scholarly journals Phage–Bacteria Interactions in Potential Applications of Bacteriophage vB_EfaS-271 against Enterococcus faecalis

Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 318
Author(s):  
Gracja Topka-Bielecka ◽  
Bożena Nejman-Faleńczyk ◽  
Sylwia Bloch ◽  
Aleksandra Dydecka ◽  
Agnieszka Necel ◽  
...  
Keyword(s):  
Enterococcus Faecalis ◽  
Mammalian Cells ◽  
Bacterial Infections ◽  
Phage Therapy ◽  
Bacterial Species ◽  
Resistant Bacteria ◽  
Bacterial Cells ◽  
Potential Applications ◽  
High Level

Phage therapy is one of main alternative option for antibiotic treatment of bacterial infections, particularly in the era of appearance of pathogenic strains revealing resistance to most or even all known antibiotics. Enterococcus faecalis is one of such pathogens causing serious human infections. In the light of high level of biodiversity of bacteriophages and specificity of phages to bacterial species or even strains, development of effective phage therapy depend, between others, on identification and characterization of a large collection of these viruses, including understanding of their interactions with host bacterial cells. Recently, isolation of molecular characterization of bacteriophage vB_EfaS-271, infecting E. faecalis strains have been reported. In this report, phage–host interactions are reported, including ability of vB_EfaS-271 to infect bacteria forming biofilms, efficiency of eliminating bacterial cells from cultures depending on multiplicity of infection (m.o.i.), toxicity of purified phage particles to mammalian cells, and efficiency of appearance of phage-resistant bacteria. The presented results indicate that vB_EfaS-271 can significantly decrease number of viable E. faecalis cells in biofilms and in liquid cultures and reveals no considerable toxicity to mammalian cells. Efficiency of formation of phage-resistant bacteria was dependent on m.o.i. and was higher when the virion-cell ratio was as high as 10 than at low (between 0.01 and 0.0001) m.o.i. values. We conclude that vB_EfaS-271 may be considered as a candidate for its further use in phage therapy.

scholarly journals Liposomes as Antibiotic Delivery Systems: A Promising Nanotechnological Strategy against Antimicrobial Resistance

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 2047
Author(s):  
Magda Ferreira ◽  
Maria Ogren ◽  
Joana N. R. Dias ◽  
Marta Silva ◽  
Solange Gil ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Bacterial Infections ◽  
Private Investment ◽  
Therapeutic Index ◽  
Multidrug Resistant ◽  
Current Treatment ◽  
Delivery Systems ◽  
Resistant Bacteria ◽  
Bacterial Cells ◽  
Antimicrobial Drugs

Antimicrobial drugs are key tools to prevent and treat bacterial infections. Despite the early success of antibiotics, the current treatment of bacterial infections faces serious challenges due to the emergence and spread of resistant bacteria. Moreover, the decline of research and private investment in new antibiotics further aggravates this antibiotic crisis era. Overcoming the complexity of antimicrobial resistance must go beyond the search of new classes of antibiotics and include the development of alternative solutions. The evolution of nanomedicine has allowed the design of new drug delivery systems with improved therapeutic index for the incorporated compounds. One of the most promising strategies is their association to lipid-based delivery (nano)systems. A drug’s encapsulation in liposomes has been demonstrated to increase its accumulation at the infection site, minimizing drug toxicity and protecting the antibiotic from peripheral degradation. In addition, liposomes may be designed to fuse with bacterial cells, holding the potential to overcome antimicrobial resistance and biofilm formation and constituting a promising solution for the treatment of potential fatal multidrug-resistant bacterial infections, such as methicillin resistant Staphylococcus aureus. In this review, we aim to address the applicability of antibiotic encapsulated liposomes as an effective therapeutic strategy for bacterial infections.

scholarly journals Bacteriophages to Control Multi-Drug Resistant Enterococcus faecalis Infection of Dental Root Canals

2021 ◽  
Vol 9 (3) ◽  
pp. 517
Author(s):  
Mohamed El-Telbany ◽  
Gamal El-Didamony ◽  
Ahmed Askora ◽  
Eman Ariny ◽  
Dalia Abdallah ◽  
...  
Keyword(s):  
Enterococcus Faecalis ◽  
Root Canal ◽  
Phage Therapy ◽  
Ex Vivo ◽  
Burst Size ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Range Analysis ◽  
Root Canals

