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1

Molecular characterization and phylogenetic analysis of porcine epidemic diarrhea virus (PEDV) field isolates in Korea.  

PubMed

Porcine epidemic diarrhea virus (PEDV) has caused enteric disease with devastating impact since the first identification of PEDV in 1992 in Korea. In this study, we investigated molecular epidemiology, showed genetic diversity, and analyzed phylogenetic relationships of Korean PEDV field isolates with other PEDV reference strains. Genetic analysis of the complete M and ORF3 genes showed that each PEDV group had several unique characteristics, and this indicated that specific groups of PEDVs may be differentiated from the other PEDVs by specific nucleotide differences. Especially, ORF3 gene analysis can be used for discrimination between vaccine and wild-type PEDVs. Sequence and phylogenetic analysis showed that recent, prevalent Korean PEDV field isolates have close relationships to Chinese field strains and differ genetically from European strains and vaccine strains used in Korea. These results raise questions as to whether a new type of PEDV vaccine may be necessary for preventing PEDV infection more effectively in Korea. PMID:21210162

Park, Seong-Jun; Kim, Hye-Kwon; Song, Dae-Sub; Moon, Hyoung-Joon; Park, Bong-Kyun

2011-01-06

2

Molecular characterization and phylogenetic analysis of porcine epidemic diarrhea virus (PEDV) field isolates in Korea  

Microsoft Academic Search

Porcine epidemic diarrhea virus (PEDV) has caused enteric disease with devastating impact since the first identification of\\u000a PEDV in 1992 in Korea. In this study, we investigated molecular epidemiology, showed genetic diversity, and analyzed phylogenetic\\u000a relationships of Korean PEDV field isolates with other PEDV reference strains. Genetic analysis of the complete M and ORF3\\u000a genes showed that each PEDV group

Seong-Jun Park; Hye-Kwon Kim; Dae-Sub Song; Hyoung-Joon Moon; Bong-Kyun Park

2011-01-01

3

Molecular epidemiology and phylogenetic analysis of porcine epidemic diarrhea virus (PEDV) field isolates in Korea.  

PubMed

Porcine epidemic diarrhea virus (PEDV) has caused devastating enteric disease in Korean pig farms since its first identification in 1992 in Korea. In the present study, the molecular epidemiology, genetic diversity, and phylogenetic relationship of Korean PEDV field isolates to other reference strains were analyzed using the complete E gene. Genetic analysis showed that each PEDV group had several unique characteristics, which indicated that a specific group PEDVs may be differentiated from another group PEDVs. Phylogenetic analysis showed that recent prevalent Korean PEDV field isolates are closely related to the Chinese field strains and differ genetically from the European strains and the vaccine strains used in Korea, which raises questions of whether a new-type PEDV vaccine may be necessary for preventing PEDV infection more effectively in Korea. Notably, a large deletion identified only in the attenuated DR13 can be utilized as a genetic marker, and the methods developed in this study will help to rapidly detect and differentiate PEDVs. PMID:23462888

Park, Seong-Jun; Song, Dae-Sub; Park, Bong-Kyun

2013-03-06

4

Molecular characterization and phylogenetic analysis of porcine epidemic diarrhea virus (PEDV) field strains in south China.  

PubMed

A total of 127 porcine samples were collected from 48 farms in six provinces in south China. The positive rate of porcine epidemic diarrhea virus (PEDV) was 43.0 % (55/127), and the co-infection rate of PEDV and transmissible gastroenteritis virus (TGEV) was 12.0 % (15/127). The partial S gene and complete M gene were amplified from PEDV-positive strains by RT-PCR, cloned, sequenced and compared with each other, as well as with the reference strains in GenBank. Sequence homology results of the partial S gene and complete M gene showed that all south China field PEDV strains had nucleotide (deduced amino acid) sequence identities of 86.7-98.7 % (83.2-99.3 %) and 96.1-100 % (95.0-100%), respectively, with the foreign reference strains reported in GenBank. Phylogenetic analysis of the partial S gene showed that all the south China PEDV strains and two Thailand strains (08UB01 and 08RB07) belong to the same group and differ genetically from European strains and early domestic strains. Phylogenetic analysis of the complete M gene showed that all south China PEDV strains have a close relationship with most of the strains in Korea and Thailand, but differ genetically from the vaccine strain (CV777). PMID:22528639

Li, Zhi-Li; Zhu, Ling; Ma, Jing-Yun; Zhou, Qing-Feng; Song, Yan-Hua; Sun, Bao-Li; Chen, Rui-Ai; Xie, Qing-Mei; Bee, Ying-Zuo

2012-04-12

5

Molecular characterization and phylogenetic analysis of porcine epidemic diarrhea virus (PEDV) samples from field cases in Fujian, China.  

PubMed

The outbreak of porcine epidemic diarrhea virus (PEDV) has been a big problem of swine industry in China in recent years. In this study, we investigated molecular diversity, phylogenetic relationships, and protein characterization of Fujian field samples with other PEDV reference strains. Sequence analysis of the S1 and sM genes showed that each sample had unique characteristics, and the sample P55 may be differentiated from the others by the unique deletions and insertions of sM gene. Phylogenetic analysis based on S1 or sM gene, which have high levels of variations, indicated that each sample was related to the specific reference strain, and this finding was consistent with the protein characterization prediction analysis. The study is useful to better understand the prevalence of PEDV and its prevention and control in Fujian. PMID:22843324

Chen, Xi; Yang, Jinxian; Yu, Fusong; Ge, Junqing; Lin, Tianlong; Song, Tieying

2012-07-29

6

Derivation of attenuated porcine epidemic diarrhea virus (PEDV) as vaccine candidate  

Microsoft Academic Search

The field isolate of porcine epidemic diarrhea virus (PEDV) was serially passaged in Vero cells. The cell passaged PEDV, designated KPEDV-9, was tested for its pathogenicity in the neonatal pigs, immunogenicity and safety in the pregnant sows. The result indicated that KPEDV-9 at the 93rd passage revealed reduced pathogenicity in the neonatal pigs. Pregnant sows inoculated with the attenuated virus

Chang-Hee Kweon; Byung-Joon Kwon; Jae-Gil Lee; Geon-Oh Kwon; Yung-Bai Kang

1999-01-01

7

Complete genome sequence of a highly prevalent isolate of porcine epidemic diarrhea virus in South China.  

PubMed

A widespread porcine epidemic diarrhea virus (PEDV) occurred in southern China during 2010 to 2012. A virulent field PEDV strain, GD-B, was isolated from a sucking piglet suffering from severe diarrhea in Guangdong, China. We sequenced and analyzed the complete genome of strain GD-B, which will promote a better understanding of the molecular epidemiology and genetic diversity of PEDV field isolates in southern China. PMID:22879620

Luo, Yongwen; Zhang, Jie; Deng, Xianbo; Ye, Yu; Liao, Ming; Fan, Huiying

2012-09-01

8

Complete Genome Sequence of a Variant Porcine Epidemic Diarrhea Virus Strain Isolated in Central China  

PubMed Central

We report here the complete genome sequence of the porcine epidemic diarrhea virus strain CH/ZMDZY/11 isolated from central China. Our data, together with sequence data of porcine epidemic diarrhea virus (PEDV) isolates from other parts in China, will help to understand better the epidemiology and genetic diversity of PEDV field isolates in China.

Wang, Xiao-Meng; Niu, Bei-Bei; Yan, He; Gao, Dong-Sheng; Huo, Jin-Yao; Chen, Lu; Chang, Hong-Tao; Wang, Chuan-qing

2013-01-01

9

Complete genome sequence of a variant porcine epidemic diarrhea virus strain isolated in central china.  

PubMed

We report here the complete genome sequence of the porcine epidemic diarrhea virus strain CH/ZMDZY/11 isolated from central China. Our data, together with sequence data of porcine epidemic diarrhea virus (PEDV) isolates from other parts in China, will help to understand better the epidemiology and genetic diversity of PEDV field isolates in China. PMID:23469356

Wang, Xiao-Meng; Niu, Bei-Bei; Yan, He; Gao, Dong-Sheng; Huo, Jin-Yao; Chen, Lu; Chang, Hong-Tao; Wang, Chuan-Qing; Zhao, Jun

2013-02-21

10

Complete genome sequence of a Vero cell-adapted isolate of porcine epidemic diarrhea virus in eastern China.  

PubMed

In early 2012, a widespread porcine epidemic diarrhea virus (PEDV) occurred in eastern China. A cell-adapted isolate, SD-M, was at the four-passage level of virulent field strain SD, which was isolated from a 2-day-old dead suckling piglet that had suffered from severe diarrhea in Shandong Province, China. We report here the complete genome sequence of SD-M. This sequence will promote a better understanding of the molecular pathogenesis of PEDV. PMID:23166259

Zhao, Mengjiao; Sun, Zhen; Zhang, Yue; Wang, Guisheng; Wang, Hui; Yang, Fangfang; Tian, Fulin; Jiang, Shijin

2012-12-01

11

Immune responses induced by DNA vaccines bearing Spike gene of PEDV combined with porcine IL-18.  

PubMed

Porcine epidemic diarrhea virus (PEDV) is the causative agent of porcine epidemic diarrhea, a highly contagious enteric disease of swine. The Spike (S) protein is one of the main structural proteins of PEDV capable of inducing neutralizing antibodies in vivo. Herein, we generated three distinct DNA constructs in the eukaryotic expression plasmid pVAX1; one encoding the S protein [pVAX1-(PEDV-S)], the second encoding the N-terminal fragment (S1) [pVAX1-(PEDV-S1)] containing potent antigenic sites, and the third expressing the porcine interleukin-18 (pIL-18) [pVAX1-(IL-18)]. Immunofluorescence assays in BHK-21 cells demonstrated successful protein expression from all 3 constructs. Kunming mice were injected separately with each of these constructs or with a pVAX1-(PEDV-S1)/pVAX1-(IL-18) combination, an attenuated PEDV vaccine, or vector only control. Animals were examined for T lymphocyte proliferation, anti-PEDV antibodies, IFN-? and IL-4 protein levels, and cytotoxic T cell function in mouse peripheral blood and spleen. In all cases, results showed that pVAX1-(PEDV-S) and the combination of pVAX1-(PEDV-S1) with pVAX1-(IL-18) induced the strongest responses; however, pIL-18 had no adjuvant effects when given in combination with pVAX1-(PEDV-S1). PMID:22643071

Suo, Siqingaowa; Ren, Yudong; Li, Guangxing; Zarlenga, Dante; Bu, Ri-E; Su, Dingding; Li, Xunliang; Li, Pengchong; Meng, Fandan; Wang, Chao; Ren, Xiaofeng

2012-05-19

12

Isolation and characterization of a variant porcine epidemic diarrhea virus in China.  

PubMed

An outbreak of diarrhea in pigs started in Guangdong, South China in January 2011. Cases were characterized by watery diarrhea, dehydration and vomiting, with 80-100% morbidity and 50-90% mortality in suckling piglets. The causative agent of the diarrhea was ultimately identified as porcine epidemic diarrhea virus (PEDV). In this study, we isolated a PEDV strain designated CHGD-01 from piglet intestines using Vero cell cultures, and its specific cytopathic effects were confirmed in susceptible cells by direct immunofluorescence testing and electron microscopy. The complete genome of CHGD-01 was shown to be 28,035 nucleotides in length, with a similar structure to that of PEDV reference strains. Phylogenetic analyses based on the whole genome revealed that CHGD-01 shared nucleotide sequence identities of 98.2-98.4% with two other Chinese isolates reported in the same year, thus constituting a new cluster. Amino acid sequence analysis based on individual virus genes indicated a close relationship between the spike protein gene of CHGD-01 and the field strain KNU0802 in Korea. Its ORF3 and nucleoprotein genes, however, were divergent from all other sequenced PEDV isolate clusters and therefore formed a new group, suggesting a new variant PEDV isolate in China. Further studies will be required to determine the immunogenicity and pathogenicity of this new variant. PMID:22967434

Pan, Yongfei; Tian, Xiaoyan; Li, Wei; Zhou, Qingfeng; Wang, Dongdong; Bi, Yingzuo; Chen, Feng; Song, Yanhua

2012-09-12

13

Molecular characterization and phylogenetic analysis of membrane protein genes of porcine epidemic diarrhea virus isolates in China  

Microsoft Academic Search

Six porcine epidemic diarrhea viruses (PEDVs) were isolated from the fecal samples of piglets infected with PEDV in 2006 in\\u000a China. The membrane (M) protein genes of six PEDV isolates were amplified by reverse transcriptase-polymerase chain reaction\\u000a (RT-PCR), then cloned, sequenced, and compared with each other as well as those ten PEDV reference strains. The M protein\\u000a genes of six

Jian-Fei Chen; Dong-Bo Sun; Cheng-Bao Wang; Hong-Yan Shi; Xiao-Chen Cui; Sheng-Wang Liu; Hua-Ji Qiu; Li Feng

2008-01-01

14

Heterogeneity in membrane protein genes of porcine epidemic diarrhea viruses isolated in China.  

PubMed

Since late 2010, porcine epidemic diarrhea virus (PEDV) has been re-emerging in immunized swine herds with devastating impact in the Hebei province of China. Seven prevailing strains of PEDV were isolated from fecal samples out of piglets suffering from severe diarrhea. The M gene of the seven PEDV isolates encompasses an open reading frame of 681 nucleotides, encoding a protein of 226 amino acids. The seven PEDV isolates showed 99.4-99.9 % nucleotide sequence identity and 98.2-99.1 % deduced amino acid identity. When compared with other Chinese isolates and foreign isolates, the seven isolates showed high nucleotide identity with the Thailand isolate M-NIAH1005 (99.6-99.9 %) and Korea isolate PFF188 (99.7-100 %), but low identity with other Chinese isolates (96.6-99.1 %) and with the vaccine strain CV777 used in China (97.8-98.2 %). Phylogenetic analyses showed that all seven Chinese field isolates were grouped together in the same cluster. Although CV777 was also separated into the same cluster with the seven isolates, they were belonged to different sub-cluster. These results showed that the seven prevailing isolates in China are closely related phylogenetically to each other and have close relationships with the Korean strain PFF188 and Thailand strain M_NIAH1005. However, they differ genetically from other Chinese isolates and the vaccine strain CV777. Therefore, a more efficient vaccine strain should be chosen to prevent outbreaks of PEDV in China. PMID:22585338

Fan, Jing-Hui; Zuo, Yu-Zhu; Li, Jian-Hui; Pei, Li-Hua

2012-05-15

15

Immune responses induced by DNA vaccines bearing Spike gene of PEDV combined with porcine IL-18  

Technology Transfer Automated Retrieval System (TEKTRAN)

Porcine epidemic diarrhea virus (PEDV) is the causative agent of porcine epidemic diarrhea, a highly contagious enteric disease of swine. The Spike (S) protein is one of the main structural proteins of PEDV capable of inducing neutralizing antibodies in vivo. Herein, we generated three distinct DNA ...

16

Complete genome sequence of porcine epidemic diarrhea virus strain AJ1102 isolated from a suckling piglet with acute diarrhea in China.  

PubMed

A diarrhea outbreak caused by porcine epidemic diarrhea virus (PEDV) has been observed in China since December 2010. We report here the complete genome sequence of PEDV strain AJ1102 isolated from a suckling piglet with acute diarrhea, which will help toward understanding the molecular and evolutionary characteristics of the epidemic PEDV in China. PMID:22966198

Bi, Jing; Zeng, Songlin; Xiao, Shaobo; Chen, Huanchun; Fang, Liurong

2012-10-01

17

Heterogeneity in spike protein genes of porcine epidemic diarrhea viruses isolated in Korea.  

PubMed

Porcine epidemic diarrhea virus (PEDV) has plagued the domestic swine industry in Korea causing significant economic impacts on pig production nationwide. In the present study, we determined the complete nucleotide sequences of the spike (S) glycoprotein genes of seven Korean PEDV isolates. The entire S genes of all isolates were found to be nine nucleotides longer in length than other PEDV reference strains. This size difference was due to the combined presence of notable 15 bp insertion and 6 bp deletion within the N-terminal region of the S1 domain of the Korean isolates. In addition, the largest number of amino acid variations was accumulated in the S1 N-terminal region, leading to the presence of hypervariability in the isolates. Sequence comparisons at the peptide level of the S proteins revealed that all seven Korean isolates shared diverse similarities ranging from a 93.6% to 99.6% identity with each other but exhibited a 92.2% to 93.7% identity with other reference strains. Collectively, the sequence analysis data indicate the diversity of the PEDV isolates currently prevalent in Korea that represents a heterogeneous group. Phylogenetic analyses showed two separate clusters, in which all Korean field isolates were grouped together in the second cluster (group 2). The results indicate that prevailing isolates in Korea are phylogenetically more closely related to each other rather than other reference strains. Interestingly, the tree topology based on the nucleotide sequences representing the S1 domain or the S1 N-terminal region most nearly resembled the full S gene-based phylogenetic tree. Therefore, our data implicates a potential usefulness of the partial S protein gene including the N-terminal region in unveiling genetic relatedness of PEDV isolates. PMID:20132850

Lee, Dong-Kyu; Park, Choi-Kyu; Kim, Seong-Hee; Lee, Changhee

2010-02-02

18

Sequence and phylogenetic analysis of nucleocapsid genes of porcine epidemic diarrhea virus (PEDV) strains in China.  

PubMed

Porcine epidemic diarrhea virus (PEDV) causes acute diarrhea and dehydration with high mortality rates in swine. It has become increasingly problematic in China. Since the nucleocapsid (N) protein is highly conserved, it is a candidate protein for early diagnosis and vaccine development. In this study, the N genes of 15 PEDV strains were amplified by RT-PCR and cloned into the pMT-19T vector, sequenced, and compared to each other as well as to PEDV reference strains. The nucleotide sequences of the N gene of the Chinese PEDV strains consist of 1326 nucleotides and encode a 441-aa-long peptide. The nucleotide sequences of the fifteen PEDV strains in our study were 96.1-100 % identical to each other, and the deduced amino acid sequences were 94.8-100 % identical. Sequence comparison with other PEDV strains selected from GenBank revealed that their nucleotide sequences were 94.2-99.7 % identical to those of the Chinese PEDV strains, and their deduced amino acid sequences were 94.1-99.5 % identical. In addition, the fifteen strains showed a high degree of nucleotide sequence identity to the early domestic strains (98.4-99.7 %) except the LZC strain, but less sequence identity to the vaccine strain (CV777) used in China (94.7-97.7 %). Phylogenetic analysis showed that the Chinese PEDV strains are composed of a separate cluster including three early domestic strains (JS-2004-02, LJB/03 and DX) but differ genetically from the vaccine strain (CV777) and the early Korean strains (Chinju99 and SM98). PMID:23389550

Li, Zhili; Chen, Feng; Yuan, Yao; Zeng, Xiduo; Wei, Zhongyan; Zhu, Ling; Sun, Baoli; Xie, Qingmei; Cao, Yongchang; Xue, Chunyi; Ma, Jingyun; Bee, Yingzuo

2013-02-07

19

Porcine aminopeptidase N is a functional receptor for the PEDV coronavirus  

Microsoft Academic Search

Porcine epidemic diarrhea virus (PEDV) causes lethal diarrhea in piglets that leads to great economic losses in East Asia. It was reported that aminopeptidase N (APN) is the receptor for transmissible gastroenteritis virus (TGEV), human coronavirus 229E (HCoV-229E) and feline coronavirus (FeCoV) which all belong to group I coronavirus including as well as PEDV. It was also confirmed previously that

B. X. Li; J. W. Ge; Y. J. Li

2007-01-01

20

PEDV ORF3 encodes an ion channel protein and regulates virus production.  

PubMed

Several studies suggest that the open reading frame 3 (ORF3) gene of porcine epidemic diarrhea virus (PEDV) is related to viral infectivity and pathogenicity, but its function remains unknown. Here, we propose a structure model of the ORF3 protein consisting of four TM domains and forming a tetrameric assembly. ORF3 protein can be detected in PEDV-infected cells and it functions as an ion channel in both Xenopus laevis oocytes and yeast. Mutation analysis showed that Tyr170 in TM4 is important for potassium channel activity. Furthermore, viral production is reduced in infected Vero cells when ORF3 gene is silenced by siRNA. Interestingly, the ORF3 gene from an attenuated PEDV encodes a truncated protein with 49 nucleotide deletions, which lacks the ion channel activity. PMID:22245155

Wang, Kai; Lu, Wei; Chen, Jianfei; Xie, Shiqi; Shi, Hongyan; Hsu, Haojen; Yu, Wenjing; Xu, Ke; Bian, Chao; Fischer, Wolfgang B; Schwarz, Wolfgang; Feng, Li; Sun, Bing

2012-01-11

21

Sequence analysis of the partial spike glycoprotein gene of porcine epidemic diarrhea viruses isolated in Korea  

Microsoft Academic Search

Porcine epidemic diarrhea virus (PEDV) causes a devastating enteric disease with acute diarrhea, dehydration and significant\\u000a mortality in swine, thereby incurring heavy economic losses in Korea. Spike (S) glycoprotein has been suggested as an important\\u000a determinant for PEDV biological properties. In this study, the nucleotide and deduced amino acid sequences of the partial\\u000a S glycoprotein genes of Korean PEDV isolates,

Seong-Jun Park; Hyoung-Joon Moon; Jeong-Sun Yang; Chul-Seung Lee; Dae-Sub Song; Bo-Kyu Kang; Bong-Kyun Park

2007-01-01

22

Heterogeneity in spike protein genes of porcine epidemic diarrhea viruses isolated in Korea  

Microsoft Academic Search

Porcine epidemic diarrhea virus (PEDV) has plagued the domestic swine industry in Korea causing significant economic impacts on pig production nationwide. In the present study, we determined the complete nucleotide sequences of the spike (S) glycoprotein genes of seven Korean PEDV isolates. The entire S genes of all isolates were found to be nine nucleotides longer in length than other

Dong-Kyu Lee; Choi-Kyu Park; Seong-Hee Kim; Changhee Lee

2010-01-01

23

Phage-displayed peptides having antigenic similarities with porcine epidemic diarrhea virus (PEDV) neutralizing epitopes  

Microsoft Academic Search

Seven-mer phage random peptide libraries were panned against 2C10, a monoclonal antibody that showed neutralizing activities against PEDV. Recombinant M13 phages displaying the peptides SHRLP(Y\\/Q)(P\\/V) or GPRPVTH on the g3p minor coat protein showed strong binding affinity with 2C10 (70% and 30% of recovered phages, respectively) after multiple panning. Sequence analysis suggested that these peptides are similar with 1368GPRLQPY1374 found

Deu John M. Cruz; Chul-Joong Kim; Hyun-Jin Shin

2006-01-01

24

Complete genome sequence of a variant porcine epidemic diarrhea virus strain isolated in China.  

PubMed

Since October 2010, an outbreak of porcine epidemic diarrhea (PED) has been observed in some provinces of China. Here we report the complete genome sequence of porcine epidemic diarrhea virus (PEDV) strain LC, which was recently isolated from sucking piglets that suffered from severe watery diarrhea in Guangdong. It will help in understanding the epidemiological and molecular characteristics of PEDV in China. PMID:23087112

Chen, Feng; Pan, Yongfei; Zhang, Xiangbin; Tian, Xiaoyan; Wang, Dongdong; Zhou, Qingfeng; Song, Yanhua; Bi, Yingzuo

2012-11-01

25

Isotype-specific antibody-secreting cells in systemic and mucosal associated lymphoid tissues and antibody responses in serum of conventional pigs inoculated with PEDV  

Microsoft Academic Search

An enzyme-linked immunospot (ELISPOT) has been developed to detect porcine epidemic diarrhea virus (PEDV)-specific antibody secreting cells (ASC) in gut associated lymphoid tissues (duodenum and ileum lamina propria and mesenteric lymph nodes) and systemic locations (spleen and blood) of conventional pigs so as to characterise the mucosal and systemic antibody response generated by the infection with PEDV. A total number

M. L de Arriba; A Carvajal; J Pozo; P Rubio

2002-01-01

26

Gradient isolator for flow field of fuel cell assembly  

DOEpatents

Isolator(s) include isolating material and optionally gasketing material strategically positioned within a fuel cell assembly. The isolating material is disposed between a solid electrolyte and a metal flow field plate. Reactant fluid carried by flow field plate channel(s) forms a generally transverse electrochemical gradient. The isolator(s) serve to isolate electrochemically a portion of the flow field plate, for example, transversely outward from the channel(s), from the electrochemical gradient. Further, the isolator(s) serve to protect a portion of the solid electrolyte from metallic ions.

Ernst, William D. (Troy, NY)

1999-01-01

27

Gradient isolator for flow field of fuel cell assembly  

DOEpatents

Isolator(s) include isolating material and optionally gasketing material strategically positioned within a fuel cell assembly. The isolating material is disposed between a solid electrolyte and a metal flow field plate. Reactant fluid carried by flow field plate channel(s) forms a generally transverse electrochemical gradient. The isolator(s) serve to isolate electrochemically a portion of the flow field plate, for example, transversely outward from the channel(s), from the electrochemical gradient. Further, the isolator(s) serve to protect a portion of the solid electrolyte from metallic ions. 4 figs.

Ernst, W.D.

1999-06-15

28

Economical development of small isolated fields  

SciTech Connect

U.K. offshore oil supplies could be in decline in 10 years unless new methods and technology are developed to open fields that are uncommercial by conventional methods. Such technology is being developed, and much of it is aimed at pressure boosting subsea stepout fields to improve production rate and recovery over increasing distances to a host platform. This paper is concerned with the development of small isolated fields for which a new platform facility is not justified or where no suitable existing host platform is available. The isolated-field production system described here comprises a two-stage subsea separator near the subsea well(s) from which production is tied in by flexible flowlines. Oil/water/gas separation is achieved at near atmosphere pressure, allowing safe loading of the ``dead`` crude into a tanker. The gas is flared at a surface buoy (directly above the separator unit) that also contains power generation and chemical injection facilities. Liquids are pumped to an offshore tanker-loading catenary anchor leg mooring (CALM) buoy, and then to the connected shuttle tanker. Control of the separator system is autonomous based on a programmable logic controller in the subsea control module, with commands and monitoring by an umbilical from a production center on the tanker.

Edwards, W.G.

1995-11-01

29

In Vitro Susceptibilities of Mycoplasma hyopneumoniae Field Isolates  

PubMed Central

The in vitro susceptibilities of 21 Mycoplasma hyopneumoniae field isolates were determined using a broth microdilution technique. One isolate showed acquired resistance to lincomycin, tilmicosin, and tylosin, while five isolates were resistant to flumequine and enrofloxacin. Acquired resistance against these antimicrobials in M. hyopneumoniae field isolates was not reported previously.

Vicca, J.; Stakenborg, T.; Maes, D.; Butaye, P.; Peeters, J.; de Kruif, A.; Haesebrouck, F.

2004-01-01

30

Sequence Heterogeneity of the ORF3 Gene of Porcine Epidemic Diarrhea Viruses Field Samples in Fujian, China, 2010-2012  

PubMed Central

Twenty-seven field samples that showed positive in PEDV detection were collected from different farms of Fujian province from 2010 to 2012. Their heterogeneity was investigated by analysis of the ORF3 gene because of its potential function as a representation of virulence. According to the results, six Fujian strains in Group 1 showed a different genotype with unique point mutations, which might be used in differentiation between PEDV groups and brought potential antigenic variation. P55 and five reference strains in Group 2 had a long length deletion, showing another genotype and might be involved in the variation of virulence. Phylogenetic analysis revealed that the collected Fujian strains were very distant from the vaccine development strain CV777, which might be the reason why the vaccine was inefficient to control the disease. The results can help to reconsider the strategy of PEDV vaccine management and prevent outbreaks of PEDV-induced diarrhea more efficiently.

Chen, Xi; Zeng, Lili; Yang, Jinxian; Yu, Fusong; Ge, Junqing; Guo, Qing; Gao, Xindang; Song, Tieying

2013-01-01

31

Sequence Heterogeneity of the ORF3 Gene of Porcine Epidemic Diarrhea Viruses Field Samples in Fujian, China, 2010-2012.  

PubMed

Twenty-seven field samples that showed positive in PEDV detection were collected from different farms of Fujian province from 2010 to 2012. Their heterogeneity was investigated by analysis of the ORF3 gene because of its potential function as a representation of virulence. According to the results, six Fujian strains in Group 1 showed a different genotype with unique point mutations, which might be used in differentiation between PEDV groups and brought potential antigenic variation. P55 and five reference strains in Group 2 had a long length deletion, showing another genotype and might be involved in the variation of virulence. Phylogenetic analysis revealed that the collected Fujian strains were very distant from the vaccine development strain CV777, which might be the reason why the vaccine was inefficient to control the disease. The results can help to reconsider the strategy of PEDV vaccine management and prevent outbreaks of PEDV-induced diarrhea more efficiently. PMID:24084234

Chen, Xi; Zeng, Lili; Yang, Jinxian; Yu, Fusong; Ge, Junqing; Guo, Qing; Gao, Xindang; Song, Tieying

2013-09-30

32

Development and evaluation of enzyme-linked immunosorbent assay based on recombinant nucleocapsid protein for detection of porcine epidemic diarrhea (PEDV) antibodies  

Microsoft Academic Search

An enzyme-linked immunosorbent assays (ELISA) based on recombinant nucleocapsid (N) protein generated in Escherichia coli was evaluated for its sensitivity and specificity for diagnosis of porcine epidemic diarrhea (PEDV) infection. The N gene encoding the N protein was cloned and expressed as a fusion protein with His tag protein in E. coli. The recombinant N protein was migrated at 48kDa

Xi-Lin Hou; Li-Yun Yu; Jianzhu Liu

2007-01-01

33

Characterization and epidemiological relationships of Spanish Brachyspira hyodysenteriae field isolates.  

PubMed

This research aimed to describe the genetic and phenotypic diversity of 74 Spanish Brachyspira hyodysenteriae field isolates, to establish epidemiological relationships between the isolates and to confirm the presence of tiamulin-resistant isolates in Spain. For these purposes, we performed biochemical tests in combination with diagnostic PCR analysis for the identification of Brachyspira spp. and for detection of the smpA/smpB gene. We also used antimicrobial susceptibility tests, random amplified polymorphic DNA (RAPD) and a new pulsed-field gel electrophoresis (PFGE) protocol. The combination of RAPD and PFGE allowed the study of epidemiological relationships. Both indole-negative and tiamulin-resistant isolates of B. hyodysenteriae are reported in Spain for the first time. The genetic analyses indicated a relationship between these Spanish isolates and indole-negative isolates previously obtained from Germany and Belgium. PMID:19480724

Hidalgo, A; Carvajal, A; Pringle, M; Rubio, P; Fellström, C

2009-06-01

34

Monensin sensitivity of recent field isolates of turkey coccidia.  

PubMed

The efficacy of monensin at concentrations of 60 and 100 ppm was evaluated against 22 isolates not exposed to monensin and 16 monensin-exposed field isolates of coccidia obtained from US and Canadian turkey flocks, respectively. Isolates not previously exposed to monensin were effectively controlled by monensin. However, 7 monensin-resistant isolates (predominantly Eimeria meleagrimitis) were independently isolated from turkey flocks in Ontario, Canada where monensin was being used as an anticoccidial. Subsequent sensitivity evaluations of two of these isolates revealed cross-resistance to lasolocid, narasin, and salinomycin. Evaluation of the stability of monensin resistance in one isolate suggested that monensin sensitivity was not restored after 10 generations of relaxed selection. Although the extent of monensin resistance among field isolates of turkey coccidia is unknown, these results provide the first unequivocal characterization of monensin resistance in field isolates of coccidia. Contrarily, after more than eight years of intensive use of monensin as an anticoccidial in US broiler production facilities, this type of resistance to the polyether antibiotic anticoccidials has not been encountered in chicken coccidia. PMID:7413578

Jeffers, T K; Bentley, E J

1980-08-01

35

Isolated Attosecond Pulses using a Detuned Second-harmonic Field  

SciTech Connect

Calculations are presented for the generation of an isolated attosecond pulse in a multicycle two-color strong-field regime. We show that the recollision of the electron wave packet can be confined to half an optical cycle using pulses of up to 40 fs in duration. The scheme is proven to be efficient using two intense beams, one producing a strong field at {omega} and the other a strong field detuned from 2{omega}. The slight detuning {delta}{omega} of the second harmonic is used to break the symmetry of the electric field over many optical cycles and provides a coherent control for the formation of an isolated attosecond pulse.

Merdji, Hamed; /Saclay /SLAC, PULSE; Auguste, Thierry; Boutu, Willem; Caumes, J.-Pascal; Carre, Bertrand; /Saclay; Pfeifer, Thomas; Jullien, Aurelie; Neumark, Daniel M.; Leone, Stephen R.; /UC, Berkeley /LBL, Berkeley

2007-11-07

36

Population structure of Citrus tristeza virus from field Argentinean isolates.  

PubMed

We studied the genetic variability of three genomic regions (p23, p25 and p27 genes) from 11 field Citrus tristeza virus isolates from the two main citrus growing areas of Argentina, a country where the most efficient vector of the virus, Toxoptera citricida, is present for decades. The pathogenicity of the isolates was determinated by biological indexing, single-strand conformation polymorphism analysis showed that most isolates contained high intra-isolate variability. Divergent sequence variants were detected in some isolates, suggesting re-infections of the field plants. Phylogenetic analysis of the predominant sequence variants of each isolate revealed similar grouping of isolates for genes p25 and p27. The analysis of p23 showed two groups contained the severe isolates. Our results showed a high intra-isolate sequence variability suggesting that re-infections could contribute to the observed variability and that the host can play an important role in the selection of the sequence variants present in these isolates. PMID:17999168

Iglesias, Néstor G; Gago-Zachert, Selma P; Robledo, Germán; Costa, Norma; Plata, María Inés; Vera, Osmar; Grau, Oscar; Semorile, Liliana C

2007-11-13

37

Comparative Transcriptional and Genomic Analysis of Plasmodium falciparum Field Isolates  

Microsoft Academic Search

Mechanisms for differential regulation of gene expression may underlie much of the phenotypic variation and adaptability of malaria parasites. Here we describe transcriptional variation among culture-adapted field isolates of Plasmodium falciparum, the species responsible for most malarial disease. It was found that genes coding for parasite protein export into the red cell cytosol and onto its surface, and genes coding

Margaret J. Mackinnon; Jinguang Li; Sachel Mok; Moses M. Kortok; Kevin Marsh; Peter R. Preiser; Zbynek Bozdech

2009-01-01

38

Electric field isolator (EFI) for isolated and electrophoretic manipulation of charged biomolecules.  

PubMed

This paper describes a novel technology-an electric field isolator (EFI)-that can be used for achieving isolated and electrophoretic manipulation of charged biomolecules inside a selected microscopic location. The EFI is a ground ring-shaped electrode (RE) surrounding a centre electrode (CE), which is comprised of a functional unit. When the CE is powered, the ground RE can inhibit the electric field from spreading to the neighbouring functional units. Therefore, the electrophoretic movement of the charged molecules in an electric field, which is based on the principle similar to that of electrophoresis, can be isolated inside a selected location. The ground RE causing this phenomenon is referred to as the EFI. In this paper, we clearly show the functionality of the EFI with mathematical and experimental studies. PMID:17594012

Yun, Jae Young; Mun, Sang Jun; Lee, Seung S; Nam, Hong Gil

2007-04-20

39

Methanococcus thermolithotrophicus Isolated from North Sea Oil Field Reservoir Water  

PubMed Central

Methanococcus thermolithotrophicus ST22 was isolated from produced water of a North Sea oil field, on mineral medium with H(inf2)-CO(inf2) as the sole source of carbon and energy. The isolate grew at 17 to 62(deg)C, with an optimum at 60(deg)C. The pH range was 4.9 to 9.8, with optimal growth at pH 5.1 to 5.9; these characteristics reflected its habitat. Strain ST22 was quickly identified and distinguished from the type strain by immunoblotting.

Nilsen, R. K.; Torsvik, T.

1996-01-01

40

Discovery of an isolated compact elliptical galaxy in the field  

NASA Astrophysics Data System (ADS)

We present the discovery of an isolated compact elliptical (cE) galaxy, found during a search of SDSS DR7 for cE galaxies, and for which we obtained William Herschel Telescope/ACAM imaging. It is ˜900 kpc distant from its nearest neighbour, has an effective r-band radius of ˜500 pc and a B-band mean surface brightness within its effective radius of 19.75 mag arcsec-1. Serendipitous deep SuprimeCam imaging shows that there is no underlying disc. Its isolated position suggests that there is an alternative channel to the stripping scenario for the formation of compact ellipticals. We also report analysis of recent deeper imaging of the previous candidate free-flying cE, which shows that it is, in fact, a normal dwarf elliptical. Hence, the new cE reported here is the first confirmed isolated cE to be found in the field.

Huxor, A. P.; Phillipps, S.; Price, J.

2013-04-01

41

[Isolation and characteristics of virus culture of porcine epidemic diarrhea virus LJB/03].  

PubMed

Porcine epidemic diarrhea virus (PEDV) LJB/03 strain was isolated from the feces of piglets suspected to be suffering from a severe diarrhea in Heilongjiang Province, and was identified by immunofluorescence test, immunelectronmicroscopy, RT-PCR and indirect ELISA assay. Characteristics of the virus culture and the methods of improvement of virus titer were explored. The results showed that the virus had the typical appearance of the coronavirus. Analysis of the nucleotide sequences of RT-PCR products revealed 98% homology with the reference strains. Indirect immunofluorescence assay showed a significant presence of green fluorescence, and an average P/N ratio of 7.6 by indirect ELISA assay. Taken together, these tests showed positive isolation of PEDV. Using the virus plaque purification cloning methods established in the test, the purified PEDV large plaque and small plaque were obtained, and the large plaque and small plaque titers were measured with significant difference. These results provide potential for the application of PEDV on the basis of the biological features of isolated virus. PMID:21344754

Mao, Ya-Yuan; Zhang, Gui-Hong; Ge, Jun-Wei; Jiang, Yan-Ping; Qiao, Xin-Yuan; Cui, Wen; Li, Yi-Jing

2010-11-01

42

Change in antimicrobial susceptibility of Mycoplasma gallisepticum field isolates.  

PubMed

This study compares the antimicrobial susceptibility over time between two groups of Mycoplasma gallisepticum (MG) isolates from the same geographical area. Minimum inhibitory concentration of 13 antimicrobials was determined against two groups of MG isolates from chickens. Group 1 strains (n=22) were isolated in 2004-2005 while group 2 strains (n=7) were isolated in 2007-2008. Minimum inhibitory concentration 50 for group 1 versus group 2 was 4/4, 0.5/0.5, ? 0.031/? 64, ? 0.031/2, ? 0.031/0.125, 1/0.5, 1/1, ? 0.031/? 0.031, ? 0.031/2, ? 0.031/2, 1/4, ? 0.031/0.062, and 0.062/2 ?g/ml against gentamicin, spectinomycin, erythromycin, tilmicosin, tylosin, florfenicol, thiamphenicol, tiamulin, ciprofloxacin, enrofloxacin, chlortetracycline, doxycycline, and oxytetracycline, respectively. There was a statistically significant increase in resistance of group 2 to erythromycin, tilmicosin, tylosin, ciprofloxacin, enrofloxacin, chlortetracycline, doxycycline, and oxytetracycline. This dramatic increase in resistance against 8 antimicrobials belonging to three different families of antimicrobials in a relatively short period of time appears to be rare and of concern. The cause of this increased resistance observed in group 2 of MG isolates was not determined and should be further investigated. Monitoring of MG field strain susceptibility is highly recommended to implement successful treatment and prophylaxis programs in endemic areas. PMID:21382675

Gharaibeh, Saad; Al-Rashdan, Mohammad

2011-02-13

43

Antimicrobial susceptibility testing of Spanish field isolates of Brachyspira hyodysenteriae.  

PubMed

This study is the first conducted in Spain to evaluate antimicrobial susceptibility of field isolates of Brachyspira hyodysenteriae. One hundred and eight isolates of the bacterium, recovered from different Spanish swine farms between 2000 and 2007, were investigated. The minimum inhibitory concentrations (MIC) of erythromycin, tylosin, tiamulin, valnemulin, clindamycin and lincomycin were determined using a broth microdilution technique. Most of the isolates showed poor susceptibility to erythromycin (MIC(90)>256 microg/ml), tylosin (MIC(90)>256 microg/ml), clindamycin (MIC(90)>4 microg/ml) and lincomycin (MIC(90)=128 microg/ml). Reduced susceptibility to tiamulin and valnemulin was observed with a MIC>2 microg/ml in 17.6% and 7.41% of the B. hyodysenteriae isolates, respectively. Moreover, a survival analysis permitted the detection of an increasing trend in the MIC values for almost all the antimicrobials used in the treatment of swine dysentery when comparing recent isolates (from 2006 to 2007) with those recovered in earlier years (between 2000 and 2004). PMID:19084246

Hidalgo, A; Carvajal, A; García-Feliz, C; Osorio, J; Rubio, P

2008-12-11

44

Pulsed-Field Gel Electrophoresis Typing of Staphylococcus aureus Isolates.  

PubMed

Pulsed-field gel electrophoresis (PFGE) is the most applied and effective genetic typing method for epidemiological studies and investigation of foodborne outbreaks caused by different pathogens, including Staphylococcus aureus. The technique relies on analysis of large DNA fragments generated by the cleavage of intact bacterial chromosomes with a rare cutting restriction enzyme, subsequently resolved by pulsed-field electrophoresis with periodic changes of the orientation of the electrical field across the gel. The high discriminatory power, improved reproducibility due to standardization of experimental protocols and data interpretation guidelines, and establishment of a national PFGE database of S. aureus profiles have made it a valuable means for global tracking of S. aureus infection sources and determination of genetic relatedness of outbreak isolates. PMID:24085692

He, Yiping; Xie, Yanping; Reed, Sue

2014-01-01

45

Characterization of field isolates of Trichoderma antagonistic against Rhizoctonia solani.  

PubMed

The aim of the present study was to characterize sixteen isolates of Trichoderma originating from a field of sugar beet where disease patches caused by Rhizoctonia solani were observed. Use of both molecular and morphological characteristics gave consistent identification of the isolates. Production of water-soluble and volatile inhibitors, mycoparasitism and induced systemic resistance in plant host were investigated using in vitro and in vivo tests in both sterilized and natural soils. This functional approach revealed the intra-specific diversity as well as biocontrol potential of the different isolates. Different antagonistic mechanisms were evident for different strains. The most antagonistic strain, T30 was identified as Trichoderma gamsii. This is the first report of an efficient antagonistic strain of T. gamsii being able to reduce the disease in different conditions. The ability to produce water-soluble inhibitors or coil around the hyphae of the pathogen in vitro was not related to the disease reduction in vivo. Additionally, the strains collected from the high disease areas in the field were better antagonists. The antagonistic activity was not characteristic of a species but that of a population. PMID:20943179

Anees, Muhammad; Tronsmo, Arne; Edel-Hermann, Véronique; Hjeljord, Linda Gordon; Héraud, Cécile; Steinberg, Christian

2010-06-09

46

Archaeoglobus fulgidus isolated from hot north sea oil field waters  

SciTech Connect

A hyperthermophilic sulfate reducer, strain 7324, was isolated from hot (75[degrees]C) oil field waters from an oil production platform in the Norwegian sector of the North Sea. It was enriched on a complex medium and isolated on lactate with sulfate. The cells were nonmotile, irregular coccoid to disc shaped, and 0.3 to 1.0 [mu]m wide. The temperature for growth was between 60 and 85[degrees]C with an optimum of 76[degrees]C. Lactate, pyruvate, and valerate plus H[sub 2] were utilized as carbon and energy sources with sulfate as electron acceptor. Lactate was completely oxidized to CO[sub 2]. The cells contained an active carbon monoxide dehydrogenase but no 2-oxoglutarate dehydrogenase pathway. The cells produced small amounts of methane simultaneously with sulfate reduction. F[sub 420] was detected in the cells which showed a blue-green fluorescence at 420 nm. On the basis of morphological, physiological, and serological features, the isolate was classified as an Archaeoglobus sp. Strain 7324 showed 100% DNA-DNA homology with A. fulgidus Z, indicating that it belongs to the species A. fulgidus. Archaeoglobus sp. has been selectively enriched and immunomagnetically captured from oil fields waters from three different platforms in the North Sea. Our results show that strain 7324 may grow in oil reservoirs at 70 to 85[degrees]C and contribute to hydrogen sulfide formation in this environment. 37 refs., 2 figs.

Beeder, J.; Nilsen, R.K.; Rosnes, J.T. Torsvik, T.; Lien, T. (Univ. of Bergen, Bergen (Norway))

1994-04-01

47

Archaeoglobus fulgidus Isolated from Hot North Sea Oil Field Waters  

PubMed Central

A hyperthermophilic sulfate reducer, strain 7324, was isolated from hot (75°C) oil field waters from an oil production platform in the Norwegian sector of the North Sea. It was enriched on a complex medium and isolated on lactate with sulfate. The cells were nonmotile, irregular coccoid to disc shaped, and 0.3 to 1.0 ?m wide. The temperature for growth was between 60 and 85°C with an optimum of 76°C. Lactate, pyruvate, and valerate plus H2 were utilized as carbon and energy sources with sulfate as electron acceptor. Lactate was completely oxidized to CO2. The cells contained an active carbon monoxide dehydrogenase but no 2-oxoglutarate dehydrogenase activity, indicating that lactate was oxidized to CO2 via the acetyl coenzyme A/carbon monoxide dehydrogenase pathway. The cells produced small amounts of methane simultaneously with sulfate reduction. F420 was detected in the cells which showed a blue-green fluorescence at 420 nm. On the basis of morphological, physiological, and serological features, the isolate was classified as an Archaeoglobus sp. Strain 7324 showed 100% DNA-DNA homology with A. fulgidus Z, indicating that it belongs to the species A. fulgidus. Archaeoglobus sp. has been selectively enriched and immunomagnetically captured from oil field waters from three different platforms in the North Sea. Our results show that strain 7324 may grow in oil reservoirs at 70 to 85°C and contribute to hydrogen sulfide formation in this environment. Images

Beeder, Janiche; Nilsen, Roald Kare; Rosnes, Jan Thomas; Torsvik, Terje; Lien, Torleiv

1994-01-01

48

Fitness of Cercospora Beticola Field Isolates – Resistant And – Sensitive to Demethylation Inhibitor Fungicides  

Microsoft Academic Search

Isolates of Cercospora beticola resistant to fungicides that inhibit sterol demethylation (DMIs) were collected from sugar beet fields in Northern Greece. Fitness of these isolates was compared to that of DMI-sensitive isolates. The parameters measured were competitive ability both under growth chamber and field conditions, mycelial growth, spore germination, germ tube length, incubation period, virulence and spore production. The competitive

G. S. Karaoglanidis; C. C. Thanassoulopoulos; P. M. Ioannidis

2001-01-01

49

Differentiation of a Vero cell adapted porcine epidemic diarrhea virus from Korean field strains by restriction fragment length polymorphism analysis of ORF 3  

Microsoft Academic Search

A porcine epidemic diarrhea virus (PEDV) designated DR13 was isolated in Vero cells and serially passaged by level 100. The virus was titrated at regular intervals of the passage level. Open reading frame (ORF) 3 sequences of the virus at passage levels 20, 40, 60, 80, and 100 were aligned and compared using a computer software program. Suitability of the

D. S Song; J. S Yang; J. S Oh; J. H Han; B. K Park

2003-01-01

50

[Detection of genetic variability in Cercospora kikuchii isolates from a single soybean field].  

PubMed

Detection of genetic variability in Cercospora kikuchii isolates from a single soybean field. Current knowledge about epidemiology and population structure of Cercospora kikuchii is little developed and no studies regarding this subject have been reported in Argentina. The aim of this work was to select primers to study genetic variability in C. kikuchii isolated from the same soybean field using RAPD (Random Amplified Polymorphism DNA). RAPD was applied to the DNA of 5 C. kikuchii, isolated from diseased tissue of the soybean in the same field, another isolate, from a strain collection. Out of seven primers, five of them proved to be useful to study the population of C. kikuchii isolates. PMID:17585651

Lurá, M C; Di Conza, J A; González, A M; Latorre Rapela, M G; Turino, L; Ibáñez, M M; Iacona, V

51

Aeromicrobium ginsengisoli sp. nov., isolated from a ginseng field.  

PubMed

Strain Gsoil 098(T), a Gram-positive, non-spore-forming, non-motile coccus, was isolated from soil from a ginseng field in South Korea and characterized in order to determine its taxonomic position. 16S rRNA gene sequence analysis revealed that strain Gsoil 098(T) belongs to the family Nocardioidaceae, and the highest degrees of sequence similarity were found with Aeromicrobium marinum T2(T) (99.0%), A. panaciterrae Gsoil 161(T) (98.9%), A. alkaliterrae KSL-107(T) (98.4%), A. fastidiosum KCTC 9576(T) (98.1%) and A. erythreum NRRL B-3381(T) (97.5%). Chemotaxonomic analysis revealed that strain Gsoil 098(T) possesses menaquinone MK-9(H(4)) and predominant fatty acids C(16 : 0), 10-methyl C(18:0) and C(18:0). DNA-DNA hybridization results and physiological and biochemical tests clearly demonstrated that strain Gsoil 098(T) represents a distinct species. Based on these data, Gsoil 098(T) (=KCTC 19207(T) =JCM 14732(T) =GBS 39(T)) should be classified as the type strain of a novel Aeromicrobium species, for which the name Aeromicrobium ginsengisoli sp. nov. is proposed. PMID:18768598

Kim, Myung Kyum; Park, Min-Ju; Im, Wan-Taek; Yang, Deok-Chun

2008-09-01

52

Permanent-magnet Faraday isolator with the field intensity of 25 kOe  

NASA Astrophysics Data System (ADS)

A Faraday isolator with a single magneto-optical element is constructed and experimentally tested. It provides the isolation ratio of 30 dB at an average laser radiation power of 650 W. These parameters are obtained by increasing the field intensity in the magnetic system of the isolator and employing a low-absorption magneto-optical element.

Mironov, E. A.; Snetkov, I. L.; Voitovich, A. V.; Palashov, O. V.

2013-08-01

53

CPm gene diversity in field isolates of Citrus tristeza virus from Colombia  

Microsoft Academic Search

The nucleotide sequence diversity of the CPm gene from 28 field isolates of Citrus tristeza virus (CTV) was assessed by SSCP and sequence analyses. These isolates showed two major shared haplotypes, which differed in distribution:\\u000a A1 was the major haplotype in 23 isolates from different geographic regions, whereas R1 was found in isolates from a discrete\\u000a region. Phylogenetic reconstruction clustered

Oscar Arturo Oliveros-Garay; Natalhie Martinez-Salazar; Yanneth Torres-Ruiz; Orlando Acosta

2009-01-01

54

High-level mucosal and systemic immune responses induced by oral administration with Lactobacillus-expressed porcine epidemic diarrhea virus (PEDV) S1 region combined with Lactobacillus-expressed N protein.  

PubMed

To develop effective mucosal vaccine formulation against porcine epidemic diarrhea virus (PEDV) infection, the DNA fragments encoding spike protein immunodominant region S1 and nucleocapsid N of PEDV were inserted into pPG1 (surface-displayed) or pPG2 (secretory) plasmids followed by electrotransformation into Lactobacillus casei (Lc) to yield four recombinant strains: PG1-S1, PG2-S1, PG1-N, and PG2-N. After intragastric administration, it was observed that live Lc-expressing S1 protein combined with Lc-expressing N protein could elicit much more potent mucosal and systemic immune responses than the former alone (P < 0.001), however slightly inferior to the latter alone (P > 0.05). Furthermore, the surface-displayed mixture (PG1-S1+ PG1-N) revealed stronger immunogenicity than the secretory mixture (PG2-S1+ PG2-N) as well as PEDV-neutralizing potency in vitro (P < 0.001). On 49th day after the last immunization, splenocytes were prepared from mice immunized with surface-displayed mixture, secretory mixture and negative control to be stimulated by purified N and S protein, respectively. The results of ELISA analysis showed that N protein was capable of inducing a higher level of IL-4 (P < 0.001) and IFN-? (P < 0.001) than S1 protein in the immunized mice. Taken together, Lc-expressed N protein as molecular adjuvant or immunoenhancer was able to effectively facilitate the induction of mucosal and systemic immune responses by Lc-expressing S1 region. PMID:22134641

Liu, Di-qiu; Ge, Jun-wei; Qiao, Xin-yuan; Jiang, Yan-ping; Liu, Song-mei; Li, Yi-jing

2011-12-02

55

Isolation, characterization, and sensitivity to 2,4-diacetylphloroglucinol of isolates of Phialophora spp. from Washington wheat fields.  

PubMed

Dark pigmented fungi of the Gaeumannomyces-Phialophora complex were isolated from the roots of wheat grown in fields in eastern Washington State. These fungi were identified as Phialophora spp. on the basis of morphological and genetic characteristics. The isolates produced lobed hyphopodia on wheat coleoptiles, phialides, and hyaline phialospores. Sequence comparison of internal transcribed spacer regions indicated that the Phialophora isolates were clearly separated from other Gaeumannomyces spp. Primers AV1 and AV3 amplified 1.3-kb portions of an avenacinase-like gene in the Phialophora isolates. Phylogenetic trees of the avenacinase-like gene in the Phialophora spp. also clearly separated them from other Gaeumannomyces spp. The Phialophora isolates were moderately virulent on wheat and barley and produced confined black lesions on the roots of wild oat and two oat cultivars. Among isolates tested for their sensitivity to 2,4-diacetylphloroglucinol (2,4-DAPG), the 90% effective dose values were 11.9 to 48.2 microg ml(-1). A representative Phialophora isolate reduced the severity of take-all on wheat caused by two different isolates of Gaeumannomyces graminis var. tritici. To our knowledge, this study provides the first report of an avenacinase-like gene in Phialophora spp. and demonstrated that the fungus is significantly less sensitive to 2,4-DAPG than G. graminis var. tritici. PMID:20373960

Kwak, Youn-Sig; Bakker, Peter A H M; Glandorf, Debora C M; Rice, Jennifer T; Paulitz, Timothy C; Weller, David M

2010-05-01

56

Interferometric optical isolator employing a nonreciprocal phase shift operated in a unidirectional magnetic field.  

PubMed

An interferometric optical isolator that employs a nonreciprocal phase shift was studied. The optical isolator consisted of an interferometer with distinct layer structures. A traveling light wave underwent distinct nonreciprocal phase shifts such that the optical isolator could be operated in a unidirectional magnetic field. The optical isolator, in which the waveguide had a HfO2 cladding layer in one of the arms, was designed at a wavelength of 1.55 microm. The propagation distance of the nonreciprocal phase shifter required for the isolator's operation was less than 1.5 mm. The device's total length was less than 2 mm. An optical isolator with distinct layer structures was fabricated and evaluated. An isolation ratio of approximately 9.9 dB was obtained in the unidirectional magnetic field. PMID:15352401

Yokoi, Hideki; Shoji, Yuya; Shin, Etsu; Mizumoto, Tetsuya

2004-08-20

57

Characterization of Isolates of Meloidogyne from Rice-Wheat Production Fields in Nepal  

PubMed Central

Thirty-three isolates of root-knot nematode were recovered from soil samples from rice-wheat fields in Nepal and maintained on rice cv. BR 11. The isolates were characterized using morphology, host range and DNA sequence analyses in order to ascertain their identity. Results indicated phenotypic similarity (juvenile measurements, perennial pattern, host range and gall shape) of the Nepalese isolates with Meloidogyne graminicola, with minor variations. The rice varieties LA 110 and Labelle were susceptible to all of the Nepalese isolates, but differences in the aggressiveness of the isolates were observed. Phylogenetic analyses based on the sequences of partial internal transcribed spacer (ITS) of the rRNA genes indicated that all Nepalese isolates formed a distinct clade with known isolates of M. graminicola with high bootstrap support. Furthermore, two groups were identified within the M. graminicola clade. No correlation between ITS haplotype and aggressiveness or host range was found among the tested isolates.

Pokharel, Ramesh R.; Abawi, George S.; Zhang, Ning; Duxbury, John M.; Smart, Christine D.

2007-01-01

58

Complete Genome Sequence of a Recombinant Porcine Epidemic Diarrhea Virus Strain from Eastern China  

PubMed Central

A field porcine epidemic diarrhea virus (PEDV) strain, JS2008, was isolated from stool samples of a piglet with acute diarrhea on a vaccinated farm in eastern China. We sequenced and analyzed the complete genome of strain JS2008, which will help increase our understanding of the molecular characteristics of the epidemic PEDV in China.

Liu, Haofei; He, Kongwang; Guo, Rongli; Ni, Yanxiu; Du, Luping; Wen, Libin; Zhang, Xuehan; Yu, Zhengyu; Zhou, Junming; Mao, Aihua; Lv, Lixin; Hu, Yiyi; Yu, Yang; Zhu, Haodan; Wang, Xiaomin

2013-01-01

59

Complete genome sequence of a recombinant porcine epidemic diarrhea virus strain from eastern china.  

PubMed

A field porcine epidemic diarrhea virus (PEDV) strain, JS2008, was isolated from stool samples of a piglet with acute diarrhea on a vaccinated farm in eastern China. We sequenced and analyzed the complete genome of strain JS2008, which will help increase our understanding of the molecular characteristics of the epidemic PEDV in China. PMID:23599287

Li, Bin; Liu, Haofei; He, Kongwang; Guo, Rongli; Ni, Yanxiu; Du, Luping; Wen, Libin; Zhang, Xuehan; Yu, Zhengyu; Zhou, Junming; Mao, Aihua; Lv, Lixin; Hu, Yiyi; Yu, Yang; Zhu, Haodan; Wang, Xiaomin

2013-04-18

60

Analysis of genotypic diversity in Cercospora beticola Sacc. field isolates  

Microsoft Academic Search

Genetic variability and population structure ofCercospora beticola, the causal agent of Cercospora leaf spot in sugarbeet, from four sugarbeet-growing regions of Greece were investigated using\\u000a growth rate, pathogenicity, and mini- and microsatellite DNA fingerprinting. Mycelial growth and pathogenicity were very diverse\\u000a within and between groups, and no correlation was found between these features and the geographic origin of the isolates.

Maddalena Moretti; George Karaoglanidis; Marco Saracchi; Anna Fontana; Gandolfina Farina

2006-01-01

61

Molecular characterization of field azoxystrobin-resistant isolates of Botrytis cinerea  

Microsoft Academic Search

Sensitivity of 184 Botrytis cinerea field isolates to a Qo inhibitor (QoI) fungicide azoxystrobin was determined in this study. Among the 184 isolates, seven showed resistance to azoxystrobin. All these seven azoxystrobin-resistant (AR) isolates were also resistant to a benzimidazole fungicide carbendazim, and a dicarboximide fungicide iprodione. Negative cross-resistance between azoxystrobin and a carboxamide fungicide boscalid was not observed in

Jinhua Jiang; Laisong Ding; Themis J. Michailides; Hongye Li; Zhonghua Ma

2009-01-01

62

Optimum design of bridges with superelastic-friction base isolators against near-field earthquakes  

Microsoft Academic Search

The seismic response of a multi-span continuous bridge isolated with novel superelastic-friction base isolator (S-FBI) is investigated under near-field earthquakes. The isolation system consists of a flat steel-Teflon sliding bearing and a superelastic NiTi shape memory alloy (SMA) device. Sliding bearings limit the maximum seismic forces transmitted to the superstructure to a certain value that is a function of friction

Osman E. Ozbulut; Stefan Hurlebaus

2010-01-01

63

Comparison of Field-Collected Ascovirus Isolates by DNA Hybridization, Host Range, and Histopathology  

Microsoft Academic Search

Six field-collected ascovirus isolates obtained from five noctuid species in the continental United States were compared with respect to the general relatedness of their DNA, host range, and histopathology. Two isolates were fromSpodoptera frugiperda,and the other four were fromAutographa precationis, Heliothis virescens, Helicoverpa zea,andTrichoplusia ni.DNA–DNA hybridization studies showed that the six isolates belonged to three distinct viral species, with the

John J Hamm; Eloise L Styer; Brian A Federici

1998-01-01

64

7 CFR 201.76 - Minimum Land, Isolation, Field, and Seed Standards.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 false Minimum Land, Isolation, Field, and Seed Standards. 201.76 Section 201.76 Agriculture...DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Certified Seed § 201.76...

