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1.

Background  

The accurate identification of Lactobacillus and other co-isolated bacteria during microbial ecological studies of ecosystems such as the human or animal intestinal tracts and food products is a hard task by phenotypic methods requiring additional tests such as protein and/or lipids profiling.  相似文献   

2.

Background  

Escherichia coli can respire anaerobically using dimethyl sulfoxide (DMSO) or trimethylamine-N-oxide (TMAO) as the terminal electron acceptor for anaerobic energy generation. Expression of the dmsABC genes that encode the membrane-associated DMSO/TMAO reductase is positively regulated during anaerobic conditions by the Fnr protein and negatively regulated by the NarL protein when nitrate is present.  相似文献   

3.

Background  

Functional studies in model organisms, such as vertebrates and Drosophila, have shown that basic Helix-loop-Helix (bHLH) proteins have important roles in different steps of neurogenesis, from the acquisition of neural fate to the differentiation into specific neural cell types. However, these studies highlighted many differences in the expression and function of orthologous bHLH proteins during neural development between vertebrates and Drosophila. To understand how the functions of neural bHLH genes have evolved among bilaterians, we have performed a detailed study of bHLH genes during nervous system development in the polychaete annelid, Platynereis dumerilii, an organism which is evolutionary distant from both Drosophila and vertebrates.  相似文献   

4.

Background  

When photosynthetic organisms are exposed to harsh environmental conditions such as high light intensities or cold stress, the production of reactive oxygen species like singlet oxygen is stimulated in the chloroplast. In Chlamydomonas reinhardtii singlet oxygen was shown to act as a specific signal inducing the expression of the nuclear glutathione peroxidase gene GPXH/GPX5 during high light stress, but little is known about the cellular mechanisms involved in this response. To investigate components affecting singlet oxygen signaling in C. reinhardtii, a mutant screen was performed.  相似文献   

5.
6.

Background  

Chromosome pairing, recombination and DNA repair are essential processes during meiosis in sexually reproducing organisms. Investigating the bread wheat (Triticum aestivum L.) Ph2 (Pairing homoeologous) locus has identified numerous candidate genes that may have a role in controlling such processes, including TaMSH7, a plant specific member of the DNA mismatch repair family.  相似文献   

7.

Background  

Genes belonging to the pathogenesis related 10 (PR10) group have been studied in several plant species, where they form multigene families. Until now, such an analysis has not been performed in Vitis vinifera, although three different PR10 genes were found to be expressed under pathogen attack or abiotic stress, and during somatic embryogenesis induction. We used the complete genome sequence for characterising the whole V. vinifera PR10 gene family. The expression of candidate genes was studied in various non-treated tissues and following somatic embryogenesis induction by the auxin 2,4-D.  相似文献   

8.

Aims

To determine the herd prevalence of Enterobacteriaceae producing CTX‐M‐type extended‐spectrum β‐lactamases (ESBLs) among 381 dairy farms in Japan.

Methods and Results

Between 2007 and 2009, we screened 897 faecal samples using BTB lactose agar plates containing cefotaxime (2 μg ml?1). Positive isolates were tested using ESBL confirmatory tests, PCR and sequencing for CTX‐M, AmpC, TEM and SHV. The incidence of Enterobacteriaceae producing CTX‐M‐15 (= 7), CTX‐M‐2 (= 12), CTX‐M‐14 (= 3), CMY‐2 (= 2) or CTX‐M‐15/2/14 and CMY‐2 (= 4) in bovine faeces was 28/897 (3·1%) faecal samples. These genes had spread to Escherichia coli (= 23) and three genera of Enterobacteriaceae (= 5). Herd prevalence was found to be 20/381 (5·2%) dairy farms. The 23 E. coli isolates showed clonal diversity, as assessed by multilocus sequence typing and pulsed‐field gel electrophoresis. The pandemic E. coli strain ST131 producing CTX‐M‐15 or CTX‐M‐27 was not detected.

Conclusions

Three clusters of CTX‐M (CTX‐M‐15, CTX‐M‐2, CTX‐M‐14) had spread among Japanese dairy farms.

Significance and Impact of the Study

This is the first report on the prevalence of multidrug‐resistant CTX‐M‐15–producing E. coli among Japanese dairy farms.  相似文献   

9.

Background  

Salmonella enterica, a common food-borne bacterial pathogen, is believed to change its protein expression profile in the presence of different environmental stress such as that caused by the exposure to hydrogen peroxide (H2O2), which can be generated by phagocytes during infection and represents an important antibacterial mechanism of host cells. Among Salmonella proteins, the effectors of Salmonella pathogenicity island 1 and 2 (SPI-1 and SPI-2) are of particular interest since they are expressed during host infection in vivo and are important for invasion of epithelial cells and for replication in organs during systemic infection, respectively. However, the expression profiles of these proteins upon exposure to H2O2 or to host cells in vivo during the established phase of systemic infection have not been extensively studied.  相似文献   

10.

Background  

Pseudomonas fluorescens is an important food spoilage organism, usually found in the form of biofilms. Bacterial biofilms are inherently resistant to a variety of antimicrobial agents, therefore alternative methods to biofilm control, such as bacteriophages (phages) have been suggested. Phage behavior on biofilms is still poorly investigated and needs further understanding. Here we describe the application of phage ϕIBB-PF7, a newly isolated phage, to control P. fluorescens biofilms. The biofilms were formed under static or dynamic conditions and with or without renewal of medium.  相似文献   

11.

