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1

Elucidating the spread of the emerging canid nematode Angiostrongylus vasorum between Palaearctic and Nearctic ecozones.  

PubMed

Angiostrongylus vasorum is an emerging parasite that is currently distributed through Western Europe and parts of South America. An isolated population is also present in Newfoundland, Canada. This presents a risk of onward spread into North America, but its origin is unknown. To ascertain the phylogeographic relationships and genetic diversity of A. vasorum within the western Palaearctic and eastern Nearctic ecozones, a total of 143 adult and larval nematode specimens were collected from foxes (Vulpes vulpes) and dogs (Canis lupus familiaris) in Canada, Denmark, France, Germany, Ireland, the Netherlands, Portugal and the United Kingdom, and a coyote (Canis latrans) in Canada. DNA was extracted and the second internal transcribed spacer and two mitochondrial loci were amplified and sequenced. Multiple haplotypes (n=35) based on combined mitochondrial sequences (1078bp) of the partial cytochrome oxidase subunit I (COI), large subunit ribosomal RNA (rrnL) and the complete nicotinamide adenine dinucleotide dehydrogenase 3 (NADH3) sequences, were observed throughout the Palaearctic countries sampled; however, only a single haplotype was observed for the Canadian A. vasorum population. The likely origin of A. vasorum in Newfoundland is therefore inferred to be within the western Palaearctic. There was no evidence of genetic segregation of parasites in dogs, foxes and coyotes, supporting the hypothesis that transmission occurs between wild and domestic canids. The transmission dynamics and population structure of this nematode are further discussed. PMID:20139034

Jefferies, R; Shaw, S E; Willesen, J; Viney, M E; Morgan, E R

2010-02-06

2

Elucidating the spread of the emerging canid nematode Angiostrongylus vasorum between Palaearctic and Nearctic ecozones  

Microsoft Academic Search

Angiostrongylus vasorum is an emerging parasite that is currently distributed through Western Europe and parts of South America. An isolated population is also present in Newfoundland, Canada. This presents a risk of onward spread into North America, but its origin is unknown. To ascertain the phylogeographic relationships and genetic diversity of A. vasorum within the western Palaearctic and eastern Nearctic

R. Jefferies; S. E. Shaw; J. Willesen; M. E. Viney; E. R. Morgan

2010-01-01

3

Larval output of infected and re-infected dogs with Angiostrongylus vasorum (Baillet, 1866) Kamensky, 1905  

Microsoft Academic Search

Canine angiostrongylosis is a nematode infection in domestic dogs and wild canids. A natural infection in a domestic dog frequently leads to pneumonia, loss of physical performance, coughing, anemia, cardiac insufficiency, pulmonary fibrosis and death. The main diagnostic method is based on the finding of Angiostrongylus vasorum first-stage larvae (L1) in infected dog feces. With this objective, 11 experimentally exposed

S. D. Oliveira-Júnior; J. M. P. Barçante; T. A. Barçante; S. R. C. Dias; W. S. Lima

2006-01-01

4

Absence of Wolbachia endobacteria in the non-filariid nematodes Angiostrongylus cantonensis and A. costaricensis  

PubMed Central

The majority of filarial nematodes harbour Wolbachia endobacteria, including the major pathogenic species in humans, Onchocerca volvulus, Brugia malayi and Wuchereria bancrofti. These obligate endosymbionts have never been demonstrated unequivocally in any non-filariid nematode. However, a recent report described the detection by PCR of Wolbachia in the metastrongylid nematode, Angiostrongylus cantonensis (rat lungworm), a leading cause of eosinophilic meningitis in humans. To address the intriguing possibility of Wolbachia infection in nematode species distinct from the Family Onchocercidae, we used both PCR and immunohistochemistry to screen samples of A. cantonensis and A. costaricensis for the presence of this endosymbiont. We were unable to detect Wolbachia in either species using these methodologies. In addition, bioinformatic and phylogenetic analyses of the Wolbachia gene sequences reported previously from A. cantonensis indicate that they most likely result from contamination with DNA from arthropods and filarial nematodes. This study demonstrates the need for caution in relying solely on PCR for identification of new endosymbiont strains from invertebrate DNA samples.

Foster, Jeremy M; Kumar, Sanjay; Ford, Louise; Johnston, Kelly L; Ben, Renata; Graeff-Teixeira, Carlos; Taylor, Mark J

2008-01-01

5

A SYBR green real-time PCR assay for the detection of the nematode Angiostrongylus vasorum in definitive and intermediate hosts  

Microsoft Academic Search

The parasitic nematode Angiostrongylus vasorum is an emerging challenge for companion animal and wildlife health, with reported increases in both distribution and incidence in Europe. To facilitate improved detection of this parasite, a SYBR green real-time polymerase chain reaction (PCR) was developed to amplify a region of the second internal transcribed spacer (ITS-2) of A. vasorum from both definitive and

R. Jefferies; E. R. Morgan; S. E. Shaw

2009-01-01

6

Angiostrongylus cantonensis (Nematode: Metastrongyloidea) in molluscs from harbour areas in Brazil.  

PubMed

Angiostrongylus cantonensis is the most common aetiological agent of human eosinophilic meningoencephalitis. Following a report indicating the presence of this parasite in Brazil in 2007, the present study was undertaken to investigate the presence of A. cantonensis in the surrounding Brazilian port areas. In total, 30 ports were investigated and the following molluscs were identified: Achatina fulica, Belocaulus sp., Bradybaena similaris sp., Cyclodontina sp., Helix sp., Leptinaria sp., Melampus sp., Melanoides tuberculata, Phyllocaulis sp., Pomacea sp., Pseudoxychona sp., Rhinus sp., Sarasinula marginata, Streptaxis sp., Subulina octona, Succinea sp., Tomigerus sp., Wayampia sp. and specimens belonging to Limacidae and Orthalicinae. Digestion and sedimentation processes were performed and the sediments were examined. DNA was extracted from the obtained larvae and the internal transcribed spacer region 2 was analysed by polymerase chain reaction-restriction fragment length polymorphism after digestion with the endonuclease ClaI. Of the 30 ports investigated in this study, 11 contained molluscs infected with A. cantonensis larvae. The set of infected species consisted of S. octona, S. marginata, A. fulica and B. similaris. A total of 36.6% of the investigated ports were positive for A. cantonensis, indicating a wide distribution of this worm. It remains uncertain when and how A. cantonensis was introduced into South America. PMID:22990962

Carvalho, Omar Dos Santos; Scholte, Ronaldo Guilherme Carvalho; Mendonça, Cristiane Lafeta Furtado de; Passos, Liana Konovaloff Jannotti; Caldeira, Roberta Lima

2012-09-01

7

Eosinophilic meningitis due to Angiostrongylus cantonensis.  

PubMed

Angiostrongylus cantonensis is a nematode parasite that inhabits the pulmonary arteries and heart of rodents. It is one of the causative agents of fatal eosinophilic meningoencephalitis in man. We present five cases of eosinophilic meningitis presumably due to infection with Angiostrongylus cantonensis . All the five patients gave history of ingestion of monitor lizard within ten days of onset of symptoms. PMID:16912445

Panackel, C; Cherian, G; Vijayakumar, K; Sharma, R N

2006-07-01

8

Pneumonia from Angiostrongylus vasorum infection in a red panda (Ailurus fulgens fulgens).  

PubMed

A 9-year-old, male, captive red panda (Ailurus fulgens fulgens) in an urban zoo in the United Kingdom presented with respiratory distress and weight loss. The animal was euthanatized, and a postmortem examination was performed. The lungs were diffusely consolidated with extensive mineralization. Microscopically, there was extensive obliteration of normal pulmonary architecture by sheets and coalescing nodules of partially mineralized fibrous tissue and granulomatous inflammation centered on large numbers of nematode larvae and eggs. First stage nematode larvae were isolated from lung tissue and were characterized as Angiostrongylus vasorum on the basis of their morphology and sequencing of the 18S ribosomal RNA gene and the entire second internal transcribed spacer. Although A. vasorum has previously been reported in red pandas in a zoological collection in Denmark, this study is the first reported case in the United Kingdom and occurs against a background of geographical spread and increased incidence of disease in domestic and wild canids. Angiostrongylus vasorum should be considered a differential diagnosis for respiratory disease in the red panda and taken into account when planning parasite and pest control programs for zoological collections. PMID:19286513

Patterson-Kane, Janet C; Gibbons, Lynda M; Jefferies, Ryan; Morgan, Eric R; Wenzlow, Nanny; Redrobe, Sharon P

2009-03-01

9

Angiostrongylus species in wild carnivores in the Iberian Peninsula.  

PubMed

A survey of Angiostrongylus parasites was carried out between 2003 and 2006 in wild carnivore species in the Basque Country (Northern Spain). Parasitological examination consisted in the dissection of heart and lungs for the extraction of adult worms. Nematodes were identified using morphometrical features and also PCR amplification and sequencing analysis. The animal species included in this study were Eurasian badger (Meles meles), Weasel (Mustela nivalis), Beech marten (Martes foina), Pine marten (Martes martes), Polecat (Mustela putorius), American mink (Mustela vison), Red fox (Vulpes vulpes), Wolf (Canis lupus), Wild cat (Felis silvestris), and Small-spotted genet (Genetta genetta). Angiostrongylus parasites were only found in foxes and badgers at prevalences of 33.3% and 24%, respectively. Identification of the nematodes by morphometrical features revealed that foxes were infected with A. vasorum while badgers were infected by a different species of Angiostrongylus most likely A. daskalovi. Sequencing data of the second internal transcribed spacer region of ribosomal DNA (ITS2) of isolates from each species confirmed the species difference. The high prevalence of Angiostrongylus found in the present survey, indicates that the wild cycle of two different species of Angiostrongylus is present in the Basque Country. To our knowledge this is the first report of A. daskalovi in the Iberian Peninsula. PMID:20728995

Gerrikagoitia, X; Barral, M; Juste, R A

2010-08-06

10

Nematodes.  

PubMed

To today's experimental biologists, the best known nematode is Caenorhabditis elegans, one of the major model organisms for genetic and biomedical research, the first metazoan with a sequenced genome and a key partner in the winning of three Nobel prizes - for the discoveries of programmed cell death and RNA interference, and for the development of green fluorescent protein (GFP) as a marker for gene expression. Approximately a thousand labs work on C. elegans worldwide; thus, this nematode is surely of great importance. PMID:24112976

Kiontke, Karin; Fitch, David H A

2013-10-01

11

PCR-Based Detection of Angiostrongylus cantonensis in Tissue and Mucus Secretions from Molluscan Hosts  

Microsoft Academic Search

Angiostrongylus cantonensis is a common cause of human eosinophilic meningitis. Recent outbreaks of this infection have shown that there is a need to determine the distribution of this nematode in the environment in order to control transmission. A. cantonensis is generally identified morphologically in the molluscan inter- mediate host by microscopic examination, which can be labor-intensive. The aim of this

Yvonne Qvarnstrom; James J. Sullivan; Henry S. Bishop; Robert Hollingsworth; Alexandre J. da Silva

2007-01-01

12

Immuno-PCR for Detection of Antigen to Angiostrongylus cantonensis Circulating Fifth-Stage Worms  

Microsoft Academic Search

Background: Definitive diagnosis of infestation with Angiostrongylus cantonensis is difficult because the par- asitic nematode is undetectable in the cerebrospinal fluid (CSF) of one-half of afflicted patients and the diagnostic sensitivity of ELISA for circulating worm antigens in patient sera is low. We studied immuno- PCR as a diagnostic tool. Methods: We studied 30 controls and 60 afflicted pa- tients

Soi-Moi Chye; Shiu-Ru Lin; Ya-Lei Chen; Lee-Yi Chung; Chuan-Min Yen

13

PCR-based detection of Angiostrongylus cantonensis in tissue and mucus secretions from molluscan hosts  

Technology Transfer Automated Retrieval System (TEKTRAN)

Angiostrongylus cantonensis is a common cause of human eosinophilic meningitis. Recent outbreaks of this infection in endemic regions have prompted a need to determine the distribution of this nematode in the environment to control transmission. A. cantonensis is generally identified morphologically...

14

The canid genome: behavioral geneticists' best friend?  

PubMed

We review a range of studies on the genetic contribution to behavior in canid species. We begin by identifying factors that make canids a promising model in behavioral genetics and proceed to review research over the last decade that has used canids to identify genetic contributions to behavior. We first review studies that have selectively bred dogs to identify genetic contributions to behavior and then review studies that estimate heritability from populations of non-laboratory bred dogs. We subsequently review studies that used molecular genetics to identify gene-behavior associations and note associations that have been uncovered. We then note challenges in canid behavioral genetics research that require further consideration. We finish by suggesting alternative phenotyping methods and identify areas in which canids may have as yet unexploited advantages, such as in gene-environment interaction studies where genetic factors are found to moderate the effects of environmental variables. PMID:22979960

Hall, N J; Wynne, C D L

2012-09-14

15

Angiostrongylus vasorum : the ‘French Heartworm’  

Microsoft Academic Search

Angiostrongylus vasorum which is commonly known as ‘French heartworm’ is a snail-born parasitic disease affecting the members of the Canidae family.\\u000a This parasite has a cosmopolitan distribution covering tropical, subtropical and temperate regions. However, its distribution\\u000a is characterised by isolated endemic foci, with only sporadic occurrences outside this areas. During the last two decades,\\u000a several sporadic occurrences in old and

Tania Ferdushy; Mohammed Tabaruk Hasan

2010-01-01

16

Human Angiostrongylus cantonensis : an update  

Microsoft Academic Search

Angiostrongylus cantonensis was first discovered in 1935 and has become an important emerging pathogen causing human angiostrongyliasis. Major outbreaks\\u000a of human angiostrongyliasis have been reported in endemic regions. Thousands of cases of human angiostrongyliasis have been\\u000a documented worldwide. A. cantonensis has spread from its traditional endemic regions of the Pacific islands and Southeast Asia to the American continent including\\u000a the

Q.-P. Wang; Z.-D. Wu; J. Wei; R. L. Owen; Z.-R. Lun

17

Characterization of Rabies virus isolated from canids and identification of the main wild canid host in Northeastern Brazil  

Microsoft Academic Search

The rabies cases in dogs and wild canids in Northeastern Brazil are a public and animal health problem. This paper describes the identities of the coding region of the N-gene of Rabies virus (RABV) isolated in canids from Northeastern Brazil. The genetic tree generated using the sequence data described here divided the cluster BRAZILAN CANIDS into two subclusters (DOG-RELATED STRAINS

Pedro Carnieli; Willian de Oliveira Fahl; Juliana Galera Castilho; Rafael de Novaes Oliveira; Carla Isabel Macedo; Ekaterina Durymanova; Rodrigo S. P. Jorge; Ronaldo G. Morato; Romualdo O. Spíndola; Lindenrberg M. Machado; José E. Úngar de Sá; Maria Luiza Carrieri; Ivanete Kotait

2008-01-01

18

Biology, Systematics, Life Cycle, and Distribution of Angiostrongylus cantonensis, the Cause of Rat Lungworm Disease  

PubMed Central

Angiostrongylus cantonensis is a metastrongyloid nematode in the family Angiostrongylidae. It is the cause of angiostrongyliasis (rat lungworm disease), which manifests as eosinophilic meningitis. First described in 1935 from rats in China, A. cantonensis was placed in the genus Parastrongylus in 1986, but most workers have not adopted this treatment. The taxonomy of A. cantonensis and related worms is largely based on adult morphology, notably of the male bursa. However, identification of infective third stage larvae is more difficult. The natural life cycle involves rats as the definitive host and snails or slugs as the intermediate host. Human infection, as accidental hosts, results in worms maturing in the brain, but dying there instead of moving back into the bloodstream, as in rats, thereby leading to eosinophilic meningitis. The disease is an emerging infectious disease; Angiostrongylus cantonensis continues to be reported in new regions beyond its native range.

2013-01-01

19

Angiostrongylus vasorum infection in a coyote (Canis latrans) from Newfoundland and Labrador, Canada.  

PubMed

Tissue samples and feces were collected from a dead, adult female coyote (Canis latrans) found at the side of the road in late March 2003 in the Avalon Peninsula region of Newfoundland, Canada. The coyote apparently died of vehicular-related trauma. Samples of lung, brain, heart, liver, and kidney were fixed in formalin and submitted for histologic examination. The entire remaining lung and heart also were submitted for examination. The coyote was diagnosed with moderate, multifocal, granulomatous interstitial pneumonia with eosinophilic vasculitis and many intralesional nematode eggs, larvae, and occasional intravascular adult worms. Adult nematodes recovered from the pulmonary arteries were identified as Angiostrongylus vasorum. Small foci of granulomatous inflammation, often containing nematode eggs and larvae, were scattered in the brain and kidney. To our knowledge, this is the first report of A. vasorum infection in a coyote from the only endemic area of infection in North America. PMID:16456176

Bourque, Andrea; Whitney, Hugh; Conboy, Gary

2005-10-01

20

Interface Molecules of Angiostrongylus cantonensis: Their Role in Parasite Survival and Modulation of Host Defenses  

PubMed Central

Angiostrongylus cantonensis is a nematode parasite that causes eosinophilic meningoencephalitis in humans. Disease presents following the ingestion of third-stage larvae residing in the intermediate mollusk host and disease manifests as an acute inflammation of the meninges characterized by eosinophil infiltrates which release a battery of proinflammatory and cytotoxic agents in response to the pathogen. As a mechanism of neutralizing these host defenses, A. cantonensis expresses different molecules with immunomodulatory properties that are excreted or secreted (ES). In this paper we discuss the role of ES proteins on disease exacerbation and their potential use as therapeutic targets.

Morassutti, Alessandra L.; Graeff-Teixeira, Carlos

2012-01-01

21

First autochthonous case of canine Angiostrongylus vasorum in Slovakia.  

PubMed

Angiostrongylus vasorum is a metastrongyloid nematode that may cause cardiopulmonary disease, neurological signs and coagulopathies in dogs. The parasite has an indirect life cycle with molluscs as intermediate hosts, in which the infective third larval stage develops. Recently, A. vasorum has been repeatedly reported in dogs outside the endemic areas, indicating that this parasite is widely distributed over Europe. This is the first record of an autochthonous infection in a dog from Slovakia that was casually diagnosed during routine preventive parasitological examination. A. vasorum first-stage larvae were recovered using the Baermann technique and identified by length and characteristic tail morphology. The animal originated from Slovakia and had not travelled abroad. The dog had been regularly walked on grass fields with a concentrated presence of common species of Gastropoda and frogs. The owner reported that the dog had been licking and eating grass and it had shown curiosity for molluscs and frogs. The first finding of A. vasorum-infected dog in Slovakia has confirmed that the parasite is spreading beyond the traditional hyperendemic foci, which accentuates the need for monitoring and increasing of disease awareness in primary care clinical practice. PMID:23851730

Hurníková, Z; Miterpáková, M; Mandelík, R

2013-07-14

22

Filaroides osleri (Oslerus osleri): two case reports and a review of canid infections in North America.  

PubMed

Infections of domesticated dogs by a worldwide parasitic nematode Filaroides osleri (Oslerus osleri) lead to verminous tracheobronchitis that are often misdiagnosed clinically as kennel cough, due to infection with the bacterium Bordetella bronchiseptica. Diagnosis of two canine cases in Wyoming, USA prompted a search of the literature of canid infections in North America. Infections of domestic dogs are reported in nine US states and four Canadian provinces. Dogs of multiple breeds and both sexes were infected. Most were two years old or younger at diagnosis. Anthelmintic treatments were effective in relieving clinical symptoms, as well as causing resolution of tracheobronchial nodules. Other canid species, including coyotes (Canis latrans) and wolves (Canis lupus), have been infected across North America with a prevalence of 23% and 4%, respectively. Infection with F. osleri should be included in the differential diagnosis of infectious tracheobronchitis of dogs. It can be confirmed most readily by endoscopic detection of distinctive submucosal parasite-filled nodules, combined with histological examination of endoscopic biopsies. PMID:21411228

Yao, Chaoqun; O'Toole, Donal; Driscoll, Mike; McFarland, Warner; Fox, Jonathan; Cornish, Todd; Jolley, William

2011-02-23

23

Quantitative PCR estimates Angiostrongylus cantonensis (rat lungworm) infection levels in semi-slugs (Parmarion martensi)  

PubMed Central

The life cycle of the nematode Angiostrongylus cantonensis involves rats as the definitive host and slugs and snails as intermediate hosts. Humans can become infected upon ingestion of intermediate or paratenic (passive carrier) hosts containing stage L3 A. cantonensis larvae. Here, we report a quantitative PCR (qPCR) assay that provides a reliable, relative measure of parasite load in intermediate hosts. Quantification of the levels of infection of intermediate hosts is critical for determining A. cantonensis intensity on the Island of Hawaii. The identification of high intensity infection ‘hotspots’ will allow for more effective targeted rat and slug control measures. qPCR appears more efficient and sensitive than microscopy and provides a new tool for quantification of larvae from intermediate hosts, and potentially from other sources as well.

Jarvi, Susan I.; Farias, Margaret E.M.; Howe, Kay; Jacquier, Steven; Hollingsworth, Robert; Pitt, William

2013-01-01

24

Toxocara canis: genes expressed by the arrested infective larval stage of a parasitic nematode  

Microsoft Academic Search

Toxocara canis is a widely distributed nematode parasite which reaches maturity in dogs. However, eggs voided by canid animals are infective to a very wide range of paratenic hosts including humans. In noncanid hosts, infective larvae emerge from the eggs and invade the soft tissues, often entering the brain and musculature. Such larvae may remain for many months or years

Rick M. Maizels; Kevin K. A. Tetteh; Alex Loukas

2000-01-01

25

Proteolytic activity in the adult and larval stages of the human roundworm parasite Angiostrongylus costaricensis.  

PubMed

Angiostrongylus costaricensis is a nematode that causes abdominal angiostrongyliasis, a widespread human parasitism in Latin America. This study aimed to characterize the protease profiles of different developmental stages of this helminth. First-stage larvae (L1) were obtained from the faeces of infected Sigmodon hispidus rodents and third-stage larvae (L3) were collected from mollusks Biomphalaria glabrata previously infected with L1. Adult worms were recovered from rodent mesenteric arteries. Protein extraction was performed after repeated freeze-thaw cycles followed by maceration of the nematodes in 40 mM Tris base. Proteolysis of gelatin was observed by zymography and found only in the larval stages. In L3, the gelatinolytic activity was effectively inhibited by orthophenanthroline, indicating the involvement of metalloproteases. The mechanistic class of the gelatinases from L1 could not be precisely determined using traditional class-specific inhibitors. Adult worm extracts were able to hydrolyze haemoglobin in solution, although no activity was observed by zymography. This haemoglobinolytic activity was ascribed to aspartic proteases following its effective inhibition by pepstatin, which also inhibited the haemoglobinolytic activity of L1 and L3 extracts. The characterization of protease expression throughout the A. costaricensis life cycle may reveal key factors influencing the process of parasitic infection and thus foster our understanding of the disease pathogenesis. PMID:22990964

Rebello, Karina Mastropasqua; Siqueira, Caroline Reis de; Ribeiro, Erika Louise; Valente, Richard Hemmi; Mota, Ester Maria; Perales, Jonas; Neves-Ferreira, Ana Gisele da Costa; Lenzi, Henrique Leonel

2012-09-01

26

Abolition of Peroxiredoxin-5 Mitochondrial Targeting during Canid Evolution.  

PubMed

In human, the subcellular targeting of peroxiredoxin-5 (PRDX5), a thioredoxin peroxidase, is dependent on the use of multiple alternative transcription start sites and two alternative in-frame translation initiation sites, which determine whether or not the region encoding a mitochondrial targeting sequence (MTS) is translated. In the present study, the abolition of PRDX5 mitochondrial targeting in dog is highlighted and the molecular mechanism underlying the loss of mitochondrial PRDX5 during evolution is examined. Here, we show that the absence of mitochondrial PRDX5 is generalized among the extant canids and that the first events leading to PRDX5 MTS abolition in canids involve a mutation in the more 5' translation initiation codon as well as the appearance of a STOP codon. Furthermore, we found that PRDX5 MTS functionality is maintained in giant panda and northern elephant seal, which are phylogenetically closely related to canids. Also, the functional consequences of the restoration of mitochondrial PRDX5 in dog Madin-Darby canine kidney (MDCK) cells were investigated. The restoration of PRDX5 mitochondrial targeting in MDCK cells, instead of protecting, provokes deleterious effects following peroxide exposure independently of its peroxidase activity, indicating that mitochondrial PRDX5 gains cytotoxic properties under acute oxidative stress in MDCK cells. Altogether our results show that, although mitochondrial PRDX5 cytoprotective function against oxidative stress has been clearly demonstrated in human and rodents, PRDX5 targeting to mitochondria has been evolutionary lost in canids. Moreover, restoration of mitochondrial PRDX5 in dog MDCK cells, instead of conferring protection against peroxide exposure, makes them more vulnerable. PMID:24023783

Van der Eecken, Valérie; Clippe, André; Dekoninck, Sophie; Goemaere, Julie; Walbrecq, Geoffroy; Van Veldhoven, Paul P; Knoops, Bernard

2013-09-02

27

Kin encounter rate and inbreeding avoidance in canids  

USGS Publications Warehouse

Mating with close kin can lead to inbreeding depression through the expression of recessive deleterious alleles and loss of heterozygosity. Mate selection may be affected by kin encounter rate, and inbreeding avoidance may not be uniform but associated with age and social system. Specifically, selection for kin recognition and inbreeding avoidance may be more developed in species that live in family groups or breed cooperatively. To test this hypothesis, we compared kin encounter rate and the proportion of related breeding pairs in noninbred and highly inbred canid populations. The chance of randomly encountering a full sib ranged between 1–8% and 20–22% in noninbred and inbred canid populations, respectively. We show that regardless of encounter rate, outside natal groups mates were selected independent of relatedness. Within natal groups, there was a significant avoidance of mating with a relative. Lack of discrimination against mating with close relatives outside packs suggests that the rate of inbreeding in canids is related to the proximity of close relatives, which could explain the high degree of inbreeding depression observed in some populations. The idea that kin encounter rate and social organization can explain the lack of inbreeding avoidance in some species is intriguing and may have implications for the management of populations at risk.

Geffen, Eli; Kam, Michael; Hefner, Reuven; Hersteinsson, Pall; Angerbjorn, Anders; Dalen, Love; Fuglei, Eva; Noren, Karin; Adams, Jennifer R.; Vicetich, John; Meier, Thomas J.; Mech, L. D.; VonHoldt, Bridgett M.; Stahler, Daniel R.; Wayne, Robert K.

2011-01-01

28

Hemoplasmas in wild canids and felids in Brazil.  

PubMed

Hemotropic mycoplasmas, epicellular erythrocytic bacterial parasites lacking a cell wall, are the causative agents of infectious anemia in numerous mammalian species. The presence of hemotropic mycoplasmas in blood samples of neotropical and exotic wild canids and felids from Brazilian zoos were recorded using molecular techniques. Blood samples were collected from 146 Brazilian wild felids, 19 exotic felids, 3 European wolves (Canis lupus), and from 97 Brazilian wild canids from zoos in the Brazilian states of São Paulo and Mato Grosso and the Federal District. Using conventional polymerase chain reaction (PCR), this work found 22 (13%) wild felids positive to Candidatus Mycoplasma haemominutum [4 jaguars (Panthera onca); 3 pumas (Puma concolor); 10 ocelots (Leopardus pardalis); 2 jaguarondis (Puma yagouaroundi); and 3 little spotted cats (Leopardus tigrinus)]. Only one little spotted cat (Leopardus tigrinus) was positive to Mycoplasma haemofelis, and none was positive to Candidatus Mycoplasma turicensis. Two bush dogs (Speothos venaticus) were positive for a Mycoplasma sp. closely related to Candidatus Mycoplasma haematoparvum, and two European wolves were positive for a Mycoplasma sp. closely related to Candidatus Mycoplasma haemominutum. This is the first study regarding the molecular detection of hemotropic mycoplasmas in wild canids. PMID:22946419

André, Marcos Rogerio; Adania, Cristina Harumi; Allegretti, Silmara Marques; Machado, Rosangela Zacarias

2011-06-01

29

Comparative Scaling of Humeral Cross-Sections of Felids and Canids Using Radiographic Images  

Microsoft Academic Search

The cortical thickness of long bones can be an effective indicator of locomotor modes and other stresses encountered by bone.\\u000a Felids and canids are two carnivoran families that have similar levels of phylogenetic diversity and overlap in body size,\\u000a but differ in their locomotor habits. Many canids and felids are cursorial, but felids also climb more frequently than canids.\\u000a Felids

Julie Meachen-Samuels

2010-01-01

30

Nematode Songs  

NSDL National Science Digital Library

Nematode Songs is a wonderful, straightforward resource maintained by Nematologist Kathy Merrifield of Oregon State University, who makes light of these microscopic worms and parasites. A collection of 15 titles, including such notables as "Good King Nematode," "The Golden Sun" and "The Parasitic Nematode Rag," offer clever (and nematode-ish) lyrics to familiar songs. An option to sing along is included (requires MIDI sound), and each feature includes sheet music as well as complete lyrics. For the more serious, links to scientific nematode resources are provided at the bottom of the page.

Merrifield, Kathy.

1998-01-01

31

Extraintestinal nematode infections of red foxes (Vulpes vulpes) in Hungary.  

PubMed

A survey was carried out to investigate the prevalence and worm burden of extraintestinal nematodes in 100 red foxes (Vulpes vulpes) of Hungary. The overall prevalence of nematode infections of the respiratory tract was 76%. Eucoleus aerophilus (Capillaria aerophila) was the predominant species (66%), followed by Crenosoma vulpis (24%), Eucoleus (Capillaria) böhmi (8%) and Angiostrongylus vasorum (5%). Pearsonema (Capillaria) plica was found in 52% of the urinary bladders. In 3% of the foxes, Trichinella britovi was present in muscle samples. The high prevalence of lungworms and P. plica and the fox colonisation in urban areas may enhance the prevalence of these nematode infections in domestic dogs and cats, and the flow of T. britovi from the sylvatic cycle to the domestic cycle, enhancing the risk of infections in humans. PMID:12944046

Sréter, T; Széll, Z; Marucci, G; Pozio, E; Varga, I

2003-08-14

32

An individual-based model of canid populations: modelling territoriality and social structure  

Microsoft Academic Search

The management of canid populations has been at the forefront of wildlife management worldwide for much of the last century. Effective management depends on the ability to integrate species biology, the environmental aspects upon which those populations depend, and the factors controlling species abundance. Further, managing canid populations requires consideration of territoriality and dominance, which may have a significant effect

William C Pitt; Paul W Box; Frederick. F Knowlton

2003-01-01

33

Historical and ecological determinants of genetic structure in arctic canids.  

PubMed

Wolves (Canis lupus) and arctic foxes (Alopex lagopus) are the only canid species found throughout the mainland tundra and arctic islands of North America. Contrasting evolutionary histories, and the contemporary ecology of each species, have combined to produce their divergent population genetic characteristics. Arctic foxes are more variable than wolves, and both island and mainland fox populations possess similarly high microsatellite variation. These differences result from larger effective population sizes in arctic foxes, and the fact that, unlike wolves, foxes were not isolated in discrete refugia during the Pleistocene. Despite the large physical distances and distinct ecotypes represented, a single, panmictic population of arctic foxes was found which spans the Svalbard Archipelago and the North American range of the species. This pattern likely reflects both the absence of historical population bottlenecks and current, high levels of gene flow following frequent long-distance foraging movements. In contrast, genetic structure in wolves correlates strongly to transitions in habitat type, and is probably determined by natal habitat-biased dispersal. Nonrandom dispersal may be cued by relative levels of vegetation cover between tundra and forest habitats, but especially by wolf prey specialization on ungulate species of familiar type and behaviour (sedentary or migratory). Results presented here suggest that, through its influence on sea ice, vegetation, prey dynamics and distribution, continued arctic climate change may have effects as dramatic as those of the Pleistocene on the genetic structure of arctic canid species. PMID:17688546

Carmichael, L E; Krizan, J; Nagy, J A; Fuglei, E; Dumond, M; Johnson, D; Veitch, A; Berteaux, D; Strobeck, C

2007-08-01

34

Phenantroline, lovastatin, and mebendazole do not inhibit oviposition in the murine experimental infection with Angiostrongylus costaricensis.  

PubMed

Abdominal angiostrongyliasis is a zoonotic infection produced by a metastrongylid intra-arterial nematode, Angiostrongylus costaricensis. Human accidental infection may result in abdominal lesions. The presence of the eggs in the tissues plays an essential role in morbidity of abdominal angiostrongyliasis. The objective of this study is to evaluate and compare the effects of lovastatin, phenanthrolin, and mebendazole on oviposition of A. costaricensis in a murine experimental model. Each group of 12 male Swiss mice (Mus musculus) was orally infected with 10 L3 of the "Santa Rosa" strain of A. costaricensis. Two control groups were established: (1) mice were infected and not treated; (2) noninfected and nontreated animals. The experimental groups received (1) lovastatin TL), at a daily dose of 250 mg/kg for 10 consecutive days 16 days after infection; (2) phenanthroline at a daily dose of 20 mg/kg for 5 consecutive days 21 days after infection; and (3) mebendazole at a daily dose of 5 mg/kg for 5 consecutive days 21 days after infection. There was no significant inhibition of oviposition for lovastatin- and mebendazole-treated animals, whereas phenanthroline was associated with the lowest averages of larviposition per postinfection day and significant reduction of mortality. PMID:16944203

Bohrer Mentz, Márcia; Dallegrave, Eliane; Agostini, Aventino; Graeff-Teixeira, Carlos

2006-08-30

35

Angiostrongylus cantonensis: morphological and behavioral investigation within the freshwater snail Pomacea canaliculata.  

PubMed

An infection with Angiostrongylus cantonensis, the main causative agent for human eosinophilic encephalitis, can be acquired through the consumption of the freshwater snail Pomacea canaliculata. This snail also provides a suitable model to study the developmental morphology and behavior of A. cantonensis larvae, facilitated by the snail's distinct lung structure. We used microanatomy for studying the natural appearance and behavior of A. cantonensis larvae while developing within P. canaliculata. The distribution of refractile granules in the larval body and characteristic head structures changed during the developmental cycle. Two well-developed, rod-like structures with expanded knob-like tips at the anterior part were observed under the buccal cavity as early as the late second developmental stage. A "T"-shaped structure at the anterior end and its tenacity distinguished the outer sheath from that shed during the second molting. Early first-stage larvae obtained from fresh rat feces are free moving and characterized by a coiled tail, whereas a mellifluous "Q"-movement was the behavioral trait of third-stage A. cantonensis larvae outside the host tissue. In combination, the distribution of refractive granules, distinct head features, variations in sheaths, and behavioral characteristics can be utilized for differentiation of larval stages, and for distinguishing A. cantonensis larvae from those of other free-living nematodes. PMID:19172296

Lv, Shan; Zhang, Yi; Liu, He-Xiang; Zhang, Chao-Wei; Steinmann, Peter; Zhou, Xiao-Nong; Utzinger, Jürg

2009-01-27

36

Nematodes parasites of the gray fox (Urocyon cinereoargenteus Schreber, 1775) in the seasonally dry tropical highlands of central Mexico.  

PubMed

The gray fox (Urocyon cinereoargenteus Schreber, 1775) is the most abundant and opportunistic wild canid in Mexico. However, the parasites of this canid in Mexico are poorly known, and an intensive parasite survey is lacking. A survey of gray fox parasitological feces was conducted in El Cimatario National Park, a protected area representative of the seasonally dry, tropical highlands of Mexico. Feces were collected in six 1-km-length transects during the summer of 2003 and spring of 2004. The coproparasitoscopical survey registered nine species of nematodes, typical of wild and domestic canids such as Strongyloides stercoralis, Uncinaria stenocephala, Toxocara canis, Toxascaris leonina, Dioctophyme renale, Trichuris vulpis, Trichuris sp., and Capillaria sp. Ecological factors such as temperature and humidity appear to play a more important role in the establishment of these species of parasites in this protected area than the presence of domestic dogs. PMID:21136079

Hernández-Camacho, Norma; Pineda-López, Raul; López-González, Carlos A; Jones, Robert W

2010-12-07

37

Larvicidal activities of ginger ( Zingiber officinale) against Angiostrongylus cantonensis  

Microsoft Academic Search

In this study, we investigated the anthelmintic activity of [6]-gingerol, [10]-shogaol, [10]-gingerol, [6]-shogaol and hexahydrocurcumin, a constituent isolate from the roots of ginger (Zingiber officinale), for the parasite Angiostrongylus cantonensis. This study found that the above constituents killed A. cantonensis larvae or reduced their spontaneous movements in a time- and dose-dependent manner. The larvicidal effect or ability to halt spontaneous

Rong-Jyh Lin; Chung-Yi Chen; Li-Yu Chung; Chuan-Min Yen

2010-01-01

38

A shared system of representation governing quantity discrimination in canids.  

PubMed

One way to investigate the evolution of cognition is to compare the abilities of phylogenetically related species. The domestic dog (Canis lupus familiaris), for example, still shares cognitive abilities with the coyote (Canis latrans). Both of these canids possess the ability to make psychophysical "less/more" discriminations of food based on quantity. Like many other species including humans, this ability is mediated by Weber's Law: discrimination of continuous quantities is dependent on the ratio between the two quantities. As two simultaneously presented quantities of food become more similar, choice of the large or small option becomes random in both dogs and coyotes. It remains unknown, however, whether these closely related species within the same family - one domesticated, and one wild - make such quantitative comparisons with comparable accuracy. Has domestication honed or diminished this quantitative ability? Might different selective and ecological pressures facing coyotes drive them to be more or less able to accurately represent and discriminate food quantity than domesticated dogs? This study is an effort to elucidate this question concerning the evolution of non-verbal quantitative cognition. Here, we tested the quantitative discrimination ability of 16 domesticated dogs. Each animal was given nine trials in which two different quantities of food were simultaneously displayed to them. The domesticated dogs' performance on this task was then compared directly to the data from 16 coyotes' performance on this same task reported by Baker et al. (2011). The quantitative discrimination abilities between the two species were strikingly similar. Domesticated dogs demonstrated similar quantitative sensitivity as coyotes, suggesting that domestication may not have significantly altered the psychophysical discrimination abilities of canids. Instead, this study provides further evidence for similar non-verbal quantitative abilities across multiple species. PMID:23060847

Baker, Joseph M; Morath, Justice; Rodzon, Katrina S; Jordan, Kerry E

2012-10-08

39

Canid Mating Systems, Social Behavior, Parental Care and Ontogeny: Are they Flexible?  

Microsoft Academic Search

Benson Ginsburg’s early studies of canid socialization and wolf social and reproductive behavior were focused, in part, on\\u000a the degree to which there was flexibility in social development and specifically whether there was a critical period during\\u000a development after which wolf pups could not be socialized to humans. My focus was the degree to which differences in canid\\u000a ecology and

Devra G. Kleiman

40

Evolution of heterochromatin-associated satellite DNA loci in felids and canids (Carnivora)  

Microsoft Academic Search

Cloned satellite DNAs that hybridize primarily to C-band-positive regions of felid and canid chromosomes were used to probe the organization of satellite families in the genomes of 16 species of felids and 15 species of canids. Southern-blot and quantitative dot-blot experiments demonstrated that satellite families within the great cats (panthera lineage) vary considerably in regard to amount and\\/or sequence mismatch

T. G. Fanning; W. S. Modi; R. K. Wayne; S. J. O’Brien

1988-01-01

41

Heterochromatin composition and nucleolus organizer activity in four canid species.  

PubMed

Sequential staining with a counterstain-contrasted fluorescent banding technique (chromomycin A3-distamycin A-DAPI) revealed the occurrence of distamycin A-4,6-diamidino-2-phenylindole (DA-DAPI) staining heterochromatin in the centromeric regions of chromosomes 33, 36, 37, and 38 in the wolf (Canis lupus pallipes) and of chromosomes 13, 16, and 23 in the blue fox (Alopex lagopus). The red fox (Vulpes vulpes) lacked such regions. Staining with DAPI--actinomycin D produced a QFH-type banding pattern with clearcut differences in the staining behaviour of DA-DAPI positive regions between these three canid species. Staining with the fluorochrome D 287/170 did not preferentially highlight any of the DA-DAPI positive regions in any of them. Counterstain-enhanced chromomycin A3 R-banding and studies of nucleolus organizer region location and activity confirmed a close relationship between the karyotype of the wolf and the domestic dog. Few heterochromatic marker bands were encountered in these two species, but heterochromatin polymorphism was evident in the blue fox. PMID:3801970

Mayr, B; Geber, G; Auer, H; Kalat, M; Schleger, W

1986-10-01

42

Improved detection of canine Angiostrongylus vasorum infection using real-time PCR and indirect ELISA.  

PubMed

This study reports the development of a real-time PCR assay and an indirect ELISA to improve on current detection of canine Angiostrongylus vasorum infection. A highly specific fluorescent probe-based, real-time PCR assay was developed to target the A. vasorum second internal transcribed spacer region and detected DNA in EDTA blood, lung tissue, broncho-alveolar larvage fluid, endotracheal mucus, pharyngeal swabs and faecal samples. PCR was fast (?1 h), highly efficient when using EDTA blood samples, consistently detected a single molecule of parasite DNA and did not amplify DNA from other parasitic nematodes or definitive host species. An indirect ELISA was also developed using the soluble protein fraction from adult A. vasorum worms. Some cross-reactive antigen recognition was observed when tested against sera from dogs infected with Crenosoma vulpis (n?=?8), Toxocara canis (n?=?5) and Dirofilaria immitis (n?=?5). This was largely overcome by setting the cut-off for a positive result at an appropriately high level. Field evaluation of the real-time PCR and ELISA was conducted by testing sera and EDTA blood from dogs with suspected A. vasorum infection (n?=?148) and compared with the Baermann's larval migration test in faeces. Thirty-one dogs were positive by at least one test. Of these, 20 (65%) were detected by the Baermann method, 18 (58%) by blood PCR, 24 (77%) by ELISA and 28 (90%) by blood PCR and ELISA together. Combined testing using real-time PCR and ELISA therefore improved the detection rate of A. vasorum infection and holds promise for improved clinical diagnosis and epidemiological investigation. PMID:21537986

Jefferies, Ryan; Morgan, Eric R; Helm, Jenny; Robinson, Matthew; Shaw, Susan E

2011-05-03

43

Prevalence of antibodies to Leishmania infantum and Trypanosoma cruzi in wild canids from South Carolina.  

PubMed

Wild canids are reservoir hosts for Leishmania infantum and Trypanosoma cruzi. The present study examined the prevalence of antibodies to these zoonotic parasites in a population of wild canids from a nonagricultural setting in South Carolina. Sera from 26 gray foxes (Urocyon cinereoargenteus) and 2 coyotes (Canis latrans) were examined for antibodies to L. infantum and T. cruzi using the indirect immunofluorescent antibody test and commercially available parasite-specific immunochromatigraphic strip assays. Antibodies to L. infantum were not detected by either assay in gray foxes or coyotes. Two (8%) of 26 gray foxes were positive in both the T. cruzi immunofluorescent antibody and strip assays. Antibodies to T. cruzi were not detected in coyotes. Results from this study indicate that wild canids are exposed to T. cruzi, but not L. infantum. in this geographic region. PMID:17918387

Rosypal, Alexa C; Tidwell, Richard R; Lindsay, David S

2007-08-01

44

[Helminthofauna of wild canids in Azerbaijan and ways of its formation].  

PubMed

The complete list of helminthes parasitizing canids in Azerbaijan is given; ways of formation of the canids' helminthofauna in Azerbaijan are reconstructed. As a result of our study, 42 helminth species were recorded; 25 of them parasitize jackals, 16 parasitize wolfs, and 39 species were found in foxes. The helminthofauna includes 5 species of Trematoda, 14 species of Cestoda, 1 species of Acanthocephala, and 22 species of Nematoda. By the life cycle, 32 species belong to biohelminthes and 10 species are geohelminthes. PMID:21874846

Fataliev, G G

45

Identification and characterisation of microRNAs in young adults of Angiostrongylus cantonensis via a deep-sequencing approach.  

PubMed

Angiostrongylus cantonensis is an important causative agent of eosinophilic meningitis and eosinophilic meningoencephalitis in humans. MicroRNAs (miRNAs) are small non-coding RNAs that participate in a wide range of biological processes. This study employed a deep-sequencing approach to study miRNAs from young adults of A. cantonensis. Based on 16,880,456 high-quality reads, 252 conserved mature miRNAs including 10 antisense miRNAs that belonging to 90 families, together with 10 antisense miRNAs were identified and characterised. Among these sequences, 53 miRNAs from 25 families displayed 50 or more reads. The conserved miRNA families were divided into four groups according to their phylogenetic distribution and a total of nine families without any members showing homology to other nematodes or adult worms were identified. Stem-loop real-time polymerase chain reaction analysis of aca-miR-1-1 and aca-miR-71-1 demonstrated that their level of expression increased dramatically from infective larvae to young adults and then decreased in adult worms, with the male worms exhibiting significantly higher levels of expression than female worms. These findings provide information related to the regulation of gene expression during the growth, development and pathogenesis of young adults of A. cantonensis. PMID:24037191

Chang, Shih-Hsin; Tang, Petrus; Lai, Cheng-Hung; Kuo, Ming-Ling; Wang, Lian-Chen

2013-09-01

46

Effects of Washing Produce Contaminated with the Snail and Slug Hosts of Angiostrongylus cantonensis with Three Common Household Solutions  

PubMed Central

The emerging infectious disease angiostrongyliasis (rat lungworm disease) is caused by ingesting snails and slugs infected by the nematode Angiostrongylus cantonensis. The definitive hosts of A. cantonensis are rats and the obligatory intermediate hosts are slugs and snails. Many cases result from accidentally ingesting infected snails or slugs on produce (eg, lettuce). This study assessed three readily available household products as washing solutions for removing snails and slugs from produce (romaine lettuce) to lower the probability of accidentally ingesting them. The solutions were acetic acid (vinegar), sodium hypochlorite (bleach), and sodium chloride (domestic salt). Snail and slug species known to be intermediate hosts and that are common in the Hawaiian Islands were used in the experiments: the alien snail Succinea tenella, the alien semi-slug Parmarion martensi, and the alien slugs Veronicella cubensis and Deroceras laeve. None of the products was any more effective than washing and rinsing with tap water alone. Most snails and slugs were removed after treatment but some remained on the lettuce even after washing and rinsing the produce. Only washing, rinsing, and then rinsing each leaf individually resulted in complete removal of all snails and slugs. The study did not address removal of any remaining slime left by the snails and slugs, nor did it address killing of worms.

Yeung, Norine W; Hayes, Kenneth A

2013-01-01

47

Control Measures for Slug and Snail Hosts of Angiostrongylus cantonensis, with Special Reference to the Semi-slug Parmarion martensi  

PubMed Central

Slugs and snails (class Gastropoda) are the obligate intermediate hosts of the rat lungworm, Angiostrongylus cantonensis. This nematode is the causative agent of human angiostrongyliasis and the most common cause of human eosinophilic meningoencephalitis. Humans can become infected by accidental consumption of slugs or snails and possibly flatworms (or a portion of one of these animals) in fresh produce, but the slime from these animals can contain nematodes and may also constitute a disease risk. Gastropod carriers in Hawa‘i include, among other species, giant African snails, veronicellid slugs, and the semi-slug Parmarion martensi. This latter species was first discovered on the island of Hawa‘i in 2004 and is now common in the area where the majority of the state's documented cases of human angiostrongyliasis occurred between 2005 and 2011. This species is considered a high risk carrier of A. cantonensis because of its climbing behavior, abundance around human dwellings, and high worm burdens. One individual collected from east Hawa‘i Island contained >6,800 infective third stage A. cantonensis larvae. Common and efficient control methods for slugs and snails include sanitation (eg, removal of objects that serve as hiding places) and the use of poison food baits, such as those containing metaldehyde and iron. An iron-containing bait that is relatively safe to non-target organisms was effective in controlling semi-slugs in cage experiments, although it killed more slowly than a metaldehyde-containing bait and the majority of slugs affected did not die until 1–2 weeks following ingestion.

Howe, Kathleen; Jarvi, Susan I

2013-01-01

48

Larvicidal activities of ginger (Zingiber officinale) against Angiostrongylus cantonensis.  

PubMed

In this study, we investigated the anthelmintic activity of [6]-gingerol, [10]-shogaol, [10]-gingerol, [6]-shogaol and hexahydrocurcumin, a constituent isolate from the roots of ginger (Zingiber officinale), for the parasite Angiostrongylus cantonensis. This study found that the above constituents killed A. cantonensis larvae or reduced their spontaneous movements in a time- and dose-dependent manner. The larvicidal effect or ability to halt spontaneous parasite movement of [10]-shogaol, [6]-gingerol, [10]-gingerol, [6]-shogaol and hexahydrocurcumin at various concentrations was reached from 24 to 72 h, respectively. Further investigation to determine minimal effective doses of [10]-gingerol and hexahydrocurcumin revealed [10]-gingerol to have a greater maximum larvicidal effect and loss of spontaneous movements than hexahydrocurcumin, mebendazole and albendazole. These constituents of ginger showed effects against DPPH and peroxyl radical under larvicidal effect. Together, these findings suggest that these constituents of ginger might be used as larvicidal agents against A. cantonensis. PMID:20045669

Lin, Rong-Jyh; Chen, Chung-Yi; Chung, Li-Yu; Yen, Chuan-Min

2010-01-04

49

Comparative Genomics of 3 Farm Canids in Relation to the Dog  

Microsoft Academic Search

There are 3 canids besides the dog (Canis familiaris): the red fox (Vulpes vulpes), arctic fox (Alopex lagopus) and Chinese raccoon dog (Nyctereutes procyonoides procyonoides), which have been extensively studied with the use of cytogenetic and molecular genetics techniques. These 3 species are considered as farm fur-bearing animals. In addition, they are also useful models in comparative genomic studies of

M. Switonski; I. Szczerbal; J. Nowacka-Woszuk

2009-01-01

50

Chronic emesis caused by a nematode-induced gastric nodule in a cat.  

PubMed

A spirurid nematode-induced gastric nodule was believed to be responsible for chronic gastric irritation and vomiting in a domestic short-hair cat. Clinical improvement was noticed following surgical removal of the parasitic nodule in the wall of the pylorus. Morphologic characteristics of the parasite were most consistent with Spirocerca lupi. Infection with Spirocerca lupi is most commonly reported in Canids, often resulting in chronic granulomatous disease of the distal portion of the esophagus. In some animals, the lesions transform into fibrosarcomas and osteogenic sarcomas. PMID:1517136

Mense, M G; Gardiner, C H; Moeller, R B; Partridge, H L; Wilson, S

1992-08-15

51

Nematodes (Rhabditida: Steinernematidae and Heterorhabditidae)  

Technology Transfer Automated Retrieval System (TEKTRAN)

Nematodes are roundworms in the phylum Nematoda. Although most are free-living, some nematodes are parasites of plants, humans, or livestock. Entomopathogenic nematodes in the families Steinernematidae & Heterorhabditidae only parasitize insects. These nematodes are used as environmentally friend...

52

Ancient DNA analysis affirms the canid from Altai as a primitive dog.  

