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

Viruses ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 482 ◽  
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.

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

Viruses ◽  
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.

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

Viruses ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2275
Author(s):  
Yanxi Liu ◽  
Mengjiao Liu ◽  
Ran Hu ◽  
Jun Bai ◽  
Xiaoqing He ◽  
...  
Keyword(s):  
Host Range ◽  
Pseudomonas Syringae ◽  
Management Strategies ◽  
Lytic Bacteriophage ◽  
Bacterial Canker ◽  
Isolation And Identification ◽  
Narrow Host Range ◽  
Development Of Resistance ◽  
Wide Range ◽  
Complete Genome Sequence Analysis

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.

scholarly journals Isolation and characterization of a lytic bacteriophage against Pseudomonas aeruginosa

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sonika Sharma ◽  
Sibnarayan Datta ◽  
Soumya Chatterjee ◽  
Moumita Dutta ◽  
Jhuma Samanta ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Burst Size ◽  
Antibiotic Resistance Genes ◽  
Multidrug Resistant ◽  
Potential Candidate ◽  
Lytic Bacteriophage ◽  
Isolation And Characterization ◽  
Phage Proteins

AbstractIn recent years, the use of bacteriophages (or 'phages') against multidrug-resistant (MDR) bacteria including Pseudomonas aeruginosa has drawn considerable attention, globally. In this work, we report the isolation and detailed characterization of a highly lytic Pseudomonasphage DRL-P1 isolated from wastewater. Under TEM, DRL-P1 appeared as a member of the phage family Myoviridae. DRL-P1 featured rapid adsorption (~ 5 min), short-latency (~ 30 min), and large burst size (~ 100 PFU per infected cell). DRL-P1 can withstand a wide temperature range (4 °C to 40 °C) and pH (5.0 to 10.0) conditions. The 66,243 bp DRL-P1 genome (MN564818) encodes at least 93 ORFs, of which 36 were functionally annotated based on homology with similar phage proteins available in the databases. Comparative analyses of related genomes suggest an independent evolutionary history and discrete taxonomic position of DRL-P1 within genus Pbunavirus. No toxin or antibiotic resistance genes was identified. DRL-P1 is tolerant to lyophilization and encapsulation techniques and retained lytic activity even after 18 months of storage. We also demonstrated decontaminating potentials of DRL-P1 in vitro, on an artificially contaminated cover-slip model. To the best of our knowledge, this is the first Pbunavirus to be reported from India. Our study suggests DRL-P1 as a potential candidate for various applications.

scholarly journals Isolation and Characterization of a Novel Lytic Bacteriophage against the K2 Capsule-Expressing Hypervirulent Klebsiella pneumoniae Strain 52145, and Identification of Its Functional Depolymerase

2021 ◽  
Vol 9 (3) ◽  
pp. 650
Author(s):  
Botond Zsombor Pertics ◽  
Alysia Cox ◽  
Adrienn Nyúl ◽  
Nóra Szamek ◽  
Tamás Kovács ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Antimicrobial Agents ◽  
Lytic Bacteriophage ◽  
Bacterial Cells ◽  
Narrow Host Range ◽  
Isolation And Characterization ◽  
Different Temperatures ◽  
Colonization Model

Klebsiella pneumoniae is among the leading bacteria that cause nosocomial infections. The capsule of this Gram-negative bacterium is a dominant virulence factor, with a prominent role in defense and biofilm formation. Bacteriophages, which are specific for one bacterial strain and its capsule type, can evoke the lysis of bacterial cells, aided by polysaccharide depolymerase enzymes. In this study, we isolated and characterized a bacteriophage against the nosocomial K. pneumoniae 52145 strain with K2 capsular serotype. The phage showed a narrow host range and stable lytic activity, even when exposed to different temperatures or detergents. Preventive effect of the phage in a nasal colonization model was investigated in vivo. Phlyogenetic analysis showed that the newly isolated Klebsiella phage B1 belongs to the Webervirus genus in Drexlerviridae family. We identified the location of the capsule depolymerase gene of the new phage, which was amplified, cloned, expressed, and purified. The efficacy of the recombinant B1dep depolymerase was tested by spotting on K. pneumoniae strains and it was confirmed that the extract lowers the thickness of the bacterium lawn as it degrades the protective capsule on bacterial cells. As K. pneumoniae strains possessing the K2 serotype have epidemiological importance, the B1 phage and its depolymerase are promising candidates for use as possible antimicrobial agents.

