scholarly journals Experiments on Staphylococcus food poisoning

1938 ◽  
Vol 38 (5) ◽  
pp. 623-637 ◽  
Author(s):  
F. C. Minett
Keyword(s):  
Culture Medium ◽  
Food Poisoning ◽  
Oral Route ◽  
Natural Conditions ◽  
Staph Aureus ◽  
Layer Cake ◽  
Feeding Experiments ◽  
Low Concentrations ◽  
C 30 ◽  
Variable Susceptibility

1. Feeding tests on monkeys (Macacus rhesus), dogs and cats are unsatisfactory for detecting the presence of enterotoxin, owing to the variable susceptibility of these animals by the oral route.2. Using Dolman's method, in which the material is injected intra-peritoneally into kittens, the production of enterotoxin has been demonstrated by: (a) sixteen out of thirty-eight strains of Staph. aureus, isolated from cases of acute or chronic mastitis or from normal udder milk; (b) four out of five strains of Bact. coli, mostly from calves with “white scours”. No enterotoxin was obtained from fifteen strains of Str. agalactiae from mastitis in cows.3. The formation of enterotoxin under natural conditions has been observed: (a) In udder milk seeded with Staph. aureus or naturally contaminated with that organism and stored at atmospheric temperatures (18 and 22°C.). The substance remains active in cheese prepared from such milk. (b) In layer cake made with cream naturally contaminated with Staph. aureus.4. A small outbreak of poisoning due to potted meat paste was shown to be caused by a non-haemolytic Staphylococcus.5. A few feeding experiments on man with milk or cream, in which food-poisoning staphylococci had grown, were negative, but on one occasion a Staphylococcus from a case of mastitis yielded a culture filtrate which caused symptoms of food poisoning.6. Enterotoxin has the following properties. It is resistant to heat (95°C., 30 min.), to low concentrations of formalin sufficient to destroy the haemolytic toxin, to acid (pH 5·0), and to rennet, but is destroyed by trypsin.It diffuses freely into the culture medium but only slightly through collodion. It is antigenic. Its properties are such that enterotoxin can be classed as a bacterial exotoxin.

Cell cycle regulation of mammary epithelial cell detachment byStaphylococcus aureus

1996 ◽  
Vol 63 (4) ◽  
pp. 543-553 ◽  
Author(s):  
Boris Zavizion ◽  
Andrew J. Bramley ◽  
Ioannis Politis
Keyword(s):  
Cell Cycle ◽  
Epithelial Cells ◽  
Culture Medium ◽  
Mammary Epithelial Cells ◽  
Mammary Epithelial ◽  
Cell Detachment ◽  
Staph Aureus ◽  
Bovine Mammary Epithelial Cells ◽  
Isogenic Mutants ◽  
Cycle Regulation

SummaryThe effect ofStaphylococcus aureuson detachment of bovine mammary epithelial cells in culture was examined. Mammary epithelial cells became detached from fresh monolayers following a 3 h incubation in the presence ofStaph. aureusM60. Two different procedures indicated that cell detachment coincided with the S-phase of the cell cycle. The roles of proteinases, toxins and Ca availability in inducing cell detachment were examined. Addition of the proteinase inhibitor phenyl-methylsulphonyl fluoride (1 mM) to the culture medium prevented cell detachment. Addition of a combination of purified staphylococcal proteinases XVI and XVII-B to the culture medium of mammary epithelial cells induced cell detachment in the absence ofStaph. aureus. Cell detachment may be caused by a staphylococcal proteinase. However, addition of Ca (10 mM) to the culture medium abolishedStaph. aureus-induced cell detachment, despite the fact that proteinase activity was still apparently present. Isogenic mutants ofStaph. aureusM60, expressing either ± or β toxins but not both, induced cell detachment, but to a lesser extent than the wild type. Thus, Ca and toxins play some role during cell detachment. Clones established from detached cells that were washed and replated showed the same susceptibility toStaph. aureus-induced cell detachment as the parental cells. This indicated that there is no subclone of mammary epithelial cells more sensitive to this effect.

scholarly journals Acanthamoeba-Campylobacter Coculture as a Novel Method for Enrichment of Campylobacter Species

