scholarly journals Discovery of a Novel Lineage Burkholderia cepacia ST 1870 Endophytically Isolated from Medicinal Polygala paniculata Which Shows Potent In Vitro Antileishmanial and Antimicrobial Effects

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Felipe de Paula Nogueira Cruz ◽  
Ailton Ferreira de Paula ◽  
Camila Tita Nogueira ◽  
Paulo Henrique Marques de Andrade ◽  
Leonardo Maurici Borges ◽  
...  
Keyword(s):  
Burkholderia Cepacia ◽  
Plant Pathogens ◽  
Leishmania Major ◽  
Micrococcus Luteus ◽  
Neglected Diseases ◽  
Isolation And Identification ◽  
Moniliophthora Perniciosa ◽  
Fungal Plant Pathogens ◽  
A Genome

In this study, we report the isolation and identification of an endophytic strain of Burkholderia cepacia (COPS strain) associated with Polygala paniculata roots. Polygala plants are rich sources of promising microbiomes, of which the literature reports several pharmacological effects, such as trypanocidal, antinociceptive, anesthetic, anxiolytics, and anticonvulsant activities. B. cepacia COPS belongs to a new sequence type (ST 1870) and harbors a genome estimated in 8.3 Mbp which exhibits the aminoglycosides and beta-lactams resistance genes aph(3′)-IIa and blaTEM-116, respectively. Analysis performed using MLST, average nucleotide identity, and digital DNA-DNA hybridization support its species-level identification and reveals its novel housekeeping genes alleles gyrB, lepA, and phaC. The root endophyte B. cepacia COPS drew our attention from a group of 14 bacterial isolates during the primary screening for being potentially active against Staphylococcus aureus ATCC 29213, Enterococcus faecalis ATCC 29212, Micrococcus luteus ATCC 9341, Escherichia coli ATCC 25922, and Candida albicans ATCC 10231 and exhibited the broad-spectrum activity against phytopathogenic fungi. In addition, COPS strain showed production of protease, lipase, and esterase in solid media, and its natural product extract showed potent inhibition against fungal plant pathogens, such as Moniliophthora perniciosa, whose antagonism index (89.32%) exceeded the positive control (74.17%), whereas Sclerotinia sclerotiorum and Ceratocystis paradoxa showed high percentages of inhibition (85.53% and 82.69%, respectively). COPS crude extract also significantly inhibited S. epidermidis ATCC 35984, E. faecium ATCC 700221 (MIC values of 32 μg/mL for both), E. faecalis ATCC 29212 (64 μg/mL), and S. aureus ATCC 25923 (128 μg/mL). We observed moderate antagonistic activity against A. baumannii ATCC 19606 and E. coli ATCC 25922 (both at 512 μg/mL), as well as potent cytotoxic effects on Leishmania infantum and Leishmania major promastigote forms with 78.25% and 57.30% inhibition. In conclusion, this study presents for the first time the isolation of an endophytic B. cepacia strain associated with P. paniculata and enough evidence that these plants may be considered a rich source of microbes for the fight against neglected diseases.

scholarly journals Identification of Resistance Determinants for a Promising Antileishmanial Oxaborole Series

2021 ◽  
Vol 9 (7) ◽  
pp. 1408
Author(s):  
Magali Van den Kerkhof ◽  
Philippe Leprohon ◽  
Dorien Mabille ◽  
Sarah Hendrickx ◽  
Lindsay B. Tulloch ◽  
...  
Keyword(s):  
Drug Exposure ◽  
In Vitro Selection ◽  
Selection Procedure ◽  
Cosmid Library ◽  
Neglected Diseases ◽  
Chromosome 2 ◽  
Resistance Determinants ◽  
A Genome

