scholarly journals Experimental observations on the pathogenesis of necrobacillosis

1990 ◽  
Vol 104 (1) ◽  
pp. 73-78 ◽  
Author(s):  
G. R. Smith ◽  
L. M. Wallace ◽  
D. E. Noakes
Keyword(s):  
Subcutaneous Injection ◽  
Normal Tissue ◽  
Virulent Strain ◽  
Fusobacterium Necrophorum ◽  
Low Grade ◽  
Faecal Contamination ◽  
E Coli ◽  
Infective Dose ◽  
Faecal Suspension ◽  
Lethal Doses

SUMMARYEarlier studies showed that the minimum infective dose (>106 organisms) of a virulent strain of Fusobacterium necrophorum could be greatly reduced by suspending the fusobacteria in sub-lethal doses of cultures of other bacteria such as Escherichia coli before inoculating mice subcutaneously.In the present study the infective dose of the same strain of F. necrophorum was reduced by a factor of >103 by suspending the fusobacteria in sub-lethal doses of 5% homogenate of gaur or wallaby faeces. Sterile faecal filtrate had no such effect. The sites of low grade infection produced by the prior subcutaneous injection of E. coli culture or gaur faecal suspension were susceptible to superinfection by doses of F. necrophorum far below those required to infect normal tissue.This work helps to explain the production of necrobacillosis by the faecal contamination of small wounds. It proved impossible, however, to produce necrobacillosis in mice by the subcutaneous injection of faecal suspensions from 33 farm cattle. This suggests that the proportion of cattle with virulent F. necrophorum in their faeces is low.

scholarly journals Further observations on enhancement of the infectivity of Fusobacterium necrophorum by other bacteria

1991 ◽  
Vol 106 (2) ◽  
pp. 305-310 ◽  
Author(s):  
G. R. Smith ◽  
S. A. Barton ◽  
L. M. Wallace
Keyword(s):  
Virulent Strain ◽  
Klebsiella Oxytoca ◽  
Fusobacterium Necrophorum ◽  
Pasteurella Haemolytica ◽  
The Other ◽  
Clostridium Sporogenes ◽  
E Coli ◽  
Virulent Strains ◽  
Lethal Doses ◽  
Subcutaneous Inoculation

SUMMARYIt had already been shown with a single virulent strain (A42) of Fusobacterium necrophorum that suspension of the fusobacteria in sub-lethal doses of broth cultures of other bacteria reduced the minimum infective dose (> 106 organisms) for mice by subcutaneous inoculation, sometimes to < 10 organisms. The present study extended the known range of bacteria with strong infectivity-enhancing properties to include Bacillus cereus, Klebsiella oxytoca and Staphylococcus aureus; and of those with weaker effect to include Bacillus subtilis, ‘Bacteroides melaninogenicus’, Clostridium sporogenes, Pasteurella haemolytica, and Proteus mirabilis.The study also showed that five further virulent strains of F. necrophorum closely resembled A42 in respect of striking susceptibility to infectivity enhancement by Escherichia coli, Actinomyces (Corynebacterium) pyogenes and S. aureus. One further strain (A6) of F. necrophorum resembled A42 in respect of strong infectivity enhancement by A. pyogenes, S. aureus, B. cereus and K. oxytoca but differed from it and the other five strains in being only slightly affected by E. coli.This work was a necessary prelude to the development of a method, based on infectivity enhancement, for the detection and isolation of F. necrophorum present in small numbers in heavily contaminated material such as faeces.

scholarly journals Enhancement of the infectivity ofFusobacterium necrophorumby other bacteria

1989 ◽  
Vol 102 (3) ◽  
pp. 447-458 ◽  
Author(s):  
G. R. Smith ◽  
D. Till ◽  
L. M. Wallace ◽  
D. E. Noakes
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Bacteroides Fragilis ◽  
Fusobacterium Necrophorum ◽  
Citrobacter Freundii ◽  
E Coli ◽  
Haemolytic Streptococcus ◽  
Sterile Filtrate ◽  
Actinomyces Pyogenes ◽  
Lethal Doses

