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1
TARAKANOV, R. I., A. N. IGNATOV e F. S. DZHALILOV. "ISOLATION OF SPECIFIC BACTERIOPHAGES - PSEUDOMONAS SAVASTANOI PV. GLYCINEA - AND THEIR USE IN SOYBEAN BACTERIAL BLIGHT CONTROL". Izvestiâ Timirâzevskoj selʹskohozâjstvennoj akademii, n. 4 (2020): 43–53. http://dx.doi.org/10.26897/0021-342x-2020-4-43-53.
Testo completoAbstract (sommario):
Bacterial blight is one of most harmful diseases of legumes, reducing the profitability of soybean production in Russian Federation. Among a number of Pseudomonas isolates obtained from diseased seeds and plants of soybean, 4 strains were selected and confirmed as Pseudomonas savastanoipv. glycinea (Psg). Properties of the isolated bacteria were similar to type strain of Psg CFBP 2214 in plant virulence, LOPAT tests, and PCR analysis for coronafacate ligase gene, and partly – in the phage reaction profile. Four isolates of bacteriophages specific to Psg were obtained from soil samples taken from fields with soybean crops. Virulence testing for the bacteriophages showed that bacteriophage ϕG17 infected 4 of 5 tested Psg strains, and it was chosen for further experiments with bacterial blight control. The bacteriophague effect control conducted on soybent plants inoculated by Psg experiments confirmed that 2 treatments of plants by the bacteriophage significantly reduced the disease development. Biological effect of the bacteriophage application was 74.75%, which is very close to the pesticide Strekar in a concentration of 0.5%.
2
Samir, Safia. "Bacteriophages as Therapeutic Agents: Alternatives to Antibiotics". Recent Patents on Biotechnology 15, n. 1 (7 maggio 2021): 25–33. http://dx.doi.org/10.2174/1872208315666210121094311.
Testo completoAbstract (sommario):
: Bacteriophages are bacterio-specific viruses that constitute the main portion of the environment. Bacteriophages inject their genome into the targeted bacterial cells and some of them can disrupt the metabolism of bacteria and cause bacterial cell disintegration. The application of bacteriophages to kill bacteria is known as bacteriophage therapy. Since bacteriophages target bacteria and are strain-specific, every bacteriophage/bacterial host pair is unique. They are believed to cause no harm to humans. An additional advantage of the strain-specific nature of bacteriophages is that they do not disrupt the beneficial natural flora in the body. Bacteriophage therapy in the West is not a recognized medicine at this time, and no products are registered. Some clinicians are turning to bacteriophage therapy for the treatment of antibiotic-resistant infections. Lack of adverse effects makes bacteriophage therapy ideal for use. Funding research, media attention, and the increased publication of articles helped in a widespread understanding of its therapeutic potential. The first prerequisite for the use of bacteriophage therapy is simply the availability of bacteriophages for treatment, which is often complicated at this stage of bacteriophage production. This includes providing access to all biologically active bacteriophages against the bacterial isolate of the patient and meeting regulatory criteria of purity, traceability, and characterization. A monophage preparation, which is a single bacteriophage, or a phage cocktail, which consists of a number of combined bacteriophages against one or more bacterial species may be used. Accordingly, the antibiotic resistance crisis brought back bacteriophage therapy as a potential complementary or alternative treatment. Bacteriophages are promising cheap antibacterials.
3
Li, Jinyu, e John J. Dennehy. "Differential Bacteriophage Mortality on Exposure to Copper". Applied and Environmental Microbiology 77, n. 19 (12 agosto 2011): 6878–83. http://dx.doi.org/10.1128/aem.05661-11.
Testo completoAbstract (sommario):
ABSTRACTMany studies report that copper can be used to control microbial growth, including that of viruses. We determined the rates of copper-mediated inactivation for a wide range of bacteriophages. We used two methods to test the effect of copper on bacteriophage survival. One method involved placing small volumes of bacteriophage lysate on copper and stainless steel coupons. Following exposure, metal coupons were rinsed with lysogeny broth, and the resulting fluid was serially diluted and plated on agar with the corresponding bacterial host. The second method involved adding copper sulfate (CuSO4) to bacteriophage lysates to a final concentration of 5 mM. Aliquots were removed from the mixture, serially diluted, and plated with the appropriate bacterial host. Significant mortality was observed among the double-stranded RNA (dsRNA) bacteriophages Φ6 and Φ8, the single-stranded RNA (ssRNA) bacteriophage PP7, the ssDNA bacteriophage ΦX174, and the dsDNA bacteriophage PM2. However, the dsDNA bacteriophages PRD1, T4, and λ were relatively unaffected by copper. Interestingly, lipid-containing bacteriophages were most susceptible to copper toxicity. In addition, in the first experimental method, the pattern of bacteriophage Φ6 survival over time showed a plateau in mortality after lysates dried out. This finding suggests that copper's effect on bacteriophage is mediated by the presence of water.
4
Gorshenin, Aleksandr Vladimirovich. "Participation of microbiologists Z.V. Ermolyeva and L.M. Yakobson in a scientific discussion about the fate of the production of Soviet cholera bacteriophages in 1967". Samara Journal of Science 10, n. 4 (1 dicembre 2021): 201–7. http://dx.doi.org/10.17816/snv2021104211.
Testo completoAbstract (sommario):
Since the late 1920s in the USSR, along with many countries, there has been an interest in studying the phenomenon of bacteriophagy and its use in medicine. Bacteriophages are called bacterial viruses. Significant work on the study of bacteriophages and their use for medical purposes was carried out by Soviet microbiologists Zinaida Vissarionovna Ermolyeva and Lidiya Mikhailovna Yakobson. They paid especially great attention to the study of cholera bacteriophage, which during the Great Patriotic War helped prevent the cholera epidemic in frontline Stalingrad. In the 1940s due to the advent of the era of antibiotics with a wider range of applications, research interest in bacteriophages was waning. Nevertheless, in the prevention and treatment of a number of infectious diseases of bacterial origin, phage continued to be used in the following decades. In 1967, one of the countrys largest microbiologists sent an appeal to the Chief Sanitary Doctor of the USSR with a proposal to stop or reduce the production of cholera bacteriophage in the country. In this regard, a scientific discussion in which Z.V. Ermolyeva and L.M. Yakobson played an important role unfolded. Using the materials of the State Archive of the Russian Federation and the Russian State Archive of Economics, involving published scientific works on microbiology and medicine, an attempt is made to analyze this scientific discussion and establish its significance in the fate of the production of cholera bacteriophage in the USSR.
5
Moon, Choi, Jeong, Sohn, Han e Oh. "Research Progress of M13 Bacteriophage-Based Biosensors". Nanomaterials 9, n. 10 (11 ottobre 2019): 1448. http://dx.doi.org/10.3390/nano9101448.
Testo completoAbstract (sommario):
Recently, new virus-based sensor systems that operate on M13 bacteriophage infrastructure have attracted considerable attention. These systems can detect a range of chemicals with excellent sensitivity and selectivity. Filaments consistent with M13 bacteriophages can be ordered by highly established forms of self-assembly. This allows M13 bacteriophages to build a homogeneous distribution and infiltrate the network structure of nanostructures under mild conditions. Phage display, involving the genetic engineering of M13 bacteriophages, is another strong feature of the M13 bacteriophage as a functional building block. The numerous genetic modification possibilities of M13 bacteriophages are clearly the key features, and far more applications are envisaged. This paper reviews the recent progress in the application of the M13 bacteriophage self-assembly structures through to sensor systems and discusses future M13 bacteriophage technology.
6
Xu, Anqi. "Draft Of Bacteriophage Therapy Review". Highlights in Science, Engineering and Technology 74 (29 dicembre 2023): 1105–16. http://dx.doi.org/10.54097/hfwfxj54.
Testo completoAbstract (sommario):
Phage therapy, which uses bacterial viruses (bacteriophages) to treat bacterial infections. In recent years, the issue of antibiotic resistance in various bacteria has become prominent, and the effectiveness of antibiotic drugs has generally declined, which has re raised people's scrutiny of bacteriophage therapy. Traditionally, bacteriophage therapy relies on the use of natural bacteriophages to infect and dissolve bacteria at the site of infection. Current research on the use of bacteriophages and their lytic proteins to combat multidrug-resistant bacterial infections suggests that bacteriophage therapy may serve as a substitute or supplement to antibiotic therapy.
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Khan, Muhammad Fayaz, Aamer Ali Khattak, Afshan Saleem, Muhammad Rizwan, Muhammad Asif e Iqbal Ahmad Alvi. "Efficient Reduction of Pseudomonas aeruginosa Biofilms Using the Myoviridae Lytic Bacteriophage vBPaeM MLG". Lahore Garrison University Journal of Life Sciences 7, n. 03 (25 settembre 2023): 262–79. http://dx.doi.org/10.54692/lgujls.2023.0703275.
Testo completoAbstract (sommario):
Pseudomonas aeruginosa biofilm infections pose significant challenges in clinical settings due to their increased resistance to conventional antibiotics. Bacteriophages, viruses that infect and kill bacteria, have emerged as promising agents for combating biofilm-related infections. This study aimed to isolate and characterize a potent bacteriophage with antibiofilm activity against P. aeruginosa. Hospital sewage was utilized to isolate a bacteriophage targeting P. aeruginosa. Quantification of phages was conducted through spot tests and doublelayer agar methods. The stability of the isolated phage was assessed under varying pH and temperature conditions. Furthermore, the bacteriophage's ability to reduce bacterial growth and exhibit antibiofilm activity was evaluated at different Multiplicity of Infection (MOI) levels. The isolated bacteriophage, named MLG, was identified as a member of the Myoviridae family within the Caudovirales order. MLG effectively reduced bacterial growth over a 14-hour period. It displayed tolerance to a pH range of 5 to 9 and temperatures spanning 25 to 60°C. Moreover, MLG demonstrated efficient inhibition of biofilm formation across various MOI levels. Given its demonstrated in vitro capacity for bacterial growth reduction and antibiofilm activity, MLG holds potential for combatting P. aeruginosa biofilm infections. This study suggests a promising avenue for the development of alternative antibiofilm strategies using bacteriophages.
