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Bacteria
Published in Julius P. Kreier, Infection, Resistance, and Immunity, 2022
Gas gangrene is an infection caused by the growth of Clostridium perfringens or closely related Clostridium species. For clostridial infections to develop, wound contamination with endospores and anaerobic conditions for germination and growth are required. The toxins produced by the Clostridia are a group of exotoxins and enzymes with a proteolytic activity that literally digest the tissue. If damaged tissue in a wound is removed, anaerobic conditions are unlikely to occur. The predominant gases produced in gas gangrene are due to carbohydrate fermentation and are carbon dioxide and hydrogen.
A Treatise on the Role of Herpesvirus in Neurodegeneration
Published in Abhai Kumar, Debasis Bagchi, Antioxidants and Functional Foods for Neurodegenerative Disorders, 2021
Bernard W. Downs, Manashi Bagchi, Bruce S. Morrison, Jeffrey Galvin, Steve Kushner, Debasis Bagchi, Kenneth Blum
Anaerobic conditions that potentiate anaerobic events (i.e., anaerobic glycolysis) are an initial stage of decay unless compensatory homeostatic mechanisms can restore and maintain an aerobic metabolic environment. The anaerobic conditions adversely affect the microbiome and impose significant to extreme demands on the immune system. The anaerobic environment combined with an excessive immune burden spurs the activation of anaerobic events and organisms, such as yeasts, parasites, pathogenic bacteria (infections), reactive oxygen species and free radical damage, intestinal dysmotility, inflammation, and notably, various herpetic species that significantly contribute to neurodegeneration among other pathologies and co-infections, including AD, PD, ALS, MS, encephalitis, meningitis, hepatitis, mononucleosis, and others [4,14,22,38,39]. Therefore, a compromised immune system, which routinely occurs due to chronic or excessive stress, trauma, and/or an anaerobic environment, can activate the herpesviruses that infect various tissues and induce neurodegenerative pathologies.
Skeletal Muscle
Published in Nassir H. Sabah, Neuromuscular Fundamentals, 2020
In practically all body cells, the main source of ATP is the citric acid cycle, also known as the tricarboxylic acid cycle or the Krebs cycle, which can metabolize all forms of nutrients, that is, carbohydrates, fats, and proteins. The input to the cycle is from glycolysis, and the output feeds oxidative phosphorylation, which provides most of the ATP, using oxygen, ADP, and phosphate (Figure 9.7). Both the citric acid cycle and oxidative phosphorylation occur in the mitochondria. Glycolysis is the metabolic pathway that breaks down one glucose molecule into two pyruvate molecules, the ionized form of pyruvic acid, and occurs in the cytoplasm outside the mitochondria. Under aerobic conditions, that is in the presence of oxygen, pyruvate feeds into the citric acid cycle, but under anaerobic conditions, that is in the absence of oxygen, pyruvate is converted to lactate.
An overview on cyanobacterial blooms and toxins production: their occurrence and influencing factors
Published in Toxin Reviews, 2022
Isaac Yaw Massey, Muwaffak Al osman, Fei Yang
It is worth noting that some cyanobacteria species appear to be able to fix atmospheric nitrogen without visible heterocysts. This may be related to the anaerobic conditions in which the organisms can survive (Paerl and Huisman 2009, Paerl and Otten 2013, Paerl et al.2016, 2001). A high density of suspended cells may lead to the formation of surface scums and high toxin concentrations. Nitrogen concentration may not be important for Cylindrospermopsis sp., due to the fact that Cylindrospermopsis sp. are nitrogen-fixing cyanobacteria species (Gondwe et al.2008, Abreu et al.2018). Rapala et al. (1997) showed that the nitrogen fixing Anabaena sp. had higher level of microcystin in nitrogen deficient medium. In contrast, Sivonen (1990) indicated that the non-nitrogen fixing Microcystis sp. and Oscillatoria sp. synthesized more toxins when nitrogen was enriched. Planktothrix agardhii and Microcystis spp. were also found to produce microcystins under the induction of nitrogen in Wascana Lake, Saskatchewan, Canada (Donald et al.2011). Further, Gobler et al. (2016) demonstrated that the rise in nitrogen favored proliferation of Microcystis sp. which induced microcystin in Lake Erie. These reveal that the presence of nitrogen concentration do not appear to be a factor for Cylindrospermopsis and Anabaena blooms but it is an important element for Microcystis, Oscillatoria and Planktothrix blooms.
