Species Distribution of Clinical Acinetobacter Isolates Revealed by Different Identification Techniques

A total of 2582 non-duplicate clinical Acinetobacter spp. isolates were collected to evaluate the performance of four identification methods because it is important to identify Acinetobacter spp. accurately and survey the species distribution to determine the appropriate antimicrobial treatment. Phenotyping (VITEK 2 and VITEK MS) and genotyping (16S rRNA and rpoB gene sequencing) methods were applied for species identification, and antimicrobial susceptibility test of imipenem and meropenem was performed with a disk diffusion assay. Generally, the phenotypic identification results were quite different from the genotyping results, and their discrimination ability was unsatisfactory, whereas 16S rRNA and rpoB gene sequencing showed consistent typing results, with different resolution. Additionally, A. pittii, A. calcoaceticus and A. nosocomialis, which were phylogenetically close to A. baumannii, accounted for 85.5% of the non-A. baumannii isolates. One group, which could not be clustered with any reference strains, consisted of 11 isolates and constituted a novel Acinetobacter species that was entitled genomic species 33YU. None of the non-A. baumannii isolates harbored a bla _OXA-51-like gene, and this gene was disrupted by ISAba19 in only one isolate; it continues to be appropriate as a genetic marker for A. baumannii identification. The resistance rate of non-A. baumannii isolates to imipenem and/or meropenem was only 2.6%, which was significantly lower than that of A. baumannii. Overall, rpoB gene sequencing was the most accurate identification method for Acinetobacter species. Except for A. baumannii, the most frequently isolated species from the nosocomial setting were A. pittii, A. calcoaceticus and A. nosocomialis.     

两株水生呼肠孤病毒部分特性的比较

水生呼肠孤病毒为感染水生动物的一类病原体,隶属于呼肠孤病毒科新建水生呼肠孤病毒属。草鱼呼肠孤病毒(Grass carp reovirus,GCRV)是引起中国南方淡水养殖草鱼暴发性出血病病原,鲅鱼呼肠孤病毒(Threadfin reovirus,TFV)是引起海水养殖鲅鱼病毒病病原。本研究将GCRV与新加坡TFV分离株进行了部分特性比较研究。结果表明,GCRV与TFV均能感染CIK细胞,但对其它鱼类细胞系的敏感性有所差异。此外,凝胶电泳与逆转录聚合酶链式扩增显示,GCRV与TFV核酸属不同的基因型。在多肽特性上,证实了GCRV的5条主要结构多肽具有与。FTV及水生呼肠孤病毒相似的特性。Westem blot检测显示,草鱼呼肠孤病毒与TFV结构蛋白拥有部分相同的抗原决定簇。     

两株水生呼肠孤病毒部分特性的比较

水生呼肠孤病毒为感染水生动物的一类病原体,隶属于呼肠孤病毒科新建水生呼肠孤病毒属.草鱼呼肠孤病毒(Grass carp reovirus,GCRV)是引起中国南方淡水养殖草鱼暴发性出血病病原,鮁鱼呼肠孤病毒(Threadfin reovirus,TFV)是引起海水养殖鮁鱼病毒病病原.本研究将GCRV与新加坡TFV分离株进行了部分特性比较研究.结果表明,GCRV与TFV均能感染CIK细胞,但对其它鱼类细胞系的敏感性有所差异.此外,凝胶电泳与逆转录聚合酶链式扩增显示,GCRV与TFV核酸属不同的基因型.在多肽特性上,证实了GCRV的5条主要结构多肽具有与FTV及水生呼肠孤病毒相似的特性.Western blot 检测显示,草鱼呼肠孤病毒与TFV结构蛋白拥有部分相同的抗原决定簇.     

Comparison of Three Serological Tests in Gonococcal Infection

Three serological tests used in the diagnosis of gonococcal infection were compared with cultural techniques in 857 females attending the Prenatal and Gynaecology Clinics at the Winnipeg General Hospital. The tests evaluated were the microflocculation technique (MFT), the indirect fluorescent-antibody technique (IFAT), and the complement-fixation technique (CFT). One hundred six patients had positive cultures for Neisseria gonorrhoeae. In this population, the MFT was reactive in 80 patients (75.4%), the IFAT was reactive in 74 (69.8%), and the CFT was reactive in 33 (31.1%). In the 751 patients with negative cultures, the MFT was positive in 11.4%, the IFAT was positive in 17.4%, and the CFT was positive in 10.5%. Sera from 9 of 10 patients with gonococcal arthritis were positive with the MFT.     

