scholarly journals Characterizing the Type 6 Secretion System (T6SS) and its role in the virulence of avian pathogenic Escherichia coli strain APECO18

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12631
Author(s):  
Aline L. de Oliveira ◽  
Nicolle L. Barbieri ◽  
Darby M. Newman ◽  
Meaghan M. Young ◽  
Lisa K. Nolan ◽  
...  
Keyword(s):  
Culture Media ◽  
Coli Strain ◽  
Infection Process ◽  
Host Cells ◽  
Economic Losses ◽  
Poultry Production ◽  
E Coli ◽  
Intestinal Infections ◽  
Animal Pathogens ◽  
Bacterial Replication

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.

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
Keyword(s):  
Chinese Cabbage ◽  
Soft Rot ◽  
Coli Strain ◽  
Economic Losses ◽  
Common Disease ◽  
Control Effect ◽  
Protein Preparation ◽  
E Coli ◽  
Wettable Powder ◽  
Harpin Protein

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.

scholarly journals The Genotoxin Colibactin Shapes Gut Microbiota in Mice

2020 ◽  
Author(s):  
Sophie Tronnet ◽  
Pauline Floch ◽  
Laetitia Lucarelli ◽  
Deborah Gaillard ◽  
Patricia Martin ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Microbial Diversity ◽  
Coli Strain ◽  
Double Strand Breaks ◽  
Host Cells ◽  
Dna Double Strand Breaks ◽  
Strand Breaks ◽  
E Coli ◽  
Pregnant Mice ◽  
Gut Microbiota Composition

Abstract Background : The genotoxin colibactin produced by resident bacteria of the gut microbiota may have tumorigenic effect by inducing DNA double strand breaks in host cells. Yet, the effect of colibactin on gut microbiota composition and functions remains unknown.Results: To address this point, we designed an experiment in which pregnant mice were colonized with: i) a commensal E. coli strain, ii) a commensal E. coli strain plus a genotoxic E. coli strain, iii) a commensal E. coli strain plus a non-genotoxic E. coli mutant strain unable to produce mature colibactin. Then, we analysed the gut microbiota in pups at day 15 and day 35 after birth. At day 15, mice that were colonized at birth with the genotoxic strain showed lower levels of Proteobacteria and belonging taxa, a modest effect on overall microbial diversity and no effect on gut microbiome. At day 35, mice that received the genotoxic strain showed lower Firmicutes and belonging taxa, together with a strong effect on overall microbial diversity and higher microbial functions related to DNA repair. Moreover, the genotoxic strain strongly affected gut microbial diversity evolution of receiving pups between day 15 and day 35.Conclusions: our data show that colibactin, beyond targeting the host, may also exerce its genotoxic effect on the gut microbiota.

scholarly journals Construction of the recombinant Escherichia coli strain producing a homologous thermolabile toxin subunit

2021 ◽  
Vol 65 (2) ◽  
pp. 185-190
Author(s):  
I. S. Kazlouski ◽  
A. I. Zinchenko ◽  
A. V. Solovyeva ◽  
O. N. Novikova ◽  
Yu. V. Lomako
Keyword(s):  
Escherichia Coli ◽  
Central Nervous System ◽  
Nervous System ◽  
Culture Liquid ◽  
Coli Strain ◽  
Central Nervous System Damage ◽  
E Coli ◽  
Intestinal Infections ◽  
The Republic ◽  
Subunit B

Colibacteriosis is an acute zoonotic disease manifested by septicaemia, toxemia, enteritis, body dehydration, and central nervous system damage. Depending on the presence of virulence factors and the nature of interaction with the intestinal mucosa, enterotoxigenic, enteroinvasive, enteropathogenic, and enterohemorrhagic E. coli are isolated. Enterotoxigenic strains of E. coli occupy one of the leading places in the etiological structure of calf colibacteriosis in many livestock farms of the Republic of Belarus. The main reason why this disease develops is the presence of thermolabile and thermostable toxins in the causative strain. The thermolabile toxin subunit B is a potent antigen that allows pet immunity to be acquired against E. coli-induced cattle diarrhea. Many foreign vaccines used against intestinal infections of cattle contain either a native or recombinant variant of the subunit B. As a result of the work, we have created a new strain of E. coli 42eLTB – the producer of the recombinant subunit B of the thermolabile toxin E. coli. The producing capacity of the obtained strain is 480 mg with 1 culture liquid liter, which exceeds the already known strains 1.37 times.

