Endotoxic activity of cell-free rumen fluid from cattle fed hay or grain

1978 ◽  
Vol 24 (10) ◽  
pp. 1253-1261 ◽  
Author(s):  
T. G. Nagaraja ◽  
L. R. Fina ◽  
E. E. Bartley ◽  
H. D. Anthony
Keyword(s):  
Actinomycin D ◽  
Rumen Fluid ◽  
Quantitative Difference ◽  
Gram Negative Bacteria ◽  
Chick Embryos ◽  
Ether Extract ◽  
Gram Negative ◽  
Bacterial Endotoxins ◽  
Phenol Water ◽  
Endotoxic Activity

The cell-free rumen fluid from cattle fed hay or grain exhibited the following biological characteristics which strongly suggest the presence of endotoxin or a toxic principle similar to endotoxin of gram-negative bacteria: proved lethal to mice when injected with actinomycin D; proved extremely lethal to chick embryos: induced biphasic pyrogenic response in rabbits; enhanced susceptibility to bacterial infection in mice; evoked positive epinephrine skin reaction in rabbits and phenol–water or aqueous ether extract proved lethal to mice and chick embryos. A quantitative difference in concentrations of endotoxin was observed, based on LD50 in mice and chick embryos and response to the epinephrine skin test in rabbits. Cell-free rumen fluid of grain-fed cattle contained at least twice as much endotoxin as that of hay-fed cattle. Endotoxin in cell-free rumen fluid and in higher concentration in cattle fed grain than in those fed hay support the hypothesis that rumen bacterial endotoxins may participate in the pathogenesis of diseases associated with high grain feeding such as lactic acidosis and the sudden-death syndrome.

Increased Survival in Irradiated Animals Treated With Bacterial Endotoxins

1957 ◽  
Vol 191 (1) ◽  
pp. 124-130 ◽  
Author(s):  
Willie W. Smith ◽  
Ilo M. Alderman ◽  
Ruth E. Gillespie
Keyword(s):  
Beneficial Effect ◽  
Single Injection ◽  
Gram Negative Bacteria ◽  
Bacterial Challenge ◽  
Gram Negative ◽  
Bacterial Endotoxins ◽  
Pseudomonas Infection

A single injection of endotoxin derived from Gram negative bacteria caused an increased survival in lethally irradiated animals when given immediately after or 24 hours before irradiation. Mice responded better to the injection before irradiation and hamsters to the injection after irradiation. The effect was associated with a reduction in infection, very pronounced in the case of α-streptococcus or Proteus and still significant in the case of Pseudomonas infection. No beneficial effect was obtained when mice were given three endotoxin injections during 1 week or six injections during 2 weeks prior to irradiation. The beneficial effect is not necessarily associated with the granulocytosis which begins within a few hours after the endotoxin injection, or with the conditions under which nonirradiated animals show an increased resistance to bacterial challenge.

scholarly journals Comparable Endotoxic Properties of Lipopolysaccharides Are Manifest in Diverse Clinical Isolates of Gram-Negative Bacteria

2000 ◽  
Vol 68 (4) ◽  
pp. 1899-1904 ◽  
Author(s):  
Michael Luchi ◽  
David C. Morrison
Keyword(s):  
Biologically Active ◽  
Clinical Isolates ◽  
Poor Correlation ◽  
Gram Negative Bacteria ◽  
Active Constituent ◽  
Necrosis Factor Alpha ◽  
Gram Negative ◽  
Factor Alpha ◽  
Phenol Water ◽  
Necrosis Factor

