scholarly journals The gut at war: the consequences of enteropathogenic Escherichia coli infection as a factor of diarrhea and malnutrition

2000 ◽  
Vol 118 (1) ◽  
pp. 21-29 ◽  
Author(s):  
Ulysses Fagundes-Neto ◽  
Isabel Cristina Affonso Scaletsky
Keyword(s):  
Escherichia Coli ◽  
Diarrheal Disease ◽  
Driving Forces ◽  
Public Health Problem ◽  
Clinical Aspects ◽  
Small Intestinal Mucosa ◽  
Enteropathogenic Escherichia Coli ◽  
Important Public Health Problem ◽  
The Impact

Diarrheal disease is still the most prevalent and important public health problem in developing countries, despite advances in knowledge, understanding, and management that have occurred over recent years. Diarrhea is the leading cause of death in children under 5 years of age. The impact of diarrheal diseases is more severe in the earliest periods of life, when taking into account both the numbers of episodes per year and hospital admission rates. This narrative review focuses on one of the major driving forces that attack the host, namely the enteropathogenic Escherichia coli (EPEC) and the consequences that generate malnutrition in an early phase of life. EPEC serotypes form dense microcolonies on the surface of tissue-culture cells in a pattern known as localized adherence (LA). When EPEC strains adhere to epithelial cells in vitro or in vivo they cause characteristic changes known as Attaching and Effacement (A/E) lesions. Surface abnormalities of the small intestinal mucosa shown by scanning electron microscopy in infants with persistent diarrhea, although non-specific, are intense enough to justify the severity of the clinical aspects displayed in a very young phase in life. Decrease in number and height of microvilli, blunting of borders of enterocytes, loss of the glycocalyx, shortening of villi and presence of a mucus pseudomembrane coating the mucosal surface were the abnormalities observed in the majority of patients. These ultrastructural derangements may be due to an association of the enteric enteropathogenic agent that triggers the diarrheic process and the onset of food intolerance responsible for perpetuation of diarrhea. An aggressive therapeutic approach based on appropriate nutritional support, especially the utilization of human milk and/or lactose-free protein hydrolyzate-based formulas and the adequate correction of the fecal losses, is required to allow complete recovery from the damage caused by this devastating enteropathogenic agent.

DURATION OF NEOMYCIN THERAPY FOR ENTEROPATHOGENIC ESCHERICHIA COLI DIARRHEAL DISEASE: A COMPARATIVE STUDY OF 113 CASES

PEDIATRICS ◽  
1971 ◽  
Vol 48 (2) ◽  
pp. 248-258
Author(s):  
John D. Nelson
Keyword(s):  
Escherichia Coli ◽  
Diarrheal Disease ◽  
Fluorescent Antibody ◽  
Infectious Complications ◽  
Term Therapy ◽  
Enteropathogenic Escherichia Coli ◽  
Short Term ◽  
Short Term Therapy

The usually recommended 7- to 10- day course of antibiotic therapy for enteropathogenic Escherichia coli diarrheal disease might be undesirable because neomycin can cause a malabsorption syndrome. One hundred thirteen infants with E. coli arrheal disease were randomly assigned to long-term therapy of 10 days or to short-term therapy. For short-term therapy neomycin was discontinued when daily fluorescent antibody and culture tests were negative; therapy averaged 3 days with a range of 2 to 4½ days for all but one patient. The pathogens were susceptible to neomycin in vitro. The initial bacteriologic response was the same in both groups. Bacteriologic relapse without return of symptoms occurred in 14 of 57 in the longterm group and in 7 of 56 babies in the short-term group. Organisms isolated during relapse remained sensitive in vitro to neomycin. In the long-term group diarrhea lasted significanfly longer with a trend to delayed onset of steady weight gain and infectious complications were twice as common. There was no significant change in indirect hemagglutinin titer between acute and convalescent sera in 91% of specimens. Current recommendations for duration of therapy should be shortened to 3 to 5 days. This study and a literature review also raise doubts about the real value of antibiotics in this disease.

scholarly journals Biofilm in Genital Ecosystem: A Potential Risk Factor for Chlamydia trachomatis Infection

2019 ◽  
Vol 2019 ◽  
pp. 1-6 ◽  
Author(s):  
Simone Filardo ◽  
Marisa Di Pietro ◽  
Giulia Tranquilli ◽  
Rosa Sessa
Keyword(s):  
Chlamydia Trachomatis ◽  
Genital Tract ◽  
Cell Monolayer ◽  
Female Genital Tract ◽  
Public Health Problem ◽  
Gardnerella Vaginalis ◽  
Important Public Health Problem ◽  
Sexually Transmitted ◽  
The Impact

