Functional Identification and Genetic Analysis of O-Antigen Gene Clusters of Food-Borne Pathogen Yersinia enterocolitica O:10 and Other Uncommon Serotypes, Further Revealing Their Virulence Profiles

Hu Bin,Wang Jing,Li Linxing,Wang Qin,Qin Jingliang,Chi Yingxin,Yan Junxiang,Sun Wenkui,Cao Boyang,Guo Xi 한국미생물·생명공학회 2024 Journal of microbiology and biotechnology Vol.34 No.8

Yersinia enterocolitica is a globally distributed food-borne gastrointestinal pathogen. The O-antigen variation-determined serotype is an important characteristic of Y. enterocolitica, allowing intraspecies classification for diagnosis and epidemiology purposes. Among the 11 serotypes associated with human yersiniosis, O:3, O:5,27, O:8, and O:9 are the most prevalent, and their O-antigen gene clusters have been well defined. In addition to the O-antigen, several virulence factors are involved in infection and pathogenesis of Y. enterocolitica strains, and these are closely related to their biotypes, reflecting pathogenic properties. In this study, we identified the O-AGC of a Y. enterocolitica strain WL-21 of serotype O:10, and confirmed its functionality in O-antigen synthesis. Furthermore, we analyzed in silico the putative O-AGCs of uncommon serotypes, and found that the O-AGCs of Y. enterocolitica were divided into two genetic patterns: (1) O-AGC within the hemH-gsk locus, possibly synthesizing the O-antigen via the Wzx/Wzy dependent pathway, and (2) O-AGC within the dcuC-galU-galF locus, very likely assembling the O-antigen via the ABC transporter dependent pathway. By screening the virulence genes against genomes from GenBank, we discovered that strains representing different serotypes were grouped according to different virulence gene profiles, indicating strong links between serotypes and virulence markers and implying an interaction between them and the synergistic effect in pathogenicity. Our study provides a framework for further research on the origin and evolution of O-AGCs from Y. enterocolitica, as well as on differences in virulent mechanisms among distinct serotypes.

Transcriptional Analysis of 10 Selected Genes in a Model of Penicillin G Induced Persistence of Chlamydophila psittaci in HeLa Cells

( Yan Qun Hu ),( Li Li Chen ),( Chuan Wang ),( Ya Feng Xie ),( Zhi Xi Chen ),( Liang Zhuan Liu ),( Ze Hong Su ),( Yi Mou Wu ) 한국미생물 · 생명공학회 2015 Journal of microbiology and biotechnology Vol.25 No.8

Chlamydophila psittaci is an important intracellular pathogen. Persistent infection is an important state of the host-parasite interaction in this chlamydial infection, which plays a significant role in spreading the organism within animal populations and in causing chronic chlamydiosis and serious sequelae. In this study, a C. psittaci persistent infection cell model was induced by penicillin G, and real-time quantitative PCR was used to study the transcriptional levels of 10 C. psittaci genes (dnaA, dnaK, ftsW, ftsY, grpE, rpsD, incC, omcB, CPSIT_0846, and CPSIT_0042) in acute and penicillin-G-induced persistent infection cultures. Compared with the acute cultures, the penicillin-G-treated cultures showed a reduced chlamydial inclusion size and a significantly decreased number of elementary body particles. Additionally, some enlarged aberrant reticulate body particles were present in the penicillin- G-treated cultures but not the acute ones. The expression levels of genes encoding products for cell division (FtsW, FtsY) and outer membrane protein E encoding gene (CPSIT_0042) were downregulated (p < 0.05) from 6 h post-infection onward in the persistent infection cultures. Also from 6 h post-infection, the expression levels of DnaA, DnaK, IncC, RpsD, GrpE, and CPSIT_0846 were upregulated (p < 0.05); however, the expression level of OmcB in the persistent infection was almost the same as that in the acute infection (p > 0.05). These results provide new insight regarding molecular activities that accompany persistence of C. psittaci, which may play important roles in the pathogenesis of C. psittaci infection.

