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Staphylococcus aureus is a pathogen that is the causative agent of several human and veterinary infections and plays a critical role in the clinical and subclinical mastitis of cattle. Autophagy is a conserved pathogen defence mechanism in eukaryotes. Studies have reported that S aureus can subvert autophagy and survive in cells. Staphylococcus aureus survival in cells is an important cause of chronic persistent mastitis infection. However, it is unclear whether S aureus can escape autophagy in innate immune cells. In this study, initiation of autophagy due to the presence of S aureus was detected in bovine macrophages. We observed autophagic vacuoles increased after S aureus infection of bovine macrophages by transmission electron microscopy (TEM). It was also found that S aureus‐infected bovine macrophages increased the expression of LC3 at different times(0, 0.5, 1, 1.5, 2, 2.5, 3 and 4 hours). Data also showed the accumulation of p62 induced by S aureus infection. Application of autophagy regulatory agents showed that the degradation of p62 was blocked in S aureus induced bovine macrophages. In addition, we also found that the accumulation of autophagosomes promotes S aureus to survive in macrophage cells. In conclusion, this study indicates that autophagy occurs in S aureus‐infected bovine macrophages but is blocked at a later stage of autophagy. The accumulation of autophagosomes facilitates the survival of S aureus in bovine macrophages. These findings provide new insights into the interaction of S aureus with autophagy in bovine macrophages.

Dimethyl itaconate (DI) is a membrane‐permeable itaconate derivative with anti‐inflammatory functions. However, the anti‐inflammatory effect of DI has never been studied in fungal keratitis. In this study, we tested the protective effect of DI against fungal keratitis and assessed the role of NF‐E2‐related factor‐2 (Nrf2)/heme oxygenase‐1 (HO‐1) signaling in this process. Eyes of C57BL/6 (B6) mice were treated with 2 mm DI after infection with Aspergillus fumigatus. Human corneal epithelial cells (HCECs) were pretreated with 0.25 mm DI and then incubated with A. fumigatus. Clinical scoring, slit‐lamp photography, myeloperoxidase determination, flow cytometry and immunostaining were used to assess the disease response and treatment efficacy. PCR, Western blot and ELISA were used to assess the expression of interleukin‐1β (IL‐1β), chemokine (C–X–C motif) ligand 1, IL‐6, IL‐8, Nrf2 and HO‐1. In addition, quantification of viable fungi, absorbance assays and fluorimetry were used to measure DI fungistatic activity. We observed that DI‐treated eyes showed decreased clinical scores, fungal loads, polymorphonuclear neutrophil (PMN) infiltration and cytokine expression, compared with phosphate‐buffered saline‐treated infected eyes. DI treatment decreased the cytokine levels in infected corneas and in HCECs stimulated with A. fumigatus. Moreover, DI treatment increased Nrf2 and HO‐1 expression in corneas and nuclear Nrf2 accumulation in HCECs. DI‐induced cytokine downregulation was inhibited by pretreatment with an Nrf2 or HO‐1 inhibitor. Finally, DI treatment reduced the A. fumigatus absorbance and fungal mass. These data indicate that DI protects against fungal keratitis by limiting inflammation via the Nrf2/HO‐1 signaling pathway and that DI inhibits the growth of A. fumigatus., In this study, we showed that dimethyl itaconate (DI) exerts protective effects in fungal keratitis. On the one hand, DI alleviates inflammation by activating the NF‐E2‐related factor‐2 (Nrf2)/heme oxygenase‐1 (HO‐1) signaling pathway in Aspergillus fumigatus‐induced keratitis. On the other hand, DI reduces the fungal load and inhibits the growth of A. fumigatus.

Summary Focusing on solving the control problem of the multimachine excitation systems with static var compensator (SVC), this paper proposes a decentralized neural adaptive dynamic surface control...

