共查询到20条相似文献,搜索用时 15 毫秒
1.
Z. Molatová E. Skřivanová B. Macias N. R. Mcewan P. Březina M. Marounek 《Folia microbiologica》2010,55(3):215-220
Organic acids can be used as feed supplements or for treatment of poultry carcasses in processing plants. The antimicrobial
activity of nineteen organic acids and two monoacylglycerols in cultures of Campylobacter jejuni CCM 6214T (ATCC 33560) was determined using a SYBR Green-based real-time PCR assay. The IC50 was a concentration at which only 50 % of a bacteria specific DNA sequence was amplified. Caprylic, capric and lauric acids
were the most efficient antimicrobials among the compounds tested (IC50 ≤ 0.1 mg/mL). In a weakly acidic environment (pH 5.5), the antimicrobial activity was more pronounced than at pH 6.5. At
pH 5.5, oleic and fumaric acid also had clear antimicrobial activity, as did monocaprylin. The antimicrobial activity of acetic,
butyric, stearic and succinic acid was low. In cells treated with fumaric acid, the potential of potassium and tetraphenylphosphonium
ion-selective electrodes changed, indicating an increase in cytoplasmic and outer membrane permeability, respectively. No
changes in membrane permeability were observed in cells treated with capric acid or monocaprin. Transmission electron microscopy
revealed separation of the inner and outer membrane in cells treated with capric and fumaric acid, as well as cytoplasmic
disorganization in cells exposed to capric acid. 相似文献
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R. C. Anderson M. D. Flythe N. A. Krueger T. R. Callaway T. S. Edrington R. B. Harvey D. J. Nisbet 《Folia microbiologica》2010,55(4):309-311
Campylobacter spp. are a leading bacterial cause of human foodborne illness. When cocultured in anaerobic Bolton broth with the hyper-ammonia
producing bacterium, Clostridium aminophilum, ammonia accumulation was greater and final growth of Campylobacter jejuni was reduced (CFU ≥ 1.4 log10/mL) compared to that obtained by pure culture controls. Co-culture with the less active ammonia-producing saccharolytic Prevotella albensis had no effect on final C. jejuni concentrations. When co-cultured similarly except with the addition of 10 μmol/L monensin, monensin-susceptible Cl. aminophilum was reduced by 2 to 4 log10 CFU/mL and concentrations of C. jejuni, which is insensitive to monensin, did not differ from its pure culture control. These results suggest that in the absence
of added monensin, the hyper ammonia-producing Cl. aminophilum may be able to outcompete asaccharolytic C. jejuni for amino acid substrates and that this competitive ability was eliminated by addition on monensin. 相似文献
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There are three most important bacterial causative agents of serious infections that could be misused for warfare purposes:
Bacillus anthracis (the causative agent of anthrax) is the most frequently mentioned one; however, Fracisella tularensis (causing tularemia) and Yersinia pestis (the causative agent of plague) are further bacterial agents enlisted by Centers for Disease Control and Prevention into the category A of potential biological weapons. This review intends to summarize basic information about these bacterial
agents. Military aspects of their pathogenesis and the detection techniques suitable for field use are discussed. 相似文献
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O. V. Golovanova V. I. Konenkov A. V. Shevchenko M. V. Smolnikova 《Russian Journal of Genetics》2009,45(8):981-986
Based on population analysis of the DRB1, DQA1, DQB1 and TNFA allele frequency distribution patterns, regional features of immunogenetic structure of the population of West Siberia were
investigated. Statistically significant linkage disequilibrium within the HLA class II region, as well as between the TNFA and DRB1, DQA1, and DQB1 was demonstrated. Population frequency distribution patterns of two- and multilocus haplotypes were examined. 相似文献
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Justin G Hovey Emily L Watson Melanie L Langford Ellen Hildebrandt Sangeetha Bathala Jeffrey R Bolland Domenico Spadafora George L Mendz David J McGee 《BMC microbiology》2007,7(1):26
Background
Clinical isolates of the gastric pathogen Helicobacter pylori display a high level of genetic macro- and microheterogeneity, featuring a panmictic, rather than clonal structure. The ability of H. pylori to survive the stomach acid is due, in part, to the arginase-urease enzyme system. Arginase (RocF) hydrolyzes L-arginine to L-ornithine and urea, and urease hydrolyzes urea to carbon dioxide and ammonium, which can neutralize acid. 相似文献8.
