Recent progress in microbial cell surface display systems and their application on biosensors

Microbial cell surface display technology is a recombinant technology to express target proteins on the cell membrane,which can be used to redesign the cell surface with functional proteins and peptides.Bacterial and yeast surface display systems are the most common cell surface display systems of prokaryotic and eukaryotic proteins,that are widely applied as the core elements in the field of biosensors due to their advantages,including enhanced stability,high yield,good safety,expression of larger and more complex proteins.To further promote the performance of biosensors,the biomineralized microbial surface display technology was proposed.This review summarized the different microbial surface display systems and the biomineralized surface display systems,where the mechanisms of surface display and biomineralization were introduced.Then we described the recent progress of their applications on biosensors for different types of detection targets.Finally,the outlooks and tendencies were discussed and forecasted with the expectation to provide some general functions and enlightenments to this aspect of research.

Interannual variability of eddy kinetic energy in the South China Sea related to two types of winter circulation events

Interannual variations of the eddy kinetic energy(EKE)related to two types of winter circulation events(“O”and“U”)were investigated based on the outputs of the Ocean General Circulation Model(OGCM)for the Earth Simulator(OFES)and the corresponding energetic analyses.Results show that the EKE is strong and extends eastward to offshore the Vietnam coast about 2°,associated with the weaker South China Sea western boundary current(SCSwbc)in“O”type years,while the EKE is weak and high value that can be attained is narrowed along the coast,associated with the stronger SCSwbc in“U”type years.The energy budget shows that the wind stress and barotropic/baroclinic instability are important factors to regulate the EKE in“U”and“O”years.For“U”years,under a strong winter monsoon forcing,the SCSwbc strengthen,the directly wind work and barotropic conversion from the mean kinetic energy(MKE)to EKE are weak,thus the EKE decrease corresponding to the baroclinic conversion from the kinetic energy to potential energy.However,the situation is reversed in“O”years.Under the influence of El Niño events,wind stress forces can weaken SCSwbc and enhance EKE in pattern“O”,whereas La Niña events have relatively weaker influences.The barotropic conversion rate in“O”type is nearly eight times of the“U”type.The pressure work and advection term are the main sources to greatly suppress EKE in the SCSwbc region.

Determining the transcriptional regulation pattern of PgTIP1 in transgenic Arabidopsis thaliana by constructing gene

The seed size, seed mass, and growth rate of transgenic Arabidopsis plants containing PgTIP1, a ginseng tonoplast aquaporin gene, are significantly higher than those of wild-type Arabidopsis plants. Whole genome expression and bioinformatics analysis, including analysis of co-expression networks and transcription factors (Tfscan), were used to determine the key genes that are activated after the expression of PgTIP1 and the transcription factors that play important roles in the regulation of the genes controlling growth of Arabidopsis thaliana seeds by using transgenic Arabidopsis plants containing PgTIP1. Differential gene analysis showed that transformation of exogenous PgTIP1 to Arabidopsis induced endogenous gene expression changes. Analysis of gene co-expression networks revealed 2 genes, PIP1 (plasma membrane aquaporin 1 gene) and RD26 (responsive to desiccation 26 gene;a NAC transcription factor), that were localized in the core of the networks. Analysis of the transcriptional regulation network of transgenic Arabidopsis plants containing PgTIP1 showed that PIP1 and RD26 were regulated via DNA binding with a finger domain on transcription factor 2 (Dof2). In this study, we demonstrated that Dof2 induces up-regulation of PIP1 and RD26 after transformation with PgTIP1. The results of this study provide a new means for conducting research into and controlling growth of Arabidopsis thaliana seeds.

