scholarly journals Don’t Shut the Stable Door after the Phage Has Bolted—The Importance of Bacteriophage Inactivation in Food Environments

Viruses ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 468 ◽  
Author(s):  
Julia Sommer ◽  
Christoph Trautner ◽  
Anna Kristina Witte ◽  
Susanne Fister ◽  
Dagmar Schoder ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Current Knowledge ◽  
Resistant Bacteria ◽  
Negative Consequences ◽  
Production Environment ◽  
Widespread Application ◽  
Foodborne Pathogenic Bacteria ◽  
Application Fields ◽  
Phage Inactivation

In recent years, a new potential measure against foodborne pathogenic bacteria was rediscovered—bacteriophages. However, despite all their advantages, in connection to their widespread application in the food industry, negative consequences such as an uncontrolled phage spread as well as a development of phage resistant bacteria can occur. These problems are mostly a result of long-term persistence of phages in the food production environment. As this topic has been neglected so far, this article reviews the current knowledge regarding the effectiveness of disinfectant strategies for phage inactivation and removal. For this purpose, the main commercial phage products, as well as their application fields are first discussed in terms of applicable inactivation strategies and legal regulations. Secondly, an overview of the effectiveness of disinfectants for bacteriophage inactivation in general and commercial phages in particular is given. Finally, this review outlines a possible strategy for users of commercial phage products in order to improve the effectiveness of phage inactivation and removal after application.

scholarly journals How to Train Your Phage: The Recent Efforts in Phage Training

Biologics ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 70-88
Author(s):  
Abdallah Abdelsattar ◽  
Alyaa Dawooud ◽  
Nouran Rezk ◽  
Salsabil Makky ◽  
Anan Safwat ◽  
...  
Keyword(s):  
Host Range ◽  
Pathogenic Bacteria ◽  
Bacterial Resistance ◽  
Phage Therapy ◽  
Current Knowledge ◽  
Lytic Replication ◽  
Resistant Bacteria ◽  
Infection Cycles ◽  
Different Strains ◽  
Specific Species

Control of pathogenic bacteria by deliberate application of predatory phages has potential as a powerful therapy against antibiotic-resistant bacteria. The key advantages of phage biocontrol over antibacterial chemotherapy are: (1) an ability to self-propagate inside host bacteria, (2) targeted predation of specific species or strains of bacteria, (3) adaptive molecular machinery to overcome resistance in target bacteria. However, realizing the potential of phage biocontrol is dependent on harnessing or adapting these responses, as many phage species switch between lytic infection cycles (resulting in lysis) and lysogenic infection cycles (resulting in genomic integration) that increase the likelihood of survival of the phage in response to external stress or host depletion. Similarly, host range will need to be optimized to make phage therapy medically viable whilst avoiding the potential for deleteriously disturbing the commensal microbiota. Phage training is a new approach to produce efficient phages by capitalizing on the evolved response of wild-type phages to bacterial resistance. Here we will review recent studies reporting successful trials of training different strains of phages to switch into lytic replication mode, overcome bacterial resistance, and increase their host range. This review will also highlight the current knowledge of phage training and future implications in phage applications and phage therapy and summarize the recent pipeline of the magistral preparation to produce a customized phage for clinical trials and medical applications.

scholarly journals Potential Solutions Using Bacteriophages against Antimicrobial Resistant Bacteria

Antibiotics ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1496
Author(s):  
Aryan-Rahimi Midani ◽  
Seon-Woo Lee ◽  
Tae-Jin Choi
Keyword(s):  
Pathogenic Bacteria ◽  
Control Agent ◽  
Future Application ◽  
Resistant Bacteria ◽  
Natural Environments ◽  
The Novel ◽  
Antibiotic Resistant ◽  
Sequencing Technologies ◽  
Crucial Information

Bacteriophages are viruses that specifically infect a bacterial host. They play a great role in the modern biotechnology and antibiotic-resistant microbe era. Since the discovery of phages, their application as a control agent has faced challenges that made antibiotics a better fit for combating pathogenic bacteria. Recently, with the novel sequencing technologies providing new insight into the nature of bacteriophages, their application has a second chance to be used. However, novel challenges need to be addressed to provide proper strategies for their practical application. This review focuses on addressing these challenges by initially introducing the nature of bacteriophages and describing the phage-host-dependent strategies for phage application. We also describe the effect of the long-term application of phages in natural environments and other bacterial communities. Overall, this review gathered crucial information for the future application of phages. We predict the use of phages will not be the only control strategy against pathogenic bacteria. Therefore, more studies must be done for low-risk control methods against antimicrobial-resistant bacteria.

scholarly journals Evolution of biofilm-forming pathogenic bacteria in the presence of nanoparticles and antibiotic: adaptation phenomena and cross-resistance

