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Sample records for non-filariid nematodes angiostrongylus

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

    PubMed

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

    2010-05-01

    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.

  2. Draft genome of neurotropic nematode parasite Angiostrongylus cantonensis, causative agent of human eosinophilic meningitis.

    PubMed

    Yong, Hoi-Sen; Eamsobhana, Praphathip; Lim, Phaik-Eem; Razali, Rozaimi; Aziz, Farhanah Abdul; Rosli, Nurul Shielawati Mohamed; Poole-Johnson, Johan; Anwar, Arif

    2015-08-01

    Angiostrongylus cantonensis is a bursate nematode parasite that causes eosinophilic meningitis (or meningoencephalitis) in humans in many parts of the world. The genomic data from A. cantonensis will form a useful resource for comparative genomic and chemogenomic studies to aid the development of diagnostics and therapeutics. We have sequenced, assembled and annotated the genome of A. cantonensis. The genome size is estimated to be ∼260 Mb, with 17,280 genomic scaffolds, 91X coverage, 81.45% for complete and 93.95% for partial score based on CEGMA analysis of genome completeness. The number of predicted genes of ≥300 bp was 17,482. A total of 7737 predicted protein-coding genes of ≥50 amino acids were identified in the assembled genome. Among the proteins of known function, kinases are the most abundant followed by transferases. The draft genome contains 34 excretory-secretory proteins (ES), a minimum of 44 Nematode Astacin (NAS) metalloproteases, 12 Homeobox (HOX) genes, and 30 neurotransmitters. The assembled genome size (260 Mb) is larger than those of Pristionchus pacificus, Caenorhabditis elegans, Necator americanus, Caenorhabditis briggsae, Trichinella spiralis, Brugia malayi and Loa loa, but smaller than Haemonchus contortus and Ascaris suum. The repeat content (25%) is similar to H. contortus. The GC content (41.17%) is lower compared to P. pacificus (42.7%) and H. contortus (43.1%) but higher compared to C. briggsae (37.69%), A. suum (37.9%) and N. americanus (40.2%) while the scaffold N50 is 42,191. This draft genome will facilitate the understanding of many unresolved issues on the parasite and the disorder it causes.

  3. Increased prevalence and geographic spread of the cardiopulmonary nematode Angiostrongylus vasorum in fox populations in Great Britain.

    PubMed

    Taylor, C S; Garcia Gato, R; Learmount, J; Aziz, N A; Montgomery, C; Rose, H; Coulthwaite, C L; McGarry, J W; Forman, D W; Allen, S; Wall, R; Morgan, E R

    2015-08-01

    The nematode Angiostrongylus vasorum is becoming more widely recorded globally, and is of increasing concern as a cause of disease in dogs. Apparent geographic spread is difficult to confirm due to a lack of standardized disease recording systems, increasing awareness among veterinary clinicians, and recent improvements in diagnostic technologies. This study examines the hypothesis that A. vasorum has spread in recent years by repeating the methods of a previous survey of the fox population. The hearts and lungs of 442 foxes from across Great Britain were collected and examined by dissection and flushing of the pulmonary circulation and microscopic inspection of tracheal scrapes. Sampling and parasite extraction methods were identical to an earlier survey in 2005 to ensure comparability. Prevalence of A. vasorum was 18·3% (exact binomial confidence bounds 14·9-22·3), compared with 7·3% previously (5·3-9·9, n = 546), and had increased significantly in most regions, e.g. 7·4% in the Northern UK (previously zero) and 50·8% in the south-east (previously 23·2%). Other nematodes identified were Crenosoma vulpis (prevalence 10·8%, CI 8·1-14·2) and Eucoleus aerophilus (31·6%, CI 27·3-36·2). These data support the proposal that A. vasorum has increased in prevalence and has spread geographically in Great Britain.

  4. Angiostrongylus species in wild carnivores in the Iberian Peninsula.

    PubMed

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

    2010-11-24

    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.

  5. The white-nosed coati (Nasua narica) is a naturally susceptible definitive host for the zoonotic nematode Angiostrongylus costaricensis in Costa Rica.

    PubMed

    Santoro, Mario; Alfaro-Alarcón, Alejandro; Veneziano, Vincenzo; Cerrone, Anna; Latrofa, Maria Stefania; Otranto, Domenico; Hagnauer, Isabel; Jiménez, Mauricio; Galiero, Giorgio

    2016-09-15

    Angiostrongylus costaricensis (Strongylida, Angiostrongylidae) is a roundworm of rodents, which may cause a severe or fatal zoonosis in several countries of the Americas. A single report indicated that the white-nosed coati (Nasua narica), acts as a potential free-ranging wildlife reservoir. Here we investigated the prevalence and features of A. costaricensis infection in two procyonid species, the white-nosed coati and the raccoon (Procyon lotor) from Costa Rica to better understand their possible role in the epidemiology of this zoonotic infection. Eighteen of 32 (56.2%) white-nosed coatis collected between July 2010 and March 2016 were infected with A. costaricensis but none of 97 raccoons from the same localities were diagnosed with this infection. First-stage larvae of A. costaricensis were obtained from feces of 17 fresh white-nosed coati carcasses by Baermann technique. Parasite identity was confirmed by morphology, histology and molecular characterization of target genes. These data demonstrate that the white-nosed coati is a naturally susceptible definitive host for A. costaricensis in Costa Rica contrary to findings in the raccoon. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Angiostrongylus cantonensis and A. malaysiensis Broadly Overlap in Thailand, Lao PDR, Cambodia and Myanmar: A Molecular Survey of Larvae in Land Snails.

    PubMed

    Rodpai, Rutchanee; Intapan, Pewpan M; Thanchomnang, Tongjit; Sanpool, Oranuch; Sadaow, Lakkhana; Laymanivong, Sakhone; Aung, Win Papa; Phosuk, Issarapong; Laummaunwai, Porntip; Maleewong, Wanchai

    2016-01-01

    Angiostrongylus cantonensis is a zoonotic nematode parasite causing human eosinophilic meningitis (or meningoencephalitis) worldwide. A closely related species, Angiostrongylus malaysiensis, might also be a human pathogen. Larvae were obtained from land snails in Lao PDR, Cambodia, Myanmar and Thailand. We sequenced two nuclear gene regions (nuclear ribosomal ITS2 and SSU rRNA) and a portion of one mitochondrial gene (COI) from these larvae. Angiostrongylus cantonensis and A. malaysiensis were identified. This is the first report of the molecular identification of the two Angiostrongylus species in Lao PDR, Cambodia and Myanmar. The regional distributions of the two species broadly overlap. Phylogenetic relationships were inferred including data from Angiostrongylus species deposited in public databases. All the gene regions we sequenced have potential value in distinguishing between species of Angiostrongylus. The COI gene exhibited the greatest intraspecific variation in the study region (five haplotypes in A. cantonensis and four in A. malaysiensis) and might be suitable for more detailed phylogeographic studies.

  7. Angiostrongylus cantonensis and A. malaysiensis Broadly Overlap in Thailand, Lao PDR, Cambodia and Myanmar: A Molecular Survey of Larvae in Land Snails

    PubMed Central

    Rodpai, Rutchanee; Intapan, Pewpan M.; Thanchomnang, Tongjit; Sanpool, Oranuch; Sadaow, Lakkhana; Laymanivong, Sakhone; Aung, Win Papa; Phosuk, Issarapong; Laummaunwai, Porntip

    2016-01-01

    Angiostrongylus cantonensis is a zoonotic nematode parasite causing human eosinophilic meningitis (or meningoencephalitis) worldwide. A closely related species, Angiostrongylus malaysiensis, might also be a human pathogen. Larvae were obtained from land snails in Lao PDR, Cambodia, Myanmar and Thailand. We sequenced two nuclear gene regions (nuclear ribosomal ITS2 and SSU rRNA) and a portion of one mitochondrial gene (COI) from these larvae. Angiostrongylus cantonensis and A. malaysiensis were identified. This is the first report of the molecular identification of the two Angiostrongylus species in Lao PDR, Cambodia and Myanmar. The regional distributions of the two species broadly overlap. Phylogenetic relationships were inferred including data from Angiostrongylus species deposited in public databases. All the gene regions we sequenced have potential value in distinguishing between species of Angiostrongylus. The COI gene exhibited the greatest intraspecific variation in the study region (five haplotypes in A. cantonensis and four in A. malaysiensis) and might be suitable for more detailed phylogeographic studies. PMID:27513930

  8. Neuroparasitic infections: nematodes.

    PubMed

    Walker, M D; Zunt, J R

    2005-09-01

    Globalization has produced an increase in the number of people at risk for contracting parasitic infection. Central nervous system infection by nematodal parasites can be devastating. Early recognition and treatment of infection can significantly decrease morbidity of the parasitic infection, as well as the risk of secondary superinfection. The clinical presentation, diagnosis, and treatment for five of the more common nematodal infections of the nervous system--Angiostrongylus spp., Baylisacaris procyonis, Gnathostoma spinigerum, Strongyloides stercoralis, and Toxocara spp.--is reviewed.

  9. Angiostrongylus chabaudi Biocca, 1957: a new parasite for domestic cats?

    PubMed

    Varcasia, Antonio; Tamponi, Claudia; Brianti, Emanuele; Cabras, Piera Angela; Boi, Roberta; Pipia, Anna Paola; Giannelli, Alessio; Otranto, Domenico; Scala, Antonio

    2014-12-17

    Natural infection with a species of Angiostrongylus has been reported only once in wildcats from central Italy by Biocca in 1957. The causative species of this infection was identified as Angiostrongylus chabaudi. Following this report, this parasite had never been found in either wild or domestic cats. The lungs and the pulmonary arteries of an adult female cat (Felis silvestris catus), road-killed in Sardinia, Italy, were macroscopically examined and dissected under a light microscope for the presence of parasites. A slender nematode was detected and its morphometrical features were consistent with those of A. chabaudi. Morphological data were supplemented by sequencing of the partial cytochrome oxidase c subunit 1 (cox1) gene, as well as the internal transcribed spacer 2 (ITS2) of the rDNA. Nucleotide sequences displayed 99% homology with the ITS2 sequence [GenBank KM216825.1] of a specimen of Angiostrongylus sp. recovered recently from the pulmonary artery of a wildcat in Germany and 91% with cox1 sequence [GenBank GU138118.1] of Angiostrongylus vasorum. The results of the present study indicate, for the first time, that A. chabaudi may also infect domestic cats, and thus should be considered in the diagnosis of metastrongyloid species infecting their cardio-pulmonary system.

  10. The Prevalence of Angiostrongylus cantonensis/mackerrasae Complex in Molluscs from the Sydney Region

    PubMed Central

    Chan, Douglas; Barratt, Joel; Roberts, Tamalee; Lee, Rogan; Shea, Michael; Marriott, Deborah; Harkness, John; Malik, Richard; Jones, Malcolm; Aghazadeh, Mahdis; Ellis, John; Stark, Damien

    2015-01-01

    Angiostrongylus cantonensis and Angiostrongylus mackerrasae are metastrongyloid nematodes that infect various rat species. Terrestrial and aquatic molluscs are intermediate hosts of these worms while humans and dogs are accidental hosts. Angiostrongylus cantonensis is the major cause of angiostrongyliasis, a disease characterised by eosinophilic meningitis. Although both A. cantonensis and A. mackerrasae are found in Australia, A. cantonensis appears to account for most infections in humans and animals. Due to the occurrence of several severe clinical cases in Sydney and Brisbane, the need for epidemiological studies on angiostrongyliasis in this region has become apparent. In the present study, a conventional PCR and a TaqMan assay were compared for their ability to amplify Angiostrongylus DNA from DNA extracted from molluscs. The TaqMan assay was more sensitive, capable of detecting the DNA equivalent to one hundredth of a nematode larva. Therefore, the TaqMan assay was used to screen molluscs (n=500) of 14 species collected from the Sydney region. Angiostrongylus DNA was detected in 2 of the 14 mollusc species; Cornu aspersum [14/312 (4.5%)], and Bradybaenia similaris [1/10 (10%)], which are non-native terrestrial snails commonly found in urban habitats. The prevalence of Angiostrongylus spp. was 3.0% ± 0.8% (CI 95%). Additionally, experimentally infected Austropeplea lessoni snails shed A. cantonensis larvae in their mucus, implicating mucus as a source of infection. This is the first Australian study to survey molluscs using real-time PCR and confirms that the garden snail, C. aspersum, is a common intermediate host for Angiostrongylus spp. in Sydney. PMID:26000568

  11. Angiostrongylus vasorum in wolves in Italy: prevalence and pathological findings.

    PubMed

    De Liberato, Claudio; Grifoni, Goffredo; Lorenzetti, Raniero; Meoli, Roberta; Cocumelli, Cristiano; Mastromattei, Antonio; Scholl, Francesco; Rombolà, Pasquale; Calderini, Pietro; Bruni, Gianpaolo; Eleni, Claudia

    2017-08-11

    Angiostrongylus vasorum is a nematode residing in the heart and pulmonary vessels of dogs and wild carnivores. In Europe the red fox is its reservoir, while only three records from wolves have been published. Angiostrongylus vasorum has a worldwide distribution, and many pieces of evidence demonstrate that it is spreading from endemic areas to new ones. In Italy, A. vasorum was reported with increasing frequency in dogs and foxes in the last decades, and now it is considered endemic throughout the country. Angiostrongylus vasorum can be asymptomatic or cause respiratory and circulatory disorders, at times causing severe disseminated infections. Between February 2012 and December 2016, 25 wolves found dead in central Italy were submitted to the Istituto Zooprofilattico del Lazio e della Toscana for post-mortem examination. Samples of lungs, heart, liver, spleen, kidneys, mediastinic lymph nodes and brain were collected from each animal for histological examination. When adult and larval nematodes were microscopically seen in lungs, the other organs were processed, and five histological sections for each organ were examined. To confirm parasite identification, lung samples were submitted to a PCR-sequencing protocol targeting the ITS2 region of A. vasorum. Seven wolves (28.0%) harboured nematode larvae in lung sections. In two of the positive wolves, adult nematodes were visible in pulmonary arteries, in four animals larvae were also detected in other organs. DNA sequencing reactions confirmed parasite identification as A. vasorum in all the cases. As a result of the high prevalence of A. vasorum reported in wolves in the present study, a focus of high circulation could be hypothesised in central Italy. Nevertheless, the similarly high prevalence in foxes originating from the same areas were reported in previous papers. Histopathological evidence highlights the pathogenic potential of A. vasorum in the wolf, especially in juvenile animals.

  12. The first report of Angiostrongylus vasorum (Nematoda; Metastrongyloidea) in Poland, in red foxes (Vulpes vulpes).

    PubMed

    Demiaszkiewicz, Aleksander W; Pyziel, Anna M; Kuligowska, Izabela; Lachowicz, Jacek

    2014-10-01

    Angiostrongylus vasorum belongs to the superfamily of Metastrongyloidea. This nematode occurs in foxes, dogs and other predators. The Nematode A. vasorum place themselves in the pulmonary artery and its branches, and in the right ventricle and atrium of the heart. Numerous species of land snails are the intermediate hosts of the parasite. In 2013, lungs and hearts of 76 foxes shot in the Forest District Głęboki Bród in Augustowska Primeval Forest were parasitologically necropsied. Four of the examined foxes were infected with the nematode A. vasorum, a prevalence of 5.2%. In one fox pericardium there were 6 male and 6 female nematodes. In the remaining three foxes nematodes were localized in the pulmonary artery. In two foxes 2 specimens of nematodes were detected (male and female, and two females) while 1 female was detected in the other fox. This is the first report of the presence of the nematode A. vasorum in fox in Poland.

  13. Neuroangiostrongyliasis due to Angiostrongylus cantonensis in gang-gang cockatoos (Callocephalon fimbriatum).

    PubMed

    Reece, R L; Perry, R A; Spratt, D M

    2013-11-01

    Four gang-gang cockatoos from an aviary in Sydney displayed severe neurological signs. Three were necropsied and histopathology of the brains and spinal cords revealed migrating nematodes, which were identified as Angiostrongylus cantonensis. The migrating larval nematodes created tracts of malacia in the brain, but elicited little inflammatory cell infiltration. However, adult nematodes that had emerged onto the meningeal surface of the spinal cord evoked a marked non-suppurative reaction. Detailed histological examination of other tissues revealed larvae embedded in arterioles in the gastrointestinal serosa, lung and heart, which were associated with a significant granulomatous response. The latter lesions were consistent with our understanding of the pathogenesis of infection with this parasite, but have not been previously described, probably as a result of limited sampling. Angiostrongylus cantonensis is still present in the Sydney area and can cause significant disease in exposed animals, including birds. It also highlights potential human health problems. © 2013 Australian Veterinary Association.

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

    PubMed Central

    2013-01-01

    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. PMID:23901372

  15. Human infections with Angiostrongylus cantonensis.

    PubMed

    Alto, W

    2001-03-01

    Angiostrongylus cantonensis is a parasite that causes eosinophilic meningitis and has been reported to be present on most Pacific islands. Rats are the principal host and several species of land snails the intermediate host. Important paratenic hosts are fresh water shrimp and fish. Modes of transmission include ingestion by man of raw fish, snails and fresh leafy vegetables contaminated by snail slime trails containing larvae. The parasitic worms are neurotropic in man, and the diagnosis should be considered in any adult or child, who presents, in endemic areas or areas with suitable intermediate hosts, with severe unrelenting headache, paresthesias, or a cranial nerve palsy. Eosinophils in the cerebral spinal fluid suggest the diagnosis. Simple analgesia is sufficient for mild cases. Treatment of those with severe symptoms remains controversial. Glucocorticoids, lumbar puncture to reduce intercranial pressure and antihelminthic agents have been used.

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

    PubMed

    Bourque, Andrea; Whitney, Hugh; Conboy, Gary

    2005-10-01

    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.

  17. Angiostrongylus vasorum in the eye: new case reports and a review of the literature.

    PubMed

    Colella, Vito; Lia, Riccardo Paolo; Premont, Johana; Gilmore, Paul; Cervone, Mario; Latrofa, Maria Stefania; D'Anna, Nunzio; Williams, Diana; Otranto, Domenico

    2016-03-21

    Nematodes of the genus Angiostrongylus are important causes of potentially life-threatening diseases in several animal species and humans. Angiostrongylus vasorum affects the right ventricle of the heart and the pulmonary arteries in dogs, red foxes and other carnivores. The diagnosis of canine angiostrongylosis may be challenging due to the wide spectrum of clinical signs. Ocular manifestations have been seldom reported but have serious implications for patients. The clinical history of three cases of infection with A. vasorum in dogs diagnosed in UK, France and Italy, was obtained from clinical records provided by the veterinary surgeons along with information on the diagnostic procedures and treatment. Nematodes collected from the eyes of infected dogs were morphologically identified to the species level and molecularly analysed by the amplification of the nuclear 18S rRNA gene. On admission, the dogs were presented with various degrees of ocular discomfort and hyphema because of the presence of a motile object in the eye. The three patients had ocular surgery during which nematodes were removed and subsequently morphologically and molecularly identified as two adult males and one female of A. vasorum. Three new cases of canine ocular angiostrongylosis are reported along with a review of other published clinical cases to improve the diagnosis and provide clinical recommendation for this parasitic condition. In addition, the significance of migratory patterns of larvae inside the host body is discussed. Veterinary healthcare workers should include canine angiostrongylosis in the differential diagnosis of ocular diseases.

