scholarly journals Host-specific differences in the contribution of an ESBL IncI1 plasmid to intestinal colonization by Escherichia coli O104:H4

2018 ◽  
Vol 73 (6) ◽  
pp. 1579-1585 ◽  
Author(s):  
M Giles ◽  
S A Cawthraw ◽  
M AbuOun ◽  
C M Thomas ◽  
D Munera ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Animal Species ◽  
Host Bacterium ◽  
Intestinal Colonization ◽  
Specific Pathogen Free ◽  
E Coli ◽  
New Zealand White Rabbits ◽  
Specific Pathogen ◽  
Transmission Reservoir

AbstractObjectivesTo assess stability and contribution of a large ESBL-encoding IncI1 plasmid to intestinal colonization by Escherichia coli O104:H4 in two different mammalian hosts.MethodsSpecific-pathogen-free 3–4-day-old New Zealand White rabbits and conventionally reared 6-week-old weaned lambs were orally infected with WT E. coli O104:H4 or the ESBL-plasmid-cured derivative, and the recovery of bacteria in intestinal homogenates and faeces monitored over time.ResultsCarriage of the ESBL plasmid had differing impacts on E. coli O104:H4 colonization of the two experimental hosts. The plasmid-cured strain was recovered at significantly higher levels than WT during late-stage colonization of rabbits, but at lower levels than WT in sheep. Regardless of the animal host, the ESBL plasmid was stably maintained in virtually all in vivo passaged bacteria that were examined.ConclusionsThese findings suggest that carriage of ESBL plasmids has distinct effects on the host bacterium depending upon the animal species it encounters and demonstrates that, as for E. coli O157:H7, ruminants could represent a potential transmission reservoir.

Prevention of 5-fluorouracil-induced infection with indigenous Escherichia coli in tumor-bearing mice by nonspecific immunostimulation

1992 ◽  
Vol 38 (8) ◽  
pp. 774-778 ◽  
Author(s):  
Koji Nomoto ◽  
Teruo Yokokura ◽  
Kikuo Nomoto
Keyword(s):  
Escherichia Coli ◽  
Lactobacillus Casei ◽  
Lethal Dose ◽  
Systemic Infection ◽  
Specific Pathogen Free ◽  
E Coli ◽  
Tumor Bearing ◽  
Lethal Toxicity ◽  
Specific Pathogen

We have previously reported that the lethal toxicity of 5-fluorouracil (5-FU) in specific-pathogen-free mice is due to an indigenous infection with Escherichia coli (K. Nomoto, T. Yokokura, Y. Yoshikai, et al. Can. J. Microbiol. 37: 244–247, 1991). In the present study, we demonstrate that nonspecific immunostimulation augments host resistance against the lethal toxicity of 5-FU in tumor-bearing mice. Intravenous administration of a preparation of heat-killed Lactobacillus casei (LC 9018), a nonspecific immunostimulant, at a dose of 20 mg/kg to BALB/c mice augmented their resistance against the lethal toxicity of 5-FU if the preparation was injected into the mice 10–40 days before administration of 5-FU. Injection of LC 9018 into BALB/c mice bearing Meth A fibrosarcoma also enhanced their resistance against the lethality of 5-FU. Systemic infection with E. coli was induced in all of the 5-FU-treated tumor-bearing mice 10 days or more after administration of the drug at a lethal dose of 500 mg/kg, and it was accompanied by an overgrowth of the bacteria in the intestine. Treatment of tumor-bearing mice with LC 9018 resulted in decreased rates of occurrence of systemic infection with E. coli and inhibition of overgrowth of the bacteria in the intestine after administration of 5-FU. A single administration of either LC 9018 or 5-FU significantly inhibited the growth of Meth A cells in vivo, and a combined antitumor effect was shown in the mice treated with both 5-FU and LC 9018. Key words: tumor-bearing mice, fluorouracil, nonspecific immunostimulation, indigenous infection, Escherichia coli.