scholarly journals Characterization of a Hemoglobin Protease Secreted by the Pathogenic Escherichia coli Strain EB1

1998 ◽  
Vol 188 (6) ◽  
pp. 1091-1103 ◽  
Author(s):  
Ben R. Otto ◽  
Silvy J.M. van Dooren ◽  
Jan H. Nuijens ◽  
Joen Luirink ◽  
Bauke Oudega
Keyword(s):  
Escherichia Coli ◽  
Pathogenic Bacteria ◽  
Affinity Purification ◽  
Coli Strain ◽  
E Coli ◽  
Heme Acquisition ◽  
Pathogenic Escherichia Coli ◽  
Iga1 Protease ◽  
Animal Pathogens

Many pathogenic bacteria can use heme compounds as a source of iron. Pathogenic Escherichia coli strains are capable of using hemoglobin as an iron source. However, the mechanism of heme acquisition from hemoglobin is not understood for this microorganism. We present the first molecular characterization of a hemoglobin protease (Hbp) from a human pathogenic E. coli strain. The enzyme also appeared to be a heme-binding protein. Affinity purification of this bifunctional protein enabled us to identify the extracellular gene product, and to clone and analyze its gene. A purification procedure developed for Hbp allowed us to perform functional studies. The protein interacted with hemoglobin, degraded it and subsequently bound the released heme. These results suggest that the protein is involved in heme acquisition by this human pathogen. Hbp belongs to the so-called IgA1 protease-like proteins, as indicated by the kinetics of its membrane transfer and DNA sequence similarity. The gene of this protein appears to be located on the large pColV-K30 episome, that only has been isolated from human and animal pathogens. All these characteristics indicate that Hbp may be an important virulence factor that may play a significant role in the pathogenesis of E. coli infections.

Transcriptional Activator OvrA Encoded in O Island 19 Modulates Virulence Gene Expression in Enterohemorrhagic Escherichia coli O157:H7

2019 ◽  
Author(s):  
Bin Liu ◽  
Junyue Wang ◽  
Lu Wang ◽  
Peng Ding ◽  
Pan Yang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Escherichia Coli ◽  
Gene Promoter ◽  
Virulence Gene ◽  
Coli Strain ◽  
Enterohemorrhagic Escherichia Coli ◽  
Bacterial Adherence ◽  
Host Cells ◽  
Virulence Gene Expression ◽  
E Coli

AbstractThe human intestinal pathogen enterohemorrhagic Escherichia coli (EHEC) O157:H7 causes bloody diarrhea, hemorrhagic colitis, and fatal hemolytic uremic syndrome. Its genome contains 177 unique O islands (OIs), which contribute largely to the high virulence and pathogenicity although most OI genes remain uncharacterized. In the current study, we demonstrated that OI-19 is required for EHEC O157:H7 adherence to host cells. Z0442 (OI-encoded virulence regulator A [OvrA]) encoded in OI-19 positively regulated bacterial adherence by activating locus of enterocyte effacement (LEE) gene expression through direct OvrA binding to the gene promoter region of the LEE gene master regulator Ler. Mouse colonization experiments revealed that OvrA promotes EHEC O157:H7 adherence in mouse intestine, preferentially the colon. Finally, OvrA also regulated virulence in other non-O157 pathogenic E. coli, including EHEC strains O145:H28 and O157:H16 and enteropathogenic E. coli strain O55:H7. Our work markedly enriches the understanding of bacterial adherence control and provides another example of laterally acquired regulators that mediate LEE gene expression.

scholarly journals Novel Avian Pathogenic Escherichia coli Genes Responsible for Adhesion to Chicken and Human Cell Lines

