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Search Results: 1 - 10 of 34428 matches for " Chengping Lu "
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Use of in vivo-induced antigen technology (IVIAT) for the identification of Streptococcus suis serotype 2 in vivo-induced bacterial protein antigens
Hongwei Gu, Haodan Zhu, Chengping Lu
BMC Microbiology , 2009, DOI: 10.1186/1471-2180-9-201
Abstract: Convalescent-phase sera from pigs infected with SS2 were pooled, adsorbed against in vitro antigens, and used to screen SS2 genomic expression libraries. Upon analysis of the identified proteins, we were able to assign a putative function to 40 of the 48 proteins. These included proteins implicated in cell envelope structure, regulation, molecule synthesis, substance and energy metabolism, transport, translation, and those with unknown functions. The in vivo-induced changes in the expression of 10 of these 40 genes were measured using real-time reverse transcription (RT)-PCR, revealing that the expression of 6 of the 10 genes was upregulated in the in vivo condition. The strain distribution of these 10 genes was analyzed by PCR, and they were found in the most virulent SS2 strains. In addition, protein sequence alignments of the newly identified proteins demonstrate that three are putative virulence-associated proteins.Collectively, our results suggest that these in vivo-induced or upregulated genes may contribute to SS2 disease development. We hypothesize that the identification of factors specifically induced or upregulated during SS2 infection will aid in our understanding of SS2 pathogenesis and may contribute to the control SS2 outbreaks. In addition, the proteins identified using IVIAT may be useful potential vaccine candidates or virulence markers.Streptococcus suis (S. suis) infections have been considered a major problem in the swine industry worldwide, particularly over the past 20 years. S. suis is a gram-positive, facultatively anaerobic coccus, and 35 serotypes (1-34 and 1/2) have been described based on their capsular antigens. Among these, serotype 2 (SS2) is the causative agent of many different syndromes worldwide, including meningitis, septicemia, arthritis, and pneumonia in humans, swine, and other animals [1]. In addition, SS2 is widely recognized as an important zoonotic agent that afflicts people in close contact with infected pigs or pork-deri
Microarray Analysis of the Effect of Streptococcus equi subsp. zooepidemicus M-Like Protein in Infecting Porcine Pulmonary Alveolar Macrophage
Zhe Ma, Hui Zhang, Li Yi, Hongjie Fan, Chengping Lu
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0036452
Abstract: Streptococcus equi subsp. zooepidemicus (S. zooepidemicus), which belongs to Lancefield group C streptococci, is an important pathogen of domesticated species, causing septicemia, meningitis and mammitis. M-like protein (SzP) is an important virulence factor of S. zooepidemicus and contributes to bacterial infection and antiphagocytosis. To increase our knowledge of the mechanism of SzP in infection, we profiled the response of porcine pulmonary alveolar macrophage (PAM) to infection with S. zooepidemicus ATCC35246 wild strain (WD) and SzP-knockout strain (KO) using the Roche NimbleGen Porcine Genome Expression Array. We found SzP contributed to differential expression of 446 genes, with upregulation of 134 genes and downregulation of 312 genes. Gene Ontology category and KEGG pathway were analyzed for relationships among differentially expressed genes. These genes were represented in a variety of functional categories, including genes involved in immune response, regulation of chemokine production, signal transduction and regulation of apoptosis. The reliability of the data obtained from the microarray was verified by performing quantitative real-time PCR on 12 representative genes. The data will contribute to understanding of SzP mediated mechanisms of S. zooepidemicus pathogenesis.
Determination of the mimic epitope of the M-like protein adhesin in swine Streptococcus equi subsp. zooepidemicus
Hongjie Fan, Yongshan Wang, Fuyu Tang, Chengping Lu
BMC Microbiology , 2008, DOI: 10.1186/1471-2180-8-170
Abstract: The gene encoding SzP was expressed in E. coli, and the purified recombinant SzP (rSzP) was recognized by rabbit anti-S. zooepidemicus antibodies using immunoblot. Furthermore, the adherence of S. zooepidemicus to HEp-2 cells was inhibited by anti-rSzP antibodies in a dose-dependent manner. We employed a random 12-peptide phage display library for screening of immunodominant mimics of the SzP, which were recognized by an anti-SzP specific monoclonal antibody (mAb 2C8). Initial positive phage clones were identified by ELISA, followed by assays to determine the adherence-inhibiting ability of the peptide.Ten out of fourteen selected positive clones showed high reactivity that effectively inhibited the binding of mAb 2C8 to rSzP. The motif XSLSRX was highly conserved among six of the ten clones.Collectively, our findings suggest that the motif XSLSRX may represent an immunodominant mimic epitope of the SzP of S. zooepidemicus strain ATCC 35246, and that the same epitope may be used to mediate SzP binding to HEp-2 cells.Streptococcus equi subsp. zooepidemicus (S. zooepidemicus), which belongs to Lancefield group C streptococci, is an important animal pathogen, especially in horse [1]. It has a broad host spectrum and occasionally infects humans. Human infections may occur following ingestion of unpasteurized milk or dairy products [2], or after contact with pigs [3]. In China, S. zooepidemicus is the main pig pathogen. In the summer of 1975, a S. zooepidemicus disease outbreak occurred among pigs in the Sichuan province, China. Clinical symptoms of the diseased pigs included painful swelling of the joints, respiratory disturbances, and diarrhea. More than 300,000 pigs died within two weeks. According to bacteriological examinations, S. zooepidemicus was isolated from most of the diseased pigs, and it appeared to be one of the major causative agents [4].M protein is an important virulence factor of group A streptococci: this fibrillar, surface-exposed protein deters opso
Effects of Aeromonas hydrophila Biofilm on the Drug Resistance

