Isolation of the Novel Phage PHB09 and Its Potential Use against the Plant Pathogen Pseudomonas syringae pv. actinidiae

Bacteriophages are viruses that specifically infect target bacteria. Recently, bacteriophages have been considered potential biological control agents for bacterial pathogens due to their host specificity. Pseudomonas syringae pv. actinidiae (Psa) is a reemerging pathogen that causes bacterial canker of kiwifruit (Actinidia sp.). The economic impact of this pest and the development of resistance to antibiotics and copper sprays in Psa and other pathovars have led to investigation of alternative management strategies. Phage therapy may be a useful alternative to conventional treatments for controlling Psa infections. Although the efficacy of bacteriophage φ6 was evaluated for the control of Psa, the characteristics of other DNA bacteriophages infecting Psa remain unclear. In this study, the PHB09 lytic bacteriophage specific to Psa was isolated from kiwifruit orchard soil. Extensive host range testing using Psa isolated from kiwifruit orchards and other Pseudomonas strains showed PHB09 has a narrow host range. It remained stable over a wide range of temperatures (4–50 °C) and pH values (pH 3–11) and maintained stability for 50 min under ultraviolet irradiation. Complete genome sequence analysis indicated PHB09 might belong to a new myovirus genus in Caudoviricetes. Its genome contains a total of 94,844 bp and 186 predicted genes associated with phage structure, packaging, host lysis, DNA manipulation, transcription, and additional functions. The isolation and identification of PHB09 enrich the research on Pseudomonas phages and provide a promising biocontrol agent against kiwifruit bacterial canker.

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Identification of Bacteriophages for Biocontrol of the Kiwifruit Canker Phytopathogen Pseudomonas syringae pv. actinidiae

Applied and Environmental Microbiology ◽

10.1128/aem.00062-14 ◽

2014 ◽

Vol 80 (7) ◽

pp. 2216-2228 ◽

Cited By ~ 44

Author(s):

Rebekah A. Frampton ◽

Corinda Taylor ◽

Angela V. Holguín Moreno ◽

Sandra B. Visnovsky ◽

Nicola K. Petty ◽

...

Keyword(s):

Host Range ◽

Pseudomonas Syringae ◽

Management Strategies ◽

Pulse Field ◽

Resistant Bacteria ◽

Bacterial Canker ◽

Content Type ◽

Narrow Host Range ◽

Pulse Field Gel Electrophoresis ◽

Isolation And Characterization

ABSTRACTPseudomonas syringaepv. actinidiae is a reemerging pathogen which causes bacterial canker of kiwifruit (Actinidiasp.). Since 2008, a global outbreak ofP. syringaepv. actinidiae has occurred, and in 2010 this pathogen was detected in New Zealand. The economic impact and the development of resistance inP. syringaepv. actinidiae and other pathovars against antibiotics and copper sprays have led to a search for alternative management strategies. We isolated 275 phages, 258 of which were active againstP. syringaepv. actinidiae. Extensive host range testing onP. syringaepv. actinidiae, other pseudomonads, and bacteria isolated from kiwifruit orchards showed that most phages have a narrow host range. Twenty-four were analyzed by electron microscopy, pulse-field gel electrophoresis, and restriction digestion. Their suitability for biocontrol was tested by assessing stability and the absence of lysogeny and transduction. A detailed host range was performed, phage-resistant bacteria were isolated, and resistance to other phages was examined. The phages belonged to theCaudoviralesand were analyzed based on morphology and genome size, which showed them to be representatives ofMyoviridae,Podoviridae, andSiphoviridae. Twenty-oneMyoviridaemembers have similar morphologies and genome sizes yet differ in restriction patterns, host range, and resistance, indicating a closely related group. Nine of theseMyoviridaemembers were sequenced, and each was unique. The most closely related sequenced phages were a group infectingPseudomonas aeruginosaand characterized by phages JG004 and PAK_P1. In summary, this study reports the isolation and characterization ofP. syringaepv. actinidiae phages and provides a framework for the intelligent formulation of phage biocontrol agents against kiwifruit bacterial canker.

