Fighting foam with phages?

2002 ◽  
Vol 46 (1-2) ◽  
pp. 511-518 ◽  
Author(s):  
J.A. Thomas ◽  
J.A. Soddell ◽  
D.I. Kurtböke
Keyword(s):  
Activated Sludge ◽  
Host Range ◽  
Contractile Tail ◽  
Icosahedral Head

Seventeen (17) phages infective for the mycolata were isolated from six samples of activated sludge using 21 prospective hosts from the genera Dietzia, Gordonia, Nocardia, Rhodococcus, Tsukamurella and Mycobacterium. Their morphology indicated that they were all members of the viral family Siphoviridae, but they varied in the size of the icosahedral head and length of non-contractile tail, suggesting they were different. This was confirmed by host-range studies with 47 strains of mycolata, which showed that each phage had a unique host-range, and this was polyvalent in the majority (15/17) of cases, with 12 phages infective for hosts representing two or three of the genera Gordonia, Nocardia and Rhodococcus. The potential for use of these phages in the control of foaming and other applications is discussed.

Bacteriophage-host interaction in the enhanced biological phosphate removing activated sludge system

2002 ◽  
Vol 46 (1-2) ◽  
pp. 39-43 ◽  
Author(s):  
M.A. Khan ◽  
H. Satoh ◽  
T. Mino ◽  
H. Katayama ◽  
F. Kurisu ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Host Range ◽  
Plaque Formation ◽  
Complex Interaction ◽  
Activated Sludge Process ◽  
Bacterial Isolates ◽  
Bacterial Host ◽  
Microbial Ecosystem ◽  
Host Interaction ◽  
Range Test

Bacteriophages were isolated from a laboratory scale enhanced biological phosphate removing (EBPR) activated sludge process, and their host range was examined. Bacterial isolates to host the bacteriophages were isolated from the EBPR activated sludge process. Bacteriophages were eluted from the EBPR activated sludge, enriched by incubation with the bacterial isolates, and then tested for plaque formation on each of the bacterial isolates. Out of 12 bacterial isolates isolated, 4 supported plaque formation. Four bacteriophages were obtained from the plaques. The host range test was conducted with the combination of the bacteriophage isolates and the bacterial isolates. Three of the bacteriophages were found to form plaques on more than one host, and one of them formed plaques on both Gram +ve and Gram −ve bacterial isolates. Two of the four bacteriophages failed to form plaques on their original bacterial host, indicating the existence of mutation on either both or one of the host and the bacteriophage. This study strongly suggests that bacteriophages are an active part of the activated sludge microbial ecosystem, having very complex interaction with their host bacteria.

scholarly journals Plasmid Donor Affects Host Range of Promiscuous IncP-1β Plasmid pB10 in an Activated-Sludge Microbial Community

2005 ◽  
Vol 71 (9) ◽  
pp. 5309-5317 ◽  
Author(s):  
Leen De Gelder ◽  
Frederik P. J. Vandecasteele ◽  
Celeste J. Brown ◽  
Larry J. Forney ◽  
Eva M. Top
Keyword(s):  
Microbial Community ◽  
Activated Sludge ◽  
Host Range ◽  
Sinorhizobium Meliloti ◽  
Ralstonia Eutropha ◽  
Rrna Gene ◽  
Broad Host Range ◽  
Donor Strain ◽  
Broad Host Range Plasmid ◽  
Mating Conditions

ABSTRACT Horizontal transfer of multiresistance plasmids in the environment contributes to the growing problem of drug-resistant pathogens. Even though the plasmid host cell is the primary environment in which the plasmid functions, possible effects of the plasmid donor on the range of bacteria to which plasmids spread in microbial communities have not been investigated. In this study we show that the host range of a broad-host-range plasmid within an activated-sludge microbial community was influenced by the donor strain and that various mating conditions and isolation strategies increased the diversity of transconjugants detected. To detect transconjugants, the plasmid pB10 was marked with lacp-rfp, while rfp expression was repressed in the donors by chromosomal lacI q. The phylogeny of 306 transconjugants obtained was determined by analysis of partial 16S rRNA gene sequences. The transconjugants belonged to 15 genera of the α- and γ-Proteobacteria. The phylogenetic diversity of transconjugants obtained in separate matings with donors Pseudomonas putida SM1443, Ralstonia eutropha JMP228, and Sinorhizobium meliloti RM1021 was significantly different. For example, the transconjugants obtained after matings in sludge with S. meliloti RM1021 included eight genera that were not represented among the transconjugants obtained with the other two donors. Our results indicate that the spectrum of hosts to which a promiscuous plasmid transfers in a microbial community can be strongly influenced by the donor from which it transfers.