Inhibition of Escherichia coli Translocation from the Gastrointestinal Tract by Normal Cecal Flora in Gnotobiotic or Antibiotic-Decontaminated Mice

1980 ◽  
Vol 29 (3) ◽  
pp. 1073-1081
Author(s):  
Rodney D. Berg
Keyword(s):  
Escherichia Coli ◽  
Gastrointestinal Tract ◽  
Lymph Nodes ◽  
Bacterial Flora ◽  
Specific Pathogen Free ◽  
Mesenteric Lymph Nodes ◽  
E Coli ◽  
Mesenteric Lymph ◽  
Specific Pathogen ◽  
Gnotobiotic Mice

Escherichia coli C25 maintained population levels of 10 9 to 10 10 per g of cecum and translocated to 100% of the middle mesenteric lymph nodes in gnotobiotic mice monoassociated with E. coli C25. Intragastric inoculation of these mice with the cecal contents from specific-pathogen-free mice reduced the population levels of E. coli C25 to 10 6 per g of cecum and completely inhibited translocation to the mesenteric lymph nodes. Intragastric inoculation with heat-treated, Formalintreated, or filtered cecal contents did not reduce the population levels of E. coli C25 or reduce the incidence of translocation of E. coli C25 to the mesenteric lymph nodes. Thus, viable bacteria apparently are required in the cecal contents inocula to reduce the population levels and the incidence of translocation of E. coli C25. Treatment with streptomycin plus bacitracin decreased the anaerobic bacterial levels in these gnotobiotic mice, allowing increased population levels of E. coli C25 and increased translocation to the mesenteric lymph nodes. E. coli C25 also translocated to the mesenteric lymph nodes of specific-pathogen-free mice treated with streptomycin and bacitracin before colonization with E. coli C25. The high cecal population levels of E. coli C25 in these antibiotic-decontaminated specific-pathogen-free mice apparently overwhelm any barrier to translocation exerted by the immunologically developed lamina propria of the specific-pathogen-free mice. Inoculation of gnotobiotic mice with a cecal flora also reduced the population levels of an indigenous strain of E. coli with a concomitant inhibition of translocation of the indigenous E. coli to the mesenteric lymph nodes. Thus, bacterial antagonism of the gastrointestinal population levels of certain indigenous bacteria, such as E. coli , by other members of the normal bacterial flora appears to be an important defense mechanism confining bacteria to the gastrointestinal tract.

scholarly journals Adaptation in a Mouse Colony Monoassociated with Escherichia coli K-12 for More than 1,000 Days

2010 ◽  
Vol 76 (14) ◽  
pp. 4655-4663 ◽  
Author(s):  
Sean M. Lee ◽  
Aaron Wyse ◽  
Aaron Lesher ◽  
Mary Lou Everett ◽  
Linda Lou ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Growth Rates ◽  
Bacterial Species ◽  
Intestinal Flora ◽  
Average Density ◽  
Host Bacterium ◽  
E Coli ◽  
K 12

ABSTRACT Although mice associated with a single bacterial species have been used to provide a simple model for analysis of host-bacteria relationships, bacteria have been shown to display adaptability when grown in a variety of novel environments. In this study, changes associated with the host-bacterium relationship in mice monoassociated with Escherichia coli K-12 over a period of 1,031 days were evaluated. After 80 days, phenotypic diversification of E. coli was observed, with the colonizing bacteria having a broader distribution of growth rates in the laboratory than the parent E. coli. After 1,031 days, which included three generations of mice and an estimated 20,000 generations of E. coli, the initially homogeneous bacteria colonizing the mice had evolved to have widely different growth rates on agar, a potential decrease in tendency for spontaneous lysis in vivo, and an increased tendency for spontaneous lysis in vitro. Importantly, mice at the end of the experiment were colonized at an average density of bacteria that was more than 3-fold greater than mice colonized on day 80. Evaluation of selected isolates on day 1,031 revealed unique restriction endonuclease patterns and differences between isolates in expression of more than 10% of the proteins identified by two-dimensional electrophoresis, suggesting complex changes underlying the evolution of diversity during the experiment. These results suggest that monoassociated mice might be used as a tool for characterizing niches occupied by the intestinal flora and potentially as a method of targeting the evolution of bacteria for applications in biotechnology.