2010-01-01

65

7 CFR 201.76 - Minimum Land, Isolation, Field, and Seed Standards.  

Code of Federal Regulations, 2010 CFR

...2009-01-01 false Minimum Land, Isolation, Field, and Seed Standards. 201.76 Section 201.76 Agriculture...DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Certified Seed § 201.76...

2009-01-01

66

Pulsed-Field Gel Electrophoresis Study of Mycobacterium abscessus Isolates Previously Affected by DNA Degradation  

Microsoft Academic Search

DNA degradation (which results in a smear pattern) occurs with almost 50% of Mycobacterium abscessus strains during pulsed-field gel electrophoresis (PFGE). We assessed the potential benefit of using thiourea- containing buffer with M. abscessus by studying 69 isolates not previously typeable by PFGE (i.e., those with a smear pattern). Random (epidemiologically unrelated) isolates that were typeable (no smear pattern) were

Yansheng Zhang; Mitchell A. Yakrus; Edward A. Graviss; Natalie Williams-Bouyer

67

Molecular-genetic analysis of field isolates of Avian Leucosis Viruses in the Russian Federation  

Technology Transfer Automated Retrieval System (TEKTRAN)

Commercial poultry farms in 14 regions of Russian Federation were monitored for avian leukosis virus (ALV) infection using virus isolation tests and serology. Results indicated the presence of two subgroups of ALV in farms located in 11 of 14 regions. Analysis of the genomes of 12 field isolates of...

68

A procedure for isolating and freezing metacyclic Trypanosoma brucei gambiense forms in the field  

Microsoft Academic Search

An adaptation of a modified procedure using anion-exchange centrifugation was evaluated to isolate and freeze in field conditions a high number of bloodstream forms of Trypanosoma brucei gambiense for direct in vitro culture. Pellets of trypanosomes were obtained from 62 patients in Central Africa. The presence of trypanosomes was detected in all 62 eluates. The isolation system was efficient. Preliminary

P Truc; C. Lekane Likeufack; N Mbongo; V Ebo’o Enyenga

2004-01-01

69

Complete Genome Sequence of a Very Virulent Porcine Epidemic Diarrhea Virus Strain, CH/GDGZ/2012, Isolated in Southern China.  

PubMed

The classical symptoms of porcine epidemic diarrhea (PED) are acute diarrhea and dehydration. The isolated porcine epidemic diarrhea virus (PEDV) CH/GDGZ/2012 strain was obtained from the feces of diseased pigs in 2012 in southern China. We report the complete genome sequence of strain CH/GDGZ/2012, which might be useful for better understanding the molecular characteristics of this virus. PMID:23969052

Tian, Ye; Su, Danping; Zhang, Haiming; Chen, Rui-Ai; He, Dongsheng

2013-08-22

70

Rhodanobacter umsongensis sp. nov., isolated from a Korean ginseng field.  

PubMed

A bacterial isolate designated GR24-2(T) was isolated from Korean soil used for cultivating ginseng (Panax ginseng C. A. Meyer). The strain was aerobic, Gram-negative, motile, and rod-shaped. It grew optimally at 28-30°C, pH 7.0, and in a range of 0-1% NaCl. Phylogenetically, the strain clustered with members of the genus Rhodanobacter. The strain exhibited the highest sequence similarities (>98%) with R. panaciterrae LnR5-47(T) (98.4%), R. soli DCY45(T) (98.2%), and R. ginsengisoli GR17-7(T) (98.0%). However, it also showed high sequence similarities (>97%) with some other Rhodanobacter and Dyella species. The strain contained Q-8 as the predominant respiratory quinone. The major fatty acids (greater than 10% of the total fatty acids) were iso-C17:1 ?9c (24.5%), iso-C16:0 (22.8%), anteiso-C15:0 (10.5%), and iso-C15:0 (10.1%). Its major polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, and an unknown aminophospholipid. The DNA G+C content of strain GR24-2(T) was 65.6 mol%. The strain showed less than 70% DNA relatedness values between the closely related Rhodanobacter and Dyella species. The phylogeny, phenotype, DNA-DNA hybridization, and chemotaxonomic data generated in this study reveal that the isolate is a novel species of the genus Rhodanobacter. The name proposed for this strain is Rhodanobacter umsongensis sp. nov. (type strain GR24-2(T) =KACC 12917(T) =DSM 21300(T)). PMID:23625230

Kim, Yi-Seul; Kim, Soo-Jin; Anandham, Rangasamy; Weon, Hang-Yeon; Kwon, Soon-Wo

2013-04-27

71

Pulsed-field gel electrophoresis typing of Staphylococcus aureus isolates  

Technology Transfer Automated Retrieval System (TEKTRAN)

Pulsed-field gel electrophoresis (PFGE) is the most applied and effective genetic typing method for epidemiological studies and investigation of foodborne outbreaks caused by different pathogens, including Staphylococcus aureus. The technique relies on analysis of large DNA fragments generated by th...

72

Characterization of nitrogen-fixing bacteria isolated from field-grown barley, oat, and wheat.  

PubMed

Diazotrophic bacteria were isolated from the rhizosphere of field-grown Triticum aestivum, Hordeum vulgare, and Avena sativa grown in various regions of Greece. One isolate, with the highest nitrogen-fixation ability from each of the eleven rhizospheres, was selected for further characterisation. Diazotrophic strains were assessed for plant-growth-promoting traits such as indoleacetic acid production and phosphate solubilisation. The phylogenies of 16S rRNA gene of the selected isolates were compared with those based on dnaK and nifH genes. The constructed trees indicated that the isolates were members of the species Azospirillum brasilense, Azospirillum zeae, and Pseudomonas stutzeri. Furthermore, the ipdC gene was detected in all A. brasilence and one A. zeae isolates. The work presented here provides the first molecular genetic evidence for the presence of culturable nitrogen-fixing P. stutzeri and A. zeae associated with field-grown A. sativa and H. vulgare in Greece. PMID:21887633

Venieraki, Anastasia; Dimou, Maria; Vezyri, Eleni; Kefalogianni, Io; Argyris, Nikolaos; Liara, Georgia; Pergalis, Panagiotis; Chatzipavlidis, Iordanis; Katinakis, Panagiotis

2011-09-02

73

Ultra-short isolated attosecond emission in mid-infrared inhomogeneous fields without CEP stabilization  

NASA Astrophysics Data System (ADS)

We theoretically investigate high-order harmonic generation in a spatially inhomogeneous field with mid-infrared driving wavelength and few-cycle duration. It is found that this spatiotemporally synthesized electric field is powerful to control the quantum path; as a result an ultra-broadband supercontinuum with bandwidth over 300 eV can be obtained successfully. Important characteristics of the attosecond pulse generation, including temporal envelope, harmonic chirp and carrier–envelope phase (CEP) dependence are further discussed. The results show that close-to-Fourier-limit 27 as isolated pulses are straightforwardly filtered from the supercontinuum. Moreover, such short isolated attosecond pulses can be supported by nearly all the CEPs of the laser electric field. This would open a way to obtain broadband isolated attosecond pulses with no need of CEP stabilization of the laser field.

Luo, Jianghua; Li, Yang; Wang, Zhe; Zhang, Qingbin; Lu, Peixiang

2013-07-01

74

Pulsed-field gel electrophoresis diversity of human and bovine clinical Salmonella isolates.  

PubMed

Pulsed-field gel electrophoresis (PFGE) characterization of 335 temporally and spatially matched clinical, bovine, and human Salmonella enterica subsp. enterica isolates revealed 167 XbaI PFGE patterns. These isolates were previously classified into 51 serotypes and 73 sequence types, as determined by multilocus sequence typing. Discriminatory power of PFGE (Simpson's index, D = 0.991) was considerably higher than that of multilocus sequence typing (D = 0.920) or serotyping (D = 0.913). Although 128 PFGE types each only represented a single isolate, 8 PFGE types represented >4 isolates, including (i) three serotype Enteritidis and Heidelberg patterns that were only identified among human isolates, (ii) two PFGE patterns (each representing serotypes Bardo and Newport) that were significantly more common among bovine isolates as compared with human isolates; (iii) two PFGE types that each includes two serotypes (4,5,12:i:- and Typhimurium; Thompson and 1,7:-:1,5); and (iv) one PFGE type that includes eight Typhimurium isolates from humans and cattle. Characterization of isolates collected over multiple farm visits indicated that given specific PFGE types persisted over time on 11 farms. On an additional seven farms, isolates with a given sequence type represented multiple PFGE type, which typically only differed by <3 bands, suggesting PFGE type diversification during strain persistence. Sixteen PFGE types were isolated from 2 or more farms, including two widely distributed serotype Newport-associated PFGE types each found on 10 farms. In six instances two or three human isolates collected in the same county in the same or consecutive months represented the same subtypes, suggesting small human case clusters. PFGE-based characterization and surveillance of human and animal isolates can provide improved understanding of Salmonella diversity and epidemiology, including identification of possible host-associated and common, widely distributed PFGE types. PMID:20180633

Soyer, Ye?im; Alcaine, Samuel D; Schoonmaker-Bopp, Dainna J; Root, Timothy P; Warnick, Lorin D; McDonough, Patrick L; Dumas, Nellie B; Gröhn, Yrjo T; Wiedmann, Martin

2010-06-01

75

Pulsed-Field Gel Electrophoresis Diversity of Human and Bovine Clinical Salmonella Isolates  

PubMed Central

Abstract Pulsed-field gel electrophoresis (PFGE) characterization of 335 temporally and spatially matched clinical, bovine, and human Salmonella enterica subsp. enterica isolates revealed 167 XbaI PFGE patterns. These isolates were previously classified into 51 serotypes and 73 sequence types, as determined by multilocus sequence typing. Discriminatory power of PFGE (Simpson's index, D?=?0.991) was considerably higher than that of multilocus sequence typing (D?=?0.920) or serotyping (D?=?0.913). Although 128 PFGE types each only represented a single isolate, 8 PFGE types represented >4 isolates, including (i) three serotype Enteritidis and Heidelberg patterns that were only identified among human isolates, (ii) two PFGE patterns (each representing serotypes Bardo and Newport) that were significantly more common among bovine isolates as compared with human isolates; (iii) two PFGE types that each includes two serotypes (4,5,12:i:- and Typhimurium; Thompson and 1,7:-:1,5); and (iv) one PFGE type that includes eight Typhimurium isolates from humans and cattle. Characterization of isolates collected over multiple farm visits indicated that given specific PFGE types persisted over time on 11 farms. On an additional seven farms, isolates with a given sequence type represented multiple PFGE type, which typically only differed by <3 bands, suggesting PFGE type diversification during strain persistence. Sixteen PFGE types were isolated from 2 or more farms, including two widely distributed serotype Newport-associated PFGE types each found on 10 farms. In six instances two or three human isolates collected in the same county in the same or consecutive months represented the same subtypes, suggesting small human case clusters. PFGE-based characterization and surveillance of human and animal isolates can provide improved understanding of Salmonella diversity and epidemiology, including identification of possible host-associated and common, widely distributed PFGE types.

Soyer, Yesim; Alcaine, Samuel D.; Schoonmaker-Bopp, Dainna J.; Root, Timothy P.; Warnick, Lorin D.; McDonough, Patrick L.; Dumas, Nellie B.; Grohn, Yrjo T.

2010-01-01

76

Genetic relatedness of Bradyrhizobium japonicum field isolates as revealed by repeated sequences and various other characteristics.  

PubMed Central

Forty-nine isolates of Bradyrhizobium japonicum indigenous to a field where soybeans were grown for 45 years without inoculation were characterized by using four DNA hybridization probes from B. japonicum. nifDK-specific hybridization clearly divided the isolates into two divergent groups. Diversity in repeated-sequence (RS)-specific hybridization was observed; 44 isolates derived from 41 nodules were divided into 33 different RS fingerprint groups. Cluster analysis showed that the RS fingerprints were correlated with the nif and hup genotypes. We found multiple bands of RS-specific hybridization for two isolates that differed from the patterns of the other isolates. These results suggest that RS fingerprinting is a valuable tool for evaluating the genetic structure of indigenous B. japonicum populations. Images

Minamisawa, K; Seki, T; Onodera, S; Kubota, M; Asami, T

1992-01-01

77

Generation of isolated attosecond extreme ultraviolet pulses employing nanoplasmonic field enhancement: optimization of coupled ellipsoids  

NASA Astrophysics Data System (ADS)

The production of extreme ultraviolet (XUV) radiation via nanoplasmonic field-enhanced high-harmonic generation (HHG) in gold nanostructures at MHz repetition rates is investigated theoretically in this paper. Analytical and numerical calculations are employed and compared in order to determine the plasmonic fields in gold ellipsoidal nanoparticles. The comparison indicates that numerical calculations can accurately predict the field enhancement and plasmonic decay, but may encounter difficulties when attempting to predict the oscillatory behavior of the plasmonic field. Numerical calculations for coupled symmetric and asymmetric ellipsoids for different carrier-envelope phases (CEPs) of the driving laser field are combined with time-dependent Schrödinger equation simulations to predict the resulting HHG spectra. The studies reveal that the plasmonic field oscillations, which are controlled by the CEP of the driving laser field, play a more important role than the nanostructure configuration in finding the optimal conditions for the generation of isolated attosecond XUV pulses via nanoplasmonic field enhancement.

Stebbings, S. L.; Süßmann, F.; Yang, Y.-Y.; Scrinzi, A.; Durach, M.; Rusina, A.; Stockman, M. I.; Kling, M. F.

2011-07-01

78

Pulsed-field gel electrophoresis for epidemiologic studies of Campylobacter hyointestinalis isolates.  

PubMed Central

Campylobacter hyointestinalis was isolated from five members of the same family who had previously consumed raw milk. Pulsed-field gel electrophoresis of genomic DNAs from the five strains, after digestion with restriction endonuclease SalI, revealed that three strains had identical genome patterns and therefore appeared to be related, whereas the other two had completely different genome patterns and appeared to be unrelated. We report here for the first time the isolation of C. hyointestinalis from family members who had consumed raw milk. Our study also demonstrates the usefulness of pulsed-field gel electrophoresis for epidemiologic studies of this unusual campylobacter. Images

Salama, S M; Tabor, H; Richter, M; Taylor, D E

1992-01-01

79

Genetic variation of nucleocapsid genes of porcine epidemic diarrhea virus field strains in China.  

PubMed

Porcine epidemic diarrhea virus (PEDV) poses a great threat to the Chinese swine industry. During 2006-2011, 74.0 % (94/127) of samples from 32 swine-raising farms in 15 provinces were positive for PEDV by reverse transcription nested polymerase chain reaction (RT-nested PCR). The sequences of nucleocapsid (N) genes of 32 representative field strains were determined, and the open reading frames (ORFs) of these N genes were 1326 nucleotides long. The N gene sequences were found to be more than 95 % identical to each other. The number of potential phosphorylation sites in the N protein varied from 5 to 12. A phylogenetic tree based on the N genes showed that the 32 Chinese field strains formed three groups. PMID:23381394

Chen, Jianfei; Liu, Xiaozhen; Lang, Hongwu; Wang, Zhongtian; Shi, Da; Shi, Hongyan; Zhang, Xin; Feng, Li

2013-02-05

80

Turning Points in the Evolution of Isolated Neutron Stars'Magnetic Fields  

Microsoft Academic Search

During the life of isolated neutron stars (NSs) their magnetic field passes through a variety of evolutionary phases. Depending\\u000a on its strength and structure and on the physical state of the NS (e.g., cooling, rotation), the field looks qualitatively\\u000a and quantitatively different after each of these phases. Three of them, the phase of MHD instabilities immediately after NS's\\u000a birth, the

Ulrich Geppert

2009-01-01

81

Pitch Discrimination in Field and Isolation-Reared Black-Capped Chickadees (Parus atricapillus )  

Microsoft Academic Search

Prior research has shown that male black-capped chickadees (Parus atricapillus) raised in the field produce constant relative pitch cues (frequency ratios) in their songs, whereas males reared in isolation from adult song do not. In this study, the authors found that field-reared male chickadees needed fewer than half as many sessions to learn an operant (go\\/no-go) auditory discrimination that linked

Milan Njegovan; Ron Weisman

1997-01-01

82

Pulsed Electric Field-Induced Structural Modification of Whey Protein Isolate  

Microsoft Academic Search

Effects of pulsed electric fields (PEF) on structural modification and surface hydrophobicity were assessed for whey protein\\u000a isolate (WPI) of protein concentrations (3% and 5%) using fluorescence spectroscopy. The effects of a factorial combination\\u000a of electric field intensities (12, 16, and 20 kV cm?1) and number of pulses (10, 20, and 30) on the intrinsic tryptophan fluorescence intensity, extrinsic fluorescence intensity,

Bob Y. Xiang; Michael O. Ngadi; Luz A. Ochoa-Martinez; Marian V. Simpson

83

Handling and Isolation in Three Strains of Rats Affect Open Field, Exploration, Hoarding and Predation  

Microsoft Academic Search

Male albino (Al), brown hooded (Br) and black hooded (Bl) rats were raised in social isolation or in pairs, with or without systematic handling. At 90 and 180 days of age, the animals were individually tested for activity in an open field (Of), exploratory behavior in a complex environment, food hoarding (Hd) and insect predation (Pd). Multivariate analysis of the

Ramiro C. R Rebouças; Werner Robert Schmidek

1997-01-01

84

Molecular Typing by Pulsed-Field Gel Electrophoresis of Spanish Animal and Human Listeria monocytogenes Isolates  

PubMed Central

A total of 153 strains of Listeria monocytogenes isolated from different sources (72 from sheep, 12 from cattle, 18 from feedstuffs, and 51 from humans) in Spain from 1989 to 2000 were characterized by pulsed-field gel electrophoresis. The strains of L. monocytogenes displayed 55 pulsotypes. The 84 animal, 51 human, and 18 feedstuff strains displayed 31, 29, and 7 different pulsotypes, respectively, indicating a great genetic diversity among the Spanish L. monocytogenes isolates studied. L. monocytogenes isolates from clinical samples and feedstuffs consumed by the diseased animals were analyzed in 21 flocks. In most cases, clinical strains from different animals of the same flock had identical pulsotypes, confirming the existence of a listeriosis outbreak. L. monocytogenes strains with pulsotypes identical to those of clinical strains were isolated from silage, potatoes, and maize stalks. This is the first study wherein potatoes and maize stalks are epidemiologically linked with clinical listeriosis.

Vela, A. I.; Fernandez-Garayzabal, J. F.; Vazquez, J. A.; Latre, M. V.; Blanco, M. M.; Moreno, M. A.; de la Fuente, L.; Marco, J.; Franco, C.; Cepeda, A.; Rodriguez Moure, A. A.; Suarez, G.; Dominguez, L.

2001-01-01

85

Aeromonas Isolates from Human Diarrheic Stool and Groundwater Compared by Pulsed-Field Gel Electrophoresis  

PubMed Central

Gastrointestinal infections of Aeromonas species are generally considered waterborne; for this reason, Aeromonas hydrophila has been placed on the United States Environmental Protection Agency Contaminant Candidate List of emerging pathogens in drinking water. In this study, we compared pulsed-field gel electrophoresis patterns of Aeromonas isolates from stool specimens of patients with diarrhea with Aeromonas isolates from patients’ drinking water. Among 2,565 diarrheic stool specimens submitted to a Wisconsin clinical reference laboratory, 17 (0.66%) tested positive for Aeromonas. Groundwater isolates of Aeromonas were obtained from private wells throughout Wisconsin and the drinking water of Aeromonas-positive patients. The analysis showed that the stool and drinking water isolates were genetically unrelated, suggesting that in this population Aeromonas gastrointestinal infections were not linked with groundwater exposures.

Stemper, Mary E.; Standridge, Jon H.

2003-01-01

86

Optimum design of bridges with superelastic-friction base isolators against near-field earthquakes  

NASA Astrophysics Data System (ADS)

The seismic response of a multi-span continuous bridge isolated with novel superelastic-friction base isolator (S-FBI) is investigated under near-field earthquakes. The isolation system consists of a flat steel-Teflon sliding bearing and a superelastic NiTi shape memory alloy (SMA) device. Sliding bearings limit the maximum seismic forces transmitted to the superstructure to a certain value that is a function of friction coefficient of sliding interface. Superelastic SMA device provides restoring capability to the isolation system together with additional damping characteristics. The key design parameters of an S-FBI system are the natural period of the isolated, yielding displacement of SMA device, and the friction coefficient of the sliding bearings. The goal of this study is to obtain optimal values for each design parameter by performing sensitivity analyses of the isolated bridge. First, a three-span continuous bridge is modeled as a two-degrees-of-freedom with S-FBI system. A neuro-fuzzy model is used to capture rate-dependent nonlinear behavior of SMA device. A time-dependent method which employs wavelets to adjust accelerograms to match a target response spectrum with minimum changes on the other characteristics of ground motions is used to generate ground motions used in the simulations. Then, a set of nonlinear time history analyses of the isolated bridge is performed. The variation of the peak response quantities of the isolated bridge is shown as a function of design parameters. Also, the influence of temperature variations on the effectiveness of S-FBI system is evaluated. The results show that the optimum design of the isolated bridge with S-FBI system can be achieved by a judicious specification of design parameters.

Ozbulut, Osman E.; Hurlebaus, Stefan

2010-03-01

87

Spore-forming thermophilic sulfate-reducing bacteria isolated from North Sea oil field waters  

SciTech Connect

Thermophilic sulfate-reducing bacteria were isolated from oil field waters from oil production platforms in the Norwegian sector of the North Sea. Spore-forming rods dominated in the enrichments when lactate, propionate, butyrate, or a mixture of aliphatic fatty acids (C{sub 4} through C{sub 6}) was added as a carbon source and electron donor. Representative strains were isolated and characterized. The isolates grew autotrophically on H{sub 2}-CO{sub 2} and heterotrophically on fatty acids such as formate, propionate, butyrate, caproate, valerate, pyruvate, and lactate and on alcohols such as methanol, ethanol, and propanol. Sulfate, sulfite, and thiosulfate but not nitrate could be used as an electron acceptor. The temperature range for growth was 43 to 78C; the spores were extremely heat resistant and survived 131C for 20 min. The optimum pH was 7.0. The isolates grew well in salt concentrations ranging from 0 to 800 mmol of NaCl per liter. Sulfite reductase P582 was present, but cytochrome c and desulfoviridin were not found. Electron micrographs revealed a gram-positive cell organization. The isolates were classified as a Desulfotomaculum sp. on the basis of spore formation, general physiological characteristics, and submicroscopic organization. To detect thermophilic spore-forming sulfate-reducing bacteria in oil field water, polyvalent antisera raised against antigens from two isolates were used. These bacteria were shown to be widespread in oil field water from different platforms. The origin of thermophilic sulfate-reducing bacteria in the pore water of oil reservoirs is discussed.

Rosnes, J.T.; Torsvik, T.; Lien, T. (Univ. of Bergen (Norway))

1991-08-01

88

Spore-Forming Thermophilic Sulfate-Reducing Bacteria Isolated from North Sea Oil Field Waters  

PubMed Central

Thermophilic sulfate-reducing bacteria were isolated from oil field waters from oil production platforms in the Norwegian sector of the North Sea. Spore-forming rods dominated in the enrichments when lactate, propionate, butyrate, or a mixture of aliphatic fatty acids (C4 through C6) was added as a carbon source and electron donor. Representative strains were isolated and characterized. The isolates grew autotrophically on H2-CO2 and heterotrophically on fatty acids such as formate, propionate, butyrate, caproate, valerate, pyruvate, and lactate and on alcohols such as methanol, ethanol, and propanol. Sulfate, sulfite, and thiosulfate but not nitrate could be used as an electron acceptor. The temperature range for growth was 43 to 78°C; the spores were extremely heat resistant and survived 131°C for 20 min. The optimum pH was 7.0. The isolates grew well in salt concentrations ranging from 0 to 800 mmol of NaCl per liter. Sulfite reductase P582 was present, but cytochrome c and desulfoviridin were not found. Electron micrographs revealed a gram-positive cell organization. The isolates were classified as a Desulfotomaculum sp. on the basis of spore formation, general physiological characteristics, and submicroscopic organization. To detect thermophilic spore-forming sulfate-reducing bacteria in oil field water, polyvalent antisera raised against antigens from two isolates were used. These bacteria were shown to be widespread in oil field water from different platforms. The origin of thermophilic sulfate-reducing bacteria in the pore water of oil reservoirs is discussed. Images

Rosnes, Jan Thomas; Torsvik, Terje; Lien, Torleiv

1991-01-01

89

Genetic Relationship between Blood and Nonblood Isolates from Bacteremic Patients Determined by Pulsed-Field Gel Electrophoresis  

PubMed Central

A total of 148 isolates from 55 bacteremic patients were examined by pulsed-field gel electrophoresis. Genetically different nonblood strains were isolated from 13.9% of patients with bacteremia caused by gram-positive cocci and 42.1% with Pseudomonas aeruginosa bacteremia, indicating that antibiograms of a single nonblood P. aeruginosa isolate are not always informative for treatment of bacteremia.

Matsuda, Junichi; Hirakata, Yoichi; Iori, Fumiaki; Mochida, Chikako; Ozaki, Yumi; Nakano, Michiko; Izumikawa, Kohichi; Yamaguchi, Toshiyuki; Yoshida, Ryoji; Miyazaki, Yoshitsugu; Maesaki, Shigefumi; Tomono, Kazunori; Yamada, Yasuaki; Kohno, Shigeru; Kamihira, Shimeru

1998-01-01

90

General field isolation and the cementation of indirect restorations: Part I.  

PubMed

This article, the first of two parts, has re-introduced the concept of general field isolation. The disadvantages were discussed and recorded as being related to the retention of the slit rubber dam. Innovative techniques which allow for an upgrading of the isolation are introduced through a pictorial essay of five case studies. Further innovations utilising absorbent wafers and cyanoacrylate tissue adhesive are reported in a further five case studies in part 2 of this article scheduled for the August issue. PMID:9508953

Liebenberg, W H

1994-07-01

91

A procedure for isolating and freezing metacyclic Trypanosoma brucei gambiense forms in the field.  

PubMed

An adaptation of a modified procedure using anion-exchange centrifugation was evaluated to isolate and freeze in field conditions a high number of bloodstream forms of Trypanosoma brucei gambiense for direct in vitro culture. Pellets of trypanosomes were obtained from 62 patients in Central Africa. The presence of trypanosomes was detected in all 62 eluates. The isolation system was efficient. Preliminary results of in vitro culture of 10 thawed samples of trypanosomes were highly promising because no fungal or bacterial contamination was noticed even after 2 weeks of culture. PMID:15177150

Truc, P; Likeufack, C Lekane; Mbongo, N; Ebo'o Enyenga, V

2004-04-01

92

Salmonella Gallinarum field isolates from laying hens are related to the vaccine strain SG9R.  

PubMed

Salmonella enterica subspecies enterica serotype Gallinarum can cause severe systemic disease in chickens and a live Salmonella Gallinarum 9R vaccine (SG9R) has been used widely to control disease. Using whole-genome sequencing we found point mutations in the pyruvate dehydrogenase (aceE) and/or lipopolysaccharide 1,2-glucosyltransferase (rfaJ) genes that likely explain the attenuation of the SG9R vaccine strain. Molecular typing using Pulsed Field Gel Electrophoresis and Multiple-Locus Variable number of tandem repeat Analysis showed that strains isolated from different layer flocks in multiple countries and the SG9R vaccine strain were similar. The genome of one Salmonella Gallinarum field strain, isolated from a flock with a mortality peak and selected on the basis of identical PFGE and MLVA patterns with SG9R, was sequenced. We found 9 non-silent single-nucleotide differences distinguishing the field strain from the SG9R vaccine strain. Our data show that a Salmonella Gallinarum field strain isolated from laying hens is almost identical to the SG9R vaccine. Mutations in the aceE and rfaJ genes could explain the reversion to a more virulent phenotype. Our results highlight the importance of using well defined gene deletion mutants as vaccines. PMID:23994381

Van Immerseel, F; Studholme, D J; Eeckhaut, V; Heyndrickx, M; Dewulf, J; Dewaele, I; Van Hoorebeke, S; Haesebrouck, F; Van Meirhaeghe, H; Ducatelle, R; Paszkiewicz, K; Titball, R W

2013-08-27

93

Pulsed-field gel electrophoresis pattern similarities between Listeria monocytogenes isolated from human patients and poultry in Chile  

Microsoft Academic Search

Listeria monocytogenes is the causal agent of listeriosis, a highly lethal food-borne disease. We identified isolates of L.monocytogenes present in poultry products bought at local retailers. The bacterial DNA was isolated and patterns were compared by pulsed-field gel electrophoresis (PFGE). Food isolates were also compared against three strains isolated from patients with listeriosis. Results showed 13 PFGE groups (>90% similarity).

Claudia Foerster; Gisela Gonzalez-Hein; Miriam Troncoso; Guillermo Figueroa

2012-01-01

94

Isolation and molecular characterization of thiosulfate-oxidizing bacteria from an Italian rice field soil.  

PubMed

In rice paddy soils an active cycling of sulfur compounds takes place. To elucidate the diversity of thiosulfate-oxidizing bacteria these organisms were enriched from bulk soil and rice roots by the most probable number method in liquid medium. From the MPN enrichment cultures 21 bacterial strains were isolated on solid mineral medium, and could be further shown to produce sulfate from thiosulfate. These strains were characterized by 16S rDNA analyses. The isolates were affiliated to seven different phylogenetic groups within the alpha- and beta-subclass of Proteobacteria. Two of these phylotypes were already described as S-oxidizers in this environment (Xanthobacter sp. and Bosea sp. related strains), but five groups represented new S-oxidizers in rice field soil. These isolates were closely related to Mesorhizobium loti, to Hydrogenophaga sp., to Delftia sp., to Pandoraea sp. or showed sequence similarity to a strain of Achromobacter sp. PMID:14529188

Graff, Andrea; Stubner, Stephan

2003-09-01

95

[Isolation, identification and diversity analysis of petroleum-degrading bacteria in Shengli Oil Field wetland soil].  

PubMed

The petroleum-degrading bacteria in Shengli Oil Field wetland soil were isolated and identified by traditional experiment methods, and their diversity was analyzed by PCR-DGGE (denaturing gradient gel electrophoresis). A total of thirteen petroleum-degrading bacterial strains were isolated, among which, six strains were found to have the ability of degrading the majority of C12-C26 petroleum hydrocarbon, with a degradation rate of > 90%. These petroleum degraders were phylogeneticly identified as the members of Halomonas, Alcanivorax, and Marinobacter, which were all belonged to gamma-proteobacteria. The uncultured predominant bacteria in Shengli Oil Field wetland soil were of Sulfurovum, Gillisia and Arcobacter. Among the predominant bacteria, gamma-proteobacteria accounted for a larger proportion, followed by alpha-proteobactiria, epsilon-proteobactiria, Actinobacteria, and Flavobacteria. PMID:19803182

Han, Ping; Zheng, Li; Cui, Zhi-Song; Guo, Xiu-Chun; Tian, Li

2009-05-01

96

Investigation of the Sterol Composition and Azole Resistance in Field Isolates of Septoria tritici  

PubMed Central

We report here a biochemical study of resistance to azole antifungal agents in a field isolate (S-27) of a fungal phytopathogen. Isolates of Septoria tritici were compared in vitro, and their responses reflected that observed in the field, with S-27 exhibiting resistance relative to RL2. In untreated cultures, both RL2 and S-27 contained isomers of ergosterol and ergosta-5,7-dienol, although in differing concentrations. Under azole treatment, this phytopathogen exhibited a response similar to that of other pathogenic fungi, with a reduction in desmethyl sterols and an accumulation of 14(alpha)-methyl sterols, indicative of inhibition of the P450-mediating sterol 14(alpha)-demethylase. Growth arrest was attributed to the reduction of ergosterol combined with an accumulation of nonutilizable sterols. Strain S-27 exhibited an azole-resistant phenotype which was correlated with decreased cellular content of azole.

Joseph-Horne, T.; Hollomon, D.; Manning, N.; Kelly, S. L.

1996-01-01

97

Analysis ofSalmonella typhiIsolates from Southeast Asia by Pulsed-Field Gel Electrophoresis  

Microsoft Academic Search

Pulsed-field gel electrophoresis (PFGE) revealed that multiple genetic variants of Salmonella typhi are simultaneously present in Southeast Asia and are associated with sporadic cases of typhoid fever and occa- sional outbreaks. Comparative analysis of PFGE patterns also suggested that considerable genetic diversity exists among S. typhi strains and that some PFGE patterns are shared between isolates obtained from Malaysia,Indonesia,andThailand,implyingmovementofthesestrainswithintheseregionsofSoutheastAsia, where

KWAI-LIN THONG; SAVITHRI PUTHUCHEARY; ROHANI M. YASSIN; PRATIWI SUDARMONO; MARIA PADMIDEWI; EDDY SOEWANDOJO; INDRO HANDOJO

98

Determination of minimum inhibitory and minimum bactericidal concentrations of tiamulin against field isolates of Actinobacillus pleuropneumoniae  

Microsoft Academic Search

Tiamulin activity was measured against 19 UK field isolates of Actinobacillus pleuropneumoniae collected between 2003 and 2009 and the type strain ATCC 27090 as a control, with the intention of comparing broth with serum as growth media. Broth microdilution MIC\\/MBC tests were performed in accordance with the Clinical and Laboratory Standards Institute (CLSI) guideline M31-A3, in ‘Veterinary Fastidious Medium’ (VFM)

Andrew Pridmore; David Burch; Peter Lees

2011-01-01

99

Complete genome sequence of a novel porcine epidemic diarrhea virus in south China.  

PubMed

Since early 2010, outbreaks of porcine epidemic diarrhea (PED) have been observed frequently in immunized swine herds in southern China. The suckling piglets are particularly susceptible to porcine epidemic diarrhea virus (PEDV), with a high mortality rate (90%). Recently, a virulent PEDV strain, GD-A, was isolated from an immunized-swine breeding farm in Guangdong, China. This report describes the complete genome sequence of GD-A, and the data will provide important insights into the variation of PEDV field isolates in southern China. PMID:22923806

Fan, Huiying; Zhang, Jie; Ye, Yu; Tong, Tiezhu; Xie, Kangshang; Liao, Ming

2012-09-01

100

Taxonomic and functional diversity of pseudomonads isolated from the roots of field-grown canola.  

PubMed

Among the most important rhizosphere bacteria are the pseudomonads, which are aggressive colonizers and utilize a wide range of substrates as carbon sources. The objective of this study was to determine if the taxonomic or metabolic diversity of pseudomonads differed among field-grown canola cultivars. Bacteria (n=2257) were isolated from the rhizosphere and root interior of six cultivars of field-grown canola, including three transgenic varieties. The bacteria were identified by fatty acid methyl ester (FAME) analysis, and about 35% were identified as Pseudomonas species. The most abundant species were Pseudomonas putida and Pseudomonas chlororaphis. Dendrograms based on FAME analysis revealed that many pseudomonad strains were found in all of the canola cultivars. Pseudomonads of the same strain were found in both the rhizosphere and the root interior of canola plants, suggesting that endophytic bacteria were a subset of the rhizosphere community. Because metabolic profiling provides more useful information than taxonomy, P. putida and P. chlororaphis isolates were characterized for their ability to utilize carbon substrates and produce several enzymes. Bacteria isolated from different plant cultivars had different carbon utilization profiles, but when only carbon substrates found in root exudates were analyzed, the cultivar effect was less pronounced. These characterizations also demonstrated that bacteria that were determined by FAME to be the same strain were metabolically different, suggesting functional redundancy among Pseudomonas isolates. The results of this study suggest that pseudomonads were functionally diverse. They differed in their metabolic potential among the canola cultivars from which they were isolated. Because bacteria capable of using many substrates can effectively adapt to new environments, these results have implications for the use of pseudomonads as biofertilizers, biological control agents and plant growth-promoting bacteria in canola. PMID:19709299

Misko, Amy L; Germida, James J

2002-12-01

101

Detection and Isolation Techniques for Methanogens from Microbial Mats (in the El Tatio Geyser Field, Chile)  

NASA Astrophysics Data System (ADS)

Isolating methanogenic archea from an extreme environment such as El Tatio (high altitude, arid climate) gives insight to the methanogenic taxas able to adapt and grow under extreme conditions. The hydrothermal waters at El Tatio geyser field demonstrate extreme geochemical conditions, with discharge water from springs and geysers at local boiling temperature (85° C) with high levels of arsenic and low DIC levels. Despite these challenges, many of El Tatio’s hundred plus hydrothermal features host extensive microbial mat communities, many showing evidence of methanogenesis. When trying to isolate methanogens unique to this area, various approaches and techniques were used. To detect the presence of methanogens in samples taken from the field, dissolved methane concentrations were determined via gas chromatography (GC) analysis. Samples were then selected for culturing and most probable number (MPN) enumeration, where growth was assessed using both methane production and observations of fluorescence under UV light. PCR was used to see if the archeal DNA was apparent directly from the field, and shotgun cloning was done to determine phylogenetic affiliation. Several culturing techniques were carried out in an attempt to isolate methanogens from samples that showed evidence of methanogenesis. The slant culturing method was used because of the increased surface area for colonization combined with the relative ease of keeping anaerobic. After a few weeks, when colonies were apparent, some were aseptically selected and inoculated to observe growth in a liquid media containing ampicillin to inhibit bacterial growth. Culturing techniques proved successful after inoculation, showing a slow growth of methanogens via GC and autofluorescence. Further PCR tests and subsequent sequencing were done to confirm and identify isolates.

Pearson, E. Z.; Franks, M. A.; Bennett, P.

2010-12-01

102

Why isolated streamer discharges hardly exist above the breakdown field in atmospheric air  

NASA Astrophysics Data System (ADS)

We investigate streamer formation in the troposphere, in electric fields above the breakdown threshold. With fully three-dimensional particle simulations, we study the combined effect of natural background ionization and of photo-ionization on the discharge morphology. In previous investigations based on deterministic fluid models without background ionization, so-called double-headed streamers emerged. But in our improved model, many electron avalanches start to grow at different locations. Eventually, the avalanches collectively screen the electric field in the interior of the discharge. This happens after what we call the "ionization screening time," for which we give an analytical estimate. As this time is comparable to the streamer formation time, we conclude that isolated streamers are unlikely to exist in fields well above breakdown in atmospheric air.

Sun, A. B.; Teunissen, J.; Ebert, U.

2013-05-01

103

Field studies on two rock phosphate solubilizing actinomycete isolates as biofertilizer sources  

NASA Astrophysics Data System (ADS)

Recently biotechnology is focusing attention on utilization of biological resources to solve a number of environmental problems such as soil fertility management. Results of microbial studies on earthworm compost in the University of Nigeria farm identified a number of rock phosphate solubilizing actinomycetes. Two of these, isclates 02 and 13, were found to be efficient rock phosphate (RP) solubilizers and fast-growing cellulolytic microbes producing extracellular hydrolase enzymes. In this preliminary field study the two microbial isolates were investigated with respect to their effects on the growth of soybean and egusi as well as their effect on the incidence of toxicity of poultry droppings. Application of these isolates in poultry manure-treated field plots, as microbial fertilizers, brought about yield increases of 43% and 17% with soybeans and 19% and 33% with egusi, respectively. Soil properties were also improved. With isolates 02 and 13, the soil available phosphorus increased at the five-leaf stage, while N-fixation in the soil increased by 45% or 11% relative to control. It was further observed that air-dried poultry manure after four days of incubation was still toxic to soybean. The toxic effect of the applied poultry manure was reduced or eliminated with microbial fertilizers 02 or 13, respectively. The beneficial effects of the microbial organic fertilizer are discussed. Justification for more intensive research on rock phosphate organic fertilizer is highlighted.

Mba, Caroline C.

1994-03-01

104

Isolation and characterization of antagonistic fungi against potato scab pathogens from potato field soils.  

PubMed

Potato scab is a serious plant disease caused by several Streptomyces sp., and effective control methods remain unavailable. Although antagonistic bacteria and phages against potato scab pathogens have been reported, to the best of our knowledge, there is no information about fungi that are antagonistic to the pathogens. The aim of this study was to isolate fungal antagonists, characterize their phylogenetic positions, determine their antagonistic activities against potato scab pathogens, and highlight their potential use as control agents under lower pH conditions. Fifteen fungal stains isolated from potato field soils were found to have antagonistic activity against three well-known potato scab pathogens: Streptomyces scabiei, Streptomyces acidiscabiei, and Streptomyces turgidiscabiei. These 15 fungal strains were phylogenetically classified into at least six orders and nine genera based on 18S rRNA gene sequencing analysis. These fungal isolates were related to members of the genera Penicillium, Eupenicillium, Chaetomium, Fusarium, Cladosporium, Mortierella, Kionochaeta, Pseudogymnoascus, and Lecythophora. The antagonistic activities of most of the fungal isolates were highly strengthened under the lower pH conditions, suggesting the advantage of combining their use with a traditional method such as soil acidification. This is the first report to demonstrate that phylogenetically diverse fungi show antagonistic activity against major potato scab pathogens. These fungal strains could be used as potential agents to control potato scab disease. PMID:20653777

Tagawa, Masahiro; Tamaki, Hideyuki; Manome, Akira; Koyama, Osamu; Kamagata, Yoichi

2010-04-01

105

Modulation by applied electric fields of Purkinje and stellate cell activity in the isolated turtle cerebellum.  

PubMed Central

Quasi steady-state electric fields were applied across the isolated turtle cerebellum to study the relationship between applied field, neuronal morphology and the modulation of the neuronal spike firing pattern. Spiking elements were identified electrophysiologically using extracellular recording methods and by subsequent horseradish peroxidase injection, which revealed their dendritic morphology and orientation. The electric field was precisely defined by measuring the voltage gradients induced in the cerebellum by 40 s constant-current pulses. The field was constant in the vertical (dorso-ventral) axis and zero in the horizontal plane, in agreement with theory. Neurones were modulated by applying a sinusoidal field at frequencies between 0.05 and 1.0 Hz. Modulated cells exhibited an increase in firing frequency and fell into one of four classes, depending on the direction of the field that produced the modulation. Thus neurones were excited by: ventricle-directed fields (V modulation), pia-directed fields (P modulation), both of the above (V/P modulation) or showed no consistent modulation (non-modulation). Most Purkinje somata and primary dendrites (nineteen out of twenty-eight) and most Purkinje dendrites (eighteen out of thirty), were V modulated with maximum rate proportional to the peak field intensity. The dendrites of these cells were consistently oriented toward the pia. Among the stellate cells, the lower molecular layer stellates, with dendrites extending predominantly towards the pia, were mostly (nineteen out of thirty-two) V modulated. The mid-molecular layer stellates, which showed much variability in dendritic orientation, were distributed among all four of the modulation classes. The upper molecular layer stellates, with a mostly horizontal dendritic alignment, were mainly (nine out of sixteen) non-modulated. All groups of spiking elements showed a correlation between patterns of modulation by applied fields and dendritic orientation, which suggests the degree of differential polarization of the extended cable elements of the neurone by the applied field as the basic mechanism for field-induced excitation or inhibition. The threshold for modulation among all neurones was 15-20 mV/mm, which is similar to the fields that modulate other nervous tissues. This suggests that many neurones can be modulated by fields of the order of 10-20 mV/mm.

Chan, C Y; Nicholson, C

1986-01-01

106

Geobacter luticola sp. nov., an Fe(III)-reducing bacterium isolated from lotus field mud.  

PubMed

A novel species of Fe(III)-reducing bacterium, designated strain OSK6(T), belonging to the genus Geobacter, was isolated from lotus field mud in Japan. Strain OSK6(T) was isolated using a solid medium containing acetate, Fe(III)-nitrilotriacetate (NTA) and gellan gum. The isolate is a strictly anaerobic, gram-negative, motile, straight rod-shaped bacterium, 0.6-1.9 µm long and 0.2-0.4 µm wide. The growth of the isolate occurred at 20-40 °C with optima of 30-37 °C and pH 6.5-7.5 in the presence of up to 0.5 g NaCl l(-1). The G+C content of the genomic DNA was determined by HPLC to be 59.7 mol%. The major respiratory quinone was MK-8. The major fatty acids were 16?:?1?7c and 16?:?0. Strain OSK6(T) was able to grow with Fe(III)-NTA, ferric citrate, amorphous iron (III) hydroxide and nitrate, but not with fumarate, malate or sulfate as electron acceptors. Among examined substrates grown with Fe(III)-NTA, the isolate grew on acetate, lactate, pyruvate and succinate. Analysis of the near full-length 16S rRNA gene sequence revealed that strain OSK6(T) is closely related to Geobacter daltonii and Geobacter toluenoxydans with 95.6?% similarity to the type strains of these species. On the basis of phylogenetic analysis and physiological tests, strain OSK6(T) is described as a representative of a novel species, Geobacter luticola sp. nov.; the type strain is OSK6(T) (?=?DSM 24905(T)?=?JCM 17780(T)). PMID:22493170

Viulu, Samson; Nakamura, Kohei; Okada, Yurina; Saitou, Sakiko; Takamizawa, Kazuhiro

2012-04-06

107

Typing of Salmonella enterica Serotype Paratyphi C Isolates from Various Countries by Plasmid Profiles and Pulsed-Field Gel Electrophoresis  

Microsoft Academic Search

Pulsed-field gel electrophoresis (PFGE) of 61 Salmonella enterica serotype Paratyphi C isolates from six coun- tries gave five distinct clusters. Twenty-four isolates from five countries were susceptible to 10 antimicrobials tested and gave similar restriction endonuclease digest patterns of the 38-MDa plasmid. In contrast, plasmid and PFGE profiles of 37 multidrug-resistant isolates from Zaire were different from those from other

S. KARIUKI; J. CHEESBROUGH; A. K. MAVRIDIS; C. A. HART

1999-01-01

108

Genetic Relationship between Blood and Nonblood Isolates from Bacteremic Patients Determined by Pulsed-Field Gel Electrophoresis  

Microsoft Academic Search

A total of 148 isolates from 55 bacteremic patients were examined by pulsed-field gel electrophoresis. Genetically different nonblood strains were isolated from 13.9% of patients with bacteremia caused by gram- positive cocci and 42.1% with Pseudomonas aeruginosa bacteremia, indicating that antibiograms of a single nonblood P. aeruginosa isolate are not always informative for treatment of bacteremia. Bacteremia arises from preexisting

JUNICHI MATSUDA; YOICHI HIRAKATA; FUMIAKI IORI; CHIKAKO MOCHIDA; YUMI OZAKI; MICHIKO NAKANO; KOHICHI IZUMIKAWA; TOSHIYUKI YAMAGUCHI; RYOJI YOSHIDA; YOSHITSUGU MIYAZAKI; SHIGEFUMI MAESAKI; KAZUNORI TOMONO; YASUAKI YAMADA; SHIGERU KOHNO; SHIMERU KAMIHIRA

109

Characterization of Salmonella isolates from retail foods based on serotyping, pulse field gel electrophoresis, antibiotic resistance and other phenotypic properties  

Microsoft Academic Search

Sixteen Salmonella strains isolated from a variety of foods during 2000 and 2003 by the Florida State Department of Agriculture were characterized by various genotypic and phenotypic tests. Among 16 isolates, 15 different serotypes were identified. Pulse-field gel electrophoresis (PFGE) fingerprinting profiles obtained using restriction endonucleases XbaI and BlnI revealed that 16 Salmonella isolates were genetically diverse with 16 unique

Xiaodong Xia; Shaohua Zhao; Allen Smith; James McEvoy; Jianghong Meng; Arvind A. Bhagwat

2009-01-01

110

Crystal field theory analysis of rovibrational spectra of carbon monoxide monomers isolated in solid parahydrogen.  

PubMed

We report the first rotationally resolved and completely assigned rovibrational spectrum for a nonhydride molecule rotating in the solid phase: carbon monoxide (CO) monomers isolated in cryogenic solid parahydrogen (p-H(2)). We employ a modified crystal field theory model, in which the CO molecular spectroscopic constants are taken as adjustable parameters, to make good spectroscopic assignments for all the observed features. We discuss the limitations of this approach and highlight the need for improved theoretical models of molecular rotation dynamics in quantum solids. PMID:19566167

Fajardo, Mario E; Lindsay, C Michael; Momose, Takamasa

2009-06-28

111

Molecular characterization and detection of overexpressed C-14 alpha-demethylase-based DMI resistance in Cercospora beticola field isolates  

Microsoft Academic Search

Cercospora beticola strains were isolated from sugar beet fields in N. Greece heavily sprayed with triazoles. Two resistant phenotypes with resistance factors ranging from 18 to 25 and 65 to 115 were identified. Epoxiconazole-resistant isolates were less sensitive to the triazole flutriafol but not to the benzimidazole benomyl and the carboxamide boscalid. No fitness penalties were associated with resistance mutations

D. Nikou; A. Malandrakis; M. Konstantakaki; J. Vontas; A. Markoglou; B. Ziogas

2009-01-01

112

Point Mutation in Cytochrome b Gene Conferring Resistance to Strobilurin Fungicides in Erysiphe graminis f. sp. tritici Field Isolates  

Microsoft Academic Search

A field isolate of Erysiphe graminis f. sp. tritici that was more than 200-fold less sensitive to strobilurin fungicides (respiration inhibitors at the Qo center of the cytochrome bc1 enzyme complex) was compared to a sensitive isolate using molecular methods. With degenerate primers, 60% of the cytochrome b gene of E. graminis was cloned and sequenced, including all known positions

H. Sierotzki; J. Wullschleger; U. Gisi

2000-01-01

113

Coherent control of broadband isolated attosecond pulses in a chirped two-color laser field  

SciTech Connect

A theoretical investigation is presented that uses a strong two-color laser field composed of a linearly chirped fundamental (900 nm) and its subharmonic (1800-nm) laser pulses to control coherently the broadband isolated attosecond pulses in high-order harmonic generations. After the subharmonic field is added, the intrinsic chirp of harmonic emission can be reduced significantly, and consequently, the temporal synchronization of harmonic emission with different photon energies at the level of the single-atom response can be realized. In addition, the scheme is robust against the carrier envelope phase variation to produce a twin pulse of stable sub-100-as duration, and the relative intensity of the twin pulses can be changed just by adjusting the relative time delay of the two driving pulses, which is of benefit in general pump-probe experiments.

Zou Pu; Zeng Zhinan; Zheng Yinghui; Lu Yingying; Liu Peng; Li Ruxin; Xu Zhizhan [State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China)

2010-03-15

114

Epidemiological survey of porcine epidemic diarrhea virus in swine farms in Shanghai, China.  

PubMed

An epidemiological survey of porcine diarrheal disease prevalence between September 2011 and January 2012 revealed that porcine epidemic diarrhea virus (PEDV) contributed to outbreaks of diarrhea in pig farms in Shanghai, China. The distribution profile of 10 PEDV strains revealed three distinct genotypes coexisting in the same pig farm. Two of the ten field strains that were isolated exhibited a distinct evolution from the others. In addition to PEDV, other enteric pathogens, including porcine kobuvirus, porcine teschovirus and Lawsonia intracellularis, were identified. PMID:23685898

Ge, Fei-Fei; Yang, De-Quan; Ju, Hou-Bin; Wang, Jian; Liu, Jian; Liu, Pei-Hong; Zhou, Jin-Ping

2013-05-18

115

Complete genome sequence of novel porcine epidemic diarrhea virus strain GD-1 in China.  

PubMed

Porcine epidemic diarrhea virus (PEDV) infection, which causes acute diarrhea and dehydration in suckling piglets, has become a serious problem for the swine industry of China in recent years. In this study, a virulent PEDV strain, GD-1, was obtained from fecal samples from suckling piglets that suffered from severe diarrhea in 2011 in Guangdong, China. Here we describe the complete genome sequence of strain GD-1, which may be helpful in further understanding the molecular epidemiology and genetic diversity of PEDV field isolates in China. PMID:23166239

Wei, Zhong-yan; Lu, Wen-hui; Li, Zhi-li; Mo, Jian-yue; Zeng, Xi-duo; Zeng, Zhi-liang; Sun, Bao-li; Chen, Feng; Xie, Qing-Mei; Bee, Ying-zuo; Ma, Jing-yun

2012-12-01

116

Comparison of Haemophilus parasuis reference strains and field isolates by using random amplified polymorphic DNA and protein profiles  

PubMed Central

Background Haemophilus parasuis is the causative agent of Glässer’s disease and is a pathogen of swine in high-health status herds. Reports on serotyping of field strains from outbreaks describe that approximately 30% of them are nontypeable and therefore cannot be traced. Molecular typing methods have been used as alternatives to serotyping. This study was done to compare random amplified polymorphic DNA (RAPD) profiles and whole cell protein (WCP) lysate profiles as methods for distinguishing H. parasuis reference strains and field isolates. Results The DNA and WCP lysate profiles of 15 reference strains and 31 field isolates of H. parasuis were analyzed using the Dice and neighbor joining algorithms. The results revealed unique and reproducible DNA and protein profiles among the reference strains and field isolates studied. Simpson’s index of diversity showed significant discrimination between isolates when three 10mer primers were combined for the RAPD method and also when both the RAPD and WCP lysate typing methods were combined. Conclusions The RAPD profiles seen among the reference strains and field isolates did not appear to change over time which may reflect a lack of DNA mutations in the genes of the samples. The recent field isolates had different WCP lysate profiles than the reference strains, possibly because the number of passages of the type strains may affect their protein expression.

2012-01-01

117

Characterization of United Kingdom Isolates of Corynebacterium pseudotuberculosis Using Pulsed-Field Gel Electrophoresis  

PubMed Central

Caseous lymphadenitis is a chronic suppurative disease caused by Corynebacterium pseudotuberculosis and is responsible for serious economic losses to the sheep and goat industry. Caseous lymphadenitis was first reported for goats in the United Kingdom in 1990 and for sheep in 1991. Recent evidence suggests that the prevalence of the disease within the national flock is increasing. Fifty isolates of C. pseudotuberculosis from the United Kingdom comprising sheep and horse isolates, the original goat outbreak strain, and the type strain were characterized by biotyping, antimicrobial susceptibility, production of phospholipase D, and genotyping by pulsed-field gel electrophoresis using SfiI and SmaI. All of the isolates were confirmed as C. pseudotuberculosis, and all produced phospholipase D but none reduced nitrate. Restriction with SfiI generated 16 to 18 bands between 48.5 and 290 kb and differentiated six pulsotypes. We conclude that 80% of the strains tested were epidemiologically related to the outbreak strain and that the equine profile was distinct both phenotypically and genotypically.

Connor, Kathleen M.; Quirie, Malcolm M.; Baird, Graham; Donachie, William

2000-01-01

118

Calcium homeostasis of isolated heart muscle cells exposed to pulsed high-frequency electromagnetic fields  

SciTech Connect

The intracellular calcium concentration ([Ca{sup 2+}]{sub i}) of isolated ventricular cardiac myocytes of the guinea pig was measured during the application of pulsed high-frequency electromagnetic fields. The high-frequency fields were applied in a transverse electromagnetic cell designed to allow microscopic observation of the myocytes during the presence of the high-frequency fields. The [Ca{sup 2+}]{sub i} was measured as fura-2 fluorescence by means of digital image analysis. Both the carrier frequency and the square-wave pulse-modulation pattern were varied during the experiments (carrier frequencies: 900, 1,300, and 1,800 MHz pulse modulated at 217 Hz with 14% duty cycle; pulsation pattern at 900 MHz; continuous wave, 16 Hz,and 50 Hz modulation with 50% duty cycle and 30 kHz modulation with 80% duty cycle). The mean specific absorption rate (SAR) values in the solution were within one order of magnitude of 1 mW/kg. They varied depending on the applied carrier frequency and pulse pattern. The experiments were designed in three phases: 500 s of sham exposure, followed by 500 s of field exposure, then chemical stimulation without field. The chemical stimulation (K{sup +}-depolarization) indicated the viability of the cells. The K{sup +} depolarization yielded a significant increase in [Ca{sup 2+}]{sub i}. Significant differences between sham exposure and high-frequency field exposure were not found except when a very small but statistically significant difference was detected in the case of 900 MHz/50 Hz. However, this small difference was not regarded as a relevant effect of the exposure.

Wolke, S.; Gollnick, F.; Meyer, R. [Univ. Bonn (Germany); Neibig, U.; Elsner, R. [Inst. fuer Nachrichtentechnik Braunschweig (Germany)

1996-05-01

119

Isolation of Key Methanogens for Global Methane Emission from Rice Paddy Fields: a Novel Isolate Affiliated with the Clone Cluster Rice Cluster I  

Microsoft Academic Search

Despite the fact that rice paddy fields (RPFs) are contributing 10 to 25% of global methane emissions, the organisms responsible for methane production in RPFs have remained uncultivated and thus uncharacterized. Here we report the isolation of a methanogen (strain SANAE) belonging to an abundant and ubiquitous group of methanogens called rice cluster I (RC-I) previously identified as an ecologically

Sanae Sakai; Hiroyuki Imachi; Yuji Sekiguchi; Akiyoshi Ohashi; Hideki Harada; Yoichi Kamagata

2007-01-01

120

Isolation and Characterization of Strains CVO and FWKO B, Two Novel Nitrate-Reducing, Sulfide-Oxidizing Bacteria Isolated from Oil Field Brine  

Microsoft Academic Search

Bacterial strains CVO and FWKO B were isolated from produced brine at the Coleville oil field in Saskatchewan, Canada. Both strains are obligate chemolithotrophs, with hydrogen, formate, and sulfide serving as the only known energy sources for FWKO B, whereas sulfide and elemental sulfur are the only known electron donors for CVO. Neither strain uses thiosulfate as an energy source.

