DISTINGUISHING SENSITIVITY OF FREE-LIVING SOIL NEMATODE GENERA TO PHYSICAL AND CHEMICAL DISTURBANCES

2002 ◽  
Vol 12 (2) ◽  
pp. 565-575 ◽  
Author(s):  
Daniel A. Fiscus ◽  
Deborah A. Neher
Keyword(s):  
Soil Nematode ◽  
Free Living ◽  
Physical And Chemical

Interaction of a Free-Living Soil Nematode, Caenorhabditis elegans, with Surrogates of Foodborne Pathogenic Bacteria

2003 ◽  
Vol 66 (9) ◽  
pp. 1543-1549 ◽  
Author(s):  
GARY L. ANDERSON ◽  
KRISHAUN N. CALDWELL ◽  
LARRY R. BEUCHAT ◽  
PHILLIP L. WILLIAMS
Keyword(s):  
Caenorhabditis Elegans ◽  
Young Adult ◽  
Salmonella Typhimurium ◽  
Avirulent Strain ◽  
Soil Nematode ◽  
Gram Negative Bacteria ◽  
Nematode Caenorhabditis Elegans ◽  
Free Living ◽  
Gram Positive ◽  
Gram Negative

Free-living nematodes may harbor, protect, and disperse bacteria, including those ingested and passed in viable form in feces. These nematodes are potential vectors for human pathogens and may play a role in foodborne diseases associated with fruits and vegetables eaten raw. In this study, we evaluated the associations between a free-living soil nematode, Caenorhabditis elegans, and Escherichia coli, an avirulent strain of Salmonella Typhimurium, Listeria welshimeri, and Bacillus cereus. On an agar medium, young adult worms quickly moved toward colonies of all four bacteria; over 90% of 3-day-old adult worms entered colonies within 16 min after inoculation. After 48 h, worms moved in and out of colonies of L. welshimeri and B. cereus but remained associated with E. coli and Salmonella Typhimurium colonies for at least 96 h. Young adult worms fed on cells of the four bacteria suspended in K medium. Worms survived and reproduced with the use of nutrients derived from all test bacteria, as determined for eggs laid by second-generation worms after culturing for 96 h. Development was slightly slower for worms fed gram-positive bacteria than for worms fed gram-negative bacteria. Worms that fed for 24 h on bacterial lawns formed on tryptic soy agar dispersed bacteria over a 3-h period when they were transferred to a bacteria-free agar surface. The results of this study suggest that C. elegans and perhaps other free-living nematodes are potential vectors for both gram-positive and gram-negative bacteria, including foodborne pathogens in soil.

Group effect in the free-living soil nematode Caenorhabditis elegans exposed to a high ambient temperature

2008 ◽  
Vol 422 (1) ◽  
pp. 321-323
Author(s):  
T. B. Kalinnikova ◽  
A. Kh. Timoshenko ◽  
D. Yu. Galaktionova ◽  
T. M. Gainutdinov ◽  
M. Kh. Gainutdinov
Keyword(s):  
Caenorhabditis Elegans ◽  
Ambient Temperature ◽  
High Ambient Temperature ◽  
Soil Nematode ◽  
Group Effect ◽  
Nematode Caenorhabditis Elegans ◽  
Free Living

scholarly journals Composition and vertical distribution of free living and plant parasitic nematodes in hop gardens in the Czech Republic

2011 ◽  
Vol 48 (2) ◽  
pp. 124-136 ◽  
Author(s):  
V. Čermák ◽  
V. Gaar ◽  
L. Háněl ◽  
K. Široká
Keyword(s):  
Czech Republic ◽  
Vertical Distribution ◽  
Soil Profile ◽  
Parasitic Nematodes ◽  
Soil Nematode ◽  
Plant Parasitic Nematodes ◽  
Free Living ◽  
The Czech Republic ◽  
Nematode Communities ◽  
Plant Parasitic

AbstractComposition and vertical distribution of soil nematode communities within soil profile were investigated in eight hop gardens in Czech Republic. In total, the presence of 78 nematode genera was confirmed. Genus Drilocephalobus (Coomans & Coomans, 1990) is new for fauna of the Czech Republic. The highest abundance of soil nematodes was found at a depth of 0–10 cm and declined with increasing depth of soil profile. The most dominant genus was Bitylenchus, followed by genera Acrobeloides, Ditylenchus, Chiloplacus and Cervidelus. Ten genera of plant parasitic nematodes were recorded: Bitylenchus (with prevalence of B. dubius), Helicotylenchus, Heterodera (with absolute prevalence of H. humuli), Geocenamus, Longidorella, Longidorus (only L. elongatus), Merlinius (with prevalence of M. brevidens), Paratylenchus and Pratylenchus. Low population densities of predators and omnivores, low values of the community indices (MI, ΣMI, SI, and CI), and high values of NCR, EI, and PPI/MI ratio indicated disturbed nematode communities in hop gardens and bacteria-dominated decomposition pathways in the soil food web.

