Blood lymphocyte ultrastructure and deoxyribonucleic acid content in children with systemic lupus erythematosis.

PubMed

Ptasekas, R; Matulis, A; Urmonas, V; Graziene, V; Zukiene, G

1980-01-01

Two varieties of peripheral blood lymphocytes have been disclosed in systemic lupus erythematosus (SLE) cases: one showing signs of degradation and nuclear chromatine elimination and the other one manifesting a state of biological activation, possibly of an immunologic nature. This karyostructural lymphocyte heterogeneity in SLE may cause a great scattering of these cells on histograms in respect to their nuclear deoxyribonucleic acid content determined by cytophotometry. On the other hand, the expressiveness of the scattering and the degree of predominance of negative tendency towards proliferation (with a shift to the left from 2 n) may thereby serve as a very objective quantitative indication of nuclear structure degradation and of loss by lymphocytes of chromatine with deoxyribonucleic acid during SLE.

Modification and restriction of T-even bacteriophages. In vitro degradation of deoxyribonucleic acid containing 5-hydroxymethylctosine.

PubMed

Fleischman, R A; Cambell, J L; Richardson, C C

1976-03-25

Using the single-stranded circular DNA of bacteriophage fd as template, double-stranded circular DNA has been prepared in vitro with either 5-hydroxymethylcytosine ([hmdC]DNA) or cytosine ([dC]DNA) in the product strand. Extracts prepared from Escherichia coli cells restrictive to T-even phage containing nonglucosylated DNA degrade [hmdC]DNA to acid-soluble material in vitro, but do not degrade [dC]dna. In contrast, extracts prepared from E. coli K12 rglA- rglB-, a strain permissive to T-even phage containing nonglucosylated DNA, do not degrade [hmdC]DNA or [dC]DNA. In addition, glucosylation of the [hmdC]DNA renders it resistant to degradation by extracts from restrictive strains. The conversion of [hmdC]DNA to acid-soluble material in vitro consists of an HmCyt-specific endonucleolytic cleavage requiring the presence of the RglB gene product to form a linear molecule, followed by a non-HmCyt-specific hydrolysis of the linear DNA to acid-soluble fragments, catalyzed in part by exonuclease V. The RglB protein present in extracts of E. coli K12 rglA- rglB+ has been purified 200-fold by complementation with extracts from E. coli K12 rglA- rglB-. The purified RglB protein does not contain detectable HmCyt-specific endonuclease or exonuclease activity. In vitro endonucleolytic cleavage of [hmdC]DNA thus requires additional factors present in cell extracts.

BASE COMPOSITION OF THE DEOXYRIBONUCLEIC ACID OF SULFATE-REDUCING BACTERIA

PubMed Central

Sigal, Nicole; Senez, Jacques C.; Le Gall, Jean; Sebald, Madeleine

1963-01-01

Sigal, Nicole (Laboratoire de Chimie Bactérienne du CNRS, Marseille, France), Jacques C. Senez, Jean Le Gall, and Madeleine Sebald. Base composition of the deoxyribonucleic acid of sulfate-reducing bacteria. J. Bacteriol. 85:1315–1318. 1963—The deoxyribonucleic acid constitution of several strains of sulfate-reducing bacteria has been analytically determined. The results of these studies show that this group of microorganisms includes at least four subgroups characterized by significantly different values of the adenine plus thymine to guanine plus cytosine ratio. The nonsporulated forms with polar flagellation, containing both cytochrome c3 and desulfoviridin, are divided into two subgroups. One includes the fresh-water, nonhalophilic strains with base ratio from 0.54 to 0.59, and the other includes the halophilic or halotolerant strains with base ratio from 0.74 to 0.77. The sporulated, peritrichous strains without cytochrome and desulfoviridin (“nigrificans” and “orientis”) are distinct from the above two types and differ from each other, having base ratios of 1.20 and 1.43, respectively. PMID:14047223

BASE COMPOSITION OF THE DEOXYRIBONUCLEIC ACID OF SULFATE-REDUCING BACTERIA.

PubMed

SIGAL, N; SENEZ, J C; LEGALL, J; SEBALD, M

1963-06-01

Sigal, Nicole (Laboratoire de Chimie Bactérienne du CNRS, Marseille, France), Jacques C. Senez, Jean Le Gall, and Madeleine Sebald. Base composition of the deoxyribonucleic acid of sulfate-reducing bacteria. J. Bacteriol. 85:1315-1318. 1963-The deoxyribonucleic acid constitution of several strains of sulfate-reducing bacteria has been analytically determined. The results of these studies show that this group of microorganisms includes at least four subgroups characterized by significantly different values of the adenine plus thymine to guanine plus cytosine ratio. The nonsporulated forms with polar flagellation, containing both cytochrome c(3) and desulfoviridin, are divided into two subgroups. One includes the fresh-water, nonhalophilic strains with base ratio from 0.54 to 0.59, and the other includes the halophilic or halotolerant strains with base ratio from 0.74 to 0.77. The sporulated, peritrichous strains without cytochrome and desulfoviridin ("nigrificans" and "orientis") are distinct from the above two types and differ from each other, having base ratios of 1.20 and 1.43, respectively.

Effect of Bromouracil-containing Deoxyribonucleic Acid on Bacillus subtilis

PubMed Central

Gimlin, Dixie M.; Hardman, Sue D.; Kelley, Betty N.; Butler, Grace C.; Leach, Franklin R.

1966-01-01

Gimlin, Dixie M. (Oklahoma State University, Stillwater), Sue D. Hardman, Betty N. Kelley, Grace C. Butler, and Franklin R. Leach. Effect of bromouracil-containing deoxyribonucleic acid on Bacillus subtilis. J. Bacteriol. 92:366–374. 1966.—Replacement of one-half of the thymine with bromouracil in Bacillus subtilis transforming deoxyribonucleic acid (DNA) resulted in a slight decrease in transforming activity, but, when used at high concentrations, this DNA preparation inhibited cell growth. Acid-hydrolyzed DNA, or addition of equivalent concentrations of the free base bromouracil in a transforming mixture, was without effect on cell growth. Treatment of the DNA preparation with deoxyribonuclease completely destroyed transforming activity and killing effect, whereas treatments with ribonuclease and trypsin were without effect on either transformation or killing activity. Growth of competent B. subtilis cells in test tubes was inhibited by high concentrations of both normal and bromouracil-containing DNA, with the bromouracil-containing DNA being significantly more inhibitory. This type of inhibition was also reflected in the time of division of the cells. The inhibitory effect was not due to viscosity, or to mutagenicity. The time course of killing paralleled transformation, and competency was required. These results can be interpreted as being due to uptake of homologous but imperfect DNA (containing bromouracil instead of thymine) by means of the systems involved in transformation, followed by either integration (resulting in lethal transformation, activation of a defective, nonlytic but lethal prophage) or interference with the recombination mechanism. PMID:16562122

Stabilization of T4 bacteriophage at acidic and basic pH by adsorption on paper.

PubMed

Meyer, Abigail; Greene, Melissa; Kimmelshue, Chad; Cademartiri, Rebecca

2017-12-01

Bacteriophages find applications in agriculture, medicine, and food safety. Many of these applications can expose bacteriophages to stresses that inactivate them including acidic and basic pH. Bacteriophages can be stabilized against these stresses by materials including paper, a common material in packaging and consumer products. Combining paper and bacteriophages creates antibacterial materials, which can reduce the use of antibiotics. Here we show that adsorption on paper protects T4, T5, and T7 bacteriophage from acidic and basic pH. We added bacteriophages to filter paper functionalized with carboxylic acid (carboxyl methyl cellulose) or amine (chitosan) groups, and exposed them to pH from 5.6 to 14. We determined the number of infective bacteriophages after exposure directly on the paper. All papers extended the lifetime of infective bacteriophage by at least a factor of four with some papers stabilizing bacteriophages for up to one week. The degree of stabilization depended on five main factors (i) the family of the bacteriophage, (ii) the charge of the paper and bacteriophages, (iii) the location of the bacteriophages within the paper, (iv) the ability of the paper to prevent bacteriophage-bacteriophage aggregation, and (v) the sensitivity of the bacteriophage proteins to the tested pH. Even when adsorbed on paper the bacteriophages were able to remove E. coli in milk. Choosing the right paper modification or material will protect bacteriophages adsorbed on that material against detrimental pH and other environmental challenges increasing the range of applications of bacteriophages on materials. Copyright © 2017 Elsevier B.V. All rights reserved.

Endonuclease from Micrococcus luteus Which Has Activity Toward Ultraviolet-Irradiated Deoxyribonucleic Acid: Its Action on Transforming Deoxyribonucleic Acid

PubMed Central

Setlow, R. B.; Setlow, Jane K.; Carrier, W. L.

1970-01-01

An endonuclease purified from Micrococcus luteus makes single-strand breaks in ultraviolet (UV)-irradiated, native deoxyribonucleic acid (DNA). The purified endonuclease is able to reactivate UV-inactivated transforming DNA of Haemophilus influenzae, especially when the DNA is assayed on a UV-sensitive mutant of H. influenzae. After extensive endonuclease action, there is a loss of transforming DNA when assayed on both UV-sensitive and -resistant cells. The endonuclease does not affect unirradiated DNA. The results indicate that the endonuclease function is involved in the repair of biological damage resulting from UV irradiation and that the UV-sensitive mutant is deficient in this step. We interpret the data as indicating that the various steps in the repair of DNA must be well coordinated if repair is to be effective. PMID:4314478

Regulation of Bacteriophage T5 Development by ColI Factors

PubMed Central

Moyer, R. W.; Fu, A. S.; Szabo, C.

1972-01-01

The I-type colicinogenic factor ColIb transforms Escherichia coli from a permissive to a nonpermissive host for bacteriophage T5 reproduction by preventing complete expression of the phage genome. T5-infected ColIb+ cells synthesize only class I (early) phage protein and ribonucleic acid (RNA). Neither phage-specific class II proteins [associated with viral deoxyribonucleic acid (DNA) replication] nor class III proteins (phage structural components) are formed due to the failure of the infected ColIb+ cells to synthesize class II or class III phage-specific messenger RNA. Comparable studies with T5-infected cells colicinogenic for the related ColIa factor revealed no decrease in the yield of progeny phage although the presence of the ColIa factor leads to a significant reduction in the amount of phage-directed class III protein synthesis. Images PMID:4554465

Adansonian Analysis and Deoxyribonucleic Acid Base Composition of Serratia marcescens

PubMed Central

Colwell, R. R.; Mandel, M.

1965-01-01

Colwell, R. R. (Georgetown University, Washington, D.C.), and M. Mandel. Adansonian analysis and deoxyribonucleic acid base composition of Serratia marcescens. J. Bacteriol. 89:454–461. 1965.—A total of 33 strains of Serratia marcescens were subjected to Adansonian analysis for which more than 200 coded features for each of the organisms were included. In addition, the base composition [expressed as moles per cent guanine + cytosine (G + C)] of the deoxyribonucleic acid (DNA) prepared from each of the strains was determined. Except for four strains which were intermediate between Serratia and the Hafnia and Aerobacter group C of Edwards and Ewing, the S. marcescens species group proved to be extremely homogeneous, and the different strains showed high affinities for each other (mean similarity, ¯S = 77%). The G + C ratio of the DNA from the Serratia strains ranged from 56.2 to 58.4% G + C. Many species names have been listed for the genus, but only a single clustering of the strains was obtained at the species level, for which the species name S. marcescens was retained. S. kiliensis, S. indica, S. plymuthica, and S. marinorubra could not be distinguished from S. marcescens; it was concluded, therefore, that there is only a single species in the genus. The variety designation kiliensis does not appear to be valid, since no subspecies clustering of strains with negative Voges-Proskauer reactions could be detected. The characteristics of the species are listed, and a description of S. marcescens is presented. PMID:14255714

Photodynamic Action on Native and Denatured Transforming Deoxyribonucleic Acid from Haemophilus influenzae

PubMed Central

León, Manuel Ponce-De; Cabrera-Juárez, Emiliano

1970-01-01

The photodynamic inactivation of native or denatured transforming deoxyribonucleic acid (DNA) from Haemophilus influenzae is described. The inactivation at the same pH was higher for denatured than native DNA. At acidic pH, the inactivation both for native and denatured DNA was faster than at alkaline pH. The guanine content of photoinactivated native DNA at neutral pH was less than untreated DNA. The inactivation of biological activity was more extensive than the alteration of guanine. The absorption spectrum of photoinactivated native or denatured DNA was only slightly different than the control DNA at the different experimental conditions. PMID:5309576

Bacteriophage Infecting the Myxobacterium Chondrococcus columnaris

PubMed Central

Kingsbury, David T.; Ordal, Erling J.

1966-01-01

Kingsbury, David T. (University of Washington, Seattle), and Erling J. Ordal. Bacteriophage infecting the myxobacterium Chondrococcus columnaris. J. Bacteriol. 91:1327–1332. 1966.—During a series of screening experiments, seven bacteriophages which infect the pathogenic myxobacterium Chondrococcus columnaris were isolated. Of these, one was chosen for detailed study. This phage has a wide host range among strains of C. columnaris, but does not infect other myxobacterial species tested. Morphologically, this phage resembles coliphage T2, though it is smaller. It has a head diameter of 600 A, a tail length of 1,000 A, and a tail width of 200 A. The head is attached to the tail by a well-defined neck. The turbid plaques produced by this phage are similar in appearance to those produced by coliphage λ, and average 1 mm in diameter. The phage has a latent period of 100 min, a rise period of an additional 90 min, and a burst size of 23. Calcium ions at a concentration of 0.004 m are required for adsorption. This requirement cannot be met by substitution of magnesium ions. A purified preparation of 2 × 1012 phage particles was extracted with phenol, and the nucleic acid was identified as deoxyribonucleic acid (DNA). Base ratios of the phage DNA and the DNA of two propagating strains were similar. Streptomycin at a concentration of 70 μg/ml inhibits phage infection at an early stage, probably by inhibiting injection of the phage DNA. Images PMID:5929758

Agreement Between Deoxyribonucleic Acid Base Composition and Taxometric Classification of Gram-Positive Cocci1

PubMed Central

Silvestri, L. G.; Hill, L. R.

1965-01-01

Silvestri, L. G. (Università Statale, Milan, Italy), and L. R. Hill. Agreement between deoxyribonucleic acid base composition and taxometric classification of gram-positive cocci. J. Bacteriol. 90:136–140. 1965.—It had been previously proposed, from taxometric analyses, that gram-positive, catalase-positive cocci be divided into two subgroups. Thirteen strains, representative of both subgroups, were examined for deoxyribonucleic acid (DNA) base composition, determined from melting temperatures. Per cent GC (guanine + cytosine/total bases) values fell into two groups: 30.8 to 36.5% GC and 69 to 75% GC. Strains with low per cent GC values belonged to the Staphylococcus aureus–S. saprophyticus–S. lactis taxometric subgroups, and those with high per cent GC values belonged to the S. roseus–S. afermentans subgroup. The hypothetical nature of any classification is emphasized, and, in the present work, the hypothesis derived from taxometric analyses of division into two subgroups is confirmed by the study of DNA base ratios. The two subgroups correspond, respectively, to the genera Staphylococcus and Micrococcus. PMID:16562008

Guanine Plus Cytosine Contents of the Deoxyribonucleic Acids of Some Sulfate-Reducing Bacteria: a Reassessment

PubMed Central

Skyring, G. W.; Jones, H. E.

1972-01-01

Guanine plus cytosine (GC) contents of the deoxyribonucleic acids of Desulfovibrio and Desulfotomaculum have been used as a basis for classification. Some of these data have been incorrectly calculated, resulting in errors of as much as 5% GC. This situation has been corrected by a reanalysis of existing data and by the contribution of new data. PMID:5011245

tif-Stimulated deoxyribonucleic acid repair in Escherichia coli K-12.

PubMed Central

Castellazzi, M; Jacques, M; George, J

1980-01-01

Bacterial survival is significantly increased after ultraviolet irradiation in tif sfi cells, provided that the thermosensitive tif mutation has been expressed at 41 degrees C before irradiation. This tif-mediated "reactivation of ultraviolet irradiated bacteria" needs de novo protein synthesis, as is the case for the tif-mediated reactivation of ultraviolet-irradiated phage lambda. However, in striking contrast to the phage reactivation process, this tif-mediated reactivation is no longer associated with mutagenesis. It also requires the presence of the uvrA+ excision function. These results strongly suggest the existence in Escherichia coli K-12 of a repair pathway acting on bacterial deoxyribonucleic acid which is inducible, error free, and uvr dependent. PMID:6451614

Ultraviolet electroluminescence from zinc oxide nanorods/deoxyribonucleic acid hybrid bio light-emitting diode

NASA Astrophysics Data System (ADS)

Gupta, Rohini Bhardwaj; Nagpal, Swati; Arora, Swati; Bhatnagar, Pramod Kumar; Mathur, Parmatma Chandra

2011-01-01

Ultraviolet (UV) light-emitting diode using salmon deoxyribonucleic acid (sDNA)-cetyltrimethylammonium complex as an electron blocking layer and zinc oxide (ZnO) nanorods as emissive material was fabricated. UV emission, which was blue shifted up to 335 nm with respect to the band edge emission of 390 nm, was observed. This blue shift was caused due to accumulation of electrons in the conduction band of ZnO because of a high potential barrier existing at the sDNA/ZnO interface.

Amplified spontaneous emission of Rhodamine 6G embedded in pure deoxyribonucleic acid

NASA Astrophysics Data System (ADS)

Rau, Ileana; Szukalski, Adam; Sznitko, Lech; Miniewicz, Andrzej; Bartkiewicz, Stanislaw; Kajzar, Francois; Sahraoui, Bouchta; Mysliwiec, Jaroslaw

2012-10-01

Deoxyribonucleic acid (DNA) is commonly viewed as a genetic information carrier. However, now it is recognized as a nanomaterial, rather than as a biological material, in the research field of nanotechnology. Here, we show that using pure DNA, doped with rhodamine 6G, we are able to observe amplified spontaneous emission (ASE) phenomenon. Moderate ASE threshold, photodegradation, and reasonable gain coefficient observed in this natural host gives some perspectives for practical applications of this system in biophotonics. Obtained results open the way and will be leading to construction of truly bio-lasers using nature made luminophores, such as anthocyanins.

Optoelectronic studies on heterocyclic bases of deoxyribonucleic acid for DNA photonics.

PubMed

El-Diasty, Fouad; Abdel-Wahab, Fathy

2015-10-01

The optoelectronics study of large molecules, particularly π-stacking molecules, such as DNA is really an extremely difficult task. We perform first electronic structure calculations on the heterocyclic bases of 2'-deoxyribonucleic acid based on Lorentz-Fresnel dispersion theory. In the UV-VIS range of spectrum, many of the optoelectronic parameters for DNA four bases namely adenine, guanine, cytosine and thymine are calculated and discussed. The results demonstrate that adenine has the highest hyperpolarizability, whereas thymine has the lowest hyperpolarizability. Cytosine has the lower average oscillator energy and the higher lattice energy. Thymine infers the most stable nucleic base with the lower phonon energy. Thymine also has the highest average oscillator energy and the lower lattice energy. Moreover, the four nucleic acid bases have large band gap energies less than 5 eV with a semiconducting behavior. Guanine shows the smallest band gap and the highest Fermi level energy, whereas adenine elucidates the highest band gap energy. Copyright © 2015. Published by Elsevier B.V.

Features of the damage produced by proflavine on transforming deoxyribonucleic acid.

PubMed Central

Cabrera-Juárez, E; Sánchez-Rincón, D A

1979-01-01

Proflavine formed a complex with transforming deoxyribonucleic acid (DNA) from Haemophilus influenzae, with optimal formation at a ratio of proflavine to DNA of 0.06. The rate of dissociation of the complex by dialysis increased in the order: native, denatured, renatured DNA. The transforming activity of the DNA was reduced by its interaction with proflavine. This inactivation was dependent on the physical state of the DNA, the proflavine concentration, and the temperature. DNA that had been denatured and renatured was most sensitive; native DNA was much less sensitive. The inactivation remained after dialysis and was stable to prolonged storage. It is concluded that the inactivation of transforming DNA by proflavine takes place by a mechanism different from that of DNA-proflavine complex formation. PMID:312284

Features of the damage produced by proflavine on transforming deoxyribonucleic acid.

PubMed

Cabrera-Juárez, E; Sánchez-Rincón, D A

1979-03-01

Proflavine formed a complex with transforming deoxyribonucleic acid (DNA) from Haemophilus influenzae, with optimal formation at a ratio of proflavine to DNA of 0.06. The rate of dissociation of the complex by dialysis increased in the order: native, denatured, renatured DNA. The transforming activity of the DNA was reduced by its interaction with proflavine. This inactivation was dependent on the physical state of the DNA, the proflavine concentration, and the temperature. DNA that had been denatured and renatured was most sensitive; native DNA was much less sensitive. The inactivation remained after dialysis and was stable to prolonged storage. It is concluded that the inactivation of transforming DNA by proflavine takes place by a mechanism different from that of DNA-proflavine complex formation.

Asymmetry and Extent of In Vivo Transcripition of R-Plasmid Deoxyribonucleic Acid in Escherichia coli

PubMed Central

Vapnek, Daniel; Spingler, Elizabeth

1974-01-01

Deoxyribonucleic acid-ribonucleic acid (DNA-RNA) hybridization studies have been performed with R-plasmid DNA (R538-1drd) and in vivo-synthesized RNA. R-plasmid DNA was isolated from Escherichia coli K-12, and the complementary strands were separated in cesium chloride-polyuridylic acid-polyguanylic acid gradients. DNA-RNA hybridization was performed with the separated DNA strands and RNA purified from R-plasmid-carrying cells. The results demonstrated that an asymmetric transcription of the R-plasmid DNA occurs in vivo. Hybridization was only detected with the H strand (denser strand in cesium chloride-polyuridylic acid-polyguanylic acid). By determining the density of the RNA-DNA hybrid in CsCl gradients, it was estimated that greater than 60% of the nucleotide sequences in the R-plasmid DNA are transcribed in logarithmically growing E. coli cells. No R-plasmid-specific RNA was detected in E. coli cells that did not carry the plasmid. PMID:4612013

Breaks induced in the deoxyribonucleic acid of aerosolized Escherichia coli by ozonized cyclohexene.

PubMed Central

De Mik, G; De Groot, I

1978-01-01

The inactivation of aerosolized Escherichia coli by ozone, cyclohexene, and ozonized cyclohexene was studied. The parameters for damage were loss of reproduction and introduction of breaks in the deoxyribonucleic acid (DNA). Aerosolization of E. coli in clean air at 80 percent relative humidity or in air containing either ozone or cyclohexene hardly affected survival; however, some breaks per DNA molecule were induced, as shown by sucrose gradient sedimentation of the DNA. Aerosolization of E. coli in air containing ozonized cyclohexene at 80 percent relative humidity decreased the survival by a factor of 10(3) or more after 1 h of exposure and induced many breaks in the DNA. PMID:341811

Genetic Control of the Secondary Modification of Deoxyribonucleic Acid in Escherichia coli1

PubMed Central

Mamelak, Linda; Boyer, Herbert W.

1970-01-01

The wild-type restriction and modification alleles of Escherichia coli K-12 and B were found to have no measurable effect on the patterns of methylated bases in the deoxyribonucleic acid (DNA) of these strains. The genetic region controlling the methylation of cytosine in E. coli K-12 was mapped close to his, and the presence or absence of this gene in E. coli B or E. coli K had no effect on the restriction and modification properties of these strains. Thus, only a few of the methylated bases in the DNA of these strains are involved in host modification, and the biological role of the remainder remains obscure. PMID:4919756

Linear, Single-Stranded Deoxyribonucleic Acid Isolated from Kilham Rat Virus

PubMed Central

Salzman, Lois Ann; White, Wesley L.; Kakefuda, Tsuyoshi

1971-01-01

Kilham rat virus (KRV) was grown in a rat nephroma cell line and was purified by two isopycnic centrifugations in cesium chloride. The virus contains single-stranded deoxyribonucleic acid (DNA) with a molecular weight of approximately 1.6 × 106. The DNA was extracted from the virion by both phenol extraction and by 2% sodium dodecyl sulfate at 50 C. KRV DNA, extracted by both procedures, was observed in an electron microscope by using a cytochrome c or diethylaminoethyldextran monolayer. The DNA was also exposed to exonuclease I, an enzyme which hydrolyzes specifically linear, single-stranded DNA. Hydrolysis of 70 to 80% of the DNA was observed. Both the enzymatic and the electron microscope studies support the conclusion that extracted KRV DNA is a single-stranded, linear molecule. The length of the DNA was measured in the electron microscope and determined to be 1.505 ± 0.206 μm. Images PMID:4327590

Synthesis of Deoxyribonucleic Acid After Ultraviolet Irradiation of Sensitive and Resistant Haemophilus influenzae

PubMed Central

Modak, Sohan P.; Setlow, Jane K.

1969-01-01

Synthesis of deoxyribonucleic acid (DNA) has been measured as a function of ultraviolet (UV) radiation dose in wild-type and seven UV-sensitive strains of Haemophilus influenzae. At the UV doses used, all strains were able to resume DNA synthesis, even those which are unable to excise pyrimidine dimers from their DNA. These excisionless strains showed longer UV-induced delays in DNA synthesis than all but one of the other strains. The longest delay was shown by DB117, a strain which can excise dimers but which is recombination deficient and unable to rejoin X ray-induced single-strand breaks. All strains showed a progressive decrease in sensitivity as they approached the stationary phase. PMID:5305934

Mechanisms of inactivation of bacteriophage phiX174 and its DNA in aerosols by ozone and ozonized cyclohexene.

PubMed Central

de Mik, G.; de Groot, I.

1977-01-01

The mechanisms of inactivation of aerosolized bacteriophage phiX174 in atmospheres containing ozone, cyclohexene, or ozonized cyclohexene were studied by using 32P-labelled phage. The inactivation of the aerosolized phage in clear air or in air containing cyclohexene is due to damage of the protein coat since the deoxyribonucleic acid (DNA) extracted from the inactivated phage retains its biological activity. Inactivation of the phage in air containing ozonized cyclohexene is due both to protein and DNA damage. Sucrose gradient analysis shows that aerosolized inactivated phiX174 releases unbroken DNA. In contrast, the DNA from phage phiX174 inactivated by ozonized cyclohexene is broken. The inactivation of aerosolized phage phiX174-DNA was studied in the same atmospheres using 32P-labelled DNA. phiX174-DNA aerosolized in clear air or air containing cyclohexene at 75% r.h. is inactivated by a factor of 2 in 30 min. The inactivated DNA is broken. Ozone as well as ozonized cyclohexene inactivates KNA very fast causing breaks in the molecule. This is in contrast with the intact bacteriophage in which ozone does not produce breaks in the DNA. PMID:265342

Ultraviolet-Induced Decrease in Integration of Haemophilus influenzae Transforming Deoxyribonucleic Acid in Sensitive and Resistant Cells

PubMed Central

Muhammed, Amir; Setlow, Jane K.

1970-01-01

The decrease in integration of transforming deoxyribonucleic acid (DNA) caused by ultraviolet irradiation of the DNA was found to be independent of the presence or absence of excision repair in the recipient cell. Much of the ultraviolet-induced inhibition of integration resulted from the presence in the transforming DNA of pyrimidine dimers, as judged by the photoreactivability of the inhibition with yeast photoreactivating enzyme. The inhibition of integration made only a small contribution to the inactivation of transforming ability of the DNA by ultraviolet radiation. PMID:5308769

Complete Nucleotide Sequence Analysis of a Novel Bacillus subtilis-Infecting Bacteriophage BSP10 and Its Effect on Poly-Gamma-Glutamic Acid Degradation

PubMed Central

Ghosh, Kuntal; Senevirathne, Amal; Kang, Hai Seong; Hyun, Woo Bin; Kim, Ji Eun; Kim, Kwang-Pyo

2018-01-01

While the harmful effects of lactic acid bacterial bacteriophages in the dairy industry are well-established, the importance of Bacillus subtilis-infecting bacteriophages on soybean fermentation is poorly-studied. In this study, we isolated a B. subtilis-infecting bacteriophage BSP10 from Meju (a brick of dried fermented soybean) and further characterized it. This Myoviridae family bacteriophage exhibited a narrow host range against B. subtilis strains (17/52, 32.7%). The genome of bacteriophage BSP10 is 153,767 bp long with 236 open reading frames and 5 tRNAs. Comparative genomics (using dot plot, progressiveMauve alignment, heat-plot, and BLASTN) and phylogenetic analysis strongly suggest its incorporation as a new species in the Nit1virus genus. Furthermore, bacteriophage BSP10 was efficient in the growth inhibition of B. subtilis ATCC 15245 in liquid culture and in Cheonggukjang (a soybean fermented food) fermentation. Artificial contamination of as low as 102 PFU/g of bacteriophage BSP10 during Cheonggukjang fermentation significantly reduced bacterial numbers by up to 112 fold in comparison to the control (no bacteriophage). Moreover, for the first time, we experimentally proved that B. subtilis-infecting bacteriophage greatly enhanced poly-γ-glutamic acid degradation during soybean fermentation, which is likely to negatively affect the functionalities of Cheonggukjang. PMID:29734701

Ultrastructure of Deoxyribonucleic Acid-Membrane Associations in Escherichia coli

PubMed Central

Altenburg, B. C.; Suit, Joan C.; Brinkley, B. R.

1970-01-01

Areas of contact between deoxyribonucleic acid (DNA) and intracytoplasmic membrane are frequently seen in the “extra” membrane-forming strain Escherichia coli 0111a1. By examination of serial sections, it has been estimated that these DNA-membrane associations occur in at least 60% of the extra membrane-containing cells. Most of the DNA masses contained only one contact area. Several cells in which the DNA had been stretched revealed individual fibers connecting to the membrane, suggesting a firm attachment of DNA to membrane. The areas of membrane associated with DNA fibers were usually between 100 and 500 nm in diameter, although some smaller areas were seen. Electron microscopic autoradiography of cells in which the replication forks were labeled showed grains over 24% of the profiles containing a contact area, whereas there were grains over only 16% of the profiles without a contact area. Data from autoradiographs of cells in which the label was “chased” away from the replication fork showed the reverse labeling pattern. These data indicate that the areas of contact between DNA and intracytoplasmic membranes seen in electron micrographs contain the DNA replication forks. Images PMID:4919755

Specific Effect of Guanidine in the Programming of Poliovirus Inhibition of Deoxyribonucleic Acid Synthesis

PubMed Central

Powers, C. D.; Miller, B. A.; Kurtz, H.; Ackermann, W. W.

1969-01-01

Inhibition of HeLa cell deoxyribonucleic acid (DNA) synthesis, which occurred by the 4th to 5th hr after infection with poliovirus, could be blocked completely by guanidine only when it was present before the 2nd hr. At the 2nd hr, there was no significant ribonucleic acid (RNA)-replicase activity, and addition of guanidine inhibited all production of virus but allowed 57% of maximal DNA inhibition to develop. Maximum DNA inhibition developed in cells infected for 4 hr in the presence of guanidine when the guanidine was removed for a 10-min interval. RNA-replicase activity was not enzymatically detectable and viral multiplication did not develop in these cells unless the interval without guanidine was extended to 60 min. The interpretation of the data was that the effect of guanidine on viral-induced inhibition of DNA synthesis was distinct and not a consequence of the inhibition of RNA-replicase. PMID:4305675

Cell transformation mediated by chromosomal deoxyribonucleic acid of polyoma virus-transformed cells.

PubMed Central

Della Valle, G; Fenton, R G; Basilico, C

1981-01-01

To study the mechanism of deoxyribonucleic acid (DNA)-mediated gene transfer, normal rat cells were transfected with total cellular DNA extracted from polyoma virus-transformed cells. This resulted in the appearance of the transformed phenotype in 1 X 10(-6) to 3 X 10(-6) of the transfected cells. Transformation was invariably associated with the acquisition of integrated viral DNA sequences characteristic of the donor DNA. This was caused not by the integration of free DNA molecules, but by the transfer of large DNA fragments (10 to 20 kilobases) containing linked cellular and viral sequences. Although Southern blot analysis showed that integration did not appear to occur in a homologous region of the recipient chromosome, the frequency of transformation was rather high when compared with that of purified polyoma DNA, perhaps due to "position" effects or to the high efficiency of recombination of large DNA fragments. Images PMID:6100965

Transcription of exogenous and endogenous deoxyribonucleic acid templates in cold-shocked Bacillus subtilis.

PubMed Central

Kuhl, S J; Brown, L R

1980-01-01

Ribonucleic acid (RNA) synthesis was examined in cold-shocked Bacillus subtilis cells. The cells were grown to mid-log stage, harvested, and cold shocked. RNA synthesis was monitored by the incorporation of [3H]uridine triphosphate or [alpha 32P]adenosine triphosphate into trichloroacetic acid-precipitable material in the presence of all four nucleoside triphosphates. The inhibition of RNA synthesis in cold-shocked cells by lipiarmycin, ethidium bromide, rifampin. or streptolydigin was analyzed using mutant or wild-type cells. Also examined were the effects of temperature, salt concentration, and the addition of polyamines or highly phosphorylated nucleotides. In ultraviolet-irradiated and cold-shocked cells, RNA wynthesis decreased to low levels. The addition of exogenous phi 29 or TSP-1 template to these cells caused a 13- to 20-fold increase in RNA synthesis, as monitored by trichloroacetic acid-precipitable counts. RNA synthesized in the presence of phi 29 deoxyribonucleic acid (DNA) hybridizes mainly to EcoRI fragments A and C of phi 29 DBA, These two fragments direct transcription by purified RNA polymerase in vitro and hybridize to early phi 29 DNA produced in vivo. Our results with TSP-1 DNA in this system indicated that the RNA produced hybridizes to the same fragments as early RNA produced in vivo. Plasmic pUB110 DNA was not transcribed in this system. Images PMID:6157674

Biophysical Properties of Frog Virus and Its Deoxyribonucleic Acid: Fate of Radioactive Virus in the Early Stage of Infection 1

PubMed Central

Smith, William R.; McAuslan, Brian R.

1969-01-01

Frog virus (FV-3) was banded by isopycnic centrifugation in cesium chloride, sucrose, or potassium tartrate. Two bands of infectivity were regularly found at positions in cesium chloride corresponding to densities of 1.26 and 1.30 g/cm3, respectively. Deoxyribonucleic acid from either band had the following characteristics: double-stranded; a Tm of 76.3 C in 0.1 SSC (0.015 m NaCl plus 0.015 m sodium citrate) and a buoyant density of 1.720 g/cm3 in cesium chloride, corresponding to a guanine plus cytosine content of 56 to 58% and a molecular weight of 130 × 106 daltons, determined by velocity sedimentation. These data, together with electron micrographs of sections of cells infected with material from either band suggest that two types of infectious frog virus particles exists, rather than a second virus in the frog virus stocks. The composition of frog virus was determined. It was found that highly purified preparations of frog virus were composed of 55.8% protein, 30.1% deoxyribonucleic acid, and 14.2% lipid. The kinetics of adsorption and uncoating of FV-3 was studied with radioactive virus. Uncoating is comparatively rapid and in contrast to poxvirus is unaffected by inhibitors of protein synthesis. Images PMID:4980848

A novel chaotic based image encryption using a hybrid model of deoxyribonucleic acid and cellular automata

NASA Astrophysics Data System (ADS)

Enayatifar, Rasul; Sadaei, Hossein Javedani; Abdullah, Abdul Hanan; Lee, Malrey; Isnin, Ismail Fauzi

2015-08-01

Currently, there are many studies have conducted on developing security of the digital image in order to protect such data while they are sending on the internet. This work aims to propose a new approach based on a hybrid model of the Tinkerbell chaotic map, deoxyribonucleic acid (DNA) and cellular automata (CA). DNA rules, DNA sequence XOR operator and CA rules are used simultaneously to encrypt the plain-image pixels. To determine rule number in DNA sequence and also CA, a 2-dimension Tinkerbell chaotic map is employed. Experimental results and computer simulations, both confirm that the proposed scheme not only demonstrates outstanding encryption, but also resists various typical attacks.

Tunable mechanical properties of green solid films based on deoxyribonucleic acids

NASA Astrophysics Data System (ADS)

Matsuno, Hisao; Morimitsu, Yuma; Ohta, Noboru; Sekiguchi, Hiroshi; Takahara, Atsushi; Tanaka, Keiji

Promoting green innovation to establish a worldwide low-carbon society is an urgent priority. We here show that solid films made from deoxyribonucleic acid (DNA) can be used as a structural material. The great advantage of DNA films over the ones made from synthetic polymers is that the mechanical properties are controllable, from glassy to rubbery, via semicrystalline by simply regulating the water content in the film. Why such unique mechanical properties can be manifested by the DNA films is determined from structural analyses using Fourier-transform infrared spectroscopy and wide-angle X-ray diffraction measurements. With increasing water content, the conformation of DNA was changed from A-form in an amorphous state to B-form in a partially packed one. DNA in the B-form became densely packed as the film was stretched. Also, DNAs were intermolecularly cross-linked using 2,5-hexanedione based on reductive amination induced by 2-picoline borane in aqueous phase. Cross-linking points were directly observed by atomic force microscopy. The tensile properties of cross-linked films were much better than those of non-cross-linked DNA films.

Characteristics of Deoxyribonucleic Acid Polymerase Isolated from Spores of Rhizopus stolonifer1

PubMed Central

Gong, Cheng-Shung; Dunkle, Larry D.; Van Etten, James L.

1973-01-01

Deoxyribonucleic acid (DNA)-dependent DNA polymerase was purified several hundredfold from germinated and ungerminated spores of the fungus Rhizopus stolonifer. The partially purified enzymes from both spore stages exhibited identical characteristics; incorporation of [3H]deoxythymidine monophosphate into DNA required Mg2+, DNA, a reducing agent, and the simultaneous presence of deoxyguanosine triphosphate, deoxycytidine triphosphate, and deoxyadenosine triphosphate. Heat-denatured and activated DNAs were better templates than were native DNAs. The buoyant density of the radioactive product of the reaction was similar to that of the template DNA. The enzyme is probably composed of a single polypeptide chain with an S value of 5.12 and an estimated molecular weight of 70,000 to 75,000. During the early stages of purification, the enzyme fraction from ungerminated spores required exogenous DNA for maximum activity, whereas the corresponding enzyme fraction from germinated spores did not require added DNA. Apparently DNA polymerase from germinated spores was more tightly bound to endogenous DNA than was the enzyme from ungerminated spores. PMID:4728271

Relation Between Deoxyribonucleic Acid and Intracytoplasmic Membranes in Escherichia coli O111a11

PubMed Central

Altenburg, Betty C.; Suit, Joan C.

1970-01-01

The possibility of a relationship between intracytoplasmic membranes and deoxyribonucleic acid (DNA) in Escherichia coli O111a1 has been investigated. To facilitate this investigation, a simple enzymatic assay for the amount of internal membrane present in a culture was developed. This assay was then used to show that the appearance of intracytoplasmic membranes is accompanied by an increase in the DNA content of the cells. Electron micrographs have confirmed this observation and have shown DNA to be in contact with the intracytoplasmic membranes. Extensive membranes were observed at sites of apparently unsuccessful attempts at cell division. These observations led to the conclusion that the internal membrane formed by strain O111a1 represents “extra” membrane, which is functional in that it contains sites for DNA replication, but is produced in excess because the organism is somehow defective in its regulation of membrane synthesis. Images PMID:4192984

DNA injection and genetic recombination of alkylated bacteriophage T7 in the presence of nalidixic acid.

PubMed Central

Karska-Wysocki, B; Mamet-Bratley, M D; Przewlocki, G

1977-01-01

Marker rescue experiments with alkylated T7 bacteriophage carried out in the presence and in the absence of nalidixic acid suggest that the gradient in rescue is due to two alkylation-induced causes: a DNA injection defect and an interference with DNA synthesis. PMID:916036

Campylobacter bacteriophages and bacteriophage therapy.

PubMed

Connerton, P L; Timms, A R; Connerton, I F

2011-08-01

Members of the genus Campylobacter are frequently responsible for human enteric disease with occasionally very serious outcomes. Much of this disease burden is thought to arise from consumption of contaminated poultry products. More than 80% of poultry in the UK harbour Campylobacter as a part of their intestinal flora. To address this unacceptably high prevalence, various interventions have been suggested and evaluated. Among these is the novel approach of using Campylobacter-specific bacteriophages, which are natural predators of the pathogen. To optimize their use as therapeutic agents, it is important to have a comprehensive understanding of the bacteriophages that infect Campylobacter, and how they can affect their host bacteria. This review will focus on many aspects of Campylobacter-specific bacteriophages including: their first isolation in the 1960s, their use in bacteriophage typing schemes, their isolation from the different biological sources and genomic characterization. As well as their use as therapeutic agents to reduce Campylobacter in poultry their future potential, including their use in bio-sanitization of food, will be explored. The evolutionary consequences of naturally occurring bacteriophage infection that have come to light through investigations of bacteriophages in the poultry ecosystem will also be discussed. © 2011 The Authors. Journal of Applied Microbiology © 2011 The Society for Applied Microbiology.

Deoxyribonucleic acid (DNA) cladding layers for nonlinear-optic-polymer-based electro-optic devices

NASA Astrophysics Data System (ADS)

Grote, James G.; Ogata, Naoya; Diggs, Darnell E.; Hopkins, Frank K.

2003-07-01

Nonlinear optic (NLO) polymer based electro-optic devices have been achieving world record low half wave voltages and high frequencies over the last 2-3 years. Part of the advancement is through the use of relatively more conductive polymers for the cladding layers. Based on the current materials available for these cladding materials, however, the desired optical and electromagnetic properites are being balanced for materials processability. One does not want the solvent present in one layer to dissovle the one deposited underneath, or be dissolved by the one being deposited on top. Optimized polymer cladding materials, to further enhance device performance, are continuing to be investigated. Thin films of deoxyribonucleic acid (DNA), derived from salmon sperm, show promise in providing both the desired optical and magnetic properties, as well as the desired resistance to various solvents used for NLO polymer device fabrication. Thin films of DNA were deposited on glass and silicon substrates and the film quality, optical and electromagnetic properties and resistance to various solvents were characterized.

Stability of pathogenic colony types of Neisseria gonorrhoeae in liquid culture by using the parameters of colonial morphology and deoxyribonucleic acid transformation.

PubMed Central

La Scolea, L J; Dul, M J; Young, F E

1975-01-01

This investigation describes the surveillance of the colonial stability of the pathogenic type 1 from the gonococcal strain F62 to the nonvirulent types 3 and 4 in different liquid media. The maintenance of the colony types was monitored by the parameters of colonial morphology and deoxyribonucleic acid-mediated transformation. During growth in a complex medium, Mueller-Hinton broth, only 46.7% of the gonococcal population remained as type 1 after 12 h. The greatest change in the type 1 colony-forming units correlated with the decline in viable count. The conversion process could not be prevented by the continual maintenance of the gonococcus in logarithmic growth. The frequency of transformation from PRO(minus) (proline) to PRO(plus) was proportional to this decrease in type 1 colony-forming units. In contrast to Mueller-Hinton medium, the chemically defined minimal medium Gonococcal Genetic Medium (GGM) was capable of maintaining approximately 90% of the gonococcal population in the type 1 colonial form after 16 h of growth, despite a decrease in the viable count. Although the percentage of type 1 appeared to remain constant in GGM, the apparent transformation frequency increased approximately 24-fold from 0 to 12 h of growth. GGM appears to stimulate or maintain competence, as evidenced by an eightfold increase in transformation when cells are exposed to deoxyribonucleic acid in GGM as compared to Mueller-Hinton. PMID:809469

Bacteriophage Infectivity Against Pseudomonas aeruginosa in Saline Conditions

PubMed Central

Scarascia, Giantommaso; Yap, Scott A.; Kaksonen, Anna H.; Hong, Pei-Ying

2018-01-01

Pseudomonas aeruginosa is a ubiquitous member of marine biofilm, and reduces thiosulfate to produce toxic hydrogen sulfide gas. In this study, lytic bacteriophages were isolated and applied to inhibit the growth of P. aeruginosa in planktonic mode at different temperature, pH, and salinity. Bacteriophages showed optimal infectivity at a multiplicity of infection of 10 in saline conditions, and demonstrated lytic abilities over all tested temperature (25, 30, 37, and 45°C) and pH 6–9. Planktonic P. aeruginosa exhibited significantly longer lag phase and lower specific growth rates upon exposure to bacteriophages. Bacteriophages were subsequently applied to P. aeruginosa-enriched biofilm and were determined to lower the relative abundance of Pseudomonas-related taxa from 0.17 to 5.58% in controls to 0.01–0.61% in treated microbial communities. The relative abundance of Alphaproteobacteria, Pseudoalteromonas, and Planococcaceae decreased, possibly due to the phage-induced disruption of the biofilm matrix. Lastly, when applied to mitigate biofouling of ultrafiltration membranes, bacteriophages were determined to reduce the transmembrane pressure increase by 18% when utilized alone, and by 49% when used in combination with citric acid. The combined treatment was more effective compared with the citric acid treatment alone, which reported ca. 30% transmembrane pressure reduction. Collectively, the findings demonstrated that bacteriophages can be used as a biocidal agent to mitigate undesirable P. aeruginosa-associated problems in seawater applications. PMID:29770130

High mobility organic field-effect transistor based on water-soluble deoxyribonucleic acid via spray coating

NASA Astrophysics Data System (ADS)

Shi, Wei; Han, Shijiao; Huang, Wei; Yu, Junsheng

2015-01-01

High mobility organic field-effect transistors (OFETs) by inserting water-soluble deoxyribonucleic acid (DNA) buffer layer between electrodes and pentacene film through spray coating process were fabricated. Compared with the OFETs incorporated with DNA in the conventional organic solvents of ethanol and methanol: water mixture, the water-soluble DNA based OFET exhibited an over four folds enhancement of field-effect mobility from 0.035 to 0.153 cm2/Vs. By characterizing the surface morphology and the crystalline structure of pentacene active layer through atomic force microscope and X-ray diffraction, it was found that the adoption of water solvent in DNA solution, which played a key role in enhancing the field-effect mobility, was ascribed to both the elimination of the irreversible organic solvent-induced bulk-like phase transition of pentacene film and the diminution of a majority of charge trapping at interfaces in OFETs.

Molecular Weight of Deoxyribonucleic Acid Synthesized During Initiation of Chromosome Replication in Escherichia coli

PubMed Central

Kuempel, Peter L.

1972-01-01

Alkaline sucrose gradients were used to study the molecular weight of deoxyribonucleic acid (DNA) synthesized during the initiation of chromosome replication in Escherichia coli 15 TAU-bar. The experiments were conducted to determine whether newly synthesized, replication origin DNA is attached to higher-molecular-weight parental DNA. Little of the DNA synthesized after readdition of required amino acids to cells previously deprived of the amino acids was present in DNA with a molecular weight comparable to that of the parental DNA. The newly synthesized, low-molecular-weight DNA rapidly appeared in higher-molecular-weight material, but there was an upper limit to the size of this intermediate-molecular-weight DNA. This limit was not observed when exponentially growing cells converted newly synthesized DNA to higher-molecular-weight material. The size of the intermediate-molecular-weight DNA was related to the age of the replication forks, and the size increased as the replication forks moved further from the replication origin. The results indicate that the newly synthesized replication origin DNA is not attached to parental DNA, but it is rapidly attached to the growing strands that extend from the replication fork to the replication origin, or to the other replication fork if replication is bidirectional. Experiments are reported which demonstrate that the DNA investigated was from the vicinity of the replication origin and was not plasmid DNA or DNA from random positions on the chromosome. PMID:4562387

Comparison of the virucidal efficacy of peracetic acid, potassium monopersulphate and sodium hypochlorite on bacteriophages P001 and MS2.

PubMed

Morin, T; Martin, H; Soumet, C; Fresnel, R; Lamaudière, S; Le Sauvage, A L; Deleurme, K; Maris, P

2015-09-01

The phagicidal activity of peroxy products against the virulent bacteriophage P001 infecting lactic acid bacteria and bacteriophage MS2 used as a surrogate of enteric viruses (EVs) was evaluated and compared to sodium hypochlorite using the EN 13610 European suspension test and a surface test developed in our laboratories. Infectivity tests were adapted and/or developed to determine the activity of disinfectants against reference P001 phage of Lactoccocus lactis and F-specific RNA phage MS2 of Escherichia coli in conditions simulating practical use. Similar concentrations of sodium hypochlorite were phagicidal against both bacteriophages, either at 0·05-0·125% of active chlorine using the suspension test or at 0·12-0·5% using the surface test. For Potassium monopersulphate (MPS), phagicidal concentrations varied from 0·006 to 0·012% whatever the type of test and phages. However, for peracetic acid products (PAP) used in suspension, concentrations 55 times higher were necessary against MS2 (0·271%) than against P001 (0·005%). With the surface test, 0·089-0·178% concentrations of PAP were effective against MS2, but these concentrations were 16-32 times greater than needed against P001. Sodium hypochlorite and MPS had similar phagicidal activities against P001 and MS2, but PAP did not. This is the first comparative study to investigate through suspension and surface tests the difference in resistance to peroxy compounds between a reference bacteriophage (P001) used to evaluate phagicidal concentrations in European standards and a surrogate of EVs (MS2). Results underline the importance of validation tests on pertinent surrogates of viruses or bacteriophages to adjust the concentration of disinfectants for use in the food and water industries. © 2015 The Society for Applied Microbiology.

High mobility organic field-effect transistor based on water-soluble deoxyribonucleic acid via spray coating

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shi, Wei; Han, Shijiao; Huang, Wei

High mobility organic field-effect transistors (OFETs) by inserting water-soluble deoxyribonucleic acid (DNA) buffer layer between electrodes and pentacene film through spray coating process were fabricated. Compared with the OFETs incorporated with DNA in the conventional organic solvents of ethanol and methanol: water mixture, the water-soluble DNA based OFET exhibited an over four folds enhancement of field-effect mobility from 0.035 to 0.153 cm{sup 2}/Vs. By characterizing the surface morphology and the crystalline structure of pentacene active layer through atomic force microscope and X-ray diffraction, it was found that the adoption of water solvent in DNA solution, which played a key role inmore » enhancing the field-effect mobility, was ascribed to both the elimination of the irreversible organic solvent-induced bulk-like phase transition of pentacene film and the diminution of a majority of charge trapping at interfaces in OFETs.« less

Lysogenic bacteriophage isolated from acidophilium

DOEpatents

Ward, Thomas W.; Bruhn, Debby F.; Bulmer, Deborah K.

1992-01-01

A bacteriophage identified as .phi.Ac1 capable of infecting acidophilic heterotropic bacteria (such as Acidiphilium sp.) and processes for genetically engineering acidophilic bacteria for biomining or sulfur removal from coal are disclosed. The bacteriophage is capable of growth in cells existing at pH at or below 3.0. Lytic forms of the phage introduced into areas experiencing acid drainage kill the bacteria causing such drainage. Lysogenic forms of the phase having genes for selective removal of metallic or nonmetallic elements can be introduced into acidophilic bacteria to effect removal of the desired element form ore or coal.

STUDIES ON THE BACTERIOPHAGE OF D'HÉRELLE

PubMed Central

Hetler, D. M.; Bronfenbrenner, J.

1928-01-01

1. During the process of lysis by bacteriophage, there is an appreciable increase in the amount of free amino acid present in the culture. 2. The increase of free amino acid is due to hydrolysis of bacterial protein. PMID:19869482

Methods for Bacteriophage Preservation.

PubMed

Łobocka, Małgorzata B; Głowacka, Aleksandra; Golec, Piotr

2018-01-01

In a view of growing interest in bacteriophages as the most abundant members of microbial communities and as antibacterial agents, reliable methods for bacteriophage long-term preservation, that warrant the access to original or mutant stocks of unchanged properties, have become of crucial importance. A storage method that retains the infectivity of any kind of bacteriophage virions, either in a cell lysate or in a purified suspension, does not exist, due to the enormous diversity of bacteriophages and hence the differentiation of their sensitivity to various storage conditions. Here, we describe a method of long-term bacteriophage preservation, which is based on freezing of freshly infected susceptible bacteria at early stages of bacteriophage development. The infected bacteria release mature bacteriophages upon melting enabling the recovery of bacteriophage virions with high efficiency. The only limitation of this method is the sensitivity of bacteriophage host to deep-freezing, and thus it can be used for the long-term preservation of the vast majority of bacteriophages.

Genomic diversity of bacteriophages infecting the fish pathogen Flavobacterium psychrophilum.

PubMed

Castillo, Daniel; Middelboe, Mathias

2016-12-01

Bacteriophages infecting the fish pathogen Flavobacterium psychrophilum can potentially be used to prevent and control outbreaks of this bacterium in salmonid aquaculture. However, the application of bacteriophages in disease control requires detailed knowledge on their genetic composition. To explore the diversity of F. pyschrophilum bacteriophages, we have analyzed the complete genome sequences of 17 phages isolated from two distant geographic areas (Denmark and Chile), including the previously characterized temperate bacteriophage 6H. Phage genome size ranged from 39 302 to 89 010 bp with a G+C content of 27%-32%. None of the bacteriophages isolated in Denmark contained genes associated with lysogeny, whereas the Chilean isolates were all putative temperate phages and similar to bacteriophage 6H. Comparative genome analysis showed that phages grouped in three different genetic clusters based on genetic composition and gene content, indicating a limited genetic diversity of F. psychrophilum-specific bacteriophages. However, amino acid sequence dissimilarity (25%) was found in putative structural proteins, which could be related to the host specificity determinants. This study represents the first analysis of genomic diversity and composition among bacteriophages infecting the fish pathogen F. psychrophilum and discusses the implications for the application of phages in disease control. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Dose dependence of the excision of ultraviolet-induced pyrimidine dimers from nuclear deoxyribonucleic acids of haploid and diploid Saccharomyces cerevisiae.

PubMed Central

Waters, R; Moustacchi, E

1975-01-01

The yield of ultraviolet-induced dimers is similar for a fixed dose in both haploid and diploid Saccharomyces cerevisiae. The excision of these photo-products from the nuclear deoxyribonucleic acids of cells of both ploidies after ultraviolet incident doses of 2 times 10-3 to 4 times 10-3 ergs/mm2 decreased with the corresponding increasing dose. Postirradiation incubation in saline followed by a further incubation in nutrient medium increases the excision as compared to that seen in either nutrient medium or saline alone. Previous data regarding both pyrimidine dimer removal and the survival of haploid and diploid cells after ultraviolet irradiation and either immediate or delayed plating are discussed. PMID:1090608

Decontamination of materials contaminated with Francisella philomiragia or MS2 bacteriophage using PES-Solid, a solid source of peracetic acid.

PubMed

Buhr, T L; Young, A A; Johnson, C A; Minter, Z A; Wells, C M

2014-08-01

The aim of the study was to develop test methods and evaluate survival of Francisella philomiragia cells and MS2 bacteriophage after exposure to PES-Solid (a solid source of peracetic acid) formulations with or without surfactants. Francisella philomiragia cells (≥7·6 log10 CFU) or MS2 bacteriophage (≥6·8 log10 PFU) were deposited on seven different test materials and treated with three different PES-Solid formulations, three different preneutralized samples and filter controls at room temperature for 15 min. There were 0-1·3 log10 CFU (<20 cells) of cell survival, or 0-1·7 log10 (<51 PFU) of bacteriophage survival in all 21 test combinations (organism, formulation and substrate) containing reactive PES-Solid. In addition, the microemulsion (Dahlgren Surfactant System) showed ≤2 log10 (100 cells) of viable F. philomiragia cells, indicating the microemulsion achieved <2 log10 CFU on its own. Three PES-Solid formulations and one microemulsion system (DSS) inactivated F. philomiragia cells and/or MS2 bacteriophage that were deposited on seven different materials. A test method was developed to show that reactive PES-Solid formulations and a microemulsion system (DSS) inactivated >6 log10 CFU/PFU F. philomiragia cells and/or MS2 bacteriophage on different materials. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

Predicting bacteriophage proteins located in host cell with feature selection technique.

PubMed

Ding, Hui; Liang, Zhi-Yong; Guo, Feng-Biao; Huang, Jian; Chen, Wei; Lin, Hao

2016-04-01

A bacteriophage is a virus that can infect a bacterium. The fate of an infected bacterium is determined by the bacteriophage proteins located in the host cell. Thus, reliably identifying bacteriophage proteins located in the host cell is extremely important to understand their functions and discover potential anti-bacterial drugs. Thus, in this paper, a computational method was developed to recognize bacteriophage proteins located in host cells based only on their amino acid sequences. The analysis of variance (ANOVA) combined with incremental feature selection (IFS) was proposed to optimize the feature set. Using a jackknife cross-validation, our method can discriminate between bacteriophage proteins located in a host cell and the bacteriophage proteins not located in a host cell with a maximum overall accuracy of 84.2%, and can further classify bacteriophage proteins located in host cell cytoplasm and in host cell membranes with a maximum overall accuracy of 92.4%. To enhance the value of the practical applications of the method, we built a web server called PHPred (〈http://lin.uestc.edu.cn/server/PHPred〉). We believe that the PHPred will become a powerful tool to study bacteriophage proteins located in host cells and to guide related drug discovery. Copyright © 2016 Elsevier Ltd. All rights reserved.

Cytoplasmic bacteriophage display system

DOEpatents

Studier, F.W.; Rosenberg, A.H.

1998-06-16

Disclosed are display vectors comprising DNA encoding a portion of a structural protein from a cytoplasmic bacteriophage, joined covalently to a protein or peptide of interest. Exemplified are display vectors wherein the structural protein is the T7 bacteriophage capsid protein. More specifically, in the exemplified display vectors the C-terminal amino acid residue of the portion of the capsid protein is joined to the N-terminal residue of the protein or peptide of interest. The portion of the T7 capsid protein exemplified comprises an N-terminal portion corresponding to form 10B of the T7 capsid protein. The display vectors are useful for high copy number display or lower copy number display (with larger fusion). Compositions of the type described herein are useful in connection with methods for producing a virus displaying a protein or peptide of interest. 1 fig.

Cytoplasmic bacteriophage display system

DOEpatents

Studier, F. William; Rosenberg, Alan H.

1998-06-16

Disclosed are display vectors comprising DNA encoding a portion of a structural protein from a cytoplasmic bacteriophage, joined covalently to a protein or peptide of interest. Exemplified are display vectors wherein the structural protein is the T7 bacteriophage capsid protein. More specifically, in the exemplified display vectors the C-terminal amino acid residue of the portion of the capsid protein is joined to the N-terminal residue of the protein or peptide of interest. The portion of the T7 capsid protein exemplified comprises an N-terminal portion corresponding to form 10B of the T7 capsid protein. The display vectors are useful for high copy number display or lower copy number display (with larger fusion). Compositions of the type described herein are useful in connection with methods for producing a virus displaying a protein or peptide of interest.

Integrity of nuclear genomic deoxyribonucleic acid in cooked meat: Implications for food traceability.

PubMed

Aslan, O; Hamill, R M; Sweeney, T; Reardon, W; Mullen, A M

2009-01-01

It is essential to isolate high-quality DNA from muscle tissue for PCR-based applications in traceability of animal origin. We wished to examine the impact of cooking meat to a range of core temperatures on the quality and quantity of subsequently isolated genomic (specifically, nuclear) DNA. Triplicate steak samples were cooked in a water bath (100 degrees C) until their final internal temperature was 75, 80, 85, 90, 95, or 100 degrees C, and DNA was extracted. Deoxyribonucleic acid quantity was significantly reduced in cooked meat samples compared with raw (6.5 vs. 56.6 ng/microL; P < 0.001), but there was no relationship with cooking temperature. Quality (A(260)/A(280), i.e., absorbance at 260 and 280 nm) was also affected by cooking (P < 0.001). For all 3 genes, large PCR amplicons (product size >800 bp) were observed only when using DNA from raw meat and steak cooked to lower core temperatures. Small amplicons (<200 bp) were present for all core temperatures. Cooking meat to high temperatures thus resulted in a reduced overall yield and probable fragmentation of DNA to sizes less than 800 bp. Although nuclear DNA is preferable to mitochondrial DNA for food authentication, it is less abundant, and results suggest that analyses should be designed to use small amplicon sizes for meat cooked to high core temperatures.

Hyperexpansion of RNA Bacteriophage Diversity

PubMed Central

Krishnamurthy, Siddharth R.; Janowski, Andrew B.; Zhao, Guoyan; Barouch, Dan; Wang, David

2016-01-01

Bacteriophage modulation of microbial populations impacts critical processes in ocean, soil, and animal ecosystems. However, the role of bacteriophages with RNA genomes (RNA bacteriophages) in these processes is poorly understood, in part because of the limited number of known RNA bacteriophage species. Here, we identify partial genome sequences of 122 RNA bacteriophage phylotypes that are highly divergent from each other and from previously described RNA bacteriophages. These novel RNA bacteriophage sequences were present in samples collected from a range of ecological niches worldwide, including invertebrates and extreme microbial sediment, demonstrating that they are more widely distributed than previously recognized. Genomic analyses of these novel bacteriophages yielded multiple novel genome organizations. Furthermore, one RNA bacteriophage was detected in the transcriptome of a pure culture of Streptomyces avermitilis, suggesting for the first time that the known tropism of RNA bacteriophages may include gram-positive bacteria. Finally, reverse transcription PCR (RT-PCR)-based screening for two specific RNA bacteriophages in stool samples from a longitudinal cohort of macaques suggested that they are generally acutely present rather than persistent. PMID:27010970

Chemical modification of M13 bacteriophage and its application in cancer cell imaging.

PubMed

Li, Kai; Chen, Yi; Li, Siqi; Nguyen, Huong Giang; Niu, Zhongwei; You, Shaojin; Mello, Charlene M; Lu, Xiaobing; Wang, Qian

2010-07-21

The M13 bacteriophage has been demonstrated to be a robust scaffold for bionanomaterial development. In this paper, we report on the chemical modifications of three kinds of reactive groups, i.e., the amino groups of lysine residues or N-terminal, the carboxylic acid groups of aspartic acid or glutamic acid residues, and the phenol group of tyrosine residues, on M13 surface. The reactivity of each group was identified through conjugation with small fluorescent molecules. Furthermore, the regioselectivity of each reaction was investigated by HPLC-MS-MS. By optimizing the reaction condition, hundreds of fluorescent moieties could be attached to create a highly fluorescent M13 bacteriophage. In addition, cancer cell targeting motifs such as folic acid could also be conjugated onto the M13 surface. Therefore, dual-modified M13 particles with folic acid and fluorescent molecules were synthesized via the selective modification of two kinds of reactive groups. Such dual-modified M13 particles showed very good binding affinity to human KB cancer cells, which demonstrated the potential applications of M13 bacteriophage in bioimaging and drug delivery.

Genetically engineered acidophilic heterotrophic bacteria by bacteriophage transduction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ward, T.E.; Bruhn, D.F.; Bulmer, D.F.

1989-05-10

A bacteriophage capable of infecting acidophilic heterotrophic bacteria and processes for genetically engineering acidophilic bacteria for biomining or sulfur removal from coal are disclosed. The bacteriophage is capable of growth in cells existing at pH at or below 3.0. Lytic forms of the phage introduced into areas experiencing acid drainage kill the bacteria causing such drainage. Lysogenic forms of the phage having genes for selective removal of metallic or nonmetallic elements can be introduced into acidophilic bacteria to effect removal of the desired element from ore or coal. 1 fig., 1 tab.

Computational Determination of the Effects of Bacteriophage Bacteriophage Interactions in Human body.

PubMed

Mostafa, Marwa Mostafa; Nassef, Mohammad; Badr, Amr

2017-10-19

Chronic diseases are becoming more serious and widely spreading and this carries a heavy burden on doctors to deal with such patients. Although many of these diseases can be treated by bacteriophages, the situation is significantly dangerous in patients having concomitant more than one chronic disease, where conflicts between phages used in treating these diseases are very closer to happen. This research paper presents a method to detecting the Bacteriophage-Bacteriophage Interaction. This method is implemented based on Domain-Domain Interactions model and it was used to infer Domain-Domain Interactions between the bacteriophages injected in the human body at the same time. By testing the method over bacteriophages that are used to treat tuberculosis, salmonella and virulent E.coli, many interactions have been inferred and detected between these bacteriophages. Several effects were detected for the resulted interactions such as: playing a role in DNA repair such as non-homologous end joining, playing a role in DNA replication, playing a role in the interaction between the immune system and the tumor cells and playing a role in the stiff man syndrome. We revised all patents relating to bacteriophage bacteriophage interactions and phage therapy. The proposed method is developed to help doctors to realize the effect of simultaneously injecting different bacteriophages into the human body to treat different diseases. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Association of the Bacillus subtilis Chromosome with the Cell Membrane: Resolution of Free and Bound Deoxyribonucleic Acid on Renografin Gradients

PubMed Central

Ivarie, Robert D.; Pène, Jacques J.

1970-01-01

Linear density gradients of Renografin have resolved two components of bacterial deoxyribonucleic acid (DNA) in sheared lysates. Component 1, at equilibrium density after 5 hr of centrifugation, is enriched for newly synthesized DNA and markers near the origin and terminus of replication. It contains 5% of total cellular protein, 25% of the phospholipids, 30 to 50% of the DNA, 4 to 11% of unstable ribonucleic acid (RNA), RNA polymerase, and low amounts of DNA polymerase. The material is sensitive to Pronase and Sarkosyl. In unsheared lysates, all of the DNA forms a band at this position. Shearing the lysate generates a slow-sedimenting fraction of DNA (component 2) which contains more uniformly labeled than newly synthesized DNA. These observations suggest that replicating DNA and DNA at the origin and possibly the terminus of replication are associated with membrane. The amount of uniformly labeled DNA in component 1 and an estimate of the number of chromosomal fragments suggest that other parts of the chromosome are possibly associated with the membrane. PMID:4992373

Bacteriophages and Biofilms

PubMed Central

Harper, David R.; Parracho, Helena M. R. T.; Walker, James; Sharp, Richard; Hughes, Gavin; Werthén, Maria; Lehman, Susan; Morales, Sandra

2014-01-01

Biofilms are an extremely common adaptation, allowing bacteria to colonize hostile environments. They present unique problems for antibiotics and biocides, both due to the nature of the extracellular matrix and to the presence within the biofilm of metabolically inactive persister cells. Such chemicals can be highly effective against planktonic bacterial cells, while being essentially ineffective against biofilms. By contrast, bacteriophages seem to have a greater ability to target this common form of bacterial growth. The high numbers of bacteria present within biofilms actually facilitate the action of bacteriophages by allowing rapid and efficient infection of the host and consequent amplification of the bacteriophage. Bacteriophages also have a number of properties that make biofilms susceptible to their action. They are known to produce (or to be able to induce) enzymes that degrade the extracellular matrix. They are also able to infect persister cells, remaining dormant within them, but re-activating when they become metabolically active. Some cultured biofilms also seem better able to support the replication of bacteriophages than comparable planktonic systems. It is perhaps unsurprising that bacteriophages, as the natural predators of bacteria, have the ability to target this common form of bacterial life.

Encapsulation Strategies of Bacteriophage (Felix O1) for Oral Therapeutic Application.

PubMed

Islam, Golam S; Wang, Qi; Sabour, Parviz M

2018-01-01

Due to emerging antibiotic-resistant strains among the pathogens, a variety of strategies, including therapeutic application of bacteriophages, have been suggested as a possible alternative to antibiotics in food animal production. As pathogen-specific biocontrol agents, bacteriophages are being studied intensively. Primarily their applications in the food industry and animal production have been recognized in the USA and Europe, for pathogens including Salmonella, Campylobacter, Escherichia coli, and Listeria. However, the viability of orally administered phage may rapidly reduce under the harsh acidic conditions of the stomach, presence of enzymes and bile. It is evident that bacteriophages, intended for phage therapy by oral administration, require efficient protection from the acidic environment of the stomach and should remain active in the animal's gastrointestinal tract where pathogen colonizes. Encapsulation of phages by spray drying or extrusion methods can protect phages from the simulated hostile gut conditions and help controlled release of phages to the digestive system when appropriate formulation strategy is implemented.

Uracil in formic acid hydrolysates of deoxyribonucleic acid

PubMed Central

Schein, Arnold H.

1966-01-01

1. When DNA is hydrolysed with formic acid for 30min. at 175° and the hydrolysate is chromatographed on paper with propan-2-ol–2n-hydrochloric acid, in addition to expected ultraviolet-absorbing spots corresponding to guanine, adenine, cytosine and thymine, an ultraviolet-absorbing region with RF similar to that of uracil can be detected. Uracil was separated from this region and identified by its spectra in acid and alkali, and by its RF in several solvent systems. 2. Cytosine, deoxyribocytidine and deoxyribocytidylic acid similarly treated with formic acid all yielded uracil, as did a mixture of deoxyribonucleotides. 3. Approx. 4% of deoxyribonucleotide cytosine was converted into uracil by the formic acid treatment. ImagesFig. 1. PMID:5949371

Rapid concentration of deoxyribonucleic acid via Joule heating induced temperature gradient focusing in poly-dimethylsiloxane microfluidic channel.

PubMed

Ge, Zhengwei; Wang, Wei; Yang, Chun

2015-02-09

This paper reports rapid microfluidic electrokinetic concentration of deoxyribonucleic acid (DNA) with the Joule heating induced temperature gradient focusing (TGF) by using our proposed combined AC and DC electric field technique. A peak of 480-fold concentration enhancement of DNA sample is achieved within 40s in a simple poly-dimethylsiloxane (PDMS) microfluidic channel of a sudden expansion in cross-section. Compared to a sole DC field, the introduction of an AC field can reduce DC field induced back-pressure and produce sufficient Joule heating effects, resulting in higher concentration enhancement. Within such microfluidic channel structure, negative charged DNA analytes can be concentrated at a location where the DNA electrophoretic motion is balanced with the bulk flow driven by DC electroosmosis under an appropriate temperature gradient field. A numerical model accounting for a combined AC and DC field and back-pressure driven flow effects is developed to describe the complex Joule heating induced TGF processes. The experimental observation of DNA concentration phenomena can be explained by the numerical model. Copyright © 2014 Elsevier B.V. All rights reserved.

Multiplex PCR for the detection and identification of dairy bacteriophages in milk.

PubMed

del Rio, B; Binetti, A G; Martín, M C; Fernández, M; Magadán, A H; Alvarez, M A

2007-02-01

Bacteriophage infections of starter lactic acid bacteria are a serious risk in the dairy industry. Phage infection can lead to slow lactic acid production or even the total failure of fermentation. The associated economic losses can be substantial. Rapid and sensitive methods are therefore required to detect and identify phages at all stages of the manufacture of fermented dairy products. This study describes a simple and rapid multiplex PCR method that, in a single reaction, detects the presence of bacteriophages infecting Streptococcus thermophilus and Lactobacillus delbrueckii, plus three genetically distinct 'species' of Lactococcus lactis phages commonly found in dairy plants (P335, 936 and c2). Available bacteriophage genome sequences were examined and the conserved regions used to design five pairs of primers, one for each of the above bacteriophage species. These primers were designed to generate specific fragments of different size depending on the species. Since this method can detect the above phages in untreated milk and can be easily incorporated into dairy industry routines, it might be readily used to earmark contaminated milk for use in processes that do not involve susceptible starter organisms or for use in those that involve phage-deactivating conditions.