Nuclear DNA content variation of three Miscanthus species in China

Xi Li,Die Hu,Manman Luo,Ming Zhu,Xinwei Li,Fan Luo,Jianqiang Li,Juan Yan 한국유전학회 2013 Genes & Genomics Vol.35 No.1

In order to estimate the variation in nuclear genome size in Miscanthus, flow cytometry of nuclei stained by propidium iodide was carried out using 36 populations of three Miscanthus species: M. lutarioriparius, M. sacchariflorus and M. sinensis, which were sampled from cold northern to warm and humid southern and central China, as well as near the sea level in eastern China to mountains in western China. The DNA content of diploid was 4.37 ±0.02 pg/2C in M. lutarioriparius, 4.37 ± 0.01 pg/2C in M. sacchariflorus, and 5.37 ± 0.03 pg/2C in M. sinensis,respectively. There was no intraspecific variation in the three Miscanthus species at the diploid level, suggesting that the genome size was stable within species and the diverse environments did not induce variation in genome size at the diploid level. However, tetraploid populations were found in M. lutarioriparius and M. sacchariflorus, and their genome sizes were 8.56 and 8.54 pg, respectively, which are lower than expected values (8.74 pg), indicating the genome downsizing after polyploidization in the genus. Our results showed that the plant height of M. lutarioriparius was the highest one among the three species and the species was more closely related to M. sacchariflorus than M. sinensis. The intra-species genomic variation and inter-species differentiation in Miscanthus species provide important genetic and genomic information for the development of Miscanthus,especially for the endemic species, M. lutarioriparius,(together with Miscanthus 9 giganteus) which are now emerging as a key bio-energy crop because of their high yields and strong adaptability.

Constrained Markov Control Model and Online Stochastic Optimization Algorithm for Power Conservation in Multimedia Server Cluster Systems

Han Hu,Jian Yan,Liyue Zhu,Hong-Sheng Xi 제어·로봇·시스템학회 2012 International Journal of Control, Automation, and Vol.10 No.6

This paper presents a novel Markov switching state space control model for dynamically switching resource configuration scheme to achieve power conservation for multimedia server cluster systems. This model exploits the hierarchical dynamic structure of network system and its construction is flexible and scalable. Using this analytical model, the problem of power conservation is posed as a constrained stochastic optimization problem with the goal of minimizing the average power consump-tion subject to the constraint on the average blocking ratio. Applying Lagrange approach and online estimation of the performance gradient, a policy iteration algorithm is proposed to search the optimal policy online. This algorithm does not depend on any prior knowledge of system parameters, and con-verges to the optimal solution. Simulation results demonstrate the convergence of the proposed algo-rithm and effectiveness to different access workloads.

Whole body hypoxic preconditioning-mediated multiorgan protection in db/db mice via nitric oxide-BDNF-GSK-3β-Nrf2 signaling pathway

Yuefang Li,Yan Huang,Xi Cheng,Youjun He,Xin Hu 대한생리학회-대한약리학회 2021 The Korean Journal of Physiology & Pharmacology Vol.25 No.4

The beneficial effects of hypoxic preconditioning are abolished in the diabetes. The present study was designed to investigate the protective effects and mechanisms of repeated episodes of whole body hypoxic preconditioning (WBHP) in db/db mice. The protective effects of preconditioning were explored on diabetes-induced vascular dysfunction, cognitive impairment and ischemia-reperfusion (IR)-induced increase in myocardial injury. Sixteen-week old db/db (diabetic) and C57BL/6 (non-diabetic) mice were employed. There was a significant impairment in cognitive function (Morris Water Maze test), endothelial function (acetylcholine-induced relaxation in aortic rings) and a significant increase in IR-induced heart in-jury (Langendorff apparatus) in db/db mice. WBHP stimulus was given by exposing mice to four alternate cycles of low (8%) and normal air O2 for 10 min each. A single episode of WBHP failed to produce protection; however, two and three episodes of WBHP significantly produced beneficial effects on the heart, brain and blood vessels. There was a significant increase in the levels of brain-derived neurotrophic factor (BDNF) and nitric oxide (NO) in response to 3 episodes of WBHP. Moreover, pretreat-ment with the BDNF receptor, TrkB antagonist (ANA-12) and NO synthase inhibitor (L-NAME) attenuated the protective effects imparted by three episodes of WBHP. These pharmacological agents abolished WBHP-induced restoration of p-GSK-3β/GSK-3βratio and Nrf2 levels in IR-subjected hearts. It is concluded that repeated episodes of WHBP attenuate cognitive impairment, vascular dysfunction and enhancement in IR-induced myocardial injury in diabetic mice be due to increase in NO and BDNF levels that may eventually activate GSK-3β and Nrf2 signaling pathway to confer protec-tion.