2020 ◽  
Vol 86 (20) ◽  
Author(s):  
Aamir Ali ◽  
Rafał Kolenda ◽  
Muhammad Moman Khan ◽  
Jörg Weinreich ◽  
Ganwu Li ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Cell Lines ◽  
Human Cell ◽  
Host Cells ◽  
Intestinal Cell ◽  
Economic Losses ◽  
Human Cell Lines ◽  
Content Type ◽  
E Coli ◽  
Commercial Poultry

ABSTRACT Avian pathogenic Escherichia coli (APEC) is a major bacterial pathogen of commercial poultry contributing to extensive economic losses and contamination of the food chain. One of the initial steps in bacterial infection and successful colonization of the host is adhesion to the host cells. A random transposon mutant library (n = 1,300) of APEC IMT 5155 was screened phenotypically for adhesion to chicken (CHIC-8E11) and human (LoVo) intestinal epithelial cell lines. The detection and quantification of adherent bacteria were performed by a modified APEC-specific antibody staining assay using fluorescence microscopy coupled to automated VideoScan technology. Eleven mutants were found to have significantly altered adhesion to the cell lines examined. Mutated genes in these 11 “adhesion-altered mutants” were identified by arbitrary PCR and DNA sequencing. The genes were amplified from wild-type APEC IMT 5155, cloned, and transformed into the respective adhesion-altered mutants, and complementation was determined in adhesion assays. Here, we report contributions of the fdtA, rluD, yjhB, ecpR, and fdeC genes of APEC in adhesion to chicken and human intestinal cell lines. Identification of the roles of these genes in APEC pathogenesis will contribute to prevention and control of APEC infections. IMPORTANCE Avian pathogenic E. coli is not only pathogenic for commercial poultry but can also cause foodborne infections in humans utilizing the same attachment and virulence mechanisms. Our aim was to identify genes of avian pathogenic E. coli involved in adhesion to chicken and human cells in order to understand the colonization and pathogenesis of these bacteria. In contrast to the recent studies based on genotypic and bioinformatics data, we have used a combination of phenotypic and genotypic approaches for identification of novel genes contributing to adhesion in chicken and human cell lines. Identification of adhesion factors remains important, as antibodies elicited against such factors have shown potential to block colonization and ultimately prevent disease as prophylactic vaccines. Therefore, the data will augment the understanding of disease pathogenesis and ultimately in designing strategies against the infections.

scholarly journals Characterization of Ictalurid herpesvirus 1 Glycoprotein ORF59 and Its Potential Role on Virus Entry into the Host Cells

Viruses ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2393
Author(s):  
Shu-Xin Li ◽  
Fei Yu ◽  
Hong-Xun Chen ◽  
Xiao-Dong Zhang ◽  
Li-Hui Meng ◽  
...  
Keyword(s):  
Channel Catfish ◽  
Expression System ◽  
Baculovirus Expression System ◽  
Inhibitory Effect ◽  
Infection Process ◽  
Host Cells ◽  
Economic Losses ◽  
Ovary Cells ◽  
Channel Catfish Virus ◽  
Herpesvirus 1

The channel catfish virus (CCV, Ictalurid herpesvirus 1) has caused sustained economic losses in the fish industry because of its strong infectivity and pathogenicity. Thus, it is necessary to determine the function of viral proteins in the CCV infection process. The present study aimed to characterize CCV glycoprotein ORF59 and explore its impact on virus infection in host cells. Firstly, its exclusive presence in the membrane fraction of the cell lysate and subcellular localization verified that CCV ORF59 is a viral membrane protein expressed at late-stage infection. A protein blocking assay using purified His6 tagged ORF59, expressed in sf9 insect cells using a baculovirus expression system, indicated a dose-dependent inhibitory effect of recombinant ORF59 protein on virus invasion. Knockdown of the ORF59 using a short hairpin (shRNA) showed that ORF59 silencing decreased the production of infectious virus particles in channel catfish ovary cells. The results of this study suggest that recombinant ORF59 protein might inhibit CCV entry into the host cells. These findings will promote future studies of the key functions of glycoprotein ORF59 during CCV infection.