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Isolation of Polyvalent Bacteriophages by Sequential Multiple-Host Approaches

Applied and Environmental Microbiology ◽

10.1128/aem.02382-15 ◽

2015 ◽

Vol 82 (3) ◽

pp. 808-815 ◽

Cited By ~ 51

Author(s):

Pingfeng Yu ◽

Jacques Mathieu ◽

Mengyan Li ◽

Zhaoyi Dai ◽

Pedro J. J. Alvarez

Keyword(s):

Host Range ◽

Pseudomonas Syringae ◽

Burst Size ◽

Broad Host Range ◽

Ecological Significance ◽

Content Type ◽

Narrow Host Range ◽

Isolation Methods ◽

Culture Independent ◽

K 12

ABSTRACTMany studies on phage biology are based on isolation methods that may inadvertently select for narrow-host-range phages. Consequently, broad-host-range phages, whose ecological significance is largely unexplored, are consistently overlooked. To enhance research on such polyvalent phages, we developed two sequential multihost isolation methods and tested both culture-dependent and culture-independent phage libraries for broad infectivity. Lytic phages isolated from activated sludge were capable of interspecies or even interorder infectivity without a significant reduction in the efficiency of plating (0.45 to 1.15). Two polyvalent phages (PX1 of thePodoviridaefamily and PEf1 of theSiphoviridaefamily) were characterized in terms of adsorption rate (3.54 × 10−10to 8.53 × 10−10ml/min), latent time (40 to 55 min), and burst size (45 to 99 PFU/cell), using different hosts. These phages were enriched with a nonpathogenic host (Pseudomonas putidaF1 orEscherichia coliK-12) and subsequently used to infect model problematic bacteria. By using a multiplicity of infection of 10 in bacterial challenge tests, >60% lethality was observed forPseudomonas aeruginosarelative to uninfected controls. The corresponding lethality forPseudomonas syringaewas ∼50%. Overall, this work suggests that polyvalent phages may be readily isolated from the environment by using different sequential hosts, and this approach should facilitate the study of their ecological significance as well as enable novel applications.

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Characterization of vB_StuS_MMDA13, a Newly Discovered Bacteriophage Infecting the Agar-Degrading Species Sphingomonas turrisvirgatae

Viruses ◽

10.3390/v12080894 ◽

2020 ◽

Vol 12 (8) ◽

pp. 894

Author(s):

Pasquale Marmo ◽

Maria Cristina Thaller ◽

Gustavo Di Lallo ◽

Lucia Henrici De Angelis ◽

Noemi Poerio ◽

...

Keyword(s):

Burst Size ◽

Latency Period ◽

Biosynthetic Gene Cluster ◽

Open Reading Frames ◽

Lytic Bacteriophage ◽

Coding Region ◽

Narrow Host Range ◽

Physiological Characterization ◽

Wide Range ◽

Valuable Compounds

Members of Sphingomonas genus have gained a notable interest for their use in a wide range of biotechnological applications, ranging from bioremediation to the production of valuable compounds of industrial interest. To date, knowledge on phages targeting Sphingomonas spp. are still scarce. Here, we describe and characterize a lytic bacteriophage, named vB_StuS_MMDA13, able to infect the Sphingomonas turrisvirgatae MCT13 type strain. Physiological characterization demonstrated that vB_StuS_MMDA13 has a narrow host range, a long latency period, a low burst size, and it is overall stable to both temperature and pH variations. The phage has a double-stranded DNA genome of 63,743 bp, with 89 open reading frames arranged in two opposite arms separated by a 1186 bp non-coding region and shows a very low global similarity to any other known phages. Interestingly, vB_StuS_MMDA13 is endowed with an original nucleotide modification biosynthetic gene cluster, which greatly differs from those of its most closely related phages of the Nipunavirus genus. vB_StuS_MMDA13 is the first characterized lytic bacteriophage of the Siphoviridae family infecting members of the Sphingomonas genus.