Type VI secretion system (T6SS) is a secretory system found in Gram-negative bacteria. One of the main structures for T6SS is Hcp (hemolysin co-regulation protein) pipeline. To investigate the role of Hcp major sub-unit genes hcp1 and hcp2 , we deleted hcp1 and hcp2 genes for constructing the in-frame gene deletion mutants. The properties of biofilm formation and the adhesion to chicken embryo fibroblasts cells (DF1 cells) were reduced in the hcp2 mutant. The knockout of hcp1 and hcp2 genes reduced the ability of the avian pathogenic Escherichia coli (APEC) strain CE129 to infect developing chicken embryos. The expression of quorum sensing (QS)-associated genes luxS, lsrR, and pfs were down-regulated in the hcp1 mutant, and the expression of type 1 fimbriae gene fimA and the adhesion-related genes fimC and papC were decreased in the hcp2 mutant, as well as the expression of anti-serum survival factor genes ompA and iss were inhibited in both hcp1 and hcp2 mutants. These results described above from this study help to further elaborate the role of HCP in APEC.

Due to the inherent expression stability and low metabolic burden to the host cell, the expression of heterologous proteins in the bacterial chromosome in a precise and efficient manner is highly desirable for metabolic engineering and live bacterial applications. However, obtaining suitable chromosome expression levels is particularly challenging. In this minireview, we briefly present the technologies available for the integration of heterologous genes into Escherichia coli chromosomes and strategies to optimize the expression levels of heterologous proteins.

Summary The type III secretion system (T3SS) is an important genetic determinant that mediates interactions between Gram-negative bacteria and their eukaryotic hosts. Our understanding of the T3SS continues to expand, yet the availability of new bacterial genomes prompts questions about its diversity, distribution and evolution. Through a comprehensive survey of ∼20 000 bacterial genomes, we identified 174 non-redundant T3SSs from 109 genera and 5 phyla. Many of the bacteria are environmental strains that have not been reported to interact with eukaryotic hosts, while several species groups carry multiple T3SSs. Four ultra-conserved Microsynteny Blocks (MSBs) were defined within the T3SSs, facilitating comprehensive clustering of the T3SSs into 13 major categories, and establishing the largest diversity of T3SSs to date. We subsequently extended our search to identify type III effectors, resulting in 8740 candidate effectors. Lastly, an analysis of the key transcriptional regulators and circuits for the T3SS families revealed that low-level T3SS regulators were more conserved than higher-level regulators. This comprehensive analysis of the T3SSs and their protein effectors provides new insight into the diversity of systems used to facilitate host-bacterial interactions.

CD4+ NKG2D+ T cells are associated with tumour, infection and autoimmune diseases. Some CD4+ NKG2D+ T cells secrete IFN-γ and TNF-α to promote inflammation, but others produce TGF-β and FasL to facilitate tumour evasion. Here, murine CD4+ NKG2D+ T cells were further classified into NK1.1- CD4+ NKG2D+ and NK1.1+ CD4+ NKG2D+ subpopulations. The frequency of NK1.1- CD4+ NKG2D+ cells decreased in inflamed colons, whereas more NK1.1+ CD4+ NKG2D+ cells infiltrated into colons of mice with DSS-induced colitis. NK1.1- CD4+ NKG2D+ cells expressed TGF-β and FasL without secreting IFN-γ, IL-21 and IL-17 and displayed no cytotoxicity. The adoptive transfer of NK1.1- CD4+ NKG2D+ cells suppressed DSS-induced colitis largely dependent on TGF-β. NK1.1- CD4+ NKG2D+ cells did not expressed Foxp3, CD223 (LAG-3) and GITR. The subpopulation was distinct from NK1.1+ CD4+ NKG2D+ cells in terms of surface markers and RNA transcription. NK1.1- CD4+ NKG2D+ cells also differed from Th2 or Th17 cells because the former did not express GATA-3 and ROR-γt. Thus, NK1.1- CD4+ NKG2D+ cells exhibited immune regulatory functions, and this T cell subset could be developed to suppress inflammation in clinics.

