scholarly journals Phage Cocktail Development against Aeromonas salmonicida subsp. salmonicida Strains Is Compromised by a Prophage

Viruses ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2241
Author(s):  
Nava Hosseini ◽  
Valérie E. Paquet ◽  
Mahdi Chehreghani ◽  
Sylvain Moineau ◽  
Steve J. Charette
Keyword(s):  
Antibiotic Resistance ◽  
Food Production ◽  
Pathogenic Bacteria ◽  
Phage Therapy ◽  
Aeromonas Salmonicida ◽  
Multiplicity Of Infection ◽  
Production Sector ◽  
Phage Cocktail ◽  
Effective Use ◽  
The Impact

Aquaculture is a rapidly growing food production sector. Fish farmers are experiencing increasing problems with antibiotic resistance when fighting against pathogenic bacteria such as Aeromonas salmonicida subsp. salmonicida, the causative agent of furunculosis. Phage therapy may provide an alternative, but effective use must be determined. Here, we studied the inhibition of A. salmonicida subsp. salmonicida strains by five phages (HER98 [44RR2.8t.2], HER110 [65.2], SW69-9, L9-6 and Riv-10) used individually or as combinations of two to five phages. A particular combination of four phages (HER98 [44RR2.8t.2], SW69-9, Riv-10, and HER110 [65.2]) was found to be the most effective when used at an initial multiplicity of infection (MOI) of 1 against the A. salmonicida subsp. salmonicida strain 01-B526. The same phage cocktail is effective against other strains except those bearing a prophage (named Prophage 3), which is present in 2/3 of the strains from the province of Quebec. To confirm the impact of this prophage, we tested the effectiveness of the same cocktail on strains that were either cured or lysogenized with Prophage 3. While the parental strains were sensitive to the phage cocktail, the lysogenized ones were much less sensitive. These data indicate that the prophage content of A. salmonicida subsp. salmonicida can affect the efficacy of a cocktail of virulent phages for phage therapy purposes.

scholarly journals Exploring Mucin as Adjunct to Phage Therapy

2021 ◽  
Vol 9 (3) ◽  
pp. 509
Author(s):  
Amanda Carroll-Portillo ◽  
Henry C. Lin
Keyword(s):  
Pathogenic Bacteria ◽  
Structural Changes ◽  
Phage Therapy ◽  
Bacterial Species ◽  
Gi Tract ◽  
Beneficial Bacteria ◽  
Phage Cocktail ◽  
Small Intestinal ◽  
Gastrointestinal Dysbiosis

Conventional phage therapy using bacteriophages (phages) for specific targeting of pathogenic bacteria is not always useful as a therapeutic for gastrointestinal (GI) dysfunction. Complex dysbiotic GI disorders such as small intestinal bowel overgrowth (SIBO), ulcerative colitis (UC), or Crohn’s disease (CD) are even more difficult to treat as these conditions have shifts in multiple populations of bacteria within the microbiome. Such community-level structural changes in the gut microbiota may require an alternative to conventional phage therapy such as fecal virome transfer or a phage cocktail capable of targeting multiple bacterial species. Additionally, manipulation of the GI microenvironment may enhance beneficial bacteria–phage interactions during treatment. Mucin, produced along the entire length of the GI tract to protect the underlying mucosa, is a prominent contributor to the GI microenvironment and may facilitate bacteria–phage interactions in multiple ways, potentially serving as an adjunct during phage therapy. In this review, we will describe what is known about the role of mucin within the GI tract and how its facilitation of bacteria–phage interactions should be considered in any effort directed at optimizing effectiveness of a phage therapy for gastrointestinal dysbiosis.

scholarly journals Phages from Genus Bruynoghevirus and Phage Therapy: Pseudomonas Phage Delta Case

Viruses ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1965
Author(s):  
Petar Knezevic ◽  
Aleksandra Petrovic Fabijan ◽  
Damir Gavric ◽  
Jovana Pejic ◽  
Zsolt Doffkay ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibiotic Resistance ◽  
Phage Therapy ◽  
In Silico Analysis ◽  
Bacterial Toxin ◽  
Broad Host Range ◽  
Multiplicity Of Infection ◽  
Promising Candidate ◽  
A Genome ◽  
Silico Analysis

