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Introduction to Cells, DNA, and Viruses
Published in Patricia G. Melloy, Viruses and Society, 2023
Our focus will be on eukaryotes, which are cells (including our cells) containing a nucleus and other organelles. However, viruses can also infect prokaryotes. The most well-known prokaryotes are bacteria. Prokaryotes lack a nucleus and membrane-bound organelles (Alberts et al. 2019). There are two prokaryotic kingdoms: Archaea and Eubacteria. Archaea includes microorganisms (or microscopic organisms) that can live in extreme environments on the planet. Eubacteria includes microorganisms also known as bacteria and cyanobacteria (Minkoff and Baker 2004d).
Bacteria
Published in Julius P. Kreier, Infection, Resistance, and Immunity, 2022
Many bacteria which cause extracellular infections are encapsulated. The capsules block complement activation by the alternative pathway and thereby prevent phagocytosis. Antibody produced during the inducible response binds to the capsular material, bringing about complement activation and phagocytosis. Bacteria producing extracellular infections usually lack mechanisms to resist killing once phagocytized. The pneumococci, streptococci, and staphylococci are examples of such bacteria. Toxins, if produced, are neutralized by antibody.
Dermal filler complications and management
Published in Michael Parker, Charlie James, Fundamentals for Cosmetic Practice, 2022
Our skin is home to millions of bacteria which normally cause us no bother whatsoever as long as they stay there. Bacteria which naturally live on (or within) us and cause us no harm are known as commensals. These microbes play a key role in normal physiological functions such as digestion as well as outcompeting the “bad” bacteria which may cause illness. The flora residing atop the skin differs between regions of our body, much like different species of animals being found in the arctic permafrost to the rainforests of Brazil. We shan’t dwell too much on commensals commonly found crawling between our toes (such as the fungus Candida albicans) as we are unlikely to be augmenting that region with dermal fillers or botulinum toxin. It is worthwhile understanding the more common bacteria to be found on the face and within the mouth as they are the bugs you are more likely to encounter whilst performing cosmetic treatments. With regards to treating the face, one key feature which influences the skin microbiota here is the relative high density of sebaceous glands, which encourages the growth of lipophilic microorganisms such as Propionibacterium spp. and Malassezia spp.
Gut dysbiosis impairs hippocampal plasticity and behaviors by remodeling serum metabolome
Published in Gut Microbes, 2022
Guoqiang Liu, Quntao Yu, Bo Tan, Xiao Ke, Chen Zhang, Hao Li, Tongmei Zhang, Youming Lu
Here, our results suggest that some bacteria may be especially important for human health and disease. We found that Alistipes, Megamonas, Desulfovibrio, and Butyrimimonas increased their abundance in antibiotic-treated mice, while other bacteria showed the opposite trend, such as the Dubosiella, Parasutterella, and Faecalibaculum. Coincidentally, the specific changes of such bacteria have been reported in patients with major depressive disorder, autism, memory deficit, and gastrointestinal disorders.24–27 It is important to note that these bacteria positively or negatively co-vary with the behavioral outcomes of our dysbiosis mice. While reconstitution of normal microbiota rescued the behavior deficits, indicating a causal role for gut microbiota in modulating CNS development. All members of the microbiota do not have the same effect on the host, some bacteria may influence the host by specialized mechanisms, such as promoting inflammation and producing bioactive metabolites. Therefore, understanding the influence of specific bacterial populations on brain development will pave the way for clinical intervention and treatment of psychiatric disorders related to gut dysbiosis.
The fecal microbiota transplantation response differs between patients with severe and moderate irritable bowel symptoms
Published in Scandinavian Journal of Gastroenterology, 2022
Magdy El-Salhy, Tarek Mazzawi, Trygve Hausken, Jan Gunnar Hatlebakk
S-IBS-S patients had lower levels of E. rectale, and higher levels of E. siraeum than Mo-IBS-S patients at 1 month after FMT. It is worthy of note that the levels of E. siraeum decreased in S-IBS-S patients 1 month after FMT. Eubacterium rectale and E. siraeum are both anaerobic rod-shaped, Gram-positive bacteria belonging to the Eubacteriaceae family. Eubacterium rectale produces butyrate and E. siraeum produces acetic acid during carbohydrate fermentation [32,33]. Butyrate is a modulator of colonic hypersensitivity, and butyrate intake decreases abdominal pain in IBS patients [34–36]. Butyrate is also used as an energy source for epithelial cells in the colon. Furthermore, butyrate decreases intestinal cell permeability and intestinal motility, and modulates the immune response [37,38]. Recent research has shown that butyric acid levels are inversely correlated with the total scores for both the IBS-SSS and FAS [39]. On the other hand, acetic acid has been indicated to induce visceral hypersensitivity in rodents [40]. It is therefore tempting to speculate that the lower levels of E. rectale and the higher levels of E. siraeum in S-IBS-S patients after FMT with the subsequent decrease of butyrate and increase in acetic acid production explains why the total IBS-SSS score was higher in S-IBS-S patients than in Mo-IBS-S patients in the present study. In support of this assumption are the present findings that E. rectale correlated negatively with IBS-SSS total score, and E. siraeum correlated positively with IBS-SSS total score.
Evaluation of zeolite supported bimetallic nanoparticles of zero-valent iron and copper (Z-nZVI/Cu) in the presence of ultrasonic for simultaneous removal of nitrate and total coliforms from aqueous solutions: optimization and modeling with response surface methodology
Published in Toxin Reviews, 2021
Abdolmotaleb Seid-Mohammadi, Ghorban Asgari, Alireza Rahmani, Tayyebeh Madrakian, Amir Karami
Pollution of surface and underground water by nitrate is one of the major environmental problems in various parts of the world (Mohammadi et al.2011). The extensive use of artificial fertilizers and the discharge of industrial and urban wastewater have resulted in large amounts of nitrate penetration into raw water (Öztürk and Bektaş 2004, Cengeloglu et al.2006). The existence of high levels of nitrate in aqueous solutions can lead to problems such as eutrophication in the receiving waters and the development of methemoglobinemia in children (Li et al.2009, Almasi et al.2018). In addition to nitrate, the presence of organisms causing disease such as bacteria, viruses, and parasites in water has led to health and environmental problems in most countries of the world (Zarpelon et al.2016). Coliform bacteria are an indicator of water contaminated with animal and human wastewater and, if this organism is absent, water can be used as safe for drinking purposes. According to reports, these bacteria are generally not harmful, but other microbes which these bacteria are their indicator can cause short-term effects, e.g. diarrhea, nausea, headaches, and other symptoms (Sun et al.2003, Devi et al.2008, Aziz et al.2013). Therefore, the need to remove this pollutant seems necessary for the purpose of water quality, such as maintaining public health.