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Jamaledin, Rezvan, Rossella Sartorius, Concetta Di Natale, Raffaele Vecchione, Piergiuseppe De Berardinis e Paolo Antonio Netti. "Recombinant Filamentous Bacteriophages Encapsulated in Biodegradable Polymeric Microparticles for Stimulation of Innate and Adaptive Immune Responses". Microorganisms 8, n. 5 (29 aprile 2020): 650. http://dx.doi.org/10.3390/microorganisms8050650.
Testo completoAbstract (sommario):
Escherichia coli filamentous bacteriophages (M13, f1, or fd) have attracted tremendous attention from vaccinologists as a promising immunogenic carrier and vaccine delivery vehicle with vast possible applications in the development of vaccines. The use of fd bacteriophage as an antigen delivery system is based on a modification of bacteriophage display technology. In particular, it is designed to express multiple copies of exogenous peptides (or polypeptides) covalently linked to viral capsid proteins. This study for the first time proposes the use of microparticles (MPs) made of poly (lactic-co-glycolic acid) (PLGA) to encapsulate fd bacteriophage. Bacteriophage–PLGA MPs were synthesized by a water in oil in water (w1/o/w2) emulsion technique, and their morphological properties were analyzed by confocal and scanning electron microscopy (SEM). Moreover, phage integrity, encapsulation efficiency, and release were investigated. Using recombinant bacteriophages expressing the ovalbumin (OVA) antigenic determinant, we demonstrated the immunogenicity of the encapsulated bacteriophage after being released by MPs. Our results reveal that encapsulated bacteriophages are stable and retain their immunogenic properties. Bacteriophage-encapsulated PLGA microparticles may thus represent an important tool for the development of different bacteriophage-based vaccine platforms.
9
SAKMANOĞLU, Aslı, e Hasan Hüseyin HADİMLİ. "Typing of ΦSP–3 lytic Salmonella bacteriophages obtained from various fecal sources". TURKISH JOURNAL OF VETERINARY AND ANIMAL SCIENCES 44, n. 5 (27 ottobre 2020): 1047–54. http://dx.doi.org/10.3906/vet-2005-105.
Testo completoAbstract (sommario):
Although several reports are available on both ΦSP–1 and ΦSP–3 lytic Salmonella bacteriophages obtained from poultry, further research is required to study the effectiveness of ΦSP–3 type on serovars isolated from other sources. In the present study, we aimed to isolate bacteriophages from 8 serovars previously obtained from 869 fecal samples (calf, dairy cow, buffalo, and camel), genotype the bacteriophages, and detect the cross-lytic activities of the bacteriophages on Salmonella enterica subsp. enterica serovar Kentucky, S.Anatum, and S.Muenchen. A total of 16 bacteriophages were detected as ΦSP–3 type via PCR. The Hunter-Gaston Discriminatory Index of SDS-PAGE was calculated to be 0.825. Determination of multiplicity of infection (MOI) values were different for each bacteriophage according to the cross-lytic activity assessment. The MOI of the most effective S. Kentucky bacteriophage was 79.11 μg/mL for 2.5×104 cells, whereas that of the most ineffective S.Muenchen bacteriophage was 1.142 μg/μL for 2.5×104 cells. In conclusion, it was assumed that owing to the high and cross-lytic activity of the S. Kentucky bacteriophage, it has a larger host range, which differs in the lytic activities of each bacteriophage, despite being the same serovar, and that calf feces is the most important source for obtaining Salmonella bacteriophages.
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Kargina, T. M., E. I. Sakanyan, D. S. Davydov e R. L. Parfenyuk. "Elaboration of Pharmacopoeial Quality Standards for Bacteriophage Products". BIOpreparations. Prevention, Diagnosis, Treatment 19, n. 4 (11 dicembre 2019): 233–41. http://dx.doi.org/10.30895/2221-996x-2019-19-4-233-241.
Testo completoAbstract (sommario):
Bacteriophages are novel safe and efficacious medicinal products that are used for treatment of intestinal infections and purulent inflammations. The fact that virulent phages can be adapted to fight antibiotic-resistant bacterial strains makes this group of medicines a promising means of treatment of infections associated with medical interventions. The elaboration of quality standards for bacteriophage products will enable alignment of the quality requirements and test methods. There are no monographs on bacteriophage products in pharmacopoeias of other countries, therefore, the development of general chapters on groups of test methods used in bacteriophage quality control and monographs on bacteriophages for the State Pharmacopoeia of the Russian Federation (Ph. Rus.) was a very relevant and timely initiative. The aim of the study was to elaborate pharmacopoeial quality standards for bacteriophages approved in the Russian Federation for therapeutic and prophylactic indications. The authors of the study analysed product specification files and master production records for bacteriophages produced in the Russian Federation. They determined common GMP-compliant production steps, the selection criteria for bacteriophage strains and bacteria production strains, and cultivation and storage conditions. The authors standardised bacteriophage quality parameters and brought the test methods in line with the test procedures described in the Ph. Rus., 14th ed. The study summarised test methods used for identification of bacteriophages and determination of their specific activity. The main results of the study were included into the general monograph «Bacteriophages» and individual monographs on bacteriophage products that were included into the current edition of the Ph. Rus. Further studies and elaboration of new quality standards for mono- and multicomponent bacteriophage products, and the use of such products in clinical practice will improve prophylaxis and treatment of various infectious diseases.
11
Schrader, Holly S., John O. Schrader, Jeremy J. Walker, Thomas A. Wolf, Kenneth W. Nickerson e Tyler A. Kokjohn. "Bacteriophage infection and multiplication occur inPseudomonas aeruginosastarved for 5 years". Canadian Journal of Microbiology 43, n. 12 (1 dicembre 1997): 1157–63. http://dx.doi.org/10.1139/m97-164.
Testo completoAbstract (sommario):
Bacteriophages specific for Pseudomonas aeruginosa and Escherichia coli were examined for their ability to multiply in stationary phase hosts. Four out of five bacteriophages tested, including E. coli bacteriophage T7M, were able to multiply in stationary phase hosts. The bacteriophage ACQ had a mean burst size of approximately 1000 in exponential phase P. aeruginosa hosts and 102 in starved hosts, with corresponding latent periods that increased from 65 to 210 min. The bacteriophage UT1 had a mean burst size of approximately 211 in exponential phase P. aeruginosa hosts and 11 in starved hosts, with latent periods that increased from a mean of 90 min in exponential phase hosts to 165 min in starved hosts. Bacteriophage multiplication occurred whether or not the hosts had entered stationary phase, either because the cultures had been incubated for 24 h or were starved. Significantly, bacteriophage multiplication occurred in P. aeruginosa, which had been starved for periods of 24 h, several weeks, or 5 years. Only one P. aeruginosa virus, BLB, was found to be incapable of multiplication in stationary phase hosts. These results reveal that starvation does not offer bacterial hosts refuge from bacteriophage infection and suggest that bacteriophages will be responsible for significant bacterial mortality in most natural ecosystems.Key words: bacteriophage multiplication, stationary phase, starvation.
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Florent, Perrine, Henry-Michel Cauchie, Malte Herold, Stéphan Jacquet e Leslie Ogorzaly. "Soil pH, Calcium Content and Bacteria as Major Factors Responsible for the Distribution of the Known Fraction of the DNA Bacteriophage Populations in Soils of Luxembourg". Microorganisms 10, n. 7 (19 luglio 2022): 1458. http://dx.doi.org/10.3390/microorganisms10071458.
Testo completoAbstract (sommario):
Bacteriophages participate in soil life by influencing bacterial community structure and function, biogeochemical cycling and horizontal gene transfer. Despite their great abundance, diversity, and importance in microbial processes, they remain little explored in environmental studies. The influence of abiotic factors on the persistence of bacteriophages is now recognized; however, it has been mainly studied under experimental conditions. This study aimed to determine whether the abiotic factors well-known to influence bacteriophage persistence also control the natural distribution of the known DNA bacteriophage populations. To this end, soil from eight study sites including forests and grasslands located in the Attert River basin (Grand Duchy of Luxembourg) were sampled, covering different soil and land cover characteristics. Shotgun metagenomics, reference-based bioinformatics and statistical analyses allowed characterising the diversity of known DNA bacteriophage and bacterial communities. After combining soil properties with the identified DNA bacteriophage populations, our in-situ study highlighted the influence of pH and calcium cations on the diversity of the known fraction of the soil DNA bacteriophages. More interestingly, significant relationships were established between bacteriophage and bacterial populations. This study provides new insights into the importance of abiotic and biotic factors in the distribution of DNA bacteriophages and the natural ecology of terrestrial bacteriophages.
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Raees, Fahad, Azian Harun, Abdalla Ahmed e Zakuan Zainy Deris. "Potential Usefulness of Bacteriophages for the Treatment of Multidrug-Resistant Acinetobacter Infection". Malaysian Journal of Medical Sciences 30, n. 5 (30 ottobre 2023): 7–22. http://dx.doi.org/10.21315/mjms2023.30.5.2.
Testo completoAbstract (sommario):
Bacteriophages were discovered in early 20th century. However, the interest in bacteriophage research was reduced with the discovery of antibiotics. With the increasing number of infections due to multidrug-resistant (MDR) organisms, the potential usefulness of bacteriophages as therapeutic agents has been re-evaluated. In this review, we found that more than 30 lytic bacteriophages that infect Acinetobacter species have been characterised. These are mainly members of Caudovirales, with genome sizes ranging from 31 kb to 234 kb and G+C contents ranging from 33.5% to 45.5%. The host range can be as low as < 10% of all tested Acinetobacter strains. Fourteen published murine trials indicated positive outcomes in bacteriophage-treated groups. Only two case reports were pertaining to the use of bacteriophages in the treatment of Acinetobacter infections in humans; in both cases, the infections were resolved with bacteriophage therapy. The use of bacteriophages has been associated with reduced Acinetobacter burden in the environment, as shown in two studies. The major limitation of bacteriophage therapy is its highly selective host strain. In conclusion, the potential usefulness of bacteriophage therapy for the treatment of MDR Acinetobacter species has been documented only in limited studies and more research is needed prior to its extensive use in clinical practice.