DIANE GEVERTZ; ANITA J. TELANG; GERRIT VOORDOUW; GARY E. JENNEMAN

2000-01-01

121

Global characteristics of particle precipitation and field-aligned electron acceleration during isolated substorms  

SciTech Connect

Global features of particle precipitation and field-aligned electron acceleration during isolated substorms were investigated using energetic particle data from the DMSP F6 and F7 satellites. The onset time and the recovery phase of each isolated substorm were determined using both the AU and AL indices and low-latitude Pi 2 magnetic pulsations. It is found that during the recovery phase the poleward edge of the precipitation region of central plasma sheet (CPS) type electrons expands to latitudes higher than 72[degrees] around midnight, while the equatorward boundary of this region expands to latitudes lower than those before the substorm onset in the postmidnight sector of 00-06 MLT. In the recovery phase, many accelerated electron precipitation events were embedded in the (CPS) type electron precipitation region for the nightside local times from 18 MLT to 09 MLT. Several different kinds of latitudinal dispersion of electron and ion energy were observed near the lowest latitude of the particle precipitation region. The features vary significantly depending on the magnetic local time. These energy dispersion features can be explained by injected particle motions in the magnetosphere. These energy dispersion features also show a possibility of some particle injections in the magnetotail even before the substorm onset. The field-aligned potential differences, estimated from the peak energy of accelerated electron energy spectra, do not change on the morningside before and after the substorm onset, while they increase up to several kilovolts on the eveningside during the recovery phase. The electron densities above the field-aligned potential difference were also estimated from an accelerated Maxwellian fitting procedure. They do not change clearly before the onset and in the recovery phase. This fact suggests that the supply and loss of electrons into the loss cone at magnetospheric altitudes are balanced during the substorms. 25 refs., 10 figs., 2 tabs.

Shiokawa, K.; Yumoto, K. (Nagoya Univ., Toyokawa (Japan))

1993-02-01

122

Sulfur oxidation in rice field soil: activity, enumeration, isolation and characterization of thiosulfate-oxidizing bacteria.  

PubMed

In rice paddy fields the bulk soil is anoxic, but oxygenated zones occur in the surrounding of the rice roots to where oxygen is transported via the aerenchyma system of the rice plants. In the anaerobic soil compartments sulfate is consumed by sulfate-reducing bacteria. In the rhizosphere the reduced sulfur compounds can be reoxidized by sulfur-oxidizing bacteria. Measurements of the potential activity of thiosulfate-oxidizing bacteria in soil slurries derived from planted rice soil microcosms showed turnover rates of 2-6 mumol d-1 g-dw-1. Thiosulfate was oxidized to sulfate with tetrathionate as intermediate. Most probable number (MPN) enumeration with three aerobic media and one anaerobic nitrate-amended medium showed that thiosulfate-oxidizing bacteria were abundant in paddy soil and in rhizosphere soil at numbers of 10(5) to 10(6) per gram dry weight soil. Nine isolates of S-oxidizing bacteria were obtained from enrichment cultures or from the highest dilutions of the MPN series and were affiliated to four different phylogenetic groups. These isolates were characterized by physiological properties and by comparative 16S rDNA sequence analysis. Three isolates (TA1-AE1, TA1-A1 and TA12-21) were shown to be facultatively chemolithoautotrophic strains of Ancylobacter aquaticus. Three further isolates (Tv6-2b, Z2A-6A and Z4A-2A) were also facultatively chemolithoautotrophic and were affiliated with the Xanthobacter sp. group, probably representing new strains of X. flavus or X. tagetidis. Strain SZ-2111 was phylogenetically related to Bosea thiooxidans. However, the genus Bosea is described as obligately heterotrophic, whereas strain 5Z-2111 was able to grow autotrophically. The isolates 5Z-C1 and TBW3 were obligate chemolithoautotrophs and were closely affiliated with Thiobacillus thioparus. Our results showed that S-oxidizing bacteria were abundant and active in rice paddy soil and consisted of physiologically and phylogenetically diverse populations. PMID:9924825

Stubner, S; Wind, T; Conrad, R

1998-12-01

123

Whole Genome Sequencing of Field Isolates Provides Robust Characterization of Genetic Diversity in Plasmodium vivax  

PubMed Central

Background An estimated 2.85 billion people live at risk of Plasmodium vivax transmission. In endemic countries vivax malaria causes significant morbidity and its mortality is becoming more widely appreciated, drug-resistant strains are increasing in prevalence, and an increasing number of reports indicate that P. vivax is capable of breaking through the Duffy-negative barrier long considered to confer resistance to blood stage infection. Absence of robust in vitro propagation limits our understanding of fundamental aspects of the parasite's biology, including the determinants of its dormant hypnozoite phase, its virulence and drug susceptibility, and the molecular mechanisms underlying red blood cell invasion. Methodology/Principal Findings Here, we report results from whole genome sequencing of five P. vivax isolates obtained from Malagasy and Cambodian patients, and of the monkey-adapted Belem strain. We obtained an average 70–400 X coverage of each genome, resulting in more than 93% of the Sal I reference sequence covered by 20 reads or more. Our study identifies more than 80,000 SNPs distributed throughout the genome which will allow designing association studies and population surveys. Analysis of the genome-wide genetic diversity in P. vivax also reveals considerable allele sharing among isolates from different continents. This observation could be consistent with a high level of gene flow among parasite strains distributed throughout the world. Conclusions Our study shows that it is feasible to perform whole genome sequencing of P. vivax field isolates and rigorously characterize the genetic diversity of this parasite. The catalogue of polymorphisms generated here will enable large-scale genotyping studies and contribute to a better understanding of P. vivax traits such as drug resistance or erythrocyte invasion, partially circumventing the lack of laboratory culture that has hampered vivax research for years.

David, Peter H.; Ratsimbasoa, Arsene; Kim, Saorin; Chim, Pheaktra; Do, Catherine; Witkowski, Benoit; Mercereau-Puijalon, Odile; Zimmerman, Peter A.; Serre, David

2012-01-01

124

Methanocella arvoryzae sp. nov., a hydrogenotrophic methanogen isolated from rice field soil.  

PubMed

A novel hydrogenotrophic methanogen, designated strain MRE50(T), was isolated from a methanogenic consortium, which was originally established from an Italian rice field soil. Cells were non-motile rods, 1.3-2.8 ?m long and 0.4-0.7 ?m wide. Coccoid cells were also observed in cultures at the late-exponential phase of growth. Strain MRE50(T) grew at 37-55 °C (optimally at 45 °C), at pH 6-7.8 (optimally at pH 7.0) and in the presence of 0-20 g NaCl l(-1). The isolate utilized H(2)/CO(2) and formate for growth and methane production. Phylogenetic analyses of the 16S rRNA gene and the methanogen-specific marker gene mcrA showed that strain MRE50(T) is affiliated with the order Methanocellales, previously known as uncultured archaeal group Rice Cluster I. Based on both 16S rRNA gene and mcrA gene sequences, strain MRE50(T) was related most closely to Methanocella paludicola SANAE(T). Levels of sequence similarity were 92.5 and 86.1?%, respectively, indicating that strains MRE50(T) and Methanocella paludicola SANAE(T) represent different species within the genus Methanocella. In addition, although these strains shared phenotypic properties including cell morphology and substrate utilization, they differed with respect to susceptibility to antibiotics, and temperature and NaCl ranges for growth. Given the phenotypic differences and the distinct phylogenetic placement of the new isolate relative to the type species of the genus Methanocella, strain MRE50(T) is considered to represent a novel species of the genus Methanocella, for which the name Methanocella arvoryzae sp. nov. is proposed. The type strain is MRE50(T) (=NBRC 105507(T) =DSM 22066(T)). PMID:20097796

Sakai, Sanae; Conrad, Ralf; Liesack, Werner; Imachi, Hiroyuki

2010-01-22

125

Attosecond lighthouses: how to use spatiotemporally coupled light fields to generate isolated attosecond pulses.  

PubMed

Under the effect of even simple optical components, the spatial properties of femtosecond laser beams can vary over the duration of the light pulse. We show how using such spatiotemporally coupled light fields in high harmonic generation experiments (e.g., in gases or dense plasmas) enables the production of attosecond lighthouses, i.e., sources emitting a collection of angularly well-separated light beams, each consisting of an isolated attosecond pulse. This general effect opens the way to a new generation of light sources, particularly suitable for attosecond pump-probe experiments, and provides a new tool for ultrafast metrology, for instance, giving direct access to fluctuations of the carrier-envelope relative phase of even the most intense ultrashort lasers. PMID:22540475

Vincenti, H; Quéré, F

2012-03-16

126

Attosecond Lighthouses: How To Use Spatiotemporally Coupled Light Fields To Generate Isolated Attosecond Pulses  

NASA Astrophysics Data System (ADS)

Under the effect of even simple optical components, the spatial properties of femtosecond laser beams can vary over the duration of the light pulse. We show how using such spatiotemporally coupled light fields in high harmonic generation experiments (e.g., in gases or dense plasmas) enables the production of attosecond lighthouses, i.e., sources emitting a collection of angularly well-separated light beams, each consisting of an isolated attosecond pulse. This general effect opens the way to a new generation of light sources, particularly suitable for attosecond pump-probe experiments, and provides a new tool for ultrafast metrology, for instance, giving direct access to fluctuations of the carrier-envelope relative phase of even the most intense ultrashort lasers.

Vincenti, H.; Quéré, F.

2012-03-01

127

Pulsed-field gel electrophoresis for isolation of full-length phytoplasma chromosomes from plants.  

PubMed

Pulsed-field gel electrophoresis (PFGE) is a powerful technique for genomic studies of unculturable plant-pathogenic phytoplasmas, which enables separation of full-length phytoplasma chromosomes from contaminating host plant nucleic acids. The PFGE method described here involves isolation of phytoplasmal DNA from high-titer phytoplasma-infected herbaceous plants using a phytoplasma enrichment procedure, embedding of phytoplasma chromosomes in agarose blocks, and separation of entire phytoplasma chromosomes from contaminating host plant nucleic acids by electrophoresis. Full-length phytoplasma chromosomes are resolved as single, discrete bands in the gel. The identity of these bands can be confirmed by Southern blot hybridization using a ribosomal DNA fragment as a probe. The method does not utilize gamma-irradiation to linearize phytoplasma chromosomes prior to electrophoresis. PMID:22987433

Marcone, Carmine

2013-01-01

128

{{{W}}_3} irregular states and isolated {N}=2 superconformal field theories  

NASA Astrophysics Data System (ADS)

We explore the proposal that the six-dimensional (2, 0) theory on the Riemann surface with irregular punctures leads to a four-dimensional gauge theory coupled to the isolated {N}=2 superconformal theories of Argyres-Douglas type, and to two-dimensional conformal field theory with irregular states. Following the approach of Gaiotto-Teschner for the Virasoro case, we construct {{{W}}_3} irregular states by colliding a single SU(3) puncture with several regular punctures of simple type. If n simple punctures are colliding with the SU(3) puncture, the resulting irregular state is a simultaneous eigenvector of the positive modes L n , . . . , L 2 n and W 2 n , . . . , W 3 n of the {{{W}}_3} algebra. We find the corresponding isolated SCFT with an SU(3) flavor symmetry as a nontrivial IR fixed point on the Coulomb branch of the SU(3) linear quiver gauge theories, by confirming that its Seiberg-Witten curve correctly predicts the conditions for the {{{W}}_3} irregular states. We also compare these SCFT's with the ones obtained from the BPS quiver method.

Kanno, Hiroaki; Maruyoshi, Kazunobu; Shiba, Shotaro; Taki, Masato

2013-03-01

129

Determination of minimum inhibitory and minimum bactericidal concentrations of tiamulin against field isolates of Actinobacillus pleuropneumoniae.  

PubMed

Tiamulin activity was measured against 19 UK field isolates of Actinobacillus pleuropneumoniae collected between 2003 and 2009 and the type strain ATCC 27090 as a control, with the intention of comparing broth with serum as growth media. Broth microdilution MIC/MBC tests were performed in accordance with the Clinical and Laboratory Standards Institute (CLSI) guideline M31-A3, in 'Veterinary Fastidious Medium' (VFM) (supplemented Mueller-Hinton broth at pH 7.3) and in 100% swine serum. For improved precision, a modified, overlapping doubling-dilution series was used (tiamulin concentration range 0.3-72 ?g/ml). The MBC was reported as the lowest concentration producing a 99.9% reduction in bacterial density in the sub-cultured well contents, relative to the starting inoculum. The mean MBC/MIC ratio for tiamulin against A. pleuropneumoniae in VFM was low (1.74:1), even though tiamulin is classed as a bacteriostatic drug. Only three of the 19 isolates and the reference strain grew in 100% serum and their MICs were higher than those determined in VFM. It is postulated that this difference was due to differences in pH of the matrices or binding of tiamulin to serum proteins or a combination of both factors. PMID:21497460

Pridmore, Andrew; Burch, David; Lees, Peter

2011-03-21

130

Isolated high-harmonic XUV photon absorption and NIR strong-field tunnel ionization  

NASA Astrophysics Data System (ADS)

Extreme ultraviolet (XUV) pulses with a duration of tens of femtoseconds initiate 4s-1 or 4p-1 photoionization of krypton, which populates highly excited satellite states through the electron correlation. The excited ions are then tunnel ionized to Kr2+4s-14p-1 or 4p-2 by a strong-field near-infrared (NIR) pulse of a similar duration. The XUV pulses are produced by high harmonic generation in a gas jet and we employ a state-of-the-art time-preserving monochromator to isolate individual XUV harmonic orders. An enhancement of the Kr2+ yield as a function of harmonic photon energy and XUV-pump NIR-probe delay is observed and compared with a two-step model, which allows the population of the satellite states to be inferred. Furthermore, relative 4s and 4p satellite excitation cross-sections are predicted at the photon energies studied. This proof-of-principle experiment demonstrates that isolated harmonics can be employed to pump specific electronic states, which will be highly complementary to synchrotron, attosecond and x-ray free-electron laser studies of complex systems.

Bryan, W. A.; Frassetto, F.; Froud, C. A.; Turcu, I. C. E.; King, R. B.; Calvert, C. R.; Nemeth, G. R. A. J.; Villoresi, P.; Poletto, L.; Springate, E.

2012-01-01

131

Comparison of implant isolation species for GaN field-effect transistor structures  

SciTech Connect

Different ions (Ti{sup +}, O{sup +}, Fe{sup +}, Cr{sup +}) were implanted at multiple energies into GaN field effect transistor structures (n and p-type). The implantation was found to create deep states with energy levels in the range E{sub c} {minus}0.20 to 0.49 eV in n-GaN and at E{sub v} + 0.44 eV in p-GaN after annealing at 450--650 C. The sheet resistance of the GaN was at a maximum after annealing at these temperatures, reaching values of {approximately}4x10{sup 12} {Omega}/{open_square} in n-GaN and {approximately}10{sup 10}{Omega}/{open_square} in p-GaN. The mechanism for the implant isolation was damage-related trap formation for all of the ions investigated, and there was no evidence of chemically induced isolation.

Dang, G.; Cao, X.A.; Ren, F.; Pearton, S.J.; Han, J.; Baca, A.G.; Shul, R.I.; Wilson, R.G.

2000-07-01

132

Molecular Typing of Penicillium marneffei Isolates from Thailand by NotI Macrorestriction and Pulsed-Field Gel Electrophoresis  

PubMed Central

Penicillium marneffei is recognized as one of the most frequently detected opportunistic pathogens of AIDS patients in northern Thailand. We undertook a genomic epidemiology study of 64 P. marneffei isolates collected from immunosuppressed patients by pulsed-field gel electrophoresis (PFGE) with restriction enzyme NotI. Among the 69 isolates fingerprinted by PFGE, 17 were compared by HaeIII restriction endonuclease typing. The PFGE method demonstrated a higher degree of discriminatory power than restriction endonuclease typing with HaeII. Moreover, an impressive diversity of P. marneffei isolates was observed, as there were 54 distinct macrorestriction profiles among the 69 isolates of P. marneffei. These profiles were grouped into two large clusters by computer-assisted similarity analysis: macrorestriction pattern I (MPI) and MPII, with nine subprofiles (MPIa to MPIf and MPIIa to MPIIc). We observed no significant correlation between the macrorestriction patterns of the P. marneffei isolates and geographical region or specimen source. It is interesting that all isolates obtained before 1995 were MPI, and we found an increase in the incidence of infections with MPII isolates after 1995. We conclude that PFGE is a highly discriminatory typing method and is well suited for computer-assisted analysis. Together, PFGE and NotI macrorestriction allow reliable identification and epidemiological characterization of isolates as well as generate a manageable database that is convenient for expansion with information on additional P. marneffei isolates.

Trewatcharegon, Sompong; Sirisinha, Stitaya; Romsai, Amparat; Eampokalap, Boonchaoy; Teanpaisan, Rawee; Chaiyaroj, Sansanee C.

2001-01-01

133

Paenibacillus ginsengisoli sp. nov., a novel bacterium isolated from soil of a ginseng field in Pocheon province, South Korea  

Microsoft Academic Search

A Gram-positive, aerobic or facultative anaerobic, motile, spore-forming bacterial strain, designated Gsoil 1638T, was isolated from a soil sample of a ginseng field in Pocheon province (South Korea), and was characterized taxonomically\\u000a by using a polyphasic approach. It grew well on nutrient agar medium, utilized a fairly narrow spectrum of carbon sources\\u000a and tolerated 10% NaCl. The isolate was positive

Myungjin Lee; Leonid N. Ten; Sang-Hoon Baek; Wan-Taek Im; Zubair Aslam; Sung-Taik Lee

2007-01-01

134

Isolation of marine bacteria with antimicrobial activities from cultured and field-collected soft corals.  

PubMed

Bacteria associated with eight field-collected and five cultured soft corals of Briareum sp., Sinularia sp., Sarcophyton sp., Nephtheidae sp., and Lobophytum sp. were screened for their abilities in producing antimicrobial metabolites. Field-collected coral samples were collected from Nanwan Bay in southern Taiwan. Cultured corals were collected from the cultivating tank at National Museum of Marine Biology and Aquarium. A total of 1,526 and 1,138 culturable, heterotrophic bacteria were isolated from wild and cultured corals, respectively; seawater requirement and antimicrobial activity were then assessed. There is no significant difference between the ratio of seawater-requiring bacteria on the wild and cultured corals. The ratio of antibiotic-producing bacteria within the seawater-requiring bacteria did not differ between the corals. Nineteen bacterial strains that showed high antimicrobial activity were selected for 16S rDNA sequencing. Three strains could be assigned at the family level (Rhodobacteraceae). The remaining 16 strains belong to eight genera: Marinobacterium (2 strains), Pseudoalteromonas (1), Vibrio (5), Enterovibrio (1), Tateyamaria (1), Labrenzia (2), and Pseudovibrio (4). The crude extract from bacteria strains CGH2XX was found to have high cytotoxicity against the cancer cell line HL-60 (IC(50) = 0.94 ?g/ml) and CCRF-CEM (IC(50) = 1.19 ?g/ml). Our results demonstrate that the marine bacteria from corals have great potential in the discovery of useful medical molecules. PMID:22872580

Chen, Yu-Hsin; Kuo, Jimmy; Sung, Ping-Jung; Chang, Yu-Chia; Lu, Mei-Chin; Wong, Tit-Yee; Liu, Jong-Kang; Weng, Ching-Feng; Twan, Wen-Hung; Kuo, Fu-Wen

2012-08-08

135

Excessive magnetic field flux density distribution from overhead isolated powerline conductors due to neutral line current.  

PubMed

Overhead isolated powerline conductors (hereinafter: "OIPLC") are the most compact form for distributing low voltage currents. From the known physics of magnetic field emission from 3-phase power lines, it is expected that excellent symmetry of the 120° shifted phase currents and where compact configuration of the 3-phase+neutral line exist, the phase current vectorial summation of the magnetic field flux density (MFFD) is expected to be extremely low. However, despite this estimation, an unexpectedly very high MFFD was found in at least three towns in Israel. This paper explains the reasons leading to high MFFD emissions from compact OIPLC and the proper technique to fix it. Analysis and measurement results had led to the failure hypothsis of neutral line poor connection design and poor grounding design of the HV-LV utility transformers. The paper elaborates on the low MFFD exposure level setup by the Israeli Environmental Protection Office which adopted a rather conservative precaution principal exposure level (2 mG averaged over 24 h). PMID:23675630

Netzer, Moshe

2013-06-01

136

Multiple mechanisms account for variation in base-line sensitivity to azole fungicides in field isolates of Mycosphaerella graminicola.  

PubMed

Molecular mechanisms that account for variation in base-line sensitivity to azole fungicides were examined in a collection of twenty field isolates, collected in France and Germany, of the wheat pathogen Mycosphaerella graminicola (Fuckel) Schroeter. The isolates tested represent the wide baseline sensitivity to the azole fungicide tebuconazole described previously. The isolates were cross-sensitive to other azoles tested, such as cyproconazole and ketoconazole, but not to unrelated chemicals like cycloheximide, kresoxim-methyl or rhodamine 6G. Progenies from a genetic cross between an isolate with an intermediate and a high sensitivity to azoles displayed a continuous range of phenotypes with respect to cyproconazole sensitivity, indicating that variation in azole sensitivity in this haploid organism is polygenic. The basal level of expression of the ATP-binding cassette transporter genes MgAtr1-MgAtr5 from Mgraminicola significantly varied amongst the isolates tested, but no clear increase in the transcript level of a particular MgAtr gene was found in the less sensitive isolates. Cyproconazole strongly induced expression of MgAtr4, but no correlation between expression levels of this gene and azole sensitivity was observed. One isolate with intermediate sensitivity to azoles over-expressed CYP51, encoding cytochrome P450 sterol 14alpha-demethylase from M graminicola. Isolates with a low or high sensitivity to azoles were tested for accumulation of cyproconazole, but no clear correlation between reduced accumulation of the fungicide in mycelium and sensitivity to azoles was observed. Therefore, differences in accumulation cannot account exclusively for the variation in base-line sensitivity of the isolates to azoles. The results indicate that multiple mechanisms account for differences in base-line sensitivity to azoles in field isolates of M graminicola. PMID:14667055

Stergiopoulos, Ioannis; van Nistelrooy, Johannes G M; Kema, Gert H J; De Waard, Maarten A

2003-12-01

137

Aeromicrobium panaciterrae sp. nov., isolated from soil of a ginseng field in South Korea.  

PubMed

A Gram-positive, rod-shaped, non-spore-forming and strictly aerobic bacterium (Gsoil 161(T)) was isolated from soil of a ginseng field in Pocheon Province, South Korea. The novel isolate was characterized using a polyphasic approach in order to determine its taxonomic position. On the basis of 16S rRNA gene sequence similarity, strain Gsoil 161(T) was shown to belong to the family Nocardioidaceae and was related to Aeromicrobium marinum (98.0 % similarity to the type strain), Aeromicrobium alkaliterrae (97.6 %), Aeromicrobium fastidiosum (97.0 %) and Aeromicrobium erythreum (96.7 %); the sequence similarity with other species within the family was less than 94.4 %. It was characterized chemotaxonomically as having ll-2,6-diaminopimelic acid in the cell-wall peptidoglycan, MK-9(H(4)) as the predominant menaquinone and C(16 : 0), 10-methyl C(18 : 0) (tuberculostearic acid), C(16 : 0) 2-OH, 10-methyl C(17 : 0) and 10-methyl-C(16 : 0) as the major fatty acids. The G+C content of the genomic DNA was 65.5 mol%. These chemotaxonomic properties and phenotypic characteristics support the affiliation of strain Gsoil 161(T) to the genus Aeromicrobium. Results of physiological and biochemical tests enabled strain Gsoil 161(T) to be differentiated genotypically and phenotypically from currently known Aeromicrobium species. Therefore, strain Gsoil 161(T) represents a novel species, for which the name Aeromicrobium panaciterrae sp. nov. is proposed. The type strain is strain Gsoil 161(T) (=KCTC 19131(T)=DSM 17939(T)=CCUG 52476(T)). PMID:17392187

Cui, Ying-Shun; Im, Wan-Taek; Yin, Cheng-Ri; Lee, Jung-Sook; Lee, Keun Chul; Lee, Sung-Taik

2007-04-01

138

Plasmodium falciparum Field Isolates from South America Use an Atypical Red Blood Cell Invasion Pathway Associated with Invasion Ligand Polymorphisms  

PubMed Central

Studies of Plasmodium falciparum invasion pathways in field isolates have been limited. Red blood cell (RBC) invasion is a complex process involving two invasion protein families; Erythrocyte Binding-Like (EBL) and the Reticulocyte Binding-Like (PfRh) proteins, which are polymorphic and not fully characterized in field isolates. To determine the various P. falciparum invasion pathways used by parasite isolates from South America, we studied the invasion phenotypes in three regions: Colombia, Peru and Brazil. Additionally, polymorphisms in three members of the EBL (EBA-181, EBA-175 and EBL-1) and five members of the PfRh (PfRh1, PfRh2a, PfRh2b, PfRh4, PfRh5) families were determined. We found that most P. falciparum field isolates from Colombia and Peru invade RBCs through an atypical invasion pathway phenotypically characterized as resistant to all enzyme treatments (NrTrCr). Moreover, the invasion pathways and the ligand polymorphisms differed substantially among the Colombian and Brazilian isolates while the Peruvian isolates represent an amalgam of those present in the Colombian and Brazilian field isolates. The NrTrCr invasion profile was associated with the presence of the PfRh2a pepC variant, the PfRh5 variant 1 and EBA-181 RVNKN variant. The ebl and Pfrh expression levels in a field isolate displaying the NrTrCr profile also pointed to PfRh2a, PfRh5 and EBA-181 as being possibly the major players in this invasion pathway. Notably, our studies demonstrate the uniqueness of the Peruvian P. falciparum field isolates in terms of their invasion profiles and ligand polymorphisms, and present a unique opportunity for studying the ability of P. falciparum parasites to expand their invasion repertoire after being reintroduced to human populations. The present study is directly relevant to asexual blood stage vaccine design focused on invasion pathway proteins, suggesting that regional invasion variants and global geographical variation are likely to preclude a simple one size fits all type of vaccine.

Lopez-Perez, Mary; Villasis, Elizabeth; Machado, Ricardo L. D.; Povoa, Marinete M.; Vinetz, Joseph M.; Blair, Silvia; Gamboa, Dionicia; Lustigman, Sara

2012-01-01

139

Field Studies Reveal Strong Postmating Isolation between Ecologically Divergent Butterfly Populations  

PubMed Central

Gene flow between populations that are adapting to distinct environments may be restricted if hybrids inherit maladaptive, intermediate phenotypes. This phenomenon, called extrinsic postzygotic isolation (EPI), is thought to play a critical role in the early stages of speciation. However, despite its intuitive appeal, we know surprisingly little about the strength and prevalence of EPI in nature, and even less about the specific phenotypes that tend to cause problems for hybrids. In this study, we searched for EPI among allopatric populations of the butterfly Euphydryas editha that have specialized on alternative host plants. These populations recall a situation thought typical of the very early stages of speciation. They lack consistent host-associated genetic differentiation at random nuclear loci and show no signs of reproductive incompatibility in the laboratory. However, they do differ consistently in diverse host-related traits. For each of these traits, we first asked whether hybrids between populations that use different hosts (different-host hybrids) were intermediate to parental populations and to hybrids between populations that use the same host (same-host hybrids). We then conducted field experiments to estimate the effects of intermediacy on fitness in nature. Our results revealed strong EPI under field conditions. Different-host hybrids exhibited an array of intermediate traits that were significantly maladaptive, including four behaviors. Intermediate foraging height slowed the growth of larvae, while intermediate oviposition preference, oviposition site height, and clutch size severely reduced the growth and survival of the offspring of adult females. We used our empirical data to construct a fitness surface on which different-host hybrids can be seen to fall in an adaptive valley between two peaks occupied by same-host hybrids. These findings demonstrate how ecological selection against hybrids can create a strong barrier to gene flow at the early stages of adaptive divergence.

McBride, Carolyn S.; Singer, Michael C.

2010-01-01

140

Genetic variation in open reading frame 2 of field isolates and laboratory strains of equine arteritis virus  

Microsoft Academic Search

The open reading frame 2 (ORF2) of three laboratory strains, the live attenuated vaccine virus, and 18 field isolates of equine arteritis virus (EAV) from Europe and North America was sequenced. The ORF2 of EAV encodes the Gs protein that is abundantly expressed in infected cells but constitutes less than 2% of the virion protein mass. Variation of ORF2 among

Jodi F. Hedges; Udeni B. R. Balasuriya; Peter J. Timoney; William H. McCollum; N. James MacLachlan

1996-01-01

141

Biodegradation of diesel oil by an Arabian Sea sediment culture isolated from the vicinity of an oil field  

Microsoft Academic Search

Laboratory scale batch studies were performed to test the diesel oil biodegradation ability of ES1 cultures isolated from Arabian Sea sediments obtained from the vicinity of an oil field. This culture could utilize diesel as the sole source of carbon and energy. Under aerobic conditions, 39% loss of diesel oil was observed over 8 days where 80% of the loss

Suparna Mukherji; Sheeja Jagadevan; Gita Mohapatra; Avinash Vijay

2004-01-01

142

Understanding the molecular mechanism of instability of the avirulence gene AVR-Pita1 in field isolates of Maganporthe oryzae  

Technology Transfer Automated Retrieval System (TEKTRAN)

The avirulence gene AVR-Pita1 in Magnaporthe oryzae triggers a resistance response in rice plants that contain the resistance gene Pi-ta. Understanding the evolution of the AVR-Pita1 gene in field isolates should benefit the deployment of Pi-ta for the control of rice blast disease. A total of 187 f...

143

Bacillus panaciterrae sp. nov., isolated from soil of a ginseng field.  

PubMed

A Gram-positive, non-motile, endospore-forming bacterium, designated Gsoil 1517(T), was isolated from soil of a ginseng field in Pocheon Province (South Korea) and was characterized in order to determine its taxonomic position, using a polyphasic approach. It was found to rod-shaped and aerobic or facultatively anaerobic. It grew optimally at 30 degrees C and at pH 6.5-7.0. Comparative 16S rRNA gene sequence analysis showed that strain Gsoil 1517(T) forms a distinct phylogenetic lineage within the genus Bacillus, being related to Bacillus funiculus JCM 11201(T) (96.8 %). The strain showed less than 94.3 % sequence similarity with other Bacillus species. The G+C content of the genomic DNA was found to be 47.8 mol% and the predominant respiratory quinone was MK-7. The major fatty acids were iso-C(15 : 0) (42.4 %), anteiso-C(15 : 0) (17.4 %), iso-C(14 : 0) (9.7 %) and C(16 : 0) (6.0 %). On the basis of its phenotypic properties and phylogenetic distinctiveness, strain Gsoil 1517(T) represents a novel species of the genus Bacillus, for which the name Bacillus panaciterrae sp. nov. is proposed. The type strain is Gsoil 1517(T) (=KCTC 13929(T)=CCUG 52470(T)=LMG 23408(T)). PMID:17158988

Ten, Leonid N; Baek, Sang-Hoon; Im, Wan-Taek; Liu, Qing-Mei; Aslam, Zubair; Lee, Sung-Taik

2006-12-01

144

Chryseobacterium yeoncheonense sp. nov., with ginsenoside converting activity isolated from soil of a ginseng field.  

PubMed

A Gram-staining negative, aerobic, non-motile, non-flagellate, yellow-pigmented, rod-shaped bacterial strain, designated strain DCY67(T), was isolated from ginseng field in Republic of Korea. Strain DCY67(T) contained ?-glucosidase activity which converts ginsenoside Rb1 to compound K. Optimum growth of DCY67(T) occurred at 30 °C and pH 6.0-6.5. Analysis of the 16S rRNA gene sequences revealed that strain DCY67(T) belonged to the family Flavobacteriaceae and was most closely related to Chryseobacterium ginsenosidimutans THG 15(T) (97.5 %). The genomic DNA G+C content was 36.1 mol%. The predominant quinones were MK-6 (90.9 %) and MK-7 (9.15 %). The major fatty acids were iso-C15:0, summed feature 3 (containing C16:1 ?7c and/or C16:1 ?6c) and iso-C17:0 3-OH. On the basis of these phenotypic, genotypic and chemotaxonomic studies, strain DCY67(T) represents a novel species of the genus Chryseobacterium, for which, name Chryseobacterium yeoncheonense sp. nov. proposed the type strain is DCY67(T) (=KCTC 32090(T) = JCM 18516(T)). PMID:23666403

Hoang, Van-An; Kim, Yeon-Ju; Nguyen, Ngoc Lan; Yang, Deok-Chun

2013-05-12

145

Lysobacter panaciterrae sp. nov., isolated from soil of a ginseng field.  

PubMed

A Gram-negative, aerobic, rod-shaped, non-spore-forming bacterial strain, designated Gsoil 068(T), was isolated from soil of a ginseng field in Pocheon Province (South Korea), and was characterized to determine its taxonomic position by using a polyphasic approach. Comparative 16S rRNA gene sequence analysis showed that strain Gsoil 068(T) belonged to the family Xanthomonadaceae, class Gammaproteobacteria, and was related most closely to Lysobacter brunescens ATCC 29482(T) and Lysobacter gummosus ATCC 29489(T) (96.1 % sequence similarity). The G+C content of the genomic DNA of strain Gsoil 068(T) was 67.0 mol%. The detection of a quinone system with ubiquinone Q-8 as the predominant component and a fatty acid profile with iso-C(15 : 0), iso-C(17 : 1)omega9c, iso-C(17 : 0) and iso-C(11 : 0) 3-OH as the major components supported the affiliation of strain Gsoil 068(T) to the genus Lysobacter. On the basis of its phenotypic properties and phylogenetic distinctiveness, strain Gsoil 068(T) is considered to represent a novel species of the genus Lysobacter, for which the name Lysobacter panaciterrae sp. nov. is proposed. The type strain is Gsoil 068(T) (=KCTC 12601(T) =DSM 17927(T)). PMID:19406775

Ten, Leonid N; Jung, Hae-Min; Im, Wan-Taek; Yoo, Soon-Ae; Oh, Hee-Mock; Lee, Sung-Taik

2009-05-01

146

Lysobacter soli sp. nov., isolated from soil of a ginseng field.  

PubMed

Strain DCY21(T), a Gram-negative, gliding and rod-shaped aerobic bacterium was isolated from soil of a ginseng field in the Republic of Korea and characterized using a polyphasic approach in order to determine its taxonomic position. Comparative 16S rRNA gene sequence analysis revealed that strain DCY21(T) clustered with the species of the genus Lysobacter. It was closely related to Lysobacter gummosus LMG 8763(T) (97.9 %), Lysobacter capsici YC5194(T) (97.6 %), Lysobacter antibioticus DSM 2044(T) (97.5 %), Lysobacter niastensis DSM 18481(T) (97.2 %) and Lysobacter enzymogenes DSM 2043(T) (96.9 %). The major cellular fatty acids of strain DCY21(T) were iso-C(15 : 0) (34.3 %), iso-C(17 : 1)omega9c (19.5 %) and iso-C(17 : 0) (17.2 %) and the major isoprenoid quinone was Q-8. The major polar lipids of strain DCY21(T) were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and phosphatidyl-N-methylethanolamine. The G+C content of the total DNA was 65.4 mol%. The DNA-DNA relatedness values, and biochemical and physiological characteristics strongly supported the genotypic and phenotypic differentiation of strain DCY21(T) from species of the genus Lysobacter. Strain DCY21(T) therefore represents a novel species, for which the name Lysobacter soli sp. nov. is proposed. The type strain is DCY21(T) (=KCTC 22011(T) =LMG 24126(T)). PMID:19684312

Srinivasan, Sathiyaraj; Kim, Myung Kyum; Sathiyaraj, Gayathri; Kim, Ho-Bin; Kim, Yeon-Ju; Yang, Deok-Chun

2009-08-14

147

Pyrosequencing analysis of the beta-tubulin gene in Spanish Teladorsagia circumcincta field isolates.  

PubMed

Benzimidazole (BZ) resistance in gastrointestinal nematodes has been associated with single nucleotide polymorphisms (SNPs) at codons 200, 167 and 198 in the beta-tubulin isotype 1 gene and, recently, these SNPs have also been found in macrocyclic lactone (ML) resistant strains of Haemonchus contortus. On this basis, we have studied the same putative SNPs in Spanish Teladorsagia circumcincta field isolates by pyrosequencing. Single L3 (infective 3rd stage larvae) from five sheep flocks were tested after confirming their BZ susceptibility and degree of ivermectin (IVM) resistance. According to the Faecal Egg Count Reduction Test (FECRT) one flock was classified as IVM susceptible, another one was resistant, and the rest had a suspicion of resistance to IVM. DNA extraction was carried out on 598 single L3 and 56% of these were identified as T. circumcincta after the amplification of a species-specific ITS2 fragment. The number of L3 analyzed for the SNPs 198/200 was 255 and for the SNP 167 was 187. Results clearly indicate no resistance-associated SNPs were present at any codon, before or after treatment. Therefore, all T. cicumcincta L3 were designated as susceptible homozygous genotypes for all SNPs. The absence of the mutations in these populations would argue against resistance haplotypes being present in the parasite population prior to drug treatment, at least in Spanish T. circumcincta. PMID:21962969

Martínez-Valladares, María; Donnan, Alison; Geldhof, Peter; Jackson, Frank; Rojo-Vázquez, Francisco-Antonio; Skuce, Philip

2011-09-12

148

Biodegradation of buprofezin by Rhodococcus sp. strain YL-1 isolated from rice field soil.  

PubMed

A buprofezin-degrading bacterium, YL-1, was isolated from rice field soil. YL-1 was identified as Rhodococcus sp. on the basis of the comparative analysis of 16S rDNA sequences. The strain could use buprofezin as the sole source of carbon and nitrogen for growth and was able to degrade 92.4% of 50 mg L(-1) buprofezin within 48 h in liquid culture. During the degradation of buprofezin, four possible metabolites, 2-tert-butylimino-3-isopropyl-1,3,5-thiadiazinan-4-one, N-tert-butyl-thioformimidic acid formylaminomethyl ester, 2-isothiocyanato-2-methyl-propane, and 2-isothiocyanato-propane, were identified using gas chromatography-mass spectrometry (GC-MS) analysis. The catechol 2,3-dioxygenase activity was strongly induced during the degradation of buprofezin. A novel microbial biodegradation pathway for buprofezin was proposed on the basis of these metabolites. The inoculation of soils treated with buprofezin with strain YL-1 resulted in a higher degradation rate than that observed in noninoculated soils, indicating that strain YL-1 has the potential to be used in the bioremediation of buprofezin-contaminated environments. PMID:22335821

Li, Chao; Zhang, Ji; Wu, Zhi-Guo; Cao, Li; Yan, Xin; Li, Shun-Peng

2012-02-28

149

Use of an internal control in a quantitative RT-PCR assay for quantitation of porcine epidemic diarrhea virus shedding in pigs  

Microsoft Academic Search

Porcine epidemic diarrhea virus (PEDV), a member of the family Coronaviridae, has caused a devastating enteric disease in the Korean swine industry. Previously, the differences between virulent field PEDV strains and a Vero cell culture adapted PEDV DR13 strain were determined using restriction fragment length polymorphism analysis (RFLP), and PEDV shedding patterns in pigs were reported. In an extension to

Dae-Sub Song; Bo-Kyu Kang; Sang-Sun Lee; Jeong-Sun Yang; Hyoung-Joon Moon; Jin-Sik Oh; Gun-Woo Ha; Yong-Suk Jang; Bong-Kyun Park

2006-01-01

150

Incidence of plasmids in marine Vibrio spp. isolated from an oil field in the northwestern Gulf of Mexico  

SciTech Connect

Presumptive marine Vibrio spp. were collected from an operational oil field and control site located in the northwest Gulf of Mexico. Of 440 isolates analyzed for the presence of extrachromosomal deoxyribonucleic acid elements or plasmids by using the cleared lysate and agarose gel techniques, 31% showed distinct plasmid bands on agarose gels. A majority of the plasmids detected were estimated to have mollecular masses of 10 x 10/sup 6/ or less. Multiple plasmids were observed in approximately half of the plasmid-containing strains. A number of isolates contained plasmids with similar banding and mobility patterns. The oil field area had noticeably more plasmid-containing strains (35 versus 23% in the control site) and a greater number of plasmids per plasmid-containing strain (an average of 2.5 plasmids, vs 1.5 in the control site). Oil field discharges might have resulted in increased plasmid incidence and diversity.

Hada, H.S.; Sizemore, R.K.

1981-01-01

151

Identification and Onion Pathogenicity of Burkholderia cepacia Complex Isolates from the Onion Rhizosphere and Onion Field Soil?  

PubMed Central

Burkholderia cepacia complex strains are genetically related but phenotypically diverse organisms that are important opportunistic pathogens in patients with cystic fibrosis (CF,) as well as pathogens of onion and banana, colonizers of the rhizospheres of many plant species, and common inhabitants of bulk soil. Genotypic identification and pathogenicity characterization were performed on B. cepacia complex isolates from the rhizosphere of onion and organic soils in Michigan. A total of 3,798 putative B. cepacia complex isolates were recovered on Pseudomonas cepacia azelaic acid tryptamine and trypan blue tetracycline semiselective media during the 2004 growing season from six commercial onion fields located in two counties in Michigan. Putative B. cepacia complex isolates were identified by hybridization to a 16S rRNA gene probe, followed by duplex PCR using primers targeted to the 16S rRNA gene and recA sequences and restriction fragment length polymorphism analysis of the recA sequence. A total of 1,290 isolates, 980 rhizosphere and 310 soil isolates, were assigned to the species B. cepacia (160), B. cenocepacia (480), B. ambifaria (623), and B. pyrrocinia (27). The majority of isolates identified as B. cepacia (85%), B. cenocepacia (90%), and B. ambifaria (76%) were pathogenic in a detached onion bulb scale assay and caused symptoms of water soaking, maceration, and/or necrosis. A phylogenetic analysis of recA sequences from representative B. cepacia complex type and panel strains, along with isolates collected in this study, revealed that the B. cenocepacia isolates associated with onion grouped within the III-B lineage and that some strains were closely related to strain AU1054, which was isolated from a CF patient. This study revealed that multiple B. cepacia complex species colonize the onion rhizosphere and have the potential to cause sour skin rot disease of onion. In addition, the onion rhizosphere is a natural habitat and a potential environmental source of B. cenocepacia.

Jacobs, Janette L.; Fasi, Anthony C.; Ramette, Alban; Smith, James J.; Hammerschmidt, Raymond; Sundin, George W.

2008-01-01

152

Improved protocol for isolation of Campylobacter spp. from retail broiler meat and use of pulsed field gel electrophoresis for the typing of isolates.  

PubMed

To improve the detection of Campylobacter spp. in retail broiler meat, a reference method (R subsamples) based on the enrichment of 25g of meat in Bolton broth at 42°C under microaerobiosis was compared with an alternative method (A subsamples) consisting in the rinsing of meat samples for 30s in buffered peptone water with antimicrobials with incubation at 42°C under aerobiosis. One piece of meat (breasts, tenderloins and thighs) was rinse in experiment 1 (A1) and two pieces in experiment 2 (A2). Campylobacter spp. were isolated on agar plates and identified by PCR. Retail samples in Alabama had less prevalence (P?0.05) than samples in the state of Washington. The percentage of positive was higher (P?0.05) in A than in R subsamples and rinsing two pieces of meat yielded the highest percentage of positive subsamples. R subsamples showed variations in the prevalence by product. However, A subsamples had similar prevalence of positives among products compare to the result from reference method. More Campylobacter coli isolates were collected in A2 subsamples. Pulse field gel electrophoresis (PFGE) was used as subtyping method to study the genome similarity among the isolates from all methods. A larger diversity of isolates were detected by PFGE in A2 subsamples. Denaturing gradient gel electrophoresis analysis suggested that the initial bacterial populations of the meat samples impact the final bacterial profile after enrichment. Rinsing broiler meats was less time consuming, required less sample preparation and was more sensitive than the reference method for the isolation of naturally occurring Campylobacter spp. This new method could help with epidemiological and intervention studies to control Campylobacter spp. PMID:23545445

Oyarzabal, Omar A; Williams, Aretha; Zhou, Ping; Samadpour, Mansour

2013-03-29

153

Combinations of Macrolide Resistance Determinants in Field Isolates of Mannheimia haemolytica and Pasteurella multocida?  

PubMed Central

Respiratory tract infections in cattle are commonly associated with the bacterial pathogens Mannheimia haemolytica and Pasteurella multocida. These infections can generally be successfully treated in the field with one of several groups of antibiotics, including macrolides. A few recent isolates of these species exhibit resistance to veterinary macrolides with phenotypes that fall into three distinct classes. The first class has type I macrolide, lincosamide, and streptogramin B antibiotic resistance and, consistent with this, the 23S rRNA nucleotide A2058 is monomethylated by the enzyme product of the erm(42) gene. The second class shows no lincosamide resistance and lacks erm(42) and concomitant 23S rRNA methylation. Sequencing of the genome of a representative strain from this class, P. multocida 3361, revealed macrolide efflux and phosphotransferase genes [respectively termed msr(E) and mph(E)] that are arranged in tandem and presumably expressed from the same promoter. The third class exhibits the most marked drug phenotype, with high resistance to all of the macrolides tested, and possesses all three resistance determinants. The combinations of erm(42), msr(E), and mph(E) are chromosomally encoded and intermingled with other exogenous genes, many of which appear to have been transferred from other members of the Pasteurellaceae. The presence of some of the exogenous genes explains recent reports of resistance to additional drug classes. We have expressed recombinant versions of the erm(42), msr(E), and mph(E) genes within an isogenic Escherichia coli background to assess their individually contributions to resistance. Our findings indicate what types of compounds might have driven the selection for these resistance determinants.

Desmolaize, Benoit; Rose, Simon; Wilhelm, Cornelia; Warrass, Ralf; Douthwaite, Stephen

2011-01-01

154

Improved pulsed-field gel electrophoresis procedure for the analysis of Flavobacterium columnare isolates previously affected by DNA degradation.  

PubMed

Flavobacterium columnare is a fresh water bacterium that causes columnaris diseases in over 36 fish species. Intra-species typing of F. columnare can be performed by pulsed-field gel electrophoresis (PFGE). However, this method is hampered by the degradation of chromosomal DNA in about 10% of strains. In the current study, DNA degradation problems caused by extracellular DNases were overcome by fixation of cells with formaldehyde prior to isolation. The results substantiate that after problems due to DNases are overcome, PFGE analysis is a reproducible highly discriminating epidemiological method for studying F. columnare isolates regardless of fish host. PMID:18023300

Soto, Esteban; Mauel, Michael; Lawrence, Mark

2007-10-10

155

Sensitivity of Penicillium expansum field isolates to tebuconazole, iprodione, fludioxonil and cyprodinil and characterization of fitness parameters and patulin production.  

PubMed

A total of 236 Penicillium expansum field isolates from decayed apple fruit collected from packinghouses and processing industries located in the region of Imathia, Northern Greece were tested for their sensitivity to tebuconazole, fludioxonil, iprodione and cyprodinil. Preliminary fungitoxicity tests on the response of the isolates showed several phenotypes, distinguished according to their sensitivity to fungicides tested. The EC(50) values ranged from 0.64 to 5 (average = 0.98) ?g/ml for iprodione, 0.9 to 7.3 (average = 2.66) ?g/ml for tebuconazole, 0.008 to 1.28 (average = 0.55) ?g/ml for cyprodinil and from 0.013 to 0.47 (average = 0.08) ?g/ml for fludioxonil. A bimodal distribution of the EC(50) values of isolates with distinct sensitive and resistant populations to fludioxonil and tebuconazole were observed. In the case of cyprodinil, a much broader, hundred-fold, range of sensitivity was found, probably indicating that some isolates are relatively insensitive to cyprodinil compared to the most sensitive ones. Isolates exhibiting simultaneously reduced sensitivity to tebuconazole and fludioxonil or tebuconazole and iprodione or to tebuconazole and cyprodinil were also observed at low frequencies. A small portion of the population (7.5%) showed multiple resistance to tebuconazole, fludioxonil and iprodione. Study of fitness determining parameters showed that the resistance to tebuconazole, fludioxonil and iprodione had a significant adverse effect on mycelial growth rate and pathogenicity. Contrary to that, these fitness parameters were not affected in the isolates showing reduced sensitivity to cyprodinil. Analysis of patulin production on YES-agar growth medium and on artificially inoculated apple fruit showed that all isolates were mycotoxigenic. Most of the cyprodinil-insensitive isolates produced patulin at concentrations similar to or relatively higher (up to 1.5-fold on growth medium) than the sensitive ones. In contrast, a significant reduction (up to 98% of multiple resistant isolates) in patulin production was observed in all other phenotypes, indicating an adverse effect of fitness penalties on the mycotoxigenic ability of resistant isolates. The above mentioned data clearly show a considerable risk for the selection of P. expansum isolates resistant to fludioxonil, iprodione, tebuconazole and cyprodinil. The potential risk of increased patulin contamination of apples and their byproducts by the appearance and predominance of highly mycotoxigenic isolates of P. expansum resistant to the anilinopyrimidines is discussed. PMID:21251724

Karaoglanidis, George S; Markoglou, Anastasios N; Bardas, George A; Doukas, Eleftherios G; Konstantinou, Sotiris; Kalampokis, John F

2010-12-28

156

Quantitative Field Testing Rotylenchulus reniformis DNA from Metagenomic Samples Isolated Directly from Soil  

Microsoft Academic Search

A quantitative PCR procedure targeting the ?-tubulin gene determined the number of Rotylenchulus reniformis Linford & Oliveira 1940 in metagenomic DNA samples isolated from soil. Of note, this outcome was in the presence of other soil-dwelling plant parasitic nematodes including its sister genus Helicotylenchus Steiner, 1945. The methodology provides a framework for molecular diagnostics of nematodes from metagenomic DNA isolated

Kurt Showmaker; Gary W. Lawrence; Shien Lu; Clarissa Balbalian; Vincent P. Klink

2011-01-01

157

Quantitative Field Testing Rotylenchulus reniformis DNA from Metagenomic Samples Isolated Directly from Soil  

PubMed Central

A quantitative PCR procedure targeting the ?-tubulin gene determined the number of Rotylenchulus reniformis Linford & Oliveira 1940 in metagenomic DNA samples isolated from soil. Of note, this outcome was in the presence of other soil-dwelling plant parasitic nematodes including its sister genus Helicotylenchus Steiner, 1945. The methodology provides a framework for molecular diagnostics of nematodes from metagenomic DNA isolated directly from soil.

Showmaker, Kurt; Lawrence, Gary W.; Lu, Shien; Balbalian, Clarissa; Klink, Vincent P.

2011-01-01

158

Kodamaea ohmeri isolates from patients in a university hospital: identification, antifungal susceptibility, and pulsed-field gel electrophoresis analysis.  

PubMed

Data on clinical isolates of Kodamaea (Pichia) ohmeri, an emerging fungal pathogen, are scarce. Over the past 5 years, we identified yeast isolates from nine patients with fungemia as K. ohmeri by using the API 20C system. Here, we reanalyzed these isolates first by sequencing the internal transcribed spacer 2 (ITS2) regions and then by growing the isolates on CHROMagar Candida medium and subjecting them to pulsed-field gel electrophoresis (PFGE). Based on their ITS2 sequences, six of the nine isolates were confirmed as K. ohmeri, while the others were identified as Candida haemulonii (n = 2) and Candida parapsilosis (n = 1). PFGE karyotyping of the K. ohmeri isolates revealed similar major bands, and their colonies showed a characteristic color change from pink to blue when grown on CHROMagar Candida medium for more than 48 h. For K. ohmeri, the ranges of MICs of fluconazole, voriconazole, caspofungin, and micafungin were 2 to 32 mug/ml, 0.03 to 0.5 mug/ml, 0.125 to 0.25 mug/ml, and 0.03 to 0.06 mug/ml, respectively. Restriction endonuclease analysis of genomic NotI-digested DNA (REAG-N) from isolates from different patients produced unique patterns, suggesting that the fungemia had occurred sporadically. This study determined that ITS2 sequence data, PFGE karyotypes, and CHROMagar Candida chromogenic culture medium are reliable diagnostic tools for identifying K. ohmeri while REAG-N is useful for genotyping the clinical isolates of K. ohmeri. PMID:17251396

Lee, Jin Sol; Shin, Jong Hee; Kim, Mi-Na; Jung, Sook-In; Park, Kyung Hwa; Cho, Duck; Kee, Seung Jung; Shin, Myung Geun; Suh, Soon Pal; Ryang, Dong Wook

2007-01-24

159

Kodamaea ohmeri Isolates from Patients in a University Hospital: Identification, Antifungal Susceptibility, and Pulsed-Field Gel Electrophoresis Analysis?  

PubMed Central

Data on clinical isolates of Kodamaea (Pichia) ohmeri, an emerging fungal pathogen, are scarce. Over the past 5 years, we identified yeast isolates from nine patients with fungemia as K. ohmeri by using the API 20C system. Here, we reanalyzed these isolates first by sequencing the internal transcribed spacer 2 (ITS2) regions and then by growing the isolates on CHROMagar Candida medium and subjecting them to pulsed-field gel electrophoresis (PFGE). Based on their ITS2 sequences, six of the nine isolates were confirmed as K. ohmeri, while the others were identified as Candida haemulonii (n = 2) and Candida parapsilosis (n = 1). PFGE karyotyping of the K. ohmeri isolates revealed similar major bands, and their colonies showed a characteristic color change from pink to blue when grown on CHROMagar Candida medium for more than 48 h. For K. ohmeri, the ranges of MICs of fluconazole, voriconazole, caspofungin, and micafungin were 2 to 32 ?g/ml, 0.03 to 0.5 ?g/ml, 0.125 to 0.25 ?g/ml, and 0.03 to 0.06 ?g/ml, respectively. Restriction endonuclease analysis of genomic NotI-digested DNA (REAG-N) from isolates from different patients produced unique patterns, suggesting that the fungemia had occurred sporadically. This study determined that ITS2 sequence data, PFGE karyotypes, and CHROMagar Candida chromogenic culture medium are reliable diagnostic tools for identifying K. ohmeri while REAG-N is useful for genotyping the clinical isolates of K. ohmeri.

Lee, Jin Sol; Shin, Jong Hee; Kim, Mi-Na; Jung, Sook-In; Park, Kyung Hwa; Cho, Duck; Kee, Seung Jung; Shin, Myung Geun; Suh, Soon Pal; Ryang, Dong Wook

2007-01-01

160

Phylogeny and expression of the nucleocapsid gene of porcine epidemic diarrhoea virus.  

PubMed

Porcine epidemic diarrhoea virus (PEDV) is one of the important pathogens that may cause severe diarrhoea in piglets. In this study, the nucleocapsid (N) gene of a Chinese PEDV isolate designated HLJBY was cloned. The phylogeny of PEDV strains was investigated by constructing a phylogenetic tree based on the N protein sequences. The results indicate that there are two major groups of Chinese PEDVs, a Japanese PEDV group and a Korean PEDV group. High-level expression of the N protein was achieved in Escherichia coli. The immunoreactivity between PEDV particles or the bacterially expressed N protein and rabbit anti-PEDV serum was confirmed by immunofluorescence assays and Western blot. Both PEDV N protein and the polyclonal antibody generated in this study are valuable diagnostic reagents for PEDV surveillance. PMID:23661393

Yang, Wei; Li, Guangxing; Ren, Yudong; Suo, Siqingaowa; Ren, Xiaofeng

2013-06-01

161

Rapid identification and differentiation of the vaccine strain Rac H from EHV 1 field isolates using a non-radioactive DNA probe  

Microsoft Academic Search

Meyer, H., Hfibert, P., Schwend, C. and Eichhorn, W., 1992. Rapid identification and differentiation of the vaccine strain Rac H from EHV 1 field isolates using a non-radioactive DNA probe. Vet. Microbiol., 30:13-20. A method for rapid differentiation between the EHV 1 live vaccine strain Rac H and field isolates is described. Total DNA was isolated from virus-infected small scale

H. Meyer; P. Hiibert; C. Schwend; W. Eichhorn

1992-01-01

162

Use of Antibiotic Susceptibility Patterns and Pulsed-Field Gel Electrophoresis To Compare Historic and Contemporary Isolates of Multi-Drug-Resistant Salmonella enterica subsp. enterica Serovar Newport  

Microsoft Academic Search

Recently, multi-drug-resistant (MDR) Salmonella enterica subspecies enterica serovar Newport reemerged as a public and animal health problem. The antibiotic resistance of 198 isolates and the pulsed-field gel electro- phoresis patterns (PFGE) of 139 isolates were determined. Serovar Newport isolates collected between 1988 and 2001 were included in the study. One hundred seventy-eight isolates were collected from the San Joaquin valley

A. C. B. Berge; J. M. Adaska; W. M. Sischo

2004-01-01

163

Isolation and Characterization of Mobile Genetic Elements from Microbial Assemblages Obtained from the Field Research Center Site  

SciTech Connect

Considerable knowledge has been gained from the intensive study of a relatively limited group of bacterial plasmids. Recent efforts have begun to focus on the characterization of, at the molecular level, plasmid populations and associated mobile genetic elements (e.g., transposons, integrons) occurring in a wider range of aquatic and terrestrial habitats. Surprisingly, however, little information is available regarding the incidence and distribution of mobile genetic elements extant in contaminated subsurface environments. Such studies will provide greater knowledge on the ecology of plasmids and their contributions to the genetic plasticity (and adaptation) of naturally occurring subsurface microbial communities. We requested soil cores from the DOE NABIR Field Research Center (FRC) located on the Oak Ridge Reservation. The cores, received in February 2003, were sampled from four areas on the Oak Ridge Site: Area 1, Area 2, Area 3 (representing contaminated subsurface locales) and the background reference sites. The average core length (24 in) was subdivided into three profiles and soil pH and moisture content were determined. Uranium concentration was also determined in bulk samples. Replicate aliquots were fixed for total cell counts and for bacterial isolation. Four different isolation media were used to culture aerobic and facultative microbes from these four study areas. Colony forming units ranged from a minimum of 100 per gram soil to a maximum of 10,000 irrespective of media composition used. The vast majority of cultured subsurface isolates were gram-positive isolates and plasmid characterization was conducted per methods routinely used in the Sobecky laboratory. The percentage of plasmid incidence ranged from 10% to 60% of all isolates tested. This frequency appears to be somewhat higher than the incidence of plasmids we have observed in other habitats and we are increasing the number of isolates screened to confirm this observation. We are also characterizing the plasmid populations at the molecular level. Isolates cultured from the background control site exhibited the lowest occurrence of plasmids (10%). Aliquots of samples were also used in enrichment assays to isolate metal resistant subsurface isolates. Samples were subjected to three different metals (chromium, mercury and cadmium) at two different concentrations and incubated following a conditioning period in which samples were amended with a carbon, nitrogen and phosphorus source. Isolates were plated on metal selection, purified to single isolates and plasmid content determined.

Patricia Sobecky; Cassie Hodges; Kerri Lafferty; Mike Humphreys; Melanie Raimondo; Kristin Tuttle; Tamar Barkay

2004-03-17

164

Isolation and Characterization of Strains CVO and FWKO B, Two Novel Nitrate-Reducing, Sulfide-Oxidizing Bacteria Isolated from Oil Field Brine  

PubMed Central

Bacterial strains CVO and FWKO B were isolated from produced brine at the Coleville oil field in Saskatchewan, Canada. Both strains are obligate chemolithotrophs, with hydrogen, formate, and sulfide serving as the only known energy sources for FWKO B, whereas sulfide and elemental sulfur are the only known electron donors for CVO. Neither strain uses thiosulfate as an energy source. Both strains are microaerophiles (1% O2). In addition, CVO grows by denitrification of nitrate or nitrite whereas FWKO B reduces nitrate only to nitrite. Elemental sulfur is the sole product of sulfide oxidation by FWKO B, while CVO produces either elemental sulfur or sulfate, depending on the initial concentration of sulfide. Both strains are capable of growth under strictly autotrophic conditions, but CVO uses acetate as well as CO2 as its sole carbon source. Neither strain reduces sulfate; however, FWKO B reduces sulfur and displays chemolithoautotrophic growth in the presence of elemental sulfur, hydrogen, and CO2. Both strains grow at temperatures between 5 and 40°C. CVO is capable of growth at NaCl concentrations as high as 7%. The present 16s rRNA analysis suggests that both strains are members of the epsilon subdivision of the division Proteobacteria, with CVO most closely related to Thiomicrospira denitrifcans and FWKO B most closely related to members of the genus Arcobacter. The isolation of these two novel chemolithotrophic sulfur bacteria from oil field brine suggests the presence of a subterranean sulfur cycle driven entirely by hydrogen, carbon dioxide, and nitrate.

