scholarly journals Application of the principles of colloidal chemistry to obtain the purest preparation of tetanotoxin

2021 ◽  
Vol 17 (2) ◽  
pp. 139-153
Author(s):  
V. M. Aristovsky

If you take a broth culture of a tetanus bacillus and filter it through a Chamberland'a candle, then, as you know, you will get a completely transparent, sterile liquid with pronounced toxic properties.

2021 ◽  
pp. 216507992110126
Author(s):  
Beverley C. Millar ◽  
John E. Moore

Background Fabric lanyards are commonly worn by health care workers (HCWs) and are known to harbor infectious organisms and contribute to the transmission of infection to HCWs and patients. A diverse range of nosocomial pathogens have been found on lanyards, but there are very few studies describing how to successfully disinfect lanyards to break the chain of transmission. Recently, a steam disinfector-dryer device has come on the market, which performs rapid disinfection against nosocomial pathogens and also dries the contents of the device. It was the aim of this study to evaluate steam disinfection-drying as a method to eliminate pathogens from lanyards. Methods Thirty-eight strips of new, unused, and autoclaved polyester neck lanyards (4 × 2 cm) were inoculated with 30 (12 Gram-positive + 18 Gram-negative) bacteria and one yeast organism. The inoculated lanyard fabric (five organisms per lanyard strip) was placed into a steam disinfector-dryer device and disinfected for 5 minutes and dried for 30 minutes, in accordance with the manufacturer’s instructions. Following disinfection and drying, the presence of viable organisms on lanyard fabric was evaluated using enhanced microbiological broth culture methods for 48 hours. Control lanyard strips were treated with organisms and left at room temperature without undergoing disinfection and drying procedures. Findings Steam disinfection-drying eradicated all test organisms from treated lanyards, with no culturable organisms detected following disinfection-drying, even when employing enhanced bacteriological culture conditions. All test organisms remained viable on the control lanyards. Conclusion/Application to Practice Steam disinfection-drying offers a simple method of decontaminating lanyards, producing dry lanyards for immediate reuse. Occupational health practitioners and hospitals should consider assessing the feasibility of adopting this method in their settings to aid in breaking the chain of transmission of nosocomial pathogens via contaminated lanyards.


1908 ◽  
Vol 54 (226) ◽  
pp. 560-561
Author(s):  
David Orr ◽  
R. G. Rows

At a quarterly meeting of this Association held last year at Nottingham, we showed the results of our experiments with toxins upon the spinal cord and brain of rabbits. Our main conclusion was, that the central nervous system could be infected by toxins passing up along the lymph channels of the perineural sheath. The method we employed in our experiments consisted in placing a celloidin capsule filled with a broth culture of an organism under the sciatic nerve or under the skin of the cheek; and we invariably found a resulting degeneration in the spinal cord or brain, according to the situation of the capsule. These lesions we found to be identical in morphological type and anatomical distribution with those found in the cord of early tabes dorsalis and in the brain and cord of general paralysis of the insane. The conclusion suggested by our work was that these two diseases, if toxic, were most probably infections of lymphogenous origin.


1986 ◽  
Vol 49 (9) ◽  
pp. 718-723 ◽  
Author(s):  
K. R. NATH ◽  
B. J. KOSTAK

Swiss cheese made from fully pasteurized milk developed white spots during hot room stay. This cheese was bitter and eye development was generally retarded. Streptococcus faecalis subsp. liquefaciens was isolated in high numbers from the spot; it caused bitterness in milk cultures with complete dissolution of the milk clot. The isolate was inhibitory to propionibacteria and Lactobacillus fermentum; CO2 production by Propionibacterium was depressed in broth culture in the presence of the S. faecalis subsp. liquefaciens isolate.


1928 ◽  
Vol 48 (1) ◽  
pp. 83-104 ◽  
Author(s):  
Alvan L. Barach ◽  

1. The antigenic function of a pneumococcus vaccine made from the intact cell was compared with that derived fron a watery extract of the cell free from formed elements. In each instance, the immunity produced was dependent upon type-specific protective substance and not upon the elaboration of the common protein antibody. 2. The vaccine made from the intact cell resulted in both active and passive immunity which began on the 3rd day, increased markedly to the 5th, and remained approximately stationery to the 7th day. In the case of the Berkefeld filtrate of the shaken bacteria and the filtrate of the broth culture, the immunity began on the 4th day, increased to the 5th, and remained approximately stationery to the 7th day. The immunity produced by Pneumococcus Type I vaccine is greater than that produced by Type II. On the 3rd day, mice vaccinated with Type I vaccine resisted 100,000 minimal lethal doses, whereas mice immunized with Type II resisted 10,000 minimal lethal doses. On the 5th day, a larger percentage of mice survived these doses than on the 3rd day. 3. Certain factors related to the preparation and dosage of the vaccine are discussed. 4. As far as the time interval and the degree of immunity produced are concerned, these results suggest the possibility of employing pneumococcus vaccine in suitable doses in the treatment of lobar pneumonia. That an earlier activity of the immunity mechanism could actually be initiated in a patient with lobar pneumonia has still to be demonstrated.


