scholarly journals Differential in vitro pathogenicity of predatory fungi of the genus Monacrosporium for phytonematodes, free-living nematodes and parasitic nematodes of cattle

1999 ◽  
Vol 32 (1) ◽  
pp. 79-83 ◽  
Author(s):  
A.P.S. Gomes ◽  
J.V. Araújo ◽  
R.C.F. Ribeiro
Keyword(s):  
Parasitic Nematodes ◽  
Free Living

Biological attributes of Salibro™, a novel sulfonamide nematicide. Part 2: Impact on the fitness of various non-target nematodes

Nematology ◽  
2020 ◽  
pp. 1-17 ◽  
Author(s):  
Tim C. Thoden ◽  
Mariam A. Alkader ◽  
John A. Wiles
Keyword(s):  
Negative Impact ◽  
Soil Health ◽  
Agar Plate ◽  
Parasitic Nematodes ◽  
Published Data ◽  
Plant Parasitic Nematodes ◽  
Free Living ◽  
Plant Parasitic ◽  
Novel Products

Summary Currently a renaissance in chemical nematicides is taking place with novel products like Nimitz® (a.s. fluensulfone), Velum Prime® (a.s. fluopyram) and Salibro™ (a.s. fluazaindolizine – Reklemel™ active) entering the marketplace. Although a considerable amount of published data is already available on their laboratory and field impact on plant-parasitic nematodes, little is understood of their compatibility with the beneficial or free-living nematodes that are part of the soil health network. In a range of laboratory studies, the effects of these nematicides on the vitality and reproduction of several species was tested, including both cosmopolitan free-living nematodes (Acrobeloides, Cruznema, Panagrobelus) as well as commercially applied entomopathogenic nematodes (Steinernema, Heterorhabditis). Within aqueous exposure and agar plate in vitro assays, species sensitivity to those nematicides differed significantly but their fitness (vitality and reproduction; infectivity to insect hosts) was generally not adversely impacted by concentrations of 5-50 ppm (a.s.) of Salibro. Even at 250 ppm (a.s.) of Salibro only some species of the bacterial-feeding species showed some negative impact. By contrast, both Nimitz at 50 ppm (a.s.) and Velum at 5 ppm (a.s.) consistently demonstrated stronger adverse impacts. In second level soil drenching assays, either no, or occasionally slight, adverse effects on the natural community of free-living nematodes were observed if soils were drenched with different volumes of Salibro at 5-50 ppm (a.s.), while relatively stronger reductions were measured within the plant-parasitic species (especially root-knot nematodes). Both Nimitz and Vydate (a.s. oxamyl) showed some degree of compatibility at 5 and 25 ppm (a.s.), respectively, which was generally higher than for Velum Prime at 5 ppm (a.s.). Overall, these data indicate that, when used at common field rates, Salibro will be one of the best options as part of integrated nematode management programmes where the use of chemical nematicides is required.

In vitro proteolysis of nematode FMRFamide-like peptides (FLPs) by preparations from a free-living nematode (Panagrellus redivivus) and two plant-parasitic nematodes (Heteroderaglycines and Meloidogyne incognita)

2011 ◽  
Vol 86 (1) ◽  
pp. 77-84 ◽  
Author(s):  
E.P. Masler
Keyword(s):  
Cathepsin L ◽  
Cysteine Proteases ◽  
Developmental Differences ◽  
Parasitic Nematodes ◽  
Free Living ◽  
Additional Species ◽  
Substrate Preferences ◽  
Panagrellus Redivivus ◽  
Species Specific