Gevertz, Diane; Telang, Anita J.; Voordouw, Gerrit; Jenneman, Gary E.

2000-01-01

165

An EIAV field isolate reveals much higher levels of subtype variability than currently reported for the equine lentivirus family  

PubMed Central

Background Equine infectious anemia virus (EIAV), a lentivirus that infects horses, has been utilized as an animal model for the study of HIV. Furthermore, the disease associated with the equine lentivirus poses a significant challenge to veterinary medicine around the world. As with all lentiviruses, EIAV has been shown to have a high propensity for genomic sequence and antigenic variation, especially in its envelope (Env) proteins. Recent studies have demonstrated Env variation to be a major determinant of vaccine efficacy, emphasizing the importance of defining natural variation among field isolates of EIAV. To date, however, published EIAV sequences have been reported only for cell-adapted strains of virus, predominantly derived from a single primary virus isolate, EIAVWyoming (EIAVWY). Results We present here the first characterization of the Env protein of a natural primary isolate from Pennsylvania (EIAVPA) since the widely utilized and referenced EIAVWY strain. The data demonstrated that the level of EIAVPA Env amino acid sequence variation, approximately 40% as compared to EIAVWY, is much greater than current perceptions or published reports of natural EIAV variation between field isolates. This variation did not appear to give rise to changes in the predicted secondary structure of the proteins. While the EIAVPA Env was serologically cross reactive with the Env proteins of the cell-adapted reference strain, EIAVPV (derivative of EIAVWY), the two variant Envs were shown to lack any cross neutralization by immune serum from horses infected with the respective virus strains. Conclusion Taking into account the significance of serum neutralization to universal vaccine efficacy, these findings are crucial considerations towards successful EIAV vaccine development and the potential inclusion of field isolate Envs in vaccine candidates.

Craigo, Jodi K; Barnes, Shannon; Zhang, Baoshan; Cook, Sheila J; Howe, Laryssa; Issel, Charles J; Montelaro, Ronald C

2009-01-01

166

Isolation of Buggy Creek Virus (Togaviridae: Alphavirus) From Field-Collected Eggs of Oeciacus vicarius (Hemiptera: Cimicidae)  

PubMed Central

Alphaviruses (Togaviridae) rarely have been found to be vertically transmitted from female arthropods to their progeny. We report two isolations of Buggy Creek virus (BCRV), an ecologically unusual alphavirus related to western equine encephalomyelitis virus, from field-collected eggs of cimicid swallow bugs (Oeciacus vicarius Horvath), the principal vector for BCRV. Ten percent of egg pools were positive for BCRV, and we estimated minimum infection rates to be 1.03 infected eggs per 1,000 tested. The results show potential vertical transmission of BCRV, represent one of the few isolations of any alphavirus from eggs or larvae of insects in the field, and are the first report of any virus in the eggs of cimicid bedbugs. The specialized ecological niche of BCRV in swallow bugs and at cliff swallow (Petrochelidon pyrrhonota Vieillot) nesting sites may promote vertical transmission of this virus.

Brown, Charles R.; Moore, Amy T.; Young, Ginger R.; Padhi, Abinash; Komar, Nicholas

2009-01-01

167

New Method of Denitrification Analysis of Bradyrhizobium Field Isolates by Gas Chromatographic Determination of 15N-Labeled N2  

PubMed Central

To evaluate the denitrification abilities of many Bradyrhizobium field isolates, we developed a new 15N-labeled N2 detection methodology, which is free from interference from atmospheric N2 contamination. 30N2 (15N15N) and 29N2 (15N14N) were detected as an apparent peak by a gas chromatograph equipped with a thermal conductivity detector with N2 gas having natural abundance of 15N (0.366 atom%) as a carrier gas. The detection limit was 0.04% 30N2, and the linearity extended at least to 40% 30N2. When Bradyrhizobium japonicum USDA110 was grown in cultures anaerobically with 15NO3?, denitrification product (30N2) was detected stoichiometrically. A total of 65 isolates of soybean bradyrhizobia from two field sites in Japan were assayed by this method. The denitrification abilities were partly correlated with filed sites, Bradyrhizobium species, and the hup genotype.

Sameshima-Saito, Reiko; Chiba, Kaori; Minamisawa, Kiwamu

2004-01-01

168

Downregulation of Mitogen-Activated Protein Kinase 1 of Leishmania donovani Field Isolates Is Associated with Antimony Resistance  

PubMed Central

Emergence of resistance to pentavalent antimonials has become a severe obstacle in the treatment of visceral leishmaniasis (VL) on the Indian subcontinent. The mechanisms operating in laboratory-generated strains are somewhat known, but the determinants of clinical antimony resistance are not well understood. By utilizing a DNA microarray expression profiling approach, we identified a gene encoding mitogen-activated protein kinase 1 (MAPK1) for the kinetoplast protozoan Leishmania donovani (LdMAPK1) that was consistently downregulated in antimony-resistant field isolates. The expression level of the gene was validated by real-time PCR. Furthermore, decreased expression of LdMAPK1 was also confirmed at the protein level in resistant isolates. Primary structure analysis of LdMAPK1 revealed the presence of all of the characteristic features of MAPK1. When expressed in Escherichia coli, the recombinant enzyme showed kinase activity with myelin basic protein as the substrate and was inhibited by staurosporine. Interestingly, overexpression of this gene in a drug-sensitive laboratory strain and a resistant field isolate resulted in increased the sensitivity of the transfectants to potassium antimony tartrate, suggesting that it has a role in antimony resistance. Our results demonstrate that downregulation of LdMAPK1 may be in part correlated with antimony drug resistance in Indian VL isolates.

Ashutosh; Garg, Mansi; Sundar, Shyam; Duncan, Robert; Nakhasi, Hira L.

2012-01-01

169

Intracellular calcium activity in isolated bovine adrenal chromaffin cells in the presence and absence of 60 Hz magnetic fields  

Microsoft Academic Search

This study examined whether 60 Hz magnetic field (MF) exposure alters intracellular calcium levels ((Ca2þ)i) in isolated bovine adrenal chromaffin cells, a classic model of neural responses. (Ca 2þ )i was monitored by fluorescence video imaging of cells loaded with the calcium indicator fluo-4 during exposures to magnetic flux densities of 0.01, 0.1, 1.0, 1.4, or 2.0 mT. MFs generated

Gale L. Craviso; James Poss; Christine Lanctot; Steven S. Lundback; Indira Chatterjee; Nelson G. Publicover

2002-01-01

170

Molecular Typing of Selected Enterococcus faecalis Isolates: Pilot Study Using Multilocus Sequence Typing and Pulsed-Field Gel Electrophoresis  

Microsoft Academic Search

The present study compared the recently developed multilocus sequence typing (MLST) approach with a well-established molecular typing technique, pulsed-field gel electrophoresis (PFGE), for subspecies differen- tiation of Enterococcus faecalis isolates. We sequenced intragenic regions of three E. faecalis antigen-encoding genes (ace, encoding a collagen and laminin adhesin; efaA, encoding an endocarditis antigen; and salA, encoding a cell wall associated antigen)

Sreedhar R. Nallapareddy; Ruay-Wang Duh; Kavindra V. Singh; Barbara E. Murray

2002-01-01

171

A new senescence-inducing mitochondrial linear plasmid in field-isolated Neurospora crassa strains from India  

Microsoft Academic Search

Several field-collected strains of Neurospora crassa from the vicinity or Aarey, Bombay, India, are prone to precocious senescence and death. Analysis of one strain, Aarely-1e, demonstrated that the genetic determinants for the predisposition to senescence are maternally inherited. The senescence-prone strains contain a 7-kb, linear, mitochondrial DNA plasmid, maranhar, which is not present in long-lived isolates from the same geographical

Deborah A. Court; Anthony J. F. Griffiths; Steven R. Kraus; Peter J. Russell; Helmut Bertrand

1991-01-01

172

Molecular analysis of Salmonella enteritidis and Typhimurium clinical and food isolates by pulsed-field gel electrophoresis in Bogotá, Colombia.  

PubMed

In 1997, the Microbiology Group of the Colombian Instituto Nacional de Salud set up a surveillance program with the National Public Health Laboratories to monitor the principal etiological agents responsible for acute diarrheal disease. The main goal of this study was to determine the XbaI DNA digestion patterns of clinical and food Salmonella spp. isolates recovered in Bogotá from 1997 to 2002, and related them to the susceptibility patterns to antimicrobial agents. Two hundred and twenty-four Salmonella spp. isolates were studied, 153 (63%) S. Enteritidis and 71 (37%) S. Typhimurium. Pulsed-field gel electrophoresis (PFGE) was done using the XbaI restriction enzyme and Salmonella Braenderup H9812 as the molecular weight marker. For S. Enteritidis, pattern S. En0001 was found to be prevalent in 127 (83%) isolates, 78 (61%) susceptible to the antimicrobial agents tested. For S. Typhimurium, pattern S. Typ0001 was predominant in 18 (25%) isolates with different antimicrobial resistance profiles. Patterns S. En0001 and S. Typ0001 prevailed monthly during the 6 years of the study. Data collected demonstrate that there was a dominant pattern of S. Enteritidis and S. Typhimurium circulating in clinical and food isolates in Bogotá, Colombia. PMID:16584312

Wiesner, Magdalena; Hidalgo, Marylin; Castañeda, Elizabeth; Agudelo, Clara Inés

2006-01-01

173

Genomic (5?UTR) and serological differences among German BVDV field isolates  

Microsoft Academic Search

Summary.  ?Isolates of bovine viral diarrhoea virus (BVDV) collected in Germany were examined for their genomic heterogeneity in sequences\\u000a from the 5?untranslated region (UTR) of the viral genome. Polymerase chain reaction (PCR) tests based on the 5?UTR and the\\u000a region coding for the NS2–3\\/4A polypeptide were used to differentiate between BVDV I and BVDV II genotypes. Eleven out of\\u000a 96 BVDV-isolates

A. Wolfmeyer; G. Wolf; M. Beer; W. Strube; H.-R. Hehnen; N. Schmeer; O.-R. Kaaden

1997-01-01

174

Field collection and genetic classification of tick-borne Rickettsiae and Rickettsiae-like pathogens from South Texas: Coxiella burnetii isolated from field-collected Amblyomma cajennense.  

PubMed

We are reporting the first known isolation of the Q-fever agent Coxiella burnetii from field-collected cayenne ticks Amblyomma cajennense in North America. Q-fever affects a number of domestic ungulates where it can lead to abortion in sheep and goats. There is far less known about the disease's effects on wild species, primarily because of the tendency of the disease to self resolve and to provide long-term immunity to subsequent infections. The first recovery of C. burnetii in North America was from the tick species Dermacentor andersoni. Since the original isolation C. burnetii has been recovered from five other North American tick species. The currently accepted mode for the majority of human infections is inhalation. The Centers for Disease Control and Prevention, Division of Viral and Rickettsial Diseases, Rickettsial Zoonoses Branch asserts the Q-fever agent as requiring as few as one organism to cause disease via inhalation in susceptible humans. However, with more and more isolations from ticks, evidence linking C. burnetii and ticks is mounting. The true role of tick species as competent vectors is still unconfirmed. Preemptive field collections of possible vector arthropods, hosts, and reservoirs can provide invaluable baseline environmental data that will prove supportive in follow-up studies and abatement efforts. PMID:19120212

Sanders, David M; Parker, Jill E; Walker, Wes W; Buchholz, Matt W; Blount, Keith; Kiel, Johnathan L

2008-12-01

175

Angle of incidence effects on the far-field noise of an isolated propeller  

NASA Astrophysics Data System (ADS)

An experimental acoustic investigation was conducted in the German/Dutch low-speed wind tunnel DNW on a six-bladed 1:5 scale model propeller. Far-field noise data are compared with theoretical data to show the capability of the prediction scheme, to estimate free-field and installed characteristics in the far-field. The aim is to compare the far-field noise changes with angle of incidence.

Sarin, S. L.; Donnelly, R. P.

176

Aquaporin 2 Mutations in Trypanosoma brucei gambiense Field Isolates Correlate with Decreased Susceptibility to Pentamidine and Melarsoprol.  

PubMed

The predominant mechanism of drug resistance in African trypanosomes is decreased drug uptake due to loss-of-function mutations in the genes for the transporters that mediate drug import. The role of transporters as determinants of drug susceptibility is well documented from laboratory-selected Trypanosoma brucei mutants. But clinical isolates, especially of T. b. gambiense, are less amenable to experimental investigation since they do not readily grow in culture without prior adaptation. Here we analyze a selected panel of 16 T. brucei ssp. field isolates that (i) have been adapted to axenic in vitro cultivation and (ii) mostly stem from treatment-refractory cases. For each isolate, we quantify the sensitivity to melarsoprol, pentamidine, and diminazene, and sequence the genomic loci of the transporter genes TbAT1 and TbAQP2. The former encodes the well-characterized aminopurine permease P2 which transports several trypanocides including melarsoprol, pentamidine, and diminazene. We find that diminazene-resistant field isolates of T. b. brucei and T. b. rhodesiense carry the same set of point mutations in TbAT1 that was previously described from lab mutants. Aquaglyceroporin 2 has only recently been identified as a second transporter involved in melarsoprol/pentamidine cross-resistance. Here we describe two different kinds of TbAQP2 mutations found in T. b. gambiense field isolates: simple loss of TbAQP2, or loss of wild-type TbAQP2 allele combined with the formation of a novel type of TbAQP2/3 chimera. The identified mutant T. b. gambiense are 40- to 50-fold less sensitive to pentamidine and 3- to 5-times less sensitive to melarsoprol than the reference isolates. We thus demonstrate for the first time that rearrangements of the TbAQP2/TbAQP3 locus accompanied by TbAQP2 gene loss also occur in the field, and that the T. b. gambiense carrying such mutations correlate with a significantly reduced susceptibility to pentamidine and melarsoprol. PMID:24130910

Graf, Fabrice E; Ludin, Philipp; Wenzler, Tanja; Kaiser, Marcel; Brun, Reto; Pyana, Patient Pati; Büscher, Philippe; de Koning, Harry P; Horn, David; Mäser, Pascal

2013-10-10

177

Aquaporin 2 Mutations in Trypanosoma brucei gambiense Field Isolates Correlate with Decreased Susceptibility to Pentamidine and Melarsoprol  

PubMed Central

The predominant mechanism of drug resistance in African trypanosomes is decreased drug uptake due to loss-of-function mutations in the genes for the transporters that mediate drug import. The role of transporters as determinants of drug susceptibility is well documented from laboratory-selected Trypanosoma brucei mutants. But clinical isolates, especially of T. b. gambiense, are less amenable to experimental investigation since they do not readily grow in culture without prior adaptation. Here we analyze a selected panel of 16 T. brucei ssp. field isolates that (i) have been adapted to axenic in vitro cultivation and (ii) mostly stem from treatment-refractory cases. For each isolate, we quantify the sensitivity to melarsoprol, pentamidine, and diminazene, and sequence the genomic loci of the transporter genes TbAT1 and TbAQP2. The former encodes the well-characterized aminopurine permease P2 which transports several trypanocides including melarsoprol, pentamidine, and diminazene. We find that diminazene-resistant field isolates of T. b. brucei and T. b. rhodesiense carry the same set of point mutations in TbAT1 that was previously described from lab mutants. Aquaglyceroporin 2 has only recently been identified as a second transporter involved in melarsoprol/pentamidine cross-resistance. Here we describe two different kinds of TbAQP2 mutations found in T. b. gambiense field isolates: simple loss of TbAQP2, or loss of wild-type TbAQP2 allele combined with the formation of a novel type of TbAQP2/3 chimera. The identified mutant T. b. gambiense are 40- to 50-fold less sensitive to pentamidine and 3- to 5-times less sensitive to melarsoprol than the reference isolates. We thus demonstrate for the first time that rearrangements of the TbAQP2/TbAQP3 locus accompanied by TbAQP2 gene loss also occur in the field, and that the T. b. gambiense carrying such mutations correlate with a significantly reduced susceptibility to pentamidine and melarsoprol.

Graf, Fabrice E.; Ludin, Philipp; Wenzler, Tanja; Kaiser, Marcel; Brun, Reto; Pyana, Patient Pati; Buscher, Philippe; de Koning, Harry P.; Horn, David; Maser, Pascal

2013-01-01

178

Identification of a field isolate of Fasciola hepatica resistant to albendazole and susceptible to triclabendazole.  

PubMed

The experiments described here were designed to characterize the status of susceptibility/resistance to albendazole (ABZ) and triclabendazole (TCBZ) of a Fasciola hepatica isolate (named CEDIVE isolate) recovered from infected sheep (Gualeguay, Argentina) and maintained under laboratory conditions. Two separate clinical efficacy experiments were performed on sheep artificially infected with the CEDIVE isolate. Experiment 1: sheep were randomly distributed either in an untreated control group or in an ABZ (7.5 mg/kg) treated group (n=4 each). Additionally, the systemic exposure of ABZ metabolites was assessed in those ABZ-treated infected animals. In Experiment 2, an untreated control group and a TCBZ (10 mg/kg) treated group was included (n=4 each). The fluckicidal efficacy of ABZ and TCBZ was assessed by the comparison of the number of flukes recovered from untreated and treated sheep at 15 days post-treatment. The efficacy against the CEDIVE isolate of F. hepatica was 29% (ABZ) and 100% (TCBZ). The plasma drug exposure (expressed as AUC and C(max)) observed in the ABZ treated animals (Experiment 1) was in agreement with data obtained in the previous studies, which indicate that the low ABZ efficacy was not related to the quality of the pharmaceutical product and/or to a low systemic availability of the active drug/metabolite. The results reported here clearly show that the CEDIVE isolate of F. hepatica behaves as resistant to ABZ and susceptible to TCBZ. PMID:23273779

Sanabria, Rodrigo; Ceballos, Laura; Moreno, Laura; Romero, Jorge; Lanusse, Carlos; Alvarez, Luis

2012-12-05

179

Genetic polymorphism of merozoite surface protein-1 and merozoite surface protein-2 in Plasmodium falciparum field isolates from Myanmar  

PubMed Central

Background Merozoite surface protein-1 (MSP-1) and MSP-2 of Plasmodium falciparum are potential vaccine candidate antigens for malaria vaccine development. However, extensive genetic polymorphism of the antigens in field isolates of P. falciparum represents a major obstacle for the development of an effective vaccine. In this study, genetic polymorphism of MSP-1 and MSP-2 among P. falciparum field isolates from Myanmar was analysed. Methods A total of 63 P. falciparum infected blood samples, which were collected from patients attending a regional hospital in Mandalay Division, Myanmar, were used in this study. The regions flanking the highly polymorphic characters, block 2 for MSP-1 and block 3 for MSP-2, were genotyped by allele-specific nested-PCR to analyse the population diversity of the parasite. Sequence analysis of the polymorphic regions of MSP-1 and MSP-2 was also conducted to identify allelic diversity in the parasite population. Results Diverse allelic polymorphism of MSP-1 and MSP-2 was identified in P. falciparum isolates from Myanmar and most of the infections were determined to be mixed infections. Sequence analysis of MSP-1 block 2 revealed that 14 different alleles for MSP-1 (5 for K1 type and 9 for MAD20 type) were identified. For MSP-2 block 3, a total of 22 alleles (7 for FC27 type and 15 for 3D7 type) were identified. Conclusion Extensive genetic polymorphism with diverse allele types was identified in MSP-1 and MSP-2 in P. falciparum field isolates from Myanmar. A high level of mixed infections was also observed, as was a high degree of multiplicity of infection.

2010-01-01

180

An algorithm to detect isolated anomalies in three-dimensional stratified data fields with an application to density fields from four deep basins of the Baltic Sea  

NASA Astrophysics Data System (ADS)

A new approach to describe the mesoscale variability caused by eddies in terms of the integral properties of all eddies contained in a certain ocean volume is suggested. For this purpose a pattern recognition algorithm to detect isolated anomalies in three-dimensional stratified data fields was developed and is introduced in detail. An application to 12 eddy-resolving density fields acquired in the framework of the German-Russian project MESODYN in four deep basins of the Baltic Sea, namely, the Arkona Basin, the Bornholm Basin, the Stolpe Furrow, and the Eastern Gotland Basin, demonstrates that the algorithm works properly. The most remarkable finding of this application is that the volume fraction occupied by the isolated anomalies or eddies is constant. It amounts to about 12% of the total volume for each data field no matter whether the stratification corresponds to a summer or a winter situation. Many possible applications of the pattern recognition are proposed to document its general usefulness. Finally, the main features of the algorithm and possible extensions are discussed extensively.

ReißMann, Jan H.

2005-12-01

181

Characterization of CbCyp51 from field isolates of Cercospora beticola.  

PubMed

The hemibiotrophic fungus Cercospora beticola causes leaf spot of sugar beet. Leaf spot control measures include the application of sterol demethylation inhibitor (DMI) fungicides. However, reduced sensitivity to DMIs has been reported recently in the Red River Valley sugar beet-growing region of North Dakota and Minnesota. Here, we report the cloning and molecular characterization of CbCyp51, which encodes the DMI target enzyme sterol P450 14?-demethylase in C. beticola. CbCyp51 is a 1,632-bp intron-free gene with obvious homology to other fungal Cyp51 genes and is present as a single copy in the C. beticola genome. Five nucleotide haplotypes were identified which encoded three amino acid sequences. Protein variant 1 composed 79% of the sequenced isolates, followed by protein variant 2 that composed 18% of the sequences and a single isolate representative of protein variant 3. Because resistance to DMIs can be related to polymorphism in promoter or coding sequences, sequence diversity was assessed by sequencing >2,440 nucleotides encompassing CbCyp51 coding and flanking regions from isolates with varying EC(50) values (effective concentration to reduce growth by 50%) to DMI fungicides. However, no mutations or haplotypes were associated with DMI resistance or sensitivity. No evidence for alternative splicing or differential methylation of CbCyp51 was found that might explain reduced sensitivity to DMIs. However, CbCyp51 was overexpressed in isolates with high EC(50) values compared with isolates with low EC(50) values. After exposure to tetraconazole, isolates with high EC(50) values responded with further induction of CbCyp51, with a positive correlation of CbCyp51 expression and tetraconazole concentration up to 2.5 ?g ml(-1). PMID:22085297

Bolton, Melvin D; Birla, Keshav; Rivera-Varas, Viviana; Rudolph, Kurt D; Secor, Gary A

2012-03-01

182

Pulsed-Field Gel Electrophoresis Analysis of Bordetella pertussis Isolates Circulating in Europe from 1998 to 2009  

PubMed Central

Between 1998 and 2009, Bordetella pertussis clinical isolates were collected during three periods, i.e., 1998 to 2001 (n = 102), 2004 to 2005 (n = 154), and 2007 to 2009 (n = 140), from nine countries with distinct vaccination programs, i.e., Denmark, Finland, France, Germany, The Netherlands, Norway, Poland, Sweden, and the United Kingdom. Pulsed-field gel electrophoresis (PFGE) analysis was performed according to standardized recommendations for epidemiological typing of B. pertussis. There were 81 different PFGE profiles, five of which (BpSR3, BpSR5, BpSR10, BpSR11, and BpSR12) were observed in 61% of the 396 isolates and shown to be predominant in almost all countries. The major profile, BpSR11, showed a decreasing trend from 25% to 30% in 1998 to 2005 to 13% in 2007 to 2009, and there were increases in BpSR3 and BpSR10 from 0% and 8% to 21% and 22%, respectively. One difference between these profiles is that BpSR11 contains isolates harboring the fim3-2 allele and BpSR3 and BpSR10 contain isolates harboring the fim3-1 allele. The total proportion of the five predominant profiles increased from 44% in 1998 to 2001 to 63% in 2004 to 2005 to 70% in 2007 to 2009. In conclusion, common PFGE profiles were identified in B. pertussis populations circulating in European countries with different vaccination programs and different vaccine coverages. These prevalent isolates contain the novel pertussis toxin promoter ptxP3 allele. However, there is evidence for diversifying selection between ptxP3 strains characterized by distinct PFGE profiles. This work shows that, even within a relatively short time span of 10 years, successful isolates which spread through Europe and cause large shifts in B. pertussis populations may emerge.

Advani, Abdolreza; Hallander, Hans O.; Dalby, Tine; Krogfelt, Karen Angeliki; Guiso, Nicole; Njamkepo, Elisabeth; von Konnig, Carl Heinz Wirsing; Riffelmann, Marion; Mooi, Frits R.; Sandven, Per; Lutynska, Anna; Fry, Norman K.; Mertsola, Jussi

2013-01-01

183

Phylogenetic characterization of bovine parainfluenza 3 from contaminated cell cultures and field isolates from Brazil.  

PubMed

Genomic fragments of the HN and L genes from Brazilian bovine parainfluenza 3 virus (bPIV-3) isolated as contaminants from cell cultures and clinical specimens were amplified by reverse transcription-polymerase chain reaction (RT-PCR), sequenced using specific degenerate primers and analyzed by phylogenetic comparison with reference strains of bPI3V. The Brazilian isolates revealed a high degree of genomic when compared to SF4/32 prototype strain, within the recently proposed genotype A of bPIV-3. PMID:24031776

de Almeida Vaucher, Rodrigo; Dezen, Diogenes; Simonetti, Amauri Braga; Spilki, Fernando Rosado; Roehe, Paulo Michel

2011-12-01

184

Phylogenetic characterization of bovine parainfluenza 3 from contaminated cell cultures and field isolates from Brazil  

PubMed Central

Genomic fragments of the HN and L genes from Brazilian bovine parainfluenza 3 virus (bPIV-3) isolated as contaminants from cell cultures and clinical specimens were amplified by reverse transcription-polymerase chain reaction (RT-PCR), sequenced using specific degenerate primers and analyzed by phylogenetic comparison with reference strains of bPI3V. The Brazilian isolates revealed a high degree of genomic when compared to SF4/32 prototype strain, within the recently proposed genotype A of bPIV-3.

de Almeida Vaucher, Rodrigo; Dezen, Diogenes; Simonetti, Amauri Braga; Spilki, Fernando Rosado; Roehe, Paulo Michel

2011-01-01

185

Isolation of key methanogens for global methane emission from rice paddy fields: a novel isolate affiliated with the clone cluster rice cluster I.  

PubMed

Despite the fact that rice paddy fields (RPFs) are contributing 10 to 25% of global methane emissions, the organisms responsible for methane production in RPFs have remained uncultivated and thus uncharacterized. Here we report the isolation of a methanogen (strain SANAE) belonging to an abundant and ubiquitous group of methanogens called rice cluster I (RC-I) previously identified as an ecologically important microbial component via culture-independent analyses. To enrich the RC-I methanogens from rice paddy samples, we attempted to mimic the in situ conditions of RC-I on the basis of the idea that methanogens in such ecosystems should thrive by receiving low concentrations of substrate (H(2)) continuously provided by heterotrophic H(2)-producing bacteria. For this purpose, we developed a coculture method using an indirect substrate (propionate) in defined medium and a propionate-oxidizing, H(2)-producing syntroph, Syntrophobacter fumaroxidans, as the H(2) supplier. By doing so, we significantly enriched the RC-I methanogens and eventually obtained a methanogen within the RC-I group in pure culture. This is the first report on the isolation of a methanogen within RC-I. PMID:17483259

Sakai, Sanae; Imachi, Hiroyuki; Sekiguchi, Yuji; Ohashi, Akiyoshi; Harada, Hideki; Kamagata, Yoichi

2007-05-04

186

Isolation of Key Methanogens for Global Methane Emission from Rice Paddy Fields: a Novel Isolate Affiliated with the Clone Cluster Rice Cluster I?  

PubMed Central

Despite the fact that rice paddy fields (RPFs) are contributing 10 to 25% of global methane emissions, the organisms responsible for methane production in RPFs have remained uncultivated and thus uncharacterized. Here we report the isolation of a methanogen (strain SANAE) belonging to an abundant and ubiquitous group of methanogens called rice cluster I (RC-I) previously identified as an ecologically important microbial component via culture-independent analyses. To enrich the RC-I methanogens from rice paddy samples, we attempted to mimic the in situ conditions of RC-I on the basis of the idea that methanogens in such ecosystems should thrive by receiving low concentrations of substrate (H2) continuously provided by heterotrophic H2-producing bacteria. For this purpose, we developed a coculture method using an indirect substrate (propionate) in defined medium and a propionate-oxidizing, H2-producing syntroph, Syntrophobacter fumaroxidans, as the H2 supplier. By doing so, we significantly enriched the RC-I methanogens and eventually obtained a methanogen within the RC-I group in pure culture. This is the first report on the isolation of a methanogen within RC-I.

Sakai, Sanae; Imachi, Hiroyuki; Sekiguchi, Yuji; Ohashi, Akiyoshi; Harada, Hideki; Kamagata, Yoichi

2007-01-01

187

Pulsed-Field Gel Electrophoresis of Staphylococcus aureus Isolates from Atopic Patients Revealing Presence of Similar Strains in Isolates from Children and Their Parents?  

PubMed Central

Skin colonization with Staphylococcus aureus is often associated with atopic dermatitis, and staphylococcal enterotoxins have been implicated in the etiology of atopic disease. In this study, the colonization of patients with atopic dermatitis and their parents was investigated in order to evaluate the possibility of intrafamiliar transmission. S. aureus strains were isolated from 30 of 45 patients (66%). In 19 of 29 families (65%), at least one parent carried S. aureus, and the overall colonization rate of the parents was 48%. All strains were typed by pulsed-field gel electrophoresis (PFGE), and the presence of enterotoxin genes in the strains was assayed by multiplex PCR. A high percentage (84%) of the isolates present on the children and on at least one of their parents displayed identical PFGE and enterotoxin patterns as well as identical antibiotic resistance profiles, indicating intrafamiliar transmission. Forty-five percent of the strains did not carry any enterotoxin gene. The most frequently found enterotoxin genes were seg and sei, which were present in 36% of the strains, and seb, which was found in 24% of the strains. The other toxin genes occurred only in low frequencies. Most strains were resistant to penicillin (82%), and 15% showed resistance to more than one antibiotic. Intermediately-vancomycin-resistant S. aureus or methicillin-resistant S. aureus strains were not detected. In conclusion, this study indicates that the colonization rate of parents of atopic children is rather high and may increase the risk of recolonization of the child.

Bonness, Sonja; Szekat, Christiane; Novak, Natalija; Bierbaum, Gabriele

2008-01-01

188

Population Synthesis of Young Isolated Neutron Stars: The Effect of Fallback Disk Accretion and Magnetic Field Evolution  

NASA Astrophysics Data System (ADS)

The spin evolution of isolated neutron stars (NSs) is dominated by their magnetic fields. The measured braking indices of young NSs show that the spin-down mechanism due to magnetic dipole radiation with constant magnetic fields is inadequate. Assuming that the NS magnetic field is buried by supernova fallback matter and re-emerges after accretion stops, we carry out a Monte Carlo simulation of the evolution of young NSs, and show that most of the pulsars have braking indices ranging from –1 to 3. The results are compatible with the observational data of NSs associated with supernova remnants. They also suggest that the initial spin periods of NSs might occupy a relatively wide range.

Fu, Lei; Li, Xiang-Dong

2013-10-01

189

Optimization of an antibiotic sensitivity assay for Mycoplasma hyosynoviae and susceptibility profiles of field isolates from 1997 to 2011.  

PubMed

Mycoplasma hyosynoviae is a common agent responsible for polyarthritis leading to decreased production in swine herds worldwide. Antimicrobial agents are used to combat infections; however breakpoints for M. hyosynoviae have not yet been established. A number of methods have previously been utilized to analyze minimum inhibitory concentrations (MICs) for antibiotics against M. hyosynoviae; however these techniques as currently described are not easily standardized between laboratories. A dry microbroth dilution method was conducted to compare the minimum inhibitory concentrations (MICs) for 18 antibiotics, representative of different classes, against 24 recent isolates (23 field isolates and the type strain) of M. hyosynoviae. The MICs were determined using standard, commercially available 96-well Sensititre(®) plates containing various freeze-dried antibiotics at a range of concentrations appropriate to their potency. Clindamycin (CLI), a lincosamide antibiotic, showed the highest activity and most consistent inhibition for all isolates with an MIC(50) of ? 0.12 ?g/ml. Tiamulin (TIA), a pleuromutilin derivative, exhibited an MIC(50) of ? 0.25 ?g/ml. The isolates had similar levels of susceptibility to the quinolones, enrofloxacin (ENRO) and danofloxacin (DANO), exhibiting an MIC(50) of 0.25 ?g/ml and 0.5 ?g/ml, respectively. For the macrolides, the MIC(50) for tylosin (TYLT) and tilmicosin (TIL) was ? 0.25 ?g/ml and ? 2 ?g/ml respectively, but was ? 16 ?g/ml for tulathromycin (TUL). For the aminoglycosides, the MIC(50) for gentamicin (GEN) was ? 0.5 ?g/ml, while spectinomycin (SPE) and neomycin (NEO) had an MIC(50) of ? 4 ?g/ml. The tetracyclines, oxytetracycline (OXY) and chlortetracycline (CTET) both had an MIC(50) of ? 2 ?g/ml. Florfenicol (FFN) exhibited a MIC(50) of ? 1 ?g/ml. All isolates were resistant to penicillin (PEN), ampicillin (AMP), ceftiofur (TIO), trimethoprim/sulfamethoxazole (SXT), and sulphadimethoxine (SDM) at all concentrations. Within the isolates tested, there was a range of sensitivity detected, with some isolates being overall more resistant while others appeared more susceptible. Further research is required to demonstrate how this MIC data correlates to clinical efficacy of the various antibiotics in the field. PMID:22397937

Schultz, K K; Strait, E L; Erickson, B Z; Levy, N

2012-02-11

190

Phylogenetic and functional diversity of denitrifying bacteria isolated from various rice paddy and rice-soybean rotation fields.  

PubMed

Denitrifiers can produce and consume nitrous oxide (N(2)O). While little N(2)O is emitted from rice paddy soil, the same soil produces N(2)O when the land is drained and used for upland crop cultivation. In this study, we collected soils from two types of fields each at three locations in Japan; one type of field had been used for continuous cultivation of rice and the other for rotational cultivation of rice and soybean. Active denitrifiers were isolated from these soils using a functional single-cell isolation method, and their taxonomy and denitrifying properties were examined. A total of 110 denitrifiers were obtained, including those previously detected by a culture-independent analysis. Strains belonging to the genus Pseudogulbenkiania were dominant at all locations, suggesting that Pseudogulbenkiania denitrifiers are ubiquitous in various rice paddy soils. Potential denitrifying activity was similar among the strains, regardless of the differences in taxonomic position and soil of origin. However, relative amounts of N(2) in denitrification end products varied among strains isolated from different locations. Our results also showed that crop rotation had minimal impact on the functional diversity of the denitrifying strains. These results indicate that soil and other environmental factors, excluding cropping systems, could select for N(2)-producing denitrifiers. PMID:21487200

Tago, Kanako; Ishii, Satoshi; Nishizawa, Tomoyasu; Otsuka, Shigeto; Senoo, Keishi

2011-01-01

191

Identification of antimony resistance markers in Leishmania tropica field isolates through a cDNA-AFLP approach.  

PubMed

Pentavalent antimonial compounds have been the first line therapy for leishmaniasis; unfortunately the rate of treatment failure of anthroponotic cutaneous leishmaniasis (ACL) is increasing due to emerging of drug resistance. Elucidation of the molecular mechanisms operating in antimony resistance is critical for development of new strategies for treatment. Here, we used a cDNA-AFLP approach to identify gene(s) which are differentially expressed in resistant and sensitive Leishmania tropica field isolates. We identified five genes, aquaglyceroporin (AQP1) acts in drug uptake, ATP-binding cassette (ABC) transporter (MRPA) involved in sequestration of drug, phosphoglycerate kinase (PGK) implicated in glycolysis metabolism, mitogen activated protein kinase (MAPK) and protein tyrosine phosphatase (PTP) responsible for phosphorylation pathway. The results were confirmed using real time RT-PCR which revealed an upregulation of MRPA, PTP and PGK genes and downregulation of AQP1 and MAPK genes in resistant isolate. To our knowledge, this is the first report of identification of PTP and PGK genes potentially implicated in resistance to antimonials. Our findings support the idea that distinct biomolecules might be involved in antimony resistance in L. tropica field isolates. PMID:23928349

Kazemi-Rad, Elham; Mohebali, Mehdi; Khadem-Erfan, Mohammad Bagher; Saffari, Mojtaba; Raoofian, Reza; Hajjaran, Homa; Hadighi, Ramtin; Khamesipour, Ali; Rezaie, Sassan; Abedkhojasteh, Hoda; Heidari, Mansour

2013-08-06

192

MAGNETIC FIELD IN THE ISOLATED MASSIVE DENSE CLUMP IRAS 20126+4104  

SciTech Connect

We measured polarized dust emission at 350 {mu}m toward the high-mass star-forming massive dense clump IRAS 20126+4104 using the SHARC II Polarimeter, SHARP, at the Caltech Submillimeter Observatory. Most of the observed magnetic field vectors agree well with magnetic field vectors obtained from a numerical simulation for the case when the global magnetic field lines are inclined with respect to the rotation axis of the dense clump. The results of the numerical simulation show that rotation plays an important role on the evolution of the massive dense clump and its magnetic field. The direction of the cold CO 1-0 bipolar outflow is parallel to the observed magnetic field within the dense clump as well as the global magnetic field, as inferred from optical polarimetry data, indicating that the magnetic field also plays a critical role in an early stage of massive star formation. The large-scale Keplerian disk of the massive (proto)star rotates in an almost opposite sense to the clump's envelope. The observed magnetic field morphology and the counterrotating feature of the massive dense clump system provide hints to constrain the role of magnetic fields in the process of high-mass star formation.

Shinnaga, Hiroko; Phillips, Thomas G. [California Institute of Technology Submillimeter Observatory, 111 Nowelo Street, Hilo, HI 96720 (United States); Novak, Giles [Department of Physics and Astronomy, Northwestern University, 633 Clark Street Evanston, IL 60208 (United States); Vaillancourt, John E. [Stratospheric Observatory for Infrared Astronomy, Universities Space Research Association, NASA Ames Research Center, Moffet Field, CA 94035 (United States); Machida, Masahiro N. [Department of Earth and Planetary Sciences, Faculty of Sciences, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan); Kataoka, Akimasa [Department of Astronomy, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502 (Japan); Tomisaka, Kohji [National Astronomical Observatory of Japan and Department of Astronomy, School of Physical Sciences, Graduate University for Advanced Studies (SOKENDAI), Osawa 2-21-1, Mitaka, Tokyo 181-8588 (Japan); Davidson, Jacqueline; Houde, Martin [School of Physics, University of Western Australia, 35 Stirling Highway, Crawley WA 6009, Perth (Australia); Dowell, C. Darren [Jet Propulsion Laboratory, California Institute of Technology, MS 169-506, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Leeuw, Lerothodi [SETI Institute, 515 North Whisman Avenue, Mountain View, CA 94043 (United States)

2012-05-10

193

Overexpression of Ubiquitin and Amino Acid Permease Genes in Association with Antimony Resistance in Leishmania tropica Field Isolates  

PubMed Central

The mainstay therapy against leishmaniasis is still pentavalent antimonial drugs; however, the rate of antimony resistance is increasing in endemic regions such as Iran. Understanding the molecular basis of resistance to antimonials could be helpful to improve treatment strategies. This study aimed to recognize genes involved in antimony resistance of Leishmania tropica field isolates. Sensitive and resistant L. tropica parasites were isolated from anthroponotic cutaneous leishmaniasis patients and drug susceptibility of parasites to meglumine antimoniate (Glucantime®) was confirmed using in vitro assay. Then, complementary DNA-amplified fragment length polymorphism (cDNA-AFLP) and real-time reverse transcriptase-PCR (RT-PCR) approaches were utilized on mRNAs from resistant and sensitive L. tropica isolates. We identified 2 known genes, ubiquitin implicated in protein degradation and amino acid permease (AAP3) involved in arginine uptake. Also, we identified 1 gene encoding hypothetical protein. Real-time RT-PCR revealed a significant upregulation of ubiquitin (2.54-fold), and AAP3 (2.86-fold) (P<0.05) in a resistant isolate compared to a sensitive one. Our results suggest that overexpression of ubiquitin and AAP3 could potentially implicated in natural antimony resistance.

Kazemi-Rad, Elham; Khadem-Erfan, Mohammad Bagher; Hajjaran, Homa; Hadighi, Ramtin; Khamesipour, Ali; Rezaie, Sassan; Saffari, Mojtaba; Raoofian, Reza

2013-01-01

194

Overexpression of Ubiquitin and Amino Acid Permease Genes in Association with Antimony Resistance in Leishmania tropica Field Isolates.  

PubMed

The mainstay therapy against leishmaniasis is still pentavalent antimonial drugs; however, the rate of antimony resistance is increasing in endemic regions such as Iran. Understanding the molecular basis of resistance to antimonials could be helpful to improve treatment strategies. This study aimed to recognize genes involved in antimony resistance of Leishmania tropica field isolates. Sensitive and resistant L. tropica parasites were isolated from anthroponotic cutaneous leishmaniasis patients and drug susceptibility of parasites to meglumine antimoniate (Glucantime®) was confirmed using in vitro assay. Then, complementary DNA-amplified fragment length polymorphism (cDNA-AFLP) and real-time reverse transcriptase-PCR (RT-PCR) approaches were utilized on mRNAs from resistant and sensitive L. tropica isolates. We identified 2 known genes, ubiquitin implicated in protein degradation and amino acid permease (AAP3) involved in arginine uptake. Also, we identified 1 gene encoding hypothetical protein. Real-time RT-PCR revealed a significant upregulation of ubiquitin (2.54-fold), and AAP3 (2.86-fold) (P<0.05) in a resistant isolate compared to a sensitive one. Our results suggest that overexpression of ubiquitin and AAP3 could potentially implicated in natural antimony resistance. PMID:24039283

Kazemi-Rad, Elham; Mohebali, Mehdi; Khadem-Erfan, Mohammad Bagher; Hajjaran, Homa; Hadighi, Ramtin; Khamesipour, Ali; Rezaie, Sassan; Saffari, Mojtaba; Raoofian, Reza; Heidari, Mansour

2013-08-30

195

7 CFR 201.76 - Minimum Land, Isolation, Field, and Seed Standards.  

Code of Federal Regulations, 2013 CFR

...isolation distance may be modified by (1) adequate...97m) and may be modified by the planting...contaminating source does not genetically differ in...contaminating source does (genetically...lines if the previous crop was grown...distance may be modified by the...

2013-01-01

196

Solution for the isolation of the working field in a difficult case of root canal therapy.  

PubMed

A technique for the isolation of a posterior tooth with large distogingival caries and which needed endodontic therapy is described. To ensure a perfect seal, avoiding contamination or infiltration of the chemicals used for irrigation during the root canal therapy, a direct resin temporary restoration was done before placing the rubber dam as required for endodontic treatment. PMID:7499983

Iglesias, A M; Urrutia, C

1995-07-01

197

Isolation of an Eimeria ninakohlyakimovae field strain (Canary Islands) and analysis of its infection characteristics in goat kids.  

PubMed

The current study was conducted to isolate a field strain of Eimeria ninakohlyakimovae, characterize its infectivity and the response to challenge under experimental conditions. The isolated strain (GC) induced a prepatent period of 14-15 days p.i., a patency of 7±2 days and a noticeable pathogenicity in infected goat kids. Challenge trials resulting in a decrease of oocysts per gram counts as well as a milder intensity of clinical signs in re-infected animals indicated the capacity of this strain to induce protective immune response. Altogether, the data reported in the present study suggest that the strain E. ninakohlyakimovae GC is a useful tool for the investigation of mechanisms of pathogenicity as well as host protective immune response in caprine coccidiosis, representing a valuable prerequisite for the development of future strategies in prophylaxis and control of this important parasitic disease in goat. PMID:22989759

Ruiz, A; Matos, L; Muñoz, M C; Hermosilla, C; Molina, J M; Andrada, M; Rodríguez, F; Pérez, D; López, A; Guedes, A; Taubert, A

2012-09-16

198

Propagation effects of isolated attosecond pulse generation with a multicycle chirped and chirped-free two-color field  

SciTech Connect

We present a theoretical study of isolated attosecond pulse generation with a multicycle chirped and chirped-free two-color field. We show that the bandwidth of the extreme ultraviolet supercontinuum can be extended by combining a multicycle chirped pulse and a multicycle chirped-free pulse. Also, the broadband supercontinuum can still be generated when the macroscopic effects are included. Furthermore, the macroscopic effects can ameliorate the temporal characteristic of the broadband supercontinuum of the single atom, and eliminate the modulations of the broadband supercontinuum. Thus a very smooth broadband supercontinuum and a pure isolated 102-as pulse can be directly obtained. Moreover, the structure of the broadband supercontinuum can be steadily maintained for a relative long distance after a certain distance.

Du Hongchuan; Hu Bitao [School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000 (China)

2011-08-15

199

Genetic Analysis of Fenhexamid-Resistant Field Isolates of the Phytopathogenic Fungus Botrytis cinerea? †  

PubMed Central

The hydroxyanilide fenhexamid, one of the latest antibotrytis fungicides, active especially against leotiomycete plant-pathogenic fungi, inhibits 3-ketoreductase of the C-4-demethylation enzyme complex during ergosterol biosynthesis. We isolated Botrytis cinerea strains resistant to various levels of fenhexamid from French and German vineyards. The sequence of the gene encoding 3-ketoreductase, erg27, varied according to levels of resistance. Highly resistant isolates, termed HydR3+, all presented a modification of the phenylalanine at the C terminus of the putative transmembrane domain at position 412, either to serine (85% of the isolates), to isoleucine (11.5% of the isolates), or to valine (3.5% of the isolates). The introduction of the \\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{pmc} \\usepackage[Euler]{upgreek} \\pagestyle{empty} \\oddsidemargin -1.0in \\begin{document} \\begin{equation*}erg27^{HydR3^{+}}\\end{equation*}\\end{document} allele into a fenhexamid-sensitive strain by means of a replicative plasmid conferred fenhexamid resistance on the resulting transformants, showing that the mutations at position 412 are responsible for fenhexamid resistance. Weakly to moderately resistant isolates, termed HydR3?, showed different point mutations between the strains in the sequenced regions of the erg27 gene, corresponding to amino acid changes between positions 195 and 400 of the protein. The \\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{pmc} \\usepackage[Euler]{upgreek} \\pagestyle{empty} \\oddsidemargin -1.0in \\begin{document} \\begin{equation*}erg27^{HydR3^{-}}\\end{equation*}\\end{document} alleles on the replicative vector introduced into a sensitive strain did not confer resistance to fenhexamid. Genetic crosses between HydR3? and sensitive strains showed strict correlation between the sequenced mutation in the erg27 gene and the resistance phenotypes, suggesting that these mutations are linked to fenhexamid resistance. The HydR3 mutations possibly modify the affinity of the 3-ketoreductase enzyme for its specific inhibitor, fenhexamid.

Fillinger, Sabine; Leroux, Pierre; Auclair, Christiane; Barreau, Christian; Al Hajj, Charbel; Debieu, Daniele

2008-01-01

200

Efficacy of commercial canarypox vaccine for protecting Hawai'i 'Amakihi from field isolates of Avipoxvirus  

USGS Publications Warehouse

At least three variants of avian pox virus are present in Hawai‘i - Fowlpox from domestic poultry and a group of genetically distinct viruses that cluster within two clades (Pox Variant 1 and Pox Variant 2) that are most similar to Canarypox based on DNA sequence of the virus 4b core protein gene. We tested whether Hawai‘i ‘Amakihi can be protected from wild virus isolates with an attenuated live Canarypox vaccine that is closely related to isolates that cluster within clade 1 (Pox Variant 1) based on sequence of the attenuated Canarypox virus 4b core protein. Thirty-one (31) Hawai`i ‘Amakihi (Hemignathus virens) with no prior physical evidence of pox infection were collected on Mauna Kea from xeric, high elevation habitats with low pox prevalence and randomly divided into two groups. One group of 16 was vaccinated with Poximmune C® while the other group received a sham vaccination with virus diluent. Four of 15 (27%) vaccinated birds developed potentially life-threatening disseminated lesions or lesions of unusually long duration, while one bird never developed a vaccine-associated lesion or "take". After vaccine-associated lesions healed, vaccinated birds were randomly divided into three groups of five and challenged with either a wild isolate of Fowlpox, a Hawai`i `Amakihi isolate of a Canarypox-like virus from clade 1 (Pox Variant 1) or a Hawai`i `Amakihi isolate of a Canarypox-like virus from clade 2 (Pox Variant 2). Similarly, three random groups of five unvaccinated ‘Amakihi were challenged with the same virus isolates. Vaccinated and unvaccinated ‘Amakihi challenged with Fowlpox had transient infections with no clinical signs of infection. Mortality in vaccinated ‘Amakihi that were challenged with Pox Variant 1 and Pox Variant 2 ranged from 0% (0/5) for Pox Variant 1 to 60% (3/5) for Pox Variant 2. Mortality in unvaccinated ‘Amakihi ranged from 40% (2/5) for Pox Variant 1 to 100% (5/5) for Pox Variant 2. While the vaccine provided some protection against Pox Variant 1, serious side effects and low efficacy against Pox Variant 2 make it risky to use in captive or wild honeycreepers.

Atkinson, Carter T.; Wiegand, Kimberly C.; Triglia, Dennis; Jarvi, Susan I.

2010-01-01

201

Identification of a novel equine infectious anemia virus field strain isolated from feral horses in southern Japan.  

PubMed

Although equine infectious anemia (EIA) was described more than 150 years ago, complete genomic sequences have only been obtained from two field strains of EIA virus (EIAV), EIAV(Wyoming) and EIAV(Liaoning). In 2011, EIA was detected within the distinctive feral Misaki horse population that inhabits the Toi-Cape area of southern Japan. Complete proviral sequences comprising a novel field strain were amplified directly from peripheral blood of one of these EIAV-infected horses and characterized by nucleotide sequencing. The complete provirus of Miyazaki2011-A strain is 8208 bp in length with an overall genomic organization typical of EIAV. However, this field isolate possesses just 77.2 and 78.7?% nucleotide sequence identity with the EIAV(Wyoming) and EIAV(Liaoning) strains, respectively, while similarity plot analysis suggested all three strains arose independently. Furthermore, phylogenetic studies using sequences obtained from all EIAV-infected Misaki horses against known viral strains strongly suggests these Japanese isolates comprise a separate monophyletic group. PMID:23100364

Dong, Jian-Bao; Zhu, Wei; Cook, Frank R; Goto, Yoshitaka; Horii, Yoichiro; Haga, Takeshi

2012-10-24

202

Molecular characterization of the env gene from Brazilian field isolates of Bovine Leukemia Virus  

Microsoft Academic Search

Molecular characterization of Bovine leukemia virus (BLV) isolates from Brazil using the env gene sequences revealed a high conservation of this gene. In most cases the substitutions corresponded to silent transitions.\\u000a In addition, cystein residues, potential glycosylation sites, neutralization domains and other critical residues involved\\u000a with the envelope structural domains and viral infectivity were conserved. Most of the substitutions found

Marcelo Fernandes Camargos; Ariel Pereda; Daniel Stancek; Maurílio Andrade Rocha; Jenner Karlisson Pimenta dos Reis; Irene Greiser-Wilke; Rômulo Cerqueira Leite

2007-01-01

203

Susceptibility testing of tulathromycin: Interpretative breakpoints and susceptibility of field isolates  

Microsoft Academic Search

In vitro susceptibility tests were conducted on bovine and porcine respiratory pathogens isolated from European countries during 2004–2006 for susceptibility to tulathromycin using the recommended methodologies for broth microdilution. The results were compared with data from a similar survey conducted prior to launch in 1998–2001 to monitor for any shift in susceptibility. The importance of maintaining the pH of the

K. S. Godinho

2008-01-01

204

In vitro interaction of dihydroartemisin and lumefantrine in clinical field isolates from Bangladesh  

Microsoft Academic Search

\\u000a Zusammenfassung  Artemether-Lumefantrin wurde im Jahr 2005 als offizielle Standardtherapie für die Behandlung der unkomplizierten Plasmodium falciparum Malaria in Bangladesh eingeführt. Um die Interaktion zwischen Dihydroartemisinin (DHA) und Lumefantrin (LUM) näher zu untersuchen,\\u000a wurden frische P. falciparum Isolate von Patienten, die mit unkomplizierter falciparum Malaria in der MARIB Feldstation im Bandarban Sadar Hospital in Bangladesh vorstellig wurden, in Checkerboard in vitro Assays

Kamala Thriemer; Wasif Ali Khan; Peter Starzengruber; Rashidul Haque; Matthias G. Vossen; Aung Swi Prue Marma; Selim Akther; Mark Fukuda; Harald Noedl

2007-01-01

205

Field trials of CpGV virus isolates overcoming resistance to CpGV-M  

Microsoft Academic Search

The Cydia pomonella granulovirus (CpGV) has been used for many years as biological agent for codling moth control in apple orchards. Resistance to the Mexican\\u000a strain of CpGV was detected in orchards in Germany, France and Italy. A laboratory insect colony was started from insects\\u000a collected in a French resistant orchard. It was named RGV. Various virus isolates were identified

M. Berling; J.-B. Rey; S.-J. Ondet; Y. Tallot; O. Soubabère; A. Bonhomme; B. Sauphanor; M. Lopez-Ferber

2009-01-01

206

Isolated High-Purity Platinum Nanowire Growth via Field Emission from a Multi-Walled Carbon Nanotube  

NASA Astrophysics Data System (ADS)

Isolated high-purity platinum nanowire growth was presented via field emission from the tip of a multi-walled carbon nanotube (MWCNT) with a precursor of cyclopentadienyl-trimethyl-platinum(IV) (CpPtMe3) inside a scanning electron microscope (SEM). A nanomanipulation system was used to adjust the gap between the anode (tungsten probe) and cathode (MWCNT) in order to control the nanowire growth length which achieved a platinum nanowire length of 1.18 ?m. The chemical composition of the platinum nanowire analyzed by energy-dispersive X-ray spectroscopy (EDS) shows that the purity of the platinum in the nanowire reaches 94.9 wt %.

Yang, Zhan; Nakajima, Masahiro; Saito, Yahachi; Ode, Yasuhito; Fukuda, Toshio

2011-03-01

207

Kenyan Plasmodium falciparum Field Isolates: Correlation between Pyrimethamine and Chlorcycloguanil Activity In Vitro and Point Mutations in the Dihydrofolate Reductase Domain  

Microsoft Academic Search

Sixty-nine Kenyan Plasmodium falciparum field isolates were tested in vitro against pyrimethamine (PM), chlorcycloguanil (CCG), sulfadoxine (SD), and dapsone (DDS), and their dihydrofolate reductase (DHFR) genotypes were determined. The in vitro data show that CCG is more potent than PM and that DDS is more potent than SD. DHFR genotype is correlated with PM and CCG drug response. Isolates can

A. NZILA-MOUNDA; E. K. MBERU; C. H. SIBLEY; C. V. PLOWE; P. A. WINSTANLEY; W. M. WATKINS

1998-01-01

208

Role of Real-Time Molecular Typing in the Surveillance of Campylobacter Enteritis and Comparison of Pulsed-Field Gel Electrophoresis Profiles from Chicken and Human Isolates  

Microsoft Academic Search

The goal of the present study was to assess the contribution of real-time molecular typing, used alone or with clinical surveillance, to the prompt identification of clusters of Campylobacter enteritis. Potential poultry sources were sought by comparing the pulsed-field gel electrophoresis genotypes of human and fresh whole retail chicken isolates collected during the same study period. Among 183 human isolates,

Sophie Michaud; Suzanne Menard; Robert D. Arbeit

2005-01-01

209

Characterization of western European field isolates and vaccine strains of avian infectious laryngotracheitis virus by restriction fragment length polymorphism and sequence analysis.  

PubMed

Infectious laryngotracheitis is a dramatic disease of the upper respiratory tract in poultry caused by a herpesvirus. In this study we investigated the characteristics of western European field isolates of infectious laryngotracheitis virus (ILTV) to gain more information on their diversity. The examined 104 isolates, collected from acute outbreaks during the last 35 years, originated from eight different countries: Switzerland (48), Germany (21), Sweden (14), the United Kingdom (9), Italy (5), Belgium (4), Austria (2), and Norway (1). Two vaccines, a chicken embryo origin product and a tissue culture origin product, were included in the survey. Polymerase chain reaction (PCR) was performed to amplify a 2.1-kb DNA fragment of ILTV using primers generated for the thymidine kinase (TK) gene. After digestion of the resulting PCR products by restriction endonuclease HaeIII, restriction fragment length polymorphism analysis was carried out. PCR amplicons of three field isolates and both vaccine strains were selected for sequencing. Here 98 field isolates showed the same cleavage pattern and were identical to both vaccine strains (clone 1). They differed from five Swiss isolates with identical cleavage pattern (clone 2) and one Swedish isolate (clone 3). The present study demonstrated that at least three clones of ILTV have been circulating in western Europe during the last 35 years. The 104 isolates analyzed showed a high genetic similarity regarding the TK gene, and a large majority of the field isolates (98/104) were genetically related to the vaccine strains. PMID:18646457

Neff, C; Sudler, C; Hoop, R K

2008-06-01

210

Differentiation of vaccine virus from field isolates of feline panleukopenia virus by polymerase chain reaction and restriction fragment length polymorphism analysis  

Microsoft Academic Search

In an attempt to distinguish feline panleukopenia virus (FPLV) live vaccine strains from FPLV field isolates in Japan, we compared restriction fragment length polymorphisms (RFLP) of polymerase chain reaction (PCR)-amplified fragments of live FPLV vaccine strains with those of FPLV Japanese field isolates. On the basis of nucleotide sequence differences between PLI-IV, a live vaccine strain, and FPV-483, a recent

Motohiro Horiuchi; Kazuyo Yuri; Takehisa Soma; Hiromi Katae; Hideyuki Nagasawa; Morikazu Shinagawa

1996-01-01

211

Molecular analysis of Leptospira spp. isolated from humans by restriction fragment length polymorphism, real-time PCR and pulsed-field gel electrophoresis.  

