Control on Soft Rot of Chinese Cabbage Using Harpin Protein

2011 ◽  
Vol 183-185 ◽  
pp. 2078-2081
Author(s):  
Tian Lei Qiu ◽  
Min Wang ◽  
Xiao Hong Sun ◽  
Mei Lin Han ◽  
Xu Ming Wang

Soft rot of Chinese cabbage is a common disease that causes serious damage and economic losses. In this study, the control on soft rot of growing and postharvest Chinese cabbage was carried out, using Harpin protein which was the expressed product of a recombinant E. coli strain. The experimental results indicate that Harpin protein preparation containing 3% pure protein powder and 97% wettable powder of Bacillus Thuringiensis (Bt), could effectively control soft rot of Chinese cabbage. The control effect on soft rot reached as high as 90% for growing Chinese cabbage using Harpin protein at 6-10mg/m2 of dosage, and the control effect reached approximately 75% for postharvest Chinese cabbage. Harpin protein stored for 6 months at 20-25 0C had the similarly biological activity with the newly prepared protein.

2011 ◽  
Vol 183-185 ◽  
pp. 971-974
Author(s):  
Min Wang ◽  
Xiao Hong Sun ◽  
Tian Lei Qiu ◽  
Mei Lin Han ◽  
Xu Ming Wang

Harpin protein was produced by a recombinant E. coli BL21(DE3)/pET30a(+)hrpNEcc in a 1-ton fermentor, and acute oral toxicity test in rats and guinea pig skin sensitization test for Harpin protein were carried out in order to determine its toxicity. The experimental results show that the protein production is up to 4.78 g/L after 16-18 h of fermentation, and the production cost of this protein is 1.75 yuan/g. Harpin protein produced by the recombinant E. coli strain is non-toxic (LD50>5000mg/kg) and has a low allergenicity (rate of sensitization is 0%). The results obtained in this study lay the foundation of the industrial manufacturing and the application on agriculture for Harpin protein.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12631
Author(s):  
Aline L. de Oliveira ◽  
Nicolle L. Barbieri ◽  
Darby M. Newman ◽  
Meaghan M. Young ◽  
Lisa K. Nolan ◽  
...  

Avian pathogenic E. coli is the causative agent of extra-intestinal infections in birds known as colibacillosis, which can manifest as localized or systemic infections. The disease affects all stages of poultry production, resulting in economic losses that occur due to morbidity, carcass condemnation and increased mortality of the birds. APEC strains have a diverse virulence trait repertoire, which includes virulence factors involved in adherence to and invasion of the host cells, serum resistance factors, and toxins. However, the pathogenesis of APEC infections remains to be fully elucidated. The Type 6 secretion (T6SS) system has recently gained attention due to its role in the infection process and protection of bacteria from host defenses in human and animal pathogens. Previous work has shown that T6SS components are involved in the adherence to and invasion of host cells, as well as in the formation of biofilm, and intramacrophage bacterial replication. Here, we analyzed the frequency of T6SS genes hcp, impK, evpB, vasK and icmF in a collection of APEC strains and their potential role in virulence-associated phenotypes of APECO18. The T6SS genes were found to be significantly more prevalent in APEC than in fecal E. coli isolates from healthy birds. Expression of T6SS genes was analyzed in culture media and upon contact with host cells. Mutants were generated for hcp, impK, evpB, and icmF and characterized for their impact on virulence-associated phenotypes, including adherence to and invasion of host model cells, and resistance to predation by Dictyostelium discoideum. Deletion of the aforementioned genes did not significantly affect adherence and invasion capabilities of APECO18. Deletion of hcp reduced resistance of APECO18 to predation by D. discoideum, suggesting that T6SS is involved in the virulence of APECO18.


1997 ◽  
Vol 35 (11-12) ◽  
pp. 351-357 ◽  
Author(s):  
R. Rothmaier ◽  
A. Weidenmann ◽  
K. Botzenhart

Isolates (50) of E. coli obtained from liquid manure (20 bovine, 20 porcine) were genotyped using random amplified polymorphic DNA (RAPD). Typing revealed 9 and 14 different strains in bovine and porcine liquid manure respectively with no strains in common. One porcine strain, showing a simple RAPD pattern, was subcultured and spread on a test field (1.5l/m2 at 1010 cfu/l) in a drinking water protection zone with loamy to sandy sediments in the Donauried area, Baden-Wurttemberg. Soil samples and groundwaters were collected at monthly intervals October 1994 – June 1995 during which 114 E. coli isolates were recovered. The first occurrence and maximum concentration of E. coli in soil samples taken from more than 20cm depth was in January 1995, declining rapidly with depth and time. All isolates from soil and only one from groundwater showed the RAPD pattern of the spread E. coli strain. The results could not demonstrate a severe negative impact of the spreading of liquid manure on the bacteriological quality of the groundwater in the given geological situation. The distinct strain patterns found in different kinds of liquid manure suggest that genotyping of E. coli by RAPD may be an adequate tool for tracing sources of faecal contamination.


