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The Role of Toll-Like Receptor Signaling in the Pathogenesis Of NEC
Published in David J. Hackam, Necrotizing Enterocolitis, 2021
Maame Efua S. Sampah, David J. Hackam
Clinical studies examining stool from infants with NEC have revealed that the disease is not associated with a single enteric pathogen. However, the fecal microbiota in infants with NEC is characteristically distinct and has been demonstrated to feature gram-negative Gammaproteobacteria predominantly (56, 57), which have also been linked to other inflammatory diseases (58, 59). Gut microbial colonization is required for NEC development (60), and treatment with broad-spectrum antibiotics that target enteric microorganisms is an essential aspect of its clinical treatment. However, it remains controversial whether dysbiosis represents a cause as opposed to a consequence of NEC. On the other hand, various cohort studies (6, 61, 62) and clinical trials (63, 64) have established that probiotic bacteria are capable of limiting the incidence of NEC via deoxyribonucleic acid (DNA)–mediated inhibition of TLR4 signaling through up-regulation of TLR9 (6, 61, 65).
The Aedes Fauna: Different Aedes Species Inhabiting the Earth
Published in Jagriti Narang, Manika Khanuja, Small Bite, Big Threat, 2020
Annette Angel, Bennet Angel, Neelam Yadav, Jagriti Narang, Surender Singh Yadav, Vinod Joshi
Nad4 gene was used for identification of the species in Germany and Liguria (Pfitzner et al., 2018; Ballardini et al., 2019). A total of 62 proteins are enlisted in the NCBI database that includes COX 1 subunit, NAD 4, and β tubulin. Microbiota present in Aedes koreicus has been demonstrated by Alfano and his team (2019) using 16srRNA for characterizing purposes. V3 and V4 regions of the 16s rDNA was used for sequencing of microbiota. The results showed presence of Proteobacteria species in the observed adults (84%) and larvae (66%), specifically Gammaproteobacteria followed by Bacteroidetesand Actinobacteria in the water, larvae, and pupae collected and Alphaproteobacteria in the adult forms collected. Firmicutes were also observed in all, except water samples. Pseudomonas, Gilliamella, Dyella and Pantoea, and Enterobacteriacea family were also seen in adults. When the trend of microbial fauna in the water samples and the larval and adult forms were compared, it was seen that only 10% of those found in water reached the larval gut and established themselves there, and as the life cycle continued, only few microbial fauna were able to invade the pupal and then the adult system (Alfani et al., 2019).
Opportunities and Challenges in Seaweeds as Feed Stock for Biofuel Production
Published in Gokare A. Ravishankar, Ranga Rao Ambati, Handbook of Algal Technologies and Phytochemicals, 2019
Mohammad Javad Hessami, Ambati Ranga Rao, Gokare A. Ravishankar
Carrageenan is another specific compound which is extracted from some species of the class Rhodophyceae, mainly Chondrus, Gigartina, Kappaphycus and Eucheuma (Necas and Bartosikova 2013). The main blocks of carrageenan are of D-galactose and 3,6-anhydro-galactose which are joined by α1→3 and β1→4 linkage. In comparison to agar-degrading bacteria, very few microorganisms have been reported to have hydrolytic activity to digest carrageenan. All these bacteria were isolated in the marine environment and belong to the gamma proteobacteria, Flavobacteria or Sphingobacteria classes. Alginate was described as being composed of different blocks of G, M and MG (Aarstad et al. 2012) and is an unbranched polysaccharide polymer without repeating subunit structures and can be found widely in brown seaweeds and some bacteria including Azotobacter vinelandii and Pseudomonas aeruginosa (Hansen et al. 1984). Numerous bacteria are capable of producing alginase, but, unlike carrageenase, the majority of them are marine bacteria which are active in algal decomposing residues (von Riesen 1980). Among all hydrolytic enzymes, commercial production of amylase is widely developed, and also great investment in production of low-cost cellulase has been made, and currently, it is claimed that the company Novozymes is on the ed ge of low-cost production of cellulase for biofuel process. A comparison of saccharification process and reducing sugars yield is presented in Table 4.2.
