Lipid-Based Nanocarriers for the Treatment of Infected Skin Lesions
Andreia Ascenso, Sandra Simões, Helena Ribeiro in Carrier-Mediated Dermal Delivery, 2017
The phage therapy represents one alternative therapeutic strategy as it involves the targeted application of bacteriophages. Bacteriophages are viruses that attack bacteria being able to replicate within them causing disruption of bacterial cells [47]. As their lytic action is highly specific, this approach can be applied for treatment of bacterial infections that do not respond to available antibiotics. Nevertheless, for the successful application of phages, the knowledge of their host range is a prerequisite. Particularly, a set of virulent phages for M. ulcerans has been reported [48]. Among this set of phages, the therapeutic effect of the mycobacteriophage D29 was evaluated in a M. ulcerans murine footpad model. This phage was subcutaneously administered in the infected footpad and a single injection was able to decrease the bacterial load in footpad in comparison with infected and untreated mice [49].
Indicators of microbial quality *
Jamie Bartram, Rachel Baum, Peter A. Coclanis, David M. Gute, David Kay, Stéphanie McFadyen, Katherine Pond, William Robertson, Michael J. Rouse in Routledge Handbook of Water and Health, 2015
Bacteriophages (or, phages) are viruses that infect bacteria. They are closely associated with their bacterial hosts, and so may be found in the same settings. Unlike their bacterial hosts, there is some evidence that they are often present in greater quantities, are more environmentally persistent, and may be better models of virus fate and transport in the environment than bacterial indicators. Bacteriodes fragilis phages, Salmonella phages, and E. coli phages (coliphages) have all been proposed as indicators of fecal contamination. Of the phages that have been studied, F-pilus-specific (F+) coliphages with RNA genomes (sometimes known as “male-specific” coliphages) have received the most attention (Sobsey et al. 1995). Less is known about F+DNA coliphages and somatic coliphages as fecal and viral indicators, though somatic coliphages may be more common in feces as well as more stable in the environment (Jofre 2003). F+RNA coliphages infect E. coli and potentially other members of the coliform group. They have been used in microbial source tracking applications (Love and Sobsey 2007; Lee et al. 2011), although their associations to health outcomes in humans have not been well characterized.
Composition and Diversity of Human Oral Microbiome
Chaminda Jayampath Seneviratne in Microbial Biofilms, 2017
Using the patterns of homologous sequences, a study attempted to envisage the putative hosts of bacteriophages [74]. It revealed members of Firmicutes (includes Streptococcus, Granulicatella and Veillonella), Bacteroidetes (includes Prevotella), Fusobacteria (includes Leptotrichia), Proteobacteria (includes Neisseria), Actinobacteria, Spirochaetes and members of the TM7 phylum as putative hosts [74,77]. The genetic makeup of the bacteriophages suggests their existence as prophages within their respective hosts. This further corroborates the presence of lysogenic viruses in the oral microbial community [74]. Although in relative minority, metagenomics studies have also identified some eukaryotic viruses which includes torque teno viruses, circoviruses, herpesviruses (HSV) and Epstein–Barr virus (EBV) among a few others in the oral cavity [74,76,89,97].
Local drug delivery in the urinary tract: current challenges and opportunities
Published in Journal of Drug Targeting, 2018
Rahul Mittal, Debbie R. Pan, James M. Parrish, Eric H. Huang, Yao Yang, Amit P. Patel, Arul K. Malhotra, Jeenu Mittal, Sanjay Chhibber, Kusum Harjai
Bacteriophages are viruses that selectively infect bacteria. Though capable of both lytic and lysogenic activity in their hosts, bacteriophages with minimal potential for lysogenic conversion are most suitable for therapeutic use, as lysogenic activity carries the risk of inducing expression of bacterial toxins [55]. The bacteriophage lytic cycle involves docking to specific bacterial surface receptors at their tail ends, injecting genetic material into the host cell, and inducing the expression of genes that help replicate their genome alongside genes that interrupt host systems and induce host cell lysis (Figure 3). Theoretically, if bacteriophages are able to reduce bacterial burden in an infection, host immune defences have a much greater chance of eradicating the remaining organisms [56].
Community-acquired pneumonia: aetiology, antibiotic resistance and prospects of phage therapy
Published in Journal of Chemotherapy, 2020
Md. Moinuddin Sheam, Shifath Bin Syed, Zulkar Nain, Swee- Seong Tang, Dipak Kumar Paul, Kazi Rejvee Ahmed, Sudhangshu Kumar Biswas
Due to the continual ineptness of antibiotic therapy, bacteriophage therapy is now coming back to the light. It is now believed to be more promising in fighting infections caused by antibiotic-resistant bacteria. Bacteriophages are viruses that infect bacteria to make progeny and kill the host bacteria in the process. Phages can be divided into different groups in terms of morphological features, genomic contents and pathogenesis. Phages can be tailed, without tail, polyhedral, filamentous or pleomorphic, and some have the envelopes of lipoprotein or lipid.100,101 On the basis of mode of infection, phages can be divided into three groups: (1) virulent phages that infect and lyse bacterial cell to let out the progeny phages, (2) temperate phages that take part in phage genome replication but no virion production and (3) filamentous phages that can attach to the sex pili of F + gram-negative bacteria and produce phage particles followed by secretion through the cell wall.102 On the basis of genetic material, phages can be single- or double-stranded DNA or RNA. The International Committee on Taxonomy of Viruses (ICTV) has classified bacteriophages into a single order, 13 families and 34 genera.103 Based on an earlier review, about 96% of phages are tailed that belong to three large families Myoviridae (25%), Siphoviridae (61%) and Podoviridae (14%) under the order Caudovirales.104 Importantly, lytic phages are the principal candidates for phage therapy development due to their ability to kill the host.
Bacteriophage for Gastrointestinal Health (PHAGE) Study: Evaluating the Safety and Tolerability of Supplemental Bacteriophage Consumption
Published in Journal of the American College of Nutrition, 2019
Melinda Gindin, Hallie P. Febvre, Sangeeta Rao, Taylor C. Wallace, Tiffany L. Weir
Under the standard definition, prebiotics are indigestible fiber components that are utilized as fermentation substrates by beneficial bacteria residing in the large bowel (10). However, this definition is expanding beyond fiber. For example, a U.S. patent was recently issued for PreforPro (Deerland Enzymes, Kennesaw, GA), a proprietary blend of bacteriophages that target Escherichia coli (12). Bacteriophages are highly specific viruses that can target, infect, and destroy pathogenic bacteria. They are believed to be the most abundant type of viruses, accounting for the majority of the 1031 viruses identified to date. In the 1930s, the use of bacteriophages for the treatment of bacterial diseases (or “phage therapy”) was popularized; however, the concept lost momentum with the introduction and widespread use of broad-spectrum antibiotics (13). The specificity of bacteriophages is now viewed advantageously because phages allow selective modulation of the gut microbiota without initiating gut dysbiosis, which occurs with antibiotic use (13,14). The U.S. Food and Drug Administration lists many bacteriophages as Generally Recognized as Safe (GRAS) for human consumption because they are abundant in nature, reside naturally in the human gastrointestinal tract, and are inadvertently consumed by humans on a daily basis (14). They represent good therapeutic agents as long as they are obligately lytic, stable under typical storage conditions and temperatures, subject to appropriate efficacy and safety studies, and ideally fully sequenced to confirm the absence of undesirable genes such as toxins (15,16).