454高通量技术比较两种不同臭豆腐卤水中微生物多样性

利用454高通量技术对两种不同臭豆腐卤水中微生物不同分类水平的多样性进行了评估和统计分析。经过与SILVA数据库对比,发现了7个门、10个纲、17个目、26个科、24个菌属。经分析发现两个样品的微生物不同分类学差异显著,主要集中在属水平上,分布都非常不均一。在样品A中厌氧球菌属和卟啉单胞菌属所占的比例最高,分别为40.22%、37.54%,成为优势菌属。两个样品之间相同的微生物属只有6个,比例差别极大。在样品B中氨基杆菌属的比例很大,为86.94%,占绝对优势。说明卤水原料来源不同对微生物的差异显著,同时发现臭豆腐卤水的发酵过程只与少数主要菌种有关。     

Differentiation of Bulgarian Isolates from Cucumber Mosaic Virus by Serological Methods

Cucumber mosaic virus (CMV) is of great importance to the Bulgarian economy and hence a detailed knowledge of its diversity under local geographic and climatic conditions is required. An extended study was carried out on CMV strains the currently occur in Bulgaria. Fifty-one isolates and strains found in different regions and various crops were biologically characterized and serologically differentiated into subgroups I and II using different variants of enzyme-linked immunosorbent assay (ELISA) [double antibody sandwich (DAS)-, antigen-coated plate (ACP)-, triple antibody sandwich (TAS)- with poly and monoclonal antibodies] and immunodiffusion tests. The ELISA modifications with monoclonal antibodies individually (ACP) or in combination with polyclonal antibodies (TAS-ELISA) are suitable for mass screening of CMV isolates. The hyperimmune sera against strains from CMV subgroups I and II were very efficient for use in isolate differentiation via gel double immunodiffusion. The results obtained correlated with the polymerase chain reaction and restriction fragment length polymorphism data reported by other authors. The majority of the isolates belonged to subgroup I, whereas 10, mainly from tomato and pepper, belonged to subgroup II. Most of the subgroup II isolates came from the north of Bulgaria. The results of the present study will help to clarify the virus epidemiology and to develop specific control measures.     

A Comparison of Some Serological and Biological Properties of Seven Isolates of Tobacco Ringspot Virus

Seven isolates of tobacco ringspot virus (TRSV) from grape, cherry, two cultivars of blueberry, tobacco, soybean and watermelon were compared in this study. The most virulent isolate was from‘Jersey’blueberry and the least virulent isolate was from soybean. The‘Jersey’blueberry isolate and the watermelon isolate could be distinguished serologically from all other isolates. The‘Jersey’blueberry isolate was different in electrophoretic mobility from the soybean and tobacco isolates. A unique technique for comparing the in vitro translation products of three of the TRSV isolates is described.     

Comparison of Levels of Inactivation of Two Isolates of Giardia lamblia Cysts by UV Light

The effects of 254-nm UV irradiation on two human isolates (WB and H3) of Giardia lamblia cysts were assessed using a collimated beam protocol and a Mongolian gerbil model. The levels of infection of cysts in the gerbils were assessed based on the presence of cysts in feces and the presence and activity of trophozoites in the small intestine of inoculated gerbils. The results suggest that there were differences in the infectivities of the WB and H3 isolates, as well as in susceptibilities of the parasites to UV light. Without UV exposure, gerbils were more readily infected by isolate H3 cysts. After UV exposure of the cysts, however, the gerbils were more susceptible to isolate WB cysts.     