SUMMARYNecrobacillosis is caused byFusobacterium necrophorum(FN), but other organisms are often present in the lesions. Their possible role was studied in experiments made with a virulent FN strain which, by itself, produced fatal necrobacillosis in mice provided that large doses ( > 106organisms, subcutaneously) were given. Mice were inoculated subcutaneously with FN suspended in sub-lethal doses (0·1 ml) of undiluted or diluted broth cultures of other bacteria. Undiluted culture of a strain ofEscherichia colireduced the infective dose of FX to < 10 organisms: in the necrobacillosis lesions that developed, fusobacteria greatly outnumberedE. coli. A heat-killed preparation or sterile filtrate ofE. coliculture had little if any effect on FN.Citrobacter freundiiand comparativelv small numbers ofCorynebacterium (Actinomyces) pyogenesproduced effects similar to that ofE. coli. An α-haemolvtic streptococcus.Pseudomonas aeruginosa.Bacteroides fragilisandFusobacterium nudeatumalso enhanced the infectivity of FN. though less strikingly thanE. coli. FN increased the persistence invivoof the α-haemolytic streptococcus andB. fragilis, and enabled the latter to multiply profusely.

scholarly journals A sensitive method for isolating Fusobacterium necrophorum from faeces

1991 ◽  
Vol 106 (2) ◽  
pp. 311-317 ◽  
Author(s):  
G. R. Smith ◽  
S. A. Barton ◽  
L. M. Wallace
Keyword(s):  
Staphylococcus Aureus ◽  
Subcutaneous Injection ◽  
Type A ◽  
Fusobacterium Necrophorum ◽  
Selective Medium ◽  
Broth Culture ◽  
Infective Dose ◽  
Sensitive Method

SUMMARYThe isolation of Fusobacterium necrophorum present in small numbers in heavily contaminated material such as faeces or soil is hampered by the lack of an efficient selective medium and by the high minimum infective dose of the organism. A sensitive method for the detection and isolation of faecal strains of F. necrophorum type A was based on the subcutaneous injection of faeces, suspended (5% w/v) in broth culture of Actinomyces (Corynebacterium) pyogenes or Staphylococcus aureus to increase fusobacterial infectivity, into mice pretreated with clostridial antitoxins. When necrobacillosis developed F. necrophorum was identified microscopically in tissue from the advancing edge of the lesion and isolated on a partly selective medium.The enhancement of fusobacterial infectivity produced by A. pyogenes and by S. aureus was high, but the latter was slightly the more efficient, enabling as few as 80 F. necrophorum organisms/g of faeces to be detected.Use of the method showed that 3 of 16 wallabies had F. necrophorum in their faeces at the time of examination. Numerous epidemiological applications are suggested.

Campylobacter in waterborne epidemics in Finland

2004 ◽  
Vol 4 (2) ◽  
pp. 39-45 ◽  
Author(s):  
M.-L. Hänninen ◽  
R. Kärenlampi
Keyword(s):  
Campylobacter Jejuni ◽  
Causative Agent ◽  
Water Samples ◽  
Fecal Coliforms ◽  
Risk Level ◽  
Source Water ◽  
Indicator Organisms ◽  
Faecal Contamination ◽  
E Coli ◽  
July August September

The sources for drinking water in Finland are surface water, groundwater or artificially recharged groundwater. There are approximately 1400 groundwater plants in Finland that are microbiologically at a high risk level because in most cases they do not use any disinfection treatment. Campylobacter jejuni has caused waterborne epidemics in several countries. Since the middle of the 1980s, C. jejuni has been identified as the causative agent in several waterborne outbreaks in Finland. Between 1998 and 2001, C. jejuni or C. upsaliensis caused seven reported waterborne epidemics. In these epidemics approximately 4000 people acquired the illness. Most of the outbreaks occurred in July, August , September or October. In four of them source water and net water samples were analysed for total coliforms or fecal coliforms, E. coli and campylobacters. We showed that large volumes of water samples in studies of indicator organisms (up to 5000 ml) and campylobacters (4000–20,000 ml) increased the possibility to identify faecal contamination and to detect the causative agent from suspected sources.