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Isolation of a Novel Lytic Bacteriophage against a Nosocomial Methicillin-Resistant Staphylococcus aureus Belonging to ST45

BioMed Research International ◽

10.1155/2020/5463801 ◽

2020 ◽

Vol 2020 ◽

pp. 1-10

Author(s):

Botond Zsombor Pertics ◽

Dalma Szénásy ◽

Dániel Dunai ◽

Yannick Born ◽

Lars Fieseler ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Methicillin Resistant Staphylococcus Aureus ◽

Lytic Bacteriophage ◽

Lytic Enzymes ◽

Methicillin Resistant ◽

Narrow Host Range ◽

Wide Range ◽

Life Threatening ◽

Amidase Gene ◽

Phage Lysin

Methicillin-resistant Staphylococcus aureus (MRSA) can cause a wide range of infections from mild to life-threatening conditions. Its enhanced antibiotic resistance often leads to therapeutic failures and therefore alternative eradication methods must be considered. Potential candidates to control MRSA infections are bacteriophages and their lytic enzymes, lysins. In this study, we isolated a bacteriophage against a nosocomial MRSA strain belonging to the ST45 epidemiologic group. The phage belonging to Caudovirales, Siphoviridae, showed a narrow host range and stable lytic activity without the emergence of resistant MRSA clones. Phylogenetic analysis showed that the newly isolated Staphylococcus phage R4 belongs to the Triavirus genus in Siphoviridae family. Genetic analysis of the 45 kb sequence of R4 revealed 69 ORFs. No remnants of mobile genetic elements and traces of truncated genes were observed. We have localized the lysin (N-acetylmuramoyl-L-alanine amidase) gene of the new phage that was amplified, cloned, expressed, and purified. Its activity was verified by zymogram analysis. Our findings could potentially be used to develop specific anti-MRSA bacteriophage- and phage lysin-based therapeutic strategies against major clonal lineages and serotypes.

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Clinico-mycological profile of onychomycosis in Assam, India

International Journal of Research in Medical Sciences ◽

10.18203/2320-6012.ijrms20183246 ◽

2018 ◽

Vol 6 (8) ◽

pp. 2656

Author(s):

Nilakshi Borah ◽

Ajanta Sharma ◽

Debeeka Hazarika

Keyword(s):

Tertiary Care ◽

Management Strategies ◽

Care Hospital ◽

Isolation And Identification ◽

Predisposing Factor ◽

Wide Range ◽

Male Preponderance ◽

Causative Fungus ◽

Microscopic Morphology ◽

Toe Nails

Background: Onychomycosis (OM) is a common nail disorder caused by dermatophytes, non-dermatophyte moulds and yeasts. The increased prevalence of OM along with the wide range of associated fungi necessitates the accurate laboratory isolation and identification of the causative fungus for optimal management strategies. The aim of the study was to evaluate clinical, epidemiological and mycological characteristics of OM in a tertiary care hospital in Assam.Methods: It was a prospective hospital-based study. Hundred consecutive patients clinically diagnosed as OM were subjected to detailed history, clinical examination and investigations. Nail clipping and subungual debris of OM patients were subjected to KOH preparation and culture. Isolates were identified by colony characters, pigment production, microscopic morphology and biochemical tests.Results: The maximum number of OM cases belonged to the age group 21-30 years with a male preponderance (M:F=1.7:1). The commonest clinical type of OM was distal lateral subungual onychomycosis (DLSO) (51%). Toe nails OM was the most common presentation (54%). Trauma (35%) was the most common predisposing factor. Farmers (agro industry labourers) (23%) were found to be the most commonly affected group. Non-dermatophyte moulds (NDM) accounted for 38(47.5%) of OM cases followed by yeast 27(33.8%) and dermatophytes 15(18.8%).Conclusions: Early diagnosis and treatment is important to prevent distortion of the nails which can prevent loss of working efficiency of the commonly affected population of this region.