Heterogeneity of Leishmania donovani Parasites Complicates Diagnosis of Visceral Leishmaniasis: Comparison of Different Serological Tests in Three Endemic Regions

Diagnostic tests for visceral leishmaniasis that are based on antigens of a single Leishmania strain can have low diagnostic performance in regions where heterologous parasites predominate. The aim of this study was to investigate and compare the performance of five serological tests, based on different Leishmania antigens, in three endemic countries for visceral leishmaniasis. A total number of 231 sera of symptomatic and asymptomatic cases and controls from three endemic regions of visceral leishmaniasis in East Sudan, North India and South France were evaluated by following serological tests: rKLO8- and rK39 ELISA, DAT (ITMA-DAT) and two rapid tests of rK39 (IT LEISH) and rKE16 (Signal-KA). Overall, rKLO8- and rK39 ELISA were most sensitive in immunocompetent patients from all endemic regions (96–100%) and the sensitivity was reduced to 81.8% in HIV co-infected patients from France. Sera of patients from India demonstrated significantly higher antibody responses to rKLO8 and rK39 compared with sera from Sudan (p<0.0001) and France (p<0.0037). Further, some Indian and Sudanese patients reacted better with rKLO8 than rK39. Sensitivity of DAT (ITMA-DAT) was high in Sudan (94%) and India (92.3%) but low in France being 88.5% and 54.5% for VL and VL/HIV patients, respectively. In contrast, rapid tests displayed high sensitivity only in patients from India (96.2%) but not Sudan (64–88%) and France (73.1–88.5% and 63.6–81.8% in VL and VL/HIV patients, respectively). While the sensitivity varied, all tests showed high specificity in Sudan (96.7–100%) and India (96.6%).Heterogeneity of Leishmania parasites which is common in many endemic regions complicates the diagnosis of visceral leishmaniasis. Therefore, tests based on homologous Leishmania antigens are required for particular endemic regions to detect cases which are difficult to be diagnosed with currently available tests.     

Serological Comparison of the Three Morphological Phases of Coccidioides immitis by the Agar Gel Diffusion Method

Hyperimmune sera against spherules and against arthrospores of Coccidioides immitis were prepared by inoculation of rabbits. The antibody content of these sera was studied by the agar gel diffusion method. It was observed that antispherule pooled sera formed multiple precipitin bands with extracts of spherules and of arthrospores. The antiarthrospore pooled serum, however, failed to precipitate with the spherule extract, and formed a single band in the presence of an arthrospore solution. When the spherule and the arthrospore extracts were tested with a variety of different antisera, it was observed that the spherule preparation formed bands only in combination with anti-purified spherule pooled serum, whereas the arthrospore extract precipitated with anti-purified spherule, antiarthrospore, and anti-Histoplasma capsulatum pooled sera. It was also observed that a spherule culture supernatant solution formed five precipitin bands in combination with anti-spherule pooled sera, formed one band with pooled antiserum from rabbits with coccidioidomycosis, and did not precipitate in the presence of antiarthrospore pooled serum. Coccidioidin, however, formed two bands in the presence of any of these antisera. It was therefore concluded that extracts from the spherule phase of C. immitis differed from solutions obtained from the arthrospore and mycelial phases.     

Biofilm Production by Candida: Comparison of Bloodstream Isolates with Cervical Isolates

The present study was undertaken to investigate biofilm formation among the clinical Candida isolates from blood and cervical swabs. A total of 16 Candida blood isolates from neonates and 21 cervical isolates from pregnant women with vulvovaginitis were included in the study. Each isolate was identified to species level by various phenotypic tests. Biofilm formation was detected by colorimetric method. C. glabrata and C. albicans were the major isolates from blood and cervical swab respectively. The biofilm formation was found in 14 (87.5 %) blood isolates and only in 4 (19.1 %) cervical isolates.     

A Comparison of Two Techniques for Wood Fibre Isolation - Evaluation by Tensile Tests on Single Fibres with Different Microfibril Angle

Abstract: Fibres (tracheids) of spruce ( Picea abies [L.] Karst.) were isolated by means of two isolation techniques. On the one hand, a soft chemical treatment with Jeffrey solution was used. The isolation was carried out with a reduced time of treatment (2 h), just to achieve the state where the fibres could be separated easily with tweezers. On the other hand, fibres were directly peeled out with tweezers, taking advantage of the low shear strength between them. Following this approach, a chemical treatment could be avoided completely. In order to compare the isolation techniques, single tracheids from tissue types with different microfibril angle (earlywood, latewood, juvenile wood, opposite wood, compression wood) were tested in the dry state. The microfibril angles were determined by X-ray diffraction. Single tracheids handled with both isolation techniques were strained in microtensile tests and load-strain diagrams were obtained. The chemically treated fibres were found to have much lower strength and stiffness compared to the mechanically isolated fibres, even though the influence of microfibril angle was still obvious for both kinds of treatment. The results clearly show the importance of single fibre extraction to preserve as much as possible the original properties.     