  18. Angiostrongylus vasorum infection in red foxes (Vulpes vulpes) in southern Italy.

    PubMed

    Santoro, Mario; D'Alessio, Nicola; Di Prisco, Francesca; Neola, Benedetto; Restucci, Brunella; Pagano, Teresa B; Veneziano, Vincenzo

    2015-06-01

    Angiostrongylus vasorum (Nematoda: Angiostrongylidae) infection was detected at post-mortem examination in the pulmonary arteries and hearts of 34/102 (33,3%) of red foxes (Vulpes vulpes) from the Campania Region in southern Italy. Pathological changes consisted of granulomatous interstitial pneumonia caused by larvae and intravascular pulmonary adult nematodes. These changes confirm that angiostrongylosis infection in red foxes has a mainly chronic course, in which the infected host may disperse parasite larvae in the environment over its lifetime. Results suggest that the life cycle of A. vasorum is well established in the red fox in the Campania Region representing a potential infection risk for dogs.

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

    PubMed

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

    2009-03-01

    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.

  20. Angiostrongylus chabaudi in felids: New findings and a review of the literature.

    PubMed

    Giannelli, Alessio; Kirkova, Zvezedlina; Abramo, Francesca; Latrofa, Maria Stefania; Campbell, Bronwyn; Zizzo, Nicola; Cantacessi, Cinzia; Dantas-Torres, Filipe; Otranto, Domenico

    2016-09-15

    Cardiopulmonary infections by Angiostrongylus chabaudi affect domestic and wild felids but, due to limited information on the biology of this nematode, its pathogenicity remains unclear. This article describes the histopathological alterations associated with Angiostrongylus infection in a wildcat from Bulgaria, and reviews current literature on this feline angiostrongylid. Nematodes were isolated from lung lavage and faecal samples of a road killed wildcat in Southern Bulgaria. The morphological identification of parasite larvae as A. chabaudi was confirmed by molecular analysis of part of the 18S ribosomal RNA gene. Upon histopathological examination, severe granulomatous pneumonia, ranging from multifocal to coalescing, and pulmonary vascular lesions were observed. Extensive alveolar collapse, alveolar emphysematous changes, parenchymal haemorrhages and small artery wall hyperplasia were observed in the parenchyma adjacent to the granulomas. Histopathological examination revealed the presence of cross-sections of adult female parasites within the lumen of the pulmonary artery branches, the intima altered markedly by subendothelial proliferation and oedematous changes. This study compliments current knowledge of the pathogenesis of feline angiostrongylosis by A. chabaudi in wildcats, as well as of the distribution of this little-known parasite.

  1. Angiostrongylus cantonensis in Introduced Gastropods in Southern Florida.

    PubMed

    Stockdale-Walden, Heather D; Slapcinsky, John; Qvarnstrom, Yvonne; McIntosh, Antoinette; Bishop, Henry S; Rosseland, Brent

    2015-04-01

    Angiostrongylus cantonensis , the rat lungworm, is a zoonotic, parasitic nematode that uses the rat as a definitive host and gastropods as intermediate hosts. It is prevalent in parts of Asia, the Pacific islands, and the Caribbean. In the United States, A. cantonensis is established in Hawaii and in recent years has been reported in Alabama, California, Louisiana, and Florida, where it has been found in the reintroduced Lissachatina fulica (also known as Achatina fulica), the giant African snail that was once eradicated from the state. Since 2004, A. cantonensis has been identified as the causative agent for 2 non-human primate deaths in Florida, one attributed to ingestion of the snail Zachrysia provisoria. Our study further supports the presence of A. cantonensis in Z. provisoria in Florida and identifies 2 additional introduced terrestrial snails, Bradybaena similaris and Alcadia striata, that serve as intermediate hosts for A. cantonensis , as well as evidence of rat infection, in southern Florida. The finding of both definitive and intermediate hosts suggests that A. cantonensis may be established in south Florida.

  2. First autochthonous case of canine Angiostrongylus vasorum in Slovakia.

    PubMed

    Hurníková, Z; Miterpáková, M; Mandelík, R

    2013-10-01

    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.

  3. Neuroparasitic Infections: Nematodes

    PubMed Central

    Walker, M.D.; Zunt, J.R.

    2009-01-01

    Globalization has produced an increase in the number of people at risk for contracting parasitic infection. Central nervous system infection by nematodal parasites can be devastating. Early recognition and treatment of infection can significantly decrease morbidity of the parasitic infection, as well as the risk of secondary superinfection. The clinical presentation, diagnosis, and treatment for five of the more common nematodal infections of the nervous system—Angiostrongylus spp., Baylisacaris procyonis, Gnathostoma spinigerum, Strongyloides stercoralis, and Toxocara spp.—is reviewed. Objectives On completion of this article, the reader should be able to summarize the clinical presentation, diagnosis, and treatment of the common nematodal infections of the nervous system. Accreditation The Indiana University School of Medicine is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. Credit The Indiana University School of Medicine designates this educational activity for a maximum of 1 Category 1 credit toward the AMA Physicians Recognition Award. Each physician should claim only those credits that he/she actually spent in the educational activity. Disclosure Statements of disclosure have been obtained regarding the authors’ relevant financial relationships. The authors have nothing to disclose. PMID:16170738

  4. First evidence of the European wildcat (Felis silvestris silvestris) as definitive host of Angiostrongylus chabaudi.

    PubMed

    Diakou, Anastasia; Psalla, Dimitra; Migli, Despina; Di Cesare, Angela; Youlatos, Dionisios; Marcer, Federica; Traversa, Donato

    2016-03-01

    Angiostrongylus chabaudi (Strongylida, Angiostrongylidae) is a parasitic nematode described for the first time last century from the pulmonary arteries of six European wildcats (Felis silvestris silvestris) in central Italy. Since then, this parasite remained practically unknown until recently, when immature A. chabaudi have been reported from one wildcat in Germany and two domestic cats (Felis silvestris catus) in Italy. The present report describes the first record of A. chabaudi in Greece and, most importantly, the first known case of patent infection by A. chabaudi. The necropsy of a road-killed F. s. silvestris found near the lake Kerkini, in the municipality of Serres (Macedonia, Greece), revealed the presence of nematodes of both sexes in the right ventricle and the pulmonary artery of the heart. All parasites were mature adults and numerous eggs were present in the uteruses of females. The morphological characteristics of the parasites were consistent with those of A. chabaudi. Moreover, Angiostrongylus-like first stage larvae (L1) were present in the faeces of the animal that was negative for any other cardio-pulmonary parasite. Genetic examination of adult parasites and L1 confirmed the morphological identification as A. chabaudi. Histopathological examination of the lungs showed severe, multifocal to coalescing, chronic, interstitial granulomatous pneumonia due to the presence of adult parasites, larvae and eggs. These findings demonstrate for the first unequivocal time that this nematode reproduces in the European wildcat which should be ultimately considered a definitive host of A. chabaudi. Finally, the L1 of A. chabaudi are described here for the first time, opening new prospects for further studies on this neglected parasite.

  5. Diverse Gastropod Hosts of Angiostrongylus cantonensis, the Rat Lungworm, Globally and with a Focus on the Hawaiian Islands

    PubMed Central

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

    2014-01-01

    Eosinophilic meningitis caused by the parasitic nematode Angiostrongylus cantonensis is an emerging infectious disease with recent outbreaks primarily in tropical and subtropical locations around the world, including Hawaii. Humans contract the disease primarily through ingestion of infected gastropods, the intermediate hosts of Angiostrongylus cantonensis. Effective prevention of the disease and control of the spread of the parasite require a thorough understanding of the parasite's hosts, including their distributions, as well as the human and environmental factors that contribute to transmission. The aim of this study was to screen a large cross section of gastropod species throughout the main Hawaiian Islands to determine which act as hosts of Angiostrongylus cantonensis and to assess the parasite loads in these species. Molecular screening of 7 native and 30 non-native gastropod species revealed the presence of the parasite in 16 species (2 native, 14 non-native). Four of the species tested are newly recorded hosts, two species introduced to Hawaii (Oxychilus alliarius, Cyclotropis sp.) and two native species (Philonesia sp., Tornatellides sp.). Those species testing positive were from a wide diversity of heterobranch taxa as well as two distantly related caenogastropod taxa. Review of the global literature showed that many gastropod species from 34 additional families can also act as hosts. There was a wide range of parasite loads among and within species, with an estimated maximum of 2.8 million larvae in one individual of Laevicaulis alte. This knowledge of the intermediate host range of Angiostrongylus cantonensis and the range of parasite loads will permit more focused efforts to detect, monitor and control the most important hosts, thereby improving disease prevention in Hawaii as well as globally. PMID:24788772

  6. [Human angiostrongyliasis caused by Angiostrongylus costaricensis].

    PubMed

    Mojon, M

    1994-04-01

    Angiostrongylus costaricensis was discovered by Morera and Céspedes in 1971, in a man suffering from an abdominal syndrome. Upon surgery, worms were observed in the cranial mesenteric artery. These worms were assigned to the metastrongylid strongyles and to the genus Angiostrongylus, which was already known, in man medicine, by the species A. cantonensis, the causative agent of an eosinophilic meningitis. Morera's parasite was named Angiostrongylus costaricensis from the place where it was described. A costaricensis is a dixenic parasite, the definitive hosts (D.H.) of which are the cotton-rat (Sigmodon hispidus) and some other rodents. Experimentally, carnivora (Nasua spp: procyonidae) and monkeys (Saguinus mystax: hapalidae) are receptive, same as dogs. The intermediary hosts (I.H.) are slugs belonging to the Veronicellidae family (order gymnophila), mainly Vaginulus plebeius. In the D.H., the parasite produces eggs that hatch into first stage larvae (L1), which are expelled with faeces, eaten by slugs and become infective third stage larvae (L3). L3 are then expelled through mucoïd secretions of the slug and pollute soil and vegetables. D.H. and man get infected with consuming polluted vegetables or even the infected slugs themselves. L3 migrate through lymphatic system and arrive inside the mesenteric artery, where they become adults. In man, the worm can reach this adult egg-laying stage, but larvae are trapped inside granulomas in the intestinal wall and cannot evolve. So, man is a dead-lock for A. costaricensis. Angiostrongylosis costaricensis is an illustration of an hemi-zoonosis (the parasite cannot go back from man to animals) of the biological pattern.

  7. Molecular identification of novel intermediate host species of Angiostrongylus vasorum in Greater London.

    PubMed

    Patel, Zainab; Gill, A Christina; Fox, Mark T; Hermosilla, Carlos; Backeljau, Thierry; Breugelmans, Karin; Keevash, Esther; McEwan, Claudia; Aghazadeh, Mahdis; Elson-Riggins, Jocelyn G

    2014-12-01

    Angiostrongylus vasorum is a parasitic nematode that can cause serious and potentially fatal disease in dogs and other canids. The aim of this study was to determine the intermediate slug species infected in nature by sampling sites in Greater London and Hertfordshire located within a known hyperendemic region. Overall, A. vasorum larvae were recovered from 6/381 slugs (1.6%) by tissue digestion, and their identity was confirmed by PCR. Infected slugs originated from three different sites in the Greater London area: one in Waltham Forest and two in Bromley. Slugs parasitised by A. vasorum were identified by a combination of external morphological characteristics and molecular techniques and belonged to three different families: the Arionidae, the Milacidae and the Limacidae. This includes two new host records for the parasite: Arion distinctus and Tandonia sowerbyi. This is the first record of A. vasorum in the family Milacidae, indicating that the parasite has a broader intermediate host range than previously recognised.

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

    PubMed Central

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

    2013-01-01

    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. PMID:22902292

  9. Eosinophilic meningitis caused by Angiostrongylus cantonensis: an emergent disease in Brazil

    PubMed Central

    Morassutti, Alessandra Loureiro; Thiengo, Silvana Carvalho; Fernandez, Monica; Sawanyawisuth, Kittisak; Graeff-Teixeira, Carlos

    2014-01-01

    Eosinophilic meningitis (EoM) is an acute disease that affects the central nervous system. It is primarily caused by infection with the nematode Angiostrongylus cantonensis. This infection was previously restricted to certain Asian countries and the Pacific Islands, but it was first reported in Brazil in 2007. Since then, intermediate and definitive hosts infected with A. cantonensis have been identified within the urban areas of many states in Brazil, including those in the northern, northeastern, southeastern and southern regions. The goals of this review are to draw the attention of the medical community and health centres to the emergence of EoM in Brazil, to compile information about several aspects of the human infection and mode of transmission and to provide a short protocol of procedures for the diagnosis of this disease. PMID:25075779

  10. Clinical manifestations of Eosinophilic meningitis due to infection with Angiostrongylus cantonensis in children.

    PubMed

    Sawanyawisuth, Kittisak; Chindaprasirt, Jarin; Senthong, Vichai; Limpawattana, Panita; Auvichayapat, Narong; Tassniyom, Sompon; Chotmongkol, Verajit; Maleewong, Wanchai; Intapan, Pewpan M

    2013-12-01

    Eosinophilic meningitis, caused by the nematode Angiostrongylus cantonensis, is prevalent in northeastern Thailand, most commonly in adults. Data regarding clinical manifestations of this condition in children is limited and may be different those in adults. A chart review was done on 19 eosinophilic meningitis patients aged less than 15 years in Srinagarind Hospital, Faculty of Medicine, Khon Kaen University, Thailand. Clinical manifestations and outcomes were reported using descriptive statistics. All patients had presented with severe headache. Most patients were males, had fever, nausea or vomiting, stiffness of the neck, and a history of snail ingestion. Six patients had papilledema or cranial nerve palsies. It was shown that the clinical manifestations of eosinophilic meningitis due to A. cantonensis in children are different from those in adult patients. Fever, nausea, vomiting, hepatomegaly, neck stiffness, and cranial nerve palsies were all more common in children than in adults.

  11. Angiostrongylus cantonensis (Nematoda: Metastrongylidae) in the Ryukyu Islands tree rat (Diplothrix legata).

    PubMed

    Okano, Tsukasa; Haga, Atsushi; Mizuno, Eriko; Onuma, Manabu; Nakaya, Yumiko; Nagamine, Takashi

    2014-04-01

    Angiostrongylus cantonensis is a zoonotic nematode with rodents serving as natural definitive hosts. We report A. cantonensis in the Ryukyu Islands tree rat (Diplothrix legata, Thomas, 1906), a native endangered species in Japan. Adult and larvae of A. cantonensis were macroscopically, histologically, and genetically detected in three tree rats collected between August 2011 and January 2012 in the Yambaru area of Okinawa Prefecture, Japan. Pathologic observations of the lungs of rats showed that infection may be lethal. We also conducted a retrospective genetic survey of helminths parasitic in lung in cryopreserved lung samples of Ryukyu Islands tree rats collected between 2007 and 2011 in the Yambaru area and found A. cantonensis DNA in one of 29 samples, which was collected in December 2010.

  12. Detection of Angiostrongylus vasorum in Red Foxes (Vulpes vulpes) from Brandenburg, Germany.

    PubMed

    Härtwig, Vera; Schulze, Christoph; Barutzki, Dieter; Schaper, Roland; Daugschies, Arwid; Dyachenko, Viktor

    2015-08-01

    Angiostrongylus (A.) vasorum is a nematode that causes angiostrongylosis in domestic and wild canids. Red foxes (Vulpes vulpes) and raccoon dogs (Nyctereutes procyonoides) are suspected of providing a wildlife reservoir for A. vasorum infections in pet dogs. To obtain data on the occurrence of A. vasorum in wildlife, red fox and raccoon dog carcasses (hunted or found dead) were collected from January to September 2009 in the Federal State of Brandenburg, Germany. Lung tissue samples were subjected to DNA extraction and examined for the presence of A. vasorum DNA by means of real-time PCR. A. vasorum DNA was detected in 11 out of 122 (9.0 %) lungs of red foxes and in none of the lung samples of raccoon dogs. These data suggest that red foxes are a reservoir of A. vasorum infections for pet dogs in this area.