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Hu, Yang, Bader Al Shaaer, Lu Liang e Ian F. Connerton. "Campylobacter Bacteriophage Infection at Refrigeration Temperatures". Applied Microbiology 3, n. 4 (13 dicembre 2023): 1392–406. http://dx.doi.org/10.3390/applmicrobiol3040094.
Testo completoAbstract (sommario):
The application of bacteriophages to control foodborne bacterial pathogens in foods has gained traction in recent years. Poultry meat is a major source of Campylobacter jejuni, and a target for the application of bacteriophages. To offer the prospect of a post-harvest control measure, the bacteriophage must function at refrigeration temperatures, where C. jejuni does not grow but can survive. Here, we report actions of three classes of Campylobacter bacteriophage at 4 °C. The pre-incubation of broth cultures at 4 °C before a shift to 42 °C under conditions that support the growth of the host bacteria revealed differences in the time to lysis compared with cultures incubated at 42 °C. The pre-adsorption of the bacteriophage to a sub-population of bacteria is consistent with the observation of asynchronous infection. To ascertain whether the bacteriophages adsorb and infect (the commitment to replicate), we investigated bacteriophage transcription at 4 °C. RNA transcripts for all the bacteriophage host combinations were detected after 15 min, indicating that the interaction is not merely passive. Bacteriophages can infect C. jejuni at refrigeration temperatures, but the infection does not proceed to lysis in the absence of host cell division.
15
Ariyanti, Tati. "The Use of Bacteriophage for Detection and Biocontrol of Foodborne Pathogen". Indonesian Bulletin of Animal and Veterinary Sciences 28, n. 1 (3 marzo 2018): 33. http://dx.doi.org/10.14334/wartazoa.v28i1.1791.
Testo completoAbstract (sommario):
Bacteriophages are viruses that have ability to attack bacterial cells in specific receptors, infect, multiply in bacterial cells and eventually lyse bacterial cells. This unique bacteriophage character is highly beneficial because it is harmless to mammalian cells and does not interfere with natural microbes. Bacteriophages are easy to obtain because they are widespread in the environment such as soil, water, animal, and farm waste or food. This paper describes the potential use of bacteriophages to detect pathogen and foodborne pathogen biocontrol. Bacteriophages are very potential to control the growth of pathogenic bacteria both in food industry and environment. Bacteriophages act as antibiotics, detection tool for pathogenic bacteria in the food chain, food biopreservative from pathogen bacteria contamination, and foodborne disease prevention. Although research on bacteriophage in Indonesia has not been widely reported, research on bacteriophage utilization is being carried on.
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Manrique, Pilar, Benjamin Bolduc, Seth T. Walk, John van der Oost, Willem M. de Vos e Mark J. Young. "Healthy human gut phageome". Proceedings of the National Academy of Sciences 113, n. 37 (29 agosto 2016): 10400–10405. http://dx.doi.org/10.1073/pnas.1601060113.
Testo completoAbstract (sommario):
The role of bacteriophages in influencing the structure and function of the healthy human gut microbiome is unknown. With few exceptions, previous studies have found a high level of heterogeneity in bacteriophages from healthy individuals. To better estimate and identify the shared phageome of humans, we analyzed a deep DNA sequence dataset of active bacteriophages and available metagenomic datasets of the gut bacteriophage community from healthy individuals. We found 23 shared bacteriophages in more than one-half of 64 healthy individuals from around the world. These shared bacteriophages were found in a significantly smaller percentage of individuals with gastrointestinal/irritable bowel disease. A network analysis identified 44 bacteriophage groups of which 9 (20%) were shared in more than one-half of all 64 individuals. These results provide strong evidence of a healthy gut phageome (HGP) in humans. The bacteriophage community in the human gut is a mixture of three classes: a set of core bacteriophages shared among more than one-half of all people, a common set of bacteriophages found in 20–50% of individuals, and a set of bacteriophages that are either rarely shared or unique to a person. We propose that the core and common bacteriophage communities are globally distributed and comprise the HGP, which plays an important role in maintaining gut microbiome structure/function and thereby contributes significantly to human health.
17
Reyneke, Brandon, Benjamin Havenga, Monique Waso-Reyneke, Sehaam Khan e Wesaal Khan. "Benefits and Challenges of Applying Bacteriophage Biocontrol in the Consumer Water Cycle". Microorganisms 12, n. 6 (7 giugno 2024): 1163. http://dx.doi.org/10.3390/microorganisms12061163.
Testo completoAbstract (sommario):
Bacteria (including disinfection- and antibiotic-resistant bacteria) are abundant in the consumer water cycle, where they may cause disease, and lead to biofouling and infrastructure damage in distributions systems, subsequently resulting in significant economic losses. Bacteriophages and their associated enzymes may then offer a biological control solution for application within the water sector. Lytic bacteriophages are of particular interest as biocontrol agents as their narrow host range can be exploited for the targeted removal of specific bacteria in a designated environment. Bacteriophages can also be used to improve processes such as wastewater treatment, while bacteriophage-derived enzymes can be applied to combat biofouling based on their effectiveness against preformed biofilms. However, the host range, environmental stability, bacteriophage resistance and biosafety risks are some of the factors that need to be considered prior to the large-scale application of these bacterial viruses. Characteristics of bacteriophages that highlight their potential as biocontrol agents are thus outlined in this review, as well as the potential application of bacteriophage biocontrol throughout the consumer water cycle. Additionally, the limitations of bacteriophage biocontrol and corresponding mitigation strategies are outlined, including the use of engineered bacteriophages for improved host ranges, environmental stability and the antimicrobial re-sensitisation of bacteria. Finally, the potential public and environmental risks associated with large-scale bacteriophage biocontrol application are considered, and alternative applications of bacteriophages to enhance the functioning of the consumer water cycle, including their use as water quality or treatment indicators and microbial source tracking markers, are discussed.
18
Putra, Ramendra Dirgantara, e Diana Lyrawati. "Interactions between Bacteriophages and Eukaryotic Cells". Scientifica 2020 (9 giugno 2020): 1–8. http://dx.doi.org/10.1155/2020/3589316.
Testo completoAbstract (sommario):
As the name implies, bacteriophage is a bacterium-specific virus. It infects and kills the bacterial host. Bacteriophages have gained attention as alternative antimicrobial entities in the science community in the western world since the alarming rise of antibiotic resistance among microbes. Although generally considered as prokaryote-specific viruses, recent studies indicate that bacteriophages can interact with eukaryotic organisms, including humans. In the current review, these interactions are divided into two categories, i.e., indirect and direct interactions, with the involvement of bacteriophages, bacteria, and eukaryotes. We discuss bacteriophage-related diseases, transcytosis of bacteriophages, bacteriophage interactions with cancer cells, collaboration of bacteriophages and eukaryotes against bacterial infections, and horizontal gene transfer between bacteriophages and eukaryotes. Such interactions are crucial for understanding and developing bacteriophages as the therapeutic agents and pharmaceutical delivery systems. With the advancement and combination of in silico, in vitro, and in vivo approaches and clinical trials, bacteriophages definitely serve as useful repertoire for biologic target-based drug development to manage many complex diseases in the future.
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Gomez, Mellissa, Alexandra Szewczyk, Jake Szamosi, Vincent Leung, Carlos Filipe e Zeinab Hosseinidoust. "Stress Exposure of Evolved Bacteriophages under Laboratory versus Food Processing Conditions Highlights Challenges in Translatability". Viruses 15, n. 1 (30 dicembre 2022): 113. http://dx.doi.org/10.3390/v15010113.
Testo completoAbstract (sommario):
Bacterial viruses, or bacteriophages, are highly potent, target-specific antimicrobials. Bacteriophages can be safely applied along the food production chain to aid control of foodborne pathogens. However, bacteriophages are often sensitive to the environments encountered in food matrices and under processing conditions, thus limiting their applicability. We sought to address this challenge by exposing commercially available Listeria monocytogenes bacteriophage, P100, to three stress conditions: desiccation, elevated temperature, and low pH, to select for stress-resistant bacteriophages. The stressed bacteriophage populations lost up to 5.1 log10 in infectivity; however, the surviving subpopulation retained their stress-resistant phenotype through five passages with a maximum of 2.0 log10 loss in infectivity when exposed to the same stressor. Sequencing identified key mutation regions but did not reveal a clear mechanism of resistance. The stress-selected bacteriophage populations effectively suppressed L. monocytogenes growth at a modest multiplicity of infection of 0.35–0.43, indicating no trade-off in lytic ability in return for improved survivability. The stressed subpopulations were tested for survival on food grade stainless steel, during milk pasteurization, and within acidic beverages. Interestingly, air drying on stainless steel and pasteurization in milk led to significantly less stress and titer loss in bacteriophage compared to similar stress under model lab conditions. This led to a diminished benefit for stress-selection, thus highlighting a major challenge in real-life translatability of bacteriophage adaptational evolution.
20
Musin, Egor V., Aleksandr L. Kim, Alexey V. Dubrovskii, Elena V. Ariskina, Ekaterina B. Kudryashova e Sergey A. Tikhonenko. "The Pathways to Create Containers for Bacteriophage Delivery". Polymers 14, n. 3 (4 febbraio 2022): 613. http://dx.doi.org/10.3390/polym14030613.
Testo completoAbstract (sommario):
Antimicrobial resistance is a global public health threat. One of the possible ways to solve this problem is phage therapy, but the instability of bacteriophages hinders the development of this approach. A bacteriophage delivery system that stabilizes the phage is one of the possible solutions to this problem. This study is dedicated to exploring methods to create encapsulated forms of bacteriophages for delivery. We studied the effect of proteolytic enzymes on the destruction of the polyelectrolyte microcapsule shell and revealed that protease from Streptomyces griseus was able to destroy the membrane of the microcapsule (dextran sulfate/polyarginine)3 ((DS/PArg)3). In addition, the protease decreased the activity of the bacteriophage in the second hour of incubation, and the phage lost activity after 16 h. It was found that a medium with pH 9.02 did not affect the survival of the bacteriophage or E. coli. The bacteriophages were encapsulated into polyelectrolyte microcapsules (DS/PArg)3. It was established that it is impossible to use microcapsules as a means of delivering bacteriophages since the bacteriophages are inactivated. When bacteriophages were included inside a CaCO3 core, it was demonstrated that the phage retained activity before and after the dissolution of the CaCO3 particle. From the results of this study, we recommend using CaCO3 microparticles as a container for bacteriophage delivery through the acidic stomach barrier.