PubMed

A total of 17 Leptospira clinical strains isolated from humans in Croatia were serologically and genetically analysed. For serovar identification, the microscopic agglutination test (MAT) and pulsed-field gel electrophoresis (PFGE) were used. To identify isolates on genomic species level, PCR-based restriction fragment length polymorphism (RFLP) and real-time PCR were performed. MAT revealed the following serogroup affinities: Grippotyphosa (seven isolates), Icterohaemorrhagiae (eight isolates) and Javanica (two isolates). RFLP of PCR products from a 331-bp-long fragment of rrs (16S rRNA gene) digested with endonucleases MnlI and DdeI and real-time PCR revealed three Leptospira genomic species. Grippotyphosa isolates belonged to Leptospira kirschneri, Icterohaemorrhagiae isolates to Leptospira interrogans and Javanica isolates to Leptospira borgpetersenii. Genomic DNA from 17 leptospiral isolates was digested with NotI and SgrAI restriction enzymes and analysed by PFGE. Results showed that seven isolates have the same binding pattern to serovar Grippotyphosa, eight isolates to serovar Icterohaemorrhagiae and two isolates to serovar Poi. Results demonstrate the diversity of leptospires circulating in Croatia. We point out the usefulness of a combination of PFGE, RFLP and real-time PCR as appropriate molecular methods in molecular analysis of leptospires. PMID:19780841

Turk, Nenad; Milas, Zoran; Mojcec, Vesna; Ruzic-Sabljic, Eva; Staresina, Vilim; Stritof, Zrinka; Habus, Josipa; Postic, Daniele

2009-08-28

212

In vitro amplification of BVDV field strains isolated in Argentina: effect of cell line and culture conditions.  

PubMed

The aim of this work was to study the in vitro amplification of BVDV (Pestivirus, Flaviridae) field isolates from Argentina in MDBK, BoTur and BHK-21 continuous cell lines. Field isolates 99/134 (mucosal disease), 00/693 (mucosal disease), 04P7016 (respiratory disease) and 04/89 (mucosal disease), genotype 1b, were used and compared with the Singer and NADL reference strains, genotype 1a. Additionally, cell lines derived from explants of bovine testis (RD-420), bovine uterus (NCL-1) and porcine kidney (PKZ) were tested as alternative substrates for BVDV propagation in vitro. The effect of cell line, harvest time and infection protocol was evaluated. The viral titers observed depended on the virus and harvest time but not on the infection protocol. We found that MDBK and BoTur cell lines were susceptible to the infection whereas BHK-21 and PKZ were not. NADL viral titers, 00/693 and 04/89, increased from 24 to 48 h p.i. in BoTur cells and then reached a plateau, whereas those of 99/134 and 04P7016 remained constant between 24 and 72 h p.i. BVDV Singer, on the other hand, presented a maximum titer at 24 h p.i. and then decreased. BVDV-NADL titers increased in MDBK and NCL-1 but not in RD-420 between 24 and 48 h p.i., and then decreased at 72 h p.i. These facts lead us to conclude that neither the subgenotypes (1a, 1b) nor the clinical symptoms of the animal from the virus had been isolated seem to affect the virus cell line kinetics of viral replication in vitro. On the other hand, the most homogenous behavior, the most similar replication curves, and highest titers observed in MDBK and NCL-1 seem to indicate that these lines are generally more susceptible to BVDV replication. PMID:19623896

Odeón, A C; Leunda, M R; Faverín, C; Boynak, N; Vena, M M; Zabal, O

213

Does courtship behavior contribute to species-level reproductive isolation in field crickets?  

Microsoft Academic Search

Reproductive behavior influences gene flow within and among species; thus, sexual selection may be a major contributor to the maintenance of species, and possibly their formation. Here I experimentally manipulate the courtship interactions of the field crickets Gryllus rubens and G. texensis to examine the potential of close-range courtship interactions to limit interspecific gene flow. Responses of males to females

David A. Gray

2005-01-01

214

Comparative Immune Response Pattern of Commercial Infectious Bursal Disease Vaccines Against Field Isolates in Pakistan  

Microsoft Academic Search

A comparative study was undertaken to evaluate immune response against four types of infectious bursal disease (IBD) vaccines in broilers. The decline pattern of maternal antibody titres in unvaccinate d chicks was compared with those given IBD vaccines, following different vaccination schedules. Indirect ELISA as well as challenge with field virus evaluated the immune response of these vaccines. The results

2003-01-01

215

Vanadium51 solid-state NMR electric field gradient tensors: A DFT-embedded ion and isolated cluster study of crystalline vanadium oxides  

Microsoft Academic Search

Density functional theory (DFT) calculations (6–311+G(2d,p)\\/B3LYP level of theory) of 51V electric field gradient (EFG) tensor elements are performed for embedded and isolated cluster models of orthovanadates. The structural models used to calculate the EFGs of 51V are (I) an isolated H4VO4+ cluster, (II) an isolated HnVO4n?3 cluster (n=number of next-neighbor cations) (III) an isolated orthovanadate anion, VO4?x, and (IV)

Becky A. Gee

2006-01-01

216

Susceptibility testing of tulathromycin: interpretative breakpoints and susceptibility of field isolates.  

PubMed

In vitro susceptibility tests were conducted on bovine and porcine respiratory pathogens isolated from European countries during 2004-2006 for susceptibility to tulathromycin using the recommended methodologies for broth microdilution. The results were compared with data from a similar survey conducted prior to launch in 1998-2001 to monitor for any shift in susceptibility. The importance of maintaining the pH of the culture media within the range 7.2-7.4 was re-affirmed as a key factor in obtaining consistent minimum inhibitory concentration data. The use of recently established interpretative breakpoints would indicate that to date there has been no apparent decrease in susceptibility to tulathromycin since it became widely used across Europe. PMID:18187275

Godinho, K S

2007-12-04

217

Molecular characterization of the avrXa7 locus from Xanthomonas oryzae pv. oryzae field isolates  

Microsoft Academic Search

The effector gene avrXa7 from Xanthomonas oryzae pv. oryzae has avirulence function in rice with the Xa7 resistance gene and confers pathogenic fitness (aggressiveness). Field strains of X. oryzae pv. oryzae displayed a diversity of phenotypes on rice ranging from complete to partial loss of these functions. To understand the molecular basis for variation in avrXa7 function, we sequenced the

Grisel Ponciano; Kimberly Webb; Jianfa Bai; Casiana Vera Cruz; Jan E. Leach

2004-01-01

218

Screening and selection of most potent diazotrophic cyanobacterial isolate exhibiting natural tolerance to rice field herbicides for exploitation as biofertilizer.  

PubMed

Periodic applications of heavy dosages of herbicides in modern rice-agriculture are a necessary evil for obtaining high crop productivity. Such herbicides are not only detrimental to weeds but biofertilizer strains of diazotrophic cyanobacteria also. It is therefore, essential to screen and select such biofertilizer strains of diazotrophic cyanobacteria exhibiting natural tolerance to common rice-field herbicides that can be further improved by mutational techniques to make biofertilizer technology a viable one. Therefore, efforts have been made to screen five dominant diazotrophic cyanobacterial forms e.g. filamentous heterocystous Nostoc punctiforme , Nostoc calcicola , Anabaena variabilis and unicellular Gloeocapsa sp. and Aphanocapsa sp. along with standard laboratory strain Nostoc muscorum ISU against increasing concentrations (0-100 mg l(-1) of four commercial grade common rice-field herbicides i.e. Arozin, Butachlor, Alachlor and 2,4-D under diazotrophic growth conditions. The lethal and IGC(50) concentrations for all four herbicides tested were found highest for A. variabilis as compared to other test cyanobacteria. The lowest reduction in chlorophyll a content, photosynthetic oxygen evolution, and N(2)-fixation was found in A. variabilis as compared to other rice field isolates and standard laboratory strain N. muscorum ISU. On the basis of prolong survival potential and lowest reductions in vital metabolic activities tested at IGC(50) concentration of four herbicides, it is concluded that A. variabilis is the most potent and promising cyanobacterial isolate as compared with other forms. This could be further improved by mutational techniques for exploitation as most potential and viable biofertilizer strain. PMID:16721882

Singh, Surendra; Datta, Pallavi

2006-01-01

219

Inotropic responses to field stimulation in isolated atrial and ventricular muscle  

Microsoft Academic Search

Summary  \\u000a \\u000a \\u000a \\u000a 1. \\u000a \\u000a Field stimulation of autonomic nerve fibres in rat, guinea-pig and rabbit atria caused an initial negative followed by a positive\\u000a inotropic response which were blocked by tetrodotoxin.\\u000a \\u000a \\u000a \\u000a \\u000a 2. \\u000a \\u000a Atropine blocked the negative and potentiated the positive inotropism. Procaine had a similar anti-muscarinic effect but lignocaine,\\u000a cinchocaine and amethocaine had not. Cocaine potentiated the positive inotropic effect apparently by

J. J. Mitchell; M. F. Murnaghan

1980-01-01

220

Genetic Characterization of Atypical Enteropathogenic Escherichia coli Isolates from Ewes' Milk, Sheep Farm Environments, and Humans by Multilocus Sequence Typing and Pulsed-Field Gel Electrophoresis.  

PubMed

A collection of 81 isolates of enteropathogenic Escherichia coli (EPEC) was obtained from samples of bulk tank sheep milk (62 isolates), ovine feces (4 isolates), sheep farm environment (water, 4 isolates; air, 1 isolate), and human stool samples (9 isolates). The strains were considered atypical EPEC organisms, carrying the eae gene without harboring the pEAF plasmid. Multilocus sequence typing (MLST) was carried out with seven housekeeping genes and 19 sequence types (ST) were detected, with none of them having been previously reported for atypical EPEC. The most frequent ST included 41 strains isolated from milk and human stool samples. Genetic typing by pulsed-field gel electrophoresis (PFGE) resulted in 57 patterns which grouped in 24 clusters. Comparison of strains isolated from the different samples showed phylogenetic relationships between milk and human isolates and also between milk and water isolates. The results obtained show a possible risk for humans due to the presence of atypical EPEC in ewes' milk and suggest a transmission route for this emerging pathogen through contaminated water. PMID:23872571

Otero, Verónica; Rodríguez-Calleja, José-María; Otero, Andrés; García-López, María-Luisa; Santos, Jesús A

2013-07-19

221

Enhanced Discrimination of Highly Clonal ST22-Methicillin-Resistant Staphylococcus aureus IV Isolates Achieved by Combining spa, dru, and Pulsed-Field Gel Electrophoresis Typing Data ? †  

PubMed Central

ST22-methicillin-resistant Staphylococcus aureus type IV (ST22-MRSA-IV) is endemic in Irish hospitals and is designated antibiogram-resistogram type-pulsed-field group (AR-PFG) 06-01. Isolates of this highly clonal strain exhibit limited numbers of pulsed-field gel electrophoresis (PFGE) patterns and spa types. This study investigated whether combining PFGE and spa typing with DNA sequencing of the staphylococcal cassette chromosome mec element (SCCmec)-associated direct repeat unit (dru typing) would improve isolate discrimination. A total of 173 MRSA isolates recovered in one Irish hospital during periods in 2007 and 2008 were investigated using antibiogram-resistogram (AR), PFGE, spa, dru, and SCCmec typing. Isolates representative of each of the 17 pulsed-field group 01 (PFG-01) spa types identified underwent multilocus sequence typing, and all isolates were ST22. Ninety-seven percent of isolates (168 of 173) exhibited AR-PFG 06-01 or closely related AR patterns, and 163 of these isolates harbored SCCmec type IVh. The combination of PFGE, spa, and dru typing methods significantly improved discrimination of the 168 PFG-01 isolates, yielding 65 type combinations with a Simpson's index of diversity (SID) of 96.53, compared to (i) pairwise combinations of spa and dru typing, spa and PFGE typing, and dru and PFGE typing, which yielded 37, 44, and 43 type combinations with SIDs of 90.84, 91.00, and 93.57, respectively, or (ii) individual spa, dru, and PFGE typing methods, which yielded 17, 17, and 21 types with SIDs of 66.9, 77.83, and 81.34, respectively. Analysis of epidemiological information for a subset of PFG-01 isolates validated the relationships inferred using combined PFGE, spa, and dru typing data. This approach significantly enhances discrimination of ST22-MRSA-IV isolates and could be applied to epidemiological investigations of other highly clonal MRSA strains.

Shore, Anna C.; Rossney, Angela S.; Kinnevey, Peter M.; Brennan, Orla M.; Creamer, Eilish; Sherlock, Orla; Dolan, Anthony; Cunney, Robert; Sullivan, Derek J.; Goering, Richard V.; Humphreys, Hilary; Coleman, David C.

2010-01-01

222

Paralcaligenes ureilyticus gen. nov., sp. nov. isolated from soil of a Korean ginseng field.  

PubMed

A bacterial strain, designated GR24-5(T), was isolated from soil cultivated with Korean ginseng. Cells were Gram-negative, strictly aerobic, catalase- and oxidase-positive, non-spore-forming motile rods. Based on the 16S rRNA gene sequence, strain GR24-5(T) could be assigned to the family Alcaligenaceae. Strain GR24-5(T) showed the highest sequence similarities with Parapusillimonas granuli Ch07(T) (97.1%), Pusillimonas noertemannii BN9(T) (96.9%), Pigmentiphaga kullae DSM 13608(T) (96.5%), and Castellaniella defragrans 54Pin(T) (96.3%). Strain GR24-5(T) demonstrated a low DNA-DNA relatedness (23%) with P. granuli Ch07(T). The major respiratory quinone is ubiquinone 8 (Q-8) and the major fatty acids are C(16:0), C(17:0) cyclo, and summed feature 1 (C(14:0) 3-OH/iso-C(16:1) I/C(12:0) aide). Putrescine, spermidine, and 2-hydroxyputrescine are the major polyamines. The major polar lipids are phosphatidylmethylethanolamine, phosphatidylethanolamine, phosphatidylglycerol, di-phosphatidylglycerol, and an unknown aminophospholipid. Polar lipid patterns of strain GR24-5(T) were unique in having a large amount of phosphatidylmethylethanolamine. Based on phylogenetic analysis and physiological and biochemical characteristics, strain GR245(T) represents a novel genus and species, for which the name Paralcaligenes ureilyticus gen. nov., sp. nov. is proposed. The type strain of P. aralcaligenes ureilyticus is GR24-5(T) (=KACC 13888 =DSM 24591(T)). PMID:21717340

Kim, Soo-Jin; Yoo, Seung-Hee; Weon, Hang-Yeon; Kim, Yi-Seul; Anandham, Rangasamy; Suh, Jang-Sun; Kwon, Soon-Wo

2011-06-30

223

Biodegradation of diesel oil by an Arabian Sea sediment culture isolated from the vicinity of an oil field.  

PubMed

Laboratory scale batch studies were performed to test the diesel oil biodegradation ability of ES1 cultures isolated from Arabian Sea sediments obtained from the vicinity of an oil field. This culture could utilize diesel as the sole source of carbon and energy. Under aerobic conditions, 39% loss of diesel oil was observed over 8 days where 80% of the loss was due to aliphatic constituents. Under anoxic nitrate reducing conditions the rate and extent of degradation was significantly lower, i.e., 18% over 50 days. Salt acclimatized cultures could tolerate salinities up to 3.5% and demonstrated optimal performance at a salinity of 0.5%. The optimum N/P ratio for these cultures was found to be in the range of 2:1-5:1. Addition of two trace elemental substance formulations exhibited a significant inhibitory effect on culture growth. This culture has good potential for decontamination of oil-contaminated marine and subsurface environments. PMID:15288270

Mukherji, Suparna; Jagadevan, Sheeja; Mohapatra, Gita; Vijay, Avinash

2004-12-01

224

Tandem electric field gradient focusing system for isolation and concentration of target proteins.  

PubMed

Two electric field gradient focusing (EFGF) systems, one based on a hollow dialysis fiber and the other based on a shaped ionically conductive polymer were serially integrated to trap and concentrate selected proteins while simultaneously desalting and removing other unwanted proteins from the sample. A series of experiments were performed to test the EFGF systems individually and after integration. Online concentration of amyloglucosidase indicated a concentration limit of detection of approximately 20 ng mL(-1) (200 pM) from a sample volume of 100 microL. Concentration of human alpha1-acid glycoprotein with simultaneous removal of human serum albumin was also demonstrated. Elimination of small buffer components while concentrating trypsin inhibitor, and selective concentration and separation of myoglobin from a mixture were performed using the integrated EFGF system. PMID:16828105

Lin, Shu-Ling; Li, Yuanyuan; Tolley, H Dennis; Humble, Paul H; Lee, Milton L

2006-07-07

225

Methanolobus profundi sp. nov., a methylotrophic methanogen isolated from deep subsurface sediments in a natural gas field.  

PubMed

A mesophilic, methylotrophic methanogen, strain MobM(T), was isolated from a natural gas field in Japan. Strain MobM(T) grew on methanol and methylamines, but not on H(2)/CO(2), formate, acetate or dimethyl sulfide. The cells were motile, irregular cocci (diameter, 0.9-1.2 microm) and occurred singly, in pairs, as tetracocci or (occasionally) as aggregates. Strain MobM(T) grew at 9-37 degrees C (optimally at 30 degrees C) and at pH 6.1-7.8 (optimally at pH 6.5). Sodium and magnesium were required for growth, at 0.1-1.0 M Na(+) (optimally at 0.35 M) and 10-400 mM Mg(2+) (optimally at 15-25 mM). The G+C content of the genomic DNA was 42.4 mol%. 16S rRNA gene sequencing revealed that the isolate is a member of the genus Methanolobus, but distinct from its closest neighbours, Methanolobus tindarius DSM 2278(T) (sequence similarity, 98.0 %) and Methanolobus vulcani DSM 3029(T) (98.1 %). On the basis of phenotypic and phylogenetic features of MobM(T), it is clear that this strain represents a novel species of the genus Methanolobus, for which the name Methanolobus profundi sp. nov. is proposed. The type strain is MobM(T) (=DSM 21213(T)=NBRC 104158(T)). PMID:19329594

Mochimaru, Hanako; Tamaki, Hideyuki; Hanada, Satoshi; Imachi, Hiroyuki; Nakamura, Kohei; Sakata, Susumu; Kamagata, Yoichi

2009-04-01

226

Characterization of humoral responses to soluble trimeric HIV gp140 from a clade A Ugandan field isolate.  

PubMed

Trimeric soluble forms of HIV gp140 envelope glycoproteins represent one of the closest molecular structures compared to native spikes present on intact virus particles. Trimeric soluble gp140 have been generated by several groups and such molecules have been shown to induce antibodies with neutralizing activity against homologous and heterologous viruses. In the present study, we generated a recombinant trimeric soluble gp140, derived from a previously identified Ugandan A-clade HIV field isolate (gp14094UG018). Antibodies elicited in immunized rabbits show a broad binding pattern to HIV envelopes of different clades. An epitope mapping analysis reveals that, on average, the binding is mostly focused on the C1, C2, V3, V5 and C5 regions. Immune sera show neutralization activity to Tier 1 isolates of different clades, demonstrating cross clade neutralizing activity which needs to be further broadened by possible structural modifications of the clade A gp14094UG018. Our results provide a rationale for the design and evaluation of immunogens and the clade A gp14094UG018 shows promising characteristics for potential involvement in an effective HIV vaccine with broad activity. PMID:23835244

Visciano, Maria Luisa; Tagliamonte, Maria; Stewart-Jones, Guillaume; Heyndrickx, Leo; Vanham, Guido; Jansson, Marianne; Fomsgaard, Anders; Grevstad, Berit; Ramaswamy, Meghna; Buonaguro, Franco M; Tornesello, Maria Lina; Biswas, Priscilla; Scarlatti, Gabriella; Buonaguro, Luigi

2013-07-08

227

Methanothermobacter tenebrarum sp. nov., a hydrogenotrophic, thermophilic methanogen isolated from gas-associated formation water of a natural gas field.  

PubMed

A thermophilic and hydrogenotrophic methanogen, strain RMAS(T), was isolated from gas-associated formation water of a gas-producing well in a natural gas field in Japan. Strain RMAS(T) grew solely on H(2)/CO(2) but required Casamino acids, tryptone, yeast extract or vitamins for growth. Growth of strain RMAS(T) was stimulated by acetate. Cells were non-motile, straight rods (0.5×3.5-10.5 µm) and occurred singly or in pairs. Bundles of fimbriae occurred at both poles of cells and the cell wall was thick (approximately 21 nm, as revealed by ultrathin section electron microscopy). Strain RMAS(T) grew at 45-80 °C (optimum, 70 °C), at pH 5.8-8.7 (optimum, pH 6.9-7.7) and with 0.001-20 g NaCl l(-1) (optimum, 2.5 g NaCl l(-1)). Phylogenetic analysis revealed that Methanothermobacter thermautotrophicus ?H(T) was most closely related to the isolate (95.7?% 16S rRNA gene sequence similarity). On the basis of morphological, phenotypic and phylogenetic characteristics, it is clear that strain RMAS(T) represents a novel species of the genus Methanothermobacter, for which we propose the name Methanothermobacter tenebrarum sp. nov. The type strain is RMAS(T) (?=?DSM 23052(T)?=?JCM 16532(T)?=?NBRC 106236(T)). PMID:22561588

Nakamura, Kohei; Takahashi, Azumi; Mori, Chikahiro; Tamaki, Hideyuki; Mochimaru, Hanako; Nakamura, Kazunori; Takamizawa, Kazuhiro; Kamagata, Yoichi

2012-05-04

228

Microarray-based comparative genomic profiling of reference strains and selected Canadian field isolates of Actinobacillus pleuropneumoniae  

PubMed Central

Background Actinobacillus pleuropneumoniae, the causative agent of porcine pleuropneumonia, is a highly contagious respiratory pathogen that causes severe losses to the swine industry worldwide. Current commercially-available vaccines are of limited value because they do not induce cross-serovar immunity and do not prevent development of the carrier state. Microarray-based comparative genomic hybridizations (M-CGH) were used to estimate whole genomic diversity of representative Actinobacillus pleuropneumoniae strains. Our goal was to identify conserved genes, especially those predicted to encode outer membrane proteins and lipoproteins because of their potential for the development of more effective vaccines. Results Using hierarchical clustering, our M-CGH results showed that the majority of the genes in the genome of the serovar 5 A. pleuropneumoniae L20 strain were conserved in the reference strains of all 15 serovars and in representative field isolates. Fifty-eight conserved genes predicted to encode for outer membrane proteins or lipoproteins were identified. As well, there were several clusters of diverged or absent genes including those associated with capsule biosynthesis, toxin production as well as genes typically associated with mobile elements. Conclusion Although A. pleuropneumoniae strains are essentially clonal, M-CGH analysis of the reference strains of the fifteen serovars and representative field isolates revealed several classes of genes that were divergent or absent. Not surprisingly, these included genes associated with capsule biosynthesis as the capsule is associated with sero-specificity. Several of the conserved genes were identified as candidates for vaccine development, and we conclude that M-CGH is a valuable tool for reverse vaccinology.

Goure, Julien; Findlay, Wendy A; Deslandes, Vincent; Bouevitch, Anne; Foote, Simon J; MacInnes, Janet I; Coulton, James W; Nash, John HE; Jacques, Mario

2009-01-01

229

Kodamaea ohmeri Isolates from Patients in a University Hospital: Identification, Antifungal Susceptibility, and Pulsed-Field Gel Electrophoresis Analysis  

Microsoft Academic Search

Data on clinical isolates of Kodamaea (Pichia) ohmeri, an emerging fungal pathogen, are scarce. Over the past 5 years, we identified yeast isolates from nine patients with fungemia as K. ohmeri by using the API 20C system. Here, we reanalyzed these isolates first by sequencing the internal transcribed spacer 2 (ITS2) regions and then by growing the isolates on CHROMagar

Jin Sol Lee; Jong Hee Shin; Mi-Na Kim; Sook-In Jung; Kyung Hwa Park; Duck Cho; Seung Jung Kee; Myung Geun Shin; Soon Pal Suh; Dong Wook Ryang

2007-01-01

230

Characterization of Staphylococcus aureus Coagulase Type VII Isolates from Staphylococcal Food Poisoning Outbreaks (1980-1995) in Tokyo, Japan, by Pulsed-Field Gel Electrophoresis  

Microsoft Academic Search

Staphylococcus aureus coagulase type VII strains have been the strains most frequently isolated from staphylococcal food poisoning outbreaks in Tokyo, Japan. We applied pulsed-field gel electrophoresis (PFGE) of chromosomal DNA digested with SmaI to characterize 129 coagulase type VII strains. These were isolated from 129 cases occurring in outbreaks in 35 districts during a 16-year period (1980-1995). The 129 outbreak

AKIRA SHIMIZU; MANABU FUJITA; HIDEO IGARASHI; MICHIHIRO TAKAGI; NAOKO NAGASE; ASAKO SASAKI; JUNICHI KAWANO

2000-01-01

231

Detection of a bacteriophage gene encoding a Mu-like portal protein in Haemophilus parasuis reference strains and field isolates by nested polymerase chain reaction.  

PubMed

A nested polymerase chain reaction (nPCR) assay was developed to determine the presence of a gene encoding a bacteriophage Mu-like portal protein, gp29, in 15 reference strains and 31 field isolates of Haemophilus parasuis. Specific primers, based on the gene's sequence, were utilized. A majority of the virulent reference strains and field isolates tested harbored the gene. The results suggest that the nPCR technique described in the current report could serve as a tool for epidemiological studies of H. parasuis. PMID:21908286

Zehr, Emilie S; Tabatabai, Louisa B

2011-05-01

232

Expression of intracellular molecular apoptosis regulator Bcl-2 in the liver in isolated and combined exposure to 24-h illumination and industrial frequency magnetic field.  

PubMed

We studied the effect of isolated and combined exposure to 24-h illumination and industrial frequency magnetic field on the expression of intracellular molecular apoptosis regulator Bcl-2 in the liver. Previous experiments showed enhanced expression of Bcl-2 protein in liver cells in animals maintained under conditions of 24-h illumination, whereas exposure to industrial frequency magnetic field had practically no effect on this process. Under conditions of combined exposure to 24-h illumination and industrial frequency magnetic field, magnetic field partially suppressed the expression of Bcl-2 induced by 24-h illumination. PMID:19110606

Borodin, Yu I; Michurina, S V; Arkhipov, S A; Belkin, A D; Jurakovsky, I P

2008-04-01

233

Comparison of Staphylococcus aureus Isolates from Bovine and Human Skin, Milking Equipment, and Bovine Milk by Phage Typing, Pulsed-Field Gel Electrophoresis, and Binary Typing  

PubMed Central

Staphylococcus aureus isolates (n = 225) from bovine teat skin, human skin, milking equipment, and bovine milk were fingerprinted by pulsed-field gel electrophoresis (PFGE). Strains were compared to assess the role of skin and milking equipment as sources of S. aureus mastitis. PFGE of SmaI-digested genomic DNA identified 24 main types and 17 subtypes among isolates from 43 herds and discriminated between isolates from bovine teat skin and milk. Earlier, phage typing (L. K. Fox, M. Gershmann, D. D. Hancock, and C. T. Hutton, Cornell Vet. 81:183-193, 1991) had failed to discriminate between isolates from skin and milk. Skin isolates from humans belonged to the same pulsotypes as skin isolates from cows. Milking equipment harbored strains from skin as well as strains from milk. We conclude that S. aureus strains from skin and from milk can both be transmitted via the milking machine, but that skin strains are not an important source of intramammary S. aureus infections in dairy cows. A subset of 142 isolates was characterized by binary typing with DNA probes developed for typing of human S. aureus. Typeability and overall concordance with epidemiological data were lower for binary typing than for PFGE while discriminatory powers were similar. Within several PFGE types, binary typing discriminated between main types and subtypes and between isolates from different herds or sources. Thus, binary typing is not suitable as replacement for PFGE but may be useful in combination with PFGE to refine strain differentiation.

Zadoks, R. N.; van Leeuwen, W. B.; Kreft, D.; Fox, L. K.; Barkema, H. W.; Schukken, Y. H.; van Belkum, A.

2002-01-01

234

Comparison of Staphylococcus aureus isolates from bovine and human skin, milking equipment, and bovine milk by phage typing, pulsed-field gel electrophoresis, and binary typing.  

PubMed

Staphylococcus aureus isolates (n = 225) from bovine teat skin, human skin, milking equipment, and bovine milk were fingerprinted by pulsed-field gel electrophoresis (PFGE). Strains were compared to assess the role of skin and milking equipment as sources of S. aureus mastitis. PFGE of SmaI-digested genomic DNA identified 24 main types and 17 subtypes among isolates from 43 herds and discriminated between isolates from bovine teat skin and milk. Earlier, phage typing (L. K. Fox, M. Gershmann, D. D. Hancock, and C. T. Hutton, Cornell Vet. 81:183-193, 1991) had failed to discriminate between isolates from skin and milk. Skin isolates from humans belonged to the same pulsotypes as skin isolates from cows. Milking equipment harbored strains from skin as well as strains from milk. We conclude that S. aureus strains from skin and from milk can both be transmitted via the milking machine, but that skin strains are not an important source of intramammary S. aureus infections in dairy cows. A subset of 142 isolates was characterized by binary typing with DNA probes developed for typing of human S. aureus. Typeability and overall concordance with epidemiological data were lower for binary typing than for PFGE while discriminatory powers were similar. Within several PFGE types, binary typing discriminated between main types and subtypes and between isolates from different herds or sources. Thus, binary typing is not suitable as replacement for PFGE but may be useful in combination with PFGE to refine strain differentiation. PMID:12409348

Zadoks, R N; van Leeuwen, W B; Kreft, D; Fox, L K; Barkema, H W; Schukken, Y H; van Belkum, A

2002-11-01

235

[Evaluation of the pathogenicity of a field isolate of Marek's disease virus integrated with retroviral long terminal repeat sequence].  

PubMed

The pathogenicity of a field isolate of Marek's disease virus (MDV) named GXY2 integrated with retroviral long terminal repeat (LTR) sequence from a chicken with MD tumors was evaluated. Experimental chickens were divided into group A, B, C, D and E. The later four groups were vaccinated on one-day-old with CVI988/Rispens for group B and D, with HVT for group C and E, while group A was taken as no-vaccinated control. On 8-day-old, group A, B and C were challenged with GXY2 by intra-abdominal injection, group D and E were kept as un-challenged control. All the birds were raised routinely until 82 days post-challenge (PC), died birds during the experiment and the slaughtered birds at the end of the experiment were necropsied and examined for gross lesions of MD and further confirmed by a developed polymerase chain reaction (PCR) based differential diagnosis technique for avian neoplastic diseases. The results showed that time of onset of MD death of group A, B and C were PC 25, 77 and 29 days with the incidences of visible MD visceral tumors. On PC 82 days, tumor incidences and mortalities of group A, B and C were 72%, 34.8% and 50%, 84%, 21.7% and 20%, respectively. The vaccination protection of CVI988/Rispense and HVT were 51.67% and 30.56% respectively. Among all the visceral organs, heart had the highest tumor incidences (23.5%), and then followed by liver (14.7%) and gizzard (10.3%). The weight-gain of unvaccinated birds was significantly depressed and severe dystrophy of thymus and bursa of Fabricius were also found. The results of the study demonstrated that isolate GXY2 possessed the ability of causing acute tumors and overcoming the protection of the vaccinations of either CVI988/Rispense or HVT. PMID:19954115

Teng, Li-Qiong; Wei, Ping; Song, Zhong-Bao; Yang, Dong-Li

2009-09-01

236

Genetic analysis of foot-and-mouth disease virus type O isolates responsible for field outbreaks in India between 1993 and 1999.  

PubMed Central

Partial nucleotide sequence at the 3' end of ID (VP1-encoding) gene of 90 foot-and-mouth disease virus type O isolates recovered from field outbreaks in India between 1993-9 were determined. The sequences were compared with each other and reference viruses. The published sequences of 15 type O isolates recovered from different parts of Asia and one isolate (O1BFS) from Europe and one from Egypt (O1/Sharquia/Egypt/72) were also included in the analysis for comparison. On the basis of phylogenetic analysis the viruses could be grouped into four distinct genotypes (genotypes I-IV). All 90 isolates from India were genotype-I, as were the reference isolates from Bangladesh, China, Egypt, Iran, Saudi Arabia, Syria and Turkey. Genotype-I isolates were further subdivided into 16 sub-genotypes. The Indian isolates were found to be extremely heterogeneous in nature and clustered into 12 different genetic groups. In genotype-I, the nucleotide sequence difference seen between the isolates was 0-11.6%, while among the Indian isolates it is 0-8.8%. Viruses of similar genetic groups are circulating in India, Bangladesh and countries of the Middle East. Genotype-II and -III are represented by isolates from Lebanon (O1/South Lebanon) and Europe (O1-BFS), respectively. Genotype-IV is formed by isolates from China, Hong Kong and Taiwan. The present study reveals the occurrence of viruses belonging to multiple genetic groups over a short period of time and persistence of single genetic group in the same geographical area over several years. This is consistent with the endemic nature of the disease in the country.

Hemadri, D.; Tosh, C.; Venkataramanan, R.; Sanyal, A.; Samuel, A. R.; Knowles, N. J.; Kitching, R. P.

2000-01-01

237

Phylogenetic analysis of classical swine fever virus (CSFV) field isolates from outbreaks in South and Central America.  

PubMed

To date, there is little information concerning the epidemiological situation of classical swine fever (CSF) in the Americas. Besides summarizing the available data, genotyping of isolates from outbreaks in domestic pigs in several countries of South and Central America was performed. For this, a 190 base fragment of the E2 envelope glycoprotein gene was used. European strains and isolates, and historical isolates from the United States (US) were included for comparison. In contrast to the situation in most parts of Europe, where group 2 isolates predominate, it was found that all the isolates from the American continent analyzed belonged to group 1 and were further resolved into three subgroups. The Cuban isolates clustered in subgroup 1.2, whereas the isolates from Honduras and Guatemala clustered in subgroup 1.3. The remaining isolates from Argentina, Brazil, Colombia and Mexico generated four poorly resolved clusters in subgroup 1.1, together with the vaccine strains, with historical European and US isolates, and with a recent Russian isolate. While the vaccine strains and the historical European isolates formed a relatively distinct cluster, one of the US isolates clustered together with the Mexican, and another one with Colombian isolates. Historically, CSF (hog cholera) was observed almost simultaneously in the US and in Europe in the first half of the 19th century, and its origin remains a matter of discussion. Our results showed that the US isolates are closely related to isolates from South America, while appearance of isolates in Cuba on one hand and in Honduras and Guatemala on the other hand, seems to have been due to unrelated events. This allows to speculate that at least in the American continent, CSF virus may have appeared independently in several regions, and spreading may have been a secondary effect. PMID:15845261

Pereda, A J; Greiser-Wilke, I; Schmitt, B; Rincon, M A; Mogollon, J D; Sabogal, Z Y; Lora, A M; Sanguinetti, H; Piccone, M E

2005-06-01

238

Chinese-like strain of porcine epidemic diarrhea virus, Thailand.  

PubMed

Since late 2007, several outbreaks of porcine epidemic diarrhea virus (PEDV) infection have emerged in Thailand. Phylogenetic analysis places all Thai PEDV isolates during the outbreaks in the same clade as the Chinese strain JS-2004-2. This new genotype PEDV is prevailing and currently causing sporadic outbreaks in Thailand. PMID:19624933

Puranaveja, Suphasawatt; Poolperm, Pariwat; Lertwatcharasarakul, Preeda; Kesdaengsakonwut, Sawang; Boonsoongnern, Alongkot; Urairong, Kitcha; Kitikoon, Pravina; Choojai, Porjit; Kedkovid, Roongtham; Teankum, Komkrich; Thanawongnuwech, Roongroje

2009-07-01

239

In vitro fungicide sensitivity of Alternaria species pathogenic to crucifers and identification of Alternaria brassicicola field isolates highly resistant to both dicarboximides and phenylpyrroles  

Microsoft Academic Search

Blackspot, caused by Alternaria spp. is one of the most important diseases in crucifers and its management mainly relies on fungicide applications. However, growers report increasing prevalence of this disease and decline in its control that might be related to the development of resistance in Alternaria species through over-use of fungicides. To test this hypothesis, field isolates of Alternaria species

Béatrice Iacomi-Vasilescu; Hervé Avenot; Nelly Bataillé-Simoneau; Emmanuelle Laurent; Michel Guénard; Philippe Simoneau

2004-01-01

240

DELETION OF THE DELTA 12-OLEIC ACID DESATURASE GENE OF A NON-AFLATOXIGENIC ASPERGILLUS PARASITICUS FIELD ISOLATE AFFECTS CONIDIATION AND SCLEROTIAL DEVELOPMENT  

Technology Transfer Automated Retrieval System (TEKTRAN)

Aims: To investigate how linoleic acid affects conidial production and sclerotial development in a strictly mitotic Aspergillus parasiticus field isolate as related to improving biocompetitivity of atoxigenic Aspergillus species. Methods and Results: We disrupted A. parasiticus delta 12-oleic acid d...

241

Phylogenetic Comparison of the S3 Gene of United States Prototype Strains of Bluetongue Virus with That of Field Isolates from California  

Microsoft Academic Search

To better define the molecular epidemiology of bluetongue virus (BTV) infection, the genetic characteristics and phylogenetic relationships of the S3 genes of the five U.S. prototype strains of BTV, the commercially available serotype 10 modified live virus vaccine, and 18 field isolates of BTV serotypes 10, 11, 13, and 17 obtained in California during 1980, 1981, 1989, and 1990 were

CECILIA C. DEMATTOS; CARLOS A. DEMATTOS; N. JAMES MACLACHLAN; LUIS D. GIAVEDONI; TILAHUN YILMA; ANDBENNIE I. OSBURN

1996-01-01

242

Effect of thiosulphate as electron acceptor on glucose and xylose oxidation by Thermoanaerobacter finnii and a Thermoanaerobacter sp. isolated from oil field water  

Microsoft Academic Search

During glucose and xylose fermentation, Thermoanaerobacter finnii was observed to produce lactate, acetate, H2 and CO2, with ethanol being the major end product. Thermoanaerobacter strain SEBR 5268, an isolate from an oil field, also produced a similar range of end product from glucose and xylose fermentation, with the exception that both ethanol and lactate were the major products of sugar

M.-L Fardeau; C Faudon; J.-L Cayol; M Magot; B. K. C Patel; B Ollivier

1996-01-01

243

Desulfothermus okinawensis sp. nov., a thermophilic and heterotrophic sulfate-reducing bacterium isolated from a deep-sea hydrothermal field.  

PubMed

A novel thermophilic and heterotrophic sulfate-reducing bacterium, strain TFISO9(T), was isolated from a deep-sea hydrothermal field at the Yonaguni Knoll IV in the Southern Okinawa Trough. The cells were motile rods 2.5-5.0 microm in length and 0.6-0.9 microm in width. Strain TFISO9(T) was an obligate heterotroph and reduced sulfate. It grew between 35 and 60 degrees C (optimum 50 degrees C), at pH 5.4-7.9 (optimum pH 5.9-6.4) and with 1.5-4.5 % NaCl (optimum 2.5 %). The fatty acid composition was C(16 : 0) (61.5 %) and 12Me(16 : 0) (38.5 %). The DNA G+C content was 34.9 mol%. The 16S rRNA gene sequence analysis indicated that strain TFISO9(T) belonged to the genus Desulfothermus. Based on physiological and phylogenetic characteristics, strain TFISO9(T) represents a novel species for which the name Desulfothermus okinawensis sp. nov. is proposed. The type strain is TFISO9(T) (=JCM 13304(T)=DSM 17375(T)). PMID:17911311

Nunoura, Takuro; Oida, Hanako; Miyazaki, Masayuki; Suzuki, Yohey; Takai, Ken; Horikoshi, Koki

2007-10-01

244

A new senescence-inducing mitochondrial linear plasmid in field-isolated Neurospora crassa strains from India.  

PubMed

Several field-collected strains of Neurospora crassa from the vicinity or Aarey, Bombay, India, are prone to precocious senescence and death. Analysis of one strain, Aarely-1e, demonstrated that the genetic determinants for the predisposition to senescence are maternally inherited. The senescence-prone strains contain a 7-kb, linear, mitochondrial DNA plasmid, maranhar, which is not present in long-lived isolates from the same geographical location. The maranhar plasmid has inverted terminal repeats with protein covalently bound at the 5' termini. Molecular hybridization experiments have demonstrated no substantial DNA sequence homology between the plasmid and the normal mitochondrial (mtDNA) and nuclear genomes of long-lived strains of N. crassa. Integrated maranhar sequences were detected in the mtDNAs of two cultures derived from Aarey-1e, and mtDNAs with the insertion sequences accumulated during subculturing. Nucleotide sequence analysis of cloned fragments of the two insertion sequences demonstrates that they are flanked by long inverted repeats of mtDNA. The senescence syndrome of the maranhar strains, and the mode of integration of the plasmid, are reminiscent of those seen in the kalilo strains of N. intermedia. Nonetheless, there is no detectable nucleotide sequence homology between the maranhar and kalilo plasmids. PMID:1648454

Court, D A; Griffiths, A J; Kraus, S R; Russell, P J; Bertrand, H

1991-02-01

245

Molecular epidemiology of porcine epidemic diarrhea virus in China  

Microsoft Academic Search

Since early 2006, porcine epidemic diarrhea virus (PEDV) has been reemerging in immunized swine herds. Open reading frame\\u000a 3 (ORF3) is the only accessory gene in the PEDV genome. The entire ORF3 genes of 12 PEDV field strains and one vaccine strain\\u000a were sequenced. The ORF3 genes of Chinese PEDV field strains (excluding CH\\/GSJIII\\/07) contain a single 672- or 675-nucleotide

Jianfei Chen; Chengbao Wang; Hongyan Shi; Huaji Qiu; Shengwang Liu; Xiaojin Chen; Zhibang Zhang; Li Feng

2010-01-01

246

Pulsed-Field Gel Electrophoresis of Staphylococcus aureus Isolates from Atopic Patients Revealing Presence of Similar Strains in Isolates from Children and Their Parents  

Microsoft Academic Search

Skin colonization with Staphylococcus aureus is often associated with atopic dermatitis, and staphylococcal enterotoxins have been implicated in the etiology of atopic disease. In this study, the colonization of patients with atopic dermatitis and their parents was investigated in order to evaluate the possibility of intrafamiliar transmission. S. aureus strains were isolated from 30 of 45 patients (66%). In 19

Sonja Bonness; Christiane Szekat; Natalija Novak; Gabriele Bierbaum

2008-01-01

247

Pulsed-Field Gel Electrophoresis of Staphylococcus aureus Isolates from Atopic Patients Revealing Presence of Similar Strains in Isolates from Children and Their Parents  

Microsoft Academic Search

Skin colonization with Staphylococcus aureus is often associated with atopic dermatitis, and staphylococcal enterotoxins have been implicated in the etiology of atopic disease. In this study, the colonization of patients with atopic dermatitis and their parents was investigated in order to evaluate the possibility of intrafamiliar transmission. S. aureus strains were isolated from 30 of 45 patients (66%). In 19

Sonja Bonness; Christiane Szekat; Natalija Novak; Gabriele Bierbaum

248

Generation of isolated attosecond pulses in the far field by spatial filtering with an intense few-cycle mid-infrared laser  

SciTech Connect

We report theoretical calculations of high-order harmonic generation (HHG) of Xe with the inclusion of multielectron effects and macroscopic propagation of the fundamental and harmonic fields in an ionizing medium. By using the time-frequency analysis we show that the reshaping of the fundamental laser field is responsible for the continuum structure in the HHG spectra. We further suggest a method for obtaining an isolated attosecond pulse (IAP) by using a filter centered on axis to select the harmonics in the far field with different divergence. We also discuss the carrier-envelope-phase dependence of an IAP and the possibility to optimize the yield of the IAP. With intense few-cycle mid-infrared lasers, this offers a possible method for generating isolated attosecond pulses.

Jin Cheng; Le, Anh-Thu; Trallero-Herrero, Carlos A.; Lin, C. D. [J. R. Macdonald Laboratory, Physics Department, Kansas State University, Manhattan, Kansas 66506-2604 (United States)

2011-10-15

249

Spodoptera frugiperda multiple nucleopolyhedrovirus as a potential biological insecticide: Genetic and phenotypic comparison of field isolates from Colombia  

Microsoft Academic Search

Thirty-eight isolates of Spodoptera frugiperda multiple nucleopolyhedrovirus (SfMNPV), collected from infected larvae on pastures, maize, and sorghum plants in three different geographical regions of Colombia, were subjected to molecular characterization and were compared with a previously characterized Nicaraguan isolate (SfNIC). Restriction endonuclease analysis (REN) using six different enzymes showed two different patterns among Colombian isolates, one profile was particularly frequent

Gloria Barrera; Oihane Simón; Laura Villamizar; Trevor Williams; Primitivo Caballero

2011-01-01

250

Isolation of halophilic and halotolerant bacteria from a Japanese salt field and comparison of the partial 16S rRNA gene sequence of an extremely halophilic isolate with those of other extreme halophiles  

Microsoft Academic Search

Halophilic and halotolerant bacteria were isolated from soil samples of a Japanese salt field, an environment where salt concentrations vary annually. From 1 g of each of the five samples collected, over 1×103 bacterial colonies (colony forming units (cfu)g-1) grew on agar medium containing 2M Na+. In contrast, 0–4 bacterial colonies (cfu g-1) were observed on agar medium containing 4M

Tomonori Takashina; Kiyotaka Otozati; Tetsuo Hamamoto; Koki Horikoshi

1994-01-01

251

Inhibitory Activity of Ferroquine, versus Chloroquine, against Western Kenya Plasmodium falciparum Field Isolates Determined by a SYBR Green I In Vitro Assay  

PubMed Central

Ferroquine (FQ), a chloroquine (CQ) analog, is being developed to treat persons with Plasmodium falciparum malaria. In 146 P. falciparum field isolates from western Kenya, we measured 50% inhibitory concentrations (IC50; nM) of CQ and FQ by a SYBR Green I in vitro assay. Reference clones included W2 (CQ resistant) and D6 (CQ sensitive). Mutation analysis was done for P. falciparum CQ-resistance transporter gene (Pfcrt K76T). Median IC50 values for FQ were lower than CQ for field isolates and the W2 clone (both P < 0.05). The Pfcrt mutation (76T), which was detected in > 80% of isolates, conferred higher CQ IC50 values (P < 0.05) and modestly lower FQ IC50 values (P < 0.05), versus Pfcrt wild type (K76). FQ is more potent than CQ against CQ-resistant P. falciparum field isolates and the W2 clone, and is less affected by Pfcrt 76T. These findings support the notion that FQ could be useful in treating persons with P. falciparum malaria.

Eyase, Fredrick L.; Akala, Hoseah M.; Johnson, Jacob D.; Walsh, Douglas S.

2011-01-01

252

Overexpression of ShCYP51B and ShatrD in Sclerotinia homoeocarpa Isolates Exhibiting Practical Field Resistance to a Demethylation Inhibitor Fungicide  

PubMed Central

We investigated genetic factors that govern the reduced propiconazole sensitivity of Sclerotinia homoeocarpa field isolates collected during a 2-year field efficacy study on dollar spot disease of turf in five New England sites. These isolates displayed a >50-fold range of in vitro sensitivity to a sterol demethylation inhibitor (DMI) fungicide, propiconazole, making them ideal for investigations of genetic mechanisms of reduced DMI sensitivity. The CYP51 gene homolog in S. homoeocarpa (ShCYP51B), encoding the enzyme target of DMIs, is likely a minor genetic factor for reduced propiconazole sensitivity, since there were no differences in constitutive relative expression (RE) values and only 2-fold-higher induced RE values for insensitive than for sensitive isolate groups. Next, we mined RNA-Seq transcriptome data for additional genetic factors and found evidence for the overexpression of a homolog of Botrytis cinerea atrD (BcatrD), ShatrD, a known efflux transporter of DMI fungicides. The ShatrD gene showed much higher constitutive and induced RE values for insensitive isolates. Several polymorphisms were found upstream of ShatrD but were not definitively linked to overexpression. The screening of constitutive RE values of ShCYP51B and ShatrD in isolates from two golf courses that exhibited practical field resistance to propiconazole uncovered evidence for significant population-specific overexpression of both genes. However, linear regression demonstrated that the RE of ShatrD displays a more significant relationship with propiconazole sensitivity than that of ShCYP51B. In summary, our results suggest that efflux is a major determinant of the reduced DMI sensitivity of S. homoeocarpa genotypes in New England, which may have implications for the emergence of practical field resistance in this important turfgrass pathogen.

Hulvey, Jon; Popko, James T.; Sang, Hyunkyu; Berg, Andrew

2012-01-01

253

Isolation and characterization of Methanothermobacter crinale sp. nov., a novel hydrogenotrophic methanogen from the Shengli oil field.  

PubMed

Syntrophic acetate oxidation coupled with hydrogenotrophic methanogenesis is an alternative methanogenic pathway in certain thermophilic anaerobic environments such as high-temperature oil reservoirs and thermophilic biogas reactors. In these environments, the dominant thermophilic methanogens were generally related to uncultured organisms of the genus Methanothermobacter. Here we isolated two representative strains, Tm2(T) and HMD, from the oil sands and oil production water in the Shengli oil field in the People's Republic of China. The type strain, Tm2(T), was nonmotile and stained Gram positive. The cells were straight to slightly curved rods (0.3 ?m in width and 2.2 to 5.9 ?m in length), but some of them possessed a coccal shape connecting with the rods at the ends. Strain Tm2(T) grew with H(2)-CO(2), but acetate is required. Optimum growth of strain Tm2(T) occurred in the presence of 0.025 g/liter NaCl at pH 6.9 and a temperature of 65°C. The G+C content of the genomic DNA was 40.1 mol% ± 1.3 mol% (by the thermal denaturation method) or 41.1 mol% (by high-performance liquid chromatography). Analysis of the 16S rRNA gene sequence indicated that Tm2(T) was most closely related to Methanothermobacter thermautotrophicus ?H(T) and Methanothermobacter wolfeii VKM B-1829(T) (both with a sequence similarity of 96.4%). Based on these phenotypic and phylogenic characteristics, a novel species was proposed and named Methanothermobacter crinale sp. nov. The type strain is Tm2(T) (ACCC 00699(T) = JCM 17393(T)). PMID:21705537

Cheng, Lei; Dai, Lirong; Li, Xia; Zhang, Hui; Lu, Yahai

2011-06-24

254

Use of polymerase chain reaction to identify Brucella abortus strain RB51 among Brucella field isolates from cattle in Italy.  

PubMed

Brucella abortus strain RB51, a rough mutant of the B. abortus 2308 virulent strain, was recently approved in the United States as the official vaccine for brucellosis in cattle. Following recent evidence of unauthorized use of RB51 vaccine in Italy, where the use of vaccines for brucellosis is no longer allowed, the suitability of an RB51-specific polymerase chain reaction assay for identifying the RB51 strain among Brucella field isolates from cattle in Italy was investigated. The oligonucleotide primers used in this study, belonging to a six-primer cocktail for Brucella species previously described by other authors, allowed the amplification of a 364-base pair (bp) fragment specific for RB51 and its parent strain 2308, and a 498-bp product specific for B. abortus. In addition, unresolved bands ranging from 600 to 700 bp were observed from RB51 strain. Brucella abortus biovars 1, 2 and 4 have only one specific sensitive 498-bp band. The B. abortus biovars 3, 5 and 6 did not give any signal. The 498-bp product from a reference Brucella strain was sequenced and submitted to EMBL with the accession number AJ271969 while the 364-bp fragment from RB51 strain was submitted to EMBL database with accession number AJ271968. The sequence studies confirmed the specificity of the detected fragments. No amplification was obtained by testing DNA from strains antigenically related to Brucella, such as Yersinia enterocolitica O:9, Escherichia coli O:157, Salmonella urbana and Pasteurella multocida. The results of this study indicate that this technique, in combination with specific serological tests, could be a useful diagnostic method to verify the use of RB51 vaccine and can contribute to the creation of a databank of circulating strains. PMID:11315520

Adone, R; Ciuchini, F; La Rosa, G; Marianelli, C; Muscillo, M

2001-03-01

255

Aciditerrimonas ferrireducens gen. nov., sp. nov., an iron-reducing thermoacidophilic actinobacterium isolated from a solfataric field.  

PubMed

An iron-reducing, moderately thermophilic, acidophilic actinobacterium, strain IC-180(T), isolated from a solfataric field in Hakone, Japan, was subjected to polyphasic taxonomic analysis. Strain IC-180(T) was a motile, short rod-shaped, Gram-positive bacterium that was able to grow at temperatures of 35-58 °C (optimally at 50 °C) and at pH 2.0-4.5 (optimally at pH 3.0). The strain grew aerobically and heterotrophically. It also grew anaerobically or autotrophically by dissimilatory reduction of ferric iron. No oxidation of ferrous iron was observed. Major cellular fatty acids detected were iso-C(16 : 0), anteiso-C(17 : 0) and iso-C(18 : 0); the major menaquinone was MK-9(H(8)). Phosphatidyl-N-methylethanolamine and an unknown ninhydrin-positive phosphoglycolipid were detected. The total DNA G+C content was 74.1 mol%. 16S rRNA gene sequence comparisons revealed that strain IC-180(T) was a member of the order Acidimicrobiales and clustered coherently with uncultured actinobacteria from a geothermal site and a bioreactor operated under moderately thermophilic conditions. This cluster could be distinguished from the two other clusters comprising the families of this order, Acidimicrobiaceae and Iamiaceae, respectively. Based on the properties of strain IC-180(T) determined in this polyphasic taxonomic study, this strain represents a novel species in a new genus in the order Acidimicrobiales, for which the name Aciditerrimonas ferrireducens gen. nov., sp. nov. is proposed; the type strain is IC-180(T) (?= JCM 15389(T) ?= DSM 45281(T)). PMID:20639230

Itoh, Takashi; Yamanoi, Kaoru; Kudo, Takuji; Ohkuma, Moriya; Takashina, Tomonori

2010-07-16

256

Phylogenetic analysis of classical swine fever virus (CSFV) field isolates from outbreaks in South and Central America  

Microsoft Academic Search

To date, there is little information concerning the epidemiological situation of classical swine fever (CSF) in the Americas. Besides summarizing the available data, genotyping of isolates from outbreaks in domestic pigs in several countries of South and Central America was performed. For this, a 190 base fragment of the E2 envelope glycoprotein gene was used. European strains and isolates, and

A. J. Pereda; I. Greiser-Wilke; B. Schmitt; M. A. Rincon; J. D. Mogollon; Z. Y. Sabogal; A. M. Lora; H. Sanguinetti; M. E. Piccone

2005-01-01

257

Associated risk factors and pulsed field gel electrophoresis of nasal isolates of Staphylococcus aureus from medical students in a tertiary hospital in Lagos, Nigeria.  

PubMed

Staphylococcus aureus infections are growing problems worldwide with important implications in hospitals. The organism is normally present in the nasal vestibule of about 35% of apparently healthy individuals and its carriage varies between different ethnic and age groups. Staphylococcal nasal carriage among health workers is particularly important to establish new clones and track origin of infections during outbreak situations. To determine the carriage rate and compare the pulsed field gel patterns of the strains, nasal swabs were collected from 185 medical students in a teaching hospital in Lagos, Nigeria. Isolates of S. aureus were tested for heamolysin production, methicillin sensitivity and Pulsed Field Gel Electrophoresis (PFGE) was performed. The results showed S.aureus nasal carrier rate of 14% with significant rate among males compared to females. All the isolates produced heamolysin. Antibiotic susceptibility pattern revealed that majority of the isolates was susceptible. Five strains (19%) harboured resistant determinants to penicillin and tetracycline. None of the strains was resistant to methicillin. 44% of the isolates typed by PFGE had type B, the most predominant pulsotype. PFGE A clone exhibited a single resistance phenotype suggesting a strong clonal relationship that could punctual an outbreak in the hospital. The results speculate that nasal carriage among medical personnel could be a function of various risk factors. Personal hygiene and behaviour may however be the means to reducing colonization and spread of S.aureus in our hospitals. PMID:17625730

Adesida, Solayide A; Abioye, Olusegun A; Bamiro, Babajide S; Brai, Bartholomew I C; Smith, Stella I; Amisu, Kehinde O; Ehichioya, Deborah U; Ogunsola, Folasade T; Coker, Akitoye O

2007-02-01

258

Effect of experimental diabetes on cholinergic, purinergic and peptidergic motor responses of the isolated rat bladder to electrical field stimulation or capsaicin  

Microsoft Academic Search

An attempt has been made to pharmacologically isolate cholinergic, P2 purinoceptor-mediated and peptidergic (capsaicin-sensitive, tachykinin-mediated) contraction of the guanethidine-treated rat bladder detrusor preparation, in vitro. The effect of experimental diabetes was assessed on these types of contraction. Responses were evoked by electrical field stimulation (single shocks or 1 Hz for 30 s or 10 Hz for 40 s). Single shocks

Rita Benkó; Zsófia Lázár; Róbert Pórszász; George T. Somogyi; Loránd Barthó

2003-01-01

259

Strain identification of probiotic Lactobacillus casei-related isolates with randomly amplified polymorphic DNA and pulsed-field gel electrophoresis methods  

Microsoft Academic Search

Typing of reference strains and isolates identified as Lactobacillus casei, Lactobacillus paracasei or Lactobacillus rhamnosus was carried out using randomly amplified polymorphic DNA (RAPD) and pulsed-field gel electrophoresis (PFGE) analyses. Strains of L. paracasei were mainly grouped in the same cluster as those of L. casei. The RAPD fingerprints of strains ATCC 393 and ATCC 15820 differ from those of the L. rhamnosus

Denis Roy; Pierre Ward; Daniel Vincent

1999-01-01

260

Validation of the Abbreviated Brucella AMOS PCR as a Rapid Screening Method for Differentiation of Brucella abortus Field Strain Isolates and the Vaccine Strains, 19 and RB51  

Microsoft Academic Search

The Brucella AMOS PCR assay was previously developed to identify and differentiate specific Brucella species. In this study, an abbreviated Brucella AMOS PCR test was evaluated to determine its accuracy in differentiating Brucella abortus into three categories: field strains, vaccine strain 19 (S19), and vaccine strain RB51\\/parent strain 2308 (S2308). Two hundred thirty-one isolates were identified and tested by the

DARLA R. EWALT; BETSY J. BRICKER

2000-01-01

261

Sphingomonas kyungheensis sp. nov., a bacterium with ginsenoside-converting activity isolated from soil of a ginseng field.  

PubMed

A bacterial strain THG-B283(T), which has ?-glucosidase activity, was isolated from soil of a ginseng field. Cells were Gram-reaction-negative, oxidase- and catalase-positive, aerobic, motile with one polar flagellum and rod-shaped. The strain was subjected to a polyphasic taxonomic study. Strain THG-B283(T) grew optimally at around pH 7.0, at 25-28 °C and in the absence of NaCl on R2A agar. 16S rRNA gene sequence analysis revealed that strain THG-B283(T) belongs to the family Sphingomonadaceae and is closely related to Sphingomonas melonis DAPP-PG 224(T) (98.2?%), S. aquatilis JSS7(T) (98.1?%), S. insulae DS-28(T) (97.6?%), S. mali IFO 15500(T) (97.1?%) and S. pruni IFO 15498(T) (97.0?%). Strain THG-B283(T) contained Q-10 as the predominant ubiquinone. The major fatty acids included summed feature 3 (comprising C16?:?1?7c and/or C16?:?1?6c), C18?:?1?7c, C14?:?0 2-OH and C16?:?0. The DNA G+C content was 72.2 mol%. The major component in the polyamine pattern was sym-homospermidine. The major polar lipids were phosphatidylglycerol, phosphatidylethanolamine, phosphatidyldimethylethanolamine, phosphatidylcholine, sphingoglycolipid, diphosphatidylglycerol, an unidentified glycolipid, unidentified aminolipids, an unidentified phospholipid and unidentified lipids. Genomic and chemotaxonomic data supported the affiliation of strain THG-B283(T) to the genus Sphingomonas. DNA-DNA relatedness between strain THG-B283(T) and its closest phylogenetic neighbours was below 23?%. On the basis of phenotypic, phylogenetic and genetic data, strain THG-B283(T) represents a novel species of genus Sphingomonas, for which the name Sphingomonas kyungheensis sp. nov. is proposed. The type strain is THG-B283(T) (?=?KACC 16224(T)?=?LMG 26582(T)). PMID:23687058

Son, Heung-Min; Yang, Jung-Eun; Park, Yongjin; Han, Chang-Kyun; Kim, Song-Gun; Kook, Moochang; Yi, Tae-Hoo

2013-05-17

262

Mucilaginibacter calamicampi sp. nov., a member of the family Sphingobacteriaceae isolated from soil at a field of reeds.  