Addition of Trichocladium canadense to an anaerobic membrane bioreactor: evaluation of the microbial composition and reactor performance
Published in Biofouling, 2021
Hadi Fakhri, Duygu Nur Arabacı, İlayda Dilara Ünlü, Cigdem Yangin-Gomec, Suleyman Ovez, Sevcan Aydin
At the phylum level, the dominant bacteria in the biofilm were similar to those that were identified in the samples from the sludge in this study. These were Proteobacteria, Bacteroidetes and Firmicutes, which were also reported to commonly exist in anaerobic treatment systems (Wagner and Loy 2002; Jang et al. 2014; Nagaraj et al. 2017). From these, Bacteroidetes and Firmicutes have been reported to take active roles in membrane biofouling in sewage WWTPs. The results of this study indicated that these two phyla were both negatively impacted by the selected antibiotics in the C2 reactor. On the other hand, Bacteroidetes increased in TC reactor whereas Firmicutes showed a significant decrease from 48% in C1 and from 24% in the C2 reactor to about 10% in the presence of T. canadense (Figure 6). Among these phyla, the classes Gammaproteobacteria, Clostridia, Bacteroidia and Deltaproteobacteria had the highest abundances. Here, the control reactors were dominated by Gammaproteobacteria and Clostridia; however, these classes were radically decreased in the TC reactor, and the classes Bacteroidia and Deltaproteobacteria were enriched compared with their low abundance in the C1 and C2 reactors. Interestingly, Gammaproteobacteria are similar to fungi in several aspects, one of which is the production of extracellular enzymes that degrade lignocellulosic biomass (Arabaci et al. 2020) and the domination of this class in the control reactors and the subsequent decrease suggests competition with T. canadense for nutrients.
Role of IgA in the early-life establishment of the gut microbiota and immunity: Implications for constructing a healthy start
Published in Gut Microbes, 2021
Jielong Guo, Chenglong Ren, Xue Han, Weidong Huang, Yilin You, Jicheng Zhan
Prolonged antibiotic therapy (≥ 5 days) is usually employed to prevent group B Streptococcus-induced early-onset sepsis, while it is associated with the development of LOS.118 Infections caused by Gammaproteobacteria members E. coli and K. pneumonia, Staphylococcus spp., and fungi, such as Candida spp., which is commonly seen after antibiotic administration, is implicated in the development of LOS in preterm infants.75,119,120 Therefore, antibiotic-induced dysbiosis may contribute to the development of LOS. Since SIgA in the gut is closely related to the clearance of Gammaproteobacteria,22 the enhancement of IgA function may contribute to the management of LOS. In addition to LOS, as discussed above, preterm infants are at risk of developing NEC, a deadly disease associated with exclusive formula-feeding and deficient IgA response, which may be prevented by enhancing IgA function.5
Isolation of pancreatic microbiota from cystic precursors of pancreatic cancer with intracellular growth and DNA damaging properties
Published in Gut Microbes, 2021
Asif Halimi, Giorgio Gabarrini, Michał Jacek Sobkowiak, Zeeshan Ateeb, Haleh Davanian, Rogier Aäron Gaiser, Urban Arnelo, Roberto Valente, Alicia Y.W. Wong, Carlos Fernández Moro, Marco Del Chiaro, Volkan Özenci, Margaret Sällberg Chen
The culture-positive samples were streaked repetitively to obtain pure monocultures for a subsequent strain identification by MALDI-TOF MS profiling. As shown in Table 2, a total of 15 bacterial strains were identified, mainly facultative anaerobes of the class Gammaproteobacteria or Bacilli. Several Klebsiella spp., and Enterococcus faecalis and Enterobacter cloacae were also repeatedly noted in varying IPMN neoplastic grades: LGD (L) and HGD (H) or invasive cancer (C). Antibiotic susceptibility reports showed that the isolates were in general susceptible to antibiotics tested (data not shown). Bacteremia was detected in only two patients, both of which belonged to the IPMN-LGD group and showed no sign of bacterial growth in their cyst fluid (data not shown).