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Basic Microbiology
Published in Philip A. Geis, Cosmetic Microbiology, 2020
Burkholderia cepacia—This species is found with the phylum Proteobacteria which contains eight classes of Gram-negative organisms. B. cepacia is placed within the class Betaproteobacteria containing about 400 different species that have bacilli morphology, are obligate aerobes, chemoorganoheterotrophs, and most are motile due to the presence of polar flagella. B. cepacian is a common inhabitant of soil and water and can cause fatal human infections in individuals who are immunocompromised and/or have pre-existing lung disease such as cystic fibrosis. In these individuals, pneumonia leading to rapid lung failure is the most common and severe form of disease.
Sleep apnea is associated with the increase of certain genera of Ruminococcaceae and Lachnospiraceae in the gut microbiome of hypertensive patients
Published in Expert Review of Respiratory Medicine, 2022
Cheng Zhang, Fengwei Chen, Yane Shen, Yuqing Chen, Jing Ma
Forth, concerning the changes of facultative bacteria, the present study showed that in patients with HTN, those who had OSA showed an increase in facultative bacteria at the class level, mainly in the abundance of bacilli, a facultative bacterium in Firmicutes, and Betaproteobacteria, a facultative bacterium in Proteobacteria (p < 0.05). The hypoxia/reoxygenation process in the intestinal mucosal epithelium caused by fluctuations in the partial pressure of blood oxygen during sleep in patients with OSA may alter the distribution of the gut microbiome. Epithelial hypoxia during respiratory events maintains the abundance of specialized anaerobes (e.g. Clostridium), but repeated reoxygenation disrupts the intestinal anaerobic environment and increases facultative anaerobes. It has been suggested that an increase in the facultative bacterium Proteobacteria is a sign of intestinal epithelial dysfunction and intestinal microbiome instability [35,36]. On the other hand, in patients with type II diabetes, the abundance of Betaproteobacteria is significantly higher than that in non-diabetic patients and is positively correlated with blood glucose levels [37]. In this study, Betaproteobacteria were significantly higher in hypertensive patients with OSA (OSA+HTN) than in non-OSA patients (HTN only), which may also be related to the higher number of diabetic patients in the OSA group. Nineteen percent of patients in the OSA+HTN group had diabetes, whereas the HTN only group had no diabetic patients.
Enhanced removal of antibiotics using Eichhornia crassipes root biomass in an aerobic hollow-fiber membrane bioreactor
Published in Biofouling, 2022
Sevcan Aydin, Duygu Nur Arabacı, Aiyoub Shahi, Hadi Fakhri, Suleyman Ovez
Proteobacteria was the most abundant bacterial phylum in the C1, C2 and EC reactors with relative abundances of 48, 36, and 49%, respectively. Betaproteobacteria was the most abundant class of Proteobacteria in all samples. with relative abundances of 43, 41 and 64% of Proteobacteria in C1, C2 and EC samples, respectively. The important role of Proteobacteria as a Gram-negative bacterial phylum in the process of removing antibiotics especially tetracycline has been mentioned in various publications. Zhu et al. (2017) reported Proteobacteria together with Bacteroidetes as the most abundant phylum with a relative abundance of ∼ 33% in MBR treating SMX and TC. The addition of WHRB allowed an increase in the relative abundance of Proteobacteria, and along with the shift in the subdivision composition of this phylum, this shift is correlated with enhanced antibiotic degradation and increased COD removal rates in the EC reactor in contrast with the C2 reactor. This effect may be due to the increased surface area WHRB can supply for biofilm growth. As bacteria in a biofilm are less susceptible to antibiotics than planktonic bacteria, the relative abundance of Proteobacteria increased in the presence of WHRB in the EC reactors.
The effect of early probiotic exposure on the preterm infant gut microbiome development
Published in Gut Microbes, 2021
Yan Hui, Birgitte Smith, Martin Steen Mortensen, Lukasz Krych, Søren J. Sørensen, Gorm Greisen, Karen Angeliki Krogfelt, Dennis Sandris Nielsen
Through 16S rRNA gene amplicon sequencing, we barely detected L. rhamnosus and B. animalis (i.e., the species to which the two probiotics belong) in the NoP samples (Supplementary Table 2). The two species were detected in most samples from the PRO but their relative abundance varied between samples. With a relative abundance threshold of > 0.1%, approximately 70% PRO samples were colonized by B. animalis and nearly 90% were colonized by L. rhamnosus (Supplementary Table 2). The relative abundance of Klebsiella and Weissella was significantly decreased in PRO at all three sampling points (Figure 5a). Veillonella experienced a stunted increase in PRO and its abundance did not reach a level comparable to NoP until day 30. The abundance of Betaproteobacteria, Aeromonas spp., Bifidobacterium breve and Clostridium butyricum only differed between the two groups on day 5. PICRUSt2 prediction also suggested a distinct change of GM functional capacity by probiotic use on day 5 and 10 (Supplementary Figure 6). Probiotic supplementation resulted in a GM with enriched capacity of fructose, mannose and galactose metabolism, and lysine biosynthesis, etc., but distinctly depleted bacteria possibly conferring virulence-relevant genes e.g., lipopolysaccharides (LPS) and siderophore biosynthesis, inorganic ion transport and metabolism (Figure 5b).