Isolation and characterization of a virulent bacteriophage for controlling Salmonella enteritidis growth in ready-to-eat mixed-ingredient salads

2021 ◽  
Author(s):  
wenyuan zhou ◽  
Si-fan Sun ◽  
Yuan-song Zhang ◽  
Qin Hu ◽  
Xiang-feng Zheng ◽  
...  
Keyword(s):  
Salmonella Enteritidis ◽  
Burst Size ◽  
Antibiotic Resistance Genes ◽  
Bacterial Count ◽  
Treatment Method ◽  
Chicken Meat ◽  
Health Concern ◽  
Lytic Bacteriophage ◽  
Bacterial Counts ◽  
Isolation And Characterization

Recently, ready-to-eat vegetable salads have gained popularity worldwide. However, the microbial safety of ready-to-eat salads is a health concern, primarily due to Salmonella enteritidis contamination during the growing, harvesting, processing, and handling of produce. This study aimed to develop a bacteriophage-based strategy to control S. enteritidis growth in mixed-ingredient salads. A lytic Salmonella-specific phage SapYZU01 was isolated from a soil sample from a suburban vegetable field in Yangzhou, China. SapYZU01 exhibited characteristics such as a short latent period, a large burst size, and a lytic effect against 13 S. enteritidis strains isolated from various sources (human, pork, deli, chicken, and chicken meat). The SapYZU01 genome did not contain virulence or antibiotic resistance genes. SapYZU01 significantly decreased the viability of S. enteritidis cells in iceberg lettuce, chicken meat, and mixed-ingredient (lettuce+chicken) salads at 37 and 25 °C. Furthermore, bacterial counts in the salad decreased significantly (by 4.0 log colony-forming units (CFU)/g) at 25 °C upon treatment of contaminated lettuce with SapYZU01 at an MOI of 100 prior to salad preparation. Bacterial counts were decreased by 3.8 log CFU/g at 25 °C in (lettuce+chicken) salads treated with SapYZU01 at an MOI of 100 after the salad preparation. In contrast, treating cooked chicken meat with SapYZU01 at an MOI of 100 before mixing it with contaminated lettuce decreased the bacterial count of the salad by 1.2 log CFU/g at 25 °C. These findings indicate the potential application of SapYZU01 as a natural biocontrol agent against S. enteritidis in mixed-ingredient salads. Furthermore, the application of lytic bacteriophage SapYZU01 in mix-ingredient salads should considered the bacteriophage treatment method in addition to the bacteriophage concentration.

scholarly journals Isolation of Polyvalent Bacteriophages by Sequential Multiple-Host Approaches

2015 ◽  
Vol 82 (3) ◽  
pp. 808-815 ◽  
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.

scholarly journals Phenotypic and Genomic Comparison of Klebsiella pneumoniae Lytic Phages: vB_KpnM-VAC66 and vB_KpnM-VAC13

Viruses ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 6
Author(s):  
Olga Pacios ◽  
Laura Fernández-García ◽  
Inés Bleriot ◽  
Lucia Blasco ◽  
Antón Ambroa ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Host Range ◽  
Burst Size ◽  
Three Dimensional ◽  
Genomic Analysis ◽  
Amino Acid Sequences ◽  
Phylogenetic Study ◽  
Tail Fiber ◽  
Homing Endonucleases ◽  
Query Cover

Klebsiella pneumoniae is a human pathogen that worsens the prognosis of many immunocompromised patients. Here, we annotated and compared the genomes of two lytic phages that infect clinical strains of K. pneumoniae (vB_KpnM-VAC13 and vB_KpnM-VAC66) and phenotypically characterized vB_KpnM-VAC66 (time of adsorption of 12 min, burst size of 31.49 ± 0.61 PFU/infected cell, and a host range of 20.8% of the tested strains). Transmission electronic microscopy showed that vB_KpnM-VAC66 belongs to the Myoviridae family. The genomic analysis of the phage vB_KpnM-VAC66 revealed that its genome encoded 289 proteins. When compared to the genome of vB_KpnM-VAC13, they showed a nucleotide similarity of 97.56%, with a 93% of query cover, and the phylogenetic study performed with other Tevenvirinae phages showed a close common ancestor. However, there were 21 coding sequences which differed. Interestingly, the main differences were that vB_KpnM-VAC66 encoded 10 more homing endonucleases than vB_KpnM-VAC13, and that the nucleotidic and amino-acid sequences of the L-shaped tail fiber protein were highly dissimilar, leading to different three-dimensional protein predictions. Both phages differed significantly in their host range. These viruses may be useful in the development of alternative therapies to antibiotics or as a co-therapy increasing its antimicrobial potential, especially when addressing multidrug resistant (MDR) pathogens.