Effect of disturbances on trophic groups in soil nematode assemblages

Nematology ◽  
2011 ◽  
Vol 13 (5) ◽  
pp. 553-559 ◽  
Author(s):  
Robert McSorley
Keyword(s):  
Plant Cover ◽  
Parasitic Nematodes ◽  
Soil Nematode ◽  
Trophic Groups ◽  
Bare Ground ◽  
Short Term ◽  
Free Living ◽  
Free Living Nematode ◽  
A Site

AbstractFree-living nematodes in soil ecosystems are vital in the decomposition of organic matter and recycling of nutrients. The effects of various types of disturbances on nematode assemblages were examined in several experiments on a single soil: a short-term detrimental disturbance from solarisation, a short-term beneficial disturbance from amendment addition, and a long-term detrimental disturbance from bare ground without plant cover. Comparison of solarised and non-solarised field plots revealed lower numbers of fungivores in solarised plots. As a result, indices involving ratios of fungivores to bacterivores and fungivores to total free-living nematodes were decreased as well. Addition of an amendment increased numbers of bacterivores. This change was also reflected in calculated indices that expressed trophic groups as percentages of the total free-living nematodes. A severely disturbed site with bare ground that was without plant cover for more than 5 years was compared with an adjacent site maintained in grass. No plant-parasitic nematodes were recovered from the bare ground site, which contained lower numbers of nematodes in all trophic groups than the grass site. However, the structure of the free-living nematode assemblages in both sites was similar, as indicated by the proportions of various trophic groups and by ratios of fungivores and bacterivores. The free-living nematode assemblage in a site with a perceived severe long-term disturbance maintained a trophic structure similar to a site with perennial plant cover.

scholarly journals Non-legume plant species effects on soil nematodes abundance in a Regosol

2019 ◽  
Vol 40 (1-2) ◽  
pp. 1-6
Author(s):  
Tancredo Souza ◽  
Lucas Sombra Barbosa ◽  
Edjane Oliveira de Lucena ◽  
Luan Nunes de Melo ◽  
Guilherme Silva de Podestá ◽  
...  
Keyword(s):  
Field Study ◽  
Cover Crop ◽  
Soil Nematode ◽  
Total Abundance ◽  
Free Living ◽  
Moist Forest ◽  
Native Weeds ◽  
Root Feeding ◽  
Term Field

The effects of a non-legume cover crop on total soil nematode abundance and soil groups of nematodes were investigated in a long-term field study. We compared total abundance of soil nematode and the abundance of both free-living soil nematode and root-feeding soil nematode under three different treatments (Pennisetum glaucum (L.) R. Br., native weeds and Caatinga moist-forest enclaves treatments) in a long-term field study cultivated on a Regosol. We found the highest abundance of free-living soil nematode in the Caatinga moist-forest enclaves treatment, whereas the highest abundance of root-feeding nematode was found in the native weeds treatment. We did not find any difference among P. glaucum and native weeds treatments for total abundance of soil nematode. Our findings suggest that the introduction of P. glaucum in sandy soil of Brazilian semiarid can increase the abundance of free-living nematode, but in other hand this cover crop did not reduce the abundance of root-feeding nematode. Our results also highlight the importance of considering the identification of soil nematode groups as indicator of soil quality and impacts of soil management.

Developmental strategies during early embryogenesis of Caenorhabditis elegans

Development ◽  
1986 ◽  
Vol 97 (Supplement) ◽  
pp. 31-44
Author(s):  
Einhard Schierenberg
Keyword(s):  
Caenorhabditis Elegans ◽  
Parasitic Nematode ◽  
Soil Nematode ◽  
Developmental Studies ◽  
Central Question ◽  
Unique Combination ◽  
Nematode Caenorhabditis Elegans ◽  
Free Living ◽  
C Elegans ◽  
Multicellular Structure

How the complex, multicellular structure of an organism is generated from the information contained in the uncleaved egg is a central question in developmental studies. Nematodes are particularly suitable for studying this question. A unique combination of favourable properties, including transparent eggshell, normal embryogenesis under the microscope outside the mother, small number of cells and rapid, reproducible development made nematodes classic models for developmental biologists (for reviews see Chitwood & Chitwood, 1974; von Ehrenstein & Schierenberg, 1980). In addition to the attractive features mentioned above, the free-living soil nematode Caenorhabditis elegans (Fig. 1) is also well suited for analysis of the genetic control of development (Brenner, 1974) unlike the classically studied parasitic nematode Parascaris equorum (Ascaris megalocephala). Recently cellular (e.g. Sulston, Schierenberg, White & Thomson, 1983) and genetic (e.g. Sternberg & Horvitz, 1984) aspects of development have been studied extensively in C. elegans.