Phage therapy is an alternative treatment to antibiotics that can overcome multi-drug resistant bacteria. In this study, we aimed to isolate and characterize lytic bacteriophages targeted against Enterococcus faecalis isolated from root canal infections obtained from clinics at the Faculty of Dentistry, Ismalia, Egypt. Bacteriophage, vB_ZEFP, was isolated from concentrated wastewater collected from hospital sewage. Morphological and genomic analysis revealed that the phage belongs to the Podoviridae family with a linear double-stranded DNA genome, consisting of 18,454, with a G + C content of 32.8%. Host range analysis revealed the phage could infect 10 of 13 E. faecalis isolates exhibiting a range of antibiotic resistances recovered from infected root canals with efficiency of plating values above 0.5. One-step growth curves of this phage showed that it has a burst size of 110 PFU per infected cell, with a latent period of 10 min. The lytic activity of this phage against E. faecalis biofilms showed that the phage was able to control the growth of E. faecalis in vitro. Phage vB_ZEFP could also prevent ex-vivo E. faecalis root canal infection. These results suggest that phage vB_ZEFP has potential for application in phage therapy and specifically in the prevention of infection after root canal treatment.

scholarly journals Recent Development of Rapid Antimicrobial Susceptibility Testing Methods through Metabolic Profiling of Bacteria

Antibiotics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 311
Author(s):  
Chen Chen ◽  
Weili Hong
Keyword(s):  
Antimicrobial Susceptibility ◽  
Metabolic Profiling ◽  
Bacterial Infections ◽  
Susceptibility Testing ◽  
Antimicrobial Susceptibility Testing ◽  
Bacterial Metabolism ◽  
Resistant Bacteria ◽  
Bacterial Cells ◽  
Inappropriate Use ◽  
Key Factor

Due to the inappropriate use and overuse of antibiotics, the emergence and spread of antibiotic-resistant bacteria are increasing and have become a major threat to human health. A key factor in the treatment of bacterial infections and slowing down the emergence of antibiotic resistance is to perform antimicrobial susceptibility testing (AST) of infecting bacteria rapidly to prescribe appropriate drugs and reduce the use of broad-spectrum antibiotics. Current phenotypic AST methods based on the detection of bacterial growth are generally reliable but are too slow. There is an urgent need for new methods that can perform AST rapidly. Bacterial metabolism is a fast process, as bacterial cells double about every 20 to 30 min for fast-growing species. Moreover, bacterial metabolism has shown to be related to drug resistance, so a comparison of differences in microbial metabolic processes in the presence or absence of antimicrobials provides an alternative approach to traditional culture for faster AST. In this review, we summarize recent developments in rapid AST methods through metabolic profiling of bacteria under antibiotic treatment.

scholarly journals Bacteriophages: the possible solution to treat infections caused by pathogenic bacteria

2017 ◽  
Vol 63 (11) ◽  
pp. 865-879 ◽  
Author(s):  
Ayman El-Shibiny ◽  
Salma El-Sahhar
Keyword(s):  
Bacterial Infections ◽  
Pathogenic Bacteria ◽  
Phage Therapy ◽  
Multidrug Resistant ◽  
Clinical Applications ◽  
Western World ◽  
Resistant Bacteria ◽  
Vaccine Production ◽  
Bacterial Populations ◽  
Antibiotic Resistant

Since their discovery in 1915, bacteriophages have been used to treat bacterial infections in animals and humans because of their unique ability to infect their specific bacterial hosts without affecting other bacterial populations. The research carried out in this field throughout the 20th century, largely in Georgia, part of USSR and Poland, led to the establishment of phage therapy protocols. However, the discovery of penicillin and sulfonamide antibiotics in the Western World during the 1930s was a setback in the advancement of phage therapy. The misuse of antibiotics has reduced their efficacy in controlling pathogens and has led to an increase in the number of antibiotic-resistant bacteria. As an alternative to antibiotics, bacteriophages have become a topic of interest with the emergence of multidrug-resistant bacteria, which are a threat to public health. Recent studies have indicated that bacteriophages can be used indirectly to detect pathogenic bacteria or directly as biocontrol agents. Moreover, they can be used to develop new molecules for clinical applications, vaccine production, drug design, and in the nanomedicine field via phage display.

scholarly journals Species, Risk Factors, and Antimicrobial Susceptibility Profiles of Bacterial Isolates from HIV-Infected Patients Suspected to Have Pneumonia in Mekelle Zone, Tigray, Northern Ethiopia

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Gebre Adhanom ◽  
Dawit Gebreegziabiher ◽  
Yemane Weldu ◽  
Araya Gebreyesus Wasihun ◽  
Tadele Araya ◽  
...  
Keyword(s):  
Risk Factors ◽  
Antimicrobial Susceptibility ◽  
Bacterial Pneumonia ◽  
Bacterial Infections ◽  
Bacterial Species ◽  
Diffusion Method ◽  
Resistant Bacteria ◽  
P Value ◽  
Northern Ethiopia ◽  
Hiv Patients