21
Levanova, L. A., Yu V. Zakharova, A. A. Markovskaya e L. Yu Otdushkina. "Bacteriophage sensitivity of opportunistic microbiota in children with gut dysbiosis". Fundamental and Clinical Medicine 7, n. 3 (30 settembre 2022): 40–45. http://dx.doi.org/10.23946/2500-0764-2022-7-3-40-45.
Testo completoAbstract (sommario):
Aim. As the activity of bacteriophages is species- and strain-specific, it is necessary to study bacteriophage sensitivity in distinct geographic regions with various disease patterns. Here, we aimed to study the lytic activity of specific commercially available bacteriophages against Klebsiella spp., Proteus spp., and Staphylococcus aureus isolated from the intestines of children with gut dysbiosis.Materials and Methods. Bacteriophage sensitivity was assessed in 315 opportunistic microorganisms (125 Staphylococcus aureus strains, 120 Klebsiella spp. strains, 70 Proteus spp. strains) isolated from the intestinal microbiota of 300 children < 4 years of age with gut dysbiosis. Bacteriophage preparations were produced by Microgen (Russian Federation). The lytic activity of bacteriophages was studied by a drip method on a Muller-Hinton medium by calculating the area of bacterial culture lysis.Results. We found low sensitivity of Klebsiella spp. (37.5% sensitive strains) and Proteus spp. (41.4% sensitive strains) to specific bacteriophages, albeit there were considerable differences between distinct Klebsiella species (Klebsiella pneumoniae, 56.7% sensitive strains; Klebsiella oxytoca, 18.3% sensitive strains, p = 0.03) and Proteus species (Proteus vulgaris, 52.0% strains; Proteus mirabilis, 35.6% strains, p = 0.04). Nevertheless, sensitivity to Staphylococcus aureus was considerably higher (78.4%). In addition, lytic activity of bacteriophages reduced along with the increasing severity of gut dysbiosis.Conclusion. Klebsiella spp. and Proteus spp. isolated from children with dysbiosis have low sensitivity to commercially available bacteriophages. Bacteriophage sensitivity positively correlated with gut dysbiosis.
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Musin, Egor V., Aleksandr L. Kim, Alexey V. Dubrovskii, Ekaterina B. Kudryashova, Elena V. Ariskina e Sergey A. Tikhonenko. "The Influence of Polyanions and Polycations on Bacteriophage Activity". Polymers 13, n. 6 (16 marzo 2021): 914. http://dx.doi.org/10.3390/polym13060914.
Testo completoAbstract (sommario):
Phage therapy is a great alternative to antibiotic drugs, but it can’t effectively overcome the over-acidic medium of the stomach. We offer the use of polyelectrolyte microcapsules as a protective means of bacteriophage. It is necessary to understand the influence of polyelectrolytes on bacteriophage survival. The work studied the effect of polyanions and polycations on the coliprotetic bacteriophage’s viability. We have shown that polyallylamine decreased bacteriophage’s viability during increasing polyelectrolyte concentration and polyarginine had a lower inhibitory effect (then PAH) on the activity of the bacteriophage due to polyelectrolyte concentration from 0.05 to 5 mg/mL. It was shown that the inhibition of the bacteriophage by polyallylamine had an electrostatic nature and the use of high ionic strength prevented the formation of the PAH-protein capsid complex. Polystyrene sulfonate does not affect bacteriophage viability during increasing polyelectrolyte concentration from 0.05 mg/mL to 1 mg/mL. Polystyrene sulfonate decreases the viability of bacteriophage from 5 mg/mL of polyelectrolyte concentration. Dextran sulfate inhibits bacteriophage activity at 20–30%. Dextran inhibits bacteriophage activity by 80% at diapason concentration from 0.05 to 5 mg/mL and loses the inhibition effect from a concentration of 5 mg/mL.
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Bach, S. J., R. P. Johnson, K. Stanford e T. A. McAllister. "Bacteriophages reduce Escherichia coli O157:H7 levels in experimentally inoculated sheep". Canadian Journal of Animal Science 89, n. 2 (1 giugno 2009): 285–93. http://dx.doi.org/10.4141/cjas08083.
Testo completoAbstract (sommario):
Bacteriophage biocontrol has potential as a means of mitigating the prevalence of Escherichia coli O157:H7 in ruminants. The efficacy of oral administration of bacteriophages for reducing fecal shedding of E. coli O157:H7 by sheep was evaluated using 20 Canadian Arcott rams (50.0 ± 3.0) housed in four rooms (n = 5) in a contained facility. The rams had ad libitum access to drinking water and a pelleted barley-based total mixed ration, delivered once daily. Experimental treatments consisted of administration of E. coli O157:H7 (O157), E. coli O157:H7+bacteriophages (O157+phage), bacteriophages (phage), and control (CON). Oral inoculation of the rams with 109 CFU of a mixture of four nalidixic acid-resistant strains of E. coli O157:H7 was performed on day 0. A mixture of 1010 PFU of bacteriophages P5, P8 and P11 was administered on days -2, -1, 0, 6 and 7. Fecal samples collected on 14 occasions over 21 d were analyzed for E. coli O157:H7, total E. coli, total coliforms and bacteriophages. Sheep in treatment O157+phage shed fewer (P < 0.05) E. coli O157:H7 than did sheep in treatment O157. Populations of total coliforms and total E. coli were similar (P < 0.05) among treatments, implying that bacteriophage lysis of non-target E. coli and coliform bacteria in the gastrointestinal tract did not occur. Bacteriophage numbers declined rapidly over 21 d, which likely reduced the chance of collision between bacteria and bacteriophage. Oral administration of bacteriophages reduced shedding of E. coli O157:H7 by sheep, but a delivery system that would protect bacteriophages during passage through the intestine may increase the effectiveness of this strategy as well as allow phage to be administered in the feed.Key words: Escherichia coli O157:H7, bacteriophage, sheep, environment, coliforms
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Kochetova, T. A., V. V. Yuskevich, F. M. Zurabov, G. T. Sadykova, P. V. Medvedev e V. M. Popova. "Isolation of novel <i>Actinomyces oris</i> and <i>Aggregatibacter actinomycetemcomitans</i> bacteriophages and study of their biological characteristics <i>in vitro</i>". Biological Products. Prevention, Diagnosis, Treatment 24, n. 1 (1 marzo 2024): 103–16. http://dx.doi.org/10.30895/2221-996x-2024-24-1-103-116.
Testo completoAbstract (sommario):
SCIENTIFIC RELEVANCE. The incidence of periodontal infections with antibiotic-resistant strains of Actinomyces oris and Aggregatibacter actinomycetemcomitans capable of forming biofilms in the oral cavity is increasing, and the effectiveness of antimicrobials against biofilms is insufficient. Therefore, the isolation of bacteriophages active against A. oris and Ag. actinomycetemcomitans is an urgent task.AIM. This study aimed to isolate bacteriophages active against A. oris and Ag. actinomycetemcomitans, study their biological properties, and select optimum culture conditions providing pure lines and high titres of bacteriophages.MATERIALS AND METHODS. Bacteriophages were isolated from biosamples of saliva, dental plaque, and periodontal pocket contents. The study determined bacteriophage characteristics, including the optimum multiplicity of infection, phage–cell system cultivation time, resistance to various temperatures and pH, and storage stability. Bacteriophage morphology was studied using transmission electron microscopy. Negative colony morphology, lytic activity, host range, and specificity were assessed using spot testing and the Gratia method. Bacterial strains were obtained from the strain collection of the Micromir research and production centre.RESULTS. The authors isolated and studied 3 novel bacteriophages active against A. oris (vB_AorP_1/G-12, vB_AorP_2/Ch-28, and vB_AorP_3/Bl-35) and 1 bacteriophage active against Ag. actinomycetemcomitans (vB_AacS_1/Dc-1). The A. oris bacteriophages were classified as podoviruses, and the vB_AacS_1/Dc-1 bacteriophage was classified as a siphovirus. The phages formed completely transparent round plaques without a halo, with a diameter ranging from 0.8±0.1 to 4.0±0.2 mm. The optimum parameters established to obtain pure phages with maximum titres included a multiplicity of infection of 0,1–10 and phage–cell system cultivation time of 8–12 hours. The study demonstrated the ability of A. oris bacteriophages to lyse Actinomyces naeslundii strains. Of the 15 A. oris bacteriophage strains studied, vB_AorP_1/G-12, vB_AorP_2/Ch-28, and vB_AorP_3/Bl-35 lysed 10, 8, and 12 bacterial strains, respectively. The vB_AacS_1/Dc-1 phage isolate exhibited lytic activity against both tested strains of Ag. actinomycetemcomitans. The studied phages demonstrated stability under abiotic stress and long-term storage conditions.CONCLUSIONS. The authors isolated 3 novel bacteriophages active against A. oris and 1 bacteriophage active against Ag. actinomycetemcomitans and studied their biological properties. The isolated bacteriophages are promising as candidates for further research using clinical strains and whole-genome sequencing.
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Abdul Choliq, Fery, Mintarto Martosudiro, Istiqomah Istiqomah e Muhammad Fanhash Nijami. "ISOLASI DAN UJI KEMAMPUAN BAKTERIOFAG SEBAGAI AGENS PENGENDALI PENYAKIT LAYU BAKTERI (Ralstonia solanacearum) PADA TANAMAN TOMAT". VIABEL: Jurnal Ilmiah Ilmu-Ilmu Pertanian 14, n. 1 (29 maggio 2020): 8–20. http://dx.doi.org/10.35457/viabel.v14i1.996.