2007 ◽  
Vol 73 (21) ◽  
pp. 6864-6869 ◽  
Author(s):  
Diana Axelsson-Olsson ◽  
Patrik Ellstr�m ◽  
Jonas Waldenstr�m ◽  
Paul D. Haemig ◽  
Lars Brudin ◽  
...  
Keyword(s):  
Culture Medium ◽  
Bacterial Species ◽  
Oxygen Quenching ◽  
Free Living ◽  
Promising Tool ◽  
Low Concentrations ◽  
Novel Method ◽  
Selective Antibiotics ◽  
Different Sources ◽  
Bacterial Concentrations

ABSTRACT In this study, we present a novel method to isolate and enrich low concentrations of Campylobacter pathogens. This method, Acanthamoeba-Campylobacter coculture (ACC), is based on the intracellular survival and multiplication of Campylobacter species in the free-living protozoan Acanthamoeba polyphaga. Four of the Campylobacter species relevant to humans and livestock, Campylobacter jejuni, C. coli, C. lari, and C. hyointestinalis, were effectively enriched by the coculture method, with growth rates comparable to those observed in other Campylobacter enrichment media. Studying six strains of C. jejuni isolated from different sources, we found that all of the strains could be enriched from an inoculum of fewer than 10 bacteria. The sensitivity of the ACC method was not negatively affected by the use of Campylobacter-selective antibiotics in the culture medium, but these were effective in suppressing the growth of seven different bacterial species added at a concentration of 104 CFU/ml of each species as deliberate contamination. The ACC method has advantages over other enrichment methods as it is not dependent on a microaerobic milieu and does not require the use of blood or other oxygen-quenching agents. Our study found the ACC method to be a promising tool for the enrichment of Campylobacter species, particularly from water samples with low bacterial concentrations.

scholarly journals FEEDING EXPERIMENTS WITH BACTERIUM PULLORUM. THE TOXICITY OF INFECTED EGGS

1916 ◽  
Vol 23 (4) ◽  
pp. 475-489 ◽  
Author(s):  
Leo F. Rettger ◽  
Thomas G. Hull ◽  
William S. Sturges
Keyword(s):  
Young Children ◽  
Guinea Pigs ◽  
Domestic Fowl ◽  
Food Poisoning ◽  
Later Life ◽  
Wide Distribution ◽  
Feeding Experiments ◽  
Large Numbers ◽  
Poultry Breeding ◽  
Viable Bacteria

The problem of eradicating ovarian infection in the domestic fowl assumes still greater importance than heretofore, in the light of data recently acquired. Not only is it of great significance to eliminate the permanent carriers of Bacterium pullorum from all flocks of fowls from the standpoint of successful poultry breeding, but also because they constitute a possible source of danger to man. Eggs which harbor Bacterium pullorum in the yolk in large numbers may produce abnormal conditions, when fed, not only in young chicks, but in adult fowls, young rabbits, guinea pigs, and kittens. The toxicity for young rabbits is most pronounced, the infection usually resulting in the death of the animals. In kittens the most prominent symptoms are those of severe food-poisoning with members of the paratyphoid group of bacteria. The possibility of infected eggs causing serious disturbances in young children and in the sick and convalescent of all ages must therefore receive serious consideration. Ovarian infection of fowls is very common throughout this country. Hence, a large proportion of the marketed eggs are infected with Bacterium pullorum. When such eggs are allowed to remain in nests under broody hens, or in warm storage places, for comparatively few hours, they contain large numbers of the organism. Soft boiling, coddling, and frying on one side only do not necessarily render the yolks free from viable bacteria; therefore, eggs which have gone through these processes may, like raw eggs, be the cause of serious disturbances in persons who are particularly susceptible to such influences, and especially to infants. That no well authenticated instances of egg-poisoning of this kind are on record does not warrant the assumption that there have been no cases. The etiology of infantile stomach and intestinal disturbances is as yet too little understood; in fact, it may be said that many of these disorders have no known cause, and almost as much may be said regarding gastro-intestinal diseases in later life. Furthermore, since the ailments caused by infected eggs would not make themselves felt presumably until several days after their ingestion, little or no suspicion would fall upon the eggs. It may be said, too, that the wide distribution of ovarian infection in the domestic fowl has come about only in the last few years, hence its possible danger to man is one of recent development.

