scholarly journals THE RELATIONSHIP BETWEEN THE VASCULAR MANIFESTATIONS OF SHOCK PRODUCED BY ENDOTOXIN, TRAUMA, AND HEMORRHAGE

1957 ◽  
Vol 106 (3) ◽  
pp. 403-414 ◽  
Author(s):  
Benjamin W. Zweifach ◽  
Baruj Benacerraf ◽  
Lewis Thomas ◽  
Keyword(s):  
Traumatic Shock ◽  
Cross Tolerance ◽  
Vascular Effects ◽  
Phagocytic Capacity ◽  
E Coli ◽  
Development Of Resistance ◽  
Bacterial Endotoxins ◽  
Induced Tolerance ◽  
The Relationship ◽  
Reticulo Endothelial System

In studies designed to establish the interrelationship between bacterial endotoxins and the vascular sequelae of hemorrhagic and traumatic shock, the effect of factors known to influence the phagocytic behavior of the reticulo-endothelial system (RES) were investigated. Measures which induced a so called "blockade" of the RES were uniformly associated with an exacerbation of the vascular effects of the endotoxin of E. coli. Such pretreatment also counteracted the cross-tolerance induced by endotoxins against the lethal effects of hemorrhage or drum trauma. The vascular reactions characteristic of irreversible hemorrhagic shock could be simulated by a combination of pretreatment with carbon or proferrin and the infusion of small doses of E. coli endotoxin. An increase in the phagocytic activity of the RES, induced by repeated injections of certain colloids, was associated with an enhanced tolerance of shock. Measurement of carbon clearance values indicated that although an augmented phagocytic capacity was present in rats with induced tolerance to bacterial endotoxins, the development of resistance to trauma was not associated with a comparable change in the phagocytic function of the RES.

scholarly journals THE RELATIONSHIP BETWEEN THE VASCULAR MANIFESTATIONS OF SHOCK PRODUCED BY ENDOTOXIN, TRAUMA, AND HEMORRHAGE

1957 ◽  
Vol 106 (3) ◽  
pp. 385-401 ◽  
Author(s):  
Benjamin W. Zweifach ◽  
Lewis Thomas ◽  
Keyword(s):  
Hemorrhagic Shock ◽  
Significant Degree ◽  
Traumatic Shock ◽  
Bacterial Endotoxin ◽  
Vascular Effects ◽  
E Coli ◽  
Initial Stage ◽  
Repeated Doses ◽  
The Relationship ◽  
Lethal Doses

The vascular effects of lethal doses of E. coli endotoxin, as observed in the mesentery of the rat, resemble the reactions of traumatic and hemorrhagic shock in the following respects: a profound inhibition of arteriolar and precapillary reactivity to topical epinephrine occurs after an initial stage of hyperreactivity; the small veins show failure to relax completely following constrictor doses of epinephrine; and the terminal vessels develop an unusual sensitivity to fluctuations in temperature of the fluid irrigating the tissue. Rats in which tolerance to bacterial endotoxin is induced, by repeated doses given daily, become highly resistant to the lethal effects of both drum trauma and hemorrhagic shock. However, rats in which the adaptation to traumatic shock is produced by repeated exposure to drum trauma, do not develop a significant degree of tolerance to lethal doses of endotoxin. The injection of small non-lethal doses of bacterial endotoxin during non-lethal episodes of trauma or hemorrhage, leads to the development of irreversible shock and death. The bearing of these findings on the problem of the relationship between endotoxin and traumatic shock is discussed.

Resistance to whole-body X-irradiation in rats made tolerant to bacterial endotoxins

1959 ◽  
Vol 197 (6) ◽  
pp. 1364-1370 ◽  
Author(s):  
B. W. Zweifach ◽  
E. Kivy-Rosenberg ◽  
Arnold L. Nagler
Keyword(s):  
Blood Platelet ◽  
Reticuloendothelial System ◽  
Whole Body ◽  
X Rays ◽  
Effective Protection ◽  
X Ray ◽  
E Coli ◽  
Bacterial Endotoxins ◽  
X Irradiation ◽  
Reticulo Endothelial System

Rats were treated with three conditioning agents (bacterial endotoxins, zymosan and compound 48/80) known to produce tolerance to other forms of stress, as a means of determining the importance of the reticulo-endothelial system in the response to WBR. Effective protection was provided by tolerance induced by lipopolysaccharide extracts of E. coli bacteria. Some protection was also afforded by conditioning with 48/80 for several days. These agents were active only when administered before exposure to x-rays. Treatment post x-ray broke down the induced resistance. Blood platelet levels remained high in conditioned animals exposed to WBR. It is suggested that a relationship exists between the priming or conditioning of the reticuloendothelial system and the maintenance of satisfactory blood platelet levels in adapted animals receiving WBR.