The applicability and safety of bacteriophage Delta as a potential anti-Pseudomonas aeruginosa agent belonging to genus Bruynoghevirus (family Podoviridae) was characterised. Phage Delta belongs to the species Pseudomonas virus PaP3, which has been described as a temperate, with cos sites at the end of the genome. The phage Delta possesses a genome of 45,970 bp that encodes tRNA for proline (Pro), aspartic acid (Asp) and asparagine (Asn) and does not encode any known protein involved in lysogeny formation or persistence. Analysis showed that phage Delta has 182 bp direct terminal repeats at the end of genome and lysogeny was confirmed, neither upon infection at low nor at high multiplicity of infection (MOI). The turbid plaques that appear on certain host lawns can result from bacteriophage insensitive mutants that occur with higher frequency (10−4). In silico analysis showed that the genome of Delta phage does not encode any known bacterial toxin or virulence factor, determinants of antibiotic resistance and known human allergens. Based on the broad host range and high lytic activity against planktonic and biofilm cells, phage Delta represents a promising candidate for phage therapy.

scholarly journals Antibiotics resistance in pathogenic bacteria isolated from water and sediment around the floating fish farms in the Nha Trang bay

2021 ◽  
Vol 20 (4A) ◽  
pp. 199-209
Author(s):  
Nguyen Kim Hanh ◽  
Nguyen Trinh Duc Hieu ◽  
Nguyen Minh Hieu ◽  
Vo Hai Thi ◽  
Pham Thi Mien ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Pathogenic Bacteria ◽  
Water Environment ◽  
Resistant Bacteria ◽  
Antibiotics Resistance ◽  
Antibiotic Resistant Bacteria ◽  
Antibiotic Resistant ◽  
Water And Sediment ◽  
Nha Trang Bay ◽  
The Impact

To assess the impact of antibiotic use in aquaculture in Nha Trang bay, we conducted this study with the aim of assessing antibiotic resistance of opportunistic pathogenic bacteria isolated from water and sediment around shrimp/fish cages in the Nha Trang bay. 109 strains of Vibrio, Salmonella-Shigella and Aeromonas groups were isolated in the surrounding environment of farming areas in Dam Bay and Hon Mieu. Antimicrobial resistance test of these 109 strains showed that in the water environment in Dam Bay, TET (96.6%) and NIT (92.5%) were the two antibiotics with the highest rates of resistant bacteria while no bacteria were resistant to RIF. All 5 types of antibiotics had a statistically insignificant percentage of antibiotic-resistant bacteria in water samples at Hon Mieu, ranging from 33.3% to 68.9%. Also in the water environment, the rate of antibiotic-resistant bacteria in Dam Bay was not influenced by the distance to the cages (42.5–66.6%). Meanwhile, in Hon Mieu, the highest rate of resistant bacteria was observed at the distance of 200 m (100%) away from cages and the lowest rate at the distance of 100 m (20%). In the sediment environment around the cages, both the Dam Bay and Hon Mieu farming areas showed the highest rates of antibiotic-resistant bacteria against TET, NIF and RIF had the lowest rate of resistant bacteria. Among the total of 109 strains tested for antibiotic resistance, 2 strains labeled TCBS_HM200 m and SS_HM200 m were found to be resistant to all 5 tested antibiotics. These two strains were respectively identified as Vibrio harveyi and Oceanimonas sp.

scholarly journals Directed Evolution of a Mycobacteriophage

Antibiotics ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 46 ◽  
Author(s):  
Cebriá-Mendoza ◽  
Sanjuán ◽  
Domingo-Calap
Keyword(s):  
Public Health ◽  
Antibiotic Resistance ◽  
Directed Evolution ◽  
Mycobacterium Smegmatis ◽  
Pathogenic Bacteria ◽  
Phage Therapy ◽  
Public Health Problem ◽  
Major Public Health Problem ◽  
Pathogenic Species ◽  
Set Up

Bacteriophages represent an alternative strategy to combat pathogenic bacteria. Currently, Mycobacterium tuberculosis infections constitute a major public health problem due to extensive antibiotic resistance in some strains. Using a non-pathogenic species of the same genus as an experimental model, Mycobacterium smegmatis, here we have set up a basic methodology for mycobacteriophage growth and we have explored directed evolution as a tool for increasing phage infectivity and lytic activity. We demonstrate mycobacteriophage adaptation to its host under different conditions. Directed evolution could be used for the development of future phage therapy applications against mycobacteria.

The relationship between the phageome and human health: are bacteriophages beneficial or harmful microbes?

