scholarly journals Naturally occurring hypothermia is more advantageous than fever in severe forms of lipopolysaccharide- and Escherichia coli-induced systemic inflammation

2012 ◽  
Vol 302 (12) ◽  
pp. R1372-R1383 ◽  
Author(s):  
Elaine Liu ◽  
Kevin Lewis ◽  
Hiba Al-Saffar ◽  
Catherine M. Krall ◽  
Anju Singh ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Systemic Inflammation ◽  
Mortality Rates ◽  
E Coli ◽  
Beneficial Effects ◽  
Warm Environment ◽  
Naturally Occurring ◽  
Cool Environment ◽  
Overall Mortality ◽  
Hypothermic Group

The natural switch from fever to hypothermia observed in the most severe cases of systemic inflammation is a phenomenon that continues to puzzle clinicians and scientists. The present study was the first to evaluate in direct experiments how the development of hypothermia vs. fever during severe forms of systemic inflammation impacts the pathophysiology of this malady and mortality rates in rats. Following administration of bacterial lipopolysaccharide (LPS; 5 or 18 mg/kg) or of a clinical Escherichia coli isolate (5 × 109or 1 × 1010CFU/kg), hypothermia developed in rats exposed to a mildly cool environment, but not in rats exposed to a warm environment; only fever was revealed in the warm environment. Development of hypothermia instead of fever suppressed endotoxemia in E. coli -infected rats, but not in LPS-injected rats. The infiltration of the lungs by neutrophils was similarly suppressed in E. coli -infected rats of the hypothermic group. These potentially beneficial effects came with costs, as hypothermia increased bacterial burden in the liver. Furthermore, the hypotensive responses to LPS or E. coli were exaggerated in rats of the hypothermic group. This exaggeration, however, occurred independently of changes in inflammatory cytokines and prostaglandins. Despite possible costs, development of hypothermia lessened abdominal organ dysfunction and reduced overall mortality rates in both the E. coli and LPS models. By demonstrating that naturally occurring hypothermia is more advantageous than fever in severe forms of aseptic (LPS-induced) or septic ( E. coli -induced) systemic inflammation, this study provides new grounds for the management of this deadly condition.

scholarly journals TmPGRP-SA regulates Antimicrobial Response to Bacteria and Fungi in the Fat Body and Gut of Tenebrio molitor

2020 ◽  
Vol 21 (6) ◽  
pp. 2113 ◽  
Author(s):  
Maryam Keshavarz ◽  
Yong Hun Jo ◽  
Tariku Tesfaye Edosa ◽  
Young Min Bae ◽  
Yeon Soo Han
Keyword(s):  
Escherichia Coli ◽  
Fat Body ◽  
Mrna Level ◽  
Tenebrio Molitor ◽  
Mortality Rates ◽  
E Coli ◽  
Peptidoglycan Recognition Protein ◽  
Recognition Protein ◽  
Bacteria And Fungi ◽  
Antimicrobial Immune Response

Antimicrobial immune response is mediated by a signal-transducing sensor, peptidoglycan recognition protein-SA (PGRP-SA), that can recognize non-self molecules. Although several studies have focused on the involvement of Drosophila PGRP-SA in antimicrobial peptide (AMP) expression in response to infections, studies on its role in Tenebrio molitor are lacking. Here, we present a functional analysis of T. molitor PGRP-SA (TmPGRP-SA). In the absence of microbes, TmPGRP-SA was highly expressed in the late-larval fat body, followed by hemocytes, and gut. Interestingly, following Escherichia coli, Staphylococcus aureus, and Candida albicans infections, the mRNA level of TmPGRP-SA was significantly upregulated in both the fat body and gut. TmPGRP-SA silencing had a significant effect on the mortality rates for all the microbes tested. Moreover, TmPGRP-SA is required for regulating the expression of eight AMP genes namely TmTenecin-1, -2, and -4; TmDefensin-1 and -2; TmColeoptericin-1; and TmAttacin-1b and -2 in the fat body in response to E. coli and S. aureus infections. TmPGRP-SA is essential for the transcription of TmTenecin-2, -4; TmDefensin-2; TmColeoptericin-1, -2; and TmAttacin-1a, -1b, and -2 in the gut upon E. coli and C. albicans infections. However, TmPGRP-SA does not regulate AMP expression in the hemocytes. Additionally, TmDorsal isoform X2, a downstream Toll transcription factor, was downregulated in TmPGRP-SA-silenced larval fat body following E. coli and S. aureus challenges, and in the gut following E. coli and C. albicans challenges.