2003 ◽  
Vol 71 (6) ◽  
pp. 3088-3096 ◽  
Author(s):  
Peter Redford ◽  
Paula L. Roesch ◽  
Rodney A. Welch

ABSTRACT Extraintestinal Escherichia coli strains cause meningitis, sepsis, urinary tract infection, and other infections outside the bowel. We examined here extraintestinal E. coli strain CFT073 by differential fluorescence induction. Pools of CFT073 clones carrying a CFT073 genomic fragment library in a promoterless gfp vector were inoculated intraperitoneally into mice; bacteria were recovered by lavage 6 h later and then subjected to fluorescence-activated cell sorting. Eleven promoters were found to be active in the mouse but not in Luria-Bertani (LB) broth culture. Three are linked to genes for enterobactin, aerobactin, and yersiniabactin. Three others are linked to the metabolic genes metA, gltB, and sucA, and another was linked to iha, a possible adhesin. Three lie before open reading frames of unknown function. One promoter is associated with degS, an inner membrane protease. Mutants of the in vivo-induced loci were tested in competition with the wild type in mouse peritonitis. Of the mutants tested, only CFT073 degS was found to be attenuated in peritoneal and in urinary tract infection, with virulence restored by complementation. CFT073 degS shows growth similar to that of the wild type at 37°C but is impaired at 43°C or in 3% ethanol LB broth at 37°C. Compared to the wild type, the mutant shows similar serum survival, motility, hemolysis, erythrocyte agglutination, and tolerance to oxidative stress. It also has the same lipopolysaccharide appearance on a silver-stained gel. The basis for the virulence attenuation is unclear, but because DegS is needed for σE activity, our findings implicate σE and its regulon in E. coli extraintestinal pathogenesis.


2011 ◽  
Vol 1306 ◽  
Author(s):  
Wenting Dong ◽  
Wendell Rhine ◽  
Greg Caggiano ◽  
Owen R. Evans ◽  
George Gould ◽  
...  

ABSTRACTRefrigeration, air conditioning, and other cooling requirements in buildings, industry, and transportation sectors account for about 10 quads of U.S. primary energy consumption. Therefore, advanced technologies for space cooling in buildings and vehicles – as well as for refrigeration in residential, commercial, and industrial applications – that are more energy efficient, avoid net direct greenhouse gas emissions, reduce lifecycle costs, and can impact large markets are needed. Although current technologies are reaching their efficiency limits, thermoelectric (TE) materials can be used for cooling applications and have potential for significant improvements. Compared to traditional bulk phase TE materials, literature results suggest that nanometer-scale materials allow additional opportunities to improve the efficiency of TE materials. Aerogels are one type of nano-material that offers opportunities to increase the efficiency of TE materials by controlling particle size, particle composition and by reducing the thermal conductivity. Bismuth telluride (Bi2Te3) is the most studied TE material and our objective was to produce bismuth telluride aerogels with controlled microstructures and thermal conductivities to increase the TE figure of merit. Aspen Aerogels developed a novel synthesis method to prepare Bi2Te3 aerogels using the principles of colloidal chemistry and sol-gel chemistry. The reaction conditions were investigated and optimized so that gels could be obtained at low reaction temperatures. The gels were aged and dried using supercritical CO2. The aerogels were characterized by BET, XRD, and SEM. The best aerogels were hot pressed and Seebeck coefficients were determined. The synthetic approach developed and the properties of the aerogels will be presented and compared with Bi2Te3 aerogels and materials prepared by other methods.


2015 ◽  
Vol 112 (37) ◽  
pp. E5208-E5217 ◽  
Author(s):  
Dervla T. Isaac ◽  
Rita K. Laguna ◽  
Nicole Valtz ◽  
Ralph R. Isberg

Iron is essential for the growth and virulence of most intravacuolar pathogens. The mechanisms by which microbes bypass host iron restriction to gain access to this metal across the host vacuolar membrane are poorly characterized. In this work, we identify a unique intracellular iron acquisition strategy used byLegionella pneumophila.The bacterial Icm/Dot (intracellular multiplication/defect in organelle trafficking) type IV secretion system targets the bacterial-derived MavN (more regions allowing vacuolar colocalization N) protein to the surface of theLegionella-containing vacuole where this putative transmembrane protein facilitates intravacuolar iron acquisition. TheΔmavNmutant exhibits a transcriptional iron-starvation signature before its growth is arrested during the very early stages of macrophage infection. This intracellular growth defect is rescued only by the addition of excess exogenous iron to the culture medium and not a variety of other metals. Consistent with MavN being a translocated substrate that plays an exclusive role during intracellular growth, the mutant shows no defect for growth in broth culture, even under severe iron-limiting conditions. Putative iron-binding residues within the MavN protein were identified, and point mutations in these residues resulted in defects specific for intracellular growth that are indistinguishable from the ΔmavNmutant. This model of a bacterial protein inserting into host membranes to mediate iron transport provides a paradigm for how intravacuolar pathogens can use virulence-associated secretion systems to manipulate and acquire host iron.