A synthetic consortium of 100 gut commensals modulates the composition and function in a colon model of the microbiome of elderly subjects
Published in Gut Microbes, 2021
Marta Perez, Alexandra Ntemiri, Huizi Tan, Hugh M. B. Harris, Henrik M. Roager, Céline Ribière, Paul W. O’Toole
Human colon conditions were simulated in a single-stage continuous fermentation system (MiniBio Reactors, Applikon Biotechnology) as described elsewhere.31 Temperature was controlled at 37°C, pH at 6.8 and stirrer at 100 rpm. Anaerobic conditions were automatically maintained by supply of O2-free N2 gas. Cultures were run for 3 days in continuous flow, with 24 h retention time. Fermentations were performed in 400 mL working volume with fermentation medium described in Supplementary Table S10 (medium 32). Fecal and MCC100 inoculum aliquots were thawed in an anaerobic cabinet for 30 min. Two vessels were inoculated in parallel with the same fecal sample at 1% (w/v) and one vessel received the MCC100 consortium while the other was the control condition. The MCC100 inoculum was added at 4 × 106 cfu mL−1 final concentration. Samples were collected at time 0 and after 3 days of culture (time 3) in continuous flow. Samples were centrifuged, and pellets and filtered supernatants were kept at −80°C for further analysis. The experiment was run in duplicate for each fecal sample. Fermentations of the MCC100 alone were performed in triplicate.
Admission hyperglycaemia as a predictor of mortality in patients hospitalized with COVID-19 regardless of diabetes status: data from the Spanish SEMI-COVID-19 Registry
Published in Annals of Medicine, 2021
Francisco Javier Carrasco-Sánchez, Mª Dolores López-Carmona, Francisco Javier Martínez-Marcos, Luis M. Pérez-Belmonte, Alicia Hidalgo-Jiménez, Verónica Buonaiuto, Carmen Suárez Fernández, Santiago Jesús Freire Castro, Davide Luordo, Paula Maria Pesqueira Fontan, Julio César Blázquez Encinar, Jeffrey Oskar Magallanes Gamboa, Andrés de la Peña Fernández, José David Torres Peña, Joaquim Fernández Solà, Jose Javier Napal Lecumberri, Francisco Amorós Martínez, María Esther Guisado Espartero, Carlos Jorge Ripper, Raquel Gómez Méndez, Natalia Vicente López, Berta Román Bernal, María Gloria Rojano Rivero, José Manuel Ramos Rincón, Ricardo Gómez Huelgas
One question that remains to be answered is whether hyperglycaemia plays any role in the physiopathology of the disease or if it is just an inflammatory bystander. Apart from the glycosylation of ACE2 receptors that facilitates virus binding and the inflammatory process that increases insulin resistance, the hypoxia that is normally present in patients with COVID-19 is frequently accompanied by disordered cellular glucose metabolism. Under anaerobic conditions, glucose ferments into lactate, which produces a limited amount of adenosine triphosphate (ATP). Hypoxia and ATP depletion cause an elevation of blood lactate and LDH levels. In our study, elevation of the LDH level was also associated with mortality according to BG levels, a finding that is consistent with the mechanism described above. This finding suggests that an early imbalance in glucose metabolism could be involved in a crucial manner in the physiopathology of the viral respiratory infection. Only one very small study suggests that supplemental oxygen at the earliest stages of COVID-19 could be useful in correcting an anaerobic glucose metabolism imbalance [20]. Adequate oxygen delivery and BG monitoring should be carried out for patients who are asked to remain at home in the early stages of the infection in order to prevent clinical deterioration. Early correction of hyperglycaemia in the course of COVID-19 could result in a decrease in the release of inflammatory cytokines and a reduction in the virus’ ACE binding capacity, consequently resulting in better outcomes [11].