scholarly journals Natural Genetic Transformation of Clinical Isolates of Escherichia coli in Urine and Water

2002 ◽  
Vol 68 (1) ◽  
pp. 440-443 ◽  
Author(s):  
Markus Woegerbauer ◽  
Bernard Jenni ◽  
Florian Thalhammer ◽  
Wolfgang Graninger ◽  
Heinz Burgmann
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Current Knowledge ◽  
Antibiotic Resistance Genes ◽  
Aquatic Environments ◽  
Wild Type ◽  
E Coli ◽  
Naturally Occurring ◽  
Natural Genetic Transformation ◽  
Type Strains

ABSTRACT Transfer of plasmid-borne antibiotic resistance genes in Escherichia coli wild-type strains is possible by transformation under naturally occurring conditions in oligotrophic, aquatic environments containing physiologic concentrations of calcium. In contrast, transformation is suppressed in nitrogen-rich body fluids like urine, a common habitat of uropathogenic strains. Current knowledge indicates that transformation of these E. coli wild-type strains is of no relevance for the acquisition of resistance in this clinically important environment.

Fate of Naturally Occurring Escherichia coli O157:H7 and Other Zoonotic Pathogens during Minimally Managed Bovine Feedlot Manure Composting Processes†

2013 ◽  
Vol 76 (8) ◽  
pp. 1308-1321 ◽  
Author(s):  
ELAINE D. BERRY ◽  
PATRICIA D. MILLNER ◽  
JAMES E. WELLS ◽  
NORASAK KALCHAYANAND ◽  
MICHAEL N. GUERINI
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
High Temperatures ◽  
Thermophilic Bacteria ◽  
Foodborne Illness ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Naturally Occurring ◽  
On Farm ◽  
Campylobacter Spp

Reducing Escherichia coli O157:H7 in livestock manures before application to cropland is critical for reducing the risk of foodborne illness associated with produce. Our objective was to determine the fate of naturally occurring E. coli O157:H7 and other pathogens during minimally managed on-farm bovine manure composting processes. Feedlot pen samples were screened to identify E. coli O157:H7–positive manure. Using this manure, four piles of each of three different composting formats were constructed in each of two replicate trials. Composting formats were (i) turned piles of manure plus hay and straw, (ii) static stockpiles of manure, and (iii) static piles of covered manure plus hay and straw. Temperatures in the tops, toes, and centers of the conical piles (ca. 6.0 m3 each) were monitored. Compost piles that were turned every 2 weeks achieved higher temperatures for longer periods in the tops and centers than did piles that were left static. E. coli O157:H7 was not recovered from top samples of turned piles of manure plus hay and straw at day 28 and beyond, but top samples from static piles were positive for the pathogen up to day 42 (static manure stockpiles) and day 56 (static covered piles of manure plus hay and straw). Salmonella, Campylobacter spp., and Listeria monocytogenes were not found in top or toe samples at the end of the composting period, but E. coli O157:H7 and Listeria spp. were recovered from toe samples at day 84. Our findings indicate that some minimally managed composting processes can reduce E. coli O157:H7 and other pathogens in bovine manure but may be affected by season and/or initial levels of indigenous thermophilic bacteria. Our results also highlight the importance of adequate C:N formulation of initial mixtures for the production of high temperatures and rapid composting, and the need for periodic turning of the piles to increase the likelihood that all parts of the mass are subjected to high temperatures.

scholarly journals Different impacts of naturally occurring variants of the globally disseminated carbapenemase-encoding plasmid pKpQIL on the biology of host strains

2018 ◽  
Author(s):  
Howard T. H. Saw ◽  
Mark A. Webber ◽  
Neil Woodford ◽  
Laura J. V. Piddock
Keyword(s):  
Escherichia Coli ◽  
Klebsiella Pneumoniae ◽  
Host Range ◽  
Generation Time ◽  
Enterobacter Cloacae ◽  
Bacterial Host ◽  
E Coli ◽  
Naturally Occurring ◽  
Filter Mating ◽  
Host Strains