Interaction of Bacteriophages with the Immune System: Induction of Bacteriophage-Specific Antibodies.

PubMed

Dąbrowska, Krystyna

2018-01-01

In all cases when a bacteriophage makes direct contact with a mammalian organism, it may challenge the mammalian immunological system. Its major consequence is production of antibodies specific to the bacteriophage. Here we present protocols applicable in studies of bacteriophage ability to induce specific antibodies. The protocols have been divided into three parts: purification, immunization, and detection (ELISA).

Degradation of Amino Acids and Structure in Model Proteins and Bacteriophage MS2 by Chlorine, Bromine, and Ozone.

PubMed

Choe, Jong Kwon; Richards, David H; Wilson, Corey J; Mitch, William A

2015-11-17

Proteins are important targets of chemical disinfectants. To improve the understanding of disinfectant-protein reactions, this study characterized the disinfectant:protein molar ratios at which 50% degradation of oxidizable amino acids (i.e., Met, Tyr, Trp, His, Lys) and structure were observed during HOCl, HOBr, and O3 treatment of three well-characterized model proteins and bacteriophage MS2. A critical question is the extent to which the targeting of amino acids is driven by their disinfectant rate constants rather than their geometrical arrangement. Across the model proteins and bacteriophage MS2 (coat protein), differing widely in structure, methionine was preferentially targeted, forming predominantly methionine sulfoxide. This targeting concurs with its high disinfectant rate constants and supports its hypothesized role as a sacrificial antioxidant. Despite higher HOCl and HOBr rate constants with histidine and lysine than for tyrosine, tyrosine generally was degraded in preference to histidine, and to a lesser extent, lysine. These results concur with the prevalence of geometrical motifs featuring histidines or lysines near tyrosines, facilitating histidine and lysine regeneration upon Cl[+1] transfer from their chloramines to tyrosines. Lysine nitrile formation occurred at or above oxidant doses where 3,5-dihalotyrosine products began to degrade. For O3, which lacks a similar oxidant transfer pathway, histidine, tyrosine, and lysine degradation followed their relative O3 rate constants. Except for its low reactivity with lysine, the O3 doses required to degrade amino acids were as low as or lower than for HOCl or HOBr, indicating its oxidative efficiency. Loss of structure did not correlate with loss of particular amino acids, suggesting the need to characterize the oxidation of specific geometric motifs to understand structural degradation.

Lytic bacteriophages

PubMed Central

Sharma, Manan

2013-01-01

Foodborne illnesses resulting from the consumption of produce commodities contaminated with enteric pathogens continue to be a significant public health issue. Lytic bacteriophages may provide an effective and natural intervention to reduce bacterial pathogens on fresh and fresh-cut produce commodities. The use of multi-phage cocktails specific for a single pathogen has been most frequently assessed on produce commodities to minimize the development of bacteriophage insensitive mutants (BIM) in target pathogen populations. Regulatory approval for the use of several lytic phage products specific for bacterial pathogens such as Escherichia coli O157:H7, Salmonella spp. and Listeria monocytogenes in foods and on food processing surfaces has been granted by various agencies in the US and other countries, possibly allowing for the more widespread use of bacteriophages in the decontamination of fresh and minimally processed produce. Research studies have shown lytic bacteriophages specific for E. coli O157:H7, Salmonella spp. and Listeria monocytogenes have been effective in reducing pathogen populations on leafy greens, sprouts and tomatoes. PMID:24228223

[RATIONAL ASPECTS OF BACTERIOPHAGES USE].

PubMed

Vakarina, A A; Kataeva, L V; Karpukhina, N F

2015-01-01

Analysis of existing aspects of bacteriophage use and study features of their lytic activity by using various techniques. Effect of monophages and associated bacteriophages (staphylococci, piopolyvalent and piocombined, intestiphage, pneumonia klebsiella and polyvalent klebsiella produced by "Microgen") was studied with 380 strains of Staphylococcus aureus and 279 cultures of Klebsiella pneumoniae in liquid and solid nutrient media. From patients with intestinal disorder, sensitivity was analyzed to 184 strains of Salmonella genus bacteria 18 serological variants to salmonella bacteriophages, 137 strains of Escherichia coli (lactose-negative, hemolytic), as well as some members of OKA groups (21 serovars) to coli-proteic and piopolyvalent bacteriophages. Lytic ability of the piobacteriophage against Klebsiella and Proteus genus bacteria was determined. Staphylococcus aureus was sensitive to staphylococcus bacteriophage in 71.6% of cases and to piobacteriophage--in 86.15% of cases. A 100% lytic ability of salmonella bacteriophage against Salmonella spp. was established. Sensitivity of E. coli of various serogroups to coli-proteic and piobacteriophage was 66 - 100%. Klebsiella, Proteus genus bacteria were sensitive to piobacteriophage in only 35% and 43.15% of cases, respectively. A more rational use of bacteriophages is necessary: development of a technique, evaluation of sensitivity of bacteria to bacteriophage, introduction of corrections into their production (expansion of bacteriophage spectra, determination and indication of their concentration in accompanying documents).

A MapReduce approach to diminish imbalance parameters for big deoxyribonucleic acid dataset.

PubMed

Kamal, Sarwar; Ripon, Shamim Hasnat; Dey, Nilanjan; Ashour, Amira S; Santhi, V

2016-07-01

In the age of information superhighway, big data play a significant role in information processing, extractions, retrieving and management. In computational biology, the continuous challenge is to manage the biological data. Data mining techniques are sometimes imperfect for new space and time requirements. Thus, it is critical to process massive amounts of data to retrieve knowledge. The existing software and automated tools to handle big data sets are not sufficient. As a result, an expandable mining technique that enfolds the large storage and processing capability of distributed or parallel processing platforms is essential. In this analysis, a contemporary distributed clustering methodology for imbalance data reduction using k-nearest neighbor (K-NN) classification approach has been introduced. The pivotal objective of this work is to illustrate real training data sets with reduced amount of elements or instances. These reduced amounts of data sets will ensure faster data classification and standard storage management with less sensitivity. However, general data reduction methods cannot manage very big data sets. To minimize these difficulties, a MapReduce-oriented framework is designed using various clusters of automated contents, comprising multiple algorithmic approaches. To test the proposed approach, a real DNA (deoxyribonucleic acid) dataset that consists of 90 million pairs has been used. The proposed model reduces the imbalance data sets from large-scale data sets without loss of its accuracy. The obtained results depict that MapReduce based K-NN classifier provided accurate results for big data of DNA. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Bacteriophages Infecting Propionibacterium acnes

PubMed Central

2013-01-01

Viruses specifically infecting bacteria, or bacteriophages, are the most common biological entity in the biosphere. As such, they greatly influence bacteria, both in terms of enhancing their virulence and in terms of killing them. Since the first identification of bacteriophages in the beginning of the 20th century, researchers have been fascinated by these microorganisms and their ability to eradicate bacteria. In this review, we will cover the history of the Propionibacterium acnes bacteriophage research and point out how bacteriophage research has been an important part of the research on P. acnes itself. We will further discuss recent findings from phage genome sequencing and the identification of phage sequence signatures in clustered regularly interspaced short palindromic repeats (CRISPRs). Finally, the potential to use P. acnes bacteriophages as a therapeutic strategy to combat P. acnes-associated diseases will be discussed. PMID:23691509

Comparison of Two Serologically Distinct Ribonucleic Acid Bacteriophages I. Properties of the Viral Particles

PubMed Central

Overby, L. R.; Barlow, G. H.; Doi, R. H.; Jacob, Monique; Spiegelman, S.

1966-01-01

Overby, L. R. (University of Illinois, Urbana), G. H. Barlow, R. H. Doi, Monique Jacob, and S. Spiegelman. Comparison of two serologically distinct ribonucleic acid bacteriophages. I. Properties of the viral particle. J. Bacteriol. 91:442–448. 1966.—Two ribonucleic acid (RNA) coliphages, MS-2 and Qβ, have been characterized physically and serologically. MS-2 has an S20, w value of 79, a molecular weight of 3.6 × 106, a density of 1.422, and pH 3.9 as its isoelectric point. Qβ has an S20, w of 84, a molecular weight of 4.2 × 106, a density of 1.439, and an isoelectric point at pH 5.3. One host (Escherichia coli A-19) permits a distinction between the two on the basis of a marked difference in plaque size. They are distinct immunochemically, no serological cross-reaction being detectable. Images PMID:5903109

Toward modern inhalational bacteriophage therapy: nebulization of bacteriophages of Burkholderia cepacia complex.

PubMed

Golshahi, Laleh; Seed, Kimberley D; Dennis, Jonathan J; Finlay, Warren H

2008-12-01

Antibiotic-resistant bacterial infections have renewed interest in finding substitute methods of treatment. The purpose of the present in vitro study was to investigate the possibility of respiratory delivery of a Burkholderia cepacia complex (BCC) bacteriophage by nebulized aerosol administration. Bacteriophages in isotonic saline were aerosolized with Pari LC star and eFlow nebulizers, at titers with mean value (standard deviation) of 2.15 x 10(8) (1.63 x 10(8)) plaque-forming unit (PFU)/mL in 2.5-mL nebulizer fills. The breathing pattern of an adult was simulated using a pulmonary waveform generator. During breath simulation, the size distributions of the nebulized aerosol were measured using phase doppler anemometry (PDA). Efficiency of nebulizer delivery was subsequently determined by collection of aerosol on low resistance filters and measurement of bacteriophage titers. These filter titers were used as input data to a mathematical lung deposition model to predict regional deposition of bacteriophages in the lung and initial bacteriophage titers in the liquid surface layer of each conducting airway generation. The results suggest that BCC bacteriophages can be nebulized successfully within a reasonable delivery time and predicted titers in the lung indicate that this method may hold potential for treatment of bacterial lung infections common among cystic fibrosis patients.

Lidocaine and ropivacaine, but not bupivacaine, demethylate deoxyribonucleic acid in breast cancer cells in vitro.

PubMed

Lirk, P; Hollmann, M W; Fleischer, M; Weber, N C; Fiegl, H

2014-07-01

Lidocaine demethylates deoxyribonucleic acid (DNA) in breast cancer cells. This modification of epigenetic information may be of therapeutic relevance in the perioperative period, because a decrease in methylation can reactivate tumour suppressor genes and inhibit tumour growth. The objectives of this study were to determine the effect of two amide local anaesthetics, ropivacaine and bupivacaine, on methylation in two breast cancer cell lines and to detect whether the combination of lidocaine with the chemotherapy agent 5-aza-2'-deoxycytidine (DAC) would result in additive demethylating effects. Breast cancer cell lines BT-20 [oestrogen receptor (ER)-negative] and MCF-7 (ER-positive) were incubated with lidocaine, bupivacaine, and ropivacaine to assess demethylating properties. Then, we tested varying concentrations of lidocaine and DAC to assess whether their demethylating effects were additive. Cell numbers and global methylation status were analysed. Lidocaine decreased methylation in BT-20 and MCF-7 cells, ropivacaine decreased methylation in BT-20 cells, and bupivacaine had no demethylating effect. When combined, lidocaine and DAC had additive demethylating effects. At clinically relevant doses, lidocaine and ropivacaine exert demethylating effects on specific breast cancer cell lines, but bupivacaine does not. The demethylating effects of lidocaine and DAC are indeed additive. © The Author [2014]. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Bacteriophage in polar inland waters

USGS Publications Warehouse

Säwström, Christin; Lisle, John; Anesio, A.M.; Priscu, John C.; Laybourn-Parry, J.

2008-01-01

Bacteriophages are found wherever microbial life is present and play a significant role in aquatic ecosystems. They mediate microbial abundance, production, respiration, diversity, genetic transfer, nutrient cycling and particle size distribution. Most studies of bacteriophage ecology have been undertaken at temperate latitudes. Data on bacteriophages in polar inland waters are scant but the indications are that they play an active and dynamic role in these microbially dominated polar ecosystems. This review summarises what is presently known about polar inland bacteriophages, ranging from subglacial Antarctic lakes to glacial ecosystems in the Arctic. The review examines interactions between bacteriophages and their hosts and the abiotic and biotic variables that influence these interactions in polar inland waters. In addition, we consider the proportion of the bacteria in Arctic and Antarctic lake and glacial waters that are lysogenic and visibly infected with viruses. We assess the relevance of bacteriophages in the microbial loop in the extreme environments of Antarctic and Arctic inland waters with an emphasis on carbon cycling.

Nanoscale bacteriophage biosensors beyond phage display.

PubMed

Lee, Jong-Wook; Song, Jangwon; Hwang, Mintai P; Lee, Kwan Hyi

2013-01-01

Bacteriophages are traditionally used for the development of phage display technology. Recently, their nanosized dimensions and ease with which genetic modifications can be made to their structure and function have put them in the spotlight towards their use in a variety of biosensors. In particular, the expression of any protein or peptide on the extraluminal surface of bacteriophages is possible by genetically engineering the genome. In addition, the relatively short replication time of bacteriophages offers researchers the ability to generate mass quantities of any given bacteriophage-based biosensor. Coupled with the emergence of various biomarkers in the clinic as a means to determine pathophysiological states, the development of current and novel technologies for their detection and quantification is imperative. In this review, we categorize bacteriophages by their morphology into M13-based filamentous bacteriophages and T4- or T7-based icosahedral bacteriophages, and examine how such advantages are utilized across a variety of biosensors. In essence, we take a comprehensive approach towards recent trends in bacteriophage-based biosensor applications and discuss their outlook with regards to the field of biotechnology.

Nanoscale bacteriophage biosensors beyond phage display

PubMed Central

Lee, Jong-Wook; Song, Jangwon; Hwang, Mintai P; Lee, Kwan Hyi

2013-01-01

Bacteriophages are traditionally used for the development of phage display technology. Recently, their nanosized dimensions and ease with which genetic modifications can be made to their structure and function have put them in the spotlight towards their use in a variety of biosensors. In particular, the expression of any protein or peptide on the extraluminal surface of bacteriophages is possible by genetically engineering the genome. In addition, the relatively short replication time of bacteriophages offers researchers the ability to generate mass quantities of any given bacteriophage-based biosensor. Coupled with the emergence of various biomarkers in the clinic as a means to determine pathophysiological states, the development of current and novel technologies for their detection and quantification is imperative. In this review, we categorize bacteriophages by their morphology into M13-based filamentous bacteriophages and T4- or T7-based icosahedral bacteriophages, and examine how such advantages are utilized across a variety of biosensors. In essence, we take a comprehensive approach towards recent trends in bacteriophage-based biosensor applications and discuss their outlook with regards to the field of biotechnology. PMID:24143096

Kinetics of Nucleic Acid Synthesis in Human Embryonic Kidney Cultures Infected with Adenovirus 2 or 12: Inhibition of Cellular Deoxyribonucleic Acid Synthesis

PubMed Central

Ledinko, Nada; Fong, Caroline K. Y.

1969-01-01

Infection of human embryonic kidney (HEK) cell cultures with adenovirus types 2 or 12 resulted in an initial drop in the rate of incorporation of 3H-thymidine into deoxyribonucleic acid (DNA) during the early latent period of virus growth, followed by a marked rise in label uptake. It was shown by cesium chloride isopycnic centrifugation that, after adenovirus 2 infection, there was a decrease in the rate of incorporation of thymidine into cellular DNA. Moreover, DNA-DNA hybridization experiments revealed that, by 28 to 32 hr after infection with either adenovirus 2 or 12, the amount of isolated pulse-labeled DNA capable of hybridizing with HEK cell DNA was reduced by approximately 60 to 70%. Autoradiographic measurements showed that the inhibition of cellular DNA synthesis was due to a decrease in the ability of an infected cell to synthesize DNA. The adenovirus-induced inhibition of host cell DNA synthesis was not due to degradation of cellular DNA. 3H-thymidine incorporated into cellular DNA at the time of infection remained acid-precipitable, and labeled material was not incorporated into viral DNA. Furthermore, when zone sedimentation through neutral or alkaline sucrose density gradients was employed, no detectable change was observed in the sedimentation rate of this cellular DNA at various times after infection with adenovirus 2 or 12. In addition, there was no increase in deoxyribonuclease activity in cells infected with either virus. Cultures infected for 38 hr with adenovirus 2 or 12 incorporated three to four times as much 3H-uridine into ribonucleic acid (RNA) as did non-infected cultures. Furthermore, the net RNA synthesized by infected cultures substantially exceeded that of control cultures. The activity of thymidine kinase was induced, but there was no stimulation of uridine kinase. PMID:5806981

Comparison of the effects of arabinosyladenine, arabinosylhypoxanthine, and arabinosyladenine 5'-monophosphate against herpes simplex virus, varicella-zoster virus, and cytomegalovirus with their effects on cellular deoxyribonucleic acid synthesis.

PubMed Central

Gephart, J F; Lerner, A M

1981-01-01

In a single line of human foreskin fibroblasts, minimum inhibitory concentrations (MICs) and the minimum intracellular virus inactivation concentrations (MIICs) of arabinosyladenine, arabinosylhypoxanthine, and arabinosyladenine 5'-monophosphate were assayed for a number of recent isolates of herpes simplex virus types 1 and 2 (HSV-1, HSV-2), varicella-zoster virus (VZV), and cytomegalovirus (CMV). (The term MIIC is used here to describe the selective qualitative intracellular inhibition of the virus inoculum in the primary tissue cultures. The inoculum is not recoverable in subcultures free of antiviral agent.) MICs and MIICs of each of the antiviral agents were readily obtained for each strain of HSV-1, HSV-2, and VZV tested, but all seven strains of CMV tested were much more resistant. At the endpoint, there was little variation in the MICs or MIICs among strans of the same virus. Final MIC results for HSV-1 and HSV-2 were complete after 3 days of incubation; CMV and VZV results required as long as 6 days. The MIC for each herpesvirus increased with incubation, but at the endpoint the MIC and MIIC were approximately equal. VZV was most susceptible to each drug, followed by HSV-1 and HSV-2. The latter two viruses were quite similar. There was no difference in antiviral susceptibilities among any of the strains of HSV-1, HSV-2, VZV, or CMV tested. The toxicities of arabinosyladenine, arabinosylhypoxanthine, and arabinosyladenine 5'-monophosphate were simultaneously compared by using both microscopic cytotoxicity and inhibition of uptakes of [14C]thymidine into cellular deoxyribonucleic acid and of 14C-labeled amino acids into protein. The selective inhibition of each antiviral agent against viral and cellular deoxyribonucleic acid polymerases was confirmed. Simultaneous assays of antiviral and anticellular activities of antiviral agents may be useful in projecting further in vivo experiments. PMID:6166244

Differential bacteriophage mortality on exposure to copper.

PubMed

Li, Jinyu; Dennehy, John J

2011-10-01

Many 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 (CuSO(4)) 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.

Screening of Pro-Asp Sequences Exposed on Bacteriophage M13 as an Ideal Anchor for Gold Nanocubes.

PubMed

Lee, Hwa Kyoung; Lee, Yujean; Kim, Hyori; Lee, Hye-Eun; Chang, Hyejin; Nam, Ki Tae; Jeong, Dae Hong; Chung, Junho

2017-09-15

Bacteriophages are thought to be ideal vehicles for linking antibodies to nanoparticles. Here, we define the sequence of peptides exposed as a fusion protein on M13 bacteriophages to yield optimal binding of gold nanocubes and efficient bacteriophage amplification. We generated five helper bacteriophage libraries using AE(X) 2 DP, AE(X) 3 DP, AE(X) 4 DP, AE(X) 5 DP, and AE(X) 6 DP as the exposed portion of pVIII, in which X was a randomized amino acid residue encoded by the nucleotide sequence NNK. Efficient phage amplification was achievable only in the AE(X) 2 DP, AE(X) 3 DP, and AE(X) 4 DP libraries. Through biopanning with gold nanocubes, we enriched the phage clones and selected the clone with the highest fold change after enrichment. This clone displayed Pro-Asp on the surface of the bacteriophage and had amplification yields similar to those of the wild-type helper bacteriophage (VCSM13). The clone displayed even binding of gold nanocubes along its length and minimal aggregation after binding. We conclude that, for efficient amplification, the exposed pVIII amino acid length should be limited to six residues and Ala-Glu-Pro-Asp-Asp-Pro (AEPDDP) is the ideal fusion protein sequence for guaranteeing the optimal formation of a complex with gold nanocubes.

[Strategies to prevent bacteriophage infection in industrial fermentation].

PubMed

Shen, Juntao; Xiu, Zhilong

2017-12-25

During the development of bacteria-based biotechnology, bacteriophage infection is one of the constant threats and troublesome problems in industrial fermentation. The core of puzzled bacteriophage infection is a complex arm race of coevolution between bacteriophages and their hosts where bacteriophage has evolved lots of escaped ways against bacterial resistance mechanisms. The strategies of rationally designing factories and rotation of starter strains could reduce the risk of bacteriophage infection, but often fail to avoid. Genetic engineering to increase bacterial resistance is one of the strategies to prevent bacteriophage infection and more knowledge about bacteriophage and its host is needed. Recently, there are some new findings on bacterial resistance mechanisms which provide new solutions for bacteriophage infection. For example, it is possible for a rational design of resistant strains to use CRISPR-Cas based technologies just based on the sequences of bacteriophages. Moreover, it is also possible to avoid the escape of bacteriophage by iteratively building up resistance levels to generate robust industrial starter cultures. Quorum-sensing signal molecules have recently been proved to be involved in the interactions between bacteria and bacteriophages, which provides a possible way to solve bacteriophage infection from a population level. Finally, the rapid development of bacteriophage genome editing and synthetic biology will bring some new cues for preventing bacteriophage infection in industrial fermentation.

Interpretation of sucrose gradient sedimentation pattern of deoxyribonucleic acid fragments resulting from random breaks.

PubMed

Litwin, S; Shahn, E; Kozinski, A W

1969-07-01

Mass distribution in a sucrose gradient of deoxyribonucleic acid (DNA) fragments arising as a result of random breaks is predicted by analytical means from which computer evaluations are plotted. The analytical results are compared with the results of verifying experiments: (i) a Monte Carlo computer experiment in which simulated molecules of DNA were individuals of unit length subjected to random "breaks" applied by a random number generator, and (ii) an in vitro experiment in which molecules of T4 DNA, highly labeled with (32)P, were stored in liquid nitrogen for variable periods of time during which a precisely known number of (32)P atoms decayed, causing single-stranded breaks. The distribution of sizes of the resulting fragments was measured in an alkaline sucrose gradient. The profiles obtained in this fashion were compared with the mathematical predictions. Both experiments agree with the analytical approach and thus permit the use of the graphs obtained from the latter as a means of determining the average number of random breaks in DNA from distributions obtained experimentally in a sucrose gradient. An example of the application of this procedure to a previously unresolved problem is provided in the case of DNA from ultraviolet-irradiated phage which undergoes a dose-dependent intracellular breakdown. The relationship between the number of lethal hits and the number of single-stranded breaks was not previously established. A comparison of the calculated number of nicks per strand of DNA with the known dose in phage-lethal hits reveals a relationship closely approximating one lethal hit to one single-stranded break.

Morphokinetic Reaction of Cells of Streptococcus faecalis (ATCC 9790) to Specific Inhibition of Macromolecular Synthesis: Dependence of Mesosome Growth on Deoxyribonucleic Acid Synthesis

PubMed Central

Higgins, Michael L.; Daneo-Moore, Lolita

1972-01-01

The application of quantitative electron microscopy to thin sections of cells of Streptococcus faecalis specifically inhibited for deoxyribonucleic acid (DNA), ribonucleic acid, and protein synthesis shows that septal mesosomes (i) increase in size when protein synthesis is inhibited by at least 80% while DNA synthesis proceeds at no less than 50% of the control rate and (ii) decrease in size when DNA synthesis is inhibited 50% or more during the initial 10 min of treatment. This indicates that fluctuations in mesosome size are dependent on the extent of DNA synthesis. The fluctuations in mesosome areas observed on treatment do not correlate with the kinetics of glycerol incorporation per milliliter of a culture. However, when glycerol incorporation is placed on a per cell basis, a strong correlation is observed between increases in (i) the thickness of the electron-transparent layer of the cytoplasmic membrane and (ii) the amount of glycerol incorporated per cell. It seems that the electron-transparent membrane layer may thicken to accommodate changes in lipid content when protein and lipid synthesis are uncoupled. Images PMID:4110926

Incorporation of T4 bacteriophage in electrospun fibres.

PubMed

Korehei, R; Kadla, J

2013-05-01

Antibacterial food packaging materials, such as bacteriophage-activated electrospun fibrous mats, may address concerns triggered by waves of bacterial food contamination. To address this, we investigated several efficient methods for incorporating T4 bacteriophage into electrospun fibrous mats. The incorporation of T4 bacteriophage using simple suspension electrospinning led to more than five orders of magnitude decrease in bacteriophage activity. To better maintain bacteriophage viability, emulsion electrospinning was developed where the T4 bacteriophage was pre-encapsulated in an alginate reservoir via an emulsification process and subsequently electrospun into fibres. This resulted in an increase in bacteriophage viability, but there was still two orders of magnitude drop in activity. Using a coaxial electrospinning process, full bacteriophage activity could be maintained. In this process, a core/shell fibre structure was formed with the T4 bacteriophage being directly incorporated into the fibre core. The core/shell fibre encapsulated bacteriophage exhibited full bacteriophage viability after storing for several weeks at +4°C. Coaxial electrospinning was shown to be capable of encapsulating bacteriophages with high loading capacity, high viability and long storage time. These results are significant in the context of controlling and preventing bacterial infections in perishable foods during storage. © 2013 The Society for Applied Microbiology.

Multiple roles of genome-attached bacteriophage terminal proteins

DOE Office of Scientific and Technical Information (OSTI.GOV)

Redrejo-Rodríguez, Modesto; Salas, Margarita, E-mail: msalas@cbm.csic.es

2014-11-15

Protein-primed replication constitutes a generalized mechanism to initiate DNA or RNA synthesis in linear genomes, including viruses, gram-positive bacteria, linear plasmids and mobile elements. By this mechanism a specific amino acid primes replication and becomes covalently linked to the genome ends. Despite the fact that TPs lack sequence homology, they share a similar structural arrangement, with the priming residue in the C-terminal half of the protein and an accumulation of positively charged residues at the N-terminal end. In addition, various bacteriophage TPs have been shown to have DNA-binding capacity that targets TPs and their attached genomes to the host nucleoid.more » Furthermore, a number of bacteriophage TPs from different viral families and with diverse hosts also contain putative nuclear localization signals and localize in the eukaryotic nucleus, which could lead to the transport of the attached DNA. This suggests a possible role of bacteriophage TPs in prokaryote-to-eukaryote horizontal gene transfer. - Highlights: • Protein-primed genome replication constitutes a strategy to initiate DNA or RNA synthesis in linear genomes. • Bacteriophage terminal proteins (TPs) are covalently attached to viral genomes by their primary function priming DNA replication. • TPs are also DNA-binding proteins and target phage genomes to the host nucleoid. • TPs can also localize in the eukaryotic nucleus and may have a role in phage-mediated interkingdom gene transfer.« less

Preliminary individualized chemotherapy for malignant astrocytomas based on O6-methylguanine-deoxyribonucleic acid methyltransferase methylation analysis.

PubMed

Watanabe, Takao; Katayama, Yoichi; Ogino, Akiyoshi; Ohta, Takashi; Yoshino, Atsuo; Fukushima, Takao

2006-08-01

O(6)-methylguanine-deoxyribonucleic acid methyltransferase gene (MGMT) methylation is apparently correlated with responsiveness to nitrosourea chemotherapy, suggesting this alkylating agent should be effective against MGMT-methylated tumors. MGMT appears not to be linked to platinum resistance, so platinum chemotherapy should be used for MGMT-unmethylated tumors. This study was a preliminary trial of individualized chemotherapy based on MGMT methylation status in a total of 20 patients with newly diagnosed malignant astrocytomas (9 anaplastic astrocytomas and 11 glioblastomas multiforme). The procarbazine, 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-2(2-chloroethyl)-3-nitrosourea, and vincristine (PAV) regimen was administered to seven patients with MGMT-methylated tumors, and the carboplatin and etoposide (CE) regimen was administered to 13 patients with MGMT-unmethylated tumors. Objective response to the PAV therapy was noted in all three patients with measurable residual tumor (2 complete responses and 1 partial response). Five of the seven patients continued to be disease-free after initiation of the PAV therapy. Objective response to the CE therapy was seen in only one of seven patients with measurable residual tumor (1 partial response). Three of the 13 patients were free from progression, whereas the remaining 10 patients showed early progression. The PAV regimen is effective against MGMT-methylated malignant astrocytomas, but the CE regimen is not useful at the given dose and schedule in MGMT-unmethylated tumors.

Bacteriophages as Potential Treatment for Urinary Tract Infections

PubMed Central

Sybesma, Wilbert; Zbinden, Reinhard; Chanishvili, Nino; Kutateladze, Mzia; Chkhotua, Archil; Ujmajuridze, Aleksandre; Mehnert, Ulrich; Kessler, Thomas M.

2016-01-01

Background: Urinary tract infections (UTIs) are among the most prevalent microbial diseases and their financial burden on society is substantial. The continuing increase of antibiotic resistance worldwide is alarming so that well-tolerated, highly effective therapeutic alternatives are urgently needed. Objective: To investigate the effect of bacteriophages on Escherichia coli and Klebsiella pneumoniae strains isolated from the urine of patients suffering from UTIs. Material and methods: Forty-one E. coli and 9 K. pneumoniae strains, isolated from the urine of patients suffering from UTIs, were tested in vitro for their susceptibility toward bacteriophages. The bacteriophages originated from either commercially available bacteriophage cocktails registered in Georgia or from the bacteriophage collection of the George Eliava Institute of Bacteriophage, Microbiology and Virology. In vitro screening of bacterial strains was performed by use of the spot-test method. The experiments were implemented three times by different groups of scientists. Results: The lytic activity of the commercial bacteriophage cocktails on the 41 E. coli strains varied between 66% (Pyo bacteriophage) and 93% (Enko bacteriophage). After bacteriophage adaptation of the Pyo bacteriophage cocktail, its lytic activity was increased from 66 to 93% and only one E. coli strain remained resistant. One bacteriophage of the Eliava collection could lyse all 9 K. pneumoniae strains. Conclusions: Based on the high lytic activity and the potential of resistance optimization by direct adaption of bacteriophages as reported in this study, and in view of the continuing increase of antibiotic resistance worldwide, bacteriophage therapy is a promising treatment option for UTIs highly warranting randomized controlled trials. PMID:27148173

Bacteriophages as Potential Treatment for Urinary Tract Infections.

PubMed

Sybesma, Wilbert; Zbinden, Reinhard; Chanishvili, Nino; Kutateladze, Mzia; Chkhotua, Archil; Ujmajuridze, Aleksandre; Mehnert, Ulrich; Kessler, Thomas M

2016-01-01

Urinary tract infections (UTIs) are among the most prevalent microbial diseases and their financial burden on society is substantial. The continuing increase of antibiotic resistance worldwide is alarming so that well-tolerated, highly effective therapeutic alternatives are urgently needed. To investigate the effect of bacteriophages on Escherichia coli and Klebsiella pneumoniae strains isolated from the urine of patients suffering from UTIs. Forty-one E. coli and 9 K. pneumoniae strains, isolated from the urine of patients suffering from UTIs, were tested in vitro for their susceptibility toward bacteriophages. The bacteriophages originated from either commercially available bacteriophage cocktails registered in Georgia or from the bacteriophage collection of the George Eliava Institute of Bacteriophage, Microbiology and Virology. In vitro screening of bacterial strains was performed by use of the spot-test method. The experiments were implemented three times by different groups of scientists. The lytic activity of the commercial bacteriophage cocktails on the 41 E. coli strains varied between 66% (Pyo bacteriophage) and 93% (Enko bacteriophage). After bacteriophage adaptation of the Pyo bacteriophage cocktail, its lytic activity was increased from 66 to 93% and only one E. coli strain remained resistant. One bacteriophage of the Eliava collection could lyse all 9 K. pneumoniae strains. Based on the high lytic activity and the potential of resistance optimization by direct adaption of bacteriophages as reported in this study, and in view of the continuing increase of antibiotic resistance worldwide, bacteriophage therapy is a promising treatment option for UTIs highly warranting randomized controlled trials.

Two New Lytic Bacteriophages of the Myoviridae Family Against Carbapenem-Resistant Acinetobacter baumannii

PubMed Central

Zhou, Weilong; Feng, Yu; Zong, Zhiyong

2018-01-01

Two lytic bacteriophages, WCHABP1 and WCHABP12, were recovered from hospital sewage and were able to infect 9 and 12 out of 18 carbapenem-resistant Acinetobacter baumannii clinical strains, which belonged to different clones. Electron microscopy scan showed that both bacteriophages had the similar morphology as those of the Myoviridae family. Whole genomic sequencing revealed 45.4- or 45.8-kb genome with a 37.6% GC content for WCHABP1 and WCHABP12, both of which showed significant DNA sequence similarity with bacteriophages of the Ap22virus genus within the Myoviridae family. Taxonomic analysis was therefore performed following the proposal approved by the International Committee on Taxonomy of Viruses, which confirmed that WCHABP1 and WCHABP12 represented two new species of the Ap22virus genus. No tRNAs but 88 and 89 open reading frames (ORFs) were predicted for the two bacteriophages, among which 22 and 21 had known function and encoded proteins for morphogenesis, packaging, lysis, and nucleiotide metabolism. The C-terminal amino acids of the large unit of fiber tail proteins varied between the bacteriophages, which may explain their different host ranges. For most lytic bacteriophages, a set of holin and endolysin are required for lysis. However, no known holin-encoding genes were identified in WCHABP1 and WCHABP12, suggesting that they may use alternative, yet-to-be-identified, novel holins for host cell membrane lysis. To test the efficacy of the bacteriophages in protecting against A. baumannii infection, a Galleria mellonella larva model was used. Only <20% G. mellonella larvae survived at 96 h after being infected by carbapenem-resistant A. baumannii strains, from which the two bacteriophages were recovered. With the administration of WCHABP1 and WCHABP12, the survival of larvae increased to 75%, while the treatment of polymyxin B only slightly increased the survival rate to 25%. The isolation of two new lytic bacteriophages in this study could expand our

Bacteriophages and bacteriophage-derived endolysins as potential therapeutics to combat Gram-positive spore forming bacteria.

PubMed

Nakonieczna, A; Cooper, C J; Gryko, R

2015-09-01

Since their discovery in 1915, bacteriophages have been routinely used within Eastern Europe to treat a variety of bacterial infections. Although initially ignored by the West due to the success of antibiotics, increasing levels and diversity of antibiotic resistance is driving a renaissance for bacteriophage-derived therapy, which is in part due to the highly specific nature of bacteriophages as well as their relative abundance. This review focuses on the bacteriophages and derived lysins of relevant Gram-positive spore formers within the Bacillus cereus group and Clostridium genus that could have applications within the medical, food and environmental sectors. © 2015 The Society for Applied Microbiology.

Isolation and characterization of two bacteriophages with strong in vitro antimicrobial activity against Pseudomonas aeruginosa isolated from dogs with ocular infections.

PubMed

Santos, Thiago M A; Ledbetter, Eric C; Caixeta, Luciano S; Bicalho, Marcela L S; Bicalho, Rodrigo C

2011-08-01

To isolate and characterize bacteriophages with strong in vitro lytic activity against various pathogenic Pseudomonas aeruginosa strains isolated from dogs with ocular infections. 26 genetically distinct P aeruginosa isolates. P aeruginosa strains were derived from dogs with naturally acquired ulcerative keratitis. From a large-scale screening for bacteriophages with potential therapeutic benefit against canine ocular infections, 2 bacteriophages (P2S2 and P5U5) were selected; host ranges were determined, and phage nucleic acid type and genetic profile were identified via enzymatic digestion. Electron microscopy was used to characterize bacteriophage ultrastructure. Bacteriophage temperature and pH stabilities were assessed by use of double-layer agar overlay titration. A cocultivation assay was used to evaluate the effect of the bacteriophages on bacterial host growth. P5U5 was active against all P aeruginosa isolates, whereas P2S2 formed lytic plaques on plates of 21 (80.8%) isolates. For each bacteriophage, the genomic nucleic acid was DNA; each was genetically distinct. Ultrastructurally, P2S2 and P5U5 appeared likely to belong to the Podoviridae and Siphoviridae families, respectively. The bacteriophages were stable within a pH range of 4 to 12; however, titers of both bacteriophages decreased following heating for 10 to 50 minutes at 45° or 60°C. Growth of each P aeruginosa isolate was significantly inhibited in coculture with P2S2 or P5U5; the dose response was related to the plaque-forming unit-to-CFU ratios. Bacteriophages P2S2 and P5U5 appear to be good candidates for phage treatment of infection caused by pathogenic P aeruginosa in dogs.

[TL, the new bacteriophage of Pseudomonas aeruginosa and its application for the search of halo-producing bacteriophages].

PubMed

Pleteneva, E A; Burkal'tseva, M V; Shaburova, O V; Krylov, S V; Pechnikova, E V; Sokolova, O S; Krylov, V N

2011-01-01

The properties of new virulent bacteriophage TL of Pseudomonas aeruginosa belonging to the family Podoviridae (genome size of 46 kb) were investigated. This bacteriophage is capable of lysogenizing the bacterial lawn in halo zones around negative colonies (NC) of other bacteriophages. TL forms large NC, that are hardly distinguishable on the lawn of P. aeruginisa PAO1. At the same time, on the lawns of some phage-resistant PAO1 mutants, as well as on those produced by a number of clinical isolates, TL forms more transparent NC. It is suggested that more effective growth of the bacteriophage TL NC is associated with the differences in outer lipopolysaccharide (LPS) layer of the cell walls of different bacterial strains, as well as of the bacteria inside and outside of the halos. This TL property was used to optimize selection of bacteriophages producing halos around NC on the lawn of P. aeruginosa PAO1. As a result, a group of bacteriophages differing in the patterns of interaction between their halos and TL bacteriophage, as well as in some characters was identified. Taking into consideration the importance of cell-surfaced structures of P. aeruginosa in manifestation of virulence and pathogenicity, possible utilization of specific phage enzymes, polysacchadide depolymerases, for more effective treatment of P. aeruginosa infections is discussed.

Genetic evolution of bacteriophage. I. Hybrids between unrelated bacteriophages P22 and Fels 2.

PubMed

Yamamoto, N

1969-01-01

A new bacteriophage species, designated F22, was isolated from phage P22 stocks grown on Salmonella typhimurium Q1 lysogenic for Fels 2 at a frequency of less than 10(-11). P22 has a very short tail with a hexagonal base plate and six spikes. Phage Fels 2 is morphologically similar to E. coli T-even phages, having a long tail with a contractile sheath and carrying no genetic region related to P22. Phage F22 is morphologically and serologically indistinguishable from Fels 2, but carries the c(c(1), c(2), and c(3)) markers of P22. The color markers h(21), g, and m(3) of P22 do not appear in F22. Thus, F22 is evidently a recombinant between the unrelated bacteriophages P22 and Fels 2. The recombination between unrelated bacteriophages could play an important role in the evolution of bacteriophages.

STUDIES ON THE BACTERIOPHAGE OF D'HERELLE : IX. EVIDENCE OF HYDROLYSIS OF BACTERIAL PROTEIN DURING LYSIS.

PubMed

Hetler, D M; Bronfenbrenner, J

1928-07-31

1. During the process of lysis by bacteriophage, there is an appreciable increase in the amount of free amino acid present in the culture. 2. The increase of free amino acid is due to hydrolysis of bacterial protein.

An Ensemble Method to Distinguish Bacteriophage Virion from Non-Virion Proteins Based on Protein Sequence Characteristics.

PubMed

Zhang, Lina; Zhang, Chengjin; Gao, Rui; Yang, Runtao

2015-09-09

Bacteriophage virion proteins and non-virion proteins have distinct functions in biological processes, such as specificity determination for host bacteria, bacteriophage replication and transcription. Accurate identification of bacteriophage virion proteins from bacteriophage protein sequences is significant to understand the complex virulence mechanism in host bacteria and the influence of bacteriophages on the development of antibacterial drugs. In this study, an ensemble method for bacteriophage virion protein prediction from bacteriophage protein sequences is put forward with hybrid feature spaces incorporating CTD (composition, transition and distribution), bi-profile Bayes, PseAAC (pseudo-amino acid composition) and PSSM (position-specific scoring matrix). When performing on the training dataset 10-fold cross-validation, the presented method achieves a satisfactory prediction result with a sensitivity of 0.870, a specificity of 0.830, an accuracy of 0.850 and Matthew's correlation coefficient (MCC) of 0.701, respectively. To evaluate the prediction performance objectively, an independent testing dataset is used to evaluate the proposed method. Encouragingly, our proposed method performs better than previous studies with a sensitivity of 0.853, a specificity of 0.815, an accuracy of 0.831 and MCC of 0.662 on the independent testing dataset. These results suggest that the proposed method can be a potential candidate for bacteriophage virion protein prediction, which may provide a useful tool to find novel antibacterial drugs and to understand the relationship between bacteriophage and host bacteria. For the convenience of the vast majority of experimental Int. J. Mol. Sci. 2015, 16,21735 scientists, a user-friendly and publicly-accessible web-server for the proposed ensemble method is established.

GENETIC EVOLUTION OF BACTERIOPHAGE, I. HYBRIDS BETWEEN UNRELATED BACTERIOPHAGES P22 AND FELS 2*

PubMed Central

Yamamoto, Nobuto

1969-01-01

A new bacteriophage species, designated F22, was isolated from phage P22 stocks grown on Salmonella typhimurium Q1 lysogenic for Fels 2 at a frequency of less than 10-11. P22 has a very short tail with a hexagonal base plate and six spikes. Phage Fels 2 is morphologically similar to E. coli T-even phages, having a long tail with a contractile sheath and carrying no genetic region related to P22. Phage F22 is morphologically and serologically indistinguishable from Fels 2, but carries the c(c1, c2, and c3) markers of P22. The color markers h21, g, and m3 of P22 do not appear in F22. Thus, F22 is evidently a recombinant between the unrelated bacteriophages P22 and Fels 2. The recombination between unrelated bacteriophages could play an important role in the evolution of bacteriophages. Images PMID:4890254

Isolation and Characterization of the Lytic Cold-Active Bacteriophage MYSP06 from the Mingyong Glacier in China.

PubMed

Li, Mingyuan; Wang, Jilian; Zhang, Qi; Lin, Lianbing; Kuang, Anxin; Materon, Luis Alberto; Ji, Xiuling; Wei, Yunlin

2016-02-01

As unique ecological systems, glaciers are characterized by low temperatures and low nutrient levels, which allow them to be considered as “living fossils” for the purpose of researching the evolution of life and the environmental evolution of the earth. Glaciers are also natural microbial “reservoirs”. In this work, a lytic cold-active bacteriophage designated MYSP06 was isolated from Janthinobacterium sp. MYB06 from the Mingyong Glacier in China, and its major characteristics were determined. Electron microscopy revealed that bacteriophage MYSP06 had an isometric head (74 nm) and a long tail (10 nm in width, 210 nm in length). It was classified as a Siphoviridae with an approximate genome size of 65–70 kb. A one-step growth curve revealed that the latent and burst periods were 95 and 65 min, respectively, with an average burst size of 16 bacteriophage particles per infected cell. The bacteriophage particles (100 %) adsorbed to the host cells within 10 min after infection. Moreover, the pH value and thermal stability of bacteriophage MYSP06 were also investigated. The maximum stability of the bacteriophage was observed at the optimal pH 7.0, and the bacteriophage became completely unstable at the extremely alkaline pH 11.0; however, it was comparatively stable at the acidic alkaline pH 6.0. As MYSP06 is a cold-active bacteriophage with a lower production temperature, its characterization and its relationship with its host Janthinobacterium sp. MYB06 deserve further study.

A novel bacteriophage KSL-1 of 2-Keto-gluconic acid producer Pseudomonas fluorescens K1005: isolation, characterization and its remedial action

PubMed Central

2012-01-01

Background Bacteriophages have the destructive damage on the industrial bioprocess. 2-Keto-gluconic acid (2KGA) producing bacteria had also been attacked and lysed by bacteriophages which lowered the glucose consumption and 2KGA yield and even stopped the fermentation process. In this study, we presented the characteristics of a novel virulent bacteriophage specifically infecting Pseudomonas fluorescens K1005 and proposed an efficient remedial action for this phage infection to reduce the production loss. Results The phage KSL-1 of Pseudomonas fluorescens K1005 was isolated from abnormal 2KGA fermentation broth. It belonged to the Siphoviridae family with a hexagonal head diameter of about 99 nm and a non-contractile tail of about 103 nm × 39 nm. The genome size of phage KSL-1 was estimated to be approximately 53 kbp. Its optimal MOI to infect P. fluorescens K1005 was about 0.001. One-step growth curve gave its latent and burst periods of 90 min and 75 min with a burst size of 52 phage particles per infected cell. This phage was stable with a pH range of 7.0–10.0, and sensitive to thermal treatment. Finally, a simple remedial action was proposed by feeding fresh seed culture. Compared with the infected 2KGA fermentation, the remedial experiments restored 2KGA fermentation performance by increasing the produced 2KGA concentration to 159.89 g/L and shortening the total fermentation time of 80 h with the productivity and yield of 2.0 g/L.h and 0.89 g/g. The obtained data proved that this method was effective to combat the phage infections problems during the 2KGA fermentation. Conclusion The phage KSL-1 was a novel bacteriophage specifically infecting Pseudomonas fluorescens K1005. The remedial action of feeding fresh seed culture to the infected broth was an easily-operating and effective method to maintain a high 2KGA yield and avoid the draft of infected broth. PMID:22747634

Plating Bacteriophage M13.

PubMed

Green, Michael R; Sambrook, Joseph

2017-10-03

A plaque of bacteriophage M13 derives from infection of a single bacterium by a single virus particle. The progeny particles infect neighboring bacteria, which, in turn, release another generation of daughter virus particles. If the bacteria are growing in semisolid medium (e.g., containing agar or agarose), then the diffusion of the progeny particles is limited. Cells infected with bacteriophage M13 are not killed, but have a longer generation time than uninfected Escherichia coli In consequence, plaques appear as areas of slower-growing cells on a faster-growing lawn of bacterial cells. This protocol describes plating of bacteriophage M13 stocks. Plaques are readily detectable on top agar after 4-8 h of incubation at 37°C. © 2017 Cold Spring Harbor Laboratory Press.

A first step toward liposome-mediated intracellular bacteriophage therapy.

PubMed

Nieth, Anita; Verseux, Cyprien; Barnert, Sabine; Süss, Regine; Römer, Winfried

2015-01-01

The emergence of antibiotic-resistant bacteria presents a severe challenge to medicine and public health. While bacteriophage therapy is a promising alternative to traditional antibiotics, the general inability of bacteriophages to penetrate eukaryotic cells limits their use against resistant bacteria, causing intracellular diseases like tuberculosis. Bacterial vectors show some promise in carrying therapeutic bacteriophages into cells, but also bring a number of risks like an overload of bacterial antigens or the acquisition of virulence genes from the pathogen. As a first step in the development of a non-bacterial vector for bacteriophage delivery into pathogen-infected cells, we attempted to encapsulate bacteriophages into liposomes. Here we report effective encapsulation of the model bacteriophage λeyfp and the mycobacteriophage TM4 into giant liposomes. Furthermore, we show that liposome-associated bacteriophages are taken up into eukaryotic cells more efficiently than free bacteriophages. These are important milestones in the development of an intracellular bacteriophage therapy that might be useful in the fight against multi-drug-resistant intracellular pathogens like Mycobacterium tuberculosis.

Heat shock protein 70 stimulation of the deoxyribonucleic acid base excision repair enzyme polymerase β

PubMed Central

Mendez, Frances; Kozin, Elliott; Bases, Robert

2003-01-01

Base excision repair (BER) of damaged deoxyribonucleic acid (DNA) is a multistep process during which potentially lethal abasic sites temporarily exist. Repair of these lesions is greatly stimulated by heat shock protein 70 (Hsp70), which enhances strand incision and removal of the abasic sites by human apurinic-apyrimidinic endonuclease (HAP1). The resulting single-strand gaps must then be filled in. Here, we show that Hsp70 and its 48- and 43-kDa N-terminal domains greatly stimulated filling in the single-strand gaps by DNA polymerase β, a novel finding that extends the role of Hsps in DNA repair. Incorporation of deoxyguanosine monophosphate (dGMP) to fill in single-strand gaps in DNA phagemid pBKS by DNA polymerase β was stimulated by Hsp70. Truncated proteins derived from the C-terminus of Hsp70 as well as unrelated proteins were less effective, but proteins derived from the N-terminus of Hsp70 remained efficient stimulators of DNA polymerase β repair of DNA single-strand gaps. In agreement with these results, repair of a gap in a 30-bp oligonucleotide by polymerase β also was strongly stimulated by Hsp70 although not by a truncated protein from the C-terminus of Hsp70. Sealing of the repaired site in the oligonucleotide by human DNA ligase 1 was not specifically stimulated by Hsp-related proteins. Results presented here now implicate and extend the role of Hsp70 as a partner in the enzymatic repair of damaged DNA. The participation of Hsp70 jointly with base excision enzymes improves repair efficiency by mechanisms that are not yet understood. PMID:14627201

Targeted binding of the M13 bacteriophage to thiamethoxam organic crystals.

PubMed

Cho, Whirang; Fowler, Jeffrey D; Furst, Eric M

2012-04-10

Phage display screening with a combinatorial library was used to identify M13-type bacteriophages that express peptides with selective binding to organic crystals of thiamethoxam. The six most strongly binding phages exhibit at least 1000 times the binding affinity of wild-type M13 and express heptapeptide sequences that are rich in hydrophobic, hydrogen-bonding amino acids and proline. Among the peptide sequences identified, M13 displaying the pIII domain heptapeptide ASTLPKA exhibits the strongest binding to thiamethoxam in competitive binding assays. Electron and confocal microscopy confirm the specific binding affinity of ASTLPKA to thiamethoxam. Using atomic force microscope (AFM) probes functionalized with ASTLPKA expressing phage, we found that the average adhesion force between the bacteriophage and a thiamethoxam surface is 1.47 ± 0.80 nN whereas the adhesion force of wild-type M13KE phage is 0.18 ± 0.07 nN. Such a strongly binding bacteriophage could be used to modify the surface chemistry of thiamethoxam crystals and other organic solids with a high degree of specificity. © 2012 American Chemical Society

Taking Bacteriophage Therapy Seriously: A Moral Argument

PubMed Central

Verbeken, Gilbert; Huys, Isabelle; Jennes, Serge; Chanishvili, Nina; Górski, Andrzej; De Vos, Daniel

2014-01-01

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. PMID:24868534

Bacteriophages in the Dairy Environment: From Enemies to Allies

PubMed Central

Fernández, Lucía; Escobedo, Susana; Gutiérrez, Diana; Portilla, Silvia; García, Pilar; Rodríguez, Ana

2017-01-01

The history of dairy farming goes back thousands of years, evolving from a traditional small-scale production to the industrialized manufacturing of fermented dairy products. Commercialization of milk and its derived products has been very important not only as a source of nourishment but also as an economic resource. However, the dairy industry has encountered several problems that have to be overcome to ensure the quality and safety of the final products, as well as to avoid economic losses. Within this context, it is interesting to highlight the role played by bacteriophages, or phages, viruses that infect bacteria. Indeed, bacteriophages were originally regarded as a nuisance, being responsible for fermentation failure and economic losses when infecting lactic acid bacteria, but are now considered promising antimicrobials to fight milk-borne pathogens without contributing to the increase in antibiotic resistance. PMID:29117107

RGD peptide-displaying M13 bacteriophage/PLGA nanofibers as cell-adhesive matrices for smooth muscle cells

NASA Astrophysics Data System (ADS)

Shin, Yong Cheol; Lee, Jong Ho; Jin, Oh Seong; Lee, Eun Ji; Jin, Lin Hua; Kim, Chang-Seok; Hong, Suck Won; Han, Dong-Wook; Kim, Chuntae; Oh, Jin-Woo

2015-01-01

Extracellular matrices (ECMs) are network structures that play an essential role in regulating cellular growth and differentiation. In this study, novel nanofibrous matrices were fabricated by electrospinning M13 bacteriophage and poly(lactic- co-glycolic acid) (PLGA) and were shown to be structurally and functionally similar to natural ECMs. A genetically-engineered M13 bacteriophage was constructed to display Arg-Gly-Asp (RGD) peptides on its surface. The physicochemical properties of RGD peptide-displaying M13 bacteriophage (RGD-M13 phage)/PLGA nanofibers were characterized by using scanning electron microscopy and Fourier-transform infrared spectroscopy. We used immunofluorescence staining to confirm that M13 bacteriophages were homogenously distributed in RGD-M13 phage/PLGA matrices. Furthermore, RGD-M13 phage/PLGA nanofibrous matrices, having excellent biocompatibility, can enhance the behaviors of vascular smooth muscle cells. This result suggests that RGD-M13 phage/PLGA nanofibrous matrices have potentials to serve as tissue engineering scaffolds.

Cationic antimicrobial peptides inactivate Shiga toxin-encoding bacteriophages

NASA Astrophysics Data System (ADS)

Del Cogliano, Manuel E.; Hollmann, Axel; Martinez, Melina; Semorile, Liliana; Ghiringhelli, Pablo D.; Maffía, Paulo C.; Bentancor, Leticia V.

2017-12-01

Shiga toxin (Stx) is the principal virulence factor during Shiga toxin-producing Escherichia coli (STEC) infections. We have previously reported the inactivation of bacteriophage encoding Stx after treatment with chitosan, a linear polysaccharide polymer with cationic properties. Cationic antimicrobial peptides (cAMPs) are short linear aminoacidic sequences, with a positive net charge, which display bactericidal or bacteriostatic activity against a wide range of bacterial species. They are promising novel antibiotics since they have shown bactericidal effects against multiresistant bacteria. To evaluate whether cationic properties are responsible for bacteriophage inactivation, we tested seven cationic peptides with proven antimicrobial activity as anti-bacteriophage agents, and one random sequence cationic peptide with no antimicrobial activity as a control. We observed bacteriophage inactivation after incubation with five cAMPs, but no inactivating activity was observed with the random sequence cationic peptide or with the non alpha helical cAMP Omiganan. Finally, to confirm peptide-bacteriophage interaction, zeta potential was analyzed by following changes on bacteriophage surface charges after peptide incubation. According to our results we could propose that: 1) direct interaction of peptides with phage is a necessary step for bacteriophage inactivation, 2) cationic properties are necessary but not sufficient for bacteriophage inactivation, and 3) inactivation by cationic peptides could be sequence (or structure) specific. Overall our data suggest that these peptides could be considered a new family of molecules potentially useful to decrease bacteriophage replication and Stx expression.

Bacteriophages in dairy products: pros and cons.

PubMed

Mc Grath, Stephen; Fitzgerald, Gerald F; van Sinderen, Douwe

2007-04-01

Since the time bacteriophages were first identified as a major cause of fermentation failure in the dairy industry, researchers have been struggling to develop strategies to exclude them from the dairy environment. Over 70 years of research has led to huge improvements in the consistency and quality of fermented dairy products, while also facilitating an appreciation of the beneficial properties of bacteriophages with respect to dairy product development. With specific reference to Lactococcus lactis and cheese production, this review outlines some recently reported novel methods aimed at limiting the bacteriophage infection as well as highlighting some beneficial aspects of bacteriophage activity.

The Baseplate of Lactobacillus delbrueckii Bacteriophage Ld17 Harbors a Glycerophosphodiesterase.

PubMed

Cornelissen, Anneleen; Sadovskaya, Irina; Vinogradov, Evgeny; Blangy, Stéphanie; Spinelli, Silvia; Casey, Eoghan; Mahony, Jennifer; Noben, Jean-Paul; Dal Bello, Fabio; Cambillau, Christian; van Sinderen, Douwe

2016-08-05

Glycerophosphodiester phosphodiesterases (GDPDs; EC 3.1.4.46) typically hydrolyze glycerophosphodiesters to sn-glycerol 3-phosphate (Gro3P) and their corresponding alcohol during patho/physiological processes in bacteria and eukaryotes. GDPD(-like) domains were identified in the structural particle of bacterial viruses (bacteriophages) specifically infecting Gram-positive bacteria. The GDPD of phage 17 (Ld17; GDPDLd17), representative of the group b Lactobacillus delbrueckii subsp. bulgaricus (Ldb)-infecting bacteriophages, was shown to hydrolyze, besides the simple glycerophosphodiester, two complex surface-associated carbohydrates of the Ldb17 cell envelope: the Gro3P decoration of the major surface polysaccharide d-galactan and the oligo(glycerol phosphate) backbone of the partially glycosylated cell wall teichoic acid, a minor Ldb17 cell envelope component. Degradation of cell wall teichoic acid occurs according to an exolytic mechanism, and Gro3P substitution is presumed to be inhibitory for GDPDLd17 activity. The presence of the GDPDLd17 homotrimer in the viral baseplate structure involved in phage-host interaction together with the dependence of native GDPD activity, adsorption, and efficiency of plating of Ca(2+) ions supports a role for GDPDLd17 activity during phage adsorption and/or phage genome injection. In contrast to GDPDLd17, we could not identify any enzymatic activity for the GDPD-like domain in the neck passage structure of phage 340, a 936-type Lactococcus lactis subsp. lactis bacteriophage. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

The Baseplate of Lactobacillus delbrueckii Bacteriophage Ld17 Harbors a Glycerophosphodiesterase*

PubMed Central

Cornelissen, Anneleen; Sadovskaya, Irina; Vinogradov, Evgeny; Blangy, Stéphanie; Spinelli, Silvia; Casey, Eoghan; Mahony, Jennifer; Noben, Jean-Paul; Dal Bello, Fabio; Cambillau, Christian; van Sinderen, Douwe

2016-01-01

Glycerophosphodiester phosphodiesterases (GDPDs; EC 3.1.4.46) typically hydrolyze glycerophosphodiesters to sn-glycerol 3-phosphate (Gro3P) and their corresponding alcohol during patho/physiological processes in bacteria and eukaryotes. GDPD(-like) domains were identified in the structural particle of bacterial viruses (bacteriophages) specifically infecting Gram-positive bacteria. The GDPD of phage 17 (Ld17; GDPDLd17), representative of the group b Lactobacillus delbrueckii subsp. bulgaricus (Ldb)-infecting bacteriophages, was shown to hydrolyze, besides the simple glycerophosphodiester, two complex surface-associated carbohydrates of the Ldb17 cell envelope: the Gro3P decoration of the major surface polysaccharide d-galactan and the oligo(glycerol phosphate) backbone of the partially glycosylated cell wall teichoic acid, a minor Ldb17 cell envelope component. Degradation of cell wall teichoic acid occurs according to an exolytic mechanism, and Gro3P substitution is presumed to be inhibitory for GDPDLd17 activity. The presence of the GDPDLd17 homotrimer in the viral baseplate structure involved in phage-host interaction together with the dependence of native GDPD activity, adsorption, and efficiency of plating of Ca2+ ions supports a role for GDPDLd17 activity during phage adsorption and/or phage genome injection. In contrast to GDPDLd17, we could not identify any enzymatic activity for the GDPD-like domain in the neck passage structure of phage 340, a 936-type Lactococcus lactis subsp. lactis bacteriophage. PMID:27268053

Identification of Bacteriophage N4 Virion RNA Polymerase-Nucleic Acid Interactions in Transcription Complexes*

PubMed Central

Davydova, Elena K.; Kaganman, Irene; Kazmierczak, Krystyna M.; Rothman-Denes, Lucia B.

2009-01-01

Bacteriophage N4 mini-virion RNA polymerase (mini-vRNAP), the 1106-amino acid transcriptionally active domain of vRNAP, recognizes single-stranded DNA template-containing promoters composed of conserved sequences and a 3-base loop–5-base pair stem hairpin structure. The major promoter recognition determinants are a purine located at the center of the hairpin loop (–11G) and a base at the hairpin stem (–8G). Mini-vRNAP is an evolutionarily highly diverged member of the T7 family of RNAPs. A two-plasmid system was developed to measure the in vivo activity of mutant mini-vRNAP enzymes. Five mini-vRNAP derivatives, each containing a pair of cysteine residues separated by ∼100 amino acids and single cysteine-containing enzymes, were generated. These reagents were used to determine the smallest catalytically active polypeptide and to map promoter, substrate, and RNA-DNA hybrid contact sites to single amino acid residues in the enzyme by using end-labeled 5-iododeoxyuridine- and azidophenacyl-substituted oligonucleotides, cross-linkable derivatives of the initiating nucleotide, and RNA products with 5-iodouridine incorporated at specific positions. Localization of functionally important amino acid residues in the recently determined crystal structures of apomini-vRNAP and the mini-vRNAP-promoter complex and comparison with the crystal structures of the T7 RNAP initiation and elongation complexes allowed us to predict major rearrangements in mini-vRNAP in the transition from transcription initiation to elongation similar to those observed in T7 RNAP, a task otherwise precluded by the lack of sequence homology between N4 mini-vRNAP and T7 RNAP. PMID:19015264

Characterization, Genome Sequence, and Analysis of Escherichia Phage CICC 80001, a Bacteriophage Infecting an Efficient L-Aspartic Acid Producing Escherichia coli.

PubMed

Xu, Youqiang; Ma, Yuyue; Yao, Su; Jiang, Zengyan; Pei, Jiangsen; Cheng, Chi

2016-03-01

Escherichia phage CICC 80001 was isolated from the bacteriophage contaminated medium of an Escherichia coli strain HY-05C (CICC 11022S) which could produce L-aspartic acid. The phage had a head diameter of 45-50 nm and a tail of about 10 nm. The one-step growth curve showed a latent period of 10 min and a rise period of about 20 min. The average burst size was about 198 phage particles per infected cell. Tests were conducted on the plaques, multiplicity of infection, and host range. The genome of CICC 80001 was sequenced with a length of 38,810 bp, and annotated. The key proteins leading to host-cell lysis were phylogenetically analyzed. One protein belonged to class II holin, and the other two belonged to the endopeptidase family and N-acetylmuramoyl-L-alanine amidase family, respectively. The genome showed the sequence identity of 82.7% with that of Enterobacteria phage T7, and carried ten unique open reading frames. The bacteriophage resistant E. coli strain designated CICC 11021S was breeding and its L-aspartase activity was 84.4% of that of CICC 11022S.

Poorly Lytic Bacteriophage from Dactylosporangium thailandensis (Actinomycetales)

PubMed Central

Higgins, M. L.; Lechevalier, Mary P.

1969-01-01

Dactylosporangiophage A1 has a polygonal head (75 nm) with spherical capsomeres (3 nm) and a noncontractile tail (200 by 10 nm) with cross-striations which is terminated with at least three prongs which are used for attachment. It contains double-stranded deoxyribonucleic acid and produces very little lysis. Intracellular phage multiplication leads to the formation of crystalline aggregates of apparently complete virions. Plaques are formed only on certain substrains of Dactylosporangium thailandensis L1 and are always small (0.5 mm or less). They are clear on some substrains and turbid on others. Formation of plaques occurs only on one medium, Czapek agar with 0.2 to 0.4% yeast extract, 0.2% peptone, or a defined mixture of amino acids. Over 100 strains of bacteria, mainly actinomycetes, were screened in a futile attempt to find an indicator strain which is not a substrain of L1. The Dactylosporangium-phage system studied is considered to be a semiresistant carrier state. Images PMID:5774140

Identification of Three Kinds of Citri Reticulatae Pericarpium Based on Deoxyribonucleic Acid Barcoding and High-performance Liquid Chromatography-diode Array Detection-electrospray Ionization/Mass Spectrometry/Mass Spectrometry Combined with Chemometric Analysis

PubMed Central

Yu, Xiaoxue; Zhang, Yafeng; Wang, Dongmei; Jiang, Lin; Xu, Xinjun

2018-01-01

Background: Citri Reticulatae Pericarpium is the dried mature pericarp of Citrus reticulata Blanco which can be divided into “Chenpi” and “Guangchenpi.” “Guangchenpi” is the genuine Chinese medicinal material in Xinhui, Guangdong province; based on the greatest quality and least amount, it is most expensive among others. Hesperidin is used as the marker to identify Citri Reticulatae Pericarpium described in the Chinese Pharmacopoeia 2010. However, both “Chenpi” and “Guangchenpi” contain hesperidin so that it is impossible to differentiate them by measuring hesperidin. Objective: Our study aims to develop an efficient and accurate method to separate and identify “Guangchenpi” from other Citri Reticulatae Pericarpium. Materials and Methods: The genomic deoxyribonucleic acid (DNA) of all the materials was extracted and then the internal transcribed spacer 2 was amplified, sequenced, aligned, and analyzed. The secondary structures were created in terms of the database and website established by Jörg Schultz et al. High-performance liquid chromatography-diode array detection-electrospray Ionization/mass spectrometry (HPLC-DAD-ESI-MS)/MS coupled with chemometric analysis was applied to compare the differences in chemical profiles of the three kinds of Citri Reticulatae Pericarpium. Results: A total of 22 samples were classified into three groups. The results of DNA barcoding were in accordance with principal component analysis and hierarchical cluster analysis. Eight compounds were deduced from HPLC-DAD-ESI-MS/MS. Conclusions: This method is a reliable and effective tool to differentiate the three Citri Reticulatae Pericarpium. SUMMARY The internal transcribed spacer 2 regions and the secondary structure among three kinds of Citri Reticulatae Pericarpium varied considerablyAll the 22 samples were analyzed by high-performance liquid chromatography (HPLC) to obtain the chemical profilesPrincipal component analysis and hierarchical cluster analysis

Growing Bacteriophage M13 in Liquid Culture.

PubMed

Green, Michael R; Sambrook, Joseph

2017-11-01

Stocks of bacteriophage M13 are usually grown in liquid culture. The infected bacteria do not lyse but, instead, grow at a slower than normal rate to form a dilute suspension. The inoculum of bacteriophage is almost always a freshly picked plaque or a suspension of bacteriophage particles obtained from a single plaque, as described here. Infected cells contain up to 200 copies of double-stranded, replicative-form DNA and extrude several hundred bacteriophage particles per generation. Thus, a 1-mL culture of infected cells can produce enough double-stranded viral DNA (1-2 mg) for restriction mapping and recovery of cloned DNA inserts and sufficient single-stranded DNA (∼5-10 mg) for site-directed mutagenesis, DNA sequencing, or synthesis of radiolabeled probes. The titer of bacteriophages in the supernatant from infected cells is so high (∼10 12 pfu/mL) that a small aliquot serves as a permanent stock of the starting plaque. © 2017 Cold Spring Harbor Laboratory Press.

A novel approach for separating bacteriophages from other bacteriophages using affinity chromatography and phage display.

PubMed

Ceglarek, Izabela; Piotrowicz, Agnieszka; Lecion, Dorota; Miernikiewicz, Paulina; Owczarek, Barbara; Hodyra, Katarzyna; Harhala, Marek; Górski, Andrzej; Dąbrowska, Krystyna

2013-11-14

Practical applications of bacteriophages in medicine and biotechnology induce a great need for technologies of phage purification. None of the popular methods offer solutions for separation of a phage from another similar phage. We used affinity chromatography combined with competitive phage display (i) to purify T4 bacteriophage from bacterial debris and (ii) to separate T4 from other contaminating bacteriophages. In 'competitive phage display' bacterial cells produced both wild types of the proteins (expression from the phage genome) and the protein fusions with affinity tags (expression from the expression vectors). Fusion proteins were competitively incorporated into the phage capsid. It allowed effective separation of T4 from a contaminating phage on standard affinity resins.

A novel approach for separating bacteriophages from other bacteriophages using affinity chromatography and phage display

PubMed Central

Ceglarek, Izabela; Piotrowicz, Agnieszka; Lecion, Dorota; Miernikiewicz, Paulina; Owczarek, Barbara; Hodyra, Katarzyna; Harhala, Marek; Górski, Andrzej; Dąbrowska, Krystyna

2013-01-01

Practical applications of bacteriophages in medicine and biotechnology induce a great need for technologies of phage purification. None of the popular methods offer solutions for separation of a phage from another similar phage. We used affinity chromatography combined with competitive phage display (i) to purify T4 bacteriophage from bacterial debris and (ii) to separate T4 from other contaminating bacteriophages. In ‘competitive phage display’ bacterial cells produced both wild types of the proteins (expression from the phage genome) and the protein fusions with affinity tags (expression from the expression vectors). Fusion proteins were competitively incorporated into the phage capsid. It allowed effective separation of T4 from a contaminating phage on standard affinity resins. PMID:24225840

Evidence for a lineage of virulent bacteriophages that target Campylobacter.

PubMed

Timms, Andrew R; Cambray-Young, Joanna; Scott, Andrew E; Petty, Nicola K; Connerton, Phillippa L; Clarke, Louise; Seeger, Kathy; Quail, Mike; Cummings, Nicola; Maskell, Duncan J; Thomson, Nicholas R; Connerton, Ian F

2010-03-30

Our understanding of the dynamics of genome stability versus gene flux within bacteriophage lineages is limited. Recently, there has been a renewed interest in the use of bacteriophages as 'therapeutic' agents; a prerequisite for their use in such therapies is a thorough understanding of their genetic complement, genome stability and their ecology to avoid the dissemination or mobilisation of phage or bacterial virulence and toxin genes. Campylobacter, a food-borne pathogen, is one of the organisms for which the use of bacteriophage is being considered to reduce human exposure to this organism. Sequencing and genome analysis was performed for two Campylobacter bacteriophages. The genomes were extremely similar at the nucleotide level (> or = 96%) with most differences accounted for by novel insertion sequences, DNA methylases and an approximately 10 kb contiguous region of metabolic genes that were dissimilar at the sequence level but similar in gene function between the two phages. Both bacteriophages contained a large number of radical S-adenosylmethionine (SAM) genes, presumably involved in boosting host metabolism during infection, as well as evidence that many genes had been acquired from a wide range of bacterial species. Further bacteriophages, from the UK Campylobacter typing set, were screened for the presence of bacteriophage structural genes, DNA methylases, mobile genetic elements and regulatory genes identified from the genome sequences. The results indicate that many of these bacteriophages are related, with 10 out of 15 showing some relationship to the sequenced genomes. Two large virulent Campylobacter bacteriophages were found to show very high levels of sequence conservation despite separation in time and place of isolation. The bacteriophages show adaptations to their host and possess genes that may enhance Campylobacter metabolism, potentially advantaging both the bacteriophage and its host. Genetic conservation has been shown to extend to other

Identification of a Herbal Powder by Deoxyribonucleic Acid Barcoding and Structural Analyses.

