scholarly journals Efficiency of Phage φ6 for Biocontrol of Pseudomonas syringae pv. syringae: An in Vitro Preliminary Study

2019 ◽  
Vol 7 (9) ◽  
pp. 286 ◽  
Author(s):  
Larindja A. M. Pinheiro ◽  
Carla Pereira ◽  
Carolina Frazão ◽  
Victor M. Balcão ◽  
Adelaide Almeida
Keyword(s):  
Solar Radiation ◽  
Host Range ◽  
Pseudomonas Syringae ◽  
Bacterial Resistance ◽  
Phage Therapy ◽  
Bacterial Species ◽  
Fruit Trees ◽  
Range Analysis ◽  
Maximum Reduction

Pseudomonas syringae is a plant-associated bacterial species that has been divided into more than 60 pathovars, with the Pseudomonas syringae pv. syringae being the main causative agent of diseases in a wide variety of fruit trees. The most common treatments for biocontrol of P. syringae pv. syringae infections has involved copper derivatives and/or antibiotics. However, these treatments should be avoided due to their high toxicity to the environment and promotion of bacterial resistance. Therefore, it is essential to search for new approaches for controlling P. syringae pv. syringae. Phage therapy can be a useful alternative tool to the conventional treatments to control P. syringae pv. syringae infections in plants. In the present study, the efficacy of bacteriophage (or phage) φ6 (a commercially available phage) was evaluated in the control of P. syringae pv. syringae. As the plants are exposed to the natural variability of physical and chemical parameters, the influence of pH, temperature, solar radiation and UV-B irradiation on phage φ6 viability was also evaluated in order to develop an effective phage therapy protocol. The host range analysis revealed that the phage, besides its host (P. syringae pv. syringae), also infects the Pseudomonas syringae pv. actinidiae CRA-FRU 12.54 and P. syringae pv. actinidiae CRA-FRU 14.10 strains, not infecting strains from the other tested species. Both multiplicities of infection (MOIs) tested, 1 and 100, were effective to inactivate the bacterium, but the MOI 1 (maximum reduction of 3.9 log CFU/mL) was more effective than MOI 100 (maximum reduction of 2.6 log CFU/mL). The viability of phage φ6 was mostly affected by exposure to UV-B irradiation (decrease of 7.3 log PFU/mL after 8 h), exposure to solar radiation (maximum reduction of 2.1 PFU/mL after 6 h), and high temperatures (decrease of 8.5 PFU/mL after 6 days at 37 °C, but a decrease of only 2.0 log PFU/mL after 67 days at 15 °C and 25 °C). The host range, high bacterial control and low rates of development of phage-resistant bacterial clones (1.20 × 10−3) suggest that this phage can be used to control P. syringae pv. syringae infections in plants, but also to control infections by P. syringae pv. actinidiae, the causal agent of bacterial canker of kiwifruit. Although the stability of phage φ6 was affected by UV-B and solar radiation, this can be overcome by the application of phage suspensions at the end of the day or at night.

Characterization and in vitro testing of newly isolated lytic bacteriophages for the biocontrol of Pseudomonas aeruginosa

2022 ◽  
Author(s):  
Liliam K Harada ◽  
Erica C Silva ◽  
Fernando PN Rossi ◽  
Basilio Cieza ◽  
Thais J Oliveira ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibiotic Resistance ◽  
Host Range ◽  
Genome Sequencing ◽  
Bacterial Resistance ◽  
Multidrug Resistant ◽  
In Vitro Testing ◽  
Range Analysis ◽  
Myoviridae Family

Aim: Two lytic phages were isolated using P. aeruginosa DSM19880 as host and fully characterized. Materials & methods: Phages were characterized physicochemically, biologically and genomically. Results & conclusion: Host range analysis revealed that the phages also infect some multidrug-resistant (MDR) P. aeruginosa clinical isolates. Increasing MOI from 1 to 1000 significantly increased phage efficiency and retarded bacteria regrowth, but phage ph0034 (reduction of 7.5 log CFU/ml) was more effective than phage ph0031 (reduction of 5.1 log CFU/ml) after 24 h. Both phages belong to Myoviridae family. Genome sequencing of phages ph0031 and ph0034 showed that they do not carry toxin, virulence, antibiotic resistance and integrase genes. The results obtained are highly relevant in the actual context of bacterial resistance to antibiotics.