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The intron sequence of chloroplast rpS16 and the secondary structure of its pre-mRNA were characterized for the first time in 26 Allium sativum accessions of different ecologo-geographical origins and seven related Allium species. The boundaries and main stem-loop consensus sequences were identified for all six domains of the intron. Polymorphism
was estimated for the total intron and its regions. The structural regions of the rpS16 intron proved to be heterogeneous for mutation rate and spectrum. Mutations were most abundant in domains II and IV, and
transition predominated in domains I, III, V, and VI. In addition to structural elements and motifs typical for group IIB
introns, several Allium-specific micro- and macrostructural mutations were revealed. A 290-bp deletion involving domains III and IV and part of domain
V was observed in A. altaicum, A. fistulosum, and A. schoenoprasum. Several indels and nucleotide substitutions were found to cause a deviation of the pre-mRNA secondary structure from the
consensus model of group II introns. 相似文献
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Yue-hua Han Wen-zhong Liu Yao-zhou Shi Li-qiong Lu Shu-dong Xiao Qing-hua Zhang 《Journal of microbiology (Seoul, Korea)》2009,47(4):455-465
A Helicobacter pylori whole-genome DNA microarray was constructed to study expression profiles of H. pylori in response to a sudden temperature transfer from 37°C to 20°C. The expression level of the genome at each of four time points
(15, 30, 60, and 120 min) after temperature downshift was compared with that just before cold treatment. Globally, 10.2 %
(n=167) of the total predicted H. pylori genes (n=1636) represented on the microarray were significantly differentially expressed (p<0.05) over a 120 min period after shift to low temperature. The expression profiles of the differentially expressed genes
were grouped, and their expression patterns were validated by quantitative real-time PCR. Up-regulated genes mainly included
genes involved in energy metabolism and substance metabolism, cellular processes, protein fate, ribosomal protein genes, and
hypothetical protein genes, which indicate the compensational responses of H. pylori to temperature downshift. Those genes play important roles in adaption to temperature downshift of H. pylori. Down-regulation of DNA metabolism genes and cell envelope genes and cellular processes genes may reflect damaged functions
under low temperature, which is unfavorable to bacterial infection and propagation. Overall, this time-course study provides
new insights into the primary response of H. pylori to a sudden temperature downshift, which allow the bacteria to survive and adapt to the new host environment. 相似文献
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To overexpress the chitosanase gene (csn) in F. solani, a vector based on pCAMBIA 1300 was constructed. The csn gene, which is under control of the Aspergillus nidulans
gpdA promoter and A. nidulans trpC terminator, was introduced back into the F. solani genome by Agrobacterium tumefaciens-mediated transformation, and the herbicide-resistance gene bar from Streptomyces hygroscopicus was used as the selection marker. Transformants which showed a significant increase in chitosanase production (~2.1-fold
than control) were obtained. Southern blot analysis indicated that most transformants had a single-copy T-DNA integration. 相似文献
13.
Hiroyoshi Kubo 《Mycoscience》2009,50(5):400-406
Pilobolus crystallinus shows unique photoresponses at various growing stages. cDNAs for putative photoreceptors were cloned from this fungus. Three
genes named pcmada1, pcmada2, and pcmada3 were identified from the PCR fragments, and amplified with degenerated primers for the LOV domain, which is conserved in
many blue-light receptors. Deduced amino acid sequences for PCMADA1, PCMADA2, and PCMADA3 had one light-oxygen-voltage (LOV)-sensing
and two PER-ARNT-SIM (PAS) domains. A zinc finger DNA-binding motif was conserved in the C-terminals of PCMADA1 and PCMADA3.