scholarly journals Efficacy of a Vaccine Based on Protective Antigen and Killed Spores against Experimental Inhalational Anthrax

2008 ◽  
Vol 77 (3) ◽  
pp. 1197-1207 ◽  
Author(s):  
Yves P. Gauthier ◽  
Jean-Nicolas Tournier ◽  
Jean-Charles Paucod ◽  
Jean-Philippe Corre ◽  
Michèle Mock ◽  
...  
Keyword(s):  
Guinea Pigs ◽  
Protective Immunity ◽  
Protective Antigen ◽  
Virulent Strain ◽  
Neutralizing Antibody ◽  
Cutaneous Anthrax ◽  
Anthrax Vaccines ◽  
Mucosal Secretions ◽  
Highly Virulent ◽  
Lethal Doses

ABSTRACTProtective antigen (PA)-based anthrax vaccines acting on toxins are less effective than live attenuated vaccines, suggesting that additional antigens may contribute to protective immunity. Several reports indicate that capsule or spore-associated antigens may enhance the protection afforded by PA. Addition of formaldehyde-inactivated spores (FIS) to PA (PA-FIS) elicits total protection against cutaneous anthrax. Nevertheless, vaccines that are effective against cutaneous anthrax may not be so against inhalational anthrax. The aim of this work was to optimize immunization with PA-FIS and to assess vaccine efficacy against inhalational anthrax. We assessed the immune response to recombinant anthrax PA fromBacillus anthracis(rPA)-FIS administered by various immunization protocols and the protection provided to mice and guinea pigs infected through the respiratory route with spores of a virulent strain ofB. anthracis. Combined subcutaneous plus intranasal immunization of mice yielded a mucosal immunoglobulin G response to rPA that was more than 20 times higher than that in lung mucosal secretions after subcutaneous vaccination. The titers of toxin-neutralizing antibody and antispore antibody were also significantly higher: nine and eight times higher, respectively. The optimized immunization elicited total protection of mice intranasally infected with the virulentB. anthracisstrain 17JB. Guinea pigs were fully protected, both against an intranasal challenge with 100 50% lethal doses (LD50) and against an aerosol with 75 LD50of spores of the highly virulent strain 9602. Conversely, immunization with PA alone did not elicit protection. These results demonstrate that the association of PA and spores is very much more effective than PA alone against experimental inhalational anthrax.

Flood and rainfall mobilisation of E. coli and faecal source tracking markers from decomposing cowpats 

2021 ◽  
Author(s):  
Megan Devane ◽  
Brent Gilpin ◽  
Jennifer Webster-Brown ◽  
Louise Weaver ◽  
Pierre Dupont ◽  
...  
Keyword(s):  
Water Quality ◽  
Overland Flow ◽  
Quantitative Polymerase Chain Reaction ◽  
Linear Regression Analysis ◽  
Water Quality Monitoring ◽  
Quality Monitoring ◽  
Source Tracking ◽  
Faecal Contamination ◽  
E Coli ◽  
Faecal Indicators