scholarly journals Bacteriophages to Control Multi-Drug Resistant Enterococcus faecalis Infection of Dental Root Canals

2021 ◽  
Vol 9 (3) ◽  
pp. 517
Author(s):  
Mohamed El-Telbany ◽  
Gamal El-Didamony ◽  
Ahmed Askora ◽  
Eman Ariny ◽  
Dalia Abdallah ◽  
...  
Keyword(s):  
Enterococcus Faecalis ◽  
Root Canal ◽  
Phage Therapy ◽  
Ex Vivo ◽  
Burst Size ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Range Analysis ◽  
Root Canals

Phage therapy is an alternative treatment to antibiotics that can overcome multi-drug resistant bacteria. In this study, we aimed to isolate and characterize lytic bacteriophages targeted against Enterococcus faecalis isolated from root canal infections obtained from clinics at the Faculty of Dentistry, Ismalia, Egypt. Bacteriophage, vB_ZEFP, was isolated from concentrated wastewater collected from hospital sewage. Morphological and genomic analysis revealed that the phage belongs to the Podoviridae family with a linear double-stranded DNA genome, consisting of 18,454, with a G + C content of 32.8%. Host range analysis revealed the phage could infect 10 of 13 E. faecalis isolates exhibiting a range of antibiotic resistances recovered from infected root canals with efficiency of plating values above 0.5. One-step growth curves of this phage showed that it has a burst size of 110 PFU per infected cell, with a latent period of 10 min. The lytic activity of this phage against E. faecalis biofilms showed that the phage was able to control the growth of E. faecalis in vitro. Phage vB_ZEFP could also prevent ex-vivo E. faecalis root canal infection. These results suggest that phage vB_ZEFP has potential for application in phage therapy and specifically in the prevention of infection after root canal treatment.

scholarly journals How to Train Your Phage: The Recent Efforts in Phage Training

Biologics ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 70-88
Author(s):  
Abdallah Abdelsattar ◽  
Alyaa Dawooud ◽  
Nouran Rezk ◽  
Salsabil Makky ◽  
Anan Safwat ◽  
...  
Keyword(s):  
Host Range ◽  
Pathogenic Bacteria ◽  
Bacterial Resistance ◽  
Phage Therapy ◽  
Current Knowledge ◽  
Lytic Replication ◽  
Resistant Bacteria ◽  
Infection Cycles ◽  
Different Strains ◽  
Specific Species

Control of pathogenic bacteria by deliberate application of predatory phages has potential as a powerful therapy against antibiotic-resistant bacteria. The key advantages of phage biocontrol over antibacterial chemotherapy are: (1) an ability to self-propagate inside host bacteria, (2) targeted predation of specific species or strains of bacteria, (3) adaptive molecular machinery to overcome resistance in target bacteria. However, realizing the potential of phage biocontrol is dependent on harnessing or adapting these responses, as many phage species switch between lytic infection cycles (resulting in lysis) and lysogenic infection cycles (resulting in genomic integration) that increase the likelihood of survival of the phage in response to external stress or host depletion. Similarly, host range will need to be optimized to make phage therapy medically viable whilst avoiding the potential for deleteriously disturbing the commensal microbiota. Phage training is a new approach to produce efficient phages by capitalizing on the evolved response of wild-type phages to bacterial resistance. Here we will review recent studies reporting successful trials of training different strains of phages to switch into lytic replication mode, overcome bacterial resistance, and increase their host range. This review will also highlight the current knowledge of phage training and future implications in phage applications and phage therapy and summarize the recent pipeline of the magistral preparation to produce a customized phage for clinical trials and medical applications.

scholarly journals Discovery and Characterization of Low-Molecular Weight Inhibitors of Erwinia tracheiphila

2020 ◽  
Vol 110 (5) ◽  
pp. 989-998
Author(s):  
Cláudio M. Vrisman ◽  
Loïc Deblais ◽  
Yosra A. Helmy ◽  
Reed Johnson ◽  
Gireesh Rajashekara ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
High Throughput Screening ◽  
Pathogenic Bacteria ◽  
Bacterial Species ◽  
Bacillus Species ◽  
Erwinia Tracheiphila ◽  
Static Activity ◽  
Low Toxicity

