scholarly journals Maternal Milk Contains Antimicrobial Factors That Protect Young Rabbits from Enteropathogenic Escherichia coli Infection

2007 ◽  
Vol 14 (5) ◽  
pp. 585-592 ◽  
Author(s):  
Mélanie Gallois ◽  
Thierry Gidenne ◽  
Christian Tasca ◽  
Cécile Caubet ◽  
Cécile Coudert ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Protective Role ◽  
Epec Strain ◽  
Mammal Species ◽  
Maternal Milk ◽  
Escherichia Coli Infection ◽  
In Vitro Antibacterial Activity

ABSTRACT Enteropathogenic Escherichia coli (EPEC) colibacillosis represents a major cause of lethal diarrhea in young children in developing countries. EPEC strains also infect numerous mammal species and represent a major economical problem in rabbit industry. Protection against this pathogen is a challenging goal both in humans and in other mammal species. Despite a good knowledge of the pathogenicity mechanisms of EPEC, the intrinsic and environmental factors that control the expression of EPEC virulence in mammals remain unknown. For instance, the exacerbated sensitivity of young mammals to EPEC infection is still unexplained. Our goal was to investigate if age or other factors, like milk consumption, could be determinants that trigger the disease. We used rabbits as an animal model to study the role of milk in the sensitivity to an EPEC infection. Weaned and suckling rabbits were orally inoculated with EPEC strain E22 (O103:H2:K−) at 28 days of age, and the evolution of the disease was investigated in the two groups. In addition, in order to better characterize the interactions between milk and EPEC, we determined in vitro bacterial growth and the abilities of EPEC cells to adhere to epithelial cells in the presence of milk. Our results demonstrate a protective role of milk in vivo in association with in vitro antibacterial activity. These effects are independent of the presence of specific anti-EPEC antibodies.

scholarly journals A Protective Role of Paeoniflorin in Fluctuant Hyperglycemia-Induced Vascular Endothelial Injuries through Antioxidative and Anti-Inflammatory Effects and Reduction of PKCβ1

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Jing-Shang Wang ◽  
Ye Huang ◽  
Shuping Zhang ◽  
Hui-Jun Yin ◽  
Lei Zhang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Protein Level ◽  
Umbilical Vein ◽  
Protective Role ◽  
Vascular Endothelial ◽  
Glucose Levels ◽  
Umbilical Vein Endothelial Cells

Hyperglycemia fluctuation is associated with diabetes mellitus (DM) complications when compared to persistent hyperglycemia. Previous studies have shown that paeoniflorin (PF), through its antiapoptosis, anti-inflammation, and antithrombotic properties, effectively protects against cardiovascular and cerebrovascular disease. However, the mechanism underlying the protection from PF against vascular injuries induced by hyperglycemia fluctuations remains poorly understood. Herein, we investigated the potential protective role of PF on human umbilical vein endothelial cells (HUVECs) subjected to intermittent glucose levels in vitro and in DM rats with fluctuating hyperglycemia in vivo. A remarkable increased apoptosis associated with elevated inflammation, increased oxidative stress, and high protein level of PKCβ1 was induced in HUVECs by intermittently changing glucose for 8 days, and PF recovered those detrimental changes. LY333531, a potent PKCβ1 inhibitor, and metformin manifested similar effects. Additionally, in DM rats with fluctuating hyperglycemia, PF protected against vascular damage as what has been observed in vitro. Taken together, PF attenuates the vascular injury induced by fluctuant hyperglycemia through oxidative stress inhibition, inflammatory reaction reduction, and PKCβ1 protein level repression, suggesting its perspective clinical usage.

scholarly journals HDAC2 attenuates airway inflammation by suppressing IL-17A production in HDM-challenged mice

2019 ◽  
Vol 316 (1) ◽  
pp. L269-L279 ◽  
Author(s):  
Tianwen Lai ◽  
Mindan Wu ◽  
Chao Zhang ◽  
Luanqing Che ◽  
Feng Xu ◽  
...  
Keyword(s):  
Airway Inflammation ◽  
Inflammatory Cytokines ◽  
Allergic Inflammation ◽  
Allergic Airway Inflammation ◽  
Inflammatory Cells ◽  
Protective Role ◽  
In Vivo Models