Spontaneous induction of bacteriophage during growth of Azospirillum brasilense in complex media

1984 ◽  
Vol 30 (6) ◽  
pp. 805-808 ◽  
Author(s):  
James J. Germida
Keyword(s):  
Electron Microscopy ◽  
Host Range ◽  
Azospirillum Brasilense ◽  
Divalent Cations ◽  
Complex Media ◽  
Icosahedral Head

Spontaneous induction of bacteriophage occurred during growth of Azospirillum brasilense ATCC 29145 in complex media incubated at 27 or 30 °C under agitated and nonagitated conditions. Phage replication on strain 29145 was stimulated by divalent cations and inhibited by NaCl or temperatures greater than 37 °C. The phage morphology as revealed by electron microscopy showed an icosahedral head of 60 nm and a tail of 208 nm. The host range was limited to A. brasilense strains 29145 and 29710. Other Azospirillum strains tested did not produce phage under any of the conditions tested.

Classification of 17 newly isolated virulent bacteriophages of Pseudomonas aeruginosa

2010 ◽  
Vol 56 (11) ◽  
pp. 925-933 ◽  
Author(s):  
Lingyan Li ◽  
Hongjiang Yang ◽  
Shuxiang Lin ◽  
Shiru Jia
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Host Range ◽  
Restriction Fragment ◽  
Range Analysis ◽  
Fragment Analysis ◽  
Dna Viruses ◽  
Restriction Fragment Analysis ◽  
Transmission Electron ◽  
Dna Restriction ◽  
Icosahedral Head

Seventeen virulent bacteriophages specific to Pseudomonas aeruginosa strains were isolated by screening various environmental samples. These isolated bacteriophages were grouped based on results obtained from restriction fragment analysis of phage genomes, random amplification of polymorphic DNA (RAPD) typing, morphology observations under transmission electron microscope, and host range analysis. All 17 bacteriophages are double-stranded DNA viruses and can be divided into 5 groups based on DNA restriction profiles. A set of 10-mer primers was used in RAPD typing of phages, and similar conclusions were obtained as for restriction fragment analysis. One phage was randomly selected from each of the 5 groups for morphology observations. Four of them had an icosahedral head with a long contractile tail, belonging to the Myoviridae family, and one phage had an icosahedral head with a short tail, thereby belonging to the Podoviridae family. Host range experiments were conducted on 7 laboratory strains and 12 clinical strains of P. aeruginosa. The results showed that 13 phages had the same infection profile, killing 8 out of 19 tested P. aeruginosa strains, and the remaining 4 phages had different and unique infection profiles. This study highlights the diversity of bacteriophages specific to P. aeruginosa in the environment.

scholarly journals Morphological, Host Range, and Genetic Characterization of Two Coliphages

2003 ◽  
Vol 69 (9) ◽  
pp. 5364-5371 ◽  
Author(s):  
Lawrence Goodridge ◽  
Alicia Gallaccio ◽  
Mansel W. Griffiths
Keyword(s):  
Host Range ◽  
Restriction Endonuclease ◽  
Genome Size ◽  
Genetic Material ◽  
Restriction Enzymes ◽  
Restriction Endonuclease Analysis ◽  
Shigella Dysenteriae ◽  
Transmission Electron ◽  
A Genome ◽  
Contractile Tail

ABSTRACT Two coliphages, AR1 and LG1, were characterized based on their morphological, host range, and genetic properties. Transmission electron microscopy showed that both phages belonged to the Myoviridae; phage particles of LG1 were smaller than those of AR1 and had an isometric head 68 nm in diameter and a complex contractile tail 111 nm in length. Transmission electron micrographs of AR1 showed phage particles consisting of an elongated isometric head of 103 by 74 nm and a complex contractile tail 116 nm in length. Both phages were extensively tested on many strains of Escherichia coli and other enterobacteria. The results showed that both phages could infect many serotypes of E. coli. Among the enterobacteria, Proteus mirabilis, Shigella dysenteriae, and two Salmonella strains were lysed by the phages. The genetic material of AR1 and LG1 was characterized. Phage LG1 had a genome size of 49.5 kb compared to 150 kb for AR1. Restriction endonuclease analysis showed that several restriction enzymes could degrade DNA from both phages. The morphological, genome size, and restriction endonuclease similarities between AR1 and phage T4 were striking. Southern hybridizations showed that AR1 and T4 are genetically related. The wide host ranges of phages AR1 and LG1 suggest that they may be useful as biocontrol, therapeutic, or diagnostic agents to control and detect the prevalence of E. coli in animals and food.

scholarly journals Phylogeny of the Major Head and Tail Genes of the Wide-Ranging T4-Type Bacteriophages

2001 ◽  
Vol 183 (1) ◽  
pp. 358-366 ◽  
Author(s):  
Françoise Tétart ◽  
Carine Desplats ◽  
Mzia Kutateladze ◽  
Caroline Monod ◽  
Hans-Wolfgang Ackermann ◽  
...  
Keyword(s):  
Sequence Comparison ◽  
Viral Genome ◽  
Common Ancestor ◽  
Ecological Niches ◽  
Molecular Evidence ◽  
Genome Length ◽  
A Genome ◽  
Tail Sheath ◽  
Contractile Tail ◽  
Icosahedral Head