  13. Intermediate Hosts of Angiostrongylus cantonensis in Tenerife, Spain

    PubMed Central

    Martin-Alonso, Aarón; Abreu-Yanes, Estefanía; Feliu, Carlos; Mas-Coma, Santiago; Bargues, María Dolores; Valladares, Basilio; Foronda, Pilar

    2015-01-01

    The nematode Angiostrongylus cantonensis is the causative agent of human angiostrongyliasis, the main clinical manifestation of which is eosinophilic meningitis. Although this parasite has been found recently in its definitive rat host in Tenerife (Canary Islands, Spain), showing a widespread distribution over the north-east part of the island, there are no available data regarding which snail and/or slug species are acting as intermediate hosts on this island. Consequently, the objective of this work was to determine the possible role of three mollusc species, Plutonia lamarckii, Cornu aspersum and Theba pisana, as intermediate hosts of A. cantonensis in Tenerife. Between 2011 and 2014, 233 molluscs were collected from five biotopes where rats had been found previously to harbor either adult worms or antibodies against A. cantonensis, and the identification was carried out on the basis of morphological features and a LAMP technique. The prevalence of A. cantonensis larvae in the mollusc samples, based on morphological identification, was 19.3%, whereas 59 out of the 98 individuals (60.2%) analyzed by LAMP were positive. Positive results were obtained for the three mollusc species analyzed and two of the positive samples, both obtained from P. lamarckii, were confirmed as positive by 18S rRNA and ITS1 PCR. Sequence analysis of 18S rRNA PCR products showed 100% similarity with previously published A. cantonensis sequences. These results may be relevant from a public health point of view, since all the biotopes from which the samples were obtained were in inhabited areas or areas with human activity, but it is also important from the perspective of a possible transmission to other accidental hosts, such as dogs and horses, animals that are present in some of the areas analyzed. PMID:25803658

  14. Mitochondrial Genome Supports Sibling Species of Angiostrongylus costaricensis (Nematoda: Angiostrongylidae)

    PubMed Central

    Yong, Hoi-Sen; Song, Sze-Looi; Eamsobhana, Praphathip; Goh, Share-Yuan; Lim, Phaik-Eem; Chow, Wan-Loo; Chan, Kok-Gan; Abrahams-Sandi, Elizabeth

    2015-01-01

    Angiostrongylus costaricensis is a zoonotic parasitic nematode that causes abdominal or intestinal angiostrongyliasis in humans. It is endemic to the Americas. Although the mitochondrial genome of the Brazil taxon has been published, there is no available mitochondrial genome data on the Costa Rica taxon. We report here the complete mitochondrial genome of the Costa Rica taxon and its genetic differentiation from the Brazil taxon. The whole mitochondrial genome was obtained from next-generation sequencing of genomic DNA. It had a total length of 13,652 bp, comprising 36 genes (12 protein-coding genes—PCGs, 2 rRNA and 22 tRNA genes) and a control region (A + T rich non-coding region). It is longer than that of the Brazil taxon (13,585 bp). The larger mitogenome size of the Costa Rica taxon is due to the size of the control region as the Brazil taxon has a shorter length (265 bp) than the Costa Rica taxon (318 bp). The size of 6 PCGs and the start codon for ATP6, CYTB and NAD5 genes are different between the Costa Rica and Brazil taxa. Additionally, the two taxa differ in the stop codon of 6 PCGs. Molecular phylogeny based on 12 PCGs was concordant with two rRNA, 22 tRNA and 36 mitochondrial genes. The two taxa have a genetic distance of p = 16.2% based on 12 PCGs, p = 15.3% based on 36 mitochondrial genes, p = 13.1% based on 2 rRNA genes and p = 10.7% based on 22 tRNA genes, indicating status of sibling species. The Costa Rica and Brazil taxa of A. costaricensis are proposed to be accorded specific status as members of a species complex. PMID:26230642

  15. Morphological aspects of Angiostrongylus costaricensis by light and scanning electron microscopy.

    PubMed

    Rebello, Karina M; Menna-Barreto, Rubem F S; Chagas-Moutinho, Vanessa A; Mota, Ester M; Perales, Jonas; Neves-Ferreira, Ana Gisele C; Oliveira-Menezes, Aleksandra; Lenzi, Henrique

    2013-09-01

    Angiostrongylus costaricensis is a parasitic nematode that can cause severe gastrointestinal disease, known as abdominal angiostrongiliasis, in humans. This paper presents the characterization of first- and third-stage larvae and male and female adult worms of A. costaricensis by scanning electron and light microscopy. Several novel anatomical structures were identified by scanning electron microscopy, including details of the cuticular striations of the spicules in male worms and a protective flap of the cuticle covering the vulvar aperture in female worms. Other taxonomic features revealed by light microscopy include the gubernaculum and the esophageal-intestinal valve. The use of two microscopy techniques allowed a detailed characterization of the morphology of this nematode. A number of previously identified taxonomic features, such as the striated nature of the spicules and the lateral alae were confirmed; however, the use of scanning electron microscopy resulted in a reassessment of the correct number of papillae distributed around the oral opening and behind the cloacal opening. These observations, in combination with light microscopy-based characterization of the gubernaculum and esophageal valves, have allowed a more detailed description of this nematode taxonomy.

  16. Use of a commercial serologic test for Angiostrongylus vasorum for the detection of A. chabaudi in wildcats and A. daskalovi in badgers.

    PubMed

    Deak, Georgiana; Gherman, Călin Mircea; Ionică, Angela Monica; Daskalaki, Aikaterini Alexandra; Matei, Ioana Adriana; D'Amico, Gianluca; Domşa, Cristian; Pantchev, Nikola; Mihalca, Andrei Daniel; Cozma, Vasile

    2017-01-15

    Three species of the genus Angiostrongylus are known to infect European carnivores: A. vasorum (mainly in canids but also in other carnivores), A. chabaudi (in felids) and A. daskalovi (in mustelids). A. vasorum is responsible for clinically severe disease in domestic dogs, most commonly diagnosed based on fecal examination and serological detection of circulating antigens. Considering the poorly known host range and the challenging larval differentiation in the feces between the three species of Angiostrongylus infecting European carnivores, our aim was to evaluate the cross-reactivity of A. chabaudi and A. daskalovi with A. vasorum using a commercial serologic test developed for domestic dogs. Badgers (Meles meles) (n=10) and wildcats (Felis silvestris) (n=8) were examined between 2015 and 2016 by full parasitological necropsy with subsequent morphological and molecular identification of nematodes and by serology, using IDEXX Angio Detect™ tests. Five out of the ten badgers and two out of the eight wildcats were harboring nematodes in the pulmonary arteries. All nematodes were identified morphologically as A. daskalovi in badgers and A. chabaudi in wildcats, respectively. Serological examination of the plasma samples revealed the positivity of the same animals as found in necropsy. None of the animals negative at necropsy was positive at serology. The 100% correlation between the necropsy results and the serologic positivity to IDEXX Angio Detect™ in badgers infected with A. daskalovi and wildcats infected with A. chabaudi suggest that these rapid tests are able to identify circulating antigens of all species of Angiostrongylus found in European carnivores: A. vasorum, A. daskalovi and A. chabaudi. The possibility for future in-clinic use of this test in domestic cats should be further investigated.

  17. Geographic distribution of Angiostrongylus cantonensis in wild rats (Rattus rattus) and terrestrial snails in Florida, USA.

    PubMed

    Stockdale Walden, Heather D; Slapcinsky, John D; Roff, Shannon; Mendieta Calle, Jorge; Diaz Goodwin, Zakia; Stern, Jere; Corlett, Rachel; Conway, Julia; McIntosh, Antoinette

    2017-01-01

    The parasitic nematode Angiostrongylus cantonensis is a major cause of eosinophilic meningitis in humans, and has been documented in other incidental hosts such as birds, horses, dogs and non-human primates. It is endemic in Hawaii, and there have been sporadic reports in the southern continental United States. This parasite uses rats as definitive hosts and snails as intermediate hosts. In this study, we collected potential definitive and intermediate hosts throughout Florida to ascertain the geographic distribution in the state: Rats, environmental rat fecal samples, and snails were collected from 18 counties throughout the state. Classical diagnostics and morphological identification, along with molecular techniques were used to identify nematode species and confirm the presence of A. cantonensis. Of the 171 Rattus rattus collected, 39 (22.8%) were positive for A. cantonensis, and 6 of the 37 (16.2%) environmental rat fecal samples collected in three of the surveyed counties were also positive for this parasite by real time PCR. We examined 1,437 gastropods, which represented 32 species; 27 (1.9%) were positive for A. cantonensis from multiple sites across Florida. Three non-native gastropod species, Bradybaena similaris, Zachrysia provisoria, and Paropeas achatinaceum, and three native gastropod species, Succinea floridana, Ventridens demissus, and Zonitoides arboreus, which are newly recorded intermediate hosts for the parasite, were positive for A. cantonensis. This study indicates that A. cantonensis is established in Florida through the finding of adult and larval stages in definitive and intermediate hosts, respectively, throughout the state. The ability for this historically subtropical nematode to thrive in a more temperate climate is alarming, however as the climate changes and average temperatures rise, gastropod distributions will probably expand, leading to the spread of this parasite in more temperate areas. Through greater awareness of host species

  18. Geographic distribution of Angiostrongylus cantonensis in wild rats (Rattus rattus) and terrestrial snails in Florida, USA

    PubMed Central

    Slapcinsky, John D.; Roff, Shannon; Mendieta Calle, Jorge; Diaz Goodwin, Zakia; Stern, Jere; Corlett, Rachel; Conway, Julia; McIntosh, Antoinette

    2017-01-01

    The parasitic nematode Angiostrongylus cantonensis is a major cause of eosinophilic meningitis in humans, and has been documented in other incidental hosts such as birds, horses, dogs and non-human primates. It is endemic in Hawaii, and there have been sporadic reports in the southern continental United States. This parasite uses rats as definitive hosts and snails as intermediate hosts. In this study, we collected potential definitive and intermediate hosts throughout Florida to ascertain the geographic distribution in the state: Rats, environmental rat fecal samples, and snails were collected from 18 counties throughout the state. Classical diagnostics and morphological identification, along with molecular techniques were used to identify nematode species and confirm the presence of A. cantonensis. Of the 171 Rattus rattus collected, 39 (22.8%) were positive for A. cantonensis, and 6 of the 37 (16.2%) environmental rat fecal samples collected in three of the surveyed counties were also positive for this parasite by real time PCR. We examined 1,437 gastropods, which represented 32 species; 27 (1.9%) were positive for A. cantonensis from multiple sites across Florida. Three non-native gastropod species, Bradybaena similaris, Zachrysia provisoria, and Paropeas achatinaceum, and three native gastropod species, Succinea floridana, Ventridens demissus, and Zonitoides arboreus, which are newly recorded intermediate hosts for the parasite, were positive for A. cantonensis. This study indicates that A. cantonensis is established in Florida through the finding of adult and larval stages in definitive and intermediate hosts, respectively, throughout the state. The ability for this historically subtropical nematode to thrive in a more temperate climate is alarming, however as the climate changes and average temperatures rise, gastropod distributions will probably expand, leading to the spread of this parasite in more temperate areas. Through greater awareness of host species

  19. Cross-reactivity of the 31 kDa antigen of Angiostrongylus cantonensis - Dealing with the immunodiagnosis of meningoencephalitis.

    PubMed

    Morassutti, Alessandra L; Rascoe, Lisa N; Handali, Sukwan; DA Silva, Alexandre J; Wilkins, Patricia P; Graeff-Teixeira, Carlos

    2017-04-01

    The primary causative agent of eosinophilic meningoencephalitis (EoM) in endemic regions is the nematode Angiostrongylus cantonensis. The occurrence of EoM was previously restricted to countries in Southeast Asia and the Pacific Islands; however, more recently, it has been reported from other regions, including Brazil. The commonly used diagnosis is detection of specific antibody reactivity to the 31 kDa antigen, which is derived from female worm somatic extracts. Here we report the occurrence of cross-reactivity to this antigen in sera from other parasitic infections, especially those that may cause EoM, such as gnathostomiasis, toxocariasis, hydatidosis and strongyloidiasis. We also demonstrated that the cross-reactivity, in part, is dependent of the concentration of antigen used in Western blot assays. We discuss the importance of these findings on the interpretation of this test.

  20. Eosinophilic meningoencephalitis associated with rat lungworm (Angiostrongylus cantonensis) migration in two nine-banded armadillos (Dasypus novemcinctus) and an opossum (Didelphis virginiana) in the southeastern United States.

    PubMed

    Dalton, Martha F; Fenton, Heather; Cleveland, Christopher A; Elsmo, Elizabeth J; Yabsley, Michael J

    2017-08-01

    Angiostrongylus cantonensis, the rat lungworm, was the cause of neural larval migrans in two nine-banded armadillos (Dasypus novemcinctus) and one Virginia opossum (Didelphis virginiana) from the southeastern United States. Histologic findings in all three cases included eosinophilic meningoencephalitis with variable numbers of nematode larvae in the meninges or the neuroparenchyma. In two of the three cases, nematodes were extracted from brain tissue via a "squash prep" method. Identification of the nematodes was confirmed by amplification and sequence analysis of the partial cytochrome c oxidase subunit I gene from all three cases. Sequences (704bp) from the two cases from Louisiana were identical and 99.7% similar to nematodes detected in the armadillo from Florida. As A. cantonensis is now considered endemic in the southern United States, it should be considered as an important differential for any wild or domestic animal or human patient with neurological signs and eosinophilic meningitis. Many wildlife species frequently consume snails and slugs and could serve as sentinels for the detection of this parasite in regions where the presence of this parasite has not been confirmed. To the authors' knowledge, this is the first report of neural larval migrans due to A. cantonensis in an armadillo and provides additional documentation that this nematode can cause disease in wildlife species in the southeastern United States.

  1. Dexamethasone inhibits brain apoptosis in mice with eosinophilic meningitis caused by Angiostrongylus cantonensis infection.

    PubMed

    Tsai, Hung-Chin; Lee, Bi-Yao; Yen, Chuan-Min; Wann, Shue-Ren; Lee, Susan Shin-Jung; Chen, Yao-Shen

    2015-04-02

    Angiostrongylus cantonensis, the rat lungworm, is the major cause of eosinophilic meningitis worldwide. Rats serve as the definitive host of the nematode, but humans can be infected incidentally, leading to eosinophilic meningitis. A previous BALB/c animal study has demonstrated increased apoptotic proteins and decreased anti-apoptotic proteins in mice infected with A. cantonensis. Steroids may be an effective treatment option for eosinophilic meningitis caused by A. cantonensis, but the involved mechanism is unclear. This study hypothesized that the beneficial effects of steroids on eosinophilic meningitis are mediated by decreased apoptosis. In a BALB/c animal model, mice were orally infected with 50 A. cantonensis L3 via an oro-gastric tube and were sacrificed every week for 3 consecutive weeks after infection or until the end of the study. Dexamethasone was injected intra-peritoneally from the 7(th) day post-infection until the end of the 21-day study. Evans blue method was used to measure changes in the blood brain barrier, while western blotting, immuno-histochemistry, and TUNEL assay were used to analyze brain homogenates expression of apoptotic and anti-apoptotic proteins. There were increased amounts of Evans blue, apoptotic proteins (caspase-3, -8, and -9 and cytochrome C), and decreased anti-apoptotic proteins (bcl-2) after 2-3 weeks of infection. Dexamethasone administration significantly decreased Evans blue extravasations and apoptotic protein expressions. Apoptosis of mice brain homogenates can be repressed by dexamethasone treatment.

  2. Seroprevalence of circulating Angiostrongylus vasorum antigen and parasite-specific antibodies in dogs from Portugal.

    PubMed

    Alho, Ana Margarida; Schnyder, Manuela; Schaper, Roland; Meireles, José; Belo, Silvana; Deplazes, Peter; de Carvalho, Luís Madeira

    2016-07-01

    Angiostrongylus vasorum is a nematode that lives in the pulmonary arteries and right cardiac ventricle of domestic dogs and wild canids. It is increasingly being reported in several European countries and North America. This parasite induces inflammatory verminous pneumonia, causing severe respiratory disease in dogs. In some instances, coagulopathies, neurological signs and even death may occur. Scant data are available regarding the occurrence of A. vasorum in Portugal. Therefore, sera of 906 shelter dogs from North to South mainland Portugal were collected. ELISAs to detect A. vasorum circulating antigen and specific antibodies against this parasite were performed. A total of six dogs [0.66 %, 95 % confidence intervals (CI) 0.24-1.43] were positive for both A. vasorum antigen and antibody detection, indicating an active infection, and 12 dogs (1.32 %, CI 0.68-2.30) were A. vasorum antibody-positive only. Regions with antigen- and antibody-positive animals overlapped and were distributed over nearly all sampled areas in the country. This is the first large-scale ELISA-based serological survey for A. vasorum in dogs from Portugal. The endemic occurrence of A. vasorum in dogs from different geographical areas of Portugal is therefore confirmed.

  3. Intrathecal Synthesis of Immunoglobulins in Eosinophilic Meningoencephalitis Due to Angiostrongylus cantonensis

    PubMed Central

    Dorta-Contreras, Alberto Juan; Reiber, Hansotto

    1998-01-01

    Eosinophilic meningoencephalitis due to the nematode Angiostrongylus cantonensis, which is endemic to Cuba, occurs in children and is due to accidental contact with soil snails. The course is less often fatal than in adult patients in southeastern Asia. Cerebrospinal fluid (CSF) and serum samples from 24 pediatric patients were analyzed and evaluated in CSF/serum quotient diagrams (Reiber graphs) to characterize the neuroimmunological response and the blood-CSF barrier dysfunction that occur in the course of the disease. At the time of the first diagnostic lumbar puncture, together with eosinophilic pleocytosis (1,920 ± 400 cells/μl), intermediate blood-CSF barrier dysfunction (i.e., an increased CSF/serum albumin quotient) with no intrathecal immunoglobulin G (IgG), IgA, and IgM class response was observed in all cases. Seven days later, at the time of early clinical recovery, the blood-CSF barrier dysfunction was normalized in 75% of the patients, but meanwhile, intrathecal immunoglobulin synthesis emerged in all cases, as either a two-class response (IgG and IgA in 85% of the patients) or a three-class response (IgG, IgA, and IgM; 30%). The fraction of eosinophilic cells (40%) remained large despite a decreasing total cell count. The neuroimmunological pattern of this inflammatory response to the parasite and its toxins is discussed with regard to the CSF patterns of other infectious diseases caused by bacteria or viruses. PMID:9665947

  4. Geographical distribution of Angiostrongylus vasorum in foxes (Vulpes vulpes) in the Republic of Ireland.

    PubMed

    McCarthy, G; Ferrand, M; De Waal, T; Zintl, A; McGrath, G; Byrne, W; O'Neill, E J

    2016-04-01

    The reported incidence of the metastrongylid nematode Angiostrongylus vasorum, that infects dogs and other canids, is increasing worldwide outside recognized endemic foci. This apparent expansion of the parasite's range is causing concern to veterinary clinicians as the disease caused in dogs can be life threatening and its treatment is not straightforward. The red fox is thought to be a reservoir host for dogs. To investigate the spatial distribution of infection in foxes in Ireland, the hearts and lungs of 542 foxes from all over Ireland were examined. The incidence of infection was found to be 39·9% [95% confidence interval (CI) 35·7-44·1] with positive samples occurring in each of the country's 26 counties. This report confirms that the parasite is endemic in Ireland and the overall prevalence is the second highest in Europe. This is the first survey of A. vasorum infection in Irish foxes and highlights the potential exposure of the Irish dog population to high risk of cross-infection. Additionally, Crenosoma vulpis was found in seven of the foxes, a parasite not previously reported in the Irish fox.

  5. Susceptibility of Biomphalaria glabrata submitted to concomitant infection with Angiostrongylus costaricensis and Schistosoma mansoni.

    PubMed

    Guerino, L R; Carvalho, J F; Magalhães, L A; Zanotti-Magalhães, E M

    2016-09-26

    The easy adaptation of Angiostrongylus costaricensis, nematode responsible for abdominal angiostrongyliasis to several species of terrestrial and freshwater molluscs and the differences observed in the interactions of trematodes with their intermediate hosts have induced us to study the concomitant infection of Biomphalaria glabrata with Schistosoma mansoni and A. costaricensis. Prior exposure of B. glabrata to A. costaricensis (with an interval of 48 hours), favored the development of S. mansoni, observing higher infection rate, increased release of cercariae and increased survival of molluscs, when compared to molluscs exposed only to S. mansoni. Prior exposure of B. glabrata to A. costaricensis and then to S. mansoni also enabled the development of A. costaricensis since in the ninth week of infection, higher amount of A. costaricensis L3 larvae was recovered (12 larvae / mollusc) while for molluscs exposed only to A. costaricensis, the number of larvae recovered was lower (8 larvae / mollusc). However, pre-exposure of B. glabrata to S. mansoni (with an interval of 24 hours), and subsequently exposure to A. costaricensis proved to be very harmful to B. glabrata, causing extensive mortality of molluscs, reduced pre-patent period to release cercariae and greater recovery of L3 A. costaricensis larvae.