Current treatment options for visceral leishmaniasis have several drawbacks, and clinicians are confronted with an increasing number of treatment failures. To overcome this, the Drugs for Neglected Diseases initiative (DNDi) has invested in the development of novel antileishmanial leads, including a very promising class of oxaboroles. The mode of action/resistance of this series to Leishmania is still unknown and may be important for its further development and implementation. Repeated in vivo drug exposure and an in vitro selection procedure on both extracellular promastigote and intracellular amastigote stages were both unable to select for resistance. The use of specific inhibitors for ABC-transporters could not demonstrate the putative involvement of efflux pumps. Selection experiments and inhibitor studies, therefore, suggest that resistance to oxaboroles may not emerge readily in the field. The selection of a genome-wide cosmid library coupled to next-generation sequencing (Cos-seq) was used to identify resistance determinants and putative targets. This resulted in the identification of a highly enriched cosmid, harboring genes of chromosome 2 that confer a subtly increased resistance to the oxaboroles tested. Moderately enriched cosmids encompassing a region of chromosome 34 contained the cleavage and polyadenylation specificity factor (cpsf) gene, encoding the molecular target of several related benzoxaboroles in other organisms.

scholarly journals Evaluation of in-vitro methods to select effective streptomycetes against toxigenic fusaria

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6905 ◽  
Author(s):  
Elena Maria Colombo ◽  
Cristina Pizzatti ◽  
Andrea Kunova ◽  
Claudio Gardana ◽  
Marco Saracchi ◽  
...  
Keyword(s):  
Plant Pathogens ◽  
Culture Media ◽  
Screening Methods ◽  
Dual Culture ◽  
In Planta ◽  
In Vitro Method ◽  
In Vitro Methods ◽  
Strain Diversity ◽  
Fungal Plant Pathogens

Biocontrol microorganisms are emerging as an effective alternative to pesticides. Ideally, biocontrol agents (BCAs) for the control of fungal plant pathogens should be selected by an in vitro method that is high-throughput and is predictive of in planta efficacy, possibly considering environmental factors, and the natural diversity of the pathogen. The purpose of our study was (1) to assess the effects ofFusariumstrain diversity (N= 5) and culture media (N= 6) on the identification of biological control activity ofStreptomycesstrains (N= 20) againstFusariumpathogens of wheat in vitro and (2) to verify the ability of our in vitro screening methods to simulate the activity in planta. Our results indicate that culture media,Fusariumstrain diversity, and their interactions affect the results of an in vitro selection by dual culture assay. The results obtained on the wheat-based culture media resulted in the highest correlation score (r= 0.5) with the in planta root rot (RR) inhibition, suggesting that this in vitro method was the best predictor of in planta performance of streptomycetes against Fusarium RR of wheat assessed as extension of the necrosis on the root. Contrarily, none of the in vitro plate assays using the media tested could appropriately predict the activity of the streptomycetes against Fusarium foot rot symptoms estimated as the necrosis at the crown level. Considering overall data of correlation, the activity in planta cannot be effectively predicted by dual culture plate studies, therefore improved in vitro methods are needed to better mimic the activity of biocontrol strains in natural conditions. This work contributes to setting up laboratory standards for preliminary screening assays ofStreptomycesBCAs against fungal pathogens.

scholarly journals Plant Defensin Peptides have Antifungal and Antibacterial Activity Against Human and Plant Pathogens

2019 ◽  
Vol 109 (3) ◽  
pp. 402-408 ◽  
Author(s):  
Andrew E. Sathoff ◽  
Siva Velivelli ◽  
Dilip M. Shah ◽  
Deborah A. Samac
Keyword(s):  
Antibacterial Activity ◽  
Plant Pathogens ◽  
Crown Rot ◽  
Plant Defensin ◽  
Core Motif ◽  
Potential Control ◽  
Fungal Plant Pathogens ◽  
Plant Defensins ◽  
Animal Pathogens