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Riti Mann ◽  
Amy Holmes ◽  
Oliver McNeilly ◽  
Rosalia Cavaliere ◽  
Georgios A. Sotiriou ◽  
...  
Keyword(s):  
Bacterial Growth ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Normal Growth ◽  
Dominant Mode ◽  
Cross Resistance ◽  
Resistant Bacteria ◽  
Bacterial Biofilms ◽  
Biofilm Growth

Abstract Background Treatment of bacterial biofilms are difficult and in many cases, expensive. Bacterial biofilms are naturally more resilient to antimicrobial agents than their free-living planktonic counterparts, rendering the community growth harder to control. The present work described the risks of long-term use of an important alternative antimicrobial, silver nanoparticles (NAg), for the first time, on the dominant mode of bacterial growth. Results NAg could inhibit the formation as well as eradicating an already grown biofilm of Pseudomonas aeruginosa, a pathogen notorious for its resilience to antibiotics. The biofilm-forming bacterium however, evolved a reduced sensitivity to the nanoparticle. Evidence suggests that survival is linked to the development of persister cells within the population. A similar adaptation was also seen upon prolonged exposures to ionic silver (Ag+). The persister population resumed normal growth after subsequent passage in the absence of silver, highlighting the potential risks of recurrent infections with long-term NAg (and Ag+) treatments of biofilm growth. The present study further observed a potential silver/antibiotic cross-resistance, whereby NAg (as well as Ag+) could not eradicate an already growing gentamicin-resistant P. aeruginosa biofilm. The phenomena is thought to result from the hindered biofilm penetration of the silver species. In contrast, both silver formulations inhibited biofilm formation of the resistant strain, presenting a promising avenue for the control of biofilm-forming antibiotic-resistant bacteria. Conclusion The findings signify the importance to study the nanoparticle adaptation phenomena in the biofilm mode of bacterial growth, which are apparently unique to those already reported with the planktonic growth counterparts. This work sets the foundation for future studies in other globally significant bacterial pathogens when present as biofilms. Scientifically based strategies for management of pathogenic growth is necessary, particularly in this era of increasing antibiotic resistance. Graphic abstract

scholarly journals Persistent Infection and Long-Term Carriage of Typhoidal and Nontyphoidal Salmonellae

2018 ◽  
Vol 32 (1) ◽  
Author(s):  
Ohad Gal-Mor
Keyword(s):  
Persistent Infection ◽  
Salmonella Enterica ◽  
Host Response ◽  
Pathogenic Bacteria ◽  
Current Knowledge ◽  
Laboratory Diagnosis ◽  
Human Pathogens ◽  
Content Type ◽  
Persistent Infections

SUMMARYThe ability of pathogenic bacteria to affect higher organisms and cause disease is one of the most dramatic properties of microorganisms. Some pathogens can establish transient colonization only, but others are capable of infecting their host for many years or even for a lifetime. Long-term infection is called persistence, and this phenotype is fundamental for the biology of important human pathogens, includingHelicobacter pylori,Mycobacterium tuberculosis, andSalmonella enterica. Both typhoidal and nontyphoidal serovars of the speciesSalmonella entericacan cause persistent infection in humans; however, as these twoSalmonellagroups cause clinically distinct diseases, the characteristics of their persistent infections in humans differ significantly. Here, following a general summary ofSalmonellapathogenicity, host specificity, epidemiology, and laboratory diagnosis, I review the current knowledge aboutSalmonellapersistence and discuss the relevant epidemiology of persistence (including carrier rate, duration of shedding, and host and pathogen risk factors), the host response toSalmonellapersistence,Salmonellagenes involved in this lifestyle, as well as genetic and phenotypic changes acquired during prolonged infection within the host. Additionally, I highlight differences between the persistence of typhoidal and nontyphoidalSalmonellastrains in humans and summarize the current gaps and limitations in our understanding, diagnosis, and curing of persistentSalmonellainfections.

Distribution of Enteric Viruses and Microorganisms in Long-Term Sewage-Treated Soil

1983 ◽  
Vol 15 (5) ◽  
pp. 129-135 ◽  
Author(s):  
Z Filip ◽  
K Seidel ◽  
H Dizer
Keyword(s):  
Soil Bacteria ◽  
Pathogenic Bacteria ◽  
Sewage Treatment ◽  
Anaerobic Bacteria ◽  
Enteric Viruses ◽  
Sewage Irrigation ◽  
Groundwater Samples ◽  
West Berlin ◽  
Aerobic Soil