PubMed

A Gram-negative, aerobic, non-flagellated, non-gliding, rod-shaped bacterial strain, designated WR-R1Y(T), was isolated from soil at a field of reeds in South Korea. Strain WR-R1Y(T) grew optimally at 30 °C, at pH 7.0-7.5 and in the absence of NaCl. Neighbour-joining phylogenetic tree based on 16S rRNA gene sequences revealed that strain WR-R1Y(T) fell within the clade comprising Mucilaginibacter species, coherently clustering with the type strain of Mucilaginibacter composti, with which it exhibited the highest 16S rRNA gene sequence similarity value of 97.6 %. Sequence similarities to the type strains of the other Mucilaginibacter species and the other species used in the phylogenetic analysis were 93.1-96.9 % and <91.1 %, respectively. Strain WR-R1Y(T) contained MK-7 as the predominant menaquinone and iso-C15:0, summed feature 3 (C16:1 ?6c and/or C16:1 ?7c), C16:0 and iso-C17:0 3-OH as the major fatty acids. The major polar lipids were phosphatidylethanolamine and one unidentified aminophospholipid. The DNA G+C content of strain WR-R1Y(T) was 43.1 mol% and its mean DNA-DNA relatedness value with M. composti KACC 14956(T) was 17 %. The differential phenotypic properties, together with the phylogenetic and genetic distinctiveness, revealed that strain WR-R1Y(T) is separate from other Mucilaginibacter species. On the basis of the data presented, strain WR-R1Y(T) represents a novel species of the genus Mucilaginibacter, for which the name Mucilaginibacter calamicampi sp. nov. is proposed. The type strain is WR-R1Y(T) (= KCTC 32214(T) = CCUG 63418(T)). PMID:23584601

Yoon, Jung-Hoon; Park, Sooyeon; Jung, Yong-Taek

2013-04-13

263

Comparative analysis of genetic variability among Borrelia burgdorferi isolates from Europe and the United States by restriction enzyme analysis, gene restriction fragment length polymorphism, and pulsed-field gel electrophoresis.  

PubMed Central

The genomes of 62 North American and European Borrelia burgdorferi isolates were examined by restriction endonuclease analysis (REA), gene probe restriction fragment length polymorphism, and pulsed-field gel electrophoresis (PFGE). Hybridization of restriction fragments with the immunologically relevant 83-kDa antigen gene revealed polymorphisms and divided the isolates into three major groups. Group I included all but two of the American isolates and some of the European isolates. One of two Californian isolates (DN 127) and one Ixodes dammini isolate from New York (strain 25015), previously described as atypical, were distinct from the isolates in the three groups. Plasmid profile analysis and REA, the method with the highest level of discrimination, revealed extensive heterogeneity among isolates of the same major group. Our study demonstrates the usefulness of the 83-kDa antigen gene probe for dividing the isolates into major genogroups, whereas REA and plasmid profile analysis allow for a distinction of individual strains within these groups. Images

Zingg, B C; Anderson, J F; Johnson, R C; LeFebvre, R B

1993-01-01

264

High heterogeneity within methicillin-resistant Staphylococcus aureus ST398 isolates, defined by Cfr9I macrorestriction-pulsed-field gel electrophoresis profiles and spa and SCCmec types.  

PubMed

During recent years, the animal-associated methicillin-resistant Staphylococcus aureus clone ST398 has extensively been studied. The DNA of these isolates turned out to be refractory to SmaI restriction, and consequently, SmaI is unsuitable for subtyping this clone by standard pulsed-field gel electrophoresis (PFGE). Very recently, ST398 DNA was shown to be digested by Cfr9I, a neoschizomer of SmaI. In the present study, we employed Cfr9I PFGE on 100 German and 5 Dutch ST398 isolates and compared their PFGE profiles, protein A gene variable repeat regions (spa types), and types of the staphylococcal cassette chromosome mec (SCCmec). The isolates (from healthy carrier pigs, clinical samples from pigs, dust from farms, milk, and meat) were assigned to 35 profiles, which were correlated to the SCCmec type. A dendrogram with the Cfr9I patterns assigned all profiles to two clusters. Cluster A grouped nearly all isolates with SCCmec type V, and cluster B comprised all SCCmec type IVa and V* (a type V variant first identified as III) carriers plus one isolate with SCCmec type V. Both clusters also grouped methicillin-susceptible S. aureus isolates. The association of the majority of isolates with SCCmec type V in one large cluster indicated the presence of a successful subclone within the clonal complex CC398 from pigs, which has diversified. In general, the combination of Cfr9I PFGE with spa and SCCmec typing demonstrated the heterogeneity of the series analyzed and can be further used for outbreak investigations and traceability studies of the MRSA ST398 emerging clone. PMID:20023093

Argudín, M A; Fetsch, A; Tenhagen, B-A; Hammerl, J A; Hertwig, S; Kowall, J; Rodicio, M R; Käsbohrer, A; Helmuth, R; Schroeter, A; Mendoza, M C; Bräunig, J; Appel, B; Guerra, B

2009-12-18

265

High Heterogeneity within Methicillin-Resistant Staphylococcus aureus ST398 Isolates, Defined by Cfr9I Macrorestriction-Pulsed-Field Gel Electrophoresis Profiles and spa and SCCmec Types ?  

PubMed Central

During recent years, the animal-associated methicillin-resistant Staphylococcus aureus clone ST398 has extensively been studied. The DNA of these isolates turned out to be refractory to SmaI restriction, and consequently, SmaI is unsuitable for subtyping this clone by standard pulsed-field gel electrophoresis (PFGE). Very recently, ST398 DNA was shown to be digested by Cfr9I, a neoschizomer of SmaI. In the present study, we employed Cfr9I PFGE on 100 German and 5 Dutch ST398 isolates and compared their PFGE profiles, protein A gene variable repeat regions (spa types), and types of the staphylococcal cassette chromosome mec (SCCmec). The isolates (from healthy carrier pigs, clinical samples from pigs, dust from farms, milk, and meat) were assigned to 35 profiles, which were correlated to the SCCmec type. A dendrogram with the Cfr9I patterns assigned all profiles to two clusters. Cluster A grouped nearly all isolates with SCCmec type V, and cluster B comprised all SCCmec type IVa and V* (a type V variant first identified as III) carriers plus one isolate with SCCmec type V. Both clusters also grouped methicillin-susceptible S. aureus isolates. The association of the majority of isolates with SCCmec type V in one large cluster indicated the presence of a successful subclone within the clonal complex CC398 from pigs, which has diversified. In general, the combination of Cfr9I PFGE with spa and SCCmec typing demonstrated the heterogeneity of the series analyzed and can be further used for outbreak investigations and traceability studies of the MRSA ST398 emerging clone.

Argudin, M. A.; Fetsch, A.; Tenhagen, B.-A.; Hammerl, J. A.; Hertwig, S.; Kowall, J.; Rodicio, M. R.; Kasbohrer, A.; Helmuth, R.; Schroeter, A.; Mendoza, M. C.; Braunig, J.; Appel, B.; Guerra, B.

2010-01-01

266

Recombination between vaccine and field strains of canine parvovirus is revealed by isolation of virus in canine and feline cell cultures.  

PubMed

Canine parvovirus type 2 (CPV) is a pathogen that causes severe hemorrhagic gastroenteritis with a high fatality rate in pups worldwide. Since CPV emerged in the late 1970s, its origin has been explored with the conclusion that CPV originated from feline panleukopenia virus or a closely related virus. Both high mutation rate and recombination are assumed to be key factors in the evolution of parvoviruses. Here we provide evidence for natural recombination in CPV isolated from dogs in cell culture. Antigenic and genetic properties of isolates from 10 diseased pups were elucidated. Six pups had been vaccinated beforehand with live combined vaccine containing original antigenic type CPV (CPV-2). Six isolates recovered from 4 vaccinated pups in cell cultures were found to contain either CPV-2 or CPV-2-like viruses. The other isolates, including all those from non-vaccinated pups, were CPV-2b viruses. Antigenic typing of two CPV-2-like isolates, 03-029/M and 1887/f, with a monoclonal antibody panel suggested they were a mixture of CPV-2 and CPV-2a (03-029/M) and a recombinant of CPV-2 and CPV-2b (1887/f). Genetic analysis of the VP1 gene indicated that isolate 03-029/M was a mixture of CPV-2, CPV-2a and a recombinant of CPV-2 and CPV-2a viruses, while isolate 1887/f was composed of a recombinant of CPV-2 and CPV-2b viruses. This is the first demonstration of natural CPV recombination in the field and suggests that recombination in the evolution of CPV is a more frequent and important process than previously believed. PMID:19122396

Mochizuki, Masami; Ohshima, Takahisa; Une, Yumi; Yachi, Akiko

2008-12-01

267

Stability and fitness of pyraclostrobin- and boscalid-resistant phenotypes in field isolates of Botrytis cinerea from apple.  

PubMed

Phenotype stability, fitness, and competitive ability of pyraclostrobin- and boscalid-resistant isolates of Botrytis cinerea from apple were investigated. Stability of resistance was determined after consecutive transfers on potato dextrose agar (PDA) or being cycled on apple fruit. In vitro fitness components mycelial growth, osmotic sensitivity, conidial germination, and sporulation were evaluated on agar media. Pathogenicity, virulence and sporulation on apple fruit were evaluated at both 20 and 0°C. Competition between fungicide-resistant and -sensitive isolates on apple fruit also was evaluated. Resistance to the two fungicides was retained at levels similar to that of the initial generation after 20 and 10 transfers on PDA and five and three disease cycles on apple fruit at 20 and 0°C, respectively. Great variability in individual fitness components tested was observed among isolates within the same phenotype groups either sensitive or resistant to the fungicides but, when compared as phenotype groups, there were no significant differences in the mean values of these fitness components between resistant and sensitive phenotypes except that the phenotype resistant only to boscalid produced fewer conidia in vitro than sensitive isolates. Resistant isolates were as pathogenic and virulent on apple fruit as sensitive isolates. There was no significant correlation between the values of individual fitness components tested and the level of resistance to pyraclostrobin or boscalid, except that virulence at 20°C positively correlated with the level of resistance to the two fungicides. The final frequency of pyraclostrobin-resistant individuals in the populations was significantly decreased compared with the initial generation and no boscalid-resistant individuals were detected after four disease cycles on apple fruit inoculated with a pair mixture of a dual-sensitive isolate and one isolate each of the three phenotypes resistant to pyraclostrobin, boscalid, or both. The results suggest that resistance of B. cinerea to pyraclostrobin and boscalid was stable in the absence of the fungicides and that resistance to the two fungicides did not significantly impair individual fitness components tested. However, both pyraclostrobin- and boscalid-resistant isolates exhibited competitive disadvantage over the dual-sensitive isolate on apple fruit. PMID:21692646

Kim, Y K; Xiao, C L

2011-11-01

268

Analysis of the dihydrofolate reductase-thymidylate synthase gene sequences in Plasmodium vivax field isolates that failed chloroquine treatment  

PubMed Central

Background To use pyrimethamine as an alternative anti-malarial drug for chloroquine-resistant malaria parasites, it was necessary to determine the enzyme's genetic variation in dihydrofolate reductase-thymidylate syntase (DHFR-TS) among Korean strains. Methods Genetic variation of dhfr-ts genes of Plasmodium vivax clinical isolates from patients who did not respond to drug treatment (n = 11) in Korea were analysed. The genes were amplified using the polymerase chain reaction (PCR) with genomic DNA as a template. Results Sequence analysis showed that the open reading frame (ORF) of 1,857 nucleotides encoded a deduced protein of 618 amino acids (aa). Alignment with the DHFR-TS genes of other malaria parasites showed that a 231-residue DHFR domain and a 286-residue TS domain were seperated by a 101-aa linker region. This ORF shows 98.7% homology with the P. vivax Sal I strain (XM001615032) in the DHFR domain, 100% in the linker region and 99% in the TS domain. Comparison of the DHFR sequences from pyrimethamine-sensitive and pyrimethamine-resistant P. vivax isolates revealed that nine isolates belonged to the sensitive strain, whereas two isolates met the criteria for resistance. In these two isolates, the amino acid at position 117 is changed from serine to asparagine (S117N). Additionally, all Korean isolates showed a deletion mutant of THGGDN in short tandem repetitive sequences between 88 and 106 amino acid. Conclusions These results suggest that sequence variations in the DHFR-TS represent the prevalence of antifolate-resistant P. vivax in Korea. Two of 11 isolates have the Ser to Asn mutation in codon 117, which is the major determinant of pyrimethamine resistance in P. vivax. Therefore, the introduction of pyrimethamine for the treatment of chloroquine-resistant vivax malaria as alternative drug in Korea should be seriously considered.

2010-01-01

269

Application of Pulsed-Field Gel Electrophoresis and Binary Typing as Tools in Veterinary Clinical Microbiology and Molecular Epidemiologic Analysis of Bovine and Human Staphylococcus aureus Isolates  

PubMed Central

Thirty-eight bovine mammary Staphylococcus aureus isolates from diverse clinical, temporal, and geographical origins were genotyped by pulsed-field gel electrophoresis (PFGE) after SmaI digestion of prokaryotic DNA and by means of binary typing using 15 strain-specific DNA probes. Seven pulsed-field types and four subtypes were identified, as were 16 binary types. Concordant delineation of genetic relatedness was documented by both techniques, yet based on practical and epidemiological considerations, binary typing was the preferable method. Genotypes of bovine isolates were compared to 55 previously characterized human S. aureus isolates through cluster analysis of binary types. Genetic clusters containing strains of both human and bovine origin were found, but bacterial genotypes were predominantly associated with a single host species. Binary typing proved an excellent tool for comparison of S. aureus strains, including methicillin-resistant S. aureus, derived from different host species and from different databases. For 28 bovine S. aureus isolates, detailed clinical observations in vivo were compared to strain typing results in vitro. Associations were found between distinct genotypes and severity of disease, suggesting strain-specific bacterial virulence. Circumstantial evidence furthermore supports strain-specific routes of bacterial dissemination. We conclude that PFGE and binary typing can be successfully applied for genetic analysis of S. aureus isolates from bovine mammary secretions. Binary typing in particular is a robust and simple method and promises to become a powerful tool for strain characterization, for resolution of clonal relationships of bacteria within and between host species, and for identification of sources and transmission routes of bovine S. aureus.

Zadoks, Ruth; van Leeuwen, Willem; Barkema, Herman; Sampimon, Otlis; Verbrugh, Henri; Schukken, Ynte Hein; van Belkum, Alex

2000-01-01

270

Application of pulsed-field gel electrophoresis and binary typing as tools in veterinary clinical microbiology and molecular epidemiologic analysis of bovine and human Staphylococcus aureus isolates.  

PubMed

Thirty-eight bovine mammary Staphylococcus aureus isolates from diverse clinical, temporal, and geographical origins were genotyped by pulsed-field gel electrophoresis (PFGE) after SmaI digestion of prokaryotic DNA and by means of binary typing using 15 strain-specific DNA probes. Seven pulsed-field types and four subtypes were identified, as were 16 binary types. Concordant delineation of genetic relatedness was documented by both techniques, yet based on practical and epidemiological considerations, binary typing was the preferable method. Genotypes of bovine isolates were compared to 55 previously characterized human S. aureus isolates through cluster analysis of binary types. Genetic clusters containing strains of both human and bovine origin were found, but bacterial genotypes were predominantly associated with a single host species. Binary typing proved an excellent tool for comparison of S. aureus strains, including methicillin-resistant S. aureus, derived from different host species and from different databases. For 28 bovine S. aureus isolates, detailed clinical observations in vivo were compared to strain typing results in vitro. Associations were found between distinct genotypes and severity of disease, suggesting strain-specific bacterial virulence. Circumstantial evidence furthermore supports strain-specific routes of bacterial dissemination. We conclude that PFGE and binary typing can be successfully applied for genetic analysis of S. aureus isolates from bovine mammary secretions. Binary typing in particular is a robust and simple method and promises to become a powerful tool for strain characterization, for resolution of clonal relationships of bacteria within and between host species, and for identification of sources and transmission routes of bovine S. aureus. PMID:10790124

Zadoks, R; van Leeuwen, W; Barkema, H; Sampimon, O; Verbrugh, H; Schukken, Y H; van Belkum, A

2000-05-01

271

Analysis of pulsed field gel electrophoresis profiles using multiple enzymes for predicting potential source reservoirs for strains of Salmonella Enteritidis and Salmonella Typhimurium isolated from humans.  

PubMed

We reported previously on a highly discriminatory pulsed field gel electrophoresis-based (PFGE) subtyping scheme for Salmonella enterica serovar Enteritidis (SE) and Salmonella Typhimurium (ST) that relies on combined cluster analysis of up to six restriction enzymes. This approach allowed for the high-resolution separation of numerous poultry-derived SE and ST isolates into several distinct clusters that sorted along several geographical and host-linked boundaries. In this study, 101 SE and 151 ST strains isolated from poultry, swine, beef, mouse, and produce origins were combined with 62 human SE and ST isolates of unknown sources. PFGE profiles were generated across six restriction enzymes (XbaI, BlnI, SpeI, SfiI, PacI, and NotI) for human SE and ST isolates. The combined six-enzyme UPGMA trees of SE and ST revealed six separate origins of North American human SE isolates including one association with a "cosmopolitan" cluster of SEs from poultry originating in Scotland, Mexico, and China. In the case of ST, human isolates assorted readily along host lines rather than geographical partitions with the majority of human STs clustering in a larger group of STs of potential porcine origin. Such observations may underscore the ecological importance of poultry and pork reservoirs for SE and ST transmission to humans, respectively. In an examination of the relationship between enzyme diversity and congruence among enzymes, pairwise genetic diversity ranged from 6.5% to 9.7% for SE isolates and, more widely, from 17.5% to 27.4% for ST isolates. Phylogenetic congruence measures singled out XbaI, BlnI, and SfiI as most concordant for SE while XbaI and SfiI were most concordant among ST strains. Thus, these data provide the first proof of principal for concatenated PFGE, when coupled with sufficient enzyme numbers and combinations, as one effective means for predicting geographical and food source reservoirs for human isolates of these two highly prevalent Salmonella serovars. PMID:23429060

Son, Insook; Zheng, Jie; Keys, Christine E; Zhao, Shaohua; Meng, Jianghong; Brown, Eric W

2013-02-18

272

Use of mgc2-polymerase chain reaction-restriction fragment length polymorphism for rapid differentiation between field isolates and vaccine strains of Mycoplasma gallisepticum in Israel.  

PubMed

Increasing use of Mycoplasma gallisepticum (MG) live vaccines has led to a need for a rapid test for differentiation of MG field strains from the live vaccine strains ts-11 and 6/85. We examined the differentiating potential of diagnostic polymerase chain reaction (PCR) primers targeted to the gene mgc2, encoding a cytadherence-related surface protein uniquely present in MG. The mgc2-PCR diagnostic primers are specific for MG in tests of all avian mycoplasmas or bacteria present in the chicken trachea and are sensitive enough to readily detect MG in tracheal swabs from field outbreaks. Differentiation of vaccine strain ts-11 was based on identification of restriction enzyme sites in the 300-base-pair (bp) mgc2-PCR amplicon present in ts-11 and missing in MG isolates from field outbreaks in Israel. Restriction sites for the enzymes HaeII and SfaN1 were identified in the amplified region in strain ts-11 and were not found in 28 field isolates of MG, comprising a representative cross section of all the MG isolates from the period 1997-2003. In practice, differential diagnosis of MG is achieved within 1 day of submission of tracheal swab samples by mgc2-PCR amplification and restriction of the amplicon with HaeII, giving a 270-bp fragment for ts-11 or no restriction for other MG strains tested. Application of the mgc2-PCR-restriction fragment length polymorphism (mgc2-PCR-RFLP) assay enabled differential diagnosis of both components of a mixture of ts-11 and non-ts-11 DNA, detecting the field strain in the presence of a large excess of ts-11. The test was successfully applied in vivo for monitoring vaccinates in a ts-11 vaccine trial. In principle, the test may also be used to identify the 6/85 vaccine strain, which yields a 237-bp product, readily differentiated from the approximately 300-bp PCR product of all other strains tested. Further testing of field isolates will be necessary to determine the applicability of this test in the United States and other countries. PMID:16094829

Lysnyansky, Inna; Garcia, Maricarmen; Levisohn, Sharon

2005-06-01

273

A deletion within glycoprotein L of Marek's disease virus (MDV) field isolates correlates with a decrease in bivalent MDV vaccine efficacy in contact-exposed chickens.  

PubMed

We examined the functional role of a naturally occurring deletion within the glycoprotein L (gL) gene of Marek's disease virus (MDV) field isolates. We previously showed that this mutation incrementally increased the virulence of an MDV in contact-exposed SPF leghorn chickens, when chickens shedding this virus were co-infected with herpesvirus of turkeys (HVT). In our present study, we examined this mutation using two stocks of the very virulent plus (vv+)MDV strain TK, one of which harbored this deletion (TK1a) while the other did not (TK2a). We report that TK1a replicating in vaccinated chickens overcame bivalent (HVT/SB1) vaccine protection in contact-exposed chickens. Treatment groups exposed to vaccinated chickens inoculated with a 1:1 mix of TK1a and TK2a showed decreased bivalent vaccine efficacy, and this decrease correlated with the prevalence of the gL deletion indicative of TK1a. These results were also found using quadruplicate treatment groups and bivalently vaccinated chickens obtained from a commercial hatchery. As this deletion was found in 25 out of 25 recent field isolates from Delaware, Maryland, North Carolina, Pennsylvania, and Virginia, we concluded that there is a strong selection for this mutation, which appears to have evolved in HVT or bivalently vaccinated chickens. This is the first report of a mutation in a vv+MDV field strain for which a putative biological phenotype has been discerned. Moreover, this mutation in gL has apparently been selected in MDV field isolates through Marek's disease vaccination. PMID:19630238

Tavlarides-Hontz, Phaedra; Kumar, Pankaj M; Amortegui, Juliana Rojas; Osterrieder, Nikolaus; Parcells, Mark S

2009-06-01

274

Ex vivo drug sensitivity profiles of Plasmodium falciparum field isolates from Cambodia and Thailand, 2005 to 2010, determined by a histidine-rich protein-2 assay  

PubMed Central

Background In vitro drug susceptibility assay of Plasmodium falciparum field isolates processed “immediate ex vivo” (IEV), without culture adaption, and tested using histidine-rich protein-2 (HRP-2) detection as an assay, is an expedient way to track drug resistance. Methods From 2005 to 2010, a HRP-2 in vitro assay assessed 451 P. falciparum field isolates obtained from subjects with malaria in western and northern Cambodia, and eastern Thailand, processed IEV, for 50% inhibitory concentrations (IC50) against seven anti-malarial drugs, including artesunate (AS), dihydroartemisinin (DHA), and piperaquine. Results In western Cambodia, from 2006 to 2010, geometric mean (GM) IC50 values for chloroquine, mefloquine, quinine, AS, DHA, and lumefantrine increased. In northern Cambodia, from 2009–2010, GM IC50 values for most drugs approximated the highest western Cambodia GM IC50 values in 2009 or 2010. Conclusions Western Cambodia is associated with sustained reductions in anti-malarial drug susceptibility, including the artemisinins, with possible emergence, or spread, to northern Cambodia. This potential public health crisis supports continued in vitro drug IC50 monitoring of P. falciparum isolates at key locations in the region.

2012-01-01

275

Pulsed-field gel electrophoresis typing of Campylobacter fetus subsp. fetus isolated from sheep abortions in New Zealand  

Microsoft Academic Search

AIMS: To genotype Campylobacter fetus subsp. fetus isolates cultured from sheep abortions submitted to diagnostic laboratories in New Zealand during the year 2000 breeding season. To compare the types found nationally with those found in the Hawke' Bay region in 1999, and strains held in the New Zealand Reference Culture Collection, Medical Section (NZRM) from a study published in 1987.METHODS:

SA Mannering; SG Fenwick; RM Marchant; NR Perkins; K OConnell

2004-01-01

276

Antimalarial Drug Sensitivity Profile of Western Kenya Plasmodium falciparum Field Isolates Determined by a SYBR Green I in vitro Assay and Molecular Analysis  

PubMed Central

In vitro drug sensitivity and molecular analyses of Plasmodium falciparum track drug resistance. DNA-binding fluorescent dyes like SYBR Green I may allow field laboratories, proximal to P. falciparum collection sites, to conduct drug assays. In 2007–2008, we assayed 121 P. falciparum field isolates from western Kenya for 50% inhibitory concentrations (IC50) against 6 antimalarial drugs using a SYBR Green I in vitro assay: 91 immediate ex vivo (IEV) and 30 culture-adapted, along with P. falciparum reference clones D6 (chloroquine [CQ] sensitive) and W2 (CQ resistant). We also assessed P. falciparum mdr1 (Pfmdr1) copy number and single nucleotide polymorphisms (SNPs) at four codons. The IC50s for IEV and culture-adapted P. falciparum isolates were similar, and approximated historical IC50s. For Pfmdr1, mean copy number was 1, with SNPs common at codons 86 and 184. The SYBR Green I assay adapted well to our field-based laboratory, for both IEV and culture-adapted P. falciparum, warranting continued use.

Akala, Hoseah M.; Eyase, Fredrick L.; Cheruiyot, Agnes C.; Omondi, Angela A.; Ogutu, Bernhards R.; Waters, Norman C.; Johnson, Jacob D.; Polhemus, Mark E.; Schnabel, David C.; Walsh, Douglas S.

2011-01-01

277

Antimalarial drug sensitivity profile of western Kenya Plasmodium falciparum field isolates determined by a SYBR Green I in vitro assay and molecular analysis.  

PubMed

In vitro drug sensitivity and molecular analyses of Plasmodium falciparum track drug resistance. DNA-binding fluorescent dyes like SYBR Green I may allow field laboratories, proximal to P. falciparum collection sites, to conduct drug assays. In 2007-2008, we assayed 121 P. falciparum field isolates from western Kenya for 50% inhibitory concentrations (IC(50)) against 6 antimalarial drugs using a SYBR Green I in vitro assay: 91 immediate ex vivo (IEV) and 30 culture-adapted, along with P. falciparum reference clones D6 (chloroquine [CQ] sensitive) and W2 (CQ resistant). We also assessed P. falciparum mdr1 (Pfmdr1) copy number and single nucleotide polymorphisms (SNPs) at four codons. The IC(50)s for IEV and culture-adapted P. falciparum isolates were similar, and approximated historical IC(50)s. For Pfmdr1, mean copy number was 1, with SNPs common at codons 86 and 184. The SYBR Green I assay adapted well to our field-based laboratory, for both IEV and culture-adapted P. falciparum, warranting continued use. PMID:21734121

Akala, Hoseah M; Eyase, Fredrick L; Cheruiyot, Agnes C; Omondi, Angela A; Ogutu, Bernhards R; Waters, Norman C; Johnson, Jacob D; Polhemus, Mark E; Schnabel, David C; Walsh, Douglas S

2011-07-01

278

Escherichia coli strains isolated from the uterus and urinary bladder of bitches suffering from pyometra: comparison by restriction enzyme digestion and pulsed-field gel electrophoresis.  

PubMed

Pyometra (uterine inflammation with accumulation of pus in the uterus) is regarded as one of the most common illnesses in bitches. The ethiology and pathogenesis are complex with both hormonal and bacterial elements. The bacteria most frequently isolated from the uterine content is Escherichia coli. In this study, 84 E. coli strains from the uteri of 70 bitches suffering from the disease were examined and their DNA-profiles compared by restriction enzyme analysis and pulsed-field gel electrophoresis (PFGE). Through variations in DNA-profiles of the E. coli isolates, this study indicates that pyometra is caused by E. coli originating from the normal flora of the dogs and not by certain clones spread between animals.E. coli strains from the urinary bladder and the uterus of six of the bitches suffering from simultaneous urinary tract infection and pyometra were examined and compared as above. The DNA-profiles of the isolates from each of the six bitches were 100% identical. This study supports the theory suggesting that in cases of simultaneous urinary tract infection and E. coli pyometra, the urinary tract and uterus are infected with the same bacterial strain. To evaluate whether the uterus was infected with a single clone of E. coli or if multiple clones were present, eight to 16 colonies of E. coli isolated from pyometra samples from a further 10 bitches were examined. All bacterial colonies from the culture of the same bitch showed identical DNA-profiles. In 14 of the 70 bitches, two macroscopically different but biochemically identical E. coli colony types were isolated. The two colony types from the same bitch proved to have identical DNA-profiles in 13 cases and almost identical in the remaining bitch. PMID:11731167

Hagman, Ragnvi; Kühn, Inger

2002-01-01

279

Investigation of the antigenic evolution of field isolates using the reverse genetics system of infectious bursal disease virus (IBDV)  

Microsoft Academic Search

The antigenic profiles of over 300 infectious bursal disease virus (IBDV) isolates were analyzed using a panel of monoclonal\\u000a antibodies in a reverse genetics system. In addition, the sequences of a large portion of the neutralizing-antibody-inducing\\u000a VP2 of IBDV were determined. Phylogenetic analysis of nucleotide and amino acid sequences in combination with the antigenic\\u000a profiles obtained using the monoclonal antibody

Vijay Durairaj; Holly S. Sellers; Erich G. Linnemann; Alan H. Icard; Egbert Mundt

280

Emergence of a mutL mutation causing multilocus sequence typing-pulsed-field gel electrophoresis discrepancy among Pseudomonas aeruginosa isolates from a cystic fibrosis patient.  

PubMed

A multilocus sequence type (MLST) shift (from ST242 to ST996) was detected in Pseudomonas aeruginosa isolates with a uniform pulsed-field gel electrophoresis (PFGE) pattern obtained from a chronically colonized patient. MLST mutational change involved the mutL gene with the consequent emergence of a hypermutable phenotype. This observation challenges the required neutrality of mutL as an appropriate marker in MLST and alerts researchers to the limitations of MLST-only-based population studies in chronic infections under constant antibiotic selective pressure. PMID:22322352

García-Castillo, María; Máiz, Luis; Morosini, María-Isabel; Rodríguez-Baños, Mercedes; Suarez, Lucrecia; Fernández-Olmos, Ana; Baquero, Fernando; Cantón, Rafael; del Campo, Rosa

2012-02-08

281

Emergence of a mutL Mutation Causing Multilocus Sequence Typing-Pulsed-Field Gel Electrophoresis Discrepancy among Pseudomonas aeruginosa Isolates from a Cystic Fibrosis Patient  

PubMed Central

A multilocus sequence type (MLST) shift (from ST242 to ST996) was detected in Pseudomonas aeruginosa isolates with a uniform pulsed-field gel electrophoresis (PFGE) pattern obtained from a chronically colonized patient. MLST mutational change involved the mutL gene with the consequent emergence of a hypermutable phenotype. This observation challenges the required neutrality of mutL as an appropriate marker in MLST and alerts researchers to the limitations of MLST-only-based population studies in chronic infections under constant antibiotic selective pressure.

Garcia-Castillo, Maria; Maiz, Luis; Morosini, Maria-Isabel; Rodriguez-Banos, Mercedes; Suarez, Lucrecia; Fernandez-Olmos, Ana; Baquero, Fernando; Canton, Rafael

2012-01-01

282

A re-appraisal of the nature of the atropine-resistant contraction to electrical field stimulation in the human isolated detrusor muscle  

Microsoft Academic Search

We investigated whether in human isolated detrusor strips the atropine-resistant contractile response to electrical field\\u000a stimulation was mediated by ATP (or a related purine), as previously shown in the urinary bladder of other mammalian species.\\u000a Electrical stimulation (1–50Hz for 5s at 1min intervals, 0.1ms pulse width, 60V) elicited reproducible, frequency-dependent\\u000a twitch contractions, which were markedly reduced by atropine (10?M). Tetrodotoxin

M. Tagliani; S. M. Candura; A. Di Nucci; G. P. Franceschetti; G. D’Agostino; P. Ricotti; E. Fiori; M. Tonini

1997-01-01

283

The isolation of high molecular weight DNA from wheat, barley and rye for analysis by pulse-field gel electrophoresis  

Microsoft Academic Search

A method is presented for the preparation of large DNA molecules from protoplasts embedded in agarose blocks of three different cereals-hexaploid bread wheat (Triticum aestivum), barley (Hordeum vulgare) and rye (Secale cereale). Pulse-field gel electrophoresis (PFGE) analysis of these DNA preparations using a contour-clamped homogeneous field (CHEF) apparatus indicated that the size of the DNA molecules was greater than 6

Wing Y. Cheung; Michael D. Gale

1990-01-01

284

Compact optical isolator.  

PubMed

This paper describes a compact Faraday rotation isolator using terbium aluminum garnet (TAG) as the Faraday rotation material and small high field permanent magnets made of copper-rare earth alloys. The nominal isolation is 26 dB with a 0.4-dB forward loss. The present isolator can be adjusted to provide effective isolation from 4880 A to 5145 A. Details of the design, fabrication, and performance of the isolator are presented. PMID:20111324

Sansalone, F J

1971-10-01

285

Implementation of an indoxacarb susceptibility monitoring program using field-collected German cockroach isolates from the United States.  

PubMed

Indoxacarb, a sodium channel-blocking insecticide, has been in widespread use for German cockroach control in the United States since 2006. A two-tiered indoxacarb susceptibility monitoring strategy was previously developed as a first step toward determining indoxacarb susceptibility levels in German cockroach field populations. This strategy entails: (tier 1) testing field-collected populations in vial bioassays at two diagnostic concentrations; and (tier 2) testing populations at three diagnostic doses in oral (feeding) bioassays with treated bait matrix. In the current study the two-tiered technique was implemented to evaluate field (n = 14) and susceptible laboratory (n = 2) strains collected from 13 different U.S. locations. Our hypothesis was that at least some of the field-collected populations would display significant survivorship in both bioassays relative to susceptible laboratory populations. In agreement with this hypothesis, significantly reduced susceptibility was detected in 13 and 7 field strains with vial and feeding bioassays, respectively. In general, the lower number of strains displaying reduced susceptibility in feeding bioassays (seven strains) supports previous findings that indoxacarb is more toxic via ingestion. Although these findings suggest a reduced risk for resistance selection via feeding on indoxacarb-containing baits, they also suggest a need for proactive resistance management with respect to both spray and bait products. PMID:23786086

Gondhalekar, Ameya D; Scherer, Clay W; Saran, Raj K; Scharf, Michael E

2013-04-01

286

Description and critical appraisal of principal components analysis (PCA) methodology applied to pulsed-field gel electrophoresis profiles of methicillin-resistant Staphylococcus aureus isolates.  

PubMed

Principal components analysis (PCA) has been described for over 50 years; however, it is rarely applied to the analysis of epidemiological data. In this study PCA was critically appraised in its ability to reveal relationships between pulsed-field gel electrophoresis (PFGE) profiles of methicillin-resistant Staphylococcus aureus (MRSA) in comparison to the more commonly employed cluster analysis and representation by dendrograms. The PFGE type following SmaI chromosomal digest was determined for 44 multidrug-resistant hospital-acquired methicillin-resistant S. aureus (MR-HA-MRSA) isolates, two multidrug-resistant community-acquired MRSA (MR-CA-MRSA), 50 hospital-acquired MRSA (HA-MRSA) isolates (from the University Hospital Birmingham, NHS Trust, UK) and 34 community-acquired MRSA (CA-MRSA) isolates (from general practitioners in Birmingham, UK). Strain relatedness was determined using Dice band-matching with UPGMA clustering and PCA. The results indicated that PCA revealed relationships between MRSA strains, which were more strongly correlated with known epidemiology, most likely because, unlike cluster analysis, PCA does not have the constraint of generating a hierarchic classification. In addition, PCA provides the opportunity for further analysis to identify key polymorphic bands within complex genotypic profiles, which is not always possible with dendrograms. Here we provide a detailed description of a PCA method for the analysis of PFGE profiles to complement further the epidemiological study of infectious disease. PMID:16076508

Caddick, Jonathan M; Hilton, Anthony C; Armstrong, Richard A; Lambert, Peter A; Worthington, Tony; Elliott, Tom S J

2005-08-01

287

Experimental/theoretical investigation of the sound field of an isolated propeller, including angle of incidence effects  

NASA Astrophysics Data System (ADS)

A detailed experimental acoustic investigation was carried out in the German/Dutch low speed wind tunnel DNW on a 6 bladed 1:5 scale model propeller. Both the propeller near field and the far field were measured with axially traversing in-flow microphones and comparisons of test data and predictions have previously been reported for zero propeller incidence. Also included were tests under non-zero angle of attack, and sideslip angle, in order to obtain also data for a noise prediction method for propeller installation effects. In this report near field experimental data are compared with theoretical data, to show the capability of such a prediction scheme, and with the aim of indicating the behavior of the main parameters that are believed to control the noise changes with angle of incidence.

Zandbergen, T.; Sarin, S. L.; Donnelly, R. P.

1990-10-01

288

Comparison of Haemophilus parasuis reference strains and field isolates by using random amplified polymorphic DNA and protein profiles  

Technology Transfer Automated Retrieval System (TEKTRAN)

Haemophilus parasuis is the causative agent of Glässer’s disease and is a pathogen of swine in high-health status herds. Reports on serotyping of field strains from outbreaks describe that approximately 30% of them are nontypable and therefore cannot be traced. Molecular typing methods have been use...

289

Pulsed-Field Gel Electrophoresis Analysis of Vibrio vulnificus Strains Isolated from Taiwan and the United States  

Microsoft Academic Search

Vibrio vulnificus is a marine bacterium that causes human wound infections and septicemia with a high mortality rate. V. vulnificus strains from different clinical and environmental sources or geographic regions have been successfully characterized by ribotyping and several other methods. Pulsed-field gel electrophoresis (PFGE) is a highly discriminative method, but previous studies suggested that it was not suitable for examining

Hin-chung Wong; Shau-Yan Chen; Meng-Yi Chen; James D. Oliver; Lien-I Hor; Wen-Cherng Tsai

2004-01-01

290

Ivermectin and moxidectin resistance characterization by larval migration inhibition test in field isolates of Cooperia spp. in beef cattle, Mato Grosso do Sul, Brazil.  

PubMed

Ivermectin (IVM) resistance of Cooperia spp. in cattle has become an increasing and global problem. The early detection of anthelmintic resistance (AR) is important to propose strategies to slow down the development of resistance and requires sensitive, reliable, economic high-throughput and practical tests. The purpose of the present study was to apply a larval migration inhibition test (LMIT) for evaluating IVM and MOX efficacy against well-characterized field isolates of Cooperia spp. infecting cattle in Brazil. Eight isolates were used for IVM and seven for MOX. The following EC50 values of IVM were observed for the isolates: susceptible, 1.16 ?mol; Nova Alvorada do Sul I, 4.09 ?mol (RF=3.52); Campo Grande BNA, 3.57 ?mol (RF=3.07); Campo Grande TBR, 4.09 ?mol (RF=3,52); Nova Alvorada do Sul II, 2.50 ?mol (RF=2.15); Bandeirantes, 11.35 ?mol (RF=9.78); Campo Grande II, 6.03 ?mol (RF=5.20); and Porto Mortinho, 8.63 ?mol (RF=7.44). For MOX, the following EC50 values were observed: susceptible, 0.75 ?mol; Campo Grande BNA, 0.93 ?mol (RF=1.24); Campo Grande TBR, 0.36 ?mol (RF=0.48); Nova Alvorada do Sul II, 2.57 ?mol (RF=3.42); Bandeirantes, 1.43 ?mol (RF=1.90); Campo Grande II, 1.08 ?mol (RF=1.44); and Porto Mortinho, 0.49 ?mol (RF=0.65). The LMIT used in the present study can be a useful tool for in vitro evaluation of IVM, but not of MOX. However, such methodology cannot be used in large-scale studies yet. The isolates of Cooperia spp. showed various degrees of resistance to IVM, though remaining susceptible to MOX. PMID:22963710

Almeida, G D; Feliz, D C; Heckler, R P; Borges, D G L; Onizuka, M K V; Tavares, L E R; Paiva, F; Borges, F A

2012-08-25

291

Comparison of pulsed-field gel electrophoresis patterns of antimicrobial-resistant Escherichia coli and enterococci isolates from the feces of livestock and livestock farmers in Japan.  

PubMed

Seven hundred thirty-nine animal strains and 662 livestock-farmer strains, consisting of Escherichia coli and enterococci, were examined for their pulsed-field gel electrophoresis (PFGE) and antimicrobial-resistance patterns. Two hundred fifty-eight and 203 PFGE patterns were found among 739 animal strains isolated from animals comprising broilers, pigs and cattle, and 662 human strains isolated from livestock farmers, respectively, from 27 farms in Japan. These results demonstrated that the PFGE patterns found among E. coli and enterococci strains from animals and livestock-farmers were heterogeneous and considerably diverse. The strains having both the identical PFGE pattern and the same drug-resistance pattern were defined as a single clone in this study. Seven types of E. coli and enterococci clones were shared among animals within the same farms and between the different farms housing the same animal species. The 25 strains (3.4%) of 739 E. coli and enterococci animal strains belonged to these seven types of clones. Only three types of E. coli clones were shared among animals between the different farms housing different animal species, but no identical E. faecalis or E. faecium clones were found between different animal species farms. The 15 strains (2.0%) of 739 E. coli and enterococci animal strains belonged to these three types of clones. Additionally, the 11 strains (1.5%) of 739 E. coli and enterococci strains isolated from animals were identical clones to strains isolated from livestock farmers of the same farm. These results suggest that the transmission of animal clones to livestock farmers or vice versa is less common. PMID:18323680

Katsunuma, Yu; Hanazumi, Michihito; Fujisaki, Hirokazu; Minato, Hajime; Kataoka, Yasushi; Sawada, Takushi; Hashimoto, Yasushi; Yonemochi, Chisato

2008-02-01

292

Isolated-attosecond-pulse generation from asymmetric molecules with an {omega}+2{omega}/3 multicycle two-color field  

SciTech Connect

The high harmonic generation from asymmetric molecules with an {omega}+2{omega}/3 multicycle bichromatic laser pulse has been investigated. It is shown that the ionization asymmetry in consecutive half optical cycles for asymmetric molecules is further enhanced since the 2{omega}/3 control laser pulse further enhances the amplitude of the ionization peak at the center of the laser pulse. The 2{omega}/3 control laser pulse also significantly enlarges the difference of the photon energies emitted from the ejected electron in the half optical cycle at the central laser pulse and its next half optical cycle. In addition, a broadband supercontinuum is produced in the plateau of the spectrum, from which an isolated 90-as pulse can be directly obtained.

Li Qianguang [Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074 (China); Department of Physics, Xiaogan University, Xiaogan 432000 (China); Hong Weiyi; Zhang Qingbin; Wang Shaoyi; Lu Peixiang [Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074 (China)

2010-05-15

293

Field application of the Numobag as a portable disposable isolation unit and for treating chemical, radiological or biologically induced wounds.  

SciTech Connect

Numotech Inc. has developed the Numobag{trademark}, a disposable, lightweight, wound healing device which produces Topical Hyperbaric Oxygen Therapy (THOT). The Numobag{trademark} is cost effective and has been clinically validated to heal large skin lesions rapidly and has proven to arrest wound advancement from several insidious forms of biological attack including dermal anthrax, small pox, necrotizing fasciitis etc. The Numobag{trademark} can treat mass casualties wounded by chemical/radiological burns or damaging biological exposures. The Numobag{trademark} can be a frontline tool as an isolation unit, reducing cross-contamination and infection of medical personnel. The heightened oxygen content kills organisms on the skin and in the wound, avoids expensive hospital trash disposal procedures, and helps the flesh heal. The Numobag{trademark} requires high purity oxygen. Numotech Inc. is teaming with Sandia National Laboratories and Spektr Conversion in Russia to develop a cost effective, portable, low power oxygen generator.

Miller, Keith A.; Felton, Robert; Vaughan, Courtenay Thomas

2005-04-01

294

Correlated cerebral events between physically and sensory isolated pairs of subjects exposed to yoked circumcerebral magnetic fields.  

PubMed

In three different experiments pairs of unrelated people sitting in two different rooms were exposed simultaneously to different rates of circumcerebral rotations of weak, complex magnetic fields in order to produce "dynamic similarity". Quantitative electroencephalographic (QEEG) measurements were taken for one member of each pair in one room while the other sat in a closed chamber in another room and intermittently observed 5Hz, 8Hz, 10Hz, or 15Hz flashing lights. Reliable increases in QEEG power within specific frequencies over the right parietal region were observed during the similar-frequency light flashes when the shared temporal-spatial complexity of the circumcerebral rotating fields was based on 100ms, the average duration of normal microstates. The development of this experimental procedure could facilitate rational understanding of this class of "coincidence" phenomena. PMID:20887774

Persinger, M A; Saroka, K S; Lavallee, C F; Booth, J N; Hunter, M D; Mulligan, B P; Koren, S A; Wu, H-P; Gang, Noa

2010-09-29

295

An international collaborative study on the detection of an HIV-1 genotype B field isolate by nucleic acid amplification techniques.  

PubMed

An international collaborative study to assess inter-laboratory variation in the sensitivity of gene amplification assays for the detection of HIV-1 RNA sequences was conducted using a panel of eight duplicate dilutions of an HIV-1 genotype B clinical isolate and negative control samples. Twenty-five laboratories participated in the study and used a variety of in-house assays and commercial assay systems. With few exceptions, the assays were more sensitive than a p24 antigen assay. Overall, the PCR-based Amplicor Monitor assay was the most sensitive and gave the highest mean copy number for any one sample. Some of the in-house assays gave results comparable with the Monitor assay whilst the NASBA and bDNA assays appeared to be less sensitive. As a result of this study, an HIV-1 Working Reagent for the standardisation of nucleic acid amplification assays was developed and assessed in a subsequent study. Similar differences in sensitivity between the different assay systems was observed. The discrepancies in viral copy number obtained using the Working Reagent highlights the need for an International Standard against which all Working Reagents may be calibrated. PMID:10204694

Bootman, J; Heath, A B; Hughes, P; Holmes, H

1999-03-01

296

Biodegradation of partially hydrolyzed polyacrylamide by bacteria isolated from production water after polymer flooding in an oil field.  

PubMed

Partially hydrolyzed polyacrylamide (HPAM) in production water after polymer flooding in oil filed causes environmental problems, such as increases the difficulty in oil-water separation, degrades naturally to produce toxic acrylamide and endanger local ecosystem. Biodegradation of HPAM may be an efficient way to solve these problems. The biodegradability of HPAM in an aerobic environment was studied. Two HPAM-degrading bacterial strains, named PM-2 and PM-3, were isolated from the produced water of polymer flooding. They were subsequently identified as Bacillus cereus and Bacillus sp., respectively. The utilization of HPAM by the two strains was explored. The amide group of HPAM could serve as a nitrogen source for the two microorganisms, the carbon backbone of these polymers could be partly utilized by microorganisms. The HPAM samples before and after bacterial biodegradation were analyzed by the infrared spectrum, high performance liquid chromatography and scanning electronic microscope. The results indicated that the amide group of HPAM in the biodegradation products had been converted to a carboxyl group, and no acrylamide monomer was found. The HPAM carbon backbone was metabolized by the bacteria during the course of its growth. Further more, the hypothesis about the biodegradation of HPAM in aerobic bacterial culture is proposed. PMID:20813455

Bao, Mutai; Chen, Qingguo; Li, Yiming; Jiang, Guancheng

2010-08-13

297

Efficacy of commercial swine influenza vaccines against challenge with a recent European H1N1 field isolate.  

PubMed

This study examines the immunogenicity and efficacy of four commercial swine influenza (SI) vaccines against challenge with a recent European H1N1 virus, Sw/Gent/112/07. The vaccines contained different H1N1 strains showing between 77% and 95% genetic homology with the haemagglutinin (HA) of the challenge virus. Four groups of 10 pigs each received a double vaccination, with a 4-week interval, with one of the vaccines; a fifth group served as unvaccinated controls. All pigs were challenged 3 weeks after the second vaccination intratracheally with 10(5.0)EID(50) of Sw/Gent/112/07. Sera were examined in haemagglutination inhibition (HI) tests against the homologous vaccine H1N1 strains, the challenge virus and a panel of five recent H1N1 isolates. Pigs were euthanized at 24 or 72h post-challenge and virus titres were determined in right and left lung halves. Two vaccines, in which the H1N1 strains showed a genetic homology of 93% and 89% to Sw/Gent/112/07, significantly reduced virus replication. The vaccine containing an H1N1 strain with 95% homology to Sw/Gent/112/07, did not offer significant protection, neither did it induce the highest HI titres. In general, pigs with HI antibody titres >or=20 against Sw/Gent/112/07 were virologically protected against challenge. HI titres against other viruses, however, differed compared to the challenge virus and between viruses. Our data clearly show that the genetic homology with the challenge virus is not the ultimate predictor for SI vaccine performance. The true reason for the differences in vaccine potency remains obscure because other factors, such as the antigen dose and/or the adjuvant, also differed between the vaccines. PMID:20116942

Kyriakis, C S; Gramer, M R; Barbé, F; Van Doorsselaere, J; Van Reeth, K

2010-01-11

298

Isolation of a field strain of Brucella abortus from RB51-vaccinated- and brucellosis-seronegative bovine yearlings that calved normally.  

PubMed

A study was carried out in Pichucalco, Chiapas (Mexico) to determine whether recently calved cows or those that aborted shed Brucella. Serological diagnosis of brucellosis was made in all animals (209). Six of the cows that calved normally and two that aborted underwent a bacteriological study of milk and vaginal exudate. Brucella abortus was isolated from vaginal exudate samples in two 3- to 4-year-old seronegative first-birth cows that had calved normally. This was confirmed through bacteriological identification and PCR as a field strain and smooth phenotypes. We conclude that seronegative cows vaccinated with RB51 which calved normally and shed B. abortus in the vaginal exudate after calving could be a serious problem because these cows are overlooked in routine diagnoses and are a source of Brucella infection. PMID:22956439

Arellano-Reynoso, Beatriz; Suárez-Güemes, Francisco; Estrada, Félix Mejía; Michel-GómezFlores, Fernando; Hernández-Castro, Rigoberto; Acosta, Rómulo Beltrán; Díaz-Aparicio, Efrén

2012-09-07

299

Impact of Reducing Shallow Trench Isolation Mechanical Stress on Active Length for 40 nm n-Type Metal--Oxide--Semiconductor Field-Effect Transistors  

NASA Astrophysics Data System (ADS)

We report an improved densification annealing process for sub atmospheric chemical vapor deposition (SACVD)-based shallow trench isolation (STI) to enhance n-type metal--oxide--semiconductor field-effect transistor (nMOSFET) performance for 40 nm node and beyond. Experimental results show that this improved STI densification process leads to lower compressive stress in the small active area compared with the standard STI process. This is beneficial to electron mobility and leads to an enhancement of on-current (ION). Moreover, comparable drain induced barrier lowering (DIBL) and subthreshold swing (SS) characteristics for both devices indicate that the improved densification process would no significant influences on process variations or dopant diffusions. Hence, the improved STI process can be adopted in 40 nm complementary metal--oxide--semiconductor (CMOS) technology and beyond.

Huang, Yao-Tsung; Wu, San-Lein; Lin, Hau-Yu; Kuo, Cheng-Wen; Chang, Shoou-Jinn; Hong, De-Gong; Wu, Chung-Yi; Huang, Cheng-Tung; Cheng, Osbert

2011-04-01

300

Marinitoga okinawensis sp. nov., a novel thermophilic and anaerobic heterotroph isolated from a deep-sea hydrothermal field, Southern Okinawa Trough.  

PubMed

A novel thermophilic and sulfur-reducing heterotrophic bacterium, strain TFS10-5(T), was isolated from a deep-sea hydrothermal field in Yonaguni Knoll IV, Southern Okinawa Trough. Cells of strain TFS10-5(T) were motile rods, 1.5-5 microm in length and 0.5-0.8 microm in width. Strain TFS10-5(T) was an obligately anaerobic heterotroph and sulfur-reduction stimulated growth. Growth was observed between 30 and 70 degrees C (optimum at 55-60 degrees C), pH 5.0-7.4 (optimum at pH 5.5-5.8), 1.0-5.5 NaCl % (optimum at 3.0-3.5 %). The fatty acid content was C(16 : 0) (71.0 %), C(16 : 1) (6.0 %), C(18 : 0) (21.4 %) and C(18 : 1) (1.6 %). The G+C content of the genomic DNA was 28 mol%. 16S rRNA gene sequence analysis indicated that strain TFS10-5(T) belongs to the genus Marinitoga. Based on the physiological and phylogenetic features of the new isolate, strain TFS10-5(T) represents a novel species in the genus Marinitoga for which the name Marinitoga okinawensis sp. nov. is proposed. The type strain is TFS10-5(T) (=JCM 13303(T)=DSM 17373(T)). PMID:17329770

Nunoura, Takuro; Oida, Hanako; Miyazaki, Masayuki; Suzuki, Yohey; Takai, Ken; Horikoshi, Koki

2007-03-01

301

Prevalence of Clostridium botulinum in Finnish Trout Farms: Pulsed-Field Gel Electrophoresis Typing Reveals Extensive Genetic Diversity among Type E Isolates  

PubMed Central

The distribution of Clostridium botulinum serotypes A, B, E, and F in Finnish trout farms was examined. A total of 333 samples were tested with a neurotoxin-specific PCR assay. C. botulinum type E was found in 68% of the farm sediment samples, in 15% of the fish intestinal samples, and in 5% of the fish skin samples. No other serotypes were found. The spore counts determined by the most-probable-number method were considerably higher for the sediments than for the fish intestines and skin; the average values were 2,020, 166, and 310 C. botulinum type E spores kg?1, respectively. The contamination rates in traditional freshwater ponds and marine net cages were high, but in concrete ponds equipped with sediment suction devices the contamination rates were significantly lower. Pulsed-field gel electrophoresis (PFGE) typing of 42 isolates obtained in this survey and 12 North American reference strains generated 28 pulsotypes upon visual inspection, suggesting that there was extensive genetic diversity and that the discriminatory power of PFGE typing in C. botulinum type E was high. A numerical analysis of SmaI-XmaI macrorestriction profiles confirmed these findings, as it divided the 54 isolates into 15 clusters at a similarity level of 76%. For this material, this level of similarity corresponded to a three-band difference in the macrorestriction profiles, which indicated that there is no genotypic proof of a close epidemiological relationship among the clusters.

Hielm, Sebastian; Bjorkroth, Johanna; Hyytia, Eija; Korkeala, Hannu

1998-01-01

302

Tracing Campylobacter jejuni strains along the poultry meat production chain from farm to retail by pulsed-field gel electrophoresis, and the antimicrobial resistance of isolates.  

PubMed

In this study Campylobacter jejuni isolates were recovered from birds, carcasses and carcass portions from two broiler chicken flocks and from equipment used for carcass and meat processing along the production chain from farms to retail stores. Isolates were subjected to pulsed-field gel electrophoresis (PFGE) using SmaI and KpnI restriction enzymes and their antimicrobial susceptibilities were determined. C. jejuni was recovered from product and equipment used with both flocks at each point in the production chain. The prevalence of C. jejuni in poultry products at retail stores was 58.97% (flock 1) and 69.23% (flock 2). SmaI divided 122 C. jejuni strains from flock 1 and 106 from flock 2 into 17 and 13 PFGE types, respectively. PFGE types H and F were present at all steps along the chain, from farms to retail products. Similarly, for both flocks PFGE type D was detected in crates, slaughterhouse and retail stores. Moreover, the PFGE types were highly diverse at the processing and retail steps. Most PFGE types were resistant to ciprofloxacin (95.45%) and tetracycline (81.82%); and multidrug resistant PFGE types were found in the final products. Our study showed that there were several points of cross-contamination of product along the chain, and a high diversity of PFGE types with antimicrobial resistance to ciprofloxacin and tetracycline in the retail products. PMID:22850383

Melero, Beatriz; Juntunen, Pekka; Hänninen, Marja-Liisa; Jaime, Isabel; Rovira, Jordi

2012-05-11

303

Molecular epidemiology of porcine epidemic diarrhea virus in China.  

PubMed

Since early 2006, porcine epidemic diarrhea virus (PEDV) has been reemerging in immunized swine herds. Open reading frame 3 (ORF3) is the only accessory gene in the PEDV genome. The entire ORF3 genes of 12 PEDV field strains and one vaccine strain were sequenced. The ORF3 genes of Chinese PEDV field strains (excluding CH/GSJIII/07) contain a single 672- or 675-nucleotide (nt) ORF, which encodes a 223- or 224-aa-long peptide. However, the CV777 vaccine strain and CH/GSJIII/07 contain a 276-nt ORF because of a 49-nt deletion at nt 245-293. The Chinese PEDV field strains and PEDV reference strains are divided into three groups based on the phylogenetic relationship of their ORF3 genes. Chinese PEDV field strains (excluding CH/GSJIII/07) have a close phylogenetic relationship to Korean strains and are genetically different from the PEDV vaccine strains. However, CH/GSJIII/07 has a close phylogenetic relationship to two vaccine strains, suggesting that it might have evolved from a live vaccine strain. Chinese PEDV field strains (excluding CH/GSJIII/07) can be differentiated from PEDV vaccine strains by a nested RT-PCR method. PMID:20544234

Chen, Jianfei; Wang, Chengbao; Shi, Hongyan; Qiu, Huaji; Liu, Shengwang; Chen, Xiaojin; Zhang, Zhibang; Feng, Li

2010-06-11

304

Efficacy of toltrazuril in broilers and development of a laboratory model for sensitivity testing of Eimeria field isolates.  