Plant defensins are small, cysteine-rich antimicrobial peptides. These peptides have previously been shown to primarily inhibit the growth of fungal plant pathogens. Plant defensins have a γ-core motif, defined as GXCX3-9C, which is required for their antifungal activity. To evaluate plant defensins as a potential control for a problematic agricultural disease (alfalfa crown rot), short, chemically synthesized peptides containing γ-core motif sequences were screened for activity against numerous crown rot pathogens. These peptides showed both antifungal and, surprisingly, antibacterial activity. Core motif peptides from Medicago truncatula defensins (MtDef4 and MtDef5) displayed high activity against both plant and human bacterial pathogens in vitro. Full-length defensins had higher antimicrobial activity compared with the peptides containing their predictive γ-core motifs. These results show the future promise for controlling a wide array of economically important fungal and bacterial plant pathogens through the transgenic expression of a plant defensin. They also suggest that plant defensins may be an untapped reservoir for development of therapeutic compounds for combating human and animal pathogens.

scholarly journals Trypanosoma cruzi Genome 15 Years Later: What Has Been Accomplished?

2020 ◽  
Vol 5 (3) ◽  
pp. 129
Author(s):  
Jose Luis Ramirez
Keyword(s):  
Trypanosoma Cruzi ◽  
Latin American ◽  
Drug Targets ◽  
Leishmania Major ◽  
Etiologic Agent ◽  
Neglected Diseases ◽  
Adaptive Capabilities ◽  
Genome Draft ◽  
Work Done

On 15 July 2020 was the 15th anniversary of the Science Magazine issue that reported three trypanosomatid genomes, namely Leishmania major, Trypanosoma brucei, and Trypanosoma cruzi. That publication was a milestone for the research community working with trypanosomatids, even more so, when considering that the first draft of the human genome was published only four years earlier after 15 years of research. Although nowadays, genome sequencing has become commonplace, the work done by researchers before that publication represented a huge challenge and a good example of international cooperation. Research in neglected diseases often faces obstacles, not only because of the unique characteristics of each biological model but also due to the lower funds the research projects receive. In the case of Trypanosoma cruzi the etiologic agent of Chagas disease, the first genome draft published in 2005 was not complete, and even after the implementation of more advanced sequencing strategies, to this date no final chromosomal map is available. However, the first genome draft enabled researchers to pick genes a la carte, produce proteins in vitro for immunological studies, and predict drug targets for the treatment of the disease or to be used in PCR diagnostic protocols. Besides, the analysis of the T. cruzi genome is revealing unique features about its organization and dynamics. In this work, I briefly summarize the actions of Latin American researchers that contributed to the first publication of the T. cruzi genome and discuss some features of the genome that may help to understand the parasite’s robustness and adaptive capabilities.

Antifungal activity of extracts from endophytic fungi associated with Smallanthus maintained in vitro as autotrophic cultures and as pot plants in the greenhouse

2012 ◽  
Vol 58 (10) ◽  
pp. 1202-1211 ◽  
Author(s):  
Luiz H. Rosa ◽  
Nurhayat Tabanca ◽  
Natascha Techen ◽  
Zhiqiang Pan ◽  
David E. Wedge ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Endophytic Fungi ◽  
Plant Pathogens ◽  
Cultivation Conditions ◽  
Smallanthus Sonchifolius ◽  
Fungal Plant Pathogens ◽  
In The Wild ◽  
Fungal Assemblages ◽  
Pot Plants

The endophytic fungal assemblages associated with Smallanthus sonchifolius (Poepp.) H. Rob. and Smallanthus uvedalius (L.) Mack. ex Small growing in vitro autotrophic cultures and in the greenhouse were identified and evaluated for their ability to produce bioactive compounds. A total of 25 isolates were recovered that were genetically closely related to species of the genera Bionectria , Cladosporium , Colletotrichum , Fusarium , Gibberella , Hypocrea , Lecythophora , Nigrospora , Plectosphaerella , and Trichoderma . The endophytic assemblages of S. sonchifolius presented a greater diversity than the group isolated from S. uvedalius and demonstrated the presence of dominant generalist fungi. Extracts of all fungi were screened against the fungal plant pathogens. Ten extracts (41.6%) displayed antifungal activities; some of them had a broad antifungal activity. The phylotypes Lecythophora sp. 1, Lecythophora sp. 2, and Fusarium oxysporum were isolated from in vitro autotrophic cultures and displayed antifungal activity. The presence of bioactive endophytic fungi within S. sonchifolius and S. uvedalius suggests an ecological advantage against pathogenic attacks. This study revealed reduced numbers of endophytes in association with both Smallanthus species in controlled cultivation conditions compared with the endophytic communities of hosts collected in the wild environments. Even as reduced endophytic communities, these fungi continue to provide chemical protection for the host.