ABSTRACT In general there is a poor correlation between serum lipopolysaccharide (LPS; the biologically active constituent of endotoxin) levels and mortality in septic patients. The objective of this study was to determine if chemical, structural, or biological differences among LPS from different clinical isolates of gram-negative bacteria might explain this discrepancy. LPS preparations were made using the hot phenol-water extraction method from eight clinical isolates of gram-negative bacteria. As a percentage of the total weight of the LPS, the phosphate content ranged from 3.0 to 13.8% (average, 6.7 ± 3.6%), and the 2-keto-3-deoxyoctonate content ranged from 1.9 to 27.4% (average, 8.9 ± 8.5%). These values were not dissimilar to those obtained for a reference endotoxin. In a standard measure of LPS activity, the Limulus amoebocyte lysate assay, there was approximately a twofold difference between the least and most active preparations. The two preparations with the greatest difference in their ability to elicit the secretion of tumor necrosis factor alpha from a mouse peritoneal macrophage cell line were similar in lethality when administered to mice sensitized to the effects of LPS by d(+)-galactosamine. These relatively minor differences in LPS activity seem unlikely to explain the generally observed discrepancy between serum endotoxin levels and mortality in patients with gram-negative sepsis.

scholarly journals Bacterial endotoxins: biological properties and mechanisms of action

1993 ◽  
Vol 2 (7) ◽  
pp. S11-S16 ◽  
Author(s):  
C. Galanos ◽  
M. A. Freudenberg
Keyword(s):  
Biological Properties ◽  
Mechanisms Of Action ◽  
Review Article ◽  
Gram Negative Bacteria ◽  
Necrosis Factor Alpha ◽  
Gram Negative ◽  
Lethal Action ◽  
Bacterial Endotoxins ◽  
Factor Alpha ◽  
Necrosis Factor

Endotoxins (lipopolysaccharides, LPS) are agents of pathogenicity of Gram-negative bacteria, implicated in the development of Gram-negative shock. Endotoxin reacts with lipopolysaccharide-sensitive cells producing endogenous mediators such as tumour necrosis factor alpha (TNFα). Macrophages are cells mediating the toxic activities of LPS and TNFα is the primary mediator of the lethal action of endotoxin. This review article discusses the various mechanisms by which endotoxin hypersensitivity in bacteria-sensitized animals develops. The paper concludes with a discussion on the possible protective effect of carnitine congeners against the lethal action of LPS.

Role of bacterial endotoxins of intestinal origin in rat heat stress mortality

1983 ◽  
Vol 54 (1) ◽  
pp. 31-36 ◽  
Author(s):  
D. A. DuBose ◽  
K. Basamania ◽  
L. Maglione ◽  
J. Rowlands
Keyword(s):  
Heat Stress ◽  
Bacterial Count ◽  
Endotoxin Tolerance ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Bacterial Endotoxins ◽  
Intestinal Origin ◽  
Heat Stress Resistance ◽  
Resistance To Heat

Using unanesthetized rats, the effect on heat stress mortality of endotoxin tolerance or zymosan treatment was determined. In addition, the incidence of invasion by gram-negative bacteria and their endotoxins was studied to evaluate the role of gut-derived bacterial endotoxins after heat stress. Endotoxin tolerance resulted in heat stress resistance. The estimated mean total thermal area, which induced an LD50 in endotoxin-tolerant rats (61.85 degrees C . min) was significantly greater (P less than 0.001) than that for non-tolerant rats (44.03 degrees C . min). Rats were significantly (P less than 0.005) more sensitive to endotoxin after zymosan treatment, but this treatment did not alter the heat stress mortality rate. The Limulus amoebocyte lysate test indicated that endotoxemia did not occur as a result of heat stress. Though a significantly increased incidence of high gram-negative bacterial count in the duodenum was noted, extraintestinal invasion was not found. It was concluded that resistance to heat stress may not be due to protection from gut-derived bacterial endotoxins, but resistance may possibly be associated with the ability of endotoxin tolerance to protect from shock syndromes. Thus bacterial endotoxins of intestinal origin did not appear to have a significant role in rat heat stress mortality.

Spheroplast formation by an anaerobic gram-negative bacterium Bacteroides ruminicola

1973 ◽  
Vol 19 (5) ◽  
pp. 667-669 ◽  
Author(s):  
K. -J. Cheng
Keyword(s):  
Stationary Phase ◽  
Rumen Fluid ◽  
Gram Negative Bacteria ◽  
Negative Bacterium ◽  
Fluid Medium ◽  
Gram Negative ◽  
Spontaneous Formation

The spontaneous formation of spheroplasts was observed in stationary phase cultures and in aging cultures of Bacteroides ruminicola when grown in synthetic or a rumen fluid medium. Unlike most other gram-negative bacteria, spheroplasts of this organism also were formed when log-phase cells were treated with lysozyme in the presence of 0.01 M Mg2+ in 0.01 M Tris, pH 8.4.

scholarly journals Binding of bacterial endotoxins to the macrophage surface: visualization by fracture-flip and immunocytochemistry.

