Salmonellae and Campylobacters in Household and Stray Dogs in Northern Taiwan

Rectal swabs were collected from 437 household and 491 stray dogs in northern Taiwan from May 2003 to June 2005 to investigate the prevalence and antimicrobial susceptibilities of salmonellae and campylobacters. The results revealed that 2.1% of household dogs and 6.3% of stray dogs were positive for salmonellae, with Salmonella Duesseldorf being the most dominant serotype in both. Additionally, 2.7% of the household dogs and 23.8% of the stray dogs were positive for campylobacters. Campylobacter jejuni was the most prevalent species (86.8%), followed by C. upsaliensis (9.3%) and C. coli (3.9%). Both salmonella and campylobacter isolation rates from the stray dogs were significantly higher than those from the household dogs (p < 0.01). The susceptibility of 33 C. jejuni isolates to eight antimicrobials was studied by the E-test. A high rate of resistance was observed to azithromycin (93.9%), clindamycin (87.9%), erythromycin (81.8%), tetracycline (78.8%), chloramphenicol (69.7%), nalidixic acid (51.5%), gentamicin (33.3%), and ciprofloxacin (18.2%). The susceptibility of 40 Salmonella isolates to 15 antimicrobials was also studied by the disc-diffusion method. All the Salmonella isolates were susceptible to ciprofloxacin and ceftriaxone. Resistance was observed most frequently to tetracycline (77.5%), chloramphenicol (52.5%), and ampicillin (50%).     

Cloning and nucleotide sequencing of the second internal transcribed spacer of ribosomal DNA for three species of Eimeria from chickens in Taiwan

Coccidiosis of chickens caused by protozoan parasites of the genus Eimeria (Coccidia: Eimeriidae) is an enteric disease that results in great economic losses throughout the world, including Taiwan. Using polymerase chain reaction (PCR) with primers specific for the second internal transcribed spacer (ITS-2) of ribosomal DNA (rDNA), three species of Eimeria, E. tenella, E. maxima, and E. acervulina have been successfully characterised from chickens in Taiwan. The sizes of PCR products from various isolates representing these three species were between 370 and 580 base pairs (bp). After cloning and sequencing of the PCR products, high nucleotide sequence identity (96.8-100%) was observed within a species. In addition, ITS-2 nucleotide sequences for E. tenella had higher homology (98.5-99.3%) than E. maxima (81.6-96.5%) when compared with appropriate sequences deposited in GenBank. To our knowledge, this is the first report of a 412-bp ITS-2 sequence for E. acervulina from chickens.     

煤矸石在高等级公路施工中的质量控制

结合依七高速公路,详细阐述了煤矸石在高等级公路施工中质量控制及施工方法,煤矸石废物利用起到的环保效果和社会效应。     

浅谈水泥混凝土病害成因及防治

依据工程实际经验,就混凝土经常遇到的普通病害成因及处理办法进行了详细论述。     

防砂坝下游河床局部冲刷现象之研究

防砂坝下游河床局部冲刷问题,对坝体安全及河道稳定具有深远之影响。因此,本研究乃利用冲射流理论分别探讨当冲刷达平衡时,冲刷坑之最大冲刷深度以及冲刷深度之时间变化,经与其他研究者试验资料验证比较,初步已获得良好之结果。     

Molecular epidemiology of avian influenza viruses circulating among healthy poultry flocks in farms in northern Vietnam

Repeated epizootics of highly pathogenic avian influenza (HPAI) virus subtype H5N1 were reported from 2003 to 2005 among poultry in Vietnam. More than 200 million birds were killed to control the spread of the disease. Human cases of H5N1 infection have been sporadically reported in an area where repeated H5N1 outbreaks among birds had occurred. Subtype H5N1 strains are established as endemic among poultry in Vietnam, however, insights into how avian influenza viruses including the H5N1 subtype are maintained in endemic areas is not clear. In order to determine the prevalence of different avian influenza viruses (AIVs), including H5N1 circulating among poultry in northern Vietnam, surveillance was conducted during the years 2006-2009. A subtype H5N1 strain was isolated from an apparently healthy duck reared on a farm in northern Vietnam in 2008 and was identified as an HPAI. Although only one H5N1 virus was isolated, it supports the view that healthy domestic ducks play a pivotal role in maintaining and transmitting H5N1 viruses which cause disease outbreaks in northern Vietnam. In addition, a total of 26 AIVs with low pathogenicity were isolated from poultry and phylogenetic analysis of all the eight gene segments revealed their diverse genetical backgrounds, implying that reassortments have occurred frequently among strains in northern Vietnam. It is, therefore, important to monitor the prevalence of influenza viruses among healthy poultry between epidemics in an area where AIVs are endemic.     

Salmonella flagellin enhances mucosal immunity of avian influenza vaccine in chickens

Flagellin, a bioactive Toll-like receptor (TLR) 5 ligand, may trigger the innate immunity that in turn is important for subsequent adaptive immune responses. In the present study, the adjuvant effects of the monomeric and polymeric forms of Salmonella flagellin (mFliC and pFliC, respectively) were examined in specific-pathogen free (SPF) chickens immunized intramuscularly (i.m.) or intranasally (i.n.) with formalin-inactivated avian influenza virus (AIV) H5N2 vaccines. Results showed that mFliC cooperating with the 64CpG adjuvant significantly induced influenza-specific antibody titers of plasma IgA in the i.m.-vaccinated animals. The nasal IgA levels in the i.n.-mFliC-coadministrated AIV vaccinated chickens were significantly elevated compared to levels observed in the control group (H5N2 vaccine alone). The pFliC cooperating with the 64CpG adjuvant significantly enhanced cell proliferation of splenocytes in the i.m.-vaccinated animals. TLR3 and TLR5 expressions were activated by flagellin stimulation in vitro and in vivo. These results suggest that flagellin can be used as an adjuvant in an AIV H5N2 vaccine, especially for mucosal immunity.     

alphaE-catenin controls cerebral cortical size by regulating the hedgehog signaling pathway

During development, cells monitor and adjust their rates of accumulation to produce organs of predetermined size. We show here that central nervous system-specific deletion of the essential adherens junction gene, alphaE-catenin, causes abnormal activation of the hedgehog pathway, resulting in shortening of the cell cycle, decreased apoptosis, and cortical hyperplasia. We propose that alphaE-catenin connects cell-density-dependent adherens junctions with the developmental hedgehog pathway and that this connection may provide a negative feedback loop controlling the size of developing cerebral cortex.     

Al:Pe projects: Water chemistry and critical loads

Water chemistry data on which all the investigations in the AL:PE 1 (Acidification of Mountain Lakes: Palaeolimnology and Ecology) and AL:PE 2 (Remote Mountain Lakes as Indicators of Air Pollution and Climate Change) projects are based, are available for 28 lakes in U.K. (Scotland), Italy, Norway and France (AL:PE 1) and in Svalbard (Norway), Ireland, Austria, Spain, Portugal, Poland, Slovakia, Slovenia and Russia (AL:PE 2). The results show high sulphate concentrations in some mountain lakes in all the countries. Nitrate and sulphate concentrations have different distribution patterns among the sites. A gradient in acidification from north (Norway) to central Europe (via U.K. to Italy) is identified for the AL:PE lakes by means of multivariate data analysis. Critical loads and their exceedance are calculated, where sufficient information is available, both according to the leaching of S, and of S plus N from the catchment. The pattern of critical load exceedance demonstrates an increasing importance of nitrate from Norway via U.K. to Italy. Leaching of N was of considerable importance to the acidification of lakes in the Italian Alps. The projects receive financial support from the European Union.