PubMed

The origin of domestic dogs remains controversial, with genetic data indicating a separation between modern dogs and wolves in the Late Pleistocene. However, only a few dog-like fossils are found prior to the Last Glacial Maximum, and it is widely accepted that the dog domestication predates the beginning of agriculture about 10,000 years ago. In order to evaluate the genetic relationship of one of the oldest dogs, we have isolated ancient DNA from the recently described putative 33,000-year old Pleistocene dog from Altai and analysed 413 nucleotides of the mitochondrial control region. Our analyses reveal that the unique haplotype of the Altai dog is more closely related to modern dogs and prehistoric New World canids than it is to contemporary wolves. Further genetic analyses of ancient canids may reveal a more exact date and centre of domestication. PMID:23483925

Druzhkova, Anna S; Thalmann, Olaf; Trifonov, Vladimir A; Leonard, Jennifer A; Vorobieva, Nadezhda V; Ovodov, Nikolai D; Graphodatsky, Alexander S; Wayne, Robert K

2013-03-06

53

Transferability of short tandem repeat markers for two wild Canid species inhabiting the Brazilian Cerrado.  

PubMed

The maned wolf (Chrysocyon brachyurus) and the crab-eating fox (Cerdocyon thous) are two wild-canid species found in the Brazilian Cerrado. We tested cross-amplification and transferability of 29 short tandem repeat primers originally developed for cattle and domestic dogs and cats on 38 individuals of each of these two species, collected in the Emas National Park, which is the largest national park in the Cerrado region. Six of these primers were successfully transferred (CSSM-038, PEZ-05, PEZ-12, LOCO-13, LOCO-15, and PEZ-20); five of which were found to be polymorphic. Genetic parameter values (number of alleles per locus, observed and expected heterozygosities, and fixation indices) were within the expected range reported for canid populations worldwide. PMID:17183492

Rodrigues, F M; Telles, M P C; Resende, L V; Soares, T N; Diniz-Filho, J A F; Jácomo, A T A; Silveira, L

2006-12-13

54

A novel bacterial symbiont in the nematode Spirocerca lupi  

PubMed Central

Background The parasitic nematode Spirocerca lupi (Spirurida: Thelaziidae), the canine esophageal worm, is the causative agent of spirocercosis, a disease causing morbidity and mortality in dogs. Spirocerca lupi has a complex life cycle, involving an obligatory coleopteran intermediate host (vector), an optional paratenic host, and a definitive canid host. The diagnosis of spirocercosis is challenging, especially in the early disease stages, when adult worms and clinical signs are absent. Thus, alternative approaches are needed to promote early diagnosis. The interaction between nematodes and their bacterial symbionts has recently become a focus of novel treatment regimens for other helminthic diseases. Results Using 16S rDNA-based molecular methods, here we found a novel bacterial symbiont in S. lupi that is closely related to Comamonas species (Brukholderiales: Comamonadaceae) of the beta-proteobacteria. Its DNA was detected in eggs, larvae and adult stages of S. lupi. Using fluorescent in situ hybridization technique, we localized Comamonas sp. to the gut epithelial cells of the nematode larvae. Specific PCR enabled the detection of this symbiont's DNA in blood obtained from dogs diagnosed with spirocercosis. Conclusions The discovery of a new Comamonas sp. in S. lupi increase the complexity of the interactions among the organisms involved in this system, and may open innovative approaches for diagnosis and control of spirocercosis in dogs.

2012-01-01

55

Human Parasitic Meningitis Caused by Angiostrongylus cantonensis Infection in Taiwan  

PubMed Central

The major cause of eosinophilic meningitis in Taiwan is Angiostrongylus cantonensis. Humans are infected by ingesting terrestrial and freshwater snails and slugs. In 1998 and 1999, two outbreaks of eosinophilic meningitis caused by A. cantonensis infection were reported among 17 adult male immigrant Thai laborers who had eaten raw golden apple snails (Pomacea canaliculata). Another outbreak associated with consuming a health drink consisting of raw vegetable juice was reported in 2001. These adult cases differed from reports in the 1970s and 1980s, in which most of the cases were in children. With improvements in public health and education of foreign laborers, there have since been only sporadic cases in Taiwan. Review of clinical research indicates inconsistent association of Magnetic Resonance Imaging (MRI) results with clinical features of eosinophilic meningitis. MRI features were nonspecific but there was an association between the presence of high brain MRI signal intensities and severity of peripheral and cerebrospinal fluid (CSF) eosinophilia. Inflammatory markers have been identified in the CSF of patients with eosinophlic meningitis caused by A. cantonensis infection, and vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF), and the matrix metalloproteinase system may be associated with blood-brain barrier disruption. Eosinophilic meningitis caused by A. cantonensis infection is not a reportable disease in Taiwan. It is important that a public advisory and education program be developed to reduce future accidental infection.

Chen, Yao-Shen; Yen, Chuan-Min

2013-01-01

56

Comparative genomics of 3 farm canids in relation to the dog.  

PubMed

There are 3 canids besides the dog (Canis familiaris): the red fox (Vulpes vulpes), arctic fox (Alopex lagopus) and Chinese raccoon dog (Nyctereutes procyonoides procyonoides), which have been extensively studied with the use of cytogenetic and molecular genetics techniques. These 3 species are considered as farm fur-bearing animals. In addition, they are also useful models in comparative genomic studies of the canids. In this review genome organization, karyotype evolution, comparative marker maps, DNA polymorphism and similarity of selected gene sequences of the 3 farm species are discussed in relation to the dog. Also the nature and variability of the B chromosomes, present in the red fox and the Chinese raccoon dog, were considered. These comparative analyses showed that among the studied canids the Chinese raccoon dog is phylogenetically the closest species to the dog. On the other hand, the most advanced linkage and cytogenetic marker maps of the red fox genome facilitate genome scanning studies with the aim to search for chromosome locations of QTL regions for behavior and production traits. PMID:20016159

Switonski, M; Szczerbal, I; Nowacka-Woszuk, J

2009-12-09

57

Definitive, intermediate, paratenic, and accidental hosts of Angiostrongylus cantonensis and its molluscan intermediate hosts in Hawa'i.  

PubMed

Eosinophilic meningitis caused by infection with Angiostrongylus cantonensis, a parasitic nematode, is an emerging infectious disease of humans and other animals, known as angiostrongyliasis or rat lungworm disease. Symptoms range from headache and muscle spasms in mild cases to coma and even death. Many human cases have been recorded around the world, with the majority in tropical and subtropical locations. The increase in numbers of human cases and the expansion of the geographic distribution of cases make this parasite and its hosts important research foci. Definitive hosts include various rat species such as Rattus norvegicus, R. rattus, and R. exulans, and a number of land and freshwater snails and slugs have previously been identified as intermediate hosts. Both definitive and intermediate hosts are obligate to the life cycle of A. cantonensis. Paratenic hosts span a wide range of fauna and are not needed in the nematode's life cycle, but act as reservoirs in which different larval stages of the parasite can persist but not develop further; they include freshwater shrimp, flatworms, and frogs. Accidental hosts, including humans and other mammals, as well as birds, permit development from the third larval stage to the subadult (fifth) stage but are then dead ends for the parasite. These hosts are infected primarily through consumption of raw or undercooked intermediate or paratenic hosts, either intentionally or accidentally via contaminated produce. In Hawa'i, there have been recent outbreaks with cases of infection on four of the main islands. Since there is currently a limited consensus on appropriate therapy, steps to prevent infection should be taken. The first step to facilitate this and to lay the groundwork for future management of the hosts is to identify the intermediate hosts of A. cantonensis and to determine its geographic distribution within the Hawaiian Islands. To do this over 1000 specimens of 37 terrestrial and freshwater snail and slug species (30 introduced, 7 native) from the six largest Hawaiian Islands were screened using a molecular approach. Total DNA was extracted from foot tissue of each specimen and was amplified using Angiostrongylus-specific primers.8 Amplicons were visualized on agarose gels to determine if specimens were positive or negative for A. cantonensis. All of the positive specimens and a random sample of all other specimens tested were also reamplified using species-specific primers. All positive samples were still positive with the newer primers. The parasite was present in 16 (14 alien, 2 native) of these species, from five of the six largest Hawaiian Islands. These species represent 10 phylogenetically diverse terrestrial pulmonate families and 2 more distantly related caenogastropod families (one terrestrial and one freshwater). This broad phylogenetic representation demonstrates that this parasite is not host specific, to the extent that perhaps even any snail or slug species could act as an intermediate host. PMID:23901373

Kim, Jaynee R; Hayes, Kenneth A; Yeung, Norine W; Cowie, Robert H

2013-06-01

58

Telomeres in nematodes  

Microsoft Academic Search

Nematode telomeres show the same highly conserved structural features which are observed in other organisms. Cytological and genetic analyses revealed that nematode telomeres are involved in important meiotic processes, such as the attachment of chromosomes to the nuclear envelope, the pairing of homologues, the initiation of synapsis and kinetochore activity during meiosis. The early development of some nematode species is

Monique C. Zetka; Fritz Müller

1996-01-01

59

How nematode sperm crawl  

Microsoft Academic Search

Sperm of the nematode, Ascaris suum, crawl using lamellipodial protrusion, adhesion and retraction, a process analogous to the amoeboid motility of other eukaryotic cells. However, rather than employing an actin cytoskeleton to generate locomotion, nematode sperm use the major sperm protein (MSP). Moreover, nematode sperm lack detectable molecular motors or the battery of actin-binding proteins that characterize actin-based motility. The

Dean Bottino; Alexander Mogilner; Tom Roberts; Murray Stewart; George Oster

60

Severe Hemorrhagic Meningoencephalitis Due to Angiostrongylus cantonensis Among Young Children in Sydney, Australia.  

PubMed

Angiostrongylus cantonensis is the most common cause of eosinophilic meningitis worldwide. We describe 2 cases among young children from Sydney, Australia, where locally acquired infection of children has not been reported previously. Both cases manifested as severe hemorrhagic meningoencephalitis, one resulting in death. Angiostrongyliasis must be considered in acute neurological presentations occurring among individuals who live in endemic areas. PMID:23843445

Morton, Nikola J; Britton, Philip; Palasanthiran, Pamela; Bye, Ann; Sugo, Ella; Kesson, Alison; Ardern-Holmes, Simone; Snelling, Thomas L

2013-07-09

61

The suitability of several aquatic snails as intermediate hosts for Angiostrongylus cantonensis  

Microsoft Academic Search

Sixteen species of aquatic snails of four families were tested by quantitative technique under standardized conditions for their suitability as intermediate hosts for Angiostrongylus cantonensis. These species were the planorbid snails Biomphalaria glabrata, Biomphalaria alexandrina, Planorbis planorbis, Planorbis intermixtus, Bulinus truncatus, Bulinus contortus, Bulinus africanus, Bulinus tropicus and Helisoma sp.; the lymnaeid snails Lymnaea natalensis, Lymnaea tomentosa, Lymnaea stagnalis, and

Fouad Yousif; Georg Lämmler

1975-01-01

62

Enzootic Angiostrongylus cantonensis in Rats and Snails after an Outbreak of Human Eosinophilic Meningitis, Jamaica  

Microsoft Academic Search

After an outbreak in 2000 of eosinophilic meningitis in tourists to Jamaica, we looked for Angiostrongylus cantonensis in rats and snails on the island. Overall, 22% (24\\/109) of rats harbored adult worms, and 8% (4\\/48) of snails harbored A. cantonensis larvae. This report is the first of enzootic A. cantonensis infec- tion in Jamaica, providing evidence that this parasite is

John F. Lindo; Cecilia Waugh; John Hall; Colette Cunningham-Myrie; Deanna Ashley; Mark L. Eberhard; James J. Sullivan; Henry S. Bishop; David G. Robinson; Timothy Holtz; Ralph D. Robinson

2002-01-01

63

Unique inhibitory cascade pattern of molars in canids contributing to their potential to evolutionary plasticity of diet  

PubMed Central

Developmental origins that guide the evolution of dental morphology and dental formulae are fundamental subjects in mammalian evolution. In a previous study, a developmental model termed the inhibitory cascade model was established. This model could explain variations in relative molar sizes and loss of the lower third molars, which sometimes reflect diet, in murine rodents and other mammals. Here, I investigated the pattern of relative molar sizes (inhibitory cascade pattern) in canids, a taxon exhibiting a wide range of dietary habits. I found that interspecific variation in canid molars suggests a unique inhibitory cascade pattern that differs from that in murine rodents and other previously reported mammals, and that this variation reflects dietary habits. This unique variability in molars was also observed in individual variation in canid species. According to these observations, canid species have greater variability in the relative sizes of first molars (carnassials), which are functionally important for dietary adaptation in the Carnivora. In conclusion, an inhibitory cascade that differs from that in murine rodents and other mammals may have contributed to diverse dietary patterns and to their parallel evolution in canids.

Asahara, Masakazu

2013-01-01

64

Biogeography and conservation of taxa from remote regions: An application of ecological-niche based models and GIS to North-African canids  

Microsoft Academic Search

In North Africa, and especially in the Sahara Desert, biodiversity is poorly known. Of the five widespread canid species present, one is Data Deficient, three are considered widespread although habitat selection could limit their area of occupancy, and distribution maps available are coarse for conservation planning. This study identifies biogeographic patterns in North-African canids through the combination of high resolution

José C. Brito; André L. Acosta; Francisco Álvares; Fabrice Cuzin

2009-01-01

65

Canid progesterone receptors lack activation function 3 domain-dependent activity.  

PubMed

Progesterone regulates multiple behavioral, physiological, and pathological aspects of female reproductive biology through its two progesterone receptors (PRs), PR-B and the truncated PR-A. PR-B is necessary for mammary gland development in mice and, compared with PR-A, is overall a stronger transactivator of target genes due to an additional activation function 3 (AF3) domain. In dogs, known for their high sensitivity to progesterone-induced mammary cancer, the PR-B function was studied. Canine PR (cPR)-B appeared to contain multiple mutations within AF3 core sequence motifs and lacks N-terminal ligand-independent posttranslational modifications. Consequently, cPR-B has a weak transactivation potential on progesterone-responsive mouse mammary tumor virus-luc and progesterone response element 2-luc reporters transiently transfected in hamster, human, or canine cells and also on known target genes FKBP5 and SGK in doxycycline-inducible, stable transfected cPR-B in canine mammary cells. The cPR-B function was restored to the level of human PR-B by the replacement of canine AF3 domain with the human one. The lack of AF3 domain-dependent transcriptional activity was unique for canids (gray wolf, red fox, and raccoon dog) and not present in closely related caniform species (brown bear, gray seal, and domestic ferret). Despite the limited transactivation potential, canids develop normal mammary glands and frequently mammary tumors. Therefore, these results question the role of PR-B in breast cancer development and may explain unique features of canid reproduction. PMID:23041671

Gracanin, Ana; van Wolferen, Monique E; Sartorius, Carol A; Brenkman, Arjan B; Schoonen, Willem G; Mol, Jan A

2012-10-05

66

Presence of antibotulinum neurotoxin antibodies in selected wild canids in Israel.  

PubMed

Serum samples from 35 golden jackals (Canis aureus syriacus), eight wolves (Canis lupus), and four red foxes (Vulpes vulpes) from various regions of Israel were collected during the years 2001-04 and tested for antibodies to Clostridium botulinum neurotoxin (BoNT) types C and D. Antibodies against BoNT types C and D were detected in 10 (29%) and in 3 (9%) of 35 golden jackals, respectively, using enzyme-linked immunosorbent assay. This report describes detection of anti BoNT antibodies in wild canids other than coyotes (Canis latrans) for the first time and demonstrates that C. botulinum type C is prevalent in Israel. PMID:17699099

Steinman, Amir; Millet, Neta; Frenkel, Chana; King, Roni; Shpigel, Nahum Y

2007-07-01

67

Wild canids as sentinels of ecological health: a conservation medicine perspective  

PubMed Central

The extinction of species across the globe is accelerating, directly or indirectly due to human activities. Biological impoverishment, habitat fragmentation, climate change, increasing toxification, and the rapid global movement of people and other living organisms have worked synergistically to diminish ecosystem function. This has resulted in unprecedented levels of disease emergence, driven by human-induced environmental degradation, which poses a threat to the survival and health of biodiversity. The emerging discipline of conservation medicine addresses these concerns through the following entities: humans; global climate; habitat destruction and alteration; biodiversity, including wildlife populations; domestic animals; and pathogens, parasites and pollutants. Furthermore, conservation medicine focuses on explicit linkages between these entities. As a crisis discipline, the usefulness of conservation medicine ultimately will depend on its applicability to solving problems. The perspectives and scientific findings of conservation medicine provide input into biomedical education; and policy and management of ecosystems, habitats and imperiled species. A sentinel species is one that has presented itself, or has been selected, to provide insight into the state (health) of an ecosystem, based on user-defined (e.g., researchers, conservationists or policymakers) objectives (e.g., disease, parasites, toxics, climate change, habitat destruction), coupled with the utility and vulnerability of this species to the perceived stress. The scientific information generated by the sentinel species should empower stakeholders and decision-makers to take mitigative action or support predictive capabilities; the "utility" of the species selected should consider its value and relevance to conservationists and to society at large (e.g., education and outreach; social sciences). Wild canids may serve as excellent sentinel species of emerging canine vector-borne diseases. Several canine vector-borne diseases or antibodies to these pathogens have been identified in wild canids including visceral leishmaniosis, Lyme disease, heartworm, hepatozoonosis and anaplasmosis to name a few. These reports are relatively recent as they relate to wildlife-domestic animal interactions, globalisation, translocations, habitat fragmentation and climate change. These pathogens and their relationship to wild canids are described herein. Further research needs to be performed to elucidate the role of the 36 extant species of wild canids in the epidemiology of canine vector-borne diseases.

Aguirre, A Alonso

2009-01-01

68

Application technology for entomopathogenic nematodes  

Technology Transfer Automated Retrieval System (TEKTRAN)

Diverse technology is available for the application of entomopathogenic nematodes. Application usually consists of nematode distribution via aqueous suspension in various irrigation systems and spray equipment. The choice of application equipment, and method in which the nematodes are applied, can...

69

Matrix Metalloproteinase-9 Leads to Claudin-5 Degradation via the NF-?B Pathway in BALB/c Mice with Eosinophilic Meningoencephalitis Caused by Angiostrongylus cantonensis  

PubMed Central

The epithelial barrier regulates the movement of ions, macromolecules, immune cells and pathogens. The objective of this study was to investigate the role of the matrix metalloproteinase (MMP)-9 in the degradation of tight junction protein during infection with rat nematode lungworm Angiostrongylus cantonensis. The results showed that phosphorylation of I?B and NF-?B was increased in mice with eosinophilic meningoencephalitis. Treatment with MG132 reduced the phosphorylation of NF-?B and the activity of MMP-9, indicating upregulation of MMP-9 through the NF-?B signaling pathway. Claudin-5 was reduced in the brain but elevated in the cerebrospinal fluid (CSF), implying that A. cantonensis infection caused tight junction breakdown and led to claudin-5 release into the CSF. Degradation of claudin-5 coincided with alteration of the blood-CSF barrier permeability and treatment with the MMP inhibitor GM6001 attenuated the degradation of claudin-5. These results suggested that degradation of claudin-5 was caused by MMP-9 in angiostrongyliasis meningoencephalitis. Claudin-5 could be used for the pathophysiologic evaluation of the blood-CSF barrier breakdown and tight junction disruption after infection with A. cantonensis.

Chiu, Ping-Sung; Lai, Shih-Chan

2013-01-01

70

Cyst Nematodes and Syncytia  

Microsoft Academic Search

\\u000a Plant-parasitic nematodes from the genera Heterodera and Globodera change the morphogenetic programme of plant root cells and induce development of a specific feeding site called a syncytium.\\u000a The syncytium is the only source of nutrients for developing parasites and functions only for the nematode’s benefit. Its\\u000a development begins from a single cell selected by the infective second stage juvenile. The

Miroslaw Sobczak; Wladyslaw Golinowski

71

A genome-wide perspective on the evolutionary history of enigmatic wolf-like canids  

PubMed Central

High-throughput genotyping technologies developed for model species can potentially increase the resolution of demographic history and ancestry in wild relatives. We use a SNP genotyping microarray developed for the domestic dog to assay variation in over 48K loci in wolf-like species worldwide. Despite the high mobility of these large carnivores, we find distinct hierarchical population units within gray wolves and coyotes that correspond with geographic and ecologic differences among populations. Further, we test controversial theories about the ancestry of the Great Lakes wolf and red wolf using an analysis of haplotype blocks across all 38 canid autosomes. We find that these enigmatic canids are highly admixed varieties derived from gray wolves and coyotes, respectively. This divergent genomic history suggests that they do not have a shared recent ancestry as proposed by previous researchers. Interspecific hybridization, as well as the process of evolutionary divergence, may be responsible for the observed phenotypic distinction of both forms. Such admixture complicates decisions regarding endangered species restoration and protection.

vonHoldt, Bridgett M.; Pollinger, John P.; Earl, Dent A.; Knowles, James C.; Boyko, Adam R.; Parker, Heidi; Geffen, Eli; Pilot, Malgorzata; Jedrzejewski, Wlodzimierz; Jedrzejewska, Bogumila; Sidorovich, Vadim; Greco, Claudia; Randi, Ettore; Musiani, Marco; Kays, Roland; Bustamante, Carlos D.; Ostrander, Elaine A.; Novembre, John; Wayne, Robert K.

2011-01-01

72

Mitochondrial DNA from prehistoric canids highlights relationships between dogs and South-East European wolves.  

PubMed

The question of the origins of the dog has been much debated. The dog is descended from the wolf that at the end of the last glaciation (the archaeologically hypothesized period of dog domestication) was one of the most widespread among Holarctic mammals. Scenarios provided by genetic studies range from multiple dog-founding events to a single origin in East Asia. The earliest fossil dogs, dated approximately 17-12,000 radiocarbon ((14)C) years ago (YA), were found in Europe and in the Middle East. Ancient DNA (a-DNA) evidence could contribute to the identification of dog-founder wolf populations. To gain insight into the relationships between ancient European wolves and dogs we analyzed a 262-bp mitochondrial DNA control region fragment retrieved from five prehistoric Italian canids ranging in age from approximately 15,000 to approximately 3,000 (14)C YA. These canids were compared to a worldwide sample of 547 purebred dogs and 341 wolves. The ancient sequences were highly diverse and joined the three major clades of extant dog sequences. Phylogenetic investigations highlighted relationships between the ancient sequences and geographically widespread extant dog matrilines and between the ancient sequences and extant wolf matrilines of mainly East European origin. The results provide a-DNA support for the involvement of European wolves in the origins of the three major dog clades. Genetic data also suggest multiple independent domestication events. East European wolves may still reflect the genetic variation of ancient dog-founder populations. PMID:16120801

Verginelli, Fabio; Capelli, Cristian; Coia, Valentina; Musiani, Marco; Falchetti, Mario; Ottini, Laura; Palmirotta, Raffaele; Tagliacozzo, Antonio; De Grossi Mazzorin, Iacopo; Mariani-Costantini, Renato

2005-08-24

73

Angiostrongylus cantonensis : morphological and behavioral investigation within the freshwater snail Pomacea canaliculata  

Microsoft Academic Search

An infection with Angiostrongylus cantonensis, the main causative agent for human eosinophilic encephalitis, can be acquired through the consumption of the freshwater\\u000a snail Pomacea canaliculata. This snail also provides a suitable model to study the developmental morphology and behavior of A. cantonensis larvae, facilitated by the snail’s distinct lung structure. We used microanatomy for studying the natural appearance and\\u000a behavior

Shan Lv; Yi Zhang; He-Xiang Liu; Chao-Wei Zhang; Peter Steinmann; Xiao-Nong Zhou; Jürg Utzinger

2009-01-01

74

The Nematode Caenorhabditis Elegans.  

ERIC Educational Resources Information Center

|Discusses advantages of nematode use for studying patterns of cell division, differentiation, and morphogenesis. Describes nematode development. Cites experimental approaches available for genetic studies. Reviews the topics of control of cell division and differentiation, the nervous system, and muscle assembly and function of the organism. (RT)|

Kenyon, Cynthia

1988-01-01

75

The Nematode Caenorhabditis Elegans.  

ERIC Educational Resources Information Center

Discusses advantages of nematode use for studying patterns of cell division, differentiation, and morphogenesis. Describes nematode development. Cites experimental approaches available for genetic studies. Reviews the topics of control of cell division and differentiation, the nervous system, and muscle assembly and function of the organism. (RT)

Kenyon, Cynthia

1988-01-01

76

THE USDA NEMATODE COLLECTION  

Technology Transfer Automated Retrieval System (TEKTRAN)

The U.S. Department of Agriculture Nematode Collection (USDANC) at Beltsville, MD, is one of the largest and most valuable international resources for nematode taxonomic research and identifications. It is widely used by U.S. and international scientists to resolve various taxonomic and nomenclatur...

77

Crab-eating fox ( Cerdocyon thous), a South American canid, as a definitive host for Hammondia heydorni  

Microsoft Academic Search

Hammondia heydorni is a cyst forming coccidia closely related to other apicomplexans, such as Toxoplasma gondii, Neospora caninum and Hammondia hammondi with a two-host life cycle. Dogs and other canids as red foxes (Vulpes vulpes) and coyotes (Canis latrans) may serve as definitive hosts for H. heydorni. Sporulated oocysts are infective for cattle, sheep and goats, which may serve as

Rodrigo M. Soares; Luiz R. P. B. Cortez; Solange M. Gennari; Michelle K. Sercundes; Lara B. Keid; Hilda F. J. Pena

2009-01-01

78

Canine and feline cardiopulmonary parasitic nematodes in Europe: emerging and underestimated  

PubMed Central

Cardiopulmonary nematodes of dogs and cats cause parasitic diseases of central relevance in current veterinary practice. In the recent past the distribution of canine and feline heartworms and lungworms has increased in various geographical areas, including Europe. This is true especially for the metastrongyloids Aelurostrongylus abstrusus, Angiostrongylus vasorum and Crenosoma vulpis, the filarioid Dirofilaria immitis and the trichuroid Eucoleus aerophilus (syn. Capillaria aerophila). The reasons of this emergence are little known but many drivers such as global warming, changes in vector epidemiology and movements in animal populations, may be taken into account. The purpose of this article is to review the knowledge of the most important heartworm and lungworm infections of dogs and cats in Europe. In particular recent advances in epidemiology, clinical and control are described and discussed.

2010-01-01

79

Lessons from a non-domestic canid: joint disease in captive raccoon dogs (Nyctereutes procyonoides).  

PubMed

The purpose of this study was to describe pathological changes of the shoulder, elbow, hip and stifle joints of 16 museum skeletons of the raccoon dog (Nyctereutes procyonoides). The subjects had been held in long-term captivity and were probably used for fur farming or research, thus allowing sufficient longevity for joint disease to become recognisable. The prevalence of disorders that include osteochondrosis, osteoarthritis and changes compatible with hip dysplasia, was surprisingly high. Other changes that reflect near-normal or mild pathological conditions, including prominent articular margins and mild bony periarticular rim, were also prevalent. Our data form a basis for comparing joint pathology of captive raccoon dogs with other mammals and also suggest that contributing roles of captivity and genetic predisposition should be explored further in non-domestic canids. PMID:23277118

Lawler, Dennis F; Evans, Richard H; Nieminen, Petteri; Mustonen, Anne-Mari; Smith, Gail K

80

Molecular characterization of Hepatozoon spp. infection in endangered Indian wild felids and canids.  

PubMed

Hepatozoon species are parasites that infect a wide variety of domestic and wild animals. The objective of this study was to perform the molecular detection and characterization of Hepatozoon spp. in Asiatic lion, Indian tiger, Indian leopard, Indian wild dog, Indian domestic dog and cat based on partial 18S rRNA gene sequences from Hepatozoon spp. in the naturally infected animals. Hepatozoon spp. could be detected in blood samples of 5 out of 9 Asiatic lions, 2 out of 5 Indian tigers, 2 out of 4 Indian leopards and 2 out of 2 Indian wild dogs and, 2 out of 4 domestic cats and 2 out of 3 domestic dog samples by PCR. Sequencing of PCR amplicon and BLAST analysis of partial 18S rRNA gene sequences indicated that the Hepatozoon spp. in Asiatic lion, Bengal tiger, Indian leopard and domestic cat was Hepatozoon felis (98-99% similarity) and in the Indian wild and domestic dog the phylogenetic neighbour was Hepatozoon canis (97-100% similarity). Presence of H. felis and H. canis in both domestic and wild animals suggested that they are not host specific and the same parasite causes infection in domestic and wild felids and canids in India and from different parts of the world. To our knowledge, this is the first report on detection and molecular characterization of H. felis infection in Asiatic lions, Indian tigers, Indian leopards and H. canis in Indian wild dog. Hepatozoon spp. may be a potential pathogen and an opportunistic parasite in immuno-compromised animals and could thus represent a threat to endangered Indian wild felids and canids. PMID:22154254

Pawar, Rahul Mohanchandra; Poornachandar, Anantula; Srinivas, Pasham; Rao, Kancharapu Ramachandra; Lakshmikantan, Uthandaraman; Shivaji, Sisinthy

2011-11-20

81

Plant Nematode Surfaces  

Microsoft Academic Search

\\u000a The outer surface of nematodes act as an external skeleton and is covered by a tough, but flexible, multi-layered, extracellular\\u000a cuticle which protects them from the external environment, maintains body shape and is involved in locomotion and defence\\u000a against their host or microorganism attack. This chapter highlights the role of the nematode surface cuticle, during the various\\u000a life-stages, with their

Rosane H. C. Curtis; John T. Jones; Keith G. Davies; Edna Sharon; Yitzhak Spiegel

82

Soil nematode biodiversity  

Microsoft Academic Search

Nematodes are the most abundant metazoans in soil, and are exceeded in species diversity only by the arthropods. Estimates of nematode diversity in natural and agroecosystems have been based on both species-level taxonomy and trophic-level guilds. Because trophic groups do not act in a unitary manner with respect to environmental alterations, species-level analysis is more meaningful and should be preferred

Ernest C. Bernard

1992-01-01

83

Drug Resistance in Nematodes  

Microsoft Academic Search

Anthelmintic drugs remain the principal means of intervention for therapy and prophylaxis of nematode parasitic diseases in\\u000a humans and animals. Other than improvements in sanitation, there are no effective alternatives to chemical control of parasitic\\u000a nematodes. However, resistance to anthelmintics has become a major problem in veterinary medicine, threatens both agricultural\\u000a production and animal welfare, and there is increasing concern

Roger Prichard

84

Angiostrongylus cantonensis: Experimental study on the susceptibility of apple snails, Pomacea canaliculata compared to Pila polita  

Microsoft Academic Search

Six groups (15 snails\\/group) of Pomacea canaliculata and Pila polita were infected orally with 0 (control), 200, 400, 800, 1600 and 3200 first-stage Angiostrongylus cantonensis larvae (L1). The respective mean±SD third stage larvae (L3) worm recovery 1-month post-infection (p.i.) for P. canaliculata was 0, 1.4±5.42 (0.7%), 0.13±0.35 (0.03%), 0.07±0.26 (0.009%), 0.07±0.26 (0.004%), 0, and for P. polita 0, 64.33±21.38 (32.25%),

Smarn Tesana; Tuanchai Srisawangwong; Paiboon Sithithaworn; Thewarach Laha

2008-01-01

85

The mode of infection with and the distribution of Angiostrongylus cantonensis larvae in the experimental intermediate hoist Biomphalaria glabrata  

Microsoft Academic Search

The mode by which molluscan hosts become infected with first-stage larvae of the metastrongylid Angiostrongylus cantonensis has received considerable attention. It was claimed by Mackerras and Sanders (1955) that infection was possible by the oral route as well as by penetration by the larvae through the moUusc body wall or foot. These two modes of infection for this parasite were

Fouad Yousif; Georg Lämmler

1977-01-01

86

The effect of temperature on the development of Angiostrongylus cantonensis (Chen 1935) in Pomacea canaliculata (Lamarck 1822)  

Microsoft Academic Search

Angiostrongyliasis cantonensis, clinically presented as eosinophilic meningitis, is a snail-borne parasitic disease. We studied the effects of different temperatures on the larval development of Angiostrongylus cantonensis in the freshwater snail Pomacea canaliculata. Six groups of snails were infected and each group was cultured under different temperature conditions. At predefined intervals, four snails from each group were dissected to examine the

Shan Lv; Xiao-Nong Zhou; Yi Zhang; He-Xiang Liu; Dan Zhu; Wei-Gang Yin; Peter Steinmann; Xian-Hong Wang; Tie-Wu Jia

2006-01-01

87

The evolutionary position of nematodes  

Microsoft Academic Search

BACKGROUND: The complete genomes of three animals have been sequenced by global research efforts: a nematode worm (Caenorhabditis elegans), an insect (Drosophila melanogaster), and a vertebrate (Homo sapiens). Remarkably, their relationships have yet to be clarified. The confusion concerns the enigmatic position of nematodes. Traditionally, nematodes have occupied a basal position, in part because they lack a true body cavity.

Jaime E Blair; Kazuho Ikeo; Takashi Gojobori; S Blair Hedges

2002-01-01

88

Evidence of Coat Color Variation Sheds New Light on Ancient Canids  

PubMed Central

We have used a paleogenetics approach to investigate the genetic landscape of coat color variation in ancient Eurasian dog and wolf populations. We amplified DNA fragments of two genes controlling coat color, Mc1r (Melanocortin 1 Receptor) and CBD103 (canine-?-defensin), in respectively 15 and 19 ancient canids (dogs and wolf morphotypes) from 14 different archeological sites, throughout Asia and Europe spanning from ca. 12 000 B.P. (end of Upper Palaeolithic) to ca. 4000 B.P. (Bronze Age). We provide evidence of a new variant (R301C) of the Melanocortin 1 receptor (Mc1r) and highlight the presence of the beta-defensin melanistic mutation (CDB103-K locus) on ancient DNA from dog-and wolf-morphotype specimens. We show that the dominant KB allele (CBD103), which causes melanism, and R301C (Mc1r), the variant that may cause light hair color, are present as early as the beginning of the Holocene, over 10 000 years ago. These results underline the genetic diversity of prehistoric dogs. This diversity may have partly stemmed not only from the wolf gene pool captured by domestication but also from mutations very likely linked to the relaxation of natural selection pressure occurring in-line with this process.

Ollivier, Morgane; Tresset, Anne; Hitte, Christophe; Petit, Coraline; Hughes, Sandrine; Gillet, Benjamin; Duffraisse, Marilyne; Pionnier-Capitan, Maud; Lagoutte, Laetitia; Arbogast, Rose-Marie; Balasescu, Adrian; Boroneant, Adina; Mashkour, Marjan; Vigne, Jean-Denis; Hanni, Catherine

2013-01-01

89

Pregnancy diagnosis in wild canids using a commercially available relaxin assay.  

PubMed

Accurate detection of pregnancy is a useful tool in zoo management and husbandry, conservation breeding programs and research settings. Our study evaluated the ability of a commercial relaxin hormone assay used in domestic dogs (ReproCHEK(TM)) to accurately detect pregnancy through plasma analysis in two wolf and two fox species. The relaxin assay detected all of the pregnancies greater than 25 days gestation for island foxes, fennec foxes, gray wolves, and Mexican gray wolves. For island foxes, three negative relaxin results were attributed to using the test earlier postconception than manufacturer recommendation (before day 20). Five other negative results were found for females estimated at 15-25 days gestation, spanning the early and intermediate period (21-30 days gestation) when relaxin may be detected but less reliably. There were no false-positive results in nonmated negative control animals. Relaxin assay results were highly correlated with ultrasound results and the intra-assay replicate agreement was 100%. Our results show that the ReproCHEK(TM) commercial relaxin assay is a minimally invasive and reliable method for pregnancy detection in these wild species when used after 25 days gestation and might be applied to other canids as well. Furthermore, this assay is easy to run and requires no specialized equipment, making it extremely useful for zoo and field research applications. Zoo Biol 27:406-413, 2008. (c) 2008 Wiley-Liss, Inc. PMID:19360634

Bauman, Joan E; Clifford, Deana L; Asa, Cheryl S

2008-09-01

90

Evidence of coat color variation sheds new light on ancient canids.  

PubMed

We have used a paleogenetics approach to investigate the genetic landscape of coat color variation in ancient Eurasian dog and wolf populations. We amplified DNA fragments of two genes controlling coat color, Mc1r (Melanocortin 1 Receptor) and CBD103 (canine-?-defensin), in respectively 15 and 19 ancient canids (dogs and wolf morphotypes) from 14 different archeological sites, throughout Asia and Europe spanning from ca. 12 000 B.P. (end of Upper Palaeolithic) to ca. 4000 B.P. (Bronze Age). We provide evidence of a new variant (R301C) of the Melanocortin 1 receptor (Mc1r) and highlight the presence of the beta-defensin melanistic mutation (CDB103-K locus) on ancient DNA from dog-and wolf-morphotype specimens. We show that the dominant K(B) allele (CBD103), which causes melanism, and R301C (Mc1r), the variant that may cause light hair color, are present as early as the beginning of the Holocene, over 10 000 years ago. These results underline the genetic diversity of prehistoric dogs. This diversity may have partly stemmed not only from the wolf gene pool captured by domestication but also from mutations very likely linked to the relaxation of natural selection pressure occurring in-line with this process. PMID:24098367

Ollivier, Morgane; Tresset, Anne; Hitte, Christophe; Petit, Coraline; Hughes, Sandrine; Gillet, Benjamin; Duffraisse, Marilyne; Pionnier-Capitan, Maud; Lagoutte, Laetitia; Arbogast, Rose-Marie; Balasescu, Adrian; Boroneant, Adina; Mashkour, Marjan; Vigne, Jean-Denis; Hänni, Catherine

2013-10-02

91

Toward 959 nematode genomes  

PubMed Central

The sequencing of the complete genome of the nematode Caenorhabditis elegans was a landmark achievement and ushered in a new era of whole-organism, systems analyses of the biology of this powerful model organism. The success of the C. elegans genome sequencing project also inspired communities working on other organisms to approach genome sequencing of their species. The phylum Nematoda is rich and diverse and of interest to a wide range of research fields from basic biology through ecology and parasitic disease. For all these communities, it is now clear that access to genome scale data will be key to advancing understanding, and in the case of parasites, developing new ways to control or cure diseases. The advent of second-generation sequencing technologies, improvements in computing algorithms and infrastructure and growth in bioinformatics and genomics literacy is making the addition of genome sequencing to the research goals of any nematode research program a less daunting prospect. To inspire, promote and coordinate genomic sequencing across the diversity of the phylum, we have launched a community wiki and the 959 Nematode Genomes initiative (www.nematodegenomes.org/). Just as the deciphering of the developmental lineage of the 959 cells of the adult hermaphrodite C. elegans was the gateway to broad advances in biomedical science, we hope that a nematode phylogeny with (at least) 959 sequenced species will underpin further advances in understanding the origins of parasitism, the dynamics of genomic change and the adaptations that have made Nematoda one of the most successful animal phyla.

Kumar, Sujai; Koutsovoulos, Georgios; Kaur, Gaganjot; Blaxter, Mark

2012-01-01

92

Factors Associated With Uterine Endometrial Hyperplasia and Pyometra in Wild Canids: Implications for Fertility.  

PubMed

The ability to safely and effectively manage reproduction is central to the success of AZA captive-breeding programs. Although the AZA Wildlife Contraception Center routinely monitors contraceptive safety, there have been no studies that compare the effects of contraceptive use to separation of males from females, the other option for preventing reproduction. We used retrospective medical records and pathology reports submitted by AZA and related facilities for the seven AZA-managed canid species to assess rates of uterine pathology relative to female reproductive life histories. Our results showed that the prevalence of both pyometra and endometrial hyperplasia (EH) was associated not only with treatment with the two most common contraceptives (Suprelorin® and MGA implants) but also with the number of years barren (i.e., not producing a litter and not contracepted). Rates of pyometra and EH were especially high in African painted dogs and red wolves, but lowest in swift and fennec foxes. The number of years producing a litter had a low association, suggesting it could be protective against uterine pathology. A more recently developed Suprelorin® protocol using Ovaban® to prevent the initial stimulation phase, followed by implant removal when reversal is desired, may be a safer contraceptive option. These results concerning the relationship between reproductive management and uterine health have important implications for AZA-managed programs, since the unsustainability of many captive populations may be due at least in part to infertility. Managing a female's reproductive lifespan to optimize or maintain fertility will require a reconsideration of how breeding recommendations are formulated. Zoo Biol. XX:XX-XX, 2013. (c) 2013 Wiley Periodicals Inc. PMID:23553688

Asa, Cheryl S; Bauman, Karen L; Devery, Sarah; Zordan, Martín; Camilo, Gerardo R; Boutelle, Sally; Moresco, Anneke

2013-04-01

93

High within-host genetic variation of the nematode Spirocerca lupi in a high-density urban dog population.  

PubMed

The nematode worm Spirocerca lupi has a cosmopolitan distribution and can cause the death of its final canid host, typically dogs. While its life cycle, which involves a coprophagous beetle intermediate host, a number of non-obligatory vertebrate paratenic hosts and a canid final host, is well understood, surprisingly little is known about its transmission dynamics and population genetic structure. Here we sequenced cox1 to quantify genetic variation and the factors that limit gene flow in a 300 km(2) area in South Africa. Three quarters of the genetic variation, was explained by differences between worms from the same host, whereas a quarter of the variation was explained by differences between worms from different hosts. With the help of a newly derived model we conclude that while the offspring from different infrapopulations mixes fairly frequently in new hosts, the level of admixture is not enough to homogenize the parasite populations among dogs. Small infrapopulation sizes along with clumped transmission may also result in members of infrapopulations being closely related. PMID:22226763

de Waal, Pamela J; Gous, Annemarie; Clift, Sarah J; Greeff, Jaco M

2011-12-19

94

Water developments and canids in two North American deserts: a test of the indirect effect of water hypothesis.  

PubMed

Anthropogenic modifications to landscapes intended to benefit wildlife may negatively influence wildlife communities. Anthropogenic provisioning of free water (water developments) to enhance abundance and distribution of wildlife is a common management practice in arid regions where water is limiting. Despite the long-term and widespread use of water developments, little is known about how they influence native species. Water developments may negatively influence arid-adapted species (e.g., kit fox, Vulpes macrotis) by enabling water-dependent competitors (e.g., coyote, Canis latrans) to expand distribution in arid landscapes (i.e., indirect effect of water hypothesis). We tested the two predictions of the indirect effect of water hypothesis (i.e., coyotes will visit areas with free water more frequently and kit foxes will spatially and temporally avoid coyotes) and evaluated relative use of free water by canids in the Great Basin and Mojave Deserts from 2010 to 2012. We established scent stations in areas with (wet) and without (dry) free water and monitored visitation by canids to these sites and visitation to water sources using infrared-triggered cameras. There was no difference in the proportions of visits to scent stations in wet or dry areas by coyotes or kit foxes at either study area. We did not detect spatial (no negative correlation between visits to scent stations) or temporal (no difference between times when stations were visited) segregation between coyotes and kit foxes. Visitation to water sources was not different for coyotes between study areas, but kit foxes visited water sources more in Mojave than Great Basin. Our results did not support the indirect effect of water hypothesis in the Great Basin or Mojave Deserts for these two canids. PMID:23844097

Hall, Lucas K; Larsen, Randy T; Knight, Robert N; Bunnell, Kevin D; McMillan, Brock R

2013-07-02

95

The evolutionary position of nematodes  

PubMed Central

Background The complete genomes of three animals have been sequenced by global research efforts: a nematode worm (Caenorhabditis elegans), an insect (Drosophila melanogaster), and a vertebrate (Homo sapiens). Remarkably, their relationships have yet to be clarified. The confusion concerns the enigmatic position of nematodes. Traditionally, nematodes have occupied a basal position, in part because they lack a true body cavity. However, the leading hypothesis now joins nematodes with arthropods in a molting clade, Ecdysozoa, based on data from several genes. Results We tested the Ecdysozoa hypothesis with analyses of more than 100 nuclear protein alignments, under conditions that would expose biases, and found that it was not supported. Instead, we found significant support for the traditional hypothesis, Coelomata. Our result is robust to different rates of sequence change among genes and lineages, different numbers of taxa, and different species of nematodes. Conclusion We conclude that insects (arthropods) are genetically and evolutionarily closer to humans than to nematode worms.

Blair, Jaime E; Ikeo, Kazuho; Gojobori, Takashi; Hedges, S Blair

2002-01-01

96

Phenotypic plasticity in nematodes  

PubMed Central

Model systems, including C. elegans, have been successfully studied to understand the genetic control of development. A genotype’s phenotype determines its evolutionary fitness in natural environments, which are typically harsh, heterogeneous and dynamic. Phenotypic plasticity, the process by which one genome can produce different phenotypes in response to the environment, allows genotypes to better match their phenotype to their environment. Phenotypic plasticity is rife among nematodes, seen both as differences among life-cycles stages, perhaps best exemplified by parasitic nematodes, as well as developmental choices, such as shown by the C. elegans dauer/non-dauer developmental choice. Understanding the genetic basis of phenotypically plastic traits will probably explain the function of many genes whose function still remains unclear. Understanding the adaptive benefits of phenotypically plastic traits requires that we understand how plasticity differs among genotypes, and the effects of this in diverse, different environments.

Viney, Mark; Diaz, Anaid

2012-01-01

97

Ever Surprising Nematode Globins  

Microsoft Academic Search

Nematodes express pseudocoelomic, body wall and cuticle globin isoforms. All globin isoforms display the major determinants\\u000a of the globin fold and a B10Tyr\\/E7Gln residue pair, which is a signature of high oxygen affinity. The hitherto studied pseudocoelomic\\u000a globins are octamers of covalently linked didomain globin chains. Body wall globins so far are monomeric, whereas cuticle\\u000a globins are tetrameric. The extremely

David Hoogewijs; Eva Geuens; Lesley Tilleman; Jacques R. Vanfleteren; Luc Moens; Sylvia Dewilde

98

Toward 959 nematode genomes.  

PubMed

The sequencing of the complete genome of the nematode Caenorhabditis elegans was a landmark achievement and ushered in a new era of whole-organism, systems analyses of the biology of this powerful model organism. The success of the C. elegans genome sequencing project also inspired communities working on other organisms to approach genome sequencing of their species. The phylum Nematoda is rich and diverse and of interest to a wide range of research fields from basic biology through ecology and parasitic disease. For all these communities, it is now clear that access to genome scale data will be key to advancing understanding, and in the case of parasites, developing new ways to control or cure diseases. The advent of second-generation sequencing technologies, improvements in computing algorithms and infrastructure and growth in bioinformatics and genomics literacy is making the addition of genome sequencing to the research goals of any nematode research program a less daunting prospect. To inspire, promote and coordinate genomic sequencing across the diversity of the phylum, we have launched a community wiki and the 959 Nematode Genomes initiative (www.nematodegenomes.org/). Just as the deciphering of the developmental lineage of the 959 cells of the adult hermaphrodite C. elegans was the gateway to broad advances in biomedical science, we hope that a nematode phylogeny with (at least) 959 sequenced species will underpin further advances in understanding the origins of parasitism, the dynamics of genomic change and the adaptations that have made Nematoda one of the most successful animal phyla. PMID:24058822

Kumar, Sujai; Koutsovoulos, Georgios; Kaur, Gaganjot; Blaxter, Mark

2012-01-01

99

A pooling strategy of a PCR-based assay to detect Angiostrongylus cantonensis in snail intermediate host, Pomacea canaliculata  

Microsoft Academic Search

Pooling field specimens could reduce the number of assay and thus increase the efficiency in detecting and screening pathogen\\u000a infections by polymerase chain reaction (PCR)-based assay. We investigated a pooling strategy in diagnosis of Angiostrongylus cantonensis in Pomacea canaliculata. Two settings of specimens were prepared, divided into portions and detected by multiplex PCR. Specimens A was 0.4490 g positive\\u000a lung

Fu-Rong Wei; Shan Lv; He-Xiang Liu; Ling Hu; Yi Zhang

2010-01-01

100

The effects of different plant extracts on nematodes.  

PubMed

The anthelminthic efficacy of some differently obtained extracts of several plants was tested in vivo in laboratory animals and in vitro. The extracts were obtained by ethanolic, methanolic, aqueous, or chloroform, respectively, acetonitrile polyethylenglycol (PEG) and/or propylencarbonate (PC) elution at room temperature or at 37°C. The plants used were bulbs of onions, garlic, chives, coconut, birch tree, ananas, cistrose, banana, chicory, date palm fruit, fig, pumpkin, and neem tree seeds. The worm systems tested both in vivo and in vitro were Trichuris muris and Angiostrongylus cantonensis but only in vivo Toxocara cati. The tests clearly showed that the different extraction methods eluted different components and different mass amounts, which had different efficacies against the above-cited worms. In vitro effects against A. cantonensis and T.muris were best with aqueous extracts, followed by chloroform extracts. The other plant extracts showed only low or no effects on A. cantonensis in vitro. In the case of T. muris, best results were obtained in vivo and in vitro with PEG/PC extracts of the onion followed by the aqueous extract of coconut. The complete elimination of worms in the in vivo experiments with T. muris was obtained when infected mice were treated with a 1:1 mixture of extracts of coconut and onion being produced by elutions with a mixture of 1:1 PEG and PC and fed daily for 8 days. T. cati in a naturally infected cat was eliminated by daily oral application of 6 ml coco's fluid for 5 days. This study shows that a broad spectrum of plants has anti-nematodal activities, the intensity of which, however, depends on the mode of extraction. This implicates that, if results should be really comparable, the same extraction methods at the same temperatures have to be used. Furthermore, efficacy in in vitro systems does not guarantee as good--if at all--efficacy in vivo. PMID:21110041

Klimpel, Sven; Abdel-Ghaffar, Fathy; Al-Rasheid, Khaled A S; Aksu, Gülendem; Fischer, Katja; Strassen, Bianca; Mehlhorn, Heinz

2010-11-26

101

BEHAVORIAL ECOLOGY OF ENTOMOPATHOGENIC NEMATODES  

Technology Transfer Automated Retrieval System (TEKTRAN)

The behavior and ecology of entomopathogenic nematodes (i.e., steinernematids and heterorhabditids) have been studied in attempts to make these natural enemies better biological control agents. Recently entomopathogenic nematodes have also been the subject of more basic studies, where they are vie...

102

Interactions Between Bacteria and Nematodes  

Microsoft Academic Search

In this review, we have described some examples of symbiotic and pathogenic interactions that occur between bacteria and soil-dwelling nematodes. Recent genetic analysis of these bacteria-nematode interactions has led to a significant increase in our understanding of the molecular mechanisms controlling how bacteria infect their hosts and, more importantly, the role of the host in determining the output of the

David J. Clarke; Leo Eberl

103

RNAi Effector Diversity in Nematodes  

Microsoft Academic Search

While RNA interference (RNAi) has been deployed to facilitate gene function studies in diverse helminths, parasitic nematodes appear variably susceptible. To test if this is due to inter-species differences in RNAi effector complements, we performed a primary sequence similarity survey for orthologs of 77 Caenorhabditis elegans RNAi pathway proteins in 13 nematode species for which genomic or transcriptomic datasets were

Johnathan J. Dalzell; Paul McVeigh; Neil D. Warnock; Makedonka Mitreva; David Mc K. Bird; Pierre Abad; Colin C. Fleming; Tim A. Day; Angela Mousley; Nikki J. Marks; Aaron G. Maule

2011-01-01

104

Cilia in Nematode Sensory Organs  

Microsoft Academic Search

Electron microscopic studies revealed the presence of true cilia in nerve processes connected with sensory organs of a nematode. These structures are important in evaluating the relation between nematodes and the other aschelminths, from which they were separated partially on the basis of the supposed total absence of cilia.