ABSTRACT We examined a number of bacteriophages with T4-type morphology that propagate in different genera of enterobacteria,Aeromonas, Burkholderia, andVibrio. Most of these phages had a prolate icosahedral head, a contractile tail, and a genome size that was similar to that of T4. A few of them had more elongated heads and larger genomes. All these phages are phylogenetically related, since they each had sequences homologous to the capsid gene (gene23), tail sheath gene (gene 18), and tail tube gene (gene 19) of T4. On the basis of the sequence comparison of their virion genes, the T4-type phages can be classified into three subgroups with increasing divergence from T4: the T-evens, pseudoT-evens, and schizoT-evens. In general, the phages that infect closely related host species have virion genes that are phylogenetically closer to each other than those of phages that infect distantly related hosts. However, some of the phages appear to be chimeras, indicating that, at least occasionally, some genetic shuffling has occurred between the different T4-type subgroups. The compilation of a number of gene 23 sequences reveals a pattern of conserved motifs separated by sequences that differ in the T4-type subgroups. Such variable patches in the gene 23sequences may determine the size of the virion head and consequently the viral genome length. This sequence analysis provides molecular evidence that phages related to T4 are widespread in the biosphere and diverged from a common ancestor in acquiring the ability to infect different host bacteria and to occupy new ecological niches.

scholarly journals Characterization of the Salmonella bacteriophage vB_SenS-Ent1

2012 ◽  
Vol 93 (9) ◽  
pp. 2046-2056 ◽  
Author(s):  
Dann Turner ◽  
Mohammed Hezwani ◽  
Shona Nelson ◽  
Vyv Salisbury ◽  
Darren Reynolds
Keyword(s):  
Nucleotide Sequence Identity ◽  
Burst Size ◽  
Genome Sequences ◽  
Sequence Identity ◽  
The Family ◽  
Contractile Tail ◽  
Transcriptional Units ◽  
High Level ◽  
Icosahedral Head

The bacteriophage vB_SenS-Ent1 (Ent1) is a member of the family Siphoviridae of tailed bacteriophages and infects a broad range of serovars of the enteric pathogen Salmonella enterica. The virion particle is composed of an icosahedral head 64 nm in diameter and a flexible, non-contractile tail of 116 × 8.5 nm possessing terminal fibres. The adsorption rate constant at 37 °C is 6.73 × 10−9 ml min−1. Latent and eclipse periods are 25 and 20 min, respectively, and the burst size is 35 progeny particles per cell after 35 min at 37 °C. Sequencing revealed a circularly permuted, 42 391 bp dsDNA genome containing 58 ORFs organized into four major transcriptional units. Comparisons with the genome sequences of other bacteriophages revealed a high level of nucleotide sequence identity and shared orthologous proteins with the Salmonella phages SETP3, SE2 and KS7 (SS3e) and the Escherichia phages K1G, K1H, K1ind1 and K1ind3.

Characteristics of two myoviruses induced from the coastal photoheterotrophic bacterium Porphyrobacter sp. YT40

2019 ◽  
Vol 366 (23) ◽  
Author(s):  
Wenxin Lin ◽  
Qi Chen ◽  
Yanting Liu ◽  
Nianzhi Jiao ◽  
Qiang Zheng
Keyword(s):  
Genome Size ◽  
Marine Bacteria ◽  
Gc Content ◽  
Functional Genes ◽  
Bacteriophage Mu ◽  
Genomic Plasticity ◽  
Viral Particles ◽  
Contractile Tail ◽  
Conserved Gene ◽  
Icosahedral Head

ABSTRACT In this study, we characterized two induced myoviruses from one marine photoheterotrophic bacterium Porphyrobacter sp. YT40 belonging to the Sphingomonadales family in Alphaproteobacteria. The genome sequence of prophage A is ∼36.9 kb with an average GC content of 67.1%, and its core or functional genes are homologous to Mu or Mu-like phages. Furthermore, induced viral particles from prophage A show a knob-like neck structure, which is only found in bacteriophage Mu. The genome size of prophage B is ∼36.8 kb with an average GC content of 65.3%. Prophage B contains a conserved gene cluster Q-P-O-N-M-L, which is unique in P2 phages. Induced viral particles from prophage B display an icosahedral head with a diameter of ∼55 nm and a 130 ± 5 nm long contractile tail. To our knowledge, this is the first report that characterizes the induced P2-like phage in marine Alphaproteobacteria. Phylogeny analyses suggest that these two types of prophages are commonly found in sequenced bacteria of the Sphingomonadales family. This study sheds light on the ongoing interaction between marine bacteria and phages, and improves our understanding of bacterial genomic plasticity and evolution.

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