The influence of external factors on bacteriophages—review

Jończyk, Ewa; Kłak, Marlena; Międzybrodzki, Ryszard; Górski, Andrzej

doi:10.1007/s12223-011-0039-8

Cited by 527 publications

(476 citation statements)

References 67 publications

(78 reference statements)

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“…Our results in agreement with Jonczy et al (2011), which they approved that some phage can be stored for a long period in neutral pH (6)(7)(8). This experiments testing the pH tolerance of the bacteriophages confirmed that the pH was very important for the infectivity of the phages.…”

Section: Of Bacteriophage Against Mrsasupporting

confidence: 92%

In Vitro Evaluation of Isolated Staphylococcal-bacteriophage in Killing Methicillin-Resistant Staphylococcus aureus

Ibrahim¹,

Sarhan²,

Salih³

2016

Adv. Anim. Vet. Sci.

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| The present study was carried out to isolate and identified the Staphylococcal-specific bacteriophage from swage water by using agar overlay method and to investigate the anti-Staphylococcal activity of Isolated Bacteriophage in-vitro. Two experiments were performed in this present study; the first one was isolation and identification of Methicillin-Resistant Staphylococcus aureus (MRSA) from post-traumatic bone infection. While the second experiment included study the infectivity of bacteriophage in-vitro to MRSA as well as effect of temperature and pH on the infectivity of phage was also studied. Results of antimicrobial susceptibility test of S. aureus isolates revealed that most of isolates were resistant to Methicillin, Cefoxitin and Pencillin G. Staphylococcus aureus phage was isolated from sewage samples by agar overlay method, the phage was characterized by clear, circular plaques ranged between 2-3 mm in diameter. TTA method for determined the Phage MIC appears to be both reliable, and reproducible. This method is laborious and time consuming, and the proposed MIC method appears to be an interesting alternative. Keywords

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Section: Of Bacteriophage Against Mrsasupporting

confidence: 92%

In Vitro Evaluation of Isolated Staphylococcal-bacteriophage in Killing Methicillin-Resistant Staphylococcus aureus

Ibrahim¹,

Sarhan²,

Salih³

2016

Adv. Anim. Vet. Sci.

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“…If contamination is discovered, a phage aliquot from a previous round can then be used to continue the process. Freezing and thawing the phages several times may be harmful to stability and so it is beneficial to perform many of the negative panning steps continuously 31 . Because the panning process does not utilize phage amplification steps after each round of positive panning 32 the process is less likely to isolate empty or incomplete phage sequences.…”

Section: Representative Resultsmentioning

confidence: 99%

Novel Atomic Force Microscopy Based Biopanning for Isolation of Morphology Specific Reagents against TDP-43 Variants in Amyotrophic Lateral Sclerosis

Williams

Venkataraman

Tian

et al. 2015

JoVE

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Because protein variants play critical roles in many diseases including TDP-43 in Amyotrophic Lateral Sclerosis (ALS), alpha-synuclein in Parkinson's disease and beta-amyloid and tau in Alzheimer's disease, it is critically important to develop morphology specific reagents that can selectively target these disease-specific protein variants to study the role of these variants in disease pathology and for potential diagnostic and therapeutic applications. We have developed novel atomic force microscopy (AFM) based biopanning techniques that enable isolation of reagents that selectively recognize disease-specific protein variants. There are two key phases involved in the process, the negative and positive panning phases. During the negative panning phase, phages that are reactive to off-target antigens are eliminated through multiple rounds of subtractive panning utilizing a series of carefully selected off-target antigens. A key feature in the negative panning phase is utilizing AFM imaging to monitor the process and confirm that all undesired phage particles are removed. For the positive panning phase, the target antigen of interest is fixed on a mica surface and bound phages are eluted and screened to identify phages that selectively bind the target antigen. The target protein variant does not need to be purified providing the appropriate negative panning controls have been used. Even target protein variants that are only present at very low concentrations in complex biological material can be utilized in the positive panning step. Through application of this technology, we acquired antibodies to protein variants of TDP-43 that are selectively found in human ALS brain tissue. We expect that this protocol should be applicable to generating reagents that selectively bind protein variants present in a wide variety of different biological processes and diseases. Video LinkThe video component of this article can be found at