A pioneering study showed that the glycosphingolipid biosynthesis-globo series pathway genes (FUT1, FUT2, ST3GAL1, HEXA, HEXB, B3GALNT1 and NAGA) may play an important regulatory role in resistance to Escherichia coli F18 in piglets. Therefore, we analysed differential gene expression in 11 tissues of two populations of piglets sensitive and resistant respectively to E. coli F18 and the correlation of differential gene expression in duodenal and jejunal tissues. We found that the mRNA expression of the seven genes was relatively high in spleen, liver, lung, kidney, stomach and intestinal tract; the levels in thymus and lymph nodes were lower, with the lowest levels in heart and muscle. FUT2 gene expression in the duodenum and jejunum of the resistant population was significantly lower than that in the sensitive group (P

The FaeG subunit is the major constituent of F4(+) fimbriae, associated with glycoprotein and/or glycolipid receptor recognition and majorly contributes to the pathogen attachment to the host cells. To investigate the key factor involved in the fimbrial binding of F4(+) Escherichia coli, both the recombinant E. coli SE5000 strains carrying the fae operon gene clusters that express the different types of fimbriae in vitro, named as rF4ab, rF4ac, and rF4ad, respectively, corresponding to the fimbrial types F4ab, F4ac, and F4ad, and the three isogenic in-frame faeG gene deletion mutants were constructed. The adhesion assays and adhesion inhibition assays showed that ΔfaeG mutants had a significant reduction in the binding to porcine brush border as well as the intestinal epithelial cell lines, while the complemented strain ΔfaeG/pfaeG restored the adhesion function. The recombinant bacterial strains rF4ab, rF4ac, and rF4ad have the same binding property as wild-type F4(+) E. coli strains do and improvement in terms of binding to porcine brush border and the intestinal epithelial cells, and the adherence was blocked by the monoclonal antibody anti-F4 fimbriae. These data demonstrate that the fimbrial binding of F4(+) E. coli is directly mediated by the major FaeG subunit.

To study the genetic basis of rice flag leaf morphology, quantitative genetic analysis was conducted in a population of 37 chromosome segment substitution lines (CSSLs) of indica elite variety ‘Habataki’ in the background of japonica cultivar ‘Sasanishiki’ across three different environments. The CSSLs showed normal distribution with transgressive segregation, indicating that these four traits are controlled by polygenes. Moreover, analyses of variance showed that these traits were highly influenced by the growing environment, which are typical for polygenic quantitative traits. Seven quantitative trait loci (QTLs) on four chromosomes were detected in total: four for flag leaf width, one for flag leaf area and two for flag leaf angle. Two key QTLs, qFLW4 and qFLAG5 controlling flag leaf width and angle, respectively, were identified in all three environments. These QTLs could provide useful information for marker-assisted selection in improving the performance of plant architecture with regard to leaf angle and area. Moreover, developed CSSLs with these QTLs information are also useful research materials to reveal the importance of leaf morphology in relation to grain yield.

As locomotive organelles, flagella allow bacteria to move toward favorable environments. A flagellum consists of three parts: the basal structure (rotary motor), the hook (universal joint), and the filament (helical propeller). For ages, flagella have been generally regarded as important virulence factors, mainly because of their motility property. However, flagella are getting recognized to play multiple roles with more functions besides motility and chemotaxis. Recent evidence has pinpointed that the bacterial flagella participate in many additional processes including adhesion, biofilm formation, virulence factor secretion, and modulation of the immune system of eukaryotic cells. This mini-review summarizes data from recent studies that elucidated how flagella, as a virulence factor, contribute to bacterial pathogenicity.

