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Nanophyetus
Published in Dongyou Liu, Handbook of Foodborne Diseases, 2018
Neorickettsia helmintheoca is a coccoid to coccobacillary bacterium (family Rickettsiaceae) of 0.3 μm in size, appears purple (i.e., gram negative) in Giemsa stain, and occurs in all stages of the trematode. The complete genome sequence of N. helminthoeca Oregon reveals a single, small circular chromosome of 884,232 bp encoding 774 potential proteins. While N. helminthoeca does not seem to produce lipopolysaccharides and most amino acids, it is capable of synthesizing vitamins, cofactors, nucleotides and bacterioferritin. In addition, by encoding nearly all enzymes required for peptidoglycan biosynthesis, N. helminthoeca has certain structural hardiness and inflammatory potential [17,18].
Iron metabolism in Pseudomonas aeruginosa biofilm and the involved iron-targeted anti-biofilm strategies
Published in Journal of Drug Targeting, 2021
Yapeng Zhang, Xuanhe Pan, Linqian Wang, Liyu Chen
As an essential element for P. aeruginosa growth, however, iron may make deleterious effects if it is excessively supplied. Iron is able to combine with oxygen to generate reactive oxygen species (ROS) via Fenton and Haber-Weiss reactions; as a result, macromolecules (such as lipids and proteins) are destroyed, which eventually leads to bacteria death. Therefore, it is vital to keep an optimal concentration of the intracellular iron. Fur is an iron-uptake regulator that directly regulates the transcription of two RNAs (PrrF1 and PrrF2) to maintain iron-homeostasis. The PrrF RNAs are transcribed in response to iron depletion and contribute to iron-homeostasis by blocking the production of nonessential iron-containing proteins. The virulence of P. aeruginosa depends on PrrF1 and PrrF2, which regulate more than 60 target genes in P. aeruginosa. PrrF1 and PrrF2 control the productions of (i) manganese- and iron-dependent superoxide dismutase enzymes like catalase, mitigating iron toxicity under iron-replete conditions; (ii) iron-chelating-related proteins, such as bacterioferritin; (iii) more than 30 carbon metabolism and aerobic or anaerobic respiration-related proteins, many of which belong to the TCA circulatory enzymes, including aconitase, fumarase and succinate dehydrogenase [31–33].
Gut Bacteroides species in health and disease
Published in Gut Microbes, 2021
The Bfr genes katA, ahpC and tpx encode catalase, alkyl hydroperoxidase and thioredoxin peroxidase, respectively. These proteins assist in the oxidative stress response by detoxifying peroxides.115 Bacterioferritin co-migratory proteins are encoded within the genomes of numerous bacterial species. These proteins are members of the thiol-specific antioxidant protein family and play key roles in the prevention of free radical formation and resultant cellular oxidative damage.116 Studies with Bfr by Nicholson et al. suggested that the bacterioferritin co- migratory protein, encoded within the recA operon, may play a role in maintaining metabolic fitness and genomic integrity in response to oxidative stress.117 This may be accomplished by assisting in the reduction of hydroperoxides, thereby preventing lipid oxidation and DNA damage during oxidative stress.
Mechanistic investigation of resistance via drug-inactivating enzymes in Mycobacterium tuberculosis
Published in Drug Metabolism Reviews, 2018
Aanchal Kashyap, Pankaj Kumar Singh, Om Silakari
Various proteins such as Rv2031c (Alpha-crystallin/HspX), a heat shock protein and Rv2005c (universal stress protein) responsible for cell protection to diverse stimuli like stress, dormancy, heat, drug, and hypoxia by preventing protein aggregation and also have established roles in resistance/stress/virulence/dormancy (Sherman et al. 2001). Another novel mechanism of drug resistance responsible in tuberculosis resistance involves the protein-protein interaction due to expression of various protein having known and unknown functionality. Recently various bioinformatics and proteomics-based tools have been utilized that can be successfully employed for exploring the drug resistance mechanism in tuberculosis that do not involve the mutation in the responsible gene and aided in exploring the unknown mechanism of drug resistance (Sharma et al. 2018). Proteomics-based strategy has been employed to identify that enzymes bacterioferritin (Rv1876) and ferritin (Rv3841) were overexpressed in aminoglycosides (amikacin and kanamycin) resistant Mtb isolates (Kumar et al. 2013; Sharma and Bisht 2017b). Bioinformatics coupled with proteomics approach has led to identification of various drug neutralizing enzymes such as hypothetical proteins (Rv2005c, Rv2744c, and Rv0148) as well as ferritin, which depicted that increased intensities of these enzymes modulate the activity of the aminoglycosides. Docking studies revealed that aminoglycosidic drugs bind to the domains of these proteins and could play probable role in conferring in resistance (Sharma et al. 2015). These potential targets can be further investigated and exploited to overcome the mechanism of kanamycin and amikacin resistance in tuberculosis (Sharma and Bisht 2017a).