PubMed

(1) The efficacy of toltrazuril (Baycox) against coccidiosis was established on a broiler farm in an intermittent application during five consecutive growing periods. Treated birds were fed a broiler ration without anticoccidials. The efficacy of Baycox was compared with the nicarbazin-salinomycin shuttle. It was concluded that Baycox retarded the onset of Eimeria infection for several weeks. During the fifth rearing period coccidiosis problems emerged on the farm in all birds during medication, suggesting development of resistance. (2) During a laboratory experiment the efficacy of Baycox was studied in birds after inoculation with different numbers of oocysts at 7, 10 or 15 days of age. Baycox was applied at 10 and 11 days of age. In all cases medication with Baycox protected birds from coccidiosis during a period of at least 7 days. This effect of Baycox could be due to the long-existing tissue levels of the product and its metabolites as well as its specific effect on the second generation of schizonts. (3) In another laboratory experiment coccidia obtained from field trials were tested for sensitivity to Baycox in conjunction with two strains obtained from farms were coccidiosis emerged during application. The inoculation model developed in this study was used for sensitivity testing. One of the Eimeria strains tested was resistant to the product, one strain was tolerant and the remaining two strains, including the control strain, were fully sensitive to Baycox. PMID:2219660

Vertommen, M H; Peek, H W; van der Laan, A

1990-07-01

305

Breast Field Cancerization: Isolation and Comparison of Telomerase-Expressing Cells in Tumor and Tumor Adjacent, Histologically Normal Breast Tissue  

PubMed Central

Telomerase stabilizes chromosomes by maintaining telomere length, immortalizes mammalian cells, and is expressed in more than 90% of human tumors. However, the expression of human telomerase reverse transcriptase (hTERT) is not restricted to tumor cells. We have previously shown that a subpopulation of human mammary epithelial cells (HMEC) in tumor-adjacent, histologically normal (TAHN) breast tissues expresses hTERT mRNA at levels comparable with levels in breast tumors. In the current study, we first validated a reporter for measuring levels of hTERT promoter activity in early-passage HMECs and then used this reporter to compare hTERT promoter activity in HMECs derived from tumor and paired TAHN tissues 1, 3, and 5 cm from the tumor (TAHN-1, TAHN-3, and TAHN-5, respectively). Cell sorting, quantitative real-time PCR, and microarray analyses showed that the 10% of HMECs with the highest hTERT promoter activity in both tumor and TAHN-1 tissues contain more than 95% of hTERT mRNA and overexpress many genes involved in cell cycle and mitosis. The percentage of HMECs within this subpopulation showing high hTERT promoter activity was significantly reduced or absent in TAHN-3 and TAHN-5 tissues. We conclude that the field of normal tissue proximal to the breast tumors contains a population of HMECs similar in hTERT expression levels and in gene expression to the HMECs within the tumor mass and that this population is significantly reduced in tissues more distal to the tumor.

Trujillo, Kristina A.; Hines, William C.; Vargas, Keith M.; Jones, Anna C.; Joste, Nancy E.; Bisoffi, Marco; Griffith, Jeffrey K.

2011-01-01

306

Breast field cancerization: isolation and comparison of telomerase-expressing cells in tumor and tumor adjacent, histologically normal breast tissue.  

PubMed

Telomerase stabilizes chromosomes by maintaining telomere length, immortalizes mammalian cells, and is expressed in more than 90% of human tumors. However, the expression of human telomerase reverse transcriptase (hTERT) is not restricted to tumor cells. We have previously shown that a subpopulation of human mammary epithelial cells (HMEC) in tumor-adjacent, histologically normal (TAHN) breast tissues expresses hTERT mRNA at levels comparable with levels in breast tumors. In the current study, we first validated a reporter for measuring levels of hTERT promoter activity in early-passage HMECs and then used this reporter to compare hTERT promoter activity in HMECs derived from tumor and paired TAHN tissues 1, 3, and 5 cm from the tumor (TAHN-1, TAHN-3, and TAHN-5, respectively). Cell sorting, quantitative real-time PCR, and microarray analyses showed that the 10% of HMECs with the highest hTERT promoter activity in both tumor and TAHN-1 tissues contain more than 95% of hTERT mRNA and overexpress many genes involved in cell cycle and mitosis. The percentage of HMECs within this subpopulation showing high hTERT promoter activity was significantly reduced or absent in TAHN-3 and TAHN-5 tissues. We conclude that the field of "normal tissue" proximal to the breast tumors contains a population of HMECs similar in hTERT expression levels and in gene expression to the HMECs within the tumor mass and that this population is significantly reduced in tissues more distal to the tumor. PMID:21775421

Trujillo, Kristina A; Hines, William C; Vargas, Keith M; Jones, Anna C; Joste, Nancy E; Bisoffi, Marco; Griffith, Jeffrey K

2011-07-20

307

Are isolated wetlands isolated?  

USGS Publications Warehouse

While federal regulations during the past 10 years have treated isolated wetlands as unconnected to aquatic resources protected by the Clean Water Act, they provide critical ecosystem services to society that extend well beyond their wetland boundaries. The authors offer well-documented examples from the scientific literature on some of the ecosystem services provided by isolated wetlands to society and other ecosystems.

Smith, Loren M.; Euliss, Ned H., Jr.; Haukos, David A.

2011-01-01

308

Atomic interferometer measurements of Berry and Aharonov-Anandan phases for isolated spins S>(1/2) nonlinearly coupled to external fields  

SciTech Connect

In a recent paper we have studied the peculiar features of the Berry and Aharonov-Anandan geometric phases for isolated spins S{>=}1. We have assumed that they are submitted to a dipole and quadrupole coupling to external E and B fields with the mild restriction E{center_dot}B=0. This implies discrete symmetries leading to remarkable simplifications of the geometry and algebra involved. The aim of the present work is to describe realistic proposals, within the realm of atomic physics, for the verification of some of our most significant theoretical predictions. There are several challenges to be overcome. For alkali-metal atoms, most commonly used in atomic interferometers, the only practical way to generate quadrupole coupling, with a strength comparable to the dipole one, is the ac Stark effect induced by a nearly resonant light beam. One then has to face the instability of the 'dressed' atom hyperfine (hf) level, a candidate for our isolated spin. One deleterious effect is the apparition of an imaginary part in the quadrupole to dipole coupling strength ratio, {lambda}. Fortunately we have found a simple way to get rid of I({lambda}) by an appropriate detuning. We are left with an unstable isolated spin. This implies an upper bound to the quantum cycle duration T{sub c}. In the case of the Berry's phase, T{sub c} has a lower bound due to the necessity of keeping the nonadiabatic corrections below a predefined level. We have found a compromise in the case of the F=2,m=0 {sup 87}Rb ground-state hf level. This is our candidate for the measurement of the somewhat ''exotic'' Berry's phase acquired by the S=2,m=0 state at the end of a quantum cycle involving a rotation of {pi} of the E field--in practice, the linear polarization of the dressing beam --about the B field direction. We have found a way to implement, in a Ramsey-type interferometric measurement, the procedures aimed at controlling the nonadiabatic corrections, as described in detail in our previous theoretical paper. A numerical simulation of our experimental proposal shows that a 0.1% accurate determination of Berry's phase, free of nonadiabatic corrections, can be achieved. Measurements could also be considered for cold {sup 52}Cr chromium atoms with S=3, where values of {lambda}{approx_equal}1 can be obtained with an instability smaller than in the {sup 87}Rb case, due to a more favorable spectroscopic structure. The F=1,m=1 hf level of the {sup 87}Rb ground state offers the opportunity to extend the measurement of Aharonov-Anandan's phases beyond the case S=(1/2). We construct, using 'light shift', the Hamiltonian H{sub ||}(t) generating a closed circuit in the density-matrix space which satisfies at any time the 'parallel transport' condition, thus making the quantum cycle free from the adiabaticity condition. We also consider the case of half-integer spins (e.g., {sup 201}Hg, {sup 135}Ba, and {sup 137}Ba), with their own specific features. We show how the difference of Berry's phases for states S=(3/2) and S=(1/2), with m=(1/2), can be exploited to achieve a holonomic maximum entanglement of three qubits.

Bouchiat, Marie-Anne; Bouchiat, Claude [Laboratoire Kastler-Brossel, CNRS, UPMC, Ecole Normale Superieure, 24 rue Lhomond, FR-75005 Paris (France); Laboratoire de Physique Theorique de l'Ecole Normale Superieure, CNRS, UPMC, 24 rue Lhomond, FR-75005 Paris (France)

2011-05-15

309

Benchmark Database on Isolated Small Peptides Containing an Aromatic Side Chain: Comparison Between Wave Function and Density Functional Theory Methods and Empirical Force Field  

SciTech Connect

A detailed quantum chemical study on five peptides (WG, WGG, FGG, GGF and GFA) containing the residues phenylalanyl (F), glycyl (G), tryptophyl (W) and alanyl (A)—where F and W are of aromatic character—is presented. When investigating isolated small peptides, the dispersion interaction is the dominant attractive force in the peptide backbone–aromatic side chain intramolecular interaction. Consequently, an accurate theoretical study of these systems requires the use of a methodology covering properly the London dispersion forces. For this reason we have assessed the performance of the MP2, SCS-MP2, MP3, TPSS-D, PBE-D, M06-2X, BH&H, TPSS, B3LYP, tight-binding DFT-D methods and ff99 empirical force field compared to CCSD(T)/complete basis set (CBS) limit benchmark data. All the DFT techniques with a ‘-D’ symbol have been augmented by empirical dispersion energy while the M06-2X functional was parameterized to cover the London dispersion energy. For the systems here studied we have concluded that the use of the ff99 force field is not recommended mainly due to problems concerning the assignment of reliable atomic charges. Tight-binding DFT-D is efficient as a screening tool providing reliable geometries. Among the DFT functionals, the M06-2X and TPSS-D show the best performance what is explained by the fact that both procedures cover the dispersion energy. The B3LYP and TPSS functionals—not covering this energy—fail systematically. Both, electronic energies and geometries obtained by means of the wave-function theory methods compare satisfactorily with the CCSD(T)/CBS benchmark data.

Valdes, Haydee; Pluhackova, Kristyna; Pitonak, Michal; Rezac, Jan; Hobza, Pavel

2008-03-13

310

Benchmark database on isolated small peptides containing an aromatic side chain: comparison between wave function and density functional theory methods and empirical force field.  

PubMed

A detailed quantum chemical study on five peptides (WG, WGG, FGG, GGF and GFA) containing the residues phenylalanyl (F), glycyl (G), tryptophyl (W) and alanyl (A) -- where F and W are of aromatic character -- is presented. When investigating isolated small peptides, the dispersion interaction is the dominant attractive force in the peptide backbone-aromatic side chain intramolecular interaction. Consequently, an accurate theoretical study of these systems requires the use of a methodology covering properly the London dispersion forces. For this reason we have assessed the performance of the MP2, SCS-MP2, MP3, TPSS-D, PBE-D, M06-2X, BH&H, TPSS, B3LYP, tight-binding DFT-D methods and ff99 empirical force field compared to CCSD(T)/complete basis set (CBS) limit benchmark data. All the DFT techniques with a '-D' symbol have been augmented by empirical dispersion energy while the M06-2X functional was parameterized to cover the London dispersion energy. For the systems here studied we have concluded that the use of the ff99 force field is not recommended mainly due to problems concerning the assignment of reliable atomic charges. Tight-binding DFT-D is efficient as a screening tool providing reliable geometries. Among the DFT functionals, the M06-2X and TPSS-D show the best performance what is explained by the fact that both procedures cover the dispersion energy. The B3LYP and TPSS functionals-not covering this energy-fail systematically. Both, electronic energies and geometries obtained by means of the wave-function theory methods compare satisfactorily with the CCSD(T)/CBS benchmark data. PMID:18464990

Valdes, Haydee; Pluhácková, Kristýna; Pitonák, Michal; Rezác, Jan; Hobza, Pavel

2008-03-13

311

Complete genome sequence of a virulent porcine epidemic diarrhea virus strain.  

PubMed

In recent years, acute outbreaks of epizootic diarrhea have occurred on many swine farms in China. Although the putative causative virus of the disease was not isolated, the genomic sequence of porcine epidemic diarrhea virus (PEDV) was consistently detected from feces of diseased pigs by reverse transcription-PCR (RT-PCR). Here we report a complete genome sequence of PEDV which is apparently different from those of early PEDV circulated in Chinese swine herds. PMID:23166262

Zhou, Yan-jun; Wu, Yu-lu; Zhu, Jian-ping; Tong, Wu; Yu, Hai; Jiang, Yi-feng; Tong, Guang-zhi

2012-12-01

312

Comparative purification and characterization of two distinct extracellular monocrotophos hydrolases secreted by Penicillium aculeatum and Fusarium pallidoroseum isolated from agricultural fields.  

PubMed

The present study aimed at a comparative characterization of two distinct extracellular monocrotophos hydrolases, from Penicillium aculeatum ITCC 7980.10 (M3) and Fusarium pallidoroseum ITCC 7785.10 (M4), isolated from agricultural fields. The MCP hydrolases were purified by Sephadex G-100 column and DEAE-Sepharose CL-6B ion-exchange column followed by SDS-PAGE analysis, which showed the presence of two hydrolases, of 33 and 67 kDa respectively. Both enzymes were most active at alkaline pH and were stable over a wide range of temperatures (60-70 °C). Between the strains, the MCP hydrolases from M3 were 2-fold more active than that from M4. Enzyme kinetic studies showed lowest Km (33.52 mM) and highest Vmax (5.18 U/mg protein) for OPH67 of M3 in comparison to the Km and Vmax of the other hydrolases purified from M3 and M4, suggesting that M3 OPH67 was the most efficient MCP hydrolase. To the best of our knowledge, this is the first report of the purification of two distinct extracellular thermostable MCP hydrolases from fungal strains Penicillium aculeatum ITCC 7980.10 and Fusarium pallidoroseum ITCC 7785.10. Owing to its potential MCP hydrolyzing activity, M3 OPH67 can perhaps used directly or in the encapsulated form for remediation of MCP contaminated sites. PMID:23666511

Jain, Rachna; Garg, Veena; Dangwal, Koushalya; Lily, Madhuri Kaushish

2013-05-11

313

The rph1 gene is a common contributor to the evolution of phosphine resistance in independent field isolates of Rhyzopertha dominica.  

PubMed

Phosphine is the only economically viable fumigant for routine control of insect pests of stored food products, but its continued use is now threatened by the world-wide emergence of high-level resistance in key pest species. Phosphine has a unique mode of action relative to well-characterised contact pesticides. Similarly, the selective pressures that lead to resistance against field sprays differ dramatically from those encountered during fumigation. The consequences of these differences have not been investigated adequately. We determine the genetic basis of phosphine resistance in Rhyzopertha dominica strains collected from New South Wales and South Australia and compare this with resistance in a previously characterised strain from Queensland. The resistance levels range from 225 and 100 times the baseline response of a sensitive reference strain. Moreover, molecular and phenotypic data indicate that high-level resistance was derived independently in each of the three widely separated geographical regions. Despite the independent origins, resistance was due to two interacting genes in each instance. Furthermore, complementation analysis reveals that all three strains contain an incompletely recessive resistance allele of the autosomal rph1 resistance gene. This is particularly noteworthy as a resistance allele at rph1 was previously proposed to be a necessary first step in the evolution of high-level resistance. Despite the capacity of phosphine to disrupt a wide range of enzymes and biological processes, it is remarkable that the initial step in the selection of resistance is so similar in isolated outbreaks. PMID:22363668

Mau, Yosep S; Collins, Patrick J; Daglish, Gregory J; Nayak, Manoj K; Pavic, Hervoika; Ebert, Paul R

2012-02-20

314

Biodegradation of alachlor in liquid and soil cultures under variable carbon and nitrogen sources by bacterial consortium isolated from corn field soil.  

PubMed

Alachlor, an aniline herbicide widely used in corn production, is frequently detected in water resources. The main objectives of this research were focused on isolating bacterial consortium capable of alachlor biodegradation, assessing the effects of carbon and nitrogen sources on alachlor biodegradation and evaluating the feasibility of using bacterial consortium in soil culture. Kavar corn field soil with a long history of alachlor application in Fars province of Iran has been explored for their potential of alachlor biodegradation. The influence of different carbon compounds (glucose, sodium citrate, sucrose, starch and the combination of these compounds), the effect of nitrogen sources (ammonium nitrate and urea) and different pH (5.5-8.5) on alachlor removal efficiency by the bacterial consortium in liquid culture were investigated. After a multi-step enrichment program 100 days of acclimation, a culture with the high capability of alachlor degradation was obtained (63%). Glucose and sodium citrate had the highest alachlor reduction rate (85%). Alachlor reduction rate increased more rapidly by the addition of ammonium nitrate (94%) compare to urea. Based on the data obtained in the present study, pH of 7.5 is optimal for alachlor biodegradation. After 30 days of incubation, the percent of alachlor reduction were significantly enhanced in the inoculated soils (74%) as compared to uninoculated control soils (17.67%) at the soil moisture content of 25%. In conclusion, bioaugmentation of soil with bacterial consortium may enhance the rate of alachlor degradation in a polluted soil. PMID:23452801

Dehghani, Mansooreh; Nasseri, Simin; Zamanian, Zahra

2013-03-01

315

Study of infection with an Iranian field-isolated H9N2 avian influenza virus in vaccinated and unvaccinated Japanese quail.  

PubMed

In the present study, we examined the mortality rate, egg production, and clinical signs of quail experimentally infected with a field isolate of A/Chicken/Iran/339/02 (H9N2) avian influenza virus obtained from an infected commercial layer farm with severe morbidity and mortality. A total of 120 quail at 14 days old were randomly divided into four groups of vaccinated (B and C) and unvaccinated (A and D) birds. Vaccination was done on days 20 and 32, and viral inoculation of birds in groups C and D was then carried out on day 43. For evaluation of viral transmission, at 24 hr postinoculation additional unvaccinated birds were placed in direct contact with challenged birds. All the birds were evaluated for clinical signs, egg production, antibody production, viral titration in lung homogenates, and viral transmission following inoculation. All unvaccinated-challenged birds were infected and showed clinical signs, whereas the infection rate along with clinical signs of vaccinated-challenged birds reached 30%-40%. Although vaccination induced high antibody titers, reduction in food and water consumption was evident in this vaccinated-challenged group compared with the unchallenged control group. These results could indicate that inactivated vaccine did not fully prevent the infection, although it was capable of protecting birds against clinical signs and significantly decreased viral titers in lungs after intranasal challenge. PMID:21793433

Ebrahimi, Seyyed Mahmoud; Ziapour, Soudeh; Tebianian, Majid; Dabaghian, Mehran; Mohammadi, Mashallah

2011-06-01

316

The rph1 Gene Is a Common Contributor to the Evolution of Phosphine Resistance in Independent Field Isolates of Rhyzopertha Dominica  

PubMed Central

Phosphine is the only economically viable fumigant for routine control of insect pests of stored food products, but its continued use is now threatened by the world-wide emergence of high-level resistance in key pest species. Phosphine has a unique mode of action relative to well-characterised contact pesticides. Similarly, the selective pressures that lead to resistance against field sprays differ dramatically from those encountered during fumigation. The consequences of these differences have not been investigated adequately. We determine the genetic basis of phosphine resistance in Rhyzopertha dominica strains collected from New South Wales and South Australia and compare this with resistance in a previously characterised strain from Queensland. The resistance levels range from 225 and 100 times the baseline response of a sensitive reference strain. Moreover, molecular and phenotypic data indicate that high-level resistance was derived independently in each of the three widely separated geographical regions. Despite the independent origins, resistance was due to two interacting genes in each instance. Furthermore, complementation analysis reveals that all three strains contain an incompletely recessive resistance allele of the autosomal rph1 resistance gene. This is particularly noteworthy as a resistance allele at rph1 was previously proposed to be a necessary first step in the evolution of high-level resistance. Despite the capacity of phosphine to disrupt a wide range of enzymes and biological processes, it is remarkable that the initial step in the selection of resistance is so similar in isolated outbreaks.

Mau, Yosep S.; Collins, Patrick J.; Daglish, Gregory J.; Nayak, Manoj K.; Pavic, Hervoika; Ebert, Paul R.

2012-01-01

317

Comparative Analysis of Multilocus Sequence Typing and Pulsed-Field Gel Electrophoresis for Characterizing Listeria monocytogenes Strains Isolated from Environmental and Clinical Sources  

PubMed Central

One hundred seventy-five Listeria monocytogenes strains were characterized by serotyping, pulsed-field gel electrophoresis (PFGE), and multilocus sequence typing (MLST) based on loci in actA, betL, hlyA, gyrB, pgm, and recA. One hundred twenty-two sequence types (STs) were identified by MLST based on allelic profiles of the four housekeeping genes (betL, gyrB, pgm, and recA), and 34 and 38 alleles were identified for hlyA and actA, respectively. Several actA and hlyA alleles appeared to be predominantly associated with clinical isolates. MLST differentiated most of the L. monocytogenes strains better than did PFGE, and the discriminating ability of PFGE was better than that of serotyping. Several strains with different serotypes were found, by MLST and PFGE, to have very closely related genetic backgrounds, which suggested possible “antigen switching” among them. MLST can be a useful typing tool for differentiating L. monocytogenes strains (including strains undistinguishable by PFGE typing and serotyping), and it may be of value during investigations of food-borne outbreaks of listeriosis.

Revazishvili, Tamara; Kotetishvili, Mamuka; Stine, O. Colin; Kreger, Arnold S.; Morris, J. Glenn; Sulakvelidze, Alexander

2004-01-01

318

Comparative analysis of multilocus sequence typing and pulsed-field gel electrophoresis for characterizing Listeria monocytogenes strains isolated from environmental and clinical sources.  

PubMed

One hundred seventy-five Listeria monocytogenes strains were characterized by serotyping, pulsed-field gel electrophoresis (PFGE), and multilocus sequence typing (MLST) based on loci in actA, betL, hlyA, gyrB, pgm, and recA. One hundred twenty-two sequence types (STs) were identified by MLST based on allelic profiles of the four housekeeping genes (betL, gyrB, pgm, and recA), and 34 and 38 alleles were identified for hlyA and actA, respectively. Several actA and hlyA alleles appeared to be predominantly associated with clinical isolates. MLST differentiated most of the L. monocytogenes strains better than did PFGE, and the discriminating ability of PFGE was better than that of serotyping. Several strains with different serotypes were found, by MLST and PFGE, to have very closely related genetic backgrounds, which suggested possible "antigen switching" among them. MLST can be a useful typing tool for differentiating L. monocytogenes strains (including strains undistinguishable by PFGE typing and serotyping), and it may be of value during investigations of food-borne outbreaks of listeriosis. PMID:14715765

Revazishvili, Tamara; Kotetishvili, Mamuka; Stine, O Colin; Kreger, Arnold S; Morris, J Glenn; Sulakvelidze, Alexander

2004-01-01

319

Phenotypic variability among strains of Pasteurella multocida isolated from avian, bovine, caprine, leporine and ovine origin  

Microsoft Academic Search

Phenotypic diversity among 69 field isolates plus 3 vaccine strains previously identified as Pasteurella multocida were investigated by extended phenotypic characterization. The field isolates were obtained in Nigeria from chickens (15 isolates), quail (5 isolates), cattle (31 isolates), goats (7 isolates), sheep (8 isolates), rabbits (3 isolates) and the vaccine strains (3 isolates), which are used as prophylaxis against fowl

Sarah O. Ekundayo; Moses O. Odugbo; Atanda O. Olabode; Philip A. Okewole

2008-01-01

320

Influence of the crystal field stabilization energy of metal(II) ions on the structural distortion of matrix-isolated SO 42- guest ions in selenate matrices  

NASA Astrophysics Data System (ADS)

Infrared spectra of metal(II) selenate hydrates (MeSeO 4· nH 2O and Na 2Me(SeO 4) 2·2H 2O; n=6, 5, 4, 1; Me=Mg, Mn, Co, Ni, Cu, Zn, Cd) containing matrix-isolated SO 42- guest ions are reported and discussed with respect to the S?O stretching modes ?3 and ?1. An adequate measure for the SO 42- guest ion distortion is the site group splitting ? ?as (? ?ab and ? ?ac in the case of a doublet and a triplet for ?3, respectively; a, being the highest wavenumbered component of ?3) and ? ?max (the difference between the highest and the lowest wavenumbered S?O stretching modes). It has been shown that the SO 42- guest ion distortion depends on both the number of the sulfate oxygen atoms involved in coordinative bonds with the metal(II) ions and the electronic configuration of the metal(II) ions, i.e. their crystal field stabilization energy (CFSE) additionally to the site symmetry and the local potential at the lattice site of the host lattice. The SO 42- guest ions matrix-isolated in MeSeO 4·H 2O (Me=Mn, Co, Zn) and in Na 2Me(SeO 4) 2·2H 2O (Me=Mn, Cu, Cd) exhibit three bands corresponding to the ?3 modes as deduced from the site group analysis and ? ?ab?? ?bc. When SO 42- guest ions are incorporated in the triclinic Na 2Me(SeO 4) 2·2H 2O host lattices (Me=Co, Ni, Zn) the ?3 stretching region resembles a higher local symmetry of the SO 42- guest ions (an approximate (A 1?E) splitting) than the crystallographic one (i.e. ? ?ab>? ?bc instead of ? ?ab?? ?bc) and, hence, the ratio ? ?ab/? ?bc has to be taken into account (the higher value of the ratio ? ?ab/? ?bc, the weaker is the distortion of the SO 42- guest ions). The SO 42- guest ions incorporated in MeSeO 4· nH 2O ( n=6, 5, 4) exhibit a higher local symmetry of the guest ions than that deduced from the site group analysis (D 2d for the SO 42- guest ions in MeSeO 4·5H 2O, MeSeO 4·4H 2O and in the monoclinic MeSeO 4·6H 2O host lattices and close to T d in the tetragonal MeSeO 4·6H 2O host lattices). The analysis of the infrared spectra of selenate host lattices containing SO 42- guest ions reveals that the guest ions are stronger distorted when the adjacent metal(II) ions have CFSE?0. These ions are more resistant to angular deformations of the MeO 6-octahedra (i.e. changes in the O?Me?O bond angles), thus facilitating the SO 42- guest ion distortion as compared to those having CFSE=0 which allow stronger angular deformations of the respective metal octahedra. Infrared spectra of kieserite-type compounds MeSeO 4·H 2O (Me=Mn, Co, Zn) containing matrix-isolated SO 42- guest ions and Me' 2+ guest ions different from those of the host ions (i.e. Me'SO 4·H 2O in MeSeO 4·H 2O) are also presented and discussed (double matrix-spectroscopy).

Stoilova, Donka

2004-08-01

321

The role of nanominerals and mineral nanoparticles in the transport of toxic trace metals: Field-flow fractionation and analytical TEM analyses after nanoparticle isolation and density separation  

NASA Astrophysics Data System (ADS)

Nanominerals and mineral nanoparticles from a mining-contaminated river system were examined to determine their potential to co-transport toxic trace metals. A recent large-scale dam removal project on the Clark Fork River in western Montana (USA) has released reservoir and upstream sediments contaminated with toxic trace metals (Pb, As, Cu and Zn), which had accumulated there as a consequence of more than a century and a half of mining activity proximal to the river's headwaters near the cities of Butte and Anaconda. To isolate the high-density nanoparticle fractions from riverbed and bank sediments, a density separation with sodium polytungstate (2.8 g/cm3) was employed prior to a standard nanoparticle extraction procedure. The stable, dispersed nanoparticulate fraction was then analyzed by analytical transmission electron microscopy (aTEM) and flow field-flow fractionation (FlFFF) coupled to both multi-angle laser light scattering (MALLS) and high-resolution, inductively coupled plasma mass spectrometry (HR-ICPMS). FlFFF analysis revealed a size distribution in the nano range and that the elution profiles of the trace metals matched most closely to that for Fe and Ti. aTEM confirmed these results as the majority of the Fe and Ti oxides analyzed were associated with one or more of the trace metals of interest. The main mineral phases hosting trace metals are goethite, ferrihydrite and brookite. This demonstrates that they are likely playing a significant role in dictating the transport and distribution of trace metals in this river system, which could affect the bioavailability and toxicity of these metals.

Plathe, Kelly L.; von der Kammer, Frank; Hassellöv, Martin; Moore, Johnnie N.; Murayama, Mitsuhiro; Hofmann, Thilo; Hochella, Michael F.

2013-02-01

322

Analysis of genetic and molecular identity among field isolates of the rice blast fungus with an international differential system, rep-PCR and DNA sequencing  

Technology Transfer Automated Retrieval System (TEKTRAN)

The Pi-ta gene deployed in the Southern US rice germplasm is effective in preventing the infection by strains of Magnaporthe oryzae isolates that carry the avirulence gene AVR-Pita1. In the present study, a total of 169 isolates from rice (Oryza sativa) cultivars, with and without Pi-ta, were analyz...

323

Genomic analysis using pulsed-field gel electrophoresis of Escherichia coli 0157:H7 isolated from dairy calves during the United States national dairy heifer evaluation project (1991–1992)  

Microsoft Academic Search

The genomic fingerprints of 26 Escherichia coli 0157:H7 isolates from calves on 20 farms in 16 states were determined by pulsed-field gel electrophoresis (PFGE). Digestion of genomic DNAs with the restriction enzymes SfiI and XbaI yielded 14 and 18 restriction endonuclease digestion profiles (REDP), respectively. Seventeen farms (85%) had E. coli 0157:H7 with a unique REDP, and when more than

Moon-Sil Lee; Charles W. Kaspar; Roland Brosch; Jack Shere; John B. Luchansky

1996-01-01

324

Comparison of Multiple-Locus Variable-Number Tandem-Repeat Analysis with Pulsed-Field Gel Electrophoresis, spa Typing, and Multilocus Sequence Typing for Clonal Characterization of Staphylococcus aureus Isolates  

Microsoft Academic Search

Multiple-locus variable-number tandem-repeat analysis (MLVA), a new PCR-based method of typing Staph- ylococcus aureus, was compared to pulsed-field gel electrophoresis (PFGE), spa typing, and multilocus sequence typing (MLST) on a group of 59 S. aureus (mostly methicillin-resistant) clinical isolates. The aim of the study was to establish possible criteria of clustering MLVA patterns and to check concordance levels between the

Natalia Malachowa; Artur Sabat; Marek Gniadkowski; Jolanta Krzyszton-Russjan; Joanna Empel; Jacek Miedzobrodzki; Klaudia Kosowska-Shick; Peter C. Appelbaum; Waleria Hryniewicz

2005-01-01

325

Polymorphic Amplified Typing Sequences and Pulsed-Field Gel Electrophoresis Yield Comparable Results in the Strain Typing of a Diverse Set of Bovine Escherichia coli O157:H7 Isolates.  

PubMed

Polymorphic amplified typing sequences (PATS), a PCR-based Escherichia coli O157:H7 (O157) strain typing system, targets insertions-deletions and single nucleotide polymorphisms at XbaI and AvrII restriction enzyme sites, respectively, and the virulence genes (stx1, stx2, eae, hlyA) in the O157 genome. In this study, the ability of PATS to discriminate O157 isolates associated with cattle was evaluated. An in-depth comparison of 25 bovine O157 isolates, from different geographic locations across Northwest United States, showed that about 85% of these isolates shared the same dendogram clade by PATS and pulsed-field gel electrophoresis (PFGE), irrespective of the restriction enzyme sites targeted. The Pearson's correlation coefficient, r, calculated at about 0.4, 0.3, and 0.4 for XbaI-based, AvrII-based and combined-enzymes PATS and PFGE similarities, respectively, indicating that these profiles shared a good but not high correlation, an expected inference given that the two techniques discriminate differently. Isolates that grouped differently were better matched to their locations using PATS. Overall, PATS discriminated the bovine O157 isolates without interpretive biases or sophisticated analytical software, and effectively complemented while not duplicating PFGE. With its quick turnaround time, PATS has excellent potential as a convenient tool for early epidemiological or food safety investigations, enabling rapid notification/implementation of quarantine measures. PMID:23049559

Kudva, Indira T; Davis, Margaret A; Griffin, Robert W; Garren, Jeonifer; Murray, Megan; John, Manohar; Hovde, Carolyn J; Calderwood, Stephen B

2012-08-07

326

Polymorphic Amplified Typing Sequences and Pulsed-Field Gel Electrophoresis Yield Comparable Results in the Strain Typing of a Diverse Set of Bovine Escherichia coli O157:H7 Isolates  

PubMed Central

Polymorphic amplified typing sequences (PATS), a PCR-based Escherichia coli O157:H7 (O157) strain typing system, targets insertions-deletions and single nucleotide polymorphisms at XbaI and AvrII restriction enzyme sites, respectively, and the virulence genes (stx1, stx2, eae, hlyA) in the O157 genome. In this study, the ability of PATS to discriminate O157 isolates associated with cattle was evaluated. An in-depth comparison of 25 bovine O157 isolates, from different geographic locations across Northwest United States, showed that about 85% of these isolates shared the same dendogram clade by PATS and pulsed-field gel electrophoresis (PFGE), irrespective of the restriction enzyme sites targeted. The Pearson's correlation coefficient, r, calculated at about 0.4, 0.3, and 0.4 for XbaI-based, AvrII-based and combined-enzymes PATS and PFGE similarities, respectively, indicating that these profiles shared a good but not high correlation, an expected inference given that the two techniques discriminate differently. Isolates that grouped differently were better matched to their locations using PATS. Overall, PATS discriminated the bovine O157 isolates without interpretive biases or sophisticated analytical software, and effectively complemented while not duplicating PFGE. With its quick turnaround time, PATS has excellent potential as a convenient tool for early epidemiological or food safety investigations, enabling rapid notification/implementation of quarantine measures.

Kudva, Indira T.; Davis, Margaret A.; Griffin, Robert W.; Garren, Jeonifer; Murray, Megan; John, Manohar; Hovde, Carolyn J.; Calderwood, Stephen B.

2012-01-01

327

Complete genome sequence of a porcine epidemic diarrhea virus variant.  

PubMed

In 2011, outbreaks of viral diarrhea were observed on most swine-breeding farms in most of the provinces of China. The disease is characterized by vomiting, severe diarrhea, and a high mortality rate (82.3%) in newborn piglets. The clinical appearance was similar to that of porcine epidemic diarrhea virus (PEDV) infection. PEDVs were detected in samples (feces or small intestines) from most farms. In order to investigate whether there is a PEDV variant circulating in China, we sequenced and analyzed the complete genome of the recently identified field strain, CH/FJND-3/2011. The sequence data indicate that this PEDV variant prevails in China. PMID:22354946

Chen, Jianfei; Liu, Xiaozhen; Shi, Da; Shi, Hongyan; Zhang, Xin; Feng, Li

2012-03-01

328

Effects of macroscopic propagation on spectra of broadband supercontinuum harmonics and isolated-attosecond-pulse generation: Coherent control of the electron quantum trajectories in two-color laser fields  

NASA Astrophysics Data System (ADS)

Recently it was shown that broadband supercontinuum harmonics can be produced from the long-trajectory electrons in the single-atom response by the coherent control of the electron trajectories through optimized two-color laser fields. Such supercontinuum harmonics can be superposed to generate an isolated sub-30-attosecond (as) pulse [Liu , Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.84.033414 84, 033414 (2011)]. In this paper, we investigate the effect of macroscopic propagation on the supercontinuum harmonic spectra and the subsequent attosecond-pulse generation of atomic hydrogen. The time-dependent Schrödinger equation is solved accurately and efficiently by means of the time-dependent generalized pseudospectral method. The effects of macroscopic propagation are investigated in near and far field by solving Maxwell's equation. The results show that the contribution of short-trajectory electron emission is increased when the macroscopic propagation is considered. However, the characteristics of the dominant long-trajectory electron emission (in the single-atom response case) are not changed, and an isolated 53 as pulse can be generated in the near field. Moreover, in the far field, the contribution of long-trajectory electron emission is still dominant for both on-axis and off-axis cases. As a result, an isolated 42 as pulse can be generated directly. Similar results are obtained when the atomic target position is changed. Therefore, the proposed method for the single ultrashort attosecond-pulse generation can be realized by means of the coherent control of the electron quantum paths in appropriately optimized two-color laser fields.

Li, Peng-Cheng; Chu, Shih-I.

2012-07-01

329

Cloning and Sequence Analysis of the Spike Gene of Porcine Epidemic Diarrhea Virus Chinju99  

Microsoft Academic Search

The spike (S) gene of the porcine epidemic diarrhea virus (PEDV) Chinju99 which was previously isolated in Chinju, Korea was cloned and sequenced to aid in the development of genetically engineered vaccines and diagnostic reagents against PEDV. The nucleotide sequence encoding the entire S gene open reading frame (ORF) of Chinju99 was 4152 bases long encoding 1383 amino acids. It

Sang-Geon Yeo; Mercedes Hernandez; Peter J. Krell; Éva É Nagy

2003-01-01

330

Cloning and sequence analysis of the Korean strain of spike gene of porcine epidemic diarrhea virus and expression of its neutralizing epitope in plants  

Microsoft Academic Search

Porcine epidemic diarrhea virus (PEDV) causes acute diarrhea and dehydration in pigs and leads to death with a high mortality rate, which has been reported notably in Korea. The spike (S) gene of the PEDV isolated in Korea was cloned and sequenced. The nucleotide sequence encoding the entire S gene open reading frame of Korean strain was 4161 bases long

Tae-Jin Kang; Jo-Eun Seo; Dae-Hyuk Kim; Tae-Geum Kim; Yong-Suk Jang; Moon-Sik Yang

2005-01-01

331

Isolations of Jamestown Canyon virus (Bunyaviridae: Orthobunyavirus) from field-collected mosquitoes (Diptera: Culicidae) in Connecticut, USA: a ten-year analysis, 1997-2006.  

PubMed

Jamestown Canyon virus (JCV) (Bunyaviridae: Orthobunyavirus) is a mosquito-borne zoonosis belonging to the California serogroup. It has a wide geographic distribution, occurring throughout much of temperate North America. White-tailed deer, Odocoileus virginianus are the principal amplification hosts, and boreal Aedes and Ochlerotatus mosquitoes are the primary vectors. A 10-year study was undertaken to identify potential mosquito vectors in Connecticut, quantify seasonal prevalence rates of infection, and define the geographic distribution of JCV in the state as a function of land use and white-tailed deer populations, which have increased substantially over this period. Jamestown Canyon virus was isolated from 22 mosquito species. Five of them, Ochlerotatus canadensis, Oc. cantator, Anopheles punctipennis, Coquillettidia perturbans, and Oc. abserratus were incriminated as the most likely vectors, based on yearly isolation frequencies and the spatial geographic distribution of infected mosquitoes. Jamestown Canyon virus was isolated from Oc. canadensis more consistently and from a greater range of collection sites than any other species. Frequent virus isolations were also made from Aedes cinereus, Aedes vexans, and Oc. sticticus, and new North American isolation records were established for Anopheles walkeri, Culex restuans, Culiseta morsitans, Oc. sticticus, Oc. taeniorhynchus, and Psorophora ferox. Other species from which JCV was isolated included C. melanura, Oc. aurifer, Oc. communis, Oc. excrucians, Oc. provocans, Oc. sollicitans, Oc. stimulans, Oc. triseriatus, and Oc. trivittatus. Jamestown Canyon virus was widely distributed throughout Connecticut and found to consistently circulate in a diverse array of mosquito vectors. Infected mosquitoes were collected from June through September, and peak infection rates paralleled mosquito abundance from mid-June through mid-July. Infection rates in mosquitoes were consistent from year to year, and overall virus activity was directly related to local mosquito abundance. Infected mosquitoes were equally distributed throughout the state, irrespective of land use, and infection rates were not directly associated with the abundance of white-tailed deer, possibly because of their saturation throughout the region. PMID:18386967

Andreadis, Theodore G; Anderson, John F; Armstrong, Philip M; Main, Andrew J

2008-04-01

332

Ardenticatena maritima gen. nov., sp. nov., a ferric iron- and nitrate-reducing bacterium of the phylum 'Chloroflexi' isolated from an iron-rich coastal hydrothermal field, and description of Ardenticatenia classis nov.  

PubMed

A novel thermophilic, chemoheterotrophic, Gram-negative-staining, multicellular filamentous bacterium, designated strain 110S(T), was isolated from an iron-rich coastal hydrothermal field in Japan. The isolate is facultatively aerobic and chemoheterotrophic. Phylogenetic analysis using 16S rRNA gene sequences nested strain 110S(T) in a novel class-level clone cluster of the phylum 'Chloroflexi'. The isolate grows by dissimilatory iron- and nitrate-reduction under anaerobic conditions, which is the first report of these abilities in the phylum 'Chloroflexi'. The organism is capable of growth with oxygen, ferric iron and nitrate as a possible electron acceptor, has a wide range of growth temperatures, and tolerates higher NaCl concentrations for growth compared to the other isolates in the phylum. Using phenotypic and phylogenetic data, strain 110S(T) (= JCM 17282(T) = NBRC 107679(T) = DSM 23922(T) = KCTC 23289(T) = ATCC BAA-2145(T)) is proposed as the type strain of a novel species in a new genus, Ardenticatena maritima gen. nov., sp. nov. In addition, as strain 110S(T) apparently constitutes a new class of the phylum 'Chloroflexi' with other related uncultivated clone sequences, we propose Ardenticatenia classis nov. and the subordinate taxa Ardenticatenales ord. nov. and Ardenticatenaceae fam. nov. PMID:23378114

Kawaichi, Satoshi; Ito, Norihiro; Kamikawa, Ryoma; Sugawara, Tatsuya; Yoshida, Takashi; Sako, Yoshihiko

2013-02-01

333

Development and field placement of an expansive salt-saturated concrete (ESC) for the Waste Isolation Pilot Plant (WIPP). Final report  

Microsoft Academic Search

An expansive salt-saturated concrete (ESC) was proportioned for placement underground in halite rock at the Waste Isolation Pilot Plant (WIPP) site, near Carlsbad, New Mexico. Requirements for this concrete were: (1) to be chemically compatible with the host rock; (2) to remain pumpable for four hours: (3) to give net volume increase beginning at an early age, and continuing until

L. D. Wakeley; D. M. Walley

1986-01-01

334

A user friendly method to isolate and single spore the fungi Magnaporthe oryzae and Magnaporthe grisea obtained from diseased field samples  

Technology Transfer Automated Retrieval System (TEKTRAN)

The fungus Magnaporthe oryzae is the causal agent for a wide range of plant diseases including diseases of rice, wheat, rye grass, turfgrass and pearl millet. A simple robust procedure for fungal isolation is not publicly available. In the present study, a user friendly method was developed to iso...

335

Escherichia coli strains isolated from the uterus and urinary bladder of bitches suffering from pyometra: comparison by restriction enzyme digestion and pulsed-field gel electrophoresis  

Microsoft Academic Search

Pyometra (uterine inflammation with accumulation of pus in the uterus) is regarded as one of the most common illnesses in bitches. The ethiology and pathogenesis are complex with both hormonal and bacterial elements. The bacteria most frequently isolated from the uterine content is Escherichia coli.In this study, 84 E. coli strains from the uteri of 70 bitches suffering from the

Ragnvi Hagman; Inger Kühn

2002-01-01

336

COMPARATIVE EVALUATION OF AN AUTOMATED RIBOTYPING SYSTEM VERSUS PULSED-FIELD GEL ELECTROPHORESIS FOR EPIDEMIOLOGY TYPING OF VETERINARY ISOLATES OF SALMONELLA ENTERICA SEROTYPE TYPHIMURIUM DT104  

Technology Transfer Automated Retrieval System (TEKTRAN)

Salmonella infections continue to be a problem in industrialized countries. The strain of Salmonella enterica serotype typhimurium known as definitive phage type 104 (DT104) emerged as a major pathogen in Europe and has since isolated in the U.S. DT104 is of major concern as it is usually resistant ...

337

Genetic and phenotypic diversity of 2,4-dichlorophenoxyacetic acid (2,4-D)-degrading bacteria isolated from 2,4-D-treated field soils.  

PubMed Central

Forty-seven numerically dominant 2,4-dichlorophenoxyacetic acid (2,4-D)-degrading bacteria were isolated at different times from 1989 through 1992 from eight agricultural plots (3.6 by 9.1 m) which were either not treated with 2,4-D or treated with 2,4-D at three different concentrations. Isolates were obtained from the most dilute positive most-probable-number tubes inoculated with soil samples from the different plots on seven sampling dates over the 3-year period. The isolates were compared by using fatty acid methyl ester (FAME) profiles, chromosomal patterns obtained by PCR amplification of repetitive extragenic palindromic (REP) sequences, and hybridization patterns obtained with probes for the tfd genes of plasmid pJP4 and a probe (Spa probe) that detects a distinctly different 2,4-D-degrading isolate, Sphingomonas paucimobilis (formerly Pseudomonas paucimobilis). A total of 57% of the isolates were identified to the species level by the FAME analysis, and these isolates were strains of Sphingomonas, Pseudomonas, or Alcaligenes species. Hybridization analysis revealed four groups. Group I strains, which exhibited sequence homology with tfdA, -B, -C, and -D genes, were rather diverse, as determined by both the FAME analysis and the REP-PCR analysis. Group II, which exhibited homology only with the tfdA gene, was a small group and was probably a subset of group I. All group I and II strains had plasmids. Hybridization analysis revealed that the tfd genes were located on plasmids in 75% of these strains and on the chromosome or a large plasmid in the other 25% of the strains. One strain exhibited tfdA and -B hybridization associated with a plasmid band, while tfdC and -D hybridized with the chromosomal band area. The group III strains exhibited no detectable homology to tfd genes but hybridized to the Spa probe. The members of this group were tightly clustered as determined by both the FAME analysis and the REP-PCR analysis, were distinctly different from group I strains as determined by the FAME analysis, and had very few plasmids; this group contained more of the 47 isolates than any other group. The group III strains were identified as S. paucimobilis. The group IV strains, which hybridized to neither the tft prove nor the Spa probe, were as diverse as the group I strains as determined by the FAME and REP-PCR analyses. Most of group IV strains could not be identified by the FAME analysis.(ABSTRACT TRUNCATED AT 250 WORDS) Images

Ka, J O; Holben, W E; Tiedje, J M

1994-01-01

338

Isolation of cDNA clones for genes showing enhanced expression in barley leaves during dark-induced senescence as well as during senescence under field conditions  

Microsoft Academic Search

.   Senescence of barley (Hordeum vulgare L. cv. Carina) primary foliage leaves was induced by transfer of the plants into darkness for 2?d. Under these conditions\\u000a senescence was characterized by a light-reversible decline in the efficiency of photosystem II, and in chlorophyll and protein\\u000a contents. To isolate senescence-associated genes a differential display of cDNA fragments amplified from reversely transcribed\\u000a RNA

Tamara Kleber-Janke; Karin Krupinska

1997-01-01

339

Comparison of rt pcr assay and virus isolation in cell cultures for the detection of bovine viral diarrhoea virus ( bvdv) in field samples  

Microsoft Academic Search

The virus isolation-immunoperoxidase test (ipx) on cell cultures and the reverse transcription-polymerase chain reaction (rt-pcr) assay were compared for the detection of bovine viral diarrhoea virus (bvdv) directly in serum samples. Material for this study consisted of 403 sera originating from cattle in 41 bvdv-infected Finnish dairy herds and one suckler cow herd. The presence of virus was demonstrated in

U. I Laamanen; E. P Neuvonen; E. M Yliviuhkola; P. M.-L Veijalainen

1997-01-01

340

Hot-Carrier Lifetime Dependence on Channel Width and Silicon Recess Depth in N-Channel Metal-Oxide-Semiconductor Field-Effect-Transistors with the Recessed Local Oxidation of Silicon Isolation Structure  

NASA Astrophysics Data System (ADS)

Narrow width n-channel metal-oxide-semiconductor field-effect-transistors (nMOSFETs) fabricated with recessed local oxidation of silicon (R-LOCOS) isolation structures and deeper field oxide recess exhibit less hot-carrier degradation as compared to wide channel devices when stressed under the maximum substrate current condition. Through the investigation of many possible causes, such as channel stop doping effect, lateral channel electric field, mechanical stress effect, and recess depth effect, the cause of the smaller degradation in narrow channel nMOSFETs was found. This was due to a hole-attractive vertical electric field across the width of the narrow channel nMOSFET, which results in less interaction of the channel hot electrons with the silicon-silicon dioxide interface, and thus contributing to less interface-state generation. It was also found that a deeper field oxide recess in narrow channel nMOSFETs leads to lesser hot-carrier degradation, which is possibly related to the reduced impact ionization rate in the channel.

Chim, Wai Kin; Cho, Byung Jin; Yue, Jeffrey Mun Pun

2002-01-01

341

Genetic polymorphisms in the glutamate-rich protein of Plasmodium falciparum field isolates from a malaria-endemic area of Brazil.  

PubMed

The genetic diversity displayed by Plasmodium falciparum, the most deadly Plasmodium species, is a significant obstacle for effective malaria vaccine development. In this study, we identified genetic polymorphisms in P. falciparum glutamate-rich protein (GLURP), which is currently being tested in clinical trials as a malaria vaccine candidate, from isolates found circulating in the Brazilian Amazon at variable transmission levels. The study was performed using samples collected in 1993 and 2008 from rural villages situated near Porto Velho, in the state of Rondônia. DNA was extracted from 126 P. falciparum-positive thick blood smears using the phenol-chloroform method and subjected to a nested polymerase chain reaction protocol with specific primers against two immunodominant regions of GLURP, R0 and R2. Only one R0 fragment and four variants of the R2 fragment were detected. No differences were observed between the two time points with regard to the frequencies of the fragment variants. Mixed infections were uncommon. Our results demonstrate conservation of GLURP-R0 and limited polymorphic variation of GLURP-R2 in P. falciparum isolates from individuals living in Porto Velho. This is an important finding, as genetic polymorphisms in B and T-cell epitopes could have implications for the immunological properties of the antigen. PMID:23828006

Pratt-Riccio, Lilian Rose; Perce-da-Silva, Daiana de Souza; Lima-Junior, Josué da Costa; Theisen, Michael; Santos, Fátima; Daniel-Ribeiro, Cláudio Tadeu; de Oliveira-Ferreira, Joseli; Banic, Dalma Maria

2013-06-01

342

Candidate isolated neutron stars and other optically blank x-ray fields identified from the rosat all-sky and sloan digital sky surveys  

SciTech Connect

Only seven radio-quiet isolated neutron stars (INSs) emitting thermal X rays are known, a sample that has yet to definitively address such fundamental issues as the equation of state of degenerate neutron matter. We describe a selection algorithm based on a cross-correlation of the ROSAT All-Sky Survey (RASS) and the Sloan Digital Sky Survey (SDSS) that identifies X-ray error circles devoid of plausible optical counterparts to the SDSS g {approx} 22 magnitudes limit. We quantitatively characterize these error circles as optically blank; they may host INSs or other similarly exotic X-ray sources such as radio-quiet BL Lacs, obscured AGN, etc. Our search is an order of magnitude more selective than previous searches for optically blank RASS error circles, and excludes the 99.9% of error circles that contain more common X-ray-emitting subclasses. We find 11 candidates, nine of which are new. While our search is designed to find the best INS candidates and not to produce a complete list of INSs in the RASS, it is reassuring that our number of candidates is consistent with predictions from INS population models. Further X-ray observations will obtain pinpoint positions and determine whether these sources are entirely optically blank at g {approx} 22, supporting the presence of likely isolated neutron stars and perhaps enabling detailed follow-up studies of neutron star physics.

Agueros, Marcel A.; Anderson, Scott F.; /Washington U., Seattle, Astron. Dept.; Margon, Bruce; /Baltimore, Space Telescope Sci.; Haberl, Frank; Voges, Wolfgang; /Garching, Max Planck Inst., MPE; Annis, James; /Fermilab; Schneider, Donald P.; /Penn State U., Astron. Astrophys.; Brinkmann, Jonathan; /Apache Point Observ.

2005-11-01

343

Comparison of Multilocus Sequence Typing, Pulsed-Field Gel Electrophoresis, and Antimicrobial Susceptibility Typing for Characterization of Salmonella enterica Serotype Newport Isolates  

Microsoft Academic Search

In the United States, multidrug-resistant phenotypes of Salmonella enterica serotype Newport (commonly referred to as MDR-AmpC) have emerged in animals and humans and have become a major public health problem. Although pulsed-field gel electrophoresis (PFGE) is the current \\

H. Harbottle; D. G. White; P. F. McDermott; R. D. Walker; S. Zhao

2006-01-01

344

Radioactive waste isolation in salt: geochemistry of brine in rock salt in temperature gradients and gamma-radiation fields - a selective annotated bibliography  

SciTech Connect

Evaluation of the extensive research concerning brine geochemistry and transport is critically important to successful exploitation of a salt formation for isolating high-level radioactive waste. This annotated bibliography has been compiled from documents considered to provide classic background material on the interactions between brine and rock salt, as well as the most important results from more recent research. Each summary elucidates the information or data most pertinent to situations encountered in siting, constructing, and operating a mined repository in salt for high-level radioactive waste. The research topics covered include the basic geology, depositional environment, mineralogy, and structure of evaporite and domal salts, as well as fluid inclusions, brine chemistry, thermal and gamma-radiation effects, radionuclide migration, and thermodynamic properties of salts and brines. 4 figs., 6 tabs.

Hull, A.B.; Williams, L.B.

1985-07-01

345

Isolation of Sox11a, Sox11b and Sox19 genes from Rice field eel (Monopterus albus) using degenerate primers and nested PCR  

Microsoft Academic Search

:   Sox proteins belong to the HMG box-containing family of DNA-binding proteins and are found in vertebrates. They have diverse\\u000a functions in the regulation of development. We present here the two kinds of Sox genes, the Sox11, Sox11a and Sox11b, and\\u000a the Sox19 genes from rice field eel (Monopterus albus) using highly degenerate and nested PCR. All the three Sox

Li Liu; Rongjia Zhou

2001-01-01

346

Distribution of repC plasmid-replication sequences among plasmids and isolates of Rhizobium leguminosarum bv. viciae from field populations  

Microsoft Academic Search

The distribution of four classes of related plasmid replication genes (repC) within three field populations of Rhizobium leguminosarum in France, Germany and the UK was investigated using RFLP, PCR-RFLP and plasmid profile analysis. The results suggest that the four repC classes are compatible: when two or more different repC sequences are present in a strain they are usually associated with

Lionel Rigottier-Gois; Sarah L. Turner; J. P. W. Young; N. Amarger

1998-01-01

347

Origin, evolution, and genotyping of emergent porcine epidemic diarrhea virus strains in the United States.  

PubMed

ABSTRACT Coronaviruses are known to infect humans and other animals and cause respiratory and gastrointestinal diseases. Here we report the emergence of porcine epidemic diarrhea virus (PEDV) in the United States and determination of its origin, evolution, and genotypes based on temporal and geographical evidence. Histological lesions in small intestine sections of affected pigs and the complete genomic sequences of three emergent strains of PEDV isolated from outbreaks in Minnesota and Iowa were characterized. Genetic and phylogenetic analyses of the three U.S. strains revealed a close relationship with Chinese PEDV strains and their likely Chinese origin. The U.S. PEDV strains underwent evolutionary divergence, which can be classified into two sublineages. The three emergent U.S. strains are most closely related to a strain isolated in 2012 from Anhui Province in China, which might be the result of multiple recombination events between different genetic lineages or sublineages of PEDV. Molecular clock analysis of the divergent time based on the complete genomic sequences is consistent with the actual time difference, approximately 2 to 3 years, of the PED outbreaks between China (December 2010) and the United States (May 2013). The finding that the emergent U.S. PEDV strains share unique genetic features at the 5'-untranslated region with a bat coronavirus provided further support of the evolutionary origin of PEDV from bats and potential cross-species transmission. The data from this study have important implications for understanding the ongoing PEDV outbreaks in the United States and will guide future efforts to develop effective preventive and control measures against PEDV. IMPORTANCE The sudden emergence of porcine epidemic diarrhea virus (PEDV), a coronavirus, for the first time in the United States causes significant economic and public health concerns. Since its recognition in May 2013, PEDV has rapidly spread across the United States, resulting in high mortality in piglets in more than 17 States now. The ongoing outbreaks of Middle East respiratory syndrome coronavirus in humans from countries in or near the Arabian Peninsula and the historical deadly nature of the 2002 outbreaks of severe acute respiratory syndrome coronavirus create further anxiety over the emergence of PEDV in the United States due to the lack of scientific information about the origin and evolution of this emerging coronavirus. Here we report the detailed genetic characterization, origin, and evolution of emergent PEDV strains in the United States. The results provide much needed information to devise effective preventive and control strategies against PEDV in the United States. PMID:24129257

Huang, Yao-Wei; Dickerman, Allan W; Piñeyro, Pablo; Li, Long; Fang, Li; Kiehne, Ross; Opriessnig, Tanja; Meng, Xiang-Jin

2013-10-15

348

Social isolation  

PubMed Central

Social species, by definition, form organizations that extend beyond the individual. These structures evolved hand in hand with behavioral, neural, hormonal, cellular, and genetic mechanisms to support them because the consequent social behaviors helped these organisms survive, reproduce, and care for offspring sufficiently long that they too reproduced. Social isolation represents a lens through which to investigate these behavioral, neural, hormonal, cellular, and genetic mechanisms. Evidence from human and nonhuman animal studies indicates that isolation heightens sensitivity to social threats (predator evasion) and motivates the renewal of social connections. The effects of perceived isolation in humans share much in common with the effects of experimental manipulations of isolation in nonhuman social species: increased tonic sympathetic tonus and HPA activation, and decreased inflammatory control, immunity, sleep salubrity, and expression of genes regulating glucocorticoid responses. Together, these effects contribute to higher rates of morbidity and mortality in older adults.

Cacioppo, John T.; Hawkley, Louise C.; Norman, Greg J.; Berntson, Gary G.

2011-01-01

349

New Degradation Mechanisms of Width-Dependent Hot Carrier Effect in Quarter-Micron Shallow-Trench-Isolated p-Channel Metal-Oxide-Semiconductor Field-Effect-Transistors  

NASA Astrophysics Data System (ADS)

In this study, width-dependent hot-carrier degradation in the p-channel metal-oxide-semiconductor field-effect transistors (p-MOSFETs) with shallow-trench-isolation (STI) is presented. Results show an enhanced drain current degradation with reducing the gate width. A new model and mechanism are proposed to explain the width-dependent hot-carrier (HC) degradation for p-MOSFETs. Based on a two-dimensional channel shortening concept, a new model is developed. The mechanical stress enhanced oxide damage at the STI edge, which will induce channel shortening, is the dominant mechanism for the drain current degradation of the devices after hot-carrier stress. This is a crucial issue for present and future complementary metal-oxide semiconductor (CMOS) ultra-large-scale integration (ULSI), and in particular for high-density dynamic random-access memory (DRAM), fabricated using STI technologies.

Chung, Steve S.; Chen, Shang-Jr; Yang, Wen-Jei; Yih, Cherng-Ming; Yang, Jiuun-Jer

2001-01-01

350

Molecular Characterization and Phylogenetic Analysis of New Variants of the Porcine Epidemic Diarrhea Virus in Gansu, China in 2012  

PubMed Central

Between January 2012 and March 2012, the infection rates of porcine epidemic diarrhea virus (PEDV) increased substantially in vaccinated swine herds in many porcine farms in Gansu Province, China. The spike (S) glycoprotein is an important determinant for PEDV biological properties. To determine the distribution profile of PEDV outbreak strains, we sequenced the full-length S gene of five samples from two farms where animals exhibited severe diarrhea and high mortality rates. Five new PEDV variants were identified, and the molecular diversity, phylogenetic relationships, and antigenicity analysis of Gansu field samples with other PEDV reference strains were investigated. A series of insertions, deletions, and mutations in the S gene was found in five PEDV variants compared with classical and vaccine strains. These mutations may provide stronger pathogenicity and antigenicity to the new PEDV variants that influenced the effectiveness of the CV777-based vaccine. Our results suggest that these new PEDV variant strains in Gansu Province might be from South Korean or South China, and the effectiveness of the CV777-based vaccine needs to be evaluated.