PubMed

Sheth, Bhavisha P; Thaker, Vrinda S

2015-10-01

Authentic identification of plants is essential for exploiting their medicinal properties as well as to stop the adulteration and malpractices with the trade of the same. To identify a herbal powder obtained from a herbalist in the local vicinity of Rajkot, Gujarat, using deoxyribonucleic acid (DNA) barcoding and molecular tools. The DNA was extracted from a herbal powder and selected Cassia species, followed by the polymerase chain reaction (PCR) and sequencing of the rbcL barcode locus. Thereafter the sequences were subjected to National Center for Biotechnology Information (NCBI) basic local alignment search tool (BLAST) analysis, followed by the protein three-dimension structure determination of the rbcL protein from the herbal powder and Cassia species namely Cassia fistula, Cassia tora and Cassia javanica (sequences obtained in the present study), Cassia Roxburghii, and Cassia abbreviata (sequences retrieved from Genbank). Further, the multiple and pairwise structural alignment were carried out in order to identify the herbal powder. The nucleotide sequences obtained from the selected species of Cassia were submitted to Genbank (Accession No. JX141397, JX141405, JX141420). The NCBI BLAST analysis of the rbcL protein from the herbal powder showed an equal sequence similarity (with reference to different parameters like E value, maximum identity, total score, query coverage) to C. javanica and C. roxburghii. In order to solve the ambiguities of the BLAST result, a protein structural approach was implemented. The protein homology models obtained in the present study were submitted to the protein model database (PM0079748-PM0079753). The pairwise structural alignment of the herbal powder (as template) and C. javanica and C. roxburghii (as targets individually) revealed a close similarity of the herbal powder with C. javanica. A strategy as used here, incorporating the integrated use of DNA barcoding and protein structural analyses could be adopted, as a novel

Bacteriophage phi 6 RNA-dependent RNA polymerase: molecular details of initiating nucleic acid synthesis without primer.

PubMed

Laurila, Minni R L; Makeyev, Eugene V; Bamford, Dennis H

2002-05-10

Like most RNA polymerases, the polymerase of double-strand RNA bacteriophage phi6 (phi6pol) is capable of primer-independent initiation. Based on the recently solved phi6pol initiation complex structure, a four-amino acid-long loop (amino acids 630-633) has been suggested to stabilize the first two incoming NTPs through stacking interactions with tyrosine, Tyr(630). A similar loop is also present in the hepatitis C virus polymerase, another enzyme capable of de novo initiation. Here, we use a series of phi6pol mutants to address the role of this element. As predicted, mutants at the Tyr(630) position are inefficient in initiation de novo. Unexpectedly, when the loop is disordered by changing Tyr(630)-Lys(631)-Trp(632) to GSG, phi6pol becomes a primer-dependent enzyme, either extending complementary oligonucleotide or, when the template 3' terminus can adopt a hairpin-like conformation, utilizing a "copy-back" initiation mechanism. In contrast to the wild-type phi6pol, the GSG mutant does not require high GTP concentration for its optimal activity. These findings suggest a general model for the initiation of de novo RNA synthesis.

Bacteriophages as indicators of faecal pollution and enteric ...

EPA Pesticide Factsheets

Bacteriophages are an attractive alternative to fecal indicator bacteria (FIB), particularly as surrogates of enteric virus fate and transport due to their closer morphological and biological properties compared to FIB. Based on a meta-analysis of published data, we summarize concentrations of coliphages (F+ and somatic), Bacteroides spp. and enterococci bacteriophages (phages) in human waste, non-human waste, fresh and marine waters as well as removal through wastewater treatment processes. We also provide comparisons with FIB and enteric viruses whenever possible. Lastly, we examine fate and transport characteristics in the environment and provide an overview of the methods available for detection and enumeration of bacteriophages. In summary, concentrations of FIB bacteriophages in various sources were consistently lower than FIB, but more reflective of infectious enteric virus levels. Our investigation supports use of bacteriophages as viral surrogates especially for wastewater treatment processes, while additional research is needed to clarify their utility as indicators of viral fate and transport in the ambient water. Describes concentrations and removal through environmental and engineered systems of bacteriophages, fecal indicator bacteria and viral pathogens.

Norovirus and FRNA bacteriophage determined by RT-qPCR and infectious FRNA bacteriophage in wastewater and oysters.

PubMed

Flannery, John; Keaveney, Sinéad; Rajko-Nenow, Paulina; O'Flaherty, Vincent; Doré, William

2013-09-15

Norovirus (NoV), the leading cause of adult non-bacterial gastroenteritis can be commonly detected in wastewater but the extent of NoV removal provided by wastewater treatment plants (WWTPs) is unclear. We monitored a newly commissioned WWTP with UV disinfection on a weekly basis over a six month period for NoV using RT-qPCR and for FRNA bacteriophage GA using both RT-qPCR (total concentration) and a plaque assay (infectious concentration). Mean concentrations of NoV GI and GII in influent wastewater were reduced by 0.25 and 0.41 log10 genome copies 100 ml(-1), respectively by the WWTP. The mean concentration of total FRNA bacteriophage GA was reduced by 0.35 log genome copies 100 ml(-1) compared to a reduction of infectious FRNA bacteriophage GA of 2.13 log PFU 100 ml(-1). A significant difference between concentrations of infectious and total FRNA bacteriophage GA was observed in treated, but not in untreated wastewaters. We conclude that RT-qPCR in isolation underestimates the reduction of infectious virus during wastewater treatment. We further compared the concentrations of infectious virus in combined sewer overflow (CSO) and UV treated effluents using FRNA bacteriophage GA. A greater percentage (98%) of infectious virus is released in CSO discharges than UV treated effluent (44%). Following a CSO discharge, concentrations of NoV GII and infectious FRNA bacteriophage GA in oysters from less than the limit of detection to 3150 genome copies 100 g(-1) and 1050 PFU 100 g(-1) respectively. Copyright © 2013 Elsevier Ltd. All rights reserved.

Call for a dedicated European legal framework for bacteriophage therapy.

PubMed

Verbeken, Gilbert; Pirnay, Jean-Paul; Lavigne, Rob; Jennes, Serge; De Vos, Daniel; Casteels, Minne; Huys, Isabelle

2014-04-01

The worldwide emergence of antibiotic resistances and the drying up of the antibiotic pipeline have spurred a search for alternative or complementary antibacterial therapies. Bacteriophages are bacterial viruses that have been used for almost a century to combat bacterial infections, particularly in Poland and the former Soviet Union. The antibiotic crisis has triggered a renewed clinical and agricultural interest in bacteriophages. This, combined with new scientific insights, has pushed bacteriophages to the forefront of the search for new approaches to fighting bacterial infections. But before bacteriophage therapy can be introduced into clinical practice in the European Union, several challenges must be overcome. One of these is the conceptualization and classification of bacteriophage therapy itself and the extent to which it constitutes a human medicinal product regulated under the European Human Code for Medicines (Directive 2001/83/EC). Can therapeutic products containing natural bacteriophages be categorized under the current European regulatory framework, or should this framework be adapted? Various actors in the field have discussed the need for an adapted (or entirely new) regulatory framework for the reintroduction of bacteriophage therapy in Europe. This led to the identification of several characteristics specific to natural bacteriophages that should be taken into consideration by regulators when evaluating bacteriophage therapy. One important consideration is whether bacteriophage therapy development occurs on an industrial scale or a hospital-based, patient-specific scale. More suitable regulatory standards may create opportunities to improve insights into this promising therapeutic approach. In light of this, we argue for the creation of a new, dedicated European regulatory framework for bacteriophage therapy.

Detection of Low Level Microwave Radiation Induced Deoxyribonucleic Acid Damage Vis-à-vis Genotoxicity in Brain of Fischer Rats

PubMed Central

Deshmukh, Pravin Suryakantrao; Megha, Kanu; Banerjee, Basu Dev; Ahmed, Rafat Sultana; Chandna, Sudhir; Abegaonkar, Mahesh Pandurang; Tripathi, Ashok Kumar

2013-01-01

Background: Non-ionizing radiofrequency radiation has been increasingly used in industry, commerce, medicine and especially in mobile phone technology and has become a matter of serious concern in present time. Objective: The present study was designed to investigate the possible deoxyribonucleic acid (DNA) damaging effects of low-level microwave radiation in brain of Fischer rats. Materials and Methods: Experiments were performed on male Fischer rats exposed to microwave radiation for 30 days at three different frequencies: 900, 1800 and 2450 MHz. Animals were divided into 4 groups: Group I (Sham exposed): Animals not exposed to microwave radiation but kept under same conditions as that of other groups, Group II: Animals exposed to microwave radiation at frequency 900 MHz at specific absorption rate (SAR) 5.953 × 10−4 W/kg, Group III: Animals exposed to 1800 MHz at SAR 5.835 × 10−4 W/kg and Group IV: Animals exposed to 2450 MHz at SAR 6.672 × 10−4 W/kg. At the end of the exposure period animals were sacrificed immediately and DNA damage in brain tissue was assessed using alkaline comet assay. Results: In the present study, we demonstrated DNA damaging effects of low level microwave radiation in brain. Conclusion: We concluded that low SAR microwave radiation exposure at these frequencies may induce DNA strand breaks in brain tissue. PMID:23833433

Bacteriophage-based nanoprobes for rapid bacteria separation

NASA Astrophysics Data System (ADS)

Chen, Juhong; Duncan, Bradley; Wang, Ziyuan; Wang, Li-Sheng; Rotello, Vincent M.; Nugen, Sam R.

2015-10-01

The lack of practical methods for bacterial separation remains a hindrance for the low-cost and successful development of rapid detection methods from complex samples. Antibody-tagged magnetic particles are commonly used to pull analytes from a liquid sample. While this method is well-established, improvements in capture efficiencies would result in an increase of the overall detection assay performance. Bacteriophages represent a low-cost and more consistent biorecognition element as compared to antibodies. We have developed nanoscale bacteriophage-tagged magnetic probes, where T7 bacteriophages were bound to magnetic nanoparticles. The nanoprobe allowed the specific recognition and attachment to E. coli cells. The phage magnetic nanprobes were directly compared to antibody-conjugated magnetic nanoprobes. The capture efficiencies of bacteriophages and antibodies on nanoparticles for the separation of E. coli K12 at varying concentrations were determined. The results indicated a similar bacteria capture efficiency between the two nanoprobes.The lack of practical methods for bacterial separation remains a hindrance for the low-cost and successful development of rapid detection methods from complex samples. Antibody-tagged magnetic particles are commonly used to pull analytes from a liquid sample. While this method is well-established, improvements in capture efficiencies would result in an increase of the overall detection assay performance. Bacteriophages represent a low-cost and more consistent biorecognition element as compared to antibodies. We have developed nanoscale bacteriophage-tagged magnetic probes, where T7 bacteriophages were bound to magnetic nanoparticles. The nanoprobe allowed the specific recognition and attachment to E. coli cells. The phage magnetic nanprobes were directly compared to antibody-conjugated magnetic nanoprobes. The capture efficiencies of bacteriophages and antibodies on nanoparticles for the separation of E. coli K12 at varying

Isolation and characterization of bacteriophages of Salmonella enterica serovar Pullorum.

PubMed

Bao, H; Zhang, H; Wang, R

2011-10-01

In this study, 2 bacteriophages of Salmonella Pullorum were isolated using an enrichment protocol and the double agar layer method. They were named PSPu-95 and PSPu-4-116, respectively, against clinical isolates of Salmonella Pullorum SPu-95 and SPu-116. The host ranges of the 2 bacteriophages were determined by performing spot tests with 20 bacteria strains. Both bacteriophages had wide host ranges. Bacteriophage PSPu-95 had a lytic effect on 17 of the 20 isolates (85%), and PSPu-4-116 produced a lytic effect on 14 isolates (70%) and was the only bacteriophage that produced a clear plaque on enterotoxigenic Escherichia coli K88. Transmission electron microscopy revealed the bacteriophages belonged to the order Caudovirales. Bacteriophage PSPu-95 was a member of the family Siphoviridae, but bacteriophage PSPu-4-116 belonged to the family Myoviridae. Both had a double-stranded DNA, which was digested with HindIII or EcoRI, that was estimated to be 58.3 kbp (PSPu-95) and 45.2 kbp (PSPu-4-116) by 1% agar electrophoresis. One-step growth kinetics showed that the latent periods were all less than 20 min, and the burst size was 77.5 pfu/cell for PSPu-95 and 86 pfu/cell for PSPu-4-116. The bacteriophages were able to survive in a pH range between 4 and 10, and they were able to survive in a treatment of 70°C for 60 min. The characterizations of these 2 bacteriophages were helpful in establishing a basis for adopting the most effective bacteriophage to control bacteria in the poultry industry.

In vivo transcription of R-plasmid deoxyribonucleic acid in Escherichia coli strains with altered antibiotic resistance levels and/or conjugal proficiency.

PubMed Central

Davis, R; Vapnek, D

1976-01-01

The amounts of plasmid deoxyribonucleic acid (DNA) and the levels of the in vivo transcription of the Escherichia coli plasmids R538-1 (repressed for conjugal transfer) and R538-1drd (derepressed for transfer) were determined by DNA-DNA hybridization and DNA-ribonucleic acid hybridization, respectively. The results demonstrate that the level of plasmid transcription is increased by two-fold in the strain carrying the derepressed plasmid, compared to an isogenic strain carrying the repressed plasmid, whereas the amount of plasmid DNA is approximately the same, suggesting that the transfer genes are under transcriptional control. Levels of plasmid DNA, plasmid DNA transcription, and chloramphenicol acetyltransferase activity were also compared in a mutant strain that carried the R538-1drd plasmid and was resistant to high levels of antibiotics. This strain produces about 13 copies of plasmid DNA per chromosome compared to five copies for the parent strain. The level of transcription of plasmid DNA was found to be twofold higher in the high-level resistant strain, whereas the level of chloramphenition, acetyltransferase activity was increased by 10-fold. In addition the levels of plasmid DNA transcription and chloramphenicol acetyltransferase activity in the high-level resistant strain were found to be further increased by the presence of high levels of chloramphenicol in the growth medium. The amount of plasmid DNA remained constant under these conditions, indicating that high levels of chloramphenicol can stimulate the expression of plasmid genes at the level of transcription in this strain. PMID:767321

Polymer-based delivery systems for support and delivery of bacteriophages

NASA Astrophysics Data System (ADS)

Brown, Alyssa Marie

One of the most urgent problems in the fields of medicine and agriculture is the decreasing effectiveness of antibiotics. Once a miracle drug, antibiotics have recently become associated with the creation of antibiotic-resistant bacteria. The main limitations of these treatments include lack of both adaptability and specificity. To overcome these shortcomings of current antibiotic treatments, there has been a renewed interest in bacteriophage research. Bacteriophages are naturally-occurring viruses that lyse bacteria. They are highly specific, with each bacteriophage type lysing a narrow range of bacteria strains. Bacteriophages are also ubiquitous biological entities, populating environments where bacterial growth is supported. Just as humans are exposed to bacteria in their daily lives, we are exposed to bacteriophages as well. To use bacteriophages in practical applications, they must be delivered to the site of an infection in a controlled-release system. Two systems were studied to observe their support of bacteriophage lytic activity, as well as investigate the possibility of controlling bacteriophage release rates. First, hydrogels were studied, using crosslinking and blending techniques to achieve a range of release profiles. Second, polyanhydride microparticles were studied, evaluating release rates as a function of monomer chemistries.

Bacteriophage Applications for Food Production and Processing

PubMed Central

Moye, Zachary D.; Woolston, Joelle; Sulakvelidze, Alexander

2018-01-01

Foodborne illnesses remain a major cause of hospitalization and death worldwide despite many advances in food sanitation techniques and pathogen surveillance. Traditional antimicrobial methods, such as pasteurization, high pressure processing, irradiation, and chemical disinfectants are capable of reducing microbial populations in foods to varying degrees, but they also have considerable drawbacks, such as a large initial investment, potential damage to processing equipment due to their corrosive nature, and a deleterious impact on organoleptic qualities (and possibly the nutritional value) of foods. Perhaps most importantly, these decontamination strategies kill indiscriminately, including many—often beneficial—bacteria that are naturally present in foods. One promising technique that addresses several of these shortcomings is bacteriophage biocontrol, a green and natural method that uses lytic bacteriophages isolated from the environment to specifically target pathogenic bacteria and eliminate them from (or significantly reduce their levels in) foods. Since the initial conception of using bacteriophages on foods, a substantial number of research reports have described the use of bacteriophage biocontrol to target a variety of bacterial pathogens in various foods, ranging from ready-to-eat deli meats to fresh fruits and vegetables, and the number of commercially available products containing bacteriophages approved for use in food safety applications has also been steadily increasing. Though some challenges remain, bacteriophage biocontrol is increasingly recognized as an attractive modality in our arsenal of tools for safely and naturally eliminating pathogenic bacteria from foods. PMID:29671810

Comparative Genomics of Bacteriophage of the Genus Seuratvirus

PubMed Central

Sazinas, Pavelas; Redgwell, Tamsin; Rihtman, Branko; Grigonyte, Aurelija; Michniewski, Slawomir; Scanlan, David J; Hobman, Jon

2018-01-01

Abstract Despite being more abundant and having smaller genomes than their bacterial host, relatively few bacteriophages have had their genomes sequenced. Here, we isolated 14 bacteriophages from cattle slurry and performed de novo genome sequencing, assembly, and annotation. The commonly used marker genes polB and terL showed these bacteriophages to be closely related to members of the genus Seuratvirus. We performed a core-gene analysis using the 14 new and four closely related genomes. A total of 58 core genes were identified, the majority of which has no known function. These genes were used to construct a core-gene phylogeny, the results of which confirmed the new isolates to be part of the genus Seuratvirus and expanded the number of species within this genus to four. All bacteriophages within the genus contained the genes queCDE encoding enzymes involved in queuosine biosynthesis. We suggest these genes are carried as a mechanism to modify DNA in order to protect these bacteriophages against host endonucleases. PMID:29272407

Bacteriophage therapy for refractory Pseudomonas aeruginosa urinary tract infection.

PubMed

Khawaldeh, A; Morales, S; Dillon, B; Alavidze, Z; Ginn, A N; Thomas, L; Chapman, S J; Dublanchet, A; Smithyman, A; Iredell, J R

2011-11-01

We describe the success of adjunctive bacteriophage therapy for refractory Pseudomonas aeruginosa urinary tract infection in the context of bilateral ureteric stents and bladder ulceration, after repeated failure of antibiotics alone. No bacteriophage-resistant bacteria arose, and the kinetics of bacteriophage and bacteria in urine suggest self-sustaining and self-limiting infection.

Highly Sensitive Detection of Deoxyribonucleic Acid Hybridization Using Au-Gated AlInN/GaN High Electron Mobility Transistor-Based Sensors

NASA Astrophysics Data System (ADS)

Zhan, Xiang-Mi; Hao, Mei-Lan; Wang, Quan; Li, Wei; Xiao, Hong-Ling; Feng, Chun; Jiang, Li-Juan; Wang, Cui-Mei; Wang, Xiao-Liang; Wang, Zhan-Guo

2017-03-01

Gallium nitride- (GaN) based high electron mobility transistors (HEMTs) provide a good platform for biological detection. In this work, both Au-gated AlInN/GaN HEMT and AlGaN/GaN HEMT biosensors are fabricated for the detection of deoxyribonucleic acid (DNA) hybridization. The Au-gated AlInN/GaN HEMT biosensor exhibits higher sensitivity in comparison with the AlGaN/GaN HEMT biosensor. For the former, the drain-source current ( {V}{DS}=0.5 V) shows a clear decrease of 69 μA upon the introduction of 1 μmolL {}-1 (μM) complimentary DNA to the probe DNA at the sensor area, while for the latter it is only 38 μA. This current reduction is a notable indication of the hybridization. The high sensitivity can be attributed to the thinner barrier of the AlInN/GaN heterostructure, which makes the two-dimensional electron gas channel more susceptible to a slight change of the surface charge. Supported by the National Key Research and Development Program of China under Grant Nos 2016YFB0400104 and 2016YFB0400301, the National Natural Sciences Foundation of China under Grant No 61334002, and the National Science and Technology Major Project.

M13 bacteriophage-activated superparamagnetic beads for affinity separation.

PubMed

Muzard, Julien; Platt, Mark; Lee, Gil U

2012-08-06

The growth of the biopharmaceutical industry has created a demand for new technologies for the purification of genetically engineered proteins.The efficiency of large-scale, high-gradient magnetic fishing could be improved if magnetic particles offering higher binding capacity and magnetization were available. This article describes several strategies for synthesizing microbeads that are composed of a M13 bacteriophage layer assembled on a superparamagnetic core. Chemical cross-linking of the pVIII proteins to a carboxyl-functionalized bead produces highly responsive superparamagnetic particles (SPM) with a side-on oriented, adherent virus monolayer. Also, the genetic manipulation of the pIII proteins with a His(6) peptide sequence allows reversible assembly of the bacteriophage on a nitrilotriacetic-acid-functionalized core in an end-on configuration. These phage-magnetic particles are successfully used to separate antibodies from high-protein concentration solutions in a single step with a >90% purity. The dense magnetic core of these particles makes them five times more responsive to magnetic fields than commercial materials composed of polymer-(iron oxide) composites and a monolayer of phage could produce a 1000 fold higher antibody binding capacity. These new bionanomaterials appear to be well-suited to large-scale high-gradient magnetic fishing separation and promise to be cost effective as a result of the self-assembling and self-replicating properties of genetically engineered M13 bacteriophage. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Occurrence of Propionibacterium freudenreichii bacteriophages in swiss cheese.

PubMed Central

Gautier, M; Rouault, A; Sommer, P; Briandet, R

1995-01-01

We isolated bacteriophages active against Propionibacterium freudenreichii from 16 of 32 swiss cheese samples. Bacteriophage concentrations ranged from 14 to 7 x 10(5) PFU/g, depending on the sample and the sensitive strain used for detection. Only a few strains, 8 of the 44 strains of P. freudenreichii in our collection, were sensitive. We observed that multiplication of bacteriophages occurred in the cheese loaf during multiplication of propionibacteria in a warm curing room, but it seems that these bacteriophages have no adverse effect on the development of the propionic flora. We also found that sensitive cells, originating from either the starter or the cheese-making milk, were present at a high level (10(9) CFU/g) in the cheese. PMID:7618869

The effect of swim-up and gradient sperm preparation techniques on deoxyribonucleic acid (DNA) fragmentation in subfertile patients.

PubMed

Oguz, Yuksel; Guler, Ismail; Erdem, Ahmet; Mutlu, Mehmet Firat; Gumuslu, Seyhan; Oktem, Mesut; Bozkurt, Nuray; Erdem, Mehmet

2018-03-23

To compare the effect of two different sperm preparation techniques, including swim-up and gradient methods on sperm deoxyribonucleic acid (DNA) fragmentation status of semen samples from unexplained and mild male factor subfertile patients undergoing intrauterine insemination (IUI). A prospective randomized study was conducted in 65 subfertile patients, including 34 unexplained and 31 male factor infertility to compare basal and post-procedure DNA fragmentation rates in swim-up and gradient techniques. Sperm DNA fragmentation rates were evaluated by a sperm chromatin dispersion (SCD) test in two portions of each sample of semen that was prepared with either swim-up or gradient techniques. Sperm motility and morphology were also assessed based on WHO 2010 criteria. Swim-up but not gradient method yielded a statistically significant reduction in the DNA fragmented sperm rate after preparation as compared to basal rates, in the semen samples of both unexplained (41.85 ± 22.04 vs. 28.58 ± 21.93, p < 0.001 for swim-up; and 41.85 ± 22.04 vs. 38.79 ± 22.30, p = 0.160 for gradient) and mild male factor (46.61 ± 19.38 vs. 30.32 ± 18.20, p < 0.001 for swim-up and 46.61 ± 19.38 vs. 44.03 ± 20.87, p = 0.470 for gradient) subgroups. Swim-up method significantly reduces sperm DNA fragmentation rates and may have some prognostic value on intrauterine insemination in patients with decreased sperm DNA integrity.

STUDIES ON THE PURIFICATION OF BACTERIOPHAGE

PubMed Central

Kalmanson, G.; Bronfenbrenner, J.

1939-01-01

A simple method of concentrating and purifying bacteriophage has been described. The procedure consisted essentially in collecting the active agent on a reinforced collodion membrane of a porosity that would just retain all the active agent and permit extraneous material to pass through. Advantage was taken of the fact that B. coli will proliferate and regenerate bacteriophage in a completely diffusible synthetic medium with ammonia as the only source of nitrogen, which permitted the purification of the bacteriophage by copious washing. The material thus obtained was concentrated by suction and after thorough washing possessed all the activity of the original filtrate. It was labile, losing its activity in a few days on standing, and was quickly and completely inactivated upon drying. This material contained approximately 15 per cent of nitrogen and with 2 or 3 mg. samples of inactive dry residue it was possible to obtain positive protein color tests. The concentrated and purified bacteriophage has about 10–14 mg. of nitrogen, or 6 x 10–17 gm. of protein per unit of lytic activity. Assuming that each unit of activity represents a molecule, the calculated maximum average molecular weight would be approximately 36,000,000, and on the assumption of a spherical shape of particles and a density of 1.3, the calculated radius would be about 22 millimicra. By measurement of the diffusion rate, the average radius of particle of the fraction of the purified bacteriophage which diffuses most readily through a porous plate was found to be of the order of magnitude of 9 millimicra, or of a calculated molecular weight of 2,250,000. Furthermore, when this purified bacteriophage was fractionated by forcing it through a thin collodion membrane, which permits the passage of only the smaller particles, it was possible to demonstrate in the ultrafiltrate active particles of about 2 millimicra in radius, and of a calculated molecular weight of 25,000. It was of interest to apply

Reduction of Salmonella in ground chicken using a bacteriophage.

PubMed

Grant, Ar'Quette; Parveen, Salina; Schwarz, Jurgen; Hashem, Fawzy; Vimini, Bob

2017-08-01

This study's goal was to ascertain the effectiveness of a commercially available Salmonella bacteriophage during ground chicken production focusing on: water source, different Salmonella serovars, and time. Salmonella-free boneless, skinless chicken meat was inoculated with 4.0 Log CFU/cm2 of either a cocktail of 3 Salmonella isolates derived from ground chicken (GC) or a cocktail of 3 Salmonella strains not isolated from ground chicken (non-GC). Bacteriophages were spread onto the chicken using sterile tap or filtered water for 30 min or 8 h. Salmonella was recovered using standard plating method. Greater Salmonella reduction was observed when the bacteriophage was diluted in sterile tap water than in sterile filtered water: 0.39 Log CFU/cm2 and 0.23 Log CFU/cm2 reduction after 30 min, respectively (P < 0.05). The non-GC isolates showed reductions of 0.71 Log CFU/cm2 and 0.90 Log CFU/cm2 after 30 min and 8 h, respectively (P < 0.05). The GC isolates were less sensitive to the bacteriophage: 0.39 Log CFU/cm2 and 0.67 Log CFU/cm2 reductions after 30 min and 8 h, respectively (P < 0.05). In conclusion, bacteriophage reduction was dependent on water used to dilute the bacteriophage, Salmonella's susceptibility to the bacteriophage, and treatment time. © 2017 Poultry Science Association Inc.

Susceptibility of Escherichia coli isolated from uteri of postpartum dairy cows to antibiotic and environmental bacteriophages. Part I: Isolation and lytic activity estimation of bacteriophages.

PubMed

Bicalho, R C; Santos, T M A; Gilbert, R O; Caixeta, L S; Teixeira, L M; Bicalho, M L S; Machado, V S

2010-01-01

The objective of this study was to isolate bacteriophages from environmental samples of 2 large commercial dairy farms using Escherichia coli isolated from the uteri of postpartum Holstein dairy cows as hosts. A total of 11 bacteriophage preparations were isolated from manure systems of commercial dairy farms and characterized for in vitro antimicrobial activity. In addition, a total of 57 E. coli uterine isolates from 5 dairy cows were phylogenetically grouped by triplex PCR. Each E. coli bacterial host from the uterus was inoculated with their respective bacteriophage preparation at several different multiplicities of infections (MOI) to determine minimum inhibitory MOI. The effect of a single dose (MOI=10(2)) of bacteriophage on the growth curve of all 57 E. coli isolates was assessed using a microplate technique. Furthermore, genetic diversity within and between the different bacteriophage preparations was assessed by bacteriophage purification followed by DNA extraction, restriction, and agarose gel electrophoresis. Phylogenetic grouping based on triplex PCR showed that all isolates of E. coli belonged to phylogroup B1. Bacterial growth was completely inhibited at considerably low MOI, and the effect of a single dose (MOI=10(2)) of bacteriophage preparations on the growth curve of all 57 E. coli isolates showed that all bacteriophage preparations significantly decreased the growth rate of the isolates. Bacteriophage preparation 1230-10 had the greatest antimicrobial activity and completely inhibited the growth of 71.7% (n=57) of the isolates. The combined action of bacteriophage preparations 1230-10, 6375-10, 2540-4, and 6547-2, each at MOI=10(2), had the broadest spectrum of action and completely inhibited the growth (final optical density at 600 nm

Heat Induction of Prophage φ105 in Bacillus subtilis: Replication of the Bacterial and Bacteriophage Genomes

PubMed Central

Armentrout, Richard W.; Rutberg, Lars

1971-01-01

A temperature-inducible mutant of temperate Bacillus bacteriophage φ105 was isolated and used to lysogenize a thymine-requiring strain of Bacillus subtilis 168. Synthesis of phage and bacterial deoxyribonucleic acid (DNA) was studied by sucrose gradient centrifugation and density equilibrium centrifugation of DNA extracted from induced bacteria. The distribution of DNA in the gradients was measured by differential isotope and density labeling of DNA before and after induction and by measuring the biological activity of the DNA in genetic transformation, in rescue of phage markers, and in infectivity assays. At early times after induction, but after at least one round of replication, phage DNA remains associated with high-molecular-weight DNA, whereas, later in the infection, phage DNA is associated with material of decreasing molecular weight. Genetic linkage between phage and bacterial markers can be demonstrated in replicated DNA from induced cells. Prophage induction is shown to affect replication of the bacterial chromosome. The overall rate of replication of prelabeled bacterial DNA is identical in temperature-induced lysogenics and in “mock-induced” wild-type φ105 lysogenics. The rate of replication of the bacterial marker phe-1 (and also of nia-38), located close to the prophage in direction of the terminus of the bacterial chromosome, is increased in induced cells, however, relative to other bacterial markers tested. In temperature-inducible lysogenics, where the prophage also carries a ts mutation which blocks phage DNA synthesis, replication of both phage and bacterial DNA stops after about 50% of the phage DNA has replicated once. The results of these experiments suggest that the prophage is not initially excised in induced cells, but rather it is specifically replicated in situ together with adjacent parts of the bacterial chromosome. PMID:5002012

Genomic Diversity of Type B3 Bacteriophages of Caulobacter crescentus.

PubMed

Ash, Kurt T; Drake, Kristina M; Gibbs, Whitney S; Ely, Bert

2017-07-01

The genomes of the type B3 bacteriophages that infect Caulobacter crescentus are among the largest phage genomes thus far deposited into GenBank with sizes over 200 kb. In this study, we introduce six new bacteriophage genomes which were obtained from phage collected from various water systems in the southeastern United States and from tropical locations across the globe. A comparative analysis of the 12 available genomes revealed a "core genome" which accounts for roughly 1/3 of these bacteriophage genomes and is predominately localized to the head, tail, and lysis gene regions. Despite being isolated from geographically distinct locations, the genomes of these bacteriophages are highly conserved in both genome sequence and gene order. We also identified the insertions, deletions, translocations, and horizontal gene transfer events which are responsible for the genomic diversity of this group of bacteriophages and demonstrated that these changes are not consistent with the idea that modular reassortment of genomes occurs in this group of bacteriophages.

Novel bacteriophage therapy for controlling metallo-beta-lactamase producing Pseudomonas aeruginosa infection in Catfish

PubMed Central

2013-01-01

Background The bacteriophage therapy is an effective antimicrobial approach with potentially important applications in medicine and biotechnology which can be seen as an additional string in the bow. Emerging drug resistant bacteria in aquaculture industry due to unrestricted use of antibiotics warrants more sustainable and environmental friendly strategies for controlling fish infections. The isolated bacteria from fish lesions was characterised based on isolation on selective and differential medium like Pseudomonas agar, gram staining, biochemical tests and 16SrRNA sequencing. The metallo-beta-lactamase (MBL) producing bacterial isolate was evaluated using Imipenem - Ethylenediaminetetraacetic acid (EDTA) disk method. The specific bacteriophage was isolated and concentrated using coal bed developed in our lab at CSIR-NEERI. The isolated and enriched bacteriophage was characterised by nucleotide sequencing and electron microscopy. The phage therapy was applied for treating ulcerative lesion in fish. Results The pathogenic bacterium responsible for causing ulcerative lesions in catfish species (Clarias gariepinus) was identified as Pseudomonas aeruginosa. One out of twenty P. aeruginosa isolate showing multi drug resistance (MDR) was incidentally found to be MBL producing as determined by Imipenem-EDTA disk method. The phage therapy effectively cured the ulcerative lesions of the infected fish in 8–10 days of treatment, with a sevenfold reduction of the lesion with untreated infection control. Conclusion Bacteriophage therapy can have potential applications soon as an alternative or as a complement to antibiotic treatment in the aquaculture. We present bacteriophage therapy as a treatment method for controlling MDR P. aeruginosa infection in C. gariepinus. To the best of our knowledge this is a first report of application of phage therapy against MBL producing P. aeruginosa isolated from aquatic ecosystem. PMID:24369750

Novel bacteriophage therapy for controlling metallo-beta-lactamase producing Pseudomonas aeruginosa infection in catfish.

PubMed

Khairnar, Krishna; Raut, Mahendra P; Chandekar, Rajshree H; Sanmukh, Swapnil G; Paunikar, Waman N

2013-12-26

The bacteriophage therapy is an effective antimicrobial approach with potentially important applications in medicine and biotechnology which can be seen as an additional string in the bow. Emerging drug resistant bacteria in aquaculture industry due to unrestricted use of antibiotics warrants more sustainable and environmental friendly strategies for controlling fish infections.The isolated bacteria from fish lesions was characterised based on isolation on selective and differential medium like Pseudomonas agar, gram staining, biochemical tests and 16SrRNA sequencing. The metallo-beta-lactamase (MBL) producing bacterial isolate was evaluated using Imipenem - Ethylenediaminetetraacetic acid (EDTA) disk method. The specific bacteriophage was isolated and concentrated using coal bed developed in our lab at CSIR-NEERI. The isolated and enriched bacteriophage was characterised by nucleotide sequencing and electron microscopy. The phage therapy was applied for treating ulcerative lesion in fish. The pathogenic bacterium responsible for causing ulcerative lesions in catfish species (Clarias gariepinus) was identified as Pseudomonas aeruginosa. One out of twenty P. aeruginosa isolate showing multi drug resistance (MDR) was incidentally found to be MBL producing as determined by Imipenem-EDTA disk method. The phage therapy effectively cured the ulcerative lesions of the infected fish in 8-10 days of treatment, with a sevenfold reduction of the lesion with untreated infection control. Bacteriophage therapy can have potential applications soon as an alternative or as a complement to antibiotic treatment in the aquaculture. We present bacteriophage therapy as a treatment method for controlling MDR P. aeruginosa infection in C. gariepinus. To the best of our knowledge this is a first report of application of phage therapy against MBL producing P. aeruginosa isolated from aquatic ecosystem.

Inactivation of Escherichia coli O157:H7 attached to spinach harvester blade using bacteriophage.

PubMed

Patel, Jitendra; Sharma, Manan; Millner, Patricia; Calaway, Todd; Singh, Manpreet

2011-04-01

Outbreaks associated with leafy greens have focused attention on the transfer of human pathogens to these commodities during harvest with commercial equipment. Attachment of Escherichia coli O157:H7 on new or rusty spinach harvester blades immersed in spinach extract or 10% tryptic soy broth (TSB) was investigated. Bacteriophages specific for E. coli O157:H7 were evaluated to kill cells attached to blade. A cocktail of five nalidixic acid-resistant E. coli O157:H7 isolates was transferred to 25 mL of spinach extract or 10% TSB. A piece of sterilized spinach harvester blade (2×1") was placed in above spinach extract or 10% TSB and incubated at room (22 °C) or dynamic (30 °C day, 20 °C night) temperatures. E. coli O157:H7 populations attached to blade during incubation in spinach extract or 10% TSB were determined. When inoculated at 1 log CFU/mL, E. coli O157:H7 attachment to blades after 24 and 48 h incubation at dynamic temperature (6.09 and 6.37 log CFU/mL) was significantly higher than when incubated at 22 °C (4.84 and 5.68 log CFU/mL), respectively. After 48 h incubation, two blades were sprayed on each side with a cocktail of E. coli O157-specific bacteriophages before scraping the blade, and subsequent plating on Sorbitol MacConkey media-nalidixic acid. Application of bacteriophages reduced E. coli O157:H7 populations by 4.5 log CFU on blades after 2 h of phage treatment. Our study demonstrates that E. coli O157:H7 can attach to and proliferate on spinach harvester blades under static and dynamic temperature conditions, and bacteriophages are able to reduce E. coli O157:H7 populations adhered to blades. © Mary Ann Liebert, Inc.

Bacteriophages as indicators of faecal pollution and enteric virus removal.

PubMed

McMinn, B R; Ashbolt, N J; Korajkic, A

2017-07-01

Bacteriophages are an attractive alternative to faecal indicator bacteria (FIB), particularly as surrogates of enteric virus fate and transport, due to their closer morphological and biological properties. Based on a review of published data, we summarize densities of coliphages (F+ and somatic), Bacteroides spp. and enterococci bacteriophages (phages) in individual human waste, raw wastewater, ambient fresh and marine waters and removal through wastewater treatment processes utilizing traditional treatments. We also provide comparisons with FIB and enteric viruses whenever possible. Lastly, we examine fate and transport characteristics in the aquatic environment and provide an overview of the environmental factors affecting their survival. In summary, concentrations of bacteriophages in various sources were consistently lower than FIB, but more reflective of infectious enteric virus levels. Overall, our investigation indicates that bacteriophages may be adequate viral surrogates, especially in built systems, such as wastewater treatment plants. Bacteriophage are alternative fecal indicators that may be better surrogates for viral pathogens than fecal indicator bacteria (FIB). This report offers a summary of the existing literature concerning the utility of bacteriophage as indicators of viral presence (fecal sources and surface waters) and persistence (in built infrastructure and aquatic environments). Our findings indicate that bacteriophage levels in all matrices examined are consistently lower than FIB, but similar to viral pathogens. Furthermore, in built infrastructure (e.g. wastewater treatment systems) bacteriophage closely mimic viral pathogen persistence suggesting they may be adequate sentinels of enteric virus removal. © 2017 The Society for Applied Microbiology.

Convection-enhanced delivery of M13 bacteriophage to the brain

PubMed Central

Ksendzovsky, Alexander; Walbridge, Stuart; Saunders, Richard C.; Asthagiri, Ashok R.; Heiss, John D.; Lonser, Russell R.

2013-01-01

Object Recent studies indicate that M13 bacteriophage, a very large nanoparticle, binds to β-amyloid and α-synuclein proteins, leading to plaque disaggregation in models of Alzheimer and Parkinson disease. To determine the feasibility, safety, and characteristics of convection-enhanced delivery (CED) of M13 bacteriophage to the brain, the authors perfused primate brains with bacteriophage. Methods Four nonhuman primates underwent CED of M13 bacteriophage (900 nm) to thalamic gray matter (4 infusions) and frontal white matter (3 infusions). Bacteriophage was coinfused with Gd-DTPA (1 mM), and serial MRI studies were performed during infusion. Animals were monitored for neurological deficits and were killed 3 days after infusion. Tissues were analyzed for bacteriophage distribution. Results Real-time T1-weighted MRI studies of coinfused Gd-DTPA during infusion demonstrated a discrete region of perfusion in both thalamic gray and frontal white matter. An MRI-volumetric analysis revealed that the mean volume of distribution (Vd) to volume of infusion (Vi) ratio of M13 bacteriophage was 2.3 ± 0.2 in gray matter and 1.9 ± 0.3 in white matter. The mean values are expressed ± SD. Immunohistochemical analysis demonstrated mean Vd:Vi ratios of 2.9 ± 0.2 in gray matter and 2.1 ± 0.3 in white matter. The Gd-DTPA accurately tracked M13 bacteriophage distribution (the mean difference between imaging and actual bacteriophage Vd was insignificant [p > 0.05], and was −2.2% ± 9.9% in thalamic gray matter and 9.1% ± 9.5% in frontal white matter). Immunohistochemical analysis revealed evidence of additional spread from the initial delivery site in white matter (mean Vd:Vi, 16.1 ± 9.1). All animals remained neurologically intact after infusion during the observation period, and histological studies revealed no evidence of toxicity. Conclusions The CED method can be used successfully and safely to distribute M13 bacteriophage in the brain. Furthermore, additional white

Convection-enhanced delivery of M13 bacteriophage to the brain.

PubMed

Ksendzovsky, Alexander; Walbridge, Stuart; Saunders, Richard C; Asthagiri, Ashok R; Heiss, John D; Lonser, Russell R

2012-08-01

Recent studies indicate that M13 bacteriophage, a very large nanoparticle, binds to β-amyloid and α-synuclein proteins, leading to plaque disaggregation in models of Alzheimer and Parkinson disease. To determine the feasibility, safety, and characteristics of convection-enhanced delivery (CED) of M13 bacteriophage to the brain, the authors perfused primate brains with bacteriophage. Four nonhuman primates underwent CED of M13 bacteriophage (900 nm) to thalamic gray matter (4 infusions) and frontal white matter (3 infusions). Bacteriophage was coinfused with Gd-DTPA (1 mM), and serial MRI studies were performed during infusion. Animals were monitored for neurological deficits and were killed 3 days after infusion. Tissues were analyzed for bacteriophage distribution. Real-time T1-weighted MRI studies of coinfused Gd-DTPA during infusion demonstrated a discrete region of perfusion in both thalamic gray and frontal white matter. An MRI-volumetric analysis revealed that the mean volume of distribution (Vd) to volume of infusion (Vi) ratio of M13 bacteriophage was 2.3 ± 0.2 in gray matter and 1.9 ± 0.3 in white matter. The mean values are expressed ± SD. Immunohistochemical analysis demonstrated mean Vd:Vi ratios of 2.9 ± 0.2 in gray matter and 2.1 ± 0.3 in white matter. The Gd-DTPA accurately tracked M13 bacteriophage distribution (the mean difference between imaging and actual bacteriophage Vd was insignificant [p > 0.05], and was -2.2% ± 9.9% in thalamic gray matter and 9.1% ± 9.5% in frontal white matter). Immunohistochemical analysis revealed evidence of additional spread from the initial delivery site in white matter (mean Vd:Vi, 16.1 ± 9.1). All animals remained neurologically intact after infusion during the observation period, and histological studies revealed no evidence of toxicity. The CED method can be used successfully and safely to distribute M13 bacteriophage in the brain. Furthermore, additional white matter spread after infusion cessation

The effects of bacteriophage and nanoparticles on microbial processes

NASA Astrophysics Data System (ADS)

Moody, Austin L.

There are approximately 1031 tailed phages in the biosphere, making them the most abundant organism. Bacteriophages are viruses that infect bacteria. Due to the large diversity and abundance, no two bacteriophages that have been isolated are genetically the same. Phage products have potential in disease therapy to solve bacteria-related problems, such as infections resulting from resistant strains of Staphylococcus aureus. A bacteriophage capable of infecting methicillin-resistant S. aureus (MRSA) was isolated from bovine hair. The bacteriophage, named JB phage, was characterized using purification, amplification, cesium chloride banding, scanning electron microscopy, and transmission electron microscopy. JB phage and nanoparticles were used in various in vitro and in vivo models to test their effects on microbial processes. Scanning and transmission electron microscopy studies revealed strong interactions between JB phage and nanoparticles, which resulted in increased bacteriophage infectivity. JB phage and nanoparticle cocktails were used as a therapeutic to treat skin and systemic infections in mice caused by MRSA.

Microneedle-mediated transdermal bacteriophage delivery

PubMed Central

Ryan, Elizabeth; Garland, Martin J.; Singh, Thakur Raghu Raj; Bambury, Eoin; O’Dea, John; Migalska, Katarzyna; Gorman, Sean P.; McCarthy, Helen O.; Gilmore, Brendan F.; Donnelly, Ryan F.

2012-01-01

Interest in bacteriophages as therapeutic agents has recently been reawakened. Parenteral delivery is the most routinely-employed method of administration. However, injection of phages has numerous disadvantages, such as the requirement of a health professional for administration and the possibility of cross-contamination. Transdermal delivery offers one potential means of overcoming many of these problems. The present study utilized a novel poly (carbonate) (PC) hollow microneedle (MN) device for the transdermal delivery of Escherichia coli-specific T4 bacteriophages both in vitro and in vivo. MN successfully achieved bacteriophage delivery in vitro across dermatomed and full thickness skin. A concentration of 2.67 × 106 PFU/ml (plaque forming units per ml) was detected in the receiver compartment when delivered across dermatomed skin and 4.0 × 103 PFU/ml was detected in the receiver compartment when delivered across full thickness skin. An in vivo study resulted in 4.13 × 103 PFU/ml being detected in blood 30 min following initial MN-mediated phage administration. Clearance occurred rapidly, with phages being completely cleared from the systemic circulation within 24 h, which was expected in the absence of infection. We have shown here that MN-mediated delivery allows successful systemic phage absorption. Accordingly, bacteriophage-based therapeutics may now have an alternative route for systemic delivery. Once fully-investigated, this could lead to more widespread investigation of these interesting therapeutic viruses. PMID:22750416

Bacteriophage GC1, a Novel Tectivirus Infecting Gluconobacter Cerinus, an Acetic Acid Bacterium Associated with Wine-Making.

PubMed

Philippe, Cécile; Krupovic, Mart; Jaomanjaka, Fety; Claisse, Olivier; Petrel, Melina; le Marrec, Claire

2018-01-16

The Gluconobacter phage GC1 is a novel member of the Tectiviridae family isolated from a juice sample collected during dry white wine making. The bacteriophage infects Gluconobacter cerinus , an acetic acid bacterium which represents a spoilage microorganism during wine making, mainly because it is able to produce ethyl alcohol and transform it into acetic acid. Transmission electron microscopy revealed tail-less icosahedral particles with a diameter of ~78 nm. The linear double-stranded DNA genome of GC1 (16,523 base pairs) contains terminal inverted repeats and carries 36 open reading frames, only a handful of which could be functionally annotated. These encode for the key proteins involved in DNA replication (protein-primed family B DNA polymerase) as well as in virion structure and assembly (major capsid protein, genome packaging ATPase (adenosine triphosphatase) and several minor capsid proteins). GC1 is the first tectivirus infecting an alphaproteobacterial host and is thus far the only temperate tectivirus of gram-negative bacteria. Based on distinctive sequence and life-style features, we propose that GC1 represents a new genus within the Tectiviridae , which we tentatively named " Gammatectivirus ". Furthermore, GC1 helps to bridge the gap in the sequence space between alphatectiviruses and betatectiviruses.

Bacteriophages of Yersinia pestis.

PubMed

Zhao, Xiangna; Skurnik, Mikael

2016-01-01

Bacteriophage play many varied roles in microbial ecology and evolution. This chapter collates a vast body of knowledge and expertise on Yersinia pestis phages, including the history of their isolation and classical methods for their isolation and identification. The genomic diversity of Y. pestis phage and bacteriophage islands in the Y. pestis genome are also discussed because all phage research represents a branch of genetics. In addition, our knowledge of the receptors that are recognized by Y. pestis phage, advances in phage therapy for Y. pestis infections, the application of phage in the detection of Y. pestis, and clustered regularly interspaced short palindromic repeats (CRISPRs) sequences of Y. pestis from prophage DNA are all reviewed here.

Bacteriophage-based synthetic biology for the study of infectious diseases

PubMed Central

Lu, Timothy K.

2014-01-01

Since their discovery, bacteriophages have contributed enormously to our understanding of molecular biology as model systems. Furthermore, bacteriophages have provided many tools that have advanced the fields of genetic engineering and synthetic biology. Here, we discuss bacteriophage-based technologies and their application to the study of infectious diseases. New strategies for engineering genomes have the potential to accelerate the design of novel phages as therapies, diagnostics, and tools. Though almost a century has elapsed since their discovery, bacteriophages continue to have a major impact on modern biological sciences, especially with the growth of multidrug-resistant bacteria and interest in the microbiome. PMID:24997401

Evolution and the complexity of bacteriophages.

PubMed

Serwer, Philip

2007-03-13

The genomes of both long-genome (> 200 Kb) bacteriophages and long-genome eukaryotic viruses have cellular gene homologs whose selective advantage is not explained. These homologs add genomic and possibly biochemical complexity. Understanding their significance requires a definition of complexity that is more biochemically oriented than past empirically based definitions. Initially, I propose two biochemistry-oriented definitions of complexity: either decreased randomness or increased encoded information that does not serve immediate needs. Then, I make the assumption that these two definitions are equivalent. This assumption and recent data lead to the following four-part hypothesis that explains the presence of cellular gene homologs in long bacteriophage genomes and also provides a pathway for complexity increases in prokaryotic cells: (1) Prokaryotes underwent evolutionary increases in biochemical complexity after the eukaryote/prokaryote splits. (2) Some of the complexity increases occurred via multi-step, weak selection that was both protected from strong selection and accelerated by embedding evolving cellular genes in the genomes of bacteriophages and, presumably, also archaeal viruses (first tier selection). (3) The mechanisms for retaining cellular genes in viral genomes evolved under additional, longer-term selection that was stronger (second tier selection). (4) The second tier selection was based on increased access by prokaryotic cells to improved biochemical systems. This access was achieved when DNA transfer moved to prokaryotic cells both the more evolved genes and their more competitive and complex biochemical systems. I propose testing this hypothesis by controlled evolution in microbial communities to (1) determine the effects of deleting individual cellular gene homologs on the growth and evolution of long genome bacteriophages and hosts, (2) find the environmental conditions that select for the presence of cellular gene homologs, (3) determine

Bacteriophage sensitivity patterns among bacteria isolated from marine waters

NASA Astrophysics Data System (ADS)

Moebus, K.; Nattkemper, H.

1981-09-01

Phage-host cross-reaction tests were performed with 774 bacterial strains and 298 bacteriophages. The bacteria (bacteriophages) were isolated at different times from water samples collected in the Atlantic Ocean between the European continental shelf and the Sargasso Sea: 733 (258) strains; in the North Sea near Helgoland: 31 (31) strains; and in the Bay of Biscay: 10 (9) strains. Of the Atlantic Ocean bacteria 326 were found to be susceptible to one or more Atlantic Ocean bacteriophage(s). The bacteriophage sensitivity patterns of these bacteria vary considerably, placing 225 of them in two large clusters of bacteriophage-host systems. Taking all into account, 250 of the 326 Atlantic Ocean bacteria are different from each other. This high degree of variation among the bacteria distinguishes microbial populations derived from widely separated eastern and western regions of the Atlantic Ocean. It also sets apart from each other the populations derived from samples collected at successive stations some 200 miles apart, although to a lesser degree. With bacterial populations found from samples collected on the way back and forth between Europe and the Sargasso Sea a gradual change was observed from "western" phage sensitivity patterns to "eastern" ones. Sixty-nine Atlantic Ocean bacteria are sensitive to bacteriophages isolated from the North Sea and the Bay of Biscay; of these only 26 strains are also susceptible to Atlantic Ocean phages. The interpretation of the results is based on the hydrographical conditions prevailing in the northern Atlantic Ocean including the North Sea, and on the assumption that the microbial populations investigated have undergone genetic changes while being transported within water masses from west to east.

Simulated hatchery system to assess bacteriophage efficacy against Vibrio harveyi.

PubMed

Raghu Patil, J; Desai, Srividya Narayanamurthy; Roy, Panchali; Durgaiah, Murali; Saravanan, R Sanjeev; Vipra, Aradhana

2014-12-02

Vibriosis caused by luminous Vibrio harveyi commonly contributes to poor survival in shrimp hatcheries and aquaculture ponds. Lytic bacteriophages pathogenic for V. harveyi are currently being investigated as an alternative to antibiotics to prevent vibriosis. Here, 8 bacteriophages were isolated from oysters and clams using V. harveyi strains as baiting hosts. Among these bacteriophages, 1 strain (VHP6b) identified as broadly pathogenic for 27 V. harveyi strains examined was further characterized by electron microscopy and genome sequence analysis. Phage VHP6b possessed a tail and morphology consistent with it being a member of the family Siphoviridae, and its genome and proteome were most closely related to the Vibrio phages SSP02 and MAR10. An integrase gene essential for lysogeny was not evident. The ability of bacteriophage VHP6b to protect shrimp postlarvae against vibriosis caused by V. harveyi strain VH6 was demonstrated in a model system designed to simulate typical hatchery conditions. Bacteriophage treatment improved survival of postlarvae by 40 to 60% under these conditions, so therapies based on this or other bacteriophages may be useful in shrimp hatcheries.

T4 bacteriophage conjugated magnetic particles for E. coli capturing: Influence of bacteriophage loading, temperature and tryptone.

PubMed

Liana, Ayu Ekajayanthi; Marquis, Christopher P; Gunawan, Cindy; Gooding, J Justin; Amal, Rose

2017-03-01

This work demonstrates the use of bacteriophage conjugated magnetic particles (Fe 3 O 4 ) for the rapid capturing and isolation of Escherichia coli. The investigation of T4 bacteriophage adsorption to silane functionalised Fe 3 O 4 with amine (NH 2 ), carboxylic (COOH) and methyl (CH 3 ) surface functional groups reveals the domination of net electrostatic and hydrophobic interactions in governing bacteriophage adsorption. The bare Fe 3 O 4 and Fe 3 O 4 -NH 2 with high T4 loading captured 3-fold more E. coli (∼70% capturing efficiency) compared to the low loading T4 on Fe 3 O 4 -COOH, suggesting the significance of T4 loading in E. coli capturing efficiency. Importantly, it is further revealed that E. coli capture is highly dependent on the incubation temperature and the presence of tryptone in the media. Effective E. coli capturing only occurs at 37°C in tryptone-containing media with the absence of either conditions resulted in poor bacteria capture. The incubation temperature dictates the capturing ability of Fe 3 O 4 /T4, whereby T4 and E. coli need to establish an irreversible binding that occurred at 37°C. The presence of tryptophan-rich tryptone in the suspending media was also critical, as shown by a 3-fold increase in E. coli capture efficiency of Fe 3 O 4 /T4 in tryptone-containing media compared to that in tryptone-free media. This highlights for the first time that successful bacteria capturing requires not only an optimum tailoring of the particle's surface physicochemical properties for favourable bacteriophage loading, but also an in-depth understanding of how factors, such as temperature and solution chemistry influence the subsequent bacteriophage-bacteria interactions. Copyright © 2016 Elsevier B.V. All rights reserved.

Carcinogenic damage to deoxyribonucleic acid is induced by near-infrared laser pulses in multiphoton microscopy via combination of two- and three-photon absorption

NASA Astrophysics Data System (ADS)

Nadiarnykh, Oleg; Thomas, Giju; Van Voskuilen, Johan; Sterenborg, Henricus J. C. M.; Gerritsen, Hans C.

2012-11-01

Nonlinear optical imaging modalities (multiphoton excited fluorescence, second and third harmonic generation) applied in vivo are increasingly promising for clinical diagnostics and the monitoring of cancer and other disorders, as they can probe tissue with high diffraction-limited resolution at near-infrared (IR) wavelengths. However, high peak intensity of femtosecond laser pulses required for two-photon processes causes formation of cyclobutane-pyrimidine-dimers (CPDs) in cellular deoxyribonucleic acid (DNA) similar to damage from exposure to solar ultraviolet (UV) light. Inaccurate repair of subsequent mutations increases the risk of carcinogenesis. In this study, we investigate CPD damage that results in Chinese hamster ovary cells in vitro from imaging them with two-photon excited autofluorescence. The CPD levels are quantified by immunofluorescent staining. We further evaluate the extent of CPD damage with respect to varied wavelength, pulse width at focal plane, and pixel dwell time as compared with more pronounced damage from UV sources. While CPD damage has been expected to result from three-photon absorption, our results reveal that CPDs are induced by competing two- and three-photon absorption processes, where the former accesses UVA absorption band. This finding is independently confirmed by nonlinear dependencies of damage on laser power, wavelength, and pulse width.

[Biological properties of bacteriophages, active to Yersinia enterocolitica].

PubMed

Darsavelidze, M A; Kapanadze, Zh S; Chanishvili, T G

2004-01-01

The biological properties of 16 clones of Y. enterolitica bacteriophages were tested to select the most active for subsequent use. For the first time Y. enterocolitica virulent phages belonging to the family of Podoviridae were described and 7 serological groups of phages with no cross reactions were registered. The technology for the production of new therapeutic and prophylactic Y. enterocolitica polyvalent bacteriophage under laboratory conditions was developed. The effective multiplicity of contamination ensuring the maximum release of phages from bacterial cells, the optimum incubation temperature and the time of exposure were established. The experimental batches of therapeutic and prophylactic Y. enterocolitica polyvalent bacteriophage thus obtained met the requirements for antibacterial preparations.

Genome Sequences of 19 Novel Erwinia amylovora Bacteriophages

PubMed Central

Esplin, Ian N. D.; Berg, Jordan A.; Sharma, Ruchira; Allen, Robert C.; Arens, Daniel K.; Ashcroft, Cody R.; Bairett, Shannon R.; Beatty, Nolan J.; Bickmore, Madeline; Bloomfield, Travis J.; Brady, T. Scott; Bybee, Rachel N.; Carter, John L.; Choi, Minsey C.; Duncan, Steven; Fajardo, Christopher P.; Foy, Brayden B.; Fuhriman, David A.; Gibby, Paul D.; Grossarth, Savannah E.; Harbaugh, Kala; Harris, Natalie; Hilton, Jared A.; Hurst, Emily; Hyde, Jonathan R.; Ingersoll, Kayleigh; Jacobson, Caitlin M.; James, Brady D.; Jarvis, Todd M.; Jaen-Anieves, Daniella; Jensen, Garrett L.; Knabe, Bradley K.; Kruger, Jared L.; Merrill, Bryan D.; Pape, Jenny A.; Payne Anderson, Ashley M.; Payne, David E.; Peck, Malia D.; Pollock, Samuel V.; Putnam, Micah J.; Ransom, Ethan K.; Ririe, Devin B.; Robinson, David M.; Rogers, Spencer L.; Russell, Kerri A.; Schoenhals, Jonathan E.; Shurtleff, Christopher A.; Simister, Austin R.; Smith, Hunter G.; Stephenson, Michael B.; Staley, Lyndsay A.; Stettler, Jason M.; Stratton, Mallorie L.; Tateoka, Olivia B.; Tatlow, P. J.; Taylor, Alexander S.; Thompson, Suzanne E.; Townsend, Michelle H.; Thurgood, Trever L.; Usher, Brittian K.; Whitley, Kiara V.; Ward, Andrew T.; Ward, Megan E. H.; Webb, Charles J.; Wienclaw, Trevor M.; Williamson, Taryn L.; Wells, Michael J.; Wright, Cole K.; Breakwell, Donald P.; Hope, Sandra

2017-01-01

ABSTRACT Erwinia amylovora is the causal agent of fire blight, a devastating disease affecting some plants of the Rosaceae family. We isolated bacteriophages from samples collected from infected apple and pear trees along the Wasatch Front in Utah. We announce 19 high-quality complete genome sequences of E. amylovora bacteriophages. PMID:29146842

Seven Bacteriophages Isolated from the Female Urinary Microbiota

PubMed Central

Malki, Kema; Sible, Emily; Cooper, Alexandria; Garretto, Andrea; Bruder, Katherine; Watkins, Siobhan C.

2016-01-01

Recent research has debunked the myth that urine is sterile, having uncovered bacteria within the bladders of healthy individuals. However, the identity, diversity, and putative roles of bacteriophages in the bladder are unknown. We report the draft genome sequences of seven bacteriophages isolated from microbial communities from adult female bladders. PMID:27881533

Methods of expanding bacteriophage host-range and bacteriophage produced by the methods

DOE Office of Scientific and Technical Information (OSTI.GOV)

Crown, Kevin K.; Santarpia, Joshua

A method of producing novel bacteriophages with expanded host-range and bacteriophages with expanded host ranges are disclosed. The method produces mutant phage strains which are infectious to a second host and can be more infectious to their natural host than in their natural state. The method includes repeatedly passaging a selected phage strain into bacterial cultures that contain varied ratios of its natural host bacterial strain with a bacterial strain that the phage of interest is unable to infect; the target-host. After each passage the resulting phage are purified and screened for activity against the target-host via double-overlay assays. Whenmore » mutant phages that are shown to infect the target-host are discovered, they are further propagated in culture that contains only the target-host to produce a stock of the resulting mutant phage.« less

Bacteriophage cocktail for biocontrol of Salmonella in dried pet food.

PubMed

Heyse, Serena; Hanna, Leigh Farris; Woolston, Joelle; Sulakvelidze, Alexander; Charbonneau, Duane

2015-01-01

Human salmonellosis has been associated with contaminated pet foods and treats. Therefore, there is interest in identifying novel approaches for reducing the risk of Salmonella contamination within pet food manufacturing environments. The use of lytic bacteriophages shows promise as a safe and effective way to mitigate Salmonella contamination in various food products. Bacteriophages are safe, natural, highly targeted antibacterial agents that specifically kill bacteria and can be targeted to kill food pathogens without affecting other microbiota. In this study, we show that a cocktail containing six bacteriophages had a broadspectrum activity in vitro against a library of 930 Salmonella enterica strains representing 44 known serovars. The cocktail was effective against 95% of the strains in this tested library. In liquid culture dose-ranging experiments, bacteriophage cocktail concentrations of ≥10(8) PFU/ml inactivated more than 90% of the Salmonella population (10(1) to 10(3) CFU/ml). Dried pet food inoculated with a mixture containing equal proportions of Salmonella serovars Enteritidis (ATCC 4931), Montevideo (ATCC 8387), Senftenberg (ATCC 8400), and Typhimurium (ATCC 13311) and then surface treated with the six-bacteriophage cocktail (≥2.5 ± 1.5 × 10(6) PFU/g) achieved a greater than 1-log (P < 0.001) reduction compared with the phosphate-buffered saline-treated control in measured viable Salmonella within 60 min. Moreover, this bacteriophage cocktail reduced natural contamination in samples taken from an undistributed lot of commercial dried dog food that tested positive for Salmonella. Our results indicate that bacteriophage biocontrol of S. enterica in dried pet food is technically feasible.

Optimizing the European regulatory framework for sustainable bacteriophage therapy in human medicine.

PubMed

Verbeken, Gilbert; Pirnay, Jean-Paul; De Vos, Daniel; Jennes, Serge; Zizi, Martin; Lavigne, Rob; Casteels, Minne; Huys, Isabelle

2012-06-01

For practitioners at hospitals seeking to use natural (not genetically modified, as appearing in nature) bacteriophages for treatment of antibiotic-resistant bacterial infections (bacteriophage therapy), Europe's current regulatory framework for medicinal products hinders more than it facilitates. Although many experts consider bacteriophage therapy to be a promising complementary (or alternative) treatment to antibiotic therapy, no bacteriophage-specific framework for documentation exists to date. Decades worth of historical clinical data on bacteriophage therapy (from Eastern Europe, particularly Poland, and the former Soviet republics, particularly Georgia and Russia, as well as from today's 27 EU member states and the US) have not been taken into account by European regulators because these data have not been validated under current Western regulatory standards. Consequently, applicants carrying out standard clinical trials on bacteriophages in Europe are obliged to initiate clinical work from scratch. This paper argues for a reduced documentation threshold for Phase 1 clinical trials of bacteriophages and maintains that bacteriophages should not be categorized as classical medicinal products for at least two reasons: (1) such a categorization is scientifically inappropriate for this specific therapy and (2) such a categorization limits the marketing authorization process to industry, the only stakeholder with sufficient financial resources to prepare a complete dossier for the competent authorities. This paper reflects on the current regulatory framework for medicines in Europe and assesses possible regulatory pathways for the (re-)introduction of bacteriophage therapy in a way that maintains its effectiveness and safety as well as its inherent characteristics of sustainability and in situ self-amplification and limitation.

Dehydration of bacteriophages in electrospun nanofibers: effect of excipients in polymeric solutions

NASA Astrophysics Data System (ADS)

Koo, Charmaine K. W.; Senecal, Kris; Senecal, Andre; Nugen, Sam R.

2016-12-01

Bacteriophages are viruses capable of infecting and lysing target bacterial cells; as such they have potential applications in agriculture for decontamination of foods, food contact surfaces and food rinse water. Although bacteriophages can retain infectivity long-term using lyophilized storage, the process of freeze-drying can be time consuming and expensive. In this study, electrospinning was used for dehydrating bacteriophages in polyvinylpyrrolidone polymer solutions with addition of excipients (sodium chloride, magnesium sulfate, Tris-HCl, sucrose) in deionized water. The high voltage dehydration reduced the infectivity of bacteriophages following electrospinning, with the damaging effect abated with addition of storage media (SM) buffer and sucrose. SM buffer and sucrose also provided the most protection over extended storage (8 weeks; 20 °C 1% relative humidity) by mitigating environmental effects on the dried bacteriophages. Magnesium sulfate however provided the least protection due to coagulation effects of the ion, which can disrupt the native conformation of the bacteriophage protein coat. Storage temperatures (20 °C, 4 °C and -20 °C 1% relative humidity) had a minimal effect while relative humidity had substantial effect on the infectivity of bacteriophages. Nanofibers stored in higher relative humidity (33% and 75%) underwent considerable damage due to extensive water absorption and disruption of the fibers. Overall, following storage of nanofiber mats for eight weeks at ambient temperatures, high infective phage concentrations (106-107 PFU ml-1) were retained. Therefore, this study provided valuable insights on preservation and dehydration of bacteriophages by electrospinning in comparison to freeze drying and liquid storage, and the influence of excipients on the viability of bacteriophages.

Potential of a lytic bacteriophage to disrupt Acinetobacter baumannii biofilms in vitro.

PubMed

Liu, Yannan; Mi, Zhiqiang; Niu, Wenkai; An, Xiaoping; Yuan, Xin; Liu, Huiying; Wang, Yong; Feng, Yuzhong; Huang, Yong; Zhang, Xianglilan; Zhang, Zhiyi; Fan, Hang; Peng, Fan; Li, Puyuan; Tong, Yigang; Bai, Changqing

2016-10-01

The ability of Acinetobacter baumannii to form biofilms and develop antibiotic resistance makes it difficult to control infections caused by this bacterium. In this study, we explored the potential of a lytic bacteriophage to disrupt A. baumannii biofilms. The potential of the lytic bacteriophage to disrupt A. baumannii biofilms was assessed by performing electron microscopy, live/dead bacterial staining, crystal violet staining and by determining adenosine triphosphate release. The bacteriophage inhibited the formation of and disrupted preformed A. baumannii biofilms. Results of disinfection assay showed that the lytic bacteriophage lysed A. baumannii cells suspended in blood or grown on metal surfaces. These results suggest the potential of the lytic bacteriophage to disrupt A. baumannii biofilms.

Intestinal colonization by enteroaggregative Escherichia coli supports long-term bacteriophage replication in mice.

PubMed

Maura, Damien; Morello, Eric; du Merle, Laurence; Bomme, Perrine; Le Bouguénec, Chantal; Debarbieux, Laurent

2012-08-01

Bacteriophages have been known to be present in the gut for many years, but studies of relationships between these viruses and their hosts in the intestine are still in their infancy. We isolated three bacteriophages specific for an enteroaggregative O104:H4 Escherichia coli (EAEC) strain responsible for diarrhoeal diseases in humans. We studied the replication of these bacteriophages in vitro and in vivo in a mouse model of gut colonization. Each bacteriophage was able to replicate in vitro in both aerobic and anaerobic conditions. Each bacteriophage individually reduced biofilms formed on plastic pegs and a cocktail of the three bacteriophages was found to be more efficient. The cocktail was also able to infect bacterial aggregates formed on the surface of epithelial cells. In the mouse intestine, bacteriophages replicated for at least 3 weeks, provided the host was present, with no change in host levels in the faeces. This model of stable and continuous viral replication provides opportunities for studying the long-term coevolution of virulent bacteriophages with their hosts within a mammalian polymicrobial ecosystem. © 2011 Society for Applied Microbiology and Blackwell Publishing Ltd.

Evaluation of aerosol spray and intramuscular injection of bacteriophage to treat an Escherichia coli respiratory infection.

PubMed

Huff, W E; Huff, G R; Rath, N C; Balog, J M; Donoghue, A M

2003-07-01

Two studies were conducted to determine the efficacy of either aerosol or i.m. injection of bacteriophage to treat an Escherichia coli respiratory infection in broiler chickens. An additional two studies were conducted to enumerate the bacteriophage in the blood of birds at 1, 2, 3, 4, 5, 6, 24, and 48 h after being sprayed or injected i.m. with bacteriophage. Five birds were bled at each period. In study 1, there were 10 treatments with three replicate pens of 10 birds. The treatments consisted of an untreated control, heat-killed bacteriophage spray, active bacteriophage spray, E. coli challenge at 7 d of age, and E. coli challenge followed by spraying the birds with heat-killed bacteriophage or active bacteriophage at 2, 24, or 48 h after challenge. In study 2 there were 11 treatments with three replicate pens of 10 birds per pen. The treatments were untreated controls, birds injected i.m. in the thigh with heat-killed or active bacteriophage, E. coli challenge at 7 d of age, PBS challenge, E. coli challenge followed by injection of heat-killed or active bacteriophage immediately after challenge or at 24 or 48 h after challenge. In both studies the E. coli challenge consisted of injecting 10(4) cfu into the thoracic air sac. Treatment of this severe E. coli infection with the bacteriophage aerosol spray significantly reduced mortality from 50 to 20% when given immediately after the challenge but had little treatment efficacy when administered 24 or 48 h after challenge. The i.m. injection of bacteriophage significantly reduced mortality from 53 to 17%, 46 to 10%, and 44 to 20% when given immediately, 24, or 48 h after challenge, respectively. Only a few birds sprayed with bacteriophage had detectable bacteriophage in their blood with an average of 96 pfu/mL 1 h after bacteriophage administration, and no bacteriophage was detected 24 and 48 h after bacteriophage administration. All birds injected i.m. with bacteriophage had detectable levels of bacteriophage in

Photodynamic Inactivation of Mammalian Viruses and Bacteriophages

PubMed Central

Costa, Liliana; Faustino, Maria Amparo F.; Neves, Maria Graça P. M. S.; Cunha, Ângela; Almeida, Adelaide

2012-01-01

Photodynamic inactivation (PDI) has been used to inactivate microorganisms through the use of photosensitizers. The inactivation of mammalian viruses and bacteriophages by photosensitization has been applied with success since the first decades of the last century. Due to the fact that mammalian viruses are known to pose a threat to public health and that bacteriophages are frequently used as models of mammalian viruses, it is important to know and understand the mechanisms and photodynamic procedures involved in their photoinactivation. The aim of this review is to (i) summarize the main approaches developed until now for the photodynamic inactivation of bacteriophages and mammalian viruses and, (ii) discuss and compare the present state of the art of mammalian viruses PDI with phage photoinactivation, with special focus on the most relevant mechanisms, molecular targets and factors affecting the viral inactivation process. PMID:22852040

Genome Sequences of 19 Novel Erwinia amylovora Bacteriophages.