  6. Larval development of Angiostrongylus vasorum in the land snail Helix aspersa.

    PubMed

    Di Cesare, Angela; Crisi, Paolo Emidio; Bartolini, Roberto; Iorio, Raffaella; Talone, Tonino; Filippi, Laura; Traversa, Donato

    2015-10-01

    The metastrongyloid nematode Angiostrongylus vasorum affects the heart and pulmonary arteries of dogs and wild animals. Over the recent years, dog angiostrongylosis has gained great attention in the veterinary community for the expansion of its geographic range and for a rise in the number of clinical cases. Global warming, changes in phenology of mollusc intermediate hosts and movements of wild reservoirs have been evocated in the spreading of mollusc-borne parasites, including A. vasorum. The land snail Helix aspersa, a vector of other respiratory metastrongyloids, is endemic in most regions of the World, where it is a pest outside its native Mediterranean range. In the present study, the susceptibility and suitability of H. aspersa as an intermediate host of A. vasorum were investigated along with the characteristics of larval recovery and development following two different ways of inoculation, i.e. experimental (group A) vs natural infection (group B). After infections, the snails were kept at environmental conditions for 2 months. Five snails from groups A and B were randomly selected, digested and examined at 15-day intervals for 2 months. L1s, L2s and L3s were microscopically identified based on key morphological and morphometric characteristics and their identity was genetically confirmed. The results showed that A. vasorum may reach the infective stage in H. aspersa and that uptake of larvae and parasitic burden within the snails depend on the grazing capability of the molluscs. Biological and epidemiological implications are discussed.

  7. The nematophagous fungus Monacrosporium thaumasium and its nematicidal activity on Angiostrongylus vasorum.

    PubMed

    Soares, Filippe Elias de Freitas; Braga, Fabio Ribeiro; de Araújo, Jackson Victor; Lima, Walter dos Santos; de Queiroz, José Humberto

    2015-01-01

    The dog acts as a reservoir and environmental disseminator of potentially zoonotic parasites. The objective of this work was to study the fungus Monacrosporium thaumasium regarding its nematicidal potential in laboratory trials and its proteolytic profile. The in vitro test was carried out through two assays (A and B). In assay A, conidia of the fungus N34a were added in positive coprocultures for Angiostrongylus vasorum. In assay B, crude extract (treated group) and distilled water (control group) were added to coprocultures. Next, the proteolytic profile of crude extract of the nematophagous fungus M. thaumasium (NF34a) was revealed by performing a zymogram. There was a reduction (p<0.01) in the averages of larvae recovered from the treated groups (conidia and crude extract) in relation to control groups. The zymogram suggested that the nematophagous fungus M. thaumasium produces a protease of approximately 40 kDa. The results of this work confirm that the conidia as well as the crude extract of the fungus M. thaumasium may be used to control A. vasorum L1. The proteolytic profile suggested the presence of one protease (Mt1) of approximately 40 kDa that in the future may be used in biological control of L1 of this nematode. Copyright © 2013 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

  8. Fatal Angiostrongylus dujardini infection in callitrichid monkeys and suricates in an Italian zoological garden.

    PubMed

    Eleni, Claudia; Di Cesare, Angela; Cavicchio, Paolo; Tonnicchia, Maria Cristina; Meoli, Roberta; di Regalbono, Antonio Frangipane; Paoletti, Barbara; Pietrobelli, Mario; De Liberato, Claudio

    2016-08-01

    This paper reports four fatal cases of metastrongylid nematode Angiostrongylus dujardini infection observed in a Saguinus oedipus and a Callimico goeldii monkey and in two suricates (Suricata suricatta). All animals were kept in captivity in a zoo of central Italy. The two monkeys died with no premonitory signs, while the two-month-old suricates showed malaise, anorexia and tachypnea for a few days prior to death. Cardiomegaly and/or granulomatous pneumonia were the major anatomo-pathological findings. Inflammatory lesions were observed in the liver, heart and kidney of the suricates at histology. A. dujardini diagnosis was confirmed through both morphological identification of adult worms recovered at necropsy and molecular characterization of larvae in tissue samples. Callitrichidae and suricates are active predators and maintain their hunting behaviour in captivity and it is then likely that they were exposed to infection by preying on parasitized gastropods, intermediate hosts of A. dujardini, entering zoo enclosures from the surrounding environment. This is the first report of A. dujardini in Italy and in S. suricatta.

  9. Species of Angiostrongylus (Nematoda: Metastrongyloidea) in wildlife: A review.

    PubMed

    Spratt, David M

    2015-08-01

    Twenty-one species of Angiostrongylus plus Angiostrongylus sp. (Nematoda: Metastrongyloidea) are known currently in wildlife. These occur naturally in rodents, tupaiids, mephitids, mustelids, procyonids, felids, and canids, and aberrantly in a range of avian, marsupial and eutherian hosts including humans. Adults inhabit the pulmonary arteries and right atrium, ventricle and vena cava, bronchioles of the lung or arteries of the caecum and mesentery. All species pass first-stage larvae in the faeces of the host and all utilise slugs and/or aquatic or terrestrial snails as intermediate hosts. Gastropods are infected by ingestion or penetration of first-stage larvae; definitive hosts by ingestion of gastropods or gastropod slime. Transmission of at least one species may involve ingestion of paratenic hosts. Five developmental pathways are identified in these life cycles. Thirteen species, including Angiostrongylus sp., are known primarily from the original descriptions suggesting limited geographic distributions. The remaining species are widespread either globally or regionally, and are continuing to spread. Small experimental doses of infective larvae (ca. 20) given to normal or aberrant hosts are tolerated, although generally eliciting a granulomatous histopathological response; large doses (100-500 larvae) often result in clinical signs and/or death. Two species, A. cantonensis and A. costaricensis, are established zoonoses causing neurological and abdominal angiostrongliasis respectively. The zoonotic potential of A. mackerrasae, A. malaysiensis and A. siamensis particularly warrant investigation. Angiostrongylus cantonensis occurs in domestic animals, mammalian and avian wildlife and humans in the metropolitan areas of Brisbane and Sydney, Australia, where it has been suggested that tawny frogmouths and brushtail possums may serve as biosentinels. A major conservation issue is the devastating role A. cantonensis may play around zoos and fauna parks where captive

  10. Species of Angiostrongylus (Nematoda: Metastrongyloidea) in wildlife: A review

    PubMed Central

    Spratt, David M.

    2015-01-01

    Twenty-one species of Angiostrongylus plus Angiostrongylus sp. (Nematoda: Metastrongyloidea) are known currently in wildlife. These occur naturally in rodents, tupaiids, mephitids, mustelids, procyonids, felids, and canids, and aberrantly in a range of avian, marsupial and eutherian hosts including humans. Adults inhabit the pulmonary arteries and right atrium, ventricle and vena cava, bronchioles of the lung or arteries of the caecum and mesentery. All species pass first-stage larvae in the faeces of the host and all utilise slugs and/or aquatic or terrestrial snails as intermediate hosts. Gastropods are infected by ingestion or penetration of first-stage larvae; definitive hosts by ingestion of gastropods or gastropod slime. Transmission of at least one species may involve ingestion of paratenic hosts. Five developmental pathways are identified in these life cycles. Thirteen species, including Angiostrongylus sp., are known primarily from the original descriptions suggesting limited geographic distributions. The remaining species are widespread either globally or regionally, and are continuing to spread. Small experimental doses of infective larvae (ca. 20) given to normal or aberrant hosts are tolerated, although generally eliciting a granulomatous histopathological response; large doses (100–500 larvae) often result in clinical signs and/or death. Two species, A. cantonensis and A. costaricensis, are established zoonoses causing neurological and abdominal angiostrongliasis respectively. The zoonotic potential of A. mackerrasae, A. malaysiensis and A. siamensis particularly warrant investigation. Angiostrongylus cantonensis occurs in domestic animals, mammalian and avian wildlife and humans in the metropolitan areas of Brisbane and Sydney, Australia, where it has been suggested that tawny frogmouths and brushtail possums may serve as biosentinels. A major conservation issue is the devastating role A. cantonensis may play around zoos and fauna parks where

  11. First report of Angiostrongylus cantonensis (Nematoda: Angiostrongylidae) infections in invasive rodents from five islands of the Ogasawara Archipelago, Japan.

    PubMed

    Tokiwa, Toshihiro; Hashimoto, Takuma; Yabe, Tatsuo; Komatsu, Noriyuki; Akao, Nobuaki; Ohta, Nobuo

    2013-01-01

    Angiostrongylus cantonensis (Chen, 1935) is a parasite of murid rodents and causative agent of human neuro-angiostrongyliasis. In 2011, the Ogasawara Islands in the western North Pacific were assigned a World Natural Heritage site status. The occurrence of A. cantonensis is well documented in the Chichijima, Hahajima, and Anijima Islands. However, the occurrence of A. cantonensis in the other islands of the Ogasawara Islands has not been reported. Between March 2010 and July 2011, 57 Rattus norvegicus and 79 R. rattus were collected from 9 islands (the Hahajima group: Anejima, Imoutojima, Meijima, Mukohjima, and Hirajima; Chichijima group: Minamijima; Mukojima group: Nakoudojima and Yomejima; and Iwojima group: Iwojima). Adult nematodes were found in the pulmonary artery of 46 R. norvegicus collected in the 5 islands of the Hahajima group (Anejima, Meijima, Imoutojima, Hrajima, and Mukohjima Islands). These nematodes were identified by molecular analysis as A. cantonensis. Comparison of the mitochondrial DNA sequences confirmed that all the samples from the Ogasawara Islands shared only a single lineage of A. cantonensis, which has been previously detected in the Okinawa, Hawaii, and Brazil. We describe new endemic foci of rat angiostrongyliasis in the Hahajima group (Anejima, Meijima, Imoutojima, Hirajima, and Mukohjima Islands) of the Ogasawara Islands. These findings indicate that the endemic foci of A. cantonensis are widely distributed in the Ogasawara Islands. Although human cases have not yet been reported in the Ogasawara Islands, the widespread detection of A. cantonensis could be of importance from the perspective of public health.

  12. Angiostrongylus cantonensis cathepsin B-like protease (Ac-cathB-1) is involved in host gut penetration

    PubMed Central

    Long, Ying; Cao, Binbin; Yu, Liang; Tukayo, Meks; Feng, Chonglv; Wang, Yinan; Luo, Damin

    2015-01-01

    Although the global spread of the emerging zoonosis, human angiostrongyliasis, has attracted increasing attention, understanding of specific gene function has been impeded by the inaccessibility of genetic manipulation of the pathogen nematode causing this disease, Angiostrongylus cantonensis. Many parasitic proteases play key roles in host-parasite interactions, but those of A. cantonensis are always expressed as the inactive form in prokaryotic expression systems, thereby impeding functional studies. Hence, a lentiviral system that drives secreted expression of target genes fused to a Myc-His tag was used to obtain recombinant Ac-cathB-1 with biological activity. Although this class of proteases was always reported to function in nutrition and immune evasion in parasitic nematodes, recombinant Ac-cathB-1 was capable of hydrolysis of fibronectin and laminin as well as the extracellular matrix of IEC-6 monolayer, so that the intercellular space of the IEC-6 monolayer increased 5.15 times as compared to the control, while the shape of the adherent cells partly rounded up. This suggests a probable role for this protease in intestinal epithelial penetration. The inhibition of Ac-cathB-1 enzymatic activity with antiserum partly suppressed larval penetration ability in the isolated intestine. Thus, an effective system for heterologous expression of parasite proteases is presented for studying gene function in A. cantonensis; and Ac-cathB-1 was related to larval penetration ability in the host small intestine. PMID:26682577

  13. Prevalence and distribution of Angiostrongylus cantonensis (Nematoda, Angiostrongylidae) in Achatina fulica (Mollusca, Gastropoda) in Baixada Santista, São Paulo, Brazil.

    PubMed

    Guerino, Laura Rocha; Pecora, Iracy Lea; Miranda, Marcel Sabino; Aguiar-Silva, Cryslaine; Carvalho, Omar Dos Santos; Caldeira, Roberta Lima; Silva, Reinaldo José da

    2017-01-01

    Angiostrongylus cantonensis is causes eosinophilic meningoencephalitis in humans. Worldwide expansion of this nematode is linked to the dispersion of their hosts. This study aimed to determine the prevalence of A. cantonensis infection in Achatina fulica in the nine municipalities that make up Baixada Santista, São Paulo, Brazil. Angiostrongylus cantonensis larvae were analyzed using optical microscopy. We performed polymerase chain reaction and restriction fragment length polymorphism using restriction endonuclease ClaI, directed to the internal transcribed spacer region 2 of A. cantonensis larval DNA. Of the 540 snails analyzed, 117 (21.7%) were infected by A. cantonensis. For morphological and morphometric analyses, 60 larvae were used. Second-stage larvae were, on average, 358.2µm long and 26.4µm wide, while third-stage larvae were, on average, 450µm long and 21.12µm wide. The tails of the larvae ended in a fine tip. All municipalities comprising Baixada Santista had A. fulica that were naturally infected with A. cantonensis. All of the observed characteristics were typical of the species.

  14. Insights into the immuno-molecular biology of Angiostrongylus vasorum through transcriptomics--prospects for new interventions.

    PubMed

    Ansell, Brendan R E; Schnyder, Manuela; Deplazes, Peter; Korhonen, Pasi K; Young, Neil D; Hall, Ross S; Mangiola, Stefano; Boag, Peter R; Hofmann, Andreas; Sternberg, Paul W; Jex, Aaron R; Gasser, Robin B

    2013-12-01

    Angiostrongylus vasorum is a metastrongyloid nematode of dogs and other canids of major clinical importance in many countries. In order to gain first insights into the molecular biology of this worm, we conducted the first large-scale exploration of its transcriptome, and predicted essential molecules linked to metabolic and biological processes as well as host immune responses. We also predicted and prioritized drug targets and drug candidates. Following Illumina sequencing (RNA-seq), 52.3 million sequence reads representing adult A. vasorum were assembled and annotated. The assembly yielded 20,033 contigs, which encoded proteins with 11,505 homologues in Caenorhabditis elegans, and additional 2252 homologues in various other parasitic helminths for which curated data sets were publicly available. Functional annotation was achieved for 11,752 (58.6%) proteins predicted for A. vasorum, including peptidases (4.5%) and peptidase inhibitors (1.6%), protein kinases (1.7%), G protein-coupled receptors (GPCRs) (1.5%) and phosphatases (1.2%). Contigs encoding excretory/secretory and immuno-modulatory proteins represented some of the most highly transcribed molecules, and encoded enzymes that digest haemoglobin were conserved between A. vasorum and other blood-feeding nematodes. Using an essentiality-based approach, drug targets, including neurotransmitter receptors, an important chemosensory ion channel and cysteine proteinase-3 were predicted in A. vasorum, as were associated small molecular inhibitors/activators. Future transcriptomic analyses of all developmental stages of A. vasorum should facilitate deep explorations of the molecular biology of this important parasitic nematode and support the sequencing of its genome. These advances will provide a foundation for exploring immuno-molecular aspects of angiostrongylosis and have the potential to underpin the discovery of new methods of intervention.

  15. Seroprevalence of Angiostrongylus cantonensis in Wild Rodents from the Canary Islands

    PubMed Central

    Martin-Alonso, Aarón; Foronda, Pilar; Quispe-Ricalde, María Antonieta; Feliu, Carlos; Valladares, Basilio

    2011-01-01

    Background Angiostrongylus cantonensis is a lungworm of rats (Muridae) that is the causative agent of human cerebral angiostrongyliasis. The life cycle of A. cantonensis involves rats and mollusks as the definitive and intermediate hosts, respectively. This study was designed to increase the knowledge about the occurrence and distribution of A. cantonensis in its definitive host in the Canary Islands, using parasitological and serological analysis in different areas and age groups. Methodology/Principal Findings Between 2009 and 2010, 54 black rats (Rattus rattus) from Tenerife were captured from six human-inhabited areas and sera samples were obtained. The lung nematodes were identified by morphological and molecular tools as A. cantonensis. The 31-kDa glycoprotein antigen was purified from A. cantonensis adult worms by electrophoresis and electroelution. Of the 54 tested rodents, 30 showed IgG antibodies against A. cantonensis 31-kDa antigen by ELISA. Therefore, the overall seroprevalence was 55.6% (95% CI: 42.4–68). Seroprevalent rodents were found in all the 6 areas. This 31-kDa antigen was not recognized by some sera of rats infected by other helminth species (but not A. cantonensis). Seroprevalence of IgG antibodies against A. cantonensis and prevalence based on the presence of adult worms showed significant correlation (R2 = 0.954, p<0.05). Conclusions/Significance The present results could indicate a high prevalence of A. cantonensis in Tenerife and suggest the inclusion of two new zones in the distribution area of the parasite. The commonness and wide distribution of A. cantonensis in rats implies the presence of intermediate hosts, indicating that humans may be at risk of getting infected. PMID:22110752

  16. Effects of experimental Angiostrongylus cantonensis infection on the reproductive biology of Biomphalaria straminea and Biomphalaria tenagophila.

    PubMed

    Lima, Mariana G; Tunholi-Alves, Vinícius M; Bonfim, Tatiane Cristina S; Gaudêncio, Fabrício N; Garcia, Juberlan S; Maldonado, Arnaldo; Pinheiro, Jairo; Thiengo, Silvana C

    2017-10-01

    Eosinophilic meningoencephalitis is an endemic zoonosis in Southeast Asia and the Pacific Islands, but in recent years, new cases have been reported in various countries outside these regions, including Brazil, where it is considered an emerging disease. In this study, the effect of infection by the nematode Angiostrongylus cantonensis, one of the main etiologic agent of this disease, on the reproductive biology of the planorbid snails Biomphalaria straminea and B. tenagophila was investigated during the pre-patent period. Alterations in the reproductive biology of B. straminea and B. tenagophila were analyzed in laboratory-reared specimens infected by A. cantonensis during 21days; the number of eggs, number of egg masses, number of eggs/mass, number of eggs/snail, viable eggs/snail, survival and galactogen content in the albumen gland were measured. The results indicated the occurrence of initial compensation in reproductive effort in both snail species, but at different moments in the pre-patent period. More specifically, a reduction of 46.53% in the eggs/egg mass ratio in infected B. straminea was observed, a reflection of a 50% decline in the concentration of galactogen contained in the albumen gland. Changes in this parameter were also noted in B. tenagophila, but only at the end of the study period, with a reduction of 15.49%. Histological analyses indicate that changes observed can be explained by the tissue damages caused by the migration and development of the larvae. These results shed more light on the host-parasite relationship and indicate the importance of studying reproductive aspects for efforts to control infected snails. Considering that terrestrial snails can also transmit eosinophilic meningitis (in addition to aquatic mollusks), the data obtained expand knowledge of this host-parasite relationship and provide support for programs to control this zoonosis. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Eosinophilic meningitis caused by Angiostrongylus cantonensis--a neglected disease with escalating importance.