Plant pathogenic bacteria in the genus Erwinia cause economically important diseases, including bacterial wilt of cucurbits caused by Erwinia tracheiphila. Conventional bactericides are insufficient to control this disease. Using high-throughput screening, 464 small molecules (SMs) with either cidal or static activity at 100 µM against a cucumber strain of E. tracheiphila were identified. Among them, 20 SMs (SM1 to SM20), composed of nine distinct chemical moiety structures, were cidal to multiple E. tracheiphila strains at 100 µM. These lead SMs had low toxicity to human cells and honey bees at 100 µM. No phytotoxicity was observed on melon plants at 100 µM, except when SM12 was either mixed with Silwet L-77 and foliar sprayed or when delivered through the roots. Lead SMs did not inhibit the growth of beneficial Pseudomonas and Enterobacter species but inhibited the growth of Bacillus species. Nineteen SMs were cidal to Xanthomonas cucurbitae and showed >50% growth inhibition against Pseudomonas syringae pv. lachrymans. In addition, 19 SMs were cidal or static against Erwinia amylovora in vitro. Five SMs demonstrated potential to suppress E. tracheiphila when foliar sprayed on melon plants at 2× the minimum bactericidal concentration. Thirteen SMs reduced Et load in melon plants when delivered via roots. Temperature and light did not affect the activity of SMs. In vitro cidal activity was observed after 3 to 10 h of exposure to these five SMs. Here, we report 19 SMs that provide chemical scaffolds for future development of bactericides against plant pathogenic bacterial species.

Dominant symbiotic bacteria associated with wild medfly populations reveal a bacteriocin-like killing phenotype: a ‘cold-case’ study

2019 ◽  
Vol 110 (4) ◽  
pp. 457-462
Author(s):  
Silvia Ciolfi ◽  
Laura Marri
Keyword(s):  
Bacterial Species ◽  
Klebsiella Oxytoca ◽  
Pcr Amplification ◽  
Fruit Trees ◽  
Antagonistic Activity ◽  
Culture Collection ◽  
Symbiotic Bacteria ◽  
Bacterial Populations

AbstractThe gut of the agricultural pest Ceratitis capitata hosts a varied community of bacteria, mainly Enterobacteriaceae, that were implicated in several processes that increase the fitness of the insect. In this study, we investigated the antagonistic activity in vitro of Klebsiella oxytoca strains isolated in the 1990s from the alimentary tract of wild medflies collected from different varieties of fruit trees at diverse localities. Assays were carried out against reference strains (representative of Gram-negative and -positive bacterial species) of the American Type Culture Collection (ATCC). Eight Klebsiella, out of 11, expressed a killing activity against Escherichia coli ATCC 23739, and Enterobacter cloacae ATCC 13047; among the eight strains, at least one showed activity against Salmonella typhimurium ATCC 23853. Genomic DNA derived from all Klebsiella strains was then subjected to PCR amplification using specific primer pairs designed from each of the four bacteriocin (KlebB, C, D, CCL) sequences found so far in Klebsiella. KlebD primer pairs were the only to produce a single product for all strains expressing the killing phenotype in vitro. One of the amplicons was cloned and sequenced; the DNA sequence shows 93% identity with a plasmid-carried colicin-D gene of a strain of Klebsiella michiganensis, and 86% identity with the sequence encoding for the klebicin D activity protein in K. oxytoca. Our work provides the first evidence that dominant symbiotic bacteria associated with wild medfly populations express a killing phenotype that may mediate inter and intraspecies competition among bacterial populations in the insect gut in vivo.

scholarly journals Shiitake Mycelial Leachate Suppresses Growth of Some Bacterial Species and Symptoms of Bacterial Wilt of Tomato and Lima Bean in vitro

Plant Disease ◽  
1999 ◽  
Vol 83 (1) ◽  
pp. 20-23 ◽  
Author(s):  
R. P. Pacumbaba ◽  
Caula A. Beyl ◽  
R. O. Pacumbaba
Keyword(s):  
Pseudomonas Syringae ◽  
Bacterial Wilt ◽  
Xanthomonas Campestris ◽  
Erwinia Amylovora ◽  
Bacterial Species ◽  
Lima Bean ◽  
Symptom Expression ◽  
Shiitake Mushroom ◽  
And Staphylococcus Aureus