AbstractProteolytic activities in extracts from three nematodes, the plant parasites Heterodera glycines and Meloidogyneincognita, and the free-living Panagrellus redivivus, were surveyed for substrate preferences using a battery of seven FRET-modified peptide substrates, all derived from members of the large FMRF-amide like peptide (FLP) family in nematodes. Overall protease activity in P. redivivus was four- to fivefold greater than in either of the parasites, a result that might reflect developmental differences. Digestion of the M. incognita FLP KHEFVRFa (substrate Abz-KHEFVRF-Y(3-NO2)a) by M. incognita extract was sevenfold greater than with H. glycines extract and twofold greater than P. redivivus, suggesting species-specific preferences. Additional species differences were revealed upon screening 12 different protease inhibitors. Two substrates were used in the screen, Abz-KHEFVRF-Y(3-NO2)a and Abz-KPSFVRF-Y(3-NO2)a), which was digested equally by all three species. The effects of various inhibitor, substrate and extract source combinations on substrate digestion suggest that M. incognita differs significantly from P. redivivus and H. glycines in its complement of cysteine proteases, particularly cathepsin L-type protease.

scholarly journals Curtisia dentata (Cornaceae) leaf extracts and isolated compounds inhibit motility of parasitic and free-living nematodes

2009 ◽  
Vol 76 (2) ◽  
Author(s):  
L.J. Shai ◽  
E.S. Bizimenyera ◽  
V. Bagla ◽  
L.J. McGaw ◽  
J.N. Eloff
Keyword(s):  
Medicinal Plant ◽  
Betulinic Acid ◽  
Small Ruminants ◽  
Anthelmintic Activity ◽  
Parasitic Nematodes ◽  
Leaf Extracts ◽  
Free Living ◽  
C Elegans

Haemonchus contortus and Trichostrongylus colubriformis are among the most important parasitic nematodes of small ruminants. Caenorhabditis elegans, a free-living nematode, is used as a model for evaluating anthelmintic activity of a variety of test substances. Extracts of several medicinal plants are useful in vitro and in vivo against nematode development. Extracts of Curtisia dentata, a South African medicinal plant, and compounds isolated from leaves of this plant were investigated for anthelmintic activity against T. colubriformis, H. contortus and C. elegans. The acetone and dichloromethane extracts were active against all nematodes at concentrations as low as 160 μg/mℓ. Betulinic acid and lupeol were active against the parasitic nematodes only at the high concentrations of 1 000 and 200 μg/mℓ, respectively. All compounds were effective against C. elegans with active concentrations as low as 8 μg/mℓ. Betulinic acid was less active than lupeol and ursolic acid against C. elegans. The acetone and dichloromethane extracts were also active against C. elegans with a concentration of 0.31 mg/mℓ resulting in almost 80 % inhibition of larval motility. The use of free-living nematodes may provide information on the activity of potential anthelmintics against parasitic nematodes. Extracts of various medicinal plant species may provide solutions to ill-health of small ruminants caused by parasitic nematodes in poor communities of southern Africa.

scholarly journals In vitro screening of new strains of predacious nematophagous fungi for biocontrol suitability when produced in liquid culture

2021 ◽  
Vol 8 (2) ◽  
pp. 3-15
Author(s):  
H. Tkalenko ◽  
Ya. Gadzalo ◽  
O. Borzykh ◽  
S. Horal
Keyword(s):  
Mass Production ◽  
Nematophagous Fungi ◽  
Submerged Cultivation ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Free Living ◽  
Predacious Fungi ◽  
First Time ◽  
Different Soils