SynopsisKlebsiella-associated plasmid pKpQIL and its variant have been isolated globally. Our study aimed to determine whether a naturally occurring variant has altered host range and impacts on the fitness of different bacterial host strains. The plasmids pKpQIL-UK and pKpQIL-D2 were transferred from the original clinical isolate host strains of Klebsiella pneumoniae into Escherichia coli, Salmonella Typhimurium, Enterobacter cloacae and Serratia marcescens strains by filter-mating and conjugation frequencies determined and compared. The fitness of the resulting transconjugants was assessed by determining growth kinetics, ability to form a biofilm and persistence of the plasmids in each host was also measured. Transfer of either plasmid into Salmonella and S. marcescens was similar. However, pKpQIL-UK transferred into E. coli at a higher rate than did pKpQIL-D2; the reverse was found for E. cloacae. Both plasmids were rapidly lost from the E. coli population. Plasmid pKpQIL-UK, but not -D2, was able to persist in Salmonella. Although pKpQIL-UK imposed a greater fitness cost (inferred from an increased generation time) than -D2 on E. cloacae, it was able to persist as well as pKpQIL-D2 in this host. The pKpQIL-D2 plasmid did not confer any fitness benefit on any of the hosts under the conditions tested. Variants of the globally important pKpQIL plasmid have arisen in patients due to recombination. The impacts of the pKpQIL-UK plasmid and the -D2 variant in various Enterobacteriaceae are host-dependent. Continuing evolution of pKpQIL may alter its host range in the future.

scholarly journals Comparative Survival of Free Shiga Toxin 2-Encoding Phages and Escherichia coli Strains outside the Gut

1999 ◽  
Vol 65 (12) ◽  
pp. 5615-5618 ◽  
Author(s):  
Maite Muniesa ◽  
Francisco Lucena ◽  
Juan Jofre
Keyword(s):  
Escherichia Coli ◽  
Heat Treatment ◽  
River Water ◽  
Shiga Toxin ◽  
Water Environment ◽  
Somatic Coliphages ◽  
E Coli ◽  
Naturally Occurring ◽  
Shiga Toxin 2

ABSTRACT The behavior outside the gut of seeded Escherichia coliO157:H7, naturally occurring E. coli, somatic coliphages, bacteriophages infecting O157:H7, and Shiga toxin 2 (Stx2)-encoding bacteriophages was studied to determine whether the last persist in the environment more successfully than their host bacteria. The ratios between the numbers of E. coli and those of the different bacteriophages were clearly lower in river water than in sewage of the area, whereas the ratios between the numbers of the different phages were similar. In addition, the numbers of bacteria decreased between 2 and 3 log units in in situ survival experiments performed in river water, whereas the numbers of phages decreased between 1 and 2 log units. Chlorination and pasteurization treatments that reduced by approximately 4 log units the numbers of bacteria reduced by less than 1 log unit the numbers of bacteriophages. Thus, it can be concluded that Stx2-encoding phages persist longer than their host bacteria in the water environment and are more resistant than their host bacteria to chlorination and heat treatment.

scholarly journals Synthetic promoter design in Escherichia coli based on a deep generative network

2020 ◽  
Vol 48 (12) ◽  
pp. 6403-6412 ◽  
Author(s):  
Ye Wang ◽  
Haochen Wang ◽  
Lei Wei ◽  
Shuailin Li ◽  
Liyang Liu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Predictive Model ◽  
De Novo ◽  
Sequence Similarity ◽  
Small Subset ◽  
Vast Number ◽  
Significant Sequence Similarity ◽  
E Coli ◽  
Synthetic Promoters ◽  
Naturally Occurring

Abstract Promoter design remains one of the most important considerations in metabolic engineering and synthetic biology applications. Theoretically, there are 450 possible sequences for a 50-nt promoter, of which naturally occurring promoters make up only a small subset. To explore the vast number of potential sequences, we report a novel AI-based framework for de novo promoter design in Escherichia coli. The model, which was guided by sequence features learned from natural promoters, could capture interactions between nucleotides at different positions and design novel synthetic promoters in silico. We combined a deep generative model that guides the search for artificial sequences with a predictive model to preselect the most promising promoters. The AI-designed promoters were optimized based on the promoter activity in E. coli and the predictive model. After two rounds of optimization, up to 70.8% of the AI-designed promoters were experimentally demonstrated to be functional, and few of them shared significant sequence similarity with the E. coli genome. Our work provided an end-to-end approach to the de novo design of novel promoter elements, indicating the potential to apply deep learning methods to de novo genetic element design.

scholarly journals Escherichia coli Survival in, and Release from, White-Tailed Deer Feces