Mycelial leachate of shiitake mushroom inhibited growth of Pseudomonas syringae pv. glycinea, P. syringae pv. tabaci, Xanthomonas campestris pv. glycines, X. campestris pv. campestris, Erwinia amylovora, Ralstonia solanacearum, Curtobacterium flaccumfaciens pv. flaccumfaciens, Bacillus cereus, Escherichia coli, Listeria monocytogenes, Salmonella typhimurium, and Staphylococcus aureus. The mycelial leachate applied as soil drench prevented symptom expression of bacterial wilt of tomato and lima bean in the laboratory. The results suggested that the shiitake mycelia leachate contained an antibiotic ingredient.

scholarly journals Analyses of Short-Term Antagonistic Evolution of Pseudomonas aeruginosa Strain PAO1 and Phage KPP22 (Myoviridae Family, PB1-Like Virus Genus)

2016 ◽  
Vol 82 (15) ◽  
pp. 4482-4491 ◽  
Author(s):  
Jumpei Uchiyama ◽  
Masato Suzuki ◽  
Koji Nishifuji ◽  
Shin-ichiro Kato ◽  
Reina Miyata ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Bacterial Resistance ◽  
Phage Therapy ◽  
Open Reading Frames ◽  
Missense Mutations ◽  
Short Term ◽  
Strain Pao1 ◽  
Content Type ◽  
Phage Adsorption

ABSTRACTPseudomonas aeruginosacauses serious intractable infections in humans and animals. Bacteriophage (phage) therapy has been applied to treatP. aeruginosainfections, and phages belonging to the PB1-like virus genus in theMyoviridaefamily have been used as therapeutic phages. To achieve safer and more effective phage therapy, the use of preadapted phages is proposed. To understand in detail such phage preadaptation, the short-term antagonistic evolution of bacteria and phages should be studied. In this study, the short-term antagonistic evolution of bacteria and PB1-like phage was examined by studying phage-resistant clones ofP. aeruginosastrain PAO1 and mutant PB1-like phages that had recovered their infectivity. First, phage KPP22 was isolated and characterized; it was classified as belonging to the PB1-like virus genus in theMyoviridaefamily. Subsequently, three KPP22-resistant PAO1 clones and three KPP22 mutant phages capable of infecting these clones were isolated in three sets ofin vitroexperiments. It was shown that the bacterial resistance to phage KPP22 was caused by significant decreases in phage adsorption and that the improved infectivity of KPP22 mutant phages was caused by significant increases in phage adsorption. The KPP22-resistant PAO1 clones and the KPP22 mutant phages were then analyzed genetically. All three KPP22-resistant PAO1 clones, which were deficient for the O5 antigen, had a common nonsense mutation in thewzygene. All the KPP22 mutant phage genomes showed the same four missense mutations in the open reading framesorf060,orf065, andorf086. The information obtained in this study should be useful for further development of safe and efficient phage therapy.IMPORTANCEPseudomonas aeruginosacauses serious intractable infections in humans and animals; bacteriophage (phage) therapy has been utilized to treatP. aeruginosainfections, and phages that belong to the PB1-like virus genus in the familyMyoviridaehave been used as therapeutic phages. The preadapted phage is trained in advance through the antagonistic evolution of bacteria and phage and is proposed to be used to achieve safer and more effective phage therapy. In this study, to understand the phage preadaptation, thein vitroshort-term antagonistic evolution was studied usingP. aeruginosastrain PAO1 and the newly isolated PB1-like phage KPP22. Phage KPP22 was characterized, and the molecular framework regarding the phage preadaptation of KPP22 was elucidated. The importance of study of antagonistic evolution of bacteria and phage in phage therapy is discussed.

scholarly journals ANTIBACTERIAL ACTIVITY OF FRESH ONION AND GARLIC JUICES

2020 ◽  
Vol 20 (3) ◽  
pp. 705-712
Author(s):  
LUCIANA TEODORA ROTARU ◽  
MARIUS NOVAC ◽  
OANA NICOLAESCU
Keyword(s):  
Bacterial Resistance ◽  
Antibacterial Effect ◽  
Bacterial Species ◽  
Antimicrobial Properties ◽  
Chemotherapeutic Agents ◽  
Active Components ◽  
Docking Method ◽  
Therapeutic Properties ◽  
Species Being

