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Plants from Brazil Used Against Snake Bites
Published in Mahendra Rai, Shandesh Bhattarai, Chistiane M. Feitosa, Wild Plants, 2020
Jocimar de Souza, Bruna Stramandinoli Deamatis, Fernanda Mayumi Ishii, Ingrid Francine Araújo de Oliveira, Gustavo Rodrigues Toledo Piza, Jorge Amaral Filho, Edson Hideaki Yoshida, José Carlos Cogo, Angela Faustino Jozala, Denise Grotto, Rauldenis Almeida Fonseca Santos, Yoko Oshima-Franco
Minimal Inhibitory Concentration (MIC) analysis was performed using the microorganisms Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. The microorganisms were grown in Erlenmeyer’s with 50 mL of the TSB broth (tryptone soya broth) at 37ºC for 24 hours (h). The suspension of each microorganism was diluted to the final concentration of 106 CFU/mL.
Physiology and Growth
Published in Paul Pumpens, Single-Stranded RNA Phages, 2020
Yamazaki (1969) explained the early inhibition of protein and RNA synthesis in the R17-infected cells by the greatly reduced capacity of the infected cells to transport exogenous amino acids. The intracellular functioning of the viral genome was not required for amino acid transport inhibition, since a UV-inactivated phage behaved similarly to the intact phage. Remarkably, this inhibition resulted in the phage-induced synchronous division of bacterial cells (Potter and Yamazaki 1969). A bit later, the early phase of inhibition of the host protein synthesis was explained by reaction of the cells to tryptone broth, which was often used to suspend the phage R17: the early inhibition was not observed when E. coli cultures were inoculated with the purified phage R17 suspended in phosphate buffer (Scott and Iglewski 1974). Therefore, the early inhibition was not an intrinsic feature of the phage R17 infection. In the same context of some uncertainty, it is worth mentioning that Jiresová and Janecek (1977), who studied the β-galactosidase synthesis after infection not only with the phage MS2, but also with the DNA phages T1, T2, T3, and T4, did not find any inhibitory effect of the MS2 infection, in contrast to the T-phages that caused immediate inhibition of the enzyme synthesis.
Challenge tests and their predictive ability
Published in R. M. Baird, S. F. Bloomfield, Microbial quality assurance in cosmetics, toiletries and non-sterile Pharmaceuticals, 2017
R. E. Leak, C. Morriis, R. Leech
Any potential product contaminants arising during manufacture will originate from the raw materials, from the environment (including the equipment) or from the operators. In other words, they will be wild strains entering the product via their natural habitat. The source of the test organism and its cultivation are likely to be important factors in the determined preservative efficacy. Strains isolated from contaminated products, water or the environment show a reduction in aggressive behaviour after subculture onto laboratory media (Gilbert et al. 1980, Carson et al. 1973). In a series of laboratory experiments (Leak 1983), the effect on resistance of a product contaminant cultivated for challenge testing in either its ‘natural’ habitat or on laboratory media was investigated, as shown in Fig. 13.1. The test organism, Enterobacter cloacae, contaminated an unpreserved sterile product, during manufacture. When cultivated in the sterile product and inoculated directly into the chlorhexidine diacetate 0.002% w/v solution the organism regrew from low levels of survivors but, after one subculture on tryptone soya agar, the organism showed a rapid loss of viability in the chlorhexidine solution. A laboratory strain of E. cloacae, grown on tryptone soya agar, also lost viability in the test system. Successive subcultures of the laboratory strain in the sterile product did not produce an organism that could reproduce the behaviour of the product strain (Fig. 13.2). Further experiments showed that other wild strains of E. cloacae (originally product contaminants, but maintained on tryptone soya agar) produced regrowth in the chlorhexidine system when grown in the sterile product. These results suggested that a stringent challenge of a test system was achieved by using a wild strain and by carrying over with the inoculum nutrients to which the test organism had adapted. This was supported by comparing the response of challenge organisms grown in the unpreserved environment (in this case water) to which preservative was added, with a tryptone soya agar culture of the organism inoculated into the preserved environment (Table 13.1). In this experiment, chlorhexidine diacetate (0.001% w/v) in sterilized distilled water was challenged using five strains of Pseudomonas aeruginosa. The organisms were grown in the sterilized water to 105−106 cfu ml−1 to which was added a concentrate of chlorhexidine (0.5% w/v) to give a 0.001% w/v solution. The organisms were also grown on tryptone soya agar and inoculated into chlorhexidine (0.001% w/v) to give 106 cfu ml−1. In all tests the organisms showed a rapid loss of viability but varying abilities to regrow. For four out of five organisms, regrowth occurred more frequently when the organism was challenged in its growth habitat (water).