Mathematical Modeling and Assessment of Microbial Migration during the Sprouting of Alfalfa in Trays in a Nonuniformly Contaminated Seed Batch Using Enterobacter aerogenes as a Surrogate for Salmonella Stanley

2007 ◽  
Vol 70 (11) ◽  
pp. 2602-2605 ◽  
Author(s):  
BIN LIU ◽  
DONALD W. SCHAFFNER
Keyword(s):  
Irrigation Water ◽  
Membrane Filtration ◽  
Microbial Contamination ◽  
Food Poisoning ◽  
Enterobacter Aerogenes ◽  
Probability Of Detection ◽  
Microbial Populations ◽  
Water Sampling ◽  
The Past ◽  
Low Concentrations

Raw seed sprouts have been implicated in several food poisoning outbreaks in the past 10 years. The U.S. Food and Drug Administration recommends that sprout growers use interventions (such as testing of spent irrigation water) to control the presence of pathogens in the finished product. During the sprouting process, initially low concentrations of pathogen may increase, and contamination may spread within a batch of sprouting seeds. A model of pathogen growth as a function of time and distance from the contamination spot during the sprouting of alfalfa in trays has been developed with Enterobacter aerogenes. The probability of detecting contamination was assessed by logistic regression at various time points and distances by sampling from sprouts or irrigation water. Our results demonstrate that microbial populations and possibility of detection were greatly reduced at distances of ≥20 cm from the point of contamination in a seed batch during tray sprouting; however, the probability of detecting microbial contamination at distances less than 10 cm from the point of inoculation was almost 100% at the end of the sprouting process. Our results also show that sampling irrigation water, especially large volumes of water, is highly effective at detecting contamination: by collecting 100 ml of irrigation water for membrane filtration, the probability of detection was increased by three to four times during the first6hof seed germination. Our findings have quantified the degree to which a small level of contamination will spread throughout a tray of sprouting alfalfa seeds and subsequently be detected by either sprout or irrigation water sampling.

scholarly journals Experimental Evidence of a Heat-Resistant Gastro-Intestinal Irritant produced by Bacilli of the Salmonella Group

1933 ◽  
Vol 33 (2) ◽  
pp. 233-244 ◽  
Author(s):  
William G. Savage
Keyword(s):  
Experimental Evidence ◽  
Food Poisoning ◽  
Oral Route ◽  
Theoretical Interest ◽  
Heat Resistant

The Salmonella group contains the organisms which are mainly responsible for outbreaks of food poisoning and the possibility of the production by these strains of bodies which are toxic, or which act as gastro-intestinal irritants, when administered by the oral route, is of practical as well as theoretical interest. This is especially the case if it can be shown that these irritant substances are heat resistant.

Isolation of estrogen-degrading bacteria from an activated sludge bioreactor treating swine waste, including a strain that converts estrone to β-estradiol

2011 ◽  
Vol 57 (7) ◽  
pp. 559-568 ◽  
Author(s):  
Martine Isabelle ◽  
Richard Villemur ◽  
Pierre Juteau ◽  
François Lépine
Keyword(s):  
Carbon Source ◽  
Culture Medium ◽  
Agar Medium ◽  
Carbon Sources ◽  
Bacterial Consortium ◽  
Swine Wastewater ◽  
Low Concentrations ◽  
Degrading Bacteria ◽  
17Β Estradiol ◽  
Reducing Activity

An estrogen-degrading bacterial consortium from a swine wastewater biotreatment was enriched in the presence of low concentrations (1 mg/L) of estrone (E1), 17β-estradiol (βE2), and equol (EQO) as sole carbon sources. The consortium removed 99% ± 1% of these three estrogens in 48 h. Estrogen removal occurred even in the presence of an ammonia monooxygenase inhibitor, suggesting that nitrifiers are not involved. Five strains showing estrogen-metabolizing activity were isolated from the consortium on mineral agar medium with estrogens as sole carbon source. They are related to four genera ( Methylobacterium (strain MI6.1R), Ochrobactrum (strains MI6.1B and MI9.3), Pseudomonas (strain MI14.1), and Mycobacterium (strain MI21.2)) distributed among three classes (Alphaproteobacteria, Gammaproteobacteria, and Actinobacteria). Depending on the culture medium, strains MI6.1B, MI9.3, MI14.1, and MI21.2 partially transform βE2 into E1, whereas Methylobacterium sp. strain MI6.1R reduces E1 into βE2 under aerobic conditions, in contrast with the usually observed conversion of βE2 into E1. Since βE2 is a more potent endocrine disruptor than E1, it means that the presence of Methylobacterium sp. strain MI6.1R (or other bacteria with the same E1-reducing activity) in a treatment could transiently increase the estrogenicity of the effluent. MI6.1R can also reduce the ketone group of 16-ketoestradiol, a hydroxylated analog of E1. All βE2 and E1 transformation activities were constitutive, and many of them are favoured in a rich medium than a medium containing no other carbon source. None of the isolated strains could degrade EQO.