Herbal extracts with antimicrobial potential represent an important research directive, in the current medical world, aiming to isolate active components, to develop new chemotherapeutic agents with applicability in the treatment or use as adjuvant therapy in infectious states. Antimicrobial properties of plants are conferred by their ability to synthesize certain secondary metabolites with relatively complex structures. The last century has been marked by sustained efforts to search for new natural compounds with antibacterial therapeutic properties, due to the gradual reduction in the number of effective allopathic antibiotics and the toxic effects of antibiotic residues. Numerous in vitro studies have shown that plants have antibacterial efficacy, discovering the importance of little-studied natural resources in this regard, as being effective in fighting against bacterial resistance and destroying bacterial agents. In this study, the antibacterial effect of the fresh onion and garlic juice was compared to the antibiotics of choice, using the diffusimetric agar method. Both plant products tested have antibacterial effect, the bacterial species being classified as sensitive to their action. The molecular docking method helps us to see the type of interaction between ligands and targets, allicin having no common binding site with antibiotics of choice.

scholarly journals In Vitro Selection and in Vitro Screening for Disease Resistance in Fruit Trees

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 695b-695
Author(s):  
Freddi A. Hammerschlag ◽  
Ghazala Hashmi ◽  
Robin Huettel ◽  
Dennis Werner ◽  
David Ritchie
Keyword(s):  
Tissue Culture ◽  
Genetic Variation ◽  
Disease Resistance ◽  
Pseudomonas Syringae ◽  
Xanthomonas Campestris ◽  
Fruit Trees ◽  
Culture Techniques ◽  
Somaclonal Variants ◽  
Tissue Culture Techniques

One approach for obtaining useful genetic variation is to select for somaclonal variants generated by tissue culture techniques. Increased levels of resistance to bacterial leaf spot (Xanthomonas campestris pv. pruni) have been observed in toxin-selected and unselected peach regenerants in vitro, in the greenhouse and under field conditions. Peach regenerants have also demonstrated increased levels of bacterial canker (Pseudomonas syringae pv. syringae) and root-knot nematode (Meloidogyne incognita) resistance. Random amplified polymorphic DNA (RAPD) primers have been used to study genetic variation at the DNA level among the somaclonal variants. Sixty RAPD primers (10-mers) were screened and 10 proved useful as markers to detect polymorphisms, thus establishing a genetic basis for somaclonal variation. These studies demonstrate the feasibility of using tissue culture techniques to generate fruit trees with increased levels of disease resistance.

scholarly journals Identification of Pseudomonas Isolates Associated With Bacterial Canker of Stone Fruit Trees in the Western Cape, South Africa

Plant Disease ◽  
2020 ◽  
Vol 104 (3) ◽  
pp. 882-892 ◽  
Author(s):  
Khumbuzile N. Bophela ◽  
Yolanda Petersen ◽  
Carolee. T. Bull ◽  
Teresa. A. Coutinho
Keyword(s):  
South Africa ◽  
Pseudomonas Syringae ◽  
Bacterial Species ◽  
Fruit Trees ◽  
Stone Fruit ◽  
Bacterial Disease ◽  
Bacterial Canker ◽  
Western Cape ◽  
Vegetable Crops ◽  
Phylogenetic Groups

Bacterial canker is a common bacterial disease of stone fruit trees. The causal agents responsible for the disease include several pathovars in Pseudomonas syringae sensu lato and newly described Pseudomonas species. Pseudomonad strains were isolated from symptomatic stone fruit trees, namely apricot, peach, and plum trees cultivated in spatially separated orchards in the Western Cape. A polyphasic approach was used to identify and characterize these strains. Using a multilocus sequence typing approach of four housekeeping loci, namely cts, gapA, gyrB, and rpoD, the pseudomonad strains were delineated into two phylogenetic groups within P. syringae sensu lato: P. syringae sensu stricto and Pseudomonas viridiflava. These results were further supported by LOPAT diagnostic assays and analysis of clades in the rep-PCR dendrogram. The pseudomonad strains were pathogenic on both apricot and plum seedlings, indicative of a lack of host specificity between Pseudomonas strains infecting Prunus spp. This is a first report of P. viridiflava isolated from plum trees showing symptoms of bacterial canker. P. viridiflava is considered to be an opportunistic pathogen that causes foliar diseases of vegetable crops, fruit trees, and aromatic herbs, and thus the isolation of pathogenic P. viridiflava from twigs of plum trees showing symptoms of bacterial canker suggests that this bacterial species is a potentially emerging stem canker pathogen of stone fruit trees in South Africa.

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