Testo completoAbstract (sommario):
Tomato is the top priority in the development of horticultural crops. The obstacle which mostly encountered is Ralstonia solanacearum pathogen attack. Bacteriophage can cause bacterial lysis after they they develop themselves inside the bacteria. The specific of the bacteriophage can provide result quickly, accurately, and efficiently so that it can be used as an alternative to control bacterial wilt disease R. solanacearum environmentally friendly. This study aims to find out the effectiveness of bacteriophage to control the bacterial wilt disease R. solanacearum. The testing method are plaque assay, bacteriophage infections test in various dilutions, bacteriophage infection test in a liquid medium, and transmission electron microscopy test. In the greenhouse scale testing using a Completely Randomized Design (CRD) with 6 treatments and 4 replications. Quantitative data were analyzed using analysis of variance 5% error level and followed by least significant different test level of 5%. The results showed that bacteriophages can infect R. solanacearum. Bacteriophage can infect bacteria R. solanacearum indicated by the appearance of plaques in NA media, the declining value of absorbance spectophotometer, and can lyse bacterial cells from dilutions 10-1 to 10-9. The morphology of bacteriophages that infect R. solanacearum have hexagonal head structure and it have which is with a size of 200 nm. In the greenhouse scale showed that the symptoms of R. solanacearum appear at 29 days after inoculation. Application of bacteriophages can control R. solanacearum with lower percentage than the control treatment.
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Siringan, Patcharin, Phillippa L. Connerton, Robert J. H. Payne e Ian F. Connerton. "Bacteriophage-Mediated Dispersal of Campylobacter jejuni Biofilms". Applied and Environmental Microbiology 77, n. 10 (25 marzo 2011): 3320–26. http://dx.doi.org/10.1128/aem.02704-10.
Testo completoAbstract (sommario):
ABSTRACTBacteria in their natural environments frequently exist as mixed surface-associated communities, protected by extracellular material, termed biofilms. Biofilms formed by the human pathogenCampylobacter jejunimay arise in the gastrointestinal tract of animals but also in water pipes and other industrial situations, leading to their possible transmission into the human food chain either directly or via farm animals. Bacteriophages are natural predators of bacteria that usually kill their prey by cell lysis and have potential application for the biocontrol and dispersal of target bacteria in biofilms. The effects of virulentCampylobacterspecific-bacteriophages CP8 and CP30 onC. jejunibiofilms formed on glass by strains NCTC 11168 and PT14 at 37°C under microaerobic conditions were investigated. Independent bacteriophage treatments (n≥ 3) led to 1 to 3 log10CFU/cm2reductions in the viable count 24 h postinfection compared with control levels. In contrast, bacteriophages applied under these conditions effected a reduction of less than 1 log10CFU/ml in planktonic cells. Resistance to bacteriophage in bacteria surviving bacteriophage treatment ofC. jejuniNCTC 11168 biofilms was 84% and 90% for CP8 and CP30, respectively, whereas bacteriophage resistance was not found in similarly recoveredC. jejuniPT14 cells. Dispersal of the biofilm matrix by bacteriophage was demonstrated by crystal violet staining and transmission electron microscopy. Bacteriophage may play an important role in the control of attachment and biofilm formation byCampylobacterin situations where biofilms occur in nature, and they have the potential for application in industrial situations leading to improvements in food safety.
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Roseline, Felicia, Diana Elizabeth Waturangi e Yogiara Y. "ISOLATION, CHARACTERIZATION, AND APPLICATION OF BACTERIOPHAGES AGAINST SEVERAL FOOD SPOILAGE BACTERIA: Bacillus subtilis, Bacillus cereus, AND Shewanella Putrefaciens". Bacterial Empire 4, n. 2 (13 aprile 2021): e263. http://dx.doi.org/10.36547/be.263.
Testo completoAbstract (sommario):
Introduction: Bacteriophages can be the natural alternative method to prevent food spoilage caused by bacteria. This research was conducted to isolate bacteriophages from a soil sample, retail food, and wastewater from fish and then the bacteriophages will be characterized for their activity against several food spoilage bacteria, such as Bacillus cereus, Bacillus subtilis, and Shewanella putrefaciens and will be further investigated for application as food preservation. Experimental: B. cereus (Atma Jaya culture collection), B. subtilis ATCC 6633, and S. putrefaciens ATCC 8071 were used for bacteriophage isolation. Food samples (rice, pasta, tofu, tempeh), soil samples (black soil and laterite), and wastewater sample of freshwater fish and seawater fish were used in this research. The overall process consists of eight steps: inoculum preparation, sample collection, bacteriophage isolation, purification and enrichment, titer determination, host range determination, the efficiency of plating (EOP), and bacteriophage application. Results: A total of four bacteriophages were isolated with B. cereus, B. subtilis, and S. putrefaciens as host bacteria. Bacteriophage titers observed around 109 PFU mL-1. Bacteriophages that isolated with B. cereus and B. subtilis as host bacteria tend to have high EOP with the same species bacteria. All the Bacillus phages (S1-BC, S2-BC, and S1-BS) can reduce the Bacillus species bacteria concentration for more than 90%. Conclusion: Refers to their activity, the isolated bacteriophages in this study might have a great prospect to be used as food biocontrol and also can be further tested to make a phage cocktail.
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Dudina, L. G., M. A. Malkova, A. V. Chernyad’ev, S. G. Litvinets e A. A. Byvalov. "Effect of Bacteriophages and Gentamycine on Morphology and Vesicle Formation of Bacteria Yersinia pestis EV". Problems of Particularly Dangerous Infections, n. 2 (3 luglio 2019): 50–54. http://dx.doi.org/10.21055/0370-1069-2019-2-50-54.
Testo completoAbstract (sommario):
Objective was to assess the effect of specific bacteriophages and gentamycine on the morphological-functional properties of bacteria in the vaccine strain Yersinia pestis EV.Materials and methods. The vaccine strain Y. pestis EV, Pokrovskaya bacteriophage and the pseudotuberculous diagnostic bacteriophage were used for the study. The microbial culture was grown on solid and in liquid growth media at 27 °C for 20–24 h. The co-incubation of bacteria and bacteriophage or gentamycine was carried out at 27 °C for 20 minutes or at 37 °C for 2 hours, respectively. Culture preparations were examined by transmission electron microscopy.Results and discussion. The influence of cultivation conditions and various stress factors on the vesicle production by the vaccine strain Y. pestis EV cells was evaluated. The nature and intensity of morphological-functional changes in Y. pestis EV cells in response to the effect of bacteriophages (plague Pokrovskaya and pseudotuberculous bacteriophages) or an antibiotic (gentamycine) were determined. It was established that co-incubation of Y. pestis EV with Pokrovskaya bacteriophage or gentamycine for 20 min leads to the increase in the production of extracellular vesicles and is accompanied by the development of degenerative changes in bacterial cells.
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Grygorcewicz, Bartłomiej, Rafał Rakoczy, Marta Roszak, Maciej Konopacki, Marian Kordas, Agnieszka Piegat, Natalia Serwin, Elżbieta Cecerska-Heryć, Miroslawa El Fray e Barbara Dołęgowska. "Rotating Magnetic Field-Assisted Reactor Enhances Mechanisms of Phage Adsorption on Bacterial Cell Surface". Current Issues in Molecular Biology 44, n. 3 (17 marzo 2022): 1316–25. http://dx.doi.org/10.3390/cimb44030088.
Testo completoAbstract (sommario):
Growing interest in bacteriophage research and use, especially as an alternative treatment option for multidrug-resistant bacterial infection, requires rapid development of production methods and strengthening of bacteriophage activities. Bacteriophage adsorption to host cells initiates the process of infection. The rotating magnetic field (RMF) is a promising biotechnological method for process intensification, especially for the intensification of micromixing and mass transfer. This study evaluates the use of RMF to enhance the infection process by influencing bacteriophage adsorption rate. The RMF exposition decreased the t50 and t75 of bacteriophages T4 on Escherichia coli cells and vb_SauM_A phages on Staphylococcus aureus cells. The T4 phage adsorption rate increased from 3.13 × 10−9 mL × min−1 to 1.64 × 10−8 mL × min−1. The adsorption rate of vb_SauM_A phages exposed to RMF increased from 4.94 × 10−9 mL × min−1 to 7.34 × 10−9 mL × min−1. Additionally, the phage T4 zeta potential changed under RMF from −11.1 ± 0.49 mV to −7.66 ± 0.29 for unexposed and RMF-exposed bacteriophages, respectively.
30
Hu, J. Y., S. L. Ong, L. F. Song, Y. Y. Feng, W. T. Liu, T. W. Tan, L. Y. Lee e W. J. Ng. "Removal of MS2 bacteriophage using membrane technologies". Water Science and Technology 47, n. 12 (1 giugno 2003): 163–68. http://dx.doi.org/10.2166/wst.2003.0642.
Testo completoAbstract (sommario):
Removals of MS2 bacteriophage virus using different membrane materials under different operating pressures were investigated. The results obtained in this study suggested that a better log removal in terms of MS2 bacteriophage virus could be achieved using Polyamide RO membrane under the optimum operating pressure of 100 psi. It is further noted that variable MS2 influent concentration levels resulted in corresponding variable log removals of the bacteriophages by the Polyamide RO membrane. The presence of MS2 bacteriophage virus in the effluent could possibly be due to leakage of bacteriophages through the membranes structure. Investigations using SEM and AFM showed that there were gaps or pores present in the membrane structure which were sufficiently large for the MS2 viruses to pass through.
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Campos, Welida F., Erica C. Silva, Thais J. Oliveira, José M. Oliveira, Matthieu Tubino, Carla Pereira, Marta MDC Vila e Victor M. Balcão. "Transdermal permeation of bacteriophage particles by choline oleate: potential for treatment of soft-tissue infections". Future Microbiology 15, n. 10 (luglio 2020): 881–96. http://dx.doi.org/10.2217/fmb-2019-0290.