scholarly journals The Relation of the Composition of the Culture Medium to the Formation of Endospores by Aerobic Bacilli

1932 ◽  
Vol 32 (4) ◽  
pp. 535-543 ◽  
Author(s):  
H. L. A. Tarr
Keyword(s):  
Amino Acids ◽  
Culture Medium ◽  
Inorganic Salt ◽  
Synthetic Medium ◽  
Ammonium Phosphate ◽  
Spore Formation ◽  
Experimental Conditions ◽  
Nitrogenous Compounds ◽  
Low Concentrations ◽  
High Concentrations

1. Spore formation in eight typical members of the genusBacillushas been studied.2. Three of these strains, including one species ofB. anthracis, have been found to be practically asporogenous under the experimental conditions. In general the following statements hold good for the sporogenous races studied.3. Spore formation is almost, or entirely, inhibited by cultivation on media rich in amino acids, such as tryptic digests of casein or meat. Similar inhibition results following cultivation on a medium containing reasonably high concentrations of a mixture of amino acids and asparagine.4. When such media are suitably diluted with standard inorganic salt solutions the percentage of spores formed is greatly increased, and frequently at least 99 per cent. of spores are formed if the dilution is sufficiently high.5. When simple nitrogenous compounds such as amino acids are added to a dilute casein digest medium in which sporulation is almost complete, a definite decrease in the percentage of spores present is observed. Asparagine, which is probably readily assimilated, apparently completely hinders spore formation in most cases. Other amino acids do not exert so pronounced an effect, and ammonium phosphate does not appreciably inhibit the formation of spores.6. The fact that the addition of glycine suppresses growth markedly when it is added to a dilute casein digest medium, but does not appreciably hinder sporulation, suggests that the formation of spores is not due to any toxic effect of added compounds, or compounds already present in the medium.7. Sporulation is almost complete in a “synthetic” medium in which low concentrations of ammonium phosphate and sucrose represent the sources of nitrogen and carbon, respectively. However, frequent transfers in such a medium may inhibit spore formation partially or entirely in certain instances. This effect probably depends upon the enhanced ability of the culture in question to utilise sucrose as a source of carbon when cultivated constantly in its presence.8. It is concluded, from the above data, that endospore formation in aerobic bacilli bears an inverse relationship to the amount of available nutrient material present in the culture medium.I am indebted to Prof. Sir F. G. Hopkins and Miss M. Stephenson for their constant encouragement during the progress of this work. My thanks are due to Mr Pirie of this Department who kindly furnished me with several of the amino acids employed, and to Dr Miles of the Department of Pathology for his kindness in supplying me with certain of the cultures.

scholarly journals Impact of Phytochemicals on Viability and Cereulide Toxin Synthesis in Bacillus cereus Revealed by a Novel High-Throughput Method, Coupling an AlamarBlue-Based Assay with UPLC-MS/MS

Toxins ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 672
Author(s):  
Markus Kranzler ◽  
Elrike Frenzel ◽  
Veronika Walser ◽  
Thomas F. Hofmann ◽  
Timo D. Stark ◽  
...  
Keyword(s):  
Bacillus Cereus ◽  
High Throughput ◽  
Food Poisoning ◽  
Small Scale ◽  
Natural Substances ◽  
Viability Assay ◽  
Food Borne ◽  
Low Concentrations ◽  
Hydroxycinnamic Acid Derivatives ◽  
Antibacterial Potential

Due to its food-poisoning potential, Bacillus cereus has attracted the attention of the food industry. The cereulide-toxin-producing subgroup is of particular concern, as cereulide toxin is implicated in broadscale food-borne outbreaks and occasionally causes fatalities. The health risks associated with long-term cereulide exposure at low doses remain largely unexplored. Natural substances, such as plant-based secondary metabolites, are widely known for their effective antibacterial potential, which makes them promising as ingredients in food and also as a surrogate for antibiotics. In this work, we tested a range of structurally related phytochemicals, including benzene derivatives, monoterpenes, hydroxycinnamic acid derivatives and vitamins, for their inhibitory effects on the growth of B. cereus and the production of cereulide toxin. For this purpose, we developed a high-throughput, small-scale method which allowed us to analyze B. cereus survival and cereulide production simultaneously in one workflow by coupling an AlamarBlue-based viability assay with ultraperformance liquid chromatography–mass spectrometry (UPLC-MS/MS). This combinatory method allowed us to identify not only phytochemicals with high antibacterial potential, but also ones specifically eradicating cereulide biosynthesis already at very low concentrations, such as gingerol and curcumin.