    PubMed

    Eamsobhana, P

    2014-12-01

    The rat lungworm Angiostrongylus cantonensis, a food-borne zoonotic parasite, has been recognized as the primary pathogen associated with human eosinophilic meningitis or eosinophilic meningoencephalitis. This neurotropic nematode has a definitive rodent host and a molluscan intermediate host. The adult worms live in the pulmonary arteries of rats. Human is a non-permissive, accidental host. Transmission to humans is by eating of infected raw or undercooked snails, poorly cleaned contaminated vegetables or other infected paratenic hosts such as freshwater prawns, crabs, frogs or monitor lizards. Thousands of diagnosed cases of eosinophilic meningitis caused by A. cantonensis have been reported worldwide. Angiostrongyliasis is of increasing public health importance as globalization contributes to the geographical spread and more international travelers encounter the disease. The parasite is on the move. It has spread from its traditional endemic areas of Asia and the Pacific Basin to the American continent including the USA, Brazil and Caribbean islands. Recently, the incidence of human infections has increased rapidly. Most reports of the disease are from Thailand and Taiwan with increasing reports from mainland China. The rapid global spread of the parasite and the emerging occurrence of the infection pose challenges in clinical and laboratory diagnosis, and in epidemiology and basic biology. Enhanced understanding of the epidemiology of angiostrongyliasis, increased public awareness about the risks associated with eating raw or undercooked food, and enhanced food safety measures are needed. Therefore, current knowledge on various aspects of the parasite and the disease it causes, as well as recent epidemiological status together with significant progress in laboratory investigation of A. cantonensis infection, are overviewed to promote understanding and awareness of this emerging neglected disease.

  18. Angiostrongylus infections in rats and snails in northeast Thailand.

    PubMed

    Pipitgool, V; Sithithaworn, P; Pongmuttasaya, P; Hinz, E

    1997-01-01

    A survey of Angiostrongylus infections in rats and snails was carried out in the provinces of Ubon Ratchathani, Udon Thani. Kalasin, Chaiyaphum and Khon Kaen in northeast Thailand. Only two Rattus norvegicus (3.8%) and one Bandicota indica (1.4%) out of 151 R. rattus, 52 R. norvegicus and 69 B. indica examined were infected with adult lung worms. All worms recovered were A. cantonensis. Prevalence of infection in 423 Pila polita was 0.9% while all of 77 P. ampullacea were negative for larvae. In contrast to this 36.4% of 500 Achatina fulica harbored L3 of Angiostrongylus (with variations of between 29% and 46% in the five provinces). The average infection intensity in A. fulica was 13.6 L3 (1 to 441). Experimental infection of Wistar rats with L3 (isolated from A. fulica resulted in a recovery rate of 48.3% of adult worms of which 91.7% and 8.3% were identified as A. cantonensis and A. malaysiensis, respectively. This is the first proven finding of A. malaysiensis in northeast Thailand.

  19. Angiostrongylus cantonensis Infection: A Cause of Fever of Unknown Origin in Pediatric Patients.

    PubMed

    Foster, Catherine E; Nicholson, Erin G; Chun, Angela C; Gharfeh, Maya; Anvari, Sara; Seeborg, Filiz O; Lopez, Michael A; Campbell, Judith R; Marquez, Lucila; Starke, Jeffrey R; Palazzi, Debra L

    2016-12-01

    Fever of unknown origin (FUO) in children is frequently caused by infectious diseases. Angiostrongylus cantonensis, while a primary cause of eosinophilic meningitis, is rarely a cause of FUO. We present 2 pediatric cases of FUO caused by Angiostrongylus cantonensis acquired in Houston, Texas, outside its usual geographic distribution. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  20. Spread of the Rat Lungworm (Angiostrongylus cantonensis) in Giant African Land Snails (Lissachatina fulica) in Florida, USA.

    PubMed

    Iwanowicz, Deborah D; Sanders, Lakyn R; Schill, W Bane; Xayavong, Maniphet V; da Silva, Alexandre J; Qvarnstrom, Yvonne; Smith, Trevor

    2015-07-01

    The rat lungworm (Angiostrongylus cantonensis) is a parasitic nematode that causes rat lungworm disease. It is the leading cause of eosinophilic meningitis and is a zoonotic health risk. We confirmed the presence of A. cantonensis using species-specific, quantitative PCR in 18 of 50 (36%) giant African land snails (Lissachatina fulica) collected from Miami, Florida, US in May 2013. These snails were collected from seven of 21 core areas that the Florida Department of Agriculture and Consumer Services monitor weekly. Rat lungworms have not previously been identified in these areas. Duplicate DNA extractions of foot muscle tissue from each snail were tested. Of the seven core areas we examined, six were positive for A. cantonensis and prevalence of infection ranged from 27% to 100%. Of the 18 positive snails, only five were positive in both extractions. Our results confirm an increase in the range and prevalence of rat lungworm infection in Miami. We also emphasize the importance of extracting sufficient host tissue to minimize false negatives.

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

    PubMed Central

    Yeung, Norine W; Hayes, Kenneth A

    2013-01-01

    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. PMID:23901391

  2. Effects of washing produce contaminated with the snail and slug hosts of Angiostrongylus cantonensis with three common household solutions.

    PubMed

    Yeung, Norine W; Hayes, Kenneth A; Cowie, Robert H

    2013-06-01

    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.

  3. Biochemical profile of Achatina fulica (Mollusca: Gastropoda) after infection by different parasitic loads of Angiostrongylus cantonensis (Nematoda, Metastrongylidae).

    PubMed

    Tunholi-Alves, Vinícius Menezes; Tunholi, Victor Menezes; Amaral, Ludimila Santos; Mota, Esther Maria; Maldonado Júnior, Arnaldo; Pinheiro, Jairo; Garcia, Juberlan

    2015-01-01

    The effect of experimental infection by different parasitic loads of Angiostrongylus cantonensis (Nematode, Metastrongylidae) on the activities of the aminotransferases and concentration of total proteins, uric acid and urea in the hemolymph of Achatina fulica (Mollusca, Gastropoda) were investigated. There was a significant decrease in the concentration of total proteins in the exposed snails to 5000 or more larvae. This change was accompanied by an increase in the concentrations of urea and uric acid in the hemolymph, suggesting a higher rate of deamination of the amino acids. Besides this, variations in the activities of the aminotransferases were also observed, with the highest values recorded in the groups exposed to greater parasite load. These results suggest an increase in the use of total proteins, since there was increased formation of nitrogenous catabolites, in conformity with an increase in the aminotransferase activities. Infection was verified by the fact that L3 larvae recovered from the snails was proportion to the exposure dose of L1 larvae. Histopathological results also indicated presence of an inflammatory cell infiltrate, favoring an increase of both transaminases.

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

    PubMed Central

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

    2013-01-01

    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

  5. First report of Angiostrongylus vasorum and Hepatozoon from a red fox (Vulpes vulpes) from West Virginia, USA.

    PubMed

    Kistler, Whitney M; Brown, Justin D; Allison, Andrew B; Nemeth, Nicole M; Yabsley, Michael J

    2014-02-24

    Angiostrongylus vasorum was identified in the lungs of a red fox (Vulpes vulpes) from West Virginia, United States (US), indicating a new geographical location for this metastrongylid nematode. The fox was euthanized and submitted for necropsy after displaying erratic behavior. We did not detect rabies virus or canine distemper virus from the fox. We observed bronchopneumonia associated with A. vasorum infection disseminated in both lungs. In addition, protozoal meronts were observed in the liver, spleen, and mesenteric lymph node, and were identified as Hepatozoon canis. Lymphoid depletion was also observed in the spleen and mesenteric lymph node. In addition to A. vasorum and H. canis infections, Eucoleus aerophilus eggs and adult worms were observed in the lungs of the fox. Severe lesions associated with A. vasorum infection were observed in the lungs and these were determined to be the likely cause of morbidity; however, synergistic effects among the multiple infections detected in this fox cannot be ruled out. This is the first report of an autochthonous A. vasorum infection in the US and from outside of Newfoundland Canada, the only place in North America where the parasite is known to be endemic. Additionally, this is the first report of a H. canis infection in a red fox from the US.

  6. Control measures for slug and snail hosts of Angiostrongylus cantonensis, with special reference to the semi-slug Parmarion martensi.

    PubMed

    Hollingsworth, Robert G; Howe, Kathleen; Jarvi, Susan I

    2013-06-01

    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.

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

    PubMed Central

    Howe, Kathleen; Jarvi, Susan I

    2013-01-01

    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 Hawai‘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 Hawai‘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 Hawai‘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. PMID:23901389

  8. [Disseminated intravascular coagulopathy in a dog with Angiostrongylus vasorum infection].

    PubMed

    Kruse, B D; Hartmann, K; Groth, A; Schulz, B; Wehner, A

    2013-01-01

    A 2-year-old female spayed Epagneul-Breton dog was presented with ecchymoses, but an undisturbed general condition. Clinical examination additionally revealed petechia and a haematoma. Travel history included Italy and Denmark. Laboratory abnormalities were moderate thrombocytopenia, prolonged PT, aPTT and TT, and elevated d-dimers. Initial therapy consisted of plasma transfusions, fluids, doxycycline and famotidine administration. Babesiosis, ehrlichiosis, leishmaniosis, dirofilariosis or anaplasmosis could not be confirmed. Abdominal ultrasound was unremarkable, while thoracic radiographs showed a bronchointerstitial pattern. Faecal samples collected over 3 days were positive for Angiostrongylus vasorum after examination using the Baermann lungworm test. The A. vasorum infection was successfully treated with fenbendazole, whereupon thrombocytopenia and prolonged coagulation times were resolved. In regions of low prevalence, an infection with A. vasorum should also be considered as a differential diagnosis in dogs with coagulation abnormalities. Respiratory signs can be absent with this disease. The patient may have acquired the infection abroad or in Germany.

  9. Parastrongylus (=Angiostrongylus) cantonensis now endemic in Louisiana wildlife.

    PubMed

    Kim, D Y; Stewart, T B; Bauer, R W; Mitchell, M

    2002-10-01

    Parastrongylus (=Angiostrongylus) cantonensis, a lung worm of rats, was first reported in the United States in 1987, with a probable introduction by infected rats from ships docking in New Orleans, Louisiana, during the mid-1980s. Since then, it has been reported in nonhuman primates and a boy from New Orleans, and in a horse from Picayune, Mississippi, a distance of 87 km from New Orleans. Parastrongylus cantonensis infection is herein reported in a lemur (Varencia variegata rubra) from New Iberia, Louisiana, a distance of 222 km from New Orleans, and in a wood rat (Neotomafloridanus) and in 4 opossums (Didelphis virginiana) from Baton Rouge, Louisiana, a distance of 124 km from New Orleans. The potential of a great variety of gastropods serving as intermediate hosts in Louisiana may pose a threat to wildlife as well as to domesticated animals in the areas where infected Norway rats (Rattus norvegicus) are present.

  10. Pathological findings of Angiostrongylus vasorum infection in red foxes (Vulpes vulpes) from Central Italy, with the first report of a disseminated infection in this host species.

    PubMed

    Eleni, Claudia; Grifoni, Goffredo; Di Egidio, Alessandra; Meoli, Roberta; De Liberato, Claudio

    2014-03-01

    In Europe, the red fox (Vulpes vulpes) is considered the reservoir of Angiostrongylus vasorum, nematode residing in the pulmonary arteries and right heart of dogs and many species of wild carnivores. Italy is considered one of the European countries where this nematode is actually spreading. Between May 2007 and November 2013, 62 foxes found dead in Central Italy were necropsied. Right heart and pulmonary arteries were opened and checked for the presence of adult parasites. Impression smears from sectioned lungs were examined for the presence of first-stage larvae, and samples of lungs were processed for histological examination. In order to detect eventual disseminated infections, samples of heart, pulmonary lymph nodes, liver, kidneys, and brain of foxes positive for A. vasorum at necropsy or lungs histological examination were processed for histological examination. An overall prevalence of 43.5% was recorded. Light, mild, and severe lung lesions were detected in 33.3, 22.2, and 25.9% of infected animals, respectively. Severe lesions were more frequent in animals younger than 12 months. In five infected foxes (18.5%), no gross lesions were observed, while for three animals, angiostrongylosis was considered the cause of death. A case of disseminated angiostrongylosis was detected and another one was suspected. This is the firs report of disseminated angiostrongylosis in the fox.

  11. GIS-supported epidemiological analysis on canine Angiostrongylus vasorum and Crenosoma vulpis infections in Germany.

    PubMed

    Maksimov, Pavlo; Hermosilla, Carlos; Taubert, Anja; Staubach, Christoph; Sauter-Louis, Carola; Conraths, Franz J; Vrhovec, Majda Globokar; Pantchev, Nikola

    2017-02-28

    Angiostrongylus vasorum infections are the cause of severe cardiopulmonary diseases in dogs. In the past, canine angiostrongylosis has largely been neglected in Europe, although some recent studies indicated an expansion of historically known endemic areas, a phenomenon that might also apply to Crenosoma vulpis. The aim of the present study was to analyse temporal and spatial trends of canine A. vasorum and C. vulpis infections and to perform GIS-supported risk factor analysis to evaluate the role of landscape, age and seasonality in the life-cycle of these nematodes. A total of 12,682 faecal samples from German dogs (collected in 2003-2015) with clinical suspicion for lungworm infection were examined for the presence of A. vasorum and C. vulpis larvae by the Baermann funnel technique and respective epidemiological data (location and age of the sampled dogs, date of sampling) were subjected to GIS-supported risk factor analysis. Overall, A. vasorum and C. vulpis larvae were detected in 288 (2.3%) and 285 (2.2%) faecal samples, respectively. In general, both lungworm infections were found to be widely spread in Germany. GIS-supported analyses demonstrate spatial differences in the occurrence of canine A. vasorum and C. vulpis infections in Germany. also, risk factor analyses revealed an overlap but also diverging risk and protective factors for A. vasorum and C. vulpis infections. The current data also indicate a significant increase of A. vasorum and C. vulpis prevalences from 2003 to 2015 and from 2008 until 2015, respectively, and a potential spread of A. vasorum endemic areas to the northeastern part of Germany. The results of the present study show an insight into the epidemiological situation of lungworm infections (A. vasorum and C. vulpis) of the past 13 years in Germany. The data clearly demonstrate an increase of diagnosed A. vasorum prevalence in the tested dog population between 2003 and 2015 as well as spatial differences in the occurrence of diagnosed

  12. Fleas infesting pets in the era of emerging extra-intestinal nematodes.

    PubMed

    Traversa, Donato

    2013-03-07

    Modifications in climatic conditions, movements of hosts and goods, changes in animal phenology and human behaviour and increase of wildlife, are presently concurring in the geographic spread of vectors and cardio-respiratory nematodes, e.g. Dirofilaria immitis, Angiostrongylus vasorum, Aelurostrongylus abstrusus and Capillaria aerophila. All these factors may also influence dispersion and clinical significance of fleas, thus posing relevant challenges in those regions where other parasites are emerging at the same time. Ctenocephalides felis, Ctenocephalides canis and Pulex irritans cause discomfort, nuisance, allergic reactions, anaemia, and may transmit several pathogens, some of them are of importance for public health. The present article reviews the importance of fleas in small animal practice and their sanitary relevance for dogs, cats and humans, and discusses current control methods in the present era of emerging extra-intestinal nematodes, towards a possible changing perspective for controlling key parasites affecting companion animals.

  13. Fleas infesting pets in the era of emerging extra-intestinal nematodes

    PubMed Central

    2013-01-01

    Modifications in climatic conditions, movements of hosts and goods, changes in animal phenology and human behaviour and increase of wildlife, are presently concurring in the geographic spread of vectors and cardio-respiratory nematodes, e.g. Dirofilaria immitis, Angiostrongylus vasorum, Aelurostrongylus abstrusus and Capillaria aerophila. All these factors may also influence dispersion and clinical significance of fleas, thus posing relevant challenges in those regions where other parasites are emerging at the same time. Ctenocephalides felis, Ctenocephalides canis and Pulex irritans cause discomfort, nuisance, allergic reactions, anaemia, and may transmit several pathogens, some of them are of importance for public health. The present article reviews the importance of fleas in small animal practice and their sanitary relevance for dogs, cats and humans, and discusses current control methods in the present era of emerging extra-intestinal nematodes, towards a possible changing perspective for controlling key parasites affecting companion animals. PMID:23497511

  14. Resveratrol relieves Angiostrongylus cantonensis - Induced meningoencephalitis by activating sirtuin-1.

    PubMed

    Chen, An-Chih; Shyu, Ling-Yuh; Hsin, Yue-Loong; Chen, Ke-Min; Lai, Shih-Chan

    2017-09-01

    Resveratrol, a natural herbal compound found in high levels in grapes and red wine, is frequently used as activator of sirtuin-1. This study investigated the potential function of sirtuin-1 in regulating angiostrongyliasis meningoencephalitis in resveratrol-treated mice. Mice were subjected to meningoencephalitis to study the protective effect of resveratrol against meningoencephalitis and investigate the effects of sirtuin-1 activation on brain. Results demonstrated that sirtuin-1 level decreased in mice with meningoencephalitis and significantly increased in resveratrol-treated mice. Moreover, resveratrol treatment significantly reduced eosinophil counts, p65, Interferon-γ, interleukin (IL)-5, IL-33, and tumor necrosis factor-α levels, matrix metalloproteinase-9 activity, claudin-5 degradation, and blood-brain barrier permeability. By contrast, the anti-inflammatory factor IL-10 was significantly increased in resveratrol-treated mice. Resveratrol treatment was partially beneficial in controlling the pathological processes of angiostrongyliasis meningoencephalitis. The results demonstrate the neuroprotective and anti-inflammatory effects of resveratrol against Angiostrongylus cantonensis-induced eosinophilic meningoencephalitis in mice. Treatment with sirtuin-1 agonist was given within a therapeutic window after A. cantonensis infection. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Human parasitic meningitis caused by Angiostrongylus cantonensis infection in Taiwan.

    PubMed

    Tsai, Hung-Chin; Chen, Yao-Shen; Yen, Chuan-Min

    2013-06-01

    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 eosinophilic 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.