Testo completoAbstract (sommario):
Aim: A sodium alginate-based biohydrogel was prepared integrating choline oleate deep euthetic solvent as facilitator of transdermal delivery and a cocktail of lytic bacteriophages for Acinetobacter baumannii, aiming at treating soft-tissue infections by the aforementioned pathogen. Materials & methods: Two bacteriophages were isolated from a hospital sewage and a wastewater treatment plant sewage in Sorocaba (Brazil), and characterized via SDS-PAGE electrophoresis, transmission electron microscope and evaluation of lytic spectra of the bacteriophage cocktail. The biohydrogel was prepared and characterized by DSC, FTIR, XRD, DESEM, XRT and transdermal permeation of the bacteriophage cocktail. Results & conclusion: The physico-chemical characterization of the biohydrogel produce indicated adequate structural characteristics and ability to promote/facilitate transdermal delivery of bacteriophage particles, thus showing potential for biopharmaceutical applications.
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Adhikari, Niran, e Krishna P. Acharya. "Effectiveness of Bacteriophage Therapy in Field Conditions and Possible Future Applications". Current Pharmaceutical Biotechnology 21, n. 5 (29 aprile 2020): 364–73. http://dx.doi.org/10.2174/1389201021666191217111156.
Testo completoAbstract (sommario):
Background: Bacteriophages are viruses, which are obligate parasites of specific bacteria for the completion of their lifecycle. Bacteriophages could be the possible alternative to antibioticresistant bacterial diseases. With this objective, extensive research in different fields is published which are discussed in this article. Results: After a review of bacteriophage therapy, bacteriophages were found to be effective against the multidrug-resistant bacteria individually or synergistically with antibiotics. They were found to be more effective, even better than the bacteria in the development of a vaccine. Conclusion: Thus, bacteriophage therapy offers promising alternatives in the treatment of antibioticresistant bacteria in different fields. However, their effectiveness is determined by a triad of bacteriophages (type & quantity), host (bacteria) and environmental factors.
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Pleška, Maroš, e Călin C. Guet. "Effects of mutations in phage restriction sites during escape from restriction–modification". Biology Letters 13, n. 12 (dicembre 2017): 20170646. http://dx.doi.org/10.1098/rsbl.2017.0646.
Testo completoAbstract (sommario):
Restriction–modification systems are widespread genetic elements that protect bacteria from bacteriophage infections by recognizing and cleaving heterologous DNA at short, well-defined sequences called restriction sites. Bioinformatic evidence shows that restriction sites are significantly underrepresented in bacteriophage genomes, presumably because bacteriophages with fewer restriction sites are more likely to escape cleavage by restriction–modification systems. However, how mutations in restriction sites affect the likelihood of bacteriophage escape is unknown. Using the bacteriophage λ and the restriction–modification system EcoRI, we show that while mutation effects at different restriction sites are unequal, they are independent. As a result, the probability of bacteriophage escape increases with each mutated restriction site. Our results experimentally support the role of restriction site avoidance as a response to selection imposed by restriction–modification systems and offer an insight into the events underlying the process of bacteriophage escape.
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Nishiyama, Hiroki, Hisashi Endo, Romain Blanc-Mathieu e Hiroyuki Ogata. "Ecological Structuring of Temperate Bacteriophages in the Inflammatory Bowel Disease-Affected Gut". Microorganisms 8, n. 11 (27 ottobre 2020): 1663. http://dx.doi.org/10.3390/microorganisms8111663.
Testo completoAbstract (sommario):
The aim of this study was to elucidate the ecological structure of the human gut temperate bacteriophage community and its role in inflammatory bowel disease (IBD). Temperate bacteriophages make up a large proportion of the human gut microbiota and are likely to play a role in IBD pathogenesis. However, many of these bacteriophages await characterization in reference databases. Therefore, we conducted a large-scale reconstruction of temperate bacteriophage and bacterial genomes from the whole-metagenome sequence data generated by the IBD Multi’omics Database project. By associating phages with their hosts via genome comparisons, we found that temperate bacteriophages infect a phylogenetically wide range of bacteria. The majority of variance in bacteriophage community composition was explained by variation among individuals, but differences in the abundance of temperate bacteriophages were identified between IBD and non-IBD patients. Of note, in active ulcerative colitis patients, temperate bacteriophages infecting Bacteroides uniformis and Bacteroides thetaiotaomicron—two species experimentally proven to be beneficial to gut homeostasis—were over-represented, whereas their hosts were under-represented in comparison with non-IBD patients. Supporting the mounting evidence that gut viral community plays a vital role in IBD, our results show potential association between temperate bacteriophages and IBD pathogenesis.
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Madere, Ferralita S., Michael Sohn, Angelina K. Winbush, Breóna Barr, Alex Grier, Cal Palumbo, James Java et al. "Transkingdom Analysis of the Female Reproductive Tract Reveals Bacteriophages form Communities". Viruses 14, n. 2 (19 febbraio 2022): 430. http://dx.doi.org/10.3390/v14020430.
Testo completoAbstract (sommario):
The female reproductive tract (FRT) microbiome plays a vital role in maintaining vaginal health. Viruses are key regulators of other microbial ecosystems, but little is known about how the FRT viruses (virome), particularly bacteriophages that comprise the phageome, impact FRT health and dysbiosis. We hypothesize that bacterial vaginosis (BV) is associated with altered FRT phageome diversity, transkingdom interplay, and bacteriophage discriminate taxa. Here, we conducted a retrospective, longitudinal analysis of vaginal swabs collected from 54 BV-positive and 46 BV-negative South African women. Bacteriome analysis revealed samples clustered into five distinct bacterial community groups (CGs), and further, bacterial alpha diversity was significantly associated with BV. Virome analysis on a subset of baseline samples showed FRT bacteriophages clustering into novel viral state types (VSTs), a viral community clustering system based on virome composition and abundance. Distinct BV bacteriophage signatures included increased alpha diversity along with discriminant Bacillus, Burkholderia, and Escherichia bacteriophages. Bacteriophage-bacteria transkingdom associations were also identified between Bacillus and Burkholderia viruses and BV-associated bacteria, providing key insights for future studies elucidating the transkingdom interactions driving BV-associated microbiome perturbations. In this cohort, bacteriophage-bacterial associations suggest complex interactions, which may play a role in the establishment and maintenance of BV.
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Ali, Mohammed, Shurooq Kadhim e Ahmed Abdulamir. "EXTRACTION, PURIFICATION AND THERAPEUTIC USE OF BACTERIOPHAGE ENDOLYSIN AGAINST MULTI-DRUG RESISTANT PSEUDOMONAS AERUGINOSA: AN IN-VITRO AND IN-VIVO STUDY". Iraqi Journal of Medical Sciences 16, n. 4 (31 dicembre 2018): 405–12. http://dx.doi.org/10.22578/ijms.16.4.8.
Testo completoAbstract (sommario):
Background: Persistent infection with multidrug resistant Pseudomonas aeruginosa (P. aeruginosa) represents a real problem for health care providers. Bacteriophage lytic enzymes or lysins are highly evolved molecules that have been specifically developed by phages to quickly and efficiently allow their progeny to be released from the host bacterium while destructing that bacterium. Objective: Isolation of endolysin from P. aeruginosa bacteriophages, and administering them systematically in vivo lab animal and measuring their therapeutic efficacy as well as evaluation of their biosafety. Methods: This study was performed from March 2015 – August 2017, during which 50 bacteriological samples of P. aeruginosa were collected, and examined for their antibiogram, then bacteriophage cocktails were done for 5 resistant strains of them. Endolysins were extracted from their corresponding bacteriophages and characterized. The enzymatic and antibacterial activities as well in vivo therapeutic efficiency of these enzymes were investigated. Results: This study showed that the extracted endolysin from these bacteriophages was effective in treating laboratory mice from bacteremia with P. aeruginosa and saving their lives when injected intraperitoneal. Conclusion: Endolysin can be extracted directly from their bacteriophages and used effectively in proper doses to treat bacteremia in mice. Keywords: Pseudomonas aeruginosa, bacteriophage, endolysin, MDR Citation: Ali MR, Kadhim SR, Abdulamir AS. Extraction, purification and therapeutic use of bacteriophage endolysin against multi-drug resistant Pseudomonas aeruginosa: An in-vitro and in-vivo study. Iraqi JMS. 2018; 16(4): 405-412. doi: 10.22578/IJMS.16.4.8
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Gordina, E. M., S. A. Bozhkova e L. N. Smirnova. "Anti-bacterial and anti-biofilm activity of bacteriophages against <i>Klebsiella pneumoniae</i> and <i>Pseudomonas aeruginosa</i> isolated from orthopedic patients". Pacific Medical Journal, n. 1 (14 aprile 2023): 59–63. http://dx.doi.org/10.34215/1609-1175-2023-1-59-63.
Testo completoAbstract (sommario):
Objective. To investigate the susceptibility of K. pneumoniae and P. aeruginosa to a polyvalent bacteriophage preparation and its effect on biofilm formation and the strain biofilms isolated from orthopedic patients.Materials and methods. The research sample included 50 clinical isolates of K. pneumoniae and 50 clinical isolates of P. aeruginosa. Identification was performed by MALDI-TOF-MS; antibiotic susceptibility was assessed in accordance with EUCAST v 21. Detection of carbapenemase genes was carried out by real-time PCR. The strain susceptibility to the bacteriophage was determined by a spot test; K. pneumoniae ATCC 33495 and P. aeruginosa ATCC 27853 were determined by assessing their growth curves. Biofilms of strains sensitive to bacteriophages were formed according to the O’Toole method by co-incubation of bacteria with phages. The effect of bacteriophages on 24-hour biofilms was assessed by comparing the optical density of dye extracts of bacteriophage-treated wells and control wells at 570 nm. The data were analyzed using the Statistica environment.Results. It was found that 7 (14%) of K. pneumoniae and 15 (30%) of P. aeruginosa were resistant to carbapenems. Six strains of K. pneumoniae produced NDM-cabapenemase, while four isolates of P. aeruginosa produced VIM-carbapenemases. The bacteriophage preparation under study was active against 36% and 56% of K. pneumoniae and P. aeruginosa strains, respectively. The majority of the studied strains reduced biofilm production upon co-incubation with a phage; however, a decrease in biomass of greater than 80% was observed only for P. aeruginosa. The effect of the bacteriophage on the already formed biofilms was less pronounced, despite a decrease in the biofilm biomass in 78% and 68% of K.pneumoniae and P. aeruginosa strains, respectively.Conclusion. The results obtained confirm the need for further research into the action of bacteriophages against pathogens caused by implant-associated infections and the development of bacteriophage therapy for orthopedic patients.