2014 ◽  
Vol 81 (3) ◽  
pp. 1168-1176 ◽  
Author(s):  
Andrey K. Guber ◽  
Jessica Fry ◽  
Rebecca L. Ives ◽  
Joan B. Rose
Keyword(s):  
Escherichia Coli ◽  
Fate And Transport ◽  
Exponential Model ◽  
Temperature Correction ◽  
Content Type ◽  
E Coli ◽  
Naturally Occurring ◽  
Different Temperatures ◽  
Kinetics Of ◽  
Source Materials

ABSTRACTWhite-tailed deer are an important reservoir for pathogens that can contribute a large portion of microbial pollution in fragmented agricultural and forest landscapes. The scarcity of experimental data on survival of microorganisms in and release from deer feces makes prediction of their fate and transport less reliable and development of efficient strategies for environment protection more difficult. The goal of this study was to estimate parameters for modelingEscherichia colisurvival in and release from deer (Odocoileus virginianus) feces. Our objectives were as follows: (i) to measure survival ofE. coliin deer pellets at different temperatures, (ii) to measure kinetics ofE. colirelease from deer pellets at different rainfall intensities, and (iii) to estimate parameters of models describing survival and release of microorganisms from deer feces. Laboratory experiments were conducted to studyE. colisurvival in deer pellets at three temperatures and to estimate parameters of Chick's exponential model with temperature correction based on the Arrhenius equation. Kinetics ofE. colirelease from deer pellets were measured at two rainfall intensities and used to derive the parameters of Bradford-Schijven model of bacterial release. The results showed that parameters of the survival and release models obtained forE. coliin this study substantially differed from those obtained by using other source materials, e.g., feces of domestic animals and manures. This emphasizes the necessity of comprehensive studies of survival of naturally occurring populations of microorganisms in and release from wildlife animal feces in order to achieve better predictions of microbial fate and transport in fragmented agricultural and forest landscapes.

scholarly journals Critical Synergistic Concentration of Lecithin Phospholipids Improves the Antimicrobial Activity of Eugenol against Escherichia coli

2017 ◽  
Vol 83 (21) ◽  
Author(s):  
Haoshu Zhang ◽  
Edward G. Dudley ◽  
Federico Harte
Keyword(s):  
Escherichia Coli ◽  
Foodborne Pathogens ◽  
Rational Design ◽  
Microbial Population ◽  
Critical Concentration ◽  
Antimicrobial Properties ◽  
Content Type ◽  
E Coli ◽  
Log Reduction ◽  
Naturally Occurring

ABSTRACT In this study, the effect of individual lecithin phospholipids on the antimicrobial properties of eugenol against Escherichia coli C600 was investigated. We tested five major phospholipids common in soy or egg lecithin (1,2-dihexadecanoyl-sn-glycero-3-phosphocholine [DPPC], 1,2-dioctadecanoyl-sn-glycero-3-phosphocholine [DSPC], 1,2-dihexadecanoyl-sn-glycero-3-phosphoethanolamine [DPPE], 1,2-dihexadecanoyl-sn-glycero-3-phosphate [sodium salt] [DPPA], and 1,2-dihexadecanoyl-sn-glycero-3-phospho-l-serine [DPPS]) and one synthetic cationic phospholipid (1,2-dioctadecanoyl-sn-glycero-3-ethylphosphocholine [18:0 EPC]). Among the six phospholipids, DPPC, DSPC, DPPE, DPPA, and the cationic 18:0 EPC showed critical synergistic concentrations that significantly improved the inactivation effect of eugenol against E. coli after 30 min of exposure. At the critical synergistic concentration, an additional ca. 0.4 to 1.9 log reduction (ca. 0.66 to 2.17 log CFU/ml reduction) in the microbial population was observed compared to eugenol-only (control) treatments (ca. 0.25 log reduction). In all cases, increasing the phospholipid amount above the critical synergistic concentration (which was different for each phospholipid) resulted in antimicrobial properties similar to those seen with the eugenol-only (control) treatments. DPPS did not affect the antimicrobial properties of eugenol at the tested concentrations. The critical synergistic concentration of phospholipids was correlated with their critical micelle concentrations (CMC). IMPORTANCE Essential oils (EOs) are naturally occurring antimicrobials, with limited use in food due to their hydrophobicity and strong aroma. Lecithin is used as a natural emulsifier to stabilize EOs in aqueous systems. We previously demonstrated that, within a narrow critical-concentration window, lecithin can synergistically enhance the antimicrobial properties of eugenol. Since lecithin is a mixture of different phospholipids, we aimed to identify which phospholipids are crucial for the observed synergistic effect. This research studied the bioactivity of lecithin phospholipids, contributing to a rational design in using lecithin to effectively control foodborne pathogens in foods.