D. R. Roggen; D. J. Raski; N. O. Jones

1966-01-01

105

Immunomodulation by filarial nematodes.  

PubMed

In order to chronically infect their hosts, filarial nematodes have generated a range of strategies to evade and down-modulate the host's immune system. The recent concept of suppression of immune responses by regulatory T cells has in part benefited from examinations in human and murine filariasis. Its further development in basic immunology animal models has in turn helped to better understand down-regulatory immune mechanisms in filariasis. Thus, filarial nematodes orchestrate down-regulation by inducing regulatory T cells and alternatively activated macrophages, which are able to suppress both Th1 and Th2 responses. Regulatory T cells can also induce the secretion of IgG4 from B cells as another arm of modulation. Dendritic cells are down-regulated upon first encounter with infective L3 larvae. Failure to respond to down-regulatory induction is based on genetic traits in hosts and leads to reduced parasite loads, albeit at the expense of pathology and disease. Since down-regulation in chronically and heavily infected hosts extends to third-party antigens, it is essential to analyse the impact of filarial infection for vaccination, allergy and important coinfections such as malaria, in order to foresee and avert potentially disastrous consequences of filariasis control programmes. PMID:16179035

Hoerauf, A; Satoguina, J; Saeftel, M; Specht, S

106

Nematode-trapping fungi eavesdrop on nematode pheromones.  

PubMed

The recognition of molecular patterns associated with specific pathogens or food sources is fundamental to ecology and plays a major role in the evolution of predator-prey relationships. Recent studies showed that nematodes produce an evolutionarily highly conserved family of small molecules, the ascarosides, which serve essential functions in regulating nematode development and behavior. Here, we show that nematophagous fungi, natural predators of soil-dwelling nematodes, can detect and respond to ascarosides. Nematophagous fungi use specialized trapping devices to catch and consume nematodes, and previous studies demonstrated that most fungal species do not produce traps constitutively but rather initiate trap formation in response to their prey. We found that ascarosides, which are constitutively secreted by many species of soil-dwelling nematodes, represent a conserved molecular pattern used by nematophagous fungi to detect prey and trigger trap formation. Ascaroside-induced morphogenesis is conserved in several closely related species of nematophagous fungi and occurs only under nutrient-deprived conditions. Our results demonstrate that microbial predators eavesdrop on chemical communication among their metazoan prey to regulate morphogenesis, providing a striking example of predator-prey coevolution. We anticipate that these findings will have broader implications for understanding other interkingdom interactions involving nematodes, which are found in almost any ecological niche on Earth. PMID:23246407

Hsueh, Yen-Ping; Mahanti, Parag; Schroeder, Frank C; Sternberg, Paul W

2012-12-13

107

Serological detection of circulating Angiostrongylus vasorum antigen- and parasite-specific antibodies in dogs from Poland.  

PubMed

Dogs infected with Angiostrongylus vasorum, a potentially lethal parasite living in the heart and pulmonary arteries, may present severe respiratory and neurological sings and coagulopathies. Its occurrence is increasingly reported from various European countries, but little is known about its presence in Poland. In this first large-scale survey, 3,345 sera from polish dogs attending veterinary clinics in different parts of Poland for various reasons were collected and tested by an ELISA for the detection of circulating antigen of A. vasorum and by a separate (n = 17, 95% Confidence Intervals, CI: 0.30–0.81 %) of the animals were positive in both ELISAs, while 0.78 % (n = 26, CI: 0.51–1.14 %) of the tested dogs were antigen- positive only and 1.29 % (n = 43, CI: 0.93–1.73 %) were positive for specific antibodies only. Regions with antigen- and antibody-positive animals were overlapping and distributed over the whole area of the country, with approximately one third of positives close to the Baltic Sea, and a limited number of cases close to the German border. These results confirm the occurrence of A. vasorum in dogs originating from different parts of Poland. A. vasorum serology presents significant advantages (diagnosis before patency, single serum sample instead of repeated faecal samples, rapidity and affordability particularly in case of large number of samples), and it can be considered a valid alternative for diagnosis in individuals and in epidemiological studies. PMID:23779223

Schnyder, Manuela; Schaper, Roland; Pantchev, Nikola; Kowalska, Dagmara; Szwedko, Aleksandra; Deplazes, Peter

2013-08-01

108

Autochtonous infection of dogs and slugs with Angiostrongylus vasorum in Hungary.  

PubMed

On the course of a helminthological survey of the dogs of Baranya County, Hungary Angiostrongylus vasorum infection was detected in two asymptomatic dogs. Identification of the parasite was based on morphology of the first-stage larvae (L1) isolated from droppings, and successful experimental infection with first stage larvae to laboratory reared Discus rotundatus and Lissachatina fulica snails, in order to exclude species of the family Filaroididae that have similar larvae to A. vasorum. While angiostrongylosis is widespread among foxes, this is the first report of A. vasorum infection in housedog in Hungary. In gardens, where infected dogs were being kept 91 specimens of 6 species of limacid and arionid slugs were collected of which 5 specimens of Arion lusitanicus were found to carry larvae of A. vasorum. Dogs usually do not ingest such large slugs willingly. Frogs are known to act as paratenic hosts in the life cycle of A. vasorum. Since one of the infected dogs harboured also infection with the intestinal trematode Alaria alata, of which frogs certainly play the role of the second intermediate host, therefore it is assumed that in this case the dog became infected with A. vasorum by eating frogs. PMID:20947255

Majoros, Gábor; Fukár, Orsolya; Farkas, Róbert

2010-09-22

109

Intrathecal synthesis of IgE in children with eosinophilic meningoencephalitis caused by Angiostrongylus cantonensis  

PubMed Central

Background Eosinophilic meningoencephalitis caused by the helminth Angiostrongylus cantonensis, is an emerging infectious disease in America. The objective of this paper was to determine if the intrathecal synthesis of immunoglobulin E is produced during the acute phase of the disease. Methods Thirteen patients, mean age 4.5 years were studied; a diagnostic lumbar puncture was performed and serum samples taken. Immunoglobulin E (IgE) in serum and in cerebrospinal fluid (CSF) was quantified by nephelometry. Control patients had other infections or other neurological diseases. Results The mean cell count in the CSF was 500 × 10-6 cells/L and of these 23% were eosinophils. In blood the eosinophils were 13%. The chief symptoms of the patients were migraine, vomiting and fever and 50% presented some meningeal signs. IgE intrathecal synthesis analyzed by the corresponding quotient diagram (Reibergram) was observed in all patients. No intrathecal IgE synthesis was seen in control patients. Conclusion Intrathecal synthesis of IgE demonstrates the participation of this immunoglobulin in the destruction of the third stage larvae of the parasite in the CSF. The test should be considered in our environment as a tool to aid diagnosis.

Padilla-Docal, Barbara; Dorta-Contreras, Alberto J; Bu-Coifiu-Fanego, Raisa; Hernandez, Hermes Fundora; Barroso, Jesus Callol; Sanchez-Martinez, Consuelo

2008-01-01

110

Angiostrongylus cantonensis: experimental study on the susceptibility of apple snails, Pomacea canaliculata compared to Pila polita.  

PubMed

Six groups (15 snails/group) of Pomacea canaliculata and Pila polita were infected orally with 0 (control), 200, 400, 800, 1600 and 3200 first-stage Angiostrongylus cantonensis larvae (L1). The respective mean+/-SD third stage larvae (L3) worm recovery 1-month post-infection (p.i.) for P. canaliculata was 0, 1.4+/-5.42 (0.7%), 0.13+/-0.35 (0.03%), 0.07+/-0.26 (0.009%), 0.07+/-0.26 (0.004%), 0, and for P. polita 0, 64.33+/-21.38 (32.25%), 115.36+/-36.82 (28.93%), 265.33+/-90.01 (33.27%), 471.33+/-92.98 (29.60%) and 849.00+/-243.23 (26.61%). The susceptibility of A. cantonensis in P. polita was dose-dependent (p<0.001). In the three groups (nine snails/group) of P. polita given 500 L1, we studied the distribution of L3 in the internal organs (i.e., foot, head+esophagus, kidney, albumin gland, mantle, intestine, digestive gland) and found the highest density after 1, 2 and 3 months p.i. in the mantle at 29.37%, 31.09% and 37.45%. The infection rate in P. canaliculata was too low to study distribution rates. PMID:18154954

Tesana, Smarn; Srisawangwong, Tuanchai; Sithithaworn, Paiboon; Laha, Thewarach

2007-11-19

111

Loop-mediated isothermal amplification: rapid detection of Angiostrongylus cantonensis infection in Pomacea canaliculata  

PubMed Central

Background Angiostrongylus cantonensis is a zoonotic parasite that causes eosinophilic meningitis in humans. The most common source of infection with A. cantonensis is the consumption of raw or undercooked mollusks (e.g., snails and slugs) harbouring infectious third-stage larvae (L3). However, the parasite is difficult to identify in snails. The purpose of this study was to develop a quick, simple molecular method to survey for A. cantonensis in intermediate host snails. Findings We used a loop-mediated isothermal amplification (LAMP) assay, which was performed using Bst DNA polymerase. Reactions amplified the A. cantonensis 18S rRNA gene and demonstrated high sensitivity; as little as 1 fg of DNA was detected in the samples. Furthermore, no cross-reactivity was found with other parasites such as Toxoplasma gondii, Plasmodium falciparum, Schistosoma japonicum, Clonorchis sinensis, Paragonimus westermani and Anisakis. Pomacea canaliculata snails were exposed to A. cantonensis first-stage larvae (L1) in the laboratory, and L3 were observed in the snails thirty-five days after infection. All nine samples were positive as determined by the LAMP assay for A. cantonensis, which was identified as positive by using PCR and microscopy, this demonstrates that LAMP is sensitive and effective for diagnosis. Conclusions LAMP is an appropriate diagnostic method for the routine identification of A. cantonensis within its intermediate host snail P. canaliculata because of its simplicity, sensitivity, and specificity. It holds great promise as a useful monitoring tool for A. cantonensis in endemic regions.

2011-01-01

112

Eosinophilic meningoencephalitis due to Angiostrongylus cantonensis as the cause of death in captive non-human primates.  

PubMed

Fatal eosinophilic meningoencephalitis due to Angiostrongylus cantonensis is reported in captive non-human primates. A howler monkey (Alouatta caraya) at the Audubon Park and Zoological Gardens, New Orleans, LA, died 21 days after initial clinical symptoms. A white-handed gibbon (Hylobates lar) died at the Ardastra Gardens and Zoo, Nassau, Bahamas, 17 days after onset of symptoms. Both had access to free-ranging gastropods within the zoos. These are the first reported cases of natural infection by A. cantonensis in non-human primates in the western hemisphere. PMID:2301708

Gardiner, C H; Wells, S; Gutter, A E; Fitzgerald, L; Anderson, D C; Harris, R K; Nichols, D K

1990-01-01

113

EOSINOPHILIC MENINGITIS CAUSED BY ANGIOSTRONGYLUS CANTONENSIS ASSOCIATED WITH EATING RAW SNAILS: CORRELATION OF BRAIN MAGNETIC RESONANCE IMAGING SCANS WITH CLINICAL FINDINGS  

Microsoft Academic Search

Angiostrongylus cantonensis is the most common cause of eosinophilic meningitis worldwide. Human infection occurs after ingestion of the worms in raw snails or fish that serve as intermediate hosts. Two outbreaks of central nervous system infection with A. cantonensis occurred in Kaoshiung, Taiwan, during 1998 and 1999 among Thai laborers who ate raw snails. A detailed clinical studies of 17

HUNG-CHIN TSAI; YUNG-CHING LIU; CALVIN M. KUNIN; PING-HONG LAI; SUSAN SHIN-JUNG LEE; YAO-SHEN CHEN; SHUE-REN WANN; WEI-RU LIN; CHUN-KAI HUANG; LUO-PING GER; HSI-HSUN LIN

2003-01-01

114

Combined Treatment with Interleukin12 and Mebendazole Lessens the Severity of Experimental Eosinophilic Meningitis Caused by Angiostrongylus cantonensis in ICR Mice  

Microsoft Academic Search

Angiostrongylus cantonensis is the major cause of eosinophilic meningoencephalitis cases in Taiwan. Mice were orally infected with 35 infective larvae. One group of mice were given a single dose of mebendazole (20 mg\\/kg of body weight) per os at various times and examined at 14 days postinfection (dpi) for worm recovery rate and pathological studies. A 94 to 97% reduction

Wen-Yuan Du; Jiunn-Wang Liao; Chia-Kwung Fan; Kua-Eyre Su

2003-01-01

115

Improved molecular detection of Angiostrongylus cantonensis in mollusks and other environmental samples with a species-specific ITS1-based TaqMan assay  

Technology Transfer Automated Retrieval System (TEKTRAN)

Angiostrongylus cantonensis is the most common cause of human eosinophilic meningitis. Humans can become infected by ingesting food items contaminated with the third-stage infectious larvae released from infected mollusks as well as by ingesting mollusks or paratenic hosts carrying the infectious st...

116

Tropical nematode diversity: vertical stratification of nematode communities in a Costa Rican humid lowland rainforest  

Microsoft Academic Search

Comparisons of nematode communities among ecosystems have indicated that, unlike many organisms, nematode communities have less diversity in the tropics than in temperate ecosystems. There are, however, few studies of tropical nematode diversity on which to base conclusions of global patterns of diversity. This study reports an attempt to estimate nematode diversity in the lowland tropical rainforest of La Selva

T. O. POWERS; D. A. NEHER; P. MULLIN; A. ESQUIVEL; R. M. GIBLIN-DAVIS; N. KANZAKI; S. P. STOCK; M. M. MORA; L. URIBE-LORIO

2009-01-01

117

A review on the role of predatory soil nematodes in the biological control of plant parasitic nematodes  

Microsoft Academic Search

Predatory nematodes feed on soil microorganisms including plant parasitic nematodes. They reduce populations of plant parasitic nematodes in virtually all soils because of their constant association with plant parasitic nematodes in the rhizosphere, and also release nutrients in plant-available forms, which may enable plants to better withstand nematode burden on their roots. Predation by nematodes of the orders Mononchida, Diplogasterida,

Zakaullah Khan; Young Ho Kim

2007-01-01

118

Cytogenetic studies and karyotype nomenclature of three wild canid species: maned wolf (Chrysocyon brachyurus), bat-eared fox (Otocyon megalotis) and fennec fox (Fennecus zerda)  

Microsoft Academic Search

We have analysed the chromosomes of three wild and endangered canid species: the maned wolf (Chrysocyon brachyurus), the bat-eared fox (Otocyon megalotis) and the fennec fox (Fennecuszerda) using classical and molecular cytogenetic methods. For the first time detailed and encompassing descriptions of the chromosomes are presented including the chromosomal assignment of nucleolar organizer regions and the 5S rRNA gene cluster.

A. Pie?kowska-Schelling; C. Schelling; M. Zawada; F. Yang; M. Bugno; M. Ferguson-Smith

2008-01-01

119

Entomopathogenic Nematodes and Methods of Their Use.  

National Technical Information Service (NTIS)

The invention generally relates to a novel strain of entomopathogenic nematode belonging to Heterorhabditis bacteriophora, named GPS11. The GPS11 strain is equal or better than existing nematode strains in its virulence toward many insect species, and sho...

P. Grewal

2005-01-01

120

Nematodes of Plants and Soils: Genus 'Ditylenchus'.  

National Technical Information Service (NTIS)

Partial Contents: Taxonomic Review of Nematodes of the Genus; Genetic Basis and Inheritance of Pathogenicity; Development and Propagation of Nematodes of the Genus Ditylenchus; Physiological Reaction of Ditylenchus; Plants as Medium of Habitat for stem In...

V. G. Gubina

1988-01-01

121

Application of recombinant SMR-domain containing protein of angiostrongylus cantonensis in immunoblot diagnosis of human angiostrongyliasis.  

PubMed

The aim of this study was to find novel proteins expressed from an Angiostrongylus cantonensis adult female worm cDNA library for serodiagnosis of angiostrongyliasis. An immuno-dominant clone, fAC22, was identified by immunoscreening with pooled positive sera from proven angiostrongyliasis patients. The clone contained an open reading frame of 2,136 bp encoding a 80.5 kDa protein with a predicted isoelectric point of 5.8. The deduced amino acid sequence (712 amino acids) contained the conserved domain of Small mutS related (Smr) superfamily protein, with similarity with the Smr domain protein of Brugia malayi. The fusion His-tagged 81 kDa recombinant protein expressed as inclusion body in Escherichia coli was solubilized and purified by Ni-affinity chromatography for use in immunoblot analysis. Its sensitivity, specificity, positive and negative predictive values in immunodiagnostic test was 93.5, 91.5, 79.0 and 97.5%, respectively. Although some cross-reactivity of the antigen was observed among gnathostomiasis, bancroftian filariasis, ascariasis, echinococcosis, paragonimiasis and opisthorchiasis, sera from 14 other infections were all negative. These data indicate its possible application in immunodiagnosis of clinically suspected angiostrongyliasis. Key words: Angiostrongylus cantonensis,eosinophilic meningitis, recombinant fusion protein, immunodiagnosis PMID:21073053

Vitta, Apichat; Yoshino, Timothy P; Kalambaheti, Thareerat; Komalamisra, Chalit; Waikagul, Jitra; Ruangsittichai, Jiraporn; Dekumyoy, Paron

2010-07-01

122

Application and commercialization of nematodes.  

PubMed

While nematodes are most commonly known for their negative impact on plants, animals, and humans, there are a number of species which are commercially explored. This review highlights some of the most important success stories for the application of nematodes. They are used as bioindicators in ecological and toxicity studies, as model organisms for elucidating fundamental biological questions and for high throughput screening of drugs. Besides these indirect uses, direct applications include the use of Beddingia siricidicola against a major forest pest and the commercialization of Steinernema, Heterorhabditis, and Phasmarhabditis as biological pest control products. New directions for the commercialization of nematodes are the use as living food, specifically loaded with essential nutrients for various fish and shrimp larvae. Even human parasites or closely related species have been successfully used for curing autoimmune disorders and are currently in the process of being developed as drugs. With the striving development of life sciences, we are likely to see more applications for nematodes in the future. A prerequisite is that we continue to explore the vast number of yet undiscovered nematode species. PMID:23780582

Peters, Arne

2013-06-19

123

Nematodes as Biological Control Agents of Insects  

NSDL National Science Digital Library

Entomogenous nematodes are covered here on a short general page that includes several links, one of which is to a PDF with more extensive bio-control with nematodes information. Nine families of nematodes are mentioned which include species that sterilize, alter behavior, or simply kill the insect host.

0002-11-30

124

Diversity and prevalence of metastrongyloid nematodes infecting the red panda ( Ailurus fulgens) in European zoos  

Microsoft Academic Search

Metastrongyloid induced pneumonia has been described sporadically in the red panda (Ailurus fulgens). Early descriptions in pandas recently imported to the USA from China involved parasites morphologically similar to Angiostrongylus spp. and Crenosomatidae. More recently, four cases of severe verminous pneumonia associated with Angiostrongylus vasorum have been reported from European zoos. A coprological survey of the red panda population within

Mads F. Bertelsen; Frederik Meyland-Smith; Jakob L. Willesen; Ryan Jefferies; Eric R. Morgan; Jesper Monrad

2010-01-01

125

Antioxidant enzymes in phytoparasitic nematodes.  

PubMed

Presence of different antioxidant enzymes, such as superoxide dismutase (SOD), catalase, and ascorbate, p-phenilendiamine-pyrocathecol (PPD-PC), o-dianisidine, and guaiacol isoperoxidases, was shown in the phytoparasific nematode species Meloidogyne incognita, M. hapla, Globodera rostochiensis, G. pallida, Heterodera schachtii, H. carotae, and Xiphinema index. The activity of the enzymes tested differed among the life stages examined. SOD was present in cysts but was not detected in Meloidogyne egg masses. Catalase activity of Meloidogyne females was higher than that of preparasitic stages and cyst-nematode females. For the first time, ascorbate peroxidase was found to occur commonly in phytoparasitic nematodes, with the highest activity in the invading life-stages. In all the life stages examined, the antioxidant enzyme activities of M. hapla were markedly higher than those of M. incognita. Glutathione peroxidase was not found in the species examined. PMID:19274144

Molinari, S; Miacola, C

1997-06-01

126

Complete sequence of the Tibetan Mastiff mitochondrial genome and its phylogenetic relationship with other Canids ( Canis, Canidae).  

PubMed

In this study, the complete sequence of the Tibetan Mastiff mitochondrial genome (mtDNA) was determined, and the phylogenetic relationships between the Tibetan Mastiff and other species of Canidae were analyzed using the coyote (Canis latrans) as an outgroup. The complete nucleotide sequence of the Tibetan Mastiff mtDNA was 16 710 bp, and included 22 tRNA genes, 2S rRNA gene, 13 protein-coding genes and one non-coding region (D-loop region), which is similar to other mammalian mitochondrial genomes. The characteristics of the protein-coding genes, non-coding region, tRNA and rRNA genes among Canidae were analyzed in detail. Neighbor-joining and maximum-parsimony trees of Canids constructed using 12 mitochondrial protein-coding genes showed that as the coyotes and Tibetan wolves clustered together, so too did the gray wolves and domestic dogs, suggesting that the Tibetan Mastiff originated from the gray wolf as did other domestic dogs. Domestic dogs clustered into four clades, implying at least four maternal origins (A to D). The Tibetan Mastiff, which belongs to clade A, appears to be closely related to the Saint Bernard and the Old English Sheepdog. PMID:22440697

Li, Yinxia; Li, Qifa; Zhao, Xingbo; Xie, Zhuang; Xu, Yinxue

2011-01-01

127

Nematode Functional Genomics  

PubMed Central

Alan Coulson has two main roles at the Sanger Centre, revolving around the worm and the human genome projects. Although the worm sequence is essentially finished, the tidying-up of that and the physical map is ongoing. There is also a continuous need for communication with the worm field with regard to information and materials relating to the sequence project. For example, the cosmids and YACs of the physical map continue to be, as they have been for many years now, an extremely powerful resource, and the Sanger Centre distributes in the order of 500 clones per month to the community. Alan is team leader of the worm functional genomics group, which is currently small but will be expanding shortly. Patricia Kuwabara is a member of the team and a description of their activities can be found below. The Human Genome Project is sequencing mapped PAC and BAC clones. Alan's primary involvement is with the team that is responsible for subcloning the 10 000 or so clones that will be required to complete the one-third of the genome sequence to be contributed by the Sanger Centre. Patricia Kuwabara has been using Caenorhabditis elegans as a model for understanding how protein–protein interactions regulate cell-to-cell signalling. Her research has focused on understanding the molecular mechanisms underlying the genetics of C. elegans sex determination. This work has led into a study of regulated proteolysis involving calpains and also into the roles of the multiple C. elegans Patched proteins, which in other organisms have been shown to be receptors for the Hedgehog morphogen. In addition, the group is taking advantage of the completion of the C. elegans genome sequence to develop whole genome DNA microarrays for expression profiling. At the Sanger Centre, DNA microarrays are providing opportunities to examine how development and physiology are regulated globally, because most nematode genes have now been identified at the sequence level. The group are being assisted in this endeavour by Dr Stuart Kim (Stanford, CA).

2000-01-01

128

ORAL NEMATODE INFECTION OF TARANTULAS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Oral nematode infection of Theraphosidae spiders, known as tarantulas, has been recently identified from several collections in the UK and mainland Europe. The disease has also been seen in captive and wild spiders from the Americas, Asia and Africa. Spider symptoms are described from anorexia until...

129

Nematode Symbiont for Photorhabdus asymbiotica  

PubMed Central

Photorhabdus asymbiotica is an emerging bacterial pathogen that causes locally invasive soft tissue and disseminated bacteremic infections in the United States and Australia. Although the source of infection was previously unknown, we report that the bacterium is found in a symbiotic association with an insect-pathogenic soil nematode of the genus Heterorhabditis.

Joyce, Susan A.; Clarke, David J.; ffrench-Constant, Richard H.; Nimmo, Graeme R.; Looke, David F.M.; Feil, Edward J.; Pearce, Lucy; Waterfield, Nick R.

2006-01-01

130

Acute neurological signs as the predominant clinical manifestation in four dogs with Angiostrongylus vasorum infections in Denmark.  

PubMed

Four dogs with acute neurological signs caused by haemorrhages in the central nervous system were diagnosed with Angiostrongylus vasorum infection as the underlying aetiology. Two dogs presented with brain lesions, one dog with spinal cord lesions and one with lesions in both the brain and spinal cord. Only one dog presented with concurrent signs of classical pulmonary angiostrongylosis (respiratory distress, cough), and only two dogs displayed overt clinical signs of haemorrhages. Results of coagulation assays were inconsistent. Neurological signs reflected the site of pathology and included seizures, various cranial nerve deficits, vestibular signs, proprioceptive deficits, ataxia and paraplegia. One dog died and three were euthanised due to lack of improvement despite medical treatment. This emphasises canine angiostrongylosis as a potential cause of fatal lesions of the central nervous system and the importance of including A. vasorum as a differential diagnosis in young dogs with acute neurological signs in Denmark. PMID:21711538

Gredal, Hanne; Willesen, Jakob L; Jensen, Henrik E; Nielsen, Ole L; Kristensen, Annemarie T; Koch, Jørgen; Kirk, Rikke K; Pors, Susanne E; Skerritt, Geoff C; Berendt, Mette

2011-06-28

131

Molecular Mechanisms of the Interaction Between Nematode-Trapping Fungi and Nematodes: Lessons From Genomics  

Microsoft Academic Search

\\u000a Soil contains a diverse range of fungi that are parasites on nematodes. These fungi include the nematode-trapping fungi that\\u000a are dependent on specific hyphal structures on or in which nematodes can be trapped mechanically or by adhesion. The interests\\u000a of studying these fungi come from their potential use as biological control agents against plant- and animal-parasitic nematodes.\\u000a Studies on the

Anders Tunlid; Dag Ahrén

132

Screens and assays for agents useful in controlling parasitic nematodes  

US Patent & Trademark Office Database

The invention provides a method of identifying anti-nematode compounds and further provides transgenic nematodes that may be used to practice the method. In particular, the invention provides a screen for compounds that inhibit a nematode secretion pathway e.g, compounds that inhibit the secretion of proteins by nematodes. The transgenic nematodes express reporters for nematode secreted proteins. In preferred embodiments of the invention the screen is performed using C. elegans, i.e., certain embodiments of the invention utilize C. elegans and C. elegans secretory pathways as a model system for parasitic nematodes and parasitic nematode secretion pathways. The invention also provides pharmaceutical compositions that may be used in the treatment and prevention of nematode infection in humans and animals and anti-nematode agents that may be used to protect plants from plant-parasitic nematodes. In addition, the invention provides a genetic screen for identifying additional targets for anti-nematode compounds.

2006-06-20

133

Metabolism of plant sterols by nematodes  

Microsoft Academic Search

Parasitic nematodes do not biosynthesize sterolsde novo and therefore possess a nutritional requirement for sterol, which must be obtained from their hosts. Consequently, the metabolism\\u000a of phytosterols by plant-parasitic nematodes is an important process with potential for selective exploitation. The sterol\\u000a compositions of several species of plant-parasitic nematodes were determined by capillary gas chromatography-mass spectrometry\\u000a and compared with the sterol

David J. Chitwood; William R. Lusby

1991-01-01

134

NEMBASE: a resource for parasitic nematode ESTs  

Microsoft Academic Search

NEMBASE (available at http:\\/\\/www.nematodes.org) is a publicly available online database providing access to the sequence and associated meta-data currently being generated as part of the Edinburgh- Wellcome Trust Sanger Institute parasitic nematode EST project. NEMBASE currently holds ~100 000 sequences from 10 different species of nematode. To facilitate ease of use, sequences have been pro- cessed to generate a non-redundant

John Parkinson; Claire Whitton; Ralf Schmid; Marian Thomson; Mark Blaxter

2004-01-01

135

Ecology and evolution of soil nematode chemotaxis.  

PubMed

Plants influence the behavior of and modify community composition of soil-dwelling organisms through the exudation of organic molecules. Given the chemical complexity of the soil matrix, soil-dwelling organisms have evolved the ability to detect and respond to these cues for successful foraging. A key question is how specific these responses are and how they may evolve. Here, we review and discuss the ecology and evolution of chemotaxis of soil nematodes. Soil nematodes are a group of diverse functional and taxonomic types, which may reveal a variety of responses. We predicted that nematodes of different feeding guilds use host-specific cues for chemotaxis. However, the examination of a comprehensive nematode phylogeny revealed that distantly related nematodes, and nematodes from different feeding guilds, can exploit the same signals for positive orientation. Carbon dioxide (CO(2)), which is ubiquitous in soil and indicates biological activity, is widely used as such a cue. The use of the same signals by a variety of species and species groups suggests that parts of the chemo-sensory machinery have remained highly conserved during the radiation of nematodes. However, besides CO(2), many other chemical compounds, belonging to different chemical classes, have been shown to induce chemotaxis in nematodes. Plants surrounded by a complex nematode community, including beneficial entomopathogenic nematodes, plant-parasitic nematodes, as well as microbial feeders, are thus under diffuse selection for producing specific molecules in the rhizosphere that maximize their fitness. However, it is largely unknown how selection may operate and how belowground signaling may evolve. Given the paucity of data for certain groups of nematodes, future work is needed to better understand the evolutionary mechanisms of communication between plant roots and soil biota. PMID:22527058

Rasmann, Sergio; Ali, Jared Gregory; Helder, Johannes; van der Putten, Wim H

2012-04-25

136

Direct nematode predation in the marine nematode Synonchiella spiculora (Selachinematidae: Nematoda)  

Microsoft Academic Search

This study documents direct evidence of nematode predation in the free living marine nematode Synonchiella spiculora recorded in the intertidal of Santa Clara beach in the Upper Gulf of California, Mexico. The heavily armored buccal cavity that allows S. spiculora to break larger particles and ingest other organisms is characteristic of nematodes categorized as predators and omnivores (Wieser, 1953). The

Tiago J. Pereira; Arely Martínez-Arce; Ruth Gingold; Axayácatl Rocha-Olivaresb

2009-01-01

137

Protein variation in cyst nematodes  

Microsoft Academic Search

The magnitude of the protein divergence strongly suggests that Globodera<\\/u>rostochiensis<\\/u> and G.<\\/u>pallida<\\/u> have experienced hardly any morphological evolution during a time period of millions of years (chapter II). These morphologically nearly indistinguishable potato cyst nematode species are discriminated from one another by 70 % of their proteins revealed by two dimensional gel electrophoresis (2-DGE), which definitively excludes a recent divergence

J. Bakker

1987-01-01

138

Neurobiology of plant parasitic nematodes  

Microsoft Academic Search

The regulatory constraints imposed on use of chemical control agents in agriculture are rendering crops increasingly vulnerable\\u000a to plant parasitic nematodes. Thus, it is important that new control strategies which meet requirements for low toxicity to\\u000a non-target species, vertebrates and the environment are pursued. This would be greatly facilitated by an improved understanding\\u000a of the physiology and pharmacology of these

Lindy Holden-DyeR; R. J. Walker

2011-01-01

139

Functional genomics of nematode acetylcholinesterases.  

PubMed

Acetylcholine is the major excitatory neurotransmitter controlling motor activities in nematodes, and the enzyme which hydrolyses and inactivates acetylcholine, acetylcholinesterase, is thus essential for regulation of cholinergic transmission. Different forms of acetylcholinesterase are encoded by multiple genes in nematodes, and analysis of the pattern of expression of these genes in Caenorhabditis elegans suggests that they perform non-redundant functions. In addition, many parasitic species which colonise host mucosal surfaces secrete hydrophilic variants of acetylcholinesterase, although the function of these enzymes is still unclear. Acetylcholinesterases have a history as targets for therapeutic agents against helminth parasites, but anti-cholinesterases have been used much more extensively as pesticides, for example to control crop damage and ectoparasitic infestation of livestock. The toxicity associated with these compounds (generally organophosphates and carbamates) has led to legislation to withdraw them from the market or restrict their use in many countries. Nevertheless, acetylcholinesterases provide a good example of a neuromuscular target enzyme in helminth parasites, and it may yet be possible to develop more selective inhibitors. In this article, we describe what is known about the structure and function of vertebrate cholinesterases, illustrate the molecular diversity and tissue distribution of these enzymes in C. elegans, and discuss to what extent this may represent a paradigm for nematodes in general. PMID:16569291

Selkirk, M E; Lazari, O; Matthews, J B

2005-01-01

140

Crab-eating fox (Cerdocyon thous), a South American canid, as a definitive host for Hammondia heydorni.  

PubMed

Hammondia heydorni is a cyst forming coccidia closely related to other apicomplexans, such as Toxoplasma gondii, Neospora caninum and Hammondia hammondi with a two-host life cycle. Dogs and other canids as red foxes (Vulpes vulpes) and coyotes (Canis latrans) may serve as definitive hosts for H. heydorni. Sporulated oocysts are infective for cattle, sheep and goats, which may serve as intermediate hosts. Herein, we describe the ability of crab-eating fox (Cerdocyon thous), a wild carnivore that is commonly found from northern Argentina to northern South America, to serve as definitive host of H. heydorni. The whole masseter muscle and brain from two 2-year-old bovines were collected, minced and pooled together for the fox infection. The bovine pooled tissues were equally administered to four foxes, in two consecutive days. Two foxes shed subspherical unsporulated oocysts measuring 10-15microm, after 8 and 9 days post-infection, respectively. One of the foxes eliminated oocysts for 5 days, while the other fox shed oocysts for 9 days. A DNA sample of oocysts detected at each day of oocyst elimination was tested by two PCRs, one of them carried out employing primers directed to the common toxoplasmatiid 18S and 5.8S ribosomal RNA coding genes (PCR-ITS1) and the other based on heat-shock protein 70kDa coding gene (PCR-HSP70). These samples were also submitted to a N. caninum specific nested-PCR protocol based on a N. caninum specific gene (Nc5-nPCR). All of them were positive by PCR-ITS1 and PCR-HSP70 but negative by Nc5-nPCR. The PCR-ITS1 and PCR-HSP70 nucleotide sequences amplified from the oocysts shed by the foxes revealed 100% identity with homologous sequences of H. heydorni. In conclusion, it is clear that H. heydorni also uses the crab-eating fox as a definitive host. The crab-eating fox is usually reported to live in close contact with livestock in several regions of Brazil. Therefore, it is reasonable to infer that such carnivores may play an important role in the sylvatic and domestic cycles of H. heydorni infection. PMID:19303215

Soares, Rodrigo M; Cortez, Luiz R P B; Gennari, Solange M; Sercundes, Michelle K; Keid, Lara B; Pena, Hilda F J

2009-02-12

141

Soil nematode biodiversity in terrestrial ecosystems  

Microsoft Academic Search

A review of the literature on nematode diversity (=number of species identified) of soil inhabiting nematodes was undertaken and analysed with regard to distance from the equator, vegetation type and sampling effort. After applying a correction factor for sampling effort the results indicated that species richness was greatest in temperate broadleaf forest (61.7 species per sample) followed by cultivated soil,

Brian Boag; Gregor W. Yeates

1998-01-01

142

Free-living and Plant-Parasitic Nematodes (Roundworms)  

NSDL National Science Digital Library

This lesson introduces learners to the world of nematodes (roundworms). Learners construct Baermann funnels to extract nematodes from soil and learn to differentiate stylet-bearing nematodes (most likely plant parasites) from free-living nematodes. This lesson includes background information, study questions with answers for learners, and diagrams. Dissecting and compound microscopes are required (not included in cost of materials).

Tylka, Gregory L.; Jasalavich, Claudia A.

2011-01-01

143

Attraction of Nematodes to Living Mycelium of Nematophagous Fungi  

Microsoft Academic Search

Methods were designed to detect attraction and repulsion of nematodes by fungi and determine the attraction intensity of different fungi. Of 23 fungi tested, 15 attracted the bacteria-feeding nematode Panagrellus redivivus. Of the 14 nematophagous fungi tested, ten attracted and one repelled nematodes, whereas three were neutral. Among nine non- nematophagous fungi, five attracted nematodes. In general, the attraction intensity

HANS-BoRJE JANSSON; BIRGIT NORDBRING-HERTZ

1979-01-01

144

Relationships between Burkholderia populations and plant parasitic nematodes in sugarcane  

Microsoft Academic Search

It is suggested that the bacterium Burkholderia tropica might be used to reduce nematode damage in sugarcane by promoting certain nematode species to create a less pathogenic nematode community. This suggestion arises from an investigation of the plant parasitic nematodes and their relationship with Burkholderia species along a sugarcane row. During the course of this analysis sugarcane root and soil

J. Omarjee; J. Balandreau; V. W. Spaull; P. Cadet

2008-01-01

145

Compositions and methods using RNA interference for control of nematodes  

US Patent & Trademark Office Database

The present invention concerns double stranded RNA compositions and transgenic plants capable of inhibiting expression of essential genes in parasitic nematodes, and methods associated therewith. Specifically, the invention relates to the use of RNA interference to inhibit expression of a target essential parasitic nematode gene selected from the group consisting of a parasitic nematode cytosolic chaperonin gene, a parasitic nematode gene encoding heat shock protein-90, a parasitic nematode gene homologous to the C. elegans Y65B4BR.5a gene, and a parasitic nematode gene homologous to a C. elegans pat-10 gene, and relates to the generation of plants that have increased tolerance to parasitic nematodes.

2009-11-24

146

Nematodes associated with Dryocoetes uniseriatus (Coleoptera: Scolytidae).  

PubMed

We examined the nematode fauna associated with a species of bark beetle, Dryocoetes uniseriatus Eggers, as part of a biodiversity survey of forest beetle-associated nematodes. Collections were made in a pine stand at an experimental forest station in Ibaraki, Japan, from April to July of 2011; we examined the nematode association in 273 insects collected during this time. In total, 68% of the insects were associated with at least one species of nematode. Six species of nematodes, including two phoretic microbe feeders (Bursaphelenchus rainulfi Braasch & Burgermeister and Micoletzkya sp.), one insect parasite and nematode predator (Devibursaphelenchus cf. eproctatus), one insect parasite (Contortylenchus sp.), one insect parasite and potential microbe feeder (unidentified rhabditid parasite), and one potential insect parasite and fungal feeder (B. sinensis) were recovered from the beetles. D. cf. eproctatus was enclosed in nematangia on the backsides of the elytra, B. rainulfi was isolated from the backsides of the elytra or enclosed in nematangia, Micoletzkya sp. was isolated from under the elytra, Contortylenchus sp. and a rhabditid parasite parasitized the body cavity, and B. sinensis was found in the digestive tract of the insect. The association patterns of the nematode species varied seasonally, although definitive interactions among species (e.g., segregation, competition) were not observed. PMID:23339788

Shimizu, Ai; Tanaka, Ryusei; Akiba, Mitsuteru; Masuya, Hayato; Iwata, Ryûtarô; Fukuda, Kenji; Kanzaki, Natsumi

2013-02-01

147

Molecular Approaches Toward Resistance to Plant-Parasitic Nematodes  

Microsoft Academic Search

Basic research in molecular plant nematology is expanding the inventory of knowledge that can be applied to provide crop resistance\\u000a to parasitic nematodes in an economically and environmentally beneficial manner. Approaches to trans-genic nematode control\\u000a can be classified as acting (1) on nematode targets, (2) at the nematode—plant interface, and (3) in the plant response. Strategies\\u000a aimed at nematode targets

J. P. McCarter

148

The use of albendazole and diammonium glycyrrhizinate in the treatment of eosinophilic meningitis in mice infected with Angiostrongylus cantonensis.  

PubMed

Angiostrongylus cantonensis (A. cantonensis) infection causes eosinophilic meningitis in humans. Eosinophilia and a Th2-type immune response are the crucial immune mechanisms for eosinophilic meningitis. CD4+CD25+ regulatory T cells (Treg) are involved in the pathogenesis of A. cantonensis. Diammonium glycyrrhizinate (DG) is a compound related to glycyrrhizin (GL), a triterpene glycoside extracted from liquorice root. We investigated the curative effects and probable mechanisms of therapy involving a combination of albendazole and DG in BALB/c mice infected with A. cantonensis, and compared these with therapy involving albendazole and dexamethasone. We analysed survival time, body weight, signs, eosinophil numbers, immunoglobulin E (IgE), interleukin-5 (IL-5), and eotaxin concentrations, numbers and Foxp3 expression of CD4+CD25+ Treg, worm recovery and histopathology. The present results demonstrated that the combination of albendazole and DG could increase survival time more efficiently and relieve neurological dysfunction; decrease weight loss, eosinophil numbers, concentrations of IgE, IL-5 and eotaxin, the number and expression of Foxp3 of CD4+CD25+ Treg; and improve worm recovery and histopathology changes in treated animals, compared with the combination of albendazole and dexamethasone. The observations presented here suggest that the albendazole and dexamethasone combination could be replaced by the combination of albendazole and DG. PMID:22152396

Li, Y; Tang, J-P; Chen, D-R; Fu, C-Y; Wang, P; Li, Z; Wei, W; Li, H; Dong, W-Q

2011-12-13

149

The effect of temperature on the development of Angiostrongylus cantonensis (Chen 1935) in Pomacea canaliculata (Lamarck 1822).  

PubMed

Angiostrongyliasis cantonensis, clinically presented as eosinophilic meningitis, is a snail-borne parasitic disease. We studied the effects of different temperatures on the larval development of Angiostrongylus cantonensis in the freshwater snail Pomacea canaliculata. Six groups of snails were infected and each group was cultured under different temperature conditions. At predefined intervals, four snails from each group were dissected to examine the larval development. The development-time curve of each group was drawn according to the fraction of third-stage larvae present. The developmental time was defined as the time needed until 50% of the first-stage larvae developed into third-stage larvae. A linear regression model was established based on the time (D; in days) and the corresponding temperature (T; in degrees Celsius): DT = 15.04 x D + 262.53. The threshold temperature for larval development was 15.04 degrees C and the thermal constant was 262.53 degree-days. These parameters could be helpful in estimating the number of parasite generations in a year and the impact of climate change on the distribution of A. cantonensis. PMID:16670882

Lv, Shan; Zhou, Xiao-Nong; Zhang, Yi; Liu, He-Xiang; Zhu, Dan; Yin, Wei-Gang; Steinmann, Peter; Wang, Xian-Hong; Jia, Tie-Wu

2006-05-03

150

Ascaroside Signaling is Widely Conserved Among Nematodes  

PubMed Central

Summary Background Nematodes are among the most successful animals on earth and include important human pathogens, yet little is known about nematode pheromone systems. A group of small molecules called ascarosides has been found to mediate mate finding, aggregation, and developmental diapause in Caenorhabditis elegans, but it is unknown whether ascaroside signaling exists outside of the genus Caenorhabditis. Results To determine whether ascarosides are used as signaling molecules by other nematode species, we performed a mass spectrometry-based screen for ascarosides in secretions from a variety of both free-living and parasitic (plant, insect, and animal) nematodes. We found that most of the species analyzed, including nematodes from several different clades, produce species-specific ascaroside mixtures. In some cases, ascaroside biosynthesis patterns appear to correlate with phylogeny, whereas in other cases, biosynthesis seems to correlate with lifestyle and ecological niche. We further show that ascarosides mediate distinct nematode behaviors, such as retention, avoidance, and long-range attraction, and that different nematode species respond to distinct, but overlapping, sets of ascarosides. Conclusions Our findings indicate that nematodes utilize a conserved family of signaling molecules despite having evolved to occupy diverse ecologies. Their structural features and level of conservation are evocative of bacterial quorum sensing, where acyl homoserine lactones (AHLs) are both produced and sensed by many species of Gram-negative bacteria. The identification of species-specific ascaroside profiles may enable pheromone-based approaches to interfere with reproduction and survival of parasitic nematodes, which are responsible for significant agricultural losses and many human diseases worldwide.

Choe, Andrea; von Reuss, Stephan H.; Kogan, Dima; Gasser, Robin B.; Platzer, Edward G.; Schroeder, Frank C.; Sternberg, Paul W.

2012-01-01

151

[Nematodes of humans in the Primorye Territory].  

PubMed

Nematodes occupy the top in the general pattern of human parasitic diseases in the Primorye Territory. In the south of the Far East, there are a total of 28 nematode species that can parasitize man. However, the authors have identified only 8 nematode-induced diseases, such as ascariasis, enterobiasis, toxocariasis, trichocephaliasis, anisakiasis, trichinosis, dirofilariasis, dioctophymosis. The latter has been found only once in the 1920s. According to official statistical data, the proportion of ascariasis and enterobiasis accounted for 43.8 and 53.5% of the total number of helminthiases, respectively. PMID:23805486

Ermolenko, A V; Rumiantseva, E E; Bartkova, A D; Voronok, V M; Poliakova, L F

152

Coprinus comatus Damages Nematode Cuticles Mechanically with Spiny Balls and Produces Potent Toxins To Immobilize Nematodes?  

PubMed Central

We reported recently a unique fungal structure, called the spiny ball, on the vegetative hyphae of Coprinus comatus (O. F. Müll.:Fr.) Pers. Although some observations regarding the role of this structure were presented, its function remained largely unknown. In this study, we showed that purified (isolated and washed) spiny balls could immobilize and kill the free-living nematode Panagrellus redivivus Goodey highly efficiently. Scanning electron microscopy studies illustrated that the spiny structure damaged the nematode cuticle, suggesting the presence of a mechanical force during the process of nematode immobilization. Severe injuries on nematode cuticles caused the leakage of inner materials of the nematodes. When these structures were ground in liquid nitrogen, their killing efficacy against nematodes was lost, indicating that the shape and the complete structure of the spiny balls are indispensable for their function. However, extraction with organic solvents never lowered their activity against P. redivivus, and the extracts showed no obvious effect on the nematode. We also investigated whether C. comatus was able to produce toxins which would aid in the immobilization of nematodes. In total, we identified seven toxins from C. comatus that showed activity to immobilize the nematodes P. redivivus and Meloidogyne incognita (Kofoid et White) Chitwood. The chemical structures of these toxins were identified with nuclear magnetic resonance, mass spectrometry, infrared, and UV spectrum analysis. Two compounds were found to be novel. The toxins found in C. comatus are O-containing heterocyclic compounds.

Luo, Hong; Liu, Yajun; Fang, Lin; Li, Xuan; Tang, Ninghua; Zhang, Keqin

2007-01-01

153

Cytogenetic studies and karyotype nomenclature of three wild canid species: maned wolf (Chrysocyon brachyurus), bat-eared fox (Otocyon megalotis) and fennec fox (Fennecus zerda).  

PubMed

We have analysed the chromosomes of three wild and endangered canid species: the maned wolf (Chrysocyon brachyurus), the bat-eared fox (Otocyon megalotis) and the fennec fox (Fennecuszerda) using classical and molecular cytogenetic methods. For the first time detailed and encompassing descriptions of the chromosomes are presented including the chromosomal assignment of nucleolar organizer regions and the 5S rRNA gene cluster. We propose a karyotype nomenclature with ideograms including more than 300 bands per haploid set for each of these three species which will form the basis for further research. In addition, we propose four basic different patterns of karyotype organization in the family Canidae. A comparison of these patterns with the most recent molecular phylogeny of Canidae revealed that the karyotype evolution of a species is not always strongly connected with its phylogenetic position. Our findings underline the need and justification for basic cytogenetic work in rare and exotic species. PMID:18544923

Pie?kowska-Schelling, A; Schelling, C; Zawada, M; Yang, F; Bugno, M; Ferguson-Smith, M

2008-05-07

154

Nematodes  

NSDL National Science Digital Library

Genetically modified foods have caused a lot of controversy among environmentalists. Some worry that these so-called "Frankenfoods" might disrupt the ecosystems they grow in, or even threaten human health. But others praise their potential to offset other environmental problems. For example, in this Science Update, you'll hear how genetically engineered tomatoes may be able to resist parasitic worms without the use of toxic pesticides.

Science Update;

2002-05-28

155

Galactosylated Fucose Epitopes in Nematodes  

PubMed Central

The modification of ?1,6-linked fucose residues attached to the proximal (reducing-terminal) core N-acetylglucosamine residue of N-glycans by ?1,4-linked galactose (“GalFuc” epitope) is a feature of a number of invertebrate species including the model nematode Caenorhabditis elegans. A pre-requisite for both core ?1,6-fucosylation and ?1,4-galactosylation is the presence of a nonreducing terminal N-acetylglucosamine; however, this residue is normally absent from the final glycan structure in invertebrates due to the action of specific hexosaminidases. Previously, we have identified two hexosaminidases (HEX-2 and HEX-3) in C. elegans, which process N-glycans. In the present study, we have prepared a hex-2;hex-3 double mutant, which possesses a radically altered N-glycomic profile. Whereas in the double mutant core ?1,3-fucosylation of the proximal N-acetylglucosamine was abolished, the degree of galactosylation of core ?1,6-fucose increased, and a novel Gal?1,2Fuc?1,3 moiety attached to the distal core N-acetylglucosamine residue was detected. Both galactosylated fucose moieties were also found in two parasitic nematodes, Ascaris suum and Oesophagostomum dentatum. As core modifications of N-glycans are known targets for fungal nematotoxic lectins, the sensitivity of the C. elegans double hexosaminidase mutant was assessed. Although this mutant displayed hypersensitivity to the GalFuc-binding lectin CGL2 and the N-acetylglucosamine-binding lectin XCL, the mutant was resistant to CCL2, which binds core ?1,3-fucose. Thus, the use of C. elegans mutants aids the identification of novel N-glycan modifications and the definition of in vivo specificities of nematotoxic lectins with potential as anthelmintic agents.

Yan, Shi; Bleuler-Martinez, Silvia; Plaza, David Fernando; Kunzler, Markus; Aebi, Markus; Joachim, Anja; Razzazi-Fazeli, Ebrahim; Jantsch, Verena; Geyer, Rudolf; Wilson, Iain B. H.; Paschinger, Katharina

2012-01-01

156

Nematodes of Plants and Soils: Neotylenchoidea.  

National Technical Information Service (NTIS)

The book presents information on the morphology, ecology, and taxonomy of nematodes of the superfamily Neotylenchoidea, which live in the rhizophere and root system of cultivated and wild plants. An analysis of the different morphological and ecological c...

N. I. Sumenkova

1988-01-01

157

[Parasitic pseudotumors due to filaroid nematodes].  

PubMed

Four cases of subcutaneous pseudo-tumour caused by filaroid nematodes are described. The histological picture was marked by granulomatous reaction, with a necrotic centre containing filariae in various stages of regression. PMID:1023847

Caprioglio, A

158

TGF-? and the evolution of nematode parasitism  

Microsoft Academic Search

The many similarities between arrested dauer larvae of free-living nematodes and infective L3 of parasitic nematodes has led to suggestions that they are analogous lifecycle stages. The control of the formation of dauer larvae in Caenorhabditis elegans is well understood, with a TGF-?-superfamily growth factor playing a central role. Recent analyses of the expression of homologous TGF-? genes in parasitic

M. E. Viney; F. J. Thompson; M. Crook

2005-01-01

159

Tropical nematode diversity: vertical stratification of nematode communities in a Costa Rican humid lowland rainforest.  