scholarly journals Antibiotic Resistance of Bacteria Isolated from Water Supplies Used in Poultry Production in Ashanti Region of Ghana

2021 ◽  
Vol 15 (1) ◽  
pp. 7-15
Author(s):  
Frank B. Osei ◽  
Vivian E. Boamah ◽  
Yaw D. Boakye ◽  
Christian Agyare ◽  
Robert C. Abaidoo
Keyword(s):  
Culture Media ◽  
Resistance Pattern ◽  
Poultry Production ◽  
Drug Resistant ◽  
Bacterial Isolates ◽  
Bacterial Strains ◽  
E Coli ◽  
Ashanti Region ◽  
Quality Of Water

Objective: Water plays an important role in both domestic and commercial settings. Pathogenic microbial contaminants, however, render water unsafe for use. There are several reports on the quality of water used for drinking purposes in humans but few studies have been conducted on the microbial quality of water used in animal farming. Methods: In this study, the resistance pattern of bacterial isolates from drinking water used in poultry production in the Ashanti region of Ghana from our previously published report was determined. The presence of Escherichia coli, Salmonella typhi, Staphylococcus aureus and coagulase-negative Staphylococci was determined using selective culture media (pour plate method) and confirmed through Gram staining and biochemical reactions. Antibiotic sensitivity of isolates was determined followed by detection of Extended-Spectrum Beta-Lactamase (ESBL) producing Gram-negative isolates. Results: The study revealed that water used in poultry farms contains sources of multi-drug resistant strains of E. coli, S. typhi, S. aureus and coagulase-negative staphylococci. E. coli, S. typhi, S. aureus and coagulase-negative staphylococci were recovered from 31%, 36%, 64% and 19% of samples, respectively. Majority of these isolates were resistant to cephalosporins and penicillins. Almost 95% of the bacterial isolates were multi-drug resistant. None of E. coli and S. typhi isolates produced ESBL. Conclusion: There is a need for stringent regulations and stringent measures should be taken to make these various sources of water safe for use in animal husbandry as these waters are a potential source of pathogenic and resistant bacterial strains which can cause infections to the animals and farm workers.

scholarly journals Monitoring of Antimicrobial Susceptibility of Bacteria Isolated from Poultry Farms from 2014 to 2018

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Engy Ahmed Hamed ◽  
May Fathy Abdelaty ◽  
Hend Karam Sorour ◽  
Heba Roshdy ◽  
Mona Aly Abdelhalim AbdelRahman ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Antimicrobial Susceptibility ◽  
Positive Sample ◽  
Economic Losses ◽  
Reference Laboratory ◽  
Poultry Production ◽  
E Coli ◽  
Antibiotic Resistance Profile ◽  
Diffusion Technique ◽  
Native Chicken

The current situation of antibiotic resistance of most bacterial pathogens was a threat to the poultry and public health with increasing economic losses. Regarding this problem, monitoring of the circulating microorganisms occurred with the antibiotic resistance profile. A total of 657 different samples from internal organs (liver, heart, lung, and yolk) and paper-lining chick boxes were collected from native chicken farms which were submitted to the Reference Laboratory for Veterinary Quality Control on Poultry Production in the period from 2014 to 2018 for the detection of Salmonella, Escherichia coli (E. coli), and Staphylococcus. The bacterial isolates were tested for their antimicrobial susceptibility by disk diffusion technique. Salmonella was isolated from 128 out of 657 (19.5%), E. coli was isolated from 496 out of 657 (75.5%), and Staphylococcus species was isolated from 497 out of 657 (75.6%). All Salmonella positive samples were examined for antibiotic resistance against 10 different antibiotics, and the highest percentage all over the five years was against penicillin, ampicillin, and tetracycline. All E. coli positive samples were examined for antibiotic resistance against 14 different antibiotics, and the highest percentage all over the five years was with ampicillin, tetracycline, norfloxacin, streptomycin, and danofloxacin. All Staphylococcus positive sample species were examined for antibiotic resistance against 14 different antibiotics, and the highest percentage of resistance all over the five years was shown with tetracycline, streptomycin, ampicillin, and nalidixic acid.

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