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Connerton, P. L., A. R. Timms e I. F. Connerton. "Campylobacter bacteriophages and bacteriophage therapy". Journal of Applied Microbiology 111, n. 2 (20 aprile 2011): 255–65. http://dx.doi.org/10.1111/j.1365-2672.2011.05012.x.
Testo completo
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Styles, Kathryn M., Rapee Thummeepak, Udomluk Leungtongkam, Sophie E. Smith, Gabrielle S. Christie, Andrew Millard, John Moat et al. "Investigating Bacteriophages Targeting the Opportunistic Pathogen Acinetobacter baumannii". Antibiotics 9, n. 4 (22 aprile 2020): 200. http://dx.doi.org/10.3390/antibiotics9040200.
Testo completoAbstract (sommario):
The multi-drug resistance of the opportunistic pathogen Acinetobacter baumannii is of growing concern, with many clinical isolates proving to be resistant to last resort as well as front line antibiotic treatments. The use of bacteriophages is an attractive alternative to controlling and treating this emerging nosocomial pathogen. In this study, we have investigated bacteriophages collected from hospital wastewater in Thailand and we have explored their activity against clinical isolates of A. baumannii. Bacteriophage vB_AbaM_PhT2 showed 28% host range against 150 multidrug resistant (MDR) isolates and whole genome sequencing did not detect any known virulence factors or antibiotic resistance genes. Purified vB_AbaM_PhT2 samples had endotoxin levels below those recommended for preclinical trials and were not shown to be directly cytotoxic to human cell lines in vitro. The treatment of human brain and bladder cell lines grown in the presence of A. baumannii with this bacteriophage released significantly less lactate dehydrogenase compared to samples with no bacteriophage treatment, indicating that vB_AbaM_PhT2 can protect from A. baumannii induced cellular damage. Our results have also indicated that there is synergy between this bacteriophage and the end line antibiotic colistin. We therefore propose bacteriophage vB_AbaM_PhT2 as a good candidate for future research and for its potential development into a surface antimicrobial for use in hospitals.
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Cheong, J. P. E., J. P. E. Cheong, J. D. Brooker e J. D. Brooker. "Isolation of a virulent bacteriophage from a Propionibacterium species in the sheep rumen". Australian Journal of Agricultural Research 51, n. 1 (2000): 119. http://dx.doi.org/10.1071/ar99069.
Testo completoAbstract (sommario):
Propionibacterium is a facultative anaerobe associated with the rumen epithelium, the presence of which may influence the anaerobic environment through oxygen scavenging, as well as providing a source of propionate. Factors such as bacteriophages that influence Propionibacterium populations may therefore be important regulators of rumen function. This study describes the isolation and identification of a ruminal Propionibacterium bacteriophage. Sheep rumen fluid was screened for Propionibacterium species and 3 isolates were identified and characterised. One isolate, PA1, was used as an indicator strain to screen for the presence of Propionibacterium-specific virulent bacteriophages. A virulent bacteriophage, PB2, was isolated from clear plaques on a lawn of PA1 cells and was shown by transmission electron microscopy to be a siphovirus-like particle comprising an icosahedral head 50 nm in diameter and a tail 140 nm in length. The bacteriophage was visibly attached to and within PA1 cells, and was shown to infect all 3 ruminal isolates of Propionibacterium and 4 of 6 clinical isolates of P. acnes. Restriction mapping of bacteriophage PB2 demonstrated a 30.8 kb genome.
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Verbeken, Gilbert, Isabelle Huys, Jean-Paul Pirnay, Serge Jennes, Nina Chanishvili, Jacques Scheres, Andrzej Górski, Daniel De Vos e Carl Ceulemans. "Taking Bacteriophage Therapy Seriously: A Moral Argument". BioMed Research International 2014 (2014): 1–8. http://dx.doi.org/10.1155/2014/621316.
Testo completoAbstract (sommario):
The excessive and improper use of antibiotics has led to an increasing incidence of bacterial resistance. In Europe the yearly number of infections caused by multidrug resistant bacteria is more than 400.000, each year resulting in 25.000 attributable deaths. Few new antibiotics are in the pipeline of the pharmaceutical industry. Early in the 20th century, bacteriophages were described as entities that can control bacterial populations. Although bacteriophage therapy was developed and practiced in Europe and the former Soviet republics, the use of bacteriophages in clinical setting was neglected in Western Europe since the introduction of traditional antibiotics. Given the worldwide antibiotic crisis there is now a growing interest in making bacteriophage therapy available for use in modern western medicine. Despite the growing interest, access to bacteriophage therapy remains highly problematic. In this paper, we argue that the current state of affairs is morally unacceptable and that all stakeholders (pharmaceutical industry, competent authorities, lawmakers, regulators, and politicians) have the moral duty and the shared responsibility towards making bacteriophage therapy urgently available for all patients in need.
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Blanc, Remy, e Abid Nasser. "Effect of effluent quality and temperature on the persistence of viruses in soil". Water Science and Technology 33, n. 10-11 (1 maggio 1996): 237–42. http://dx.doi.org/10.2166/wst.1996.0680.
Testo completoAbstract (sommario):
Survival and adsorption of pathogenic viruses in soil material can effect the extent of groundwater pollution by the application of wastewater effluents to soil. This study was conducted to determine the effect of soil composition and wastewater quality on the adsorption of pathogenic viruses (hepatitis A virus and poliovirus 1) and model bacteriophages onto soil. Moreover, the effect of temperature, soil composition and water quality on the die-off of pathogenic viruses and model bacteriophages was also studied. The effect of water quality on virus adsorption to soil was virus type dependant. Poliovirus 1 adsorption was the highest regardless of water type, whereas the poorest adsorption was observed for MS2 bacteriophage. Intermediate adsorption rates were observed for PRD-1 bacteriophage. No die-off was observed for any one of the studied viruses (HAV, poliol, MS2 and PRD-1) after 20 days incubation in soil saturated with secondary/tertiary treated wastewater at 10°C. At 23°C, the greatest die-off was observed for MS2 bacteriophage, which was incubated in soil saturated with secondary and tertiary treated effluents. Intermediate die-off was observed for poliovirus 1, whereas negligible die-off was observed for HAV and PRD-1 bacteriophages. This indicates that pathogenic viruses can survive for long period of time in soil at ambient temperatures. Our results indicate that polio 1 and MS2 bacteriophage can not be used as models for the persistence of pathogenic viruses such as HAV in soil. PRD-1 bacteriophage has been found to be more suitable than MS2 to predict the persistence of pathogenic viruses especially at ambient temperatures.
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Kharaeva, Z. F., M. Sh Mustafaev, L. Z. Blieva, E. B. Barokova, S. M. Mustafaeva e S. A. Dyshekova. "Evaluation of sensitivity to bacteriophages of strains isolated from children with congenital malformations of the maxillofacial region". REPORTS ADYGE (CIRCASSIAN) INTERNATIONAL ACADEMY OF SCIENCES 20, n. 1 (2020): 40–45. http://dx.doi.org/10.47928/1726-9946-2020-20-1-40-45.
Testo completoAbstract (sommario):
Bacteriophage are used in clinical practice along with antibiotics. It is known that in many cases phage drugs are superior to other antibacterial drugs in their activity against antibiotic-resistant pathogens. Bacteriophages do not cause toxic or allergic side effects and have no contraindications.The use of bacteriophage preparations stimulates the activation of adaptive and innate immune factors, so phage therapy is particularly effective in the treatment of chronic inflammatory diseases against the background of immunosuppressive States. Bacteriophages do not interfere with the implementation of the therapeutic effect of other drugs (antibiotics, probiotics, synbiotics) and are not sensitive to their effects. The paper evaluates the sensitivity of different types of staphylococci and streptococci to specific bacteriophages, as well as to sextaphage - polyvalent piobacteriophage. In the course of research, it was found that bacterial cultures of Staphylococcus aureus showed a fairly high sensitivity to sextaphage, to which 83,3% (10 strains) of the total number of studied strains of this species were susceptible. Sensitivity to bacteriophages in Staphylococcus epidermidis strains was low. Bacterial strains of Streptococcus pyogenes showed greater susceptibility to streptococcal phage than to sextaphage. 87,5% of the strains were susceptible to streptococcal bacteriophage. Bacterial cultures of Streptococcus salivarius showed moderate susceptibility to bacteriophages.
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García-Aljaro, Cristina, Xavier Muñoz-Berbel, A. Toby A. Jenkins, Anicet R. Blanch e Francesc Xavier Muñoz. "Surface Plasmon Resonance Assay for Real-Time Monitoring of Somatic Coliphages in Wastewaters". Applied and Environmental Microbiology 74, n. 13 (9 maggio 2008): 4054–58. http://dx.doi.org/10.1128/aem.02806-07.
Testo completoAbstract (sommario):
ABSTRACT The surface plasmon resonance (SPR) technique is a well-established method for the measurement of molecules binding to surfaces and the quantification of binding constants between surface-immobilized proteins and proteins in solution. In this paper we describe an extension of the methodology to study bacteriophage-bacterium interactions. A two-channel microfluidic SPR sensor device was used to detect the presence of somatic coliphages, a group of bacteriophages that have been proposed as fecal pollution indicators in water, using their host, Escherichia coli WG5, as a target for their selective detection. The bacterium, E. coli WG5, was immobilized on gold sensor chips using avidin-biotin and bacteriophages extracted from wastewater added. The initial binding of the bacteriophage was observed at high concentrations, and a separate, time-delayed cell lysis event also was observed, which was sensitive to bacteriophage at low concentrations. As few as 1 PFU/ml of bacteriophage injected into the chamber could be detected after a phage incubation period of 120 min, which equates to an approximate limit of detection of around 102 PFU/ml. The bacteriophage-bacterium interaction appeared to cause a structural change in the surface-bound bacteria, possibly due to collapse of the cell, which was observed as an increase in mass density on the sensor chip. These results suggest that this methodology could be employed for future biosensor technologies and for quantification of the bacteriophage concentration.