Chemostat modeling ofEscherichia colipersistence in conventionalized mono-associated and streptomycin-treated mice

2001 ◽  
Vol 47 (1) ◽  
pp. 86-90 ◽  
Author(s):  
Camilla Rang ◽  
Tore Midtvedt ◽  
Søren Molin ◽  
Lin Chao
Keyword(s):  
Escherichia Coli ◽  
Doubling Time ◽  
Keystone Species ◽  
Intestinal Bacteria ◽  
Intestinal Colonization ◽  
Chemostat Model ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Intestinal Ecology

We have previously shown that Escherichia coli BJ4 has similar doubling time in mice that are mono-associated (having only the inoculated E. coli BJ4) or streptomycin-treated (having mainly gram-positive bacteria plus the inoculated E. coli BJ4). We also showed that when the mice were conventionalized (fed cecum homogenate from conventional mice or ones with a complete microbial flora), the introduction of complete flora in both cases increased the in vivo doubling time, while decreasing the colony counts in fecal samples. To determine whether the increase in doubling time could explain the decrease in colony counts, we analyzed our previous results by a chemostat model. The analysis shows that the increasing doubling time alone is sufficient to explain the decrease in colony counts in mono-associated mice, but not in the streptomycin-treated mice. The observed decreasing rate in colony counts in streptomycin-treated mice is slower than predicted. Furthermore, whereas the model predicted a decrease to extinction in both mice, the E. coli persist at a frequency 10-80 times higher in streptomycin-treated mice than in mono-associated mice. Thus, while a chemostat model is able to explain some of the population dynamics of intestinal bacteria in mice, additional factors not included in the model are stabilizing the system. Because we find that E. coli declines more slowly and to a higher stabilization frequency in streptomycin-treated mice, which have a more diverse flora before conventionalization, we take these results to suggest that the persistence of E. coli populations is promoted by species diversity. We propose that a mechanism for the persistence may be the presence of new E. coli niches created by keystone species in the more diverse flora.Key words: intestinal ecology, intestinal colonization, chemostat, keystone species, conventionalization.

scholarly journals Mycotoxin Fumonisin B1 Increases Intestinal Colonization by Pathogenic Escherichia coli in Pigs

2003 ◽  
Vol 69 (10) ◽  
pp. 5870-5874 ◽  
Author(s):  
Isabelle P. Oswald ◽  
Clarisse Desautels ◽  
Joëlle Laffitte ◽  
Sylvie Fournout ◽  
Sylvie Y. Peres ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Animal Species ◽  
Fumonisin B1 ◽  
Dietary Exposure ◽  
Biochemical Profile ◽  
Intestinal Colonization ◽  
Predisposing Factor ◽  
E Coli ◽  
Pathogenic Escherichia Coli ◽  
Contaminated Food

ABSTRACT Fumonisin B1 (FB1) is a mycotoxin that commonly occurs in maize. FB1 causes a variety of toxic effects in different animal species and has been implicated as a contributing factor of esophageal cancers in humans. In the present study, we examined the effect of dietary exposure to FB1 on intestinal colonization by pathogenic Escherichia coli associated with extraintestinal infection. Three-week-old weaned pigs were given FB1 by gavage as a crude extract or as a purified toxin at a dose of 0.5 mg/kg of body weight daily for 6 days. On the last day of the toxin treatment, the pigs were orally inoculated with an extraintestinal pathogenic E. coli strain. All animals were euthanized 24 h later, necropsies were performed, and tissues were taken for bacterial counts and light microscopic examination. Ingestion of FB1 had only a minimal effect on animal weight gain, did not cause any macroscopic or microscopic lesions, and did not change the plasma biochemical profile. However, colonization of the small and large intestines by an extraintestinal pathogenic E. coli strain was significantly increased. Our results show that FB1 is a predisposing factor to infectious disease and that the pig can be used as a model for the study of the consequences of ingesting mycotoxin-contaminated food.

scholarly journals Targeted Delivery of Narrow-Spectrum Protein Antibiotics to the Lower Gastrointestinal Tract in a Murine Model of Escherichia coli Colonization