Tian, Yufei; Yu, Zhijun; Cheng, Kaihui; Liu, Yuxiu; Huang, Jing; Xin, Yue; Li, Yuanguo; Fan, Shengtao; Wang, Tiecheng; Huang, Geng; Feng, Na; Yang, Zhenguo; Yang, Songtao; Gao, Yuwei; Xia, Xianzhu

2013-01-01

351

Isolation of a wheat (Triticum aestivum L.) mutant in ABA 8?-hydroxylase gene: effect of reduced ABA catabolism on germination inhibition under field condition  

PubMed Central

Pre-harvest sprouting, the germination of mature seeds on the mother plant under moist condition, is a serious problem in cereals. To investigate the effect of reduced abscisic acid (ABA) catabolism on germination in hexaploid wheat (Triticum aestivum L.), we cloned the wheat ABA 8?-hydroxyase gene which was highly expressed during seed development (TaABA8?OH1) and screened for mutations that lead to reduced ABA catabolism. In a screen for natural variation, one insertion mutation in exon 5 of TaABA8?OH1 on the D genome (TaABA8?OH1-D) was identified in Japanese cultivars including ‘Tamaizumi’. However, a single mutation in TaABA8?OH1-D had no clear effect on germination inhibition in double haploid lines. In a screen for a mutation, one deletion mutant lacking the entire TaABA8?OH1 on the A genome (TaABA8?OH1-A), TM1833, was identified from gamma-ray irradiation lines of ‘Tamaizumi’. TM1833 (a double mutant in TaABA8?OH1-A and TaABA8?OH1-D) showed lower TaABA8?OH1 expression, higher ABA content in embryos during seed development under field condition and lower germination than those in ‘Tamaizumi’ (a single mutant in TaABA8?OH1-D). These results indicate that reduced ABA catabolism through mutations in TaABA8?OH1 may be effective in germination inhibition in field-grown wheat.

Chono, Makiko; Matsunaka, Hitoshi; Seki, Masako; Fujita, Masaya; Kiribuchi-Otobe, Chikako; Oda, Shunsuke; Kojima, Hisayo; Kobayashi, Daisuke; Kawakami, Naoto

2013-01-01

352

Geotail observations of energetic ion species and magnetic field in plasmoid-like structures in the course of an isolated substorm event  

SciTech Connect

On January 15, 1994, the ion spectrometer high energy particle{endash}low energy particle detector (HEP-LD) on the Japanese spacecraft Geotail observed five quasi-periodic energetic ion bursts in the deep tail (X={minus}96R{sub E}). These bursts were associated with plasmoid-like structures in the magnetic field components. In addition, three multiple TCR groups were identified in the interval. The observations in the distant tail occurred during a time interval of substorm activity which also produced multiple injections in the geosynchronous orbit region. The HEP-LD observations show that B{sub z} bipolar plasmoid-like structures are associated with tailward flowing particle bursts. However, earthward flowing particle bursts are predominantly associated with bipolar signatures in B{sub y}. In addition, an oxygen burst was seen in the back of a plasmoid (postplasmoid) which showed both B{sub y} and B{sub z} bipolar magnetic field signatures. The oxygen burst lasted for 23 min, and the density ratio (O/H) reached 15{percent} for the HEP-LD energy range (in the same plasmoid, this ratio was approximately 1{percent} before the oxygen burst). The oxygen burst exhibited a strong beam-like structure which occupied only 6{approximately}7{percent} of the full solid angle (4{pi}). We suggest that energized oxygen ions of ionospheric origin travel downtail in the narrow postplasmoid-plasma sheet which trails the plasmoid. Furthermore, we suggest that the magnetosphere dissipated larger quantities of energy during this very intense substorm event by ejecting multiple relatively small plasmoids rather than through the formation and ejection of a single large plasmoid.{copyright} 1997 American Geophysical Union

Zong, Q.; Wilken, B. [Max-Planck-Institut fuer Aeronomie, Katlenburg-Lindau (Germany); Reeves, G.D. [Los Alamos National Laboratory, Los Alamos, New Mexico (United States); Daglis, I.A. [Max-Planck-Institut fuer Aeronomie, Katlenburg-Lindau (Germany)]|[Institute of Ionospheric and Space Research, National Observatory of Athens (Greece); Doke, T. [Department of Physics, Nagoya University, Nagoya (Japan); Iyemori, T. [WDC-C2 for Geomagnetism, Faculty of Science, Kyoto University, Kyoto (Japan); Livi, S. [Max-Planck-Institut fuer Aeronomie, Katlenburg-Lindau (Germany); Maezawa, K. [Advanced Research Center for Science and Engineering, Waseda University, Tokyo (Japan); Mukai, T. [Institute of Space Astronautical and Science, Kanagawa (Japan); Kokubun, S. [Solar-Terrestrial Environment Laboratory, Nagoya University, Toyokawa (Japan); Pu, Z. [Department of Geophysics, Peking University, Beijing (China); Ullaland, S. [University of Bergen, Bergen (Norway); Woch, J. [Max-Planck-Institut fuer Aeronomie, Katlenburg-Lindau (Germany); Lepping, R. [NASA Goddard Space Flight Center, Greenbelt, Maryland (United States); Yamamoto, T. [Institute of Space Astronautical and Science, Kanagawa (Japan)

1997-06-01

353

Isolation of a wheat (Triticum aestivum L.) mutant in ABA 8'-hydroxylase gene: effect of reduced ABA catabolism on germination inhibition under field condition.  

PubMed

Pre-harvest sprouting, the germination of mature seeds on the mother plant under moist condition, is a serious problem in cereals. To investigate the effect of reduced abscisic acid (ABA) catabolism on germination in hexaploid wheat (Triticum aestivum L.), we cloned the wheat ABA 8'-hydroxyase gene which was highly expressed during seed development (TaABA8'OH1) and screened for mutations that lead to reduced ABA catabolism. In a screen for natural variation, one insertion mutation in exon 5 of TaABA8'OH1 on the D genome (TaABA8'OH1-D) was identified in Japanese cultivars including 'Tamaizumi'. However, a single mutation in TaABA8'OH1-D had no clear effect on germination inhibition in double haploid lines. In a screen for a mutation, one deletion mutant lacking the entire TaABA8'OH1 on the A genome (TaABA8'OH1-A), TM1833, was identified from gamma-ray irradiation lines of 'Tamaizumi'. TM1833 (a double mutant in TaABA8'OH1-A and TaABA8'OH1-D) showed lower TaABA8'OH1 expression, higher ABA content in embryos during seed development under field condition and lower germination than those in 'Tamaizumi' (a single mutant in TaABA8'OH1-D). These results indicate that reduced ABA catabolism through mutations in TaABA8'OH1 may be effective in germination inhibition in field-grown wheat. PMID:23641187

Chono, Makiko; Matsunaka, Hitoshi; Seki, Masako; Fujita, Masaya; Kiribuchi-Otobe, Chikako; Oda, Shunsuke; Kojima, Hisayo; Kobayashi, Daisuke; Kawakami, Naoto

2013-03-01

354

Study of the bioremediation of atrazine under variable carbon and nitrogen sources by mixed bacterial consortium isolated from corn field soil in Fars province of Iran.  

PubMed

Atrazine herbicide that is widely used in corn production is frequently detected in water resources. The main objectives of this research were focused on assessing the effects of carbon and nitrogen sources on atrazine biodegradation by mixed bacterial consortium and by evaluating the feasibility of using mixed bacterial consortium in soil culture. Shiraz corn field soil with a long history of atrazine application has been explored for their potential of atrazine biodegradation. The influence of different carbon compounds and the effect of nitrogen sources and a different pH (5.5-8.5) on atrazine removal efficiency by mixed bacterial consortium in liquid culture were investigated. Sodium citrate and sucrose had the highest atrazine biodegradation rate (87.22%) among different carbon sources. Atrazine biodegradation rate decreased more quickly by the addition of urea (26.76%) compared to ammonium nitrate. Based on the data obtained in this study, pH of 7.0 is optimum for atrazine biodegradation. After 30 days of incubation, the percent of atrazine reduction rates were significantly enhanced in the inoculated soils (60.5%) as compared to uninoculated control soils (12%) at the soil moisture content of 25%. In conclusion, bioaugmentation of soil with mixed bacterial consortium may enhance the rate of atrazine degradation in a highly polluted soil. PMID:23533452

Dehghani, Mansooreh; Nasseri, Simin; Hashemi, Hassan

2013-03-05

355

Evaluation of a reverse transcriptase polymerase chain reaction test and virus isolation on field samples collected for the diagnosis of infectious hematopoietic necrosis virus in cultured Atlantic salmon in British Columbia.  

PubMed

Infectious hematopoietic necrosis virus (IHNV) has been found to cause disease in cultured salmon of the Pacific Northwest region of North America. Diagnosis of IHNV by virus isolation (VI) can take over 2 weeks. Recently, a rapid reverse transcriptase (RT) polymerase chain reaction (PCR) test on fish tissues has been used for diagnosis. Test performances of the VI and RT PCR assays were compared using samples collected in the field. The effect of different storage conditions (tissue frozen with or without RNAlater [Ambion, Inc., Austin, Texas] versus fresh tissue) on the diagnostic tests was also evaluated. Based on the limited number of samples tested, the operating characteristics of RT PCR were very similar to those of VI; therefore, this method is likely suitable for testing field samples for IHNV. The ability of the tests to identify a positive fish ranged from 74% to 89%. Freezing samples at -80 degrees C before testing did not negatively affect the performance of RT PCR or VI. However, due to reduced test performance, RNAlater frozen storage is not recommended without further investigation. PMID:18536498

McClure, Carol; Saksida, Sonja; Karreman, Grace; Constantine, Joanne; Robinson, John; Traxler, Garth; Hammell, Larry

2008-03-01

356

Nonorthogonally magnetised permanent-magnet Faraday isolators  

SciTech Connect

This paper describes a novel configuration of permanent-magnet magnetic systems for high-power Faraday isolators that are used in high-power lasers. An increase in magnetic field is ensured by magnets with a magnetisation vector inclined to the isolator axis. Numerical simulation results agree well with experimentally determined magnetic field distributions. (quantum electronic devices)

Mironov, E A; Voitovich, A V; Palashov, O V [Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod (Russian Federation)

2011-01-31

357

Enhanced cell fusion activity in porcine epidemic diarrhea virus adapted to suckling mice.  

PubMed

Porcine epidemic diarrhea virus (PEDV) is the major causative agent of fatal diarrhea in piglets. To study the pathogenic features of PEDV using a mouse model, PEDV with virulence in mice is required. In pursuit of this, we adapted a tissue-culture-passed PEDV MK strain to suckling mouse brains. PEDV obtained after ten passages through the brains (MK-p10) had increased virulence for mice, and its fusion activity in cultured cells exceeded that of the original strain. However, the replication kinetics of MK and MK-p10 did not differ from each other in the brain and in cultured cells. The spike (S) protein of MK-p10 had four amino acid substitutions relative to the original strain. One of these (an H-to-R substitution at residue 1,381) was first detected in PEDV isolated after eight passages, and both this virus (MK-p8) and MK-p10 showed enhanced syncytium formation relative to the original MK strain and viruses isolated after two, four, and six passages, suggesting the possibility that the H-to-R mutation was responsible for this activity. This mutation could be also involved in the increased virulence of PEDV observed for MK-p10. PMID:20827493

Shirato, Kazuya; Maejima, Madoka; Hirai, Asuka; Ami, Yasushi; Takeyama, Natsumi; Tsuchiya, Kotaro; Kusanagi, Kouich; Nunoya, Tetsuo; Taguchi, Fumihiro

2010-09-09

358

Isolating Triggered Star Formation  

SciTech Connect

Galaxy pairs provide a potentially powerful means of studying triggered star formation from galaxy interactions. We use a large cosmological N-body simulation coupled with a well-tested semi-analytic substructure model to demonstrate that the majority of galaxies in close pairs reside within cluster or group-size halos and therefore represent a biased population, poorly suited for direct comparison to 'field' galaxies. Thus, the frequent observation that some types of galaxies in pairs have redder colors than 'field' galaxies is primarily a selection effect. We use our simulations to devise a means to select galaxy pairs that are isolated in their dark matter halos with respect to other massive subhalos (N= 2 halos) and to select a control sample of isolated galaxies (N= 1 halos) for comparison. We then apply these selection criteria to a volume-limited subset of the 2dF Galaxy Redshift Survey with M{sub B,j} {le} -19 and obtain the first clean measure of the typical fraction of galaxies affected by triggered star formation and the average elevation in the star formation rate. We find that 24% (30.5 %) of these L* and sub-L* galaxies in isolated 50 (30) h{sup -1} kpc pairs exhibit star formation that is boosted by a factor of {approx}> 5 above their average past value, while only 10% of isolated galaxies in the control sample show this level of enhancement. Thus, 14% (20 %) of the galaxies in these close pairs show clear triggered star formation. Our orbit models suggest that 12% (16%) of 50 (30) h{sup -1} kpc close pairs that are isolated according to our definition have had a close ({le} 30 h{sup -1} kpc) pass within the last Gyr. Thus, the data are broadly consistent with a scenario in which most or all close passes of isolated pairs result in triggered star formation. The isolation criteria we develop provide a means to constrain star formation and feedback prescriptions in hydrodynamic simulations and a very general method of understanding the importance of triggered star formation in a cosmological context.

Barton, Elizabeth J.; Arnold, Jacob A.; /UC, Irvine; Zentner, Andrew R.; /KICP, Chicago /Chicago U., EFI; Bullock, James S.; /UC, Irvine; Wechsler, Risa H.; /KIPAC, Menlo Park /SLAC

2007-09-12

359

Origin, Evolution, and Genotyping of Emergent Porcine Epidemic Diarrhea Virus Strains in the United States  

PubMed Central

ABSTRACT Coronaviruses are known to infect humans and other animals and cause respiratory and gastrointestinal diseases. Here we report the emergence of porcine epidemic diarrhea virus (PEDV) in the United States and determination of its origin, evolution, and genotypes based on temporal and geographical evidence. Histological lesions in small intestine sections of affected pigs and the complete genomic sequences of three emergent strains of PEDV isolated from outbreaks in Minnesota and Iowa were characterized. Genetic and phylogenetic analyses of the three U.S. strains revealed a close relationship with Chinese PEDV strains and their likely Chinese origin. The U.S. PEDV strains underwent evolutionary divergence, which can be classified into two sublineages. The three emergent U.S. strains are most closely related to a strain isolated in 2012 from Anhui Province in China, which might be the result of multiple recombination events between different genetic lineages or sublineages of PEDV. Molecular clock analysis of the divergent time based on the complete genomic sequences is consistent with the actual time difference, approximately 2 to 3 years, of the PED outbreaks between China (December 2010) and the United States (May 2013). The finding that the emergent U.S. PEDV strains share unique genetic features at the 5?-untranslated region with a bat coronavirus provided further support of the evolutionary origin of PEDV from bats and potential cross-species transmission. The data from this study have important implications for understanding the ongoing PEDV outbreaks in the United States and will guide future efforts to develop effective preventive and control measures against PEDV.

Huang, Yao-Wei; Dickerman, Allan W.; Pineyro, Pablo; Li, Long; Fang, Li; Kiehne, Ross; Opriessnig, Tanja; Meng, Xiang-Jin

2013-01-01

360

Genetic variation analysis of reemerging porcine epidemic diarrhea virus prevailing in central China from 2010 to 2011.  

PubMed

Porcine epidemic diarrhea has re-emerged with devastating impact in central China since October 2010. To investigate and analyze the reason of this outbreak, the M and ORF3 genes of 15 porcine epidemic diarrhea viruses (PEDV), which were collected from different areas of central China during October 2010 and December 2011, were amplified by reverse transcriptase polymerase chain reaction, cloned, sequenced, and analyzed. Sequence analyses showed that the nucleotides and amino acids were changed at some sites in the M and ORF3 genes of the 15 PEDV strains compared with those genes of CV777 reference strain. Based on the phylogenetic analyses, PEDVs in central China and reference strains could be separated into three groups: G1, G2, and G3. The 15 PEDV strains belonged to G3 group and showed a close relationship with Korean strains (2007), Thai strains (2007-2008), and partial other Chinese strains (2010-2011), but differed genetically from European strains (Br1/87) and the vaccine strain (CV777 vs) being used in China. Furthermore, all 15 PEDV strains from central China and some other isolates in China from 2003 to 2007 (LJB-03, QH, and LZC) belonged to different group. Therefore, PEDV exhibits rapid variation and genetic evolution, and the currently prevailing PEDV strains in central China are a new genotype. PMID:23269482

Yang, Xia; Huo, Jin-Yao; Chen, Lu; Zheng, Feng-Mei; Chang, Hong-Tao; Zhao, Jun; Wang, Xin-Wei; Wang, Chuan-Qing

2012-12-27

361

Tiamulin resistance in porcine Brachyspira pilosicoli isolates.  

PubMed

There are few studies on antimicrobial susceptibility of Brachyspira pilosicoli, therefore this study was performed to investigate the situation among isolates from pigs. The tiamulin and tylosin susceptibility was determined by broth dilution for 93 and 86 porcine B. pilosicoli isolates, respectively. The isolates came from clinical samples taken in Swedish pig herds during the years 2002 and 2003. The tylosin minimal inhibitory concentration (MIC) was >16 microg/ml for 50% (n=43) of the isolates tested. A tiamulin MIC >2 microg/ml was obtained for 14% (n=13) of the isolates and these were also tested against doxycycline, salinomycin, valnemulin, lincomycin and aivlosin. For these isolates the susceptibility to salinomycin and doxycycline was high but the MICs for aivlosin varied. The relationship between the 13 tiamulin resistant isolates was analyzed by pulsed-field gel electrophoresis (PFGE). Among the 13 isolates 10 different PFGE patterns were identified. PMID:16253666

Pringle, M; Landén, A; Franklin, A

2005-04-02

362

Influence of the crystal field stabilization energy of metal(II) ions on the structural distortion of matrix-isolated SO4(2-) guest ions in selenate matrices.  

PubMed

Infrared spectra of metal(II) selenate hydrates (MeSeO4.nH2O and Na2Me(SeO4)2.2H2O; n=6, 5, 4, 1; Me=Mg, Mn, Co, Ni, Cu, Zn, Cd) containing matrix-isolated SO42- guest ions are reported and discussed with respect to the S-O stretching modes 3 and 1. An adequate measure for the SO42- guest ion distortion is the site group splitting deltanuas (deltanuab and deltanuac in the case of a doublet and a triplet for 3, respectively; a, being the highest wavenumbered component of nu3) and deltanumax (the difference between the highest and the lowest wave numbered S-O stretching modes). It has been shown that the SO42- guest ion distortion depends on both the number of the sulfate oxygen atoms involved in coordinative bonds with the metal(II) ions and the electronic configuration of the metal(II) ions, i.e. their crystal field stabilization energy (CFSE) additionally to the site symmetry and the local potential at the lattice site of the host lattice. The SO42- guest ions matrix-isolated in MeSeO4.H2O (Me=Mn, Co, Zn) and in Na2Me(SeO4)2.2H2O (Me=Mn, Cu, Cd) exhibit three bands corresponding to the nu3 modes as deduced from the site group analysis and deltanuab approximately equal to deltanubc. When SO42- guest ions are incorporated in the triclinic Na2Me(SeO4)2.2H2O host lattices (Me=Co, Ni, Zn) the nu3 stretching region resembles a higher local symmetry of the SO42- guest ions (an approximate (A1 + E) splitting) than the crystallographic one (i.e. deltanuab>deltanubc instead of deltanuab approximately equal to deltanubc) and, hence, the ratio deltanuab/deltanubc has to be taken into account (the higher value of the ratio deltanuab/deltanubc, the weaker is the distortion of the SO42- guest ions). The SO42- guest ions incorporated in MeSeO4.nH2O (n=6, 5, 4) exhibit a higher local symmetry of the guest ions than that deduced from the site group analysis (D2d for the SO42- guest ions in MeSeO4.5H2O, MeSeO4.4H2O and in the monoclinic MeSeO4.6H2O host lattices and close to Td in the tetragonal MeSeO4.6H2O host lattices). The analysis of the infrared spectra of selenate host lattices containing SO42- guest ions reveals that the guest ions are stronger distorted when the adjacent metal(II) ions have CFSE not equal to 0. These ions are more resistant to angular deformations of the MeO6-octahedra (i.e. changes in the O-Me-O bond angles), thus facilitating the SO42- guest ion distortion as compared to those having CFSE=0 which allow stronger angular deformations of the respective metal octahedra. Infrared spectra of kieserite-type compounds MeSeO4.H2O (Me=Mn, Co, Zn) containing matrix-isolated SO42- guest ions and Me'2+ guest ions different from those of the host ions (i.e. Me'SO4.H2O in MeSeO4.H2O) are also presented and discussed (double matrix-spectroscopy). PMID:15249012

Stoilova, Donka

2004-08-01

363

Challenges in hardening technologies using shallow-trench isolation  

SciTech Connect

Challenges related to radiation hardening CMOS technologies with shallow-trench isolation are explored. Results show that trench hardening can be more difficult than simply replacing the trench isolation oxide with a hardened field oxide.

Shaneyfelt, M.R.; Dodd, P.E.; Draper, B.L.; Flores, R.S.

1998-02-01

364

Arenimonas oryziterrae sp. nov., isolated from a field of rice (Oryza sativa L.) managed under a no-tillage regime, and reclassification of Aspromonas composti as Arenimonas composti comb. nov.  

PubMed

The taxonomic position of a novel bacterial strain, YC6267(T) isolated from a field of rice (Oryza sativa L.) managed under a no-tillage regime in Jinju, Korea, was studied using a polyphasic taxonomic approach. Cells of the strain were Gram-stain-negative, rod-shaped and aerobic. It grew at 15-37 degrees C (optimum at 28 degrees C). Growth of the strain occurred between pH 5.0 and 10.0, with an optimum of pH 7.0-8.0. The G+C content of the total DNA was 65.8 mol%. The 16S rRNA gene sequence of the strain was most closely related to species of the genera Arenimonas (95.6-94.4 %) and Aspromonas (95.1 %), with <95.0 % similarity to species of the genus Lysobacter and other genera of the family Xanthomonadaceae. Chemotaxonomic data (major quinone Q-8; major polar lipids phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol; and major fatty acids iso-C(15 : 0), iso-C(14 : 0), iso-C(16 : 0), and iso-C(17 : 1)omega9c) supported the affiliation of strain YC6267(T) to the genus Arenimonas. Phylogenetic analysis based on 16S rRNA gene sequences and biochemical and physiological characteristics strongly supported the genotypic and phenotypic differentiation of strain YC6267(T) from described species of the genus Arenimonas. Strain YC6267(T), therefore, represents a novel species, for which the name Arenimonas oryziterrae sp. nov. is proposed. The type strain is YC6267(T) (=KCTC 22247(T) =DSM 21050(T)). In addition, the reclassification of Aspromonas composti as Arenimonas composti comb. nov. is proposed (type strain TR7-09(T) =KCTC 12666(T) =DSM 18010(T)). A common line of descent and a number of shared phenotypic traits support this reclassification. PMID:19628604

Aslam, Zubair; Park, Joo Hwang; Kim, Seon Won; Jeon, Che Ok; Chung, Young Ryun

2009-07-23

365

Epidemiology of Tsutsugamushi disease in relation to the serotypes of Rickettsia tsutsugamushi isolated from patients, field mice, and unfed chiggers on the eastern slope of Mount Fuji, Shizuoka Prefecture, Japan.  

PubMed Central

A total of 59 strains of Rickettsia tsutsugamushi were isolated from patients (24 isolates), Apodemus speciosus mice (30 isolates), and unfed larvae of Leptotrombidium scutellare (2 isolates) and Leptotrombidium pallidum (3 isolates) in the Gotenba-Oyama District, Shizuoka Prefecture, Japan. All these isolates were classified into the three serotypes Karp, Kawasaki, and Kuroki based on reactivity with strain-specific monoclonal antibodies. Kawasaki- and Karp-type rickettsiae were isolated from L. scutellare and L. pallidum, respectively, and the geographic distribution of patients and rodents infected with these two types of rickettsiae coincided with the areas densely populated by the respective chiggers. From these results, we conclude that Kawasaki-type rickettsiae are transmitted by L. scutellare and Karp-type ones are transmitted by L. pallidum. Kawasaki-type rickettsial infections were prevalent in early autumn, and Karp-type infections showed a peak of occurrence in the late autumn, reflecting the seasonal fluctuations of L. scutellare and L. pallidum. Isolates of Kuroki-type rickettsiae were obtained only from four patients in October and November, and the relationship between this type of rickettsia and its vector species could not be fully defined.

Kawamori, F; Akiyama, M; Sugieda, M; Kanda, T; Akahane, S; Uchikawa, K; Yamada, Y; Kumada, N; Furuya, Y; Yoshida, Y

1992-01-01

366

Magnetar fields  

NASA Astrophysics Data System (ADS)

There is growing evidence that soft gamma-ray repeaters (SGR) and anomalous X-ray pulsars (AXP) are isolated neutron stars with super-strong magnetic fields (B>1014G), known as magnetars. If such strong fields are supported by currents residing entirely within the star then all the electrons would be confined to the ground Landau level. The ratio between the Landau level spacing (E_LL), near the ground state, and the Fermi energy (E_F), given by, E_F/? E_LL ˜ 5 × 10^4 ?-2/3 ho152/3 B15-1, (ho = ho15 1015 gm cm-3, B = Bp15 1015 G}) , (where ? is the mean molecular weight per electron) is close to unity for a large range of densities where the quantum Hall regime prevails. Consequently, the transport properties are highly anisotropic as well as field-dependent in such strongly quantizing fields (Ghost et al. 2002, Yakovlev 1984). This in turn affects the evolution of the magnetic field itself. Assuming the n-p-e-plasma, in the core, to be non-superfluid the evolution of the magnetic field is governed by the following induction equation (Goldreich & Reisenegger, 1992) partial B/partial t = - c nabla × ( J/?(B=0) ) + nabla × (v × B) - (m_p/?pn - m_e/?en)/(m_p/?pn + m_e/?en) nabla × (J × B)/n_e ) , where m,? correspond to the masses and relaxation times for the relevant species of particles. Evidently, the second and the third terms, corresponding to Hall drift and Ambipolar diffusion would be important for the magnetar field evolution. The anisotropy in the conductivity gives rise to strong Hall currents inducing rapid transfer of energy from dipolar component of the field to higher multi-poles. Since, currents of higher order multi-poles dissipate faster (Mitra, Konar & Bhattacharya 1999) the field would decay rapidly because of this. References Ghosh S. et al., 2002, IJMPD, 11, 843 Goldreich P., Reisenegger A., 1992, ApJ, 395, 250 Mitra D.,Konar S., Bhattacharya D., 1999, MNRAS, 307, 459 Yakovlev D. G., 1984, ApSS, 98, 37

Konar, S.

367

Isolation and Structure of Cribrostatin 6.  

National Technical Information Service (NTIS)

Cribrostatin 6, a dark blue cancer cell growth inhibiting constituent of the Republic of Maldives marine sponge Cribrochalina sp. has been isolated, and its structure elucidated, based on a combination of RMS, high field (500 MHz, HMBC, and GOESY experime...

G. R. Pettit J. C. Knight

2004-01-01

368

Cloning and Sequence Analysis of the M gene of Porcine Epidemic Diarrhea Virus LJB\\/03  

Microsoft Academic Search

Porcine epidemic diarrhea virus (PEDV) LJB\\/03 was isolated from the fece of piglets infected with PEDV on a pig farm, Heilongjiang province, China. The M gene of LJB\\/03 was amplified from the RNA extracted directly from the fece samples by RT-PCR and cloned into pMD18-T vector. The M gene cDNA was sequenced and encompasses an open reading frame of 681

Fan Jinghui; Li Yijing

2005-01-01

369

Cloning the structure genes and expression the N gene of porcine epidemic diarrhea virus DX  

Microsoft Academic Search

The structure genes spike (S), nucleocapsid (N), membrane (M), small membrane (sM) of a porcine epidemic diarrhea virus (PEDV)\\u000a strain DX isolated in Gansu province, North-west of China, were cloned, sequenced and compared with published sequences of\\u000a PEDV strains. The nucleotide sequences encoding the entire S, sM, M and N genes open reading frame (ORF) of DX were 4 152,

Jian-qiang Li; Ji-xing Liu; Xi Lan; Jie Cheng; Run Wu; Zhong-Zi Lou; Xiang-ping Yin; Xue-rui Li; Bao-yu Li; Bin Yang; Zhi-yong Li

2009-01-01

370

Isolation Enhancement Between Two Closely Packed Antennas  

Microsoft Academic Search

This paper introduces a coupling element to enhance the isolation between two closely packed antennas operating at the same frequency band. The proposed structure consists of two antenna elements and a coupling element which is located in between the two antenna elements. The idea is to use field cancellation to enhance isolation by putting a coupling element which artificially creates

Angus C. K. Mak; Corbett R. Rowell; Ross D. Murch

2008-01-01

371

Characteristics of isolates of Pseudomonas solanacearum from Heliconia  

Microsoft Academic Search

Pseudomonas solanacearum was isolated from Heliconia showing bacterial wilt in field-grown and imported plants. These isolates were compared with indigenous isolates from Strelitzia, Synedrella, Alpinia, Alexandra palm, tomato and sapote. They were characterised biochemically into biovars and pathogenically into races. Biovar\\u000a 3 isolates were pathogenic on tomato but not on diploid nor triploid bananas. Only the Heliconia isolates were pathogenic

A. Diatloff; E. Akiew; B. A. Wood; K. D. Hyde

1992-01-01

372

Isolation and characterization of a heavy metal-resistant Burkholderia sp. from heavy metal-contaminated paddy field soil and its potential in promoting plant growth and heavy metal accumulation in metal-polluted soil.  

PubMed

A heavy metal-resistant bacterial strain was isolated from heavy metal-contaminated soils and identified as Burkholderia sp. J62 based on the 16S rDNA gene sequence analysis. The heavy metal- and antibiotic resistance, heavy metal solubilization of the isolate were investigated. The isolate was also evaluated for promoting plant growth and Pb and Cd uptakes of the plants from heavy metal-contaminated soils in pot experiments. The isolate was found to exhibit different multiple heavy metal and antibiotic resistance characteristics. Atomic absorption spectrometer analysis showed increased bacterial solubilization of lead and cadmium in solution culture and in soils. The isolate produced indole acetic acid, siderophore and 1-aminocyclopropane-1-carboxylate deaminase. The isolate also solubilized inorganic phosphate. Inoculation with the isolate was found to significantly (p<0.05) increase the biomass of maize and tomato plants. Increase in tissue Pb and Cd contents varied from 38% to 192% and from 5% to 191% in inoculated plants growing in heavy metal-contaminated soils compared to the uninoculated control, respectively. These results show that heavy metal-solubilizing and plant growth promoting bacteria are important for plant growth and heavy metal uptake which may provide a new microbial enhanced-phytoremediation of metal-polluted soils. PMID:18348897

Jiang, Chun-yu; Sheng, Xia-fang; Qian, Meng; Wang, Qing-ya

2008-03-17

373

Comparing Pulsed-Field Gel Electrophoresis with Multilocus Sequence Typing, spa Typing, Staphylococcal Cassette Chromosome mec (SCCmec) Typing, and PCR for Panton-Valentine Leukocidin, arcA, and opp3 in Methicillin-Resistant Staphylococcus aureus Isolates at a U.S. Medical Center  

PubMed Central

Methicillin-resistant Staphylococcus aureus (MRSA) has become a common cause of skin infections and invasive infections in community dwellers in the United States since the late 1990s. Isolates characterized as USA300 by pulsed-field gel electrophoresis (PFGE) are the predominant strain type in these infections. USA100 and USA500 strains commonly cause health care-associated infections. We compared PFGE with a number of other methods of genotyping in a sample of 149 clinical MRSA isolates from the University of Chicago Medical Center. The 5 USA500 isolates yielded 3 spa types and 2 multilocus sequence types (MLSTs). Among the 24 USA100 isolates, 21 (88%) were of spa type t002, 19 (79%) were of ST5, 2 carried arcA and opp3, and 1 was Panton-Valentine leukocidin positive (PVL+). Among the 102 USA300 isolates, 96 (94%) were of ST8 and 94 (92%) were of spa type t008. The combination of traits that provided the best sensitivity (98%), specificity (97%), positive predictive value (PPV) (99%), and negative predictive value (NPV) (95%) for identifying USA300 isolates were the presence of the arcA gene and the presence of the PVL genes (area under the curve, 0.980; 95% confidence interval [CI], 0.955 to 1.0). PFGE did not delineate a homogeneous group of MRSA genetic backgrounds, as documented for other typing methods, particularly for USA500 and USA100 pulsotypes. Documenting the presence of arcA and PVL genes by PCR was an efficient and accurate means of identifying USA300 in a collection of MRSA isolates in which USA300 is common. None of the tested genotyping methods provided an accurate means of identifying the next most common PFGE-based backgrounds, USA100 and USA500.

Taylor, Alexis; Lynfield, Ruth; Boxrud, Dave J.; Short, Ginette; Zychowski, Diana; Boyle-Vavra, Susan; Daum, Robert S.

2013-01-01

374

Cloning and further sequence analysis of the ORF3 gene of wild- and attenuated-type porcine epidemic diarrhea viruses  

Microsoft Academic Search

The open reading frame (ORF3) genes of the parent DR13, attenuated DR13, KPED-9, P-5V, and 12 field samples were cloned and\\u000a sequenced to further explore the functions of wild- and attenuated-type porcine epidemic diarrhea viruses (PEDVs). Sequencing\\u000a revealed that wild-type PEDVs ORF3 genes had a single ORF of 675 nucleotides encoding a protein of 224 amino acids with a\\u000a predicted

Seong-Jun Park; Hyoung-Joon Moon; Yuzi Luo; Hye-Kwon Kim; Eun-Mi Kim; Jeong-Sun Yang; Dae-Sub Song; Bo-Kyu Kang; Chul-Seung Lee; Bong-Kyun Park

2008-01-01

375

Isolation and identification of locally isolated bacterial strains effective against whitefly Bemisia tabaci  

Microsoft Academic Search

Potent bacterial strains effective against the whitefly, Bemisia tabaci, nymphs (second instar), were isolated from tomato cultivated fields at Fayoum governorate, Giza, Egypt. Of 72 isolates, 12 with the most morphologically distinct-looking bacterial colonies were selected and named A1, A2, A3, A6, A7, A9, A12, A13, A107, B37, B45 and B100. All isolates were preliminarily identified as members of the

Salah El-Din El-Assal; Narmen A. Youssef; Gamil A. Amin

2012-01-01

376

Pharmacokinetics of tildipirosin in porcine plasma, lung tissue, and bronchial fluid and effects of test conditions on in vitro activity against reference strains and field isolates of Actinobacillus pleuropneumoniae.  

PubMed

The pharmacokinetics of tildipirosin (Zuprevo(®) 40 mg/mL solution for injection for pigs), a novel 16-membered-ring macrolide for the treatment for swine respiratory disease (SRD), was investigated in studies collecting blood plasma and postmortem samples of lung tissue and bronchial fluid (BF) from swine. In view of factors influencing the in vitro activity of macrolides, and for the interpretation of tildipirosin pharmacokinetics in relation to minimum inhibitory concentrations (MIC), additional experiments were conducted to study the effects of pH, carbon dioxide-enriched atmosphere, buffers, and serum on tildipirosin MICs for various reference strains and Actinobacillus (A.) pleuropneumoniae field isolates. After single intramuscular (i.m.) injection at 4 mg/kg body weight, maximum plasma concentration (Cmax) was 0.9 ?g/mL observed within 23 min (Tmax ). Mean residence time from the time of dosing to the time of last measurable concentration (MRTlast) and terminal half-life (T1/2) both were about 4 days. A dose-response relationship with no significant sex effect is observed for area under the plasma concentration-time curve from time 0 to the last sampling time with a quantifiable drug concentration (AUClast) over the range of doses up to 6 mg/kg. However, linear dose proportionality could not be proven with statistical methods. The time-concentration profile of tildipirosin in BF and lung far exceeded that in blood plasma. In lung, tildipirosin concentrations reached 3.1 ?g/g at 2 h, peaked at 4.3 ?g/g at day 1, and slowly declined to 0.8 ?g/g at day 17. In BF, tildipirosin levels were 14.3, 7.0, and 6.5 ?g/g at days 5, 10, and 14. T1/2 in lung was ?7 days. Tildipirosin is rapidly and extensively distributed to the respiratory tract followed by slow elimination. Culture media pH and carbon dioxide-enriched atmosphere (CO2 -EA) had a marked impact on in vitro activity of tildipirosin in reference strains of various rapidly growing aerobic and fastidious bacteria including Histophilus (H.) somni ATCC 700025 and A. pleuropneumoniae ATCC 27090. For A. pleuropneumoniae ATCC 27090 testing conditions without CO2 -EA resulted in reduced acidification of culture media pH and a reduction in the minimum inhibitory concentrations compared to standard in vitro test conditions by 2 log2 dilution steps (4-fold) from 8 to 2 ?g/mL. Supplementary buffering of standard culture media resulted in a reduction in the A. pleuropneumoniae (n = 8) MIC range by 4 log2 dilution steps (16-fold) from 8-16 to 0.5-1 ?g/mL. Incremental supplementation of culture media with 50% serum resulted in noticeable shifts to lower minimum or maximum MICs by at least 2 log2 dilution steps (?4-fold) in all aerobic and fastidious reference strains tested except for Pasteurella (P.) multocida. The MIC of A. pleuropneumoniae ATCC 27090 decreased by 2-4 log2 dilution steps (4 to 16-fold) from 8 to 0.5-2 ?g/mL when 50% serum was added to the standard assay. Considering a higher presence of serum and the rather neutral pH conditions maintained in vivo, it is suggested to take the influence of these factors on in vitro activity into account when interpreting tildipirosin MICs for A. pleuropneumoniae in relation to pharmacokinetics. PMID:22500881

Rose, M; Menge, M; Bohland, C; Zschiesche, E; Wilhelm, C; Kilp, S; Metz, W; Allan, M; Röpke, R; Nürnberger, M

2012-04-15

377

DISCRIMINATION OF STEM PITTING CITRUS TRISTEZA VIRUS ISOLATES FROM OTHER CTV ISOLATES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Technical Abstract: Stem pitting isolates of Citrus tristeza virus (CTV) are not thought to be widely distributed in Florida, but are of concern and a test was needed for rapid discrimination of stem pitting from other severe CTV isolates in field trees. Four published techniques were evaluated f...

378

Cryogenic Faraday isolator  

SciTech Connect

A Faraday isolator is described in which thermal effects are suppressed by cooling down to liquid nitrogen temperatures. The principal scheme, main characteristics and modifications of the isolator are presented. The isolation degree is studied experimentally for the subkilowatt average laser radiation power. It is shown that the isolator can be used at radiation powers up to tens of kilowatts. (quantum electronic devices)

Zheleznov, D S; Zelenogorskii, V V; Katin, E V; Mukhin, I B; Palashov, O V; Khazanov, Efim A [Institute of Applied Physics, Russian Academy of Sciences, Nizhnii Novgorod (Russian Federation)

2010-05-26

379

Heterogeneity in the circumsporozoite protein gene of Plasmodium malariae isolates from sub-Saharan Africa 1 Note: Nucleotide sequence data reported in this paper are available in the EMBL, GenBank™ and DDJB databases under the accession numbers AJ001523, isolate 410; AJ001524, isolate 412; AJ001525, isolate 413; AJ001526, isolate KA; AJ002575, isolate 401; AJ002576, isolate 402; AJ002577, isolate 403; AJ002578, isolate 404; AJ002579, isolate 405; AJ002580, isolate 406; AJ002581, isolate 407; AJ002582, isolate 408; AJ002583, isolate 409. 1  

Microsoft Academic Search

Polymorphism of the circumsporozoite protein (CSP) of Plasmodium malariae was characterized by comparing gene sequences of twelve field isolates obtained in Yaoundé, Cameroon, Central Africa, and one clinical isolate originating from Côte d'Ivoire, West Africa. The length of the CSP gene ranged from 1266 to 1302 bp. The size polymorphism was due to variation in the number of tandem repeat

Rachida Tahar; Pascal Ringwald; Leonardo K Basco

1998-01-01

380

Comparative studies on the pathogenicity and tissue distribution of three virulence variants of classical swine fever virus, two field isolates and one vaccine strain, with special regard to immunohistochemical investigations  

PubMed Central

Background The aim of this study was to compare the tissue distribution and pathogenicity of three virulence variants of classical swine fever virus (CSFV) and to investigate the applicability of various conventional diagnostic procedures. Methods 64 pigs were divided into three groups and infected with the highly virulent isolate ISS/60, the moderately virulent isolate Wingene'93 and the live attenuated vaccine strain Riems, respectively. Clinical signs, gross and histopathological changes were compared in relation to time elapsed post infection. Virus spread in various organs was followed by virus isolation, by immunohistochemistry, applying monoclonal antibodies in a two-step method and by in situ hybridisation using a digoxigenin-labelled riboprobe. Results The tissue distribution data are discussed in details, analyzing the results of the various diagnostic approaches. The comparative studies revealed remarkable differences in the onset of clinical signs as well as in the development of the macro- and microscopical changes, and in the tissue distribution of CSFV in the three experimental groups. Conclusion The present study demonstrates that in the case of highly and moderately virulent virus variants the virulence does not affect the pattern of the viral spread, however, it influences the outcome, the duration and the intensity of the disease. Immunohistochemistry has the advantage to allow the rapid detection and localisation of the virus, especially in cases of early infection, when clinical signs are still absent. Compared to virus isolation, the advantage of this method is that no cell culture facilities are required. Thus, immunohistochemistry provides simple and sensitive tools for the prompt detection of newly emerging variants of CSFV, including the viruses of very mild virulence.

Belak, Katinka; Koenen, Frank; Vanderhallen, Hans; Mittelholzer, Christian; Feliziani, Francesco; De Mia, Gian Mario; Belak, Sandor

2008-01-01

381

Isolation and Characterization of Listeria monocytogenes Isolates from Retail Foods in Shaanxi Province, China.  

PubMed

Abstract Listeria monocytogenes is an important foodborne pathogen of public health concern. A total of 902 retail food samples, including 342 ready-to-eat (RTE) foods, 366 infant foods, and 194 raw chickens were collected randomly in supermarkets and farmers' markets in 12 geographic areas in Shaanxi Province, China and screened for L. monocytogenes. All L. monocytogenes isolates were characterized by antimicrobial susceptibility testing, serotyping, and pulsed-field gel electrophoresis (PFGE). Twenty-seven (3.0%) samples were positive for L. monocytogenes, and 39 L. monocytogenes isolates were recovered from positive samples. Of these L. monocytogenes isolates, 21 isolates (53.8%) showed resistance to at least one antimicrobial. The isolates displayed resistance most frequently to oxacillin (18 isolates, 46.2%), followed by tetracycline (five isolates, 12.8%), erythromycin (four isolates, 10.3%), trimethoprim/sulfamethoxazole (three isolates, 7.7%), chloramphenicol (two isolates, 5.1%), and vancomycin (one isolate, 2.6%). All isolates were sensitive or displayed intermediate resistance to gentamicin, ampicillin, ciprofloxacin, and amikacin. Four serotypes including serotype 1/2b, 4b, 4e, and 1/2a were identified in those foodborne isolates. PFGE analysis demonstrated that some isolates with the same PFGE patterns came from different food sources, and isolates from the same food source tend to cluster closely. Presence of L. monocytogenes of clinically important serotypes in retail foods and their antimicrobial resistance constitute a potential risk for the public. Appropriate measures should be taken by government, industry, and consumers to reduce the risk posed by this ubiquitous pathogen. PMID:23841657

Zhang, Weisong; Wang, Xin; Xia, Xiaodong; Yang, Baowei; Xi, Meili; Meng, Jianghong

2013-07-10

382

Polarization proximity effect in isolator crystal pairs.  

PubMed

We experimentally study the polarization dynamics (orientation and ellipticity) of near-infrared light transmitted through magneto-optical yttrium iron garnet isolator crystal pairs using a modified balanced detection scheme. When the pair separation is in the submillimeter range, we observed a proximity effect in which the saturation field is reduced by up to 20%. One-dimensional calculations suggest that the proximity effect originates from magnetostatic interactions between the dipole moments of the isolator crystals. PMID:19037456

Linzon, Y; Ferrera, M; Razzari, L; Pignolet, A; Morandotti, R

2008-12-01

383

In vitro susceptibilities of recent field isolates of Mycoplasma hyopneumoniae and Mycoplasma hyosynoviae to valnemulin (Econor®), tiamulin and enrofloxacin and the in vitro development of resistance to certain antimicrobial agents in Mycoplasma hyopneumoniae  

Microsoft Academic Search

The in vitro activities of valnemulin (Econor®) and two other antimicrobial agents were determined against recent field strains of Mycoplasma hyopneumoniae and Mycoplasma hyosynoviae using a broth microdilution method. Valnemulin showed exceptional activity against M hyopneumoniae (MIC90 0·0005 ?g ml?1) and M hyosynoviae (MIC range 0·0001 ?g ml?1 to 0·00025 ?g ml?1) field strains. Tiamulin was 100-fold less active (MIC90

P. H Ripley

1997-01-01

384

Some physiological properties of citrus and noncitrus races of Geotrichum candidum isolated from soil in Japan  

Microsoft Academic Search

Some physiological properties of citrus and noncitrus races ofGeotrichum candidum isolated from soils of citrus groves and noncitrus fields in Japan were studied. Of 358 isolated of citrus race, 260 isolates\\u000a required pyridoxine for growth on asparagine-glucose agar, while 98 isolates could grow in the absence of pyridoxine. On the\\u000a other hand, of 11 isolates of noncitrus race, 10 isolates

Dewa Ngurah Suprapta; Kei Arai; Hisashi Iwai

1996-01-01

385

Analog signal isolation techniques  

SciTech Connect

This paper discusses several techniques for isolating analog signals in an accelerator environment. The techniques presented here encompass isolation amplifiers, voltage-to-frequency converters (VIFCs), transformers, optocouplers, discrete fiber optics, and commercial fiber optic links. Included within the presentation of each method are the design issues that must be considered when selecting the isolation method for a specific application.

Beadle, E.R.

1992-12-31

386

Analog signal isolation techniques  

SciTech Connect

This paper discusses several techniques for isolating analog signals in an accelerator environment. The techniques presented here encompass isolation amplifiers, voltage-to-frequency converters (VIFCs), transformers, optocouplers, discrete fiber optics, and commercial fiber optic links. Included within the presentation of each method are the design issues that must be considered when selecting the isolation method for a specific application.

Beadle, E.R.

1992-01-01

387

Genetic and antigenic variability in bovine viral diarrhea virus (BVDV) isolates from Belgium  

Microsoft Academic Search

This report describes the genetic and antigenic variability of bovine viral diarrhea virus strains isolated in Belgium. Part of the 5? untranslated region and the 5? end of the gp53 (E2) coding sequence were amplified by PCR and sequenced. Phylogenetic analysis showed that most field isolates segregated into genotypes Ib or II. Only one out of 28 field isolates belonged

B. Couvreur; C. Letellier; A. Collard; P. Quenon; P. Dehan; C. Hamers; P.-P. Pastoret; P. Kerkhofs

2002-01-01

388

Inoculation of newly hatched broiler chicks with two Brazilian isolates of Salmonella Heidelberg strains with different virulence gene profiles, antimicrobial resistance, and pulsed field gel electrophoresis patterns to intestinal changes evaluation.  

PubMed

Salmonella Heidelberg is one of the 3 most frequently isolated serovars from human Salmonella cases in Canada, and the fourth most commonly reported Salmonella serovar in human foodborne disease cases in the United States. Since 1962, Salmonella Heidelberg has been isolated and reported in poultry and poultry products in Brazil. The poultry industry has focused efforts on reducing salmonellae incidence in live production in an effort to reduce Salmonella in the processing plant. A better understanding of the initial infection in chicks could provide approaches to control Salmonella contamination. The objective of the present study was to evaluate 2 Salmonella Heidelberg strains that differed in the presence of virulence genes invA, agfA, and lpfA; antimicrobial resistance profiles; and epidemiologic profiles on aspects of pathogenicity and intestinal morphology. Newly hatched broiler chicks were inoculated with 2 strains (SH23 and SH35) of Salmonella Heidelberg and cecal morphometry, histopathology, electron microscopy, and bacterial counts in the liver and cecum were assessed. The SH23 and SH35 strains resulted in different changes in villi height and crypt depth and inflammatory cell infiltration in the cecum. The SH35 group had higher liver and cecum bacterial cell counts when compared with SH23 strains. PMID:19276418

Borsoi, A; Santin, E; Santos, L R; Salle, C T P; Moraes, H L S; Nascimento, V P

2009-04-01

389

NON-TOXIGENIC ASPERGILLUS FLAVUS ISOLATES FOR REDUCING AFLATOXIN IN MISSISSIPPI DELTA CORN  

Technology Transfer Automated Retrieval System (TEKTRAN)

The potential for two non-toxigenic isolates of Aspergillus flavus CT3 and K49 isolated from the Mississippi Delta to reduce aflatoxin contamination of corn was assessed in a field study. These two isolates exhibited comparable growth and aggressiveness as the toxigenic A. flavus isolate F3W4. The...

390

DNA Macrorestriction Analysis of Nontypeable Group B Streptococcal Isolates: Clonal Evolution of Nontypeable and Type V Isolates  

PubMed Central

Group B streptococci (GBS) are serotyped according to capsular polysaccharide (CPS) type (Ia to VIII); an isolate is classified as nontypeable (NT) if no detectable CPS is found. Surface-localized protein antigens (?, ?, R1, and R4) serve as additional markers to classify GBS isolates, which is particularly useful since NT isolates often express one or more of these proteins. To compare genetic resemblance among isolates with similar protein profiles, we studied 58 NT isolates digested with the SmaI macrorestriction enzyme prior to pulsed-field gel electrophoresis (PFGE). Of these 58, 15.5% expressed ? only, 20.7% expressed ?+?, 15.5% expressed R4, and 25.8% expressed R1,R4, while 22.4% of the isolates expressed no detectable proteins. The largest PFGE profile group, with 48% of the isolates, was group 4, composed primarily of isolates that expressed R1,R4 or no proteins. The second most common profiles were 3 and 32, each with 13.8% of the isolates. Since NT isolates in profile group 4 were highly related to type V isolates, as demonstrated by PFGE profiles, we investigated 45 type V isolates. Two-thirds of the type V isolates within profile group 4 were classified into subgroup 4a, compared to 28.2% of 39 NT isolates. Only 11% of the V/R1,R4 isolates were identical to the prototype group 4 profile, in contrast to 75% of the NT/R1,R4 isolates. A shift of type V isolates into profile 4 subgroups may be indicative of a genetic change over time. PFGE is a valuable approach for comparison of GBS isolate relatedness and for monitoring of NT and typeable GBS isolates for potential clonal divergence.

Amundson, Nicole R.; Flores, Aurea E.; Hillier, Sharon L.; Baker, Carol J.; Ferrieri, Patricia

2005-01-01

391

Flexure Elastomer Antenna Isolation System.  

National Technical Information Service (NTIS)

A vibration isolation system for a payload. The vibration isolation system provides a level of vibration isolation for all vibration translational and rotational components, while minimizing the moment of the payload mass relative to the isolation system....

A. J. Vajanyi D. Calhoun M. Hoffman R. I. Harless R. T. Fandrich

2004-01-01

392

Comparative evaluation of an automated ribotyping system versus pulsed-field gel electrophoresis for epidemiological typing of clinical isolates of Escherichia coli and Pseudomonas aeruginosa from patients with recurrent gram-negative bacteremia  

Microsoft Academic Search

Ribotyping and macrorestriction analysis of chromosomal DNA using pulsed-field gel electrophoresis (PFGE) are among the more useful molecular epidemiologic typing methods. Because these techniques are labor intensive, automation of one or more steps may allow clinical laboratories to apply molecular typing methods. We compared the recently developed automated ribotyping system, the RiboPrinter™ Microbial Characterization System (DuPont), with PFGE as a

M. A. Pfaller; C. Wendt; R. J. Hollis; R. P. Wenzel; S. J. Fritschel; J. J. Neubauer; L. A. Herwaldt

1996-01-01

393

Field Notes  

USGS Multimedia Gallery

The Field Records Collection has many materials types including: field notebooks, sketches, annotated maps, unpublished manuscripts, plane-table sheets, annotated aerial photographs, sample analysis, stratigraphic columns, lithologic logs, and geologic cross sections. Materials in the Field Records ...

2009-04-09

394

Active isolation systems  

Microsoft Academic Search

This paper summarizes microgravity experiments for space platforms and presents test results of a three-axes active isolation demonstration system that has been built and tested. This mount has demonstrated isolation capability down to 0.05 Hz nd a transmissibility curve which provides isolation levels necessary for microgravity and precision pointing aboard space platforms. The system has high-bandwidth inertial servo loops using

Lawrence M. Germann; Avanindra A. Gupta

1993-01-01

395

Active isolation systems  

NASA Astrophysics Data System (ADS)

This paper summarizes microgravity experiments for space platforms and presents test results of a three-axes active isolation demonstration system that has been built and tested. This mount has demonstrated isolation capability down to 0.05 Hz nd a transmissibility curve which provides isolation levels necessary for microgravity and precision pointing aboard space platforms. The system has high-bandwidth inertial servo loops using accelerometers for active disturbance rejection to isolate the payload from external torque disturbances by the utility transfer devices and moving mechanisms.

Germann, Lawrence M.; Gupta, Avanindra A.

1993-09-01

396

Fasciola hepatica: histological demonstration of apoptosis in the reproductive organs of flukes of triclabendazole-sensitive and triclabendazole-resistant isolates, and in field-derived flukes from triclabendazole-treated hosts, using in situ hybridisation to visualise endonuclease-generated DNA strand breaks.  

PubMed

Investigation of the triclabendazole (TCBZ) resistance status of populations of Fasciola hepatica in field cases of fasciolosis, where treatment failure has been reported, can be supported by histological examination of flukes collected from recently treated hosts. In TCBZ-sensitive flukes (TCBZ-S) exposed to TCBZ metabolites for 1-4days in vivo, but not in TCBZ-resistant flukes (TCBZ-R), morphological changes suggestive of apoptosis occur in cells undergoing meiosis or mitosis in the testis, ovary and vitelline follicles. In order to verify or refute the contention that efficacy of TCBZ treatment is associated with apoptosis in the reproductive organs of flukes, histological sections of TCBZ-S (Cullompton isolate) flukes and TCBZ-R (Sligo isolate) flukes were subjected to the TdT-mediated dUDP nick end labelling (TUNEL) in situ hybridisation method, a commercially available test specifically designed to label endonuclease-induced DNA strand breaks associated with apoptosis. Additionally, sections of in vivo-treated and untreated flukes originating from field outbreaks of suspected TCBZ-S and TCBZ-R fasciolosis were labelled by the TUNEL method. It was found that in treated TCBZ-S flukes, strong positive labelling indicating apoptosis was associated with morphologically abnormal cells undergoing mitosis or meiosis in the testis, ovary and vitelline follicles. Background labelling in the positive testis sections was attributed to heterophagy of cell debris by the sustentacular tissue. The triggering of apoptosis was probably related to failure of spindle formation at cell division, supporting the contention that TCBZ inhibits microtubule formation. In treated TCBZ-R (Sligo Type 1) flukes, and in treated flukes from field outbreaks of suspected TCBZ-R fasciolosis, no significant labelling was observed, while sections of fluke derived from a field case of fasciolosis where TCBZ resistance was not suspected were heavily labelled. Light labelling was associated with the testis of untreated Cullompton (TCBZ-S) and Sligo Type 2 (TCBZ-R) flukes, which exhibit abnormal spermatogenesis and spermiogenesis, respectively. This was attributed to apoptosis and to heterophagy of effete germ line cells by the sustentacular tissue. It is concluded that demonstration of apoptosis by in situ hybridisation using the TUNEL method on sections of 1-4days in vivo TCBZ-treated F. hepatica can contribute to the diagnosis of TCBZ resistance in field outbreaks of fasciolosis. PMID:23062689

Hanna, R E B; Forster, F I; Brennan, G P; Fairweather, I

2012-09-18

397

Experimental study and modeling of a novel magnetorheological elastomer isolator  

NASA Astrophysics Data System (ADS)

This paper reports an experimental setup aiming at evaluating the performance of a newly designed magnetorheological elastomer (MRE) seismic isolator. As a further effort to explore the field-dependent stiffness/damping properties of the MRE isolator, a series of experimental testing were conducted. Based upon the analysis of the experimental responses and the characteristics of the MRE isolator, a new model that is capable of reproducing the unique MRE isolator dynamics behaviors is proposed. The validation results verify the model’s effectiveness to portray the MRE isolator. A study on the field-dependent parameters is then provided to make the model valid with fluctuating magnetic fields. To fully explore the mechanism of the proposed model, an investigation relating the dependence of the proposed model on every parameter is carried out.

Yang, Jian; Du, Haiping; Li, Weihua; Li, Yancheng; Li, Jianchun; Sun, Shuaishuai; Deng, H. X.

2013-11-01

398

Investigation of Hot Carrier Degradation in Shallow-Trench-Isolation-Based High-Voltage Laterally Diffused Metal--Oxide--Semiconductor Field-Effect Transistors by a Novel Direct Current Current--Voltage Technique  

NASA Astrophysics Data System (ADS)

Shallow trench isolation (STI) based laterally diffused metal--oxide--semiconductor (LDMOS) devices have become popular with its better tradeoff between breakdown voltage and on-resistance and its compatibility with the standard complementary metal--oxide--semiconductor (CMOS) process. A novel direct current current--voltage (DCIV) technique demonstrated with multiple sharp peak signals is proposed to characterize interface state generation in the channel and in the STI drift regions separately. Degradation of STI-based LDMOS transistors in various hot-carrier stress modes is investigated experimentally by proposed technique. A two-dimensional numerical device simulation is performed to obtain insight into the proposed technique and device degradation characteristics under hot-carrier stress conditions. The impact of interface state location on device electrical characteristics is analyzed from measurement and simulation. Our results show that the maximum Isub stress becomes the worst hot-carrier degradation mode in term of the on-resistance degradation, which is attributed to interface state generation under STI drift region.

He, Yandong; Zhang, Ganggang

2012-04-01

399

Antimicrobial Resistance in Enterococci Isolated from Turkey Flocks Fed Virginiamycin  

Microsoft Academic Search

From 125 separate cloacal cultures from three turkey flocks fed virginiamycin, 104 Enterococcus faecium and 186 Enterococcus faecalis isolates were obtained. As the turkeys aged, there was a higher percentage of quinupristin-dalfopristin-resistant E. faecium isolates, with isolates from the oldest flock being 100% resistant. There were no vancomycin-resistant enterococci. Results of pulsed-field gel electrophoresis (PFGE) indicated there were 11 PFGE

L. A. WELTON; L. A. THAL; M. B. PERRI; S. DONABEDIAN; J. MCMAHON; J. W. CHOW; M. J. ZERVOS

1998-01-01

400

Isolation of thermotolerant, halotolerant, facultative biosurfactant-producing bacteria  

Microsoft Academic Search

Several facultative bacterial strains tolerant to high temperature and salinity were isolated from the oil reservoir brines\\u000a of an Iranian oil field (Masjed-I Soleyman). Some of these isolates were able to grow up to 60°C and at high concentration\\u000a of NaCl (15% w\\/v). One of the isolates grew at 40°C, while it was able to grow at 15% w\\/v NaCl.

H. Ghojavand; F. Vahabzadeh; M. Mehranian; M. Radmehr; Kh. A. Shahraki; F. Zolfagharian; M. A. Emadi; E. Roayaei

2008-01-01