scholarly journals Distribution of Ecosystem Health Indicators for Biomonitoring of Oil Pollution in the Western Niger Delta, Nigeria

2019 ◽  
pp. 1-5
Author(s):  
Tambeke N. Gbarakoro ◽  
Onome Okagbare ◽  
Adanna Ucheagwu ◽  
M. Aline E. Noutcha ◽  
Samuel N. Okiwelu
Keyword(s):  
Niger Delta ◽  
Ecosystem Health ◽  
Oil Pollution ◽  
Health Indicators ◽  
Free Living ◽  
Swamp Forest ◽  
Soil Microarthropods ◽  
Freshwater Swamp ◽  
Full Complement ◽  
Physical And Chemical

As a result of the limitations of physical and chemical methods for monitoring pollution, interest on the more reliable biological monitoring intensified over the past four decades. Soil microarthropods, specifically the free-living mites (Cryptostigmata, Mesostigmata, Prostigmata) and Collembolans were used as monitor (ability to withstand pollutants) and indicator (sensitive to pollutants) species in the Eastern Niger Delta. Study was undertaken in the Western Niger Delta (Delta State) across three eco-vegetational zones (freshwater swamp forest, Mangrove swamp forest, Lowland rainforest) in the area to determine if these ecosystem health indicators were widely distributed in these zones. Collections were made during the rainy season over a 4-month period. A modified Berlese-Tullgren funnel was used for extraction of microarthropds. Free-living mites: Cryptostigmata (Oribatida) – Archogozettes magnus, Opiida sp., Annecticarus sp., Bicyrthermania negeriana, Cephalida sp., Scheloribates sp., Galumnida sp., Mesostigmata (Gamasida) - Asca sp., Trichuropodida and Collembolan – Paronella sp., were widely distributed across the eco-vegetational zones. Oribatids were most abundant across eco-vegetational zones. These mesofauna contained the full complement of monitor and indicator species. It is therefore possible to use these mesofauna for biomonitoring of oil pollution across the Niger Delta (eastern and western sectors), Nigeria.

scholarly journals NEUROTOXIC EFFECT OF ACETYLCHOLINESTERASE INHIBITORS ON THE ORGANISM OF THE FREE-LIVING SOIL NEMATODE CAENORHABDITIS ELEGANS MAUPAS

2021 ◽  
pp. 39
Author(s):  
Анастасия Васильевна Егорова ◽  
Татьяна Борисовна Калинникова ◽  
Диляра Махмутриевна Хакимова ◽  
Рифгат Роальдович Шагидуллин ◽  
Anastasia Egorova ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Acetylcholinesterase Inhibitors ◽  
Soil Nematode ◽  
Neurotoxic Effect ◽  
Nematode Caenorhabditis Elegans ◽  
Free Living

Domorganus macronephriticus n.g.,n.sp., a new cylindrolaimid free-living soil nematode

1946 ◽  
Vol 21 (4) ◽  
pp. 175-180 ◽  
Author(s):  
T. Goodey
Keyword(s):  
Female Worm ◽  
Living Condition ◽  
Soil Nematode ◽  
Single Female ◽  
Free Living ◽  
Pasture Soil ◽  
Baermann Funnel

The nematodes described and figured in the following pages are specimens mounted in glycerine which were obtained in 1931 (5 males and 4 females) and in 1932 (one female) from pasture soil at Winches Farm, St. Albans. Unfortunately they were not closely examined in the living condition and it is therefore impossible to give any information about their appearance and movements when alive. The nine specimens obtained at the earlier date were passed on to the writer by Dr. D. O. Morgan (who at that time was on the staff of this Institute) and had been found by him whilst examining earthworms in connection with investigations on “gapes” in chickens and young starlings upon which he was engaged at that time, i.e. March, 1931. These worms, after being killed and fixed in weak formalin and processed through dilute glycerine, were finally mounted in glycerine but no detailed study of them was made until recently when, in the course of re-arranging the slide preparations of free-living nematodes, made during the course of several years, they called for identification. The single female worm obtained in April, 1932, was found on a slide along with specimens of Anguillulina agricola, Anguillulina dubia and a female of Teratocephalus terrestris, all of which had been obtained in a Baermann funnel extraction of a piece of turf taken from one of the meadows at Winches Farm.

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