Aim. To isolate, identify, and evaluate in vitro the predacious ability of nematophagous fungi strains, to determine their eligibility for mass production under submerged cultivation; to select the most efficient isolates of predacious nematopha- gous fungi as promising producers of the biopreparation to control plant-parasitic nematodes. Methods. Microbiological, microscopical, cultural-morphological, statistical. Results. The screening to determine the presence of predacious nema- tophagous fungi in different soils from different regions has been conducted for the first time in Ukraine. Out of 75 soil samples, isolated in Kyiv, Chernihiv, Dnipropetrovsk, Volyn and Odesa regions, 88 isolates of predacious nematophagous fungi were obtained which belong to 11 genera by their cultural-morphological characteristics: Arthrobotrys oligospo- ra – 39 isolates, A. musiformis – 25, A. conoides – 11, Drechslerella dactyloides – 3, A. artrobotryoides –2, A. superba – 2, A. megalospora – 2, A. sphaeroides –1, A. flagrans – 1, A. amerospora – 1, A. thaumasia – 1. High nematophagous activity in vitro (90–100 % trapping) regarding free-living nematodes (Rhabditis spp). was demonstrated by 4 isolates of A. oligospora, 18 isolates of A. musiformis, 5 isolates of A. conoides, 3 isolates of D. dactyloides, and one isolate of A. megalospora. Among the 47 most active isolates, 4 isolates of predacious fungi formed chlamydospores under submerged cultivation on two types of liquid media – wort medium and corn-molasses medium: A. musiformis-711, A. musiformis-911, A. conoides-90, D. dactyloides-19. It was found that isolate A. musiformis-911 and A. conoides-90 could form conidia in the submerged culture. Further experiments in determining the character of development for two latter isolates in different types of media under submerged cultivation established that the largest number of chlamydo- spores and conidia were formed by the isolates of A. conoides 90 and A. musiformis 911 on potato dextrose medium, 7.6·105 and 6.5·105 spores/ml respectively. In the wort medium, the productivity of spore formation for the isolate of A. conoides 90 was 35 times lower, amounting to 2.2·104 spores/ml, and in peptone-glucose medium – 90 times lower (8.5·103 spores/ml). The isolate of A. musiformis 911 in the wort medium produced 325 times fewer spores (2.0× ×103 spores/ml) than in potato-dextrose medium, while no chlamydospores and conidia were formed in the peptone- glucose medium. More detailed study of the ratio between isolates-producers and different sources of nutrition as the basis for the optimization of liquid media is required. Conclusions. According to the results of determining nematoph- agous activity regarding free-living nematodes, isolated from different soils in Ukraine and evaluating the character of development under submerged cultivation, two isolates of predacious fungi were selected – Arthrobotrys conoides-90 and A. musiformis-911, which are promising producers of a biological preparation eventually to be used in the biocon- trol of plant-parasitic nematodes. Conidia formation of the two isolates in liquid culture under mass production condi- tions was observed for the first time and could also contribute to their suitability for mass production and biocontrol.

scholarly journals Nematicidal Activity of Essential Oils on a Psychrophilic Panagrolaimus sp. (Nematoda: Panagrolaimidae)

Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1588
Author(s):  
Violeta Oro ◽  
Slobodan Krnjajic ◽  
Marijenka Tabakovic ◽  
Jelena S. Stanojevic ◽  
Snezana Ilic-Stojanovic
Keyword(s):  
Essential Oils ◽  
Test Organism ◽  
Biological Properties ◽  
Probit Analysis ◽  
Nematicidal Activity ◽  
Chemical Components ◽  
Parasitic Nematodes ◽  
Free Living ◽  
Term Survival

Essential oils (EOs) have historically been used for centuries in folk medicine, and nowadays they seem to be a promising control strategy against wide spectra of pathogens, diseases, and parasites. Studies on free-living nematodes are scarce. The free-living microbivorous nematode Panagrolaimus sp. was chosen as the test organism. The nematode possesses extraordinary biological properties, such as resistance to extremely low temperatures and long-term survival under minimal metabolic activity. Fifty EOs from 22 plant families of gymnosperms and angiosperms were tested on Panagrolaimus sp. The aims of this study were to investigate the in vitro impact of EOs on the psychrophilic nematode Panagrolaimus sp. in a direct contact bioassay, to list the activity of EOs based on median lethal concentration (LC50), to determine the composition of the EOs with the best nematicidal activity, and to compare the activity of EOs on Panagrolaimus sp. versus plant parasitic nematodes. The results based on the LC50 values, calculated using Probit analysis, categorized the EOs into three categories: low, moderate and highly active. The members of the laurel family, i.e., Cinnamomum cassia and C. burmannii, exhibited the best nematicidal activity. Aldehydes were generally the major chemical components of the most active EOs and were the chemicals potentially responsible for the nematicidal activity.