scholarly journals Homoeopathic Viscum album extract inhibits the growth of osteosarcoma cells

2020 ◽  
Vol 3 ◽  
pp. 59-63
Author(s):  
Ana Catarina Viana Valle ◽  
Lana Ribeiro Aguiar ◽  
Hilana dos Santos Sena Brunel ◽  
Patricia Furtado Malard ◽  
Rosângela Vieira Andrade
Keyword(s):  
Cell Line ◽  
Mtt Assay ◽  
Culture Medium ◽  
Promising Result ◽  
Viscum Album ◽  
Control Group ◽  
Cytotoxic Action ◽  
Osteosarcoma Cell ◽  
Low Concentrations ◽  
The Mean

Objectives: This study is aimed to evaluate the cytotoxic action of two homoeopathic medicines that are derived from Viscum album (VA) extract. Materials and Methods: An osteosarcoma cell line was cultured in the presence of two homoeopathic VA preparations (VAD3 and VAD30) and cell viability was evaluated using MTT assay. The cell line U-2 OS was plated in two 96-well plates for 24 h with culture medium at 37 5°C and 5% CO2. Subsequently, this medium was replaced by another one containing VAD3 and VAD30 separately in concentrations ranging from 10 to 100 μL/mL, as well as a control group (culture medium only). These plates were kept in culture for 48 h. MTT assay was performed to evaluate the percentage of viable cells. Subsequently, concentrations ranging from 1 to 10 μL/mL were tested. Results were compared to those of the control group and the mean half maximal inhibitory concentration (IC50) was calculated. Results: The MTT assay showed that it is possible to reduce 50% of the osteosarcoma cell population with low concentrations of the homeopathic VAD3 and VAD30 with IC50 of 6 62 μL/mL and 5 82 μL/mL, respectively. Conclusion: This is a promising result that shows the action of VAD3 and VAD30 in the U-2 OS lineage of osteosarcoma cancer cells. This opens up the possibility of using this medicine in the treatment of these tumours; if not alone, at least in association with other medicines or techniques.

scholarly journals Cellular Calcium Distribution Modulates the Growth of Callus and Protoplasts of Halophyte Mangrove Plant, Avicennia Alba - an X-ray Microanalysis

2017 ◽  
Vol 6 (2) ◽  
pp. 18
Author(s):  
Manabu Hayatsu ◽  
Suechika Suzuki ◽  
Shinpei Tsuchiya ◽  
Hamako Sasamoto
Keyword(s):  
Cell Wall ◽  
Culture Medium ◽  
Middle Lamella ◽  
Mangrove Plant ◽  
Callus Line ◽  
Cytoplasmic Matrix ◽  
X Ray ◽  
Low Concentrations ◽  
Avicennia Alba ◽  
Cellular Ca

Two cultured cell lines were developed from cotyledons of a halophyte mangrove, Avicennia alba.In the high-Ca callus line, which was sub-cultured in amodified amino acid medium containing 3 mM CaCl2, growth of calluses and their protoplasts were both inhibited by low concentrations of CaCl2 in the culture medium. Removal of Ca2+ from the culture medium stimulated callus growth and the calluses could be sub-cultured without CaCl2 (low-Ca callus line). The intra- (cytoplasmic matrix and vacuole) and extra- (cell wall) cellular concentrations of elements, i.e., [Ca], [K], [Cl], [Na], [Mg], [P] and [S] were investigated using quantitative X-ray microanalysis of cryosections of calluses from bothcell lines. [Ca] was high in the cytoplasmic matrix and cell wall of the high-Ca line. [Ca] was lowered in the low-Calineinall cell compartments, though still detected. Ca-containing electron-dense precipitates were accumulated in the middle lamella of cell walls in resin-embedded sections of the high-Ca line. CaCl2 in the medium stimulated protoplast growth only in the low-Caline. These results suggested that a low cellular [Ca] is needed for protoplasts growth of A. alba. The importance of cellular [Ca] for the growth of halophilic mangrove plant cells was discussed.

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