PubMed

Esplin, Ian N D; Berg, Jordan A; Sharma, Ruchira; Allen, Robert C; Arens, Daniel K; Ashcroft, Cody R; Bairett, Shannon R; Beatty, Nolan J; Bickmore, Madeline; Bloomfield, Travis J; Brady, T Scott; Bybee, Rachel N; Carter, John L; Choi, Minsey C; Duncan, Steven; Fajardo, Christopher P; Foy, Brayden B; Fuhriman, David A; Gibby, Paul D; Grossarth, Savannah E; Harbaugh, Kala; Harris, Natalie; Hilton, Jared A; Hurst, Emily; Hyde, Jonathan R; Ingersoll, Kayleigh; Jacobson, Caitlin M; James, Brady D; Jarvis, Todd M; Jaen-Anieves, Daniella; Jensen, Garrett L; Knabe, Bradley K; Kruger, Jared L; Merrill, Bryan D; Pape, Jenny A; Payne Anderson, Ashley M; Payne, David E; Peck, Malia D; Pollock, Samuel V; Putnam, Micah J; Ransom, Ethan K; Ririe, Devin B; Robinson, David M; Rogers, Spencer L; Russell, Kerri A; Schoenhals, Jonathan E; Shurtleff, Christopher A; Simister, Austin R; Smith, Hunter G; Stephenson, Michael B; Staley, Lyndsay A; Stettler, Jason M; Stratton, Mallorie L; Tateoka, Olivia B; Tatlow, P J; Taylor, Alexander S; Thompson, Suzanne E; Townsend, Michelle H; Thurgood, Trever L; Usher, Brittian K; Whitley, Kiara V; Ward, Andrew T; Ward, Megan E H; Webb, Charles J; Wienclaw, Trevor M; Williamson, Taryn L; Wells, Michael J; Wright, Cole K; Breakwell, Donald P; Hope, Sandra; Grose, Julianne H

2017-11-16

Erwinia amylovora is the causal agent of fire blight, a devastating disease affecting some plants of the Rosaceae family. We isolated bacteriophages from samples collected from infected apple and pear trees along the Wasatch Front in Utah. We announce 19 high-quality complete genome sequences of E. amylovora bacteriophages. Copyright © 2017 Esplin et al.

Alternative bacteriophage life cycles: the carrier state of Campylobacter jejuni

PubMed Central

Siringan, Patcharin; Connerton, Phillippa L.; Cummings, Nicola J.; Connerton, Ian F.

2014-01-01

Members of the genus Campylobacter are frequently responsible for human enteric disease, often through consumption of contaminated poultry products. Bacteriophages are viruses that have the potential to control pathogenic bacteria, but understanding their complex life cycles is key to their successful exploitation. Treatment of Campylobacter jejuni biofilms with bacteriophages led to the discovery that phages had established a relationship with their hosts typical of the carrier state life cycle (CSLC), where bacteria and bacteriophages remain associated in equilibrium. Significant phenotypic changes include improved aerotolerance under nutrient-limited conditions that would confer an advantage to survive in extra-intestinal environments, but a lack in motility eliminated their ability to colonize chickens. Under these circumstances, phages can remain associated with a compatible host and continue to produce free virions to prospect for new hosts. Moreover, we demonstrate that CSLC host bacteria can act as expendable vehicles for the delivery of bacteriophages to new host bacteria within pre-colonized chickens. The CSLC represents an important phase in the ecology of Campylobacter bacteriophage. PMID:24671947

Alternative bacteriophage life cycles: the carrier state of Campylobacter jejuni.

PubMed

Siringan, Patcharin; Connerton, Phillippa L; Cummings, Nicola J; Connerton, Ian F

2014-03-26

Members of the genus Campylobacter are frequently responsible for human enteric disease, often through consumption of contaminated poultry products. Bacteriophages are viruses that have the potential to control pathogenic bacteria, but understanding their complex life cycles is key to their successful exploitation. Treatment of Campylobacter jejuni biofilms with bacteriophages led to the discovery that phages had established a relationship with their hosts typical of the carrier state life cycle (CSLC), where bacteria and bacteriophages remain associated in equilibrium. Significant phenotypic changes include improved aerotolerance under nutrient-limited conditions that would confer an advantage to survive in extra-intestinal environments, but a lack in motility eliminated their ability to colonize chickens. Under these circumstances, phages can remain associated with a compatible host and continue to produce free virions to prospect for new hosts. Moreover, we demonstrate that CSLC host bacteria can act as expendable vehicles for the delivery of bacteriophages to new host bacteria within pre-colonized chickens. The CSLC represents an important phase in the ecology of Campylobacter bacteriophage.

Development of a novel and highly efficient method of isolating bacteriophages from water.

PubMed

Liu, Weili; Li, Chao; Qiu, Zhi-Gang; Jin, Min; Wang, Jing-Feng; Yang, Dong; Xiao, Zhong-Hai; Yuan, Zhao-Kang; Li, Jun-Wen; Xu, Qun-Ying; Shen, Zhi-Qiang

2017-08-01

Bacteriophages are widely used to the treatment of drug-resistant bacteria and the improvement of food safety through bacterial lysis. However, the limited investigations on bacteriophage restrict their further application. In this study, a novel and highly efficient method was developed for isolating bacteriophage from water based on the electropositive silica gel particles (ESPs) method. To optimize the ESPs method, we evaluated the eluent type, flow rate, pH, temperature, and inoculation concentration of bacteriophage using bacteriophage f2. The quantitative detection reported that the recovery of the ESPs method reached over 90%. The qualitative detection demonstrated that the ESPs method effectively isolated 70% of extremely low-concentration bacteriophage (10 0 PFU/100L). Based on the host bacteria composed of 33 standard strains and 10 isolated strains, the bacteriophages in 18 water samples collected from the three sites in the Tianjin Haihe River Basin were isolated by the ESPs and traditional methods. Results showed that the ESPs method was significantly superior to the traditional method. The ESPs method isolated 32 strains of bacteriophage, whereas the traditional method isolated 15 strains. The sample isolation efficiency and bacteriophage isolation efficiency of the ESPs method were 3.28 and 2.13 times higher than those of the traditional method. The developed ESPs method was characterized by high isolation efficiency, efficient handling of large water sample size and low requirement on water quality. Copyright © 2017. Published by Elsevier B.V.

Predicting In Vivo Efficacy of Therapeutic Bacteriophages Used To Treat Pulmonary Infections

PubMed Central

Henry, Marine; Lavigne, Rob

2013-01-01

The potential of bacteriophage therapy to treat infections caused by antibiotic-resistant bacteria has now been well established using various animal models. While numerous newly isolated bacteriophages have been claimed to be potential therapeutic candidates on the basis of in vitro observations, the parameters used to guide their choice among billions of available bacteriophages are still not clearly defined. We made use of a mouse lung infection model and a bioluminescent strain of Pseudomonas aeruginosa to compare the activities in vitro and in vivo of a set of nine different bacteriophages (PAK_P1, PAK_P2, PAK_P3, PAK_P4, PAK_P5, CHA_P1, LBL3, LUZ19, and PhiKZ). For seven bacteriophages, a good correlation was found between in vitro and in vivo activity. While the remaining two bacteriophages were active in vitro, they were not sufficiently active in vivo under similar conditions to rescue infected animals. Based on the bioluminescence recorded at 2 and 8 h postinfection, we also define for the first time a reliable index to predict treatment efficacy. Our results showed that the bacteriophages isolated directly on the targeted host were the most efficient in vivo, supporting a personalized approach favoring an optimal treatment. PMID:24041900

Arthrobacter globiformis and its bacteriophage in soil

NASA Technical Reports Server (NTRS)

Casida, L. E., Jr.; Liu, K.-C.

1974-01-01

An attempt was made to correlate bacteriophages for Arthrobacter globiformis with soils containing that bacterium. The phages were not detected unless the soil was nutritionally amended (with glucose or sucrose) and incubated for several days. Phage was continuously produced after amendment without the addition of host Arthrobacter. These results indicate that the bacteriophage is present in a masked state and that the bacteria are present in an insensitive form which becomes sensitive after addition of nutrient.

Aligning the unalignable: bacteriophage whole genome alignments.

PubMed

Bérard, Sèverine; Chateau, Annie; Pompidor, Nicolas; Guertin, Paul; Bergeron, Anne; Swenson, Krister M

2016-01-13

In recent years, many studies focused on the description and comparison of large sets of related bacteriophage genomes. Due to the peculiar mosaic structure of these genomes, few informative approaches for comparing whole genomes exist: dot plots diagrams give a mostly qualitative assessment of the similarity/dissimilarity between two or more genomes, and clustering techniques are used to classify genomes. Multiple alignments are conspicuously absent from this scene. Indeed, whole genome aligners interpret lack of similarity between sequences as an indication of rearrangements, insertions, or losses. This behavior makes them ill-prepared to align bacteriophage genomes, where even closely related strains can accomplish the same biological function with highly dissimilar sequences. In this paper, we propose a multiple alignment strategy that exploits functional collinearity shared by related strains of bacteriophages, and uses partial orders to capture mosaicism of sets of genomes. As classical alignments do, the computed alignments can be used to predict that genes have the same biological function, even in the absence of detectable similarity. The Alpha aligner implements these ideas in visual interactive displays, and is used to compute several examples of alignments of Staphylococcus aureus and Mycobacterium bacteriophages, involving up to 29 genomes. Using these datasets, we prove that Alpha alignments are at least as good as those computed by standard aligners. Comparison with the progressive Mauve aligner - which implements a partial order strategy, but whose alignments are linearized - shows a greatly improved interactive graphic display, while avoiding misalignments. Multiple alignments of whole bacteriophage genomes work, and will become an important conceptual and visual tool in comparative genomics of sets of related strains. A python implementation of Alpha, along with installation instructions for Ubuntu and OSX, is available on bitbucket (https://bitbucket.org/thekswenson/alpha).

Bacteriophage lambda: The path from biology to theranostic agent.

PubMed

Catalano, Carlos E

2018-03-13

Viral particles provide an attractive platform for the engineering of semisynthetic therapeutic nanoparticles. They can be modified both genetically and chemically in a defined manner to alter their surface characteristics, for targeting specific cell types, to improve their pharmacokinetic features and to attenuate (or enhance) their antigenicity. These advantages derive from a detailed understanding of virus biology, gleaned from decades of fundamental genetic, biochemical, and structural studies that have provided mechanistic insight into virus assembly pathways. In particular, bacteriophages offer significant advantages as nanoparticle platforms and several have been adapted toward the design and engineering of "designer" nanoparticles for therapeutic and diagnostic (theranostic) applications. The present review focuses on one such virus, bacteriophage lambda; I discuss the biology of lambda, the tools developed to faithfully recapitulate the lambda assembly reactions in vitro and the observations that have led to cooptation of the lambda system for nanoparticle design. This discussion illustrates how a fundamental understanding of virus assembly has allowed the rational design and construction of semisynthetic nanoparticles as potential theranostic agents and illustrates the concept of benchtop to bedside translational research. This article is categorized under: Biology-Inspired Nanomaterials> Protein and Virus-Based Structures Biology-Inspired Nanomaterials> Nucleic Acid-Based Structures. © 2018 Wiley Periodicals, Inc.

Time-resolved studies of energy transfer from meso-tetrakis(N-methylpyridinium-4-yl)- porphyrin to 3,3'-diethyl-2,2'-thiatricarbocyanine iodide along deoxyribonucleic acid Chain.

PubMed

Kakiuchi, Toshifumi; Ito, Fuyuki; Nagamura, Toshihiko

2008-04-03

The excitation energy transfer from meso-tetrakis(N-methylpyridinium-4-yl)porphyrin (TMPyP) to 3,3'-diethyl-2,2'-thiatricarbocyanine iodide (DTTCI) along the deoxyribonucleic acid (DNA) double strand was investigated by the steady-state absorption and fluorescence measurements and time-resolved fluorescence measurements. The steady-state fluorescence spectra showed that the near-infrared fluorescence of DTTCI was strongly enhanced up to 86 times due to the energy transfer from the excited TMPyP molecule in DNA buffer solution. Furthermore, we elucidated the mechanism of fluorescence quenching and enhancement by the direct observation of energy transfer using the time-resolved measurements. The fluorescence quenching of TMPyP chiefly consists of a static component due to the formation of complex and dynamic components due to the excitation energy transfer. In a heterogeneous one-dimensional system such as a DNA chain, it was proved that the energy transfer process only carries out within the critical distance based on the Förster theory and within a threshold value estimated from the modified Stern-Volmer equation. The present results showed that DNA chain is one of the most powerful tools for nanoassemblies and will give a novel concepts of material design.

Effect of Thymine Starvation on Messenger Ribonucleic Acid Synthesis in Escherichia coli

PubMed Central

Luzzati, Denise

1966-01-01

Luzzati, Denise (Institut de Biologie Physico-Chimique, Paris, France). Effect of thymine starvation on messenger ribonucleic acid synthesis in Escherichia coli. J. Bacteriol. 92:1435–1446. 1966.—During the course of thymine starvation, the rate of synthesis of messenger ribonucleic acid (mRNA, the rapidly labeled fraction of the RNA which decays in the presence of dinitrophenol or which hybridizes with deoxyribonucleic acid) decreases exponentially, in parallel with the viability of the thymine-starved bacteria. The ability of cell-free extracts of starved bacteria to incorporate ribonucleoside triphosphates into RNA was determined; it was found to be inferior to that of extracts from control cells. The analysis of the properties of cell-free extracts of starved cells shows that their decreased RNA polymerase activity is the consequence of a modification of their deoxyribonucleic acid, the ability of which to serve as a template for RNA polymerase decreases during starvation. PMID:5332402

The role of bacteriophages in periodontal health and disease.

PubMed

Pinto, Graça; Silva, Maria Daniela; Peddey, Mark; Sillankorva, Sanna; Azeredo, Joana

2016-10-01

The human periodontium health is commonly compromised by chronic inflammatory conditions and has become a major public health concern. Dental plaque, the precursor of periodontal disease, is a complex biofilm consisting mainly of bacteria, but also archaea, protozoa, fungi and viruses. Viruses that specifically infect bacteria - bacteriophages - are most common in the oral cavity. Despite this, their role in the progression of periodontal disease remains poorly explored. This review aims to summarize how bacteriophages interact with the oral microbiota, their ability to increase bacterial virulence and mediate the transfer of resistance genes and suggests how bacteriophages can be used as an alternative to the current periodontal disease therapies.

Potential impact of environmental bacteriophages in spreading antibiotic resistance genes.

PubMed

Muniesa, Maite; Colomer-Lluch, Marta; Jofre, Juan

2013-06-01

The idea that bacteriophage transduction plays a role in the horizontal transfer of antibiotic resistance genes is gaining momentum. Such transduction might be vital in horizontal transfer from environmental to human body-associated biomes and here we review many lines of evidence supporting this notion. It is well accepted that bacteriophages are the most abundant entities in most environments, where they have been shown to be quite persistent. This fact, together with the ability of many phages to infect bacteria belonging to different taxa, makes them suitable vehicles for gene transfer. Metagenomic studies confirm that substantial percentages of the bacteriophage particles present in most environments contain bacterial genes, including mobile genetic elements and antibiotic resistance genes. When specific genes of resistance to antibiotics are detected by real-time PCR in the bacteriophage populations of different environments, only tenfold lower numbers of these genes are observed, compared with those found in the corresponding bacterial populations. In addition, the antibiotic resistance genes from these bacteriophages are functional and generate resistance to the bacteria when these genes are transfected. Finally, reports about the transduction of antibiotic resistance genes are on the increase.

Bacteriophage-based Probiotic Preparation for Managing Shigella Infections

DTIC Science & Technology

2015-04-16

for a probiotic preparation – based on naturally occurring bacteriophages – as a way to condition the GI tract’s microflora gently and favorably...10-Apr-2013 Approved for Public Release; Distribution Unlimited Final Report: Bacteriophage-based Probiotic Preparation for Managing Shigella...Research Office P.O. Box 12211 Research Triangle Park, NC 27709-2211 Phage, Shigella, probiotics REPORT DOCUMENTATION PAGE 11. SPONSOR/MONITOR’S

40 CFR 180.1307 - Bacteriophage of Clavibacter michiganensis subspecies michiganensis; exemption from the...

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Bacteriophage of Clavibacter... EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From Tolerances § 180.1307 Bacteriophage of... exemption from the requirement of a tolerance is established for residues of lytic bacteriophage of...

40 CFR 180.1307 - Bacteriophage of Clavibacter michiganensis subspecies michiganensis; exemption from the...

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Bacteriophage of Clavibacter... EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From Tolerances § 180.1307 Bacteriophage of... exemption from the requirement of a tolerance is established for residues of lytic bacteriophage of...

40 CFR 180.1307 - Bacteriophage of Clavibacter michiganensis subspecies michiganensis; exemption from the...

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Bacteriophage of Clavibacter... EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From Tolerances § 180.1307 Bacteriophage of... exemption from the requirement of a tolerance is established for residues of lytic bacteriophage of...

Template reporter bacteriophage platform and multiple bacterial detection assays based thereon

NASA Technical Reports Server (NTRS)

Goodridge, Lawrence (Inventor)

2007-01-01

The invention is a method for the development of assays for the simultaneous detection of multiple bacteria. A bacteria of interest is selected. A host bacteria containing plasmid DNA from a T even bacteriophage that infects the bacteria of interest is infected with T4 reporter bacteriophage. After infection, the progeny bacteriophage are plating onto the bacteria of interest. The invention also includes single-tube, fast and sensitive assays which utilize the novel method.

Newly Isolated Bacteriophages from the Podoviridae, Siphoviridae, and Myoviridae Families Have Variable Effects on Putative Novel Dickeya spp.

PubMed

Alič, Špela; Naglič, Tina; Tušek-Žnidarič, Magda; Ravnikar, Maja; Rački, Nejc; Peterka, Matjaž; Dreo, Tanja

2017-01-01

Soft rot pathogenic bacteria from the genus Dickeya cause severe economic losses in orchid nurseries worldwide, and there is no effective control currently available. In the last decade, the genus Dickeya has undergone multiple changes as multiple new taxa have been described, and just recently a new putative Dickeya species was reported. This study reports the isolation of three bacteriophages active against putative novel Dickeya spp. isolates from commercially produced infected orchids that show variable host-range profiles. Bacteriophages were isolated through enrichment from Dickeya -infected orchid tissue. Convective interaction media monolith chromatography was used to isolate bacteriophages from wastewaters, demonstrating its suitability for the isolation of infective bacteriophages from natural sources. Based on bacteriophage morphology, all isolated bacteriophages were classified as being in the order Caudovirales , belonging to three different families, Podoviridae , Myoviridae , and Siphoviridae . The presence of three different groups of bacteriophages was confirmed by analyzing the bacteriophage specificity of bacterial hosts, restriction fragment length polymorphism and plaque morphology. Bacteriophage BF25/12, the first reported Podoviridae bacteriophage effective against Dickeya spp., was selected for further characterization. Its genome sequence determined by next-generation sequencing showed limited similarity to other characterized Podoviridae bacteriophages. Interactions among the bacteriophages and Dickeya spp. were examined using transmission electron microscopy, which revealed degradation of electron-dense granules in response to bacteriophage infection in some Dickeya strains. The temperature stability of the chosen Podoviridae bacteriophage monitored over 1 year showed a substantial decrease in the survival of bacteriophages stored at -20°C over longer periods. It showed susceptibility to low pH and UV radiation but was stable in neutral

Newly Isolated Bacteriophages from the Podoviridae, Siphoviridae, and Myoviridae Families Have Variable Effects on Putative Novel Dickeya spp.

PubMed Central

Alič, Špela; Naglič, Tina; Tušek-Žnidarič, Magda; Ravnikar, Maja; Rački, Nejc; Peterka, Matjaž; Dreo, Tanja

2017-01-01

Soft rot pathogenic bacteria from the genus Dickeya cause severe economic losses in orchid nurseries worldwide, and there is no effective control currently available. In the last decade, the genus Dickeya has undergone multiple changes as multiple new taxa have been described, and just recently a new putative Dickeya species was reported. This study reports the isolation of three bacteriophages active against putative novel Dickeya spp. isolates from commercially produced infected orchids that show variable host-range profiles. Bacteriophages were isolated through enrichment from Dickeya-infected orchid tissue. Convective interaction media monolith chromatography was used to isolate bacteriophages from wastewaters, demonstrating its suitability for the isolation of infective bacteriophages from natural sources. Based on bacteriophage morphology, all isolated bacteriophages were classified as being in the order Caudovirales, belonging to three different families, Podoviridae, Myoviridae, and Siphoviridae. The presence of three different groups of bacteriophages was confirmed by analyzing the bacteriophage specificity of bacterial hosts, restriction fragment length polymorphism and plaque morphology. Bacteriophage BF25/12, the first reported Podoviridae bacteriophage effective against Dickeya spp., was selected for further characterization. Its genome sequence determined by next-generation sequencing showed limited similarity to other characterized Podoviridae bacteriophages. Interactions among the bacteriophages and Dickeya spp. were examined using transmission electron microscopy, which revealed degradation of electron-dense granules in response to bacteriophage infection in some Dickeya strains. The temperature stability of the chosen Podoviridae bacteriophage monitored over 1 year showed a substantial decrease in the survival of bacteriophages stored at -20°C over longer periods. It showed susceptibility to low pH and UV radiation but was stable in neutral and

Expression of a bioactive bacteriophage endolysin in Nicotiana benthamiana plants

USDA-ARS?s Scientific Manuscript database

The emergence and spread of antibiotic-resistant pathogens has led to an increased interest in alternative antimicrobial treatments, such as bacteriophage, bacteriophage-encoded peptidoglycan hydrolases (endolysins) and antimicrobial peptides. In our study, the antimicrobial activity of the CP933 en...

Metavirome Sequencing of the Termite Gut Reveals the Presence of an Unexplored Bacteriophage Community

PubMed Central

Tikhe, Chinmay V.; Husseneder, Claudia

2018-01-01

The Formosan subterranean termite; Coptotermes formosanus is nutritionally dependent on the complex and diverse community of bacteria and protozoa in their gut. Although, there have been many studies to decipher the taxonomic and functional diversity of bacterial communities in the guts of termites, their bacteriophages remain unstudied. We sequenced the metavirome of the guts of Formosan subterranean termite workers to study the diversity of bacteriophages and other associated viruses. Results showed that the termites harbor a virome in their gut comprised of varied and previously unknown bacteriophages. Between 87–90% of the predicted dsDNA virus genes by Metavir showed similarity to the tailed bacteriophages (Caudovirales). Many predicted genes from the virome matched to bacterial prophage regions. These data are suggestive of a virome dominated by temperate bacteriophages. We predicted the genomes of seven novel Caudovirales bacteriophages from the termite gut. Three of these predicted bacteriophage genomes were found in high proportions in all the three termite colonies tested. Two bacteriophages are predicted to infect endosymbiotic bacteria of the gut protozoa. The presence of these putative bacteriophages infecting endosymbionts of the gut protozoa, suggests a quadripartite relationship between the termites their symbiotic protozoa, endosymbiotic bacteria of the protozoa and their bacteriophages. Other than Caudovirales, ss-DNA virus related genes were also present in the termite gut. We predicted the genomes of 12 novel Microviridae phages from the termite gut and seven of those possibly represent a new proposed subfamily. Circovirus like genomes were also assembled from the termite gut at lower relative abundance. We predicted 10 novel circovirus genomes in this study. Whether these circoviruses infect the termites remains elusive at the moment. The functional and taxonomical annotations suggest that the termites may harbor a core virome comprised of

Effect of a bacteriophage cocktail in combination with modified atmosphere packaging in controlling Listeria monocytogenes on fresh-cut spinach

USDA-ARS?s Scientific Manuscript database

A Listeria monocytogenes-specific bacteriophage cocktail (ListShield™) was evaluated for its activity against a nalidixic acid-resistant L. monocytogenes (Lm-NalR) isolate on fresh-cut spinach stored under modified atmosphere packaging (MAP) at various temperatures. Pieces (~2x2 cm2) of fresh spinac...

Effect of Inhibition of Deoxyribonucleic Acid and Protein Synthesis on the Direction of Cell Wall Growth in Streptococcus faecalis

PubMed Central

Higgins, M. L.; Daneo-Moore, L.; Boothby, D.; Shockman, G. D.

1974-01-01

Selective inhibition of protein synthesis in Streptococcus faecalis (ATCC 9790) was accompanied by a rapid and severe inhibition of cell division and a reduction of enlargement of cellular surface area. Continued synthesis of cell wall polymers resulted in rapid thickening of the wall to an extent not seen in exponential-phase populations. Thus, the normal direction of wall growth was changed from a preferential feeding out of new wall surface to that of thickening existing cell surfaces. However, the overall manner in which the wall thickened, from nascent septa toward polar regions, was the same in both exponential-phase and inhibited populations. In contrast, selective inhibition of deoxyribonucleic acid (DNA) synthesis using mitomycin C was accompanied by an increase in cellular surface area and by division of about 80% of the cells in random populations. Little or no wall thickening was observed until the synthesis of macromolecules other than DNA was impaired and further cell division ceased. Concomitant inhibition of both DNA and protein synthesis inhibited cell division but permitted an increase in average cell volume. In such doubly inhibited cells, walls thickened less than in cells inhibited for protein synthesis only. On the basis of the results obtained, a model for cell surface enlargement and cell division is presented. The model proposes that: (i) each wall enlargement site is influenced by an individual chromosome replication cycle; (ii) during chromosome replication peripheral surface enlargement would be favored over thickening (or septation); (iii) a signal associated with chromosome termination would favor thickening (and septation) at the expense of surface enlargement; and (iv) a factor or signal related to protein synthesis would be required for one or more of the near terminal stages of cell division or cell separation, or both. Images PMID:4133352

Genomics of Three New Bacteriophages Useful in the Biocontrol of Salmonella

PubMed Central

Bardina, Carlota; Colom, Joan; Spricigo, Denis A.; Otero, Jennifer; Sánchez-Osuna, Miquel; Cortés, Pilar; Llagostera, Montserrat

2016-01-01

Non-typhoid Salmonella is the principal pathogen related to food-borne diseases throughout the world. Widespread antibiotic resistance has adversely affected human health and has encouraged the search for alternative antimicrobial agents. The advances in bacteriophage therapy highlight their use in controlling a broad spectrum of food-borne pathogens. One requirement for the use of bacteriophages as antibacterials is the characterization of their genomes. In this work, complete genome sequencing and molecular analyses were carried out for three new virulent Salmonella-specific bacteriophages (UAB_Phi20, UAB_Phi78, and UAB_Phi87) able to infect a broad range of Salmonella strains. Sequence analysis of the genomes of UAB_Phi20, UAB_Phi78, and UAB_Phi87 bacteriophages did not evidence the presence of known virulence-associated and antibiotic resistance genes, and potential immunoreactive food allergens. The UAB_Phi20 genome comprised 41,809 base pairs with 80 open reading frames (ORFs); 24 of them with assigned function. Genome sequence showed a high homology of UAB_Phi20 with Salmonella bacteriophage P22 and other P22likeviruses genus of the Podoviridae family, including ST64T and ST104. The DNA of UAB_Phi78 contained 44,110 bp including direct terminal repeats (DTR) of 179 bp and 58 putative ORFs were predicted and 20 were assigned function. This bacteriophage was assigned to the SP6likeviruses genus of the Podoviridae family based on its high similarity not only with SP6 but also with the K1-5, K1E, and K1F bacteriophages, all of which infect Escherichia coli. The UAB_Phi87 genome sequence consisted of 87,669 bp with terminal direct repeats of 608 bp; although 148 ORFs were identified, putative functions could be assigned to only 29 of them. Sequence comparisons revealed the mosaic structure of UAB_Phi87 and its high similarity with bacteriophages Felix O1 and wV8 of E. coli with respect to genetic content and functional organization. Phylogenetic analysis of large

[Advance on genome research of Yersinia pestis bacteriophage].

PubMed

Tan, H L; Wang, P; Li, W

2017-04-10

Completion of the genome sequences on Yersinia pestis bacteriophage offered unprecedented opportunity for researchers to carry out related genomic studies. This review was based on the genomic sequences and provided a genomic perspective in describing the essential features of genome on Yersinia pestis bacteriophage. Based on the comparative genomics, genetic evolutionary relationship was discussed. Description of functions from the gene prediction and protein annotation provided evidence for further related studies.

Bacteriophage immobilized graphene electrodes for impedimetric sensing of bacteria (Staphylococcus arlettae).

PubMed

Bhardwaj, Neha; Bhardwaj, Sanjeev K; Mehta, Jyotsana; Mohanta, Girish C; Deep, Akash

2016-07-15

Bacteriophages are a class of viruses that specifically infect and replicate within a bacterium. They possess inherent affinity and specificity to the particular bacterial cells. This property of bacteriophages makes them an attractive biorecognition element in the field of biosensor development. In this work, we report the use of an immobilized bacteriophage for the development of a highly sensitive electrochemical sensor for Staphylococcus arlettae, bacteria from the pathogenic family of coagulase-negative staphylococci (CNS). The specific bacteriophages were covalently immobilized on the screen-printed graphene electrodes. Thus, the fabricated bacteriophage biosensor displayed quantitative response for the target bacteria (S. arlettae) for a broad detection range (2.0-2.0 × 10(6) cfu). A fast response time (2 min), low limit of detection (2 cfu), specificity, and stability over a prolonged period (3 months) are some of the important highlights of the proposed sensor. The practical utility of the developed sensor has been demonstrated by the analysis of S. arlettae in spiked water and apple juice samples. Copyright © 2016 Elsevier Inc. All rights reserved.

PCR method for detection and identification of Lactobacillus casei/paracasei bacteriophages in dairy products.

PubMed

Binetti, Ana G; Capra, M Luján; Alvarez, Miguel A; Reinheimer, Jorge A

2008-05-31

Bacteriophage infections of starter lactic acid bacteria (LAB) pose a serious risk to the dairy industry. Nowadays, the expanding use of valuable Lactobacillus strains as probiotic starters determines an increase in the frequency of specific bacteriophage infections in dairy plants. This work describes a simple and rapid Polymerase Chain Reaction (PCR) method that detects and identifies bacteriophages infecting Lactobacillus casei/paracasei, the main bacterial species used as probiotic. Based on a highly conserved region of the NTP-binding genes belonging to the replication module of L. casei phages phiA2 and phiAT3 (the only two whose genomes are completely sequenced), a pair of primers was designed to generate a specific fragment. Furthermore, this PCR detection method proved to be a useful tool for monitoring and identifying L. casei/paracasei phages in industrial samples since specific PCR signals were obtained from phage contaminated milk (detection limit: 10(4) PFU/mL milk) and other commercial samples (fermented milks and cheese whey) that include L. casei/paracasei as probiotic starter (detection limit: 10(6) PFU/mL fermented milk). Since this method can detect the above phages in industrial samples and can be easily incorporated into dairy industry routines, it might be readily used to earmark contaminated milk for use in processes that do not involve susceptible starter organisms, or processes which involve phage-deactivating conditions.

Bacteriophage-nanocomposites: an easy and reproducible method for the construction, handling, storage and transport of conjugates for deployment of bacteriophages active against Pseudomonas aeruginosa.

PubMed

Cooper, Ian R; Illsley, Matthew; Korobeinyk, Alina V; Whitby, Raymond L D

2015-04-01

The purpose of this work was proof of concept to develop a novel, cost effective protocol for the binding of bacteriophages to a surface without loss of function, after storage in various media. The technology platform involved covalently bonding bacteriophage 13 (a Pseudomonas aeruginosa bacteriophage) to two magnetised multiwalled carbon nanotube scaffolds using a series of buffers; bacteriophage-nanotube (B-N) conjugates were efficacious after storage at 20 °C for six weeks. B-N conjugates were added to human cell culture in vitro for 9 days without causing necrosis and apoptosis. B-N conjugates were frozen (-20 °C) in cell culture media for several weeks, after which recovery from the human cell culture medium was possible using a simple magnetic separation technique. The retention of viral infective potential was demonstrated by subsequent spread plating onto lawns of susceptible P. aeruginosa. Analysis of the human cell culture medium revealed the production of interleukins by the human fibroblasts upon exposure to the bacteriophage. One day after exposure, IL-8 levels transitorily increased between 60 and 100 pg/mL, but this level was not found on any subsequent days, suggesting an initial but not long lasting response. This paper outlines the development of a method to deliver antimicrobial activity to a surface that is small enough to be combined with other materials. To our knowledge at time of publication, this is the first report of magnetically coupled bacteriophages specific to human pathogens which can be recovered from test systems, and could represent a novel means to conditionally deploy antibacterial agents into living eukaryotic systems without the risks of some antibiotic therapies. Copyright © 2015. Published by Elsevier B.V.

Bioorthogonal Modification of the Major Sheath Protein of Bacteriophage M13: Extending the Versatility of Bionanomaterial Scaffolds.

PubMed

Urquhart, Taylor; Daub, Elisabeth; Honek, John Frank

2016-10-19

With a mass of ∼1.6 × 10 7 Daltons and composed of approximately 2700 proteins, bacteriophage M13 has been employed as a molecular scaffold in bionanomaterials fabrication. In order to extend the versatility of M13 in this area, residue-specific unnatural amino acid incorporation was employed to successfully display azide functionalities on specific solvent-exposed positions of the pVIII major sheath protein of this bacteriophage. Employing a combination of engineered mutants of the gene coding for the pVIII protein, the methionine (Met) analog, l-azidohomoalanine (Aha), and a suitable Escherichia coli Met auxotroph for phage production, conditions were developed to produce M13 bacteriophage labeled with over 350 active azides (estimated by fluorescent dye labeling utilizing a strain-promoted azide-alkyne cycloaddition) and capable of azide-selective attachment to 5 nm gold nanoparticles as visualized by transmission electron microscopy. The capability of this system to undergo dual labeling utilizing both chemical acylation and bioorthogonal cycloaddition reactions was also verified. The above stratagem should prove particularly advantageous in the preparation of assemblies of larger and more complex molecular architectures based on the M13 building block.

Contribution of silent mutations to thermal adaptation of RNA bacteriophage Qβ.

PubMed

Kashiwagi, Akiko; Sugawara, Ryu; Sano Tsushima, Fumie; Kumagai, Tomofumi; Yomo, Tetsuya

2014-10-01

Changes in protein function and other biological properties, such as RNA structure, are crucial for adaptation of organisms to novel or inhibitory environments. To investigate how mutations that do not alter amino acid sequence may be positively selected, we performed a thermal adaptation experiment using the single-stranded RNA bacteriophage Qβ in which the culture temperature was increased from 37.2°C to 41.2°C and finally to an inhibitory temperature of 43.6°C in a stepwise manner in three independent lines. Whole-genome analysis revealed 31 mutations, including 14 mutations that did not result in amino acid sequence alterations, in this thermal adaptation. Eight of the 31 mutations were observed in all three lines. Reconstruction and fitness analyses of Qβ strains containing only mutations observed in all three lines indicated that five mutations that did not result in amino acid sequence changes but increased the amplification ratio appeared in the course of adaptation to growth at 41.2°C. Moreover, these mutations provided a suitable genetic background for subsequent mutations, altering the fitness contribution from deleterious to beneficial. These results clearly showed that mutations that do not alter the amino acid sequence play important roles in adaptation of this single-stranded RNA virus to elevated temperature. Recent studies using whole-genome analysis technology suggested the importance of mutations that do not alter the amino acid sequence for adaptation of organisms to novel environmental conditions. It is necessary to investigate how these mutations may be positively selected and to determine to what degree such mutations that do not alter amino acid sequences contribute to adaptive evolution. Here, we report the roles of these silent mutations in thermal adaptation of RNA bacteriophage Qβ based on experimental evolution during which Qβ showed adaptation to growth at an inhibitory temperature. Intriguingly, four synonymous mutations and

Cell-Adhesive Matrices Composed of RGD Peptide-Displaying M13 Bacteriophage/Poly(lactic-co-glycolic acid) Nanofibers Beneficial to Myoblast Differentiation.

PubMed

Shin, Yong Cheol; Lee, Jong Ho; Jin, Linhua; Kim, Min Jeong; Kim, Chuntae; Hong, Suck Won; Oh, Jin Woo; Han, Dong-Wook

2015-10-01

Recently, there has been considerable effort to develop suitable scaffolds for tissue engineering applications. Cell adhesion is a prerequisite for cells to survive. In nature, the extracellular matrix (ECM) plays this role. Therefore, an ideal scaffold should be structurally similar to the natural ECM and have biocompatibility and biodegradability. In addition, the scaffold should have biofunctionality, which provides the potent ability to enhance the cellular behaviors, such as adhesion, proliferation and differentiation. This study concentrates on fabricating cell-adhesive matrices composed of RGD peptide-displaying M13 bacteriophage (RGD-M13 phage) and poly(lactic-co-glycolic acid, PLGA) nanofibers. Long rod-shaped M13 bacteriophages are non-toxic and can express many desired proteins on their surface. A genetically engineered M13 phage was constructed to display RGD peptides on its surface. PLGA is a biodegradable polymer with excellent biocompatibility and suitable physicochemical property for adhesive matrices. In this study, RGD-M13 phage/PLGA hybrid nanofiber matrices were fabricated by electrospinning. The physicochemical properties of these matrices were characterized by scanning electron microscopy, atomic force microscopy, Raman spectroscopy, and contact angle measurement. In addition, the cellular behaviors, such as the initial attachment, proliferation and differentiation, were analyzed by a CCK-8 assay and immunofluorescence staining to evaluate the potential application of these matrices to tissue engineering scaffolds. The RGD-M13 phage/PLGA nanofiber matrices could enhance the cellular behaviors and promote the differentiation of C2C12 myoblasts. These results suggest that the RGD-M13 phage/PLGA nanofiber matrices are beneficial to myoblast differentiation and can serve as effective tissue engineering scaffolds.

Improved bacteriophage genome data is necessary for integrating viral and bacterial ecology.

PubMed

Bibby, Kyle

2014-02-01

The recent rise in "omics"-enabled approaches has lead to improved understanding in many areas of microbial ecology. However, despite the importance that viruses play in a broad microbial ecology context, viral ecology remains largely not integrated into high-throughput microbial ecology studies. A fundamental hindrance to the integration of viral ecology into omics-enabled microbial ecology studies is the lack of suitable reference bacteriophage genomes in reference databases-currently, only 0.001% of bacteriophage diversity is represented in genome sequence databases. This commentary serves to highlight this issue and to promote bacteriophage genome sequencing as a valuable scientific undertaking to both better understand bacteriophage diversity and move towards a more holistic view of microbial ecology.

Comparison of the Deoxyribonucleic Acid Molecular Weights and Homologies of Plasmids Conferring Linked Resistance to Streptomycin and Sulfonamides

PubMed Central

Barth, Peter T.; Grinter, Nigel J.

1974-01-01

Bacterial strains showing linked resistance to streptomycin (Sm) and sulfonamides (Su) were chosen representing a wide taxonomic and geographical range. Their SmSu resistances were transferred to Escherichia coli K-12 and then plasmid deoxyribonucleic acid (DNA) was isolated by ethidium bromide CsCl centrifugation. The plasmid DNA was examined by electron microscopy and analyzed by sedimentation through 5 to 20% neutral sucrose gradients. Plasmid DNA from strains having transmissible SmSu resistance consisted of two or three molecular species, one of which had a molecular mass of about 5.7 Mdal (106 daltons), the others varying between 20 to 60 Mdal. By using transformation or F′ mobilization, we isolated the SmSu-resistance determinant from any fellow resident plasmids in each strain and again isolated the plasmid DNA. Cosedimentation of each of these with a differently labeled reference plasmid DNA (R300B) showed 9 out of 12 of the plasmids to have a molecular mass not significantly different from the reference (5.7 Mdal); two others were 6.3 and 9.2 Mdal, but PB165 consisted of three plasmids of 7.4, 14.7, and 21.4 Mdal. Three separate isolations of the SmSu determinant from PB165 gave the same three plasmids, which we conclude may be monomer, dimer, and trimer, respectively. DNA-DNA hybridizations at 75 C demonstrated 80 to 93% homology between reference R300B DNA and each isolated SmSu plasmid DNA, except for the 9.2-Mdal plasmid which had 45% homology and PB165 which had 35%. All the SmSu plasmids were present as multiple copies (about 10) per chromosome. The conjugative plasmid of R300 (present as 1.3 copies per chromosome) has been shown to have negligible effect on the number of copies of its accompanying SmSu plasmid R300B. We conclude that the SmSu plasmids are closely related and probably have a common evolutionary origin. Images PMID:4616941

Application of bacteriophages in post-harvest control of human pathogenic and food spoiling bacteria.

PubMed

Pérez Pulido, Rubén; Grande Burgos, Maria José; Gálvez, Antonio; Lucas López, Rosario

2016-10-01

Bacteriophages have attracted great attention for application in food biopreservation. Lytic bacteriophages specific for human pathogenic bacteria can be isolated from natural sources such as animal feces or industrial wastes where the target bacteria inhabit. Lytic bacteriophages have been tested in different food systems for inactivation of main food-borne pathogens including Listeria monocytogenes, Staphylococcus aureus, Escherichia coli O157:H7, Salmonella enterica, Shigella spp., Campylobacter jejuni and Cronobacter sakazkii, and also for control of spoilage bacteria. Application of lytic bacteriophages could selectively control host populations of concern without interfering with the remaining food microbiota. Bacteriophages could also be applied for inactivation of bacteria attached to food contact surfaces or grown as biofilms. Bacteriophages may receive a generally recognized as safe status based on their lack of toxicity and other detrimental effects to human health. Phage preparations specific for L. monocytogenes, E. coli O157:H7 and S. enterica serotypes have been commercialized and approved for application in foods or as part of surface decontamination protocols. Phage endolysins have a broader host specificity compared to lytic bacteriophages. Cloned endolysins could be used as natural preservatives, singly or in combination with other antimicrobials such as bacteriocins.

Effect of dietary bacteriophage supplementation in internal organs, fecal excretion and ileal immune response in laying hens challenged with salmonella enteritidis

USDA-ARS?s Scientific Manuscript database

A study was conducted to evaluate the role of bacteriophage (BP) against Salmonella enterica serovar Enteritidis (SE) internal organs colonization and ileum immune response in laying hens. Hens were challenged both orally and intracloacally with 108 cfu/mL cells of nalidixic acid resistant Salmonell...

Application of bacteriophages in sensor development.

PubMed

Peltomaa, Riikka; López-Perolio, Irene; Benito-Peña, Elena; Barderas, Rodrigo; Moreno-Bondi, María Cruz

2016-03-01

Bacteriophage-based bioassays are a promising alternative to traditional antibody-based immunoassays. Bacteriophages, shortened to phages, can be easily conjugated or genetically engineered. Phages are robust, ubiquitous in nature, and harmless to humans. Notably, phages do not usually require inoculation and killing of animals; and thus, the production of phages is simple and economical. In recent years, phage-based biosensors have been developed featuring excellent robustness, sensitivity, and selectivity in combination with the ease of integration into transduction devices. This review provides a critical overview of phage-based bioassays and biosensors developed in the last few years using different interrogation methods such as colorimetric, enzymatic, fluorescence, surface plasmon resonance, quartz crystal microbalance, magnetoelastic, Raman, or electrochemical techniques.

Isolation, characterization, and application of bacteriophages for Salmonella spp. biocontrol in pigs.

PubMed

Albino, Luiz A A; Rostagno, Marcos H; Húngaro, Humberto M; Mendonça, Regina C S

2014-08-01

Foodborne illness due to Salmonella-contaminated pork products is an important public health problem, causing significant economic losses worldwide. The use of bacteriophages is a potential intervention tool that has attracted interest for the control of foodborne pathogens. The objective of this study was to detect the presence of Salmonella in commercial pig farms and to isolate specific autochthonous bacteriophages against Salmonella Typhimurium, to characterize them and to evaluate their lytic capacity against Salmonella Typhimurium in vivo and in vitro. Salmonella was isolated on 50% (4/8) of the farms, with serotype Typhimurium being the most prevalent, detected in 48.2% of samples (13/27). The isolated Salmonella Typhimurium bacteriophages belong to the Podoviridae family, were active against serotypes Abony, Enteritidis, Typhi, and Typhimurium, but not against serotypes Arizonae, Cholerasuis, Gallinarum, and Pullorum. In in vitro tests, bacteriophage at 10(7) PFU/mL and 10(9) PFU/mL significantly reduced (p<0.05) Salmonella Typhimurium counts in 1.6 and 2.5 log10 colony-forming units (CFU)/mL, respectively, after 24 h. Before the in vivo treatment with bacteriophages, Salmonella was identified in 93.3% (28/30) of the fecal samples from the pigs inoculated with 10(6) CFU/mL, and only in 56.6% (17/30) after the treatment consisting of oral administration of the pool of the bacteriophages after the fasting period, simulating a common preslaughter practice. These results indicate that the pool of bacteriophages administered was capable of reducing the colonization of Salmonella in pigs.

Significance of the Bacteriophage Treatment Schedule in Reducing Salmonella Colonization of Poultry

PubMed Central

Bardina, Carlota; Spricigo, Denis A.; Cortés, Pilar

2012-01-01

Salmonella remains 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 reducing Salmonella colonization 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 against Salmonella enterica serovar Enteritidis and Salmonella enterica serovar 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 of S. Enteritidis and S. Typhimurium cultures than any of the three bacteriophages alone. In addition, the cocktail was able to lyse the Salmonella enterica serovars Virchow, Hadar, and Infantis. The effectiveness of the bacteriophage cocktail in reducing the concentration of S. 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 of Salmonella concentration 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 by Salmonella, is required to achieve effective bacterial reduction over time. PMID:22773654

Characterization of the endolysin from the Enterococcus faecalis bacteriophage VD13

USDA-ARS?s Scientific Manuscript database

Bacteriophage infecting bacteria produce endolysins (peptidoglycan hydrolases) to lyse the host cell from within and release nascent bacteriophage particles. Recombinant endolysins can also lyse Gram-positive bacteria when added exogenously. As a potential alternative to antibiotics, we cloned and...

[Genetic study of bacteriophage phi81. I. Isolation, study of complementation and preliminary mapping of amber-mutants of bacteriophage phi81].

PubMed

Sineokiĭ, S P; Pogosov, V Z; Iankovskiĭ, N K; Krylov, V N

1976-01-01

123 Amber mutants of lambdoid bacteriophage phi81 are isolated and distributed into 19 complementation groups. Deletion mapping made possible to locate 5 gene groups on the genetic map of bacteriophage phi81 and to determine a region of possible location of mm' sticky ends on the prophage genetic map. A gene of phage phi81 is localized, which controls the adsorption specificity, and which functional similarity to a respective gene of phage phi80 is demonstrated.

Adsorption of bacteriophages on clay minerals

USGS Publications Warehouse

Chattopadhyay, Sandip; Puls, Robert W.

1999-01-01

The ability to predict the fate of microorganisms in soil is dependent on an understanding of the process of their sorption on soil and subsurface materials. Presently, we have focused on studying the thermodynamics of sorption of bacteriophages (T-2, MS-2, and φX-174) on clays (hectorite, saponite, kaolinite, and clay fraction of samples collected from a landfill site). The thermodynamic study not only determines the feasibility of the process but also provides information on the relative magnitudes of the different forces under a particular set of conditions. The total free energy of interaction during sorption of bacteriophages on clays (ΔG) has been assumed to be the summation of ΔGH (ΔG due to hydrophobic interactions) and ΔGEL (ΔG due to electrostatic interactions). The magnitude of ΔGH was determined from the different interfacial tensions (γ) present in the system, while ΔGEL was calculated from ζ-potentials of the colloidal particles. Calculated results show that surface hydrophobicities of the selected sorbents and sorbates dictate sorption. Among the selected bacteriophages, maximum sorption was observed with T-2, while hectorite has the maximum sorption capacity. Experimental results obtained from the batch adsorption studies also corroborated those obtained from the theoretical study.

Novel bacteriophages containing a genome of another bacteriophage within their genomes.

PubMed

Swanson, Maud M; Reavy, Brian; Makarova, Kira S; Cock, Peter J; Hopkins, David W; Torrance, Lesley; Koonin, Eugene V; Taliansky, Michael

2012-01-01

A novel bacteriophage infecting Staphylococus pasteuri was isolated during a screen for phages in Antarctic soils. The phage named SpaA1 is morphologically similar to phages of the family Siphoviridae. The 42,784 bp genome of SpaA1 is a linear, double-stranded DNA molecule with 3' protruding cohesive ends. The SpaA1 genome encompasses 63 predicted protein-coding genes which cluster within three regions of the genome, each of apparently different origin, in a mosaic pattern. In two of these regions, the gene sets resemble those in prophages of Bacillus thuringiensis kurstaki str. T03a001 (genes involved in DNA replication/transcription, cell entry and exit) and B. cereus AH676 (additional regulatory and recombination genes), respectively. The third region represents an almost complete genome (except for the short terminal segments) of a distinct bacteriophage, MZTP02. Nearly the same gene module was identified in prophages of B. thuringiensis serovar monterrey BGSC 4AJ1 and B. cereus Rock4-2. These findings suggest that MZTP02 can be shuttled between genomes of other bacteriophages and prophages, leading to the formation of chimeric genomes. The presence of a complete phage genome in the genome of other phages apparently has not been described previously and might represent a 'fast track' route of virus evolution and horizontal gene transfer. Another phage (BceA1) nearly identical in sequence to SpaA1, and also including the almost complete MZTP02 genome within its own genome, was isolated from a bacterium of the B. cereus/B. thuringiensis group. Remarkably, both SpaA1 and BceA1 phages can infect B. cereus and B. thuringiensis, but only one of them, SpaA1, can infect S. pasteuri. This finding is best compatible with a scenario in which MZTP02 was originally contained in BceA1 infecting Bacillus spp, the common hosts for these two phages, followed by emergence of SpaA1 infecting S. pasteuri.

Isolation and Characterization of Lytic Properties of Bacteriophages Specific for M. haemolytica Strains.

PubMed

Urban-Chmiel, Renata; Wernicki, Andrzej; Stęgierska, Diana; Dec, Marta; Dudzic, Anna; Puchalski, Andrzej

2015-01-01

The objective of this study was isolation and morphological characterization of temperate bacteriophages obtained from M. haemolytica strains and evaluation of their lytic properties in vitro against M. haemolytica isolated from the respiratory tract of calves. The material for the study consisted of the reference strain M. haemolytica serotype 1 (ATCC®) BAA-410™, reference serotypes A1, A2, A5, A6, A7, A9 and A11, and wild-type isolates of M. haemolytica. Bacteriophages were induced from an overnight bacterial starter culture of all examined M. haemolytica strains treated with mitomycin C. The lytic properties and host ranges were determined by plaque assays. The morphology of the bacteriophages was examined in negative-stained smears with 5% uranyl acetate solution using a transmission electron microscope. The genetic analysis of the bacteriophages was followed by restriction analysis of bacteriophage DNA. This was followed by analysis of genetic material by polymerase chain reaction (PCR). Eight bacteriophages were obtained, like typical of the families Myoviridae, Siphoviridae and Podoviridae. Most of the bacteriophages exhibited lytic properties against the M. haemolytica strains. Restriction analysis revealed similarities to the P2-like phage obtained from the strain M. haemolytica BAA-410. The most similar profiles were observed in the case of bacteriophages φA1 and φA5. All of the bacteriophages obtained were characterized by the presence of additional fragments in the restriction profiles with respect to the P2-like reference phage. In the analysis of PCR products for the P2-like reference phage phi-MhaA1-PHL101 (DQ426904) and the phages of the M. haemolytica serotypes, a 734-bp phage PCR product was obtained. The primers were programmed in Primer-Blast software using the structure of the sequence DQ426904 of reference phage PHL101. The results obtained indicate the need for further research aimed at isolating and characterizing bacteriophages

Cell-adhesive RGD peptide-displaying M13 bacteriophage/PLGA nanofiber matrices for growth of fibroblasts.

PubMed

Shin, Yong Cheol; Lee, Jong Ho; Jin, Linhua; Kim, Min Jeong; Oh, Jin-Woo; Kim, Tai Wan; Han, Dong-Wook

2014-01-01

M13 bacteriophages can be readily fabricated as nanofibers due to non-toxic bacterial virus with a nanofiber-like shape. In the present study, we prepared hybrid nanofiber matrices composed of poly(lactic-co-glycolic acid, PLGA) and M13 bacteriophages which were genetically modified to display the RGD peptide on their surface (RGD-M13 phage). The surface morphology and chemical composition of hybrid nanofiber matrices were characterized by scanning electron microscopy (SEM) and Raman spectroscopy, respectively. Immunofluorescence staining was conducted to investigate the existence of M13 bacteriophages in RGD-M13 phage/PLGA hybrid nanofibers. In addition, the attachment and proliferation of three different types of fibroblasts on RGD-M13 phage/PLGA nanofiber matrices were evaluated to explore how fibroblasts interact with these matrices. SEM images showed that RGD-M13 phage/PLGA hybrid matrices had the non-woven porous structure, quite similar to that of natural extracellular matrices, having an average fiber diameter of about 190 nm. Immunofluorescence images and Raman spectra revealed that RGD-M13 phages were homogeneously distributed in entire matrices. Moreover, the attachment and proliferation of fibroblasts cultured on RGD-M13 phage/PLGA matrices were significantly enhanced due to enriched RGD moieties on hybrid matrices. These results suggest that RGD-M13 phage/PLGA matrices can be efficiently used as biomimetic scaffolds for tissue engineering applications.

Receptor binding proteins of Listeria monocytogenes bacteriophages A118 and P35 recognize serovar-specific teichoic acids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bielmann, Regula; Habann, Matthias; Eugster, Marcel R.

Adsorption of a bacteriophage to the host requires recognition of a cell wall-associated receptor by a receptor binding protein (RBP). This recognition is specific, and high affinity binding is essential for efficient virus attachment. The molecular details of phage adsorption to the Gram-positive cell are poorly understood. We present the first description of receptor binding proteins and a tail tip structure for the siphovirus group infecting Listeria monocytogenes. The host-range determining factors in two phages, A118 and P35 specific for L. monocytogenes serovar 1/2 have been determined. Two proteins were identified as RBPs in phage A118. Rhamnose residues in wallmore » teichoic acids represent the binding ligands for both proteins. In phage P35, protein gp16 could be identified as RBP and the role of both rhamnose and N-acetylglucosamine in phage adsorption was confirmed. Immunogold-labeling and transmission electron microscopy allowed the creation of a topological model of the A118 phage tail. - Highlights: • We present the first description of receptor binding proteins and a tail tip structure for the Siphovirus group infecting Listeria monocytogenes. • The host-range determining factors in two phages, A118 and P35 specific for L. monocytogenes serovar 1/2 have been determined. • Rhamnose residues in wall teichoic acids represent the binding ligands for both receptor binding proteins in phage A118. • Rhamnose and N-acetylglucosamine are required for adsorption of phage P35. • We preset a topological model of the A118 phage tail.« less

[Determination of Azospirillum Brasilense Cells With Bacteriophages via Electrooptical Analysis of Microbial Suspensions].

PubMed

Gulii, O I; Karavayeva, O A; Pavlii, S A; Sokolov, O I; Bunin, V D; Ignatov, O V

2015-01-01

The dependence-of changes in the electrooptical properties of Azospirillum brasilense cell suspension Sp7 during interaction with bacteriophage ΦAb-Sp7 on the number and time of interactions was studied. Incubation of cells with bacteriophage significantly changed the electrooptical signal within one minute. The selective effect of bacteriophage ΦAb on 18 strains of bacteria of the genus Azospirillum was studied: A. amazonense Ami4, A. brasilense Sp7, Cd, Sp107, Sp245, Jm6B2, Brl4, KR77, S17, S27, SR55, SR75, A. halopraeferans Au4, A. irakense KBC1, K A3, A. lipoferum Sp59b, SR65 and RG20a. We determined the limit of reliable determination of microbial cells infected with bacteriophage: - 10(4) cells/mL. The presence of foreign cell cultures of E. coli B-878 and E. coli XL-1 did not complicate the detection of A brasilense Sp7 cells with the use of bacteriophage ΦAb-Sp7. The results demonstrated that bacteriophage (ΦAb-Sp7 can be used for the detection of Azospirillum microbial cells via t electrooptical analysis of cell suspensions.

The Genome Sequence of Bacteriophage CPV1 Virulent for Clostridium perfringens

USDA-ARS?s Scientific Manuscript database

Application of bacteriophages and their lytic enzymes to control Clostridium perfringens is one potential approach to reduce the pathogen on poultry farms and in poultry-processing facilities. Bacteriophages lytic for C. perfringens were isolated from sewage, feces and broiler intestinal contents. P...

M13 Bacteriophage-Based Self-Assembly Structures and Their Functional Capabilities.

PubMed

Moon, Jong-Sik; Kim, Won-Geun; Kim, Chuntae; Park, Geun-Tae; Heo, Jeong; Yoo, So Y; Oh, Jin-Woo

2015-06-01

Controlling the assembly of basic structural building blocks in a systematic and orderly fashion is an emerging issue in various areas of science and engineering such as physics, chemistry, material science, biological engineering, and electrical engineering. The self-assembly technique, among many other kinds of ordering techniques, has several unique advantages and the M13 bacteriophage can be utilized as part of this technique. The M13 bacteriophage (Phage) can easily be modified genetically and chemically to demonstrate specific functions. This allows for its use as a template to determine the homogeneous distribution and percolated network structures of inorganic nanostructures under ambient conditions. Inexpensive and environmentally friendly synthesis can be achieved by using the M13 bacteriophage as a novel functional building block. Here, we discuss recent advances in the application of M13 bacteriophage self-assembly structures and the future of this technology.

M13 Bacteriophage-Based Self-Assembly Structures and Their Functional Capabilities

PubMed Central

Moon, Jong-Sik; Kim, Won-Geun; Kim, Chuntae; Park, Geun-Tae; Heo, Jeong; Yoo, So Y; Oh, Jin-Woo

2015-01-01

Controlling the assembly of basic structural building blocks in a systematic and orderly fashion is an emerging issue in various areas of science and engineering such as physics, chemistry, material science, biological engineering, and electrical engineering. The self-assembly technique, among many other kinds of ordering techniques, has several unique advantages and the M13 bacteriophage can be utilized as part of this technique. The M13 bacteriophage (Phage) can easily be modified genetically and chemically to demonstrate specific functions. This allows for its use as a template to determine the homogeneous distribution and percolated network structures of inorganic nanostructures under ambient conditions. Inexpensive and environmentally friendly synthesis can be achieved by using the M13 bacteriophage as a novel functional building block. Here, we discuss recent advances in the application of M13 bacteriophage self-assembly structures and the future of this technology. PMID:26146494

Engineering of filamentous bacteriophage for protein sensing

NASA Astrophysics Data System (ADS)

Brasino, Michael

Methods of high throughput, sensitive and cost effective quantification of proteins enables personalized medicine by allowing healthcare professionals to better monitor patient condition and response to treatment. My doctoral research has attempted to advance these methods through the use of filamentous bacteriophage (phage). These bacterial viruses are particularly amenable to both genetic and chemical engineering and can be produced efficiently in large amounts. Here, I discuss several strategies for modifying phage for use in protein sensing assays. These include the expression of bio-orthogonal conjugation handles on the phage coat, the incorporation of specific recognition sequences within the phage genome, and the creation of antibody-phage conjugates via a photo-crosslinking non-canonical amino acid. The physical and chemical characterization of these engineered phage and the results of their use in modified protein sensing assays will be presented.

Crystallogenesis of bacteriophage P22 tail accessory factor gp26 at acidic and neutral pH

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cingolani, Gino, E-mail: cingolag@upstate.edu; Andrews, Dewan; Casjens, Sherwood

2006-05-01

The crystallogenesis of bacteriophage P22 tail-fiber gp26 is described. To study possible pH-induced conformational changes in gp26 structure, native trimeric gp26 has been crystallized at acidic pH (4.6) and a chimera of gp26 fused to maltose-binding protein (MBP-gp26) has been crystallized at neutral and alkaline pH (7-10). Gp26 is one of three phage P22-encoded tail accessory factors essential for stabilization of viral DNA within the mature capsid. In solution, gp26 exists as an extended triple-stranded coiled-coil protein which shares profound structural similarities with class I viral membrane-fusion protein. In the cryo-EM reconstruction of P22 tail extracted from mature virions, gp26more » forms an ∼220 Å extended needle structure emanating from the neck of the tail, which is likely to be brought into contact with the cell’s outer membrane when the viral DNA-injection process is initiated. To shed light on the potential role of gp26 in cell-wall penetration and DNA injection, gp26 has been crystallized at acidic, neutral and alkaline pH. Crystals of native gp26 grown at pH 4.6 diffract X-rays to 2.0 Å resolution and belong to space group P2{sub 1}, with a dimer of trimeric gp26 molecules in the asymmetric unit. To study potential pH-induced conformational changes in the gp26 structure, a chimera of gp26 fused to maltose-binding protein (MBP-gp26) was generated. Hexagonal crystals of MBP-gp26 were obtained at neutral and alkaline pH using the high-throughput crystallization robot at the Hauptman–Woodward Medical Research Institute, Buffalo, NY, USA. These crystals diffract X-rays to beyond 2.0 Å resolution. Structural analysis of gp26 crystallized at acidic, neutral and alkaline pH is in progress.« less

Nucleic Acid-Induced Resistance to Viral Infection

PubMed Central

Takano, Kouichi; Warren, Joel; Jensen, Keith E.; Neal, Alan L.

1965-01-01

Takano, Kouichi (Chas. Pfizer & Co., Inc., Terre Haute, Ind.), Joel Warren, Keith E. Jensen, and Alan L. Neal. Nucleic acid resistance to viral infection. J. Bacteriol. 90:1542–1547. 1965.—Administration of nonviral nucleic acids to mice increased their resistance to a subsequent infection with influenza or encephalomyocarditis viruses. Injection of ribonucleic acid or deoxyribonucleic acid by peripheral routes did not modify susceptibility to intranasal infection. Lung tissue extracts from animals previously treated with yeast nucleic acid inhibited the growth of vaccinia and influenza viruses. The protective effect of exogenous nucleic acids persisted in mice for several days, but gradually diminished to undetectable levels. PMID:4285332

[Preparation and activity validation of PP7 bacteriophage-like particles displaying PAP114-128 peptide].

PubMed

Sun, Yanli; Sun, Yanhua

2016-10-01

Objective To obtain the PP7 bacteriophage-like particles carrying the peptide of prostatic acid phosphatase PAP 114-128 , and prove that they retain the original biological activity. Methods First, the plasmid pETDuet-2PP7 was constructed as follows: the gene of PP7 coat protein dimer was amplified by gene mutation combined with overlapping PCR technology, and inserted into the vector pETDuet-1. Following that, the plasmid pETDuet-2PP7-PAP 114-128 was constructed as follows: the PP7 coat protein gene carrying the coding gene of PAP 114-128 peptide was amplified using PCR, and then inserted into the vector pETDuet-2PP7. Both pETDuet-2PP7 and pETDuet-2PP7-PAP 114-128 were transformed into E.coli and expressed. The expression product was verified by SDS-PAGE, double immunodiffusion assay and ELISA. Results The gene fragment of PP7 coat protein dimer was obtained by overlapping PCR using Ex Taq DNA polymerase, and the antigenicity of its expression product was the same as that of the coat protein of wild-type PP7 bacteriophage. Moreover, the PAP 114-128 peptide epitope that was displayed on the surface of PP7 bacteriophage was identical with the corresponding epitope of natural human PAP, and it was able to induce high levels of antibodies. Conclusion The gene of PP7 coat protein dimer with repeated sequences can be prepared by gene mutation combined with overlapping PCR. Based on this, PP7 bacteriophage-like particles carrying PAP peptide can be prepared, which not only solves the problem of the instability of the peptides, but also lays a foundation for the study on their delivery and function.

Application of bacteriophages to reduce Salmonella contamination on workers' boots in rendering-processing environment.

PubMed

Gong, C; Jiang, X; Wang, J

2017-10-01

Workers' boots are considered one of the re-contamination routes of Salmonella for rendered meals in the rendering-processing environment. This study was conducted to evaluate the efficacy of a bacteriophage cocktail for reducing Salmonella on workers' boots and ultimately for preventing Salmonella re-contamination of rendered meals. Under laboratory conditions, biofilms of Salmonella Typhimurium avirulent strain 8243 formed on rubber templates or boots were treated with a bacteriophage cocktail of 6 strains (ca. 9 log PFU/mL) for 6 h at room temperature. Bacteriophage treatments combined with sodium hypochlorite (400 ppm) or 30-second brush scrubbing also were investigated for a synergistic effect on reducing Salmonella biofilms. Sodium magnesium (SM) buffer and sodium hypochlorite (400 ppm) were used as controls. To reduce indigenous Salmonella on workers' boots, a field study was conducted to apply a bacteriophage cocktail and other combined treatments 3 times within one wk in a rendering-processing environment. Prior to and after bacteriophage treatments, Salmonella populations on the soles of rubber boots were swabbed and enumerated on XLT-4, Miller-Mallinson or CHROMagar™ plates. Under laboratory conditions, Salmonella biofilms formed on rubber templates and boots were reduced by 95.1 to 99.999% and 91.5 to 99.2%, respectively. In a rendering-processing environment (ave. temperature: 19.3°C; ave. relative humidity: 48%), indigenous Salmonella populations on workers' boots were reduced by 84.2, 92.9, and 93.2% after being treated with bacteriophages alone, bacteriophages + sodium hypochlorite, and bacteriophages + scrubbing for one wk, respectively. Our results demonstrated the effectiveness of bacteriophage treatments in reducing Salmonella contamination on the boots in both laboratory and the rendering-processing environment. © 2017 Poultry Science Association Inc.

Bacteriophage ecology in environmental biotechnology processes.

PubMed

Shapiro, Orr H; Kushmaro, Ariel

2011-06-01

Heterotrophic bacteria are an integral part of any environmental biotechnology process (EBP). Therefore, factors controlling bacterial abundance, activity, and community composition are central to the understanding of such processes. Among these factors, top-down control by bacteriophage predation has so far received very limited attention. With over 10(8) particles per ml, phage appear to be the most numerous biological entities in EBP. Phage populations in EBP appear to be highly dynamic and to correlate with the population dynamics of their hosts and genomic evidence suggests bacteria evolve to avoid phage predation. Clearly, there is much to learn regarding bacteriophage in EBP before we can truly understand the microbial ecology of these globally important systems. Copyright © 2011 Elsevier Ltd. All rights reserved.

Phenotypic, fermentation characterization, and resistance mechanism analysis of bacteriophage-resistant mutants of Lactobacillus delbrueckii ssp. bulgaricus isolated from traditional Chinese dairy products.

PubMed

Deng, Kaibo; Fang, Wei; Zheng, Baodong; Miao, Song; Huo, Guicheng

2018-03-01

Bacteriophage infection is a large factor in dairy industrial production failure on the basis of pure inoculation fermentation, and developing good commercial starter cultures from wild dairy products and improving the environmental vigor of starter cultures by enhancing their phage resistance are still the most effective solutions. Here we used a spontaneous isolation method to obtain bacteriophage-resistant mutants of Lactobacillus delbrueckii ssp. bulgaricus strains that are used in traditional Chinese fermented dairy products. We analyzed their phenotypes, fermentation characteristics, and resistance mechanisms. The results showed that bacteriophage-insensitive mutants (BIM) BIM8 and BIM12 had high bacteriophage resistance while exhibiting fermentation and coagulation attributes that were as satisfying as those of their respective parent strains KLDS1.1016 and KLDS1.1028. According to the attachment receptor detection, mutants BIM8 and BIM12 exhibited reduced absorption to bacteriophage phiLdb compared with their respective bacteriophage-sensitive parent strains because of changes to the polysaccharides or teichoic acids connected to their peptidoglycan layer. Additionally, genes, including HSDR, HSDM, and HSDS, encoding 3 subunits of a type I restriction-modification system were identified in their respective parent strains. We also discovered that HSDR and HSDM were highly conserved but that HSDS was variable because it is responsible for the DNA specificity of the complex. The late lysis that occurred only in strain KLDS1.1016 and not in strain KLDS1.1028 suggests that the former and its mutant BIM8 also may have an activatable restriction-modification mechanism. We conclude that the L. bulgaricus BIM8 and BIM12 mutants have great potential in the dairy industry as starter cultures, and their phage-resistance mechanism was effective mainly due to the adsorption interference and restriction-modification system. Copyright © 2018 American Dairy Science

Natural mummification of the human gut preserves bacteriophage DNA.

PubMed

Santiago-Rodriguez, Tasha M; Fornaciari, Gino; Luciani, Stefania; Dowd, Scot E; Toranzos, Gary A; Marota, Isolina; Cano, Raul J

2016-01-01

The natural mummification process of the human gut represents a unique opportunity to study the resulting microbial community structure and composition. While results are providing insights into the preservation of bacteria, fungi, pathogenic eukaryotes and eukaryotic viruses, no studies have demonstrated that the process of natural mummification also results in the preservation of bacteriophage DNA. We characterized the gut microbiome of three pre-Columbian Andean mummies, namely FI3, FI9 and FI12, and found sequences homologous to viruses. From the sequences attributable to viruses, 50.4% (mummy FI3), 1.0% (mummy FI9) and 84.4% (mummy FI12) were homologous to bacteriophages. Sequences corresponding to the Siphoviridae, Myoviridae, Podoviridae and Microviridae families were identified. Predicted putative bacterial hosts corresponded mainly to the Firmicutes and Proteobacteria, and included Bacillus, Staphylococcus, Clostridium, Escherichia, Vibrio, Klebsiella, Pseudomonas and Yersinia. Predicted functional categories associated with bacteriophages showed a representation of structural, replication, integration and entry and lysis genes. The present study suggests that the natural mummification of the human gut results in the preservation of bacteriophage DNA, representing an opportunity to elucidate the ancient phageome and to hypothesize possible mechanisms of preservation. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Comparison of Polymerase Subunits from Double-Stranded RNA Bacteriophages

PubMed Central

Yang, Hongyan; Makeyev, Eugene V.; Bamford, Dennis H.