Inhibition, Resistance Development, and Increased Antibiotic and Antimicrobial Resistance Caused by Nutraceuticals

2002 ◽  
Vol 65 (3) ◽  
pp. 528-533 ◽  
Author(s):  
PAULA MARIE L. WARD ◽  
STAMATIA FASITSAS ◽  
STANLEY E. KATZ
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Herbal Remedies ◽  
Indicator Organism ◽  
Resistance Development ◽  
E Coli ◽  
Development Of Resistance ◽  
Lack Of Information ◽  
Baseline Values ◽  
The Relationship

With the increasing use of herbal remedies by the general public worldwide, there remains a lack of information on the relationship between nutraceutical use and antibiotic resistance. Historically, there have been claims that nutraceuticals possess antibacterial and antiviral activity. However, the claims come with little or no documentation and no information related to the development of resistance to the nutraceutical or the cause of increases in resistance to antibiotics. These studies investigate the ability of nutraceutical exposure to influence the development of antibiotic resistance in bacteria. Two antibiotic-sensitive organisms, Staphylococcus aureus ATCC 29213 and Escherichia coli ATCC 25922, were used as representative of the gram-positive and gram-negative bacteria. These preliminary investigations showed a general increase to the ampicillin marker by the products studied, using Staphylococcus aureus ATCC 29213 as the indicator organism. There were 13 product-related increases in the MIC, 2 decreases, and 7 no changes. All six of the garlic products increased the MIC of the norfloxacin marker to greater than fourfold above baseline. Using E. coli ATCC 25922 as the indicator organism, the greatest product–antibiotic marker interaction was with the ampicillin marker. Garlic, Echinacea, and zinc products all caused large increases in the MIC to ampicillin over baseline values.

scholarly journals STUDIES OF THE EFFECT OF BACTERIAL ENDOTOXINS ON RABBIT LEUCOCYTES

1953 ◽  
Vol 98 (4) ◽  
pp. 349-364 ◽  
Author(s):  
Leighton E. Cluff
Keyword(s):  
Buffy Coat ◽  
Development Of Resistance ◽  
Bacterial Endotoxins ◽  
Leucocyte Migration ◽  
Shwartzman Reaction ◽  
Rapid Removal ◽  
And Migration ◽  
Shwartzman Phenomenon ◽  
Reticulo Endothelial System ◽  
Development Of Tolerance

Bacterial endotoxin injected intravenously into rabbits inhibited the migration of leucocytes from the buffy coat of centrifuged blood (4). Repeated daily injections of endotoxin resulted in the rabbits becoming resistant to the fever-inducing action of the toxin, and migration of leucocytes from centrifuged blood was no longer inhibited by injection of the toxin. Leucocyte migration from the buffy coat of centrifuged blood after injection of toxin into the rabbits appeared gradually over the first few days of repeated injections, and disappeared during the 10 to 15 days after cessation of daily injections of toxin. The resistance to endotoxin, demonstrated by leucocyte migration and pyrogen tolerance, could not be passively transferred with serum from resistant animals, and was non-specific, in that resistance to one endotoxin conferred some resistance to toxin from an organism of a different species. No relationship could be demonstrated between precipitin titer and resistance. Thorotrast abolished resistance to the fever-inducing activity of endotoxin, but its effect on leucocyte resistance was not clear, since when injected alone it inhibited migration of leucocytes from the buffy coat of centrifuged blood. The suggestion is made that the failure of toxin to inhibit the migration of leucocytes from resistant rabbits is due either to the presence of leucocytes which have become adapted to the toxin by repeated exposure, or to rapid removal of the toxin by the reticulo-endothelial system. It is unlikely that leucocyte resistance participates in the development of tolerance to the fever-inducing action of endotoxin. However, in view of the participation of the leucocyte in the pathogenesis of the Shwartzman reaction, the presence of leucocytes resistant to endotoxin may be responsible in part for the development of resistance to the Shwartzman phenomenon.