Background. Pneumonia is a condition, where bacterial infections are implicated as the most common causes of morbidity and mortality in humans. The actual burden of HIV-infected patients with pneumonia is not well documented in Mekelle region of Ethiopia. This study estimated the prevalence of bacterial pneumonia in HIV patients, antimicrobial susceptibility patterns of pathogens implicated in pneumonia, and associated risk factors in Mekelle zone, Tigray, Northern Ethiopia, during August-December 2016. Methods. Sputum specimens were collected from 252 HIV seropositive individuals with suspected pneumonia. Data on sociodemographics and risk factors were also collected using a structured questionnaire. Blood, Chocolate, and Mac Conkey agar plates (Oxoid, Hampshire, UK) were used to grow the isolates. The isolated colonies were identified based on Gram stain, colony morphology, pigmentation, hemolysis, and biochemical tests. The antimicrobial susceptibility test was performed using the modified Kirby-Bauer disc diffusion method. The analysis was performed using SPSS version 22 and p-value < 0.05 with corresponding 95% confidence interval (CI) was considered statistically significant. Results. Out of the 252 samples, 110 (43.7%) were positive for various bacterial species. The predominant bacterial species were Klebsiella pneumoniae (n=26, 23.6 %) followed by Streptococcus pneumoniae (n=17, 15.5 %), Escherichia coli (n=16, 14.5%), Klebsiella spp. (n=15, 13.6%), Staphylococcus aureus (n=9, 8.2%), Enterobacter spp. (n=7, 6.3%), Pseudomonas aeruginosa (4, n=3.6%), Proteus spp. (n=4, 3.6%), Citrobacter freundii (n=7, 6.3%), Streptococcus pyogenes (3, 2.7%), and Haemophilus influenzae (n=2, 1.8%). Young age (18-29), recent CD4+ count less than 350 cells/mL, alcohol consumption, and HIV WHO stage II showed significant association with the occurrence of bacterial pneumonia. Resistance to penicillin, co-trimoxazole, and tetracycline was observed in 81.8%, 39.8%, and 24.5% of the isolates, respectively. Conclusions. The problem of pneumonia among HIV patients was significant in the study area. The high prevalence of drug-resistant bacteria isolated from the patient’s samples possesses a health risk in immunocompromised HIV patients. There is a need to strengthen and expand culture and susceptibility procedures for the administration of appropriate therapy to improve patients management and care which may aid in decreasing the mortality.

scholarly journals Evolution of Pseudomonas aeruginosa Virulence as a Result of Phage Predation

2013 ◽  
Vol 79 (19) ◽  
pp. 6110-6116 ◽  
Author(s):  
Zeinab Hosseinidoust ◽  
Theo G. M. van de Ven ◽  
Nathalie Tufenkji
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Mammalian Cells ◽  
Bacterial Infections ◽  
Membrane Damage ◽  
Human Keratinocytes ◽  
Host Population ◽  
Resistant Bacteria ◽  
Content Type ◽  
Metabolic Action

ABSTRACTThe rapid increase in the emergence of antibiotic-resistant bacteria has attracted attention to bacteriophages for treating and preventing bacterial infections. Bacteriophages can drive the diversification ofPseudomonas aeruginosa, giving rise to phage-resistant variants with different phenotypes from their ancestral hosts. In this study, we sought to investigate the effect of phage resistance on cytotoxicity of host populations toward cultured mammalian cells. The library of phage-resistantP. aeruginosaPAO1 variants used was developed previously via experimental evolution of an isogenic host population using phages PP7 and E79. Our results presented herein indicate that the phage-resistant variants developed in a heterogeneous phage environment exhibit a greater ability to impede metabolic action of cultured human keratinocytes and have a greater tendency to cause membrane damage even though they cannot invade the cells in large numbers. They also show a heightened resistance to phagocytosis by model murine macrophages. Furthermore, all isolates produced higher levels of at least one of the secreted virulence factors, namely, total proteases, elastase, phospholipase C, and hemolysins. Reverse transcription-quantitative PCR (RT-qPCR) revealed upregulation in the transcription of a number of genes associated with virulence ofP. aeruginosafor the phage-resistant variants. The results of this study indicate a significant change in thein vitrovirulence ofP. aeruginosafollowing phage predation and highlight the need for caution in the selection and design of phages and phage cocktails for therapeutic use.