2001-01-01

The family Cystoviridae comprises several bacteriophages with double-stranded RNA (dsRNA) genomes. We have previously purified the catalytic polymerase subunit (Pol) of one of the Cystoviridae members, bacteriophage φ6, and shown that the protein can catalyze RNA synthesis in vitro. In this reaction, both bacteriophage-specific and heterologous RNAs can serve as templates, but those containing 3′ termini from the φ6 minus strands are favored. This provides a molecular basis for the observation that only plus strands, not minus strands, are transcribed from φ6 dsRNA segments in vivo. To test whether such a regulatory mechanism is also found in other dsRNA viruses, we purified recombinant Pol subunits from the φ6-related bacteriophages φ8 and φ13 and assayed their polymerase activities in vitro. The enzymes catalyze template-dependent RNA synthesis using both single-stranded-RNA (ssRNA) and dsRNA templates. However, they differ from each other as well as from φ6 Pol in certain biochemical properties. Notably, each polymerase demonstrates a distinct preference for ssRNAs bearing short 3′-terminal sequences from the virus-specific minus strands. This suggests that, in addition to other factors, RNA transcription in Cystoviridae is controlled by the template specificity of the polymerase subunit. PMID:11602748

40 CFR 180.1261 - Xanthomonas campestris pv. vesicatoria and Pseudomonas syringae pv. tomato specific Bacteriophages.

Code of Federal Regulations, 2014 CFR

2014-07-01

... and Pseudomonas syringae pv. tomato specific Bacteriophages. 180.1261 Section 180.1261 Protection of.... vesicatoria and Pseudomonas syringae pv. tomato specific Bacteriophages. An exemption from the requirement of... syringae pv. tomato specific bacteriophages in or on pepper and tomato. [74 FR 26536, June 3, 2009] ...

40 CFR 180.1261 - Xanthomonas campestris pv. vesicatoria and Pseudomonas syringae pv. tomato specific Bacteriophages.

Code of Federal Regulations, 2012 CFR

2012-07-01

... and Pseudomonas syringae pv. tomato specific Bacteriophages. 180.1261 Section 180.1261 Protection of.... vesicatoria and Pseudomonas syringae pv. tomato specific Bacteriophages. An exemption from the requirement of... syringae pv. tomato specific bacteriophages in or on pepper and tomato. [74 FR 26536, June 3, 2009] ...

40 CFR 180.1261 - Xanthomonas campestris pv. vesicatoria and Pseudomonas syringae pv. tomato specific Bacteriophages.

Code of Federal Regulations, 2011 CFR

2011-07-01

... and Pseudomonas syringae pv. tomato specific Bacteriophages. 180.1261 Section 180.1261 Protection of.... vesicatoria and Pseudomonas syringae pv. tomato specific Bacteriophages. An exemption from the requirement of... syringae pv. tomato specific bacteriophages in or on pepper and tomato. [74 FR 26536, June 3, 2009] ...

40 CFR 180.1261 - Xanthomonas campestris pv. vesicatoria and Pseudomonas syringae pv. tomato specific Bacteriophages.

Code of Federal Regulations, 2013 CFR

2013-07-01

... and Pseudomonas syringae pv. tomato specific Bacteriophages. 180.1261 Section 180.1261 Protection of.... vesicatoria and Pseudomonas syringae pv. tomato specific Bacteriophages. An exemption from the requirement of... syringae pv. tomato specific bacteriophages in or on pepper and tomato. [74 FR 26536, June 3, 2009] ...

40 CFR 180.1261 - Xanthomonas campestris pv. vesicatoria and Pseudomonas syringae pv. tomato specific Bacteriophages.

Code of Federal Regulations, 2010 CFR

2010-07-01

... and Pseudomonas syringae pv. tomato specific Bacteriophages. 180.1261 Section 180.1261 Protection of.... vesicatoria and Pseudomonas syringae pv. tomato specific Bacteriophages. An exemption from the requirement of... syringae pv. tomato specific bacteriophages in or on pepper and tomato. [74 FR 26536, June 3, 2009] ...

Development of a bacteriophage displayed peptide library and biosensor

NASA Astrophysics Data System (ADS)

Chin, Robert C.; Salazar, Noe; Mayo, Michael W.; Villavicencio, Victor I.; Taylor, Richard B.; Chambers, James P.; Valdes, James J.

1996-04-01

A miniaturized, handheld biosensor for identification of hazardous biowarfare agents with high specificity is being developed. An innovative biological recognition system based on bacteriophage displayed peptide receptors will be utilized in conjunction with the miniature biosensor technology being developed. A bacteriophage library has been constructed to provide the artificial receptors. The library can contain millions of bacteriophage with randomly displayed peptide sequences in the phage outer protein coat which act as binding sites for the agents of interest. This library will be used to 'bio-pan' for phages that bind to a number of toxins and infectious agents and can, thus, provide an endless supply of low cost, reliable, specific, and stable artificial receptors. The biosensor instrument will utilize evanescent wave, planar waveguide, far-red dyes, diode laser and miniature circuit technologies for performance and portability.

Bacteriophage T5 DNA ejection under pressure.

PubMed

Leforestier, A; Brasilès, S; de Frutos, M; Raspaud, E; Letellier, L; Tavares, P; Livolant, F

2008-12-19

The transfer of the bacteriophage genome from the capsid into the host cell is a key step of the infectious process. In bacteriophage T5, DNA ejection can be triggered in vitro by simple binding of the phage to its purified Escherichia coli receptor FhuA. Using electrophoresis and cryo-electron microscopy, we measure the extent of DNA ejection as a function of the external osmotic pressure. In the high pressure range (7-16 atm), the amount of DNA ejected decreases with increasing pressure, as theoretically predicted and observed for lambda and SPP1 bacteriophages. In the low and moderate pressure range (2-7 atm), T5 exhibits an unexpected behavior. Instead of a unique ejected length, multiple populations coexist. Some phages eject their complete genome, whereas others stop at some nonrandom states that do not depend on the applied pressure. We show that contrarily to what is observed for the phages SPP1 and lambda, T5 ejection cannot be explained as resulting from a simple pressure equilibrium between the inside and outside of the capsid. Kinetics parameters and/or structural characteristics of the ejection machinery could play a determinant role in T5 DNA ejection.

Isolation of Dickeya dadantii strains from potato disease and biocontrol by their bacteriophages.

PubMed

Soleimani-Delfan, Abbas; Etemadifar, Zahra; Emtiazi, Giti; Bouzari, Majid

2015-01-01

One of the most economically important bacterial pathogens of plants and plant products is Dickeya dadantii. This bacterium causes soft rot disease in tubers and other parts of the potato and other plants of the Solanaceae family. The application of restricted host range bacteriophages as biocontrol agents has recently gained widespread interest. This study purposed to isolate the infectious agent of the potato and evaluate its biocontrol by bacteriophages. Two phytopathogenic strains were isolated from infected potatoes, identified based on biochemical and 16S rRNA gene sequencing, and submitted to GenBank as D. dadantii strain pis3 (accession no. HQ423668) and D. dadantii strain sip4 (accession no. HQ423669). Their bacteriophages were isolated from Caspian Sea water by enriching the water filtrate with D. dadantii strains as hosts using spot or overlay methods. On the basis of morphotypes, the isolated bacteriophages were identified as members of the Myoviridae and Siphoviridae families and could inhibit the growth of antibiotic resistant D. dadantii strains in culture medium. Moreover, in Dickeya infected plants treated with bacteriophage, no disease progression was detected. No significant difference was seen between phage-treated and control plants. Thus, isolated bacteriophages can be suggested for the biocontrol of plant disease caused by Dickeya strains.

Antigenic properties of HCMV peptides displayed by filamentous bacteriophages vs. synthetic peptides.

PubMed

Ulivieri, Cristina; Citro, Alessandra; Ivaldi, Federico; Mascolo, Dina; Ghittoni, Raffaella; Fanigliulo, Daniela; Manca, Fabrizio; Baldari, Cosima Tatiana; Li Pira, Giuseppina; Del Pozzo, Giovanna

2008-08-15

Several efforts have been invested in the identification of CTL and Th epitopes, as well as in the characterization of their immunodominance and MHC restriction, for the generation of a peptide-based HCMV vaccine. Small synthetic peptides are, however, poor antigens and carrier proteins are important for improving the efficacy of synthetic peptide vaccines. Recombinant bacteriophages appear as promising tools in the design of subunit vaccines. To investigate the antigenicity of peptides carried by recombinant bacteriophages we displayed different HCMV MHCII restricted peptides on the capsid of filamentous bacteriophage (fd) and found that hybrid bacteriophages are processed by human APC and activate HCMV-specific CD4 T-cells. Furthermore we constructed a reporter T-cell hybridoma expressing a chimeric TCR comprising murine alphabeta constant regions and human variable regions specific for the HLA-A2 restricted immunodominant NLV peptide of HCMV. Using the filamentous bacteriophage as an epitope carrier, we detected a more robust and long lasting response of the reporter T-cell hybridoma compared to peptide stimulation. Our results show a general enhancement of T-cell responses when antigenic peptides are carried by phages.

Removal of MS2, Qβ and GA bacteriophages during drinking water treatment at pilot scale.

PubMed

Boudaud, Nicolas; Machinal, Claire; David, Fabienne; Fréval-Le Bourdonnec, Armelle; Jossent, Jérôme; Bakanga, Fanny; Arnal, Charlotte; Jaffrezic, Marie Pierre; Oberti, Sandrine; Gantzer, Christophe

2012-05-15

The removal of MS2, Qβ and GA, F-specific RNA bacteriophages, potential surrogates for pathogenic waterborne viruses, was investigated during a conventional drinking water treatment at pilot scale by using river water, artificially and independently spiked with these bacteriophages. The objective of this work is to develop a standard system for assessing the effectiveness of drinking water plants with respect to the removal of MS2, Qβ and GA bacteriophages by a conventional pre-treatment process (coagulation-flocculation-settling-sand filtration) followed or not by an ultrafiltration (UF) membrane (complete treatment process). The specific performances of three UF membranes alone were assessed by using (i) pre-treated water and (ii) 0.1 mM sterile phosphate buffer solution (PBS), spiked with bacteriophages. These UF membranes tested in this work were designed for drinking water treatment market and were also selected for research purpose. The hypothesis serving as base for this study was that the interfacial properties for these three bacteriophages, in terms of electrostatic charge and the degree of hydrophobicity, could induce variations in the removal performances achieved by drinking water treatments. The comparison of the results showed a similar behaviour for both MS2 and Qβ surrogates whereas it was particularly atypical for the GA surrogate. The infectious character of MS2 and Qβ bacteriophages was mostly removed after clarification followed by sand filtration processes (more than a 4.8-log reduction) while genomic copies were removed at more than a 4.0-log after the complete treatment process. On the contrary, GA bacteriophage was only slightly removed by clarification followed by sand filtration, with less than 1.7-log and 1.2-log reduction, respectively. After the complete treatment process achieved, GA bacteriophage was removed with less than 2.2-log and 1.6-log reduction, respectively. The effectiveness of the three UF membranes tested in terms of

Process of Infection with Bacteriophage φX174

PubMed Central

Dalgarno, L.; Sinsheimer, Robert L.

1968-01-01

A group of temperature-sensitive mutants of φX174 has been isolated which can go through a single, normal one-step growth cycle at 40 C but fail to form plaques at this temperature. Such mutants fail to initiate a second cycle at 40 C; however they can gain the capacity to infect at 40 C, upon incubation for 10 min in broth at 30 C. In regaining the ability to infect, the phage appear to undergo a temperature-dependent conformational alteration. The inverse process, a reversible loss of ability to infect at 40 C, is observed when such phage produced at 30 C are incubated for 2 hr at 40 C. The defect in initiation of a second cycle of infection appears to be in the injection of viral deoxyribonucleic acid. A two-step complementation test has been used to identify the cistron coding for the affected function. Such mutants are also unusually sensitive to an irreversible thermal inactivation when incubated at 40 C. PMID:4883013

Membrane filtration immobilization technique-a simple and novel method for primary isolation and enrichment of bacteriophages.

PubMed

Ghugare, G S; Nair, A; Nimkande, V; Sarode, P; Rangari, P; Khairnar, K

2017-02-01

To develop a method for the isolation and enrichment of bacteriophages selectively against specific bacteria coupled with a membrane filtration technique. Rapid isolation and concentration of host-specific bacteriophages was achieved by exposure of the sample suspected to contain bacteriophages to a specific host immobilized on a 0·45 μm membrane in a membrane filtration unit. The principle behind this method is the exploitation of host-specific interaction of bacteriophages with their host and maximizing this interaction using a classic membrane filtration method. This provides a chance for each bacteriophage in the sample to interact with the specific host on the membrane filter fitted with a vacuum pump. Specific bacteriophages of the host are retained on the membrane along with its host cells due to the effect of adsorption and these adsorbed bacteriophages (along with their hosts) on the filter disc are then amplified and enriched in regular nutritive broth tryptose soya broth by incubation. With the help of the plaque assay method, host-specific phages of various bacterial species were isolated, segregated and enriched. The phage concentration method coupled with membrane filtration immobilization of host bacteria was able to isolate and enrich the host-specific bacteriophages by several fold using a lower quantity of an environmental water sample, or other phage suspensions. Enrichment of phages from single plaques was also achieved. The isolation and detection of host-specific bacteriophages from a low density bacteriophage water sample in a single step by the use of a simple and basic microbiological technique can be achieved. Enrichment of phages from low phage titre suspensions is also achieved very effectively. © 2016 The Society for Applied Microbiology.

Microbiological Activities of Lysostaphin and Penicillins Against Bacteriophage 80/81 Strains of Staphylococcus aureus

PubMed Central

Zygmunt, Walter A.; Harrison, Edward F.; Browder, Henry P.

1965-01-01

Using 20 clinical isolates of S. aureus (all bacteriophage 80/81 type), we found that lysostaphin inhibits the growth of all cultures at concentrations significantly lower than those observed with any of eight penicillins, a penicillin-like compound (cephalothin), or fusidic acid (a steroid antibiotic). All test cultures were shown to be resistant to penicillin G, ampicillin, and propicillin. Of the remaining penicillins (all penicillinase-insensitive), oxacillin, nafcillin, cloxacillin, and cephalothin were approximately equal in antimicrobial activity. Ancillin was slightly less active, and methicillin was even lower in potency. Cultures varied more widely in susceptibility to fusidic acid. None of the clinical isolates tested was found to be resistant to lysostaphin. PMID:14325294

Bacteriophage-Based Bacterial Wilt Biocontrol for an Environmentally Sustainable Agriculture

PubMed Central

Álvarez, Belén; Biosca, Elena G.

2017-01-01

Bacterial wilt diseases caused by Ralstonia solanacearum, R. pseudosolanacearum, and R. syzygii subsp. indonesiensis (former R. solanacearum species complex) are among the most important plant diseases worldwide, severely affecting a high number of crops and ornamentals. Difficulties of bacterial wilt control by non-biological methods are related to effectiveness, bacterial resistance and environmental impact. Alternatively, a great many biocontrol strategies have been carried out, with the advantage of being environmentally friendly. Advances in bacterial wilt biocontrol include an increasing interest in bacteriophage-based treatments as a promising re-emerging strategy. Bacteriophages against the bacterial wilt pathogens have been described with either lytic or lysogenic effect but, they were proved to be active against strains belonging to R. pseudosolanacearum and/or R. syzygii subsp. indonesiensis, not to the present R. solanacearum species, and only two of them demonstrated successful biocontrol potential in planta. Despite the publication of three patents on the topic, until now no bacteriophage-based product is commercially available. Therefore, there is still much to be done to incorporate valid bacteriophages in an integrated management program to effectively fight bacterial wilt in the field. PMID:28769942

Bacteriophage-Based Bacterial Wilt Biocontrol for an Environmentally Sustainable Agriculture.

PubMed

Álvarez, Belén; Biosca, Elena G

2017-01-01

Bacterial wilt diseases caused by Ralstonia solanacearum , R. pseudosolanacearum , and R. syzygii subsp. indonesiensis (former R. solanacearum species complex) are among the most important plant diseases worldwide, severely affecting a high number of crops and ornamentals. Difficulties of bacterial wilt control by non-biological methods are related to effectiveness, bacterial resistance and environmental impact. Alternatively, a great many biocontrol strategies have been carried out, with the advantage of being environmentally friendly. Advances in bacterial wilt biocontrol include an increasing interest in bacteriophage-based treatments as a promising re-emerging strategy. Bacteriophages against the bacterial wilt pathogens have been described with either lytic or lysogenic effect but, they were proved to be active against strains belonging to R. pseudosolanacearum and/or R. syzygii subsp. indonesiensis , not to the present R. solanacearum species, and only two of them demonstrated successful biocontrol potential in planta . Despite the publication of three patents on the topic, until now no bacteriophage-based product is commercially available. Therefore, there is still much to be done to incorporate valid bacteriophages in an integrated management program to effectively fight bacterial wilt in the field.

Self-Assembled Nanoporous Biofilms from Functionalized Nanofibrous M13 Bacteriophage.

PubMed

Devaraj, Vasanthan; Han, Jiye; Kim, Chuntae; Kang, Yong-Cheol; Oh, Jin-Woo

2018-06-12

Highly periodic and uniform nanostructures, based on a genetically engineered M13 bacteriophage, displayed unique properties at the nanoscale that have the potential for a variety of applications. In this work, we report a multilayer biofilm with self-assembled nanoporous surfaces involving a nanofiber-like genetically engineered 4E-type M13 bacteriophage, which was fabricated using a simple pulling method. The nanoporous surfaces were effectively formed by using the networking-like structural layers of the M13 bacteriophage during self-assembly. Therefore, an external template was not required. The actual M13 bacteriophage-based fabricated multilayered biofilm with porous nanostructures agreed well with experimental and simulation results. Pores formed in the final layer had a diameter of about 150⁻500 nm and a depth of about 15⁻30 nm. We outline a filter application for this multilayered biofilm that enables selected ions to be extracted from a sodium chloride solution. Here, we describe a simple, environmentally friendly, and inexpensive fabrication approach with large-scale production potential. The technique and the multi-layered biofilms produced may be applied to sensor, filter, plasmonics, and bio-mimetic fields.

Ultrastructure and Viral Metagenome of Bacteriophages from an Anaerobic Methane Oxidizing Methylomirabilis Bioreactor Enrichment Culture

PubMed Central

Gambelli, Lavinia; Cremers, Geert; Mesman, Rob; Guerrero, Simon; Dutilh, Bas E.; Jetten, Mike S. M.; Op den Camp, Huub J. M.; van Niftrik, Laura

2016-01-01

With its capacity for anaerobic methane oxidation and denitrification, the bacterium Methylomirabilis oxyfera plays an important role in natural ecosystems. Its unique physiology can be exploited for more sustainable wastewater treatment technologies. However, operational stability of full-scale bioreactors can experience setbacks due to, for example, bacteriophage blooms. By shaping microbial communities through mortality, horizontal gene transfer, and metabolic reprogramming, bacteriophages are important players in most ecosystems. Here, we analyzed an infected Methylomirabilis sp. bioreactor enrichment culture using (advanced) electron microscopy, viral metagenomics and bioinformatics. Electron micrographs revealed four different viral morphotypes, one of which was observed to infect Methylomirabilis cells. The infected cells contained densely packed ~55 nm icosahedral bacteriophage particles with a putative internal membrane. Various stages of virion assembly were observed. Moreover, during the bacteriophage replication, the host cytoplasmic membrane appeared extremely patchy, which suggests that the bacteriophages may use host bacterial lipids to build their own putative internal membrane. The viral metagenome contained 1.87 million base pairs of assembled viral sequences, from which five putative complete viral genomes were assembled and manually annotated. Using bioinformatics analyses, we could not identify which viral genome belonged to the Methylomirabilis- infecting bacteriophage, in part because the obtained viral genome sequences were novel and unique to this reactor system. Taken together these results show that new bacteriophages can be detected in anaerobic cultivation systems and that the effect of bacteriophages on the microbial community in these systems is a topic for further study. PMID:27877158

Isolation of bacteriophages from air using vacuum filtration technique: an improved and novel method.

PubMed

Magare, B; Nair, A; Khairnar, K

2017-10-01

Development of a simple and economical air sampler for isolation and enrichment of bacteriophages from air samples. A vacuum filtration unit with simple modifications was used for isolation of bacteriophages from air sampled in the lavatory. Air was sampled at the rate of 62 l min -1 by bubbling into Mcllvaine buffer for 30 min, which was used as bacteriophage solution for enrichment and plaque assessment against individual hosts. Alternatively, the aforementioned phage solution was enriched using a host consortium before plaque assessment. Phages were isolated in the range of 1-12 PFU per ml by the first method, whereas enrichment with host consortium gave phages around 10- to 1000-folds higher in number. Combining with established enrichment method, an improvement of about 10 times in phage isolation efficiency was attained. The method is very useful for studying the natural bacteriophages of air, requiring only a basic microbiological laboratory setup making it simple and economical. This study brings out a simple, economical air sampler for assessing air bacteriophages that can be employed by any microbial laboratory. Although various methods are available for studying bacteriophages in water and soil, very limited are available for air. To the best of our knowledge, the method developed in this study is unique in its design and concept for studying bacteriophages in air. The sampler is sterilizable by autoclaving and maintains a healthy rate of airflow provided by conventional vacuum pumps. The use of a nonspecific 'trapping solution' allows for the qualitative and quantitative study of air bacteriophages. © 2017 The Society for Applied Microbiology.

Isolation and characterization of bacteriophages specific to hydrogen-sulfide-producing bacteria.

PubMed

Gong, Chao; Heringa, Spencer; Singh, Randhir; Kim, Jinkyung; Jiang, Xiuping

2013-01-01

The objectives of this study were to isolate and characterize bacteriophages specific to hydrogen-sulfide-producing bacteria (SPB) from raw animal materials, and to develop a SPB-specific bacteriophage cocktail for rendering application. Meat, chicken offal, and feather samples collected from local supermarkets and rendering processing plants were used to isolate SPB (n = 142). Bacteriophages (n = 52) specific to SPB were isolated and purified from the above samples using 18 of those isolated SPB strains as hosts. The host ranges of bacteriophages against 5 selected SPB strains (Escherichia coli, Citrobacter freundii, and Hafnia alvei) were determined. Electron microscopy observation of 9 phages selected for the phage cocktail revealed that 6 phages belonged to the family of Siphoviridae and 3 belonged to the Myoviridae family. Restriction enzyme digestion analysis with endonuclease DraI detected 6 distinguished patterns among the 9 phages. Phage treatment prevented the growth of SPB for up to 10 h with multiplicity of infection ratios of 1, 10, 100, and 1000 in tryptic soy broth at 30 °C, and extended the lag phase of SPB growth for 2 h at 22 °C with multiplicities of infection of 10, 100, and 1000. These results suggest that the selected bacteriophage cocktail has a high potential for phage application to control SPB in raw animal materials destined for the rendering process.

Bacteriophage-based therapy in cystic fibrosis-associated Pseudomonas aeruginosa infections: rationale and current status

PubMed Central

Hraiech, Sami; Brégeon, Fabienne; Rolain, Jean-Marc

2015-01-01

Pulmonary infections involving Pseudomonas aeruginosa are among the leading causes of the deterioration of the respiratory status of cystic fibrosis (CF) patients. The emergence of multidrug-resistant strains in such populations, favored by iterative antibiotic cures, has led to the urgent need for new therapies. Among them, bacteriophage-based therapies deserve a focus. One century of empiric use in the ex-USSR countries suggests that bacteriophages may have beneficial effects against a large range of bacterial infections. Interest in bacteriophages has recently renewed in Western countries, and the in vitro data available suggest that bacteriophage-based therapy may be of significant interest for the treatment of pulmonary infections in CF patients. Although the clinical data concerning this specific population are relatively scarce, the beginning of the first large randomized study evaluating bacteriophage-based therapy in burn infections suggests that the time has come to assess the effectiveness of this new therapy in CF P. aeruginosa pneumonia. Consequently, the aim of this review is, after a brief history, to summarize the evidence concerning bacteriophage efficacy against P. aeruginosa and, more specifically, the in vitro studies, animal models, and clinical trials targeting CF. PMID:26213462

Bacteriophage Procurement for Therapeutic Purposes

PubMed Central

Weber-Dąbrowska, Beata; Jończyk-Matysiak, Ewa; Żaczek, Maciej; Łobocka, Małgorzata; Łusiak-Szelachowska, Marzanna; Górski, Andrzej

2016-01-01

Bacteriophages (phages), discovered 100 years ago, are able to infect and destroy only bacterial cells. In the current crisis of antibiotic efficacy, phage therapy is considered as a supplementary or even alternative therapeutic approach. Evolution of multidrug-resistant and pandrug-resistant bacterial strains poses a real threat, so it is extremely important to have the possibility to isolate new phages for therapeutic purposes. Our phage laboratory and therapy center has extensive experience with phage isolation, characterization, and therapeutic application. In this article we present current progress in bacteriophages isolation and use for therapeutic purposes, our experience in this field and its practical implications for phage therapy. We attempt to summarize the state of the art: properties of phages, the methods for their isolation, criteria of phage selection for therapeutic purposes and limitations of their use. Perspectives for the use of genetically engineered phages to specifically target bacterial virulence-associated genes are also briefly presented. PMID:27570518

Assessment of drinking water quality using indicator bacteria and bacteriophages.

PubMed

Méndez, Javier; Audicana, Ana; Cancer, Mercedes; Isern, Anna; Llaneza, Julian; Moreno, Belén; Navarro, Mercedes; Tarancón, M Lluisa; Valero, Fernando; Ribas, Ferran; Jofre, Juan; Lucena, Francisco

2004-09-01

Bacterial indicators and bacteriophages suggested as potential indicators of water quality were determined by public laboratories in water from springs, household water wells, and rural and metropolitan water supplies in north-eastern Spain. Indicator bacteria were detected more frequently than bacteriophages in springs, household water wells and rural water supplies. In contrast, positive bacteriophage detections were more numerous than those of bacteria in metropolitan water supplies. Most of the metropolitan water supply samples containing indicators had concentrations of chlorine below 0.1 mg l(-1), their indicator loads resembling more closely those of rural water supplies than any other samples taken from metropolitan water supplies. The number of samples from metropolitan water supplies containing more than 0.1 mg l(-1) of chlorine that contained phages clearly outnumbered those containing indicator bacteria. Some association was observed between rainfall and the presence of indicators. Sediments from service reservoirs and water from dead ends in the distribution network of one of the metropolitan water supplies were also tested. Bacterial indicators and phages were detected in a higher percentage than in samples of tap water from the same network. Additionally, indicator bacteria were detected more frequently than bacteriophages in sediments of service reservoirs and water from dead end samples. We conclude that naturally occurring indicator bacteria and bacteriophages respond differently to chlorination and behave differently in drinking water distribution networks. Moreover, this study has shown that testing for the three groups of phages in routine laboratories is easy to implement and feasible without the requirement for additional material resources for the laboratories.

Phage-host interactions analysis of newly characterized Oenococcus oeni bacteriophages: Implications for malolactic fermentation in wine.

PubMed

Costantini, Antonella; Doria, Francesca; Saiz, Juan-Carlos; Garcia-Moruno, Emilia

2017-04-04

Nowadays, only few phages infecting Oenococcus oeni, the principal lactic acid bacteria (LAB) species responsible for malolactic fermentation (MLF) in wine, have been characterized. In the present study, to better understanding the factors affecting the lytic activity of Oenococcus phages, fifteen O. oeni bacteriophages have been studied in detail, both with molecular and microbiological methods. No correlations were found between genome sizes, type of integrase genes, or morphology and the lytic activity of the 15 tested phages. Interestingly, though phage attack in a wine at the end of alcoholic fermentation seems not to be a problem, it can indeed represent a risk factor for MLF when the alcohol content is low, feature that may be a key point for choosing the appropriate time for malolactic starter inoculation. Additionally, it was observed that some phages genomes bear 2 or 3 types of integrase genes, which point to horizontal gene transfer between O. oeni bacteriophages. Copyright © 2017. Published by Elsevier B.V.

Virulent Bacteriophages Can Target O104:H4 Enteroaggregative Escherichia coli in the Mouse Intestine

PubMed Central

Maura, Damien; Galtier, Matthieu; Le Bouguénec, Chantal

2012-01-01

In vivo bacteriophage targeting of enteroaggregative Escherichia coli (EAEC) was assessed using a mouse intestinal model of colonization with the O104:H4 55989Str strain and a cocktail of three virulent bacteriophages. The colonization model was shown to mimic asymptomatic intestinal carriage found in humans. The addition of the cocktail to drinking water for 24 h strongly decreased ileal and weakly decreased fecal 55989Str concentrations in a dose-dependent manner. These decreases in ileal and fecal bacterial concentrations were only transient, since 55989Str concentrations returned to their original levels 3 days later. These transient decreases were independent of the mouse microbiota, as similar results were obtained with axenic mice. We studied the infectivity of each bacteriophage in the ileal and fecal environments and found that 55989Str bacteria in the mouse ileum were permissive to all three bacteriophages, whereas those in the feces were permissive to only one bacteriophage. Our results provide the first demonstration that bacterial permissivity to infection with virulent bacteriophages is not uniform throughout the gut; this highlights the need for a detailed characterization of the interactions between bacteria and bacteriophages in vivo for the further development of phage therapy targeting intestinal pathogens found in the gut of asymptomatic human carriers. PMID:23006754

The Effectiveness of Bacteriophages against Methicillin-Resistant Staphylococcus aureus ST398 Nasal Colonization in Pigs.

PubMed

Verstappen, Koen M; Tulinski, Pawel; Duim, Birgitta; Fluit, Ad C; Carney, Jennifer; van Nes, Arie; Wagenaar, Jaap A

2016-01-01

Methicillin-resistant Staphylococcus aureus (MRSA) is an important colonizer in animals and an opportunistic pathogen in humans. In humans, MRSA can cause infections that might be difficult to treat because of antimicrobial resistance. The use of bacteriophages has been suggested as a potential approach for the control of MRSA colonization to minimize the-often occupational-exposure of humans. The aim of this study was to assess the efficacy of bacteriophage treatment on porcine nasal colonization with MRSA in vitro, in vivo, and ex vivo. The effectiveness of a bacteriophage combination of phage K*710 and P68 was assessed in vitro by incubating them with MRSA V0608892/1 (ST398) measuring the OD600 hourly. To study the in vivo effect, bacteriophages were administered in a gel developed for human application, which contain 109 plaque-forming units (pfu)/mL (K and P68 in a 19.25:1 ratio) for 5 days to piglets (N = 8) that were experimentally colonized with the MRSA strain. Eight piglets experimentally colonized were used as a negative control. The MRSA strain was also used to colonize porcine nasal mucosa explants and bacteriophages were applied to assess the ex vivo efficacy of treatment. Bacteriophages were effective in vitro. In vivo, sixteen piglets were colonized with MRSA but the number of CFU recovered after the application of the bacteriophages in 8 piglets was not reduced compared to the control animals (approx. 105 CFU/swab). In the ex vivo model, 108 CFU were used to establish colonization with MRSA; a reduction of colonization was not observed after application of bacteriophages. However, application of mupirocin both in vivo and ex vivo resulted in a near eradication of MRSA. i) The MRSA strain was killed in the presence of the bacteriophages phage K*710 and P68 in vitro. ii) Bacteriophages did not reduce porcine nasal colonization in vivo or ex vivo. Physiological in vivo and ex vivo conditions may explain these observations. Efficacy in the ex vivo

The Effectiveness of Bacteriophages against Methicillin-Resistant Staphylococcus aureus ST398 Nasal Colonization in Pigs

PubMed Central

Duim, Birgitta; Fluit, Ad C; Carney, Jennifer; van Nes, Arie; Wagenaar, Jaap A

2016-01-01

Methicillin-resistant Staphylococcus aureus (MRSA) is an important colonizer in animals and an opportunistic pathogen in humans. In humans, MRSA can cause infections that might be difficult to treat because of antimicrobial resistance. The use of bacteriophages has been suggested as a potential approach for the control of MRSA colonization to minimize the—often occupational—exposure of humans. The aim of this study was to assess the efficacy of bacteriophage treatment on porcine nasal colonization with MRSA in vitro, in vivo, and ex vivo. The effectiveness of a bacteriophage combination of phage K*710 and P68 was assessed in vitro by incubating them with MRSA V0608892/1 (ST398) measuring the OD600 hourly. To study the in vivo effect, bacteriophages were administered in a gel developed for human application, which contain 109 plaque-forming units (pfu)/mL (K and P68 in a 19.25:1 ratio) for 5 days to piglets (N = 8) that were experimentally colonized with the MRSA strain. Eight piglets experimentally colonized were used as a negative control. The MRSA strain was also used to colonize porcine nasal mucosa explants and bacteriophages were applied to assess the ex vivo efficacy of treatment. Bacteriophages were effective in vitro. In vivo, sixteen piglets were colonized with MRSA but the number of CFU recovered after the application of the bacteriophages in 8 piglets was not reduced compared to the control animals (approx. 105 CFU/swab). In the ex vivo model, 108 CFU were used to establish colonization with MRSA; a reduction of colonization was not observed after application of bacteriophages. However, application of mupirocin both in vivo and ex vivo resulted in a near eradication of MRSA. In conclusion: i) The MRSA strain was killed in the presence of the bacteriophages phage K*710 and P68 in vitro. ii) Bacteriophages did not reduce porcine nasal colonization in vivo or ex vivo. Physiological in vivo and ex vivo conditions may explain these observations. Efficacy

Treatment of Highly Virulent Extraintestinal Pathogenic Escherichia coli Pneumonia With Bacteriophages.

PubMed

Dufour, Nicolas; Debarbieux, Laurent; Fromentin, Mélanie; Ricard, Jean-Damien

2015-06-01

To study the effect of bacteriophage treatment on highly virulent extraintestinal Escherichia coli pneumonia in mice and compare it with conventional antimicrobial treatment. Animal investigation. University research laboratory. Pathogen-free 8-week-old Balb/cJRj male mice. Two bacteriophages (536_P1 and 536_P7) were isolated from sewage using strain 536, a highly virulent extraintestinal E. coli. Their in vitro and in vivo efficacy against strain 536 and a ventilator-associated pneumonia E. coli were tested. The first group of mice were infected by intranasal instillation of bioluminescent strain 536 and received 536_P1 intranasally, ceftriaxone, or control. The second group of mice was infected with the ventilator-associated pneumonia strain and received 536_P7. Adaptation of 536_P7 to this clinical isolate was also evaluated in vitro and in vivo. In vivo efficacy of bacteriophage and antibiotic treatment were assessed by recording bioluminescence for short-time periods and by recording body weight and survival of mice for longer periods. Both treatments improved survival compared with control (100% vs 0%), and in vivo bioluminescence recordings showed a similar rapid decrease of emitted light, suggesting prompt bacterial clearance. The majority of mice infected by the ventilator-associated pneumonia strain were not rescued by treatment with 536_P7; however, in vitro adaptation of this bacteriophage toward the ventilator-associated pneumonia strain led to isolate a variant which significantly improved in vivo treatment efficacy (animal survival increased from 20% to 75%). Bacteriophage treatment was as effective as antibiotherapy to provide 100% survival rate in a lethal model of highly virulent E. coli pneumonia. Adaptation of a bacteriophage is a rapid solution to improve its efficacy toward specific strains. These results suggest that phage therapy could be a promising therapeutic strategy for ventilator-associated pneumonia.

Identification and Characterization of T5-Like Bacteriophages Representing Two Novel Subgroups from Food Products

PubMed Central

Sváb, Domonkos; Falgenhauer, Linda; Rohde, Manfred; Szabó, Judit; Chakraborty, Trinad; Tóth, István

2018-01-01

During recent years, interest in the use of bacteriophages as biocontrol agents against foodborne pathogens has increased, particularly for members of the family Enterobacteriaceae, with pathogenic Escherichia coli, Shigella, and Salmonella strains among them. Here, we report the isolation and characterisation of 12 novel T5-like bacteriophages from confiscated food samples. All bacterophages effectively lysed E. coli K-12 strains and were able to infect pathogenic E. coli strains representing enterohaemorrhagic (EHEC), enteropathogenic (EPEC), enterotoxigenic (ETEC), and enteroinvasive (EIEC) pathotypes, Shigella dysenteriae, S. sonnei strains, as well as multidrug-resistant (MDR) E. coli and multiple strains representing different Salmonella enterica serovars. All the bacteriophages exhibited Siphoviridae morphology. Whole genome sequencing of the novel T5-like bacteriophages showed that they represent two distinct groups, with the genome-based grouping correlating to the different host spectra. As these bacteriophages are of food origin, their stability and lack of any virulence genes, as well as their broad and mutually complementary host spectrum makes these new T5-like bacteriophages valuable candidates for use as biocontrol agents against foodborne pathogenic enterobacteria. PMID:29487585

[Immunodetection of bacteriophages by a piezoelectric resonator with lateral electric field].

PubMed

Gulii, O I; Zaitsev, B D; Shikhabudinov, A M; Teplykh, A A; Borodina, I A; Pavlii, S A; Larionova, O S; Fomin, A S; Staroverov, S A; Dykman, L A; Ignatov, O V

2016-01-01

It has been demonstrated that electroacoustic analysis with polyclonal antibodies can be used for bacteriophage detection. The frequency dependences of the real and imaginary parts of electrical impedance of a resonator with a viral suspension with antibodies were shown to be essentially different from the dependences of a resonator with control viral suspension without antibodies. It was shown that ΦAl-Sp59b bacteriophages were detected with the use of antibodies in the presence of foreign virus particles. The ΦAl-Sp59b bacteriophage content in the analyzed suspension was ~1010–106 phages/mL; the time of analysis was no more than 5 min. The optimally informative parameter for obtaining reliable information was the change in the real or imaginary part of electrical impedance at a fixed frequency near the resonance upon the addition of specific antibodies to the analyzed suspension. It was demonstrated that the interaction between bacteriophages and antibodies can be recorded, offering good prospects for the development of a biological sensor for liquid-phase identification and virus detection.

Isolation and characterization of glacier VMY22, a novel lytic cold-active bacteriophage of Bacillus cereus.

PubMed

Ji, Xiuling; Zhang, Chunjing; Fang, Yuan; Zhang, Qi; Lin, Lianbing; Tang, Bing; Wei, Yunlin

2015-02-01

As a unique ecological system with low temperature and low nutrient levels, glaciers are considered a "living fossil" for the research of evolution. In this work, a lytic cold-active bacteriophage designated VMY22 against Bacillus cereus MYB41-22 was isolated from Mingyong Glacier in China, and its characteristics were studied. Electron microscopy revealed that VMY22 has an icosahedral head (59.2 nm in length, 31.9 nm in width) and a tail (43.2 nm in length). Bacteriophage VMY22 was classified as a Podoviridae with an approximate genome size of 18 to 20 kb. A one-step growth curve revealed that the latent and the burst periods were 70 and 70 min, respectively, with an average burst size of 78 bacteriophage particles per infected cell. The pH and thermal stability of bacteriophage VMY22 were also investigated. The maximum stability of the bacteriophage was observed to be at pH 8.0 and it was comparatively stable at pH 5.0-9.0. As VMY22 is a cold-active bacteriophage with low production temperature, its characterization and the relationship between MYB41-22 and Bacillus cereus bacteriophage deserve further study.

The Role of Solution Conditions in the Bacteriophage PP7 Capsid Charge Regulation

DOE PAGES

Nap, Rikkert J.; Bozic, Anze Losdorfer; Szleifer, Igal; ...

2014-10-21

Here, we investigate and quantify the effects of pH and salt concentration on the charge regulation of the bacteriophage PP7 capsid. These effects are found to be extremely important and substantial, introducing qualitative changes in the charge state of the capsid such as a transition from net-positive to net-negative charge depending on the solution pH. The overall charge of the virus capsid arises as a consequence of a complicated balance with the chemical dissociation equilibrium of the amino acids and the electrostatic interaction between them, and the translational entropy of the mobile solution ions, i.e., counterion release. We show thatmore » to properly describe and predict the charging equilibrium of viral capsids in general, one needs to include molecular details as exemplified by the acid-base equilibrium of the detailed distribution of amino acids in the proteinaceous capsid shell.« less

MetaPhinder-Identifying Bacteriophage Sequences in Metagenomic Data Sets.

PubMed

Jurtz, Vanessa Isabell; Villarroel, Julia; Lund, Ole; Voldby Larsen, Mette; Nielsen, Morten

Bacteriophages are the most abundant biological entity on the planet, but at the same time do not account for much of the genetic material isolated from most environments due to their small genome sizes. They also show great genetic diversity and mosaic genomes making it challenging to analyze and understand them. Here we present MetaPhinder, a method to identify assembled genomic fragments (i.e.contigs) of phage origin in metagenomic data sets. The method is based on a comparison to a database of whole genome bacteriophage sequences, integrating hits to multiple genomes to accomodate for the mosaic genome structure of many bacteriophages. The method is demonstrated to out-perform both BLAST methods based on single hits and methods based on k-mer comparisons. MetaPhinder is available as a web service at the Center for Genomic Epidemiology https://cge.cbs.dtu.dk/services/MetaPhinder/, while the source code can be downloaded from https://bitbucket.org/genomicepidemiology/metaphinder or https://github.com/vanessajurtz/MetaPhinder.

MOF-Bacteriophage Biosensor for Highly Sensitive and Specific Detection of Staphylococcus aureus.

PubMed

Bhardwaj, Neha; Bhardwaj, Sanjeev K; Mehta, Jyotsana; Kim, Ki-Hyun; Deep, Akash

2017-10-04

To produce a sensitive and specific biosensor for Staphylococcus aureus, bacteriophages have been interfaced with a water-dispersible and environmentally stable metal-organic framework (MOF), NH 2 -MIL-53(Fe). The conjugation of the MOF with bacteriophages has been achieved through the use of glutaraldehyde as cross-linker. Highly sensitive detection of S. aureus in both synthetic and real samples was realized by the proposed MOF-bacteriophage biosensor based on the photoluminescence quenching phenomena: limit of detection (31 CFU/mL) and range of detection (40 to 4 × 10 8 CFU/mL). This is the first report exploiting the use of an MOF-bacteriophage complex for the biosensing of S. aureus. The results of our study highlight that the proposed biosensor is more sensitive than most of the previous methods while exhibiting some advanced features like specificity, regenerability, extended range of linear detection, and stability for long-term storage (even at room temperature).

Effects of bacteriophage on the quality and shelf life of Paralichthys olivaceus during chilled storage.

PubMed

Li, Meng; Lin, Hong; Khan, Muhammad Naseem; Wang, Jingxue; Kong, Linghong

2014-06-01

The microbiological spoilage of fishery foods is mainly due to specific spoilage organisms (SSOs), with Shewanella putrefaciens being the SSO of most chilled marine fish. Bacteriophages have shown excellent capability to control micro-organisms. The aim of this study was to determine a specific bacteriophage to prevent spoilage by reducing SSO (S. putrefaciens) levels in the marine fish Paralichthys olivaceus (olive flounder) under chilled storage. Chilled flounder fillets were inoculated with S. putrefaciens and treated with different concentrations of bacteriophage Spp001 ranging from 10(4) to 10(8) plaque-forming units (pfu) mL(-1) . Bacterial growth (including total viable count and SSO) of the bacteriophage-treated groups was significantly inhibited compared with that of the negative control group (P < 0.05). Sensory evaluation and biochemical parameters revealed that the bacteriophage could extend the shelf life of chilled flounder fillets (from <4 to 14 days) with good esthetic quality, even at low temperature (4 °C). Furthermore, bacteriophage concentrations of 10(6) and 10(8) pfu mL(-1) were more effective than the chemical preservative potassium sorbate (5 g L(-1) ). The bacteriophage Spp001 offered effective biocontrol of S. putrefaciens under chilled conditions, retaining the quality characteristics of spiked fish fillets, and thus could be a potential candidate for use in chilled fish fillet biopreservation. © 2013 Society of Chemical Industry.

Pulmonary Bacteriophage Therapy on Pseudomonas aeruginosa Cystic Fibrosis Strains: First Steps Towards Treatment and Prevention

PubMed Central

Morello, Eric; Saussereau, Emilie; Maura, Damien; Huerre, Michel; Touqui, Lhousseine; Debarbieux, Laurent

2011-01-01

Multidrug-resistant bacteria are the cause of an increasing number of deadly pulmonary infections. Because there is currently a paucity of novel antibiotics, phage therapy—the use of specific viruses that infect bacteria—is now more frequently being considered as a potential treatment for bacterial infections. Using a mouse lung-infection model caused by a multidrug resistant Pseudomonas aeruginosa mucoid strain isolated from a cystic fibrosis patient, we evaluated bacteriophage treatments. New bacteriophages were isolated from environmental samples and characterized. Bacteria and bacteriophages were applied intranasally to the immunocompetent mice. Survival was monitored and bronchoalveolar fluids were analysed. Quantification of bacteria, bacteriophages, pro-inflammatory and cytotoxicity markers, as well as histology and immunohistochemistry analyses were performed. A curative treatment (one single dose) administrated 2 h after the onset of the infection allowed over 95% survival. A four-day preventive treatment (one single dose) resulted in a 100% survival. All of the parameters measured correlated with the efficacy of both curative and preventive bacteriophage treatments. We also showed that in vitro optimization of a bacteriophage towards a clinical strain improved both its efficacy on in vivo treatments and its host range on a panel of 20 P. aeruginosa cystic fibrosis strains. This work provides an incentive to develop clinical studies on pulmonary bacteriophage therapy to combat multidrug-resistant lung infections. PMID:21347240

Genomic and proteomic characterization of SuMu, a Mu-like bacteriophage infecting Haemophilus parasuis

PubMed Central

2012-01-01

Background Haemophilus parasuis, the causative agent of Glässer’s disease, is prevalent in swine herds and clinical signs associated with this disease are meningitis, polyserositis, polyarthritis, and bacterial pneumonia. Six to eight week old pigs in segregated early weaning herds are particularly susceptible to the disease. Insufficient colostral antibody at weaning or the mixing of pigs with heterologous virulent H. parasuis strains from other farm sources in the nursery or grower-finisher stage are considered to be factors for the outbreak of Glässer’s disease. Previously, a Mu-like bacteriophage portal gene was detected in a virulent swine isolate of H. parasuis by nested polymerase chain reaction. Mu-like bacteriophages are related phyologenetically to enterobacteriophage Mu and are thought to carry virulence genes or to induce host expression of virulence genes. This study characterizes the Mu-like bacteriophage, named SuMu, isolated from a virulent H. parasuis isolate. Results Characterization was done by genomic comparison to enterobacteriophage Mu and proteomic identification of various homologs by mass spectrometry. This is the first report of isolation and characterization of this bacteriophage from the Myoviridae family, a double-stranded DNA bacteriophage with a contractile tail, from a virulent field isolate of H. parasuis. The genome size of bacteriophage SuMu was 37,151 bp. DNA sequencing revealed fifty five open reading frames, including twenty five homologs to Mu-like bacteriophage proteins: Nlp, phage transposase-C-terminal, COG2842, Gam-like protein, gp16, Mor, peptidoglycan recognition protein, gp29, gp30, gpG, gp32, gp34, gp36, gp37, gpL, phage tail tube protein, DNA circulation protein, gpP, gp45, gp46, gp47, COG3778, tail fiber protein gp37-C terminal, tail fiber assembly protein, and Com. The last open reading frame was homologous to IS1414. The G + C content of bacteriophage SuMu was 41.87% while its H. parasuis host genome�

Genomic and proteomic characterization of SuMu, a Mu-like bacteriophage infecting Haemophilus parasuis.

PubMed

Zehr, Emilie S; Tabatabai, Louisa B; Bayles, Darrell O

2012-07-23

Haemophilus parasuis, the causative agent of Glässer's disease, is prevalent in swine herds and clinical signs associated with this disease are meningitis, polyserositis, polyarthritis, and bacterial pneumonia. Six to eight week old pigs in segregated early weaning herds are particularly susceptible to the disease. Insufficient colostral antibody at weaning or the mixing of pigs with heterologous virulent H. parasuis strains from other farm sources in the nursery or grower-finisher stage are considered to be factors for the outbreak of Glässer's disease. Previously, a Mu-like bacteriophage portal gene was detected in a virulent swine isolate of H. parasuis by nested polymerase chain reaction. Mu-like bacteriophages are related phyologenetically to enterobacteriophage Mu and are thought to carry virulence genes or to induce host expression of virulence genes. This study characterizes the Mu-like bacteriophage, named SuMu, isolated from a virulent H. parasuis isolate. Characterization was done by genomic comparison to enterobacteriophage Mu and proteomic identification of various homologs by mass spectrometry. This is the first report of isolation and characterization of this bacteriophage from the Myoviridae family, a double-stranded DNA bacteriophage with a contractile tail, from a virulent field isolate of H. parasuis. The genome size of bacteriophage SuMu was 37,151 bp. DNA sequencing revealed fifty five open reading frames, including twenty five homologs to Mu-like bacteriophage proteins: Nlp, phage transposase-C-terminal, COG2842, Gam-like protein, gp16, Mor, peptidoglycan recognition protein, gp29, gp30, gpG, gp32, gp34, gp36, gp37, gpL, phage tail tube protein, DNA circulation protein, gpP, gp45, gp46, gp47, COG3778, tail fiber protein gp37-C terminal, tail fiber assembly protein, and Com. The last open reading frame was homologous to IS1414. The G + C content of bacteriophage SuMu was 41.87% while its H. parasuis host genome's G + C content was

Occurrence of bacteriophages infecting Aeromonas, Enterobacter, and Klebsiella in water and association with contamination sources in Thailand.

PubMed

Wangkahad, Bencharong; Bosup, Suchada; Mongkolsuk, Skorn; Sirikanchana, Kwanrawee

2015-06-01

The co-residence of bacteriophages and their bacterial hosts in humans, animals, and environmental sources directed the use of bacteriophages to track the origins of the pathogenic bacteria that can be found in contaminated water. The objective of this study was to enumerate bacteriophages of Aeromonas caviae (AecaKS148), Enterobacter sp. (EnspKS513), and Klebsiella pneumoniae (KlpnKS648) in water and evaluate their association with contamination sources (human vs. animals). Bacterial host strains were isolated from untreated wastewater in Bangkok, Thailand. A double-layer agar technique was used to detect bacteriophages. All three bacteriophages were detected in polluted canal samples, with likely contamination from human wastewater, whereas none was found in non-polluted river samples. AecaKS148 was found to be associated with human fecal sources, while EnspKS513 and KlpnKS648 seemed to be equally prevalent in both human and animal fecal sources. Both bacteriophages were also present in polluted canals that could receive contamination from other fecal sources or the environment. In conclusion, all three bacteriophages were successfully monitored in Bangkok, Thailand. This study provided an example of bacteriophages for potential use as source identifiers of pathogen contamination. The results from this study will assist in controlling sources of pathogen contamination, especially in developing countries.

76 FR 72950 - Draft Guidance for Industry: Use of Nucleic Acid Tests on Pooled and Individual Samples From...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-28

... Hepatitis B Virus AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The Food and Drug... Risk of Transmission of Hepatitis B Virus (HBV), and Requalification of Donors Who Test HBV NAT...-licensed nucleic acid tests (NAT) to screen blood donors for hepatitis B virus (HBV) deoxyribonucleic acid...

Interference with propagation of typing bacteriophages by extrachromosomal elements in Salmonella typhimurium: bacteriophage type 505.

PubMed Central

van Embden, J D; van Leeuwen, W J; Guinée, P A

1976-01-01

Samonella typhimurium bacteriophage type 505 is the most frequently encountered phage type in the Netherlands and its neighboring countries. Phage type 505 was analyzed with regard o the interference with propagation of the typing phages by the prophages and plasmids, present in the type strain S. typhimurium 505... Images PMID:783145

76 FR 66187 - Bacteriophage of Clavibacter Michiganensis Subspecies Michiganensis; Exemption From the...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-26

... bacteria, which means they attach to, infect, and reproduce in bacteria, and are host-specific for bacteria... bacteria. In addition, there is no evidence for bacteriophage infecting any other life form, including humans, except bacteria (Refs. 7, 12, and 13). Humans and other animals commonly consume bacteriophage as...

Molecular Biology and Biotechnology of Bacteriophage

NASA Astrophysics Data System (ADS)

Onodera, Kazukiyo

The development of the molecular biology of bacteriophage such as T4, lambda and filamentous phages was described and the process that the fundamental knowledge obtained in this field has subsequently led us to the technology of phage display was introduced.

Comparative persistence of human sewage-specific enterococcal bacteriophages in freshwater and seawater.

PubMed

Booncharoen, Namfon; Mongkolsuk, Skorn; Sirikanchana, Kwanrawee

2018-07-01

Enterococcus faecalis bacteria have been recently reported for their ability to host bacteriophages that are specifically from human sewage, suggesting their application to track human fecal contamination in water resources. However, little is known about the survivability of sewage-specific enterococcal bacteriophages in various water matrices under ambient and storage conditions. In this study, bacteriophages that were derived from the Thailand-isolated E. faecalis strains AIM06 and SR14 exhibited morphologies consistent with the Siphoviridae, Podoviridae, and Myoviridae families. Four representative bacteriophages were separately spiked into environmental water samples (n = 7) comprising freshwater and seawater with low- and high-pollution (LF, HF, LS, and HS, respectively) levels, defined according to Thailand Water Quality Standards. All bacteriophages decayed fastest in HS or HF samples at 30 °C, reaching a 5-log 10 reduction in 2.2 to 9.8 days, and slowest in LS samples, requiring 8.8 to 23.5 days. The decay rates were 5 to 53 times lower at a storage temperature of 5 °C. HF samples could be stored for as little as 2.5 days to prevent the decay of 50% of the phages. Myoviridae phages decayed faster than Siphoviridae phages and Podoviridae phages in most water matrices at 30 °C. Moreover, the decay rates were 1.8 to 92 times slower in filtered samples, emphasizing a strong role for water constituents, i.e., suspended solids and natural microorganisms, in phage persistence. This study emphasized that differential enterococcal bacteriophage persistence should be considered when planning the monitoring and interpreting of fecal sources by microbial source tracking.

Use of encapsulated bacteriophages to enhance farm to fork food safety.

PubMed

Hussain, Malik A; Liu, Huan; Wang, Qi; Zhong, Fang; Guo, Qian; Balamurugan, Sampathkumar

2017-09-02

Bacteriophages have been successfully applied to control the growth of pathogens in foods and to reduce the colonization and shedding of pathogens by food animals. They are set to play a dominant role in food safety in the future. However, many food-processing operations and the microenvironments in food animals' guts inactivate phages and reduce their infectivity. Encapsulation technologies have been used successfully to protect phages against extreme environments, and have been shown to preserve their activity and enable their release in targeted environments. A number of encapsulation technologies have shown potential for use with bacteriophages. This review discusses the current state of knowledge about the use of encapsulation technologies with bacteriophages to control pathogens in foods and food animals.

Occurrence and numbers of bacteriophages and bacterial indicators in faeces of yellow-legged seagull (Larus cachinnans).

PubMed

Muniesa, M; Jofre, J; Lucena, F

1999-12-01

Faeces from feral populations of yellow-legged seagulls from the northern coastal area of Catalonia (North-eastern Spain) contained variable amounts of faecal coliforms, faecal streptococci, somatic coliphages, F-specific bacteriophages and Bacteroides fragilis bacteriophages. Occurrence and numbers of bacterial indicators and bacteriophages in the faeces of yellow-legged seagulls are in the ranges described in the faeces of different animals. The ratios between numbers of bacterial indicators and numbers of bacteriophages are much higher in faeces of seagulls than in treated or raw sewage contributed by out-falls of the same area.

Methods for generation of reporter phages and immobilization of active bacteriophages on a polymer surface

NASA Technical Reports Server (NTRS)

Morgan, Mark Thomas (Inventor); Kothapalli, Aparna (Inventor); Applegate, Bruce Michael (Inventor); Perry, Lynda Louise (Inventor)

2012-01-01

Novel reporter bacteriophages are provided. Provided are compositions and methods that allow bacteriophages that are used for specific detection or killing of E. coli 0157:H7 to be propagated in nonpathogenic E. coli, thereby eliminating the safety and security risks of propagation in E. coli 0157:H7. Provided are compositions and methods for attaching active bacteriophages to the surface of a polymer in order to kill target bacteria with which the phage comes into contact. Provided are modified bacteriophages immobilized to a surface, which capture E. coli 0157:H7 and cause the captured cells to emit light or fluorescence, allowing detection of the bacteria in a sample.

Bacteriophages as vehicles for gene delivery into mammalian cells: prospects and problems.

PubMed

Bakhshinejad, Babak; Sadeghizadeh, Majid

2014-10-01

The identification of more efficient gene delivery vehicles (GDVs) is essential to fulfill the expectations of clinical gene therapy. Bacteriophages, due to their excellent safety profile, extreme stability under a variety of harsh environmental conditions and the capability for being genetically manipulated, have drawn a flurry of interest to be applied as a newly arisen category of gene delivery platforms. The incessant evolutionary interaction of bacteriophages with human cells has turned them into a part of our body's natural ecosystem. However, these carriers represent several barriers to gene transduction of mammalian cells. The lack of evolvement of specialized machinery for targeted cellular internalization, endosomal, lysosomal and proteasomal escape, cytoplasmic entry, nuclear localization and intranuclear transcription poses major challenges to the expression of the phage-carried gene. In this review, we describe pros and cons of bacteriophages as GDVs, provide an insight into numerous barriers that bacteriophages face for entry into and subsequent trafficking inside mammalian cells and elaborate on the strategies used to bypass these barriers. Tremendous genetic flexibility of bacteriophages to undergo numerous surface modifications through phage display technology has proven to be a turning point in the uncompromising efforts to surmount the limitations of phage-mediated gene expression. The revelatory outcomes of the studies undertaken within the recent years have been promising for phage-mediated gene delivery to move from concept to reality.

The effect of prepartum intravaginal bacteriophage administration on the incidence of retained placenta and metritis.

PubMed

Meira, E B S; Rossi, R S; Teixeira, A G; Kaçar, C; Oikonomou, G; Gregory, L; Bicalho, R C

2013-01-01

The objective of this study was to evaluate the effect of prepartum intravaginal administration of an anti-Escherichia coli bacteriophage cocktail on uterine health and reproductive performance of lactating dairy cows. The study was conducted on a commercial dairy farm located near Ithaca, New York, from March to September 2012, and 107 cows were enrolled. The cows were divided randomly into 2 groups (treatment and control); treatment group cows were submitted to 3 intravaginal administrations of 20 mL of a bacteriophage cocktail including 10 different phages in a lysate with titration of approximately 10(9) plaque-forming units, on d 230, 260, and 275 of gestation. Control cows were not treated with a placebo, and physical examination and sample collection was conducted equally for both groups. Vaginal swabs were collected at d 230, 260, and 275 d of gestation, cervical swabs were collected at 3±1 d in milk, and blood was collected at 275 d of gestation for nonesterified fatty acids and interleukin (IL)-6 serum level measurements and at 10 DIM for β-hydroxybutyrate and IL-6 serum level measurements. The bacteriophage cocktail significantly increased the incidence of retained placenta and metritis. Swab samples were cultured for E. coli and no difference was found between treatment and control groups. The lysate contained 6×10(9) IU of lipopolysaccharide/mL and could have caused prepartum overstimulation of toll-like receptor-4 (TLR4)-chemokine pathway, leading to a weaker immune response. However, IL-6 was not affected by treatment, although sample size was insufficient to prove a treatment effect on the suppression of the chemokine cascade and innate immune system. Bacteriophage treatment had an excellent bactericidal effect in previous in vitro trials; however, special attention must be given to production of the cocktail to obtain a purified solution free of E. coli bacterial products and fragments, particularly lipopolysaccharide. Copyright © 2013 American

ADSORPTION OF BACTERIOPHAGES ON CLAY MINERALS

EPA Science Inventory

Theability to predict the fate of microorganisms in soil is dependent on an understanding of the process of their sorption on soil and subsurface materials. Presently, we have focused on studying the thermodynamics of sorption of bacteriophages (T-2, MS-2, and

Soil-based systemic delivery and phyllosphere in vivo propagation of bacteriophages: Two possible strategies for improving bacteriophage persistence for plant disease control.

PubMed

Iriarte, Fanny B; Obradović, Aleksa; Wernsing, Mine H; Jackson, Lee E; Balogh, Botond; Hong, Jason A; Momol, M Timur; Jones, Jeffrey B; Vallad, Gary E

2012-10-01

Soil-based root applications and attenuated bacterial strains were evaluated as means to enhance bacteriophage persistence on plants for bacterial disease control. In addition, the systemic nature of phage applied to tomato roots was also evaluated. Several experiments were conducted applying either single phages or phage mixtures specific for Ralstonia solanacearum , Xanthomonas perforans or X. euvesicatoria to soil surrounding tomato plants and measuring the persistence and translocation of the phages over time. In general, all phages persisted in the roots of treated plants and were detected in stems and leaves; although phage level varied and persistence in stems and leaves was at a much lower level compared with persistence in roots. Bacterial wilt control was typically best if the phage or phage mixtures were applied to the soil surrounding tomatoes at the time of inoculation, less effective if applied 3 days before inoculation, and ineffective if applied 3 days after inoculation. The use of an attenuated X. perforans strain was also evaluated to improve the persistence of phage populations on tomato leaf surfaces. In greenhouse and field experiments, foliar applications of an attenuated mutant X. perforans 91-118:∆ OPGH strain prior to phage applications significantly improved phage persistence on tomato foliage compared with untreated tomato foliage. Both the soil-based bacteriophage delivery and the use of attenuated bacterial strains improved bacteriophage persistence on respective root and foliar tissues, with evidence of translocation with soil-based bacteriophage applications. Both strategies could lead to improved control of bacterial pathogens on plants.

Use of a bacteriophage cocktail to control Salmonella in food and the food industry.

PubMed

Spricigo, Denis Augusto; Bardina, Carlota; Cortés, Pilar; Llagostera, Montserrat

2013-07-15

The use of lytic bacteriophages for the biocontrol of food-borne pathogens in food and in the food industry is gaining increasing acceptance. In this study, the effectiveness of a bacteriophage cocktail composed of three different lytic bacteriophages (UAB_Phi 20, UAB_Phi78, and UAB_Phi87) was determined in four different food matrices (pig skin, chicken breasts, fresh eggs, and packaged lettuce) experimentally contaminated with Salmonella enterica serovar Typhimurium and S. enterica serovar Enteritidis. A significant bacterial reduction (>4 and 2 log/cm(2) for S. Typhimurium and S. Enteritidis, respectively; p≤0.005) was obtained in pig skin sprayed with the bacteriophage cocktail and then incubated at 33 °C for 6h. Significant decreases in the concentration of S. Typhimurium and S. Enteritidis were also measured in chicken breasts dipped for 5 min in a solution containing the bacteriophage cocktail and then refrigerated at 4 °C for 7 days (2.2 and 0.9 log10 cfu/g, respectively; p≤0.0001) as well as in lettuce similarly treated for 60 min at room temperature (3.9 and 2.2 log10 cfu/g, respectively; p≤0.005). However, only a minor reduction of the bacterial concentration (0.9 log10 cfu/cm(2) of S. Enteritidis and S. Typhimurium; p≤0.005) was achieved in fresh eggs sprayed with the bacteriophage cocktail and then incubated at 25 °C for 2 h. These results show the potential effectiveness of this bacteriophage cocktail as a biocontrol agent of Salmonella in several food matrices under conditions similar to those used in their production. Copyright © 2013 Elsevier B.V. All rights reserved.

Characterization and formulation into solid dosage forms of a novel bacteriophage lytic against Klebsiella oxytoca.

PubMed

Brown, Teagan L; Petrovski, Steve; Hoyle, Dannielle; Chan, Hiu Tat; Lock, Peter; Tucci, Joseph

2017-01-01

To isolate and characterize bacteriophage lytic for the opportunistic pathogen Klebsiella oxytoca and their formulation into a range of solid dosage forms for in-vitro testing. We report the isolation, genomic and functional characterization of a novel bacteriophage lytic for Klebsiella oxytoca, which does not infect the closely related Klebsiella pneumoniae. This bacteriophage was formulated into suppositories and troches and shown to be released and lyse underlying Klebsiella oxytoca bacteria in an in-vitro model. These bacteriophage formulations were stable for at least 49 days at 4°C. The successful in-vitro assay of these formulations here suggests that they could potentially be tested in-vivo to determine whether such a therapeutic approach could modulate the gut microbiome, and control Klebsiella oxytoca overgrowth, during antibiotic therapy regimes. This study reports a novel bacteriophage specific for Klebsiella oxytoca which can be formulated into solid dosage forms appropriate for potential delivery in testing as a therapy to modulate gut microbiome during antibiotic therapies.

DECAY OF INCORPORATED RADIOACTIVE PHOSPHORUS DURING REPRODUCTION OF BACTERIOPHAGE T2

PubMed Central

Stent, Gunther S.

1955-01-01

analogous to multiplicity reactivation or, (b) there occurs a change in state of the deoxyribonucleic acid (DNA) preliminary to or in the course of its replication that renders it refractory to destruction by P32 decay, or, finally (c) there occurs a transfer of the genetic factors from the DNA of the infecting phage to another substance not sensitive to destruction by P32 decay. PMID:13242767

Survival studies of a temperate and lytic bacteriophage in bovine faeces and slurry.

PubMed

Nyambe, S; Burgess, C; Whyte, P; Bolton, D

2016-10-01

Cattle are the main reservoir of verocytotoxigenic Escherichia coli (VTEC), food-borne pathogens that express verocytotoxins (vtx) encoded by temperate bacteriophage. Bovine faeces and unturned manure heaps can support the survival of VTEC and may propagate and transmit VTEC. This study investigated the survival of a vtx2 bacteriophage, φ24B ::Kan, in bovine faeces and slurry. The survival of an anti-Escherichia coli O157:H7 lytic bacteriophage, e11/2, was examined in the same matrices, as a possible bio-control option for VTEC. Samples were inoculated with φ24B ::Kan and/or e11/2 bacteriophage at a concentration of 7-8 log10  PFU g(-1)  (faeces) or ml(-1) (slurry), stored at 4 and 14°C and examined every 2 days for 36 days. The ability of φ24B ::Kan to transduce E. coli cells was examined. Moreover, E. coli concentrations in the faeces and slurry were monitored throughout the experiment as were the pH and aw (faeces only). Both bacteriophages survived well in faeces and slurry. In addition, φ24B ::Kan was able to form lysogens. φ24B ::Kan and e11/2 phage can survive and remain infective in bovine faeces and slurry for at least 30 days under representative Irish temperatures. Bovine faeces and slurry may act as a reservoir for vtx bacteriophages. The survival of the anti-O157 phage suggests it may be a suitable bio-control option in these matrices. © 2016 The Society for Applied Microbiology.

Antibiotic Resistant Bacterial Isolates from Captive Green Turtles and In Vitro Sensitivity to Bacteriophages

PubMed Central

Ariel, Ellen; Picard, Jacqueline; Elliott, Lisa

2017-01-01

This study aimed to test multidrug resistant isolates from hospitalised green turtles (Chelonia mydas) and their environment in North Queensland, Australia, for in vitro susceptibility to bacteriophages. Seventy-one Gram-negative bacteria were isolated from green turtle eye swabs and water samples. Broth microdilution tests were used to determine antibiotic susceptibility. All isolates were resistant to at least two antibiotics, with 24% being resistant to seven of the eight antibiotics. Highest resistance rates were detected to enrofloxacin (77%) and ampicillin (69.2%). More than 50% resistance was also found to amoxicillin/clavulanic acid (62.5%), ceftiofur (53.8%), and erythromycin (53.3%). All the enriched phage filtrate mixtures resulted in the lysis of one or more of the multidrug resistant bacteria, including Vibrio harveyi and V. parahaemolyticus. These results indicate that antibiotic resistance is common in Gram-negative bacteria isolated from hospitalised sea turtles and their marine environment in North Queensland, supporting global concern over the rapid evolution of multidrug resistant genes in the environment. Using virulent bacteriophages as antibiotic alternatives would not only be beneficial to turtle health but also prevent further addition of multidrug resistant genes to coastal waters. PMID:29147114

MetaPhinder—Identifying Bacteriophage Sequences in Metagenomic Data Sets

PubMed Central

Villarroel, Julia; Lund, Ole; Voldby Larsen, Mette; Nielsen, Morten

2016-01-01

Bacteriophages are the most abundant biological entity on the planet, but at the same time do not account for much of the genetic material isolated from most environments due to their small genome sizes. They also show great genetic diversity and mosaic genomes making it challenging to analyze and understand them. Here we present MetaPhinder, a method to identify assembled genomic fragments (i.e.contigs) of phage origin in metagenomic data sets. The method is based on a comparison to a database of whole genome bacteriophage sequences, integrating hits to multiple genomes to accomodate for the mosaic genome structure of many bacteriophages. The method is demonstrated to out-perform both BLAST methods based on single hits and methods based on k-mer comparisons. MetaPhinder is available as a web service at the Center for Genomic Epidemiology https://cge.cbs.dtu.dk/services/MetaPhinder/, while the source code can be downloaded from https://bitbucket.org/genomicepidemiology/metaphinder or https://github.com/vanessajurtz/MetaPhinder. PMID:27684958

FRNA Bacteriophages as Viral Indicators of Faecal Contamination in Mexican Tropical Aquatic Systems.

PubMed

Arredondo-Hernandez, Luis Jose Rene; Diaz-Avalos, Carlos; Lopez-Vidal, Yolanda; Castillo-Rojas, Gonzalo; Mazari-Hiriart, Marisa

2017-01-01

A particular challenge to water safety in populous intertropical regions is the lack of reliable faecal indicators to detect microbiological contamination of water, while the numerical relationships of specific viral indicators remain largely unexplored. The aim of this study was to investigate the numerical relationships of FRNA-bacteriophage genotypes, adenovirus 41, and human adenoviruses (HADV) in Mexican surface water systems to assess sewage contamination. We studied the presence of HADV, HADV41 and FRNA bacteriophage genotypes in water samples and quantified by qPCR and RT-qPCR. Virus and water quality indicator variances, as analyzed by principal component analysis and partial least squared regression, followed along the major percentiles of water faecal enterococci. FRNA bacteriophages adequately deciphered viral and point source water contamination. The strongest correlation for HADV was with FRNA bacteriophage type II, in water samples higher than the 50th percentiles of faecal enterococci, thus indicating urban pollution. FRNA bacteriophage genotypes I and III virus indicator performances were assisted by their associations with electrical conductivity and faecal enterococci. In combination, our methods are useful for inferring water quality degradation caused by sewage contamination. The methods used have potential for determining source contamination in water and, specifically, the presence of enteric viruses where clean and contaminated water have mixed.