In healthy women, the cervicovaginal microbiota is mostly populated by Lactobacillus spp., the main host defense factor of the female genital tract. In addition to Lactobacilli, other microorganisms populate the cervicovaginal microbiota, like Candida spp. and Gardnerella vaginalis. The overgrowth of Candida spp. or G. vaginalis, known as biofilm-producing microorganisms in the genital ecosystem, may lead to microbial dysbiosis that increases the risk of acquiring sexually transmitted infections, like Chlamydia trachomatis. C. trachomatis, the leading cause of bacterial sexually transmitted diseases, is still considered an important public health problem worldwide because of the impact of asymptomatic infections on long-term reproductive sequelae, including pelvic inflammatory disease and infertility. The aim of our study was to investigate the interaction between C. trachomatis and the biofilm produced by Candida albicans or Gardnerella vaginalis, evaluating whether the biofilm can harbor C. trachomatis and influence its survival as well as its infectious properties. In order to do so, we developed an in vitro coculture transwell-based biofilm model. Our findings proved, for the first time, that C. trachomatis, an intracellular obligate pathogen, survived, for up to 72 hours after exposure, inside the biofilm produced by C. albicans or G. vaginalis, retaining its infectious properties, as evidenced by the typical chlamydial inclusions observed in the cell monolayer (chlamydial inclusion-forming units at 72 h: 9255 ± 1139 and 9873 ± 1015, respectively). In conclusion, our results suggest that the biofilm related to Candida or Gardnerella genital infections may act as a reservoir of C. trachomatis and, thus, contribute to the transmission of the infection in the population as well as to its dissemination into the upper genital tract, increasing the risk of developing severe reproductive sequelae.

scholarly journals Interaction of Escherichia coli O157:H7 with Leafy Green Produce

2009 ◽  
Vol 72 (7) ◽  
pp. 1531-1537 ◽  
Author(s):  
JUAN XICOHTENCATL-CORTES ◽  
ETHEL SÁNCHEZ CHACÓN ◽  
ZEUS SALDAÑA ◽  
ENRIQUE FREER ◽  
JORGE A. GIRÓN
Keyword(s):  
Escherichia Coli ◽  
Diarrheal Disease ◽  
Foodborne Pathogen ◽  
Enterohemorrhagic Escherichia Coli ◽  
Animal Products ◽  
Atpase Gene ◽  
Type 3 Secretion System ◽  
Human Infections ◽  
Type 3

Enterohemorrhagic Escherichia coli (EHEC) is a foodborne pathogen responsible for human diarrheal disease. EHEC lives in the intestinal tract of cattle and other farm and wild animals, which may be the source of environmental contamination particularly of agricultural fields. Human infections are associated with consumption of tainted animal products and fresh produce. How the bacteria interact with the plant phyllosphere and withstand industrial decontamination remain to be elucidated. The goals of the present study were to investigate the environmental conditions and surface structures that influence the interaction of EHEC O157:H7 with baby spinach and lettuce leaves in vitro. Independently of the production of Shiga toxin, EHEC O157:H7 colonizes the leaf surface via flagella and the type 3 secretion system (T3SS). Ultrastructural analysis of EHEC-infected leafy greens revealed the presence of flagellated bacteria, and mutation of the fliC flagellin gene in EHEC EDL933 rendered the bacteria significantly less adherent, suggesting the involvement of flagella in the bacteria-leaf interaction. EDL933 mutated in the escN (ATPase) gene associated with the function of the T3SS but not in the eae (intimin adhesin) gene required for adherence to host intestinal cells had significantly reduced adherence compared with that of the parental strain. The data suggest a compelling role of flagella and the T3SS in colonization of leafy green produce. Colonization of salad leaves by EHEC strains may be a strategy that ensures survival of these bacteria in the environment and allows transmission to the human host.

scholarly journals In VivoTransmission of an IncA/C Plasmid in Escherichia coli Depends on Tetracycline Concentration, and Acquisition of the Plasmid Results in a Variable Cost of Fitness

2015 ◽  
Vol 81 (10) ◽  
pp. 3561-3570 ◽  
Author(s):  
Timothy J. Johnson ◽  
Randall S. Singer ◽  
Richard E. Isaacson ◽  
Jessica L. Danzeisen ◽  
Kevin Lang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
High Dose ◽  
Broad Host Range ◽  
Antibiotic Administration ◽  
Dose Administration ◽  
Content Type ◽  
E Coli ◽  
The Impact ◽  
Selection Of

ABSTRACTIncA/C plasmids are broad-host-range plasmids enabling multidrug resistance that have emerged worldwide among bacterial pathogens of humans and animals. Although antibiotic usage is suspected to be a driving force in the emergence of such strains, few studies have examined the impact of different types of antibiotic administration on the selection of plasmid-containing multidrug resistant isolates. In this study, chlortetracycline treatment at different concentrations in pig feed was examined for its impact on selection and dissemination of an IncA/C plasmid introduced orally via a commensalEscherichia colihost. Continuous low-dose administration of chlortetracycline at 50 g per ton had no observable impact on the proportions of IncA/C plasmid-containingE. colifrom pig feces over the course of 35 days. In contrast, high-dose administration of chlortetracycline at 350 g per ton significantly increased IncA/C plasmid-containingE. coliin pig feces (P< 0.001) and increased movement of the IncA/C plasmid to other indigenousE. colihosts. There was no evidence of conjugal transfer of the IncA/C plasmid to bacterial species other thanE. coli.In vitrocompetition assays demonstrated that bacterial host background substantially impacted the cost of IncA/C plasmid carriage inE. coliandSalmonella.In vitrotransfer and selection experiments demonstrated that tetracycline at 32 μg/ml was necessary to enhance IncA/C plasmid conjugative transfer, while subinhibitory concentrations of tetracyclinein vitrostrongly selected for IncA/C plasmid-containingE. coli. Together, these experiments improve our knowledge on the impact of differing concentrations of tetracycline on the selection of IncA/C-type plasmids.