  16. Human Parasitic Meningitis Caused by Angiostrongylus cantonensis Infection in Taiwan

    PubMed Central

    Chen, Yao-Shen; Yen, Chuan-Min

    2013-01-01

    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. PMID:23901378

  17. Angiostrongylus cantonensis infection in captive Geoffroy's tamarins (Saguinus geoffroyi).

    PubMed

    Kottwitz, Jack J; Perry, Kaylee K; Rose, Heidi H; Hendrix, Charles M

    2014-10-01

    3 Geoffroy's tamarins (Saguinus geoffroyi) in a zoo in east central Alabama developed neurologic signs shortly after a tamarin kept in the same enclosure was found dead. Neurologic abnormalities varied among animals and were progressive. One female tamarin with a head tilt, nystagmus, mild ataxia, and paresis of a thoracic limb had gram-positive cocci present in an ear canal with otitis media and interna suspected. Another female with mild ataxia attributed to previous tail amputation developed seizures, and a male tamarin with tail tip trauma also developed ataxia. The tamarin with suspected otitis received cephalexin and prednisolone, but neurologic signs worsened, and the patient died. Preliminary examination of necropsy samples revealed severe meningoencephalitis in both deceased tamarins. Prednisolone and phenobarbital treatment was initiated for the tamarin with seizures, but rapid neurologic deterioration led to euthanasia. Further histologic examination of the 3 deceased tamarins revealed meningitis and acute perivascular hemorrhage in the meninges. Parasites morphologically consistent with Angiostrongylus (Parastrongylus) cantonensis were present in the lungs of 1 animal and in the meninges of 2. The surviving tamarin received cephalexin for tail tip trauma and prednisolone and albendazole for presumed meningoencephalitis and parasitic infection but had permanent neurologic deficits. To our knowledge, these represent the first cases of A cantonensis infection in Geoffroy's tamarins and the first report of its presence in the United States not associated with a major shipping port. The presence of a mature worm in the lungs of 1 tamarin suggested completion of the parasite life cycle, previously reported only in rats.

  18. Nematodes (Rhabditida: Steinernematidae and Heterorhabditidae)

    USDA-ARS?s Scientific Manuscript database

    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...

  19. Angiostrongylus cantonensis in the vector snails Pomacea canaliculata and Achatina fulica in China: a meta-analysis.

    PubMed

    Song, Langui; Wang, Xiaowen; Yang, Zi; Lv, Zhiyue; Wu, Zhongdao

    2016-03-01

    Angiostrongyliasis is a food-borne parasitic disease induced by the nematode Angiostrongylus cantonensis, and has been recognized as the main cause leading to human eosinophilic meningitis. Humans usually acquire infection by digestion of infected Pomacea canaliculata and Achatina fulica, the most predominant intermediate hosts found in China. This meta-analysis was aimed to assess the prevalence of A. cantonensis infection among these two snails in China in the past 10 years. Data were systematically collected in electronic databases such as PubMed, Web of Science, ScienceDirect, CNKI, SinoMed, VIP, CSCD, and Wanfang from 2005 to 2015. Thirty-eight studies with a total of 41,299 P. canaliculata and 21,138 Ac. fulica were included in the present study. The overall infection rate of A. cantonensis in China was estimated to be 7.6 % (95 % confidential interval (CI) = 0.063 to 0.090) in P. canaliculata and 21.5 % in Ac. fulica (95 % CI = 0.184 to 0.245), respectively. No significant difference was observed in prevalence rates among publication year and sample size for both snails. Also, it was found that the prevalence in Ac. fulica is significantly higher than that in P. canaliculata (odds ratio (OR) = 3.946, 95 % CI = 3.070 to 5.073). The present study reveals that snail infection with A. cantonensis is clearly prevalent in China. Further studies are required to improve strategies for control of infections of snails, particularly those of Ac. fulica, and to detect further factors and conditions such as geographic region, temperatures, and diagnosis method.

  20. Characterisation of the vascular pathology in Sigmodon hispidus (Rodentia: Cricetidae) following experimental infection with Angiostrongylus costaricensis (Nematoda: Metastrongylidae).

    PubMed

    Vasconcelos, Danielle Ingrid Bezerra de; Mota, Ester Maria; Pelajo-Machado, Marcelo

    2017-05-01

    Angiostrongylus costaricensis is a nematode that causes human abdominal angiostrongyliasis, a disease found mainly in Latin American countries and particularly in Brazil and Costa Rica. Its life cycle involves exploitation of both invertebrate and vertebrate hosts. Its natural reservoir is a vertebrate host, the cotton rat Sigmodon hispidus. The adult worms live in the ileo-colic branches of the upper mesenteric artery of S. hispidus, causing periarteritis. However, there is a lack of data on the development of vasculitis in the course of infection. To describe the histopathology of vascular lesions in S. hispidus following infection with A. costaricensis. Twenty-one S. hispidus were euthanised at 30, 50, 90 and 114 days post-infection (dpi), and guts and mesentery (including the cecal artery) were collected. Tissues were fixed in Carson's Millonig formalin, histologically processed for paraffin embedding, sectioned with a rotary microtome, and stained with hematoxylin-eosin, resorcin-fuchsin, Perls, Sirius Red (pH = 10.2), Congo Red, and Azan trichrome for brightfield microscopy analysis. At 30 and 50 dpi, live eggs and larvae were present inside the vasa vasorum of the cecal artery, leading to eosinophil infiltrates throughout the vessel adventitia and promoting centripetal vasculitis with disruption of the elastic layers. Disease severity increased at 90 and 114 dpi, when many worms had died and the intensity of the vascular lesions was greatest, with intimal alterations, thrombus formation, iron accumulation, and atherosclerosis. In addition to abdominal angiostrongyliasis, our data suggest that this model could be very useful for autoimune vasculitis and atherosclerosis studies.

  1. Combined Serological Detection of Circulating Angiostrongylus vasorum Antigen and Parasite-specific Antibodies in Dogs from Hungary.

    PubMed

    Schnyder, Manuela; Schaper, Roland; Lukács, Zoltán; Hornok, Sándor; Farkas, Róbert

    2015-08-01

    The occurrence of the nematode Angiostrongylus vasorum, also known as the French heartworm, is increasingly being reported from various European countries. The adults of this parasite species live in the pulmonary arteries and right cardiac ventricle of wild canids and domestic dogs. Larval stages and eggs in the lungs induce inflammatory verminous pneumonia, causing severe respiratory disease in dogs. Furthermore, haematological and neurological signs and even death may occur. In Hungary, A. vasorum has been identified in red foxes, golden jackals and in two dogs and some slugs. In this first large-scale survey, 1247 sera from pet dogs were collected and tested by an ELISA for the detection of circulating antigen of A. vasorum and by a separate ELISA to detect specific antibodies against the parasite. A total of 1.36% (n = 17, 95 % confidence intervals, CI: 0.80 - 2.17 %) of the animals were positive in both ELISAs, while 1.76 % (n = 22, CI: 1.11 - 2.66 %) of the tested dogs were antigen-positive only and 2.73 % (n = 34, CI: 1.90 - 3.79 %) were positive for specific antibodies only. Regions with antigen- and antibody-positive animals overlapped and were distributed over nearly the whole sampled areas of the country. A considerable number of cases was observed in Budapest and also in the southern part of the country bordering Croatia, while in the most eastern part bordering Ukraine no positive samples were detected. These results confirm the endemic occurrence of A. vasorum in dogs originating from different parts of Hungary and the significant advantages of A. vasorum serology in epidemiological studies.

  2. Gallus gallus domesticus: paratenic host of Angiostrongylus vasorum.

    PubMed

    Mozzer, L R; Lima, W S

    2015-01-15

    Angiostrongylus vasorum, a parasite of the cardiorespiratory system in canids, has a heteroxenous biological cycle in which the intermediate hosts are terrestrial and aquatic mollusks. Generally, canids become infected by ingesting the intermediate host or paratenic hosts, such as amphibians, that contain infective larvae (L3). However, there are no reports of birds as paratenic hosts of A. vasorum. To evaluate the susceptibility and viability of Gallus gallus domesticus as a paratenic host of A. vasorum, 17 Cobb chickens were randomly divided into two groups. The animals in group A were inoculated with third stage larvae of A. vasorum, and those in group B ate snails inoculated with A. vasorum L3. At 30 days post-infection, the chickens were killed, and the muscles and organs were placed in a pepsin-HCl solution (1% HCl (37%), 1% pepsin) for 3h in an oven at 40°C to recover the L3. In group A, 1863 L3 were recovered per chicken. In group B, 2585 L3 were recovered. A dog that ingested organs and tissues from a chicken from group A released first-stage larvae of A. vasorum in its feces 51 days after infection; the dynamics of this process were monitored for 107 days, when treatment with 25 mg fenbendazole/kg body weight was performed for 21 days. Chickens nourished with infected snails or with infective L3 may be a source of infection for dogs indicate that G. gallus is a potential paratenic host for this parasite. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Preliminary molecular characterization of the human pathogen Angiostrongylus cantonensis

    PubMed Central

    He, Hualiang; Cheng, Mei; Yang, Xiao; Meng, Jinxiu; He, Ai; Zheng, Xiaoying; Li, Zhuoya; Guo, Pengjuan; Pan, Zhihua; Zhan, Ximei

    2009-01-01

    Background Human angiostrongyliasis is an emerging food-borne public health problem, with the number of cases increasing worldwide, especially in mainland China. Angiostrongylus cantonensis is the causative agent of this severe disease. However, little is known about the genetics and basic biology of A. cantonensis. Results A cDNA library of A. cantonensis fourth-stage larvae was constructed, and ~1,200 clones were sequenced. Bioinformatic analyses revealed 378 cDNA clusters, 54.2% of which matched known genes at a cutoff expectation value of 10-20. Of these 378 unique cDNAs, 168 contained open reading frames encoding proteins containing an average of 238 amino acids. Characterization of the functions of these encoded proteins by Gene Ontology analysis showed enrichment in proteins with binding and catalytic activity. The observed pattern of enzymes involved in protein metabolism, lipid metabolism and glycolysis may reflect the central nervous system habitat of this pathogen. Four proteins were tested for their immunogenicity using enzyme-linked immunosorbent assays and histopathological examinations. The specificity of each of the four proteins was superior to that of crude somatic and excretory/secretory antigens of larvae, although their sensitivity was relatively low. We further showed that mice immunized with recombinant cystatin, a product of one of the four cDNA candidate genes, were partially protected from A. cantonensis infection. Conclusion The data presented here substantially expand the available genetic information about the human pathogen A. cantonensis, and should be a significant resource for angiostrongyliasis researchers. As such, this work serves as a starting point for molecular approaches for diagnosing and controlling human angiostrongyliasis. PMID:19852860

  4. Development-specific differences in the proteomics of Angiostrongylus cantonensis.

    PubMed

    Huang, Hui-Cong; Yao, Li-Li; Song, Zeng-Mei; Li, Xing-Pan; Hua, Qian-Qian; Li, Qiang; Pan, Chang-Wang; Xia, Chao-Ming

    2013-01-01

    Angiostrongyliasis is an emerging communicable disease. Several different hosts are required to complete the life cycle of Angiostrongylus cantonensis. However, we lack a complete understanding of variability of proteins across different developmental stages and their contribution to parasite survival and progression. In this study, we extracted soluble proteins from various stages of the A. cantonensis life cycle [female adults, male adults, the fifth-stage female larvae (FL5), the fifth-stage male larvae (ML5) and third-stage larvae (L3)], separated those proteins using two-dimensional difference gel electrophoresis (2D-DIGE) at pH 4-7, and analyzed the gel images using DeCyder 7.0 software. This proteomic analysis produced a total of 183 different dominant protein spots. Thirty-seven protein spots were found to have high confidence scores (>95%) by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Comparative proteomic analyses revealed that 29 spots represented cytoskeleton-associated proteins and functional proteins. Eight spots were unnamed proteins. Twelve protein spots that were matched to the EST of different-stage larvae of A. cantonensis were identified. Two genes and the internal control 18s were chosen for quantitative real-time PCR (qPCR) and the qPCR results were consistent with those of the DIGE studies. These findings will provide a new basis for understanding the characteristics of growth and development of A. cantonensis and the host-parasite relationship. They may also assist searches for candidate proteins suitable for use in diagnostic assays and as drug targets for the control of eosinophilic meningitis caused by A. cantonensis.

  5. Development of Angiostrongylus costaricensis Morera and Céspedes 1971 (Nematoda: Angiostrongylidae) larvae in the intermediate host Sarasinula marginata (Semper 1885) (Mollusca: Soleolifera).

    PubMed

    Mendonça, Cristiane L G F; Carvalho, Omar S; Mota, Ester M; Lenzi, Henrique L

    2008-04-01

    In life cycle of Angiostrongylus costaricensis, veronicellidae mollusks participate as the invertebrate host while rodents as the main vertebrate host. The current work shows a sequential larval development of A. costaricensis in Sarasinula marginata, individually killed and digested from day 1 to 43, post infection. Some larvae, recovered from sedimentation, were submitted to selective staining after paraffin embedded or inclusion in JB-4 to study inner structures. As control, four slugs were used, two killed at the beginning of infection and the others at the end of the experiment. At day 2 post infection, larvae were motionless and thick, presenting initial retention of granules. At day 4, L2 were detected, persisting until 43 days post infection. Larvae L2 displayed a large amount of granules rich in lipids and carbohydrates through its overall body, with more accumulation at the medial third corresponding to the esophagus-intestine transition site. Lipid granules, the main energetic source, were located at the basal and apical regions of intestinal cells. Both L1 and L3 presented bilateral alae, which is also common in other nematodes. Transition forms between L2 to L3 molts were also observed.

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

    PubMed Central

    Chiu, Ping-Sung; Lai, Shih-Chan

    2013-01-01

    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 IκB and NF-κB was increased in mice with eosinophilic meningoencephalitis. Treatment with MG132 reduced the phosphorylation of NF-κB and the activity of MMP-9, indicating upregulation of MMP-9 through the NF-κB 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. PMID:23505411

  7. Vectors and Spatial Patterns of Angiostrongylus cantonensis in Selected Rice-Farming Villages of Muñoz, Nueva Ecija, Philippines

    PubMed Central

    Tujan, Ma. Angelica A.; Fontanilla, Ian Kendrich C.; Paller, Vachel Gay V.

    2016-01-01

    In the Philippines, rats and snails abound in agricultural areas as pests and source of food for some of the local people which poses risks of parasite transmission to humans such as Angiostrongylus cantonensis. This study was conducted to determine the extent of A. cantonensis infection among rats and snails collected from rice-farming villages of Muñoz, Nueva Ecija. A total of 209 rats, 781 freshwater snails, and 120 terrestrial snails were collected for the study. Heart and lungs of rats and snail tissues were examined and subjected to artificial digestion for parasite collection. Adult worms from rats were identified using SSU rDNA gene. Seven nematode sequences obtained matched A. cantonensis. Results revealed that 31% of the rats examined were positive with A. cantonensis. Rattus norvegicus and R. tanezumi showed prevalence of 46% and 29%, respectively. Furthermore, only Pomacea canaliculata (2%) and Melanoides maculata (1%) were found to be positive for A. cantonensis among the snails collected. Analysis of host distribution showed overlapping habitats of rats and snails as well as residential and agricultural areas indicating risks to public health. This study presents a possible route of human infection for A. cantonensis through handling and consumption of P. canaliculata and M. maculata or crops contaminated by these snails. PMID:27313865

  8. Extraintestinal nematodes of the red fox Vulpes vulpes in north-west Italy.

    PubMed

    Magi, M; Guardone, L; Prati, M C; Mignone, W; Macchioni, F

    2015-07-01

    Extraintestinal nematodes of the red fox (Vulpes vulpes) are a wide group of parasites that infect wild and domestic carnivores and occasionally humans. Nematodes in the cardiopulmonary system, stomach, urinary apparatus and muscle tissue of 165 red foxes (Vulpes vulpes) from north-west Italy (Liguria and Piedmont) were investigated between 2009 and 2012. Of the cardiopulmonary nematodes, a high prevalence of Angiostrongylus vasorum and Eucoleus aerophilus (syn. Capillaria aerophila) was found, 78.2% and 41.8% respectively; Crenosoma vulpis (15.8%) and Filaroides spp. (4.8%) were also found. Spirocerca lupi (23.5%), Aonchotheca putorii (syn. Capillaria putorii) (8.6%) and Physaloptera spp. (2.5%) were detected in the stomach and Pearsonema plica (syn. Capillaria plica) (56.8%) in the bladder. Eucoleus boehmi (syn. Capillaria boehmi) was also detected in the nasal cavities of one of the two foxes examined. A coprological examination revealed eggs of E. aerophilus, A. putorii, S. lupi, Physaloptera spp. and eggs of intestinal parasites. Filarial worms were absent in all the 165 animals examined, nor was there evidence of Trichinella spp. in any of the foxes. The foxes were found to host a high prevalence of many species of extraintestinal nematodes. The prevalence of A. vasorum in foxes found in the present study is among the highest in Europe. In addition, to the best of our knowledge, E. boehmi and Filaroides spp. have never been reported before in this host in Italy.

  9. Predatory activity of the fungi Duddingtonia flagrans, Monacrosporium thaumasium, Monacrosporium sinense and Arthrobotrys robusta on Angiostrongylus vasorum first-stage larvae.

    PubMed

    Braga, F R; Carvalho, R O; Araujo, J M; Silva, A R; Araújo, J V; Lima, W S; Tavela, A O; Ferreira, S R

    2009-12-01

    Angiostrongylus vasorum is a nematode that parasitizes domestic dogs and wild canids. We compared the predatory capacity of isolates from the predatory fungi Duddingtonia flagrans (AC001), Monacrosporium thaumasium (NF34), Monacrosporium sinense (SF53) and Arthrobotrys robusta (I31) on first-stage larvae (L1) of A. vasorum under laboratory conditions. L1 A. vasorum were plated on 2% water-agar (WA) Petri dishes marked into 4 mm diameter fields with the four grown isolates and a control without fungus. Plates of treated groups contained each 1000 L1 A. vasorum and 1000 conidia of the fungal isolates AC001, NF34, SF53 and I31 on 2% WA. Plates of the control group (without fungus) contained only 1000 L1 A. vasorum on 2% WA. Ten random fields (4 mm diameter) were examined per plate of treated and control groups, every 24 h for 7 days. Nematophagous fungi were not observed in the control group during the experiment. There was no variation in the predatory capacity among the tested fungal isolates (P>0.05) during the 7 days of the experiment. There was a significant reduction (P < 0.05) of 80.3%, 74.5%, 74.2% and 71.8% in the means of A. vasorum L1 recovered from treatments with isolates AC001, NF34, SF53 and I31, respectively, compared to the control without fungi. In this study, the four isolates of predatory fungi were efficient in the in vitro capture and destruction of A. vasorum L1, confirming previous work on the efficiency of nematophagous fungi in the control of nematode parasites of dogs and as a possible alternative method of biological control.