To determine whether long-term sewage treatment can take place without a pollution risk for soil and groundwater, samples from sewage irrigation fields in West Berlin which have been in use since about 1890 were analyzed for enteric viruses and microorganisms. Enteric viruses were detected in only seven samples from a total number of eighty seven taken from different soil depths. With only one exception, no viruses were found below 60 cm. No viruses were detected in groundwater samples. Long-term sewage irrigation did not result in significant changes in the colony courts of aerobic soil bacteria, but the counts of anaerobic bacteria and actinomycetes were slightly elevated and those of microscopic fungi slightly decreased. Potentially pathogenic bacteria were not detected in soil below 90 cm.

scholarly journals Impact of mobile stroke units

2021 ◽  
pp. jnnp-2020-324005
Author(s):  
Klaus Fassbender ◽  
Fatma Merzou ◽  
Martin Lesmeister ◽  
Silke Walter ◽  
Iris Quasar Grunwald ◽  
...  
Keyword(s):  
Cost Efficiency ◽  
Current Knowledge ◽  
Vascular Imaging ◽  
Vessel Occlusion ◽  
Stroke Units ◽  
Stroke Treatment ◽  
Stroke Research ◽  
Mobile Stroke Unit ◽  
Novel Strategy

Since its first introduction in clinical practice in 2008, the concept of mobile stroke unit enabling prehospital stroke treatment has rapidly expanded worldwide. This review summarises current knowledge in this young field of stroke research, discussing topics such as benefits in reduction of delay before treatment, vascular imaging-based triage of patients with large-vessel occlusion in the field, differential blood pressure management or prehospital antagonisation of anticoagulants. However, before mobile stroke units can become routine, several questions remain to be answered. Current research, therefore, focuses on safety, long-term medical benefit, best setting and cost-efficiency as crucial determinants for the sustainability of this novel strategy of acute stroke management.

scholarly journals Assessing the Molecular Targets and Mode of Action of Furanone C-30 on Pseudomonas aeruginosa Quorum Sensing

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1620
Author(s):  
Victor Markus ◽  
Karina Golberg ◽  
Kerem Teralı ◽  
Nazmi Ozer ◽  
Esti Kramarsky-Winter ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibiotic Resistance ◽  
Quorum Sensing ◽  
Conformational Changes ◽  
Mode Of Action ◽  
Pathogenic Bacteria ◽  
Molecular Targets ◽  
Resistant Bacteria ◽  
Public Healthcare ◽  
C 30

Quorum sensing (QS), a sophisticated system of bacterial communication that depends on population density, is employed by many pathogenic bacteria to regulate virulence. In view of the current reality of antibiotic resistance, it is expected that interfering with QS can address bacterial pathogenicity without stimulating the incidence of resistance. Thus, harnessing QS inhibitors has been considered a promising approach to overriding bacterial infections and combating antibiotic resistance that has become a major threat to public healthcare around the globe. Pseudomonas aeruginosa is one of the most frequent multidrug-resistant bacteria that utilize QS to control virulence. Many natural compounds, including furanones, have demonstrated strong inhibitory effects on several pathogens via blocking or attenuating QS. While the natural furanones show no activity against P. aeruginosa, furanone C-30, a brominated derivative of natural furanone compounds, has been reported to be a potent inhibitor of the QS system of the notorious opportunistic pathogen. In the present study, we assess the molecular targets and mode of action of furanone C-30 on P. aeruginosa QS system. Our results suggest that furanone C-30 binds to LasR at the ligand-binding site but fails to establish interactions with the residues crucial for the protein’s productive conformational changes and folding, thus rendering the protein dysfunctional. We also show that furanone C-30 inhibits RhlR, independent of LasR, suggesting a complex mechanism for the agent beyond what is known to date.

scholarly journals Cardiac Cell Therapy: Insights into the Mechanisms of Tissue Repair

2021 ◽  
Vol 22 (3) ◽  
pp. 1201
Author(s):  
Hsuan Peng ◽  
Kazuhiro Shindo ◽  
Renée R. Donahue ◽  
Ahmed Abdel-Latif
Keyword(s):  
Stem Cell ◽  
Immune Responses ◽  
Tissue Repair ◽  
Molecular Mechanisms ◽  
Clinical Evidence ◽  
Current Knowledge ◽  
Cell Delivery ◽  
Cardiac Cell Therapy ◽  
Stem Cell Treatment

Stem cell-based cardiac therapies have been extensively studied in recent years. However, the efficacy of cell delivery, engraftment, and differentiation post-transplant remain continuous challenges and represent opportunities to further refine our current strategies. Despite limited long-term cardiac retention, stem cell treatment leads to sustained cardiac benefit following myocardial infarction (MI). This review summarizes the current knowledge on stem cell based cardiac immunomodulation by highlighting the cellular and molecular mechanisms of different immune responses to mesenchymal stem cells (MSCs) and their secretory factors. This review also addresses the clinical evidence in the field.

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