Vitamin C induced DevR-dependent synchronization of Mycobacterium smegmatis growth and its effect on the proliferation of mycobacteriophage D29

Dietary Effects on the Gut Phageome

As knowledge of the gut microbiome has expanded our understanding of the symbiotic and dysbiotic relationships between the human host and its microbial constituents, the influence of gastrointestinal (GI) microbes both locally and beyond the intestine has become evident. Shifts in bacterial populations have now been associated with several conditions including Crohn's disease (CD), Ulcerative Colitis (UC), irritable bowel syndrome (IBS), Alzheimer's disease, Parkinson's Disease, liver diseases, obesity, metabolic syndrome, anxiety, depression, and cancers. As the bacteria in our gut thrive on the food we eat, diet plays a critical role in the functional aspects of our gut microbiome, influencing not only health but also the development of disease. While the bacterial microbiome in the context of disease is well studied, the associated gut phageome-bacteriophages living amongst and within our bacterial microbiome-is less well understood. With growing evidence that fluctuations in the phageome also correlate with dysbiosis, how diet influences this population needs to be better understood. This review surveys the current understanding of the effects of diet on the gut phageome.

Synchronization of Mycobacterium life cycle: A possible novel mechanism of antimycobacterial drug resistance evolution and its manipulation

Mycobacterium Tuberculosis (Mtb) causing Tuberculosis (TB) is a widespread disease infecting millions of people worldwide. Additionally, emergence of drug resistant tuberculosis is a major challenge and concern in high TB burden countries. Most of the drug resistance in mycobacteria is attributed to developing acquired resistance due to spontaneous mutations or intrinsic resistance mechanisms. In this review, we emphasize on the role of bacterial cell cycle synchronization as one of the intrinsic mechanisms used by the bacteria to cope with stress response and perhaps involved in evolution of its drug resistance. The importance of cell cycle synchronization and its function in drug resistance in cancer cells, malarial and viral pathogens is well understood, but its role in bacterial pathogens has yet to be established. From the extensive literature survey, we could collect information regarding how mycobacteria use synchronization to overcome the stress response. Additionally, it has been observed that most of the microbial pathogens including mycobacteria are responsive to drugs predominantly in their logarithmic phase, while they show resistance to antibiotics when they are in the lag or stationary phase. Therefore, we speculate that Mtb might use this novel strategy wherein they regulate their cell cycle upon antibiotic pressure such that they either enter in their low metabolic phase i.e., either the lag or stationary phase to overcome the antibiotic pressure and function as persister cells. Thus, we propose that manipulating the mycobacterial drug resistance could be possible by fine-tuning its cell cycle.

A pro-oxidant property of vitamin C to overcome the burden of latent Mycobacterium tuberculosis infection: A cross-talk review with Fenton reaction

Tuberculosis (TB), caused by the bacillus M. tuberculosis, is one of the deadliest infectious illnesses of our day, along with HIV and malaria.Chemotherapy, the cornerstone of TB control efforts, is jeopardized by the advent of M. tuberculosis strains resistant to many, if not all, of the existing medications.Isoniazid (INH), rifampicin (RIF), pyrazinamide, and ethambutol are used to treat drug-susceptible TB for two months, followed by four months of INH and RIF, but chemotherapy with potentially harmful side effects is sometimes needed to treat multidrug-resistant (MDR) TB for up to two years. Chemotherapy might be greatly shortened by drugs that kill M. tuberculosis more quickly while simultaneously limiting the emergence of drug resistance.Regardless of their intended target, bactericidal medicines commonly kill pathogenic bacteria (gram-negative and gram-positive) by producing hydroxyl radicals via the Fenton reaction.Researchers have concentrated on vitamins with bactericidal properties to address the rising cases globally and have discovered that these vitamins are effective when given along with first-line drugs. The presence of elevated iron content, reactive oxygen species (ROS) generation, and DNA damage all contributed to VC's sterilizing action on M. tb in vitro. Moreover, it has a pleiotropic effect on a variety of biological processes such as detoxification, protein folding - chaperons, cell wall processes, information pathways, regulatory, virulence, metabolism etc.In this review report, the authors extensively discussed the effects of VC on M. tb., such as the generation of free radicals and bactericidal mechanisms with existing treatments, and their further drug development based on ROS production.