  10. Rupture of the thoracic aorta associated with experimental Angiostrongylus vasorum infection in a dog.

    PubMed

    Mozzer, L R; Lima, W S

    2012-05-01

    This note describes the sudden death of a dog by the rupture of the thoracic aorta caused by the presence of Angiostrongylus vasorum. A female mongrel canine with a history of weight loss and exhaustion died two hours after clinical examination. At necropsy, performed one hour after death, showed the presence of clotted blood in the thoracic cavity. Haemothorax was diagnosed. The thoracic aorta wall was thin, congested and an abnormal hole in the wall was detected approximately 0.5 cm from the entrance to the diaphragm. From clotted blood collected from the thoracic cavity, 224 first stage larvae (L1) and 15 adults of Angiostrongylus vasorum were recovered alive. Also, from a blood clot found in the aorta, four adult females and 47 L1 larvae were recovered alive. Possibly, this parasite was responsible for the aortic rupture and death of the animal.

  11. Clinical aspects of eosinophilic meningitis and meningoencephalitis caused by Angiostrongylus cantonensis, the rat lungworm.

    PubMed

    Murphy, Gerald S; Johnson, Stuart

    2013-06-01

    Angiostrongylus Eosinophilic Meningitis is caused by human infection with larvae of the rat lungworm, Angiostrongylus cantonensis. The clinical presentation includes a spectrum of disease, from meningitis through radiculitis, cranial nerve abnormalities, ataxia, encephalitis, coma, and rarely death. The condition is diagnosed by recognizing the triad of: the clinical syndrome, eosinophils in the cerebrospinal fluid or blood, and exposure history. A history of eating raw or poorly cooked snails is classic, but ingestion of other intermediate hosts or unwashed produce (such as lettuce) harboring hosts is not uncommon. Several serologic tests exist but none has yet been fully validated. There is good evidence that a 2 week course of high dose corticosteroids shortens the duration and severity of symptoms. There is somewhat weaker evidence that albendazole reduces symptoms. The combination of prednisolone and albendazole is being used more commonly for treatment. Some suggestions for future research are given.

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

    PubMed Central

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

    2002-01-01

    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 infection in Jamaica, providing evidence that this parasite is likely to cause human cases of eosinophilic meningitis. PMID:11927033

  13. Entomopathogenic nematodes and insect management

    USDA-ARS?s Scientific Manuscript database

    Entomopathogenic nematodes (genera Heterorhabditis, Steinernema, and Neosteinernema) are used as bioinsecticides. The nematodes are ubiquitous and have been isolated in soil of every continent except Antarctica. The nematodes kill insects through a mutualism with a bacterium (Photorhabdus spp. or ...

  14. Respiratory nematodes in cat populations of Italy.

    PubMed

    Di Cesare, Angela; Veronesi, Fabrizia; Grillotti, Eleonora; Manzocchi, Simone; Perrucci, Stefania; Beraldo, Paola; Cazzin, Stefania; De Liberato, Claudio; Barros, Luciano A; Simonato, Giulia; Traversa, Donato

    2015-12-01

    The occurrence of common respiratory parasites of domestic cats (the metastrongyloid "cat lungworm" Aelurostrongylus abstrusus and the trichuroid Capillaria aerophila) and of neglected respiratory nematodes of felids (Troglostrongylus brevior, Angiostrongylus chabaudi and Oslerus rostratus) was here evaluated in two and three geographical sites of Northern and Central Italy, respectively. In 2014-2015, individual fecal samples of 868 domestic cats were examined microscopically and genetically, and epidemiological data related to parasitic infections were evaluated as possible risk factors by binary logistic regression models. The most common parasite was A. abstrusus in both mono- and poli-specific infections, followed by T. brevior and C. aerophila, while cats scored negative for other parasites. Cats positive for A. abstrusus (1.9-17 % infection rate) and C. aerophila (0.9-4.8 % infection rate) were found in all examined sites, while cats scored positive for T. brevior (1-14.3 % infection rate) in four sites. Also, T. brevior was here found for the first time in a domestic cat from a mountainous area of Northern Italy. The occurrence of lungworms was statistically related to the presence of respiratory signs and more significant in cats with mixed infection by other lungworms and/or intestinal parasites. Cats living in site C of Central Italy resulted statistically more at risk of infection for lungworms than cats living in the other study sites, while animals ageing less than 1 year were at more risk for troglostrongylosis. Finally, the presence of lungworms was more significant in cats with mixed infection by other lungworms and/or intestinal parasites. These results are discussed under epidemiological and clinical points of views.

  15. Comparative pathogenesis of eosinophilic meningitis caused by Angiostrongylus mackerrasae and Angiostrongylus cantonensis in murine and guinea pig models of human infection.

    PubMed

    Aghazadeh, Mahdis; Harvie, Marina C; Owen, Helen C; Veríssimo, Carolina; Aland, Kieran V; Reid, Simon A; Traub, Rebecca J; McMANUS, Donald P; McCARTHY, James S; Jones, Malcolm K

    2016-09-01

    This study investigated comparatively the pathogenicity of experimental infection of mice and guinea pigs, with Angiostrongylus mackerrasae and the closely related species A. cantonensis. Time course analyses showed that A. mackerrasae causes eosinophilic meningitis in these hosts, which suggests that the species has the potential to cause meningitis in humans and domestic animals. Both A. mackerrasae and the genetically similar A. cantonensis caused eosinophilic meningitis in mice at two time points of 14 and 21 days post infection (dpi). The brain lesions in mice infected with A. mackerrasae were more granulomatous in nature and the parasites were more likely to appear degenerate compared with lesions caused by A. cantonensis. This may indicate that the mouse immune system eliminates A. mackerrasae infection more effectively. The immunologic responses of mice infected with the two Angiostrongylus species was compared by assessing ex vivo stimulated spleen derived T cells and cytokines including interferon-gamma, interleukin 4 and interleukin 17 on 14 and 21 dpi. The results were similar for mice infected with A. cantonensis and A. mackerrasae. Serum from the infected animals with either A. cantonensis or A. mackerrasae recognized total soluble antigen of A. cantonensis female worms on Western blot.

  16. Permissibility of Mongolian gerbil for Angiostrongylus cantonensis infection and utility of this animal model for anthelmintic studies.

    PubMed

    Wei, Yongfang; Hong, Qing; Chen, Daixiong; Liang, Chenjie; Liu, Haiying; Luo, Xiaodong; Zhu, Xunmin

    2014-05-01

    The Mongolian gerbil (Meriones unguiculatus) has been indicated to be a useful experimental model host for studying nematode. To understand the possibility of the Mongolian gerbil as an animal model of Angiostrongylus cantonensis infection, we investigated the development, migration, and tissue distribution of A. cantonensis and pathological changes in the brain and lungs of the infected Mongolian gerbils. The first stage larvae of A. cantonensis in the stool of the infected gerbils were examined by direct smear method at 45th day postinfection (PI). In addition, a group of the infected gerbils were orally fed with albendazole (100 mg/kg/day/gerbil) at the 8th day PI and continued for 3 consecutive days. The results showed that mortality rate of Mongolian gerbils infected with 10 third stage larvae of A. cantonensis was about 62% at the 30th day PI; the peak period of death was from the 23rd to 30th day PI. About 93% (27/29) of the worms in survivors of infected gerbils could develop to complete sexual maturity at the 46th day PI, and the examinations of 12 gerbils in G3 group revealed that first stage larvae of A. cantonensis could be found in the feces of 4 gerbils at the 45th day PI. About 80% of the worms were in the brain of infected gerbils and 20% in the lungs from the 23rd to 25th day PI; during migration of the worms from the brain to lungs, more than 90% of the worms arrived to the lungs and less than 10% of them still stayed in the brain during from the 45th to 46th day PI. Pathological examination revealed that injuries induced by A. cantonensis in infected gerbils were characterized by eosinophilic meningitis and granulomatous pneumonia. Otherwise, albendazole exhibited a good larvicidal activity in the infected Mongolian gerbils. In contrast with infected control group, no gerbils died in administering albendazole, no worms were recovered, and no nervous system symptoms caused by the infection occurred at the 26th day PI. These findings clearly

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

    PubMed Central

    2010-01-01

    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. PMID:20653938

  18. The Nematode Caenorhabditis Elegans.

    ERIC Educational Resources Information Center

    Kenyon, Cynthia

    1988-01-01

    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)

  19. Nematode nervous systems.

    PubMed

    Schafer, William

    2016-10-24

    Nematodes comprise one of the largest phyla in the animal kingdom, both in terms of individual numbers and species diversity. Although only 20,000-30,000 species have been described, it is estimated that the true number ranges between 100,000 and 10 million. Marine, freshwater, and terrestrial species are all widespread, and some nematodes have even been isolated from such inhospitable environments as deserts, hot springs, and polar seas. Some nematode species are parasitic, with either plant or animal hosts; other species are free-living microbivores, scavengers, or predators of insects or other nematodes. Nematodes vary widely in size, from small microbivores that grow no larger than 100 μm to large animal parasites growing to several meters in length. They adopt a variety of reproductive strategies: most species are gonochoristic (i.e., have male and female sexes), but self-fertile hermaphroditic species are not uncommon, and parthenogenetic species are also known. Nematodes belong to the superphylum Ecdysozoa, a clade of moulting animals that also includes arthropods, tardigrades and priapulids. Although nematode fossils are rare, the origin of the nematode phylum is believed to be very ancient, with the divergence from arthropods estimated based on molecular data to have been between 900 and 1,300 Ma.

  20. The Nematode Caenorhabditis Elegans.

    ERIC Educational Resources Information Center

    Kenyon, Cynthia

    1988-01-01

    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)

  1. Nematode-Trapping Fungi.

    PubMed

    Jiang, Xiangzhi; Xiang, Meichun; Liu, Xingzhong

    2017-01-01

    Nematode-trapping fungi are a unique and intriguing group of carnivorous microorganisms that can trap and digest nematodes by means of specialized trapping structures. They can develop diverse trapping devices, such as adhesive hyphae, adhesive knobs, adhesive networks, constricting rings, and nonconstricting rings. Nematode-trapping fungi have been found in all regions of the world, from the tropics to Antarctica, from terrestrial to aquatic ecosystems. They play an important ecological role in regulating nematode dynamics in soil. Molecular phylogenetic studies have shown that the majority of nematode-trapping fungi belong to a monophyletic group in the order Orbiliales (Ascomycota). Nematode-trapping fungi serve as an excellent model system for understanding fungal evolution and interaction between fungi and nematodes. With the development of molecular techniques and genome sequencing, their evolutionary origins and divergence, and the mechanisms underlying fungus-nematode interactions have been well studied. In recent decades, an increasing concern about the environmental hazards of using chemical nematicides has led to the application of these biological control agents as a rapidly developing component of crop protection.

  2. New host, geographic records, and histopathologic studies of Angiostrongylus spp (Nematoda: Angiostrongylidae) in rodents from Argentina with updated summary of records from rodent hosts and host specificity assessment.

    PubMed

    Robles, María del Rosario; Kinsella, John M; Galliari, Carlos; Navone, Graciela T

    2016-03-01

    To date, 21 species of the genus Angiostrongylus (Nematoda: Angiostrongylidae) have been reported around the world, 15 of which are parasites of rodents. In this study, new host, geographic records, and histopathologic studies of Angiostrongylus spp in sigmodontine rodents from Argentina, with an updated summary of records from rodent hosts and host specificity assessment, are provided. Records of Angiostrongylus costaricensis from Akodon montensis and Angiostrongylus morerai from six new hosts and geographical localities in Argentina are reported. The gross and histopathologic changes in the lungs of the host species due to angiostrongylosis are described. Published records of the genus Angiostrongylus from rodents and patterns of host specificity are presented. Individual Angiostrongylus species parasitise between one-19 different host species. The most frequent values of the specificity index (STD) were between 1-5.97. The elevated number of host species (n = 7) of A. morerai with a STD = 1.86 is a reflection of multiple systematic studies of parasites from sigmodontine rodents in the area of Cuenca del Plata, Argentina, showing that an increase in sampling effort can result in new findings. The combination of low host specificity and a wide geographic distribution of Angiostrongylus spp indicates a troubling epidemiological scenario although, as yet, no human cases have been reported.

  3. Reibergram of Intrathecal Synthesis of C4 in Patients with Eosinophilic Meningitis Caused by Angiostrongylus cantonensis

    PubMed Central

    Padilla-Docal, Bárbara; Dorta-Contreras, Alberto Juan; Bu-Coifiu-Fanego, Raisa; Rodríguez-Rey, Alexis; Gutiérrez-Hernández, Juan Carlos; de Paula-Almeida, Susana Olga

    2010-01-01

    Angiostrongylus cantonensis produces eosinophilic meningitis in humans and is endemic in Thailand, Taiwan, China, and the Caribbean region. During infection with this parasite, it is important to know if the complement system may be activated by the classical or lectin pathway. Cerebrospinal fluid and serum samples from 20 patients with meningitic angiostrongyliasis were used to quantify C4 levels and albumin. Results were plotted on a C4 CSF/serum quotient diagram or Reibergram. Twelve patients showed intrathecal synthesis of C4. Antibody-dependent complement cytotoxicity should be considered as a possible mechanism that destroys third-stage larvae of this helminth in cerebrospinal fluid of affected patients. PMID:20519605

  4. Sacral myeloradiculitis (Elsberg syndrome) secondary to eosinophilic meningitis caused by Angiostrongylus cantonensis

    PubMed Central

    Hsu, Jui-Jen; Chuang, Shin-Hung; Chen, Chia-Hsin; Huang, Mao-Hsiung

    2009-01-01

    Elsberg syndrome secondary to eosinophilic meningitis caused by Angiostrongylus cantonensis is uncommon. Clinicians should consider a wide differential diagnosis including tumour, spinal cord infarction, necrosis, vasculitis, drug induced or other sources of infection. In addition, acute urinary retention is a urological emergency and clinicians should keep in mind the prevention of bladder overdistension. The intervention of rehabilitation programmes and clean intermittent catheterisation education for bladder management, in accordance with the patient’s condition, is also important. Earlier rehabilitation is important to ensure a speedy recovery and to prevent further complications. PMID:21811516

  5. Entomopathogenic nematode application technology

    USDA-ARS?s Scientific Manuscript database

    Biocontrol success when using entomopathogenic nematodes (EPNs) in the genera Heterorhabditis and Steinernema relies on a variety of factors including components of the application event itself. Successful application encompasses both abiotic and biotic influences. For example, adverse array of equi...

  6. Formulation of Nematodes.

    PubMed

    Peters, Arne

    2016-01-01

    The enduring stages of entomopathogenic nematodes of the genera Steinernema and Heterorhabditis are infective juveniles, which require a high humidity and sufficient ventilation for survival. Formulations must account for these requirements. Nematodes may be formulated inside the insects in which they reproduced or they need to be cleaned and mixed with a suitable binder to maintain humidity but allowing for gas exchange. Another method for formulation is the encapsulation in beads of Ca-alginate. Generic procedures for these formulation techniques are described.

  7. Differences in microglia activation between rats-derived cell and mice-derived cell after stimulating by soluble antigen of IV larva from Angiostrongylus cantonensis in vitro.

    PubMed

    Wei, Jie; Wu, Feng; Sun, Xi; Zeng, Xin; Liang, Jin-Yi; Zheng, Huan-Qin; Yu, Xin-Bing; Zhang, Kou-Xing; Wu, Zhong-Dao

    2013-01-01

    Angiostrongylus cantonensis is a rodent nematode. Adult worms of A. cantonensis live in the pulmonary arteries of rats. Humans and mice are accidental hosts or named nonpermissive hosts. The larva cannot develop into an adult worm and only causes serious eosinophilic meningitis or meningoencephalitis if humans or mice eat food containing larva of A. cantonensis in the third stage. The differing consequences largely depend on differing immune responses of the host to parasite during A. cantonensis invasion and development. Microglia is considered to be the key immune cell in the central nervous system like macrophage. To further understand the reasons for why mice and rats attain different outcomes in A. cantonensis infection, we set up the method to isolate and culture newborn rats' primary microglia and observe the activation of the microglia cells, comparing with mice microglia cell line N9. We treated cells with soluble antigen of the fourth larva of A. cantonensis (L4 larva) and measured mRNA levels of IL-1β, IL-5, IL-6, IL-13, eotaxin, iNOS, and TNF-α by real-time PCR. The results showed that N9 expressed high mRNA level of IL-6, IL-1β, TNF-α, iNOS, IL-5, IL-13, and eotaxin, but primary microglia only had IL-5, IL-13, and eotaxin mRNA level. It implies that microglia from rats and mice had different reaction to soluble antigen of A. cantonensis. Therefore, we supposed that microglia may play an immune modulation role during the brain inflammation induced by A. cantonensis.

  8. Detection of Angiostrongylus cantonensis in the Blood and Peripheral Tissues of Wild Hawaiian Rats (Rattus rattus) by a Quantitative PCR (qPCR) Assay

    PubMed Central

    2015-01-01

    The nematode Angiostrongylus cantonensis is a rat lungworm, a zoonotic pathogen that causes human eosinophilic meningitis and ocular angiostrongyliasis characteristic of rat lungworm (RLW) disease. Definitive diagnosis is made by finding and identifying A. cantonensis larvae in the cerebral spinal fluid or by using a custom immunological or molecular test. This study was conducted to determine if genomic DNA from A. cantonensis is detectable by qPCR in the blood or tissues of experimentally infected rats. F1 offspring from wild rats were subjected to experimental infection with RLW larvae isolated from slugs, then blood or tissue samples were collected over multiple time points. Blood samples were collected from 21 rats throughout the course of two trials (15 rats in Trial I, and 6 rats in Trial II). In addition to a control group, each trial had two treatment groups: the rats in the low dose (LD) group were infected by approximately 10 larvae and the rats in the high dose (HD) group were infected with approximately 50 larvae. In Trial I, parasite DNA was detected in cardiac bleed samples from five of five LD rats and five of five HD rats at six weeks post-infection (PI), and three of five LD rats and five of five HD rats from tail tissue. In Trial II, parasite DNA was detected in peripheral blood samples from one of two HD rats at 53 minutes PI, one of two LD rats at 1.5 hours PI, one of two HD rats at 18 hours PI, one of two LD rats at five weeks PI and two of two at six weeks PI, and two of two HD rats at weeks five and six PI. These data demonstrate that parasite DNA can be detected in peripheral blood at various time points throughout RLW infection in rats. PMID:25910229

  9. Severe eosinophilic meningitis owing to Angiostrongylus cantonensis in young Jamaican children: case report and literature review.