PubMed

Comparisons of nematode communities among ecosystems have indicated that, unlike many organisms, nematode communities have less diversity in the tropics than in temperate ecosystems. There are, however, few studies of tropical nematode diversity on which to base conclusions of global patterns of diversity. This study reports an attempt to estimate nematode diversity in the lowland tropical rainforest of La Selva Biological Research Station in Costa Rica. We suggest one reason that previous estimates of tropical nematode diversity were low is because habitats above the mineral soil are seldom sampled. As much as 62% of the overall genetic diversity, measured by an 18S ribosomal barcode, existed in litter and understorey habitats and not in soil. A maximum-likelihood tree of barcodes from 360 individual nematodes indicated most major terrestrial nematode lineages were represented in the samples. Estimated 'species' richness ranged from 464 to 502 within the four 40 x 40 m plots. Directed sampling of insects and their associated nematodes produced a second set of barcodes that were not recovered by habitat sampling, yet may constitute a major class of tropical nematode diversity. While the generation of novel nematode barcodes proved relatively easy, their identity remains obscure due to deficiencies in existing taxonomic databases. Specimens of Criconematina, a monophyletic group of soil-dwelling plant-parasitic nematodes were examined in detail to assess the steps necessary for associating barcodes with nominal species. Our results highlight the difficulties associated with studying poorly understood organisms in an understudied ecosystem using a destructive (i.e. barcode) sampling method. PMID:19207247

Powers, T O; Neher, D A; Mullin, P; Esquivel, A; Giblin-Davis, R M; Kanzaki, N; Stock, S P; Mora, M M; Uribe-Lorio, L

2009-03-01

160

Bacillus thuringiensis crystal proteins that target nematodes  

PubMed Central

Bacillus thuringiensis (Bt) crystal proteins are pore-forming toxins used as insecticides around the world. Previously, the extent to which these proteins might also target the invertebrate phylum Nematoda has been mostly ignored. We have expressed seven different crystal toxin proteins from two largely unstudied Bt crystal protein subfamilies. By assaying their toxicity on diverse free-living nematode species, we demonstrate that four of these crystal proteins are active against multiple nematode species and that each nematode species tested is susceptible to at least one toxin. We also demonstrate that a rat intestinal nematode is susceptible to some of the nematicidal crystal proteins, indicating these may hold promise in controlling vertebrate-parasitic nematodes. Toxicity in nematodes correlates with damage to the intestine, consistent with the mechanism of crystal toxin action in insects. Structure–function analyses indicate that one novel nematicidal crystal protein can be engineered to a small 43-kDa active core. These data demonstrate that at least two Bt crystal protein subfamilies contain nematicidal toxins.

Wei, Jun-Zhi; Hale, Kristina; Carta, Lynn; Platzer, Edward; Wong, Cynthie; Fang, Su-Chiung; Aroian, Raffi V.

2003-01-01

161

Interspecific Nematode Signals Regulate Dispersal Behavior  

PubMed Central

Background Dispersal is an important nematode behavior. Upon crowding or food depletion, the free living bacteriovorus nematode Caenorhabditis elegans produces stress resistant dispersal larvae, called dauer, which are analogous to second stage juveniles (J2) of plant parasitic Meloidogyne spp. and infective juveniles (IJ)s of entomopathogenic nematodes (EPN), e.g., Steinernema feltiae. Regulation of dispersal behavior has not been thoroughly investigated for C. elegans or any other nematode species. Based on the fact that ascarosides regulate entry in dauer stage as well as multiple behaviors in C. elegans adults including mating, avoidance and aggregation, we hypothesized that ascarosides might also be involved in regulation of dispersal behavior in C. elegans and for other nematodes such as IJ of phylogenetically related EPNs. Methodology/Principal Findings Liquid chromatography-mass spectrometry analysis of C. elegans dauer conditioned media, which shows strong dispersing activity, revealed four known ascarosides (ascr#2, ascr#3, ascr#8, icas#9). A synthetic blend of these ascarosides at physiologically relevant concentrations dispersed C. elegans dauer in the presence of food and also caused dispersion of IJs of S. feltiae and J2s of plant parasitic Meloidogyne spp. Assay guided fractionation revealed structural analogs as major active components of the S. feltiae (ascr#9) and C. elegans (ascr#2) dispersal blends. Further analysis revealed ascr#9 in all Steinernema spp. and Heterorhabditis spp. infected insect host cadavers. Conclusions/Significance Ascaroside blends represent evolutionarily conserved, fundamentally important communication systems for nematodes from diverse habitats, and thus may provide sustainable means for control of parasitic nematodes.

Kaplan, Fatma; Alborn, Hans T.; von Reuss, Stephan H.; Ajredini, Ramadan; Ali, Jared G.; Akyazi, Faruk; Stelinski, Lukasz L.; Edison, Arthur S.; Schroeder, Frank C.; Teal, Peter E.

2012-01-01

162

Nematodes associated with blackberry in arkansas.  

PubMed

A survey of the nematodes in blackberry (Rubus sp.) rhizospheres was conducted in Arkansas from 1986 to 1989. The state was divided arbitrarily into four quadrants. A total of 134 soil samples was collected, and 150-cm 3 subsamples were assayed for nematodes. Twenty-one species of plant-parasitic nematodes in 11 genera were extracted from the samples. There were differences (P = 0.05) among quadrants of the state in percentage occurrence of the nematodes and in population densities in samples. Xiphinema americanum, Helicotylenchus spp. (H. paraplatyurus, H. platyurus, and H. pseudorobustus), and Pratylenchus spp. (P. vulnus and P. zeae) were found in all quadrants. Xiphinema americanum population density was near 1,000 per 150 cm(3) soil in soil samples from two locations. Other nematodes found in one or more quadrants were Criconemella spp. (C. axeste, C. curvata, C. denoudeni, C. ornata, C. sphaerocephala, and C. xenoplax), Paratrichodorus minor, Tylenchorhynchus claytoni, Hirschmanniella oryzae, Hoplolaimus magnistylus, Scutellonema bradys, and undescribed species of Criconema, Tylenchulus, Xiphinema, and Meloidogyne. Criconemella sphaerocephala and Helicotylenchus platyurus are reported from Arkansas for the first time. Helicotylenchus paraplatyurus is reported from the United States for the first time. PMID:19283173

Wehunt, E J; Golden, A M; Clark, J R; Kirkpatrick, T L; Baker, E C; Brown, M A

1991-10-01

163

Xenobiotic Detoxification in the Nematode Caenorhabditis elegans  

PubMed Central

The nematode Caenorhabditis elegans is an important model organism for the study of such diverse aspects of animal physiology and behavior as embryonic development, chemoreception, and the genetic control of lifespan. Yet, even though the entire genome sequence of this organism was deposited into public databases several years ago, little is known about xenobiotic metabolism in C. elegans. In part, the paucity of detoxification information may be due to the plush life enjoyed by nematodes raised in the laboratory. In the wild, however, these animals experience a much greater array of chemical assaults. Living in the interstitial water of the soil, populations of C. elegans exhibit a boom and bust lifestyle characterized by prodigious predation of soil microbes punctuated by periods of dispersal as a non-developing alternative larval stage. During the booming periods of population expansion, these animals almost indiscriminately consume everything in their environment including any number of compounds from other animals, microorganisms, plants, and xenobiotics. Several recent studies have identified many genes encoding sensors and enzymes these nematodes may use in their xeno-coping strategies. Here, we will discuss these recent advances, as well as the efforts by our lab and others to utilize the genomic resources of the C. elegans system to elucidate this nematode’s molecular defenses against toxins.

Lindblom, Tim H.; Dodd, Allyn K.

2009-01-01

164

Microbial Ecology and Nematode Control in Natural Ecosystems  

Microsoft Academic Search

\\u000a Plant-parasitic nematodes have traditionally been studied in agricultural systems, where they can be pests of importance on\\u000a a wide range of crops. Nevertheless, nematode ecology in natural ecosystems is receiving increasing interest because of the\\u000a role of nematodes in soil food webs, nutrient cycling, influences on vegetation composition, and because of their indicator\\u000a value. In natural ecosystems, plant-parasitic nematode populations

Sofia R. Costa; Wim H. van der Putten; Brian R. Kerry

2011-01-01

165

Mass production of entomopathogenic nematodes for plant protection  

Microsoft Academic Search

Entomopathogenic nematodes of the genera Heterorhabditis and Steinernema are commercially used to control pest insects. They are symbiotically associated with bacteria of the genera Photorhabdus and Xenorhabdus, respectively, which are the major food source for the nematodes. The biology of the nematode-bacterium complex is described, a historical review of the development of in vitro cultivation techniques is given and the

Ralf-Udo Ehlers

2001-01-01

166

Present and future prospects for entomopathogenic nematode products  

Microsoft Academic Search

Entomopathogenic nematodes in the genera Steinernema and Heterorhabditis have emerged as excellent candidates for biological control of insect pests. Attributes making the nematodes ideal biological insecticides include their broad host range, high virulence, safety for nontarget organisms and high efficacy in favourable habitats. Progress achieved in liquid fermentation, formulation stability and application strategy has allowed nematode?based products to become competitive

Ramon Georgis

1992-01-01

167

Towards a genome sequence for reniform nematode (Rotylenchulus reniformis)  

Technology Transfer Automated Retrieval System (TEKTRAN)

Reniform nematode (Rotylenchulus reniformis) currently accounts for $130M in annual losses to the U.S. cotton industry and has supplanted root-knot nematode as the major nematode pest of cotton in Mississippi, Louisiana, and Alabama. Moreover, in other cotton-producing states the range and influenc...

168

Nematode CLE signaling in Arabidopsis requires CLAVATA2 and CORYNE  

Technology Transfer Automated Retrieval System (TEKTRAN)

Plant-parasitic cyst nematodes secrete CLAVATA3 (CLV3)/ESR(CLE)-like effector proteins. These proteins have been shown to act as ligand mimics of plant CLE peptides and are required for successful nematode infection; however, the receptors for nematode CLE-like peptides have not been identified. Her...

169

ROOT-KNOT NEMATODE TOLERANCE IN COMMERCIAL COTTON CULTIVARS  

Technology Transfer Automated Retrieval System (TEKTRAN)

The southern root-knot nematode, Meloidogyne incognita, causes significant yield reductions throughout the U.S. cotton belt. Susceptible means the nematode can reproduce freely, and tolerance means that crop yield is affected little by nematode feeding. Virtually all cotton cultivars are susceptib...

170

How to identify nematode problems and why it is important  

Technology Transfer Automated Retrieval System (TEKTRAN)

Plant-parasitic nematodes are microscopic worms that feed on plants. Several nematode species are serious pathogens of cotton, reducing overall US cotton production by an estimated 4.7%. Though losses in nematode infested fields are frequently 10 to 30%, losses can be greater than 50%. Cotton pla...

171

Analysis of the sensory responses of parasitic nematodes using electrophysiology  

Microsoft Academic Search

Use of the electrophysiological technique to examine the sensory perception of live, intact nematodes has provided detailed analysis of responses to known concentrations of test chemicals. The use of larger nematodes, such as the animal-parasite Syngamus trachea, enabled direct extracellular recordings from individual sensilla; with smaller nematodes, the recording electrode was inserted close to the cephalic region. Extracellular recordings from

Roland N Perry

2001-01-01

172

Theory of the locomotion of nematodes  

PubMed Central

We develop a model of the undulatory locomotion of nematodes, in particular that of Caenorhabditis elegans, based on mechanics. The model takes into account the most important forces acting on a moving worm and allows the computer simulation of a creeping nematode. These forces are produced by the interior pressure in the liquid-filled body cavity, the elasticity of the cuticle, the excitation of certain sets of muscles and the friction between the body and its support. We propose that muscle excitation patterns can be generated by stretch receptor control. By solving numerically the equations of motion of the model of the nematode, we demonstrate that these muscle excitation patterns are suitable for the propulsion of the animal.

Niebur, Ernst; Erdos, Paul

1991-01-01

173

Electrophysiological recording from parasitic nematode muscle  

PubMed Central

Infection of man and animals with parasitic nematodes is recognized as a significant global problem (McLeod in Int J Parasitol 25(11):1363–1367, 1994; Hotez et al. in N Engl J Med 357(10):1018–1027, 2007). At present control of these infections relies primarily on chemotherapy. There are a limited number of classes of anthelmintic compounds and the majority of these act on ion-channels of the parasite (Martin et al. in Parasitology 113:S137–S156, 1996). In this report, we describe electrophysiological recording techniques as applied to parasitic nematodes. The aim of this report is: (1) to promote the study of ion channels in nematodes to help further the understanding of antinematodal drug action; (2) to describe our recording equipment and experimental protocols; and (3) provide some examples of the information to be gleaned from this approach and how it can increase our understanding of these important pathogens.

Puttachary, Sreekanth; Buxton, Samuel K.; Martin, Richard J.

2009-01-01

174

UDP-galactopyranose mutase in nematodes.  

PubMed

Nematodes represent a diverse phylum of both free living and parasitic species. While the species Caenorhabditis elegans is a valuable model organism, parasitic nematodes or helminths pose a serious threat to human health. Indeed, helminths cause many neglected tropical diseases that afflict humans. Nematode glycoconjugates have been implicated in evasive immunomodulation, a hallmark of nematode infections. One monosaccharide residue present in the glycoconjugates of several human pathogens is galactofuranose (Galf). This five-membered ring isomer of galactose has not been detected in mammals, making Galf metabolic enzymes attractive therapeutic targets. The only known pathway for biosynthetic incorporation of Galf into glycoconjugates depends upon generation of the glycosyl donor UDP-Galf by the flavoenzyme uridine 5'-diphosphate (UDP) galactopyranose mutase (UGM or Glf). A putative UGM encoding gene (glf-1) was recently identified in C. elegans. We sought to assess the catalytic activity of the corresponding gene product (CeUGM). CeUGM catalyzes the isomerization of UDP-Galf and UDP-galactopyranose (UDP-Galp). In the presence of enzyme, substrate, and a hydride source, a galactose-N5-FAD adduct was isolated, suggesting the CeUGM flavin adenine dinucleotide (FAD) cofactor serves as a nucleophile in covalent catalysis. Homology modeling and protein variants indicate that CeUGM possesses an active site similar to that of prokaryotic enzymes, despite the low sequence identity (?15%) between eukaryotic and prokaryotic UGM proteins. Even with the primary sequence differences, heterocyclic UGM inhibitors developed against prokaryotic proteins also inhibit CeUGM activity. We postulate that inhibitors of CeUGM can serve as chemical probes of Galf in nematodes and as anthelmintic leads. The available data suggest that CeUGM facilitates the biosynthetic incorporation of Galf into nematode glycoconjugates through generation of the glycosyl donor UDP-Galf. PMID:23697711

Wesener, Darryl A; May, John F; Huffman, Elizabeth M; Kiessling, Laura L

2013-06-11

175

Hsp-90 and the biology of nematodes  

PubMed Central

Background Hsp-90 from the free-living nematode Caenorhabditis elegans is unique in that it fails to bind to the specific Hsp-90 inhibitor, geldanamycin (GA). Here we surveyed 24 different free-living or parasitic nematodes with the aim of determining whether C. elegans Hsp-90 was the exception or the norm amongst the nematodes. We combined these data with codon evolution models in an attempt to identify whether hsp-90 from GA-binding and non-binding species has evolved under different evolutionary constraints. Results We show that GA-binding is associated with life history: free-living nematodes and those parasitic species with free-living larval stages failed to bind GA. In contrast, obligate parasites and those worms in which the free-living stage in the environment is enclosed within a resistant egg, possess a GA-binding Hsp-90. We analysed Hsp-90 sequences from fifteen nematode species to determine whether nematode hsp-90s have undergone adaptive evolution that influences GA-binding. Our data provide evidence of rapid diversifying selection in the evolution of the hsp-90 gene along three separate lineages, and identified a number of residues showing significant evidence of adaptive evolution. However, we were unable to prove that the selection observed is correlated with the ability to bind geldanamycin or not. Conclusion Hsp-90 is a multi-functional protein and the rapid evolution of the hsp-90 gene presumably correlates with other key cellular functions. Factors other than primary amino acid sequence may influence the ability of Hsp-90 to bind to geldanamycin.

Him, Nik AIIN; Gillan, Victoria; Emes, Richard D; Maitland, Kirsty; Devaney, Eileen

2009-01-01

176

Delayed response to ring nematode (Mesocriconema xenoplax) feeding on grape roots linked to vine carbohydrate reserves and nematode feeding pressure  

Technology Transfer Automated Retrieval System (TEKTRAN)

The chronic impact of ring nematode (Mesocriconema xenoplax) feeding on grapevine (Vitis vinifera) was studied under controlled conditions. 'Pinot noir' grapevines were exposed to ring nematode or kept nematode-free for three growing seasons, and vines were either grown in full sunlight, 15% of full...

177

Free-living and Plant-Parasitic Nematodes (Roundworms)  

NSDL National Science Digital Library

This resource serves as an introduction to the world of nematodes. The objectives of this exercise include introducing students to the world of nematodes, illustrating a method of extraction of nematodes from soil, and learning to differentiate stylet-bearing nematodes from free-living nematodes. This exercise will be most useful for grades 7-12 in classrooms where dissecting and compound microscopes are available. It requires minimal materials (funnels, screen, tubing, clamps, 2-ply tissues, ring stand, soil sample, and water) and preparation.

Gregory L. Tylka (Iowa State University;); Claudia A. Jasalavich (Nashua, NH;)

2001-04-09

178

Unravelling parasitic nematode natural history using population genetics.  

PubMed

The health and economic importance of parasitic nematodes cannot be overstated. Moreover, they offer a complex and diverse array of life strategies, raising a multitude of evolutionary questions. Researchers are applying population genetics to parasitic nematodes in order to disentangle some aspects of their life strategies, improve our knowledge about disease epidemiology, and design control strategies. However, population genetics studies of nematodes have been constrained due to the difficulty in sampling nematodes and developing molecular markers. In this context, new computational and sequencing technologies represent promising tools to investigate population genomics of parasitic, non-model, nematode species in an epidemiological context. PMID:23948430

Gilabert, Aude; Wasmuth, James D

2013-08-12

179

Nematode-enhanced microbial colonization of the wheat rhizosphere.  

PubMed

The mechanisms by which seed-applied bacteria colonize the rhizosphere in the absence of percolating water are poorly understood. Without mass flow, transport of bacteria by growing roots or soil animals, particularly nematodes may be important. We used a sand-based microcosm system to investigate the ability of three species of nematodes (Caenorhabditis elegans, Acrobeloides thornei and a Cruznema sp.) to promote rhizosphere colonization by four strains of beneficial rhizobacteria. In nearly all cases, rhizosphere colonization was substantially increased by the presence of nematodes, irrespective of bacterial or nematode species. Our results suggest that nematodes are important vectors for bacteria rhizosphere colonization in the absence of percolating water. PMID:12951246

Knox, O G G; Killham, K; Mullins, C E; Wilson, M J

2003-08-29

180

Association of MC3R gene polymorphisms with body weight in the red fox and comparative gene organization in four canids.  

PubMed

There are five genes encoding melanocortin receptors. Among canids, the genes have mainly been studied in the dog (MC1R, MC2R and MC4R). The MC4R gene has also been analysed in the red fox. In this report, we present a study of chromosome localization, comparative sequence analysis and polymorphism of the MC3R gene in the dog, red fox, arctic fox and Chinese raccoon dog. The gene was localized by FISH to the following chromosome: 24q24-25 in the dog, 14p16 in the red fox, 18q13 in the arctic fox and NPP4p15 in the Chinese raccoon dog. A high identity level of the MC3R gene sequences was observed among the species, ranging from 96.0% (red fox--Chinese raccoon dog) to 99.5% (red fox--arctic fox). Altogether, eight polymorphic sites were found in the red fox, six in the Chinese raccoon dog and two in the dog, while the arctic fox appeared to be monomorphic. In addition, association of several polymorphisms with body weight was analysed in red foxes (the number of genotyped animals ranged from 319 to 379). Two polymorphisms in the red fox, i.e. a silent substitution c.957A>C and c.*185C>T in the 3'-flanking sequence, showed a significant association (P < 0.01) with body weight. PMID:20477806

Skorczyk, A; Flisikowski, K; Szydlowski, M; Cieslak, J; Fries, R; Switonski, M

2011-02-01

181

Strong bottom-up and weak top-down effects in soil: nematode-parasitized insects and nematode-trapping fungi  

Microsoft Academic Search

The soils of the Bodega Marine Reserve (BMR, Sonoma County, California) contain many nematode-trapping fungi and many ghost moth larvae parasitized by entomopathogenic nematodes. The current study determined whether these nematode-parasitized moth larvae, which can produce very large numbers of nematodes, enhanced the population densities of nematode-trapping fungi and whether the fungi trapped substantial numbers of nematodes emerging and dispersing

B. A. Jaffee; D. R. Strong

2005-01-01

182

Molecular phylogeny of beetle associated diplogastrid nematodes suggests host switching rather than nematode-beetle coevolution  

PubMed Central

Background Nematodes are putatively the most species-rich animal phylum. They have various life styles and occur in a variety of habitats, ranging from free-living nematodes in aquatic or terrestrial environments to parasites of animals and plants. The rhabditid nematode Caenorhabditis elegans is one of the most important model organisms in modern biology. Pristionchus pacificus of the family of the Diplogastridae has been developed as a satellite model for comparison to C. elegans. The Diplogastridae, a monophyletic clade within the rhabditid nematodes, are frequently associated with beetles. How this beetle-association evolved and whether beetle-nematode coevolution occurred is still elusive. As a prerequisite to answering this question a robust phylogeny of beetle-associated Diplogastridae is needed. Results Sequences for the nuclear small subunit ribosomal RNA and for 12 ribosomal protein encoding nucleotide sequences were collected for 14 diplogastrid taxa yielding a dataset of 5996 bp of concatenated aligned sequences. A molecular phylogeny of beetle-associated diplogastrid nematodes was established by various algorithms. Robust subclades could be demonstrated embedded in a phylogenetic tree topology with short internal branches, indicating rapid ancestral divergences. Comparison of the diplogastrid phylogeny to a comprehensive beetle phylogeny revealed no major congruence and thus no evidence for a long-term coevolution. Conclusion Reconstruction of the phylogenetic history of beetle-associated Diplogastridae yields four distinct subclades, whose deep phylogenetic divergence, as indicated by short internal branch lengths, shows evidence for evolution by successions of ancient rapid radiation events. The stem species of the Diplogastridae existed at the same time period when the major radiations of the beetles occurred. Comparison of nematode and beetle phylogenies provides, however, no evidence for long-term coevolution of diplogastrid nematodes and their beetle hosts. Instead, frequent host switching is observed. The molecular phylogeny of the Diplogastridae provides a framework for further examinations of the evolution of these associations, for the study of interactions within the ecosystems, and for investigations of diplogastrid genome evolution.

Mayer, Werner E; Herrmann, Matthias; Sommer, Ralf J

2009-01-01

183

A Trojan horse mechanism of bacterial pathogenesis against nematodes  

PubMed Central

Understanding the mechanisms of host–pathogen interaction can provide crucial information for successfully manipulating their relationships. Because of its genetic background and practical advantages over vertebrate model systems, the nematode Caenorhabditis elegans model has become an attractive host for studying microbial pathogenesis. Here we report a “Trojan horse” mechanism of bacterial pathogenesis against nematodes. We show that the bacterium Bacillus nematocida B16 lures nematodes by emitting potent volatile organic compounds that are much more attractive to worms than those from ordinary dietary bacteria. Seventeen B. nematocida-attractant volatile organic compounds are identified, and seven are individually confirmed to lure nematodes. Once the bacteria enter the intestine of nematodes, they secrete two proteases with broad substrate ranges but preferentially target essential intestinal proteins, leading to nematode death. This Trojan horse pattern of bacterium–nematode interaction enriches our understanding of microbial pathogenesis.

Niu, Qiuhong; Huang, Xiaowei; Zhang, Lin; Xu, Jianping; Yang, Dongmei; Wei, Kangbi; Niu, Xuemei; An, Zhiqiang; Bennett, Joan Wennstrom; Zou, Chenggang; Yang, Jinkui; Zhang, Ke-Qin

2010-01-01

184

The apple snail Pomacea canaliculata, a novel vector of the rat lungworm, Angiostrongylus cantonensis: its introduction, spread, and control in China.  

PubMed

The freshwater apple snail Pomacea canaliculata was introduced to Taiwan then to mainland China in the early 1980s from Argentina, its native region, for the purpose of aquaculture. Because of the lack of natural enemies and its tolerance of a wide range of environmental conditions, both its abundance and distribution have dramatically increased and it has become a harmful species to local agriculture and other native species in many areas of China. Unfortunately, the snail also acts as an intermediate host of Angiostrongylus cantonensis, and has been implicated in transfer of the parasite to people, resulting in angiostrongyliasis manifested as eosinophilic meningitis. Efforts to prevent its further spread and population expansion were initiated many years ago, including the use of chemicals and biological control agents to control the snail. PMID:23901377

Yang, Ting-Bao; Wu, Zhong-Dao; Lun, Zhao-Rong

2013-06-01

185

Parasitic Nematode Interactions with Mammals and Plants  

Microsoft Academic Search

Parasitic nematodes that infect humans, animals, and plants cause serious diseases that are deleterious to human health and agricultural productivity. Chemical and biological control methods have reduced the impact of these parasites. However, surviving environmental stages lead to persistent reinfection of host species. In addition, development of resistance to nematicides and anthelmintics by these parasites and reduced availability of some

Douglas P. Jasmer; Aska Goverse; Geert Smant

2003-01-01

186

Nuclear receptors in nematodes: themes and variations  

Microsoft Academic Search

Large-scale sequencing efforts are providing new perspectives on similarities and differences among species. Sequences encoding nuclear receptor (NR) transcription factors furnish one striking example of this. The three complete or nearly complete metazoan genome sequences – those of the nematode Caenorhabditis elegans, the fruit fly (Drosophila melanogaster) and the human – reveal dramatically different numbers of predicted NR genes: 270

Ann E. Sluder; Claude V. Maina

2001-01-01

187

Evolution of male longevity bias in nematodes  

Microsoft Academic Search

Summary Many animal species exhibit sex differences in aging. In the nematode Caenorhabditis elegans , under conditions that minimize mortality, males are the longer-lived sex. In a survey of 12 independent C. elegans isolates, we find that this is a species-typical character. To test the hypothesis that the C. elegans male longevity bias evolved as a consequence of androdioecy (having

Diana McCulloch; David Gems

2003-01-01

188

Gnathostomiasis-A Rare Nematode Infection  

Microsoft Academic Search

Gnathostoma, primarily an animal nematode, is rusty in colour, 2-3 cm long in adult stage, can infect man by their larval form. Human infection occurs by the third stage larva by consumption of undercooked or raw fish, poultry, or pork and rarely by skin penetration, In Bangladesh gnathostomiasis is not reported. But recently a female of 38 year of age

M M Rahman

2003-01-01

189

NEMATODES, A HIDDEN PROBLEM FOR PECAN PRODUCTION  

Technology Transfer Automated Retrieval System (TEKTRAN)

The pecan root knot nematode, Meloidogyne partityla (Mp), has been associated with pecan trees exhibiting above-ground symptoms that included dead branches in the upper canopy, severely stunted growth, and (or) mouse-ear leaf symptoms. In 2003 04, a survey was conducted in the major pecan growing r...

190

Survival of chlorophyceae ingested by saprozoic nematodes.  

PubMed

The saprozoic nematode, Pristionchus lheritieri ingested cells of four species of unicellular Chlorophyceae (grass-green algae) including Chlamydomonas reinhardi and unidentified species of Ankistrodesmus, Chlamydornonas and Scenedesmus. Additional tests with Ankistrodesmus sp. and Chlamydomonas sp., indicated cells of Ankistrodesmus survived passage through the alimentary canal and were subsequently cultured, while viable cells of Chlarnydomonas were only occasionally recovered. PMID:19322324

Leake, P A; Jensen, H J

1970-10-01

191

Survival of Chlorophyceae Ingested by Saprozoic Nematodes  

PubMed Central

The saprozoic nematode, Pristionchus lheritieri ingested cells of four species of unicellular Chlorophyceae (grass-green algae) including Chlamydomonas reinhardi and unidentified species of Ankistrodesmus, Chlamydornonas and Scenedesmus. Additional tests with Ankistrodesmus sp. and Chlamydomonas sp., indicated cells of Ankistrodesmus survived passage through the alimentary canal and were subsequently cultured, while viable cells of Chlarnydomonas were only occasionally recovered.

Leake, P. A.; Jensen, H. J.

1970-01-01

192

Potato cyst nematodes: pests of national importance  

Technology Transfer Automated Retrieval System (TEKTRAN)

Potato cyst nematodes (PCN; G. rostochiensis and G. pallida) are internationally-recognized quarantine pests and considered the most devastating pests of potatoes due to annual worldwide yield losses estimated at 12.2%. PCNs continue to spread throughout North America and were recently detected in I...

193

The genomes of root-knot nematodes.  

PubMed

Plant-parasitic nematodes are the most destructive group of plant pathogens worldwide and are extremely challenging to control. The recent completion of two root-knot nematode genomes opens the way for a comparative genomics approach to elucidate the success of these parasites. Sequencing revealed that Meloidogyne hapla, a diploid that reproduces by facultative, meiotic parthenogenesis, encodes approximately 14,200 genes in a compact, 54 Mpb genome. Indeed, this is the smallest metazoan genome completed to date. By contrast, the 86 Mbp Meloidogyne incognita genome encodes approximately 19,200 genes. This species reproduces by obligate mitotic parthenogenesis and exhibits a complex pattern of aneuploidy. The genome includes triplicated regions and contains allelic pairs with exceptionally high degrees of sequence divergence, presumably reflecting adaptations to the strictly asexual reproductive mode. Both root-knot nematode genomes have compacted gene families compared with the free-living nematode Caenorhabditis elegans, and both encode large suites of enzymes that uniquely target the host plant. Acquisition of these genes, apparently via horizontal gene transfer, and their subsequent expansion and diversification point to the evolutionary history of these parasites. It also suggests new routes to their control. PMID:19400640

Bird, David McK; Williamson, Valerie M; Abad, Pierre; McCarter, James; Danchin, Etienne G J; Castagnone-Sereno, Philippe; Opperman, Charles H

2009-01-01

194

Mass production of entomopathogenic nematodes for plant protection.  

PubMed

Entomopathogenic nematodes of the genera Heterorhabditis and Steinernema are commercially used to control pest insects. They are symbiotically associated with bacteria of the genera Photorhabdus and Xenorhabdus, respectively, which are the major food source for the nematodes. The biology of the nematode-bacterium complex is described, a historical review of the development of in vitro cultivation techniques is given and the current use in agriculture is summarised. Cultures of the complex are pre-incubated with the symbiotic bacteria before the nematodes are inoculated. Whereas the inoculum preparation and preservation of bacterial stocks follow standard rules, nematodes need special treatment. Media development is mainly directed towards cost reduction, as the bacteria are able to metabolise a variety of protein sources to provide optimal conditions for nematode reproduction. The process technology is described, discussing the influence of bioreactor design and process parameters required to obtain high nematode yields. As two organisms are grown in one vessel and one of them is a multicellular organism, the population dynamics and symbiotic interactions need to be understood in order to improve process management. Major problems can originate from the delayed or slow development of the nematode inoculum and from phase variants of the symbiotic bacteria that have negative effects on nematode development and reproduction. Recent scientific progress has helped to understand the biological and technical parameters that influence the process, thus enabling transfer to an industrial scale. As a consequence, costs for nematode-based products could be significantly reduced. PMID:11601608

Ehlers, R U

2001-09-01

195

Characterization of Root-Knot Nematode Resistance in Medicago truncatula  

PubMed Central

Root knot (Meloidogyne spp.) and cyst (Heterodera and Globodera spp.) nematodes infect all important crop species, and the annual economic loss due to these pathogens exceeds $90 billion. We screened the worldwide accession collection with the root-knot nematodes Meloidogyne incognita, M. arenaria and M. hapla, soybean cyst nematode (SCN-Heterodera glycines), sugar beet cyst nematode (SBCN-Heterodera schachtii) and clover cyst nematode (CLCN-Heterodera trifolii), revealing resistant and susceptible accessions. In the over 100 accessions evaluated, we observed a range of responses to the root-knot nematode species, and a non-host response was observed for SCN and SBCN infection. However, variation was observed with respect to infection by CLCN. While many cultivars including Jemalong A17 were resistant to H. trifolii, cultivar Paraggio was highly susceptible. Identification of M. truncatula as a host for root-knot nematodes and H. trifolii and the differential host response to both RKN and CLCN provide the opportunity to genetically and molecularly characterize genes involved in plant-nematode interaction. Accession DZA045, obtained from an Algerian population, was resistant to all three root-knot nematode species and was used for further studies. The mechanism of resistance in DZA045 appears different from Mi-mediated root-knot nematode resistance in tomato. Temporal analysis of nematode infection showed that there is no difference in nematode penetration between the resistant and susceptible accessions, and no hypersensitive response was observed in the resistant accession even several days after infection. However, less than 5% of the nematode population completed the life cycle as females in the resistant accession. The remainder emigrated from the roots, developed as males, or died inside the roots as undeveloped larvae. Genetic analyses carried out by crossing DZA045 with a susceptible French accession, F83005, suggest that one gene controls resistance in DZA045.

Dhandaydham, Murali; Charles, Lauren; Zhu, Hongyan; Starr, James L.; Huguet, Thierry; Cook, Douglas R.; Prosperi, Jean-Marie; Opperman, Charles

2008-01-01

196

Nitrogen addition regulates soil nematode community composition through ammonium suppression.  

PubMed

Nitrogen (N) enrichment resulting from anthropogenic activities has greatly changed the composition and functioning of soil communities. Nematodes are one of the most abundant and diverse groups of soil organisms, and they occupy key trophic positions in the soil detritus food web. Nematodes have therefore been proposed as useful indicators for shifts in soil ecosystem functioning under N enrichment. Here, we monitored temporal dynamics of the soil nematode community using a multi-level N addition experiment in an Inner Mongolia grassland. Measurements were made three years after the start of the experiment. We used structural equation modeling (SEM) to explore the mechanisms regulating nematode responses to N enrichment. Across the N enrichment gradient, significant reductions in total nematode abundance, diversity (H' and taxonomic richness), maturity index (MI), and the abundance of root herbivores, fungivores and omnivores-predators were found in August. Root herbivores recovered in September, contributing to the temporal variation of total nematode abundance across the N gradient. Bacterivores showed a hump-shaped relationship with N addition rate, both in August and September. Ammonium concentration was negatively correlated with the abundance of total and herbivorous nematodes in August, but not in September. Ammonium suppression explained 61% of the variation in nematode richness and 43% of the variation in nematode trophic group composition. Ammonium toxicity may occur when herbivorous nematodes feed on root fluid, providing a possible explanation for the negative relationship between herbivorous nematodes and ammonium concentration in August. We found a significantly positive relationship between fungivores and fungal phospholipid fatty acids (PLFA), suggesting bottom-up control of fungivores. No such relationship was found between bacterivorous nematodes and bacterial PLFA. Our findings contribute to the understanding of effects of N enrichment in semiarid grassland on soil nematode trophic groups, and the cascading effects in the detrital soil food web. PMID:22952671

Wei, Cunzheng; Zheng, Huifen; Li, Qi; Lü, Xiaotao; Yu, Qiang; Zhang, Haiyang; Chen, Quansheng; He, Nianpeng; Kardol, Paul; Liang, Wenju; Han, Xingguo

2012-08-31

197

Nitrogen Addition Regulates Soil Nematode Community Composition through Ammonium Suppression  

PubMed Central

Nitrogen (N) enrichment resulting from anthropogenic activities has greatly changed the composition and functioning of soil communities. Nematodes are one of the most abundant and diverse groups of soil organisms, and they occupy key trophic positions in the soil detritus food web. Nematodes have therefore been proposed as useful indicators for shifts in soil ecosystem functioning under N enrichment. Here, we monitored temporal dynamics of the soil nematode community using a multi-level N addition experiment in an Inner Mongolia grassland. Measurements were made three years after the start of the experiment. We used structural equation modeling (SEM) to explore the mechanisms regulating nematode responses to N enrichment. Across the N enrichment gradient, significant reductions in total nematode abundance, diversity (H' and taxonomic richness), maturity index (MI), and the abundance of root herbivores, fungivores and omnivores-predators were found in August. Root herbivores recovered in September, contributing to the temporal variation of total nematode abundance across the N gradient. Bacterivores showed a hump-shaped relationship with N addition rate, both in August and September. Ammonium concentration was negatively correlated with the abundance of total and herbivorous nematodes in August, but not in September. Ammonium suppression explained 61% of the variation in nematode richness and 43% of the variation in nematode trophic group composition. Ammonium toxicity may occur when herbivorous nematodes feed on root fluid, providing a possible explanation for the negative relationship between herbivorous nematodes and ammonium concentration in August. We found a significantly positive relationship between fungivores and fungal phospholipid fatty acids (PLFA), suggesting bottom-up control of fungivores. No such relationship was found between bacterivorous nematodes and bacterial PLFA. Our findings contribute to the understanding of effects of N enrichment in semiarid grassland on soil nematode trophic groups, and the cascading effects in the detrital soil food web.

Wei, Cunzheng; Zheng, Huifen; Li, Qi; Lu, Xiaotao; Yu, Qiang; Zhang, Haiyang; Chen, Quansheng; He, Nianpeng; Kardol, Paul; Liang, Wenju; Han, Xingguo

2012-01-01

198

Assessment of the efficacy of oral vaccination of livestock guardian dogs in the framework of oral rabies vaccination of wild canids in Israel.  

PubMed

Since 1956, red foxes (Vulpes vulpes) and golden jackals (Canis aureus) have been the primary vectors maintaining wildlife rabies in Israel. Oral rabies vaccination of wild canids, initiated in 1998, resulted in near-elimination of the disease in wildlife by 2005. In 2005 and 2006, an outbreak of rabies was observed in stray dogs in the vaccinated area of the Golan Heights, with no cases in foxes or jackals. Epidemiological investigations showed that the infected dogs were from territories across the border. This was confirmed by molecular analysis, which showed that the virus was different from rabies isolates endemic to this area. The objective of this study was to determine bait acceptance and the feasibility of oral rabies vaccination in packs of livestock guardian dogs. Coated sachets and fishmeal polymer baits of Raboral V-RG (Merial, USA) were tested in five different test zones. Both formats were hand-fed to individual dogs and to dogs belonging to dog packs. Bait uptake and consumption were observed in each dog. The estimated efficacy of oral rabies vaccination was very low (a maximum of 28%). Vaccine delivery problems were observed in dogs belonging to packs, whereby dominant animals consumed multiple baits and in competitive situations baits were swallowed whole. The uncertainty of oral vaccination necessitated turning to other methods to control this outbreak: stray dogs were removed and herd dogs were vaccinated parenterally. This study showed that oral rabies vaccination of dogs in packs using baits designed for wildlife would not be effective. Possibly, different baits or steps to circumvent competition within the pack will make this approach feasible. PMID:18634475

Yakobson, B A; King, R; Sheichat, N; Eventov, B; David, D

2008-01-01

199

7 CFR 301.85-9 - Movement of live golden nematodes.  

Code of Federal Regulations, 2010 CFR

... false Movement of live golden nematodes. 301.85-9 Section 301...DOMESTIC QUARANTINE NOTICES Golden Nematode Quarantine and Regulations § 301.85-9 Movement of live golden nematodes. Regulations requiring a...

2010-01-01

200

7 CFR 301.85-9 - Movement of live golden nematodes.  

Code of Federal Regulations, 2010 CFR

... false Movement of live golden nematodes. 301.85-9 Section 301...DOMESTIC QUARANTINE NOTICES Golden Nematode Quarantine and Regulations § 301.85-9 Movement of live golden nematodes. Regulations requiring a...

2009-01-01

201

Nematode suppression with brassicaceous amendments: application based upon glucosinolate profiles  

Microsoft Academic Search

Glucosinolate profiles differ among plant species and their isothiocyanate (ITC) derivatives differ in toxicity to nematodes. Successful management of plant–parasitic nematodes by ITCs requires the incorporation of appropriate amounts of glucosinolate-containing biomass. Plant materials, containing glucosinolate-precursors of the ITCs most toxic to nematodes, were selected and applied to soil based upon ITC lethal concentration (LC) values. This provided a reliable

I. A. Zasada; H. Ferris

2004-01-01

202

Nematode-plant interactions in grasslands under restoration management  

Microsoft Academic Search

Keywords<\\/strong> : competition, fertilisation, food quality, grassland, herbivory, nitrogen, nutrients, plant-feeding nematodes, productivity, restoration management, succession, synergism, vegetationPlant-feeding nematodes may have a considerable impact on the rate and direction of plant succession. In this thesis the interactions between plants and plant-feeding nematodes in grasslands under restoration management were studied. In these grasslands, a management of ceasing fertiliser application and annual

B. C. Verschoor

2001-01-01

203

Attraction of Pinewood Nematode to Endoparasitic Nematophagous Fungus Esteya vermicola  

Microsoft Academic Search

The investigations on attraction of nematodes to nematophagous fungi have mostly dealt with the nematode-trapping species.\\u000a Esteya vermicola is the endoparasitic fungus of pinewood nematode (PWN) with high infection activity. In the present study, the attraction\\u000a of PWNs to E. vermicola was investigated. It was confirmed that the living mycelia and exudative substances of E. vermicola were attractive to PWN.

Chun Yan Wang; Zhen Wang; Zhe Ming Fang; Dong Liang Zhang; Li Juan Gu; Lei Liu; Chang Keun Sung

2010-01-01

204

Introduction to Plant-Parasitic Nematodes; Modes of Parasitism  

Microsoft Academic Search

\\u000a Plant-parasitic nematodes are pests of agricultural crops and cause considerable economic loss and, especially in developing\\u000a countries, adverse social impact. They exhibit a variety of parasitic modes, with the endoparasitic cyst and root-knot nematodes\\u000a attracting the most research interest. As a group, plant-parasitic nematodes display a variety of adaptations to the parasitic\\u000a lifestyle and some species show remarkable abilities to

Roland N. Perry; Maurice Moens

205

Unravelling the Plant Cell Cycle in Nematode Induced Feeding Sites  

Microsoft Academic Search

\\u000a Cell cycle activation is a key component of host plant manipulation by sedentary nematodes. It is generally believed that\\u000a root-knot nematodes induce giant cells by repeated cycles of acytokinetic mitosis accompanied by endocycles while cyst nematodes\\u000a induce extra rounds of DNA synthesis. Microscopic expression analysis of genes that encode key regulators of the cell cycle\\u000a and the use of cell

Janice de Almeida Engler; Gilbert Engler; Godelieve Gheysen

206

Cell Wall Modifications Induced by Nematodes  

Microsoft Academic Search

\\u000a Sedentary plant parasitic nematodes can induce development of specific feeding structures inside plant roots via reprogramming\\u000a of plant morphogenetic pathways. The most remarkable examples of this ability are structural, physiological and chemical changes\\u000a occurring in cell walls of syncytia and giant-cells. The cell walls of feeding structures have to fulfil different requirements.\\u000a They become thickened to counteract growing internal pressure,

Miroslaw Sobczak; Sylwia Fudali; Krzysztof Wieczorek

207

Nematode worm egg output by ewes  

Microsoft Academic Search

The results from routine monitoring of parasite burdens in ewe flocks from 1980 to 1991 by the Massey University Veterinary Clinic were analysed. Faecal strongylate nematode egg counts from 401 flock samples were analysed according to ewe age (two-tooth, 16-23 month-old vs mixed-age, greater than 2-year-old ewes) and month of the year. Each flock sample contained faeces from ten ewes

K. J. Stafford; D. M. West; W. E. Pornroy

1994-01-01

208

Caenorhabditis Elegans--Applications to Nematode Genomics  

PubMed Central

The complete genome sequence of the free-living nematode Caenorhabditis elegans was published 4 years ago. Since then, we have seen great strides in technologies that seek to exploit this data. Here we describe the application of some of these techniques and other advances that are helping us to understand about not only the biology of this important model organism but also the entire phylum Nematoda.

Parkinson, John

2003-01-01

209

NemaPath: online exploration of KEGG-based metabolic pathways for nematodes  

Microsoft Academic Search

BACKGROUND: Nematode.net http:\\/\\/www.nematode.net is a web-accessible resource for investigating gene sequences from parasitic and free-living nematode genomes. Beyond the well-characterized model nematode C. elegans, over 500,000 expressed sequence tags (ESTs) and nearly 600,000 genome survey sequences (GSSs) have been generated from 36 nematode species as part of the Parasitic Nematode Genomics Program undertaken by the Genome Center at Washington University

Todd Wylie; John Martin; Sahar Abubucker; Yong Yin; David Messina; Zhengyuan Wang; James P McCarter; Makedonka Mitreva

2008-01-01

210

Assaying Environmental Nickel Toxicity Using Model Nematodes  

PubMed Central

Although nickel exposure results in allergic reactions, respiratory conditions, and cancer in humans and rodents, the ramifications of excess nickel in the environment for animal and human health remain largely undescribed. Nickel and other cationic metals travel through waterways and bind to soils and sediments. To evaluate the potential toxic effects of nickel at environmental contaminant levels (8.9-7,600 µg Ni/g dry weight of sediment and 50-800 µg NiCl2/L of water), we conducted assays using two cosmopolitan nematodes, Caenorhabditis elegans and Pristionchus pacificus. We assayed the effects of both sediment-bound and aqueous nickel upon animal growth, developmental survival, lifespan, and fecundity. Uncontaminated sediments were collected from sites in the Midwestern United States and spiked with a range of nickel concentrations. We found that nickel-spiked sediment substantially impairs both survival from larval to adult stages and adult longevity in a concentration-dependent manner. Further, while aqueous nickel showed no adverse effects on either survivorship or longevity, we observed a significant decrease in fecundity, indicating that aqueous nickel could have a negative impact on nematode physiology. Intriguingly, C. elegans and P. pacificus exhibit similar, but not identical, responses to nickel exposure. Moreover, P. pacificus could be tested successfully in sediments inhospitable to C. elegans. Our results add to a growing body of literature documenting the impact of nickel on animal physiology, and suggest that environmental toxicological studies could gain an advantage by widening their repertoire of nematode species.

Rudel, David; Douglas, Chandler D.; Huffnagle, Ian M.; Besser, John M.; Ingersoll, Christopher G.

2013-01-01

211

Optimization of inoculation for in vivo production of entomopathogenic nematodes.  

PubMed

Entomopathogenic nematodes are potent biopesticides that can be mass-produced by in vitro or in vivo methods. For in vivo production, consistently high infection rates are critical to efficiency of the process. Our objective was to optimize in vivo inoculation of Steinernema carpocapsae and Heterorhabditis bacteriophora in Galleria mellonella and Tenebrio molitor by determining effects of inoculation method, nematode concentration, and host density. We found immersing hosts in a nematode suspension to be approximately four times more efficient in time than pipeting inoculum onto the hosts. The number of hosts exhibiting signs of nematode infection increased with nematode concentration and decreased with host density per unit area. This is the first report indicating an effect of host density on inoculation efficiency. We did not detect an effect of nematode inoculum concentration on nematode yield per host or per gram of host. Yield was affected by host density in one of the four nematode-host combinations (S. carpocapsae and T. molitor). We conclude that optimization of inoculation parameters is a necessary component of developing an in vivo production system for entomopathogenic nematodes. PMID:19265954

Shapiro-Ilan, David I; Gaugler, Randy; Tedders, W Louis; Brown, Ian; Lewis, Edwin E

2002-12-01

212

Two candidate genes (FTO and INSIG2) for fat accumulation in four canids: chromosome mapping, gene polymorphisms and association studies of body and skin weight of red foxes.  

PubMed

Fat accumulation is a polygenic trait which has a significant impact on human health and animal production. Obesity is also an increasingly serious problem in dog breeding. The FTO and INSIG2 are considered as candidate genes associated with predisposition for human obesity. In this report we present a comparative genomic analysis of these 2 genes in 4 species belonging to the family Canidae - the dog and 3 species which are kept in captivity for fur production, i.e. red fox, arctic fox and Chinese raccoon dog. We cytogenetically mapped these 2 loci by FISH and compared the entire coding sequence of INSIG2 and a fragment of the coding sequence of FTO. The FTO gene was assigned to the following chromosomes: CFA2q25 (dog), VVU2q21 (red fox), ALA8q25 (arctic fox) and NPP10q24-25 (Chinese raccoon dog), while the INSIG2 was mapped to CFA19q17, VVU5p14, ALA24q15 and NPP9q22, respectively. Altogether, 29 SNPs were identified (16 in INSIG2 and 13 in FTO) and among them 2 were missense substitutions in the dog (23C/T, Thr>Met in the FTO gene and 40C/A, Arg>Ser in INSIG2). The distribution of these 2 SNPs was studied in 14 dog breeds. Two synonymous SNPs, one in the FTO gene (-28T>C in the 5'-flanking region) and one in the INSIG2 (10175C>T in intron 2), were used for the association studies in red foxes (n = 390) and suggestive evidence was observed for their association with body weight (FTO, p < 0.08) and weight of raw skin (INSIG2, p < 0.05). These associations indicate that both genes are potential candidates for growth or adipose tissue accumulation in canids. We also suggest that the 2 missense substitutions found in dogs should be studied in terms of genetic predisposition to obesity. PMID:21846970

Grzes, M; Szczerbal, I; Fijak-Nowak, H; Szydlowski, M; Switonski, M

2011-08-12

213

Invasive Insect and Nematode Pests from North America  

Microsoft Academic Search

Of 447 alien insect, phytophagous mite, spider and nematode species in Japan, 415 are insect species. Most were introduced after the end of the Edo period (1859). Coleoptera, Hemiptera, Lepidoptera, Diptera and Hymenoptera represent the major taxonomic groups in decreasing order of number of species. They include 58 insect and nematode species from the United States. Among them, the following

Keizi KIRITANI; Nobuo MORIMOTO

2004-01-01

214

Thermal constraints to population growth of bacterial-feeding nematodes  

Microsoft Academic Search

Bacterial-feeding nematodes are important participants in decomposition pathways and nutrient cycles in soils. The contribution of each species to component processes depends upon the physiology of individuals and the dynamics of populations. Having determined the effects of temperature on metabolic rates of several species of bacterial-feeding nematodes, we now present the effects of temperature on population growth rates and relate

R. C. Venette; H. Ferris

1997-01-01

215

Soybean Cyst Nematode in North America - 55 Years Later  

Technology Transfer Automated Retrieval System (TEKTRAN)

Soybean cyst nematode, Heterodera glycines, was first discovered in North America in 1954 in Hanover County, North Carolina, USA, when it was found on soybean in a field that had been planted to Easter lilies obtained from Japan prior to World War II. The nematode is now distributed throughout soybe...

216

Granite Rock Outcrops: An Extreme Environment for Soil Nematodes?  