Histone deacetylase (HDAC)2 is expressed in airway epithelium and plays a pivotal role in inflammatory cells. However, the role of HDAC2 in allergic airway inflammation remains poorly understood. In the present study, we determined the role of HDAC2 in airway inflammation using in vivo models of house dust mite (HDM)-induced allergic inflammation and in vitro cultures of human bronchial epithelial (HBE) cells exposed to HDM, IL-17A, or both. We observed that HDM-challenged Hdac2+/− mice exhibited substantially enhanced infiltration of inflammatory cells. Higher levels of T helper 2 cytokines and IL-17A expression were found in lung tissues of HDM-challenged Hdac2+/− mice. Interestingly, IL-17A deletion or anti-IL-17A treatment reversed the enhanced airway inflammation induced by HDAC2 impairment. In vitro, HDM and IL-17A synergistically decreased HDAC2 expression in HBE cells. HDAC2 gene silencing further enhanced HDM- and/or IL-17A-induced inflammatory cytokines in HBE cells. HDAC2 overexpresion or blocking IL-17A gene expression restored the enhanced inflammatory cytokines. Collectively, these results support a protective role of HDAC2 in HDM-induced airway inflammation by suppressing IL-17A production and might suggest that activation of HDAC2 and/or inhibition of IL-17A production could prevent the development of allergic airway inflammation.

scholarly journals Fimbria-Encoding GeneyadCHas a Pleiotropic Effect on Several Biological Characteristics and Plays a Role in Avian Pathogenic Escherichia coli Pathogenicity

2015 ◽  
Vol 84 (1) ◽  
pp. 187-193 ◽  
Author(s):  
Renu Verma ◽  
Thaís Cabrera Galvão Rojas ◽  
Renato Pariz Maluta ◽  
Janaína Luisa Leite ◽  
Livia Pilatti Mendes da Silva ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Soft Agar ◽  
Pleiotropic Effect ◽  
Biological Characteristics ◽  
Wild Type ◽  
Content Type ◽  
Pathogenic Escherichia Coli

The extraintestinal pathogen termed avian pathogenicEscherichia coli(APEC) is known to cause colibacillosis in chickens. The molecular basis of APEC pathogenesis is not fully elucidated yet. In this work, we deleted a component of the Yad gene cluster (yadC) in order to understand the role of Yad in the pathogenicity of the APEC strain SCI-07.In vitro, the transcription level ofyadCwas upregulated at 41°C and downregulated at 22°C. TheyadCexpressionin vivowas more pronounced in lungs than in spleen, suggesting a role in the early steps of the infection. Chicks infected with the wild-type and mutant strains presented, respectively, 80% and 50% mortality rates. The ΔyadCstrain presented a slightly decreased ability to adhere to HeLa cells with or without thed-mannose analog compared with the wild type. Real-time PCR (RT-PCR) assays showed thatfimHwas downregulated (P< 0.05) andcsgAandecpAwere slightly upregulated in the mutant strain, showing thatyadCmodulates expression of other fimbriae. Bacterial internalization studies showed that the ΔyadCstrain had a lower number of intracellular bacteria recovered from Hep-2 cells and HD11 cells than the wild-type strain (P< 0.05). Motility assays in soft agar demonstrated that the ΔyadCstrain was less motile than the wild type (P< 0.01). Curiously, flagellum-associated genes were not dramatically downregulated in the ΔyadCstrain. Taken together, the results show that the fimbrial adhesin Yad contributes to the pathogenicity and modulates different biological characteristics of the APEC strain SCI-07.

scholarly journals Interaction of Enteropathogenic and Shiga Toxin-Producing Escherichia coli and Porcine Intestinal Mucosa: Role of Intimin and Tir in Adherence

2005 ◽  
Vol 73 (9) ◽  
pp. 6005-6016 ◽  
Author(s):  
Francis Girard ◽  
Isabelle Batisson ◽  
Gad M. Frankel ◽  
Josée Harel ◽  
John M. Fairbrother
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Actin Polymerization ◽  
Animal Species ◽  
Ex Vivo ◽  
Epec Strain ◽  
E Coli ◽  
In Vitro Organ Culture

ABSTRACT The ileal in vitro organ culture (IVOC) model using tissues originating from colostrum-deprived newborn piglets has proven to be an effective way to study the attaching and effacing (A/E) phenotype of porcine enteropathogenic Escherichia coli (EPEC) ex vivo. The aim of this study was to investigate the role of intimin subtype and Tir in the adherence of EPEC and Shiga-toxin-producing E. coli (STEC), isolated from different animal species, to porcine intestinal IVOC. Moreover, the role of intimin in Tir-independent adherence of the human EPEC strain E2348/69 was investigated using intimin and Tir-deficient derivatives. Our results demonstrated that A/E E. coli strains (AEEC) from various animal species and humans induce the A/E phenotype in porcine ileal IVOC and that intimin subtype influences intestinal adherence and tropism of AEEC strains. We also showed that a tir mutant of EPEC strain E2348/69 demonstrates close adherence to the epithelial cells of porcine ileal IVOC segments, with microvillous effacement but with no evidence of actin polymerization or pedestal formation, and that intimin seems to be involved in this phenotype. Overall, this study provides further evidence for the existence of one or more host-cell-encoded intimin receptor(s) in the pig gut.

scholarly journals Cooperative Role of Antibodies against Heat-Labile Toxin and the EtpA Adhesin in Preventing Toxin Delivery and Intestinal Colonization by Enterotoxigenic Escherichia coli