A New Fluorogenic Substrate Method for Assay of Bacterial Endotoxins Using Limulus Hemocyte Lysate

1979 ◽  
Author(s):  
T Harada ◽  
M Ohki ◽  
M Niwa ◽  
S Iwanaga
Keyword(s):  
Antithrombin Iii ◽  
Assay Method ◽  
Sensitive Assay ◽  
Fluorogenic Substrate ◽  
Toxin Concentration ◽  
Amidase Activity ◽  
E Coli ◽  
Bacterial Endotoxins ◽  
Plasmin Inhibitor ◽  
Limulus Test

Limulus hemocyte lysate contains a proclotting enzyme, which is transformed to the active clotting enzyme in the presence of gram-negative bacterial endotoxins. The clotting enzyme coagulates a clottable protein, named coagulogen, contained also in the lysate. This gelation reaction of the lysate, named Limulus test, has been widely employed as a simple and very sensitive assay method for endotoxins. We developed a new fluorogenic substrate, Boc-Leu-Gly-Arg-4-methylcoumarin amide, for Limulus clotting enzyme and established an enzymatic assay method for endotoxins, using the substrate. Because the endotoxin mediates the activation of proclotting enzyme in the lysate, the measurement of amidase activity could be applicable for quantitation of the endotoxins. In fact, the amidase activity determined fluorometrically increased by increasing concentration of E. coli 0111: B4 endotoxin added to the lysate, and a linear relationship between the toxin concentration and the activity was observed in the range of 5X10-6to 5xl0-2 µg endotoxin. The method was a fifty times more sensitive than that of the Limulus test and was very reproducible. However, the method was not directly applicable for the assay of endotoxins in circulating blood, as the amidase activity was strongly inhibited by antithrombin III and α2-plasmin inhibitor. Thus, some pretreatment with heat or chloroform on plasma samples before the assay was required.

The relationship between health effects in triathletes and microbiological quality of freshwater

1995 ◽  
Vol 31 (5-6) ◽  
pp. 19-26 ◽  
Author(s):  
G. J. Medema ◽  
I. A. van Asperen ◽  
J. M. Klokman-Houweling ◽  
A. Nooitgedagt ◽  
M. J. W. van de Laar ◽  
...  
Keyword(s):  
Water Quality ◽  
Geometric Mean ◽  
Microbiological Quality ◽  
Quality Parameters ◽  
Health Complaints ◽  
E Coli ◽  
Thermotolerant Coliforms ◽  
Microbiological Water Quality ◽  
The Relationship ◽  
Faecal Streptococci

This pilot study was carried out to determine the relationship between microbiological water quality parameters and the occurrence of health complaints among triathletes. Data were collected at an Olympic distance triathlon (n=314) and a run-bike-run (n=81; controls for exposure to fresh water). At the time of the triathlon, the concentrations of Escherichia coli , thermotolerant coliforms, faecal streptococci, entero- and reoviruses, F-specific RNA phages, Salmonella, Campylobacter, Aeromonas, Plesiomonas shigelloides, Pseudomonas aeruginosa and Staphylococcus aureus were examined over the swimming course. Information on the occurrence of health complaints during the competition and in the week thereafter was collected through a written questionnaire. The results show that triathletes and run-bike-runners are comparable with respect to factors other than water exposure (age, sex, training history, physical stress, lower intestinal health complaints during the competition) that may influence the occurrence of health complaints in the week after the competition. Triathletes and run-bike-runners reported gastro-intestinal (7.7% vs 2.5%), respiratory (5.5% vs 3.7%), skin/mucosal (2.6% vs 1.2%), general (3.5% vs 1.2%) and total symptoms (14.8% vs 7.4%) in the week after the event. The health risks for triathletes for all symptom groups are not significantly higher than for run-bike-runners. The geometric mean concentration of faecal indicator bacteria is relatively low: E. coli 170/100 ml; faecal streptococci 13/100 ml, enteroviruses were present at concentrations of 0.1/l. The group of triathletes was homogeneusly and relatively intensely exposed to water; they all swam in the same body of water at the same time and 75% reported to have swallowed freshwater. It was concluded that this study design is suitable to study the relationship between health complaints and microbiological water quality. In the summers of 1993 and 1994, a study will be carried out concerning several run-bike-runs and triathlons in freshwaters of different quality.