scholarly journals A multi-country study using MALDI-TOF mass spectrometry for rapid identification of Burkholderia pseudomallei

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Wanitda Watthanaworawit ◽  
Tamalee Roberts ◽  
Jill Hopkins ◽  
Ian Gassiep ◽  
Robert Norton ◽  
...  
Keyword(s):  
Burkholderia Cepacia ◽  
Burkholderia Pseudomallei ◽  
Research Unit ◽  
Rapid Identification ◽  
Geographical Differences ◽  
Isolation And Identification ◽  
Maldi Tof ◽  
The Impact ◽  
Vitek Ms

Abstract Background Burkholderia pseudomallei is the bacterial causative agent of melioidosis, a difficult disease to diagnose clinically with high mortality if not appropriately treated. Definitive diagnosis requires isolation and identification of the organism. With the increased adoption of MALDI-TOF MS for the identification of bacteria, we established a method for rapid identification of B. pseudomallei using the Vitek MS, a system that does not currently have B. pseudomallei in its in-vitro diagnostic database. Results A routine direct spotting method was employed to create spectra and SuperSpectra. An initial B. pseudomallei SuperSpectrum was created at Shoklo Malaria Research Unit (SMRU) from 17 reference isolates (46 spectra). When tested, this initial SMRU SuperSpectrum was able to identify 98.2 % (54/55) of Asian isolates, but just 46.7 % (35/75) of Australian isolates. Using spectra (430) from different reference and clinical isolates, two additional SMRU SuperSpectra were created. Using the combination of all SMRU SuperSpectra with seven existing SuperSpectra from Townsville, Australia 119 (100 %) Asian isolates and 31 (100 %) Australian isolates were correctly identified. In addition, no misidentifications were obtained when using these 11 SuperSpectra when tested with 34 isolates of other bacteria including the closely related species Burkholderia thailandensis and Burkholderia cepacia. Conclusions This study has established a method for identification of B. pseudomallei using Vitek MS, and highlights the impact of geographical differences between strains for identification using this technique.

Douglas-fir root-associated microorganisms with inhibitory activity towards fungal plant pathogens and human bacterial pathogens

1996 ◽  
Vol 42 (7) ◽  
pp. 690-700 ◽  
Author(s):  
Paige E. Axelrood ◽  
Alison M. Clarke ◽  
Reed Radley ◽  
S. Janet V. Zemcov
Keyword(s):  
Antifungal Activity ◽  
Inhibitory Activity ◽  
Plant Pathogens ◽  
Bacterial Pathogens ◽  
Douglas Fir ◽  
Microbial Culture ◽  
Bacterial Strains ◽  
Fungal Plant Pathogens ◽  
Forest Sites

A microbial culture collection composed of 1820 bacterial strains, including 298 actinomycete strains, was established from the roots of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings harvested from conifer nurseries and forest sites. Two hundred and thirty-four strains inhibited the growth of Fusarium, Cylindrocarpon, and (or) Pythium spp. in in vitro assays. A significantly greater proportion of bacterial strains from actinomycete genera exhibited antifungal properties compared with bacterial strains from nonactinomycete genera. Eighty-nine percent of identified inhibitory strains were Streptomyces, Streptoverticillium, Bacillus, Pseudomonas, or Burkholderia species. The actinomycete species were isolated almost exclusively from forest seedlings. Recovery of inhibitory strains representing 29 microbial species was enhanced using a variety of methods to isolate microorganisms from the roots of seedlings from nursery and forest sites. Bacterial strains (including actinomycete strains) with antifungal activity were tested for in vitro growth inhibition of six clinical human bacterial pathogens (Enterococcus faecalis, Staphylococcus aureus, Klebsiella pneumoniae, Escherichia coli, Proteus mirabilis, and Pseudomonas aeruginosa). Forty-eight percent of the tested strains inhibited one or more human pathogens. Inhibitory activity towards fungal and bacterial pathogens was strain specific, not species specific, and many inhibitory strains exhibited broad-spectrum activity. Strains with antifungal activity against several conifer root pathogens were also more likely to inhibit multiple species of clinical bacterial pathogens.Key words: in vitro, antimicrobial, conifer rhizosphere.