PubMed Central

We studied soil nematode communities from the surface of granite flatrock outcrops in the eastern Piedmont region of the United States. The thin soils that develop here experience high light intensity and extreme fluctuations in temperature and moisture and host unique plant communities. We collected soils from outcrop microsites in Virginia (VA) and North Carolina (NC) in various stages of succession (Primitive, Minimal, and Mature) and compared soil properties and nematode communities to those of adjacent forest soils. Nematodes were present in most outcrop soils, with densities comparable to forest soils (P > 0.05). Nematode communities in Mature and Minimal soils had lower species richness than forest soils (P < 0.05) and contained more bacterial-feeders and fewer fungal-feeders (P < 0.05). Primitive soils contained either no nematodes (NC) or only a single species (Mesodorylaimus sp., VA). Nematode communities were similar between Mature and Minimal soils, according to trophic group representation, MI, PPI, EI, SI, and CI (P > 0.05). Forest soils had a higher PPI value (P < 0.05), but otherwise community indices were similar to outcrop soils (P > 0.05). Outcrop nematode communities failed to group together in a Bray-Curtis cluster analysis, indicating higher variability in community structure than the Forest soils, which did cluster together. A high proportion of the nematodes were extracted from outcrop soils in coiled form (33-89%), indicating that they used anhydrobiosis to persist in this unique environment.

Austin, Erin; Semmens, Katharine; Parsons, Charles

2009-01-01

217

Granite rock outcrops: an extreme environment for soil nematodes?  

PubMed

We studied soil nematode communities from the surface of granite flatrock outcrops in the eastern Piedmont region of the United States. The thin soils that develop here experience high light intensity and extreme fluctuations in temperature and moisture and host unique plant communities. We collected soils from outcrop microsites in Virginia (VA) and North Carolina (NC) in various stages of succession (Primitive, Minimal, and Mature) and compared soil properties and nematode communities to those of adjacent forest soils. Nematodes were present in most outcrop soils, with densities comparable to forest soils (P > 0.05). Nematode communities in Mature and Minimal soils had lower species richness than forest soils (P < 0.05) and contained more bacterial-feeders and fewer fungal-feeders (P < 0.05). Primitive soils contained either no nematodes (NC) or only a single species (Mesodorylaimus sp., VA). Nematode communities were similar between Mature and Minimal soils, according to trophic group representation, MI, PPI, EI, SI, and CI (P > 0.05). Forest soils had a higher PPI value (P < 0.05), but otherwise community indices were similar to outcrop soils (P > 0.05). Outcrop nematode communities failed to group together in a Bray-Curtis cluster analysis, indicating higher variability in community structure than the Forest soils, which did cluster together. A high proportion of the nematodes were extracted from outcrop soils in coiled form (33-89%), indicating that they used anhydrobiosis to persist in this unique environment. PMID:22661780

Austin, Erin; Semmens, Katharine; Parsons, Charles; Treonis, Amy

2009-03-01

218

Anthelmintics Are Substrates and Activators of Nematode P Glycoprotein?  

PubMed Central

P glycoproteins (Pgp), members of the ABC transporter superfamily, play a major role in chemoresistance. In nematodes, Pgp are responsible for resistance to anthelmintics, suggesting that they are Pgp substrates, as they are in mammalian cells. However, their binding to nematode Pgp and the functional consequences of this interaction have not been investigated. Our study showed that levamisole and most of the macrocyclic lactones (MLs) are Pgp substrates in nematodes. Ivermectin, although a very good substrate in mammalian cells, is poorly transported. In contrast to their inhibitory effect on mammalian Pgp, these drugs had a stimulatory effect on the transport activity of the reference Pgp substrate rhodamine 123 (R123) in the nematode. This may be due to a specific sequence of nematode Pgp, which shares only 44% identity with mammalian Pgp. Other factors, such as the affinity of anthelmintics for Pgp and their concentration in the Pgp microenvironment, could also differ in nematodes, as suggested by the specific relationship observed between the octanol-water partition coefficient (log P) of MLs and R123 efflux. Nevertheless, some similarities were also observed in the functional activities of the mammalian and nematode Pgp. As in mammalian cells, substrates known to bind the H site (Hoechst 33342 and colchicine) activated the R site, resulting in an increased R123 efflux. Our findings thus show that ML anthelmintics, which inhibit Pgp-mediated efflux in mammals, activate transport activity in nematodes and suggest that several substituents in the ML structure are involved in modulating the stimulatory effect.

Kerboeuf, Dominique; Guegnard, Fabrice

2011-01-01

219

A satellite explosion in the genome of holocentric nematodes.  

PubMed

Centromere sequences in the genome are associated with the formation of kinetochores, where spindle microtubules grow in mitosis. Centromere sequences usually have long tandem repeats (satellites). In holocentric nematodes it is not clear how kinetochores are formed during mitosis; they are distributed throughout the chromosomes. For this reason it appeared of interest to study the satellites in nematodes in order to determine if they offer any clue on how kinetochores are assembled in these species. We have studied the satellites in the genome of six nematode species. We found that the presence of satellites depends on whether the nematode chromosomes are holocentric or monocentric. It turns out that holocentric nematodes are unique because they have a large number of satellites scattered throughout their genome. Their number, length and composition are different in each species: they apparently have very little evolutionary conservation. In contrast, no scattered satellites are found in the monocentric nematode Trichinella spiralis. It appears that the absence/presence of scattered satellites in the genome distinguishes monocentric from holocentric nematodes. We conclude that the presence of satellites is related to the holocentric nature of the chromosomes of most nematodes. Satellites may stabilize a higher order structure of chromatin and facilitate the formation of kinetochores. We also present a new program, SATFIND, which is suited to find satellite sequences. PMID:23638010

Subirana, Juan A; Messeguer, Xavier

2013-04-24

220

Harmful effects of mustard bio-fumigants on entomopathogenic nematodes  

Microsoft Academic Search

Mustard (Brassica and Sinapis spp.) green manures tilled into the soil preceding potato crops act as bio-fumigants that are toxic to plant–parasitic nematodes, providing an alternative to synthetic soil fumigants. However, it is not known whether mustard green manures also kill beneficial entomopathogenic nematodes (EPNs) that contribute to the control of pest insects. We used sentinel insect prey (Galleria mellonella

Ricardo A. Ramirez; Donna R. Henderson; Ekaterini Riga; Lawrence A. Lacey; William E. Snyder

2009-01-01

221

Evaluation of Nematode Resistant Grape Rootstock for Managing Mesocriconema xenoplax  

Technology Transfer Automated Retrieval System (TEKTRAN)

The objective of this study is to better understand the impact of the ring nematode, Mesocriconema xenoplax, on the productivity and physiology of grapevines grafted onto different rootstocks that showed varying resistance to ring nematodes under greenhouse conditions. Pinot noir grapevines (grafted...

222

BREEDING FOR RESISTANCE TO NEMATODE-INCITED DISEASES OF POTATO  

Technology Transfer Automated Retrieval System (TEKTRAN)

Two nematode-caused problems of potato cost growers 200-300 dollars per acre to control with soil fumigants. They are Columbia root knot nematode which caused discoloration of the tuber flesh and deformation of the tuber surface, and Corky ringspot disease, a necrosis of the tuber flesh incited by i...

223

Plant species effects on soil nematode communities in experimental grasslands  

Microsoft Academic Search

We examined the effects of 12 different plant species on soil nematode abundance and community composition, and rotifer abundance, in an experimental grassland in Northern Sweden. Monocultures were grown for six or seven growing seasons before sampling. Four monocultures were grasses, four were legumes and four were non-leguminous forbs. Plant species identity had an effect on the nematode community, both

Maria Viketoft; Cecilia Palmborg; Björn Sohlenius; Kerstin Huss-Danell; Jan Bengtsson

2005-01-01

224

Collective behavior of nematodes in a thin fluid  

NASA Astrophysics Data System (ADS)

Many organisms live in a confined fluidic environment such as in a thin fluid layer on dermal tissues, in saturated soil, and others. In this study, we investigate collective behaviors of nematodes in a thin fluid layer. The actively moving nematodes feel various hydrodynamic forces such as surface tension from the top air-liquid interface, viscous stress from the bottom surface, and more. Two or more nematodes in close proximity can be drawn together by the capillary force between bodies. This capillary force also makes it difficult for nematodes to separate. The Strouhal number and a ratio of amplitude to wavelength are measured before and after nematode aggregation and separation. Grouped and separate nematodes have no significant changes of the Strouhal number and the ratio of amplitude to wavelength, which shows that body stroke and kinematic performance do not change while grouped together. This result implies that nematodes gain no mechanical advantage during locomotion when grouped but that the capillary force draws and keeps nematodes joined together.

Gart, Sean; Jung, Sunghwan

2010-11-01

225

Ecosystem type affects interpretation of soil nematode community measures  

Microsoft Academic Search

A better understanding of performance among major ecosystem types is necessary before nematode community indices can be applied at large geographic scales, ranging from regional to global. The objectives of this study were to: (1) determine the inherent variability in soil properties among and within wetland, forest and agricultural ecosystems; (2) compare nematode community composition among and within ecosystem types

D. A. Neher; J. Wub; M. E. Barbercheck; O. Anas

2005-01-01

226

Phylogenetic Relationships of the Wolbachia of Nematodes and Arthropods  

Microsoft Academic Search

Wolbachia are well known as bacterial symbionts of arthropods, where they are reproductive parasites, but have also been described from nematode hosts, where the symbiotic interaction has features of mutualism. The majority of arthropod Wolbachia belong to clades A and B, while nematode Wolbachia mostly belong to clades C and D, but these relationships have been based on analysis of

Katelyn Fenn; Claire Conlon; Martin Jones; Michael A Quail; Nancy E Holroyd; Julian Parkhill; Mark Blaxter

2006-01-01

227

Book review: Systematics of Cyst Nematodes (Nematoda: Heteroderinae)  

Technology Transfer Automated Retrieval System (TEKTRAN)

The cyst nematodes are an important group of plant-parasitic nematodes that cause billions of dollars in economic damage to crops every year. This article reviews a recently published, two-volume monograph that describes the morphological and molecular characteristics of these agriculturally signif...

228

Nematode-trapping fungi in organic and conventional cropping systems.  

PubMed

ABSTRACT Nematode-trapping fungi, nematodes, and microbial biomass were quantified in conventionally and organically managed field plots in the Sustainable Agriculture Farming Systems Project at the University of California at Davis. There were four replicate plots (0.135 ha per plot) for each management system, and plots were sampled three times each year for 2 years. The hypothesis that nematode-trapping fungi would be more abundant in organically managed plots was partially supported: the number of species of nematode-trapping fungi was slightly but significantly greater in organic than in conventional plots, two species (Arthrobotrys dactyloides and Nematoctonus leiosporus) were detected more frequently in organic plots, and the population densities of A. dactyloides and N. leiosporus were greater in organic than in conventional plots. Two other species (A. haptotyla and A. thaumasia), however, tended to be more numerous in conventional than in organic plots, and the total density of nematode-trapping fungi was similar in organic and conventional plots. Bacterivorous nematodes were more abundant and microbial biomass (substrate-induced respiration) was greater in organic than in conventional plots. Suppression of the root-knot nematode Meloidogyne javanica, as measured in a bioassay, was not related to management system or population density of nematode-trapping fungi but was positively related to microbial biomass. PMID:18944958

Jaffee, B A; Ferris, H; Scow, K M

1998-04-01

229

Gastrointestinal nematodes in dogs from Debre Zeit, Ethiopia  

Microsoft Academic Search

The study was conducted during the period between January 2005 and June 2006 to determine the frequency of gastrointestinal (GI) nematode infections of dogs in and around Debre Zeit, using qualitative and quantitative coprological (N=100) and postmortem examinations (N=20). By coproscopy 51% dogs were positive for different types of nematodal eggs, out of which 23.5% were with mixed infections. On

H. T. Yacob; T. Ayele; R. Fikru; A. K. Basu

2007-01-01

230

NEMATODE-INDUCED SYNCYTIUM—A MULTINUCLEATE TRANSFER CELL  

Microsoft Academic Search

SUMMARY The formation and structure of asyncytium induced by the potato cyst-nematode {Heterodera rostockiensis Woll.) in potato roots is described. At the permanent feeding site of the nematode larva, usually in the root cortex, the larva pierces a cell with its mouth stylet and injects saliva. Cell wall dissolution occurs to incorporate neighbouring cells into a syncytium. A column of

M. G. K. JONES; D. H. NORTHCOTE

1972-01-01

231

TOLERANCE OF POPULAR COTTON VARIETIES TO THE RENIFORM NEMATODE  

Technology Transfer Automated Retrieval System (TEKTRAN)

Thirty-three commercial cotton varieties were evaluated for tolerance to the reniform nematode in 2003 and 2004. Tolerance was measured by comparing nematode counts and seed cotton yields of each variety in untreated plots and plots treated with 3.5 gallons of Telone II per acre or 7.5 lb of Temik 1...

232

Parasitic Nematodes of Southeast Asia as Potential Zoonoses.  

National Technical Information Service (NTIS)

Studies on the nematodes of fishes of Palawan were completed. An 'anasakid-type' larva was very common in the material and probably represents a threat as a zoonosis. All nematodes from birds from Borneo and Palawan have been identified to genus. Many new...

G. D. Schmidt

1969-01-01

233

Predation of entomopathogenic nematodes by Sancassania sp. (Acari: Acaridae).  

PubMed

Predation of the entomopathogenic nematode, Steinernema feltiae (Rhabditida: Steinernematidae), by Sancassania sp. (Acari: Acaridae) isolated from field-collected scarab larvae was examined under laboratory conditions. Adult female mites consumed more than 80% of the infective juvenile (IJ) stage of S. feltiae within 24 h. When S. feltiae IJs were exposed to the mites for 24 h and then exposed to Galleria mellonella (Lepidoptera: Pyralidae) larvae, the number of nematodes penetrating into the larvae was significantly lower compared to S. feltiae IJs that were not exposed to mites (control). Soil type significantly affected the predation rate of IJs by the mites. Mites preyed more on nematodes in sandy soil than in loamy soil. We also observed that the mites consumed more S. feltiae IJs than Heterorhabditis bacteriophora (Rhabditida: Heterorhabditidae). No phoretic relationship was observed between mites and nematodes and the nematodes did not infect the mites. PMID:17924198

Karagoz, Mehmet; Gulcu, Baris; Cakmak, Ibrahim; Kaya, Harry K; Hazir, Selcuk

2007-01-01

234

Cryopreservation of nematode Caenorhabditis elegans in the adult stage.  

PubMed

Cryopreservation of nematode Caenorhabditis elegans in the adult stage is of importance as the nematode is a powerful research model organism. In this study, we applied the protocol previously established for cryopreservation of the L4 nematode to the adult one, and achieved a survival rate of 84%. When ice seeding was induced with bacteria P. syringae directly added to the nematode suspension instead of using a pre-cooled steel sticking needle, comparable survival rate was obtained after thawing. Moreover, a simple freezing device composed of a polystyrene foam box surrounded by a Dewar vessel put in a deep freezer was developed for a practical use. This simple method obtained a survival rate of 69 ± 4% for the adult nematode after thawing. PMID:23995406

Hayashi, M; Amino, H; Kita, K; Murase, N

235

Phytochemical based strategies for nematode control.  

PubMed

This review examines the discovery of naturally occurring phytochemicals antagonistic toward plant-parasitic and other nematodes. Higher plants have yielded a broad spectrum of active compounds, including polythienyls, isothiocyanates, glucosinolates, cyanogenic glycosides, polyacetylenes, alkaloids, lipids, terpenoids, sesquiterpenoids, diterpenoids, quassinoids, steroids, triterpenoids, simple and complex phenolics, and several other classes. Many other antinematodal compounds have been isolated from biocontrol and other fungi. Natural products active against mammalian parasites can serve as useful sources of compounds for examination of activity against plant parasites. The agricultural utilization of phytochemicals, although currently uneconomic in many situations, offers tremendous potential. PMID:12147760

Chitwood, David J

2002-05-13

236

Expressed sequence tags of the peanut pod nematode Ditylenchus africanus: the first transcriptome analysis of an Anguinid nematode  

PubMed Central

In this study, 4847 expressed sequenced tags (ESTs) from mixed stages of the migratory plant-parasitic nematode Ditylenchus africanus (peanut pod nematode) were investigated. It is the first molecular survey of a nematode which belongs to the family of the Anguinidae (order Rhabditida, superfamily Sphaerularioidea). The sequences were clustered into 2596 unigenes, of which 43% did not show any homology to known protein, nucleotide, nematode EST or plant-parasitic nematode genome sequences. Gene ontology mapping revealed that most putative proteins are involved in developmental and reproductive processes. In addition unigenes involved in oxidative stress as well as in anhydrobiosis, such as LEA (late embryogenesis abundant protein) and trehalose-6-phosphate synthase were identified. Other tags showed homology to genes previously described as being involved in parasitism (expansin, SEC-2, calreticulin, 14-3-3b and various allergen proteins). In situ hybridization revealed that the expression of a putative expansin and a venom allergen protein was restricted to the gland cell area of the nematode, being in agreement with their presumed role in parasitism. Furthermore, 7 putative novel candidate parasitism genes were identified based on the prediction of a signal peptide in the corresponding protein sequence and homologous ESTs exclusively in parasitic nematodes. These genes are interesting for further research and functional characterization. Finally, 34 unigenes were retained as good target candidates for future RNAi experiments, because of their nematode specific nature and observed lethal phenotypes of Caenorhabditis elegans homologs.

Haegeman, Annelies; Jacob, Joachim; Vanholme, Bartel; Kyndt, Tina; Mitreva, Makedonka; Gheysen, Godelieve

2009-01-01

237

Dot immunogold filtration assay (DIGFA) for the rapid detection of specific antibodies against the rat lungworm Angiostrongylus cantonensis (Nematoda: Metastrongyloidea) using purified 31-kDa antigen.  

PubMed

A rapid dot immunogold filtration assay (DIGFA) was adopted for specific immunodiagnosis of human cerebral angiostrongyliasis, using purified 31-kDa glycoprotein specific to Angiostrongylus cantonensis as diagnostic antigen and protein A colloidal gold conjugate as antigen-antibody detector. A total of 59 serum samples were assayed - 11 samples from clinically diagnosed patients with detectable A. cantonensis-specific antibody in immunoblotting; 23 samples from patients with other related parasitic diseases, i.e. gnathostomiasis (n= 8), cysticercosis (n= 5), toxocariasis (n= 2), filariasis (n= 4), paragonimiasis (n= 2) and malaria (n= 2); and 25 samples from normal healthy subjects. The sensitivity and specificity of DIGFA to detect anti-A. cantonensis specific antibodies in serologically confirmed angiostrongyliasis cases, were both 100%. No positive DIGFA was observed in cases with other parasitic diseases, and the healthy control subjects. The 3-min DIGFA is as sensitive and specific as the 3-h immunoblot test in angiostrongyliasis confirmed cases that revealed a 31-kDa reactive band. The gold-based DIGFA is more rapid and easier to perform than the traditional enzyme-linked immunosorbent assay (ELISA). The test utilizing purified A. cantonensis antigen is reliable and reproducible for specific immunodiagnosis of human infection with A. cantonensis - thus can be applied as an additional routine test for clinical diagnostic support. Large-scale sero-epidemiological studies in endemic communities in north-east Thailand are under way to evaluate its usefulness under field conditions. PMID:23710755

Eamsobhana, P; Gan, X X; Ma, A; Wang, Y; Wanachiwanawin, D; Yong, H S

2013-05-28

238

Angiostrongylus cantonensis: tegumental and hypodermic alterations of the fourth-stage larvae following administration of tribendimidine in vivo and in vitro.  

PubMed

Angiostrongylus cantonensis is a parasitic pathogen whose forth-stage larvae (L4) parasitize in the central nervous system (CNS) of the human cause severe eosinophilic encephalitis or meningoencephalitis. Previous study indicated an impressive anthelmintic efficacy of tribendimidine (TBD) against CNS parasitized L4 of A. cantonensis. Tegument of the larvae is the first physical barrier to protect them from attack by the host immune system. In the present study, tegumental and hypodermic alterations were observed by scanning electron microscopy and transmission electron microscopy after administration of TBD. During treatment of TBD in vivo, L4 presented wizened side sensor, disappearance of mastoids and longitudinal grain, prominent surface coat, heterogeneous tegumental layers, incompact hypodermic cell junctions, blurred myotube, and small scale of vacuole in a basal layer. After incubation with TBD in vitro, L4 exhibited a swollen side sensor and mastoids disappearance in head end. Abundant tegumental blebs and obvious deformation of both cross-grain and longitudinal grain were detected on the surface, and shrinkage of all tegumental layers, chaotic cell junction, turbid muscle cell, disappearance of myotubes, and vacuole-like changes were visible under the electron microscope. The results implied the potential mechanism of the anthelmintic effect of tribendimidine against L4 of A. cantonensis by direct damages to tegumental and hypodermic. PMID:23728774

Zeng, Xin; Wang, Juan; Wei, Jie; Wu, Feng; Fung, Feng; Wu, Xiaoying; Sun, Xi; Zheng, Huanqing; Lv, Zhiyue; Wu, Zhongdao

2013-06-02

239

Control of plant-parasitic nematodes by Paecilomyces lilacinus and Monacrosporium lysipagum in pot trials  

Microsoft Academic Search

The common soil inhabiting nematophagous fungus Paecilomyces lilacinus (Thom) Samson and the nematode trapping fungus Monacrosporium lysipagum (Drechsler) Subram were assayed for their ability to reduce the populations of three economically important plant-parasitic nematodes in pot trials. The fungi were tested individually and in combination against the root-knot nematode Meloidogyne javanica (Treub) Chitwood, cereal cyst nematode Heterodera avenae Wollenweber, or

Alamgir Khan; Keith L. Williams; Helena K. M. Nevalainen

2006-01-01

240

Arthrobotrys oligospora: a model organism for understanding the interaction between fungi and nematodes  

Microsoft Academic Search

Arthrobotrys oligospora, a predacious fungus of nematodes, has been very useful in understanding the relationship between nematophagous fungi and their nematode hosts. Arthrobotrys oligospora is by far the most common nematode-trapping fungus with the characteristic ability of forming adhesive trapping nets once in contact with nematodes. This review highlights the versatility and development of A. oligospora as a system to

Xue-Mei Niu; Ke-Qin Zhang

2011-01-01

241

Nematodes as an Indicator of Biological Crust Development in the Tengger Desert, China  

Microsoft Academic Search

Nematode communities were investigated on bare soil, physical soil crusts, algal crusts, and moss crusts in Shapotou in the Tengger Desert, China. The objective of the present study is to examine whether nematode communities develop parallel to the biological crust succession. The abundance of nematodes, the proportion of predators, maturity index, the number of nematode taxa identified, and Shannon index

Dejuan Zhi; Xiaoxia Ding; Wenbin Nan; Hongyu Li

2009-01-01

242

SSR MARKER(S) ASSOCIATED WITH ROOT-KNOT NEMATODE RESISTANCE GENE(S) IN COTTON  

Technology Transfer Automated Retrieval System (TEKTRAN)

Nematodes cause significant yield loss in US cotton, Gossypium hirsutum. Very few cotton lines are resistant to root-knot nematode [RKN] (Meloidogyne incognita spp.), one of the major nematode pest species in the US Cotton Belt. DNA markers for root-knot nematode resistance gene(s) will provide to...

243

Chemoattraction in Pristionchus nematodes and implications for insect recognition.  

PubMed

Nematodes and insects are the two dominant animal taxa in species numbers, and nematode-insect interactions constitute a significant portion of interspecies associations in a diversity of ecosystems. It has been speculated that most insects represent mobile microhabitats in which nematodes can obtain food, mobility, and shelter. Nematode-insect associations can be classified as phoretic (insects used for transportation, not as food), necromenic (insect used for transportation, then carcass as food), and entomopathogenic (insect is killed and used as food). To determine how nematodes target their hosts, we analyzed the chemosensory response and behavioral parameters of closely related Pristionchus nematodes that form species-specific necromenic associations with scarab beetles and the Colorado potato beetle. We found that all four studied Pristionchus species displayed unique chemoattractive profiles toward insect pheromones and plant volatiles with links to Pristionchus habitats. Moreover, chemoattraction in P. pacificus differs from that of C. elegans not only in the types of attractants, but also in its tempo, mode, and concentration response range. We conclude that Pristionchus olfaction is highly diverse among closely related species and is likely to be involved in shaping nematode-host interactions. PMID:17141618

Hong, Ray L; Sommer, Ralf J

2006-12-01

244

Horizontal gene transfer in nematodes: a catalyst for plant parasitism?  

PubMed

The origin of plant parasitism within the phylum Nematoda is intriguing. The ability to parasitize plants has originated independently at least three times during nematode evolution and, as more molecular data has emerged, it has become clear that multiple instances of horizontal gene transfer (HGT) from bacteria and fungi have played a crucial role in the nematode's adaptation to this new lifestyle. The first reported HGT cases in plant-parasitic nematodes were genes encoding plant cell wall-degrading enzymes. Other putative examples of HGT were subsequently described, including genes that may be involved in the modulation of the plant's defense system, the establishment of a nematode feeding site, and the synthesis or processing of nutrients. Although, in many cases, it is difficult to pinpoint the donor organism, candidate donors are usually soil dwelling and are either plant-pathogenic or plant-associated microorganisms, hence occupying the same ecological niche as the nematodes. The exact mechanisms of transfer are unknown, although close contacts with donor microorganisms, such as symbiotic or trophic interactions, are a possibility. The widespread occurrence of horizontally transferred genes in evolutionarily independent plant-parasitic nematode lineages suggests that HGT may be a prerequisite for successful plant parasitism in nematodes. PMID:21539433

Haegeman, Annelies; Jones, John T; Danchin, Etienne G J

2011-08-01

245

Resistance of Grape Rootstocks to Plant-parasitic Nematodes.  

PubMed

Candidate grape rootstocks were selected through a rigorous screening program initiated with important sources of resistance to Meloidogyne pathotypes and to Xiphinema index in Muscadinia rotundifolia and Vitis species native to North America. Based on their rooting capability and horticultural characteristics, 200 candidates were selected from 5,000 progeny of multiple crosses between commercial grape rootstocks and wild grape species that exhibited resistance to nematodes. After a 15-year screening process, 13 selections emerged with either almost complete or complete combined resistance to M. incognita Race 3, M. incognita pathotype Harmony C, M. arenaria pathotype Harmony A, and X. index, important nematode pests of grapevines. Durability of this broad resistance was tested by challenging the selections with the target nematodes in combination and with the target nematodes in combinations with species not included in the screening process. Durability of resistance of the candidate rootstocks was also tested by exposure to the nematode communities of infested field soils from different locations. Breadth of resistance was determined on the basis of their host status to non-target nematodes, including Mesocriconema xenoplax, Pratylenchus vulnus, Tylenchulus semipenetrans and Paratylenchus hamatus. After a total of 204 separate trials, the rootstocks were released to the grape industry as UCD GRN1, UCD GRN2, UCD GRN3, UCD GRN4, and UCD GRN5. We provide a compilation of current knowledge of the host status of these five newly released rootstocks and of 27 other rootstock cultivars to plant-parasitic nematodes. PMID:23482972

Ferris, H; Zheng, L; Walker, M A

2012-12-01

246

Resistance of Grape Rootstocks to Plant-parasitic Nematodes  

PubMed Central

Candidate grape rootstocks were selected through a rigorous screening program initiated with important sources of resistance to Meloidogyne pathotypes and to Xiphinema index in Muscadinia rotundifolia and Vitis species native to North America. Based on their rooting capability and horticultural characteristics, 200 candidates were selected from 5,000 progeny of multiple crosses between commercial grape rootstocks and wild grape species that exhibited resistance to nematodes. After a 15-year screening process, 13 selections emerged with either almost complete or complete combined resistance to M. incognita Race 3, M. incognita pathotype Harmony C, M. arenaria pathotype Harmony A, and X. index, important nematode pests of grapevines. Durability of this broad resistance was tested by challenging the selections with the target nematodes in combination and with the target nematodes in combinations with species not included in the screening process. Durability of resistance of the candidate rootstocks was also tested by exposure to the nematode communities of infested field soils from different locations. Breadth of resistance was determined on the basis of their host status to non-target nematodes, including Mesocriconema xenoplax, Pratylenchus vulnus, Tylenchulus semipenetrans and Paratylenchus hamatus. After a total of 204 separate trials, the rootstocks were released to the grape industry as UCD GRN1, UCD GRN2, UCD GRN3, UCD GRN4, and UCD GRN5. We provide a compilation of current knowledge of the host status of these five newly released rootstocks and of 27 other rootstock cultivars to plant-parasitic nematodes.

Ferris, H.; Zheng, L.; Walker, M. A.

2012-01-01

247

Microsporidian Infection in a Free-Living Marine Nematode  

PubMed Central

Microsporidia are unicellular fungi that are obligate endoparasites. Although nematodes are one of the most abundant and diverse animal groups, the only confirmed report of microsporidian infection was that of the “nematode killer” (Nematocida parisii). N. parisii was isolated from a wild Caenorhabditis sp. and causes an acute and lethal intestinal infection in a lab strain of Caenorhabditis elegans. We set out to characterize a microsporidian infection in a wild nematode to determine whether the infection pattern of N. parisii in the lab is typical of microsporidian infections in nematodes. We describe a novel microsporidian species named Sporanauta perivermis (marine spore of roundworms) and characterize its infection in its natural host, the free-living marine nematode Odontophora rectangula. S. perivermis is not closely related to N. parisii and differs strikingly in all aspects of infection. Examination by transmission electron microscopy (TEM) revealed that the infection was localized in the hypodermal and muscle tissues only and did not involve the intestines. Fluorescent in situ hybridization (FISH) confirmed infection in the muscle and hypodermis, and surprisingly, it also revealed that the parasite infects O. rectangula eggs, suggesting a vertical mode of transmission. Our observations highlight the importance of studying parasites in their natural hosts and indicate that not all nematode-infecting microsporidia are “nematode killers”; instead, microsporidiosis can be more versatile and chronic in the wild.

Ardila-Garcia, A. M.

2012-01-01

248

Nematodes as bioindicators of soil degradation due to heavy metals.  

PubMed

The effect of distance from a heavy metal pollution source on the soil nematode community was investigated on four sampling sites along an 4 km transect originating at the Kovohuty a.s. Krompachy (pollution source). The soil nematode communities were exposed to heavy metal influence directly and through soil properties changes. We quantified the relative effects of total and mobile fraction of metals (As, Cd, Cr, Cu, Pb, and Zn) on soil ecosystem using the nematode community structure (trophic and c-p groups,) and ecological indices (Richness of genera, H', MI2-5, etc.). Pollution effects on the community structure of soil free living nematodes was found to be the highest near the pollution source, with relatively low population density and domination of insensitive taxa. A decrease in heavy metals contents along the transect was linked with an increase in complexity of nematode community. The majority of used indices (MI2-5, SI, H') negatively correlated (P < 0.05 or P < 0.01) with heavy metals content and were sensitive to soil ecosystem disturbance. Contamination by heavy metals has negatively affected the soil environment, which resulted in nematode community structure and ecological indices changes. Results showed that the free-living nematodes are useful tools for bioindication of contamination and could be used as an alternative to the common approaches based on chemical methods. PMID:22923372

Šalamún, Peter; Ren?o, Marek; Kucanová, Eva; Brázová, Tímea; Papajová, Ingrid; Miklisová, Dana; Hanzelová, Vladimíra

2012-08-26

249

Computational and phylogenetic validation of nematode horizontal gene transfer  

PubMed Central

Sequencing of expressed genes has shown that nematodes, particularly the plant-parasitic nematodes, have genes purportedly acquired from other kingdoms by horizontal gene transfer. The prevailing orthodoxy is that such transfer has been a driving force in the evolution of niche specificity, and a recent paper in BMC Evolutionary Biology that presents a detailed phylogenetic analysis of cellulase genes in the free-living nematode Pristionchus pacificus at the species, genus and family levels substantiates this hypothesis. See research article: http://www.biomedcentral.com/1471-2148/11/13

2011-01-01

250

Detection and quantification of root-knot nematode (Meloidogyne javanica), lesion nematode (Pratylenchus zeae) and dagger nematode (Xiphinema elongatum) parasites of sugarcane using real-time PCR.  

PubMed

A number of different plant parasitic nematode species are found associated with sugarcane in South Africa. Of these, the root-knot nematode (Meloidogyne javanica), the lesion nematode (Pratylenchus zeae) and the dagger nematode (Xiphinema elongatum) are potentially the most damaging pests. Identification and enumeration of the number of these nematodes are necessary for providing advice to farmers as well as studying the effects of various treatments in field and glasshouse trials. We report on the development, use, and extent of specificity of three sets of primers, for M. javanica, P. zeae and X. elongatum, and on tests to detect and quantify the number of these nematodes in soil samples using SYBR Green I dye and real-time PCR technology. Amplicons from the three target species (obtained with their respective primer sets) are discernible in size by gel electrophoresis (380bp for M. javanica, 250bp for P. zeae and 500bp for X. elongatum). Also, these amplicons have characteristic melting temperatures of 83.8 degrees C (M. javanica), 86.6 degrees C (P. zeae) and 86.1 degrees C (X. elongatum). Investigations into multiplex reactions found competition between species with M. javanica competing with P. zeae and X. elongatum. Subsequent single tube (simplex) assays, enabled the construction of calibration curves for each of the three species. These were then used for quantification of the numbers of each of these species in nematode samples extracted from the field, with a high (R2=0.83) and significant positive correlation between real-time PCR and counts performed with microscopy. PMID:18378423

Berry, Shaun D; Fargette, Mireille; Spaull, Vaughan W; Morand, Serge; Cadet, Patrice

2008-02-15

251

Trophic interactions in soils as they affect energy and nutrient dynamics. III. Biotic interactions of bacteria, amoebae, and nematodes  

Microsoft Academic Search

Bacteria (Pseudomonas), amoebae (Acanthamoeba), and nematodes (Mesodiplogaster) were raised in soil microcosms with and without glucose additions. Nematode and amoebal grazing on bacteria significantly reduced bacterial populations by the end of a 24-day incubation period. Amoebal numbers decreased in the presence of nematodes with a corresponding increase in nematode numbers which reached a maximum of 230 nematodes\\/g of soil in

R. V. Anderson; E. T. Elliott; J. F. McClellan; D. C. Coleman; C. V. Cole; H. W. Hunt

1977-01-01

252

Strongyloidiasis and other intestinal nematode infections.  

PubMed

In contrast to other helminthic parasites, Strongyloides stercoralis can replicate within humans, causing a chronic persistent infection that can be severe and fatal in compromised hosts. This article reviews new developments to help meet the clinical challenges of this infection, including clinical clues to the diagnosis, new diagnostic methods, including stool culture and serological assays, new drugs such as albendazole and ivermectin, and difficult treatment issues. The other major intestinal nematode parasites, including Ascaris, hookworm, and Trichuris, are extremely common worldwide, but in North America their clinical presentation is often more subtly related to low-grade worm burdens or allergic manifestations. Special consideration is given to difficult management issues, including the patient with unexplained eosinophilia, the pregnant patient, and the patient who passes a worm. PMID:8254165

Liu, L X; Weller, P F

1993-09-01

253

MSP Dynamics Drives Nematode Sperm Locomotion  

PubMed Central

Most eukaryotic cells can crawl over surfaces. In general, this motility requires three sequential actions: polymerization at the leading edge, adhesion to the substrate, and retraction at the rear. Recent in vitro experiments with extracts from spermatozoa from the nematode Ascaris suum suggest that retraction forces are generated by depolymerization of the major sperm protein cytoskeleton. Combining polymer entropy with a simple kinetic model for disassembly we propose a model for disassembly-induced retraction that fits the in vitro experimental data. This model explains the mechanism by which disassembly of the cytoskeleton generates the force necessary to pull the cell body forward and suggests further experiments that can test the validity of the models.

Wolgemuth, Charles W.; Miao, Long; Vanderlinde, Orion; Roberts, Tom; Oster, George

2005-01-01

254

MSP dynamics and retraction in nematode sperm  

NASA Astrophysics Data System (ADS)

Most eukaryotic cells can crawl over surfaces. In general, this motility requires three distinct actions: polymerization at the leading edge, adhesion to the substrate, and retraction at the rear. Recent in vitro experiments with extracts from spermatozoa from the nematode Ascaris suum suggest that retraction forces are generated by depolymerization of the Major Sperm Protein (MSP) cytoskeleton. Combining polymer entropy with a simple kinetic model for disassembly I propose a model for disassembly-induced retraction that fit the in vitro experimental data. This model explains the mechanism by which deconstruction of the cytoskeleton produces the force necessary to pull the cell body forward and suggest further experiments that can test the validity of the model.

Wolgemuth, Charles; Miao, Long; Vanderlinde, Orion; Roberts, Tom; Oster, George

2005-03-01

255

MSP Dynamics and Retraction in Nematode Sperm  

NASA Astrophysics Data System (ADS)

Most eukaryotic cells can crawl over surfaces. In general, this motility requires three distinct actions: polymerization at the leading edge, adhesion to the substrate, and retraction at the rear. Recent in vitro experiments with extracts from spermatozoa from the nematode Ascaris suum suggest that retraction forces are generated by depolymerization of the Major Sperm Protein (MSP) cytoskeleton. Combining polymer entropy with a simple kinetic model for disassembly I propose a model for disassembly-induced retraction that fit the in vitro experimental data. This model explains the mechanism by which deconstruction of the cytoskeleton produces the force necessary to pull the cell body forward and suggest further experiments that can test the validity of the model.

Wolgemuth, Charles W.

2005-03-01

256

Robustness and flexibility in nematode vulva development.  

PubMed

The Caenorhabditis elegans vulva has served as a paradigm for how conserved developmental pathways, such as EGF-Ras-MAPK, Notch and Wnt signaling, participate in networks driving animal organogenesis. Here, we discuss an emerging direction in the field, which places vulva research in a quantitative and microevolutionary framework. The final vulval cell fate pattern is known to be robust to change, but only recently has the variation of vulval traits been measured under stochastic, environmental or genetic variation. Whereas the resulting cell fate pattern is invariant among rhabditid nematodes, recent studies indicate that the developmental system has accumulated cryptic variation, even among wild C. elegans isolates. Quantitative differences in the signaling network have emerged through experiments and modeling as the driving force behind cryptic variation in Caenorhabditis species. On a wider evolutionary scale, the establishment of new model species has informed about the presence of qualitative variation in vulval signaling pathways. PMID:22325232

Félix, Marie-Anne; Barkoulas, Michalis

2012-02-09

257

Storage and Shipment of Osmotically Desiccated Entomogenous Nematodes.  

National Technical Information Service (NTIS)

The patent application relates to insect control employing biological agents especially for the benefit of agriculture, garden and household environments. In particular, it relates to methods to desiccate insect parasitic nematodes osmotically, and to pac...

I. Popiel I. Glazer J. E. Lindegren

1987-01-01

258

Survey of fresh vegetables for nematodes, amoebae, and Salmonella.  

PubMed

Contamination by nematodes, amoebae, and bacteria of the genus Salmonella was estimated in a 2-year survey of salad vegetables obtained from wholesale and retail sources. The vegetables examined were cucumbers, cabbage, lettuce, celery, carrots, radishes, tomatoes, mushrooms, cauliflower, and spinach. Nematode eggs and larvae were recovered by the Nacconol-ether centrifugation method. Some nematode eggs were identified as parasitic Ascaris sp.; the majority of larval nematodes were thought to be soil-dwelling species. Amoebae were recovered by rinsing the vegetables with distilled water, centrifuging the rinse water, and transferring the sediment to agar plates on which a bacterial lawn had previously been grown; trophozoites identified as the potentially pathogenic species--Acanthamoeba polyphaga, A. rhysodes, and A. castellanii--were the most common amoebae recovered on the plates. Salmonella spp. were grown from 4 of 50 samples. PMID:6540260

Rude, R A; Jackson, G J; Bier, J W; Sawyer, T K; Risty, N G

259

Control of Parasitic Nematode Ova with 'Bacillus sphaericus'.  

National Technical Information Service (NTIS)

Typically, high concentrations of anthelmintic compounds are required for killing parasites in their habitat within a host. In the case of intestinal nematodes, anthelmintics must be ingested or absorbed by the worms for expulsion of the parasite from the...

L. W. Bone

1987-01-01

260

Nematode parasites of waterfowl (Anseriformes) from western United States  

USGS Publications Warehouse

Thirty-four species of nematodes were found in 415 Anseriformes (Anatidae) of 27 species; 93.7% of birds over 4 weeks old were infected. Data on prevalence, host specificity, age of host, and geographic distribution are given. Infections were more intense in sick birds and birds in poor physical condition. Accidental or abnormal infection was more likely in sick than in normal birds. From 1 to 13 species of nematodes are reported from each host species, including 118 new host records, 3 nematodes new for North America, and 1 new species. Multiple infections were present in 76.5% of birds parasitized; eight species of nematodes were found in one whistling swan (Olor columbianus).

McDonald, M. E.

1974-01-01

261

Motility of small nematodes in disordered wet granular media  

NASA Astrophysics Data System (ADS)

Organisms that evolve within complex fluidic environments often develop unique methods of locomotion that allow them to exploit the properties of the media. In this talk, we present an investigation on the motility of the worm nematode Caenorhabditis elegans in shallow, wet granular media as a function of particle size dispersity and area density (?) using both particle- and nematode-tracking methods. Surprisingly, the nematode's propulsion speed is enhanced by the presence of particles in a fluid and is nearly independent of local area density. The undulation speed, often used to differentiate locomotion gaits, is significantly affected by particle size dispersity for area densities above ?> 0.55, and is characterized by a change in the nematode's waveform from swimming to crawling. This change occurs for dense polydisperse media only and highlights the organism's adaptability to subtle differences in local structure between monodisperse and polydisperse media.

Juarez, Gabriel; Lu, Kevin; Sznitman, Josue; Arratia, Paulo E.

2010-11-01

262

Gastrointestinal nematodes in dogs from Debre Zeit, Ethiopia.  

PubMed

The study was conducted during the period between January 2005 and June 2006 to determine the frequency of gastrointestinal (GI) nematode infections of dogs in and around Debre Zeit, using qualitative and quantitative coprological (N = 100) and postmortem examinations (N = 20). By coproscopy 51% dogs were positive for different types of nematodal eggs, out of which 23.5% were with mixed infections. On necropsy 95% animals were found positive for adult parasites, of which 31.6% were showing more than one species of adult nematodes. The coproscopical examination revealed 32% infection with Ancylostoma caninum followed by Toxocara canis (21%), Spirocerca lupi (7%) and Trichuris vulpis (3%), while postmortem examination showed 70, 45, 23.5 and 5% infection, respectively. The study further indicated significant difference (P < 0.05) in overall frequency of GI nematode infections among different age groups but no difference (P > 0.05) between sexes. PMID:17614203

Yacob, H T; Ayele, T; Fikru, R; Basu, A K

2007-07-05

263

Human gastrointestinal nematode infections: are new control methods required?  

PubMed Central

Gastrointestinal (GI) nematode infections affect 50% of the human population worldwide, and cause great morbidity as well as hundreds of thousands of deaths. Despite modern medical practices, the proportion of the population infected with GI nematodes is not falling. This is due to a number of factors, the most important being the lack of good healthcare, sanitation and health education in many developing countries. A relatively new problem is the development of resistance to the small number of drugs available to treat GI nematode infections. Here we review the most important parasitic GI nematodes and the methods available to control them. In addition, we discuss the current status of new anthelmintic treatments, particularly the plant cysteine proteinases from various sources of latex-bearing plants and fruits.

Stepek, Gillian; Buttle, David J; Duce, Ian R; Behnke, Jerzy M

2006-01-01

264

Challenges in developing phytochemicals for use as nematode management agents  

Technology Transfer Automated Retrieval System (TEKTRAN)

Plants and fungi produce diverse classes of chemicals toxic or otherwise antagonistic to nematodes. Because phytochemicals are often safer than synthetic compounds and consequently receive less regulation, researchers are actively engaged in development of these materials as components of management...

265

The draft genome of the parasitic nematode Trichinella spiralis  

PubMed Central

Genome-based studies of metazoan evolution are most informative when phylogenetically diverse species are incorporated in the analysis. As such, evolutionary trends within and outside the phylum Nematoda have been less revealing by focusing only on comparisons involving Caenorhabditis elegans. Herein, we present a draft of the 64 megabase nuclear genome of Trichinella spiralis, containing 15,808 protein coding genes. This parasitic nematode is an extant member of a clade that diverged early in the evolution of the phylum enabling identification of archetypical genes and molecular signatures exclusive to nematodes. Comparative analyses support intrachromosomal rearrangements across the phylum, disproportionate numbers of protein family deaths over births in parasitic vs. a non-parasitic nematode, and a preponderance of gene loss and gain events in nematodes relative to Drosophila melanogaster. This sequence and the panphylum characteristics identified herein will advance evolutionary studies and strategies to combat global parasites of humans, food animals and crops.

Mitreva, Makedonka; Jasmer, Douglas P.; Zarlenga, Dante S.; Wang, Zhengyuan; Abubucker, Sahar; Martin, John; Taylor, Christina M.; Yin, Yong; Fulton, Lucinda; Minx, Pat; Yang, Shiaw-Pyng; Warren, Wesley C.; Fulton, Robert S.; Bhonagiri, Veena; Zhang, Xu; Hallsworth-Pepin, Kym; Clifton, Sandra W.; McCarter, James P.; Appleton, Judith; Mardis, Elaine R.; Wilson, Richard K.

2011-01-01

266

Mucosal mast cells and the allergic response against nematode parasites  

Microsoft Academic Search

IgE-mediated Type-I allergic reactions at nematode-infected mucosal surfaces are considered to have a direct protective function. The contribution of mucosal mast cells (MMC) to these mucosal allergic responses is reviewed. In addition to the T helper 2 cell-mediated regulation of MMC hyperplasia during nematode infection the kit ligand, stem cell factor (SCF), plays a key role in the early development

Hugh R. P. Miller

1996-01-01

267

Utilization of Biological Control for Managing Plant-Parasitic Nematodes  

Microsoft Academic Search

\\u000a Biological control of plant-parasitic nematodes can be accomplished either by application of antagonistic organisms, conservation\\u000a and enhancement of indigenous antagonists, or a combination of both strategies. The application of biological control has\\u000a been inconsistent in suppressing nematode populations because the efficacy of antagonists is influenced by other soil organisms\\u000a and the host-plant. Integration of biological control with nematicides, solarization, organic

Patricia Timper

268

Development of the Root-Knot Nematode Feeding Cell  

Microsoft Academic Search

The root-knot nematode feeding cell is a remarkable example of the reprogramming of plant cells by biotrophic pathogens. With\\u000a the aid of molecules secreted into plant cells from three esophageal gland cells, the root-knot nematode Meloidogyne sp. orchestrates a fundamental change in those cells surrounding its head in the plant root. These cells expand in volume\\u000a over tenfold and become

R. Berg; Thomas Fester; Christopher Taylor

269

Multifocal electroretinography response after laser photocoagulation of a subretinal nematode  

Microsoft Academic Search

PURPOSE: To describe multifocal electroretinography findings before and after laser photocoagulation of a subretinal nematode in diffuse unilateral subacute neuroretinitis.METHOD: Observational case report. A 45-year-old woman with left eye inflammation, subretinal tracts superior and temporal to the fovea, and a subretinal coiled mobile parasite was treated with laser photocoagulation to destroy the nematode. Multifocal electroretinography was performed before and after

Adam Martidis; Paul B Greenberg; Adam H Rogers; Leonardo J Velázquez-Estades; Caroline R Baumal

2002-01-01

270

Phylogenetic relationships of the Wolbachia of nematodes and arthropods.  

PubMed

Wolbachia are well known as bacterial symbionts of arthropods, where they are reproductive parasites, but have also been described from nematode hosts, where the symbiotic interaction has features of mutualism. The majority of arthropod Wolbachia belong to clades A and B, while nematode Wolbachia mostly belong to clades C and D, but these relationships have been based on analysis of a small number of genes. To investigate the evolution and relationships of Wolbachia symbionts we have sequenced over 70 kb of the genome of wOvo, a Wolbachia from the human-parasitic nematode Onchocerca volvulus, and compared the genes identified to orthologues in other sequenced Wolbachia genomes. In comparisons of conserved local synteny, we find that wBm, from the nematode Brugia malayi, and wMel, from Drosophila melanogaster, are more similar to each other than either is to wOvo. Phylogenetic analysis of the protein-coding and ribosomal RNA genes on the sequenced fragments supports reciprocal monophyly of nematode and arthropod Wolbachia. The nematode Wolbachia did not arise from within the A clade of arthropod Wolbachia, and the root of the Wolbachia clade lies between the nematode and arthropod symbionts. Using the wOvo sequence, we identified a lateral transfer event whereby segments of the Wolbachia genome were inserted into the Onchocerca nuclear genome. This event predated the separation of the human parasite O. volvulus from its cattle-parasitic sister species, O. ochengi. The long association between filarial nematodes and Wolbachia symbionts may permit more frequent genetic exchange between their genomes. PMID:17040125

Fenn, Katelyn; Conlon, Claire; Jones, Martin; Quail, Michael A; Holroyd, Nancy E; Parkhill, Julian; Blaxter, Mark

2006-10-01

271

Kinetics of movement of normal and mutant nematodes  

Microsoft Academic Search

The nematode,Caenorhabditis elegans, is strongly attracted towards secretions ofEscherichia coli. The movement of a population of nematodes from the center of an agar plate through a gradient of these secretions towards bacteria at the circumference can be represented by a series of first-order rate processes. Normal and mutant strains of various kinds demonstrate marked differences in their rates of movement.

Henry F. Epstein; Mette M. Isachsen; Edwin A. Suddleson

1976-01-01

272

Allelopathy in the management of plant-parasitic nematodes.  

PubMed

There are numerous reports of nematicidal chemicals in crude plant homogenates, leachates, and decomposing residues. These compounds are usually assumed to be secondary metabolites, which serve as chemical defenses against disease and parasites. When such compounds are released into the rhizosphere, they are known as allelochemicals. The possibility exists to exploit allelochemicals for nematode control, and there have been many attempts to use this approach either by rotation, intercropping, or green manure treatments. Results have met with mixed success. Proof of allelochemical activity in field situations is difficult to obtain, but it is evident that some rotation crops are significantly better at reducing nematode populations than others. Rotations with non-host plants may simply deny the nematode population an adequate food source for reproduction (passive suppression), whereas allelopathic crops kill nematodes by the production of toxic compounds (active suppression). Progress toward sustainable agriculture should benefit from studies on allelopathic nematode control. However, grower acceptance of new plant-rotation strategies are based on economic and logistical considerations as well as efficacy. A potential practical application of allelopathic nematode control that involves using rapeseed as a green manure crop to reduce populations of Xiphinema americanum sensu lato in temperate orchards is presented. PMID:19277340

Halbrendt, J M

1996-03-01

273

Nematode communities in organically and conventionally managed agricultural soils.  