&lt;p&gt;The intensification of dairy farming on the agricultural landscape in New Zealand has raised concerns about pollution sources from dairy faecal runoff into waterways. The transport of faecal pollution from farms into waterways is facilitated by overland flow, which can result from rain and flood events, poorly designed irrigation practices and the washing down of milking sheds.&lt;/p&gt;&lt;p&gt;An important step for mitigation of pollution is the identification of the source(s) of faecal contamination. When elevated levels of faecal indicator bacteria (FIB) such as &lt;em&gt;Escherichia coli &lt;/em&gt;are identified in a waterway, faecal source tracking (FST) tools such as microbial source tracking (MST) using quantitative polymerase chain reaction (qPCR), and faecal steroids (for example, cholesterol) provide information about the sources of faecal contamination. The understanding of the fate (degradation/persistence) and transport of these FST markers in the environment is recognised as an important requirement for the interpretation of water quality monitoring in aquatic environments.&lt;/p&gt;&lt;p&gt;This study investigated the effects of faecal decomposition on bovine faecal indicators (&lt;em&gt;E. coli &lt;/em&gt;and FST markers: bovine-associated qPCR markers and ten faecal steroids) by monitoring the effect of flood and rainfall events on simulated cowpats over a five and a half month period under field conditions. Two separate spring/summer trials were conducted to evaluate: Trial 1) the mobilisation under simulated flood conditions of the faecal indicators from irrigated versus non-irrigated cowpats, Trial 2) the mobilisation of faecal indicators from non-irrigated cowpat flood runoff versus runoff after simulated rainfall onto non-irrigated cowpats.&lt;/p&gt;&lt;p&gt;The microbial community changes within the decomposing cowpat (as illustrated by amplicon-based metagenomic analysis) were expected to impact on the survival/persistence of the bacterial targets of the MST markers, and also alter the ratio between faecal sterols and their biodegradation products, the stanols. It was hypothesised, therefore, that there would be:&lt;/p&gt;&lt;ul&gt;&lt;li&gt;Changes over time in the concentration of&lt;em&gt; E. coli &lt;/em&gt;and the bovine-associated MST markers mobilised into the cowpat runoff&lt;/li&gt; &lt;li&gt;Alterations in the FST ratio signature of the ten measured faecal steroids, resulting in a change from a bovine faecal steroid signature in fresh cowpat runoff to other animal faecal signatures in the runoff from decomposing cowpats&lt;/li&gt; &lt;li&gt;A difference in the mobilisation decline rates of all FST and microbial markers within a treatment regime and between treatments.&lt;/li&gt; &lt;/ul&gt;&lt;p&gt;Linear regression analysis was undertaken to establish mobilisation decline rates for each of the analytes in the mobilisable phase from the cowpat runoff treatments, with calculation of the time taken in days for reduction in 90% of the concentration (T&lt;sub&gt;90&lt;/sub&gt;), and statistical comparison of the regression coefficients (slopes) of all analytes. The results will include a discussion of the impacts of the study&amp;#8217;s observations on the interpretation of faecal indicator assessments for water quality monitoring in waterways influenced by sources of faecal contamination.&lt;/p&gt;

scholarly journals Low-grade endotoxaemia enhances artery thrombus growth via Toll-like receptor 4: implication for myocardial infarction

2020 ◽  
Vol 41 (33) ◽  
pp. 3156-3165 ◽  
Author(s):  
Roberto Carnevale ◽  
Sebastiano Sciarretta ◽  
Valentina Valenti ◽  
Flavio di Nonno ◽  
Camilla Calvieri ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Escherichia Coli ◽  
Platelet Activation ◽  
Cathepsin G ◽  
Low Grade ◽  
Toll Like Receptor ◽  
Gut Permeability ◽  
Toll Like Receptor 4 ◽  
E Coli ◽  
St Elevation