The effect of type of water supply on water quality in a developing community in South Africa

1997 ◽  
Vol 35 (11-12) ◽  
pp. 35-40 ◽  
Author(s):  
B. Genthe ◽  
N. Strauss ◽  
J. Seager ◽  
C. Vundule ◽  
F. Maforah ◽  
...  
Keyword(s):  
Water Quality ◽  
Water Supply ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
E Coli ◽  
Guideline Values ◽  
Developing Communities ◽  
Quality Guideline ◽  
And Control ◽  
The Relationship

Efforts to provide water to developing communities in South Africa have resulted in various types of water supplies being used. This study examined the relationship between the type of water supply and the quality of water used. Source (communal taps, private outdoor and indoor taps) and point-of-use water samples were examined for heterotrophic plate counts (HPC), total and faecal coliforms, E. coli, and coliphages. Ten percent of samples were also analysed for enteric viruses, Giardia and Cryptosporidium. Approximately 320 households were included in a case-control study. In addition, a cross-sectional study was conducted. Both studies examined the relationship between different types of water facilities and diarrhoea among pre-school children. The source water was of good microbial quality, but water quality was found to have deteriorated significantly after handling and storage in both case and control households, exceeding drinking water quality guideline values by 1-6 orders of magnitude. Coliphage counts were low for all water samples tested. Enteric viruses and Cryptosporidium oocysts were not detected. Giardia cysts were detected on one occasion in case and control in-house samples. Comparisons of whether in-house water, after handling and storage, complied with water quality guideline values demonstrated households using communal taps to have significantly poorer quality than households using private outdoor or indoor taps for HPC and E. coli (χ2 = 14.9, P = 0.001; χ2 = 6.6, P = 0.04 respectively). A similar trend (although not statistically significant) was observed for the other microbial indicators. The cross-sectional study demonstrated an apparent decrease in health risk associated with private outdoor taps in comparison to communal taps. This study suggests that a private outdoor tap is the minimum level of water supply in order to ensure the supply of safe water to developing communities.

scholarly journals Exploring the taxonomical and functional profile of As Burgas hot spring focusing on thermostable β-galactosidases

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
María-Eugenia DeCastro ◽  
Michael P. Doane ◽  
Elizabeth Ann Dinsdale ◽  
Esther Rodríguez-Belmonte ◽  
María-Isabel González-Siso
Keyword(s):  
Microbial Community ◽  
Hot Spring ◽  
Functional Characterization ◽  
Tca Cycle ◽  
Maximal Activity ◽  
Sulfur Cycle ◽  
E Coli ◽  
Complex Microbial Community ◽  
Relationship Of ◽  
The Relationship

AbstractIn the present study we investigate the microbial community inhabiting As Burgas geothermal spring, located in Ourense (Galicia, Spain). The approximately 23 Gbp of Illumina sequences generated for each replicate revealed a complex microbial community dominated by Bacteria in which Proteobacteria and Aquificae were the two prevalent phyla. An association between the two most prevalent genera, Thermus and Hydrogenobacter, was suggested by the relationship of their metabolism. The high relative abundance of sequences involved in the Calvin–Benson cycle and the reductive TCA cycle unveils the dominance of an autotrophic population. Important pathways from the nitrogen and sulfur cycle are potentially taking place in As Burgas hot spring. In the assembled reads, two complete ORFs matching GH2 beta-galactosidases were found. To assess their functional characterization, the two ORFs were cloned and overexpressed in E. coli. The pTsbg enzyme had activity towards o-Nitrophenyl-β-d-galactopyranoside (ONPG) and p-Nitrophenyl-β-d-fucopyranoside, with high thermal stability and showing maximal activity at 85 °C and pH 6, nevertheless the enzyme failed to hydrolyze lactose. The other enzyme, Tsbg, was unable to hydrolyze even ONPG or lactose. This finding highlights the challenge of finding novel active enzymes based only on their sequence.

scholarly journals 1576. Re-Evaluation of cefepime or piperacillin-tazobactam to Decrease Use of Carbapenems in ESBL-Producing Enterobacterales BloodStream Infections (REDUCE-BSI)