2021 ◽  
pp. 1-14
Author(s):  
L. Fernández ◽  
A.C. Duarte ◽  
A. Rodríguez ◽  
P. García
Keyword(s):  
Antibiotic Resistance ◽  
Human Health ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Phage Therapy ◽  
Negative Impact ◽  
Antibiotic Resistance Genes ◽  
Resistant Bacteria ◽  
Potential Risks

In the context of the global antibiotic resistance crisis, bacteriophages are increasingly becoming promising antimicrobial agents against multi-resistant bacteria. Indeed, a huge effort is being made to bring phage-derived products to the market, a process that will also require revising the current regulations in order to facilitate their approval. However, despite the evidence supporting the safety of phages for humans, the general public would still be reluctant to use ‘viruses’ for therapeutic purposes. In this scenario, we consider that it is important to discuss the role of these microorganisms in the equilibrium of the microbiota and how this relates to human health. To do that, this review starts by examining the role of phages as key players in bacterial communities (including those that naturally inhabit the human body), modulating the species composition and contributing to maintain a ‘healthy’ status quo. Additionally, in specific situations, e.g. an infectious disease, bacteriophages can be used as target-specific antimicrobials against pathogenic bacteria (phage therapy), while being harmless to the desirable microbiota. Apart from that, incipient research shows the potential application of these viruses to treat diseases caused by bacterial dysbiosis. This latter application would be comparable to the use of probiotics or prebiotics, since bacteriophages can indirectly improve the growth of beneficial bacteria in the gastrointestinal tract by removing undesirable competitors. On the other hand, possible adverse effects do not appear to be an impediment to promote phage therapy. Nonetheless, it is important to remember their potentially negative impact, mainly concerning their immunogenicity or their potential spread of virulence and antibiotic resistance genes, especially by temperate phages. Overall, we believe that phages should be largely considered beneficial microbes, although it is paramount not to overlook their potential risks.

scholarly journals The meiofauna as neglected carriers of antibiotic resistant and pathogenic bacteria in freshwater ecosystems

2021 ◽  
Vol 80 (3) ◽  
Author(s):  
Maria Belen Sathicq ◽  
Tomasa Sbaffi ◽  
Giulia Borgomaneiro ◽  
Andrea Di Cesare ◽  
Raffaella Sabatino
Keyword(s):  
Antibiotic Resistance ◽  
Pathogenic Bacteria ◽  
Anthropogenic Activities ◽  
Animal Health ◽  
Freshwater Ecosystems ◽  
World Health ◽  
Resistant Bacteria ◽  
Antibiotic Resistant ◽  
Health Organization ◽  
The Impact

The World Health Organization considers antibiotic resistance as one of the main threats to human and other animals' health. Despite the measures used to limit the spread of antibiotic resistance, the efforts made are not enough to tackle this problem. Thus, it has become important to understand how bacteria acquire and transmit antibiotic resistant genes (ARGs), in particular in the environment, given the close connection between the latter and human and animal health, as defined by the One-Health concept. Aquatic ecosystems are often strongly impacted by anthropogenic activities, making them a source for ARGs and antibiotic resistant bacteria (ARB). Although freshwater meiofauna have been the object of active research, few studies have focused on the relationship between the spread of antibiotic resistance and these organisms. In this review, we investigated freshwater meiofauna as carriers of resistances since they play a central role in the aquatic environments and can harbor human and animal potential pathogens. We assessed if these animals could contribute to the spread of ARGs and of potentially pathogenic bacteria. Only four taxa (Rotifera, Chironomidae, Cladocera, Copepoda) were found to be the subject of studies focused on antibiotic resistance. The studies we analyzed, although with some limitations, demonstrated that ARGs and ARB can be found in these animals, and several of them showed the presence of potentially pathogenic bacteria for humans and animals within their microbiome. Thus, meiofauna can be considered a source and a reservoir, even if neglected, of ARGs and ARB for the freshwater environments. However, further studies are needed to evaluate the impact of the meiofauna on the spread and persistence of antibiotic resistance in these ecosystems.