显微镜下三联手术治疗合并白内障的孔源性视网膜脱离的效果

目的:分析显微镜下白内障超声乳化吸除、人工晶状体植入和巩膜外加压三联手术治疗合并白内障的孔源性视网膜脱离(RRD)的疗效。方法:回顾性研究。选择2010年1月至2017年12月在常熟市第二人民医院眼科住院的合并白内障的RRD患者17例(17眼)。患者均在显微镜下行白内障超声乳化吸除、人工晶状体植入和巩膜外加压三联手术,术后随访观察视网膜的解剖复位、视力、并发症等情况,随访时间为(15.2±3.6)个月。手术前后最佳矫正视力(BCVA)及预设术后屈光度与术后实测屈光度的比较行Wilcoxon符号秩和检验。结果:所有术眼的视网膜裂孔在显微镜下清晰可见,视网膜压嵴位置良好,裂孔封闭,视网膜均解剖复位,视力较术前明显提高(Z=3.825,P<0.001)。预设屈光度与术后实测屈光度差异无统计学意义(Z=1.519,P=0.13)。术后I到II级角膜内皮水肿2眼,一过性高眼压2眼,轻中度前房纤维蛋白渗出2眼,不同程度后囊膜混浊4眼,黄斑前膜1眼,未出现视网膜下液引流和玻璃体腔感染、眼底出血等并发症。结论:显微镜下白内障超声乳化吸除、人工晶状体植入和巩膜外加压三联手术能安全有效治疗合并白内障的RRD。

The oral microbiome of pregnant women facilitates gestational diabetes discrimination

The oral microbiota plays an important role in the development of various diseases,whereas its association with gestational diabetes mellitus (GDM) remains largely unclear.The aim of this study is to identify biomarkers from the oral microbiota of GDM patients by analyzing the microbiome of the saliva and dental plaque samples of 111 pregnant women.We find that the microbiota of both types of oral samples in GDM patients exhibits differences and significantly varies from that of patients with periodontitis or dental caries.Using bacterial biomarkers from the oral microbiota,GDM classification models based on support vector machine and random forest algorithms are constructed.The area under curve (AUC) value of the classification model constructed by combination of Lautropia and Neisseria in dental plaque and Streptococcus in saliva reaches 0.83,and the value achieves a maximum value of 0.89 by adding clinical features.These findings suggest that certain bacteria in either saliva or dental plaque can effectively distinguish women with GDM from healthy pregnant women,which provides evidence of oral microbiome as an informative source for developing noninvasive biomarkers of GDM.

A relatively high zoonotic trematode prevalence in Orientogalba ollula and the developmental characteristics of isolated trematodes by experimental infection in the animal model

Background:Food-borne parasitic diseases decrease food safety and threaten public health.The snail species is an intermediate host for numerous human parasitic trematodes.Orientogalba ollula has been reported as intermediate hosts of many zoonotic trematodes.Here,we investigated the prevalence of zoonotic trematodes withinO.ollula in Guangxi,China,and assessed their zoonotic potential.Methods:Snails were collected from 54 sites in 9 cities throughout Guangxi.The snail and trematode larvae species were determined by combining morphological characteristics and molecular markers.The trematodes prevalence and constituent ratio were calculated and compared among different habitat environments.Phylogenetic trees of the trematode species were constructed using the neighbor-joining method with nuclear internal transcribed spacer 2(ITS2)sequences.The developmental cycles of the isolated trematodes were examined by experimental infection in ducks.The developmental characteristics ofEchinostoma revolutum was recorded by dissecting infected ducklings from 1-day post infection(dpi)to 10 dpi.Results:The overall prevalence of trematode larvae was 22.1%(1818/8238)inO.ollula from 11 sample sites.Morphological together with molecular identification,showed thatE.revolutum,Australapatemon sp.,Hypoderaeum conoideum,Pharyngostomum cordatum,andEchinostoma sp.parasitizedO.ollula,with the highest infection rate ofE.revolutum(13.0%).However,noFasciola larvae were detected.The trematodes prevalence and constituent ratio varied in two sub-biotypes(P<0.01).A neighbor-joining tree analysis of ITS2 sequences resulted in distinct monophyletic clades supported by sequences from isolated larvae with high bootstrap values.Ducklings exposed toO.ollula infected withEchinostoma sp.,E.revolutum,andH.conoideum larvae were successfully infected.The animal model forEchinostoma revolutum was successfully established.E.revolutum matured from larvae to adult at 10 dpi in the intestine of the duck,and the developmental characteristics ofE.revolutum were characterized by the maturation of the reproductive and digestive organs at 6-8 dpi.Conclusions:This study revealed a high prevalence of zoonotic trematodes inO.ollula from Guangxi,China.Existing trematodes infection in animals and human clinical cases,coupled with the wide geographical distribution ofO.ollula,necessitate further evaluations of the potential risk of spillover of zoonotic infection from animal to human and vice versa.