Soil versus Pond Ash Surfacing of Feedlot Pens: Occurrence of Escherichia coli O157:H7 in Cattle and Persistence in Manure†

2010 ◽  
Vol 73 (7) ◽  
pp. 1269-1277 ◽  
Author(s):  
ELAINE D. BERRY ◽  
JAMES E. WELLS ◽  
TERRANCE M. ARTHUR ◽  
BRYAN L. WOODBURY ◽  
JOHN A. NIENABER ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Sampling Period ◽  
Escherichia Coli O157 ◽  
Surface Material ◽  
Beef Heifers ◽  
Pond Ash ◽  
E Coli ◽  
Cattle Feces ◽  
Naturally Occurring ◽  
Survival Differences

Reducing Escherichia coli O157:H7 in cattle and their manure is critical for reducing the risk for human foodborne and waterborne illness. The objective of this study was to evaluate the effects of soil and pond ash surfaces for feedlot pens on the prevalence, levels, and/or persistence of naturally occurring E. coli O157:H7 and total E. coli in cattle (feces and hides) and manure. Cattle (128 beef heifers) were sorted among 16 pens: 8 surfaced with soil and 8 surfaced with pond ash. The prevalence of E. coli O157:H7 in feces decreased (P < 0.0001) during the study from 57.0% on day 0 to 3.9% on day 84 but did not differ (P ≥ 0.05) between cattle on soil and on pond ash pens at any sampling period. The prevalence of the pathogen on hides and in feedlot surface material (FSM) also decreased (P < 0.0001), with no effect of soil or pond ash surface (P ≥ 0.05). Similarly, levels of E. coli in FSM did not differ (P ≥ 0.05) at any sampling period, and there were no clear trends for survival differences of E. coli O157:H7 or E. coli in FSM between pond ash and soil surfaces, although E. coli populations survived at 5.0 log CFU/g of FSM on the pen surfaces 6 weeks after the cattle were removed. These results indicate that housing cattle on pens surfaced with pond ash versus pens surfaced with soil does not affect E. coli O157:H7 in cattle or their manure.

scholarly journals Extended Phylogeny and Extraintestinal Virulence Potential of Commensal Escherichia coli from Piglets and Sows

2020 ◽  
Vol 17 (1) ◽  
pp. 366
Author(s):  
Ewa Bok ◽  
Aleksandra Kożańska ◽  
Justyna Mazurek-Popczyk ◽  
Magdalena Wojciech ◽  
Katarzyna Baldy-Chudzik
Keyword(s):  
Escherichia Coli ◽  
Economic Losses ◽  
Type I ◽  
Swine Industry ◽  
Typing Method ◽  
Phylogenetic Structure ◽  
E Coli ◽  
Naturally Occurring ◽  
Virulence Potential ◽  
Weaning Piglets

Commensal Escherichia coli, naturally occurring in the intestinal tract, can be the origin of extraintestinal pathogenic E. coli (ExPEC) strains. ExPEC causes high mortality and significant economic losses in the swine industry in several countries and poses a serious threat to public health worldwide. The aim of this study was to analyze the extended phylogenetic structure and extraintestinal virulence potential in two groups of commensal E. coli isolates from post-weaning piglets and sows. The phylogenetic assignment to eight groups was determined using the revised Clermont phylogenetic typing method in quadruplex PCR. Identification of extraintestinal virulence genes (VGs) and adhesin operon genes was performed using multiplex or simplex PCR. The revised phylogenetic assignment allowed us to distinguish E. coli with significantly higher (groups C and F) or lower (group E) virulence potential in isolates from piglets. The majority of the tested VGs occurred more frequently in isolates from piglets than from sows, with statistically significant differences for seven genes: fimH, papAH, iutA, iroN, ompT, traT, and iss. Complete operons for type I and P fimbriae significantly prevailed among E. coli from piglets. This study provides insight into the extended phylogenetic structure of porcine commensal E. coli and showed that these strains, particularly from piglets, constitute a considerable reservoir of extraintestinal VGs and may increase the potential risk of extraintestinal infections.

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