the mF plasmid was demonstrated when we used PFGE to analyze isolated mitochondria from the plasmodial strain DP89 x NG7 carrying the mF plasmid (mF+). The PFGE system can be used not only to determine whether the form of mtDNA is linear or circular but also to analyze the dynamic conformational changes of mtDNA.     

The polysaccharides of the brown seaweed Turbinaria murrayana

Polysaccharides of the brown seaweed Turbinaria murrayana were isolated. Laminaran (3.2%) was isolated from the hot-water extract of the algae by using ion-exchange chromatography. Fucans (2.1%) were isolated from the hot-water extract, as well (4.7%) as from the extract of the algae with dilute acid. Acid hydrolsysis of the isolated fucans revealed glucose, amnnose, fucose, glucuronic acid, xylose, and galactose. Alginic acid (22.6%) was separated, and reduced to a neutral polysaccharide. The polysaccharides isolated were analyzed by methylation and Smith degradation.     

Light-induced conversion of nicotinamide adenine dinucleotide to nicotinamide adenine dinucleotide phosphate in higher plant leaves

Light-induced conversion of NAD to NADP was investigated in higher plants. Upon illumination, conversion of NAD to NADP was observed in intact leaves of wheat and pea following incubation in the dark. This conversion was also observed in mesophyll protoplasts of wheat leaves when they were isolated in the dark or isolated in light and then preincubated in the dark. Chloroplasts isolated from wheat protoplasts prepared in the dark carried out the conversion. The conversion in the mechanically isolated spinach chloroplasts was observed only when they were isolated in the dark from leaves preincubated in darkness.     

Genotyping of rubella virus circulating in Western Siberia of Russia during 2004-2006 epidemic period

Twenty one strains of rubella virus were isolated in the Western Siberia during 2004-2006 epidemic period. Genotyping of isolated strains was performed by partial sequencing of glycoprotein E1 gene. Phylogenetic analysis showed that 20 out of 21 isolated in the Western Siberia strains of rubella virus belonged to genotype 1g, and 1 strain (isolated in Altai region in 2006)--to genotype 1E.     

烧伤病房患者创面金葡菌分布及耐药性分析

目的分析烧伤病房患者不同创面金葡菌的分布及耐药性,为临床合理选用抗菌药提供依据。方法对2006年1月至2013年12月间中国人民解放军第八五医院烧伤病房患者创面分离出金葡菌,采用K—B纸片扩散法进行药物敏感试验。分析金葡菌的耐药性,并对难愈性创面、非难愈性创面的耐甲氧西林金葡菌（MRSA）与甲氧西林敏感金葡菌（MSSA）的耐药性进行对比分析。结果分离出金葡菌112株,其中难愈性创面有70株MRSA和17株MSSA来自难愈性创面,16株MRSA和9株MSSA来自非难愈性创面。金葡菌对青霉素、红霉素、克林霉素的耐药率较高（分别为94．64％、81．25％和74．11％）,对复方新诺明、呋喃妥因的耐药率较低（分别为16．07％和1．79％）,对万古霉素、利奈唑烷的耐药率为0。MRSA的耐药率高于MSSA。来源于难愈性创面与非难愈性创面的MRSA仅在对利福平的耐药率上有明显差异,而来源于两创面的MSSA的耐药率无明显差异。结论创面金葡菌中MRSA的构成比高,难愈性创面MRSA耐药严重,应积极防控创面MRSA感染和扩散。     

The effect of prefixation on the diameter of chromosome fibers isolated by the Langmuir trough-critical point method

The effect of prefixation on the diameter of chromosome fibers isolated by the Langmuir trough-critical point method has been investigated in several species of plants and animals. In barley, fibers isolated from endosperm without prefixation have an average diameter of between 240 and 250 A, and are similar in dimensions and structure to the chromosome fibers isolated from animals by this method. Chromosome fibers from other tissues of the same plant are smaller in diameter when isolated without prefixation, approximating 200 A. After prefixation in 2% buffered formalin, isolated fibers from the three barley tissues studied are reduced in diameter, to approximately 120-130 A for endosperm and leaflet and to 140 A for root tip. Chromosome fibers isolated from newt erythrocytes also show a significantly reduced diameter after formalin prefixation, to approximately 120 A.