焦化废水处理系统中不同培养基分离的细菌种群多样性

以焦化废水处理系统的微生物群落为对象,对3种不同培养基（YPG、LB、WW）分离细菌的能力及分离物的种群多样性组成进行了比较研究。同一悬浮污泥样品在YPG、LB和WW培养基上的活菌计数结果分别为1.6×10.6 CFU/mL、7.0×10.5 CFU/mL和98×10.5CFU/mL。从每种培养基10-4稀释度平板上共分离137株分离物。将所有分离物扩增近全长的16S rDNA并用限制性内切酶HinfI对PCR产物进行ARDRA（Amplified rDNA restriction analysis）多态性分析,共得到14种不同的操作分类单元（Operational Taxonomic Unit, OUT）。其中YPG培养基上的分离物显示了8种不同的OTUs,而WW培养基和LB培养基分离物只分别显示了6种和4种OTUs。YPGOTU1和WWOTU6所包含的菌株分别占到总分离物的30%和22.3%,为优势分离物。ERICPCR基因组指纹图分析表明,前者的34株分离物共有20种不同的指纹图类型,而后者的25株分离物只有3种。因此,就分离焦化废水处理系统中的细菌及对分离物进行种群多样性的研究而言,YPG培养基比其他两种培养基更合适。     

Comparison of Two Techniques for Surveying Headwater Stream Amphibians

Abstract: We compared rubble-rousing versus light-touch stream amphibian survey techniques in multiple 1-m plots across 10 streams in southwest Washington, USA. Specifically, we wanted to determine if light-touch surveys provide unbiased estimates of abundance (i.e., provide counts correlated with rubble-rousing counts) and which method would provide more cost-effective presence or absence information. Rubble-rousing, a common technique for surveying stream-associated amphibians in the Pacific Northwest, took 12 times as long as light-touch to apply. Abundance estimates and standard errors for rubble-rousing were consistently higher than those for light-touch for all life stages for the coastal tailed frog (Ascaphus truei) and Columbia torrent salamander (Rhyacotriton kezeri). Except for eggs, light-touch detected all life stages found during rubble-rousing. For frogs, only some rubble-rousing abundance estimates, mostly involving second-year larvae, were highly correlated with their light-touch counterparts, whereas for salamanders, similar comparisons generated high correlations across most life stages. Correlations between methods were consistently greater for salamanders than for frogs. However the smaller tailed frog sample sizes and the cryptozoic nature of some life stages may have contributed to this pattern. Depending on the degree to which researchers can tolerate false-negative error rates, light-touch may prove less costly than rubble-rousing for detecting species presence. For the cost of obtaining one rubble-rousing sample, many light-touch samples can be used across a range of habitats for detecting species patchily distributed.     

Comparison of Three Methods for Assessing Plum Pox Virus Variability: Further Evidence for the Existence of Two Major Groups of Isolates

Twenty-eight plum pox virus isolates from several European and Mediterranean countries were compared by electrophoretic mobility of their coat protein subunit measured by Electroblot Immuno-Assay (EBIA), antigenic properties of the N- and C-terminal parts of the coat protein and restriction fragment length polymorphism (RFLP) and analysis of polymerase chain reaction (PCR) amplification of the C-terminal part of the coat protein gene. Similar results were obtained by each of the three methods. These confirm the existence of the two major subgroups of PPV, and which we now propose to designate PPV-D and PPV-M, respectively.     

