Heterologous expression of Intimin and IpaB fusion protein in Lactococcus lactis and its mucosal delivery elicit protection against pathogenicity of Escherichia coli O157 and Shigella flexneri in a murine model.

In this study, we have synthesized chimera of immunodominant regions of Intimin (eae) and IpaB (ipaB) designated as EI and expressed it in Lactococcus lactis (LL-EI) to develop a combinatorial oral vaccine candidate. Immune parameters and protective efficacy of orally administered LL-EI were assessed in the murine model. Significant EI-specific serum IgG, IgA, and fecal IgA antibody titer were observed in the LL-EI group. Considerable increase in EI-specific splenocyte proliferation and a concurrent upregulation of both Th1 and Th2 cytokines was observed in LL-EI immunized mice. Flow cytometry analysis also revealed a significant increase in CD4 and CD8 cell counts in LL-EI immunized group compared to PBS, LL control group.In vitro studies using LL-EI immunized mice sera showed substantial protection against bacterial adhesion and invasion caused by E. coli O157 and Shigella flexneri¸ respectively. LL-EI immunized group challenged with E. coli O157 ceased fecal shedding within 6 days, and mice challenged with S. flexneri showed 93% survival with minimal bacterial load in the lungs. Our results indicate that LL-EI immunization elicits systemic, mucosal and cell-mediated immune responses, and can be a promising candidate for oral vaccine development against these pathogens. PMID: 32464569 [PubMed - as supplied by publisher]
Source: International Immunopharmacology - Category: Allergy & Immunology Authors: Tags: Int Immunopharmacol Source Type: research

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The objective of this research was to determine changes to lettuce phyllosphere microbiota, inoculated ARB, and the resistome (profile of ARGs) following washing with a sanitizer, gamma irradiation, and cold storage. To simulate potential sources of pre-harvest contamination, romaine lettuce leaves were inoculated with compost slurry containing antibiotic-resistant strains of pathogenic (Escherichia coli O157:H7) and representative of spoilage bacteria (Pseudomonas aeruginosa). Various combinations of washing with sodium hypochlorite (50 ppm free chlorine), packaging under modified atmosphere (98% nitrogen), irradiating (1...
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research
Purpose of review Atypical hemolytic uremic syndrome (aHUS) is a diagnosis that has captured the interest of specialists across multiple fields. The hallmark features of aHUS are microangiopathic hemolysis and thrombocytopenia, which creates a diagnostic dilemma because of the occurrence of these findings in a wide variety of clinical disorders. Recent findings In most of the instances, aHUS is a diagnosis of exclusion after ruling out causes such as Shigella toxin, acquired or genetic a disintegrin and metalloproteinase thrombospondin motif 13 deficiency (thrombotic thrombocytopenic purpura), and vitamin B12 deficien...
Source: Current Opinion in Nephrology and Hypertension - Category: Urology & Nephrology Tags: SPECIAL COMMENTARY Source Type: research
We report 2 cases of HUS, respectively, caused by salmonella and Campylobacter jejuni infections. None of these bacteria produce shigatoxins, and the underlying mechanism of HUS development remains unknown. In streptococcus pneumoniae–associated HUS, bacterial neuraminidase cleaves neuraminic acid and causes exposure of Thomsen-Friedenreich cryptantigen on the cell surface of, for example, erythrocytes, which induces an inflammatory response caused by binding of preformed IgM. Both campylobacter and salmonella bacteria also produce neuraminidase, and HUS development could be explained by a similar mechanism.
Source: Journal of Pediatric Hematology Oncology - Category: Hematology Tags: Online Articles: Clinical and Laboratory Observations Source Type: research
Immunological detection assays for recombinant Shiga toxin &Shigella dysenteriae. Indian J Med Res. 2019 Mar;149(3):412-417 Authors: Gupta P, Dhaked RK Abstract Background &objectives: : Shiga toxin (Stx) is produced by Shigella dysenteriae, a Gram-negative, facultative anaerobic bacillus that causes shigellosis, haemolytic uraemic syndrome (HUS) and Reiter's syndrome. The detection methods for shiga toxin needs to be rapid, accurate, reliable and must be extensively evaluated under field conditions. The aim of this study was to develop rapid, sensitive and specific detection method for Stx. ...
Source: The Indian Journal of Medical Research - Category: Biomedical Science Authors: Tags: Indian J Med Res Source Type: research
Conclusion This result showed that probiotic bacteria not only could effect on pathogens bacteria by bacteriocins it could down-regulate the toxin and virulence genes as well. PMID: 30633636 [PubMed - as supplied by publisher]
Source: British Journal of Biomedical Science - Category: Laboratory Medicine Tags: Br J Biomed Sci Source Type: research
Abstract The Shiga toxins comprise a family of related protein toxins produced by bacteria Shigella dysenteriae and some strains of Escherichia coli that cause severe clinical manifestations. Severe Shiga toxin intoxication results in hemolytic-uremic syndrome (HUS), up to 50% of HUS patients manifest some degree of renal failure and ∼10% of such cases develop permanent renal failure or death. Purification of Shiga toxin from bacteria is a multistep time consuming process resulting in low yield. E. coli clones expressing recombinant A and B subunits (rStxA and rStxB) were established for in vitro reconstitutio...
Source: Protein and Peptide Letters - Category: Biochemistry Authors: Tags: Protein Pept Lett Source Type: research
CONCLUSION: This study reveals a higher prevalence of GI pathogens in anti-FH positive than in negative patients. No single pathogen was implicated exclusively in one form of HUS. These pathogens may play a role in the disease initiation by inducing complement activation or an autoimmune response. PMID: 29795200 [PubMed - as supplied by publisher]
Source: Pediatric Research - Category: Pediatrics Authors: Tags: Pediatr Res Source Type: research
Publication date: April 2018 Source:Food Control, Volume 86 Author(s): Yuejiao Liu, Prashant Singh, Azlin Mustapha Among the disease-causing Shiga toxin-producing Escherichia coli (STEC), E. coli O157:H7 is estimated to cause one-third of the total STEC illnesses and the most cases of hemolytic uremic syndrome (HUS) in the U.S. The uidA gene which is present in the majority of E. coli strains, codes for the synthesis of β-d-glucuronidase (GUD). In E. coli O157:H7, the uidA gene has a single point mutation at the +93 position that leads to an alteration in the amino acid sequence encoding the GUD e...
Source: Food Control - Category: Food Science Source Type: research
Publication date: Available online 24 June 2017 Source:IDCases Author(s): Pauline Condom, Jean-Michel Mansuy, Stéphane Decramer, Jacques Izopet, Catherine Mengelle Varicella Zoster Virus (VZV) is a well-known virus that belongs to the Herpesviridae family which induces a self-limited disease except in specific cases in particular among stem cell transplant patients. This virus is not known however to trigger atypical Hemolytic Uremic Syndrome (aHUS). Here we report the case of a six-year-old boy who was hospitalized with fever and abdominal pains associated to pruritic and vesicular rash, thrombocytopenia and acute...
Source: IDCases - Category: Infectious Diseases Source Type: research
We present a case of a 27 year-old man with jaundice, thrombocytopenia, and renal dysfunction who was found to have HUS in the setting of Shigella sonnei infection. Outside of developing countries, cases of HUS related to S. sonnei are largely unreported.
Source: IDCases - Category: Infectious Diseases Source Type: research
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