1916 ◽  
Vol 19 (3) ◽  
pp. 452-477 ◽  
Author(s):  
M. von Krogh
Keyword(s):  

Author(s):  
Aseel Alsarahni ◽  
Zuhair Muhi Eldeen ◽  
Elham Al-kaissi ◽  
Hiba Al-malliti

Objective: To determine the time needed for killing different types of microorganisms by a newly synthesized 2-mercapto-1,3-benzothiazole derivative in comparison to ciprofloxacin and fluconazole.Methods: The minimum bactericidal concentration (MBC) and minimum fungicidal concentration (MFC) for 2-{[4-(2,6-dimethylPiperidin-1-yl)but-2-yn-1-yl]Sulfanyl}-1,3-benzothiazole(AZ3) compound were determined, using the broth dilution method. The MBC and MFC dilutions were prepared. Broth cultures of Staphylococcus aureus (S. aureus), Bacillus subtilis (B. subtilis), Escherichia coli (E. coli), and Pseudomonas aeruginosa (P. aeruginosa) were incubated at 37 °C for 24 h, and Candida albicans (C. albicans) was incubated at 25 °C for 48 h. 0.1 ml of each broth culture represent 1.5 x 106 CFU/ml was challenged with 9.9 ml broth containing the MBC or MFC concentrations of the AZ3 compound. From each sample at different time intervals, 1 ml was taken and added to 9 ml of sterile distilled water, in order to neutralize the effect of AZ3. Serial dilution was done and a viable count was determined from the appropriate dilutions.Results: The viability of the P. aeruginosa, E. coli, S. aureus, B. subtilis and C. albicans were killed within 3.5 h, 5 h, 24 h, 3 h and 5 h respectively. The time killing curves showed that AZ3 needed longer time for killing S. aureus than the time needed to kill B. subtilis. On the other hand, AZ3 needed a shorter time to kill P. aeruginosa, than the time needed to kill E. coli. In comparison with ciprofloxacin, AZ3 needed a shorter time to kill P. aeruginosa and E. coli, and the same time to kill B. subtilis, while it needed longer time than ciprofloxacin to kill S. aureus. In comparison with fluconazole, AZ3 with lower MFC than fluconazole needed longer time to kill C. albicans.Conclusion: AZ3 showed promising antimicrobial killing activities, in compared with ciprofloxacin and fluconazole, which promoted our interest to investigate the time of killing needed for other 2-mercaptobenzothiazole derivatives against different types of microorganisms.


2002 ◽  
Vol 65 (1) ◽  
pp. 153-160 ◽  
Author(s):  
HIROSHI KANO ◽  
TSUTOMU KANEKO ◽  
SHUICHI KAMINOGAWA

Oral intake of some lactic acid bacteria can have beneficial effects on the host by activating immune responses and enhancing resistance to infection by pathogens. In this study, effects of Lactobacillus sp. on the development of autoimmune disease were examined in mice with collagen-induced arthritis (CIA). CIA, a model of some types of rheumatoid arthritis (RA), can be induced in DBA/1J mice by immunizing them with bovine type II collagen (bCII). Oral intake of skimmed milk (SM) fermented with Lactobacillus delbrueckii subsp. bulgaricus OLL1073R-1 (SM/OLL1073R-1) was found to markedly inhibit the development of CIA in these mice, compared with a control group fed the control foodstuff. The inhibitory effect of SM fermented with L. delbrueckii subsp. bulgaricus OLL1102 (SM/OLL1102) or fresh SM was weaker than that of SM/OLL1073R-1. A deMan Rogosa Sharpe (MRS) broth culture of OLL1073R-1 without any major components of SM had the same inhibitory effect as SM/OLL1073R-1, suggesting that the inhibitory effect of SM/OLL1073R-1 is attributable not only to SM components but also to OLL1073R-1 cells, their metabolites, or both. We found that SM/OLL1073R-1 and SM caused reduced secretion of the cytokine IFN-γ by lymph node cells (LNCs) in response to bCII. However, SM/OLL1102 did not affect the secretion of IFN-γ. A polysaccharide fraction secreted by OLL1073R-1 also exhibited the inhibitory effects on both development of CIA and secretion of IFN-γ.


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