Comparison of Aflatoxigenic and Nonaflatoxigenic Isolates of Aspergillus flavus using DNA Amplification Fingerprinting Techniques

Aspergillus flavus is a filamentous fungus that produces mycotoxins in many food and feed crops, such as maize (Zea mays L.). Isolates were analyzed for toxin production by nucleic acid profiles in an attempt to differentiate aflatoxigenic from nonaflatoxigenic isolates. A total of 41 aflatoxigenic and 34 nonalfatoxigenic isolates were included in the study. The isolates were evaluated initially using DNA amplification fingerprinting (DAF) without clear resolution of the groups. A weak association of aflatoxigenic isolates was observed, as evidenced by their clustering in 18 of 81 trees recovered from maximum parsimony analysis of binary characters derived from arbitrary signatures from amplification profiles (ASAP) data; nonaflatoxigenic isolates exhibited a pattern of paraphyletic laddering. Up to five markers unambiguously supported the aflatoxigenic isolate grouping, but the presence of alternative conflicting topologies in equally parsimonious trees precluded the observation of meaningful statistical support. With additional markers for genome of A. flavus, this method could be used to resolve toxigenic from nontoxigenic strains. This additional work could resolve aflatoxigenic isolates of A. flavus present on maize plants using ASAP, which would reduce labor intense costs and potentially lead to faster determination of resistant cultivars in breeding efforts.     

Serological Comparison of Two Races of Fusarium oxysporum f. sp. lupini

Water-soluble mycelial antigens from two physiological races (2 and 3) of Fusarium oxysporum L. sp. lupini were compared by tandem-crossed immunoelectrophoresis. When antiserum against race 3 was tested some 50 antigens were detected. The two races had apparently almost identical antigenic patterns differing only in one antigen specific to race 3. This specific antigen might be related to the virulence of this fungus.     

天然氨基酸物质的不同制造技术的比较研究

依据 1 7～ 1 8种天然氨基酸物质的三种制造技术的比较研究 ,无论是基于生物资源还是基于其产品销售和环境保护方面 ,都证明了蛋白质水解制造法优于发酵法和合成法     

Combined Biochemical and Serological Typing of Clinical Isolates of Klebsiella

In a series of 640 strains of Klebsiella isolated from clinical specimens over a 7-month period, there were sufficient biochemical differences between strains to allow a biochemical typing system to be established. Biochemical tests were done in solid media inoculated with a modified Steers inocula replicator. Biotypes were designated by a numerical coding system; 29 distinct biotypes were found among the 640 strains of Klebsiella. Serotyping of 270 of the strains was done by the Quellung reaction, and 40 capsular types were identified. Numerical biotypes and serotypes of strains appeared to vary independently. When used in conjunction, the two methods subdivided the strains into many more distinct types than either used alone. With the combined method over 100 types of Klebsiella were distinguished among the 270 isolates.     

A Comparison of Endogenous Development of Three Isolates of Cryptosporidium in Suckling Mice1

ABSTRACT. Suckling mice were used as a model host to compare the endogenous development of three different isolates of Cryptosporidium: one from a naturally infected calf, one from an immunocompetent human with a short-term diarrheal illness, and one from a patient with acquired immune deficiency syndrome (AIDS) and persistent, life-threatening, gastrointestinal cryptosporidiosis. After oral inoculation of mice with oocysts, no differences were noted among developmental stages of the three isolates in their sites of infection, times of appearance, and duration, morphology, and fine structure. Sporozoites excysted within the lumen of the duodenum and ileum, penetrated into the microvillous region of villous enterocytes, and developed into type I meronts with six or eight merozoites. Type I merozoites penetrated enterocytes and underwent cyclic development as type I meronts or they became type II meronts with four merozoites. Type II merozoites did not exhibit cyclic development but developed directly into sexual forms. Microgamonts produced £16 small, bullet-shaped microgametes, which were observed attaching to and penetrating macrogametes. Approximately 80% of the oocysts observed in enterocytes had a thick, two-layered wall. After sporulating within the parasitophorous vacuole, these thick-walled oocysts passed through the gut unaltered and were the resistant forms that transmitted the infection to a new host. Approximately 20% of the oocysts in enterocytes consisted of four sporozoites and a residuum surrounded only by a single oocyst membrane that ruptured soon after the parasite was released from the host cell. The presence of thin-walled, autoinfective oocysts and recycling of type I meronts may explain why a small oral inoculum can produce an overwhelming infection in a suitable host and why immune deficient persons can have persistent, life-threatening cryptosporidiosis in the absence of repeated oral exposure to thick-walled oocysts.