2012 ◽  
Vol 19 (10) ◽  
pp. 1603-1608 ◽  
Author(s):  
Koushik Roy ◽  
David J. Hamilton ◽  
James M. Fleckenstein
Keyword(s):  
Escherichia Coli ◽  
Diarrheal Disease ◽  
Vaccine Development ◽  
Enterotoxigenic Escherichia Coli ◽  
Intestinal Colonization ◽  
Content Type ◽  
Heat Labile

ABSTRACTEnterotoxigenicEscherichia coli(ETEC) is an important cause of diarrheal disease in developing countries, where it is responsible for hundreds of thousands of deaths each year. Vaccine development for ETEC has been hindered by the heterogeneity of known molecular targets and the lack of broad-based sustained protection afforded by existing vaccine strategies. In an effort to explore the potential role of novel antigens in ETEC vaccines, we examined the ability of antibodies directed against the ETEC heat-labile toxin (LT) and the recently described EtpA adhesin to prevent intestinal colonizationin vivoand toxin delivery to epithelial cellsin vitro. We demonstrate that EtpA is required for the optimal delivery of LT and that antibodies against this adhesin play at least an additive role in preventing delivery of LT to target intestinal cells when combined with antibodies against either the A or B subunits of the toxin. Moreover, vaccination with a combination of LT and EtpA significantly impaired intestinal colonization. Together, these results suggest that the incorporation of recently identified molecules such as EtpA could be used to enhance current approaches to ETEC vaccine development.

Protective role of Mycobacterium leprae small heat-shock protein in heterologous hosts, Escherichia coli and Mycobacterium smegmatis, grown under stress

2013 ◽  
Vol 62 (7) ◽  
pp. 959-967 ◽  
Author(s):  
Jayapal Jeya Maheshwari ◽  
Kuppamuthu Dharmalingam
Keyword(s):  
Escherichia Coli ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Mycobacterium Smegmatis ◽  
Small Heat Shock Protein ◽  
Mycobacterium Leprae ◽  
Protective Role ◽  
Low Oxygen

The aim of this study is to examine the in vivo role of a small heat-shock protein (sHsp18) from Mycobacterium leprae in the survival of heterologous recombinant hosts carrying the gene encoding this protein under different environmental conditions that are normally encountered by M. leprae during its infection of the human host. Using an Escherichia coli system where shsp18 expression is controlled by its native promoter, we show that expression of shsp18 is induced under low oxygen tension, nutrient depletion and oxidative stress, all of which reflect the natural internal environment of the granulomas where the pathogen resides for long periods. We demonstrate the in vivo chaperone activity of sHsp18 through its ability to confer survival advantage to recombinant E. coli at heat-shock temperatures. Additional evidence for the protective role of sHsp18 was obtained when Mycobacterium smegmatis harbouring a copy of shsp18 was found to multiply better in human macrophages. Furthermore, the autokinase activity of sHsp18 protein demonstrated for what is believed to be the first time in this study implies that some of the functions of sHsp18 might be controlled by the phosphorylation state of this protein. Results from this study suggest that shsp18 might be one of the factors that facilitate the survival and persistence of M. leprae under stress and autophosphorylation of sHsp18 protein could be a mechanism used by this protein to sense changes in the external environment.

scholarly journals Regulatory Role of PlaR (YiaJ) for Plant Utilization in Escherichia coli K-12

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Tomohiro Shimada ◽  
Yui Yokoyama ◽  
Takumi Anzai ◽  
Kaneyoshi Yamamoto ◽  
Akira Ishihama
Keyword(s):  
Escherichia Coli ◽  
Genetic System ◽  
Regulatory Role ◽  
E Coli ◽  
Warm Blooded Animal ◽  
Plant Utilization ◽  
K 12

AbstractOutside a warm-blooded animal host, the enterobacterium Escherichia coli K-12 is also able to grow and survive in stressful nature. The major organic substance in nature is plant, but the genetic system of E. coli how to utilize plant-derived materials as nutrients is poorly understood. Here we describe the set of regulatory targets for uncharacterized IclR-family transcription factor YiaJ on the E. coli genome, using gSELEX screening system. Among a total of 18 high-affinity binding targets of YiaJ, the major regulatory target was identified to be the yiaLMNOPQRS operon for utilization of ascorbate from fruits and galacturonate from plant pectin. The targets of YiaJ also include the genes involved in the utilization for other plant-derived materials as nutrients such as fructose, sorbitol, glycerol and fructoselysine. Detailed in vitro and in vivo analyses suggest that L-ascorbate and α-D-galacturonate are the effector ligands for regulation of YiaJ function. These findings altogether indicate that YiaJ plays a major regulatory role in expression of a set of the genes for the utilization of plant-derived materials as nutrients for survival. PlaR was also suggested to play protecting roles of E. coli under stressful environments in nature, including the formation of biofilm. We then propose renaming YiaJ to PlaR (regulator of plant utilization).

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