PubMed

Interpretation of nematode community indices requires a reference to a relatively undisturbed community. Maturity and trophic diversity index values were compared for five pairs of certified organically and conventionally managed soils in the Piedmont region of North Carolina. Available nitrogen (nitrate, ammonium) was estimated at various lag periods relative to times of sampling for nematode communities to determine the strength of correlative relationship between nematode communities and nitrogen availability. Soils were sampled six times yearly in 1993 and 1994 to determine the best time of year to sample. Maturity values for plant parasites were greater in organically than conventionally managed soils, and differences between management systems were greater in fall than spring months. However, other maturity and diversity indices did not differ between the two management practices. Differences in crop species grown in the two systems accounted for most differences observed in the community of plant-parasitic nematodes. Indices of free-living nematodes were correlated negatively with concentrations of ammonium, whereas indices of plant-parasitic nematodes were correlated positively with concentrations of nitrate. Due to the similarity of index values between the two systems, organically managed soils are not suitable reference sites for monitoring and assessing the biological aspects of soil quality for annually harvested crops. PMID:19270884

Neher, D A

1999-06-01

274

The environmental physiology of Antarctic terrestrial nematodes: a review.  

PubMed

The environmental physiology of terrestrial Antarctic nematodes is reviewed with an emphasis on their cold-tolerance strategies. These nematodes are living in one of the most extreme environments on Earth and face a variety of stresses, including low temperatures and desiccation. Their diversity is low and declines with latitude. They show resistance adaptation, surviving freezing and desiccation in a dormant state but reproducing when conditions are favourable. At high freezing rates in the surrounding medium the Antarctic nematode Panagrolaimus davidi freezes by inoculative freezing but can survive intracellular freezing. At slow freezing rates this nematode does not freeze but undergoes cryoprotective dehydration. Cold tolerance may be aided by rapid freezing, the production of trehalose and by an ice-active protein that inhibits recrystallisation. P. davidi relies on slow rates of water loss from its habitat, and can survive in a state of anhydrobiosis, perhaps aided by the ability to synthesise trehalose. Teratocephalus tilbrooki and Ditylenchus parcevivens are fast-dehydration strategists. Little is known of the osmoregulatory mechanisms of Antarctic nematodes. Freezing rates are likely to vary with water content in Antarctic soils. Saturated soils may produce slow freezing rates and favour cryoprotective dehydration. As the soil dries freezing rates may become faster, favouring freezing tolerance. When the soil dries completely the nematodes survive anhydrobiotically. Terrestrial Antarctic nematodes thus have a variety of strategies that ensure their survival in a harsh and variable environment. We need to more fully understand the conditions to which they are exposed in Antarctic soils and to apply more natural rates of freezing and desiccation to our studies. PMID:14615899

Wharton, D A

2003-08-28

275

[Biology of gastrointestinal nematodes of ruminants].  

PubMed

The development and survival of free-living stages of gastro-intestinal nematodes of small ruminants are influenced by several abiotic and biotic factors. Within the abiotic factors, most important are the environmental temperature and humidity. They regulate the development of larvae from eggs dispersed on the pasture by the animals faeces. Each parasite species that infect ruminants requires a different time to development, depending on temperature and humidity. Among trichostrongylids, Ostertagia, Teladorsagia and Nematodirus show a strong adaptation to low temperatures. Nematodirus larvae are able to survive to winter inside the egg shell. Temperature and humidity influence the distribution and survival of larvae on pasture. The larval third stage can migrate from faeces to pasture vegetation and they accumulate at the basis of vegetation where stay during the day or in the soil to avoid the desiccation. The forage species affects the migration of larvae on herbage too. Many biological factors contribute to disperse the larvae on the pasture. Dung burying beetles, coprophagous beetles and earthworms can greatly reduce the larvae of some trichostrongylids on pasture. They contribute to the spread of the faecal material on the pasture and allow the larval death as a consequence of drying. PMID:17176950

Manfredi, M T

2006-09-01

276

Inbreeding and outbreeding depression in Caenorhabditis nematodes.  

PubMed

The nematode Caenorhabditis elegans reproduces primarily by self-fertilization of hermaphrodites, yet males are present at low frequencies in natural populations (androdioecy). The ancestral state of C. elegans was probably gonochorism (separate males and females), as in its relative C. remanei. Males may be maintained in C. elegans because outcrossed individuals escape inbreeding depression. The level of inbreeding depression is, however, expected to be low in such a highly selfing species, compared with an outcrosser like C. remanei. To investigate these issues, we measured life-history traits in the progeny of inbred versus outcrossed C. elegans and C. remanei individuals derived from recently isolated natural populations. In addition, we maintained inbred lines of C. remanei through 13 generations of full-sibling mating. Highly inbred C. remanei showed dramatic reductions in brood size and relative fitness compared to outcrossed individuals, with evidence of both direct genetic and maternal-effect inbreeding depression. This decline in fitness accumulated over time, causing extinction of nearly 90% of inbred lines, with no evidence of purging of deleterious mutations from the remaining lines. In contrast, pure strains of C. elegans performed better than crosses between strains, indicating outbreeding depression. The results are discussed in relation to the evolution of androdioecy and the effect of mating system on the level of inbreeding depression. PMID:17542844

Dolgin, Elie S; Charlesworth, Brian; Baird, Scott E; Cutter, Asher D

2007-06-01

277

Evolution of early embryogenesis in rhabditid nematodes  

PubMed Central

The cell biological events that guide early embryonic development occur with great precision within species but can be quite diverse across species. How these cellular processes evolve and which molecular components underlie evolutionary changes is poorly understood. To begin to address these questions, we systematically investigated early embryogenesis, from the one- to the four-cell embryo, in 34 nematode species related to C. elegans. We found 40 cell-biological characters that captured the phenotypic differences between these species. By tracing the evolutionary changes on a molecular phylogeny, we found that these characters evolved multiple times and independently of one another. Strikingly, all these phenotypes are mimicked by single-gene RNAi experiments in C. elegans. We use these comparisons to hypothesize the molecular mechanisms underlying the evolutionary changes. For example, we predict that a cell polarity module was altered during the evolution of the Protorhabditis group and show that PAR-1, a kinase localized asymmetrically in C. elegans early embryos, is symmetrically localized in the one-cell stage of Protorhabditis group species. Our genome-wide approach identifies candidate molecules—and thereby modules—associated with evolutionary changes in cell-biological phenotypes.

Brauchle, Michael; Kiontke, Karin; MacMenamin, Philip; Fitch, David H. A.; Piano, Fabio

2009-01-01

278

BACTERIAL PREFERENCES OF THE BACTERIVOROUS SOIL NEMATODE CEPHALOBUS BREVICAUDA (CEPHALOBIDATE): EFFECT OF BACTERIAL TYPE AND SIZE  

EPA Science Inventory

Cell size and type may affect availability of bacteria for consumption by bacterivorous nematodes in the soil and in culture. This study explored the bacterial preferences of the bacterivorous soil nematode Cephalobus brevicauda (Cephalobidae) by comparing bactgeria isolated dir...

279

In vitro proteolysis of nematode FLPs by preparations from the free-living nematode Panagrellus redivivus and two plant-parasitic nematodes (Heterodera glycines and Meloidogyne incognita)  

Technology Transfer Automated Retrieval System (TEKTRAN)

Proteolytic activities in extracts from three nematodes, the plant parasites Heterodera glycines and Meloidogyne incognita, 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 la...

280

Nematode Chemotaxis: Gradual Turns, Sharp Turns, and Modulated Turn Angles  

NASA Astrophysics Data System (ADS)

We examine strategies used by the soil-dwelling nematode Caenorhabditis Elegans for chemotaxis in complex environments. The proposed description is based on our recently developed piecewise-harmonic-curvature model of nematode locomotion [PLoS ONE, 7(7) e40121 (2012)], where random harmonic-curvature modes represent elementary locomotory movements. We show that the previously described gradual-turn and sharp-turn chemotaxis strategies can be unified in our model. The gradual-turn mechanism relies on crawling amplitude changes commensurate with the undulation frequency. The sharp-turn mechanism consists in modulation of the frequency of jumps to large-amplitude modes. We hypothesize that there exists a third strategy, where the nematode adjusts the variance of the amplitude distribution. Such adjustments result in a modulation of the magnitude of random turns, with smaller turns performed when the nematode moves toward the increasing chemoatractant concentration. Experiments are proposed to determine if the third strategy is present in the nematode behavior.

Patel, Amar; Padmanabhan, Venkat; Rumbaugh, Kendra; Vanapalli, Siva; Blawzdziewicz, Jerzy

2013-03-01

281

Nucleic acid transfection and transgenesis in parasitic nematodes.  

PubMed

Transgenesis is an essential tool for assessing gene function in any organism, and it is especially crucial for parasitic nematodes given the dwindling armamentarium of effective anthelmintics and the consequent need to validate essential molecular targets for new drugs and vaccines. Two of the major routes of gene delivery evaluated to date in parasitic nematodes, bombardment with DNA-coated microparticles and intragonadal microinjection of DNA constructs, draw upon experience with the free-living nematode Caenorhabditis elegans. Bombardment has been used to transiently transfect Ascaris suum, Brugia malayi and Litomosoides sigmodontis with both RNA and DNA. Microinjection has been used to achieve heritable transgenesis in Strongyloides stercoralis, S. ratti and Parastrongyloides trichosuri and for additional transient expression studies in B. malayi. A third route of gene delivery revisits a classic method involving DNA transfer facilitated by calcium-mediated permeabilization of recipient cells in developing B. malayi larvae and results in transgene inheritance through host and vector passage. Assembly of microinjected transgenes into multi-copy episomal arrays likely results in their transcriptional silencing in some parasitic nematodes. Methods such as transposon-mediated transgenesis that favour low-copy number chromosomal integration may remedy this impediment to establishing stable transgenic lines. In the future, stable transgenesis in parasitic nematodes could enable loss-of-function approaches by insertional mutagenesis, in situ expression of inhibitory double-stranded RNA or boosting RNAi susceptibility through heterologous expression of dsRNA processing and transport proteins. PMID:21880161

Lok, James B

2011-08-31

282

Coprinus comatus: A basidiomycete fungus forms novel spiny structures and infects nematode  

Microsoft Academic Search

Nematophagous basidiomycete fungi kill nematodes by trapping, endoparasitizing and pro- ducing toxin. In our studies Coprinus comatus (O.F.Mull. : Fr.) Pers. is found to be a nematode-de- stroying fungus; this fungus immobilizes, kills and uses free-living nematode Panagrellus redivivus Good- ey and root-knot nematode Meloidogyne arenaria Neal. C. comatus produces an unusual structure des- ignated spiny ball. Set on a

Hong Luo; Minghe Mo; Xiaowei Huang; Xuan Li

283

Tidal flat nematode responses to hypoxia and subsequent macrofauna-mediated alterations of sediment properties  

Microsoft Academic Search

To assess the role of macrofauna-mediated sediment changes on nematode community recovery, we examined the temporal development of macrobenthos, nematode communities and sediment properties following hypoxia in 16 m2 replicated plots over a 6 mo period. Hypoxia drastically changed nematode community composition (i.e. reduced diversity and abundances of all dominant nematodes, except Odontophora spp.), but complete mortality, as was the

C. Van Colen; F. Montserrat Trotsenburg; K. Verbist; M. Vincx; M. Steyaert; J. Vanaverbeke; P. M. J. Herman; S. Degraer; T. J. W. Ysebaert

2009-01-01

284

Isolation of naturally associated bacteria of necromenic Pristionchus nematodes and fitness consequences.  

PubMed

Nematodes and bacteria are major components of the soil ecosystem. Many nematodes use bacteria for food, whereas others evolved specialized bacterial interactions ranging from mutualism to parasitism. Little is known about the biological mechanisms by which nematode-bacterial interactions are achieved, largely because in the laboratory nematodes are often cultured under artificial conditions. We investigated the bacterial interactions of nematodes from the genus Pristionchus that have a strong association with scarab beetles. Pristionchus has a different feeding strategy than Caenorhabditis and meta-genomic 16S sequence analysis of Pristionchus individuals showed a diversity of living bacteria within the nematode gut and on the nematode cuticle. Twenty-three different bacterial strains were isolated from three Pristionchus-beetle associations and were used to study nematode-bacterial interactions under controlled laboratory conditions. We show a continuum of bacterial interactions from dissemination, to reduction in brood size and nematode mortality caused by bacteria derived from insect hosts. Olfactory discrimination experiments show distinct chemoattraction and fitness profiles of Pristionchus nematodes when exposed to different bacteria. For example, Pristionchus pacificus avoids Serratia marcescens possibly because of pathogenicity. Also, P. pacificus avoids Bacillus thuringiensis and insect pathogenic bacteria but is resistant to the human pathogens Staphylococcus aureus and Pseudomonas aeruginosa, unlike Caenorhabditis elegans. Pristionchus specifically recognize and respond to bacteria that cause ill health. Bringing the nematode-bacterial interaction into the laboratory allows detailed functional studies, including the genetic manipulation of the interaction in both nematodes and bacteria. PMID:18515723

Rae, Robbie; Riebesell, Metta; Dinkelacker, Iris; Wang, Qiong; Herrmann, Matthias; Weller, Andreas M; Dieterich, Christoph; Sommer, Ralf J

2008-06-01

285

Soil nematodes associated with the mammal pathogenic fungal genus Malassezia (Basidiomycota: Ustilaginomycetes) in Central European forests  

Microsoft Academic Search

Screening forest soil nematodes for associated fungi by PCR, and sequencing the internal transcribed spacer detected the human, and other mammals, patho- genic fungus Malassezia in association with soil nema- todes for the first time in Europe. Malassezia restricta and M. globosa were associated with the nematode genus Malenchus sp., whereas another nematode, Tylolaimopho- rus typicus hosted only M. restricta.

Carsten Renker; Jrn Alphei; Franois Buscot

2003-01-01

286

Infection of plant-parasitic nematodes by Paecilomyces lilacinus and Monacrosporium lysipagum  

Microsoft Academic Search

Studying the mode of infection of a biocontrol agent is important in order to assess its efficiency. The mode and severity of infection of nematodes by a soil saprophyte Paecilomyces lilacinus (Thom) Samson and a knob-producing nematode trapping fungus Monacrosporium lysipagum (Drechsler) Subram were studied under laboratory conditions using microscopy. Infection of stationary stages of nematodes by P. lilacinus was

Alamgir Khan; Keith L. Williams; Helena K. M. Nevalainen

2006-01-01

287

Spatial Patterns of Entomopathogenic Nematodes in Microcosms: Implications for Laboratory Experiments  

PubMed Central

Laboratory microcosms were used to: i) measure the effects of soil moisture on survival of Steinernema riobravis and ii) investigate the suitability of using microcosms to study motility and survival of these nematodes. Nematodes recovered from soil contained in petri dishes declined by more than 95% during 7 days, whereas nematodes recovered from the inner surfaces of dishes increased 35-fold. After 7 days in dishes, >20 times as many nematodes were recovered from dish surfaces than from soil. Nematodes exhibited a negative geotropism; greater numbers of nematodes were recovered from the lid surfaces than from the surfaces of dishes. Survivorship of nematodes in soil in plastic centrifuge tubes was somewhat greater than in petri dishes, and fewer nematodes ascended above the soil line in tubes than dishes. Downward migration of nematodes was inversely related to soil column diameter, possibly due to relatively unimpeded movement along container surfaces. An assay was developed by which nematodes were rinsed from the inner surfaces of centrifuge tubes into the soil. The resulting slurry was then processed on Baermann trays to recover motile nematodes. Nematode survival in soil in centrifuge tubes was higher at soil moistures between 2-4% than at lower (0.5-1.0%) and higher (4.0-12.0%) moisture levels. Survival of S. riobravis may be enhanced by quiescence induced by moisture deficits.

Duncan, L. W.; Dunn, D. G.; McCoy, C. W.

1996-01-01

288

Spatial patterns of entomopathogenic nematodes in microcosms: implications for laboratory experiments.  

PubMed

LABORATORY MICROCOSMS WERE USED TO: i) measure the effects of soil moisture on survival of Steinernema riobravis and ii) investigate the suitability of using microcosms to study motility and survival of these nematodes. Nematodes recovered from soil contained in petri dishes declined by more than 95% during 7 days, whereas nematodes recovered from the inner surfaces of dishes increased 35-fold. After 7 days in dishes, >20 times as many nematodes were recovered from dish surfaces than from soil. Nematodes exhibited a negative geotropism; greater numbers of nematodes were recovered from the lid surfaces than from the surfaces of dishes. Survivorship of nematodes in soil in plastic centrifuge tubes was somewhat greater than in petri dishes, and fewer nematodes ascended above the soil line in tubes than dishes. Downward migration of nematodes was inversely related to soil column diameter, possibly due to relatively unimpeded movement along container surfaces. An assay was developed by which nematodes were rinsed from the inner surfaces of centrifuge tubes into the soil. The resulting slurry was then processed on Baermann trays to recover motile nematodes. Nematode survival in soil in centrifuge tubes was higher at soil moistures between 2-4% than at lower (0.5-1.0%) and higher (4.0-12.0%) moisture levels. Survival of S. riobravis may be enhanced by quiescence induced by moisture deficits. PMID:19277142

Duncan, L W; Dunn, D G; McCoy, C W

1996-06-01

289

DIVERSE ROLES \\/ UTILITY OF NEMATODES IN NATURE DO WE UNDERSTAND THEM ALL?  

Microsoft Academic Search

Presence of nematodes in various ecosystems and mediums such as soil, water, plants, humans, animals, fishes and other aquatic resources etc., is of great importance and concern. In every ecosystem, the nematodes like any other organisms must be playing a role. So far, nematodes associated with plants, insects and animals as harmful or useful organisms have been studied reasonably well

R. AZMAT; Y. AKHTER

290

A Treadmill to Localize, Exercise, and Measure the Propulsive Power of Nematodes  

NASA Astrophysics Data System (ADS)

The nematodes C. elegans is often used as model biological system to study the genetic basis of behavior, disease-progression, and aging, as well as to develop new therapies and screen drugs. On occasion, it is desirable to quantify the nematode's muscle power. Here, we present a kind of nematode treadmill. The device consists of a tapered conduit filled with aqueous solution. The conduit is subjected to a DC electric field and to pressure-driven flow directed from the narrow end. The nematode is inserted at the conduit's wide end. Directed by the electric field (through electrotaxis), the nematode swims deliberately upstream toward the negative pole. As the conduit narrows, the average fluid velocity and the drag force on the nematode increase. Eventually, the nematode arrives at an equilibrium position, at which its propulsive power balances the viscous drag force. The nematode's propulsive power is estimated with direct numerical simulations of the flow field around the nematode. The calculations utilize the experimentally imaged gait as a boundary condition. The device is useful to retain the nematode at a nearly fixed position for prolonged observations under a microscope, to keep the nematode exercising, and to estimate the nematode's power based on the conduit's width at the equilibrium position.

Yuan, Jinzhou; Chuan, Han-Sheng; Gnatt, Michael; Raizen, David; Bau, Haim

2011-11-01

291

Influence of bacterial type and density on population growth of bacterial-feeding nematodes  

Microsoft Academic Search

The contribution of bacterial-feeding nematodes to litter decomposition and nutrient mineralization depends, in part, on the abundance of particular nematode species. Population dynamics will be constrained by edaphic factors, food availability and food quality. We report the population growth rates for six nematode species as affected by different bacterial isolates and by changes in food supply. Populations of Caenorhabditis elegans

R. C. Venette; H. Ferris

1998-01-01

292

Foliar calcium concentration of potato and its relation to genotype lateness and tolerance of cyst nematodes  

Microsoft Academic Search

In field trials during three years respectively 18, 22 and 57 potato genotypes were grown on soils moderately or heavily infested with potato cyst nematodes (Globodera pallida) after soils were fumigated or not. Nematode infection increased leaf calcium contents but genotypes that were relatively tolerant of potato cyst nematodes (Globodera pallida) had lower leaf calcium concentrations on a particular sampling

A. J. Haverkort; F. J. de Ruijter; M. Boerma; M. van de Waart

1996-01-01

293

Divergent ghrelin expression patterns in sheep genetically resistant or susceptible to gastrointestinal nematodes  

Microsoft Academic Search

Gastrointestinal nematodes are a major problem for pastoral ruminant production systems. This problem could be reduced by the application of breeding strategies that select for nematode resistant sheep, but no suitable molecular markers are available. Research selection flocks containing lines that are resistant (R) or susceptible (S) to gastrointestinal nematodes provide an excellent resource for discovering selectable markers, and for

Aaron Ingham; Moira Menzies; Peter Hunt; Antonio Reverter; Ross Windon; Nicholas Andronicos

2011-01-01

294

RNA interference in nematodes and the chance that favored Sydney Brenner.  

PubMed

The efficiency of RNA interference varies between different organisms, even among nematodes. A recent report of successful RNA interference in the nematode Panagrolaimus superbus in BMC Molecular Biology has implications for the comparative study of the functional genomics of nematode species, and prompts reflections on the choice of Caenorhabditis elegans as a model organism. PMID:19014674

Félix, Marie-Anne

2008-11-13

295

Nematode biomass spectra as descriptors of functional changes due to human and natural impact  

Microsoft Academic Search

Nematode biomass spectra (NBS) for different nematode communities —subject to dif- ferent forms of stress and enrichment —from the Belgian continental shelf have been constructed and analysed. These analyses showed that non-normalised NBS yield better results for comparisons of nematode assemblages than normalised NBS (in which the biomass in a weight class is divided by its corresponding weight interval) since

Jan Vanaverbeke; Maaike Steyaert; Ann Vanreusel; Magda Vincx

2003-01-01

296

Ultrastructure of root cortical cells parasitized by the ring nematode Criconemella xenoplax  

Microsoft Academic Search

Summary Individuals of the plant-parasitic nematodeCriconemella xenoplax, monoxenically cultured on root expiants of clover, carnation, and tomato, fed continuously for up to 8 days from single cells in the outer root cortex. Individual cortical cells parasitized by nematodes were modified into discrete “food cells” in all hosts examined. The nematode's stylet penetrated between epidermal cells and frequently through a subepidermal

R. S. Hussey; C. W. Mires; S. W. Westcott

1992-01-01

297

The distribution and abundance of soil nematodes in East African savannas  

Microsoft Academic Search

Nematodes were sampled from sites under and between tree canopies in Tsavo National Park, Kenya. We tested the hypothesis that more nematodes would be present in the generally moister soil, under the canopy, with a larger biomass of green grass prevailing for many months of the year. We found that microbivorous nematodes comprised the bulk of the populations, approximately 90%

D. C. Coleman; A. L. Edwards; A. J. Belsky; S. Mwonga

1991-01-01

298

Effect of irrigation on nematode population dynamics and activity in desert soils  

Microsoft Academic Search

The nematode community in litter and soil was examined for a year in the Chihuahuan desert, before and after supplemental rainfall application. Proportions of nematode-active or anhydrobiotic forms and population densities were determined for 3 treatments: control (natural rainfall), a single, large (25-mm) monthly irrigation pulse, and 4 smaller (6-mm) irrigations spaced at weekly intervals. In litter the greatest nematode

D. W. Freckman; W. G. Whitford; Y. Steinberger

1987-01-01

299

Mechanisms of molecular mimicry of plant CLE peptide ligands by the parasitic nematode Globodera rostochiensis  

Technology Transfer Automated Retrieval System (TEKTRAN)

Nematodes that parasitize plant roots cause huge economic losses and have few mechanisms for control. Many parasitic nematodes infect plants by reprogramming root development to drive the formation of feeding structures. How nematodes take control of plant development is largely unknown. The CLE ...

300

Studies on Plant Parasitic Nematodes Associated with Banana in Sindh, Pakistan  

Microsoft Academic Search

A survey of banana was conducted to study the occurrence and distribution of plant parasitic nematodes. The samples of soil and banana plants showing retarded growth were collected from three fields of Nasimabad (Khisano Mori), Tando Allah Yar and Mirpurkhas. The nematodes isolated from the roots and soil samples showed the presence of seven genera of plant parasitic nematodes, Hoplolaimus

M. A. Pathan; Muzaffar A. Talpur; M. M. Jiskani; K. H. Wagan

2004-01-01

301

Adhesion to nematodes of conidia from the nematophagous fungus Drechmeria coniospora  