scholarly journals Anthelmintic tolerance in free-living and facultative parasitic isolates of Halicephalobus (Panagrolaimidae)

Parasitology ◽  
2012 ◽  
Vol 139 (10) ◽  
pp. 1301-1308 ◽  
Author(s):  
P. FONDERIE ◽  
W. BERT ◽  
F. HENDRICKX ◽  
W. HOUTHOOFD ◽  
T. MOENS
Keyword(s):  
Larval Development ◽  
Anthelmintic Resistance ◽  
Positive Control ◽  
Parasitic Nematodes ◽  
Free Living ◽  
Egg Hatching ◽  
Complete Life Cycle ◽  
Panagrellus Redivivus ◽  
Halicephalobus Gingivalis

SUMMARYStudies on anthelmintic resistance in equine parasites do not include facultative parasites. Halicephalobus gingivalis is a free-living bacterivorous nematode and a known facultative parasite of horses with a strong indication of some form of tolerance to common anthelmintic drugs. This research presents the results of an in vitro study on the anthelmintic tolerance of several isolates of Halicephalobus to thiabendazole and ivermectin using an adaptation of the Micro-Agar Larval Development Test hereby focusing on egg hatching and larval development. Panagrellus redivivus and Panagrolaimus superbus were included as a positive control. The results generally show that the anthelmintic tolerance of Halicephalobus to both thiabendazole and ivermectin was considerably higher than that of the closely related Panagrolaimidae and, compared to other studies, than that of obligatory equine parasites. Our results further reveal a remarkable trend of increasing tolerance from fully free-living isolates towards horse-associated isolates. In vitro anthelmintic testing with free-living and facultative parasitic nematodes offers the advantage of observing drug effect on the complete life cycle as opposed to obligatory parasites that can only be followed until the third larval stage. We therefore propose Halicephalobus gingivalis as an experimental tool to deepen our understanding of the biology of anthelmintic tolerance.

scholarly journals Effect of Gaseous Ozone on Listeria monocytogenes Planktonic Cells and Biofilm: An In Vitro Study

Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1484
Author(s):  
Felice Panebianco ◽  
Selene Rubiola ◽  
Francesco Chiesa ◽  
Tiziana Civera ◽  
Pierluigi Aldo Di Ciccio
Keyword(s):  
Listeria Monocytogenes ◽  
In Vitro Study ◽  
Planktonic Cells ◽  
Free Living ◽  
Biofilm Inhibition ◽  
Additional Tool ◽  
Complete Inactivation ◽  
Gaseous Ozone ◽  
Food Borne

Among food-borne pathogens, Listeria monocytogenes continues to pose concerns to food business operators due to its capacity to form biofilm in processing environments. Ozone may be an eco-friendly technology to control microbial contaminations, but data concerning its effect on Listeria monocytogenes biofilm are still limited. In this study, the effect of gaseous ozone at 50 ppm on planktonic cells and biofilm of reference and food-related Listeria monocytogenes strains was evaluated. Ozone caused a reduction in microbial loads of 3.7 ± 0.4 and 3.9 ± 0.4 Log10 CFU/mL after 10 and 30 min, respectively. A complete inactivation of planktonic cells after 6 h of treatment was observed. Biofilm inhibition and eradication treatments (50 ppm, 6 h) resulted in a significant decrease of the biofilm biomass for 59% of the strains tested, whilst a slight dampening of live cell loads in the biofilm state was observed. In conclusion, gaseous ozone is not sufficient to completely counteract Listeria monocytogenes biofilm, but it may be useful as an additional tool to contrast Listeria monocytogenes free-living cells and to improve the existing sanitization procedures in food processing environments.

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