scholarly journals Sensitivity of Bacterial and Fungal Plant Pathogens to the Lytic Peptides, MSI-99, Magainin II, and Cecropin B

2002 ◽  
Vol 15 (7) ◽  
pp. 701-708 ◽  
Author(s):  
Ali R. Alan ◽  
Elizabeth D. Earle
Keyword(s):  
Phytophthora Infestans ◽  
Plant Pathogens ◽  
Fungal Spores ◽  
Alternaria Solani ◽  
Leaf Disk ◽  
Cecropin B ◽  
Fungal Plant Pathogens ◽  
Magainin Ii ◽  
Lytic Peptides

In vitro and leaf disk assays of bacterial and fungal plant pathogens were conducted using three cationic lytic peptides, MSI-99, magainin II (MII), and cecropin B (CB). Growth of bacterial organisms was retarded or completely inhibited by low concentrations of these lytic peptides. The peptides also significantly reduced germination of fungal spores and growth of mycelia; however, higher concentrations of peptides were needed to inhibit fungal growth compared with those needed to inhibit bacteria. The relative efficacy of the peptides depended on the microorganism tested, but CB was the most inhibitory to the majority of the bacteria and fungi assayed. MSI-99, a synthetic derivative of MII with increased positive charge, showed equal or two- to fivefold higher antibacterial activity compared to MII in the in vitro assays. MSI-99 was also superior to MII against the oomycete, Phytophthora infestans but was slightly inferior to MII in assays with the true fungi, Penicillium digitatum and Alternaria solani. In the leaf disk assays, pretreating spores of Alternaria solani and Phytophthora infestans with the peptides at concentrations as low as 10 μg per ml led to significant reductions in the size of early blight lesions and prevented development of any late blight lesions on tomato leaf disks. Our results from in vitro and leaf disk assays suggest that MSI-99 can be used as a transgene to generate tomato lines with enhanced resistance to bacterial and fungal diseases of this crop.

scholarly journals Transfection of Sclerotinia sclerotiorum withIn VitroTranscripts of a Naturally Occurring Interspecific Recombinant of Sclerotinia sclerotiorum Hypovirus 2 Significantly Reduces Virulence of the Fungus

2015 ◽  
Vol 89 (9) ◽  
pp. 5060-5071 ◽  
Author(s):  
Shin-Yi Lee Marzano ◽  
Houston A. Hobbs ◽  
Berlin D. Nelson ◽  
Glen L. Hartman ◽  
Darin M. Eastburn ◽  
...  
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Plant Pathogens ◽  
High Throughput Sequencing ◽  
Infectious Clone ◽  
White Mold ◽  
Content Type ◽  
Fungal Plant Pathogens ◽  
Rapid Amplification ◽  
Valsa Ceratosperma