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Heringa, Spencer D., JinKyung Kim, Xiuping Jiang, M. P. Doyle e M. C. Erickson. "Use of a Mixture of Bacteriophages for Biological Control of Salmonella enterica Strains in Compost". Applied and Environmental Microbiology 76, n. 15 (4 giugno 2010): 5327–32. http://dx.doi.org/10.1128/aem.00075-10.
Testo completoAbstract (sommario):
ABSTRACT Bacteriophages specific to Salmonella strains were isolated from sewage effluent and characterized. A five-strain bacteriophage mixture was applied to dairy manure compost inoculated with Salmonella enterica serotype Typhimurium. Bacteriophage treatment resulted in a greater than 2-log-unit reduction of Salmonella within 4 h at all moisture levels compared to the controls.
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Kang, Ilnam, Hani Jang, Hyun-Myung Oh e Jang-Cheon Cho. "Complete Genome Sequence of Marinomonas Bacteriophage P12026". Journal of Virology 86, n. 16 (27 luglio 2012): 8909–10. http://dx.doi.org/10.1128/jvi.01328-12.
Testo completoAbstract (sommario):
Members of the genusMarinomonasin theGammaproteobacteriaare broadly distributed in marine environments where they could be infected by bacteriophages. Here we report the genome sequence of bacteriophage P12026 that can lytically infect bacterial strain IMCC12026, a member of the genusMarinomonas. To our knowledge, this is the first genome sequence of a lytic bacteriophage infecting the genusMarinomonas.
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Bardina, Carlota, Denis A. Spricigo, Pilar Cortés e Montserrat Llagostera. "Significance of the Bacteriophage Treatment Schedule in Reducing Salmonella Colonization of Poultry". Applied and Environmental Microbiology 78, n. 18 (6 luglio 2012): 6600–6607. http://dx.doi.org/10.1128/aem.01257-12.
Testo completoAbstract (sommario):
ABSTRACTSalmonellaremains the major cause of food-borne diseases worldwide, with chickens known to be the main reservoir for this zoonotic pathogen. Among the many approaches to reducingSalmonellacolonization of broilers, bacteriophage offers several advantages. In this study, three bacteriophages (UAB_Phi20, UAB_Phi78, and UAB_Phi87) obtained from our collection that exhibited a broad host range againstSalmonella entericaserovar Enteritidis andSalmonella entericaserovar Typhimurium were characterized with respect to morphology, genome size, and restriction patterns. A cocktail composed of the three bacteriophages was more effective in promoting the lysis ofS.Enteritidis andS.Typhimurium cultures than any of the three bacteriophages alone. In addition, the cocktail was able to lyse theSalmonella entericaserovars Virchow, Hadar, and Infantis. The effectiveness of the bacteriophage cocktail in reducing the concentration ofS.Typhimurium was tested in two animal models using different treatment schedules. In the mouse model, 50% survival was obtained when the cocktail was administered simultaneously with bacterial infection and again at 6, 24, and 30 h postinfection. Likewise, in the White Leghorn chicken specific-pathogen-free (SPF) model, the best results, defined as a reduction ofSalmonellaconcentration in the chicken cecum, were obtained when the bacteriophage cocktail was administered 1 day before or just after bacterial infection and then again on different days postinfection. Our results show that frequent treatment of the chickens with bacteriophage, and especially prior to colonization of the intestinal tract bySalmonella, is required to achieve effective bacterial reduction over time.
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Shaikh, Nurmohammad, e Phillip I. Tarr. "Escherichia coli O157:H7 Shiga Toxin-Encoding Bacteriophages: Integrations, Excisions, Truncations, and Evolutionary Implications". Journal of Bacteriology 185, n. 12 (15 giugno 2003): 3596–605. http://dx.doi.org/10.1128/jb.185.12.3596-3605.2003.
Testo completoAbstract (sommario):
ABSTRACT As it descended from Escherichia coli O55:H7, Shiga toxin (Stx)-producing E. coli (STEC) O157:H7 is believed to have acquired, in sequence, a bacteriophage encoding Stx2 and another encoding Stx1. Between these events, sorbitol-fermenting E. coli O157:H− presumably diverged from this clade. We employed PCR and sequence analyses to investigate sites of bacteriophage integration into the chromosome, using evolutionarily informative STEC to trace the sequence of acquisition of elements encoding Stx. Contrary to expectations from the two currently sequenced strains, truncated bacteriophages occupy yehV in almost all E. coli O157:H7 strains that lack stx1 (stx1 -negative strains). Two truncated variants were determined to contain either GTT or TGACTGTT sequence, in lieu of 20,214 or 18,895 bp, respectively, of the bacteriophage central region. A single-nucleotide polymorphism in the latter variant suggests that recombination in that element extended beyond the inserted octamer. An stx2 bacteriophage usually occupies wrbA in stx1 +/stx2 + E. coli O157:H7, but wrbA is unexpectedly unoccupied in most stx1 -negative/stx2 + E. coli O157:H7 strains, the presumed progenitors of stx1 +/stx2 + E. coli O157:H7. Trimethoprim-sulfamethoxazole promotes the excision of all, and ciprofloxacin and fosfomycin significantly promote the excision of a subset of complete and truncated stx bacteriophages from the E. coli O157:H7 strains tested; bile salts usually attenuate excision. These data demonstrate the unexpected diversity of the chromosomal architecture of E. coli O157:H7 (with novel truncated bacteriophages and multiple stx2 bacteriophage insertion sites), suggest that stx1 acquisition might be a multistep process, and compel the consideration of multiple exogenous factors, including antibiotics and bile, when chromosome stability is examined.
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Doore, Sarah M., Jason R. Schrad, William F. Dean, John A. Dover e Kristin N. Parent. "ShigellaPhages Isolated during a Dysentery Outbreak Reveal Uncommon Structures and Broad Species Diversity". Journal of Virology 92, n. 8 (7 febbraio 2018): e02117-17. http://dx.doi.org/10.1128/jvi.02117-17.
Testo completoAbstract (sommario):
ABSTRACTIn 2016, Michigan experienced the largest outbreak of shigellosis, a type of bacillary dysentery caused byShigellaspp., since 1988. Following this outbreak, we isolated 16 novelShigella-infecting bacteriophages (viruses that infect bacteria) from environmental water sources. Most well-known bacteriophages infect the common laboratory speciesEscherichia coliandSalmonella enterica, and these phages have built the foundation of molecular and bacteriophage biology. Until now, comparatively few bacteriophages were known to infectShigellaspp., which are close relatives ofE. coli. We present a comprehensive analysis of these phages' host ranges, genomes, and structures, revealing genome sizes and capsid properties that are shared by very few previously described phages. After sequencing, a majority of theShigellaphages were found to have genomes of an uncommon size, shared by only 2% of all reported phage genomes. To investigate the structural implications of this unusual genome size, we used cryo-electron microscopy to resolve their capsid structures. We determined that these bacteriophage capsids have similarly uncommon geometry. Only two other viruses with this capsid structure have been described. Since most well-known bacteriophages infectEscherichiaorSalmonella, our understanding of bacteriophages has been limited to a subset of well-described systems. Continuing to isolate phages using nontraditional strains of bacteria can fill gaps that currently exist in bacteriophage biology. In addition, the prevalence ofShigellaphages during a shigellosis outbreak may suggest a potential impact of human health epidemics on local microbial communities.IMPORTANCEShigellaspp. bacteria are causative agents of dysentery and affect more than 164 million people worldwide every year. Despite the need to combat antibiotic-resistantShigellastrains, relatively fewShigella-infecting bacteriophages have been described. By specifically looking forShigella-infecting phages, this work has identified new isolates that (i) may be useful to combatShigellainfections and (ii) fill gaps in our knowledge of bacteriophage biology. The rare qualities of these new isolates emphasize the importance of isolating phages on “nontraditional” laboratory strains of bacteria to more fully understand both the basic biology and diversity of bacteriophages.
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Sturino, Joseph M., e Todd R. Klaenhammer. "Expression of Antisense RNA Targeted against Streptococcus thermophilus Bacteriophages". Applied and Environmental Microbiology 68, n. 2 (febbraio 2002): 588–96. http://dx.doi.org/10.1128/aem.68.2.588-596.2002.
Testo completoAbstract (sommario):
ABSTRACT Antisense RNA complementary to a putative helicase gene (hel3.1) of a cos-type Streptococcus thermophilus bacteriophage was used to impede the proliferation of a number of cos-type S. thermophilus bacteriophages and one pac-type bacteriophage. The putative helicase gene is a component of the Sfi21-type DNA replication module, which is found in a majority of the S. thermophilus bacteriophages of industrial importance. All bacteriophages that strongly hybridized a 689-bp internal hel3.1 probe were sensitive to the expression of antisense hel3.1 RNA. A 40 to 70% reduction in efficiency of plaquing (EOP) was consistently observed, with a concomitant decrease in plaque size relative to that of the S. thermophilus parental strain. When progeny were released, the burst size was reduced. Growth curves of S. thermophilus NCK1125, in the presence of variable levels of bacteriophage κ3, showed that antisense hel3.1 conferred protection, even at a multiplicity of infection of approximately 1.0. When the hel3.1 antisense RNA cassette was expressed in cis from the κ3-derived phage-encoded resistance (PER) plasmid pTRK690::ori3.1, the EOP for bacteriophages sensitive to PER and antisense targeting was reduced to between 10−7 and 10−8, beyond the resistance conferred by the PER element alone (less than 10−6). These results illustrate the first successful applications of antisense RNA and explosive delivery of antisense RNA to inhibit the proliferation of S. thermophilus bacteriophages.