Vitamin C and the management of diabetic foot ulcers: a literature review

OBJECTIVE

The lifetime risk of developing a diabetic foot ulcer (DFU) in people with diabetes is as high as 25%. A trio of factors constitute the diabetic foot syndrome that characterises DFUs, including neuropathy, vascular disease and infections. Vitamin C has important functions in the nervous, cardiovascular, and immune systems that are implicated in DFU development. Furthermore, vitamin C deficiency has been observed in individuals with DFUs, suggesting an important function of vitamin C in DFU management and treatment. Therefore, this literature review evaluates the role of vitamin C in the nervous, cardiovascular and immune systems in relation to wound healing and DFUs, as well as discussing vitamin C's lesser known role in depression, a condition that affects many individuals with a DFU.

METHOD

A literature search was done using PubMed, Cochrane Library, Embase, Ovid, Computer Retrieval of Information on Scientific Projects, and NIH Clinical Center. Search terms included 'diabetic foot ulcer,' 'diabetic foot,' 'vitamin C,' and 'ascorbic acid.'

RESULTS

Of the 71 studies initially identified, seven studies met the inclusion criteria, and only three were human clinical trials. Overall, the literature on this subject is limited, with mainly observational and animal studies, and few human clinical trials.

CONCLUSION

There is a need for additional human clinical trials on vitamin C supplementation in individuals with a DFU to fill the knowledge gap and guide clinical practice.

Evidence of positive regulation of mycobacteriophage D29 early gene expression obtained from an investigation using a temperature-sensitive mutant of the phage

Mycobacteriophages are phages that infect and kill Mycobacteria, several of which, Mycobacterium tuberculosis (Mtb), for example, cause the disease tuberculosis. Although genomes of many such phages have been sequenced, we have very little insight into how they express their genes in a controlled manner. To address this issue, we have raised a temperature-sensitive (ts) mutant of phage D29 that can grow at 37°C but not at 42°C and used it to perform differential gene expression and proteome analysis studies. Our analysis results indicate that expression of genes located in the right arm, considered to be early expressed, was lowered as the temperature was shifted from 37°C to 42°C. In contrast, expression of those on the left, the late genes were only marginally affected. Thus, we conclude that transcription of genes from the two arms takes place independently of each other and that a specific factor must be controlling the expression of the right arm genes. We also observe that within the right arm itself; there exists a mechanism to ensure high-level synthesis of Gp48, a thymidylate synthase X. Enhanced presence of this protein in infected cells results in delayed lysis and higher phage yields.

Dietary Modulation of Bacteriophages as an Additional Player in Inflammation and Cancer

Natural compounds such as essential oils and tea have been used successfully in naturopathy and folk medicine for hundreds of years. Current research is unveiling the molecular role of their antibacterial, anti-inflammatory, and anticancer properties. Nevertheless, the effect of these compounds on bacteriophages is still poorly understood. The application of bacteriophages against bacteria has gained a particular interest in recent years due to, e.g., the constant rise of antimicrobial resistance to antibiotics, or an increasing awareness of different types of microbiota and their potential contribution to gastrointestinal diseases, including inflammatory and malignant conditions. Thus, a better knowledge of how dietary products can affect bacteriophages and, in turn, the whole gut microbiome can help maintain healthy homeostasis, reducing the risk of developing diseases such as diverse types of gastroenteritis, inflammatory bowel disease, or even cancer. The present review summarizes the effect of dietary compounds on the physiology of bacteriophages. In a majority of works, the substance class of polyphenols showed a particular activity against bacteriophages, and the primary mechanism of action involved structural damage of the capsid, inhibiting bacteriophage activity and infectivity. Some further dietary compounds such as caffeine, salt or oregano have been shown to induce or suppress prophages, whereas others, such as the natural sweeter stevia, promoted species-specific phage responses. A better understanding of how dietary compounds could selectively, and specifically, modulate the activity of individual phages opens the possibility to reorganize the microbial network as an additional strategy to support in the combat, or in prevention, of gastrointestinal diseases, including inflammation and cancer.