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“…Temperature determines the occurrence and viability of the phages in different environments. In terms of pH, some phages persist well in acidic environments (19), but this is not the case for Cdt phages, which lose their infectivity when stored for 1 day at pH 3. In contrast, Cdt phages retain their infectivity better at pH 7 and 9, which is in line with reports of phage (17).…”

Section: Discussionmentioning

confidence: 98%

Stability and Infectivity of Cytolethal Distending Toxin Type V Gene-Carrying Bacteriophages in a Water Mesocosm and under Different Inactivation Conditions

Allué-Guardia

Jofre

Muniesa

2012

Appl Environ Microbiol

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Two cytolethal distending toxin (Cdt) type V-encoding bacteriophages (⌽62 and ⌽125) were induced spontaneously from their wild-type Escherichia coli strains and from the lysogens generated in Shigella sonnei. The stability of Cdt phages was determined at various temperatures and pH values after 1 month of storage by means of infectivity tests using a plaque blot assay and analysis of phage genomes using real-time quantitative PCR (qPCR): both were highly stable. We assessed the inactivation of Cdt phages by thermal treatment, chlorination, UV radiation, and in a mesocosm in both summer and winter. The results for the two Cdt phages showed similar trends and were also similar to the phage SOM23 used for reference, but they showed a much higher persistence than Cdt-producing E. coli. Cdt phages showed maximal inactivation after 1 h at 70°C, 30 min of UV radiation, and 30 min of contact with a 10-ppm chlorine treatment. Inactivation in a mesocosm was higher in summer than in winter, probably because of solar radiation. The treatments reduced the number of infectious phages but did not have a significant effect on the Cdt phage particles detected by qPCR. Cdt phages were quantified by qPCR in 73% of river samples, and these results suggest that Cdt phages are a genetic vehicle and the natural reservoir for cdt in the environment. Cytolethal distending toxin (Cdt) is produced by different pathogenic microorganisms, including Escherichia coli, Shigella dysenteriae (29), and Campylobacter spp. (18), among others (15,22,33). Its cytolethal distending action consists of blocking the G 2 and M phases during mitosis, which distends the cells, since cell division ceases but growth continues.Cdt consists of three subunits (CdtA, CdtB, and CdtC) that are encoded by three adjacent genes. The catalytic subunit CdtB is homologous to DNase I and is the most conserved gene due to its essential role in cellular toxicity. The other subunits act as binding proteins that deliver CdtB into target cells, thus producing the cytotoxic effect (13). Five variants of the toxin have been reported in E. coli. In some of these variants, the cdt genes are flanked by lambda-like and bacteriophage P2 genes (Cdt-I and Cdt-IV) (32). Some variants are present in inducible lambdoid prophages, such as Cdt-I (5) and Cdt-V (2), or are encoded in pVir, a conjugative plasmid (Cdt-III) (30).Recent genomic sequencing of different E. coli strains indicates that a large part of the genome consists of bacteriophage genes and that they constitute an important mechanism for adaptation to new hosts through the horizontal transfer of virulence genes (7). Cdt genes in E. coli occur independently of the presence of other virulence traits (21), which strongly suggests that they are independently acquired by horizontal gene transfer, probably by means of bacteriophages. cdt can be transduced from a cdt-positive bacteria to a cdt-negative strain by means of bacteriophages (2,5). This is an important process because this gene exchange can lead to the emergence of virulen...

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The influence of external factors on bacteriophages—review

Cited by 527 publications

References 67 publications

In Vitro Evaluation of Isolated Staphylococcal-bacteriophage in Killing Methicillin-Resistant Staphylococcus aureus

In Vitro Evaluation of Isolated Staphylococcal-bacteriophage in Killing Methicillin-Resistant Staphylococcus aureus

Novel Atomic Force Microscopy Based Biopanning for Isolation of Morphology Specific Reagents against TDP-43 Variants in Amyotrophic Lateral Sclerosis

Stability and Infectivity of Cytolethal Distending Toxin Type V Gene-Carrying Bacteriophages in a Water Mesocosm and under Different Inactivation Conditions

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