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S786-S787
Author(s):  
Catherine H Vu ◽  
Veena Venugopalan ◽  
Barbara A Santevecchi ◽  
Stacy A Voils ◽  
Kartikeya Cherabuddi ◽  
...  
Keyword(s):  
Hospital Mortality ◽  
Bloodstream Infections ◽  
Causative Organism ◽  
E Coli ◽  
Development Of Resistance ◽  
Baseline Characteristics ◽  
Secondary Outcomes ◽  
Klebsiella Spp ◽  
Decrease Use ◽  
Infection Recurrence

Abstract Background The ideal therapy for treatment of bloodstream infections (BSI) due to ESBL-producing organisms is widely debated. Although prior studies have demonstrated efficacy of non-carbapenems (CBPNs) for ESBL infections, results from the MERINO study group found increased mortality associated with piperacillin/tazobactam (PT) when compared with meropenem for treatment of ESBL BSI. The goal of this study was to investigate patient outcomes associated with the use of CBPN-sparing therapies (PT and cefepime (CEF)) for ESBL BSI. The primary outcome was in-hospital mortality between non-CBPN (PT and CEF) and CBPN groups. Secondary outcomes included clinical cure, microbiologic cure, infection recurrence, and development of resistance. Methods This was a retrospective observational study of patients admitted to the hospital from May 2016 - May 2019 with a positive blood culture for an ESBL-producing organism. Patients receiving meropenem, ertapenem, PT, or CEF were included. Patients were excluded if < 18 years old, receiving antibiotics for < 24 hours, treated for a polymicrobial BSI, or receiving concomitant antibiotic therapy for another gram-negative (non-ESBL) infection. Results One hundred and fourteen patients were analyzed; 74 (65%) patients received CBPN therapy compared with 40 (35%) patients that received a non-CBPN (CEF N=30, PT N=10). There were no statistically significant differences in baseline characteristics between groups. The overall in-hospital mortality rate was 6% (N=7). Eight percent of patients (N=6) in the CBPN arm died compared to 3% (N=1) of patients in the non-CBPN arm, P = 0.42. No difference in mortality was detected between groups when evaluating subgroups with Pitt bacteremia score ≥4 (N=25), requiring ICU admission (N=50), non-genitourinary source (N=50), or by causative organism (N=76 E. coli; N=38 Klebsiella spp.). There was no difference between groups for secondary outcomes. Conclusion CEF and PT are reasonable options for the treatment of ESBL BSI and did not result in increased mortality or decreased clinical efficacy when compared to CBPNs in this cohort. Disclosures All Authors: No reported disclosures

scholarly journals Cryo-EM structure of mycobacterial cytochrome bd reveals two oxygen access channels

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Weiwei Wang ◽  
Yan Gao ◽  
Yanting Tang ◽  
Xiaoting Zhou ◽  
Yuezheng Lai ◽  
...  
Keyword(s):  
Rational Design ◽  
Pathogenic Bacteria ◽  
Structural Topology ◽  
Antimicrobial Drugs ◽  
E Coli ◽  
Cytochrome Bd ◽  
Cryo Electron Microscopy ◽  
Functional Mechanisms ◽  
The Relationship ◽  
Potential Oxygen

AbstractCytochromes bd are ubiquitous amongst prokaryotes including many human-pathogenic bacteria. Such complexes are targets for the development of antimicrobial drugs. However, an understanding of the relationship between the structure and functional mechanisms of these oxidases is incomplete. Here, we have determined the 2.8 Å structure of Mycobacterium smegmatis cytochrome bd by single-particle cryo-electron microscopy. This bd oxidase consists of two subunits CydA and CydB, that adopt a pseudo two-fold symmetrical arrangement. The structural topology of its Q-loop domain, whose function is to bind the substrate, quinol, is significantly different compared to the C-terminal region reported for cytochromes bd from Geobacillus thermodenitrificans (G. th) and Escherichia coli (E. coli). In addition, we have identified two potential oxygen access channels in the structure and shown that similar tunnels also exist in G. th and E. coli cytochromes bd. This study provides insights to develop a framework for the rational design of antituberculosis compounds that block the oxygen access channels of this oxidase.

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