Background

Hyperemesis gravidarum remains a common, distressing, and significant yet poorly understood disorder during pregnancy. The association between maternal Helicobacter pylori (H. pylori) infection and hyperemesis gravidarum has been increasingly recognized and investigated. This study thus aimed to provide an updated review and meta‐analysis of the topic.

Methods

Using the search terms (H. pyloriOR Helicobacter ORHelicobacter pyloriOR infection) AND (pregnancy OR emesis OR hyperemesis gravidarum OR nausea OR vomiting), a preliminary search on the PubMed, Ovid, Web of Science, Google Scholar, and WanFang database yielded 372 papers published in English between January 1st, 1960 and June 1st, 2017.

Results

A total of 38 cross‐sectional and case‐control studies, with a total of 10 289 patients were eligible for review. Meta‐analysis revealed a significant association between H. pylori infection and hyperemesis gravidarum during pregnancy, with a pooled odds ratio of 1.348 (95% CI: 1.156‐1.539, P < .001). Subgroup analysis found that serologic and stool antigen tests were comparable methods of detecting H. pylori as they yielded similar odds ratios.

Limitations

Although the studies did not have high heterogeneity (I2 = 28%), publication bias was observed, and interstudy discrepancies in the diagnostic criteria adopted for hyperemesis gravidarum limit the reliability of findings. Also, 15 of the included studies were from the same country (Turkey), which could limit the generalizability of current findings. The prevalence of H. pylori infection varies throughout the world, and there may also be pathogenic differences as most strains of H. pylori in East Asia carry the cytotoxin‐associated gene A gene.

Conclusion

H. pylori infection was associated with an increased likelihood of hyperemesis gravidarum during pregnancy. Given the high prevalence of H. pylori infections worldwide, detecting H. pylori infection and the eradication of maternal H. pylori infection could be part of maternal hyperemesis gravidarum management. Further confirmation with robust longitudinal studies and mechanistic investigations are needed.  相似文献   

12.

Background  

Cystic fibrosis (CF) is an inherited multi-system disorder characterised by chronic airway infection with pathogens such as Pseudomonas aeruginosa.  相似文献   

13.

Background  

The use of a multistarter fermentation process with Saccharomyces cerevisiae and non-Saccharomyces wine yeasts has been proposed to simulate natural must fermentation and to confer greater complexity and specificity to wine. In this context, the combined use of S. cerevisiae and immobilized Starmerella bombicola cells (formerly Candida stellata) was assayed to enhance glycerol concentration, reduce ethanol content and to improve the analytical composition of wine. In order to investigate yeast metabolic interaction during controlled mixed fermentation and to evaluate the influence of S. bombicola on S. cerevisiae, the gene expression and enzymatic activity of two key enzymes of the alcoholic fermentation pathway such as pyruvate decarboxylase (Pdc1) and alcohol dehydrogenase (Adh1) were studied.  相似文献   

14.

Background  

The genes of plants can be up- or down-regulated during viral infection to influence the replication of viruses. Identification of these differentially expressed genes could shed light on the defense systems employed by plants and the mechanisms involved in the adaption of viruses to plant cells. Differential gene expression in Nicotiana benthamiana plants in response to infection with Bamboo mosaic virus (BaMV) was revealed using cDNA-amplified fragment length polymorphism (AFLP).  相似文献   

15.

Background  

Legionella pneumophila, the intracellular bacterial pathogen that causes Legionnaires' disease, exhibit characteristic transmission traits such as elevated stress tolerance, shortened length and virulence during the transition from the replication phase to the transmission phase. ClpP, the catalytic core of the Clp proteolytic complex, is widely involved in many cellular processes via the regulation of intracellular protein quality.  相似文献   

16.
17.

Background  

Verticillium spp. are major pathogens of dicotyledonous plants such as cotton, tomato, olive or oilseed rape. Verticillium symptoms are often ambiguous and influenced by development and environment. The aim of the present study was to define disease and resistance traits of the complex Verticillium longisporum syndrome in Arabidopsis thaliana (L.) Heynh. A genetic approach was used to determine genetic, developmental and environmental factors controlling specific disease and resistance traits and to study their interrelations.  相似文献   

18.

Background  

Modification of teichoic acids with D-alanine by the products of the dlt operon protects Gram-positive bacteria against major antimicrobial host defense molecules such as defensins, cathelicidins, myeloperoxidase or phospholipase. The graRS regulatory genes have recently been implicated in the control of D-alanylation in Staphylococcus aureus.  相似文献   

19.
20.

Background  

FK506 binding proteins (FKBPs) and cyclophilins (CYPs) are abundant and ubiquitous proteins belonging to the peptidyl-prolyl cis/trans isomerase (PPIase) superfamily, which regulate much of metabolism through a chaperone or an isomerization of proline residues during protein folding. They are collectively referred to as immunophilin (IMM), being present in almost all cellular organs. In particular, a number of IMMs relate to environmental stresses.  相似文献   

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