2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 139-140
Author(s):  
Frédéric A Vangroenweghe

Abstract Post-weaning Escherichia coli diarrhea (PWD) remains a major cause of economic losses for the pig industry. PWD, caused by enterotoxigenic E. coli (ETEC), typically provokes mild to severe watery diarrhea between 5–10 days after weaning. Recently, an oral live bivalent E. coli F4/F18 vaccine (Coliprotec® F4/F18; Elanco) was approved on the European market, which reduces the impact of PWD provoked by F4-ETEC and F18-ETEC. The objective was to compare technical results and antibiotic use following E. coli F4/F18 vaccination with previous standard therapeutic approach under field conditions. A 1600-sow farm (weaning at 26 days) with diagnosed problems of PWD due to F18-ETEC was selected. Piglets were vaccinated at 21 days with the oral live bivalent E. coli F4/F18 vaccine. At weaning, no standard group medication (ZnO and antibiotics) was applied for prevention of PWD. Several performance parameters were collected: treatment incidence (TI100), mortality and days in nursery. Statistical analysis was performed using JMP 14.0 – comparison of means. Oral E. coli F4/F18 vaccination significantly reduced TI100 (7 ± 2 days to 0 ± 1 days; P < 0.05). Mortality rate remained stable (2.05% in Control to 1.96% in Vaccinated group; P < 0.05). Days in nursery (40 ± 3 days) remained at the same level compared to pre-vaccination. The results show that live E. coli F4/F18 vaccination against PWD has led to similar technical performance parameters and mortality, in combination with a significant reduction in medication use. In conclusion, control of PWD through oral vaccination is a successful option in order to prevent piglets from the negative clinical outcomes of F18-ETEC infection during the post-weaning period.


Pathogens ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 549
Author(s):  
Julia Ittensohn ◽  
Jacqueline Hemberger ◽  
Hannah Griffiths ◽  
Maren Keller ◽  
Simone Albrecht ◽  
...  

The uropathogenic Escherichia coli strain CFT073 causes kidney abscesses in mice Toll/interleukin-1 receptor domain-containing protein C (TcpC) dependently and the corresponding gene is present in around 40% of E. coli isolates of pyelonephritis patients. It impairs the Toll-like receptor (TLR) signaling chain and the NACHT leucin-rich repeat PYD protein 3 inflammasome (NLRP3) by binding to TLR4 and myeloid differentiation factor 88 as well as to NLRP3 and caspase-1, respectively. Overexpression of the tcpC gene stopped replication of CFT073. Overexpression of several tcpC-truncation constructs revealed a transmembrane region, while its TIR domain induced filamentous bacteria. Based on these observations, we hypothesized that tcpC expression is presumably tightly controlled. We tested two putative promoters designated P1 and P2 located at 5′ of the gene c2397 and 5′ of the tcpC gene (c2398), respectively, which may form an operon. High pH and increasing glucose concentrations stimulated a P2 reporter construct that was considerably stronger than a P1 reporter construct, while increasing FeSO4 concentrations suppressed their activity. Human urine activated P2, demonstrating that tcpC might be induced in the urinary tract of infected patients. We conclude that P2, consisting of a 240 bp region 5′ of the tcpC gene, represents the major regulator of tcpC expression.


2021 ◽  
Vol 22 (12) ◽  
pp. 6361
Author(s):  
Eunyoung Lee ◽  
Michelle Novais de Paula ◽  
Sangki Baek ◽  
Huynh Kim Khanh Ta ◽  
Minh Tan Nguyen ◽  
...  

Human stem-cell factor (hSCF) stimulates the survival, proliferation, and differentiation of hematopoietic cells by binding to the c-Kit receptor. Various applications of hSCF require the efficient and reliable production of hSCF. hSCF exists in three forms: as two membrane-spanning proteins hSCF248 and hSCF229 and truncated soluble N-terminal protein hSCF164. hSCF164 is known to be insoluble when expressed in Escherichia coli cytoplasm, requiring a complex refolding procedure. The activity of hSCF248 has never been studied. Here, we investigated novel production methods for recombinant hSCF164 and hSCF248 without the refolding process. To increase the solubility of hSCF164, maltose-binding protein (MBP) and protein disulfide isomerase b’a’ domain (PDIb’a’) tags were attached to the N-terminus of hSCF164. These fusion proteins were overexpressed in soluble form in the Origami 2(DE3) E. coli strain. These solubilization effects were enhanced at a low temperature. His-hSCF248, the poly-His tagged form of hSCF248, was expressed in a highly soluble form without a solubilization tag protein, which was unexpected because His-hSCF248 contains a transmembrane domain. hSCF164 was purified using affinity and ion-exchange chromatography, and His-hSCF248 was purified by ion-exchange and gel filtration chromatography. The purified proteins stimulated the proliferation of TF-1 cells. Interestingly, the EC50 value of His-hSCF248 was 1 pg/mL, 100-fold lower than 9 ng/mL hSCF164. Additionally, His-hSCF248 decreased the doubling time, increased the proportion of S and G2/M stages in the cell cycle, and increased the c-Myc expression at a 1000-fold lower concentration than hSCF164. In conclusion, His-hSCF248 was expressed in a soluble form in E. coli and had stronger activity than hSCF164. The molecular chaperone, MBP, enabled the soluble overexpression of hSCF164.


Sign in / Sign up

Export Citation Format

Share Document