Microsoft Academic Search

~~~~ Conidia of the endoparasitic nematophagous fungus Drechmeria coniospora adhere to the sensory organs of many nematode species. In some cases the adhesion phase is followed by penetration of the nematode cuticle and subsequent infection. In a study of eight different nematode species and five strains of the fungus only two species were infected: Panagrellus vedivivus was infeted by all

H.-B. Jansson

1993-01-01

302

The Endoparasitic Nematophagous Fungus Meria coniospora Infects Nematodes Specifically at the Chemosensory Organs  

Microsoft Academic Search

Conidia of the endoparasitic fungus Meria coniospora infected the bacterial-feeding nematode Panagreflus rediviuus at specific sites, namely the mouth region and in male nematodes also in the tail. Plant-parasitic nematodes were also infected in other parts of the body. The specific infection sites in P. redivivus were the sensory organs, which are the sites of chemoreception. Blocking of chemoreceptors by

HANS-BORJE JANSSON; BIRGIT NORDBRING-HERTZ

1983-01-01

303

Nematode reproductive and ingestive responses to helminth and host chemical stimuli  

Microsoft Academic Search

Current knowledge of the involvement of chemical stimuli in the reproductive and ingestive physiology of zooparasitic nematodes is reviewed. The habitat of zooparasitic nematodes, coupled with their sensory reduction, indicates that chemical stimuli may modulate most aspects of their behavioral physiology. Nematodes respond to the feeding status of the host so that the helminth's pharyngeal pumping, site selection, and sexual

Leon W. Bone

1986-01-01

304

Body size change in various nematodes depending on bacterial food, sex and growth temperature  

PubMed Central

We previously reported significant body size change in the nematode Caenorhabditis elegans, depending on the food strain of E. coli. Here, we examined this body size change in 11 other nematode species as well, and found that it is common to most of these nematodes. Furthermore, this food-dependent body size change is influenced by sex and growth temperature.

So, Shuhei; Garan, Yohei; Miyahara, Kohji; Ohshima, Yasumi

2012-01-01

305

New insights into the mechanism of fertilization in nematodes.  

PubMed

Fertilization results from the fusion of male and female gametes in all sexually reproducing organisms. Much of nematode fertility work was focused on Caenorhabditis elegans and Ascaris suum. The C. elegans hermaphrodite produces a limited number of sperm initially and then commits to the exclusive production of oocytes. The postmeiotic differentiation called spermiogenesis converts sessile spermatids into motile spermatozoa. The motility of spermatozoa depends on dynamic assembly and disassembly of a major sperm protein-based cytoskeleton uniquely found in nematodes. Both self-derived and male-derived spermatozoa are stored in spermatheca, the site of fertilization in hermaphrodites. The oocyte is arrested in meiotic prophase I until a sperm-derived signal relieves the inhibition allowing the meiotic maturation to occur. Oocyte undergoes meiotic maturation, enters into spermatheca, gets fertilized, completes meiosis, and exits into uterus as a zygote. This review focuses on our current understanding of the events around fertilization in nematodes. PMID:21749902

Singaravelu, Gunasekaran; Singson, Andrew

2011-01-01

306

Plant-parasitic nematodes in maine agricultural soils.  

PubMed

In a survey of plant-parasitic nematodes associated with agricultural crops in nine Maine counties, 744 soil samples from 26 potential host plants were analyzed between November 1987 and January 1989. The most commonly encountered nematode genus was Pratylenchus, occurring in 85% of the samples from most crops, except blueberries and onions. Pratylenchus penetrans and P. crenatus were found commonly as species mixtures, with P. penetrans composing 40-80% of the mixture. Meloidogyne hapla was encountered in 16% of the samples in four counties, generally in potato rotations. Other nematodes encountered were Aphelenchoides spp., Criconemella curvature, Ditylenchus spp., Helicotylenchus pseudorobustus, H. digonicus, Heterodera trifolii, Paratylenchus projectus, Trichodorus spp., Tylenchorhynchus maximus, and Xiphinema americanum. Potato fields were the most heavily sampled and thus weighted the statewide results. PMID:19287791

Huettel, W N; Francl, L J; Henn, A; Bourgoin, T

1990-10-01

307

Atomic force microscopy of plant-parasitic nematodes.  

PubMed

A simple method for atomic force microscopy (AFM) of nematode cuticle was developed to visualize the external topography of Helicotylenchus lobus, Meloidogyne javanica, M. incognita, and Xiphinema diversicaudatum. Endospores of two isolates of the nematode parasite, Pasteuria penetrans, adhering to M. incognita and X. diversicaudatum were also visualized and measured by this technique. Scanning procedures were applied to specimens killed and dehydrated in air or dehydrated and stored in glycerol. Atomic force microscopy scanning of nematodes in constant height mode yielded replicated high-resolution images of the cuticle showing anatomical details such as annulations and lateral fields. Submicrometer scale images allowed the identification of planar regions for further higher resolution scans. PMID:19277280

Ciancio, A

1995-06-01

308

Navigation and chemotaxis of nematodes in bulk and confined fluids  

NASA Astrophysics Data System (ADS)

Small nematodes, such as the model organism C. elegans, propel themselves by producing sinuous undulations along the body and perform turns by varying the undulation amplitude. We have recently demonstrated [PLoS ONE 7(7) e40121 (2012)] that such motions can be accurately represented in terms of a piecewise-harmonic body curvature. We combine our harmonic-curvature description with highly accurate hydrodynamic bead-chain models to investigate the swimming efficiency and turning capabilities of the worm in bulk and confined fluids. Our results indicate that for the same change of the curvature-wave amplitude, a swimming nematode turns by a smaller angle compared to a crawling worm. The difference is due to rotational slip with respect to the surrounding medium, but the angles are sufficiently large to allow for efficient turning maneuvers. We use our description of nematode maneuverability to study chemotaxis in both confined and unconfined fluids.

Bilbao, Alejandro; Padmanabhan, Venkat; Rumbaugh, Kendra; Vanapalli, Siva; Blawzdziewicz, Jerzy

2013-03-01

309

New Insights into the Mechanism of Fertilization in Nematodes  

PubMed Central

Fertilization results from the fusion of male and female gametes in all sexually reproducing organisms. Much of nematode fertility work was focused on Caenorhabditis elegans and Ascaris suum. The C. elegans hermaphrodite produces a limited number of sperm initially, and then commits to the exclusive production of oocytes. The post-meiotic differentiation called spermiogenesis converts sessile spermatids into motile spermatozoa. The motility of spermatozoa depends on dynamic assembly and disassembly of a MSP (Major Sperm Protein)-based cytoskeleton uniquely found in nematodes. Both self-derived and male-derived spermatozoa are stored in spermatheca, the site of fertilization in hermaphrodites. The oocytes are arrested in meiotic prophase I until a sperm derived signal relieves the inhibition allowing the meiotic maturation to occur. Oocyte undergoes meiotic maturation, enters into spermatheca, gets fertilized, completes meiosis and exits into uterus as a zygote. This review focuses on our current understanding of the events around fertilization in nematodes.

Singaravelu, Gunasekaran; Singson, Andrew

2012-01-01

310

Motility of small nematodes in wet granular media  

NASA Astrophysics Data System (ADS)

The motility of the worm nematode Caenorhabditis elegans is investigated in shallow, wet granular media as a function of particle size dispersity and area density (phi). Surprisingly, we find that the nematode's propulsion speed is enhanced by the presence of particles in a fluid and is nearly independent of area density. The undulation speed, often used to differentiate locomotion gaits, is significantly affected by the bulk material properties of wet mono- and polydisperse granular media for phi>=0.55. This difference is characterized by a change in the nematode's waveform from swimming to crawling in dense polydisperse media only. This change highlights the organism's adaptability to subtle differences in local structure and response between monodisperse and polydisperse media.

Juarez, G.; Lu, K.; Sznitman, J.; Arratia, P. E.

2010-11-01

311

Efficacy of extracts of immature mango on ovine gastrointestinal nematodes.  

PubMed

The principal health problem in small ruminants is helminthiasis and the rapid development of nematode resistance to anthelminthics has limited the success of control in several countries, stimulating the search for alternatives. In this study, extracts of immature fruits of the mango Mangifera indica L. var Ubá were evaluated for inhibition of larval development and fecal egg count reduction in sheep naturally infected with gastrointestinal nematodes. In the phytochemical analyses, tannins and flavonoids were the metabolites identified. Aqueous extracts of immature fruits at 100 mg ml(-1) showed 100 % inhibition of larval development. The LC(90) of the extract was 35.9 mg ml(-1) and the in vivo anthelminthic efficacy at 0.740 g kg(-1) (BW, orally) was 53 %. The identification of larvae showed that 99.8 % were Haemonchus spp. In vitro and in vivo results indicate that this fruit could assist ovine nematode control. PMID:22773010

Nery, Patrícia S; Nogueira, Flávia A; Oliveira, Neide J F; Martins, Ernane R; Duarte, Eduardo R

2012-07-07

312

The Pumping Mechanism of the Nematode Esophagus  

PubMed Central

The radial orientation of the myofilaments in the nematode esophagus raises interesting questions as to how such a structure can function as a pump. A physical model of the esophagus of Ascaris lumbricoides was developed and the membrane theory of shells applied in order to relate the observed dimensional changes to myofilament force, pressure stresses, and membrane elastic constants. By stressing the excised esophagus passively with osmotic pressure, the esophagus was shown to be elastically anisotropic with the ratio of circumferential to longitudinal elastic constants, E?/El ? 2.74. When this value was incorporated, the model predicted the ratio of the respective strains, ??/?l, to be 0.52 during an equilibrium contraction of the esophagus. This agreed with the experimental value, 0.46 ± 0.10, measured during occasional, prolonged muscle contractions. When measured during normal pumping, on the other hand, the value of ??/?l was 0 ± 0.10. This indicated that a nonequilibrium condition normally occurs in which a greater myofilament force per unit area of lumen membrane is not balanced by internal pressure and therefore acceleration of the lumen contents and negative intraluminal pressure occurs. The pumping action of esophagi dissected from Ascaris was observed to be normally peristaltic and periodic. Contraction was initiated by a spontaneous depolarization that propagated at 4.0 ± 0.20 cm/s along the esophageal membrane. A wave of localized increases in the internal pressure of the muscle and localized changes in external dimensions was observed. A subsequent spontaneous repolarization, which propagated at 5.8 ± 0.23 cm/s, triggered relaxation of the muscle during which the localized pressure and dimensional changes returned to resting values. A mechanism was deduced in which fluid is drawn into and moved along the lumen by the wave of contraction. During the wave of relaxation, the lumen contents are pressurized and injected into the intestine by elastic restoring forces. ImagesFIGURE 1

Saunders, J. Richard; Burr, A. H.

1978-01-01

313

A nematode effector protein similar to annexins in host plants  

PubMed Central

Nematode parasitism genes encode secreted effector proteins that play a role in host infection. A homologue of the expressed Hg4F01 gene of the root-parasitic soybean cyst nematode, Heterodera glycines, encoding an annexin-like effector, was isolated in the related Heterodera schachtii to facilitate use of Arabidopsis thaliana as a model host. Hs4F01 and its protein product were exclusively expressed within the dorsal oesophageal gland secretory cell in the parasitic stages of H. schachtii. Hs4F01 had a 41% predicted amino acid sequence identity to the nex-1 annexin of C. elegans and 33% identity to annexin-1 (annAt1) of Arabidopsis, it contained four conserved domains typical of the annexin family of calcium and phospholipid binding proteins, and it had a predicted signal peptide for secretion that was present in nematode annexins of only Heterodera spp. Constitutive expression of Hs4F01 in wild-type Arabidopsis promoted hyper-susceptibility to H. schachtii infection. Complementation of an AnnAt1 mutant by constitutive expression of Hs4F01 reverted mutant sensitivity to 75mM NaCl, suggesting a similar function of the Hs4F01 annexin-like effector in the stress response by plant cells. Yeast two-hybrid assays confirmed a specific interaction between Hs4F01 and an Arabidopsis oxidoreductase member of the 2OG-Fe(II) oxygenase family, a type of plant enzyme demonstrated to promote susceptibility to oomycete pathogens. RNA interference assays that expressed double-stranded RNA complementary to Hs4F01 in transgenic Arabidopsis specifically decreased parasitic nematode Hs4F01 transcript levels and significantly reduced nematode infection levels. The combined data suggest that nematode secretion of an Hs4F01 annexin-like effector into host root cells may mimic plant annexin function during the parasitic interaction.

Patel, Nrupali; Hamamouch, Noureddine; Li, Chunying; Hewezi, Tarek; Hussey, Richard S.; Baum, Thomas J.; Mitchum, Melissa G.; Davis, Eric L.

2010-01-01

314

[Nematode infections of the respiratory tract in dogs in Germany].  

PubMed

Recent studies have shown that the risk of lungworm infection may have increased in dogs in Germany in recent years. Analysis of the fecal examination of dogs has shown that Angiostrongylus vasorum, Crenosoma vulpis and Eucoleus aerophilus are endemic in Germany. Infections with A. vasorum were diagnosed in 223 of the examined dogs. A total of 102 A. vasorum-positive dogs were located in Baden-Wuerttemberg, 65 in North Rhine-Westphalia, 27 in Saarland, 15 in Bavaria, 7 in Rhineland-Palatinate, 5 in Hessen and 2 in Brandenburg. A total of 170 dogs were infected with C. vulpis, 54 of which came from North Rhine-Westphalia, 40 from Baden-Wuerttemberg, 30 from Bavaria, 17 from Rhineland-Palatinate, 17 from Saarland, 9 from Hessen and 1 each from Lower Saxony, Berlin and Mecklenburg-Western Pomerania. Infections with E. aerophilus were detected in 83 dogs, of which 23 lived in Baden-Wuerttemberg, 20 in North Rhine-Westphalia, 17 in Bavaria, 11 in Rhineland-Palatinate, 7 in Hessen, 4 in Saarland and 1 in Mecklenburg-Western Pomerania. Lungworm infections in dogs appear to be well established in Germany. The aim of the study presented was to assess the main facts, occurrence, geographical distribution, clinical signs, diagnosis and therapy of lungworm infections in dogs. PMID:24127030

Barutzki, D

2013-10-15

315

Commercial Development and Future Prospects for Entomogenous Nematodes  

PubMed Central

Although entomogenous nenmtodes generally have many of the attributes of the ideal biocontrol agent, many of these attributes make the nematodes less than desirable for commercial production. Environmental limitations, lack of patent protection, "shelf life," shipping problems, and the need for users to receive specialized training are factors that have discouraged the involvement of larger companies. The future of these nematodes as commercially available biocontrol products appears to lie with the smaller "cottage industries" or with government-subsidized production. Problems encountered with attempts to produce commercially the mosquito parasite Romanomermis culicivorax are discussed.

Petersen, J. J.; Cupello, J. M.

1981-01-01

316

Control of Citrus Nematode, Tylenchulus seimipenetrans, with Cadusafos.  

PubMed

Granular (Rugby 10G) and liquid (Rugby 100 ME) formulations of cadusafos were evaluated for the control of Tylenchulus semipenetrans on mature lemon trees in a commercial citrus orchard at Yuma, Arizona. Three applications of cadusafos, with 2 months between applications, at the rate of 2 g a.i./m(2) reduced nematode populations to undetectable levels and increased the yield and rate of fruit maturity of 'Rosenberger' lemons. Yields were increased 12,587 kg/ha with Rugby 100ME and 8,392 kg/ha with Rugby 10G. Nematode populations were suppressed for at least 12 months after the last application. PMID:19277185

McClure, M A; Schmitt, M E

1996-12-01

317

Control of Citrus Nematode, Tylenchulus seimipenetrans, with Cadusafos  

PubMed Central

Granular (Rugby 10G) and liquid (Rugby 100 ME) formulations of cadusafos were evaluated for the control of Tylenchulus semipenetrans on mature lemon trees in a commercial citrus orchard at Yuma, Arizona. Three applications of cadusafos, with 2 months between applications, at the rate of 2 g a.i./m² reduced nematode populations to undetectable levels and increased the yield and rate of fruit maturity of 'Rosenberger' lemons. Yields were increased 12,587 kg/ha with Rugby 100ME and 8,392 kg/ha with Rugby 10G. Nematode populations were suppressed for at least 12 months after the last application.

McClure, M. A.; Schmitt, M. E.

1996-01-01

318

Intraocular nematode with diffuse unilateral subacute neuroretinitis: case report  

Microsoft Academic Search

Background  Live intraocular nematode is a rare occurrence. Nematode can migrate actively within the eye, creating visual symptoms and\\u000a damaging ocular tissue.\\u000a \\u000a \\u000a \\u000a \\u000a Case presentation  A 26-year old man presented with painless reduced vision of the left eye for one week duration. It was associated with floaters.\\u000a Visual acuity on the left eye was hand movement. Anterior segment examination was normal with normal

Munira Yusoff; Azma-Azalina Ahmad Alwi; Mariyani Mad Said; Sakinah Zakariah; Zulkifli Abdul Ghani; Embong Zunaina

2011-01-01

319

[Diversity of actinomycetes associated with root-knot nematode and their potential for nematode control].  

PubMed

Twenty actinomycetes were isolated from root-knot nematode eggs and females collected from 11 plant root samples infested by Meloidogyne spp.. The isolates were assigned to the genera Streptomyces, Nocardia and Pseudonocardia respectively, based on analysis of morphological characteristics, cell-wall DAPs and 16S rRNA gene sequences. 80% of them were streptomycetes. Biocontrol potential of the isolates against Meloidogyne hapla was evaluated in liquid culture in vitro. The average percentages of egg parasitism, egg hatching, and juvenile mortality were 54.1, 40.4 and 26.2, respectively. Three Streptomyces strains and one Nocardia strain with high pathogenicity in vitro were selected to determine their ability to reduce tomato root galls in greenhouse. The results demonstrated good biocontrol efficacy (31.4%-56.4%) of the strains. PMID:17037062

Luo, Hong-li; Sun, Man-hong; Xie, Jian-ping; Liu, Zhi-heng; Huang, Ying

2006-08-01

320

The complete mitochondrial genomes of three parasitic nematodes of birds: a unique gene order and insights into nematode phylogeny  

PubMed Central

Background Analyses of mitochondrial (mt) genome sequences in recent years challenge the current working hypothesis of Nematoda phylogeny proposed from morphology, ecology and nuclear small subunit rRNA gene sequences, and raise the need to sequence additional mt genomes for a broad range of nematode lineages. Results We sequenced the complete mt genomes of three Ascaridia species (family Ascaridiidae) that infest chickens, pigeons and parrots, respectively. These three Ascaridia species have an identical arrangement of mt genes to each other but differ substantially from other nematodes. Phylogenetic analyses of the mt genome sequences of the Ascaridia species, together with 62 other nematode species, support the monophylies of seven high-level taxa of the phylum Nematoda: 1) the subclass Dorylaimia; 2) the orders Rhabditida, Trichinellida and Mermithida; 3) the suborder Rhabditina; and 4) the infraorders Spiruromorpha and Oxyuridomorpha. Analyses of mt genome sequences, however, reject the monophylies of the suborders Spirurina and Tylenchina, and the infraorders Rhabditomorpha, Panagrolaimomorpha and Tylenchomorpha. Monophyly of the infraorder Ascaridomorpha varies depending on the methods of phylogenetic analysis. The Ascaridomorpha was more closely related to the infraorders Rhabditomorpha and Diplogasteromorpha (suborder Rhabditina) than they were to the other two infraorders of the Spirurina: Oxyuridorpha and Spiruromorpha. The closer relationship among Ascaridomorpha, Rhabditomorpha and Diplogasteromorpha was also supported by a shared common pattern of mitochondrial gene arrangement. Conclusions Analyses of mitochondrial genome sequences and gene arrangement has provided novel insights into the phylogenetic relationships among several major lineages of nematodes. Many lineages of nematodes, however, are underrepresented or not represented in these analyses. Expanding taxon sampling is necessary for future phylogenetic studies of nematodes with mt genome sequences.

2013-01-01

321

Risk factors associated with occurrence of nematodes in free range pigs in Busia District, Kenya.  

PubMed

Nematode infections are a serious constraint to pig production, especially where free range pig keeping is practiced. This study investigated the epidemiology of nematodes in free range pigs in Busia District, Kenya. Three hundred and six pigs from 135 farms were sampled for faeces that were analysed for nematode eggs per gram (EPG) of faeces using the McMaster technique. The nematode eggs were also identified to genus and species based on morphology. A questionnaire on risk factors was also administered to the pig owners. The overall prevalence and mean nematode EPG were 84.2% and 2,355, respectively. The nematode eggs were identified as those belonging to Oesophagostomum spp. (75%), Strongyloides ransomi (37%), Ascaris suum (18%), Metastrongylus spp. (11%), Trichuris suis (7%) and Physocephalus sexalatus (3%). The prevalence of nematodes was positively correlated (p?nematodes except S. ransomi). The prevalence of nematodes was also associated with the age of the pigs. A lower burden of nematodes was associated (p?nematode infections and the associated risk factors for free range pigs in Busia District, which can be used when implementing integrated control measures. PMID:21833678

Kagira, John Maina; Kanyari, Paul Njuki; Githigia, Samuel Maina; Maingi, Ndicho; Ng'ang'a, James Chege; Gachohi, John Mwangi

2011-08-11

322

Autophagy is required for trap formation in the nematode-trapping fungus Arthrobotrys oligospora.  

PubMed

Nematode-trapping fungi live mainly as saprobes in soil environments. When encountering nematodes, these fungi become 'carnivorous' and develop specialized trapping devices to attack their hosts for extracting nutrients, especially nitrogen source. Thus, nematode-trapping fungi are model organisms for understanding the molecular mechanism of the switch between saprobic and parasitic phases of pathogen life cycles. Arthrobotrys oligospora, one of the best-studied nematode-trapping fungi, mainly lives as a saprobe. In the presence of nematodes, A.oligospora enters the parasitic stage by forming adhesive reticulate traps to capture nematodes. In filamentous fungi, autophagy has been shown to be involved in morphogenesis and morphology. In this study, we demonstrate that autophagy is induced by nematodes during the early stage of trap formation in A.oligospora. Disruption of atg8 gene not only abolishes the nematode-induced autophagy, but also suppresses trap formation and reduces pathogenicity for nematodes. During the early stage of trap formation, the expression of genes involved in amino acid biosynthesis is upregulated and the transcriptional activity of GCN4 is induced in A.oligospora, suggesting that nematodes induce autophagy probably by triggering intracellular amino acid starvation. Autophagy is thus crucial for trap formation in A.oligospora during infection of nematodes. PMID:23864564

Chen, Yuan-Li; Gao, Ying; Zhang, Ke-Qin; Zou, Cheng-Gang

2013-04-19

323

Infection Behavior and Overwintering Survival of Foliar Nematodes, Aphelenchoides fragariae, on Hosta  

PubMed Central

We studied the pathogenicity and overwintering survival of the foliar nematode, Aphelenchoides fragariae, infecting Hosta spp. Nematodes applied to either lower or upper sides of noninjured and injured hosta leaves were able to infect and produce typical symptoms on nine cultivars. Leaves of only four cultivars (Borschi, Fragrant Blue, Patomic Pride, and Olive Bailey Langdon) showed no symptoms of nematode infection. The nematodes overwintered as juveniles and adults in soil, dry leaves, and dormant buds, but not in roots. Nematode winter survival was higher in dormant buds and soil from the polyhouse than in an open home garden. Of the nematodes found in the dormant buds, 35% to 79% were located between the first two outside layers of the buds. The nematodes tolerated 8 hr exposure to 40°C and ?80°C in leaf tissues. Relative humidity influenced nematode migration from soil to leaves. The presence of nematodes only on the outer surface of foliage (leaves and petioles) confirmed the migration of A. fragariae on the surface of the plants. Of the total number of nematodes found on the foliage, 25% to 46% and 66% to 77% were alive at 90% and 100% relative humidity, respectively, suggesting that high moisture is required for the survival and upward movement of nematodes. We conclude that A. fragariae can overwinter in soil, infected dry leaves, and dormant buds and migrate in films of water on the outer surface of the plant during spring to leaves to initiate infection.

Jagdale, Ganpati B.; Grewal, Parwinder S.

2006-01-01

324

RESISTANCE TO RENIFORM NEMATODE IN EXOTIC COTTON LINES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Reniform nematode has caused significant yield reductions for many years in cotton production across the Mid-South. Without any resistant cultivars available at this time, crop rotation and the use of insecticides/nematicides are the only means of reducing the amount of infestation in the fields. ...

325

REACTION OF GRAPE ROOTSTOCKS TO RING NEMATODE MESOCRICONEMA XENOPLAX.  

Technology Transfer Automated Retrieval System (TEKTRAN)

The reaction of grape rootstocks to the ring nematode, Mesocriconema xenoplax¸ was studied in glasshouse experiments and in a vineyard trial. Growth of one Oregon population of M. xenoplax differed among 20 rootstock and self-rooted cultivars grown in the glasshouse for 8 months. The reproductive ...

326

Resistance to root-knot nematodes, Meloidogyne spp., I potato  

Microsoft Academic Search

Root-knot nematodes, Meloidogyne spp., are world-wide one of the most damaging pests to arable farming. In North Western Europe, the species M. chitwoodi, M. fallax and M. hapla are becoming a serious problem in potato growing areas as a result of recent changes in crop rotation, that now include highly profitable host crops, and a reduced use of nematicides in

G. J. W. Janssen

1997-01-01

327

Effects of gastrointestinal nematode infection on the ruminant immune system  

Microsoft Academic Search

Gastrointestinal (GI) nematodes of ruminants evoke a wide variety of immune responses in their hosts. In terms of specific immune responses directed against parasite antigens, the resulting immune responses may vary from those that give strong protection from reinfection after a relatively light exposure (e.g. Oesophagostomum radiatum) to responses that are very weak and delayed in their onset (e.g. Ostertagia

Louis C. Gasbarre

1997-01-01

328

Evolutionary history of nematodes associated with sweat bees.  

PubMed

Organisms that live in close association with other organisms make up a large part of the world's diversity. One driver of this diversity is the evolution of host-species specificity, which can occur via reproductive isolation following a host-switch or, given the correct circumstances, via cospeciation. In this study, we explored the diversity and evolutionary history of Acrostichus nematodes that are associated with halictid bees in North America. First, we conducted surveys of bees in Virginia, and found six halictid species that host Acrostichus. To test the hypothesis of cospeciation, we constructed phylogenetic hypotheses of Acrostichus based on three genes. We found Acrostichus puri and Acrostichus halicti to be species complexes comprising cryptic, host-specific species. Although several nodes in the host and symbiont phylogenies were congruent and tests for cospeciation were significant, the host's biogeography, the apparent patchiness of the association across the host's phylogeny, and the amount of evolution in the nematode sequence suggested a mixture of cospeciation, host switching, and extinction events instead of strict cospeciation. Cospeciation can explain the relationships between Ac. puri and its augochlorine hosts, but colonization of Halictus hosts is more likely than cospeciation. The nematodes are vertically transmitted, but sexual transmission is also likely. Both of these transmission modes may explain host-species specificity and congruent bee and nematode phylogenies. Additionally, all halictid hosts come from eusocial or socially polymorphic lineages, suggesting that sociality may be a factor in the suitability of hosts for Acrostichus. PMID:23159895

McFrederick, Quinn S; Taylor, Douglas R

2012-11-15

329

The transcriptomes of the cattle parasitic nematode Ostertagia ostartagi  

Technology Transfer Automated Retrieval System (TEKTRAN)

Ostertagia ostertagi is a gastrointestinal parasitic nematode that affects cattle and leads to a loss of production. In this study, we present the first large-scale genomic survey of O. ostertagi by the analysis of expressed transcripts from three stages of the parasite: third-stage larvae, fourth-s...

330

Amphiregulin-a Th2 cytokine enhancing resistance to nematodes  

Technology Transfer Automated Retrieval System (TEKTRAN)

Intestinal nematode infections remain a major health threat to humans despite improved sanitation. Protection is mainly mediated by Type 2-biased immune responses, characterized by Th2 lymphocytes and other cells secreting a set of cytokines including Interleukin 4 (IL-4), IL-5, IL-10, and IL-13. I...

331

TROPICAL SPIDERWORT AS A HOST FOR NEMATODES AND DISEASES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Nematodes are the most damaging pathogens of cotton, and one of the most important pathogens of peanut. Crop rotations utilizing cotton, peanut, and corn can be used to manage the southern root-knot (Meloidogyne incognita), peanut root-knot (M. arenaria), and reniform (Rotylenchulus reniformis) nem...

332

Evaluation of Nematode Resistant Grape Rootstock for Managing Mesocriconema xenoplax  

Technology Transfer Automated Retrieval System (TEKTRAN)

Grafted grapevines were planted on May 3, 2006 in microplots (25 gallon pot-n-pot) that were inoculated with arbuscular mycorrhizal fungi (AMF). Half of the plots received 100,000 ring nematodes (M. xenoplax) at planting. Vines were thinned to 1 shoot on June 8, which was trained upright on a bamboo...

333

An rxr\\/ usp homolog from the parasitic nematode, Dirofilaria immitis  

Microsoft Academic Search

Filarial parasites are responsible for several serious human diseases with symptoms such as lymphoedema, elephantiasis, and blindness. An understanding of how these parasites pass through developmental checkpoints may suggest potential targets for intervention. A useful model system for the study of the human parasites is the closely related nematode Dirofilaria immitis, the causative agent of dog heartworm disease. In D.

Cathy Shea; David Hough; Jianping Xiao; George Tzertzinis; Claude V Maina

2004-01-01

334

Trait-mediated diversification in nematode predator-prey systems.  

PubMed

Nematodes are presumably the most numerous Metazoans in terrestrial habitats. They are represented at all trophic levels and are known to respond to nutrient limitation, prey availability, and microbial resources. Predatory nematodes reside at the highest trophic level, and as such their feeding habits could have a major impact on soil food web functioning. Here, we investigate the effects of gender and developmental stage on the nematode body sizes in coarse and loamy soils. Besides Neodiplogasteridae, our predators are much larger than other soil-dwelling nematodes from their early developmental stage onwards. From juvenile to adult, the predatory Aporcelaimellus (Kruskal-Wallis P < 0.001), Dorylaimoides, and Tripyla (both P < 0.01) show great length increases during their developmental growth, in contrast to their possible prey (almost all P < 0.001). Less than 4% of the prey exceeds the length of the predatory adults, but more than 30% of the prey exceeds the length of the predatory juveniles. Potential body size ratios and some physical problems experienced by small fluid feeders attacking large prey are discussed in an attempt to summarize different prey-searching mechanisms and aggregative predatory responses in the soil system. PMID:22393508

Mulder, Christian; Helder, Johannes; Vervoort, Mariëtte T W; Arie Vonk, J

2011-11-01

335

Trait-mediated diversification in nematode predator-prey systems  

PubMed Central

Nematodes are presumably the most numerous Metazoans in terrestrial habitats. They are represented at all trophic levels and are known to respond to nutrient limitation, prey availability, and microbial resources. Predatory nematodes reside at the highest trophic level, and as such their feeding habits could have a major impact on soil food web functioning. Here, we investigate the effects of gender and developmental stage on the nematode body sizes in coarse and loamy soils. Besides Neodiplogasteridae, our predators are much larger than other soil-dwelling nematodes from their early developmental stage onwards. From juvenile to adult, the predatory Aporcelaimellus (Kruskal–Wallis P < 0.001), Dorylaimoides, and Tripyla (both P < 0.01) show great length increases during their developmental growth, in contrast to their possible prey (almost all P < 0.001). Less than 4% of the prey exceeds the length of the predatory adults, but more than 30% of the prey exceeds the length of the predatory juveniles. Potential body size ratios and some physical problems experienced by small fluid feeders attacking large prey are discussed in an attempt to summarize different prey-searching mechanisms and aggregative predatory responses in the soil system.

Mulder, Christian; Helder, Johannes; Vervoort, Mariette T W; Arie Vonk, J

2011-01-01

336

Phytoparasitic nematodes associated with three types of blueberries in arkansas.  

PubMed

Research and commercial blueberry plantings were sampled in October 1991 to determine the population densities and species of phytoparasitic nematodes associated with rabbiteye (Vaccinium ashei), southern highbush (Vaccinium sp.), and highbusb (V. corymbosum) blueberry cultivars and the sod middles between the blueberry rows. In the research planting at Clarksville, Arkansas, samples from the highbush cv. Bluecrop, the southern highbush cv. Cooper and Gulf Coast, and the sod middles had similar numbers of total vermiform phytoparasitic nematodes (125-451/250 cm(3) soil), whereas the samples from rabbiteye cv. Climax and Tifblue had significantly lower numbers (4/250 cm(3)). The major nematode species associated with blueberries and sod was Xiphinema americanum. In a research planting at Bald Knob, Arkansas, which contained Bluecrop and rabbiteye cultivars only, samples from Bluecrop and the sod had similar numbers (288 and 334/250 cm(3)), and the rabbiteye samples had significantly lower numbers (6-14/250 cm(3)). Xiphinema americanum was the major species found in the blueberry samples, whereas Mesocriconema ornata was the major species in the sod. Nematode population densities and species distribution in commercial rabbiteye plantings in nine counties in central and southwestern Arkansas varied greatly. The average population density for rabbiteye samples was 129/250 cm(3) and for sod was 577/250 cm(3). Weed infestations in the blueberry rows in the commercial plantings probably increased the population size and species distribution. PMID:19279961

Clark, J R; Robbins, R T

1994-12-01

337

Influence of Lysobacter enzymogenes Strain C3 on Nematodes.  

PubMed

Chitinolytic microflora may contribute to biological control of plant-parasitic nematodes by causing decreased egg viability through degradation of egg shells. Here, the influence of Lysobacter enzymogenes strain C3 on Caenorhabditis elegans, Heterodera schachtii, Meloidogyne javanica, Pratylenchus penetrans, and Aphelenchoides fragariae is described. Exposure of C. elegans to L. enzymogenes strain C3 on agar resulted in almost complete elimination of egg production and death of 94% of hatched juveniles after 2 d. Hatch of H. schachtii eggs was about 50% on a lawn of L. enzymogenes strain C3 on agar as compared to 80% on a lawn of E. coli. Juveniles that hatched on a lawn of L. enzymogenes strain C3 on agar died due to disintegration of the cuticle and body contents. Meloidogyne javanica juveniles died after 4 d exposure to a 7-d-old chitin broth culture of L. enzymogenes strain C3. Immersion of A. fragariae, M. javanica, and P. penetrans juveniles and adults in a nutrient broth culture of L. enzymogenes strain C3 led to rapid death and disintegration of the nematodes. Upon exposure to L. enzymogenes strain C3 cultures in nutrient broth, H. schachtii juveniles were rapidly immobilized and then lysed after three days. The death and disintegration of the tested nematodes suggests that toxins and enzymes produced by this strain are active against a range of nematode species. PMID:19259452

Chen, J; Moore, W H; Yuen, G Y; Kobayashi, D; Caswell-Chen, E P

2006-06-01

338

Strongyloides ratti: A Nematode with Extraordinary Plasticity in Aging  

Microsoft Academic Search

Aging has been characterized in detail in relatively few animal species. Here we describe the aging process of a nematode with an unusual life-cycle, Strongyloides ratti. This organism has distinct parasitic and free-living reproductive adult forms, which are genetically identical. S. ratti exhibits a remarkably high degree of pheno- typic plasticity of aging: the maximum lifespan of parasitic adults is

Michael P. Gardner; Mark E. Viney; David Gems

339

Seasonal dynamics of endosymbiotic ciliates and nematodes in Dreissena polymorpha  

Microsoft Academic Search

We report the results of a two-year study in the Svisloch River (Minsk, Belarus) on the dynamics of infection in Dreissena polymorpha by nematodes and three ciliate species Conchophthirus acuminatus, Ophryoglena sp., and Ancistrumina limnica. Although these endosymbionts were present in most of the samples, their prevalence and infection intensity differed significantly. C. acuminatus and A. limnica infection intensities in

Alexander Y. Karatayev; Sergey E. Mastitsky; Lyubov E. Burlakova; Daniel P. Molloy; Galina G. Vezhnovetsb

2003-01-01

340

The major gut esterase locus in the nematode Caenorhabditis elegans  

Microsoft Academic Search

Mutations in the major gut esterase of the nematode Caenorhabditis elegans have been induced by ethylmethane sulfonate and detected by isoelectric focusing. The gut esterase locus, denoted ges-1, maps less than 0.3 map units to the right of the unc-60 locus, at the left end of chromosome V.

James D. McGhee; Denise A. Cottrell

1986-01-01

341

Reducing Intestinal Nematode Infection: Efficacy of Albendazole and Mebendazole  

Microsoft Academic Search

The widespread use of mebendazole and albendazole for treating intestinal nematode infections in human populations is raising concerns that careful monitoring pro- cedures should be in place to identify any emergence of drug resistance. In this article, Andy Bennett and Helen Guyatt discuss whether benchmark parasitological drug efficacy rates can be defined for these anthelmintics, by analysing published data on

Andrew Bennett; Helen Guyatt

2000-01-01

342

Toxicity evaluation in nematode Caenorhabditis elegans after chronic metal exposure  

Microsoft Academic Search

In this study, specific developmental stage for adults from day 1 to day 10 was selected to evaluate the chronic metal toxicity, because the population of dead nematodes and the accumulation of intestinal autofluorescence increased sharply after day 10. Chronic exposure to Cr, Pb, Cu, and Hg caused a significant elevation in fractions of dead animals after day 4, and

Lulu Shen; Jing Xiao; Huayue Ye; Dayong Wang

2009-01-01

343

Ecotoxicological evaluation of chlorpyrifos exposure on the nematode Caenorhabditis elegans  

Microsoft Academic Search

To investigate the effects of chlorpyrifos (CP), an organophosphorus insecticide, on the soil nematode Caenorhabditis elegans, the toxicity of the insecticide on the molecular, biochemical, and physiological levels were investigated upon sublethal exposure, and an acute toxicity test was conducted using lethality as an endpoint. To assess the molecular-level effect, stress-related gene expression was investigated, and the neurotoxicity indicator, acetylcholinesterase

Ji-Yeon Roh; Jinhee Choi

2008-01-01

344

Longevity and ageing in parasitic and free-living nematodes  

Microsoft Academic Search

In the developing field of biological gerontology, rapid advances have recently been made in the genetics of ageing in the nematode Caenorhabditis elegans. The aim of this work is to develop an understanding of the general mechanisms determining the ageing process. Within the last decade the prospect of actually achieving this somewhat hubristic aim has begun to look startlingly real.

David Gems

2000-01-01

345

Hox Gene Loss during Dynamic Evolution of the Nematode Cluster  

Microsoft Academic Search

Hox genes are important: their central role in anterior-posterior patterning provides a framework for molecular comparison of animal body plan evolution [1]. The nematode Caenorhabditis elegans stands out as having a greatly reduced Hox gene complement [2]. To address this, orthologs of C. elegans Hox genes were identified in six species from across the Nematoda, and they show that rapid

A. Aziz Aboobaker; Mark L. Blaxter

2003-01-01

346

Garlic exhibits lack of control over gastrointestinal nematodes in goats  

Technology Transfer Automated Retrieval System (TEKTRAN)

Gastrointestinal nematodes (GIN) continue to hinder small ruminant production because of anthelmintic resistance and lack of effective products for GIN control in organic production. The objective of this study was to examine the effectiveness of a commercially available certified organic garlic pr...

347

WEEDS AS HOSTS FOR THE SOUTHERN ROOT-KNOT NEMATODE  

Technology Transfer Automated Retrieval System (TEKTRAN)

The southern root-knot nematode, Meloidogyne incognita, can reproduce on many different plants, including many weeds, but the amount of reproduction that occurs on weeds is not well documented. This study was conducted to document the relative host status of weeds common in Georgia. Seeds of cotton,...

348

Centrosome duplication and nematodes: recent insights from an old relationship.  

PubMed

Centrosome duplication is required for proper cell division, and centriole formation is a key step in this process. This review discusses recent studies in C. elegans that have identified five core proteins required for centriole formation, thus shedding light into the mechanisms underlying centrosome duplication in nematodes and beyond. PMID:16139223

Leidel, Sebastian; Gönczy, Pierre

2005-09-01

349

Dietary copper sulfate for control of gastrointestinal nematodes in goats  

Technology Transfer Automated Retrieval System (TEKTRAN)

Prevalence of anthelmintic resistance in goats has necessitated studies for alternative means of gastrointestinal nematode (GIN) control. The objective was to determine the effectiveness of dietary copper sulfate for control of GIN in meat goats. Naturally infected buck kids received 0 (LC), 78 (M...

350

Appetitive response of the nematode Caenorhabditis elegans to oxygen  

Microsoft Academic Search

Using a technique of recording the behavior of individual nematodes during exposure to various solutions, it was demonstrated thatC. elegans made more reversal behaviors after transfer to solutions of lower oxygen tension than higher. The response was stronger after the first hour in the apparatus than initially. This change was not dependent on reduced oxygen availability during the initial period.

David B. Dusenbery

1980-01-01

351

Growth and metabolism in a marine nematode, Enoplus communis Bastian  

Microsoft Academic Search

The life history and metabolism of a marine nematode, Enoplus communisBastian, was studied. The species has an annual life cycle, spawning taking place in early spring. Maturity is reached in fall and early winter, and both sexes overwinter with their gonads fully developed.

Wolfgang Wieser; John Kanwisher

1960-01-01

352

Responses of the nematode Caenorhabditis elegans to controlled chemical stimulation  

Microsoft Academic Search

A new method is described for studying the behavioral responses of nematodes to controlled chemical stimulation. The worm is held by the tail with a suction pipet. Behavior is recorded by an array of light sensors connected to a multichannel recorder. Several types of behavior can be detected in addition to the normal backward propagating waves of about 2 Hz

David B. Dusenbery

1980-01-01

353

Evidence for the Two-state Model of Nematode Behaviour  

Microsoft Academic Search

A MODEL for the swimming and orientation of Panagrellus silusiae based on transitions between two behavioural states has been proposed1. The basis of this model is that in normal, unstimulated conditions the nematode follows a more or less linear path with the anterior and posterior ends of the animal sweeping through a minimal area. This is termed the `normal' behavioural

M. R. Samoiloff; S. Balakanich; M. Petrovich

1974-01-01

354

Computational Rules for Chemotaxis in the Nematode C. elegans  

Microsoft Academic Search

We derive a linear neural network model of the chemotaxis control circuit in the nematode Caenorhab- ditis elegans and demonstrate that this model is capable of producing nematodelike chemotaxis. By expanding the analytic solution for the network output in time-derivatives of the network input, we extract simple computational rules that reveal how the model network controls chemotaxis. Based on these

Thomas C. Ferrée; Shawn R. Lockery

1999-01-01

355

Genome-scale evidence of the nematode-arthropod clade  

PubMed Central

Background The issue of whether coelomates form a single clade, the Coelomata, or whether all animals that moult an exoskeleton (such as the coelomate arthropods and the pseudocoelomate nematodes) form a distinct clade, the Ecdysozoa, is the most puzzling issue in animal systematics and a major open-ended subject in evolutionary biology. Previous single-gene and genome-scale analyses designed to resolve the issue have produced contradictory results. Here we present the first genome-scale phylogenetic evidence that strongly supports the Ecdysozoa hypothesis. Results Through the most extensive phylogenetic analysis carried out to date, the complete genomes of 11 eukaryotic species have been analyzed in order to find homologous sequences derived from 18 human chromosomes. Phylogenetic analysis of datasets showing an increased adjustment to equal evolutionary rates between nematode and arthropod sequences produced a gradual change from support for Coelomata to support for Ecdysozoa. Transition between topologies occurred when fast-evolving sequences of Caenorhabditis elegans were removed. When chordate, nematode and arthropod sequences were constrained to fit equal evolutionary rates, the Ecdysozoa topology was statistically accepted whereas Coelomata was rejected. Conclusions The reliability of a monophyletic group clustering arthropods and nematodes was unequivocally accepted in datasets where traces of the long-branch attraction effect were removed. This is the first phylogenomic evidence to strongly support the 'moulting clade' hypothesis.

Dopazo, Hernan; Dopazo, Joaquin

2005-01-01

356

Mermithid nematodes found in adult Anopheles from southeastern Senegal  

PubMed Central

Background Over two dozen mermithid nematodes have been described parasitizing mosquitoes worldwide, however, only two species were found in Africa. Mermithid nematodes kill their mosquito host upon emergence, which suggests that they could be developed as biological control agents of mosquitoes. Both Romanomermis culicivorax and Romanomermis iyengari have been reared for mass release to control numerous Anopheles species vector populations, and in one instance this may have led to reduced malaria prevalence in a human population. Methods Anopheles mosquitoes were collected during a malaria study in southeastern Senegal. Two different adult blood fed mosquitoes had a single mermithid nematode emerge from their anus while they were being held post-capture. Primers from the 18?S rDNA were developed to sequence nematode DNA and screen mosquitoes for mermithid DNA. 18?S rDNA from the Senegalese mermithid and other mermithid entries in GenBank were used to create a Maximum Parsimony tree of the Mermithidae family. Results The mermithid was present in 1.8% (10/551) of the sampled adult Anopheles species in our study area. The mermithid was found in An. gambiae s.s., An. funestus, and An. rufipes from the villages of Ndebou, Boundoucondi, and Damboucoye. Maximum parsimony analysis confirmed that the nematode parasites found in Anopheles were indeed mermithid parasites, and of the mermithid sequences available in GenBank, they are most closely related to Strelkovimermis spiculatus. Conclusions To our knowledge, this is the first report of mermithids from adult Anopheles mosquitoes in Senegal. The mermithid appears to infect Anopheles mosquitoes that develop in diverse larval habitats. Although maximum parsimony analysis determined the mermithid was closely related to Strelkovimermis spiculatus, several characteristics of the mermithid were more similar to the Empidomermis genus. Future mermithid isolations will hopefully allow: formal taxonomic identification, laboratory colonization, determination of life history traits and species specificity, and characterize its usefulness as a biological control agent.

2012-01-01

357

Detrended-Fluctuation Analysis of Nematode Movement in Heterogeneous Environment  

NASA Astrophysics Data System (ADS)

We consider multifractal analysis in time scale to analyse the effect of structural heterogeneity on the movement of the slug-parasitic nematode, Phasmarhabditis hermaphrodita. The study involves image recording and analysis of nematode movement on a homogeneous layer of technical agar compared to movement of nematodes in a structurally heterogeneous environment that was created by adding sand particles to the plates of agar. The temporal scaling properties of the recorded trails were studied using a detrended fluctuation based method to capture the complex dynamic of movement data by comparing the multiscaling characteristics of nematode step lengths as affected by the different environments. A systematic analysis of the exponent of the structure function and the generalized Hurst exponent revealed that, while in homogeneous environment the movement was characterized by a long-range correlation with a Hurst exponent H(q) close to 1, varying little with respect to the order q of the fluctuation function, the impact of sand particle was to reduce the degree of persistence in the movement, the step lenghts being characterized by a smaller Hurst exponent, yet more variable. The results suggest that the presence of structural heterogeneity introduces a new bias into the movement, which plays an important role in complex environments where the nematode movement may be obstructed by soil particles. References Tarquis, A.M., Morato, M. C., Castellanos M.T., Perdigones A. 2009. Comparison of Structure Function and Detrended Fluctuation Analysis of Wind Time Series, Riv. Nuevo Cimento, in press. Gao, J., Cao, Y., Tung, W.-W., Hu J., 2007. Multiscale Analysis of Complex Times Series. Eds. John Wiley & Sons.

Hapca, S. M.; Gonzalez-Nieto, P.; Tarquis, A. M.

2009-04-01

358

Diversity and prevalence of metastrongyloid nematodes infecting the red panda (Ailurus fulgens) in European zoos.  

PubMed

Metastrongyloid induced pneumonia has been described sporadically in the red panda (Ailurus fulgens). Early descriptions in pandas recently imported to the USA from China involved parasites morphologically similar to Angiostrongylus spp. and Crenosomatidae. More recently, four cases of severe verminous pneumonia associated with Angiostrongylus vasorum have been reported from European zoos. A coprological survey of the red panda population within European zoos was conducted in 2008. Faecal samples from 115 pandas originating from 54 zoos were collected on 3 consecutive days. Using Baermann technique, 40 animals (35%) from 20 zoos (37%) were found to shed metastrongyloid first stage larvae (L(1)). Based on their morphology and size, the L(1) observed could be divided into three morphologically distinct types: (1) a Crenosoma sp. type (n=5, overall prevalence: 4.3%), (2) an A. vasorum type (n=3, 2.6%), and (3) an unidentified metastrongyloid species, similar to, but morphologically distinct from A. vasorum (n=32, 27.8%). Further confirmation of species identification was provided by PCR amplification and sequencing of the 18S rRNA gene, which confirmed three different species. The novel Crenosoma species was most genetically analogous to Crenosoma mephitidis and the unidentified metastrongyloid species was most similar to Stenurus minor and Torynurus convulutus. Routine and quarantine health care of red pandas in captivity should take account of the risk of Angiostrongylus and Crenosoma infection in endemic areas, but should also be cognisant of the widespread presence of an apparently less pathogenic species of lungworm. The identity of the two potentially novel species is subject to further work. PMID:20570049

Bertelsen, Mads F; Meyland-Smith, Frederik; Willesen, Jakob L; Jefferies, Ryan; Morgan, Eric R; Monrad, Jesper

2010-05-12

359

Bioinformatic prediction of arthropod\\/nematode-like peptides in non-arthropod, non-nematode members of the Ecdysozoa  

Microsoft Academic Search

The Onychophora, Priapulida and Tardigrada, along with the Arthropoda, Nematoda and several other small phyla, form the superphylum Ecdysozoa. Numerous peptidomic studies have been undertaken for both the arthropods and nematodes, resulting in the identification of many peptides from each group. In contrast, little is known about the peptides used as paracrines\\/hormones by species from the other ecdysozoan taxa. Here,

Andrew E. Christie; Daniel H. Nolan; Zachery A. Garcia; Matthew D. McCoole; Sarah M. Harmon; Benjamin Congdon-Jones; Paul Ohno; Niko Hartline; Clare Bates Congdon; Kevin N. Baer; Petra H. Lenz

2011-01-01

360

ENTOMOPATHOGENIC NEMATODES FOR CONTROL OF CODLING MOTH (LEPIDOPTERA: TORTRICIDAE) IN APPLE AND PEAR ORCHARDS: EFFECT OF NEMATODE SPECIES AND SEASONAL TEMPERATURES, ADJUVANTS, APPLICATION EQUIPMENT AND POST-APPLICATION  

Technology Transfer Automated Retrieval System (TEKTRAN)

Field trials of the insect-specific nematodes, Steinernema carpocapsae and S. feltiae were conducted in apple and pear orchards under a variety of conditions to determine the effects of nematode species and seasonal temperature, formulation, post-application irrigation and method of application on ...

361

A novel ascaroside controls the parasitic life cycle of the entomopathogenic nematode Heterorhabditis bacteriophora  

PubMed Central

Entomopathogenic nematodes survive in the soil as stress-resistant infective juveniles that seek out and infect insect hosts. Upon sensing internal host cues, the infective juveniles regurgitate bacterial pathogens from their gut that ultimately kill the host. Inside the host, the nematode develops into a reproductive adult and multiplies until unknown cues trigger the accumulation of infective juveniles. Here, we show that the entomopathogenic nematode Heterorhabditis bacteriophora uses a small-molecule pheromone to control infective juvenile development. The pheromone is structurally related to the dauer pheromone ascarosides that the free-living nematode Caenorhabditis elegans uses to control its development. However, none of the C. elegans ascarosides are effective in H. bacteriophora, suggesting that there is a high degree of species specificity. Our report is the first to show that ascarosides are important regulators of development in a parasitic nematode species. An understanding of chemical signaling in parasitic nematodes may enable the development of chemical tools to control these species.

Noguez, Jaime H.; Conner, Elizabeth S.; Zhou, Yue; Ciche, Todd A.; Ragains, Justin R.; Butcher, Rebecca A.

2012-01-01

362

Parasitism genes and host range disparities in biotrophic nematodes: the conundrum of polyphagy versus specialisation.  

PubMed

This essay considers biotrophic cyst and root-knot nematodes in relation to their biology, host-parasite interactions and molecular genetics. These nematodes have to face the biological consequences of the physical constraints imposed by the soil environment in which they live while their hosts inhabit both above and below ground environments. The two groups of nematodes appear to have adopted radically different solutions to these problems with the result that one group is a host specialist and reproduces sexually while the other has an enormous host range and reproduces by mitotic parthenogenesis. We consider what is known about the modes of parasitism used by these nematodes and how it relates to their host range, including the surprising finding that parasitism genes in both nematode groups have been recruited from bacteria. The nuclear and mitochondrial genomes of these two nematode groups are very different and we consider how these findings relate to the biology of the organisms. PMID:18293363

Blok, Vivian C; Jones, John T; Phillips, Mark S; Trudgill, David L

2008-03-01

363

[Effects of vegetation coverage on spatial distribution of soil nematode trophic groups].  

PubMed

By the methods of classic statistics and geostatistics, this paper examined the spatial variability of soil nematodes and their trophic groups in bare and fallow plots at Shenyang Experimental Station of Ecology, Chinese Academy of Sciences. The results showed that soil pH had a negative effect on the plant-parasitic nematodes in both bare and fallow plots. The total number of soil nematodes was significantly higher in fallow than in bare plot, being 1 485.3 and 464.0 individuals per 100 g dry soil, respectively. The nugget (C0)/sill (C0 + C) ratio of total nematodes, plant-parasites and bacterivores were lower in fallow plot (27.3%-45.6%) than in bare plot (49.5%-100%). There was a significant difference in the spatial distribution of total nematodes and trophic groups between fallow and bare plots, indicating that vegetation coverage had an obvious effect on soil nematodes. PMID:16706057

Hua, Jianfen; Jiang, Yong; Liang, Wenju

2006-02-01

364

Distribution, frequency, and population density of nematodes in west virginia peach orchards.  

PubMed

Nematode population densities were determined in soil and root samples collected from 205 peach (Prunus persica L.) orchard blocks between 25 March and 5 May 1986. Representative specimens from 75 blocks were identified to species; 28 species of plant-parasitic nematodes were identified. Predaceous nematodes (Mononchidae) were observed in 71% of the samples. The most common plant-parasitic genera were Paratylenchus, Helicotylenchus, Pratylenchus, and Xiphinema, occurring in 85, 84, 77, and 74% of the samples, respectively. Population densities of Xiphinema, Pratylenchus, Meloidogyne, Hoplolaimus, and Criconemella were at potentially damaging levels in 74, 19, 13, 10, and 2% of the samples, respectively. Potentially damaging nematode densities were observed in 78% of orchard blocks surveyed, with 35% having two or more nematodes with densities high enough to warrant concern. Nematode densities differed among soil types and tree rootstocks and were correlated with tree mortality rates. PMID:19287785

Kotcon, J B

1990-10-01

365

Ion beam mutagenesis in Arthrobotrys oligospora enhances nematode-trapping ability.  

PubMed

The nematode-trapping fungus Arthrobotrys oligospora is able to produce extracellular protease that degrades the body walls of parasitic nematode larvae found in livestock and immobilizes the nematodes. Our aim was to obtain a strain of A. oligospora with a strong ability to trap nematodes by production of high levels of extracellular protease. A wild type strain of A. oligospora was subjected to mutagenic treatments involving low-energy ion beam implantation to generate mutants. Among these mutants, A. oligospora N showed high efficiency in trapping nematodes and was also able to secrete more extracellular protease, helping it to penetrate and digest the body walls of larvae. This work represents the first application of low-energy ion beams to generate mutations in a nematode-trapping fungus, and provides a new method of obtaining a fungus with high potential application. PMID:23370734

Wang, Jun; Wang, Rui; Yang, Xiaoye

2013-01-31

366

Reflections on Plant and Soil Nematode Ecology: Past, Present and Future  

PubMed Central

The purpose of this review is to highlight key developments in nematode ecology from its beginnings to where it stands today as a discipline within nematology. Emerging areas of research appear to be driven by crop production constraints, environmental health concerns, and advances in technology. In contrast to past ecological studies which mainly focused on management of plant-parasitic nematodes, current studies reflect differential sensitivity of nematode faunae. These differences, identified in both aquatic and terrestrial environments include response to stressors, environmental conditions, and management practices. Methodological advances will continue to influence the role nematodes have in addressing the nature of interactions between organisms, and of organisms with their environments. In particular, the C. elegans genetic model, nematode faunal analysis and nematode metagenetic analysis can be used by ecologists generally and not restricted to nematologists.

Ferris, Howard; Griffiths, Bryan S.; Porazinska, Dorota L.; Powers, Thomas O.; Wang, Koon-Hui; Tenuta, Mario

2012-01-01

367

Underground leaves of Philcoxia trap and digest nematodes.  

PubMed

The recently described genus Philcoxia comprises three species restricted to well lit and low-nutrient soils in the Brazilian Cerrado. The morphological and habitat similarities of Philcoxia to those of some carnivorous plants, along with recent observations of nematodes over its subterranean leaves, prompted the suggestion that the genus is carnivorous. Here we report compelling evidence of carnivory in Philcoxia of the Plantaginaceae, a family in which no carnivorous members are otherwise known. We also document both a unique capturing strategy for carnivorous plants and a case of a plant that traps and digests nematodes with underground adhesive leaves. Our findings illustrate how much can still be discovered about the origin, distribution, and frequency of the carnivorous syndrome in angiosperms and, more generally, about the diversity of nutrient-acquisition mechanisms that have evolved in plants growing in severely nutrient-impoverished environments such as the Brazilian Cerrado, one of the world's 34 biodiversity hotspots. PMID:22232687

Pereira, Caio G; Almenara, Daniela P; Winter, Carlos E; Fritsch, Peter W; Lambers, Hans; Oliveira, Rafael S

2012-01-09

368

Nematode effector proteins: an emerging paradigm of parasitism.  

PubMed

Phytonematodes use a stylet and secreted effectors to modify host cells and ingest nutrients to support their growth and development. The molecular function of nematode effectors is currently the subject of intense investigation. In this review, we summarize our current understanding of nematode effectors, with a particular focus on proteinaceous stylet-secreted effectors of sedentary endoparasitic phytonematodes, for which a wealth of information has surfaced in the past 10 yr. We provide an update on the effector repertoires of several of the most economically important genera of phytonematodes and discuss current approaches to dissecting their function. Lastly, we highlight the latest breakthroughs in effector discovery that promise to shed new light on effector diversity and function across the phylum Nematoda. PMID:23691972

Mitchum, Melissa G; Hussey, Richard S; Baum, Thomas J; Wang, Xiaohong; Elling, Axel A; Wubben, Martin; Davis, Eric L

2013-05-21

369

Phenotypic plasticity in nematodes: Evolutionary and ecological significance.  

PubMed

Model systems, including C. elegans, have been successfully studied to understand the genetic control of development. A genotype's phenotype determines its evolutionary fitness in natural environments, which are typically harsh, heterogeneous and dynamic. Phenotypic plasticity, the process by which one genome can produce different phenotypes in response to the environment, allows genotypes to better match their phenotype to their environment. Phenotypic plasticity is rife among nematodes, seen both as differences among life-cycles stages, perhaps best exemplified by parasitic nematodes, as well as developmental choices, such as shown by the C. elegans dauer/non-dauer developmental choice. Understanding the genetic basis of phenotypically plastic traits will probably explain the function of many genes whose function still remains unclear. Understanding the adaptive benefits of phenotypically plastic traits requires that we understand how plasticity differs among genotypes, and the effects of this in diverse, different environments. PMID:24058831

Viney, Mark; Diaz, Anaid

2012-04-01

370

Structure and Function of Nematode RNA-Binding Proteins  

PubMed Central

RNA-binding proteins are critical effectors of gene expression. They guide mRNA localization, translation, and stability, and potentially play a role in regulating mRNA synthesis. The structural basis for RNA recognition by RNA-binding proteins is the key to understanding how they target specific transcripts for regulation. Compared to other metazoans, nematode genomes contain a significant expansion in several RNA-binding protein families, including Pumilio-FBF (PUF), TTP-like zinc finger (TZF), and argonaute-like (AGO) proteins. Genetic data suggest that individual members of each family have distinct functions, presumably due to sequence variations that alter RNA binding specificity or protein interaction partners. In this review, we highlight example structures and identify the variable regions that likely contribute to functional divergence in nematodes.

Kaymak, Ebru; Wee, L.M.; Ryder, Sean P.

2010-01-01

371

Functional characterisation of a nematode secreted GM2-activator protein.  

PubMed

We have identified a GM2-activator protein (GM2AP) with highly unusual properties secreted by the nematode parasite Trichinella spiralis. Expression in Pichia pastoris resulted in a hyperglycosylated protein of 28 kDa, but the 18 kDa native protein was not glycosylated. The parasite GM2AP does not facilitate degradation of GM2 ganglioside by N-acetyl-beta-hexosaminidase A, although it does inhibit phospholipase D activity. Lack of the former activity might be explained by the absence of a domain implicated in binding to hexosaminidase. In addition, and contrary to data on the human GM2AP, the nematode homologue does not inhibit platelet activating factor-induced calcium mobilisation in neutrophils, but actually enhances mediator-induced chemotaxis. PMID:16569450

Bruce, Alexandra F; Gares, Marie-Pierre; Selkirk, Murray E; Gounaris, Kleoniki

2006-03-10

372

Cattle nematodes resistant to anthelmintics: why so few cases?  

PubMed

The apparent lack of anthelmintic resistant nematodes in cattle is due to the management systems used with most cattle and the lack of surveys for resistance. With extensive beef grazing or with beef suckler herds a large percentage of worms are in refugia (not exposed to anthelmintic) and few anthelmintic treatments are used. With dairy replacement heifers resistance can become a problem unless only first year animals are treated and different fields are used for grazing the animals each year. Intensive beefproduction on grass is unsustainable and in New Zealand resistance is already becoming a serious problem. Individual farms require monitoring for resistance and steps taken to avoid the introduction of resistance. New validated tests and surveys for resistance are required as the extent of anthelmintic resistant bovine nematodes is not known. PMID:12387485

Coles, Gerald C

373

Optimizing the application of entomopathogenic nematodes: experimental set-up.  

PubMed

The complex issue concerning the spray application of Entomopathogenic Nematodes (EPNs) with a hydraulic sprayer is still not solved. This research project focuses on the effect of spray application technique on the viability and deposition of EPNs. In this paper the experimental set-up used for this evaluation is described. A modular spray application system has been developed and is currently used to evaluate the effect of different parts of a sprayer on the viability of the EPNs. Based on the results of experiments using this modular spray application system, recommendations regarding pump type, mixing system, nozzle type and filter size will be formulated. Because of the large number of experiments in this research project, an image analysis system for the determination of the viability of the nematodes is developed. This paper describes two experiments comparing the new developed image processing technique with the standard microscopic counting technique. PMID:18399427

Brusselman, E; Steurbaut, W; Sonck, B

2007-01-01

374

WormBase: a comprehensive resource for nematode research  

PubMed Central

WormBase (http://www.wormbase.org) is a central data repository for nematode biology. Initially created as a service to the Caenorhabditis elegans research field, WormBase has evolved into a powerful research tool in its own right. In the past 2 years, we expanded WormBase to include the complete genomic sequence, gene predictions and orthology assignments from a range of related nematodes. This comparative data enrich the C. elegans data with improved gene predictions and a better understanding of gene function. In turn, they bring the wealth of experimental knowledge of C. elegans to other systems of medical and agricultural importance. Here, we describe new species and data types now available at WormBase. In addition, we detail enhancements to our curatorial pipeline and website infrastructure to accommodate new genomes and an extensive user base.