2021 ◽  
Vol 12 ◽  
Author(s):  
Nuria Carpena ◽  
Kerry Richards ◽  
Teresita D. J. Bello Gonzalez ◽  
Alberto Bravo-Blas ◽  
Nicholas G. Housden ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Drug Delivery ◽  
Controlled Release ◽  
Animal Models ◽  
Targeted Delivery ◽  
Intestinal Colonization ◽  
Ph Responsive ◽  
Human Gut ◽  
E Coli

Bacteriocins are narrow-spectrum protein antibiotics that could potentially be used to engineer the human gut microbiota. However, technologies for targeted delivery of proteins to the lower gastrointestinal (GI) tract in preclinical animal models are currently lacking. In this work, we have developed methods for the microencapsulation of Escherichia coli targeting bacteriocins, colicin E9 and Ia, in a pH responsive formulation to allow their targeted delivery and controlled release in an in vivo murine model of E. coli colonization. Membrane emulsification was used to produce a water-in-oil emulsion with the water-soluble polymer subsequently cross-linked to produce hydrogel microcapsules. The microcapsule fabrication process allowed control of the size of the drug delivery system and a near 100% yield of the encapsulated therapeutic cargo. pH-triggered release of the encapsulated colicins was achieved using a widely available pH-responsive anionic copolymer in combination with alginate biopolymers. In vivo experiments using a murine E. coli intestinal colonization model demonstrated that oral delivery of the encapsulated colicins resulted in a significant decrease in intestinal colonization and reduction in E. coli shedding in the feces of the animals. Employing controlled release drug delivery systems such as that described here is essential to enable delivery of new protein therapeutics or other biological interventions for testing within small animal models of infection. Such approaches may have considerable value for the future development of strategies to engineer the human gut microbiota, which is central to health and disease.

scholarly journals Virulence Characteristic of Avian Pathogenic Escherichia coli (APEC) Isolates

2020 ◽  
Vol 38 (1) ◽  
pp. 61
Author(s):  
Sruti Listra Adrenalin ◽  
Lynda Nugrahaning Imanjati ◽  
Ima Fauziah ◽  
Vinsa Cantya Prakasita ◽  
Sitarina Widyarini ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Respiratory Disease ◽  
High Mortality ◽  
Specific Pathogen Free ◽  
Avian Pathogenic Escherichia Coli ◽  
E Coli ◽  
Pathogenic Escherichia Coli ◽  
High Virulence ◽  
Specific Pathogen ◽  
Costs Of Treatment

Avian pathogenic Escherichia coli (APEC) is a cause of colibacillosis in poultry, one of the respiratory disease that causes serious problems in the poultry industry. The APEC can cause high mortality and culling, decreased production, and high costs of treatment. Manifestations of colibacillosis are airsacculitis, perihepatitis, and pericarditis. The APEC serotypes that are widely identified in the field are O1K1, O2K1, and O78K80. Embryo lethality assay (ELA) is a method for determine the virulence of APEC serotypes. The aim of this study was to determine the virulence characteristic of APEC isolates. Five APEC serotypes O1K1, O2K1, O78K80, O157H7, and unknown serotype were used for ELA method by inoculated E. coli into chorioallantoic of specific pathogen free 12-days old embryos. Each group of 10 embryos, inoculated E. coli dose of 100-500 CFU/ 0,1 ml. Candling was carried out for 6 days (18-days old embryo) to determined the mortality and pathological lesions. The percentage of embryo mortality post-inoculated with APEC O1K1, O2K1, unknown serotypes were 100% (10/10), O78K80 serotype was 90% (9/10), and O157H7 serotype was 70% (70%). Lesions of all embryos were cranial and extremity hemorrhage. In this study, E. coli isolates had high virulence. 

scholarly journals Long Polar Fimbriae Contribute to Colonization by Escherichia coli O157:H7 In Vivo

2004 ◽  
Vol 72 (10) ◽  
pp. 6168-6171 ◽  
Author(s):  
Dianna M. Jordan ◽  
Nancy Cornick ◽  
Alfredo G. Torres ◽  
Evelyn A. Dean-Nystrom ◽  
James B. Kaper ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Parent Strain ◽  
Escherichia Coli O157 ◽  
Intestinal Colonization ◽  
E Coli ◽  
Gnotobiotic Piglets

