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Control of the Large Bowel Microflora
Published in Michael J. Hill, Philip D. Marsh, Human Microbial Ecology, 2020
Bohumil S. Drasar, April K. Roberts
Among the most striking findings of these international studies has been the low numbers of bacteroides isolated from feces collected from the rural populations in Africa.81–83 These studies suggest that bacteroides may be associated with meat consumption, but this was not supported by a study of fecal samples from a number of people living on a strict “vegan” diet in London; they had bacterial counts very similar to those of people living on mixed diets.84 However, one particular bacterial species, Sarcina ventriculi, has been found virtually confined to the vegetarian populations and in some vegetarians the fecal count reached 107/g.85 This is thought to result from environmental contamination of vegetables rather than specifically induced colonization. The lack of influence of changes in diet in the adult can be explained by consideration of the large intestine as an analogue of a continuous culture apparatus. The colon can be thought of as a fermenter but it should be remembered that the composition of the medium depends upon the activity of the small intestine, and is thus unknown. Contributions to the nutrients available to the microflora are from two major sources: the diet and the body. The body contributes intestinal cells, digestive residues, and biliary excretion products; auto-digestion and absorption will recycle some of the intestinal residue. Digestion and absorption from the intestine is an efficient process and the major dietary components available to the microflora must be nonabsorbable residues such as plant steroids, fiber, and food additives. The efficiency of absorption probably contributes to the apparent lack of effect of most dietary changes on the fecal microflora.
Drug discovery through the isolation of natural products from Burkholderia
Published in Expert Opinion on Drug Discovery, 2021
Adam Foxfire, Andrew Riley Buhrow, Ravi S. Orugunty, Leif Smith
Bactobolin: The first reported isolation of bactobolin was by Kondo et al. [50] in 1979 from Pseudomonas BMG 13-A7. The authors elucidated the structure by mass spectrometry and NMR and showed that this compound was active against a variety of Gram-positive and Gram-negative bacteria, including S. aureus, Sarcina lutea, Bacillus anthracis, Corynebacterimn bovis, Escherichia coli, Klebsiella pneumoniae, and Shigella dysenteriae. Bactobolin was not active against P. aeruginosa. Interestingly, these authors reported a marked increase in survival of mice implanted with mouse leukemia L-1210 cells, but did not elaborate on the matter [51]. In Burkholderia bactobolin was first found in the secondary metabolome of B. thailandensis strain E264, as it was noted a few years prior that production of this activity was under quorum-sensing control [52,53].
Investigation of the population dynamics within a Pseudomonas aeruginosa biofilm using a flow based biofilm model system and flow cytometric evaluation of cellular physiology
Published in Biofouling, 2018
Juzwa Wojciech, Myszka Kamila, Białas Wojciech
The ability to resolve the non-active and active bacterial sub-population using the redox potential-sensitive reagent BacLight™ Redox Sensor™ Green Vitality Kit had been evaluated in previously published studies (Juzwa et al. 2016). Escherichia coli ATCC 10536, Sarcina lutea (from the microbial collection of the Department of Biotechnology and Food Microbiology, Poznan University of Life Sciences), Bacillus subtilis ATCC 6633 and Staphylococcus aureus ATCC 33592 strains were used in reference analysis, which involved 1:1 mixtures of heat-inactivated and non-treated log phase cultures. The results of the reference analysis demonstrated the feasibility of the reagent used for this study to measure cellular redox potential and discriminate between active and non-active sub-populations of microbial cells (Juzwa et al. 2016).
Initial microbial community of the neonatal stomach immediately after birth
Published in Gut Microbes, 2019
Sarah Bajorek, Leslie Parker, Nan Li, Kathryn Winglee, Michael Weaver, James Johnson, Michael Sioda, Josee Gauthier, Dominick J. Lemas, Christian Jobin, Graciela Lorca, Josef Neu, Anthony A Fodor
The low microbial load present in many of our pre-term samples lead to substantial challenges in data analysis. In our negative control sample, we noticed that two most abundant genera, Escherichia/Shigella and Clostridium sensu stricto, made up over 51% of all the reads in our negative control. These taxa were abundant in many of our samples as well (supplementary File 1), which we took as further evidence of a low microbial biomass causing detection of contamination. When analyzed with a two-way ANOVA at a significance threshold of FDR adjusted p < .05 with fixed terms of group (1–5) and birth mode (C-section or vaginal), 5 genera (Lactobacillus, Clostridium XI, Clostridium sensu stricto, Sarcina, and Enterococcus) as well as Shannon diversity were significantly different between C-section and vaginal delivery (supplementary Table 1; supplementary File 1). However, Shannon diversity and all of these taxa (except for Lactobacillus) were also more abundant in our negative control than in our C-section samples, suggesting that all of these taxa except Lactobacillus likely reflect contaminants19 that more substantially affect our low microbial biomass C-section than our vaginal samples. By contrast, Lactobacillus is significantly associated with both vaginal delivery and birth group but is largely absent from our negative controls (Figure 3A). Indeed, Lactobacillus was the only taxa significantly different by birth group number (FDR adjusted p < .05) in our dataset (supplementary Table 1). Lactobacillus is therefore associated with full-term, vaginal delivery, and this association is unlikely to be due to background contamination.