Purification of ice structuring protein complexes from winter wheat using Triton X-114 phase partitioning

Ice structuring proteins(ISPs)isolated from the cold-acclimated plants have a great potential in improving the quality of frozen foods.The purification of ISP complexes from winter wheat was achieved using an aqueous two-phase system of Triton X-114.The highly reactive phenols were removed,and the ISP complexes remained in the aqueous phase after phase separation.The ISP complexes treated by this procedure retained higher thermal hysteresis activity than those treated by ammonium sulfate method.The phase separation technique provides a simple and mild way for removing phenols from ISP complexes.

Isolation and in vitro cultivation of Babesia venatorum(Apicomplexa:Babesiidae),a zoonotic hemoprotozoan from Ixodes persulcatus ticks in China

The emerging Babesia venatorum upsurges as a potential health threat occurring in China and other endemic countries.Few attempts to isolate and culture the Babesia species had been conducted in vitro.We collected the questing Ixodes persulcatus from identified endemic areas and allowed them to feed on the severe combined immunodeficiency(SCID)mice.The positive mice were chosen to provide positive erythrocytes with asexual B.venatorum for continuous culture in mouse or human erythrocytes in vitro,with RPMI 1640 medium and appropriate serum.With B.venatorum in the SCID mice,erythrocytes were cultured in vitro for confirmation by morphological observations with transmission electron microscopes.Sequences of B.venatorum were then identified by way of conventional PCR amplification.Parasitemia counts monitored the growth of B.venatorum on thin blood smears and real-time quantitative PCR in parallel.As expected,B.venatorum positive mice were harvested by sufficient attacks of I.persulcatus ticks.The erythrocytes of the infected mice were then inoculated and successfully cultured in donated erythrocytes from humans and mice in RPMI 1640 culture medium.Active growth of B.venatorum was well demonstrated in human erythrocytes with 3.3 times parasite-load when compared with a mouse under similar conditions.With the increased subcultures,a prolonged period of detectable parasitemia with much higher peak parasitemia and shorter time to reach peak parasitemia were observed in the following subcultures.A new strategy for isolation and in vitro culture of B.venatorum has been provided with a continuous supply of sufficient pathogens to satisfy human babesiosis's testings and clinical therapies.

Genomic Characterization of a New Coronavirus from Migratory Birds in Jiangxi Province of China

Dear Editor,The emergence of COVID-19 since December 2019 has attracted great attention around the world and reminds the powerful pathogenic potential of viruses(Zhou et al.2020).The subfamily Orthocoronavirinae of the family Coronaviridae contains four genera Alphacoronavirus,Betacoronavirus,Gammacoronavirus,and Deltacoronavirus,which are the largest group of positive-sense,non-segmented,single-stranded,enveloped RNA viruses(Woo et al.2012;Shi et al.2016).The genus Gammacoronavirus currently has five species(https://talk.ictvonline.org/taxonomy/),which are primarily spread through birds(Woo et al.2012).

天时地利星坠如雨

流星雨来自于彗星或小行星弥散在轨道上的细小物质,当它们成群地高速冲入大气层并发光时,就形成了流星雨。比如猎户座流星雨就是由著名的哈雷彗星形成的,而双子座流星雨的母体是小行星法厄同。流星雨稍纵即逝,莫慌,快门一样可以锁住它们的魅影。