FRNA Bacteriophages as Viral Indicators of Faecal Contamination in Mexican Tropical Aquatic Systems

PubMed Central

Diaz-Avalos, Carlos; Lopez-Vidal, Yolanda; Castillo-Rojas, Gonzalo; Mazari-Hiriart, Marisa

2017-01-01

A particular challenge to water safety in populous intertropical regions is the lack of reliable faecal indicators to detect microbiological contamination of water, while the numerical relationships of specific viral indicators remain largely unexplored. The aim of this study was to investigate the numerical relationships of FRNA-bacteriophage genotypes, adenovirus 41, and human adenoviruses (HADV) in Mexican surface water systems to assess sewage contamination. We studied the presence of HADV, HADV41 and FRNA bacteriophage genotypes in water samples and quantified by qPCR and RT-qPCR. Virus and water quality indicator variances, as analyzed by principal component analysis and partial least squared regression, followed along the major percentiles of water faecal enterococci. FRNA bacteriophages adequately deciphered viral and point source water contamination. The strongest correlation for HADV was with FRNA bacteriophage type II, in water samples higher than the 50th percentiles of faecal enterococci, thus indicating urban pollution. FRNA bacteriophage genotypes I and III virus indicator performances were assisted by their associations with electrical conductivity and faecal enterococci. In combination, our methods are useful for inferring water quality degradation caused by sewage contamination. The methods used have potential for determining source contamination in water and, specifically, the presence of enteric viruses where clean and contaminated water have mixed. PMID:28114378

Phage-Encoded Colanic Acid-Degrading Enzyme Permits Lytic Phage Infection of a Capsule-Forming Resistant Mutant Escherichia coli Strain

PubMed Central

Kim, Min Soo; Kim, Young Deuk; Hong, Sung Sik; Park, Kwangseo; Ko, Kwan Soo

2014-01-01

In this study, we isolated a bacteriophage T7-resistant mutant strain of Escherichia coli (named S3) and then proceeded to characterize it. The mutant bacterial colonies appeared to be mucoid. Microarray analysis revealed that genes related to colanic acid production were upregulated in the mutant. Increases in colanic acid production by the mutant bacteria were observed when l-fucose was measured biochemically, and protective capsule formation was observed under an electron microscope. We found a point mutation in the lon gene promoter in S3, the mutant bacterium. Overproduction of colanic acid was observed in some phage-resistant mutant bacteria after infection with other bacteriophages, T4 and lambda. Colanic acid overproduction was also observed in clinical isolates of E. coli upon phage infection. The overproduction of colanic acid resulted in the inhibition of bacteriophage adsorption to the host. Biofilm formation initially decreased shortly after infection but eventually increased after 48 h of incubation due to the emergence of the mutant bacteria. Bacteriophage PBECO4 was shown to infect the colanic acid-overproducing mutant strains of E. coli. We confirmed that the gene product of open reading frame 547 (ORF547) of PBECO4 harbored colanic acid-degrading enzymatic (CAE) activity. Treatment of the T7-resistant bacteria with both T7 and PBECO4 or its purified enzyme (CAE) led to successful T7 infection. Biofilm formation decreased with the mixed infection, too. This procedure, using a phage cocktail different from those exploiting solely receptor differences, represents a novel strategy for overcoming phage resistance in mutant bacteria. PMID:25416767

Transformation of Clostridium acetobutylicum Protoplasts with Bacteriophage DNA

PubMed Central

Reid, Sharon J.; Allcock, Errol R.; Jones, David T.; Woods, David R.

1983-01-01

Techniques for the transformation of Clostridium acetobutylicum protoplasts with bacteriophage DNA are described. Transformation required regeneration of protoplasts and a 2-h eclipse period. PMID:16346174

Engineered enzymatically active bacteriophages and methods of uses thereof

DOEpatents

Collins, James J [Newton, MA; Kobayashi, Hideki [Yokohama, JP; Kearn, Mads [Ottawa, CA; Araki, Michihiro [Minatoku, JP; Friedland, Ari [Boston, MA; Lu, Timothy Kuan-Ta [Palo Alto, CA

2012-05-22

The present invention provides engineered bacteriophages that express at least one biofilm degrading enzyme on their surface and uses thereof for degrading bacterial biofilms. The invention also provides genetically engineered bacteriophages expressing the biofilm degrading enzymes and proteins necessary for the phage to replicate in different naturally occurring biofilm producing bacteria. The phages of the invention allow a method of biofilm degradation by the use of one or only a few administration of the phage because the system using these phages is self perpetuating, and capable of degrading biofilm even when the concentration of bacteria within the biofilm is low.

Access to bacteriophage therapy: discouraging experiences from the human cell and tissue legal framework.

PubMed

Verbeken, G; Huys, I; De Vos, D; De Coninck, A; Roseeuw, D; Kets, E; Vanderkelen, A; Draye, J P; Rose, T; Jennes, S; Ceulemans, C; Pirnay, J P

2016-02-01

Cultures of human epithelial cells (keratinocytes) are used as an additional surgical tool to treat critically burnt patients. Initially, the production environment of keratinocyte grafts was regulated exclusively by national regulations. In 2004, the European Tissues and Cells Directive 2004/23/EC (transposed into Belgian Law) imposed requirements that resulted in increased production costs and no significant increase in quality and/or safety. In 2007, Europe published Regulation (EC) No. 1394/2007 on Advanced Therapy Medicinal Products. Overnight, cultured keratinocytes became (arguably) 'Advanced' Therapy Medicinal Products to be produced as human medicinal products. The practical impact of these amendments was (and still is) considerable. A similar development appears imminent in bacteriophage therapy. Bacteriophages are bacterial viruses that can be used for tackling the problem of bacterial resistance development to antibiotics. Therapeutic natural bacteriophages have been in clinical use for almost 100 years. Regulators today are framing the (re-)introduction of (natural) bacteriophage therapy into 'modern western' medicine as biological medicinal products, also subject to stringent regulatory medicinal products requirements. In this paper, we look back on a century of bacteriophage therapy to make the case that therapeutic natural bacteriophages should not be classified under the medicinal product regulatory frames as they exist today. It is our call to authorities to not repeat the mistake of the past. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

A filamentous bacteriophage targeted to carcinoembryonic antigen induces tumor regression in mouse models of colorectal cancer.

PubMed

Murgas, Paola; Bustamante, Nicolás; Araya, Nicole; Cruz-Gómez, Sebastián; Durán, Eduardo; Gaete, Diana; Oyarce, César; López, Ernesto; Herrada, Andrés Alonso; Ferreira, Nicolás; Pieringer, Hans; Lladser, Alvaro

2018-02-01

Colorectal cancer is a deadly disease, which is frequently diagnosed at advanced stages, where conventional treatments are no longer effective. Cancer immunotherapy has emerged as a new form to treat different malignancies by turning-on the immune system against tumors. However, tumors are able to evade antitumor immune responses by promoting an immunosuppressive microenvironment. Single-stranded DNA containing M13 bacteriophages are highly immunogenic and can be specifically targeted to the surface of tumor cells to trigger inflammation and infiltration of activated innate immune cells, overcoming tumor-associated immunosuppression and promoting antitumor immunity. Carcinoembryonic antigen (CEA) is highly expressed in colorectal cancers and has been shown to promote several malignant features of colorectal cancer cells. In this work, we targeted M13 bacteriophage to CEA, a tumor-associated antigen over-expressed in a high proportion of colorectal cancers but largely absent in normal cells. The CEA-targeted M13 bacteriophage was shown to specifically bind to purified CEA and CEA-expressing tumor cells in vitro. Both intratumoral and systemic administration of CEA-specific bacteriophages significantly reduced tumor growth of mouse models of colorectal cancer, as compared to PBS and control bacteriophage administration. CEA-specific bacteriophages promoted tumor infiltration of neutrophils and macrophages, as well as maturation dendritic cells in tumor-draining lymph nodes, suggesting that antitumor T-cell responses were elicited. Finally, we demonstrated that tumor protection provided by CEA-specific bacteriophage particles is mediated by CD8 + T cells, as depletion of circulating CD8 + T cells completely abrogated antitumor protection. In summary, we demonstrated that CEA-specific M13 bacteriophages represent a potential immunotherapy against colorectal cancer.

Enhancement of the antimicrobial properties of bacteriophage-K via stabilization using oil-in-water nano-emulsions.

PubMed

Esteban, Patricia Perez; Alves, Diana R; Enright, Mark C; Bean, Jessica E; Gaudion, Alison; Jenkins, A T A; Young, Amber E R; Arnot, Tom C

2014-01-01

Bacteriophage therapy is a promising new treatment that may help overcome the threat posed by antibiotic-resistant pathogenic bacteria, which are increasingly identified in hospitalized patients. The development of biocompatible and sustainable vehicles for incorporation of viable bacterial viruses into a wound dressing is a promising alternative. This article evaluates the antimicrobial efficacy of Bacteriophage K against Staphylococcus aureus over time, when stabilized and delivered via an oil-in-water nano-emulsion. Nano-emulsions were formulated via thermal phase inversion emulsification, and then bacterial growth was challenged with either native emulsion, or emulsion combined with Bacteriophage K. Bacteriophage infectivity, and the influence of storage time of the preparation, were assessed by turbidity measurements of bacterial samples. Newly prepared Bacteriophage K/nano-emulsion formulations have greater antimicrobial activity than freely suspended bacteriophage. The phage-loaded emulsions caused rapid and complete bacterial death of three different strains of S. aureus. The same effect was observed for preparations that were either stored at room temperature (18-20°C), or chilled at 4°C, for up to 10 days of storage. A response surface design of experiments was used to gain insight on the relative effects of the emulsion formulation on bacterial growth and phage lytic activity. More diluted emulsions had a less significant effect on bacterial growth, and diluted bacteriophage-emulsion preparations yielded greater antibacterial activity. The enhancement of bacteriophage activity when delivered via nano-emulsions is yet to be reported. This prompts further investigation into the use of these formulations for the development of novel anti-microbial wound management strategies. © 2014 American Institute of Chemical Engineers.

Bacteriophages as indicators of human and animal faecal contamination in raw and treated wastewaters from Tunisia.

PubMed

Yahya, M; Hmaied, F; Jebri, S; Jofre, J; Hamdi, M

2015-05-01

We aimed at quantifying bacteriophages in raw and treated wastewaters of human and animal origin in Tunisia to assess their usefulness for tracking the origin of faecal pollution and in the follow-up of effectiveness of water treatments process. The concentrations of bacteriophages in wastewater samples were determined by double layer agar technique. Somatic coliphages and F-specific RNA bacteriophages were present in all types of samples in high concentrations. The values of Escherichia coli were variable depending on geographical location. On the other hand, bacteriophages infecting strain GA17 were detected preferably when human faecal contamination was occurred. Bacteriophages appear as a feasible and widely applicable manner to detect faecal contamination in Tunisia. On the other hand, phages infecting GA17 could be good markers for tracking the origin of faecal pollution in the area studied. The reuse of treated wastewaters can be a solution to meet the needs of water in the geographical area of study. Bacteriophages seem to predict differently the presence of faecal contamination in water than bacterial indicators. Consequently, they can be a valuable additional tool to improve water resources management for minimizing health risks. © 2015 The Society for Applied Microbiology.

Quality-Controlled Small-Scale Production of a Well-Defined Bacteriophage Cocktail for Use in Human Clinical Trials

PubMed Central

Merabishvili, Maya; Pirnay, Jean-Paul; Verbeken, Gilbert; Chanishvili, Nina; Tediashvili, Marina; Lashkhi, Nino; Glonti, Thea; Krylov, Victor; Mast, Jan; Van Parys, Luc; Lavigne, Rob; Volckaert, Guido; Mattheus, Wesley; Verween, Gunther; De Corte, Peter; Rose, Thomas; Jennes, Serge; Zizi, Martin; De Vos, Daniel; Vaneechoutte, Mario

2009-01-01

We describe the small-scale, laboratory-based, production and quality control of a cocktail, consisting of exclusively lytic bacteriophages, designed for the treatment of Pseudomonas aeruginosa and Staphylococcus aureus infections in burn wound patients. Based on succesive selection rounds three bacteriophages were retained from an initial pool of 82 P. aeruginosa and 8 S. aureus bacteriophages, specific for prevalent P. aeruginosa and S. aureus strains in the Burn Centre of the Queen Astrid Military Hospital in Brussels, Belgium. This cocktail, consisting of P. aeruginosa phages 14/1 (Myoviridae) and PNM (Podoviridae) and S. aureus phage ISP (Myoviridae) was produced and purified of endotoxin. Quality control included Stability (shelf life), determination of pyrogenicity, sterility and cytotoxicity, confirmation of the absence of temperate bacteriophages and transmission electron microscopy-based confirmation of the presence of the expected virion morphologic particles as well as of their specific interaction with the target bacteria. Bacteriophage genome and proteome analysis confirmed the lytic nature of the bacteriophages, the absence of toxin-coding genes and showed that the selected phages 14/1, PNM and ISP are close relatives of respectively F8, φKMV and phage G1. The bacteriophage cocktail is currently being evaluated in a pilot clinical study cleared by a leading Medical Ethical Committee. PMID:19300511

Mutation of M13 Bacteriophage Major Coat Protein for Increased Conjugation to Exogenous Compounds.

PubMed

Tridgett, Matthew; Lloyd, James R; Kennefick, Jack; Moore-Kelly, Charles; Dafforn, Timothy R

2018-06-20

Over the past ten years there has been increasing interest in the conjugation of exogenous compounds to the surface of the M13 bacteriophage. M13 offers a convenient scaffold for the development of nanoassemblies with useful functions, such as highly specific drug delivery and pathogen detection. However, the progress of these technologies has been hindered by the limited efficiency of conjugation to the bacteriophage. Here we generate a mutant version of M13 with an additional lysine residue expressed on the outer surface of the M13 major coat protein, pVIII. We show that this mutation is accommodated by the bacteriophage and that up to an additional 520 exogenous groups can be attached to the bacteriophage surface via amine-directed conjugation. These results could aid the development of high payload drug delivery nanoassemblies and pathogen detection systems with increased sensitivity.

Anticancer activity of bacteriophage T4 and its mutant HAP1 in mouse experimental tumour models.

PubMed

Dabrowska, Krystyna; Opolski, Adam; Wietrzyk, Joanna; Switala-Jelen, Kinga; Godlewska, Joanna; Boratynski, Janusz; Syper, Danuta; Weber-Dabrowska, Beata; Gorski, Andrzej

2004-01-01

Previously, we have shown the ability of the bacteriophage T4 and its substrain HAP1 (selected for a higher affinity to melanoma cells) to reveal antimetastatic activity in a mouse melanoma model. Here, we investigated the potential phage anticancer activity in primary tumour models. Mice were inoculated subcutaneously with B16 or LLC cells (collected from in vitro culture). Bacteriophages T4 and HAP1 were injected intraperitoneally daily (8 x 10(8)pfu/mouse, except the experiment concerning the dose-dependence). Treatment with purified preparations of bacteriophage T4 resulted in significant reduction of tumour size, the effect being dose-dependent. HAP1 was more effective than T4 and its activity was also dose-dependent. Parallel experiments with non-purified bacteriophage lysates resulted in significant stimulation of tumour growth. These data suggest that purified bacteriophages may inhibit tumour growth, a phenomenon with potentially important clinical implications in oncology.

A Bacteriophage-Related Chimeric Marine Virus Infecting Abalone

PubMed Central

Zhuang, Jun; Cai, Guiqin; Lin, Qiying; Wu, Zujian; Xie, Lianhui

2010-01-01

Marine viruses shape microbial communities with the most genetic diversity in the sea by multiple genetic exchanges and infect multiple marine organisms. Here we provide proof from experimental infection that abalone shriveling syndrome-associated virus (AbSV) can cause abalone shriveling syndrome. This malady produces histological necrosis and abnormally modified macromolecules (hemocyanin and ferritin). The AbSV genome is a 34.952-kilobase circular double-stranded DNA, containing putative genes with similarity to bacteriophages, eukaryotic viruses, bacteria and endosymbionts. Of the 28 predicted open reading frames (ORFs), eight ORF-encoded proteins have identifiable functional homologues. The 4 ORF products correspond to a predicted terminase large subunit and an endonuclease in bacteriophage, and both an integrase and an exonuclease from bacteria. The other four proteins are homologous to an endosymbiont-derived helicase, primase, single-stranded binding (SSB) protein, and thymidylate kinase, individually. Additionally, AbSV exhibits a common gene arrangement similar to the majority of bacteriophages. Unique to AbSV, the viral genome also contains genes associated with bacterial outer membrane proteins and may lack the structural protein-encoding ORFs. Genomic characterization of AbSV indicates that it may represent a transitional form of microbial evolution from viruses to bacteria. PMID:21079776

Characterization and formulation into solid dosage forms of a novel bacteriophage lytic against Klebsiella oxytoca

PubMed Central

Petrovski, Steve; Hoyle, Dannielle; Chan, Hiu Tat; Lock, Peter; Tucci, Joseph

2017-01-01

Aim To isolate and characterize bacteriophage lytic for the opportunistic pathogen Klebsiella oxytoca and their formulation into a range of solid dosage forms for in-vitro testing. Methods and results We report the isolation, genomic and functional characterization of a novel bacteriophage lytic for Klebsiella oxytoca, which does not infect the closely related Klebsiella pneumoniae. This bacteriophage was formulated into suppositories and troches and shown to be released and lyse underlying Klebsiella oxytoca bacteria in an in-vitro model. These bacteriophage formulations were stable for at least 49 days at 4°C. Conclusions The successful in-vitro assay of these formulations here suggests that they could potentially be tested in-vivo to determine whether such a therapeutic approach could modulate the gut microbiome, and control Klebsiella oxytoca overgrowth, during antibiotic therapy regimes. Significance and impact of the study This study reports a novel bacteriophage specific for Klebsiella oxytoca which can be formulated into solid dosage forms appropriate for potential delivery in testing as a therapy to modulate gut microbiome during antibiotic therapies. PMID:28817689

Effectiveness of cooking to reduce norovirus and infectious F-specific RNA bacteriophage concentrations in Mytilus edulis.

PubMed

Flannery, J; Rajko-Nenow, P; Winterbourn, J B; Malham, S K; Jones, D L

2014-08-01

The aim of this study was to determine if domestic cooking practices can reduce concentrations of norovirus (NoV) and F-specific RNA (FRNA) bacteriophage in experimentally contaminated mussels. Mussels (n = 600) contaminated with NoV and FRNA bacteriophage underwent four different cooking experiments performed in triplicate at ~70°C and >90°C. Concentrations of infectious FRNA bacteriophage (using a plaque assay) were compared with concentrations of FRNA bacteriophage and NoV determined using a standardised RT-qPCR. Initial concentrations of infectious FRNA bacteriophage (7·05 log10  PFU g(-1) ) in mussels were not significantly reduced in simmering water (~70°C); however, cooking at higher temperatures (>90°C) reduced infectious FRNA bacteriophage to undetected levels within 3 min. Further investigation determined the time required for a 1-log reduction of infectious FRNA bacteriophage at 90°C to be 42 s therefore a >3-log reduction in infectious virus can be obtained by heating mussel digestive tissue to 90°C for 126 s. Domestic cooking practices based on shell opening alone do not inactivate infectious virus in mussels, however, cooking mussels at high temperatures is effective to reduce infectious virus concentrations and the risk of illness in consumers. The data will contribute towards evidence-based cooking recommendations for shellfish to provide a safe product for human consumption. © 2014 The Society for Applied Microbiology.

M13 Bacteriophage Based Protein Sensors

NASA Astrophysics Data System (ADS)

Lee, Ju Hun

Despite significant progress in biotechnology and biosensing, early detection and disease diagnosis remains a critical issue for improving patient survival rates and well-being. Many of the typical detection schemes currently used possess issues such as low sensitivity and accuracy and are also time consuming to run and expensive. In addition, multiplexed detection remains difficult to achieve. Therefore, developing advanced approaches for reliable, simple, quantitative analysis of multiple markers in solution that also are highly sensitive are still in demand. In recent years, much of the research has primarily focused on improving two key components of biosensors: the bio-recognition agent (bio-receptor) and the transducer. Particular bio-receptors that have been used include antibodies, aptamers, molecular imprinted polymers, and small affinity peptides. In terms of transducing agents, nanomaterials have been considered as attractive candidates due to their inherent nanoscale size, durability and unique chemical and physical properties. The key focus of this thesis is the design of a protein detection and identification system that is based on chemically engineered M13 bacteriophage coupled with nanomaterials. The first chapter provides an introduction of biosensors and M13 bacteriophage in general, where the advantages of each are provided. In chapter 2, an efficient and enzyme-free sensor is demonstrated from modified M13 bacteriophage to generate highly sensitive colorimetric signals from gold nanocrystals. In chapter 3, DNA conjugated M13 were used to enable facile and rapid detection of antigens in solution that also provides modalities for identification. Lastly, high DNA loadings per phage was achieved via hydrozone chemistry and these were applied in conjunction with Raman active DNA-gold/silver core/shell nanoparticles toward highly sensitive SERS sensing.

In vitro Effectiveness of Commercial Bacteriophage Cocktails on Diverse Extended-Spectrum Beta-Lactamase Producing Escherichia coli Strains.

PubMed

Gundogdu, Aycan; Bolkvadze, Darajen; Kilic, Huseyin

2016-01-01

The objective of this study is to determine the in vitro susceptibility of Georgian bacteriophage cocktails on multidrug resistant (MDR) extended-spectrum beta-lactamase producing Escherichia coli (ESBL-EC) isolated from patients' blood and urine cultures. A total of 615 E. coli isolates were included in this study. Phene Plate (PhP)-typing and phylogenetic grouping were used for the typing. Antimicrobial resistance profiles and ESBL production of all isolates were confirmed according to Clinical and Laboratory Standards Institute (CLSI) criteria. The activities of four bacteriophage cocktails (Enko-phage, SES-bacteriophage, Pyo-bacteriophage, and Intesti-bacteriophage) were determined against 142 ESBL-EC using in vitro spot tests. According to this, Enko-phage were active against 87.3% of the tested strains while that ratio was 81.7% for Intesti-bacteriophage, 81.7% for Pyo-bacteriophage, and 59.2% for SES-bacteriophage cocktails. Based on the contingency tests, the phage cocktails were observed to be statistically significantly ( p < 0.001) more effective on ESBL-EC strains belonging to phylogenetic groups D and B2. The employed phage cocktails were found to be affective against all tested resistant types. These results are promising especially for the infections that are caused by MDR pathogens that are difficult to treat. As this is a preliminary step to the potential clinical trials to be designed for the country, in vitro confirmation of their success on a MDR ESBL-EC collection should be accepted as an initial action, which is encouraging to consider clinical trials of phage therapy especially in countries which are not introduce phage therapy.

In vitro Effectiveness of Commercial Bacteriophage Cocktails on Diverse Extended-Spectrum Beta-Lactamase Producing Escherichia coli Strains

PubMed Central

Gundogdu, Aycan; Bolkvadze, Darajen; Kilic, Huseyin

2016-01-01

The objective of this study is to determine the in vitro susceptibility of Georgian bacteriophage cocktails on multidrug resistant (MDR) extended-spectrum beta-lactamase producing Escherichia coli (ESBL-EC) isolated from patients’ blood and urine cultures. A total of 615 E. coli isolates were included in this study. Phene Plate (PhP)-typing and phylogenetic grouping were used for the typing. Antimicrobial resistance profiles and ESBL production of all isolates were confirmed according to Clinical and Laboratory Standards Institute (CLSI) criteria. The activities of four bacteriophage cocktails (Enko-phage, SES-bacteriophage, Pyo-bacteriophage, and Intesti-bacteriophage) were determined against 142 ESBL-EC using in vitro spot tests. According to this, Enko-phage were active against 87.3% of the tested strains while that ratio was 81.7% for Intesti-bacteriophage, 81.7% for Pyo-bacteriophage, and 59.2% for SES-bacteriophage cocktails. Based on the contingency tests, the phage cocktails were observed to be statistically significantly (p < 0.001) more effective on ESBL-EC strains belonging to phylogenetic groups D and B2. The employed phage cocktails were found to be affective against all tested resistant types. These results are promising especially for the infections that are caused by MDR pathogens that are difficult to treat. As this is a preliminary step to the potential clinical trials to be designed for the country, in vitro confirmation of their success on a MDR ESBL-EC collection should be accepted as an initial action, which is encouraging to consider clinical trials of phage therapy especially in countries which are not introduce phage therapy. PMID:27857711

Isolation and characterisation of lytic bacteriophages of Klebsiella pneumoniae and Klebsiella oxytoca.

PubMed

Karumidze, Natia; Kusradze, Ia; Rigvava, Sophio; Goderdzishvili, Marine; Rajakumar, Kumar; Alavidze, Zemphira

2013-03-01

Klebsiella bacteria have emerged as an increasingly important cause of community-acquired nosocomial infections. Extensive use of broad-spectrum antibiotics in hospitalised patients has led to both increased carriage of Klebsiella and the development of multidrug-resistant strains that frequently produce extended-spectrum β-lactamases and/or other defences against antibiotics. Many of these strains are highly virulent and exhibit a strong propensity to spread. In this study, six lytic Klebsiella bacteriophages were isolated from sewage-contaminated river water in Georgia and characterised as phage therapy candidates. Two of the phages were investigated in greater detail. Biological properties, including phage morphology, nucleic acid composition, host range, growth phenotype, and thermal and pH stability were studied for all six phages. Limited sample sequencing was performed to define the phylogeny of the K. pneumoniae- and K. oxytoca-specific bacteriophages vB_Klp_5 and vB_Klox_2, respectively. Both of the latter phages had large burst sizes, efficient rates of adsorption and were stable under different adverse conditions. Phages reported in this study are double-stranded DNA bacterial viruses belonging to the families Podoviridae and Siphoviridae. One or more of the six phages was capable of efficiently lysing ~63 % of Klebsiella strains comprising a collection of 123 clinical isolates from Georgia and the United Kingdom. These phages exhibit a number of properties indicative of potential utility in phage therapy cocktails.

Guidelines for Bacteriophage Product Certification.

PubMed

Fauconnier, Alan

2018-01-01

Following decades in the wilderness, bacteriophage therapy is now appearing as a credible antimicrobial strategy. However, this reemerging therapy does not rekindle without raising sensitive regulatory concerns. Indeed, whereas the European regulatory framework has been basically implemented to tackle ready-to-use pharmaceuticals produced on a large scale, bacteriophage therapy relies on a dynamic approach requiring a regulation on personalized medicine, nonexistent at present. Because of this, no guideline are currently available for addressing the scientific and regulatory issues specifically related to phage therapy medicinal products (PTMP).Pending to the implementation of an appropriate regulatory framework and to the development of ensuing guidelines, several avenues which might lead to PTMP regulatory compliance are explored here. Insights might come from the multi-strain dossier approach set up for particular animal vaccines, from the homologous group concept developed for the allergen products or from the licensing process for veterinary autogenous vaccines. Depending on national legislations, customized preparations prescribed as magistral formulas or to be used on a named-patient basis are possible regulatory approaches to be considered. However, these schemes are not optimal and should thus be regarded as transitional.

Bacteriophages for detection and control of bacterial pathogens in food and food-processing environment.

PubMed

Brovko, Lubov Y; Anany, Hany; Griffiths, Mansel W

2012-01-01

This chapter presents recent advances in bacteriophage research and their application in the area of food safety. Section 1 describes general facts on phage biology that are relevant to their application for control and detection of bacterial pathogens in food and environmental samples. Section 2 summarizes the recently acquired data on application of bacteriophages to control growth of bacterial pathogens and spoilage organisms in food and food-processing environment. Section 3 deals with application of bacteriophages for detection and identification of bacterial pathogens. Advantages of bacteriophage-based methods are presented and their shortcomings are discussed. The chapter is intended for food scientist and food product developers, and people in food inspection and health agencies with the ultimate goal to attract their attention to the new developing technology that has a tremendous potential in providing means for producing wholesome and safe food. Copyright © 2012 Elsevier Inc. All rights reserved.

Structure of the Cell Wall of Bacillus stearothermophilus: Mode of Action of a Thermophilic Bacteriophage Lytic Enzyme

PubMed Central

Welker, N. E.

1971-01-01

The mode of action of a bacteriophage lytic enzyme on cell walls of Bacillus stearothermophilus (NCA 1503-4R) has been investigated. The enzyme is an endopeptidase which catalyzes the hydrolysis of the l-alanyl-d-glutamyl linkage in peptide subunits of the cell wall peptidoglycan. Preliminary studies on the soluble components in lytic cell wall digests indicate that the glycan moiety is composed of alternating glucosamine and muramic acid; one half of the muramic acid residues contain the tripeptide, l-alanyl-d-glutamyldiaminopimelic acid, and the remaining residues contain the tetrapeptide, l-alanyl-d-glutamyldiaminopimeyl-d-alanine. Almost one half of the peptide subunits are involved in cross-linkages of chemotype I. A structure for the cell wall peptidoglycan is proposed in the light of these findings. PMID:4255338

Co-option of bacteriophage lysozyme genes by bivalve genomes.

PubMed

Ren, Qian; Wang, Chunyang; Jin, Min; Lan, Jiangfeng; Ye, Ting; Hui, Kaimin; Tan, Jingmin; Wang, Zheng; Wyckoff, Gerald J; Wang, Wen; Han, Guan-Zhu

2017-01-01

Eukaryotes have occasionally acquired genetic material through horizontal gene transfer (HGT). However, little is known about the evolutionary and functional significance of such acquisitions. Lysozymes are ubiquitous enzymes that degrade bacterial cell walls. Here, we provide evidence that two subclasses of bivalves (Heterodonta and Palaeoheterodonta) acquired a lysozyme gene via HGT, building on earlier findings. Phylogenetic analyses place the bivalve lysozyme genes within the clade of bacteriophage lysozyme genes, indicating that the bivalves acquired the phage-type lysozyme genes from bacteriophages, either directly or through intermediate hosts. These bivalve lysozyme genes underwent dramatic structural changes after their co-option, including intron gain and fusion with other genes. Moreover, evidence suggests that recurrent gene duplication occurred in the bivalve lysozyme genes. Finally, we show the co-opted lysozymes exhibit a capacity for antibacterial action, potentially augmenting the immune function of related bivalves. This represents an intriguing evolutionary strategy in the eukaryote-microbe arms race, in which the genetic materials of bacteriophages are co-opted by eukaryotes, and then used by eukaryotes to combat bacteria, using a shared weapon against a common enemy. © 2017 The Authors.

Two-Stage Dynamics of In Vivo Bacteriophage Genome Ejection

NASA Astrophysics Data System (ADS)

Chen, Yi-Ju; Wu, David; Gelbart, William; Knobler, Charles M.; Phillips, Rob; Kegel, Willem K.

2018-04-01

Biopolymer translocation is a key step in viral infection processes. The transfer of information-encoding genomes allows viruses to reprogram the cell fate of their hosts. Constituting 96% of all known bacterial viruses [A. Fokine and M. G. Rossmann, Molecular architecture of tailed double-stranded DNA phages, Bacteriophage 4, e28281 (2014)], the tailed bacteriophages deliver their DNA into host cells via an "ejection" process, leaving their protein shells outside of the bacteria; a similar scenario occurs for mammalian viruses like herpes, where the DNA genome is ejected into the nucleus of host cells, while the viral capsid remains bound outside to a nuclear-pore complex. In light of previous experimental measurements of in vivo bacteriophage λ ejection, we analyze here the physical processes that give rise to the observed dynamics. We propose that, after an initial phase driven by self-repulsion of DNA in the capsid, the ejection is driven by anomalous diffusion of phage DNA in the crowded bacterial cytoplasm. We expect that this two-step mechanism is general for phages that operate by pressure-driven ejection, and we discuss predictions of our theory to be tested in future experiments.

Control of Listeria monocytogenes growth in soft cheeses by bacteriophage P100.

PubMed

Silva, Elaine Nóbrega Gibson; Figueiredo, Ana Cláudia Leite; Miranda, Fernanda Araújo; de Castro Almeida, Rogeria Comastri

2014-01-01

The purpose of this study was to determine the effect of bacteriophage P100 on strains of Listeria monocytogenes in artificially inoculated soft cheeses. A mix of L. monocytogenes 1/2a and Scott A was inoculated in Minas Frescal and Coalho cheeses (approximately 10(5) cfu/g) with the bacteriophage added thereafter (8.3 × 10(7) PFU/g). Samples were analyzed immediately, and then stored at 10 °C for seven days. At time zero, 30 min post-infection, the bacteriophage P100 reduced L. monocytogenes counts by 2.3 log units in Minas Frescal cheese and by 2.1 log units in Coalho cheese, compared to controls without bacteriophage. However, in samples stored under refrigeration for seven days, the bacteriophage P100 was only weakly antilisterial, with the lowest decimal reduction (DR) for the cheeses: 1.0 log unit for Minas Frescal and 0.8 log units for Coalho cheese. The treatment produced a statistically significant decrease in the counts of viable cells (p < 0.05) and in all assays performed, we observed an increase of approximately one log cycle in the number of viable cells of L. monocytogenes in the samples under refrigeration for seven days. Moreover, a smaller effect of phages was observed. These results, along with other published data, indicate that the effectiveness of the phage treatment depends on the initial concentration of L. monocytogenes, and that a high concentration of phages per unit area is required to ensure sustained inactivation of target pathogens on food surfaces.

Antimicrobial bacteriophage-derived proteins and therapeutic applications

USDA-ARS?s Scientific Manuscript database

Antibiotics have the remarkable power to control bacterial infections. Unfortunately, widespread use, whether regarded as prudent or not, has favored the emergence and persistence of antibiotic resistant strains of human pathogenic bacteria, resulting in a global health threat. Bacteriophages (pha...

Isolation and Genome Characterization of the Virulent Staphylococcus aureus Bacteriophage SA97

PubMed Central

Chang, Yoonjee; Shin, Hakdong; Lee, Ju-Hoon; Park, Chul Jong; Paik, Soon-Young; Ryu, Sangryeol

2015-01-01

A novel bacteriophage that infects S. aureus, SA97, was isolated and characterized. The phage SA97 belongs to the Siphoviridae family, and the cell wall teichoic acid (WTA) was found to be a host receptor of the phage SA97. Genome analysis revealed that SA97 contains 40,592 bp of DNA encoding 54 predicted open reading frames (ORFs), and none of these genes were related to virulence or drug resistance. Although a few genes associated with lysogen formation were detected in the phage SA97 genome, the phage SA97 produced neither lysogen nor transductant in S. aureus. These results suggest that the phage SA97 may be a promising candidate for controlling S. aureus. PMID:26437428

Hexagonally packed DNA within bacteriophage T7 stabilized by curvature stress.

PubMed Central

Odijk, T

1998-01-01

A continuum computation is proposed for the bending stress stabilizing DNA that is hexagonally packed within bacteriophage T7. Because the inner radius of the DNA spool is rather small, the stress of the curved DNA genome is strong enough to balance its electrostatic self-repulsion so as to form a stable hexagonal phase. The theory is in accord with the microscopically determined structure of bacteriophage T7 filled with DNA within the experimental margin of error. PMID:9726924

Evaluation of consumers’ perception and willingness to pay for bacteriophage treated fresh produce

PubMed Central

Naanwaab, Cephas; Yeboah, Osei-Agyeman; Ofori Kyei, Foster; Sulakvelidze, Alexander; Goktepe, Ipek

2014-01-01

Food-borne illnesses caused by bacteria such as enterohemorrhagic E. coli and Salmonella spp. take a significant toll on American consumers’ health; they also cost the United States an estimated $77.7 billion annually in health care and other losses.1 One novel modality for improving the safety of foods is application of lytic bacteriophages directly onto foods, in order to reduce or eliminate their contamination with specific foodborne bacterial pathogens. The main objective of this study was to assess consumers’ perception about foods treated with bacteriophages and examine their willingness to pay (WTP) an additional amount (10–30 cents/lb) for bacteriophage-treated fresh produce. The study utilized a survey questionnaire administered by telephone to consumers in 4 different states: Alabama, Georgia, North Carolina, and South Carolina. The results show that consumers are in general willing to pay extra for bacteriophage-treated fresh produce if it improves their food safety. However, income, race, and the state where a consumer lives are significant determinants in their WTP. PMID:26713224

Dietary supplementation with docosahexaenoic acid (DHA) improves seminal antioxidant status and decreases sperm DNA fragmentation.

PubMed

Martínez-Soto, Juan Carlos; Domingo, Joan Carles; Cordobilla, Begoña; Nicolás, María; Fernández, Laura; Albero, Pilar; Gadea, Joaquín; Landeras, José

2016-12-01

The purpose of this study was to evaluate the effect of docosahexaenoic acid (DHA) dietary supplementation on semen quality, fatty acid composition, antioxidant capacity, and DNA fragmentation. In this randomized, double blind, placebo-controlled, parallel-group study, 74 subjects were recruited and randomly assigned to either the placebo group (n=32) or to the DHA group (n=42) to consume three 500-mg capsules of oil per day over 10 weeks. The placebo group received 1,500 mg/day of sunflower oil and the DHA group 1,500 mg/day of DHA-enriched oil. Seminal parameters (semen volume, sperm concentration, motility, morphology, and vitality), total antioxidant capacity, deoxyribonucleic acid fragmentation, and lipid composition were evaluated prior to the treatment and after 10 weeks. Finally, 57 subjects were included in the study with 25 in the placebo group and 32 in the DHA group. No differences were found in traditional sperm parameters or lipid composition of the sperm membrane after treatment. However, an increase in DHA and Omega-3 fatty acid content in seminal plasma, an improvement in antioxidant status, and a reduction in the percentage of spermatozoa with deoxyribonucleic acid damage were observed in the DHA group after 10 weeks of treatment.

Methods for Initial Characterization of Campylobacter jejuni Bacteriophages.

PubMed

Sørensen, Martine Camilla Holst; Gencay, Yilmaz Emre; Brøndsted, Lone

2017-01-01

Here we describe an initial characterization of Campylobacter jejuni bacteriophages by host range analysis, genome size determination by pulsed-field gel electrophoresis, and receptor-type identification by screening mutants for phage sensitivity.

Marine Transducing Bacteriophage Attacking a Luminous Bacterium

PubMed Central

Keynan, Alex; Nealson, Kenneth; Sideropoulos, Henry; Hastings, J. W.

1974-01-01

The isolation and partial characterization of a marine bacteriophage attacking a strain of luminous bacteria is described, including some physical, biological, and genetic properties. It is a DNA phage of density of 1.52 with a long flexible tail and an apparently icosohedral head. With respect to stability in suspension, it has a rather specific requirement for the sodium ion in high concentration; it is further stabilized by the addition of calcium and magnesium ions. These same ions are likewise all required for both good plating efficiency and plaque uniformity. Although it goes through a typical lytic growth cycle (about 45 min), with a burst size of 100, and no stable lysogens have been isolated, it is nevertheless a transducing phage specifically for the tryptophan region, transducing several, but not all, independently isolated Trp− auxotrophs to protrophy. No other auxotrophs of a variety of amino acids were transduced by this phage to prototrophy. Phage infection does not change the normal expression of the luminescent system, and light remains at near normal levels until cell lysis occurs. Images PMID:16789143

Isolation and in vitro evaluation of bacteriophages against MDR-bacterial isolates from septic wound infections.

PubMed

Pallavali, Roja Rani; Degati, Vijaya Lakshmi; Lomada, Dakshayani; Reddy, Madhava C; Durbaka, Vijaya Raghava Prasad

2017-01-01

Multi-drug resistance has become a major problem for the treatment of pathogenic bacterial infections. The use of bacteriophages is an attractive approach to overcome the problem of drug resistance in several pathogens that cause fatal diseases. Our study aimed to isolate multi drug resistant bacteria from patients with septic wounds and then isolate and apply bacteriophages in vitro as alternative therapeutic agents. Pus samples were aseptically collected from Rajiv Gandhi Institute of Medical Science (RIMS), Kadapa, A.P., and samples were analyzed by gram staining, evaluating morphological characteristics, and biochemical methods. MDR-bacterial strains were collected using the Kirby-Bauer disk diffusion method against a variety of antibiotics. Bacteriophages were collected and tested in vitro for lytic activity against MDR-bacterial isolates. Analysis of the pus swab samples revealed that the most of the isolates detected had Pseudomonas aeruginosa as the predominant bacterium, followed by Staphylococcus aureus, Klebsiella pneumoniae and Escherichia coli. Our results suggested that gram-negative bacteria were more predominant than gram-positive bacteria in septic wounds; most of these isolates were resistant to ampicillin, amoxicillin, penicillin, vancomycin and tetracycline. All the gram-positive isolates (100%) were multi-drug resistant, whereas 86% of the gram-negative isolates had a drug resistant nature. Further bacteriophages isolated from sewage demonstrated perfect lytic activity against the multi-drug resistant bacteria causing septic wounds. In vitro analysis of the isolated bacteriophages demonstrated perfect lysis against the corresponding MDR-bacteria, and these isolated phages may be promising as a first choice for prophylaxis against wound sepsis, Moreover, phage therapy does not enhance multi-drug resistance in bacteria and could work simultaneously on a wide variety of MDR-bacteria when used in a bacteriophage cocktail. Hence, our results suggest

Evaluation of the broad-spectrum lytic capability of bacteriophage cocktails against various Salmonella serovars and their effects on weaned pigs infected with Salmonella Typhimurium.

PubMed

Seo, Byoung-Joo; Song, Eu-Tteum; Lee, Kichan; Kim, Jong-Won; Jeong, Chang-Gi; Moon, Sung-Hyun; Son, Jee Soo; Kang, Sang Hyeon; Cho, Ho-Seong; Jung, Byeong Yeal; Kim, Won-Il

2018-06-06

The broad-spectrum lytic capability of Salmonella bacteriophages against various Salmonella species was evaluated to determine their potential as an alternative for antibiotics, and the safety and preventive effects of the bacteriophages were assessed on mice and pigs. Four bacteriophage cocktails were prepared using 13 bacteriophages, and the lytic capability of the four bacteriophage cocktails was tested using Salmonella reference strains and field isolates. Bacteriophage cocktail C (SEP-1, SGP-1, STP-1, SS3eP-1, STP-2, SChP-1, SAP-1, SAP-2; ≥10 9 pfu/ml) showed the best lytic activity against the Salmonella reference strains (100% of 34) and field isolates (92.5% of 107). Fifty mice were then orally inoculated with bacteriophage cocktail C to determine the distribution of bacteriophages in various organs, blood and feces. The effects of bacteriophages on Salmonella infection in weaned pigs (n=15) were also evaluated through an experimental challenge with Salmonella Typhimurium after treatment with bacteriophage cocktail C. All mice exhibited distribution of the bacteriophages in all organs, blood and feces until 15 days post infection (dpi). After 35 dpi, bacteriophages were not detected in any of these specimens. As demonstrated in a pig challenge study, treatment with bacteriophage cocktail C reduced the level of Salmonella shedding in feces. The metagenomic analyses of these pig feces also revealed that bacteriophage treatment decreased the number of species of the Enterobacteriaceae family without significant disturbance to the normal fecal flora. This study showed that bacteriophages effectively controlled Salmonella in a pig challenge model and could be a good alternative for antibiotics to control Salmonella infection.

Modeling removal of bacteriophages MS2 and PRD1 by dune recharge at Castricum, Netherlands

NASA Astrophysics Data System (ADS)

Schijven, Jack F.; Hoogenboezem, Wim; Hassanizadeh, S. Majid; Peters, Jos H.

1999-04-01

Removal of model viruses by dune recharge was studied at a field site in the dune area of Castricum, Netherlands. Recharge water was dosed with bacteriophages MS2 and PRD1 for 11 days at a constant concentration in a 10- by 15-m compartment that was isolated in a recharge basin. Breakthrough was monitored for 120 days at six wells with their screens along a flow line. Concentrations of both phages were reduced about 3 log10 within the first 2.4 m and another 5 log10 in a linear fashion within the following 27 m. A model accounting for one-site kinetic attachment as well as first-order inactivation was employed to simulate the bacteriophage breakthrough curves. The major removal process was found to be attachment of the bacteriophages. Detachment was very slow. After passage of the pulse of dosed bacteriophages, there was a long tail whose slope corresponds to the inactivation rate coefficient of 0.07-0.09 day-1 for attached bacteriophages. The end of the rising and the start of the declining limbs of the breakthrough curves could not be simulated completely, probably because of an as yet unknown process.

40 CFR 180.1301 - Escherichia coli O157:H7 specific bacteriophages; temporary exemption from the requirement of a...

Code of Federal Regulations, 2011 CFR

2011-07-01

... bacteriophages; temporary exemption from the requirement of a tolerance. 180.1301 Section 180.1301 Protection of... bacteriophages; temporary exemption from the requirement of a tolerance. A temporary exemption from the requirement of a tolerance is established for residues of lytic bacteriophages that are specific to...

40 CFR 180.1301 - Escherichia coli O157:H7 specific bacteriophages; temporary exemption from the requirement of a...

Code of Federal Regulations, 2014 CFR

2014-07-01

... bacteriophages; temporary exemption from the requirement of a tolerance. 180.1301 Section 180.1301 Protection of... bacteriophages; temporary exemption from the requirement of a tolerance. A temporary exemption from the requirement of a tolerance is established for residues of lytic bacteriophages that are specific to...

40 CFR 180.1301 - Escherichia coli O157:H7 specific bacteriophages; temporary exemption from the requirement of a...

Code of Federal Regulations, 2013 CFR

2013-07-01

... bacteriophages; temporary exemption from the requirement of a tolerance. 180.1301 Section 180.1301 Protection of... bacteriophages; temporary exemption from the requirement of a tolerance. A temporary exemption from the requirement of a tolerance is established for residues of lytic bacteriophages that are specific to...

40 CFR 180.1301 - Escherichia coli O157:H7 specific bacteriophages; temporary exemption from the requirement of a...

Code of Federal Regulations, 2012 CFR

2012-07-01

... bacteriophages; temporary exemption from the requirement of a tolerance. 180.1301 Section 180.1301 Protection of... bacteriophages; temporary exemption from the requirement of a tolerance. A temporary exemption from the requirement of a tolerance is established for residues of lytic bacteriophages that are specific to...

A review of current methods using bacteriophages in live animals, food and animal products intended for human consumption.

PubMed

Cooper, Ian R

2016-11-01

Bacteriophages are utilised in the food industry as biocontrol agents to reduce the load of bacteria, and thus reduce potential for human infection. This review focuses on current methods using bacteriophages within the food chain. Limitations of research will be discussed, and the potential for future food-based bacteriophage research. Copyright © 2016 Elsevier B.V. All rights reserved.

Removal of adenovirus, calicivirus, and bacteriophages by conventional drinking water treatment.

PubMed

Abbaszadegan, Morteza; Monteiro, Patricia; Nwachuku, Nena; Alum, Absar; Ryu, Hodon

2008-02-01

This study was conducted to evaluate the removal of adenovirus, feline calicivirus (FCV), and bacteriophages MS-2, fr, PRD-1, and Phi X-174 during conventional drinking water treatment using ferric chloride as a coagulant. Adenovirus and FCV were removed to a greater extent than PRD-1 and Phi X-174, indicating that these bacteriophages may be appropriate surrogates for both adenovirus and FCV. Of the four bacteriophages studied in the pilot plant, MS-2 was removed to the greatest extent (5.1 log), followed by fr (4.9 log), PRD-1 (3.5 log), and Phi X-174 (1.3 log). The virus removal trend in the pilot-scale testing was similar to the bench-scale testing; however, the bench-scale testing seemed to provide a conservative estimate of the pilot plant performance. In the pilot-scale testing, MS-2 and fr were removed with the greatest efficiency during filtration, whereas PRD-1 and Phi X-174 showed the greatest removal during sedimentation.

21 CFR 866.2050 - Staphylococcal typing bacteriophage.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Staphylococcal typing bacteriophage. 866.2050 Section 866.2050 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2050...

21 CFR 866.2050 - Staphylococcal typing bacteriophage.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Staphylococcal typing bacteriophage. 866.2050 Section 866.2050 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2050...

21 CFR 866.2050 - Staphylococcal typing bacteriophage.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Staphylococcal typing bacteriophage. 866.2050 Section 866.2050 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2050...

A simple and novel modification of comet assay for determination of bacteriophage mediated bacterial cell lysis.

PubMed

Khairnar, Krishna; Sanmukh, Swapnil; Chandekar, Rajshree; Paunikar, Waman

2014-07-01

The comet assay is the widely used method for in vitro toxicity testing which is also an alternative to the use of animal models for in vivo testing. Since, its inception in 1984 by Ostling and Johansson, it is being modified frequently for a wide range of application. In spite of its wide applicability, unfortunately there is no report of its application in bacteriophages research. In this study, a novel application of comet assay for the detection of bacteriophage mediated bacterial cell lysis was described. The conventional methods in bacteriophage research for studying bacterial lysis by bacteriophages are plaque assay method. It is time consuming, laborious and costly. The lytic activity of bacteriophage devours the bacterial cell which results in the release of bacterial genomic material that gets detected by ethidium bromide staining method by the comet assay protocol. The objective of this study was to compare efficacy of comet assay with different assay used to study phage mediated bacterial lysis. The assay was performed on culture isolates (N=80 studies), modified comet assay appear to have relatively higher sensitivity and specificity than other assay. The results of the study showed that the application of comet assay can be an economical, time saving and less laborious alternative to conventional plaque assay for the detection of bacteriophage mediated bacterial cell lysis. Copyright © 2014 Elsevier B.V. All rights reserved.

Bacteriophage use to control Salmonella biofilm on surfaces present in chicken slaughterhouses.

PubMed

Garcia, Keila Carolina de Ornellas Dutka; Corrêa, Isadora Mainieri de Oliveira; Pereira, Larissa Quinto; Silva, Tarcísio Macedo; Mioni, Mateus de Souza Ribeiro; Izidoro, Ana Carolina de Moraes; Bastos, Igor Henrique Vellano; Gonçalves, Guilherme Augusto Marietto; Okamoto, Adriano Sakai; Andreatti Filho, Raphael Lucio

2017-09-01

Foodborne diseases represent a major risk to public health worldwide. Pathogenic bacteria can live in the form of biofilm within the food industry, providing a permanent source of contamination. The aim of this study was to evaluate the influence of the types of adhesion surfaces on Salmonella biofilm formation at eight different times, and analyze the action time of a bacteriophage pool on established biofilms. Most of the samples used were classified as weak biofilm producers, with serovars Enteritidis and Heidelberg showing the highest frequency of biofilm formation. Glass and stainless steel surfaces significantly favored biofilm formation at 60 and 36 h of incubation respectively, but the polyvinyl chloride surface did not favor biofilm production, suggesting that the type of material may interfere with production. The bacteriophage pool action period focused on 3 h, but treatment of 9 h on glass surface biofilms was superior to other treatments because it affected the largest number of samples. These results suggests that some surface types and Salmonella serotypes may promote biofilm formation and indicate bacteriophages as an alternative to control biofilms. But further studies are required to prove the effectiveness and safety of bacteriophage therapy as an alternative in the antimicrobial control in the processing plants. © 2017 Poultry Science Association Inc.

Susceptibility of Escherichia coli isolated from uteri of postpartum dairy cows to antibiotic and environmental bacteriophages. Part II: In vitro antimicrobial activity evaluation of a bacteriophage cocktail and several antibiotics.

PubMed

Santos, T M A; Gilbert, R O; Caixeta, L S; Machado, V S; Teixeira, L M; Bicalho, R C

2010-01-01

The use of pathogenic-specific antimicrobials, as proposed by bacteriophage therapy, is expected to reduce the incidence of resistance development. Eighty Escherichia coli isolated from uteri of Holstein dairy cows were phenotypically characterized for antimicrobial resistance to ampicillin, ceftiofur, chloramphenicol, florfenicol, spectinomycin, streptomycin, and tetracycline by broth microdilution method. The lytic activity of a bacteriophage cocktail against all isolates was performed by a similar method. Additionally, the effect of different concentrations of antimicrobials and multiplicities of infections (MOI) of the bacteriophage cocktail on E. coli growth curve was measured. Isolates exhibited resistance to ampicillin (33.7%), ceftiofur (1.2%), chloramphenicol (100%), and florfenicol (100%). All strains were resistant to at least 2 of the antimicrobial agents tested; multidrug resistance (>or=3 of 7 antimicrobials tested) was observed in 35% of E. coli isolates. The major multidrug resistance profile was found for ampicillin-chloramphenicol-florfenicol, which was observed in more than 96.4% of the multidrug-resistant isolates. The bacteriophage cocktail preparation showed strong antimicrobial activity against multidrug-resistant E. coli. Multiplicity of infection as low as 10(-4) affected the growth of the E. coli isolates. The ratio of 10 bacteriophage particles per bacterial cell (MOI=10(1)) was efficient in inhibiting at least 50% of all isolates. Higher MOI should be tested in future in vitro studies to establish ratios that completely inhibit bacterial growth during longer periods. All isolates resistant to florfenicol were resistant to chloramphenicol and, because florfenicol was recently introduced into veterinary clinics, this finding suggests that the selection pressure of chloramphenicol, as well as other antimicrobials, may still play a relevant role in the emergence and dissemination of florfenicol resistance in E. coli. The bacteriophage

In vitro design of a novel lytic bacteriophage cocktail with therapeutic potential against organisms causing diabetic foot infections.

PubMed

Mendes, João J; Leandro, Clara; Mottola, Carla; Barbosa, Raquel; Silva, Filipa A; Oliveira, Manuela; Vilela, Cristina L; Melo-Cristino, José; Górski, Andrzej; Pimentel, Madalena; São-José, Carlos; Cavaco-Silva, Patrícia; Garcia, Miguel

2014-08-01

In patients with diabetes mellitus, foot infections pose a significant risk. These are complex infections commonly caused by Staphylococcus aureus, Pseudomonas aeruginosa and Acinetobacter baumannii, all of which are potentially susceptible to bacteriophages. Here, we characterized five bacteriophages that we had determined previously to have antimicrobial and wound-healing potential in chronic S. aureus, P. aeruginosa and A. baumannii infections. Morphological and genetic features indicated that the bacteriophages were lytic members of the family Myoviridae or Podoviridae and did not harbour any known bacterial virulence genes. Combinations of the bacteriophages had broad host ranges for the different target bacterial species. The activity of the bacteriophages against planktonic cells revealed effective, early killing at 4 h, followed by bacterial regrowth to pre-treatment levels by 24 h. Using metabolic activity as a measure of cell viability within established biofilms, we found significant cell impairment following bacteriophage exposure. Repeated treatment every 4 h caused a further decrease in cell activity. The greatest effects on both planktonic and biofilm cells occurred at a bacteriophage : bacterium input multiplicity of 10. These studies on both planktonic cells and established biofilms allowed us to better evaluate the effects of a high input multiplicity and a multiple-dose treatment protocol, and the findings support further clinical development of bacteriophage therapy. © 2014 The Authors.

Near infrared fluorescence-based bacteriophage particles for ratiometric pH imaging.

PubMed

Hilderbrand, Scott A; Kelly, Kimberly A; Niedre, Mark; Weissleder, Ralph

2008-08-01

Fluorogenic imaging agents emitting in the near-infrared are becoming important research tools for disease investigation in vivo. Often pathophysiological states such as cancer and cystic fibrosis are associated with disruptions in acid/base homeostasis. The development of optical sensors for pH imaging would facilitate the investigation of these diseased conditions. In this report, the design and synthesis of a ratiometric near-infrared emitting probe for pH quantification is detailed. The pH-responsive probe is prepared by covalent attachment of pH-sensitive and pH-insensitive fluorophores to a bacteriophage particle scaffold. The pH-responsive cyanine dye, HCyC-646, used to construct the probe, has a fluorogenic pKa of 6.2, which is optimized for visualization of acidic pH often associated with tumor hypoxia and other diseased states. Incorporation of pH-insensitive reference dyes enables the ratiometric determination of pH independent of the probe concentration. With the pH-responsive construct, measurement of intracellular pH and accurate determination of pH through optically diffuse biological tissue is demonstrated.

Bacteriophages and medical oncology: targeted gene therapy of cancer.

PubMed

Bakhshinejad, Babak; Karimi, Marzieh; Sadeghizadeh, Majid

2014-08-01

Targeted gene therapy of cancer is of paramount importance in medical oncology. Bacteriophages, viruses that specifically infect bacterial cells, offer a variety of potential applications in biomedicine. Their genetic flexibility to go under a variety of surface modifications serves as a basis for phage display methodology. These surface manipulations allow bacteriophages to be exploited for targeted delivery of therapeutic genes. Moreover, the excellent safety profile of these viruses paves the way for their potential use as cancer gene therapy platforms. The merge of phage display and combinatorial technology has led to the emergence of phage libraries turning phage display into a high throughput technology. Random peptide libraries, as one of the most frequently used phage libraries, provide a rich source of clinically useful peptide ligands. Peptides are known as a promising category of pharmaceutical agents in medical oncology that present advantages such as inexpensive synthesis, efficient tissue penetration and the lack of immunogenicity. Phage peptide libraries can be screened, through biopanning, against various targets including cancer cells and tissues that results in obtaining cancer-homing ligands. Cancer-specific peptides isolated from phage libraries show huge promise to be utilized for targeting of various gene therapy vectors towards malignant cells. Beyond doubt, bacteriophages will play a more impressive role in the future of medical oncology.

Use of bacteriophage to prevent Pseudomonas aeruginosa contamination and fouling in Jet A aviation fuel.

PubMed

Bojanowski, Caitlin L; Crookes-Goodson, Wendy J; Robinson, Jayne B

2016-11-01

In the present study, the use of bacteriophages to prevent growth and/or biofouling by Pseudomonas aeruginosa PAO1 was investigated in microcosms containing Jet A aviation fuel as the carbon source. Bacteriophages were found to be effective at preventing biofilm formation but did not always prevent planktonic growth in the microcosms. This result was at odds with experiments conducted in nutrient-rich medium, demonstrating the necessity to test antimicrobial and antifouling strategies under conditions as near as possible to the 'real world'. The success of the bacteriophages at preventing biofilm formation makes them potential candidates as antifouling agents for fuel systems.

Engineering of M13 Bacteriophage for Development of Tissue Engineering Materials.

PubMed

Jin, Hyo-Eon; Lee, Seung-Wuk

2018-01-01

M13 bacteriophages have several qualities that make them attractive candidates as building blocks for tissue regenerating scaffold materials. Through genetic engineering, a high density of functional peptides and proteins can be simultaneously displayed on the M13 bacteriophage's outer coat proteins. The resulting phage can self-assemble into nanofibrous network structures and can guide the tissue morphogenesis through proliferation, differentiation and apoptosis. In this manuscript, we will describe methods to develop major coat-engineered M13 phages as a basic building block and aligned tissue-like matrices to develop regenerative nanomaterials.

Attenuation and colloidal mobilization of bacteriophages in natural sediments under anoxic as compared to oxic conditions.

PubMed

Klitzke, Sondra; Schroeder, Jendrik; Selinka, Hans-Christoph; Szewzyk, Regine; Chorus, Ingrid

2015-06-15

Redox conditions are known to affect the fate of viruses in porous media. Several studies report the relevance of colloid-facilitated virus transport in the subsurface, but detailed studies on the effect of anoxic conditions on virus retention in natural sediments are still missing. Therefore, we investigated the fate of viruses in natural flood plain sediments with different sesquioxide contents under anoxic conditions by considering sorption to the solid phase, sorption to mobilized colloids, and inactivation in the aqueous phase. Batch experiments were conducted under oxic and anoxic conditions at pH values between 5.1 and 7.6, using bacteriophages MS2 and PhiX174 as model viruses. In addition to free and colloid-associated bacteriophages, dissolved and colloidal concentrations of Fe, Al and organic C as well as dissolved Ca were determined. Results showed that regardless of redox conditions, bacteriophages did not adsorb to mobilized colloids, even under favourable charge conditions. Under anoxic conditions, attenuation of bacteriophages was dominated by sorption over inactivation, with MS2 showing a higher degree of sorption than PhiX174. Inactivation in water was low under anoxic conditions for both bacteriophages with about one log10 decrease in concentration during 16 h. Increased Fe/Al concentrations and a low organic carbon content of the sediment led to enhanced bacteriophage removal under anoxic conditions. However, even in the presence of sufficient Fe/A-(hydr)oxides on the solid phase, bacteriophage sorption was low. We presume that organic matter may limit the potential retention of sesquioxides in anoxic sediments and should thus be considered for the risk assessment of virus breakthrough in the subsurface. Copyright © 2015 Elsevier B.V. All rights reserved.

Bacteriophages infecting Bacteroides as a marker for microbial source tracking.

PubMed

Jofre, Joan; Blanch, Anicet R; Lucena, Francisco; Muniesa, Maite

2014-05-15

Bacteriophages infecting certain strains of Bacteroides are amid the numerous procedures proposed for tracking the source of faecal pollution. These bacteriophages fulfil reasonably well most of the requirements identified as appropriate for a suitable marker of faecal sources. Thus, different host strains are available that detect bacteriophages preferably in water contaminated with faecal wastes corresponding to different animal species. For phages found preferably in human faecal wastes, which are the ones that have been more extensively studied, the amounts of phages found in waters contaminated with human fecal samples is reasonably high; these amounts are invariable through the time; their resistance to natural and anthropogenic stressors is comparable to that of other relatively resistant indicator of faecal pollution such us coliphages; the abundance ratios of somatic coliphages and bacteriophages infecting Bacteroides thetaiotaomicron GA17 are unvarying in recent and aged contamination; and standardised detection methods exist. These methods are easy, cost effective and provide data susceptible of numerical analysis. In contrast, there are some uncertainties regarding their geographical stability, and consequently suitable hosts need to be isolated for different geographical areas. However, a feasible method has been described to isolate suitable hosts in a given geographical area. In summary, phages infecting Bacteroides are a marker of faecal sources that in our opinion merits being included in the "toolbox" for microbial source tracking. However, further research is still needed in order to make clear some uncertainties regarding some of their characteristics and behaviour, to compare their suitability to the one of emerging methods such us targeting Bacteroidetes by qPCR assays; or settling molecular methods for their determination. Copyright © 2014 Elsevier Ltd. All rights reserved.

Bacteriophage application on red meats and poultry: Effects on Salmonella population in final ground products.

PubMed

Yeh, Y; Purushothaman, P; Gupta, N; Ragnone, M; Verma, S C; de Mello, A S

2017-05-01

This research was conducted to study the effects of bacteriophage application during tumbling on Salmonella populations in ground meat and poultry. Red meat trim and poultry were inoculated with a Salmonella cocktail to result in a contamination level of 7logCFU/g in ground products. A commercial preparation containing bacteriophages S16 and Felix-O1a (FO1a) was applied during tumbling at 10 7 and 10 8 PFU/ml. Samples were held at 4°C for 6h and 18h (red meat) and 30min and 6h (poultry). Overall, bacteriophage application on trim reduced 1 and 0.8logCFU/g of Salmonella in ground beef and ground pork, respectively. For ground chicken and ground turkey, Salmonella was reduced by 1.1 and 0.9logCFU/g, respectively. This study shows that bacteriophage application during tumbling of red meat trim and poultry can provide additional Salmonella control in ground products. Copyright © 2017 Elsevier Ltd. All rights reserved.

TF1, the bacteriophage SPO1-encoded type II DNA-binding protein, is essential for viral multiplication.

PubMed

Sayre, M H; Geiduschek, E P

1988-09-01

The lytic Bacillus subtilis bacteriophage SPO1 encodes an abundant, 99-amino-acid type II DNA-binding protein, transcription factor 1 (TF1). TF1 is special in this family of procaryotic chromatin-forming proteins in its preference for hydroxymethyluracil-containing DNA, such as SPO1 DNA, and in binding with high affinity to specific sites in the SPO1 chromosome. We constructed recessive null alleles of the TF1 gene and introduced them into SPO1 chromosomes. Segregation analysis with partially diploid phage heterozygous for TF1 showed that phage bearing only these null alleles was inviable. Deletion of the nine C-proximal amino acids of TF1 prohibited phage multiplication in vivo and abolished its site-specific DNA-binding activity in vitro.

Multiplex PCR to detect bacteriophages from natural whey cultures of buffalo milk and characterisation of two phages active against Lactococcus lactis, ΦApr-1 and ΦApr-2.

PubMed

Aprea, Giuseppe; Mullan, William Michael; Murru, Nicoletta; Fitzgerald, Gerald; Buonanno, Marialuisa; Cortesi, Maria Luisa; Prencipe, Vincenza Annunziata; Migliorati, Giacomo

2017-09-30

This work investigated bacteriophage induced starter failures in artisanal buffalo Mozzarella production plants in Southern Italy. Two hundred and ten samples of whey starter cultures were screened for bacteriophage infection. Multiplex polymerase chain reaction (PCR) revealed phage infection in 28.56% of samples, all showing acidification problems during cheese making. Based on DNA sequences, bacteriophages for Lactococcus lactis (L. lactis), Lactobacillus delbruekii (L. delbruekii) and Streptococcus thermophilus (S. thermophilus) were detected. Two phages active against L. lactis, ΦApr-1 and ΦApr-2, were isolated and characterised. The genomes, approximately 31.4 kb and 31 kb for ΦApr-1 and ΦApr-2 respectively, consisted of double-stranded linear DNA with pac-type system. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS‑PAGE) showed one major structural protein of approximately 32.5 kDa and several minor proteins. This is the first report of phage isolation in buffalo milk and of the use of multiplex PCR to screen and study the diversity of phages against Lactic Acid Bacteria (LAB) strains in artisanal Water Buffalo Mozzarella starters.

Comparative Inactivation of Murine Norovirus and MS2 Bacteriophage by Peracetic Acid and Monochloramine in Municipal Secondary Wastewater Effluent.

PubMed

Dunkin, Nathan; Weng, ShihChi; Schwab, Kellogg J; McQuarrie, James; Bell, Kati; Jacangelo, Joseph G

2017-03-07

Chlorination has long been used for disinfection of municipal wastewater (MWW) effluent while the use peracetic acid (PAA) has been proposed more recently in the United States. Previous work has demonstrated the bactericidal effectiveness of PAA and monochloramine in wastewater, but limited information is available for viruses, especially ones of mammalian origin (e.g., norovirus). Therefore, a comparative assessment was performed of the virucidal efficacy of PAA and monochloramine against murine norovirus (MNV) and MS2 bacteriophage in secondary effluent MWW and phosphate buffer (PB). A suite of inactivation kinetic models was fit to the viral inactivation data. Predicted concentration-time (CT) values for 1-log 10 MS2 reduction by PAA and monochloramine in MWW were 1254 and 1228 mg-min/L, respectively. The 1-, 2-, and 3-log 10 model predicted CT values for MNV viral reduction in MWW were 32, 47, and 69 mg-min/L for PAA and 6, 13, and 28 mg-min/L for monochloramine, respectively. Wastewater treatment plant disinfection practices informed by MS2 inactivation data will likely be protective for public health but may overestimate CT values for reduction of MNV. Additionally, equivalent CT values in PB resulted in greater viral reduction which indicate that viral inactivation data in laboratory grade water may not be generalizable to MWW applications.

Effect of goethite coating and humic acid on the transport of bacteriophage PRD1 in columns of saturated sand

NASA Astrophysics Data System (ADS)

Foppen, J. W. A.; Okletey, S.; Schijven, J. F.

2006-05-01

The transport of bacteriophage PRD1, a model virus, was studied in columns containing sediment mixtures of quartz sand with goethite-coated sand and using various solutions consisting of monovalent and divalent salts and humic acid (HA). Without HA and in the absence of sand, the inactivation rate of PRD1 was found to be as low as 0.014 day - 1 (at 5 ± 3 °C), but in the presence of HA it was much lower (0.0009 day - 1 ), indicating that HA helps PRD1 to survive. When the fraction of goethite in the sediment was increased, the removal of PRD1 also increased. However, in the presence of HA, C/ C0 values of PRD1 increased by as much as 5 log units, thereby almost completely eliminating the effect of addition of goethite. The sticking efficiency was not linearly dependent on the amount of goethite added to the quartz sand; this is apparently due to surface charge heterogeneity of PRD1. Our results imply that, in the presence of dissolved organic matter (DOM), viruses can be transported for long distances thanks to two effects: attachment is poor because DOM has occupied favourable sites for attachment and inactivation of virus may have decreased. This conclusion justifies making conservative assumptions about the attachment of viruses when calculating protection zones for groundwater wells.

Molecular and chemical engineering of bacteriophages for potential medical applications.

PubMed

Hodyra, Katarzyna; Dąbrowska, Krystyna

2015-04-01

Recent progress in molecular engineering has contributed to the great progress of medicine. However, there are still difficult problems constituting a challenge for molecular biology and biotechnology, e.g. new generation of anticancer agents, alternative biosensors or vaccines. As a biotechnological tool, bacteriophages (phages) offer a promising alternative to traditional approaches. They can be applied as anticancer agents, novel platforms in vaccine design, or as target carriers in drug discovery. Phages also offer solutions for modern cell imaging, biosensor construction or food pathogen detection. Here we present a review of bacteriophage research as a dynamically developing field with promising prospects for further development of medicine and biotechnology.

[Isolation and characterization of a lytic bacteriophage from Mingyong glacier melt water].

PubMed

Li, Mingyuan; Ji, Xiuling; Wang, Baoqiang; Zhang, Qi; Lin, Lianbing; Zhang, Bing; Wei, Yunlin

2012-02-04

Glacier is a unique ecological system. This study focused on the isolation and characterization of a cold-active bateriophage from Mingyong glacier area in northwest Yunnan. Bacterial strains isolated from glacial melt water were used as host cells to isolate and purify bacteriophages by double-layer plate method. The morphology of the isolated phages and their host strains were observed by electron microscope. Restriction fragment length polymorphism (RFLP) analysis of genomic DNA, constituent proteins and physiological analysis of the bacteriophages were further carried out to characterize the phages. A lytic cold-active bacteriophage, designated as MYSP03, was isolated from Mingyong glacier. Its host strain MYB03 was identified as a member of genus Flavobacterium, based on the 16S rRNA sequence analysis. The bacteriophage MYSP03 has a isometric head (about 72 nm in diameter) and a long tail (about 240 nm in length and 10 nm in width), but no envelope was detected. Physiological analysis results showed that MYSP03 had infection activity at 4 degrees C, and clear and transparent plaques were formed on double-layer plates between 4 and 20 degrees C. Its optimum infection temperature was 10 degrees C and optimal pH 9.4, respectively. It is insensitive to chloroform. Furthermore, the genome of MYSP03 consists of double-stranded DNA and is approximately 66 kb.

Characterization of a novel lytic bacteriophage from an industrial Escherichia coli fermentation process and elimination of virulence using a heterologous CRISPR-Cas9 system.

PubMed

Halter, Mathew C; Zahn, James A

2018-03-01

Bacterial-bacteriophage interactions are a well-studied and ecologically-important aspect of microbiology. Many commercial fermentation processes are susceptible to bacteriophage infections due to the use of high-density, clonal cell populations. Lytic infections of bacterial cells in these fermentations are especially problematic due to their negative impacts on product quality, asset utilization, and fouling of downstream equipment. Here, we report the isolation and characterization of a novel lytic bacteriophage, referred to as bacteriophage DTL that is capable of rapid lytic infections of an Escherichia coli K12 strain used for commercial production of 1,3-propanediol (PDO). The bacteriophage genome was sequenced and annotated, which identified 67 potential open-reading frames (ORF). The tail fiber ORF, the largest in the genome, was most closely related to bacteriophage RTP, a T1-like bacteriophage reported from a commercial E. coli fermentation process in Germany. To eliminate virulence, both a fully functional Streptococcus thermophilus CRISPR3 plasmid and a customized S. thermophilus CRISPR3 plasmid with disabled spacer acquisition elements and seven spacers targeting the bacteriophage DTL genome were constructed. Both plasmids were separately integrated into a PDO production strain, which was subsequently infected with bacteriophage DTL. The native S. thermophilus CRISPR3 operon was shown to decrease phage susceptibility by approximately 96%, while the customized CRISPR3 operon provided complete resistance to bacteriophage DTL. The results indicate that the heterologous bacteriophage-resistance system described herein is useful in eliminating lytic infections of bacteriophage DTL, which was prevalent in environment surrounding the manufacturing facility.

Bacteriophage Transduction in Staphylococcus aureus.