Harris, Todd W.; Antoshechkin, Igor; Bieri, Tamberlyn; Blasiar, Darin; Chan, Juancarlos; Chen, Wen J.; De La Cruz, Norie; Davis, Paul; Duesbury, Margaret; Fang, Ruihua; Fernandes, Jolene; Han, Michael; Kishore, Ranjana; Lee, Raymond; Muller, Hans-Michael; Nakamura, Cecilia; Ozersky, Philip; Petcherski, Andrei; Rangarajan, Arun; Rogers, Anthony; Schindelman, Gary; Schwarz, Erich M.; Tuli, Mary Ann; Van Auken, Kimberly; Wang, Daniel; Wang, Xiaodong; Williams, Gary; Yook, Karen; Durbin, Richard; Stein, Lincoln D.; Spieth, John; Sternberg, Paul W.

2010-01-01

375

Nematode control practices and anthelmintic resistance on British sheep farms.  

PubMed

Nearly 23 per cent of 3000 randomly selected sheep farmers returned questionnaires on strategies to control the development of anthelmintic resistance. Twenty-five per cent stated that they regularly checked the accuracy of their drenching gun, and 52 per cent stated that they weighed a few animals and treated the whole flock like the heaviest. The mean annual frequency of dosing lambs was 4.39 compared with 2.43 for ewes. Forty-eight per cent stated that they changed the anthelmintic group annually. Seventeen per cent always treated sheep brought on to their farm with ivermectin. However, only 7 per cent had had their flocks tested for anthelmintic-resistant nematodes. The responses suggest that most sheep farmers are not actively seeking to prevent the development and spread of anthelmintic-resistant nematodes. PMID:9265708

Coles, G C

1997-07-26

376

Host and Penetration Site Location by Entomopathogenic Nematodes against Japanese Beetle Larvae  

Microsoft Academic Search

Entomopathogenic nematodes are soil-inhabiting parasites of insects. Behavioral responses to host and host environmental cues are critical steps in the infection process for some nematode species, such asSteinernema glaseriandHeterorhabditis bacteriophora,of finding, recognizing, and penetrating insects. We investigated the impact of host and host environmental cues on the infectivity of these two nematodes by testing their response to whole and wounded

Yi Wang; Randy Gaugler

1998-01-01

377

Additive and Synergistic Interaction between Entomopathogenic Nematodes and Bacillus thuringiensisfor Scarab Grub Control  

Microsoft Academic Search

We studied the interactions betweenBacillus thuringiensissubspeciesjaponensisBuibui strain (Btj) and entomopathogenic nematodes on the white grubs,Cyclocephala hirtaandC. pasadenae.Field-collected third instar grubs were kept individually in microcosms filled with soil and fed grass seeds. Grubs were exposed to various concentrations ofBtjand\\/or entomopathogenic nematodes and grub mortality was assessed at weekly intervals. Nematodes were added at 0 to 14 days after application ofBtj.Throughout

A. M. Koppenhöfer; H. K. Kaya

1997-01-01

378

Threshold chemosensitivity and hypothetical chemoreceptor function of the nematode Caenorhabditis elegans  

Microsoft Academic Search

The behavioral responses by the nematodeCaenorhabditis elegans to 12 organic compounds was explored using tethered nematode and computer tracking methods. Results indicate that the nematode is attracted to acetone, diethyl ether, isoamyl acetate, isoamyl alcohol, 2,4-pentanedione, andn-propanol. No responses were detected to acetaldehyde, acetylcholine, ethanol, formaldehyde, i-propanol, and valerate. Isoamyl acetate and acetone were found to be the most potent

William F. Terrill; David B. Dusenbery

1996-01-01

379

Population growth kinetics of the nematode, Steinernema feltiae, in submerged monoxenic culture  

Microsoft Academic Search

Monoxenic cultures of the nematode, Steinernema feltiae, were carried out on two complex liquid media: P1, mainly soybean flour\\/egg yolk\\/yeast extract, and P2, mainly egg yolk\\/yeast extract. Up to 140 000–200 000 nematodes ml-1 were produced within 7 days, and more than 95% of the final population was in the infective juvenile stage. The total nematode concentration growth curve had

Norberto Chavarría-Hernández; Mayra de la Torre

2001-01-01

380

Phenotypic and molecular evaluation of cotton hairy roots as a model system for studying nematode resistance  

Microsoft Academic Search

Agrobacterium rhizogenes-induced cotton (Gossypium hirsutum L.) hairy roots were evaluated as a model system for studying molecular cotton–nematode interactions. Hairy root cultures\\u000a were developed from the root-knot nematode (RKN) (Meloidogyne incognita [Kofoid and White] Chitwood, race 3)-resistant breeding line M315 and from the reniform nematode (RN) (Rotylenchulus reniformis Linford & Oliveira)-resistant accession GB713 (G. barbadense L.) and compared to a

Martin J. Wubben; Franklin E. Callahan; Barbara A. Triplett; Johnie N. Jenkins

2009-01-01

381

?-Tubulin Genes from the Parasitic Nematode Haemonchus contortusModulate Drug Resistance in Caenorhabditis elegans  

Microsoft Academic Search

Resistance to antimitotic chemotherapeutics in pathogenic nematodes, fungi and mammalian cells is closely associated with structural changes in cytoskeletal ?-tubulin. We investigated the possibility of using the well-characterised free-living nematodeCaenorhabditis elegansas a model for studying the mechanism of resistance against benzimidazole (BZ) drugs in the parasitic nematodeHaemonchus contortus. Functional analysis of a conserved ?-tubulin isotype (tub-1) mutation near GTP-binding domain

Marcel S. G. Kwa; Jetty G. Veenstra; Marjon Van Dijk; Marleen H. Roos

1995-01-01

382

A semi-fluid gellan gum medium improves nematode toxicity testing  

Microsoft Academic Search

This study examined an alternative test medium for nematodes that use gellan gum as the gelling agent instead of agar. The semi-fluid consistency of the gel-like component nematode growth gellan gum (CNGG) supports three-dimensional distribution of the nematodes and food bacteria, but still allows free movement of the former. Moreover, flexible preparation of the medium and easy recovery of the

Marvin Brinke; Peter Heininger; Walter Traunspurger

2011-01-01

383

Population energetics of bacterial-feeding nematodes: Carbon and nitrogen budgets  

Microsoft Academic Search

Bacterial-feeding nematodes participate in nitrogen mineralization in decomposition food webs to an extent determined by metabolic and behavioral attributes, by life history, and by the relative C-to-N ratios of the nematodes and their bacterial prey. The mean C-to-N ratio for eight nematode species cultured on Escherichia coli on agar was 5.89 (range 5.16–6.83). The mean C-to-N ratio was similar, although

H. Ferris; R. C. Venette; S. S. Lau

1997-01-01

384

POPlJLATION ENERGETICS OF BACTERIAL-FEEDING NEMATODES: CARBON AND NITROGEN BUDGETS  

Microsoft Academic Search

Summary-Ibacterial-feeding nematodes participate in nitrogen mineralization in decomposition food webs to an extent determined by metabolic and behavioral attributes, by life history, and by the relative C-to-N ratios of the nematodes and their bacterial prey. The mean C-to-N ratio for eight nematode species cultured on Escherichia coli on agar was 5.89 (range 5.16-6.83). The mean C-to-N ratio was similar, although

H. FERRIS; R. C. VENETTE; S. S. LAU

385

A soil toxicity test using the nematode Caenorhabditis elegans and an effective method of recovery  

Microsoft Academic Search

A new method for recovering nematodes from soils in an efficient, reproducible, and non-destructive manner has been developed. It was used to conduct short-term soil toxicity tests using the soil-dwelling nematode Caenorhabditis elegans and several different soil types spiked with copper chloride. The recovery method, which involves centrifugation through a colloidal silica suspension, allows the nematodes to be extracted from

Steven G. Donkin; David B. Dusenbery

1993-01-01

386

Recovery of soil nematode populations from cropping stress by natural secondary succession to meadow land  

Microsoft Academic Search

The spectrum and densities of soil nematode species were studied in an extensively managed sub-thermophilous meadow and in conventionally managed and abandoned fallow fields left to natural succession. In the meadow, 115 species and 71 genera of soil nematodes were found and the total mean nematode abundance was 1019×103 individuals\\/m2. The dominant feeding groups were root-fungal feeders (31%, mainly Filenchus),

Ladislav Hán?l

2003-01-01

387

The neurons of class ALD mediate thermotaxis in the parasitic nematode, Strongyloides stercoralis  

Microsoft Academic Search

Strongyloides stercoralis, a skin-penetrating nematode parasite of homeotherms, migrates to warmth. In nematodes, the amphids, anteriorly positioned, paired sensilla, each contain a bundle of sensory neurons. In the amphids of the free-living nematode Caenorhabditis elegans, a pair of neurons, each of which ends in a cluster of microvilli-like projections, are known to be the primary thermoreceptors, and have been named

P. Mark Lopez; Ray Boston; Francis T. Ashton; Gerhard A. Schad

2000-01-01

388

Effects of Metal Exposure on Associative Learning Behavior in Nematode Caenorhabditis elegans  

Microsoft Academic Search

In the present study, the thermotaxis model was used to evaluate the effects of metal exposure at different concentrations\\u000a on associative learning behavior in nematodes. The examined nematodes were cultured at 25 or 17°C, and then shifted to 20°C\\u000a condition. Based on the ability of nematodes to trace the temperature of 20°C, exposure to 10 ?M of all examined metals and

Yanfen Zhang; Boping Ye; Dayong Wang

2010-01-01

389

Grain Yield and Heterosis of Maize Hybrids under Nematode Infested and Nematicide Treated Conditions  

PubMed Central

Plant-parasitic nematodes are present on maize but resistant genotypes have not been identified in Uganda. This study was aimed at determining the level of nematode resistance among F1 hybrids, and to estimate grain yield, heterosis and yield losses associated with maize hybrids under nematode infestation. The 30 F1 hybrids and two local checks were evaluated in a split plot design with nematode treatment (nematode infested versus nematicide treated) as the whole plot factor, and the hybrids as subplot factors arranged in an 8 x 4 alpha-lattice design. The experiment was conducted simultaneously at three sites. The hybrids were also evaluated in a split plot design under greenhouse conditions at IITA-Namulonge. Results revealed 24 P. zeae susceptible hybrids compared to only six P. zeae resistant hybrids. Grain yield across sites was higher by about 400 kg ha-1 under nematicide treatment than under nematode infestation. The nematode tolerant/resistant hybrids exhibited yields ranging from 5.0 to 8.4 t ha-1 compared to 5.0 t ha-1 obtained from the best check. Grain yield loss was up to 28% among susceptible hybrids, indicating substantial economic yield losses due to nematodes. Under field conditions, desired heterosis was recorded on 18 hybrids for P. zeae, and on three hybrids for Meloidogyne spp. Under nematode infestation, only 16 hybrids had higher relative yield compared to the mean of both checks, the best check and the trial mean, whereas it was 20 hybrids under nematicide treated plots. Overall, most outstanding hybrids under nematode infestation were CML395/MP709, CML312/5057, CML312/CML206, CML312/CML444, CML395/CML312 and CML312/CML395. Therefore, grain yield loss due to nematodes is existent but can be significantly reduced by growing nematode resistant hybrids.

Kagoda, Frank; Derera, John; Tongoona, Pangirayi; Coyne, Daniel L.; Talwana, Herbert L.

2011-01-01

390

Diversity and distribution of plant-parasitic nematodes in golf greens and football pitches  

Microsoft Academic Search

We surveyed golf greens and football pitches to characterise the species diversity, distribution and importance of plant-parasitic nematodes in Belgian turf grass. The survey included quantification and identification. Extraction-efficiencies of centrifugal flotation method and Baermann funnel techniques were statistically compared. Fifty-five nematode-taxa were morphologically identified from the in total 46 soil samples. Identified plant-parasitic nematodes belong to twenty-three different genera

B. Vandenbossche; W. Bert; G. Borgonie; Sutter de N; G. Karssen; N. Viaene

2008-01-01

391

Development of Dirofilaria and Setaria nematodes in Aedes albopictus.  

PubMed

The development of Dirofilaria repens, D immitis and Setaria labiatopapillosa up to L3 stage was documented in a laboratory colony of Aedes albopictus originating from specimens collected in Civitavecchia (Central Italy). The susceptibility of Ae albopictus and its plastic trophic habits, strongly suggest that this mosquito may contribute to the spreading of these nematodes in the country. It is particularly emphasized the danger for human health of an increased probability of transmission of Dirofilaria in urban areas. PMID:8778656

Cancrini, G; Pietrobelli, M; Frangipane di Regalbono, A F; Tampieri, M P; della Torre, A

1995-12-01

392

Effects of seven organic pollutants on soil nematode Caenorhabditis elegans  

Microsoft Academic Search

Caenorhabditis elegans is a free-living soil nematode that is commonly used as a model for toxicity tests. The aim of this study was to investigate the toxicity of seven organic pollutants: four azaarenes (quinoline, acridine, phenazine, and 1,10-phenanthroline), short-chain chlorinated paraffins, and two organochlorinated pesticides (toxaphene and hexachlorobenzene). The exposure to all chemicals was carried out in three test media

Ivana Sochová; Jakub Hofman; Ivan Holoubek

2007-01-01

393

BROAD OXYGEN TOLERANCE IN THE NEMATODE CAENORHABDITIS ELEGANS  

Microsoft Academic Search

This study examined the effects of oxygen tensions ranging from 0 to 90 kPa on the metabolic rate (rate of carbon dioxide production), movement and survivorship of the free-living soil nematode Caenorhabditis elegans. C. elegans requires oxygen to develop and survive. However, it can maintain a normal metabolic rate at oxygen levels of 3.6 kPa and has near-normal metabolic rates

WAYNE A. VAN VOORHIES; SAMUEL WARD

394

Endosymbiotic Wolbachia of parasitic filarial nematodes as drug targets.  

PubMed

The parasitic nematodes Wuchereria bancrofti, Brugia malayi and B. timori cause a dreadful disease in humans known as lymphatic filariasis, which afflicts more than 120 million people worldwide. As per recent epidemiologic estimates on prevalence of W. bancrofti and B. malayi, about 428 million people are at risk, with 28 million microfilaria carriers and 21 million clinical cases spread out in 13 States and 5 Union Territories of India. The Indian subcontinent that comprises Bangladesh, India, Maldives, Nepal and Sri Lanka harbours 50 per cent of the world's lymphatic filarial disease burden. Recently, an endobacterium of Wolbachia species that belongs to the family Rickettsiaceae was found in all life cycle stages of these nematodes and the transmission is exclusively vertical through the embryonic stages of the female worms. People with filariasis have been exposed to these Wolbachia bacteria or their proteins by the natural killing of parasites. Wolbachia have also been identified occasionally in body fluids of infected patients. Evidence suggests that these Wolbachia are mutualistic symbionts and can be cured from the nematodes by several antibiotics having antirickettsial properties. Treatment of nematodes with tetracyclines affect Wolbachia and they get cleared from worm tissues; and this elimination causes reproductive abnormalities in worms and affect worm's embryogenesis, resulting in sterility. Although it is impractical, prolonged treatment with doxycycline significantly reduces the numbers of microfilaria in circulation, which is an important strategy to control transmission of filariasis by mosquito vectors. In this review, the current knowledge of Wolbachia as a drug target and potential ways to reduce the infection through anti-Wolbachia treatments is discussed. PMID:16251775

Rao, Ramakrishna U

2005-09-01

395

The dynamics of the root-knot nematode galls  

Microsoft Academic Search

The dynamic nature of the galls evoked by species ofMeloidogyne (root-knot nematode) involves many hypersensitive reactions. Energy relations in the galls of the suscep-tible hosts reflect\\u000a the combat capabilities centering around functional resistance. Factors associated with resistance are indicated. The futurology\\u000a of the problem of containing the infection is discussed. Chemotherapy consisting of imparting resistance in susceptible hosts\\u000a is suggested,

S Kannan; T Chandraguru

1984-01-01

396

Mutations affecting sensitivity to ethanol in the nematode, Caenorhabditis elegans.  

PubMed

Mutations in nine genes have been identified in the nematode, Caenorhabditis elegans, which control sensitivity to ethanol. The interaction of these genes has been examined and used to determine a genetic pathway controlling sensitivity to ethanol. The nature of this pathway indicates that ethanol exerts its anesthetic actions at more than one site of action. These results also indicate that ethanol is similar in its effects to the volatile anesthetics, enflurane and isoflurane. PMID:8749805

Morgan, P G; Sedensky, M M

1995-12-01

397

Pasteuria penetrans and Its Parasitic Interaction with Plant Parasitic Nematodes  

Microsoft Academic Search

\\u000a The genus Pasteuria comprises a truly extraordinary group of unculturable bacteria that are obligate parasites of either water fleas or plant\\u000a parasitic nematodes. They have an astonishing vegetative morphology that, through an intricate process of differentiation,\\u000a leads to a structurally unique endospore form. Remarkably, phylogenetic studies indicate that this genus is ancestral to the\\u000a genus Bacillus. P.\\u000a penetrans is the

Alistair H. Bishop

398

Plant-parasitic nematodes on pasture in New Zealand  

Microsoft Academic Search

White clover (Trifolium repens) fixes nitrogen and provides high-quality feed and is, therefore, a key contributor to New Zealand’s grazed pasture systems.\\u000a However, its productive potential is rarely reached due to abiotic factors (e.g. drought) and various biotic constraints,\\u000a including nematodes. In a recurrent selection program based in the greenhouse, resistance to Meloidogyne trifoliophila and Heterodera trifolii has been improved

C. F. Mercer; N. L. Bell; G. W. Yeates

2008-01-01

399

Surfactant stimulation of growth in the nematode Caenorhabditis elegans  

Microsoft Academic Search

Size fractionation has been used to isolate L1L2 larvae from mixed cultures of the nematode, Caenorhabditis elegans. Worm lengths have been compared during growth in synchronized liquid and agar cultures. Supplementation of liquid S medium with 10 ppm surfactant (Pluronics F-68, F-127, F-38, L-35; Tween-20 or Triton X-100) promoted a significant stimulation of growth over three days in all cases.

Mohammed H. A. Z. Mutwakil; Tamazin J. G. Steele; Kenneth C. Lowe; David I. de Pomerai

1997-01-01

400

Nucleoside diphosphate kinase from the parasitic nematode Brugia malayi  

Microsoft Academic Search

Using a reverse transcription-polymerase chain reaction (RT-PCR) procedure that exploited the presence of a conserved 22-nucleotide spliced leader (SL) sequence that is trans-spliced to the 5? end of nematode transcripts, a novel Brugia malayi (Bm) infective-stage SL cDNA expression library was constructed and characterized. The library was immunoscreened with rabbit anti-infective-stage antibodies (Ab) and an immunodominant clone, BmG4–7, was identified

Inca Ghosh; Nithyakalyani Raghavan; Peter C. Fitzgerald; Alan L. Scott

1995-01-01

401

Long-Term Survival of the Entomopathogenic Nematode Heterorhabditis marelatus  

Microsoft Academic Search

Entomopathogenic nematodes are important biological control agents for a variety of soil- and litter-dwelling insect pests. A major drawback to their use against pest species is their low level of persistence in many agricultural systems. While a number of studies have examined the persistence of these biological control agents over periods of days and\\/or weeks, the longer-term survival of these

Evan L. Preisser; Christopher J. Dugaw; Brian Dennis; Donald R. Strong

2005-01-01

402

Genetic Transformation of an Entomopathogenic Nematode by Microinjection  

Microsoft Academic Search

We report the first successful transformation of an entomopathogenic nematode. Foreign genes were introduced in Heterorhabditis bacteriophora HP88 by microinjection using vectors carrying the Caenorhabditis elegans genes coding for the roller phenotype and 16-kDa heat shock protein (hsp16) gene. A translational fusion made by inserting lacZ in frame into hsp16 was expressed in the body musculature, hypodermis, and pharyngeal muscles.

Sarwar Hashmi; Ghazala Hashmi; Randy Gaugler

1995-01-01

403

Persistent efficacy of topical eprinomectin against nematode parasites in cattle  

Microsoft Academic Search

Six studies were conducted to evaluate the persistent efficacy of eprinomectin pour-on against experimental challenges with\\u000a infective nematode larvae in calves. In each study, calves were randomly assigned to one untreated group and up to four test\\u000a groups, which were treated with eprinomectin at 500??g\\/kg body weight at weekly intervals before single bolus challenge. The\\u000a calves were necropsied approximately 4?weeks

Luiz G. Cramer; Simon R. Pitt; Steffen Rehbein; Ronald P. Gogolewski; Bruce N. Kunkle; Wayne K. Langholff; Karen G. Bond; Ana E. Maciel

2000-01-01

404

The comparative morphology of three equine habronematid nematodes: SEM observations  

Microsoft Academic Search

Drashia megastoma Rudolphi, 1819, Habronema muscae Carter, 1861 and Habronema microstoma Schneider, 1866 are found in the stomach of equine definitive hosts and are known to cause pathogenic effects in the stomach\\u000a wall, skin, eye and occasionally other sites. These nematodes utilise either house flies or stable flies as their intermediate\\u000a hosts. Apart from molecular findings that have demonstrated some

Soraya Naem

2007-01-01

405

Hampton: A main season golden nematode resistant variety  

Microsoft Academic Search

Hampton is a golden nematode resistant variety suited for main season tablestock production. It is resistant toVerticillium wilt, but susceptible to scab and late blight. Hampton yields as well as Katahdin and produces essentially the same distribution\\u000a of tuber sizes. Its shape is distinctively spherical with shallow eyes. Its specific gravity is like Katahdin and it will\\u000a not produce acceptably

R. L. Plaisted; H. D. Thurston; B. B. Brodie; E. D. Jones; R. Loria; D. Halseth; J. B. Sieczka; D. D. Moyer

1985-01-01

406

Stable Isotope Labeling with Amino acids in Nematodes  

PubMed Central

We describe an approach for the accurate quantitation of global protein dynamics in Caenorhabditis elegans. We adapted Stable Isotope Labeling with Amino acids in Cell culture (SILAC) for nematodes, by feeding worms a heavy lysine- and arginine-labeled E. coli strain. We also report a genetic solution to remove the arginine-to-proline conversion problem. Combining our approach with quantitative proteomics methods, we characterized the heatshock response in worms.

Larance, Mark; Bailly, Aymeric P.; Pourkarimi, Ehsan; Hay, Ronald T.; Buchanan, Grant; Coulthurst, Sarah; Xirodimas, Dimitris P.; Gartner, Anton; Lamond, Angus I.

2011-01-01

407

Food preferences and nematode parasitism in mycophagous Drosophila  

Microsoft Academic Search

Food preferences and nematode parasitism were studied in natural populations of mycophagousDrosophila in and near Sapporo, northern Japan. Species which preferred fresh mushrooms showed species-specific responses toPleurotus mushrooms:D. pirka bred only onPleurotus cornucopiae, D. trivitata onP. cornucopiae andP. ostreatus, D. trilineata on these twoPleurotus mushrooms and some other mushrooms, whileD. sexvittata bred on a wide variety of mushrooms but seldom

Masahito T. Kimura; Masanori J. Toda

1989-01-01

408

Osmotic stress tolerance and osmoregulation of intertidal and subtidal nematodes  

Microsoft Academic Search

Four species of free-living marine nematode were studied to assess their ability to osmoregulate under various conditions of osmotic stress. Axonolaimus paraspinosusStekhoven and Adams, 1931(Monhysterida, Axonolaimidae), from the upper intertidal zone, Cervonema tenuicauda (Stekhoven, 1950) (Chromadorida Comesomatidae), upper intertidal, Daptonema oxycerca (De Man, 1888) (Monhysterida, Xyalidae), lower intertidal and Sabatieria punctata (Kreis, 1924) (Chromadorida, Comesomatidae), subtidal, were collected. Each was

S. J Forster

1998-01-01

409

Efficacy of neem seed derivatives against nematodes affecting banana  

Microsoft Academic Search

Soil applications of powdered neem seed or neem cake at 100 g\\/plant at planting and, subsequently, at 3-month intervals, reduced\\u000a the populations ofPratylenchus goodeyi Sher & Allen andMeloidogyne spp. on par with Furadan 5G (carbofuran) applied at 40 g\\/plant at planting and then at 6-month intervals to banana plants\\u000a grown in 100-\\/ containers with controlled levels of banana nematode infestations.

T. Musabyimana; R. C. Saxena

1999-01-01

410

OSMOTIC AVOIDANCE DEFECTIVE MUTANTS OF THE NEMATODE CAENORHABDITIS ELEGANS  

Microsoft Academic Search

A wild-type strain of the nematode Caenorhabditis elegans has been shown to avoid high concentrations of a number of sugars and salts. Individual and population assays for this response were developed and mutants were selected for their inability to avoid high concentrations of fructose or NaC1. Seven nonavoiding mutants representing six complementation groups were isolated and characterized. Genetic studies indicate

JOSEPH G. CULOTTI; RICHARD L. RUSSELL

1978-01-01

411

FMRFamide-related peptides in potato cyst nematodes  

Microsoft Academic Search

This study presents data demonstrating the presence of FMRFamide-related peptides (FaRPs) in potato cyst nematodes (PCN). Five transcripts of FaRP encoding genes, designated gpflp-1 to gpflp-5, were characterised using RACE. In terms of ORFs, gpflp-1 was 444 base pairs (bp) long and coded for four copies of the FaRP, PF3 (KSAYMRFamide) whilst gpflp-2 was 309 bp long and encoded one

Michael J. Kimber; Colin C. Fleming; Anthony J. Bjourson; David W. Halton; Aaron G. Maule

2001-01-01

412

Survival of freezing by free-living Antarctic soil nematodes.  

PubMed

Free-living microbivorous nematodes become numerically dominant in Antarctic terrestrial faunas as environmental conditions become more severe, while also reaching very high levels of abundance in moist, vegetated habitats. Nematodes have little resistance to freezing via exogenous ice nucleation, such as would occur as their microhabitat freezes. We report the results of experiments testing the ability of seven maritime Antarctic nematode taxa to survive freezing in small water droplets at high sub-zero temperatures. Isolated individuals of these species possessed supercooling characteristics similar to those previously reported (supercooling points -6 to -25 degree C). When frozen in water at -3 to -6 degree C, most showed high (> 70%) survival both (i) after rapid cooling (1 degree C/min) to c. -60 degree C followed by immediate rewarming, and (ii) when held for 7-12 h at either -10 or -30 degree C, although the proportions surviving varied between species. We propose that the ability to survive freezing while fully hydrated at high sub-zero temperatures is one of the most important aspects of these species' survival tactics. PMID:12148024

Convey, P; Worland, M R

413

The dynamics of nematode infections of farmed ruminants.  

PubMed

In this paper the dynamics and control of nematode parasites of farmed ruminants are discussed via a qualitative analysis of a differential equation model. To achieve this a quantity, 'the basic reproduction quotient' (Q0), whose definition coincides with previous definitions of R0 for macroparasites, but extends to models with periodic time-varying transition rates between parasite stages or management interventions, is introduced. This quantity has the usual threshold property: if Q0 is less than one the parasite population cannot maintain itself in the host population, and in the long term becomes extinct; but if Q0 is greater than one the parasite can invade the host population. An alternative quantity, R(E), that is often easier to calculate is also introduced, and shown to have the same threshold property. The use of these two quantities in analysing models for the dynamics of nematodes in complex situations is then demonstrated, with reference to the dynamics of mixed parasite species in one host; the effects of breeding host animals for resistance to parasitism; and the development of parasite strains that are resistant to chemotherapy. Five examples are discussed using parameters for the dynamics of nematode infections in sheep, and some statements on control policies are derived. PMID:7753588

Roberts, M G; Heesterbeek, J A

1995-05-01

414

Bacterial parasite of a plant nematode: morphology and ultrastructure.  

PubMed Central

The life cycle of a bacterial endoparasite of the plant-parasitic nematode Meloidogyne incognita was examined by scanning and transmission electron microscopy. The infective stage begins with the attachment of an endospore to the surface of the nematode. A germ tube then penetrates the cuticle, and mycelil colonies form in the pseudocoelom. Sporulation is initiated when terminal cells of the mycelium enlarge to form sporangia. A septum within each sporangium divides the forespore from the basal or parasporal portion of the cell. The forespore becomes enclosed by several laminar coats. The parasporal cell remains attached to the forespore and forms the parasporal microfibers. After the newly formed spores are released into the soil, these microfibers apparently enable a mature spore to attach to the nematode. These results indicate that the endoparasite is a procaryotic organism having structural features that are more common to members of Actinomycetales and to the bacterium Pasteuria ramosa than to the sporozoans or to the family Bacillaceae, as previous investigatios have concluded. Images

Sayre, R M; Wergin, W P

1977-01-01

415

Host-finding behaviour in the nematode Pristionchus pacificus  

PubMed Central

Costs and benefits of foraging have been studied in predatory animals. In nematodes, ambushing or cruising behaviours represent adaptations that optimize foraging strategies for survival and host finding. A behaviour associated with host finding of ambushing nematode dauer juveniles is a sit-and-wait behaviour, otherwise known as nictation. Here, we test the function of nictation by relating occurrence of nictation in Pristionchus pacificus dauer juveniles to the ability to attach to laboratory host Galleria mellonella. We used populations of recently isolated and mutagenized laboratory strains. We found that nictation can be disrupted using a classical forward genetic approach and characterized two novel nictation-defective mutant strains. We identified two recently isolated strains from la Réunion island, one with a higher proportion of nictating individuals than the laboratory strain P. pacificus PS312. We found a positive correlation between nictation frequencies and host attachment in these strains. Taken together, our combination of genetic analyses with natural variation studies presents a new approach to the investigation of behavioural and ecological functionality. We show that nictation behaviour in P. pacificus nematodes serves as a host-finding behaviour. Our results suggest that nictation plays a role in the evolution of new life-history strategies, such as the evolution of parasitism.

Brown, Federico D.; D'Anna, Isabella; Sommer, Ralf J.

2011-01-01

416

Plant-parasitic Nematodes Associated with Cotton in Florida.  

PubMed

A sampling of 15% of the cotton hectarage in each Florida county was assayed for nematodes and soil particle components following the 1990 harvest. The distribution of juveniles of Meloidogyne spp., which were found in 61% of the 178 fields sampled statewide, was not influenced by soil type. Rotylenchulus reniformis was more prevalent in the heavier soils and occurred in 15% of the sampled fields. In fields with concomitant infestations (9% of the sampled fields), densities of root-knot juveniles per 10 cm(3) soil wer e negatively related to those of reniform nematodes (R(2) =-0.32; P < 0.02; df = 14). Gall ratings of cotton plants, assayed in sampled soils, were positively related to the densities of root-knot juveniles per 100 cm(3) soil (R(2) = 0.23; P < 0.01; df = 175). Other nematode genera and their frequency of occurrence were Helicotylenchus (76%), Paratrichodorus (57%), Criconemella (53%), Pratylenchus (42%), Xiphinema (7%), Heterodera (2%), and Hoplolaimus (1%). PMID:19279958

Kinlock, R A; Sprenkel, R K

1994-12-01

417

Pratylenchus, paratylenchus, helicotylenchus, and other nematodes on soybean in missouri.  

PubMed

Eighteen species in eight genera of plant-parasitic nematodes were identified from soil samples collected from soybean fields throughout Missouri. The genera represented were Helicotylenchus, Heterodera, Hoplolaimus, Meloidogyne, Paratylenchus, Pratylenchus, Tylenchorhynchus, and Xiphinema. Three fields, each with high densities of Helicotylenchus pseudorobustus, Pratylenchus hexincisus, or Paratylenchus projectus, were planted in 1989 with six soybean cultivars, with plots of each cultivar either not treated or treated with 5.43 kg/ha aldicarb, to determine whether economically important relationships existed. In none of the sites were nematode densities affected by either aldicarb treatment or cultivar, nor were seed yields related to nematode densities; however, mean seed yield was significantly lower in the P. projectus site. In 1990, seed yield was negatively correlated (r = -0.34, P < 0.05) with P. projectus density at planting. Based on the present and previous studies, H. pseudorobustus and P. hexincisus do not appear to be of economic interest on soybean, but P. projectus probably deserves more study. PMID:19283055

Niblack, T L

1992-12-01

418

Carbohydrate-recognition domains on the surface of phytophagous nematodes.  

PubMed

Human red blood cells (HRBC) adhered to preparasitic second-stage juveniles (J2) of Heterodera avenae, Heterodera schachtii, Meloidogyne javanica, Pratylenchus mediterraneus, Rotylenchulus reniformis, and Tylenchulus semipenetrans over the entire nematode body. Binding was conspicuously confined to the head and tail of Longidorus cohni, Xiphinema brevicolle, and Xiphinema index. Binding was Ca2+ and Mg2+ dependent. In contrast, HRBC did not adhere to Anguina tritici, Aphelenchoides subtenius, Ditylenchus dipsaci, M. javanica females, and Panagrellus redivivus, even in the presence of these cations. Incubation of M. javanica J2 with fucose, glucose, N-acetylglucosamine, mannose, or trypsin decreased the intensity of subsequent HRBC binding, while galactose and N-acetylgalactosamine increased binding intensity. HRBC binding was diminished when nematodes were pretreated with trypsin and eliminated when pretreatments with detergents removed the surface coat. HRBC adhered to nylon fibers coated with surface coat extracted from M. javanica J2; binding was Ca2+ and Mg2+ dependent and diminished when the nylon fibers were coated with bovine serum albumin or preincubated with fucose and mannose. These results demonstrate that HRBC adhesion involves carbohydrate moieties of HRBC and corresponding carbohydrate-recognition domains (CRD) distributed in the nematode surface coat. To our knowledge this is the first report of a surface CRD in the phylum Nematoda. PMID:7895833

Spiegel, Y; Inbar, J; Kahane, I; Sharon, E

1995-03-01

419

Functional diversification of Argonautes in nematodes: an expanding universe  

PubMed Central

In the last decade, many diverse RNAi (RNA interference) pathways have been discovered that mediate gene silencing at epigenetic, transcriptional and post-transcriptional levels. The diversity of RNAi pathways is inherently linked to the evolution of Ago (Argonaute) proteins, the central protein component of RISCs (RNA-induced silencing complexes). An increasing number of diverse Agos have been identified in different species. The functions of most of these proteins are not yet known, but they are generally assumed to play roles in development, genome stability and/or protection against viruses. Recent research in the nematode Caenorhabditis elegans has expanded the breadth of RNAi functions to include transgenerational epigenetic memory and, possibly, environmental sensing. These functions are inherently linked to the production of secondary siRNAs (small interfering RNAs) that bind to members of a clade of WAGOs (worm-specific Agos). In the present article, we review briefly what is known about the evolution and function of Ago proteins in eukaryotes, including the expansion of WAGOs in nematodes. We postulate that the rapid evolution of WAGOs enables the exceptional functional plasticity of nematodes, including their capacity for parasitism.

Buck, Amy H.; Blaxter, Mark

2013-01-01

420

Analysis of nematode mechanics by piezoresistive displacement clamp  

PubMed Central

Studying animal mechanics is critical for understanding how signals in the neuromuscular system give rise to behavior and how force-sensing organs and sensory neurons work. Few techniques exist to provide forces and displacements appropriate for such studies. To address this technological gap, we developed a metrology using piezoresistive cantilevers as force–displacement sensors coupled to a feedback system to apply and maintain defined load profiles to micrometer-scale animals. We show that this system can deliver forces between 10?8 and 10?3 N across distances of up to 100 ?m with a resolution of 12 nN between 0.1 Hz and 100 kHz. We use this new metrology to show that force–displacement curves of wild-type nematodes (Caenorhabditis elegans) are linear. Because nematodes have approximately cylindrical bodies, this finding demonstrates that nematode body mechanics can be modeled as a cylindrical shell under pressure. Little is known about the relative importance of hydrostatic pressure and shell mechanics, however. We show that dissipating pressure by cuticle puncture or decreasing it by hyperosmotic shock has only a modest effect on stiffness, whereas defects in the dpy-5 and lon-2 genes, which alter body shape and cuticle proteins, decrease and increase stiffness by 25% and 50%, respectively. This initial analysis of C. elegans body mechanics suggests that shell mechanics dominates stiffness and is a first step in understanding how body mechanics affect locomotion and force sensing.

Park, Sung-Jin; Goodman, Miriam B.; Pruitt, Beth L.

2007-01-01

421

Control of Larval Northern Corn Rootworm. (Diabrotica barberi) with Two Steinernematid Nematode Species  

PubMed Central

The entomogenous nematodes Steinerema feltiae and S. bibionis did not penetrate the roots of corn, Zea mays, to infect larval northern corn rootworm (NCR), Diabrotica barberi, feeding within. Laboratory bioassays against first instar NCR indicated that S. feltiae, Mexican strain (LD?? = 49 nematodes/insect) is more virulent than S. bibionis (LD?? = 100). Numbers of NCR larvae in a grain corn crop were reduced by both nematode species applied at corn seeding time at the rate of 10,000 infective-stage juveniles per linear meter of corn row. The chemical insecticide fonofos provided significantly better control than either nematode species.

Thurston, G. S.; Yule, W. N.

1990-01-01

422

Control of Larval Northern Corn Rootworm. (Diabrotica barberi) with Two Steinernematid Nematode Species.  

PubMed

The entomogenous nematodes Steinerema feltiae and S. bibionis did not penetrate the roots of corn, Zea mays, to infect larval northern corn rootworm (NCR), Diabrotica barberi, feeding within. Laboratory bioassays against first instar NCR indicated that S. feltiae, Mexican strain (LD = 49 nematodes/insect) is more virulent than S. bibionis (LD = 100). Numbers of NCR larvae in a grain corn crop were reduced by both nematode species applied at corn seeding time at the rate of 10,000 infective-stage juveniles per linear meter of corn row. The chemical insecticide fonofos provided significantly better control than either nematode species. PMID:19287699

Thurston, G S; Yule, W N

1990-01-01

423

Control of root-knot nematodes on tomato in stone wool substrate with biological nematicides.  

PubMed

The efficacy of four biological nematicides on root-galling, root-knot nematode (Meloidogyne incognita) reproduction, and shoot weight of tomato (Solanum lycopersicum) grown in stone wool substrate or in pots with sandy soil was compared to an oxamyl treatment and a non-treated control. In stone wool grown tomato, Avid® (a.i. abamectin) was highly effective when applied as a drench at time of nematode inoculation. It strongly reduced root-galling and nematode reproduction, and prevented a reduction in tomato shoot weight. However, applying the product one week before, or two weeks after nematode inoculation was largely ineffective. This shows that Avid® has short-lived, non-systemic activity. The effects of Avid® on nematode symptoms and reproduction on soil-grown tomato were only very minor, probably due to the known strong adsorption of the active ingredient abamectin to soil particles. The neem derived product Ornazin® strongly reduced tomato root-galling and nematode reproduction only in stone wool and only when applied as a drench one week prior to nematode inoculation, suggesting a local systemic activity or modification of the root system, rendering them less suitable host for the nematodes. This application however also had some phytotoxic effect, reducing tomato shoot weights. The other two products, Nema-Q™ and DiTera®, did not result in strong or consistent effects on nematode symptoms or reproduction. PMID:22791920

López-Pérez, Jose Antonio; Edwards, Scott; Ploeg, Antoon

2011-06-01

424

Transcriptomic analysis of the entomopathogenic nematode Heterorhabditis bacteriophora TTO1  

PubMed Central

Background The entomopathogenic nematode Heterorhabditis bacteriophora and its symbiotic bacterium, Photorhabdus luminescens, are important biological control agents of insect pests. This nematode-bacterium-insect association represents an emerging tripartite model for research on mutualistic and parasitic symbioses. Elucidation of mechanisms underlying these biological processes may serve as a foundation for improving the biological control potential of the nematode-bacterium complex. This large-scale expressed sequence tag (EST) analysis effort enables gene discovery and development of microsatellite markers. These ESTs will also aid in the annotation of the upcoming complete genome sequence of H. bacteriophora. Results A total of 31,485 high quality ESTs were generated from cDNA libraries of the adult H. bacteriophora TTO1 strain. Cluster analysis revealed the presence of 3,051 contigs and 7,835 singletons, representing 10,886 distinct EST sequences. About 72% of the distinct EST sequences had significant matches (E value < 1e-5) to proteins in GenBank's non-redundant (nr) and Wormpep190 databases. We have identified 12 ESTs corresponding to 8 genes potentially involved in RNA interference, 22 ESTs corresponding to 14 genes potentially involved in dauer-related processes, and 51 ESTs corresponding to 27 genes potentially involved in defense and stress responses. Comparison to ESTs and proteins of free-living nematodes led to the identification of 554 parasitic nematode-specific ESTs in H. bacteriophora, among which are those encoding F-box-like/WD-repeat protein theromacin, Bax inhibitor-1-like protein, and PAZ domain containing protein. Gene Ontology terms were assigned to 6,685 of the 10,886 ESTs. A total of 168 microsatellite loci were identified with primers designable for 141 loci. Conclusion A total of 10,886 distinct EST sequences were identified from adult H. bacteriophora cDNA libraries. BLAST searches revealed ESTs potentially involved in parasitism, RNA interference, defense responses, stress responses, and dauer-related processes. The putative microsatellite markers identified in H. bacteriophora ESTs will enable genetic mapping and population genetic studies. These genomic resources provide the material base necessary for genome annotation, microarray development, and in-depth gene functional analysis.

Bai, Xiaodong; Adams, Byron J; Ciche, Todd A; Clifton, Sandra; Gaugler, Randy; Hogenhout, Saskia A; Spieth, John; Sternberg, Paul W; Wilson, Richard K; Grewal, Parwinder S

2009-01-01

425

Molecular detection of predation by soil micro-arthropods on nematodes.  

PubMed

The relative importance of the factors driving change in the population dynamics of nematodes in the soil is almost completely unknown. Top-down control by micro-arthropod predators may have a significant impact on nematode population dynamics. We report experiments showing that mites and Collembola were capable of reducing nematode numbers in the laboratory and were feeding on a targeted nematode species in the field. A PCR-based approach was developed for the detection of predation on three species of slug- and insect-pathogenic nematodes: Phasmarhabditis hermaphrodita, Heterorhabditis megidis and Steinernema feltiae. The collembolan Folsomia candida and the mesostigmatid mite Stratiolaelaps miles were employed as model predators to calibrate post-ingestion prey DNA detection times. Fragments of cytochrome oxidase I (COI) mtDNA were sequenced and species-specific primers were designed, amplifying 154-, 154- and 203-bp fragments for each of the nematode species. Detection times for nematode DNA within the guts of Collembola were longer than in mites, with half-lives (50% of samples testing positive) of 08.75 h and 05.03 h, respectively. F. candida significantly reduced numbers of the nematode H. megidis, with rates of predation of approximately 0.4 nematode infective juveniles per collembolan per hour over 10 h. Four taxa of field-caught micro-arthropod that had been exposed to the nematode P. hermaphrodita for a period of 12 h were analysed and significant numbers of three taxa tested positive. This is the first application of PCR techniques for the study of nematophagy and the first time these techniques have been used to measure predation on nematodes in the field. PMID:16689911

Read, D S; Sheppard, S K; Bruford, M W; Glen, D M; Symondson, W O C

2006-06-01

426

Successional trends in the characteristics of soil nematode communities in cropped and fallow lands in Senegal (Sonkorong)  

Microsoft Academic Search

Soil nematode communities in the 0–15cm soil layer are used as indicators for describing the processes of fallow succession in the semi-arid zone of West Africa (Senegal). Abundance of plant feeding nematodes, non-plant feeding nematodes, plant parasite index (PPI), species richness and Shannon evenness of plant parasitic nematodes were measured at five stages of succession: fields, early (1–3 years), intermediate

E. Pate; N. Ndiaye-Fayea; J. Thioulouseb; C. Villenave; T. Bongersc; P. Cadet; D. Debouzie

2000-01-01

427

The origin and distribution of the golden nematode and its potential in the U.S.A  

Microsoft Academic Search

Potato cyst-nematodes,Globodera pallida andG. rostochiensis (golden nematode), and their preferred host, the potato, originated in the Andes of South America. Both were introduced into\\u000a Europe from the Andean region, the potato about 1570 and the nematode nearly 300 years later. Potato cyst-nematodes are believed\\u000a to have been introduced into Europe in the 1850’s along with potato collections from the Andes

K. Evans; B. B. Brodie

1980-01-01

428

Public Soybean Breeding Lines Tested for Reniform Nematode (Rotylenchulus reniformis) Reproduction  

Technology Transfer Automated Retrieval System (TEKTRAN)

In the Southeastern United States reniform nematode (Rotylenchulus reniformis) causes considerable damage and yield loss to soybean and cotton. No cotton varieties have reniform nematode resistance, whereas several sources of resistance exist in soybean. This resistance is often linked to resistance...

429

Mass cultivation and storage of the rhabditid nematode Phasmarhabditis hermaphrodita, a biocontrol agent for slugs  

Microsoft Academic Search

The rhabditid nematode Phasmarhabditis hermaphrodita (a parasite capable of killing pest slugs) was grown in vitro, in association with a mixed bacterial flora on foam chips impregnated with a kidney?based nutrient medium in aerated bags, to provide sufficient numbers for laboratory and field experiments. The feasibility of producing nematodes in liquid culture was investigated using 250 ml flasks. Baffled flasks

M. J. Wilson; D. M. Glen; S. K. George; R. C. Butler

1993-01-01

430

Integration of Entomopathogenic Nematodes with Bacillus thuringiensis or Pesticidal Soap for Control of Insect Pests  

Microsoft Academic Search

The integration of entomopathogenic nematodes and Bacillus thuringiensis subspecies kurstaki or a pesticidal soap controlled insect pests inhabiting the soil and foliage in the greenhouse. The nematode Heterorhabditis bacteriophora controlled larvae of the masked chafer Cyclocephala hirta or the black vine weevil Otiorhynchus sulcatus in the soil and a commercial formulation of B. thuringiensis (Javelin) controlled larvae of the cabbage

H. K. Kaya; T. M. Burlando; H. Y. Choo; G. S. Thurston

1995-01-01

431

Current status of phytoparasitic nematodes and their host plants in Egypt  

Technology Transfer Automated Retrieval System (TEKTRAN)

In Egypt many phytoparasitic nematodes constitute a major constraint to agricultural production, especially in sandy soil and reclaimed desert lands. Nematological surveys were conducted to determine the genera and species of phytoparasitic nematodes on associated host plants in Egypt. The results i...

432

Resistance to soybean cyst nematode and molecular polymorphism in various sources of Peking soybean  

Microsoft Academic Search

Cultivar Peking has been extensively used as a source of resistance to Race 3 and Race 5 of soybean cyst nematode, Heterodera glycines I., and Peking genes for resistance are present in a wide range of resistant soybean cultivars. Peking is also used as a host differential in the soybean cyst nematode race classification system. Thirteen Peking lines maintained in

H. T. Skorupska; I. S. Choi; A. P. Rao-Arelli; W. C. Bridges

1994-01-01

433

Does scavenging extend the host range of entomopathogenic nematodes (Nematoda: Steinernematidae)?  

Microsoft Academic Search

Living and freeze-killed natural and laboratory hosts, with different susceptibility to entomopathogenic nematodes, were exposed to the larvae of Steinernema affine and Steinernema kraussei in two different experimental arenas (Eppendorf tubes, Petri dishes), and the success of the colonisation and eventual progeny production were observed. Both nematodes were able to colonise both living and dead larvae of Galleria mellonella (Lepidoptera)

Vladimír P?ža; Zden?k Mrá?ek

2010-01-01

434

Role of nematode peptides and other small molecules in plant parasitism  

Technology Transfer Automated Retrieval System (TEKTRAN)

Molecular, genetic, and biochemical studies are demonstrating an increasingly important role of peptide signaling in nematode parasitism of plants. To date, the majority of nematode-secreted peptides identified share similarity with plant CLAVATA3/ESR (CLE) peptides, but bioinformatics analyses of n...

435

Susceptibility of Aethina tumida (Coleoptera: Nitidulidae) Larvae and Pupae to Entomopathogenic Nematodes  

Microsoft Academic Search

In this study, we evaluated the potential use of entomopathogenic nematodes as a control for the beetle Aethina tumida Murray (Coleoptera: Nitidulidae). In particular, we conducted 1) four screening bioassays to determine nematode (seven species, 10 total strains tested) and application level effects on A. tumida larvae and pupae, 2) a generational persistence bioassay to determine whether single inoculations with

J. D. Ellis; S. Spiewok; K. S. Delaplane; S. Buchholz; P. Neumann; W. L. Tedders

2010-01-01

436

Colonization of plant roots by egg-parasitic and nematode-trapping fungi  

Microsoft Academic Search

Summary • The ability of the nematode-trapping fungus Arthrobotrys oligospora and the nematode egg parasite Verticillium chlamydosporium to colonize barley ( Hordeum vulgare ) and tomato ( Lycopersicum esculentum ) roots was examined, together with capability of the fungi to induce cell wall modifications in root cells. • Chemotropism was studied using an agar plate technique. Root colonization was investigated

J. J. Bordallo; L. V. Lopez-Llorca; H.-B. Jansson; J. Salinas; L. Persmark; L. Asensio

2002-01-01

437

RECYCLING POTENTIAL AND FITNESS IN STEINERNEMATID NEMATODES CULTURED IN CURCULIO CARYAE  

Technology Transfer Automated Retrieval System (TEKTRAN)

The recycling potential of entomopathogenic nematodes in the pecan weevil, Curculio caryae, is an important factor in considering whether nematodes could be incorporated into a C. caryae management strategy. Our objective was to determine the recycling potential and fitness of S. carpocapsae and S....

438

Interactions between nutrition and gastrointestinal infections with parasitic nematodes in goats  

Microsoft Academic Search

Parasitic nematodes of the digestive tract remain one of the main constraints to goat production both in temperate and tropical countries. The usual mode of control of these gastrointestinal nematodes (GIN) based on the repeated use of anthelmintics is now strongly questioned because of the increasing development of resistance to these molecules. Among the alternative methods to anthelmintics currently available,

H. Hoste; J. F. Torres-Acosta; V. Paolini; A. Aguilar-Caballero; E. Etter; Y. Lefrileux; C. Chartier; C. Broqua

2005-01-01

439

Reduced Protective Efficacy of a Blood-Stage Malaria Vaccine by Concurrent Nematode Infection  

PubMed Central

Helminth infections, which are prevalent in areas where malaria is endemic, have been shown to modulate immune responses to unrelated pathogens and have been implicated in poor efficacy of malaria vaccines in humans. We established a murine coinfection model involving blood-stage Plasmodium chabaudi AS malaria and a gastrointestinal nematode, Heligmosomoides polygyrus, to investigate the impact of nematode infection on the protective efficacy of a malaria vaccine. C57BL/6 mice immunized with crude blood-stage P. chabaudi AS antigen in TiterMax adjuvant developed strong protection against malaria challenge. The same immunization protocol failed to induce strong protection in H. polygyrus-infected mice. Immunized nematode-infected mice produced significantly lower levels of malaria-specific antibody than nematode-free mice produced. In response to nematode and malarial antigens, spleen cells from immunized nematode-infected mice produced significantly lower levels of gamma interferon but more interleukin-4 (IL-4), IL-13, and IL-10 in vitro than spleen cells from immunized nematode-free mice produced. Furthermore, H. polygyrus infection also induced a strong transforming growth factor ?1 response in vivo and in vitro. Deworming treatment of H. polygyrus-infected mice before antimalarial immunization, but not deworming treatment after antimalarial immunization, restored the protective immunity to malaria challenge. These results demonstrate that concurrent nematode infection strongly modulates immune responses induced by an experimental malaria vaccine and consequently suppresses the protective efficacy of the vaccine against malaria challenge.

Su, Zhong; Segura, Mariela; Stevenson, Mary M.

2006-01-01

440

Molecular evolution in Panagrolaimus nematodes: origins of parthenogenesis, hermaphroditism and the Antarctic species P. davidi  

Microsoft Academic Search

BACKGROUND: As exemplified by the famously successful model organism Caenorhabditis elegans, nematodes offer outstanding animal systems for investigating diverse biological phenomena due to their small genome sizes, short generation times and ease of laboratory maintenance. Nematodes in the genus Panagrolaimus have served in comparative development and anhydrobiosis studies, and the Antarctic species P. davidi offers a powerful paradigm for understanding

Samantha C Lewis; Leslie A Dyal; Caroline F Hilburn; Stephanie Weitz; Wei-Siang Liau; Craig W LaMunyon; Dee R Denver

2009-01-01

441

Parasitism by Oestrus ovis: Influence of sheep breed and nematode infections  

Microsoft Academic Search

Previous studies showed that Santa Ines (SI) hair sheep were more resistant to gastrointestinal nematode infections (GIN) than Ile de France (IF) sheep. The present experiment aimed to evaluate if that reported resistance difference against GIN also occurred against Oestrus ovis infestation and also to evaluate the influence of O. ovis infestation on the gastrointestinal nematodes (GIN) infections. SI (n=12)

B. F. Silva; C. C. Bassetto; R. J. Shaw; A. M. O. Canavessi; A. F. T. Amarante

442

Structure, functions and interguild relationships of the soil nematode assemblage in organic vegetable production  

Technology Transfer Automated Retrieval System (TEKTRAN)

The abundance and metabolic footprints of soil nematodes were quantified during four of eight years of an intensive organic vegetable production system. Treatment variables included cover crop mixtures and frequency, and compost application rates. The abundances of bacterivore and fungivore nematode...

443

Bacteria associated with the pinewood nematode Bursaphelenchus xylophilus collected in Portugal.  

PubMed

In this study, we report on the bacterial community associated with the pinewood nematode Bursaphelenchus xylophilus from symptomatic pine wilted trees, as well as from long-term preserved B. xylophilus laboratory collection specimens, emphasizing the close bacteria-nematode associations that may contribute to pine wilt disease development. PMID:21656192

Vicente, Cláudia S L; Nascimento, Francisco; Espada, Margarida; Mota, Manuel; Oliveira, Solange

2011-06-09

444

A review of introductions of pathogens and nematodes for classical biological control of insects and mites  

Microsoft Academic Search

Abstract Compared with parasitoids and predators, classical biological control programs targeting arthropod pests have used pathogens and nematodes very little. However, some pathogens and nematodes that have been introduced have become established and provided excel- lent control and have been introduced in increasing numbers of areas over decades, often after distributions of pests have increased. We summarize 131 introductions, the

Ann E. Hajek; Michael L. McManus; Italo Delalibera Júnior

2007-01-01

445

Distribution and infestation rate of cyst nematodes (Tylenchida: Heteroderidae) in cabbage growing areas in Samsun  

Technology Transfer Automated Retrieval System (TEKTRAN)

Information concerning the occurrence and distribution of cyst nematodes (Heterodera spp.) in Samsun, Turkey is needed to assess their potential to cause economic damage on many crop plants. Surveys on the distribution and infestation rates of cyst nematodes in cabbage fields in Samsun were conducte...

446

First report of Lance Nematode (Hoplolaimus magnistylus) on corn, soybean and cotton in Tennessee  

Technology Transfer Automated Retrieval System (TEKTRAN)

Lance nematode, Hoplolaimus galeatus, has been reported in Tennessee on field crops, forage pastures, home gardens, woody ornamentals, turf, and commercial vegetables across the state. In May 2011, another lance nematodes, H. magnistylus, was recovered from corn, cotton and soybean fields in west Te...

447

Interaction between Endemic and Introduced Entomopathogenic Nematodes in Conventional-Till and No-Till Corn  

Microsoft Academic Search

We used entomopathogenic nematodes as a model to address the issue of environmental impact of introduced biological control agents in the soil. The study was conducted during three field seasons (1997, 1998, and 1999) in no-till and conventional-till corn near Goldsboro, North Carolina. The main objective was to evaluate the interaction of two endemic nematodes, Steinernema carpocapsae and Heterorhabditis bacteriophora,

Leah C Millar; Mary E Barbercheck

2001-01-01

448

QTLs associated with resistance in soybean PI567516C to synthetic nematode population infecting cv. Hartwig  

Technology Transfer Automated Retrieval System (TEKTRAN)

Worldwide, soybean cyst nematode (SCN, Heterodera glycines Ichinohe) is the most destructive pathogen of soybean [Glycine max (L.) Merr.]. Crop losses are primarily mitigated by the use of resistant cultivars. Nematode populations are variable and have adapted to reproduce on resistant cultivars ov...

449

Toxicity of 2,4-diacetylphloroglucinol (DAPG) to plant-parasitic and bacterial-feeding nematodes.  

PubMed

The antibiotic 2,4-diacetylphloroglucinol (DAPG) is produced by some isolates of the beneficial bacterium Pseudomonas fluorescens. DAPG is toxic to many organisms, and crop yield increases have been reported after application of DAPG-producing P. fluorescens. This study was conducted to determine whether DAPG is toxic to selected nematodes. The plant-parasitic nematodes Heterodera glycines, Meloidogyne incognita, Pratylenchus scribneri and Xiphinema americanum, and the bacterial-feeding nematodes Caenorhabditis elegans, Pristionchus pacificus, and Rhabditis rainai, were immersed in concentrations ranging from 0 to 100 ?g/ml DAPG. Egg hatch and viability of juveniles and adults were determined. DAPG was toxic to X. americanum adults, with an LD?? of 8.3 ?g/ml DAPG. DAPG decreased M. incognita egg hatch, but stimulated C. elegans hatch during the first hours of incubation. Viability of M. incognita J2 and of C. elegans J1 and adults was not affected. There were no observed effects on the other nematodes. The study indicated that DAPG is not toxic to all nematodes, and did not affect the tested species of beneficial bacterial-feeding nematodes. Augmentation of DAPG-producing P. fluorescens populations for nematode biocontrol could be targeted to specific nematode species known to be affected by this compound and by other antibiotics produced by the bacteria, or these bacteria could be used for other possible effects, such as induced plant resistance. PMID:22736826

Meyer, Susan L F; Halbrendt, John M; Carta, Lynn K; Skantar, Andrea M; Liu, Ting; Abdelnabby, Hazem M E; Vinyard, Bryan T

2009-12-01

450

Toxicity of 2,4-diacetylphloroglucinol (DAPG) to Plant-parasitic and Bacterial-feeding Nematodes  

PubMed Central

The antibiotic 2,4-diacetylphloroglucinol (DAPG) is produced by some isolates of the beneficial bacterium Pseudomonas fluorescens. DAPG is toxic to many organisms, and crop yield increases have been reported after application of DAPG-producing P. fluorescens. This study was conducted to determine whether DAPG is toxic to selected nematodes. The plant-parasitic nematodes Heterodera glycines, Meloidogyne incognita, Pratylenchus scribneri and Xiphinema americanum, and the bacterial-feeding nematodes Caenorhabditis elegans, Pristionchus pacificus, and Rhabditis rainai, were immersed in concentrations ranging from 0 to 100 ?g/ml DAPG. Egg hatch and viability of juveniles and adults were determined. DAPG was toxic to X. americanum adults, with an LD50 of 8.3 ?g/ml DAPG. DAPG decreased M. incognita egg hatch, but stimulated C. elegans hatch during the first hours of incubation. Viability of M. incognita J2 and of C. elegans J1 and adults was not affected. There were no observed effects on the other nematodes. The study indicated that DAPG is not toxic to all nematodes, and did not affect the tested species of beneficial bacterial-feeding nematodes. Augmentation of DAPG-producing P. fluorescens populations for nematode biocontrol could be targeted to specific nematode species known to be affected by this compound and by other antibiotics produced by the bacteria, or these bacteria could be used for other possible effects, such as induced plant resistance.

Halbrendt, John M.; Carta, Lynn K.; Skantar, Andrea M.; Liu, Ting; Abdelnabby, Hazem M. E.; Vinyard, Bryan T.

2009-01-01

451

Immunofluorescent Localization of Tobacco Ringspot Nepovirus in the Vector Nematode Xiphinema americanum.  

PubMed

ABSTRACT An indirect immunofluorescent technique was developed to localize tobacco ringspot nepovirus (TRSV) in the vector nematode Xiphinema americanum sensu stricto. A population of this nematode that efficiently transmitted TRSV was given an acquisition access period of 10 days on TRSV-infected cucumber. Treatment of fragments of viruliferous nematodes with a polyclonal antiserum against TRSV followed by fluorescein isothiocyanate-conjugated goat anti-rabbit immunoglobulin G resulted in virus-specific bright fluorescence only in the lumen of the stylet extension and esophagus. Virus-specific fluorescent signals were observed in the virus-retention region of 44% of the nematode fragments examined. The percentage of nematodes labeled with virus-specific fluorescence increased as the acquisition access period increased from 0 to 22 days; the increase paralleled the increase in the transmission efficiency of the nematode population. Visualization of the entire virus-retention region of individual nematodes within a population of vector or nonvector nematodes provides a rapid and simple means of monitoring specific attachment of plant viruses. PMID:18944864

Wang, S; Gererich, R C

1998-09-01

452

Nematode and grape rootstock interactions including an improved understanding of tolerance.  

PubMed

Sixteen cultivars of grape were screened over a two-year period in the presence or absence of 10 different nematode populations. Populations of Meloidogyne spp., Xiphinema index, and Mesocriconema xenoplax developed more rapidly and caused greater damage than populations of X. americanum and Tylenchulus semipenetrans. Populations of mixed Meloidogyne spp. having a history of feeding on grape were among the fastest developing populations. Tolerance to nematode parasitism appeared to be based on different mechanisms. Slow developing, less pathogenic nematode populations often stimulated vine growth, thus vines appeared to possess tolerance. Likewise, cultivars selected for nematode resistance often stimulated vine growth when fed upon by the nematode. However, tolerance sources that resulted from nematode resistance are vulnerable due to the occurrence of populations that break resistance mechanisms. Growth of cultivars with phylloxera (Daktalospharia vitifoliae) resistance was unchanged by the presence of nematodes, indicating that phylloxera resistance may provide a useful source of nematode relief. These and several additional sources of specific tolerance are discussed. PMID:19259534

McKenry, M V; Anwar, Safdar A

2006-09-01

453

Migration of bacterial-feeding nematodes, but not protozoa, to decomposing grass residues  

Microsoft Academic Search

Populations of bacterial-feeding nematodes and protozoa developing in soil amended with dried grass powder or a nutrient solution were monitored in experimental systems designed to prevent migration from surrounding unamended soil. The addition of nutrient solution stimulated both microbial activity, as determined by dehydrogenase activity, and protozoa, but brought about no increase in nematode numbers. Amendment of soil with grass,

B. S. Griffiths; S. Caul

1993-01-01

454

Crop damage by nematodes in improved-fallow fields in western Kenya  

Microsoft Academic Search

The rotation of leguminous shrubs and crops is being tested on farms and recommended as a means of improving soil fertility and increasing crop yield in eastern and southern Africa, including western Kenya. However, this improved fallow practice may also increase the nematode population in the soil. An experiment was conducted to monitor the effects of plant-parasitic nematodes on crops

Serigne T. Kandji; Callistus K. P. O. Ogol; Alain Albrecht

2003-01-01

455

Effect of nematode infections on productivity of young and adult cattle on commercial dairy farms  

Microsoft Academic Search

In this study relationships between levels of exposure to gastrointestinal and lung nematode infections and production were investigated on commercial dairy farms in the Netherlands. Little was known about theserelationships, particularly with respect to second-year cattle and adult cows. Knowledge about the effects of different levels of exposure to nematode infection on growth performance and milk production on commercial farms,

H. W. Ploeger

1989-01-01

456

Study on epidemic pattern of nematode and its larvae on parasitic phase in yak  

Microsoft Academic Search

Summary Skrjabinema method and water bath separating and numbering method was used to study the natural growth and decline rule of yak nematode simultaneously with adult insect and larvae on parasitic phase by yak post-mortem examination. The results indicated the general rule of yak nematode was that the number of larvae on parasitic phase gradually increased in August to December

Cai Jinzhong; Li Chunhua; Liu Shengcai; He Zhong

457

Gastro-intestinal nematode infections in a goat breeding farm in North-Western Sri Lanka  

Microsoft Academic Search

Faecal egg counts were used to study patterns of nematode infestation of adult female goats and their offspring according to season, pregnancy and lactation or age on a goat farm (n=2000) in north-western Sri Lanka. Average rainfall in the area is 825 mm and temperature is between 23 and 33°C throughout the year. The only nematode species present on the

D. VAN AKEN; J. DE Borer; J. Vercruysse; P. Dorny

1990-01-01

458

Cloning, expression and functional characterisation of a peroxiredoxin from the potato cyst nematode Globodera rostochiensis  

Microsoft Academic Search

We report the cloning, expression and functional characterisation of a peroxidase belonging to the peroxiredoxin family from the potato cyst nematode Globodera rostochiensis, the first molecule of this type from any nematode parasitic on plants. The G. rostochiensis peroxiredoxin catalyses the breakdown of hydrogen peroxide, but not cumene or t-butyl hydroperoxide, in a trypanosomatid reducing system comprising trypanothione reductase, trypanothione

Lee Robertson; Walter M Robertson; Miroslaw Sobczak; Johannes Helder; Emmanuel Tetaud; Mark R Ariyanayagam; Mike A. J Ferguson; Alan Fairlamb; John T Jones

2000-01-01

459

Poly(T) variation in heteroderid nematode mitochondrial genomes is predominantly an artifact of amplification  

Technology Transfer Automated Retrieval System (TEKTRAN)

We assessed the rate of in vitro polymerase errors at polythymidine tracts in the mitochondrial DNA (mtDNA) of a heteroderid nematode (Heterodera cajani). The mtDNA of these nematodes contains unusually high numbers of poly(T) tracts, and has previously been suggested to contain biological poly(T) l...

460

Anthelmintic efficacy and dose determination of Albizia anthelmintica against gastrointestinal nematodes in naturally infected Ugandan sheep  

Microsoft Academic Search

Weight loss, stunted growth, and death caused by gastrointestinal parasites are major constraints to livestock productivity, especially in tropical and developing countries where regular use, and misuse, of anthelmintics has led to nematode resistance. Albizia anthelmintica Brong. (Fabaceae) is traditionally employed throughout East Africa to treat helminth parasitosis in livestock. Reported efficacy has varied from 90% against mixed nematodes to

J. T. Gradé; B. L. Arble; R. B. Weladji; P. Van Damme

2008-01-01