Zhang Jihong Lu Chengping,

微生物学报 , 2003,
Abstract: Aeromonas hydrophila (Ah) biofilm (BF) model in vitro was established and antibiotic effects of 11 antimicrobials on BF and free-cell(FC) bacteria were tested. After the Ah J-1 on the surfaces of the silicon pieces was incubated for 7 days in TSB, the intact BF was formed by detection of AgNO3 solution staining. The FC bacteria were resistant to Penicillin but susceptible to Enrofloxacin and Fulgram. Their minimum bactericidal concentrations (MBCs) were 256 microg/mL, 0.03 microg/mL and 0.25 microg/mL respectively. Florfenicol had a strong antibacterial effect on BF bacteria and the ratio of MBC between BF and FC bacteria was 2 to 1, but more than 32 to 1 occurred for Kanamycin, Penicillin and Neomycin. Morphology and structure of BFs with/without the treatment of Enrofloxacin were observed under scanning electron microscope, while the bactericidal curve was detected. Enrofloxacin could eradicate the FC bacteria completely but not the BF bacteria at a concentration of 4 fold MBC. The 32 fold MBC Enrofloxacin could entirely kill the FC bacteria in 4h, but in 24h for BF bacteria. The result suggested that BF enabled Ah to have strong resistance to antimicrobials and the potential influence of BF should be highly considered.
Identification and characterization of a novel infection-related factor (cell wall hydrolase/autolysin) of Streptococcus suis serotype 2

Hongwei Gu,Chengping Lu,

微生物学报 , 2008,
Abstract: Streptococcus suis serotype 2 (SS2) is an economically important, zoonotic agent causing death and disease in both human and swine. According to published SS2 European strain P1/7 complete genomic sequence, primers for detection and amplification autolysin were designed. Autolysin gene was detected by PCR with genomic DNA of HA9801 (Jiangsu isolate), ZY05719 (Sichuan isolate), ATCC43765 (reference strain), other SS2 isolates from different regions, and strains of other different serotypes (such as serotype 1, 1/2, 7 and 9). PCR results showed that all 27 SS2 virulent isolates harbored gene autolysin, but not in non-virulent SS2 strain. Among other serotypes, only serotype 7 strain had this gene. The complete autolysin genes of HA9801 and ZY05719 were respectively amplified by PCR and sequenced. Their putative protein sequences were analyzed through online software, results showed both had six repeated domain "GBS_Bsp-like" and one domain "N-acetylmuramoyl-L-alanine amidase". In addition, sequence similarity analysis demonstrated that autolysins of the two strains (HA9801 and ZY05719) showed high homologue to that of European strain P1/7 (99.8%), but obviously differed from Canada strain 89/1589, the latter lacked one domain "GBS Bsp-like". Software DNASTAR was used to analyze autolysin protein sequence and predicted its putative antigenicity. Then partial antigentic segment of autolysin was amplified, cloned and inserted into expression vector pET30a(+), and induced by IPTG to express recombinant autolysin. Its reactivity was analyzed by SDS-PAGE and western blot with swine convalescent sera, blot result showed that the recombinant protein had good reactivity and could be considered as a vaccine candidate.
The Fusion and Expression of Genes Encoding Heat-stable and Heat-labile Enterotoxins of Escherichia coli from Porcine Origin

Wang Jiafu,Lu Chengping,

微生物学报 , 2003,
Abstract: The genes encoding precursor heat-stabile (pro-ST) and mature peptide of B unit of heat-labile (LT) enterotoxins of Escherichia coli from piglet were amplified by polymerase chain reaction (PCR). The 3' terminus of gene encoding pro-ST was genetically fused to the 5' terminus of the LTB subunit gene in nest-PCR. The fusion genes encoding pro-ST and LTB were cloned into pGEM-T vector and subcloned into the pQE30. The recombinant plasmid was expressed in E. coli by IPTG induction. The fusion protein possessed both ST and LTB antigenicity, as well as it had lost the biological toxicity of ST or LT toxin.
Swine influenza virus: evolution mechanism and Epidemic characterization-A review