Efficacy of experimental phage therapies in livestock

2020 ◽  
Vol 21 (1) ◽  
pp. 69-83 ◽  
Author(s):  
Marta Dec ◽  
Andrzej Wernicki ◽  
Renata Urban-Chmiel
Keyword(s):  
Bacterial Infections ◽  
Phage Therapy ◽  
Resistant Bacteria ◽  
Form Of Life ◽  
Drug Resistant Bacteria ◽  
Experimental Therapies ◽  
History Of ◽  
Experimental Treatments ◽  
Human Infections ◽  
Life On Earth

AbstractBacteriophages are the most abundant form of life on earth and are present everywhere. The total number of bacteriophages has been estimated to be 1032 virions. The main division of bacteriophages is based on the type of nucleic acid (DNA or RNA) and on the structure of the capsid. Due to the significant increase in the number of multi-drug-resistant bacteria, bacteriophages could be a useful tool as an alternative to antibiotics in experimental therapies to prevent and to control bacterial infections in people and animals. The aim of this review was to discuss the history of phage therapy as a replacement for antibiotics, in response to EU regulations prohibiting the use of antibiotics in livestock, and to present current examples and results of experimental phage treatments in comparison to antibiotics. The use of bacteriophages to control human infections has had a high success rate, especially in mixed infections caused mainly by Staphylococcus, Pseudomonas, Enterobacter, and Enterococcus. Bacteriophages have also proven to be an effective tool in experimental treatments for combating diseases in livestock.

scholarly journals Effects of Sequential and Simultaneous Applications of Bacteriophages on Populations of Pseudomonas aeruginosaIn Vitroand in Wax Moth Larvae

2012 ◽  
Vol 78 (16) ◽  
pp. 5646-5652 ◽  
Author(s):  
Alex R. Hall ◽  
Daniel De Vos ◽  
Ville-Petri Friman ◽  
Jean-Paul Pirnay ◽  
Angus Buckling
Keyword(s):  
Bacterial Infections ◽  
Phage Therapy ◽  
Phage Type ◽  
Resistant Bacteria ◽  
Short Term ◽  
Short Term Treatment ◽  
Simultaneous Application ◽  
Content Type ◽  
Wax Moth

ABSTRACTInterest in using bacteriophages to treat bacterial infections (phage therapy) is growing, but there have been few experiments comparing the effects of different treatment strategies on both bacterial densities and resistance evolution. While it is established that multiphage therapy is typically more effective than the application of a single phage type, it is not clear if it is best to apply phages simultaneously or sequentially. We tried single- and multiphage therapy againstPseudomonas aeruginosaPAO1in vitro, using different combinations of phages either simultaneously or sequentially. Across different phage combinations, simultaneous application was consistently equal or superior to sequential application in terms of reducing bacterial population density, and there was no difference (on average) in terms of minimizing resistance. Phage-resistant bacteria emerged in all experimental treatments and incurred significant fitness costs, expressed as reduced growth rate in the absence of phages. Finally, phage therapy increased the life span of wax moth larvae infected withP. aeruginosa, and a phage cocktail was the most effective short-term treatment. When the ratio of phages to bacteria was very high, phage cocktails cured otherwise lethal infections. These results suggest that while adding all available phages simultaneously tends to be the most successful short-term strategy, there are sequential strategies that are equally effective and potentially better over longer time scales.

scholarly journals Phage Therapy -- Everything Old Is New again

2006 ◽  
Vol 17 (5) ◽  
pp. 297-306 ◽  
Author(s):  
Andrew M Kropinski
Keyword(s):  
Bacterial Infections ◽  
Phage Therapy ◽  
Therapeutic Modality ◽  
Resistant Bacteria ◽  
Pathogenic Potential ◽  
Microbial Genetics ◽  
Antibiotic Resistant ◽  
Vector Systems ◽  
Variable Success ◽  
Bacterial Viruses

The study of bacterial viruses (bacteriophages or phages) proved pivotal in the nascence of the disciplines of molecular biology and microbial genetics, providing important information on the central processes of the bacterial cell (DNA replication, transcription and translation) and on how DNA can be transferred from one cell to another. As a result of the pioneering genetics studies and modern genomics, it is now known that phages have contributed to the evolution of the microbial cell and to its pathogenic potential. Because of their ability to transmit genes, phages have been exploited to develop cloning vector systems. They also provide a plethora of enzymes for the modern molecular biologist. Until the introduction of antibiotics, phages were used to treat bacterial infections (with variable success). Western science is now having to re-evaluate the application of phage therapy -- a therapeutic modality that never went out of vogue in Eastern Europe -- because of the emergence of an alarming number of antibiotic-resistant bacteria. The present article introduces the reader to phage biology, and the benefits and pitfalls of phage therapy in humans and animals.

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