Abstract Aims Low-grade endotoxaemia is detectable in human circulation but its role in thrombosis is still unclear. Methods and results We measured serum lipopolysaccharide (LPS) concentration, soluble P-selectin (sP-selectin), a marker of platelet activation, and zonulin, a marker of gut permeability, in peripheral circulation, coronary thrombi, and intracoronary blood of patients with ST-elevation myocardial infarction (STEMI, n = 50) and stable angina (SA) (n = 50), respectively, and in controls (n = 50). Experimental study was carried out in mice to assess if Escherichia coli-LPS (E. coli-LPS) possess thrombotic property. Coronary thrombi from STEMI showed higher concentrations of LPS, sP-selectin vs. intracoronary blood of SA and peripheral blood of controls (P &lt; 0.001). Zonulin was higher in STEMI compared to the other two groups [4.57 (3.34–5.22); 2.56 (0.41–4.36); 1.95 (1.22–2.65) ng/mL; P &lt; 0.001] and correlated with LPS (Rs = 0.585; P &lt; 0.001). Escherichia coli DNA was positive in 34% of STEMI vs. 12% of SA and 4% of controls (P &lt; 0.001). In a subgroup of 12 STEMI, immunohistochemical analysis of coronary thrombi showed positivity for leucocyte Toll-like receptor 4 (TLR4), cathepsin G, and LPS from E. coli in 100%, 80%, and 25% of samples, respectively. E. coli-LPS injected in mice to reach LPS concentrations like those detected in coronary thrombi was associated with enhanced artery thrombosis and platelet activation, an effect blunted by TLR4 inhibitor co-administration. In vitro study demonstrated that LPS from E. coli enhanced platelet aggregation via TLR4-mediated leucocyte cathepsin G activation. Conclusion ST-elevation myocardial infarction patients disclose an enhanced gut permeability that results in LPS translocation in human circulation and eventually thrombus growth at site of artery lesion via leucocyte–platelet interaction.

scholarly journals Evaluation of the Hippocampal Normal Tissue Complication Model in a Prospective Cohort of Low Grade Glioma Patients—An Analysis Within the EORTC 22033 Clinical Trial

2019 ◽  
Vol 9 ◽  
Author(s):  
Jaap Jaspers ◽  
Alejandra Mèndez Romero ◽  
Mischa S. Hoogeman ◽  
Martin van den Bent ◽  
Ruud G. J. Wiggenraad ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Prospective Cohort ◽  
Normal Tissue ◽  
Low Grade Glioma ◽  
Low Grade

scholarly journals Occurrence of Escherichia coli in meat preparations

Meso ◽  
2018 ◽  
Vol 20 (5) ◽  
pp. 401-404
Author(s):  
Ana Robina ◽  
Lidija Kozačinski
Keyword(s):  
Escherichia Coli ◽  
Bacterial Contamination ◽  
Faecal Contamination ◽  
E Coli ◽  
Production And Distribution ◽  
Microbiological Criteria ◽  
Minced Meat

Meat preparations are produced from one or more types of minced meat with added seasonings or additives, and are usually placed on the market under labels: ćevapčići, meat patty or hamburger/burger. The bacterial contamination of such products with Escherichia coli during production and distribution is invariably possible. In this paper, we have tested 50 samples of meat preparations for bacteria E. coli, whose presence points to the faecal contamination of food. Only 8 % of meat preparation samples had an E. coli count of less than 500 cfu/g, suggesting that all samples tested in this study yielded satisfactory results regarding the prescribed microbiological criteria for food.

Effect of bacterial endotoxemia on succinic dehydrogenase of liver and kidney of rabbit

1961 ◽  
Vol 201 (1) ◽  
pp. 16-18 ◽  
Author(s):  
J. Cascarano ◽  
A. D. Rubin ◽  
A. K. Neumann ◽  
B. W. Zweifach
Keyword(s):  
Succinic Dehydrogenase ◽  
Significant Inhibition ◽  
Frozen Sections ◽  
Experimental Animals ◽  
E Coli ◽  
Fresh Frozen ◽  
Tissue Homogenates ◽  
Liver And Kidney ◽  
Lethal Doses

The in vivo inhibition of liver and kidney succinic dehydrogenase by administration of lethal doses of bacterial endotoxin ( Escherichia coli and Salmonella typhosa) was investigated. Quantitative determinations conducted on tissue homogenates revealed significant inhibition of activity only in liver of rabbits injected with E. coli lipopolysaccharide. The histochemical distribution of succinic dehydrogenase in fresh frozen sections of kidney was the same in both control and experimental animals. However, the centrolobular areas of liver appeared considerably depressed in activity in both E. coli and S. typhosa endotoxin-treated animals. These data, along with those presented by other studies in the literature, suggest that the action of endotoxin appears to be restricted to certain cells.

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