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Characterization and identification of naturally transgenic species Linaria vulgaris pathogenic mycromycetes

Ecological genetics ◽

10.17816/ecogen16127-34 ◽

2018 ◽

Vol 16 (1) ◽

pp. 27-34

Author(s):

Sofia V. Sokornova ◽

Elena L. Gasich ◽

Victoria D. Bemova ◽

Tatiana V. Matveeva

Keyword(s):

Host Range ◽

Large Subunit ◽

Molecular Data ◽

Microbial Interactions ◽

Internal Transcribed Spacers ◽

Broad Host Range ◽

Narrow Host Range ◽

Wide Range ◽

Phoma Herbarum

In nature there are species containing homologs of T-DNA genes of agrobacteria (сT-DNA) in their genomes. Such plants are called naturally transgenic ones. Interaction with the microbiota is one of the possible functions of cT-DNA, discussed in the literature. Linaria plants are the most suitable for the investigation of the probable ecological role of T-DNA, since they widely spread. The first stage in the evaluation of plant-microbial interactions involving these plants is the description of isolates with contrasting virulence for toadflax. The search and DNA-barcoding of such isolates of Phoma-like fungi was the goal of this work. 14 strains isolated from the plants of the families Plantaginaceae and Scrophullariaceae were analyzed. The of multilocus analysis included amplification and sequencing of internal transcribed spacers, a large subunit of RNA, a tubulin gene. Based on molecular data, 9 strains were assigned to the species Boeremia exigua, which has a wide range of habitats and a wide specialization. Strains of this species were virulent against L. vulgaris, but differed in aggressiveness with respect to this plant. Thus, a collection of strains was characterized, which can later be used for a more detailed study of the immune response of the naturally-transgenic L. vulgaris plant in response to inoculation with the B. exigua phytopathogen. As a result of the work, we identified the narrow host range fungi Heterophoma novae-verbascicola, and broad host range pathogens Plectosphaerella cucumerina, Phoma herbarum and Trichothecium roseum. Among them, only P. cucumerina was a weak pathogen of L. vulgaris. These results confirm the early data on the depleted mycobiota of L. vulgaris.

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Characterization of vB_Kpn_F48, a Newly Discovered Lytic Bacteriophage for Klebsiella pneumoniae of Sequence Type 101

Viruses ◽

10.3390/v10090482 ◽

2018 ◽

Vol 10 (9) ◽

pp. 482 ◽

Cited By ~ 10

Author(s):

Nagaia Ciacci ◽

Marco D’Andrea ◽

Pasquale Marmo ◽

Elisa Demattè ◽

Francesco Amisano ◽

...

Keyword(s):

Klebsiella Pneumoniae ◽

Host Range ◽

High Throughput Sequencing ◽

Burst Size ◽

Antibiotic Resistance Genes ◽

Clinical Problem ◽

Lytic Bacteriophage ◽

Transmission Electron Microscopy Analysis ◽

Narrow Host Range ◽

Physiological Characterization

Resistance to carbapenems in Enterobacteriaceae, including Klebsiella pneumoniae, represents a major clinical problem given the lack of effective alternative antibiotics. Bacteriophages could provide a valuable tool to control the dissemination of antibiotic resistant isolates, for the decolonization of colonized individuals and for treatment purposes. In this work, we have characterized a lytic bacteriophage, named vB_Kpn_F48, specific for K. pneumoniae isolates belonging to clonal group 101. Phage vB_Kpn_F48 was classified as a member of Myoviridae, order Caudovirales, on the basis of transmission electron microscopy analysis. Physiological characterization demonstrated that vB_Kpn_F48 showed a narrow host range, a short latent period, a low burst size and it is highly stable to both temperature and pH variations. High throughput sequencing and bioinformatics analysis revealed that the phage is characterized by a 171 Kb dsDNA genome that lacks genes undesirable for a therapeutic perspective such integrases, antibiotic resistance genes and toxin encoding genes. Phylogenetic analysis suggests that vB_Kpn_F48 is a T4-like bacteriophage which belongs to a novel genus within the Tevenvirinae subfamily, which we tentatively named “F48virus”. Considering the narrow host range, the genomic features and overall physiological parameters phage vB_Kpn_F48 could be a promising candidate to be used alone or in cocktails for phage therapy applications.