ABSTRACTA recombinant strain ofSclerotinia sclerotiorumhypovirus 2 (SsHV2) was identified from a North AmericanSclerotinia sclerotiorumisolate (328) from lettuce (Lactuca sativaL.) by high-throughput sequencing of total RNA. The 5′- and 3′-terminal regions of the genome were determined by rapid amplification of cDNA ends. The assembled nucleotide sequence was up to 92% identical to two recently reported SsHV2 strains but contained a deletion near its 5′ terminus of more than 1.2 kb relative to the other SsHV2 strains and an insertion of 524 nucleotides (nt) that was distantly related toValsa ceratospermahypovirus 1. This suggests that the new isolate is a heterologous recombinant of SsHV2 with a yet-uncharacterized hypovirus. We named the new strainSclerotinia sclerotiorumhypovirus 2 Lactuca (SsHV2L) and deposited the sequence in GenBank with accession numberKF898354.Sclerotinia sclerotiorumisolate 328 was coinfected with a strain ofSclerotinia sclerotiorumendornavirus 1 and was debilitated compared to cultures of the same isolate that had been cured of virus infection by cycloheximide treatment and hyphal tipping. To determine whether SsHV2L alone could induce hypovirulence inS. sclerotiorum, a full-length cDNA of the 14,538-nt viral genome was cloned. Transcripts corresponding to the viral RNA were synthesizedin vitroand transfected into a virus-free isolate ofS. sclerotiorum, DK3. Isolate DK3 transfected with SsHV2L was hypovirulent on soybean and lettuce and exhibited delayed maturation of sclerotia relative to virus-free DK3, completing Koch's postulates for the association of hypovirulence with SsHV2L.IMPORTANCEA cosmopolitan fungus,Sclerotinia sclerotioruminfects more than 400 plant species and causes a plant disease known as white mold that produces significant yield losses in major crops annually. Mycoviruses have been used successfully to reduce losses caused by fungal plant pathogens, but definitive relationships between hypovirus infections and hypovirulence inS. sclerotiorumwere lacking. By establishing a cause-and-effect relationship betweenSclerotinia sclerotiorumhypovirus Lactuca (SsHV2L) infection and the reduction in host virulence, we showed direct evidence that hypoviruses have the potential to reduce the severity of white mold disease. In addition to intraspecific recombination, this study showed that recent interspecific recombination is an important factor shaping viral genomes. The construction of an infectious clone of SsHV2L allows future exploration of the interactions between SsHV2L andS. sclerotiorum, a widespread fungal pathogen of plants.

scholarly journals Diversity of biocontrol agents, isolated from several sources, inhibitory to several fungal plant pathogens

2020 ◽  
Vol 22 (1) ◽  
Author(s):  
Yan Ramona ◽  
IDA BAGUS GEDE DARMAYASA ◽  
ANAK AGUNG NGURAH NARA KUSUMA ◽  
Martin Line
Keyword(s):  
Fungal Pathogens ◽  
Plant Pathogens ◽  
Antagonistic Activity ◽  
Significant Inhibition ◽  
Biocontrol Agents ◽  
Dual Culture ◽  
Rdna Sequences ◽  
Fungal Plant Pathogens ◽  
Mature Compost

Abstract. Ramona Y, Darmayasa IBG, Kusuma AANN, Line MA. 2021. Diversity of biocontrol agents, isolated from several sources, inhibitory to several fungal plant pathogens. Biodiversitas 22: 298-303. This study investigated the inhibitory potential of diversity of antagonist bacteria residing in the rhizosphere zone and mature compost to counter fungal plant pathogens. Soils collected from rhizosphere of lettuce farms in Bali-Indonesia and Tasmania-Australia, mature compost, commercial biocontrol (Dipel®), and laboratory contaminants with significant inhibition against tested fungal pathogens were used as sources of antagonist bacteria. These antagonists were isolated by applying dilution and spread method on trypticase soya agar (TSA) or potato dextrose agar (PDA), and their ability to inhibit Sclerotinia minor, Sclerotinia sclerotiorum, Fusarium spp., and Rhizoctonia solani was assessed in dual culture assays. The results showed that 67 out of more than 100 isolates had antagonistic activity in vitro against at least one of tested fungal pathogens. In the preliminary identification, Bacillus spp. or Pseudomonas spp. were found to be pre-dominant isolates. Following screening studies in a non-replicated glasshouse experiment against S. minor and S. sclerotiorum, 8 of the most promising isolates were further identified using molecular methods based on their 16s rDNA sequences aligned with those deposited at the GeneBank. These 8 isolates were identified as Pseudomonas corrugata, Bacillus megaterium, Bacillus polymyxa, Bacillus mojavensis, Bacillus pumilus, Bacillus thuringiensis, Exiguobacterium acetylicum, and Chryseobacterium indologenes.

Sign in / Sign up

Export Citation Format

Share Document