PubMed

Olson, Michael E

2016-01-01

The genetic manipulation of Staphylococcus aureus for molecular experimentation is a valuable tool for assessing gene function and virulence. Genetic variability between strains coupled with difficult laboratory techniques for strain construction is a frequent roadblock in S. aureus research. Bacteriophage transduction greatly increases the speed and ease of S. aureus studies by allowing movement of chromosomal markers and plasmids between strains. This technique enables the S. aureus research community to focus investigations on clinically relevant isolates.

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

PubMed

El-Shibiny, Ayman; El-Sahhar, Salma

2017-11-01

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

Comparative genomic analysis of novel bacteriophages infecting Vibrio parahaemolyticus isolated from western and southern coastal areas of Korea.

PubMed

Yu, Junhyeok; Lim, Jeong-A; Kwak, Su-Jin; Park, Jong-Hyun; Chang, Hyun-Joo

2018-05-01

Vibrio parahaemolyticus, a foodborne pathogen, has become resistant to antibiotics. Therefore, alternative bio-control agents such bacteriophage are urgently needed for its control. Six novel bacteriophages specific to V. parahaemolyticus (vB_VpaP_KF1~2, vB_VpaS_KF3~6) were characterized at the molecular level in this study. Genomic similarity analysis revealed that these six bacteriophages could be divided into two groups with different genomic features, phylogenetic grouping, and morphologies. Two groups of bacteriophages had their own genes with different mechanisms for infection, assembly, and metabolism. Our results could be used as a future reference to study phage genomics or apply phages in future bio-control studies.

The action of Escherichia coli CRISPR-Cas system on lytic bacteriophages with different lifestyles and development strategies.

PubMed

Strotskaya, Alexandra; Savitskaya, Ekaterina; Metlitskaya, Anastasia; Morozova, Natalia; Datsenko, Kirill A; Semenova, Ekaterina; Severinov, Konstantin

2017-02-28

CRISPR-Cas systems provide prokaryotes with adaptive defense against bacteriophage infections. Given an enormous variety of strategies used by phages to overcome their hosts, one can expect that the efficiency of protective action of CRISPR-Cas systems against different viruses should vary. Here, we created a collection of Escherichia coli strains with type I-E CRISPR-Cas system targeting various positions in the genomes of bacteriophages λ, T5, T7, T4 and R1-37 and investigated the ability of these strains to resist the infection and acquire additional CRISPR spacers from the infecting phage. We find that the efficiency of CRISPR-Cas targeting by the host is determined by phage life style, the positions of the targeted protospacer within the genome, and the state of phage DNA. The results also suggest that during infection by lytic phages that are susceptible to CRISPR interference, CRISPR-Cas does not act as a true immunity system that saves the infected cell but rather enforces an abortive infection pathway leading to infected cell death with no phage progeny release. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

Characterization of tail sheath protein of giant bacteriophage phiKZ Pseudomonas aeruginosa

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kurochkina, Lidia P., E-mail: lpk@ibch.r; Aksyuk, Anastasia A.; Sachkova, Maria Yu.

2009-12-20

The tail sheath protein of giant bacteriophage phiKZ Pseudomonas aeruginosa encoded by gene 29 was identified and its expression system was developed. Localization of the protein on the virion was confirmed by immunoelectron microscopy. Properties of gene product (gp) 29 were studied by electron microscopy, immunoblotting and limited trypsinolysis. Recombinant gp29 assembles into the regular tubular structures (polysheaths) of variable length. Trypsin digestion of gp29 within polysheaths or extended sheath of virion results in specific cleavage of the peptide bond between Arg135 and Asp136. However, this cleavage does not affect polymeric structure of polysheaths, sheaths and viral infectivity. Digestion bymore » trypsin of the C-truncated gp29 mutant, lacking the ability to self-assemble, results in formation of a stable protease-resistant fragment. Although there is no sequence homology of phiKZ proteins to proteins of other bacteriophages, some characteristic biochemical properties of gp29 revealed similarities to the tail sheath protein of bacteriophage T4.« less

Structure of the bacteriophage T4 long tail fiber receptor-binding tip

PubMed Central

Bartual, Sergio G.; Otero, José M.; Garcia-Doval, Carmela; Llamas-Saiz, Antonio L.; Kahn, Richard; Fox, Gavin C.; van Raaij, Mark J.

2010-01-01

Bacteriophages are the most numerous organisms in the biosphere. In spite of their biological significance and the spectrum of potential applications, little high-resolution structural detail is available on their receptor-binding fibers. Here we present the crystal structure of the receptor-binding tip of the bacteriophage T4 long tail fiber, which is highly homologous to the tip of the bacteriophage lambda side tail fibers. This structure reveals an unusual elongated six-stranded antiparallel beta-strand needle domain containing seven iron ions coordinated by histidine residues arranged colinearly along the core of the biological unit. At the end of the tip, the three chains intertwine forming a broader head domain, which contains the putative receptor interaction site. The structure reveals a previously unknown beta-structured fibrous fold, provides insights into the remarkable stability of the fiber, and suggests a framework for mutations to expand or modulate receptor-binding specificity. PMID:21041684

Stability of bacteriophages in burn wound care products

PubMed Central

Monserez, Riet; van Belleghem, Jonas; Rose, Thomas; Jennes, Serge; De Vos, Daniel; Verbeken, Gilbert; Vaneechoutte, Mario; Pirnay, Jean-Paul

2017-01-01

Bacteriophages could be used along with burn wound care products to enhance antimicrobial pressure during treatment. However, some of the components of the topical antimicrobials that are traditionally used for the prevention and treatment of burn wound infection might affect the activity of phages. Therefore, it is imperative to determine the counteraction of therapeutic phage preparations by burn wound care products before application in patients. Five phages, representatives of two morphological families (Myoviridae and Podoviridae) and active against 3 common bacterial burn wound pathogens (Acinetobacter baumannii, Pseudomonas aeruginosa and Staphylococcus aureus) were tested against 13 different products commonly used in the treatment of burn wounds. The inactivation of the phages was quite variable for different phages and different products. Majority of the anti-infective products affected phage activity negatively either immediately or in the course of time, although impact was not always significant. Products with high acidity had the most adverse effect on phages. Our findings demonstrate that during combined treatment the choice of phages and wound care products must be carefully defined in advance. PMID:28750102

Feasibility of using a bacteriophage-based structural color sensor for screening the geographical origins of agricultural products

NASA Astrophysics Data System (ADS)

Seol, Daun; Moon, Jong-Sik; Lee, Yujin; Han, Jiye; Jang, Daeil; Kang, Dong-Jin; Moon, Jiyoung; Jang, Eunjin; Oh, Jin-Woo; Chung, Hoeil

2018-05-01

An M13 bacteriophage-based color sensor, which can change its structural color upon interaction with a gaseous molecule, was evaluated as a screening tool for the discrimination of the geographical origins of three different agricultural products (garlic, onion, and perilla). Exposure of the color sensor to sample odors induced the self-assembled M13 bacteriophage bundles to swell by the interaction of amino acid residues (repeating units of four glutamates) on the bacteriophage with the odor components, resulting in a change in the structural color of the sensor. When the sensor was exposed to the odors of garlic and onion samples, the RGB color changes were considerable because of the strong interactions of the odor components such as disulfides with the glutamate residues on the sensor. Although the patterns of the color variations were generally similar between the domestic and imported samples, some degrees of dissimilarities in their intensities were also observed. Although the magnitude of color change decreased for perilla, the color change patterns between the two groups were somewhat different. With the acquired RGB data, a support vector machine was employed to distinguish the domestic and imported samples, and the resulting accuracies in the measurements of garlic, onion, and perilla samples were 94.1, 88.7, and 91.6%, respectively. The differences in the concentrations of the odor components between both groups and/or the presence of specific components exclusively in the odor of one group allowed the color sensor-based discrimination. The demonstrated color sensor was thus shown to be a potentially versatile and simple as an on-site screening tool. Strategies able to further improve the sensor performance were also discussed.

BACTERIOPHAGE TRANSPORT IN SANDY SOIL AND FRACTURED TUFF

EPA Science Inventory

Bacteriophage transport was investigated in laboratory column experiments using sandy soil, a controlled field study in a sandy wash, and laboratory experiments using fractured rock. In the soil columns, the phage MS-2 exhibited significant dispersion and was excluded from 35 to ...

Polymorphism of DNA conformation inside the bacteriophage capsid.

PubMed

Leforestier, Amélie

2013-03-01

Double-stranded DNA bacteriophage genomes are packaged into their icosahedral capsids at the highest densities known so far (about 50 % w:v). How the molecule is folded at such density and how its conformation changes upon ejection or packaging are fascinating questions still largely open. We review cryo-TEM analyses of DNA conformation inside partially filled capsids as a function of the physico-chemical environment (ions, osmotic pressure, temperature). We show that there exists a wide variety of DNA conformations. Strikingly, the different observed structures can be described by some of the different models proposed over the years for DNA organisation inside bacteriophage capsids: either spool-like structures with axial or concentric symmetries, or liquid crystalline structures characterised by a DNA homogeneous density. The relevance of these conformations for the understanding of DNA folding and unfolding upon ejection and packaging in vivo is discussed.

Bacteriophages and their applications in the diagnosis and treatment of hepatitis B virus infection.

PubMed

Bakhshinejad, Babak; Sadeghizadeh, Majid

2014-09-07

Hepatitis B virus (HBV) infection is a major global health challenge leading to serious disorders such as cirrhosis and hepatocellular carcinoma. Currently, there exist various diagnostic and therapeutic approaches for HBV infection. However, prevalence and hazardous effects of chronic viral infection heighten the need to develop novel methodologies for the detection and treatment of this infection. Bacteriophages, viruses that specifically infect bacterial cells, with a long-established tradition in molecular biology and biotechnology have recently been introduced as novel tools for the prevention, diagnosis and treatment of HBV infection. Bacteriophages, due to tremendous genetic flexibility, represent potential to undergo a huge variety of surface modifications. This property has been the rationale behind introduction of phage display concept. This powerful approach, together with combinatorial chemistry, has shaped the concept of phage display libraries with diverse applications for the detection and therapy of HBV infection. This review aims to offer an insightful overview of the potential of bacteriophages in the development of helpful prophylactic (vaccine design), diagnostic and therapeutic strategies for HBV infection thereby providing new perspectives to the growing field of bacteriophage researches directing towards HBV infection.

Bacteriophages and their applications in the diagnosis and treatment of hepatitis B virus infection

PubMed Central

Bakhshinejad, Babak; Sadeghizadeh, Majid

2014-01-01

Hepatitis B virus (HBV) infection is a major global health challenge leading to serious disorders such as cirrhosis and hepatocellular carcinoma. Currently, there exist various diagnostic and therapeutic approaches for HBV infection. However, prevalence and hazardous effects of chronic viral infection heighten the need to develop novel methodologies for the detection and treatment of this infection. Bacteriophages, viruses that specifically infect bacterial cells, with a long-established tradition in molecular biology and biotechnology have recently been introduced as novel tools for the prevention, diagnosis and treatment of HBV infection. Bacteriophages, due to tremendous genetic flexibility, represent potential to undergo a huge variety of surface modifications. This property has been the rationale behind introduction of phage display concept. This powerful approach, together with combinatorial chemistry, has shaped the concept of phage display libraries with diverse applications for the detection and therapy of HBV infection. This review aims to offer an insightful overview of the potential of bacteriophages in the development of helpful prophylactic (vaccine design), diagnostic and therapeutic strategies for HBV infection thereby providing new perspectives to the growing field of bacteriophage researches directing towards HBV infection. PMID:25206272

Quick bacteriophage-mediated bioluminescence assay for detecting Staphylococcus spp. in sonicate fluid of orthopaedic artificial joints.

PubMed

Šuster, Katja; Podgornik, Aleš; Cör, Andrej

2017-07-01

Staphylococcus spp. accounts for up to two thirds of all microorganisms causing prosthetic joint infections, with Staphylococcus aureus and Staphylococcus epidermidis being the major cause. The present study describes a diagnostic model to detect staphylococci using a specific bacteriophage and bioluminescence detection, exploring the possibility of its use on sonicate fluid of orthopaedic artificial joints. Intracellular adenosine-5'-triphosphate release by bacteriophage mediated lysis of staphylococci was assessed to determine optimal parameters for detection. With the optimized method, a limit of detection of around 103 CFU/mL was obtained after incubation with bacteriophage for 2 h. Importantly, sonicate fluid did not prevent the ability of bacteriophage to infect bacteria and all simulated infected sonicate fluid as well as 6 clinical samples with microbiologically proven staphylococcal infection were detected as positive. The total assay took approximately 4 h. Collectively, the results indicate that the developed method promises a rapid, inexpensive and specific diagnostic detection of staphylococci in sonicate fluid of infected prosthetic joints. In addition, the unlimited pool of different existing bacteriophages, with different specificity for all kind of bacteria gives the opportunity for further investigations, improvements of the current model and implementation in other medical fields for the purpose of the establishment of a rapid diagnosis.

Bacteriophages to combat foodborne infections caused by food contamination by bacteria of the Campylobacter genus.

PubMed

Myga-Nowak, Magdalena; Godela, Agnieszka; Głąb, Tomasz; Lewańska, Monika; Boratyński, Janusz

2016-09-26

It is estimated that each year more than 2 million people suffer from diarrheal diseases, resulting from the consumption of contaminated meat. Foodborne infections are most frequently caused by small Gram-negative rods Campylobacter. The hosts of these bacteria are mainly birds wherein they are part of the normal intestinal flora. During the commercial slaughter, there is a likelihood of contamination of carcasses by the bacteria found in the intestinal content. In Europe, up to 90% of poultry flocks can be a reservoir of the pathogen. According to the European Food Safety Authority report from 2015, the number of reported and confirmed cases of human campylobacteriosis exceeds 200 thousands per year, and such trend remains at constant level for several years. The occurrence of growing antibiotic resistance in bacteria forces the limitation of antibiotic use in the animal production. Therefore, the European Union allows only using stringent preventive and hygienic treatment on farms. Achieving Campylobacter free chickens using these methods is possible, but difficult to implement and expensive. Utilization of bacterial viruses - bacteriophages, can be a path to provide the hygienic conditions of poultry production and food processing. Formulations applied in the food protection should contain strictly lytic bacteriophages, be non-pyrogenic and retain long lasting biological activity. Currently, on the market there are available commercial bacteriophage preparations for agricultural use, but neither includes phages against Campylobacter. However, papers on the application of bacteriophages against Campylobacter in chickens and poultry products were published in the last few years. In accordance with the estimates, 2-logarithm reduction of Campylobacter in poultry carcases will contribute to the 30-fold reduction in the incidence of campylobacteriosis in humans. Research on bacteriophages against Campylobacter have cognitive and economic importance. The paper

Bacteriophage-Resistant Mutants in Yersinia pestis: Identification of Phage Receptors and Attenuation for Mice

PubMed Central

Filippov, Andrey A.; Sergueev, Kirill V.; He, Yunxiu; Huang, Xiao-Zhe; Gnade, Bryan T.; Mueller, Allen J.; Fernandez-Prada, Carmen M.; Nikolich, Mikeljon P.

2011-01-01

Background Bacteriophages specific for Yersinia pestis are routinely used for plague diagnostics and could be an alternative to antibiotics in case of drug-resistant plague. A major concern of bacteriophage therapy is the emergence of phage-resistant mutants. The use of phage cocktails can overcome this problem but only if the phages exploit different receptors. Some phage-resistant mutants lose virulence and therefore should not complicate bacteriophage therapy. Methodology/Principal Findings The purpose of this work was to identify Y. pestis phage receptors using site-directed mutagenesis and trans-complementation and to determine potential attenuation of phage-resistant mutants for mice. Six receptors for eight phages were found in different parts of the lipopolysaccharide (LPS) inner and outer core. The receptor for R phage was localized beyond the LPS core. Most spontaneous and defined phage-resistant mutants of Y. pestis were attenuated, showing increase in LD50 and time to death. The loss of different LPS core biosynthesis enzymes resulted in the reduction of Y. pestis virulence and there was a correlation between the degree of core truncation and the impact on virulence. The yrbH and waaA mutants completely lost their virulence. Conclusions/Significance We identified Y. pestis receptors for eight bacteriophages. Nine phages together use at least seven different Y. pestis receptors that makes some of them promising for formulation of plague therapeutic cocktails. Most phage-resistant Y. pestis mutants become attenuated and thus should not pose a serious problem for bacteriophage therapy of plague. LPS is a critical virulence factor of Y. pestis. PMID:21980477

Bacteriophage-resistant mutants in Yersinia pestis: identification of phage receptors and attenuation for mice.

PubMed

Filippov, Andrey A; Sergueev, Kirill V; He, Yunxiu; Huang, Xiao-Zhe; Gnade, Bryan T; Mueller, Allen J; Fernandez-Prada, Carmen M; Nikolich, Mikeljon P

2011-01-01

Bacteriophages specific for Yersinia pestis are routinely used for plague diagnostics and could be an alternative to antibiotics in case of drug-resistant plague. A major concern of bacteriophage therapy is the emergence of phage-resistant mutants. The use of phage cocktails can overcome this problem but only if the phages exploit different receptors. Some phage-resistant mutants lose virulence and therefore should not complicate bacteriophage therapy. The purpose of this work was to identify Y. pestis phage receptors using site-directed mutagenesis and trans-complementation and to determine potential attenuation of phage-resistant mutants for mice. Six receptors for eight phages were found in different parts of the lipopolysaccharide (LPS) inner and outer core. The receptor for R phage was localized beyond the LPS core. Most spontaneous and defined phage-resistant mutants of Y. pestis were attenuated, showing increase in LD₅₀ and time to death. The loss of different LPS core biosynthesis enzymes resulted in the reduction of Y. pestis virulence and there was a correlation between the degree of core truncation and the impact on virulence. The yrbH and waaA mutants completely lost their virulence. We identified Y. pestis receptors for eight bacteriophages. Nine phages together use at least seven different Y. pestis receptors that makes some of them promising for formulation of plague therapeutic cocktails. Most phage-resistant Y. pestis mutants become attenuated and thus should not pose a serious problem for bacteriophage therapy of plague. LPS is a critical virulence factor of Y. pestis.

Inactivation of F-specific bacteriophages during flocculation with polyaluminum chloride - a mechanistic study.

PubMed

Kreißel, Katja; Bösl, Monika; Hügler, Michael; Lipp, Pia; Franzreb, Matthias; Hambsch, Beate

2014-03-15

Bacteriophages are often used as surrogates for enteric viruses in spiking experiments to determine the efficiencies of virus removal of certain water treatment measures, like e.g. flocculation or filtration steps. Such spiking experiments with bacteriophages are indispensable if the natural virus concentrations in the raw water of water treatment plants are too low to allow the determination of elimination levels over several orders of magnitude. In order to obtain reliable results from such spiking tests, it is essential that bacteriophages behave comparable to viruses and remain stable during the experiments. To test this, the influence of flocculation parameters on the bacteriophages MS2, Qβ and phiX174 was examined. Notably, the F-specific phages MS2 and Qβ were found to be inactivated in flocculation processes with polyaluminum chloride (PACl). In contrast, other aluminum coagulants like AlCl3 or Al2(SO4)3 did not show a comparable effect on MS2 in this study. In experiments testing the influence of different PACl species on MS2 and Qβ inactivation during flocculation, it could be shown that cationic dissolved PACl species (Al13) interacted with the MS2 surface and hereby reduced the surviving phage fraction to c/c0 values below 1*10(-4) even at very low PACl concentrations of 7 μmol Al/L. Other inactivation mechanisms like the irreversible adsorption of phages to the floc structure or the damage of phage surfaces due to entrapment into the floc during coagulation and floc formation do not seem to contribute to the low surviving fraction found for both F-specific bacteriophages. Furthermore, no influence of phage agglomeration or pH drops during the flocculation process on phage inactivation could be observed. The somatic coliphage phiX174 in contrast did not show sensitivity to chemical stress and in accordance only slight interaction between Al13 and the phage surface was observed. Consequently, F-specific phages like MS2 should not be used as

77 FR 68133 - Guidance for Industry: Use of Nucleic Acid Tests on Pooled and Individual Samples From Donors of...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-15

... Blood and Blood Components, Including Source Plasma, To Reduce the Risk of Transmission of Hepatitis B... Components, including Source Plasma, to Reduce the Risk of Transmission of Hepatitis B Virus,'' dated October... (NAT) to screen blood donors for hepatitis B virus (HBV) deoxyribonucleic acid (DNA) and...

In vitro evaluation of a novel bacteriophage cocktail as a preventative for bovine coliform mastitis.

PubMed

Porter, J; Anderson, J; Carter, L; Donjacour, E; Paros, M

2016-03-01

The objective of this study was to investigate the potential use of bacteriophage in preventing Escherichia coli mastitis on dairies. A cocktail consisting of 4 distinct bacteriophages was generated by screening against 36 E. coli isolates from dairy cows in Washington State with clinical mastitis. The bacteriophage significantly inhibited growth of 58% of the Washington State isolates and 54% of E. coli mastitis isolates from New York State, suggesting that the cocktail of phages had a relatively broad spectrum of action against relevant strains from 2 distinct geographies. The ability to suppress bacterial growth of these isolates in a liquid growth medium was not affected by the ratio of bacteriophage particles to bacterial cells (multiplicity of infection, MOI). For those E. coli that were completely inhibited by the phage cocktail, an MOI as low as 10 had the same effect as 10 µg/mL of ceftiofur on the growth rate of E. coli over a 12-h period using optical density measurements. A 3.3- to 5.6-log reduction of growth was achieved when E. coli was co-incubated with our phage cocktail in raw milk over a 12-h period at physiologic temperature. A modified gentamicin protection assay using bovine mammary epithelial cells provided a model to test whether bacteriophage could prevent cell attachment and invasion by chronic coliform mastitis strains. Pretreatment of cell cultures with the phage cocktail significantly reduced adhesion and intracellular survival of E. coli compared with controls. When combined with a bismuth-based teat sealant, the phage cocktail was able to inhibit bacterial growth when challenged with 1.6 × 10(3) cfu/mL of a clinical mastitis E. coli strain. In vitro results show bactericidal activity by our phage in raw milk and mammary tissue culture systems. Before a bacteriophage-based dry-cow treatment becomes a potential option for dairies, in vivo studies must be able to demonstrate that a specific dose of bacteriophage can protect cows from

Identification of novel bacteriophage peptides using a combination of gene sequence LC-MS-MS analysis and BLASTP

USDA-ARS?s Scientific Manuscript database

Introduction: In an effort to characterize novel bacteriophage with lytic activity against pathogenic E.coli associated with foodborne illness, gene sequencing and mass spectrometry have been used to identify expressed peptides which differentiate isolated bacteriophage from other known phage. Here,...

Comparative analysis of the biological and physical properties of Enterococcus faecalis bacteriophage vB_EfaS_GEC-EfS_3 and Streptococcus mitis bacteriophage vB_SmM_GEC-SmitisM_2.

PubMed

Rigvava, Sophio; Tchgkonia, Irina; Jgenti, Darejan; Dvalidze, Teona; Carpino, James; Goderdzishvili, Marina

2013-01-01

Enterococcus faecalis and Streptococcus mitis are common commensal inhabitants of the human gastrointestinal and genitourinary tracts. However, both species can be opportunistic pathogens and cause disease in nosocomial settings. These infections can be difficult to treat because of the frequency of antibiotic resistance among these strains. Bacteriophages are often suggested as an alternative therapeutic agent against these infections. In this study, E. faecalis and S. mitis strains were isolated from female patients with urinary tract infections. Bacteriophages active against these strains were isolated from sewage water from the Mtkvari River. Two phages, designated vB_EfaS_GEC-EfS_3 (Syphoviridae) and vB_SmM_GEC-SmitisM_2 (Myoviridae), were specific for E. faecalis and S. mitis, respectively. Each phage's growth patterns and adsorption rates were quantified. Sensitivity to ultraviolet light and temperature was determined, as was host range and serology. The S. mitis bacteriophage was found to be more resistant to ultraviolet light and exposure to high temperatures than the E. faecalis bacteriophage, despite having a much greater rate of replication. While each phage was able to infect a broad range of strains of the same species as the host species from which they were isolated, they were unable to infect other host species tested.

Top-down effects of a lytic bacteriophage and protozoa on bacteria in aqueous and biofilm phases.

PubMed

Zhang, Ji; Ormälä-Odegrip, Anni-Maria; Mappes, Johanna; Laakso, Jouni

2014-12-01

Lytic bacteriophages and protozoan predators are the major causes of bacterial mortality in natural microbial communities, which also makes them potential candidates for biological control of bacterial pathogens. However, little is known about the relative impact of bacteriophages and protozoa on the dynamics of bacterial biomass in aqueous and biofilm phases. Here, we studied the temporal and spatial dynamics of bacterial biomass in a microcosm experiment where opportunistic pathogenic bacteria Serratia marcescens was exposed to particle-feeding ciliates, surface-feeding amoebas, and lytic bacteriophages for 8 weeks, ca. 1300 generations. We found that ciliates were the most efficient enemy type in reducing bacterial biomass in the open water, but least efficient in reducing the biofilm biomass. Biofilm was rather resistant against bacterivores, but amoebae had a significant long-term negative effect on bacterial biomass both in the open-water phase and biofilm. Bacteriophages had only a minor long-term effect on bacterial biomass in open-water and biofilm phases. However, separate short-term experiments with the ancestral bacteriophages and bacteria revealed that bacteriophages crash the bacterial biomass dramatically in the open-water phase within the first 24 h. Thereafter, the bacteria evolve phage-resistance that largely prevents top-down effects. The combination of all three enemy types was most effective in reducing biofilm biomass, whereas in the open-water phase the ciliates dominated the trophic effects. Our results highlight the importance of enemy feeding mode on determining the spatial distribution and abundance of bacterial biomass. Moreover, the enemy type can be crucially important predictor of whether the rapid defense evolution can significantly affect top-down regulation of bacteria.

Characterization of a novel bacteriophage, Phda1, infecting the histamine-producing Photobacterium damselae subsp. damselae.

PubMed

Yamaki, S; Kawai, Y; Yamazaki, K

2015-06-01

Photobacterium damselae subsp. damselae is a potent histamine-producing micro-organism. The aim of this study was to isolate and characterize a bacteriophage Phda1 that infected P. damselae subsp. damselae to inhibit its growth and histamine accumulation. Phda1 was isolated from a raw oyster, and the host range, morphology and the bacteriophage genome size were analysed. Phda1 formed a clear plaque only against P. damselae subsp. damselae JCM8969 among five Gram-positive and 32 Gram-negative bacterial strains tested. Phda1 belongs to the family Myoviridae, and its genome size was estimated as 35·2-39·5 kb. According to the one-step growth curve analysis, the latent period, rise period and burst size of Phda1 were 60 min, 50 min and 19 plaque-forming units per infected cell, respectively. Divalent cations, especially Ca(2+) and Mg(2+) , strongly improved Phda1 adsorption to the host cells and its propagation. Phda1 treatment delayed the growth and histamine production of P. damselae subsp. damselae in an in vitro challenge test. The bacteriophage Phda1 might serve as a potential antimicrobial agent to inhibit the histamine poisoning caused by P. damselae subsp. damselae. This is the first description of a bacteriophage specifically infecting P. damselae subsp. damselae and its potential applications. Bacteriophage therapy could prove useful in the prevention of histamine poisoning. © 2015 The Society for Applied Microbiology.

21 CFR 172.785 - Listeria-specific bacteriophage preparation.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Listeria-specific bacteriophage preparation. 172.785 Section 172.785 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO...

Recombination between bacteriophage lambda and plasmid pBR322 in Escherichia coli.

PubMed Central

Pogue-Geile, K L; Dassarma, S; King, S R; Jaskunas, S R

1980-01-01

Recombinant lambda phages were isolated that resulted from recombination between the lambda genome and plasmid pBR322 in Escherichia coli, even though these deoxyribonucleic acids (DNAs) did not share extensive regions of homology. The characterization of these recombinant DNAs by heteroduplex analysis and restriction endonucleases is described. All but one of the recombinants appeared to have resulted from reciprocal recombination between a site on lambda DNA and a site on the plasmid. In general, there were two classes of recombinants. One class appeared to have resulted from recombination at the phage attachment site that probably resulted from lambda integration into secondary attachment sites on the plasmid. Seven different secondary attachment sites on pBR322 were found. The other class resulted from plasmid integration at other sites that were widely scattered on the lambda genome. For this second class of recombinants, more than one site on the plasmid could recombine with lambda DNA. Thus, the recombination did not appear to be site specific with respect to lambda or the plasmid. Possible mechanisms for generating these recombinants are discussed. Images PMID:6247334

Abundance of Antibiotic Resistance Genes in Bacteriophage following Soil Fertilization with Dairy Manure or Municipal Biosolids, and Evidence for Potential Transduction

PubMed Central

Ross, Joseph

2015-01-01

Animal manures and municipal biosolids recycled onto crop production land carry antibiotic-resistant bacteria that can influence the antibiotic resistome of agricultural soils, but little is known about the contribution of bacteriophage to the dissemination of antibiotic resistance genes (ARGs) in this context. In this work, we quantified a set of ARGs in the bacterial and bacteriophage fractions of agricultural soil by quantitative PCR. All tested ARGs were present in both the bacterial and phage fractions. We demonstrate that fertilization of soil with dairy manure or human biosolids increases ARG abundance in the bacterial fraction but not the bacteriophage fraction and further show that pretreatment of dairy manure can impact ARG abundance in the bacterial fraction. Finally, we show that purified bacteriophage can confer increased antibiotic resistance to soil bacteria when combined with selective pressure. The results indicate that soilborne bacteriophage represents a substantial reservoir of antibiotic resistance and that bacteriophage could play a significant role in the horizontal transfer of resistance genes in the context of an agricultural soil microbiome. Overall, our work reinforces the advisability of composting or digesting fecal material prior to field application and suggests that application of some antibiotics at subclinical concentrations can promote bacteriophage-mediated horizontal transfer of ARGs in agricultural soil microbiomes. PMID:26341211

Insights into Bacteriophage Application in Controlling Vibrio Species

PubMed Central

Letchumanan, Vengadesh; Chan, Kok-Gan; Pusparajah, Priyia; Saokaew, Surasak; Duangjai, Acharaporn; Goh, Bey-Hing; Ab Mutalib, Nurul-Syakima; Lee, Learn-Han

2016-01-01

Bacterial infections from various organisms including Vibrio sp. pose a serious hazard to humans in many forms from clinical infection to affecting the yield of agriculture and aquaculture via infection of livestock. Vibrio sp. is one of the main foodborne pathogens causing human infection and is also a common cause of losses in the aquaculture industry. Prophylactic and therapeutic usage of antibiotics has become the mainstay of managing this problem, however, this in turn led to the emergence of multidrug resistant strains of bacteria in the environment; which has raised awareness of the critical need for alternative non-antibiotic based methods of preventing and treating bacterial infections. Bacteriophages – viruses that infect and result in the death of bacteria – are currently of great interest as a highly viable alternative to antibiotics. This article provides an insight into bacteriophage application in controlling Vibrio species as well underlining the advantages and drawbacks of phage therapy. PMID:27486446

Bacteriophages and phage-inspired nanocarriers for targeted delivery of therapeutic cargos.

PubMed

Karimi, Mahdi; Mirshekari, Hamed; Moosavi Basri, Seyed Masoud; Bahrami, Sajad; Moghoofei, Mohsen; Hamblin, Michael R

2016-11-15

The main goal of drug delivery systems is to target therapeutic cargoes to desired cells and to ensure their efficient uptake. Recently a number of studies have focused on designing bio-inspired nanocarriers, such as bacteriophages, and synthetic carriers based on the bacteriophage structure. Bacteriophages are viruses that specifically recognize their bacterial hosts. They can replicate only inside their host cell and can act as natural gene carriers. Each type of phage has a particular shape, a different capacity for loading cargo, a specific production time, and their own mechanisms of supramolecular assembly, that have enabled them to act as tunable carriers. New phage-based technologies have led to the construction of different peptide libraries, and recognition abilities provided by novel targeting ligands. Phage hybridization with non-organic compounds introduces new properties to phages and could be a suitable strategy for construction of bio-inorganic carriers. In this review we try to cover the major phage species that have been used in drug and gene delivery systems, and the biological application of phages as novel targeting ligands and targeted therapeutics. Copyright © 2016 Elsevier B.V. All rights reserved.

Evidence of translation efficiency adaptation of the coding regions of the bacteriophage lambda.

PubMed

Goz, Eli; Mioduser, Oriah; Diament, Alon; Tuller, Tamir

2017-08-01

Deciphering the way gene expression regulatory aspects are encoded in viral genomes is a challenging mission with ramifications related to all biomedical disciplines. Here, we aimed to understand how the evolution shapes the bacteriophage lambda genes by performing a high resolution analysis of ribosomal profiling data and gene expression related synonymous/silent information encoded in bacteriophage coding regions.We demonstrated evidence of selection for distinct compositions of synonymous codons in early and late viral genes related to the adaptation of translation efficiency to different bacteriophage developmental stages. Specifically, we showed that evolution of viral coding regions is driven, among others, by selection for codons with higher decoding rates; during the initial/progressive stages of infection the decoding rates in early/late genes were found to be superior to those in late/early genes, respectively. Moreover, we argued that selection for translation efficiency could be partially explained by adaptation to Escherichia coli tRNA pool and the fact that it can change during the bacteriophage life cycle.An analysis of additional aspects related to the expression of viral genes, such as mRNA folding and more complex/longer regulatory signals in the coding regions, is also reported. The reported conclusions are likely to be relevant also to additional viruses. © The Author 2017. Published by Oxford University Press on behalf of Kazusa DNA Research Institute.

UPTAKE OF BACTERIOPHAGE F2 THROUGH PLANT ROOTS

EPA Science Inventory

A model system was designed to measure viral uptake through the roots of plants and translocation to distal plant parts. For this study, uptake of bacteriophage f2 was measured in corn and bean plants growing in hydroponic solutions. Few phage were detected in plants with uncut r...

Bacteriophages encode factors required for protection in a symbiotic mutualism.

PubMed

Oliver, Kerry M; Degnan, Patrick H; Hunter, Martha S; Moran, Nancy A

2009-08-21

Bacteriophages are known to carry key virulence factors for pathogenic bacteria, but their roles in symbiotic bacteria are less well understood. The heritable symbiont Hamiltonella defensa protects the aphid Acyrthosiphon pisum from attack by the parasitoid Aphidius ervi by killing developing wasp larvae. In a controlled genetic background, we show that a toxin-encoding bacteriophage is required to produce the protective phenotype. Phage loss occurs repeatedly in laboratory-held H. defensa-infected aphid clonal lines, resulting in increased susceptibility to parasitism in each instance. Our results show that these mobile genetic elements can endow a bacterial symbiont with benefits that extend to the animal host. Thus, phages vector ecologically important traits, such as defense against parasitoids, within and among symbiont and animal host lineages.

Double-stranded DNA organization in bacteriophage heads: an alternative toroid-based model.

PubMed Central

Hud, N V

1995-01-01

Studies of the organization of double-stranded DNA within bacteriophage heads during the past four decades have produced a wealth of data. However, despite the presentation of numerous models, the true organization of DNA within phage heads remains unresolved. The observations of toroidal DNA structures in electron micrographs of phage lysates have long been cited as support for the organization of DNA in a spool-like fashion. This particular model, like all other models, has not been found to be consistent will all available data. Recently we proposed that DNA within toroidal condensates produced in vitro is organized in a manner significantly different from that suggested by the spool model. This new toroid model has allowed the development of an alternative model for DNA organization within bacteriophage heads that is consistent with a wide range of biophysical data. Here we propose that bacteriophage DNA is packaged in a toroid that is folded into a highly compact structure. Images FIGURE 1 FIGURE 2 FIGURE 3 FIGURE 4 PMID:8534805

Biomimetic self-templating optical structures fabricated by genetically engineered M13 bacteriophage.

PubMed

Kim, Won-Geun; Song, Hyerin; Kim, Chuntae; Moon, Jong-Sik; Kim, Kyujung; Lee, Seung-Wuk; Oh, Jin-Woo

2016-11-15

Here, we describe a highly sensitive and selective surface plasmon resonance sensor system by utilizing self-assembly of genetically engineered M13 bacteriophage. About 2700 copies of genetically expressed peptide copies give superior selectivity and sensitivity to M13 phage-based SPR sensor. Furthermore, the sensitivity of the M13 phage-based SPR sensor was enhanced due to the aligning of receptor matrix in specific direction. Incorporation of specific binding peptide (His Pro Gln: HPQ) gives M13 bacteriophage high selectivity for the streptavidin. Our M13 phage-based SPR sensor takes advantage of simplicity of self-assembly compared with relatively complex photolithography techniques or chemical conjugations. Additionally, designed structure which is composed of functionalized M13 bacteriophage can simultaneously improve the sensitivity and selectivity of SPR sensor evidently. By taking advantages of the genetic engineering and self-assembly, we propose the simple method for fabricating novel M13 phage-based SPR sensor system which has a high sensitivity and high selectivity. Copyright © 2016 Elsevier B.V. All rights reserved.

The allosteric switching mechanism in bacteriophage MS2

NASA Astrophysics Data System (ADS)

Perkett, Matthew R.; Mirijanian, Dina T.; Hagan, Michael F.

2016-07-01

We use all-atom simulations to elucidate the mechanisms underlying conformational switching and allostery within the coat protein of the bacteriophage MS2. Assembly of most icosahedral virus capsids requires that the capsid protein adopts different conformations at precise locations within the capsid. It has been shown that a 19 nucleotide stem loop (TR) from the MS2 genome acts as an allosteric effector, guiding conformational switching of the coat protein during capsid assembly. Since the principal conformational changes occur far from the TR binding site, it is important to understand the molecular mechanism underlying this allosteric communication. To this end, we use all-atom simulations with explicit water combined with a path sampling technique to sample the MS2 coat protein conformational transition, in the presence and absence of TR-binding. The calculations find that TR binding strongly alters the transition free energy profile, leading to a switch in the favored conformation. We discuss changes in molecular interactions responsible for this shift. We then identify networks of amino acids with correlated motions to reveal the mechanism by which effects of TR binding span the protein. We find that TR binding strongly affects residues located at the 5-fold and quasi-sixfold interfaces in the assembled capsid, suggesting a mechanism by which the TR binding could direct formation of the native capsid geometry. The analysis predicts amino acids whose substitution by mutagenesis could alter populations of the conformational substates or their transition rates.

The allosteric switching mechanism in bacteriophage MS2

PubMed Central

Perkett, Matthew R.; Mirijanian, Dina T.

2016-01-01

We use all-atom simulations to elucidate the mechanisms underlying conformational switching and allostery within the coat protein of the bacteriophage MS2. Assembly of most icosahedral virus capsids requires that the capsid protein adopts different conformations at precise locations within the capsid. It has been shown that a 19 nucleotide stem loop (TR) from the MS2 genome acts as an allosteric effector, guiding conformational switching of the coat protein during capsid assembly. Since the principal conformational changes occur far from the TR binding site, it is important to understand the molecular mechanism underlying this allosteric communication. To this end, we use all-atom simulations with explicit water combined with a path sampling technique to sample the MS2 coat protein conformational transition, in the presence and absence of TR-binding. The calculations find that TR binding strongly alters the transition free energy profile, leading to a switch in the favored conformation. We discuss changes in molecular interactions responsible for this shift. We then identify networks of amino acids with correlated motions to reveal the mechanism by which effects of TR binding span the protein. We find that TR binding strongly affects residues located at the 5-fold and quasi-sixfold interfaces in the assembled capsid, suggesting a mechanism by which the TR binding could direct formation of the native capsid geometry. The analysis predicts amino acids whose substitution by mutagenesis could alter populations of the conformational substates or their transition rates. PMID:27448905

From Bits and Pieces to Whole Phage to Nanomachines: Pathogen Detection Using Bacteriophages.

PubMed

Anany, H; Chou, Y; Cucic, S; Derda, R; Evoy, S; Griffiths, M W

2017-02-28

The innate specificity of bacteriophages toward their hosts makes them excellent candidates for the development of detection assays. They can be used in many ways to detect pathogens, and each has its own advantages and disadvantages. Whole bacteriophages can carry reporter genes to alter the phenotype of the target. Bacteriophages can act as staining agents or the progeny of the infection process can be detected, which further increases the sensitivity of the detection assay. Compared with whole-phage particles, use of phage components as probes offers other advantages: for example, smaller probe size to enhance binding activity, phage structures that can be engineered for better affinity, as well as specificity, binding properties, and robustness. When no natural binding with the target exists, phages can be used as vehicles to identify new protein-ligand interactions necessary for diagnostics. This review comprehensively summarizes many uses of phages as detection tools and points the way toward how phage-based technologies may be improved.

Bacteriophage cocktail and multi-strain probiotics in the feed for weanling pigs: effects on intestine morphology and targeted intestinal coliforms and Clostridium.

PubMed

Kim, J S; Hosseindoust, A; Lee, S H; Choi, Y H; Kim, M J; Lee, J H; Kwon, I K; Chae, B J

2017-01-01

Two experiments were conducted to investigate the effects of dietary supplementation of bacteriophage cocktail, probiotics and a combination of these two supplements on performance and gut health of weanling pigs. In Experiment 1, 150 weaned piglets were randomly allotted to three treatments on the basis of BW. The dietary treatments included a basal diet supplemented with 0 (control), 1.0 and 1.5 g/kg bacteriophage cocktail. Pigs fed 1.0 and 1.5 g/kg bacteriophage product had greater (P<0.05) average daily gain (ADG), apparent total tract digestibility of dry matter from day 22 to 35, ileal Lactobacillus spp., villus height (duodenum and jejunum), and fewer coliforms (ileum) and Clostridium spp. (ileum). In Experiment 2, 200 weaned piglets were randomly allotted to four treatments. Dietary treatments included basal diet, basal diet supplemented with 3.0 g/kg fermented probiotic product (P), 1.0 g/kg bacteriophage cocktail (B) and combination of 1.0 g/kg bacteriophage cocktail and 3.0 g/kg fermented probiotic product. Pigs fed bacteriophage cocktail diets had greater (P<0.05) overall ADG, gain to feed ratio (G : F), fecal score from day 8 to day 21, and pigs fed bacteriophage cocktail diets had fewer coliforms (ileum) Clostridium spp. (ileum and cecum). Probiotics significantly increased G : F, colonization of Lactobacillus spp. in ileum. At day 35, bacteriophage treatment group showed greater (P<0.05) villus height of the duodenum, but a deeper crypt in duodenum. The present results indicate that the bacteriophage cocktail had a potential to enhance the performance and gut health of weanling pigs, however their combination with probiotics did not show an interaction.

Feasibility of using a bacteriophage-based structural color sensor for screening the geographical origins of agricultural products.

PubMed

Seol, Daun; Moon, Jong-Sik; Lee, Yujin; Han, Jiye; Jang, Daeil; Kang, Dong-Jin; Moon, Jiyoung; Jang, Eunjin; Oh, Jin-Woo; Chung, Hoeil

2018-05-15

An M13 bacteriophage-based color sensor, which can change its structural color upon interaction with a gaseous molecule, was evaluated as a screening tool for the discrimination of the geographical origins of three different agricultural products (garlic, onion, and perilla). Exposure of the color sensor to sample odors induced the self-assembled M13 bacteriophage bundles to swell by the interaction of amino acid residues (repeating units of four glutamates) on the bacteriophage with the odor components, resulting in a change in the structural color of the sensor. When the sensor was exposed to the odors of garlic and onion samples, the RGB color changes were considerable because of the strong interactions of the odor components such as disulfides with the glutamate residues on the sensor. Although the patterns of the color variations were generally similar between the domestic and imported samples, some degrees of dissimilarities in their intensities were also observed. Although the magnitude of color change decreased for perilla, the color change patterns between the two groups were somewhat different. With the acquired RGB data, a support vector machine was employed to distinguish the domestic and imported samples, and the resulting accuracies in the measurements of garlic, onion, and perilla samples were 94.1, 88.7, and 91.6%, respectively. The differences in the concentrations of the odor components between both groups and/or the presence of specific components exclusively in the odor of one group allowed the color sensor-based discrimination. The demonstrated color sensor was thus shown to be a potentially versatile and simple as an on-site screening tool. Strategies able to further improve the sensor performance were also discussed. Copyright © 2018. Published by Elsevier B.V.

Doxorubicin-conjugated bacteriophages carrying anti-MHC class I chain-related A for targeted cancer therapy in vitro.

PubMed

Phumyen, Achara; Jantasorn, Siriporn; Jumnainsong, Amonrat; Leelayuwat, Chanvit

2014-01-01

Cancer therapy by systemic administration of anticancer drugs, besides the effectiveness shown on cancer cells, demonstrated the side effects and cytotoxicity on normal cells. The targeted drug-carrying nanoparticles may decrease the required drug concentration at the site and the distribution of drugs to normal tissues. Overexpression of major histocompatibility complex class I chain-related A (MICA) in cancer is useful as a targeted molecule for the delivery of doxorubicin to MICA-expressing cell lines. The application of 1-ethyl-3-[3-dimethylaminopropyl] carbodiimide (EDC) chemistry was employed to conjugate the major coat protein of bacteriophages carrying anti-MICA and doxorubicin in a mildly acid condition. Doxorubicin (Dox) on phages was determined by double fluorescence of phage particles stained by M13-fluorescein isothiocyanate (FITC) and drug autofluorescence by flow cytometry. The ability of anti-MICA on phages to bind MICA after doxorubicin conjugation was evaluated by indirect enzyme-linked immunosorbent assay. One cervical cancer and four cholangiocarcinoma cell lines expressing MICA were used as models to evaluate targeting activity by cell cytotoxicity test. Flow cytometry and indirect enzyme-linked immunosorbent assay demonstrated that most of the phages (82%) could be conjugated with doxorubicin, and the Dox-carrying phage-displaying anti-MICA (Dox-phage) remained the binding activity against MICA. Dox-phage was more efficient than free drugs in killing all the cell lines tested. The half maximal inhibitory concentration (IC50) values of Dox-phage were lower than those of free drugs at approximately 1.6-6 times depending on MICA expressions and the cell lines tested. Evidently, the application of 1-ethyl-3-[3-dimethylaminopropyl] carbodiimide chemistry is effective to conjugate doxorubicin and major coat protein of bacteriophages without destroying binding activity of MICA antibodies. Dox-carrying bacteriophages targeting MICA have been

Elucidating the pH-Dependent Structural Transition of T7 Bacteriophage Endolysin.

PubMed

Sharma, Meenakshi; Kumar, Dinesh; Poluri, Krishna Mohan

2016-08-23

Bacteriophages are the most abundant and diverse biological entities on earth. Bacteriophage endolysins are unique peptidoglycan hydrolases and have huge potential as effective enzybiotics in various infectious models. T7 bacteriophage endolysin (T7L), also known as N-acetylmuramoyl-l-alanine amidase or T7 lysozyme, is a 17 kDa protein that lyses a range of Gram-negative bacteria by hydrolyzing the amide bond between N-acetylmuramoyl residues and the l-alanine of the peptidoglycan layer. Although the activity profiles of several of the T7 family members have been known for many years, the molecular basis for their pH-dependent differential activity is not clear. In this study, we explored the pH-induced structural, stability, and activity characteristics of T7L by applying a variety of biophysical techniques and protein nuclear magnetic resonance (NMR) spectroscopy. Our studies established a reversible structural transition of T7L below pH 6 and the formation of a partially denatured conformation at pH 3. This low-pH conformation is thermally stable and exposed its hydrophobic pockets. Further, NMR relaxation measurements and structural analysis unraveled that T7L is highly dynamic in its native state and a network of His residues are responsible for the observed pH-dependent conformational dynamics and transitions. As bacteriophage chimeric and engineered endolysins are being developed as novel therapeutics against multiple drug resistance pathogens, we believe that our results are of great help in designing these entities as broadband antimicrobial and/or antibacterial agents.

The roles of bacteriophages in membrane-based water and wastewater treatment processes: A review.

PubMed

Wu, Bing; Wang, Rong; Fane, Anthony G

2017-03-01

Membrane filtration processes have been widely applied in water and wastewater treatment for many decades. Concerns related to membrane treatment effectiveness, membrane lifespan, and membrane fouling control have been paid great attention. To achieve sustainable membrane operation with regards to low energy and maintenance cost, monitoring membrane performance and applying suitable membrane control strategies are required. As the most abundant species in water and wastewater, bacteriophages have shown great potential to be employed in membrane processes as (1) indicators to assess membrane performance considering their similar properties to human pathogenic waterborne viruses; (2) surrogate particles to monitor membrane integrity due to their nano-sized nature; and (3) biological agents to alleviate membrane fouling because of their antimicrobial properties. This study aims to provide a comprehensive review on the roles of bacteriophages in membrane-based water and wastewater treatment processes, with focuses on their uses for membrane performance examination, membrane integrity monitoring, and membrane biofouling control. The advantages, limitations, and influencing factors for bacteriophage-based applications are reported. Finally, the challenges and prospects of bacteriophage-based applications in membrane processes for water treatment are highlighted. Copyright © 2016 Elsevier Ltd. All rights reserved.

Elucidation of the mechanisms of action of Bacteriophage K/nano-emulsion formulations against S. aureus via measurement of particle size and zeta potential.

PubMed

Esteban, Patricia Perez; Jenkins, A Toby A; Arnot, Tom C

2016-03-01

In earlier work we have demonstrated the effect that nano-emulsions have on bacterial growth, and most importantly the enhanced bacteriophage infectivity against Staphylococcus aureus in planktonic culture when phage are carried in nano-emulsions. However, the mechanisms of enhancement of the bacteriophage killing effect are not specifically understood. This work focuses on the investigation of the possible interactions between emulsion droplets and bacterial cells, between emulsion droplets and bacteriophages, and finally interactions between all three components: nano-emulsion droplets, bacteria, and bacteriophages. The first approach consists of simple calculations to determine the spatial distribution of the components, based on measurements of particle size. It was found that nano-emulsion droplets are much more numerous than bacteria or bacteriophage, and due to their size and surface area they must be covering the surface of both cells and bacteriophage particles. Stabilisation of bacteriophages due to electrostatic forces and interaction with nano-emulsion droplets is suspected, since bacteriophages may be protected against inactivation due to 'charge shielding'. Zeta potential was measured for the individual components in the system, and for all of them combined. It was concluded that the presence of nano-emulsions could be reducing electrostatic repulsion between bacterial cells and bacteriophage, both of which are very negatively 'charged'. Moreover, nano-emulsions lead to more favourable interaction between bacteriophages and bacteria, enhancing the anti-microbial or killing effect. These findings are relevant since the physicochemical properties of nano-emulsions (i.e. particle size distribution and zeta potential) are key in determining the efficacy of the formulation against infection in the context of responsive burn wound dressings-which is the main target for this work. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Inhibiting the Growth of Escherichia coli O157:H7 in Beef, Pork, and Chicken Meat using a Bacteriophage

PubMed Central

Seo, Jina; Seo, Dong Joo; Oh, Hyejin; Jeon, Su Been; Oh, Mi-Hwa; Choi, Changsun

2016-01-01

This study aimed to inhibit Escherichia coli (E. coli) O157:H7 artificially contaminated in fresh meat using bacteriophage. Among 14 bacteriophages, the highly lytic bacteriophage BPECO19 strain was selected to inhibit E. coli O157:H7 in artificially contaminated meat samples. Bacteriophage BPECO19 significantly reduced E. coli O157:H7 bacterial load in vitro in a multiplicity of infection (MOI)-dependent manner. E. coli O157:H7 was completely inhibited only in 10 min in vitro by the treatment of 10,000 MOI BPECO19. The treatment of BPECO19 at 100,000 MOI completely reduced 5 Log CFU/cm2 E. coli O157:H7 bacterial load in beef and pork at 4 and 8h, respectively. In chicken meat, a 4.65 log reduction of E. coli O157:H7 was observed at 4 h by 100,000 MOI. The treatment of single bacteriophage BPECO19 was an effective method to control E. coli O157:H7 in meat samples. PMID:27194926

Abundance of Antibiotic Resistance Genes in Bacteriophage following Soil Fertilization with Dairy Manure or Municipal Biosolids, and Evidence for Potential Transduction.

PubMed

Ross, Joseph; Topp, Edward

2015-11-01

Animal manures and municipal biosolids recycled onto crop production land carry antibiotic-resistant bacteria that can influence the antibiotic resistome of agricultural soils, but little is known about the contribution of bacteriophage to the dissemination of antibiotic resistance genes (ARGs) in this context. In this work, we quantified a set of ARGs in the bacterial and bacteriophage fractions of agricultural soil by quantitative PCR. All tested ARGs were present in both the bacterial and phage fractions. We demonstrate that fertilization of soil with dairy manure or human biosolids increases ARG abundance in the bacterial fraction but not the bacteriophage fraction and further show that pretreatment of dairy manure can impact ARG abundance in the bacterial fraction. Finally, we show that purified bacteriophage can confer increased antibiotic resistance to soil bacteria when combined with selective pressure. The results indicate that soilborne bacteriophage represents a substantial reservoir of antibiotic resistance and that bacteriophage could play a significant role in the horizontal transfer of resistance genes in the context of an agricultural soil microbiome. Overall, our work reinforces the advisability of composting or digesting fecal material prior to field application and suggests that application of some antibiotics at subclinical concentrations can promote bacteriophage-mediated horizontal transfer of ARGs in agricultural soil microbiomes. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Binding mechanisms for histamine and agmatine ligands in plasmid deoxyribonucleic acid purifications.

PubMed

Sousa, Ângela; Pereira, Patrícia; Sousa, Fani; Queiroz, João A

2014-10-31

Histamine and agmatine amino acid derivatives were immobilized into monolithic disks, in order to combine the specificity and selectivity of the ligand with the high mass transfer and binding capacity offered by monolithic supports, to purify potential plasmid DNA biopharmaceuticals. Different elution strategies were explored by changing the type and salt concentration, as well as the pH, in order to understand the retention pattern of different plasmids isoforms The pVAX1-LacZ supercoiled isoform was isolated from a mixture of pDNA isoforms by using NaCl increasing stepwise gradient and also by ammonium sulfate decreasing stepwise gradient, in both histamine and agmatine monoliths. Acidic pH in the binding buffer mainly strengthened ionic interactions with both ligands in the presence of sodium chloride. Otherwise, for histamine ligand, pH values higher than 7 intensified hydrophobic interactions in the presence of ammonium sulfate. In addition, circular dichroism spectroscopy studies revealed that the binding and elution chromatographic conditions, such as the combination of high ionic strength with extreme pH values can reversibly influence the structural stability of the target nucleic acid. Therefore, ascending sodium chloride gradients with pH manipulation can be preferable chromatographic conditions to be explored in the purification of plasmid DNA biopharmaceuticals, in order to avoid the environmental impact of ammonium sulfate. Copyright © 2014. Published by Elsevier B.V.

Bacteriophages and Their Role in Food Safety

PubMed Central

Sillankorva, Sanna M.; Oliveira, Hugo; Azeredo, Joana

2012-01-01

The interest for natural antimicrobial compounds has increased due to alterations in consumer positions towards the use of chemical preservatives in foodstuff and food processing surfaces. Bacteriophages fit in the class of natural antimicrobial and their effectiveness in controlling bacterial pathogens in agro-food industry has led to the development of different phage products already approved by USFDA and USDA. The majority of these products are to be used in farm animals or animal products such as carcasses, meats and also in agricultural and horticultural products. Treatment with specific phages in the food industry can prevent the decay of products and the spread of bacterial diseases and ultimately promote safe environments in animal and plant food production, processing, and handling. This is an overview of recent work carried out with phages as tools to promote food safety, starting with a general introduction describing the prevalence of foodborne pathogens and bacteriophages and a more detailed discussion on the use of phage therapy to prevent and treat experimentally induced infections of animals against the most common foodborne pathogens, the use of phages as biocontrol agents in foods, and also their use as biosanitizers of food contact surfaces. PMID:23316235

Bacteriophage T5 encodes a homolog of the eukaryotic transcription coactivator PC4 implicated in recombination-dependent DNA replication.

PubMed

Steigemann, Birthe; Schulz, Annina; Werten, Sebastiaan

2013-11-15

The RNA polymerase II cofactor PC4 globally regulates transcription of protein-encoding genes through interactions with unwinding DNA, the basal transcription machinery and transcription activators. Here, we report the surprising identification of PC4 homologs in all sequenced representatives of the T5 family of bacteriophages, as well as in an archaeon and seven phyla of eubacteria. We have solved the crystal structure of the full-length T5 protein at 1.9Å, revealing a striking resemblance to the characteristic single-stranded DNA (ssDNA)-binding core domain of PC4. Intriguing novel structural features include a potential regulatory region at the N-terminus and a C-terminal extension of the homodimerisation interface. The genome organisation of T5-related bacteriophages points at involvement of the PC4 homolog in recombination-dependent DNA replication, strongly suggesting that the protein corresponds to the hitherto elusive replicative ssDNA-binding protein of the T5 family. Our findings imply that PC4-like factors intervene in multiple unwinding-related processes by acting as versatile modifiers of nucleic acid conformation and raise the possibility that the eukaryotic transcription coactivator derives from ancestral DNA replication, recombination and repair factors. © 2013.

Bacteriophages as Weapons Against Bacterial Biofilms in the Food Industry.

PubMed

Gutiérrez, Diana; Rodríguez-Rubio, Lorena; Martínez, Beatriz; Rodríguez, Ana; García, Pilar

2016-01-01

Microbiological contamination in the food industry is often attributed to the presence of biofilms in processing plants. Bacterial biofilms are complex communities of bacteria attached to a surface and surrounded by an extracellular polymeric material. Their extreme resistance to cleaning and disinfecting processes is related to a unique organization, which implies a differential bacterial growth and gene expression inside the biofilm. The impact of biofilms on health, and the economic consequences, has promoted the development of different approaches to control or remove biofilm formation. Recently, successful results in phage therapy have boosted new research in bacteriophages and phage lytic proteins for biofilm eradication. In this regard, this review examines the environmental factors that determine biofilm development in food-processing equipment. In addition, future perspectives for the use of bacteriophage-derived tools as disinfectants are discussed.

Biotinylation of environmentally isolated Shiga toxin-producing Escherichia coli (STEC) – specific bacteriophages for biosensor and biocontrol applications

USDA-ARS?s Scientific Manuscript database

Like common bacteriophages, Shiga toxin-producing Escherichia coli (STEC) bacteriophages are viruses that recognize and bind to specific bacterial host (STEC) for propagation. They co-exist with STEC hosts, which cause epidemic food and waterborne illnesses, but may act as host populations limiting ...

Bacteriophages as Biological Control Agents of Enteric Bacteria Contaminating Edible Oysters.

PubMed

Le, Tuan Son; Southgate, Paul C; O'Connor, Wayne; Poole, Sue; Kurtbӧke, D Ipek

2018-05-01

Bacterial contamination on seafood resulting from unhygienic food-handling practices causes foodborne diseases and significant revenue losses. Moreover, control measures are complicated by a high prevalence of antibiotic-resistant bacteria. Alternative measures such as the phage therapy, therefore, is considered as an environmental and consumer-friendly biological control strategy for controlling such bacterial contamination. In this study, we determined the effectiveness of a bacteriophage cocktail in controlling E. coli strains [JM 109, ATCC 13706 and the, extended spectrum beta-lactamase resistant strain (ATCC BAA 196)] and S. enterica subsp. enterica (ATCC 13311) as single and combined contaminants of the edible oysters. Five different E. coli-specific phages (belonging to the Siphoviridae family) and a Salmonella phage (belonging to the Tectiviridae family) were successfully isolated from sewage water samples taken from a local sewage treatment plan in the Sunshine Coast region of Australia. Phage treatments applied to the pathogens when they were presented on the oysters as either single or combined hosts, resulted in significant decrease of the number of these bacteria on edible oysters. Results obtained indicated that bacteriophages could have beneficial applications in oyster-processing plants in controlling pathogenic bacterial infestations. This study thus contributes towards ongoing international efforts into the effective use of bacteriophages for biological control purposes.

Drug delivery vectors based on filamentous bacteriophages and phage-mimetic nanoparticles.

PubMed

Ju, Zhigang; Sun, Wei

2017-11-01

With the development of nanomedicine, a mass of nanocarriers have been exploited and utilized for targeted drug delivery, including liposomes, polymers, nanoparticles, viruses, and stem cells. Due to huge surface bearing capacity and flexible genetic engineering property, filamentous bacteriophage and phage-mimetic nanoparticles are attracting more and more attentions. As a rod-like bio-nanofiber without tropism to mammalian cells, filamentous phage can be easily loaded with drugs and directly delivered to the lesion location. In particular, chemical drugs can be conjugated on phage surface by chemical modification, and gene drugs can also be inserted into the genome of phage by recombinant DNA technology. Meanwhile, specific peptides/proteins displayed on the phage surface are able to conjugate with nanoparticles which will endow them specific-targeting and huge drug-loading capacity. Additionally, phage peptides/proteins can directly self-assemble into phage-mimetic nanoparticles which may be applied for self-navigating drug delivery nanovehicles. In this review, we summarize the production of phage particles, the identification of targeting peptides, and the recent applications of filamentous bacteriophages as well as their protein/peptide for targeting drug delivery in vitro and in vivo. The improvement of our understanding of filamentous bacteriophage and phage-mimetic nanoparticles will supply new tools for biotechnological approaches.

Inhibition of protein synthesis in intact HeLa cells by Shigella dysenteriae 1 toxin.

PubMed

Brown, J E; Rothman, S W; Doctor, B P

1980-07-01

Shiga toxin purified to near homogeneity from cell lysates of Shigella dysenteriae 1 inhibited protein and deoxyribonucle acid syntheses in intact HeLa cells. Inhibition was dependent on toxin concentration and time of incubation. A minimal latent period of 30 min was observed with saturating doses of toxin. Ribonucleic acid synthesis, uptake of alpha-aminoisobutyric acid, and maintenance of intracellular K+ concentrations were not affected until well after maximal inhibition of protein and deoxyribonucleic acid syntheses. The inhibitory effect of toxin was sensitive to heat inactivation and was prevented by antibody neutralization. Several cytotoxic components were separated by polyacrylamide gel electrophoresis of the purified toxin preparations; all inhibited protein and deoxyribonucleic acid syntheses equally.

Lytic bacteriophages reduce Escherichia coli O157

PubMed Central

Ferguson, Sean; Roberts, Cheryl; Handy, Eric; Sharma, Manan

2013-01-01

The role of lytic bacteriophages in preventing cross contamination of produce has not been evaluated. A cocktail of three lytic phages specific for E. coli O157:H7 (EcoShield™) or a control (phosphate buffered saline, PBS) was applied to lettuce by either; (1) immersion of lettuce in 500 ml of EcoShield™ 8.3 log PFU/ml or 9.8 log PFU/ml for up to 2 min before inoculation with E. coli O157:H7; (2) spray-application of EcoShield™ (9.3 log PFU/ml) to lettuce after inoculation with E. coli O157:H7 (4.10 CFU/cm2) following exposure to 50 μg/ml chlorine for 30 sec. After immersion studies, lettuce was spot-inoculated with E. coli O157:H7 (2.38 CFU/cm2). Phage-treated, inoculated lettuce pieces were stored at 4°C for and analyzed for E. coli O157:H7 populations for up to 7 d. Immersion of lettuce in 9.8 log PFU/ml EcoShield™ for 2 min significantly (p < 0.05) reduced E. coli O157:H7 populations after 24 h when stored at 4°C compared with controls. Immersion of lettuce in suspensions containing high concentrations of EcoShield™ (9.8 log PFU/ml) resulted in the deposition of high concentrations (7.8 log log PFU/cm2) of bacteriophages on the surface of fresh cut lettuce, potentially contributing to the efficacy of the lytic phages on lettuce. Spraying phages on to inoculated fresh cut lettuce after being washed in hypochlorite solution was significantly more effective in reducing E. coli O157:H7 populations (2.22 log CFU/cm2) on day 0 compared with control treatments (4.10 log CFU/cm2). Both immersion and spray treatments provided protection from E. coli O157:H7 contamination on lettuce, but spray application of lytic bacteriophages to lettuce was more effective in immediately reducing E. coli O157:H7 populations fresh cut lettuce. PMID:23819106

Interaction of colicin E7 with the major coat protein (g8p) may confer limited protection on colicinogenic Escherichia coli against M13 bacteriophage infection.

PubMed

Chen, Yuh-Ren; Yang, Tsung-Yeh; Lei, Guang-Sheng; Liao, Chen-Chung; Chak, Kin-Fu

2010-11-01

Colicin release provides producer strains with a competitive advantage under certain circumstances. We found that propagation of M13 bacteriophage in cells producing colicin E7 is impaired, without alteration in the efficiency of bacteriophage adsorption, as compared with non-producing cells. In contrast to the protective effect of the colicin against M13 bacteriophage infection, the endogenously expressed colicin does not confer limited protection against transfection with M13 bacteriophage DNA. Furthermore, it was found that the translocation-receptor-binding domain and toxicity domain of the colicin are able to interact with the M13 major coat protein, g8p, during bacteriophage infection. Based on these observations, we propose that interaction between colicin E7 and g8p during infection interferes with g8p depolymerizing into the cytoplasmic membrane during bacteriophage DNA penetration, thus resulting in the limited protection against M13 bacteriophage infection.

Bacteriophage recombination systems and biotechnical applications.

PubMed

Nafissi, Nafiseh; Slavcev, Roderick

2014-04-01

Bacteriophage recombination systems have been widely used in biotechnology for modifying prokaryotic species, for creating transgenic animals and plants, and more recently, for human cell gene manipulation. In contrast to homologous recombination, which benefits from the endogenous recombination machinery of the cell, site-specific recombination requires an exogenous source of recombinase in mammalian cells. The mechanism of bacteriophage evolution and their coexistence with bacterial cells has become a point of interest ever since bacterial viruses' life cycles were first explored. Phage recombinases have already been exploited as valuable genetic tools and new phage enzymes, and their potential application to genetic engineering and genome manipulation, vectorology, and generation of new transgene delivery vectors, and cell therapy are attractive areas of research that continue to be investigated. The significance and role of phage recombination systems in biotechnology is reviewed in this paper, with specific focus on homologous and site-specific recombination conferred by the coli phages, λ, and N15, the integrase from the Streptomyces phage, ΦC31, the recombination system of phage P1, and the recently characterized recombination functions of Yersinia phage, PY54. Key steps of the molecular mechanisms involving phage recombination functions and their application to molecular engineering, our novel exploitations of the PY54-derived recombination system, and its application to the development of new DNA vectors are discussed.

[POSSIBILITIES OF APPLICATION OF MALDI-TOF MASS-SPECTROMETRY FOR STUDY OF CARBOHYDRATE-SPECIFIC RECEPTORS FOR DIAGNOSTIC BACTERIOPHAGE EL TOR].

PubMed

Telesmanich, N R; Goncharenko, E V; Chaika, S O; Chaika, I A; Telicheva, V O

2016-01-01

Study mechanisms of interaction of diagnostic bacteriophage El Tor with sensitive strain Vibrio cholerae El Tor 18507 using direct protein profiling, identification of constant and variable proteins, taking part in interaction of the phage and cell, as well as carbohydrate-specific phage receptors. . A commercial preparation of cholera diagnostic bacteriophage El Tor, strain V. cholerae El Tor 18507 were used. Effect of carbohydrates on bacteriophage activity was determined in experiments with phage by a classic and modified by us method. Protein profiles of the studied objects were studied using MSP-analysis method. Sucrose was shown to inhibit lytic activity of bacteriophage. Proteome profiles of El Tor bacteriophage and sensitive indicator strains were studied, identification of constant and variable proteins of the studied objects by MSP Peak-list program was carried out. Analysis of changes of profiles of phage and microbial cell during interaction with sucrose gave a basis for assuming, that sucrose in the mixture of culture-phage enters interaction namely with phage protein receptors, blocking receptors specific for cholera vibrio, that subsequently manifests in a sharp decrease of phage activity against the sensitive strain.

Gene transfer of Hodgkin cell lines via multivalent anti-CD30 scFv displaying bacteriophage.

PubMed

Chung, Yoon-Suk A; Sabel, Katja; Krönke, Martin; Klimka, Alexander

2008-04-16

The display of binding ligands, such as recombinant antibody fragments, on the surface of filamentous phage makes it possible to specifically attach these phage particles to target cells. After uptake of the phage, their internal single-stranded DNA is processed by the host cell, which allows transient expression of an encoded eukaryotic gene cassette. This opens the possibility to use bacteriophage as vectors for targeted gene therapy, although the transduction efficiency is very low. Here we demonstrate the display of an anti-CD30 single chain variable fragment fused to the major coat protein pVIII on the surface of bacteriophage. These phage particles showed an improved binding and transduction efficiency of CD30 positive Hodgkin-lymphoma cells, compared to bacteriophage with the anti-CD30 single chain variable fragment fused to the minor coat protein pIII. We can conclude from the results that the postulated multivalency of the anti-CD30-pVIII displaying bacteriophage combined with disseminated display of the anti-CD30 scFv on the whole particle surface is responsible for the improved gene transfer rate. These results mark an important step towards the use of phage particles as a cheap and safe gene transfer vehicle for the gene delivery of the desired target cells via their specific surface receptors.

Development and Use of Personalized Bacteriophage-Based Therapeutic Cocktails To Treat a Patient with a Disseminated Resistant Acinetobacter baumannii Infection.

PubMed

Schooley, Robert T; Biswas, Biswajit; Gill, Jason J; Hernandez-Morales, Adriana; Lancaster, Jacob; Lessor, Lauren; Barr, Jeremy J; Reed, Sharon L; Rohwer, Forest; Benler, Sean; Segall, Anca M; Taplitz, Randy; Smith, Davey M; Kerr, Kim; Kumaraswamy, Monika; Nizet, Victor; Lin, Leo; McCauley, Melanie D; Strathdee, Steffanie A; Benson, Constance A; Pope, Robert K; Leroux, Brian M; Picel, Andrew C; Mateczun, Alfred J; Cilwa, Katherine E; Regeimbal, James M; Estrella, Luis A; Wolfe, David M; Henry, Matthew S; Quinones, Javier; Salka, Scott; Bishop-Lilly, Kimberly A; Young, Ry; Hamilton, Theron

2017-10-01

Widespread antibiotic use in clinical medicine and the livestock industry has contributed to the global spread of multidrug-resistant (MDR) bacterial pathogens, including Acinetobacter baumannii We report on a method used to produce a personalized bacteriophage-based therapeutic treatment for a 68-year-old diabetic patient with necrotizing pancreatitis complicated by an MDR A. baumannii infection. Despite multiple antibiotic courses and efforts at percutaneous drainage of a pancreatic pseudocyst, the patient deteriorated over a 4-month period. In the absence of effective antibiotics, two laboratories identified nine different bacteriophages with lytic activity for an A. baumannii isolate from the patient. Administration of these bacteriophages intravenously and percutaneously into the abscess cavities was associated with reversal of the patient's downward clinical trajectory, clearance of the A. baumannii infection, and a return to health. The outcome of this case suggests that the methods described here for the production of bacteriophage therapeutics could be applied to similar cases and that more concerted efforts to investigate the use of therapeutic bacteriophages for MDR bacterial infections are warranted.