Antibiotic Resistance: A Global, Interdisciplinary Concern

2011 ◽  
Vol 73 (6) ◽  
pp. 314-321 ◽  
Author(s):  
Richard A. Stein
Keyword(s):  
Antibiotic Resistance ◽  
Antimicrobial Resistance ◽  
Environmental Science ◽  
Clinical Medicine ◽  
Antibiotic Use ◽  
Global Perspective ◽  
Interdisciplinary Framework ◽  
Resistant Strains ◽  
Effective Use ◽  
The Impact

This article presents a brief overview of the impact that antibiotic use in clinical medicine and in other settings, such as agriculture and animal farming, exerts on antimicrobial resistance. Resistance has been described to all antibiotics that are currently in use, and resistant strains were sometimes reported as soon as months after specific antibiotics became commercially available. There are many examples in which the increasing prevalence of resistant microbial strains jeopardized the continuing effective use of the respective antibiotics in clinical medicine. In addition to resistant infections that occur in health-care establishments, one of the recent challenges is the emergence of pathogens, such as MRSA, in the community, among individuals without any apparent risk factors for the infection. The transmission of resistant pathogens and antimicrobial resistance determinants across different components of the ecosystem transforms antibiotic resistance into a topic that extends beyond the scope of clinical medicine and needs to be visualized through an integrated global perspective that should incorporate a broad range of disciplines, including molecular genetics, microbiology, food science, ecology, agriculture, and environmental science. Understanding this complex multi- and interdisciplinary framework will enable the implementation of the most appropriate interventions toward determining the dynamics of antimicrobial resistance, limiting the emergence and spread of resistant strains, and ensuring the ongoing effective and safe use of antibiotics.

scholarly journals Mobile resistome of human gut and pathogen drives anthropogenic bloom of antibiotic resistance

Microbiome ◽  
2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Kihyun Lee ◽  
Dae-Wi Kim ◽  
Do-Hoon Lee ◽  
Yong-Seok Kim ◽  
Ji-Hye Bu ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Microbial Communities ◽  
Human Activities ◽  
Pathogenic Bacteria ◽  
Anthropogenic Activities ◽  
Antibiotic Resistance Genes ◽  
Anthropogenic Influences ◽  
Human Gut ◽  
The Impact ◽  
Spatial Continuum

Abstract Background The impact of human activities on the environmental resistome has been documented in many studies, but there remains the controversial question of whether the increased antibiotic resistance observed in anthropogenically impacted environments is just a result of contamination by resistant fecal microbes or is mediated by indigenous environmental organisms. Here, to determine exactly how anthropogenic influences shape the environmental resistome, we resolved the microbiome, resistome, and mobilome of the planktonic microbial communities along a single river, the Han, which spans a gradient of human activities. Results The bloom of antibiotic resistance genes (ARGs) was evident in the downstream regions and distinct successional dynamics of the river resistome occurred across the spatial continuum. We identified a number of widespread ARG sequences shared between the river, human gut, and pathogenic bacteria. These human-related ARGs were largely associated with mobile genetic elements rather than particular gut taxa and mainly responsible for anthropogenically driven bloom of the downstream river resistome. Furthermore, both sequence- and phenotype-based analyses revealed environmental relatives of clinically important proteobacteria as major carriers of these ARGs. Conclusions Our results demonstrate a more nuanced view of the impact of anthropogenic activities on the river resistome: fecal contamination is present and allows the transmission of ARGs to the environmental resistome, but these mobile genes rather than resistant fecal bacteria proliferate in environmental relatives of their original hosts.

The Impact of Visual Feedback Type on the Mastery of Visuo-Motor Transformations

2012 ◽  
Vol 220 (1) ◽  
pp. 3-9 ◽  
Author(s):  
Sandra Sülzenbrück
Keyword(s):  
Empirical Research ◽  
Visual Feedback ◽  
Closed Loop ◽  
Motor Planning ◽  
Visual Input ◽  
Closed Loop Control ◽  
Loop Control ◽  
Feedback Type ◽  
Effective Use ◽  
The Impact

For the effective use of modern tools, the inherent visuo-motor transformation needs to be mastered. The successful adjustment to and learning of these transformations crucially depends on practice conditions, particularly on the type of visual feedback during practice. Here, a review about empirical research exploring the influence of continuous and terminal visual feedback during practice on the mastery of visuo-motor transformations is provided. Two studies investigating the impact of the type of visual feedback on either direction-dependent visuo-motor gains or the complex visuo-motor transformation of a virtual two-sided lever are presented in more detail. The findings of these studies indicate that the continuous availability of visual feedback supports performance when closed-loop control is possible, but impairs performance when visual input is no longer available. Different approaches to explain these performance differences due to the type of visual feedback during practice are considered. For example, these differences could reflect a process of re-optimization of motor planning in a novel environment or represent effects of the specificity of practice. Furthermore, differences in the allocation of attention during movements with terminal and continuous visual feedback could account for the observed differences.

Sign in / Sign up

Export Citation Format

Share Document