However, PCMADA2 lacked the zinc finger motif. Expression of pcmada1 was suppressed by blue light whereas that of pcmada3 was promoted by blue-light irradiation. 相似文献
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Hua Piao Motozumi Minohara Nobutoshi Kawamura Wei Li Takuya Matsushita Ryo Yamasaki Yoshimitsu Mizunoe Jun-ichi Kira 《Neurochemical research》2011,36(1):58-66
Campylobacter jejuni (C. jejuni) is frequently associated with axonal Guillain-Barré syndrome (GBS). We reported that C. jejuni DNA-binding protein from starved cells (C-Dps) binds to and damages myelinated nerves in vivo. We studied the binding patterns
of C-Dps to nervous tissues and its in vitro effects on neural cells. Immunohistochemically, C-Dps labeled the nodes of Ranvier,
the outermost parts of internodal myelin and the basement membrane in the peripheral nerves, and neurons and myelin in the
central nervous tissues. Its binding was blocked by sulfatide. C-Dps bound to the cell surfaces of nerve growth factor (NGF)-treated
PC12 cells leading to dose-dependent LDH release, which was inhibited by either heat-denaturation of C-Dps or coincubation
with an anti-C-Dps mAb. However, its binding to the surfaces of cultured NSC34 cells, S16 cells, or dorsal root ganglion cells,
did not induce cytotoxicity. These findings suggest a possible involvement of C-Dps in C. jejuni-related GBS. 相似文献
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Gaye Öngen Gaye Güngör Bahar Kanberoglu 《World journal of microbiology & biotechnology》2007,23(4):519-524
Aspergillus section Nigri strains Aspergillus aculeatus Ege-K 258, A.
foeditus var. pallidus Ege-K156, A. niger Ege-K 4 and A. tubingensis Ege-K 265 were used to treat olive mill wastewater (OMW) in an investigation aimed at exploring their dephenolisation and
decolourisation ability and, consequently, the economic feasibility of using any or all of these strains in a pre-treatment
step in the processing of OMW. Of these strains A. tubingensis Ege-K 265 resulted in an 80% decolourisation of twofold-diluted OMW and a 30% decolourisation of undiluted OMW; in addition,
it was able to remove approximately 30% of all phenolic compounds in both twofold-diluted and undiluted OMW. We conclude that
A. tubingensis Ege-K 265 could be effectively used in the pre-treatment step of a combined aerobic-anaerobic process to solve the environmental
problems caused by OMW in Mediterranean countries. 相似文献
18.
I. Rosario G. Soro S. Déniz O. Ferrer F. Acosta D. Padilla B. Acosta 《Mycopathologia》2010,169(4):315-319
Columba livia is an important reservoir and carrier of Cryptococcus neoformans, Cryptococcus uniguttulatus, Cryptococcus laurentii and Cryptococcus albidus. Upper digestive tract of this species is also known as a habitat for Cryptococcus neoformans. Given the increasing clinical interest of this microorganism, 331 swabs from crop and 174 dropping samples from pigeon lofts
in Grand Canary Island have been studied. The obtained results show an extensive presence samples 81 positive (24.47%) of
Cryptococcus spp. in analysed crops: 32 (9.66%) for C. neoformans, 24 (7.2%) for C. uniguttulatus, 23 (6.9%) for C. albidus and 2 (0.6%) for C. laurentii. In the same way, Cryptococcus spp was also isolated in 82 (47.13%), dropping samples: C. neoformans in 59 (33.9%), C. uniguttulatus, in 9 (5.17%), C. laurentii in 8 (4.59%) and C. albidus in 6 (3.44%) of the investigated samples, respectively. The cryptococcosis produced by species of cryptococci other than C. neoformans has become more important during the last decade, supporting the study on the role of pigeon in the epidemiology of this
disease. 相似文献
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