scholarly journals Complete Genome Sequence of vB_EcoP_SU7, a Podoviridae Coliphage with the Rare C3 Morphotype

2021 ◽  
Vol 9 (8) ◽  
pp. 1576
Author(s):  
Shazeeda Koonjan ◽  
Callum J. Cooper ◽  
Anders S. Nilsson
Keyword(s):  
Host Range ◽  
Burst Size ◽  
Phylogenetic Analyses ◽  
Treatment Plant ◽  
Latency Period ◽  
Enterotoxigenic Escherichia Coli ◽  
Therapeutic Success ◽  
Significant Similarity ◽  
Narrow Host Range ◽  
E Coli

Enterotoxigenic Escherichia coli (ETEC) strains are an important cause of bacterial diarrheal illness in humans and animals. Infections arising from ETEC could potentially be treated through the use of bacteriophage (phage) therapy, as phages encode for enzymes capable of bacterial cell lysis. vB_EcoP_SU7 was isolated from the Käppala wastewater treatment plant in Stockholm, Sweden, and propagated on an ETEC strain exhibiting the O:139 serovar. Transmission electron microscopy confirmed that vB_EcoP_SU7 belongs to the Podoviridae family and has the rare C3 morphotype of an elongated head. Bioinformatic analyses showed that the genome was 76,626 base pairs long and contained 35 genes with predicted functions. A total of 81 open reading frames encoding proteins with hypothetical function and two encoding proteins of no significant similarity were also found. A putative tRNA gene, which may aid in vB_EcoP_SU7’s translation, was also identified. Phylogenetic analyses showed that compared to other Podoviridae, vB_EcoP_SU7 is a rare Kuravirus and is closely related to E. coli phages with the uncommon C3 morphotype, such as ECBP2, EK010, vB_EcoP_EcoN5, and vB_EcoP_SU10. Phage vB_EcoP_SU7 has a narrow host range, infecting 11 out of the 137 E. coli strains tested, a latency period of 30 min, a burst size of 12 PFU/cell, and an adsorption rate of 8.78 × 10−9 mL/min five minutes post infection. With a limited host range and poor infection kinetics, it is unlikely that SU7 can be a standalone phage used for therapeutic purposes; rather, it must be used in combination with other phages for broad-spectrum therapeutic success.

scholarly journals Isolation and selection of Bacillus cereus specific phages from hospital wastewater

2020 ◽  
Vol 21 (7) ◽  
Author(s):  
Anwar Rovik ◽  
SAEFUDDIN ‘AZIZ ◽  
HENDRO PRAMONO
Keyword(s):  
Escherichia Coli ◽  
Klebsiella Pneumoniae ◽  
Bacillus Cereus ◽  
Host Range ◽  
Latency Period ◽  
Pathogenic Bacterium ◽  
Citrobacter Freundii ◽  
Hospital Wastewater ◽  
Narrow Host Range ◽  
Selection Of

Abstract. Rovik A, ‘Aziz S, Pramono H. 2020. Isolation and selection of Bacillus cereus specific phages from hospital wastewater. Biodiversitas 21: 2871-2877. Bacillus cereus (B. cereus) is a pathogenic bacterium that frequently contaminates food by producing entero and emetic toxins. B. cereus has shown resistance to various antibiotics, especially β-lactam antibiotics. An alternative to control B. cereus contamination is the use of bacteriophages. This study aimed to isolate and screen B. cereus specific phages from hospital wastewater in Banyumas District. The research was conducted descriptively through isolation, purification, titer determination, host ranges, and adsorption rate determination. A total of 29 isolates of B. cereus-phages were isolated from hospital wastewater in Banyumas with various titers, ranged from 0.14-3.76 x 107 PFU.mL-1. Isolated phages could be grouped into two, narrow host range (14 phages) and broad activity spectra (15 phages) that infect both Gram-positive and negative bacteria i.e. B. subtilis, B. fragilis, B. licheniformis, Citrobacter freundii, Klebsiella pneumoniae, Salmonella thypi, and Escherichia coli. The infections had a latency period of 60-120 minutes. The decrease of culture absorbance value ranged from 0.06 to 0.41, while the control tended to increase by 0.39. The largest decreases were showed by phage isolates RSBMS-2 and RSBMT-1 with 0.41 and 0.37, respectively.

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