Leprosy (Hansen’s disease)

2010 ◽  
pp. 836-848
Author(s):  
Diana N.J. Lockwood
Keyword(s):  
Public Health ◽  
Chronic Granulomatous Disease ◽  
Health Problem ◽  
Disease Transmission ◽  
Public Health Problem ◽  
Mycobacterium Leprae ◽  
Granulomatous Disease ◽  
Important Public Health Problem ◽  
Important Public Health

Leprosy is a chronic granulomatous disease caused by Mycobacterium leprae, an acid-fast intracellular organism not yet cultivated in vitro. It is an important public health problem worldwide, with an estimated 4 million people disabled by the disease. Transmission of M. leprae is only partially understood, but untreated lepromatous patients discharge abundant organisms from their nasal mucosa into the environment....

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.

scholarly journals Localized adherence by enteropathogenic Escherichia coli is an inducible phenotype associated with the expression of new outer membrane proteins.

1991 ◽  
Vol 174 (5) ◽  
pp. 1167-1177 ◽  
Author(s):  
J Vuopio-Varkila ◽  
G K Schoolnik
Keyword(s):  
Escherichia Coli ◽  
Membrane Proteins ◽  
Outer Membrane ◽  
De Novo ◽  
Outer Membrane Proteins ◽  
Temporal Correlation ◽  
Enteropathogenic Escherichia Coli ◽  
E Coli

Enteropathogenic Escherichia coli grow as discrete colonies on the mucous membranes of the small intestine. A similar pattern can be demonstrated in vitro; termed localized adherence (LA), it is characterized by the presence of circumscribed clusters of bacteria attached to the surfaces of cultured epithelial cells. The LA phenotype was studied using B171, an O111:NM enteropathogenic E. coli (EPEC) strain, and HEp-2 cell monolayers. LA could be detected 30-60 min after exposure of HEp-2 cells to B171. However, bacteria transferred from infected HEp-2 cells to fresh monolayers exhibited LA within 15 min, indicating that LA is an inducible phenotype. Induction of the LA phenotype was found to be associated with de novo protein synthesis and changes in the outer membrane proteins, including the production of a new 18.5-kD polypeptide. A partial NH2-terminal amino acid sequence of this polypeptide was obtained and showed it to be identical through residue 12 to the recently described bundle-forming pilus subunit of EPEC. Expression of the 18.5-kD polypeptide required the 57-megadalton enteropathogenic E. coli adherence plasmid previously shown to be required for the LA phenotype in vitro and full virulence in vivo. This observation, the correspondence of the 18.5-kD polypeptide to an EPEC-specific pilus protein, and the temporal correlation of its expression with the development of the LA phenotype suggest that it may contribute to the EPEC colonial mode of growth.

scholarly journals DIETARY FACTORS AND COGNITIVE DECLINE

2015 ◽  
pp. 1-12
Author(s):  
P.J. Smith ◽  
J.A. Blumenthal
Keyword(s):  
Fatty Acids ◽  
Cognitive Decline ◽  
Randomized Clinical Trials ◽  
Public Health Problem ◽  
Later Life ◽  
Epidemiological Studies ◽  
Dietary Factors ◽  
B Vitamins ◽  
Important Public Health Problem ◽  
The Impact

Cognitive decline is an increasingly important public health problem, with more than 100 million adults worldwide projected to develop dementia by 2050. Accordingly, there has been an increased interest in preventive strategies that diminish this risk. It has been recognized that lifestyle factors including dietary patterns, may be important in the prevention of cognitive decline and dementia in later life. Several dietary components have been examined, including antioxidants, fatty acids, and B vitamins. In addition, whole dietary eating plans, including the Mediterranean diet (MeDi), and the Dietary Approaches to Stop Hypertension (DASH) diet, with and without weight loss, have become areas of increasing interest. Although prospective epidemiological studies have observed that antioxidants, fatty acids, and B vitamins are associated with better cognitive functioning, randomized clinical trials have generally failed to confirm the value of any specific dietary component in improving neurocognition. Several randomized trials have examined the impact of changing ‘whole’ diets on cognitive outcomes. The MeDi and DASH diets offer promising preliminary results, but data are limited and more research in this area is needed.

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