1993 ◽  
Vol 41 (4) ◽  
pp. 601-608 ◽  
Author(s):  
C Risco ◽  
P Pinto da Silva
Keyword(s):  
Macrophage Activation ◽  
Cell Activation ◽  
Endotoxic Shock ◽  
Host Cells ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Bacterial Endotoxins ◽  
Surface Visualization ◽  
High Resolution Images ◽  
Open Question

Endotoxins (lipopolysaccharides, LPS) are surface components of gram-negative bacteria that stimulate macrophage activation and cause endotoxic shock. How LPS is recognized by host cells is still an open question, but it is generally accepted that many effects of endotoxins follow the overproduction of cytokines by macrophages. In the present study, we used fracture-flip and immunolabeling to study the morphology of isolated commercial LPS (C-LPS), the endotoxin release from the bacterial wall in presence of serum (S-LPS), and the distribution of these two endotoxins on the macrophage surface. Cells treated with C-LPS exhibited large LPS aggregates bound to smooth and particulate areas of the membrane and to microvilli. In contrast, macrophages incubated with S-LPS showed a uniform monodispersed labeling over the free surface of the membrane. Our results show that fracture-flip provides high-resolution images of the binding of ligands to the cell surface. They also suggest the importance of using highly dispersed LPS suspensions when the mechanisms of cell activation and damage by endotoxins are studied.

scholarly journals Digestion of rumen bacteria in vitro

1983 ◽  
Vol 49 (1) ◽  
pp. 101-108 ◽  
Author(s):  
R. J. Wallace
Keyword(s):  
Rumen Fluid ◽  
Individual Species ◽  
Rumen Bacteria ◽  
Gram Negative Bacteria ◽  
Bacterial Protein ◽  
Gram Positive ◽  
Gram Negative ◽  
Pure Cultures ◽  
Mixed Bacteria

1. A pepsin + pancreatin method was used to assess the digestibility of pure cultures of rumen bacteria and mixed bacteria prepared from rumen fluid.2. Individual species of Gram-negative rumen bacteria were highly digestible, whereas Gram-positive species, especially cocci, were more resistant to digestion.3. A similar difference was observed microscopically with mixed rumen bacteria, but the influence of the relative proportions of Gram-positive and Gram-negative bacteria on the digestibility of bacterial protein in rumen fluid was small.

scholarly journals Lipopolysaccharides/endotoxins of gram-negative bacteria: their role in the development of intoxication

2014 ◽  
Vol 19 (2) ◽  
pp. 11-16
Author(s):  
N. M. Gyulazyan ◽  
O. F. Belaia ◽  
V. A Malovv ◽  
Paks. Grigor'evich G ◽  
E. V. Volchkova
Keyword(s):  
Biological Effects ◽  
Experimental Studies ◽  
Clinical Manifestations ◽  
The Body ◽  
Gram Negative Bacteria ◽  
Serological Markers ◽  
Gram Negative ◽  
Inflammatory Reactions ◽  
Bacterial Endotoxins ◽  
Main Factors

Numerous clinical and experimental studies allow us to consider bacterial endotoxins as the main factors inducing the development of intoxication syndrome in infectious and non-infectious diseases. LPS is themajor structural component of Gram-negative bacteria; its effect on the body is related to all the objective clinical manifestations of intoxication. The activation of immune cells by LPS results in the release of inflammatory mediators: cytokines, chemokines, enzymes, eicosanoids, adhesion agents and free radicals that are responsible for the progression of inflammatory reactions and may induce pathophysiological processes including septic shock. Currently, various techniques are developed and used for endotoxin /LPS determinationin biological environmentsthat are based both on detection of its serological markers and registration of its biological effects.

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