Optimal Tracking Performance of NCSs with Time-delay and Encoding-decoding Constraints

Jun-Wei Hu,Xi-Sheng Zhan,Jie Wu,Huai-Cheng Yan 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.4

In this paper, the tracking performance of networked control systems (NCSs) under energy constraints with time-delay and encoding-decoding is studied. Through spectral factorization and partial decomposition techniques, we can obtain the explicit representation of the optimal performance. It is shown that the optimal performance is affected by non minimum phase (NMP) zeros, unstable poles and other multiple communication constraints such as time-delay, encoding-decoding and additive white Gaussian noise (AWGN). At the same time, the obtained result shows that a two-parameter compensator is superior to a one-parameter compensator. In addition, it is found that time-delay, encoding-decoding and AWGN affected the tracking capability of NCSs. Finally, an example is given for verifying the correctness of the conclusions.

Vesicular Stomatitis Virus G Glycoprotein and ATRA Enhanced Bystander Killing of Chemoresistant Leukemic Cells by Herpes Simplex Virus Thymidine Kinase/Ganciclovir

( Bin Yin ),( Chen Xi Hu ),( Zheng Chen ),( Wen Jun Zhao ),( Li Rong Wei ),( Yan Wen Zheng ),( Chao He ),( Yan Zeng ) 한국응용약물학회 2014 Biomolecules & Therapeutics(구 응용약물학회지) Vol.22 No.2

Vesicular Stomatitis Virus G Glycoprotein and ATRA EnhancedBystander Killing of Chemoresistant Leukemic Cells by HerpesSimplex Virus Thymidine Kinase/Ganciclovir

THE PERIODIC JACOBI MATRIX PROCRUSTES PROBLEM

Jiao-fen Li,XI-YAN HU 한국전산응용수학회 2010 Journal of applied mathematics & informatics Vol.28 No.3

The following ”Periodic Jacobi Procrustes” problem is stud-ied: find the Periodic Jacobi matrix X which minimizes the Frobenius (or Euclidean) norm of AX −B, with A and B as given rectangular matrices. The class of Procrustes problems has many application in the biological,physical and social sciences just as in the investigation of elastic struc-tures. The different problems are obtained varying the structure of the matrices belonging to the feasible set. Higham has solved the orthogonal,the symmetric and the positive definite cases. Andersson and Elfving have studied the symmetric positive semidefinite case and the (symmetric) el-ementwise nonnegative case. In this contribution, we extend and develop these research, however, in a relatively simple way. Numerical difficulties are discussed and illustrated by examples.

THE PERIODIC JACOBI MATRIX PROCRUSTES PROBLEM

Li, Jiao-Fen,Hu, Xi-Yan The Korean Society for Computational and Applied M 2010 Journal of applied mathematics & informatics Vol.28 No.3

The following "Periodic Jacobi Procrustes" problem is studied: find the Periodic Jacobi matrix X which minimizes the Frobenius (or Euclidean) norm of AX - B, with A and B as given rectangular matrices. The class of Procrustes problems has many application in the biological, physical and social sciences just as in the investigation of elastic structures. The different problems are obtained varying the structure of the matrices belonging to the feasible set. Higham has solved the orthogonal, the symmetric and the positive definite cases. Andersson and Elfving have studied the symmetric positive semidefinite case and the (symmetric) elementwise nonnegative case. In this contribution, we extend and develop these research, however, in a relatively simple way. Numerical difficulties are discussed and illustrated by examples.

The solvability conditions for a class of constrained inverse eigenvalue problem of antisymmetric matrices

Xiao-ping Pan,Xi-yan Hu,Lei Zhang 대한수학회 2006 대한수학회지 Vol.43 No.1

In this paper, a class of constrained inverse eigenvalue problem for antisymmetric matrices and their optimal approximation problem are considered. Some sufficient and necessary conditions of the solvability for the inverse eigenvalue problem are given. A general representation of the solution is presented for a solvable case. Furthermore, an expression of the solution for the optimal approximation problem is given.