Summary In this study, Agilent two-colour microarray-based gene expression profiling was used to detect differential gene expression in duodenal tissues collected from eight full-sib pairs of Sutai pigs differing in adhesion phenotype (sensitivity and resistance to Escherichia coli F18). Using a two-fold change minimum threshold, we found 18 genes that were differentially expressed (10 up-regulated and eight down-regulated) between the sensitive and resistant animal groups. Our gene ontology analysis revealed that these differentially expressed genes are involved in a variety of biological processes, including immune responses, extracellular modification (e.g. glycosylation), cell adhesion and signal transduction, all of which are related to the anabolic metabolism of glycolipids, as well as to inflammation- and immune-related pathways. Based on the genes identified in the screen and the pathway analysis results, real-time PCR was used to test the involvement of ST3GAL1 and A genes (of glycolipid-related pathways), SLA-1 and SLA-3 genes (of inflammation- and immune-related pathways), as well as the differential genes FUT1, TAP1 and SLA-DQA. Subsequently, real-time PCR was performed to validate seven differentially expressed genes screened out by the microarray approach, and sufficient consistency was observed between the two methods. The results support the conclusion that these genes are related to the E. coli F18 receptor and susceptibility to E. coli F18.

Melatonin has been shown to improve lipid metabolism and gut microbiota communities in animals and humans; however, it remains to know whether melatonin prevents obesity through gut microbiota. Here, we found that high-fat diet promoted the lipid accumulation and intestinal microbiota dysbiosis in mice, while oral melatonin supplementation alleviated the lipid accumulation and reversed gut microbiota dysbiosis, including the diversity of intestinal microbiota, relative abundances of Bacteroides and Alistipes, and functional profiling of microbial communities, such as energy metabolism, lipid metabolism, and carbohydrate metabolism. Interestingly, melatonin failed to alleviate the high-fat-induced lipid accumulation in antibiotic-treated mice; however, microbiota transplantation from melatonin-treated mice alleviated high-fat diet-induced lipid metabolic disorders. Notably, short-chain fatty acids were decreased in high-fat diet-fed mice, while melatonin treatment improved the production of acetic acid. Correlation analysis found a marked correlation between production of acetic acid and relative abundances of Bacteroides and Alistipes. Importantly, sodium acetate treatment also alleviated high-fat diet-induced lipid metabolic disorders. Taken together, our results suggest that melatonin improves lipid metabolism in high-fat diet-fed mice, and the potential mechanisms may be associated with reprogramming gut microbiota, especially, Bacteroides and Alistipes-mediated acetic acid production. Future studies are needed for patients with metabolic syndrome to fully understand melatonin's effects on body weight and lipid profiles and the potential mechanism of gut microbiota.

SEF14 fimbriae are only found in some strains of serogroup-D Salmonella such as S. enteritidis, suggesting that SEF14 fimbriae may affect serovar-specific virulence traits. In this study, we found that prevalence of sefA, sefD and sefR genes in S. dublin and S. enteritidis was 100%. In 18 isolates of S. pullorum, the prevalence of sefA gene was 100%, while the prevalence of sefD and sefR genes was 38.9% (7/18), and 11 strains isolated after 1980s did not contain any gene sefD or sefR. Interestingly, among the 7 strains of S. pullorum before 1980s, the sefD sequence has a missing base pair at position 196 and caused open reading frame (ORF) shift, resulting in a stop codon (TAG) at position 71 amino acid residual (Leu of TTA at position 214–216 shift into stop codon of TAG at position 215–217). Unlike S. pullorum, all S. enteritidis and S. dublin tested could express SEF14 fimbriae in vitro. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

The performance of a multitarget constant modulus algorithm (MU-CMA) adaptive array located on a regular conducting plate is studied in this paper. The effects of mutual coupling (MC) between array elements and diffraction caused by the conducting plate are taken into account. A hybrid method of equivalent edge current method (ECM) and moment method (MM) is employed in electromagnetic calculation to investigate the distortion of initial array pattern. We compare the capture property of three well-known MU-CMA arrays, respectively: multitarget least-squares constant modulus array (MT-LSCMA), multitarget decision-directed array (MT-DD) and least-squares despread respread multitarget constant modulus array (LS-DRMTCMA). Simulation result shows that: (i) the distorted initial pattern leads to the descending of the signal catch performance of MT-LSCMA and MT-DD; (ii) only the LS-DRMTCMA can work correctly due to its stronger anti-jamming ability in the presence of MC and diffraction. Copyright © 2006 John Wiley & Sons, Ltd.