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Zucchini Vein Clearing Disease Is Caused by Several Lineages Within Pseudomonas syringae Species Complex

Phytopathology ◽

10.1094/phyto-07-19-0266-r ◽

2020 ◽

Vol 110 (4) ◽

pp. 744-757

Author(s):

Caroline Lacault ◽

Martial Briand ◽

Marie-Agnès Jacques ◽

Armelle Darrasse

Keyword(s):

Host Range ◽

Pseudomonas Syringae ◽

Species Complex ◽

Whole Genome Sequence ◽

Narrow Host Range ◽

Vein Clearing ◽

Main Cluster ◽

Genome Analyses ◽

Large Host ◽

Insight Into

Zucchini (Cucurbita pepo) is worldwide affected by Pseudomonas syringae, inducing vein clearing, stunting, and necroses during plantlet development. A collection of 58 P. syringae strains isolated from diseased zucchini plantlets was characterized by multilocus sequence analysis (MLSA). A subset of 23 strains responsible for vein clearing of zucchini (VCZ) was evaluated for pathogenicity on zucchini, and their genomes were sequenced. The host range of six VCZ strains was evaluated on 11 cucurbit species. Most VCZ strains belong to clades 2a and 2b-a within phylogroup 2 of P. syringae species complex and are closely related to other strains previously isolated from cucurbits. Genome analyses revealed diversity among VCZ strains within each clade. One main cluster, once referred to by the invalid pathovar name (peponis), gathers VCZ strains presenting a narrow host range including zucchini and squashes. Other VCZ strains present a large host range including zucchini, squashes, cucumber, melons, and in some cases watermelon. The VCZ strain pathogenic features are strongly associated with type III effector repertoires. The presence of avrRpt2 and absence of hopZ5 are associated with a narrow host range, whereas the presence of hopZ5 and absence of avrRpt2 are most generally associated with a large host range. To better detect the different clusters identified with whole genome sequence and pathogenicity analyses, we used a specific-k-mers approach to refine the MLSA scheme. Using this novel MLSA scheme to type P. syringae isolates from diseased cucurbits would give insight into distribution of worldwide strains and origin of epidemics.

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Isolation and properties of a bacteriophage lytic for a wide range of pseudomonads

Canadian Journal of Microbiology ◽

10.1139/m71-109 ◽

1971 ◽

Vol 17 (5) ◽

pp. 677-682 ◽

Cited By ~ 18

Author(s):

R. A. Kelln ◽

R. A. J. Warren

Keyword(s):

Latent Period ◽

Pseudomonas Fluorescens ◽

Host Range ◽

Burst Size ◽

Broad Host Range ◽

Lytic Bacteriophage ◽

Bacterial Strains ◽

Short Tail ◽

Wide Range ◽

Different Strains

The lytic bacteriophage ø-S1 was isolated from sewage using a strain of Pseudomonas fluorescens as host. It had a hexagonal head 60 nm in diameter and a short tail 30 nm long. ø-S1 had a broad host range, lysing strains from 10 biotypes of Pseudomonads. Although the latent period was fairly constant for the bacterial strains tested, the burst size varied considerably. The rate of adsorption of the phage to different strains also varied considerably.

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Understanding Limited Use of Amplification in Infants and Children Who Are Hard of Hearing

Perspectives on Hearing and Hearing Disorders in Childhood ◽

10.1044/hhdc25.1.15 ◽

2015 ◽

Vol 25 (1) ◽

pp. 15-23 ◽

Cited By ~ 1

Author(s):

Ryan W. McCreery ◽

Elizabeth A. Walker ◽

Meredith Spratford

Keyword(s):

Hard Of Hearing ◽

Hearing Aid ◽

Management Strategies ◽

Infants And Children ◽

Future Research ◽

Research Needs ◽

Case Examples ◽

Hearing Aid Use ◽

Wide Range ◽

In Infants And Children

The effectiveness of amplification for infants and children can be mediated by how much the child uses the device. Existing research suggests that establishing hearing aid use can be challenging. A wide range of factors can influence hearing aid use in children, including the child's age, degree of hearing loss, and socioeconomic status. Audiological interventions, including using validated prescriptive approaches and verification, performing on-going training and orientation, and communicating with caregivers about hearing aid use can also increase hearing aid use by infants and children. Case examples are used to highlight the factors that influence hearing aid use. Potential management strategies and future research needs are also discussed.

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