Prebiotic Chondroitin Sulfate Disaccharide Isolated from Chicken Keel Bone Exhibiting Anticancer Potential Against Human Colon Cancer Cells
Published in Nutrition and Cancer, 2019
Aruna Rani, Rwivoo Baruah, Arun Goyal
The effect of CS-Keel disaccharide and inulin (standard prebiotic) were studied as carbon source on the growth of probiotic bacteria (Lactobacillus acidophilus NRRL B-4495 and Bifidobacterium infantis NRRL B-41661) along with non-probiotic enteric bacteria (E. coli DH5α and Enterococcus aerogenes MTCC7016). MRS medium (pH 6.4) devoid of any carbon source but supplemented with 0.5 mg mL−1 cysteine was used to analyze the growth profiles of probiotic bacteria (30). The probiotic bacterial cultures (∼106 CFU mL−1) were transferred to 5 mL MRS medium containing 1% (w/v) of glucose or standard prebiotic inulin or 0.5% (w/v) CS-Keel disaccharide and incubated under anaerobic conditions at 37 °C for 24 h. TGY medium (pH 7.0) containing tryptone (5 g L−1), glucose (1 g L−1), yeast extract (5 g L−1), and dipotassium hydrogen phosphate K2HPO4 (1 g L−1) was to evaluate the growth of enteric bacteria. The enteric mixture of nonprobiotic E. coli DH5α and E. aerogenes MTCC 7016 was transferred to 5 mL of TGY medium supplemented with 1% (w/v) of glucose or standard prebiotic inulin or 0.5% (w/v) CS-Keel disaccharide was incubated under anaerobic conditions at 37 °C for 24 h. The microbial growth of probiotic bacteria and enteric bacteria was enumerated after for 12 and 24 h by plate count method and expressed as CFU/mL by growing on MRS agar and TGY agar plate, respectively, at 37 °C.
An anti-TL1A antibody for the treatment of asthma and inflammatory bowel disease
Published in mAbs, 2018
Adam W. Clarke, Lynn Poulton, Doris Shim, David Mabon, Danyal Butt, Matthew Pollard, Vanya Pande, Jean Husten, Jacquelyn Lyons, Chen Tian, Anthony G. Doyle
TL1A was produced using the mammalian HEK293E/pTT5 expression system28 from an expression cassette encoding the extracellular domain of TL1A with N-terminally located HIS and FLAG tag. HEK293E cells were cultured in complete cell growth media (1 L of F17 medium (Thermo), 9 ml of Pluronic F68 (Thermo), 2 mM glutamine containing 20% (w/v) Tryptone NI (Organotechnie) with Geneticin™ (Thermo)) at 50 µl/100 ml culture. On the day before transfection, cells were harvested and resuspended in fresh media without Geneticin™. For transfection, DNA was mixed with FreeStyle MAX reagent and added to the culture drop-wise. The culture was incubated overnight at 37°C, 5% CO2 and 120rpm without Geneticin™. The next day 12.5 ml of Tryptone and 250 μl of Geneticin™ were added per 500 ml culture. The culture was incubated at 37°C, 5% CO2 and 120rpm for seven days, then the supernatants were harvested and purified.
A putative LysR-type transcriptional regulator inhibits biofilm synthesis in Pseudomonas aeruginosa
Published in Biofouling, 2019
Xiaojing Yang, Zhiqiang Zhang, Zhiwei Huang, Xixi Zhang, Donghang Li, Li Sun, Jiajia You, Xuewei Pan, Hongjiang Yang
For exopolysaccharide analysis, overnight cultures (12 h) of the indicated strains were to centrifuged to harvest the bacterial cells. The pelleted cells were washed and resuspended with 1 ml of tryptone broth (tryptone 20 g l−1 and NaCl 5 g l−1). Then, the suspensions were subjected to sonication (3W for 10 s, three times). Cell debris were collected and resuspended in 0.5 ml of tryptone broth supplemented with Congo red at 40 μg ml−1. After 250 rpm shaking at 37 °C for 2 h, the supernatants were collected by centrifugation and subjected to optical density measurement at a wavelength of 490 nm (Ueda and Wood 2009). Triplicates of each sample were tested and the Student’s t-test was performed to analyze the differences.