Development and Use of Personalized Bacteriophage-Based Therapeutic Cocktails To Treat a Patient with a Disseminated Resistant Acinetobacter baumannii Infection

PubMed Central

Biswas, Biswajit; Gill, Jason J.; Hernandez-Morales, Adriana; Lancaster, Jacob; Lessor, Lauren; Barr, Jeremy J.; Reed, Sharon L.; Rohwer, Forest; Benler, Sean; Segall, Anca M.; Taplitz, Randy; Smith, Davey M.; Kerr, Kim; Kumaraswamy, Monika; Nizet, Victor; Lin, Leo; McCauley, Melanie D.; Strathdee, Steffanie A.; Benson, Constance A.; Pope, Robert K.; Leroux, Brian M.; Picel, Andrew C.; Mateczun, Alfred J.; Cilwa, Katherine E.; Regeimbal, James M.; Estrella, Luis A.; Wolfe, David M.; Henry, Matthew S.; Quinones, Javier; Salka, Scott; Bishop-Lilly, Kimberly A.; Young, Ry; Hamilton, Theron

2017-01-01

ABSTRACT Widespread antibiotic use in clinical medicine and the livestock industry has contributed to the global spread of multidrug-resistant (MDR) bacterial pathogens, including Acinetobacter baumannii. We report on a method used to produce a personalized bacteriophage-based therapeutic treatment for a 68-year-old diabetic patient with necrotizing pancreatitis complicated by an MDR A. baumannii infection. Despite multiple antibiotic courses and efforts at percutaneous drainage of a pancreatic pseudocyst, the patient deteriorated over a 4-month period. In the absence of effective antibiotics, two laboratories identified nine different bacteriophages with lytic activity for an A. baumannii isolate from the patient. Administration of these bacteriophages intravenously and percutaneously into the abscess cavities was associated with reversal of the patient's downward clinical trajectory, clearance of the A. baumannii infection, and a return to health. The outcome of this case suggests that the methods described here for the production of bacteriophage therapeutics could be applied to similar cases and that more concerted efforts to investigate the use of therapeutic bacteriophages for MDR bacterial infections are warranted. PMID:28807909

Characterization of a new ViI-like Erwinia amylovora bacteriophage phiEa2809.

PubMed

Lagonenko, Alexander L; Sadovskaya, Olga; Valentovich, Leonid N; Evtushenkov, Anatoly N

2015-04-01

Erwinia amylovora is a Gram-negative plant pathogenic bacteria causing fire blight disease in many Rosaceae species. A novel E. amylovora bacteriophage, phiEa2809, was isolated from symptomless apple leaf sample collected in Belarus. This phage was also able to infect Pantoea agglomerans strains. The genome of phiEa2809 is a double-stranded linear DNA 162,160 bp in length, including 145 ORFs and one tRNA gene. The phiEa2809 genomic sequence is similar to the genomes of the Serratia plymutica phage MAM1, Shigella phage AG-3, Dickeya phage vB DsoM LIMEstone1 and Salmonella phage ViI and lacks similarity to described E. amylovora phage genomes. Based on virion morphology (an icosahedral head, long contractile tail) and genome structure, phiEa2809 was classified as a member of Myoviridae, ViI-like bacteriophages group. PhiEa2809 is the firstly characterized ViI-like bacteriophage able to lyse E. amylovora. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Environmental Augmentation with Bacteriophage Prevents Colibacillosis in Broiler Chickens

USDA-ARS?s Scientific Manuscript database

Bacteriophages are viruses that kill bacteria. They are plentiful in nature, are safe having no known activity to human or animal cells, and are an attractive alternative to antibiotics. The objectives of this research were to establish an experimental model of colibacillosis induced by indirect e...

Complete genome sequence of IME15, the first T7-like bacteriophage lytic to pan-antibiotic-resistant Stenotrophomonas maltophilia.

PubMed

Huang, Yong; Fan, Huahao; Pei, Guangqian; Fan, Hang; Zhang, Zhiyi; An, Xiaoping; Mi, Zhiqiang; Shi, Taoxing; Tong, Yigang

2012-12-01

T7-like bacteriophages are a class of virulent bacteriophages which have a clearer genetic background and smaller genomes than other phages. In addition, it grows faster and is easier to culture than other phages. At present, the numbers of available T7-like bacteriophage genomes and Stenotrophomonas maltophilia genomes are small, and IME15 is the first T7-like virulent Stenotrophomonas phage whose sequence has been reported. It shows effective lysis of S. maltophilia. Here we announce its complete genome, and major findings from its annotation are described.

Novel Podoviridae Family Bacteriophage Infecting Weissella cibaria Isolated from Kimchi

PubMed Central

Holo, Helge; Jeon, Sang-Rok; Nes, Ingolf F.; Yoon, Sung-Sik

2012-01-01

The first complete genome sequence of a phage infecting Weissella cibaria (Weissella kimchii) is presented. The bacteriophage ϕYS61 was isolated from kimchi, a Korean fermented vegetable dish. Bacteriophages are recognized as a serious problem in industrial fermentations; however, ϕYS61 differed from many virulent phages associated with food fermentations since it was difficult to propagate and was very susceptible to resistance development. Sequence analysis revealed that ϕYS61 resembles Podoviridae of the subfamily Picovirinae. Within the subfamily Picovirinae, the ϕ29-like phages have been extensively studied, and their terminal protein-primed DNA replication is well characterized. Our data strongly suggest that ϕYS61 also replicates by a protein-primed mechanism. Weissella phage ϕYS61 is, however, markedly different from members of the Picovirinae with respect to genome size and morphology. Picovirinae are characterized by small (approximately 20-kb) genomes which contrasts with the 33,594-bp genome of ϕYS61. Based on electron microscopy analysis, ϕYS61 was classified as a member of the Podoviridae of morphotype C2, similar to the ϕ29-like phages, but its capsid dimensions are significantly larger than those reported for these phages. The novelty of ϕYS61 was also emphasized by the low number of open reading frames (ORFs) showing significant similarity to database sequences. We propose that the bacteriophage ϕYS61 should represent a new subfamily within the family Podoviridae. PMID:22885743

Binding of radiation-induced phenylalanine radicals to DNA: influence on the biological activity of the DNA and on its sensitivity to the induction of breaks by gamma rays

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vanderschans, G.P.; Vanrijn, C.J.S.; Bleichrodt, J.F.

1975-11-01

When an aqueous solution of double-stranded deoxyribonucleic acid (DNA) of bacteriophage PM2 containing phenylalanine and saturated with N2O is irradiated with gamma rays, radiation induced phenylalanine radicals are bound covalently. Under the conditions used about 25 phenylalanine molecules may be bound per lethal hit. Also for single-stranded PM2 DNA most of the phenylalanine radicals bound are nonlethal. Evidence is presented that in double-stranded DNA an appreciable fraction of the single-strand breaks is induced by phenylalanine radicals. Radiation products of phenylalanine and the phenylalanine bound to the DNA decrease the sensitivity of the DNA to the induction of single-strand breaks. Theremore » are indications that the high efficiency of protection by radiation products of phenylalanine is due to their positive charge, which will result in a relatively high concentration of these compounds in the vicinity of the negatively charged DNA molecules. (Author) (GRA)« less

Filamentous bacteriophage as a novel therapeutic tool for Alzheimer's disease treatment.

PubMed

Solomon, Beka

2008-10-01

Antibodies towards the N-terminal region of the amyloid-beta peptide (AbetaP) bind to Abeta fibrils, leading to their disaggregation. We developed an immunization procedure using filamentous phages displaying the only four amino acids EFRH encompassing amino acids 3-6 of the 42 residues of AbetaP, found to be the main regulatory site for Abeta formation. Phages displaying EFRH epitope are effective in eliciting humoral response against AbetaP which, in turn, relieves amyloid burden in brains of amyloid-beta protein precursor transgenic mice, improving their ability to perform cognitive tasks. In order to overcome the low permeability of the blood brain barrier for targeting 'anti-aggregating' monoclonal antibodies (mAbs) to Abeta plaques in the brain, we applied antibody engineering methods to minimize the size of mAbs while maintaining their biological activity. Single-chain antibodies displayed on the surface of filamentous phage showed the ability to enter the central nervous system (CNS). The genetically engineered filamentous bacteriophage proved to be an efficient, nontoxic viral delivery vector to the brain, offering an obvious advantage over other mammalian vectors. The feasibility of these novel strategies for production and targeting of anti-aggregating antibodies against Abeta plaques to disease affected regions in the CNS may have clinical potential for treatment of Alzheimer's disease.

Bacteriophages as Weapons Against Bacterial Biofilms in the Food Industry

PubMed Central

Gutiérrez, Diana; Rodríguez-Rubio, Lorena; Martínez, Beatriz; Rodríguez, Ana; García, Pilar

2016-01-01

Microbiological contamination in the food industry is often attributed to the presence of biofilms in processing plants. Bacterial biofilms are complex communities of bacteria attached to a surface and surrounded by an extracellular polymeric material. Their extreme resistance to cleaning and disinfecting processes is related to a unique organization, which implies a differential bacterial growth and gene expression inside the biofilm. The impact of biofilms on health, and the economic consequences, has promoted the development of different approaches to control or remove biofilm formation. Recently, successful results in phage therapy have boosted new research in bacteriophages and phage lytic proteins for biofilm eradication. In this regard, this review examines the environmental factors that determine biofilm development in food-processing equipment. In addition, future perspectives for the use of bacteriophage-derived tools as disinfectants are discussed. PMID:27375566

Spectroscopic and microcalorimetric studies on the molecular binding of food colorant acid red 27 with deoxyribonucleic acid.

PubMed

Basu, Anirban; Kumar, Gopinatha Suresh

2016-08-01

Interaction of the food colorant acid red 27 with double stranded DNA was investigated using spectroscopic and calorimetric methods. Absorbance and fluorescence studies suggested an intimate binding interaction between the dye and DNA. The quantum efficiency value testified an effective energy transfer from the DNA base pairs to the dye molecules. Minor groove displacement assay with Hoechst 33258 revealed that the binding occurs in the minor groove of DNA. Circular dichroism studies revealed that acid red 27 induces moderate conformational perturbations in DNA. Results of calorimetric studies suggested that the complexation process was driven largely by positive entropic contribution with a smaller favorable enthalpy contribution. The equilibrium constant of the binding was calculated to be (3.04 ± 0.09) × 10(4)  M(-1) at 298.15 K. Negative heat capacity value along with the enthalpy-entropy compensation phenomenon established the involvement of dominant hydrophobic forces in the binding process. Differential scanning calorimetry studies presented evidence for an increased thermal stability of DNA on binding of acid red 27. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

The allosteric switching mechanism in bacteriophage MS2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Perkett, Matthew R.; Mirijanian, Dina T.; Hagan, Michael F., E-mail: hagan@brandeis.edu

2016-07-21

We use all-atom simulations to elucidate the mechanisms underlying conformational switching and allostery within the coat protein of the bacteriophage MS2. Assembly of most icosahedral virus capsids requires that the capsid protein adopts different conformations at precise locations within the capsid. It has been shown that a 19 nucleotide stem loop (TR) from the MS2 genome acts as an allosteric effector, guiding conformational switching of the coat protein during capsid assembly. Since the principal conformational changes occur far from the TR binding site, it is important to understand the molecular mechanism underlying this allosteric communication. To this end, we usemore » all-atom simulations with explicit water combined with a path sampling technique to sample the MS2 coat protein conformational transition, in the presence and absence of TR-binding. The calculations find that TR binding strongly alters the transition free energy profile, leading to a switch in the favored conformation. We discuss changes in molecular interactions responsible for this shift. We then identify networks of amino acids with correlated motions to reveal the mechanism by which effects of TR binding span the protein. We find that TR binding strongly affects residues located at the 5-fold and quasi-sixfold interfaces in the assembled capsid, suggesting a mechanism by which the TR binding could direct formation of the native capsid geometry. The analysis predicts amino acids whose substitution by mutagenesis could alter populations of the conformational substates or their transition rates.« less

Bacteriophages carrying antibiotic resistance genes in fecal waste from cattle, pigs, and poultry.

PubMed

Colomer-Lluch, Marta; Imamovic, Lejla; Jofre, Juan; Muniesa, Maite

2011-10-01

This study evaluates the occurrence of bacteriophages carrying antibiotic resistance genes in animal environments. bla(TEM), bla(CTX-M) (clusters 1 and 9), and mecA were quantified by quantitative PCR in 71 phage DNA samples from pigs, poultry, and cattle fecal wastes. Densities of 3 to 4 log(10) gene copies (GC) of bla(TEM), 2 to 3 log(10) GC of bla(CTX-M), and 1 to 3 log(10) GC of mecA per milliliter or gram of sample were detected, suggesting that bacteriophages can be environmental vectors for the horizontal transfer of antibiotic resistance genes.

Learning from Bacteriophages - Advantages and Limitations of Phage and Phage-Encoded Protein Applications

PubMed Central

Drulis-Kawa, Zuzanna; Majkowska-Skrobek, Grażyna; Maciejewska, Barbara; Delattre, Anne-Sophie; Lavigne, Rob

2012-01-01

The emergence of bacteria resistance to most of the currently available antibiotics has become a critical therapeutic problem. The bacteria causing both hospital and community-acquired infections are most often multidrug resistant. In view of the alarming level of antibiotic resistance between bacterial species and difficulties with treatment, alternative or supportive antibacterial cure has to be developed. The presented review focuses on the major characteristics of bacteriophages and phage-encoded proteins affecting their usefulness as antimicrobial agents. We discuss several issues such as mode of action, pharmacodynamics, pharmacokinetics, resistance and manufacturing aspects of bacteriophages and phage-encoded proteins application. PMID:23305359

Bacteriophage removal efficiency as a validation and operational monitoring tool for virus reduction in wastewater reclamation: Review.

PubMed

Amarasiri, Mohan; Kitajima, Masaaki; Nguyen, Thanh H; Okabe, Satoshi; Sano, Daisuke

2017-09-15

The multiple-barrier concept is widely employed in international and domestic guidelines for wastewater reclamation and reuse for microbiological risk management, in which a wastewater reclamation system is designed to achieve guideline values of the performance target of microbe reduction. Enteric viruses are one of the pathogens for which the target reduction values are stipulated in guidelines, but frequent monitoring to validate human virus removal efficacy is challenging in a daily operation due to the cumbersome procedures for virus quantification in wastewater. Bacteriophages have been the first choice surrogate for this task, because of the well-characterized nature of strains and the presence of established protocols for quantification. Here, we performed a meta-analysis to calculate the average log 10 reduction values (LRVs) of somatic coliphages, F-specific phages, MS2 coliphage and T4 phage by membrane bioreactor, activated sludge, constructed wetlands, pond systems, microfiltration and ultrafiltration. The calculated LRVs of bacteriophages were then compared with reported human enteric virus LRVs. MS2 coliphage LRVs in MBR processes were shown to be lower than those of norovirus GII and enterovirus, suggesting it as a possible validation and operational monitoring tool. The other bacteriophages provided higher LRVs compared to human viruses. The data sets on LRVs of human viruses and bacteriophages are scarce except for MBR and conventional activated sludge processes, which highlights the necessity of investigating LRVs of human viruses and bacteriophages in multiple treatment unit processes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Chemical modulation of M13 bacteriophage and its functional opportunities for nanomedicine

PubMed Central

Chung, Woo-Jae; Lee, Doe-Young; Yoo, So Young

2014-01-01

M13 bacteriophage (phage) has emerged as an attractive bionanomaterial owing to its genetically tunable surface chemistry and its potential to self-assemble into hierarchical structures. Furthermore, because of its unique nanoscopic structure, phage has been proposed as a model system in soft condensed physics and as a biomimetic building block for structured functional materials. Genetic engineering of phage provides great opportunities to develop novel nanomaterials with functional surface peptide motifs; however, this biological approach is generally limited to peptides containing the 20 natural amino acids. To extend the scope of phage applications, strategies involving chemical modification have been employed to incorporate a wider range of functional groups, including synthetic chemical compounds. In this review, we introduce the design of chemoselective phage functionalization and discuss how such a strategy is combined with genetic engineering for a variety of medical applications, as reported in recent literature. PMID:25540583

Chemical modulation of M13 bacteriophage and its functional opportunities for nanomedicine.

PubMed

Chung, Woo-Jae; Lee, Doe-Young; Yoo, So Young

2014-01-01

M13 bacteriophage (phage) has emerged as an attractive bionanomaterial owing to its genetically tunable surface chemistry and its potential to self-assemble into hierarchical structures. Furthermore, because of its unique nanoscopic structure, phage has been proposed as a model system in soft condensed physics and as a biomimetic building block for structured functional materials. Genetic engineering of phage provides great opportunities to develop novel nanomaterials with functional surface peptide motifs; however, this biological approach is generally limited to peptides containing the 20 natural amino acids. To extend the scope of phage applications, strategies involving chemical modification have been employed to incorporate a wider range of functional groups, including synthetic chemical compounds. In this review, we introduce the design of chemoselective phage functionalization and discuss how such a strategy is combined with genetic engineering for a variety of medical applications, as reported in recent literature.

A bacteriophages journey through the human body.

PubMed

Barr, Jeremy J

2017-09-01

The human body is colonized by a diverse collective of microorganisms, including bacteria, fungi, protozoa and viruses. The smallest entity of this microbial conglomerate are the bacterial viruses. Bacteriophages, or phages for short, exert significant selective pressure on their bacterial hosts, undoubtedly influencing the human microbiome and its impact on our health and well-being. Phages colonize all niches of the body, including the skin, oral cavity, lungs, gut, and urinary tract. As such our bodies are frequently and continuously exposed to diverse collections of phages. Despite the prevalence of phages throughout our bodies, the extent of their interactions with human cells, organs, and immune system is still largely unknown. Phages physically interact with our mucosal surfaces, are capable of bypassing epithelial cell layers, disseminate throughout the body and may manipulate our immune system. Here, I establish the novel concept of an "intra-body phageome," which encompasses the collection of phages residing within the classically "sterile" regions of the body. This review will take a phage-centric view of the microbiota, human body, and immune system with the ultimate goal of inspiring a greater appreciation for both the indirect and direct interactions between bacteriophages and their mammalian hosts. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Bacteriophages as indicators of faecal pollution and enteric virus removal

EPA Science Inventory

Bacteriophages are an attractive alternative to fecal indicator bacteria (FIB), particularly as surrogates of enteric virus fate and transport due to their closer morphological and biological properties compared to FIB. Based on a meta-analysis of published data, we summarize con...

Magic-angle spinning NMR of intact bacteriophages: Insights into the capsid, DNA and their interface

NASA Astrophysics Data System (ADS)

Abramov, Gili; Morag, Omry; Goldbourt, Amir

2015-04-01

Bacteriophages are viruses that infect bacteria. They are complex macromolecular assemblies, which are composed of multiple protein subunits that protect genomic material and deliver it to specific hosts. Various biophysical techniques have been used to characterize their structure in order to unravel phage morphogenesis. Yet, most bacteriophages are non-crystalline and have very high molecular weights, in the order of tens of MegaDaltons. Therefore, complete atomic-resolution characterization on such systems that encompass both capsid and DNA is scarce. In this perspective article we demonstrate how magic-angle spinning solid-state NMR has and is used to characterize in detail bacteriophage viruses, including filamentous and icosahedral phage. We discuss the process of sample preparation, spectral assignment of both capsid and DNA and the use of chemical shifts and dipolar couplings to probe the capsid-DNA interface, describe capsid structure and dynamics and extract structural differences between viruses.

Performance of viruses and bacteriophages for fecal source determination in a multi-laboratory, comparative study.

PubMed

Harwood, Valerie J; Boehm, Alexandria B; Sassoubre, Lauren M; Vijayavel, Kannappan; Stewart, Jill R; Fong, Theng-Theng; Caprais, Marie-Paule; Converse, Reagan R; Diston, David; Ebdon, James; Fuhrman, Jed A; Gourmelon, Michele; Gentry-Shields, Jennifer; Griffith, John F; Kashian, Donna R; Noble, Rachel T; Taylor, Huw; Wicki, Melanie

2013-11-15

An inter-laboratory study of the accuracy of microbial source tracking (MST) methods was conducted using challenge fecal and sewage samples that were spiked into artificial freshwater and provided as unknowns (blind test samples) to the laboratories. The results of the Source Identification Protocol Project (SIPP) are presented in a series of papers that cover 41 MST methods. This contribution details the results of the virus and bacteriophage methods targeting human fecal or sewage contamination. Human viruses used as source identifiers included adenoviruses (HAdV), enteroviruses (EV), norovirus Groups I and II (NoVI and NoVII), and polyomaviruses (HPyVs). Bacteriophages were also employed, including somatic coliphages and F-specific RNA bacteriophages (FRNAPH) as general indicators of fecal contamination. Bacteriophage methods targeting human fecal sources included genotyping of FRNAPH isolates and plaque formation on bacterial hosts Enterococcus faecium MB-55, Bacteroides HB-73 and Bacteroides GB-124. The use of small sample volumes (≤50 ml) resulted in relatively insensitive theoretical limits of detection (10-50 gene copies or plaques × 50 ml(-1)) which, coupled with low virus concentrations in samples, resulted in high false-negative rates, low sensitivity, and low negative predictive values. On the other hand, the specificity of the human virus methods was generally close to 100% and positive predictive values were ∼40-70% with the exception of NoVs, which were not detected. The bacteriophage methods were generally much less specific toward human sewage than virus methods, although FRNAPH II genotyping was relatively successful, with 18% sensitivity and 85% specificity. While the specificity of the human virus methods engenders great confidence in a positive result, better concentration methods and larger sample volumes must be utilized for greater accuracy of negative results, i.e. the prediction that a human contamination source is absent. Copyright �

Complete Genome Sequences of 38 Gordonia sp. Bacteriophages

PubMed Central

Montgomery, Matthew T.; Bonilla, J. Alfred; Dejong, Randall; Garlena, Rebecca A.; Guerrero Bustamante, Carlos; Klyczek, Karen K.; Russell, Daniel A.; Wertz, John T.; Jacobs-Sera, Deborah; Hatfull, Graham F.

2017-01-01

ABSTRACT We report here the genome sequences of 38 newly isolated bacteriophages using Gordonia terrae 3612 (ATCC 25594) and Gordonia neofelifaecis NRRL59395 as bacterial hosts. All of the phages are double-stranded DNA (dsDNA) tail phages with siphoviral morphologies, with genome sizes ranging from 17,118 bp to 93,843 bp and spanning considerable nucleotide sequence diversity. PMID:28057748

Determinants of affinity and mode of DNA binding at the carboxy terminus of the bacteriophage SPO1-encoded type II DNA-binding protein, TF1.

PubMed

Andera, L; Geiduschek, E P

1994-03-01

The role of the carboxy-terminal amino acids of the bacteriophage SPO1-encoded type II DNA-binding protein, TF1, in DNA binding was analyzed. Chain-terminating mutations truncating the normally 99-amino-acid TF1 at amino acids 96, 97, and 98 were constructed, as were missense mutations substituting cysteine, arginine, and serine for phenylalanine at amino acid 97 and tryptophan for lysine at amino acid 99. The binding of the resulting proteins to a synthetic 44-bp binding site in 5-(hydroxymethyl)uracil DNA, to binding sites in larger SPO1 [5-(hydroxymethyl)uracil-containing] DNA fragments, and to thymine-containing homologous DNA was analyzed by gel retardation and also by DNase I and hydroxy radical footprinting. We conclude that the C tail up to and including phenylalanine at amino acid 97 is essential for DNA binding and that the two C-terminal amino acids, 98 and 99, are involved in protein-protein interactions between TF1 dimers bound to DNA.

Cellular responses in Bacillus thuringiensis CS33 during bacteriophage BtCS33 infection.

PubMed

Wu, Dandan; Yuan, Yihui; Liu, Pengming; Wu, Yan; Gao, Meiying

2014-04-14

Bacillus thuringiensis (Bt) has been widely used for 50years as a biopesticide for controlling insect pests. However, bacteriophage infection can cause failures in 50%-80% of the batches during Bt fermentation, resulting in severe losses. In the present work, the physiological and biochemical impacts of Bt strain CS33 have been studied during bacteriophage infection. This study adopted a gel-based proteomics approach to probe the sequential changed proteins in phage-infected Bt cells. To phage, it depressed the host energy metabolism by suppressing the respiration chain, the TCA cycle, and the utilization of PHB on one hand; on the other hand, it hijacked the host translational machine for its own macromolecular synthesis. To host, superinfection exclusion might be triggered by the changes of S-layer protein and flagella related proteins, which were located on the cell surface and might play as the candidates for the phage recognition. More importantly, the growth rate, cell mass, and ICPs yield were significantly decreased. The low yield of ICPs was mainly due to the suppressed utilization of PHB granules. Further functional study on these altered proteins may lead to a better understanding of the pathogenic mechanisms and the identification of new targets for phage control. B. thuringiensis (Bt) has been widely used for 50years as a safe biopesticide for controlling agricultural and sanitary insect pests. However, bacteriophage infection can cause severe losses during B. thuringiensis fermentation. The processes and consequences of interactions between bacteriophage and Bt were still poorly understood, and the molecular mechanisms involved were more unknown. This study adopted a gel-based proteomics approach to probe the physiological and biochemical impacts of Bt strain CS33 after phage-infection. The interactions between phage BtCS33 and its host Bt strain CS33 occurred mainly on four aspects. First, phage synthesized its nucleic acids through metabolic

Recent advances in M13 bacteriophage-based optical sensing applications.

PubMed

Kim, Inhong; Moon, Jong-Sik; Oh, Jin-Woo

2016-01-01

Recently, M13 bacteriophage has started to be widely used as a functional nanomaterial for various electrical, chemical, or optical applications, such as battery components, photovoltaic cells, sensors, and optics. In addition, the use of M13 bacteriophage has expanded into novel research, such as exciton transporting. In these applications, the versatility of M13 phage is a result of its nontoxic, self-assembling, and specific binding properties. For these reasons, M13 phage is the most powerful candidate as a receptor for transducing chemical or optical phenomena of various analytes into electrical or optical signal. In this review, we will overview the recent progress in optical sensing applications of M13 phage. The structural and functional characters of M13 phage will be described and the recent results in optical sensing application using fluorescence, surface plasmon resonance, Förster resonance energy transfer, and surface enhanced Raman scattering will be outlined.

Recent advances in M13 bacteriophage-based optical sensing applications

NASA Astrophysics Data System (ADS)

Kim, Inhong; Moon, Jong-Sik; Oh, Jin-Woo

2016-10-01

Recently, M13 bacteriophage has started to be widely used as a functional nanomaterial for various electrical, chemical, or optical applications, such as battery components, photovoltaic cells, sensors, and optics. In addition, the use of M13 bacteriophage has expanded into novel research, such as exciton transporting. In these applications, the versatility of M13 phage is a result of its nontoxic, self-assembling, and specific binding properties. For these reasons, M13 phage is the most powerful candidate as a receptor for transducing chemical or optical phenomena of various analytes into electrical or optical signal. In this review, we will overview the recent progress in optical sensing applications of M13 phage. The structural and functional characters of M13 phage will be described and the recent results in optical sensing application using fluorescence, surface plasmon resonance, Förster resonance energy transfer, and surface enhanced Raman scattering will be outlined.

Rapid Identification of Intact Staphylococcal Bacteriophages Using Matrix-Assisted Laser Desorption Ionization-Time-of-Flight Mass Spectrometry.

PubMed

Štveráková, Dana; Šedo, Ondrej; Benešík, Martin; Zdráhal, Zbyněk; Doškař, Jiří; Pantůček, Roman

2018-04-04

Staphylococcus aureus is a major causative agent of infections associated with hospital environments, where antibiotic-resistant strains have emerged as a significant threat. Phage therapy could offer a safe and effective alternative to antibiotics. Phage preparations should comply with quality and safety requirements; therefore, it is important to develop efficient production control technologies. This study was conducted to develop and evaluate a rapid and reliable method for identifying staphylococcal bacteriophages, based on detecting their specific proteins using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) profiling that is among the suggested methods for meeting the regulations of pharmaceutical authorities. Five different phage purification techniques were tested in combination with two MALDI-TOF MS matrices. Phages, either purified by CsCl density gradient centrifugation or as resuspended phage pellets, yielded mass spectra with the highest information value if ferulic acid was used as the MALDI matrix. Phage tail and capsid proteins yielded the strongest signals whereas the culture conditions had no effect on mass spectral quality. Thirty-seven phages from Myoviridae , Siphoviridae or Podoviridae families were analysed, including 23 siphophages belonging to the International Typing Set for human strains of S. aureus , as well as phages in preparations produced by Microgen, Bohemia Pharmaceuticals and MB Pharma. The data obtained demonstrate that MALDI-TOF MS can be used to effectively distinguish between Staphylococcus -specific bacteriophages.

Rapid Identification of Intact Staphylococcal Bacteriophages Using Matrix-Assisted Laser Desorption Ionization-Time-of-Flight Mass Spectrometry

PubMed Central

Štveráková, Dana; Šedo, Ondrej; Benešík, Martin; Zdráhal, Zbyněk; Doškař, Jiří

2018-01-01

Staphylococcus aureus is a major causative agent of infections associated with hospital environments, where antibiotic-resistant strains have emerged as a significant threat. Phage therapy could offer a safe and effective alternative to antibiotics. Phage preparations should comply with quality and safety requirements; therefore, it is important to develop efficient production control technologies. This study was conducted to develop and evaluate a rapid and reliable method for identifying staphylococcal bacteriophages, based on detecting their specific proteins using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) profiling that is among the suggested methods for meeting the regulations of pharmaceutical authorities. Five different phage purification techniques were tested in combination with two MALDI-TOF MS matrices. Phages, either purified by CsCl density gradient centrifugation or as resuspended phage pellets, yielded mass spectra with the highest information value if ferulic acid was used as the MALDI matrix. Phage tail and capsid proteins yielded the strongest signals whereas the culture conditions had no effect on mass spectral quality. Thirty-seven phages from Myoviridae, Siphoviridae or Podoviridae families were analysed, including 23 siphophages belonging to the International Typing Set for human strains of S. aureus, as well as phages in preparations produced by Microgen, Bohemia Pharmaceuticals and MB Pharma. The data obtained demonstrate that MALDI-TOF MS can be used to effectively distinguish between Staphylococcus-specific bacteriophages. PMID:29617332

Productive performance of weanling piglets was improved by administration of a mixture of bacteriophages, targeted to control Coliforms and Clostridium spp. shedding in a challenging environment.

PubMed

Hosseindoust, A R; Lee, S H; Kim, J S; Choi, Y H; Kwon, I K; Chae, B J

2017-10-01

This study was conducted to investigate the effects of bacteriophages in different environments on growth performance, digestibility, ileal and caecal microbiota, gut morphology and immunity of weanling pigs. Two hundred piglets were randomly assigned to four treatment groups with five replicate pens with 10 pigs per pen. A 2 × 2 factorial arrangement of treatments was used to investigate the response of weanling pigs to supplemental bacteriophages (0 and 1.0 g/kg of diet) in contaminated or hygienic environments. Bacteriophages supplementation did not affect average daily gain (ADG), average daily feed intake (ADFI) and gain:feed in phases I and III; however, there was a significant improvement in ADG and gain:feed in phase II. The supplementation of bacteriophages increased the overall gain:feed of pigs. The overall result showed a greater ADG and ADFI in hygienic room. There were reductions in population of both ileal (p < 0.05) and caecal (p < 0.01) Clostridium spp. and ileal coliforms (p < 0.01) with the inclusion of bacteriophages in the diet. Bacteriophages increased ileal Lactobacillus and caecal Bifidobacterium and tended to increase ileal Bifidobacterium (p = 0.08). Contaminated environment decreased ileal Lactobacillus and caecal Bifidobacterium and tended to increase ileal Clostridium (p = 0.08) and coliforms (p = 0.08). Total anaerobic bacteria was tended to decrease (p = 0.06) in contaminated environment. Jejunal villus height increased in pigs received bacteriophages, but they did not affect other morphological items. The interaction between bacteriophages and environment tended to be significant (p = 0.06) for ileal villus height and ileal villus height to crypt depth ratio. The overall faecal score was significantly greater in hygienic environment and bacteriophages groups. The present findings indicate that there is an interactive effect on feed efficiency between bacteriophages and contaminated environment. In addition

Experimental bacteriophage treatment of honeybees (Apis mellifera) infected with Paenibacillus larvae, the causative agent of American Foulbrood Disease

PubMed Central

Yost, Diane G.; Tsourkas, Philippos; Amy, Penny S.

2016-01-01

ABSTRACT American Foulbrood Disease (AFB) is an infection of honeybees caused by the bacterium Paenibacillus larvae. One potential remedy involves using biocontrol, such as bacteriophages (phages) to lyse P. larvae. Therefore, bacteriophages specific for P. larvae were isolated to determine their efficacy in lysing P. larvae cells. Samples from soil, beehive materials, cosmetics, and lysogenized P. larvae strains were screened; of 157 total samples, 28 were positive for at least one P. larvae bacteriophage, with a total of 30. Newly isolated bacteriophages were tested for the ability to lyse each of 11 P. larvae strains. Electron microscopy demonstrated that the phage isolates were from the family Siphoviridae. Seven phages with the broadest host ranges were combined into a cocktail for use in experimental treatments of infected bee larvae; both prophylactic and post-infection treatments were conducted. Results indicated that although both pre- and post-treatments were effective, prophylactic administration of the phages increased the survival of larvae more than post-treatment experiments. These preliminary experiments demonstrate the likelihood that phage therapy could be an effective method to control AFB. PMID:27144085

Evolutionary adaptation of an RNA bacteriophage to the simultaneous increase in the within-host and extracellular temperatures.

PubMed

Lázaro, Ester; Arribas, María; Cabanillas, Laura; Román, Ismael; Acosta, Esther

2018-05-24

Bacteriophages are the most numerous biological entities on Earth. They are on the basis of most ecosystems, regulating the diversity and abundance of bacterial populations and contributing to the nutrient and energy cycles. Bacteriophages have two well differentiated phases in their life cycle, one extracellular, in which they behave as inert particles, and other one inside their hosts, where they replicate to give rise to a progeny. In both phases they are exposed to environmental conditions that often act as selective pressures that limit both their survival in the environment and their ability to replicate, two fitness traits that frequently cannot be optimised simultaneously. In this study we have analysed the evolutionary ability of an RNA bacteriophage, the bacteriophage Qβ, when it is confronted with a temperature increase that affects both the extracellular and the intracellular media. Our results show that Qβ can optimise its survivability when exposed to short-term high temperature extracellular heat shocks, as well as its replicative ability at higher-than-optimal temperature. Mutations responsible for simultaneous adaptation were the same as those selected when adaptation to each condition proceeded separately, showing the absence of important trade-offs between survival and reproduction in this virus.

Immobilization of Active Bacteriophages on Polyhydroxyalkanoate Surfaces.

PubMed

Wang, Chanchan; Sauvageau, Dominic; Elias, Anastasia

2016-01-20

A rapid, efficient technique for the attachment of bacteriophages (phages) onto polyhydroxyalkanoate (PHA) surfaces has been developed and compared to three reported methods for phage immobilization. Polymer surfaces were modified to facilitate phage attachment using (1) plasma treatment alone, (2) plasma treatment followed by activation by 1-ethyl-3-(3-(dimethylamino)propyl)carbodiimide hydrochloride (EDC) and N-hydroxysulfosuccinimide (sulfo-NHS), (3) plasma-initiated acrylic acid grafting, or (4) plasma-initiated acrylic acid grafting with activation by EDC and sulfo-NHS. The impact of each method on the surface chemistry of PHA was investigated using contact angle analysis and X-ray photoelectron spectroscopy. Each of the four treatments was shown to result in both increased hydrophilicity and in the modification of the surface functional groups. Modified surfaces were immersed in suspensions of phage T4 for immobilization. The highest level of phage binding was observed for the surfaces modified by plasma treatment alone. The change in chemical bond states observed for surfaces that underwent plasma treatment is suspected to be the cause of the increased binding of active phages. Plasma-treated surfaces were further analyzed through phage-staining and fluorescence microscopy to assess the surface density of immobilized phages and their capacity to capture hosts. The infective capability of attached phages was confirmed by exposing the phage-immobilized surfaces to the host bacteria Escherichia coli in both plaque and infection dynamic assays. Plasma-treated surfaces with immobilized phages displayed higher infectivity than surfaces treated with other methods; in fact, the equivalent initial multiplicity of infection was 2 orders of magnitude greater than with other methods. Control samples - prepared by immersing polymer surfaces in phage suspensions (without prior plasma treatment) - did not show any bacterial growth inhibition, suggesting they did not bind

Magic-angle spinning NMR of intact bacteriophages: insights into the capsid, DNA and their interface.

PubMed

Abramov, Gili; Morag, Omry; Goldbourt, Amir

2015-04-01

Bacteriophages are viruses that infect bacteria. They are complex macromolecular assemblies, which are composed of multiple protein subunits that protect genomic material and deliver it to specific hosts. Various biophysical techniques have been used to characterize their structure in order to unravel phage morphogenesis. Yet, most bacteriophages are non-crystalline and have very high molecular weights, in the order of tens of MegaDaltons. Therefore, complete atomic-resolution characterization on such systems that encompass both capsid and DNA is scarce. In this perspective article we demonstrate how magic-angle spinning solid-state NMR has and is used to characterize in detail bacteriophage viruses, including filamentous and icosahedral phage. We discuss the process of sample preparation, spectral assignment of both capsid and DNA and the use of chemical shifts and dipolar couplings to probe the capsid-DNA interface, describe capsid structure and dynamics and extract structural differences between viruses. Copyright © 2015 Elsevier Inc. All rights reserved.

Impact of iron particles in groundwater on the UV inactivation of bacteriophages MS2 and T4.

PubMed

Templeton, M R; Andrews, R C; Hofmann, R

2006-09-01

To investigate the impact of iron particles in groundwater on the inactivation of two model viruses, bacteriophages MS2 and T4, by 254-nm ultraviolet (UV) light. One-litre samples of groundwater with high iron content (from the Indianapolis Water Company, mean dissolved iron concentration 1.3 mg l(-1)) were stirred vigorously while exposed to air, which oxidized and precipitated the dissolved iron. In parallel samples, ethylenediaminetetra-acetic acid (EDTA) was added to chelate the iron and prevent formation of iron precipitate. The average turbidity in the samples without EDTA (called the 'raw' samples) after 210 min of stirring was 2.7 +/- 0.1 NTU while the average turbidity of the samples containing EDTA (called the 'preserved' samples) was 1.0 +/- 0.1 NTU. 'Raw' and 'preserved' samples containing bacteriophage MS2 were exposed to 254-nm UV light at doses of 20, 40, or 60 mJ (cm(2))(-1), while samples containing bacteriophage T4 were exposed to 2 or 5 mJ (cm(2))(-1), using a low pressure UV collimated beam. The UV inactivation of both phages in the 'raw' groundwater was lower than in the EDTA-'preserved' groundwater to a statistically significant degree (alpha = 0.05), due to the association of phage with the UV-absorbing iron precipitate particles. A phage elution technique confirmed that a large fraction of the phage that survived the UV exposures were particle-associated. Phages that are associated with iron oxide particles in groundwater are shielded from UV light to a measurable and statistically significant degree at a turbidity level of 2.7 NTU when the phage particle association is induced under experimental conditions. While the particle association of the phage in this study was induced experimentally, the findings provide further evidence that certain particles in natural waters and wastewaters (e.g. iron oxide particles) may have the potential to shield viruses from UV light.

Modified Filamentous Bacteriophage as a Scaffold for Carbon Nanofiber.

PubMed

Szot-Karpińska, Katarzyna; Golec, Piotr; Leśniewski, Adam; Pałys, Barbara; Marken, Frank; Niedziółka-Jönsson, Joanna; Węgrzyn, Grzegorz; Łoś, Marcin

2016-12-21

With the advent of nanotechnology, carbon nanomaterials such as carbon nanofibers (CNF) have aroused substantial interest in various research fields, including energy storage and sensing. Further improvement of their properties might be achieved via the application of viral particles such as bacteriophages. In this report, we present a filamentous M13 bacteriophage with a point mutation in gene VII (pVII-mutant-M13) that selectively binds to the carbon nanofibers to form 3D structures. The phage-display technique was utilized for the selection of the pVII-mutant-M13 phage from the phage display peptide library. The properties of this phage make it a prospective candidate for a scaffold material for CNFs. The results for binding of CNF by mutant phage were compared with those for maternal bacteriophage (pVII-M13). The efficiency of binding between pVII-mutant-M13 and CNF is about 2 orders of magnitude higher compared to that of the pVII-M13. Binding affinity between pVII-mutant-M13 and CNF was also characterized using atomic force microscopy, scanning electron microscopy, and transmission electron microscopy, which confirmed the specificity of the interaction of the phage pVII-mutant-M13 and the CNF; the binding occurs via the phage's ending, where the mutated pVII protein is located. No similar behavior has been observed for other carbon nanomaterials such as graphite, reduced graphene oxide, single-walled carbon nanotubes, and multiwalled carbon nanotubes. Infrared spectra confirmed differences in the interaction with CNF between the pVII-mutant-M13 and the pVII-M13. Basing on conducted research, we hypothesize that the interactions are noncovalent in nature, with π-π interactions playing the dominant role. Herein, the new bioconjugate material is introduced.

The endolysins of bacteriophages CMP1 and CN77 are specific for the lysis of Clavibacter michiganensis strains.

PubMed

Wittmann, Johannes; Eichenlaub, Rudolf; Dreiseikelmann, Brigitte

2010-08-01

Putative endolysin genes of bacteriophages CMP1 and CN77, which infect Clavibacter michiganensis subsp. michiganensis and C. michiganensis subsp. nebraskensis, respectively, were cloned and expressed in Escherichia coli. The His-tagged endolysin of CMP1 consists of 306 amino acids and has a calculated molecular mass of 34.8 kDa, while the His-tagged endolysin of CN77 has 290 amino acids with a molecular mass of 31.9 kDa. The proteins were purified and their bacteriolytic activity was demonstrated. The bacteriolytic activity of both enzymes showed a host range which was limited to the respective C. michiganensis subspecies and did not affect other bacteria, even those closely related to Clavibacter. Due to the high specificity of the CMP1 and CN77 endolysins they may be useful tools for biocontrol of plant-pathogenic C. michiganensis without affecting other bacteria in the soil.

Application of zinc chloride precipitation method for rapid isolation and concentration of infectious Pectobacterium spp. and Dickeya spp. lytic bacteriophages from surface water and plant and soil extracts.

PubMed

Czajkowski, Robert; Ozymko, Zofia; Lojkowska, Ewa

2016-01-01

This is the first report describing precipitation of bacteriophage particles with zinc chloride as a method of choice to isolate infectious lytic bacteriophages against Pectobacterium spp. and Dickeya spp. from environmental samples. The isolated bacteriophages are ready to use to study various (ecological) aspects of bacteria-bacteriophage interactions. The method comprises the well-known precipitation of phages from aqueous extracts of the test material by addition of ZnCl2, resuscitation of bacteriophage particles in Ringer's buffer to remove the ZnCl2 excess and a soft agar overlay assay with the host bacterium to isolate infectious individual phage plaques. The method requires neither an enrichment step nor other steps (e. g., PEG precipitation, ultrafiltration, or ultracentrifugation) commonly used in other procedures and results in isolation of active viable bacteriophage particles.

Crystallographic Insights into the Autocatalytic Assembly Mechanism of a Bacteriophage Tail Spike

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xiang, Ye; Leiman, Petr G.; Li, Long

2010-02-03

The tailed bacteriophage phi29 has 12 'appendages' (gene product 12, gp12) attached to its neck region that participate in host cell recognition and entry. In the cell, monomeric gp12 undergoes proteolytic processing that releases the C-terminal domain during assembly into trimers. We report here crystal structures of the protein before and after catalytic processing and show that the C-terminal domain of gp12 is an 'autochaperone' that aids trimerization. We also show that autocleavage of the C-terminal domain is a posttrimerization event that is followed by a unique ATP-dependent release. The posttranslationally modified N-terminal part has three domains that function tomore » attach the appendages to the phage, digest the cell wall teichoic acids, and bind irreversibly to the host, respectively. Structural and sequence comparisons suggest that some eukaryotic and bacterial viruses as well as bacterial adhesins might have a similar maturation mechanism as is performed by phi29 gp12 for Bacillus subtilis.« less

Helicase-dependent amplification of nucleic acids.

PubMed

Cao, Yun; Kim, Hyun-Jin; Li, Ying; Kong, Huimin; Lemieux, Bertrand

2013-10-11

Helicase-dependent amplification (HDA) is a novel method for the isothermal in vitro amplification of nucleic acids. The HDA reaction selectively amplifies a target sequence by extension of two oligonucleotide primers. Unlike the polymerase chain reaction (PCR), HDA uses a helicase enzyme to separate the deoxyribonucleic acid (DNA) strands, rather than heat denaturation. This allows DNA amplification without the need for thermal cycling. The helicase used in HDA is a helicase super family II protein obtained from a thermophilic organism, Thermoanaerobacter tengcongensis (TteUvrD). This thermostable helicase is capable of unwinding blunt-end nucleic acid substrates at elevated temperatures (60° to 65°C). The HDA reaction can also be coupled with reverse transcription for ribonucleic acid (RNA) amplification. The products of this reaction can be detected during the reaction using fluorescent probes when incubations are conducted in a fluorimeter. Alternatively, products can be detected after amplification using a disposable amplicon containment device that contains an embedded lateral flow strip. Copyright © 2013 John Wiley & Sons, Inc.

First steps of bacteriophage SPP1 entry into Bacillus subtilis.

PubMed

Jakutytė, Lina; Lurz, Rudi; Baptista, Catarina; Carballido-Lopez, Rut; São-José, Carlos; Tavares, Paulo; Daugelavičius, Rimantas

2012-01-20

The mechanism of genome transfer from the virion to the host cytoplasm is critical to understand and control the beginning of viral infection. The initial steps of bacteriophage SPP1 infection of the Gram-positive bacterium Bacillus subtilis were monitored by following changes in permeability of the cytoplasmic membrane (CM). SPP1 leads to a distinctively faster CM depolarization than the one caused by podovirus ϕ29 or myovirus SP01 during B. subtilis infection. Depolarization requires interaction of SPP1 infective virion to its receptor protein YueB. The amplitude of depolarization depends on phage input and concentration of YueB at the cell surface. Sub-millimolar concentrations of Ca(2+) are necessary and sufficient for SPP1 reversible binding to the host envelope and thus to trigger depolarization while DNA delivery to the cytoplasm depends on millimolar concentrations of this divalent cation. A model describing the early events of bacteriophage SPP1 infection is presented. Copyright © 2011 Elsevier Inc. All rights reserved.

Genomic characterization of key bacteriophages to formulate the potential biocontrol agent to combat enteric pathogenic bacteria.

PubMed

Parmar, Krupa M; Dafale, Nishant A; Tikariha, Hitesh; Purohit, Hemant J

2018-05-01

Combating bacterial pathogens has become a global concern especially when the antibiotics and chemical agents are failing to control the spread due to its resistance. Bacteriophages act as a safe biocontrol agent by selectively lysing the bacterial pathogens without affecting the natural beneficial microflora. The present study describes the screening of prominent enteric pathogens NDK1, NDK2, NDK3, and NDK4 (Escherichia, Klebsiella, Enterobacter, and Serratia) mostly observed in domestic wastewater; against which KNP1, KNP2, KNP3, and KNP4 phages were isolated. To analyze their potential role in eradicating enteric pathogens and toxicity issue, these bacteriophages were sequenced using next-generation sequencing and characterized based on its genomic content. The isolated bacteriophages were homologous to Escherichia phage (KNP1), Klebsiella phage (KNP2), Enterobacter phage (KNP3), Serratia phage (KNP4), and belonged to Myoviridae family of Caudovirales except for the unclassified KNP4 phage. Draft genome analysis revealed the presence of lytic enzymes such as holing and lysozyme in KNP1 phage, endolysin in KNP2 phage, and endopeptidase with holin in KNP3 phage. The absence of any lysogenic and virulent genes makes this bacteriophage suitable candidate for preparation of phage cocktail to combat the pathogens present in wastewater. However, KNP4 contained a virulent gene rendering it unsuitable to be used as a biocontrol agent. These findings make the phages (KNP1-KNP3) as a promising alternative for the biocontrol of pathogens in wastewater which is the main culprit to spread these dominated pathogens in different natural water bodies. This study also necessitates for genomic screening of bacteriophages for lysogenic and virulence genes prior to its use as a biocontrol agent.

Application of a bacteriophage lysin to disrupt biofilms formed by the animal pathogen Streptococcus suis.

PubMed

Meng, Xiangpeng; Shi, Yibo; Ji, Wenhui; Meng, Xueling; Zhang, Jing; Wang, Hengan; Lu, Chengping; Sun, Jianhe; Yan, Yaxian

2011-12-01

Bacterial biofilms are crucial to the pathogenesis of many important infections and are difficult to eradicate. Streptococcus suis is an important pathogen of pigs, and here the biofilm-forming ability of 32 strains of this species was determined. Significant biofilms were completely formed by 10 of the strains after 60 h of incubation, with exopolysaccharide production in the biofilm significantly higher than that in the corresponding planktonic cultures. S. suis strain SS2-4 formed a dense biofilm, as revealed by scanning electron microscopy, and in this state exhibited increased resistance to a number of antibiotics (ampicillin, amoxicillin, ciprofloxacin, kanamycin, and rifampin) compared to that of planktonic cultures. A bacteriophage lysin, designated LySMP, was used to attack biofilms alone and in combination with antibiotics and bacteriophage. The results demonstrated that the biofilms formed by S. suis, especially strains SS2-4 and SS2-H, could be dispersed by LySMP and with >80% removal compared to a biofilm reduction by treatment with either antibiotics or bacteriophage alone of less than 20%; in addition to disruption of the biofilm structure, the S. suis cells themselves were inactivated by LySMP. The efficacy of LySMP was not dose dependent, and in combination with antibiotics, it acted synergistically to maximize dispersal of the S. suis biofilm and inactivate the released cells. These data suggest that bacteriophage lysin could form part of an effective strategy to treat S. suis infections and represents a new class of antibiofilm agents.

A model system for pathogen detection using a two-component bacteriophage/bioluminescent signal amplification assay

NASA Astrophysics Data System (ADS)

Bright, Nathan G.; Carroll, Richard J.; Applegate, Bruce M.

2004-03-01

Microbial contamination has become a mounting concern the last decade due to an increased emphasis of minimally processed food products specifically produce, and the recognition of foodborne pathogens such as Campylobacter jejuni, Escherichia coli O157:H7, and Listeria monocytogenes. This research investigates a detection approach utilizing bacteriophage pathogen specificity coupled with a bacterial bioluminescent bioreporter utilizing the quorum sensing molecule from Vibrio fischeri, N-(3-oxohexanoyl)-homoserine lactone (3-oxo-C6-HSL). The 3-oxo-C6-HSL molecules diffuse out of the target cell after infection and induce bioluminescence from a population of 3-oxo-C6-HSL bioreporters (ROLux). E. coli phage M13, a well-characterized bacteriophage, offers a model system testing the use of bacteriophage for pathogen detection through cell-to-cell communication via a LuxR/3-oxo-C6-HSL system. Simulated temperate phage assays tested functionality of the ROLux reporter and production of 3-oxo-C6-HSL by various test strains. These assays showed detection limits of 102cfu after 24 hours in a varietry of detection formats. Assays incorporating the bacteriophage M13-luxI with the ROLux reporter and a known population of target cells were subsequently developed and have shown consistent detection limits of 105cfu target organisms. Measurable light response from high concentrations of target cells was almost immediate, suggesting an enrichment step to further improve detection limits and reduce assay time.

Bacteriophages for treating urinary tract infections in patients undergoing transurethral resection of the prostate: a randomized, placebo-controlled, double-blind clinical trial.

PubMed

Leitner, Lorenz; Sybesma, Wilbert; Chanishvili, Nina; Goderdzishvili, Marina; Chkhotua, Archil; Ujmajuridze, Aleksandre; Schneider, Marc P; Sartori, Andrea; Mehnert, Ulrich; Bachmann, Lucas M; Kessler, Thomas M

2017-09-26

Urinary tract infections (UTI) are among the most prevalent microbial diseases and their financial burden on society is substantial. The continuing increase of antibiotic resistance worldwide is alarming. Thus, well-tolerated, highly effective therapeutic alternatives are urgently needed. Although there is evidence indicating that bacteriophage therapy may be effective and safe for treating UTIs, the number of investigated patients is low and there is a lack of randomized controlled trials. This study is the first randomized, placebo-controlled, double-blind trial investigating bacteriophages in UTI treatment. Patients planned for transurethral resection of the prostate are screened for UTIs and enrolled if in urine culture eligible microorganisms ≥10 4 colony forming units/mL are found. Patients are randomized in a double-blind fashion to the 3 study treatment arms in a 1:1:1 ratio to receive either: a) bacteriophage (i.e. commercially available Pyo bacteriophage) solution, b) placebo solution, or c) antibiotic treatment according to the antibiotic sensitivity pattern. All treatments are intended for 7 days. No antibiotic prophylaxes will be given to the double-blinded treatment arms a) and b). As common practice, the Pyo bacteriophage cocktail is subjected to periodic adaptation cycles during the study. Urinalysis, urine culture, bladder and pain diary, and IPSS questionnaire will be completed prior to and at the end of treatment (i.e. after 7 days) or at withdrawal/drop out from the study. Patients with persistent UTIs will undergo antibiotic treatment according to antibiotic sensitivity pattern. Based on the high lytic activity and the potential of resistance optimization by direct adaptation of bacteriophages, and considering the continuing increase of antibiotic resistance worldwide, bacteriophage therapy is a very promising treatment option for UTIs. Thus, our randomized controlled trial investigating bacteriophages for treating UTIs will provide

Chemostat studies of bacteriophage M13 infected Escherichia coli JM109 for continuous ssDNA production.

PubMed

Kick, Benjamin; Behler, Karl Lorenz; Severin, Timm Steffen; Weuster-Botz, Dirk

2017-09-20

Steady state studies in a chemostat enable the control of microbial growth rate at defined reaction conditions. The effects of bacteriophage M13 infection on maximum growth rate of Escherichia coli JM109 were studied in parallel operated chemostats on a milliliter-scale to analyze the steady state kinetics of phage production. The bacteriophage infection led to a decrease in maximum specific growth rate of 15% from 0.74h -1 to 0.63h -1 . Under steady state conditions, a constant cell specific ssDNA formation rate of 0.15±0.004 mg ssDNA g CDW -1 h -1 was observed, which was independent of the growth rate. Using the estimated kinetic parameters for E. coli infected with bacteriophage M13, the ssDNA concentration in the steady state could be predicted as function of the dilution rate and the glucose concentration in the substrate. Scalability of milliliter-scale data was approved by steady state studies on a liter-scale at a selected dilution rate. An ssDNA space-time yield of 5.7mgL -1 h -1 was achieved with increased glucose concentration in the feed at a dilution rate of 0.3h -1 , which is comparable to established fed-batch fermentation with bacteriophage M13 for ssDNA production. Copyright © 2017 Elsevier B.V. All rights reserved.

Spray-dried respirable powders containing bacteriophages for the treatment of pulmonary infections.

PubMed

Matinkhoo, Sadaf; Lynch, Karlene H; Dennis, Jonathan J; Finlay, Warren H; Vehring, Reinhard

2011-12-01

Myoviridae bacteriophages were processed into a dry powder inhalable dosage form using a low-temperature spray-drying process. The phages were incorporated into microparticles consisting of trehalose, leucine, and optionally a third excipient (either a surfactant or casein sodium salt). The particles were designed to have high dispersibility and a respirable particle size, and to preserve the phages during processing. Bacteriophages KS4- M, KS14, and cocktails of phages ΦKZ/D3 and ΦKZ/D3/KS4-M were spray-dried with a processing loss ranging from 0.4 to 0.8 log pfu. The aerosol performance of the resulting dry powders as delivered from an Aerolizer® dry powder inhaler (DPI) exceeded the performance of commercially available DPIs; the emitted mass and the in vitro total lung mass of the lead formulation were 82.7% and 69.7% of filled capsule mass, respectively. The total lung mass had a mass median aerodynamic diameter of 2.5-2.8 µm. The total in vitro lung doses of the phages, delivered from a single actuation of the inhaler, ranged from 10(7) to 10(8) pfu, levels that are expected to be efficacious in vivo. Spray drying of bacteriophages into a respirable dry powder was found to be feasible. Copyright © 2011 Wiley-Liss, Inc.

Direct feeding of microencapsulated bacteriophages to reduce Salmonella colonization in pigs

USDA-ARS?s Scientific Manuscript database

Salmonella shedding often increases in pigs following pre-slaughter transportation and/or lairage. We previously showed that administering anti-Salmonella bacteriophages to pigs by gavage significantly reduced Salmonella colonization when the pigs were exposed to a Salmonella-contaminated pen. In ...

Molecular Basis for Lytic Bacteriophage Resistance in Enterococci.

PubMed

Duerkop, Breck A; Huo, Wenwen; Bhardwaj, Pooja; Palmer, Kelli L; Hooper, Lora V

2016-08-30

The human intestine harbors diverse communities of bacteria and bacteriophages. Given the specificity of phages for their bacterial hosts, there is growing interest in using phage therapies to combat the rising incidence of multidrug-resistant bacterial infections. A significant barrier to such therapies is the rapid development of phage-resistant bacteria, highlighting the need to understand how bacteria acquire phage resistance in vivo Here we identify novel lytic phages in municipal raw sewage that kill Enterococcus faecalis, a Gram-positive opportunistic pathogen that resides in the human intestine. We show that phage infection of E. faecalis requires a predicted integral membrane protein that we have named PIPEF (for phage infection protein from E. faecalis). We find that PIPEF is conserved in E. faecalis and harbors a 160-amino-acid hypervariable region that determines phage tropism for distinct enterococcal strains. Finally, we use a gnotobiotic mouse model of in vivo phage predation to show that the sewage phages temporarily reduce E. faecalis colonization of the intestine but that E. faecalis acquires phage resistance through mutations in PIPEF Our findings define the molecular basis for an evolutionary arms race between E. faecalis and the lytic phages that prey on them. They also suggest approaches for engineering E. faecalis phages that have altered host specificity and that can subvert phage resistance in the host bacteria. Bacteriophage therapy has received renewed attention as a potential solution to the rise in antibiotic-resistant bacterial infections. However, bacteria can acquire phage resistance, posing a major barrier to phage therapy. To overcome this problem, it is necessary to understand phage resistance mechanisms in bacteria. We have unraveled one such resistance mechanism in Enterococcus faecalis, a Gram-positive natural resident of the human intestine that has acquired antibiotic resistance and can cause opportunistic infections

Effects of Bacteriophage Supplementation on Egg Performance, Egg Quality, Excreta Microflora, and Moisture Content in Laying Hens

PubMed Central

Zhao, P. Y.; Baek, H. Y.; Kim, I. H.

2012-01-01

An experiment was conducted to evaluate the effects of bacteriophage supplementation on egg performance, egg quality, excreta microflora, and moisture content in laying hens. A total of 288 Hy-line brown commercial laying hens (36-wk-old) were randomly allotted to 4 treatments in this 6-wk trial and dietary treatments included: i) CON, basal diet; ii) T1, CON+0.020% bacteriophage; iii) T2, CON+0.035% bacteriophage; iv) T3, CON+0.050% bacteriophage. There were 6 replicates for each treatment with 6 adjacent cages (2 hens/cage). Laying hens in T2 and T3 treatments had higher (p<0.05) egg production than those in CON and T1 treatments during wk 0 to 3. In addition, egg production in T1, T2, and T3 treatments was increased (p<0.05) compared with that in CON treatment during wk 4 to 6. At wk 4 and 5, birds in T2 group had higher (p<0.05) HU than those in CON. In addition, at wk 5 and 6, HU in birds fed T1 and T3 diets was greater (p<0.05) than those fed CON diet. E. coli and Salmonella spp. concentrations in excreta were decreased (p<0.05) by T1, T2, and T3 treatments. However, egg weight, egg shell color, yolk height, yolk color unit, egg shell strength, egg shell thickness, egg gravity, and excreta moisture content were not influenced by dietary treatments during the entire experimental period. In conclusion, bacteriophage supplementation has beneficial effects on egg production, egg albumen, and excreta microflora concentration in laying hens. PMID:25049658

Effect of bacterial growth rate on bacteriophage population growth rate.

PubMed

Nabergoj, Dominik; Modic, Petra; Podgornik, Aleš

2018-04-01

It is important to understand how physiological state of the host influence propagation of bacteriophages (phages), due to the potential higher phage production needs in the future. In our study, we tried to elucidate the effect of bacterial growth rate on adsorption constant (δ), latent period (L), burst size (b), and bacteriophage population growth rate (λ). As a model system, a well-studied phage T4 and Escherichia coli K-12 as a host was used. Bacteria were grown in a continuous culture operating at dilution rates in the range between 0.06 and 0.98 hr -1 . It was found that the burst size increases linearly from 8 PFU·cell -1 to 89 PFU·cell -1 with increase in bacteria growth rate. On the other hand, adsorption constant and latent period were both decreasing from 2.6∙10 -9  ml·min -1 and 80 min to reach limiting values of 0.5 × 10 -9  ml·min -1 and 27 min at higher growth rates, respectively. Both trends were mathematically described with Michaelis-Menten based type of equation and reasons for such form are discussed. By applying selected equations, a mathematical equation for prediction of bacteriophage population growth rate as a function of dilution rate was derived, reaching values around 8 hr -1 at highest dilution rate. Interestingly, almost identical description can be obtained using much simpler Monod type equation and possible reasons for this finding are discussed. © 2017 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

Biodiversity of bacteriophages: morphological and biological properties of a large group of phages isolated from urban sewage

PubMed Central

Jurczak-Kurek, Agata; Gąsior, Tomasz; Nejman-Faleńczyk, Bożena; Bloch, Sylwia; Dydecka, Aleksandra; Topka, Gracja; Necel, Agnieszka; Jakubowska-Deredas, Magdalena; Narajczyk, Magdalena; Richert, Malwina; Mieszkowska, Agata; Wróbel, Borys; Węgrzyn, Grzegorz; Węgrzyn, Alicja

2016-01-01

A large scale analysis presented in this article focuses on biological and physiological variety of bacteriophages. A collection of 83 bacteriophages, isolated from urban sewage and able to propagate in cells of different bacterial hosts, has been obtained (60 infecting Escherichia coli, 10 infecting Pseudomonas aeruginosa, 4 infecting Salmonella enterica, 3 infecting Staphylococcus sciuri, and 6 infecting Enterococcus faecalis). High biological diversity of the collection is indicated by its characteristics, both morphological (electron microscopic analyses) and biological (host range, plaque size and morphology, growth at various temperatures, thermal inactivation, sensitivity to low and high pH, sensitivity to osmotic stress, survivability upon treatment with organic solvents and detergents), and further supported by hierarchical cluster analysis. By the end of the research no larger collection of phages from a single environmental source investigated by these means had been found. The finding was confirmed by whole genome analysis of 7 selected bacteriophages. Moreover, particular bacteriophages revealed unusual biological features, like the ability to form plaques at low temperature (4 °C), resist high temperature (62 °C or 95 °C) or survive in the presence of an organic solvents (ethanol, acetone, DMSO, chloroform) or detergent (SDS, CTAB, sarkosyl) making them potentially interesting in the context of biotechnological applications. PMID:27698408

Isolation and characterization of two lytic cold-active bacteriophages infecting Pseudomonas fluorescens from the Napahai plateau wetland.

PubMed

Xiang, Yingying; Wang, Shuang; Li, Jiankai; Wei, Yunlin; Zhang, Qi; Lin, Lianbing; Ji, Xiuling

2018-03-01

As the "kidneys of the Earth", wetlands play important roles as biodiversity reservoirs, in water purification, and in flood control. In this study, 2 lytic cold-active bacteriophages, named VW-6S and VW-6B, infecting Pseudomonas fluorescens W-6 cells from the Napahai plateau wetland in China were isolated and characterized. Electron microscopy showed that both VW-6S and VW-6B had an icosahedral head (66.7 and 61.1 nm, respectively) and a long tail (8.3 nm width × 233.3 nm length and 11.1 nm width × 166.7 nm length, respectively). The bacteriophages VW-6S and VW-6B were classified as Siphoviridae and had an approximate genome size of 30-40 kb. The latent and burst periods of VW-6S were 60 and 30 min, whereas those of VW-6B were 30 and 30 min, respectively. The optimal pH values for the bacteriophages VW-6S and VW-6B were 8.0 and 10.0, respectively, and their activity decreased rapidly at temperatures higher than 60 °C. These cold-active bacteriophages provide good materials for further study of cold-adaptation mechanisms and interaction with the host P. fluorescens.

Preparation of Single-Stranded Bacteriophage M13 DNA by Precipitation with Polyethylene Glycol.

PubMed

Green, Michael R; Sambrook, Joseph

2017-11-01

Bacteriophage M13 single-stranded DNA is prepared from virus particles secreted by infected bacteria into the surrounding medium. Several methods are available to purify the polymorphic filamentous particles. In this protocol, the particles are concentrated by precipitation with polyethylene glycol (PEG) in the presence of high salt. Subsequent extraction with phenol releases the single-stranded DNA, which is then collected by precipitation with ethanol. The resulting preparation is pure enough to be used as a template for DNA sequencing. A yield of 5-10 µg of single-stranded DNA/mL of infected cells may be expected from recombinant bacteriophages bearing inserts of 300-1000 nt. © 2017 Cold Spring Harbor Laboratory Press.

Crystal and cryoEM structural studies of a cell wall degrading enzyme in the bacteriophage [psi]29 tail

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xiang, Ye; Morais, Marc C.; Cohen, Daniel N.

2009-08-28

The small bacteriophage {phi}29 must penetrate the {approx}250-{angstrom} thick external peptidoglycan cell wall and cell membrane of the Gram-positive Bacillus subtilis, before ejecting its dsDNA genome through its tail into the bacterial cytoplasm. The tail of bacteriophage {phi}29 is noncontractile and {approx}380 {angstrom} long. A 1.8-{angstrom} resolution crystal structure of gene product 13 (gp13) shows that this tail protein has spatially well separated N- and C-terminal domains, whose structures resemble lysozyme-like enzymes and metallo-endopeptidases, respectively. CryoEM reconstructions of the WT bacteriophage and mutant bacteriophages missing some or most of gp13 shows that this enzyme is located at the distal endmore » of the {phi}29 tail knob. This finding suggests that gp13 functions as a tail-associated, peptidoglycan-degrading enzyme able to cleave both the polysaccharide backbone and peptide cross-links of the peptidoglycan cell wall. Comparisons of the gp13{sup -} mutants with the {phi}29 mature and emptied phage structures suggest the sequence of events that occur during the penetration of the tail through the peptidoglycan layer.« less

Homology among tet determinants in conjugative elements of streptococci.

PubMed Central

Smith, M D; Hazum, S; Guild, W R

1981-01-01

A mutation to tetracycline sensitivity in a resistant strain of Streptococcus pneumoniae was shown by several criteria to be due to a point mutation in the conjugative omega (cat-tet) element found in the chromosomes of strains derived from BM6001, a clinical strain resistant to tetracycline and chloramphenicol. Strains carrying the mutation were transformed back to tetracycline resistance with the high efficiency of a point marker by donor deoxyribonucleic acids from its ancestral strain and from nine other clinical isolates of pneumococcus and by deoxyribonucleic acids from group D Streptococcus faecalis and group B Streptococcus agalactiae strains that also carry conjugative tet elements in their chromosomes. It was not transformed to resistance by tet plasmid deoxyribonucleic acids from either gram-negative or gram-positive species, except for one that carried transposon Tn916, the conjugative tet element present in the chromosomes of some S. faecalis strains. The results showed that the tet determinants in conjugative elements of several streptococcal species share a high degree of deoxyribonucleic acid sequence homology and suggested that they differ from other tet genes. PMID:6270063

Complementary deoxyribonucleic acid cloning of spermatogonial stem cell renewal factor.

PubMed

Miura, Takeshi; Ohta, Takashi; Miura, Chiemi I; Yamauchi, Kohei

2003-12-01

Spermatogonial mitosis can be subdivided into two processes: spermatogonial stem cell renewal and spermatogonial proliferation toward meiosis. Recently it has been indicated that estrogen, estradiol-17beta, is involved in regulating the renewal of spermatogonial stem cells in eel. To determine the genes that directly regulate this process, we used expression screening to identify genes whose expression is regulated by estradiol-17beta in testes. We detected a previously unidentified cDNA clone that is up-regulated by estradiol-17beta stimulation and named it eel spermatogenesis-related substances 34 (eSRS34) cDNA. Homology searching showed that eSRS34 shares amino acid sequence similarity with human platelet-derived endothelial cell growth factor. We examined the function of eSRS34 using several in vitro systems. Recombinant eSRS34 produced by a baculovirus system induced spermatogonial mitosis in testicular organ culture. Furthermore, the addition of an antibody specific for eSRS34 prevented spermatogonial mitosis induced by estradiol-17beta stimulation in a germ cell/somatic cell coculture system. We therefore conclude that eSRS34 is a "spermatogonial stem cell renewal factor."

Isolation and characterization of Yersinia-specific bacteriophages from pig stools in Finland.

PubMed

Salem, M; Virtanen, S; Korkeala, H; Skurnik, M

2015-03-01

Bacteriophages infect bacteria, and they are present everywhere in the world including the intestinal tracts of animals. Yersiniosis is a common foodborne infection caused by Yersinia enterocolitica and Yersinia pseudotuberculosis. As these bacteria are frequently isolated from pigs, we wanted to know whether Yersinia-specific bacteriophages are also present in the pig stools and, if so, whether there is a positive or negative association between the prevalence of the Yersinia phages and the pathogenic Yersinia in the stool samples. Altogether 793 pig stool samples collected between November 2010 and March 2012 from 14 Finnish pig farms were screened for the presence of bacteriophages able to infect Y. enterocolitica serotype O:3, O:5,27 or O:9 strains, or Y. pseudotuberculosis serotype O:1a, O:1b or O:3 strains. Yersinia phages were isolated from 90 samples from eight farms. Yersinia enterocolitica O:3 was infected by 59 phages, 28 phages infected serotypes O:3 and O:5,27, and eight phages infected serotypes O:3, O:5,27 and O:9, and Y. pseudotuberculosis O:1a by eight phages. Many phages originating from pigs in the same farm were identical based on their restriction enzyme digestion patterns; 20 clearly different phages were selected for further characterization. Host ranges of these phages were tested with 94 Yersinia strains. Six of the phages infected eight strains, 13 phages infected three strains, and one phage infected only one strain, indicating that the phages had a relatively narrow host range. There was a clear association between the presence of the host bacteria and specific phages in the stools. The isolated bacteriophages may have potential as biocontrol agents for yersiniosis in both humans and pigs in future, and as alternatives or in addition to antibiotics. To our knowledge, this is the first reported isolation of Yersinia-specific phages from pig stool samples. © 2014 The Society for Applied Microbiology.