Xian Qi,Chengping Lu,

微生物学报 , 2009,
Abstract: 摘要:猪在甲型流感病毒生态分布和遗传进化中占有重要地位。猪的呼吸道上皮同时具有禽和人流感病毒2种类型的受体,因此人和禽流感病毒都可以感染猪,猪被认为是禽、人流感病毒的中间宿主和不同来源流感病毒的基因“混合器”。猪流感病毒(Swine influenza virus, SIV)的进化方式包括基因重配、抗原漂移和宿主适应性进化,其中基因重配是主要进化方式。与人类季节性流感病毒相比,SIV在全球的流行情况各不相同,呈地方流行性,并具有明显的地区差异。全球范围内流行的SIV亚型主要有3种:H1N1、H3N2和H1N2亚型,其中各亚型内病毒基因来源又不尽相同。欧洲、北美及我国猪群中流行的流感病毒在遗传进化和基因来源方面各具特色。目前欧洲猪群中流行的主要是类禽H1N1、H1N2和H3N2病毒,其中后两者是基因重配病毒。从1998年开始,古典猪H1N1、“人-猪-禽”三源基因重配H3N2、H1N1和H1N2病毒共存于北美的猪群中,其遗传变异日趋复杂。在基因进化上,欧洲和北美基因重配的SIV是目前新的人类大流感病毒-“甲型H1N1病毒”-的母源病毒。我国猪群中流感病毒主要是古典猪H1N1和类人H3N2病毒,但近年来在我国猪群中分离到遗传上与欧洲和北美SIV高度相关的病毒,提示我国SIV的进化趋势值得关注。1970年代以来,全球已报道了50多起人感染SIV事件,表明SIV也是一种值得重视的人兽共患病,预示了SIV可能成为人类大流感毒株或为大流感毒株提供基因。鉴于SIV在甲型流感病毒生态学上的重要意义,以及对人类公共卫生的潜在威胁,建议应尽早启动我国SIV的常规监测工作,密切关注SIV的流行动态,掌握其分子遗传进化规律。同时,将SIV的监测工作纳入整个流感病毒(人和动物流感病毒)的监测网络,在信息上实现共享,从生态学的高度把握我国流感病毒的流行和进化趋势,这对保护动物健康和预防人类大流感都有重要意义。

Huang Xinxin,Lu Chengping,

微生物学报 , 2001,
Abstract: The SDS\|PAGE profiles of out membrane protein(OMP) of 27 Et strains showed diverse patterns and they could be divided into six types. Between 21 pathogenic strains and 6 non\|pathogenic strains there were obviously difference. The pathogenic strains isolated from China belong to E type and were simary to ATCC 15947. The OMP bands of pathogenic strains were more and denser than those of the non\|pathogenic strains, and the strains from same souce had the identical patters. Interestingly, the non\|pathogenic strains from different sources also had the almost same OMP profiles. What\'s more, they were also high resistant to some antibiotics such as Smx, Gem Tet and so on, while the 18 pathogenic strains were senstivity to these.

Xiong Qingming Lu Chengping,

微生物学报 , 2001,
Abstract: 25 Edwardsiella tarda(Et) strains had been detected both on their viruslent factor Excellular Product (ECP), including the hemolysin and extracellular protease (ECPase), and on their pathogenicity to mice and Xiphophorus helleri. ECP was detected by Dot-ELISA with rabbit antiserum against ECP of reference strain JEL4. The results showed that the animal pathogenicity of Et had good correlation with its hemolysin other than with ECPase. The agreement between Dot-ELISA of JEL4 ECP and pathogenicity to animal was up to 100%. It was desirable to establish a detecting method, which only need detect the ECP with plate assay (PA) and Dot-ELISA, but needn't have animal experiment. Furthermore it is possible to develop a diagnosis kit of application to simplify the detecting procedure of pathogenic Et.
Analysis of Virulence-Related Proteins of Streptococcus suis Type 2 from Swine Streptococcus Isolatrd in China

Ou Yu,Lu Chengping,

微生物学报 , 2002,
Abstract: Virulence-related proteins, muraminidase-released protein (MRP) and extracellular factor (EF) of Streptococcus suis type 2, were extracted from Jiangsu Isolate HA9801 and were used as antigens for preparation of antibodies. Bacterium cell envelope proteins and extracellular proteins of swine Streptococcus strains including 17 Chinese isolates, 1 German strain and 1 human isolate of Streptococcus suis type 2, were analyzed by SDS-PAGE and immunoblotting using the above antibodies, 11 strains produced MRP and 10 strains possessed EF or EF *. They exist four phenotypes:MRP +EF +(8/19), MRP +EF *(1/19),MRP +EF -(1/19),MRP -EF -(10/19).
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