ABSTRACT The contribution of long polar fimbriae to intestinal colonization by Escherichia coli O157:H7 was evaluated in sheep, conventional pigs, and gnotobiotic piglets. E. coli O157:H7 strains with lpfA1 and lpfA2 mutated were recovered in significantly lower numbers and caused fewer attachment and effacement lesions than the parent strain.

scholarly journals Role for Flagella but Not Intimin in the Persistent Infection of the Gastrointestinal Tissues of Specific-Pathogen-Free Chicks by Shiga Toxin-Negative Escherichia coli O157:H7

2005 ◽  
Vol 73 (3) ◽  
pp. 1836-1846 ◽  
Author(s):  
Angus Best ◽  
Roberto M. La Ragione ◽  
A. Robin Sayers ◽  
Martin J. Woodward
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Escherichia Coli O157 ◽  
Specific Pathogen Free ◽  
Similar Time ◽  
E Coli ◽  
Oral Inoculation ◽  
Specific Pathogen ◽  
Significant Attenuation

ABSTRACT Shiga toxin (Stx)-positive Escherichia coli O157:H7 readily colonize and persist in specific-pathogen-free (SPF) chicks, and we have shown that an Stx-negative E. coli O157:H7 isolate (NCTC12900) readily colonizes SPF chicks for up to 169 days after oral inoculation at 1 day of age. However, the role of intimin in the persistent colonization of poultry remains unclear. Thus, to investigate the role of intimin and flagella, which is a known factor in the persistence of non-O157 E. coli in poultry, isogenic single- and double-intimin and aflagellar mutants were constructed in E. coli O157:H7 isolate NCTC12900. These mutants were used to inoculate (105 CFU) 1-day-old SPF chicks. In general, significant attenuation of the aflagellate and intimin-aflagellate mutants, but not the intimin mutant, was noted at similar time points between 22 and 92 days after inoculation. The intimin-deficient mutant was still being shed at the end of the experiment, which was 211 days after inoculation, 84 days more than the wild type. Shedding of the aflagellar and intimin-aflagellar mutants ceased 99 and 113 days after inoculation, respectively. Histological analysis of gastrointestinal tissues from inoculated birds gave no evidence for true microcolony formation by NCTC12900 or intimin and aflagellar mutants to epithelial cells. However, NCTC12900 mutant derivatives associated with the mucosa were observed as individual cells and/or as large aggregates. Association with luminal contents was also noted. These data suggest that O157 organisms do not require intimin for the persistent colonization of chickens, whereas flagella do play a role in this process.

scholarly journals Role of Intimin-Tir Interactions and the Tir-Cytoskeleton Coupling Protein in the Colonization of Calves and Lambs by Escherichia coli O157:H7

2006 ◽  
Vol 74 (1) ◽  
pp. 758-764 ◽  
Author(s):  
Isabella Vlisidou ◽  
Francis Dziva ◽  
Roberto M. La Ragione ◽  
Angus Best ◽  
Junkal Garmendia ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Loop Model ◽  
Intestinal Colonization ◽  
Actin Assembly ◽  
Ileal Loop ◽  
E Coli ◽  
Coupling Protein

ABSTRACT Intimin facilitates intestinal colonization by enterohemorrhagic Escherichia coli O157:H7; however, the importance of intimin binding to its translocated receptor (Tir) as opposed to cellular coreceptors is unknown. The intimin-Tir interaction is needed for optimal actin assembly under adherent bacteria in vitro, a process which requires the Tir-cytoskeleton coupling protein (TccP/EspFU) in E. coli O157:H7. Here we report that E. coli O157:H7 tir mutants are at least as attenuated as isogenic eae mutants in calves and lambs, implying that the role of intimin in the colonization of reservoir hosts can be explained largely by its binding to Tir. Mutation of tccP uncoupled actin assembly from the intimin-Tir-mediated adherence of E. coli O157:H7 in vitro but did not impair intestinal colonization in calves and lambs, implying that pedestal formation may not be necessary for persistence. However, an E. coli O157:H7 tccP mutant induced typical attaching and effacing lesions in a bovine ligated ileal loop model of infection, suggesting that TccP-independent mechanisms of actin assembly may operate in vivo.

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