    PubMed

    Evans-Gilbert, Tracy; Lindo, John F; Henry, Sonia; Brown, Paul; Christie, Celia D C

    2014-05-01

    Eosinophilic meningitis caused by Angiostrongylus cantonensis is an endemic and emerging disease that affects adults and children in Jamaica. Most cases resolve without sequelae, but young children are at high risk of neurological damage and death. Treatment with corticosteroids and albendazole is considered safe for adults and children, but protocols for its use in children have not been established. A 19-month-old infant with permanent neurological sequlae caused by Angiostrongylus cantonensis meningitis is reported, and five other Jamaican cases are summarized. A review of the literature of children with permanent neurological sequlae and death is presented. Children <5 years (especially <2) were at increased risk of incomplete recovery and death if they presented with bulbar signs, flaccid paresis and coma. None of the severe or fatal cases received early intervention with anthelminthics, and disease progression was not altered with corticosteroids. In view of the pathophysiology, necropsy reports and animal studies, it seems that the early use of larvicidals may change the course of severe presentations.

  10. PHYLOGENY OF ANGIOSTRONGYLUS CANTONENSIS IN THAILAND BASED ON CYTOCHROME C OXIDASE SUBUNIT I GENE SEQUENCE.

    PubMed

    Apichat, Vitta; Narongrit, Srisongcram; Jittranuch, Thiproaj; Anucha, Wongma; Wilaiwan, Polsut; Chamaiporn, Fukruksa; Thatcha, Yimthin; Bandid, Mangkit; Aunchalee, Thanwisai; Paron, Dekumyoy

    2016-05-01

    Angiostrongylus cantonensis is an emerging infectious agent causing eosinophilic meningitis or meningoencephalitis in humans with clinical manifestation of severe headache. Molecular genetic studies on classification and phylogeny of A. cantonensis in Thailand are limited. This study surveyed A. cantonensis larvae prevalence in natural intermediate hosts across Thailand and analyzed their phylogenetic relationships. A total of 14,032 freshwater and land snails were collected from 19 provinces of Thailand. None of Filopaludina sp, Pomacea sp, and Cyclophorus sp were infected with Angiostrongylus larvae, whereas Achatina fulica, Cryptozona siamensis, and Megaustenia siamensis collected from Kalasin, Kamphaeng Phet, Phetchabun, Phitsanulok, and Tak Provinces were infected, with C. siamensis being the common intermediate host. Based on morphology, larvae isolated from 11 samples of these naturally infected snails preliminarily were identified as A. cantonensis. Comparison of partial nucleotide sequences of cytochrome c oxidase subunit I gene revealed that four sequences are identical to A. cantonensis haplotype ac4 from Bangkok and the other seven to that of A. cantonensis isolate AC Thai, indicating two independent lineages of A. cantonensis in Thailand.

  11. New host, geographic records, and histopathologic studies of Angiostrongylus spp (Nematoda: Angiostrongylidae) in rodents from Argentina with updated summary of records from rodent hosts and host specificity assessment

    PubMed Central

    Robles, María del Rosario; Kinsella, John M; Galliari, Carlos; Navone, Graciela T

    2016-01-01

    To date, 21 species of the genus Angiostrongylus (Nematoda: Angiostrongylidae) have been reported around the world, 15 of which are parasites of rodents. In this study, new host, geographic records, and histopathologic studies of Angiostrongylus spp in sigmodontine rodents from Argentina, with an updated summary of records from rodent hosts and host specificity assessment, are provided. Records of Angiostrongylus costaricensis from Akodon montensis andAngiostrongylus morerai from six new hosts and geographical localities in Argentina are reported. The gross and histopathologic changes in the lungs of the host species due to angiostrongylosis are described. Published records of the genus Angiostrongylus from rodents and patterns of host specificity are presented. Individual Angiostrongylusspecies parasitise between one-19 different host species. The most frequent values of the specificity index (STD) were between 1-5.97. The elevated number of host species (n = 7) of A. morerai with a STD = 1.86 is a reflection of multiple systematic studies of parasites from sigmodontine rodents in the area of Cuenca del Plata, Argentina, showing that an increase in sampling effort can result in new findings. The combination of low host specificity and a wide geographic distribution of Angiostrongylus spp indicates a troubling epidemiological scenario although, as yet, no human cases have been reported. PMID:26982178

  12. Roles of Steroids in Nematodes

    USDA-ARS?s Scientific Manuscript database

    The inability of nematodes to biosynthesize steroids de novo and the resulting dependence of parasitic nematodes upon their hosts have enhanced the importance of elucidating the metabolism of sterols and the hormonal and other functions of steroids in nematodes. Biochemical research has revealed th...

  13. Nematode-borne plant viruses

    USDA-ARS?s Scientific Manuscript database

    There are 30 plant-parasitic nematode species that are known to transmit 14 plant viruses. Nematode-transmitted viruses affect a range of agriculturally important crops including grape, cherry, potato, and tomato. The nematodes that transmit viruses are found in two families, Longidoridae and Tric...

  14. Nematode cholinergic pharmacology

    SciTech Connect

    Segerberg, M.A.

    1989-01-01

    Nematode acetylcholine (ACh) receptors were characterized using both biochemical and electrophysiological techniques, including: (1) receptor binding studies in crude homogenates of the free-living nematode Caenorhabditis elegans and the parasitic nematode Ascaris lumbricoides with the high-affinity probe ({sup 3}H)N-methylscopolamine (({sup 3}H)NMS) which binds to muscarinic receptors in many vertebrate and invertebrate tissues (2) measurement of depolarization and contraction induced by a variety of cholinergic agents, including N-methylscopolamine (NMS), in an innervated dorsal muscle strip preparation of Ascaris; (3) examination of the antagonistic actions of d-tubocurarine (dTC) and NMS at dorsal neuromuscular junction; (4) measurement of input resistance changes in Ascaris commissural motorneurons induced by ACh, dTC, NMS, pilocarpine and other cholinergic drugs.

  15. Comparative genomics of nematodes.

    PubMed

    Mitreva, Makedonka; Blaxter, Mark L; Bird, David M; McCarter, James P

    2005-10-01

    Recent transcriptome and genome projects have dramatically expanded the biological data available across the phylum Nematoda. Here we summarize analyses of these sequences, which have revealed multiple unexpected results. Despite a uniform body plan, nematodes are more diverse at the molecular level than was previously recognized, with many species- and group-specific novel genes. In the genus Caenorhabditis, changes in chromosome arrangement, particularly local inversions, are also rapid, with breakpoints occurring at 50-fold the rate in vertebrates. Tylenchid plant parasitic nematode genomes contain several genes closely related to genes in bacteria, implicating horizontal gene transfer events in the origins of plant parasitism. Functional genomics techniques are also moving from Caenorhabditis elegans to application throughout the phylum. Soon, eight more draft nematode genome sequences will be available. This unique resource will underpin both molecular understanding of these most abundant metazoan organisms and aid in the examination of the dynamics of genome evolution in animals.

  16. Signaling between nematodes and plants.

    PubMed

    Bird, David McK

    2004-08-01

    After hatching in the soil, root-knot nematodes must locate and penetrate a root, migrate into the vascular cylinder, and establish a permanent feeding site. Presumably, these events are accompanied by extensive signaling between the nematode parasite and the host. Hence, much emphasis has been placed on identifying proteins that are secreted by the nematode during the migratory phase. Further progress in understanding the signaling events has been made recently by studying the host response. Striking parallels can be drawn between the nematode-plant interaction and plant symbioses with other microorganisms, and evidence is emerging to suggest that nematodes acquired components of their parasitic armory from those microbes.

  17. Development of Lateral Flow Immunoassay for Antigen Detection in Human Angiostrongylus cantonensis Infection.

    PubMed

    Chen, Mu-Xin; Chen, Jia-Xu; Chen, Shao-Hong; Huang, Da-Na; Ai, Lin; Zhang, Ren-Li

    2016-06-01

    Angiostrongyliasis is difficult to be diagnosed for the reason that no ideal method can be used. Serologic tests require specific equipment and are not always available in poverty-stricken zone and are time-consuming. A lateral flow immunoassay (LFIA) may be useful for angiostrongyliasis control. We established a LFIA for the diagnosis of angiostrongyliasis based on 2 monoclonal antibodies (mAbs) against antigens of Angiostrongylus cantonensis adults. The sensitivity and specificity were 91.1% and 100% in LFIA, while those of commercial ELISA kit was 97.8% and 86.3%, respectively. Youden index was 0.91 in LFIA and 0.84 in commercial ELISA kit. LFIA showed detection limit of 1 ng/ml of A. cantonensis ES antigens. This LFIA was simple, rapid, highly sensitive and specific, which opened an alternative approach for the diagnosis of human angiostrongyliasis.

  18. Development of Lateral Flow Immunoassay for Antigen Detection in Human Angiostrongylus cantonensis Infection

    PubMed Central

    Chen, Mu-Xin; Chen, Jia-Xu; Chen, Shao-Hong; Huang, Da-Na; Ai, Lin; Zhang, Ren-Li

    2016-01-01

    Angiostrongyliasis is difficult to be diagnosed for the reason that no ideal method can be used. Serologic tests require specific equipment and are not always available in poverty-stricken zone and are time-consuming. A lateral flow immunoassay (LFIA) may be useful for angiostrongyliasis control. We established a LFIA for the diagnosis of angiostrongyliasis based on 2 monoclonal antibodies (mAbs) against antigens of Angiostrongylus cantonensis adults. The sensitivity and specificity were 91.1% and 100% in LFIA, while those of commercial ELISA kit was 97.8% and 86.3%, respectively. Youden index was 0.91 in LFIA and 0.84 in commercial ELISA kit. LFIA showed detection limit of 1 ng/ml of A. cantonensis ES antigens. This LFIA was simple, rapid, highly sensitive and specific, which opened an alternative approach for the diagnosis of human angiostrongyliasis. PMID:27417097

  19. How nematode sperm crawl.

    PubMed

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

    2002-01-15

    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 Ascaris system provides a simple 'stripped down' version of a crawling cell in which to examine the basic mechanism of cell locomotion independently of other cellular functions that involve the cytoskeleton. Here we present a mechanochemical analysis of crawling in Ascaris sperm. We construct a finite element model wherein (a) localized filament polymerization and bundling generate the force for lamellipodial extension and (b) energy stored in the gel formed from the filament bundles at the leading edge is subsequently used to produce the contraction that pulls the rear of the cell forward. The model reproduces the major features of crawling sperm and provides a framework in which amoeboid cell motility can be analyzed. Although the model refers primarily to the locomotion of nematode sperm, it has important implications for the mechanics of actin-based cell motility.

  20. Nematode management in pecans

    USDA-ARS?s Scientific Manuscript database

    In 2002, the pecan root-knot nematode (Meloidogyne partityla = PRKN) was found on pecan in the southeastern U.S. and was associated with stressed trees exhibiting dead branches in the upper canopy and (or) typical mouse ear (ME) associated foliar symptoms. This research evaluates the host susceptib...

  1. [Trophic types of the nematodes].

    PubMed

    Kornobis, Franciszek Wojciech

    2008-01-01

    The aim of the article is to present trophic types (i.e non-systematic groups feeding on the same kind of food) of the nematodes. Seven trophic types (covering all known species) are described: (1) microbivores (nematodes feeding on unicellular microorganisms) with two examples: C. elegans and the nematodes of two families: Steinernematidae and Heterorhabditidae, (2) parasites of Vertebrates, (3) parasites of Invertebrates with example of the family Acugutturidae, (4) parasites of plants with two examples: Tylenchorhynchus dubius and Heterodera schachtii, (5) parasites of fungi, (6) predatory nematodes, (7) omnivores (nematodes feeding on different kinds of food). Basic information on the anatomy of the alimentary canal and feeding behaviour of the nematodes are also provided.

  2. Soil Nematodes in Terrestrial Ecosystems

    PubMed Central

    Yeates, G. W.

    1979-01-01

    There has been much work on plant-feeding nematodes, and less on other soil nematodes, their distribution, abundance, intrinsic properties, and interactions with biotic and abiotic factors. Seasonal variation in nematode fauna as a whole is correlated with factors such as moisture, temperature, and plant growth; at each site nematode distribution generally reflects root distribution. There is a positive correlation between average nematode abundance and primary production as controlled by moisture, temperature, nutrients, etc. Soil nematodes, whether bacterial feeders, fungivores, plant feeders, omnivores, or predators, all influence the populations of the organisms they feed on. Although soil trematodes probably contribute less than 1% to soil respiration they may play an important role in nutrient cycling in the soil through their influence on bacterial growth and plant nutrient availability. PMID:19300638

  3. RNAi from plants to nematodes.

    PubMed

    Gheysen, Godelieve; Vanholme, Bartel

    2007-03-01

    Coincident with the award of the Nobel Prize for Medicine in 2006 to Fire and Mello for their discovery of RNAi, plant scientists have succeeded in using RNAi-based techniques to control nematodes, a hitherto unmanageable plant parasite. Recent work has demonstrated that the expression in a host plant of double-stranded RNA targeting housekeeping or parasitism genes in the root-knot nematode resulted in resistance to nematode infection.

  4. Toward 959 nematode genomes

    PubMed Central

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

    2012-01-01

    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

  5. Intestinal nematodes: biology and control.

    PubMed

    Epe, Christian

    2009-11-01

    A variety of nematodes occur in dogs and cats. Several nematode species inhabit the small and large intestines. Important species that live in the small intestine are roundworms of the genus Toxocara (T canis, T cati) and Toxascaris (ie, T leonina), and hookworms of the genus Ancylostoma (A caninum, A braziliense, A tubaeforme) or Uncinaria (U stenocephala). Parasites of the large intestine are nematodes of the genus Trichuris (ie, whipworms, T vulpis). After a comprehensive description of their life cycle and biology, which are indispensable for understanding and justifying their control, current recommendations for nematode control are presented and discussed thereafter.

  6. New frontiers in nematode ecology.

    PubMed

    Ferris, H

    1993-09-01

    Future areas of emphasis for research and scholarship in nematode ecology are indicated by pressing agricultural and environmental issues, by new directions in applied nematology, and by current technological advances. Studies in nematode ecology must extend beyond observation, counting, and simple statistical analysis. Experimentation and the testing of hypotheses are needed for understanding the biological mechanisms of ecological systems. Opportunities for fruitful experimentation in nematode ecology are emerging at the ecosystem, community, population, and individual levels. Nematode ecologists will best promote their field of study by closely monitoring and participating in the advances, initiatives, developments, and directions in the larger field of ecology.

  7. New Frontiers in Nematode Ecology

    PubMed Central

    Ferris, Howard

    1993-01-01

    Future areas of emphasis for research and scholarship in nematode ecology are indicated by pressing agricultural and environmental issues, by new directions in applied nematology, and by current technological advances. Studies in nematode ecology must extend beyond observation, counting, and simple statistical analysis. Experimentation and the testing of hypotheses are needed for understanding the biological mechanisms of ecological systems. Opportunities for fruitful experimentation in nematode ecology are emerging at the ecosystem, community, population, and individual levels. Nematode ecologists will best promote their field of study by closely monitoring and participating in the advances, initiatives, developments, and directions in the larger field of ecology. PMID:19279783

  8. Distribution of Angiostrongylus vasorum and its gastropod intermediate hosts along the rural-urban gradient in two cities in the United Kingdom, using real time PCR.

    PubMed

    Aziz, Nor Azlina A; Daly, Elizabeth; Allen, Simon; Rowson, Ben; Greig, Carolyn; Forman, Dan; Morgan, Eric R

    2016-02-02

    Angiostrongylus vasorum is a highly pathogenic metastrongylid nematode affecting dogs, which uses gastropod molluscs as intermediate hosts. The geographical distribution of the parasite appears to be heterogeneous or patchy and understanding of the factors underlying this heterogeneity is limited. In this study, we compared the species of gastropod present and the prevalence of A. vasorum along a rural-urban gradient in two cities in the south-west United Kingdom. The study was conducted in Swansea in south Wales (a known endemic hotspot for A. vasorum) and Bristol in south-west England (where reported cases are rare). In each location, slugs were sampled from nine sites across three broad habitat types (urban, suburban and rural). A total of 180 slugs were collected in Swansea in autumn 2012 and 338 in Bristol in summer 2014. A 10 mg sample of foot tissue was tested for the presence of A. vasorum by amplification of the second internal transcribed spacer (ITS-2) using a previously validated real-time PCR assay. There was a significant difference in the prevalence of A. vasorum in slugs between cities: 29.4% in Swansea and 0.3% in Bristol. In Swansea, prevalence was higher in suburban than in rural and urban areas. Comparing the sampled slug fauna, Arion rufus was found in greater numbers in Swansea than Bristol, and was commonly infected (prevalence 41%). This, alongside the timing of slug collections in summer rather than autumn, could explain low infection prevalence in the Bristol sample. In the absence of Ar. rufus as a preferred host for A. vasorum, Ar. flagellus and Limacus maculatus appear to act as versatile hosts that are present in suburban and urban areas in Swansea (prevalence in Ar. flagellus 33%; in L. maculatus 44%) and in Bristol (prevalence in Ar. flagellus 0.9%). These slug species might provide A. vasorum with an alternative vehicle to reach the final host, when the main host Ar. rufus is scarce or absent. We conclude that the composition of the

  9. Bacteria can mobilize nematode-trapping fungi to kill nematodes.

    PubMed

    Wang, Xin; Li, Guo-Hong; Zou, Cheng-Gang; Ji, Xing-Lai; Liu, Tong; Zhao, Pei-Ji; Liang, Lian-Ming; Xu, Jian-Ping; An, Zhi-Qiang; Zheng, Xi; Qin, Yue-Ke; Tian, Meng-Qing; Xu, You-Yao; Ma, Yi-Cheng; Yu, Ze-Fen; Huang, Xiao-Wei; Liu, Shu-Qun; Niu, Xue-Mei; Yang, Jin-Kui; Huang, Ying; Zhang, Ke-Qin

    2014-12-16

    In their natural habitat, bacteria are consumed by bacterivorous nematodes; however, they are not simply passive preys. Here we report a defensive mechanism used by certain bacteria to mobilize nematode-trapping fungi to kill nematodes. These bacteria release urea, which triggers a lifestyle switch in the fungus Arthrobotrys oligospora from saprophytic to nematode-predatory form; this predacious form is characterized by formation of specialized cellular structures or 'traps'. The bacteria significantly promote the elimination of nematodes by A. oligospora. Disruption of genes involved in urea transport and metabolism in A. oligospora abolishes the urea-induced trap formation. Furthermore, the urea metabolite ammonia functions as a signal molecule in the fungus to initiate the lifestyle switch to form trap structures. Our findings highlight the importance of multiple predator-prey interactions in prey defense mechanisms.

  10. Managing Nematodes without Methyl Bromide

    USDA-ARS?s Scientific Manuscript database

    Methyl bromide is an effective pre-plant soil fumigant used to control nematodes in many high-input, high-value production systems including vegetables, nurseries, ornamentals, tree fruits, strawberries, and grapes. Because methyl bromide has provided a reliable return on investment for nematode c...

  11. Social networks of educated nematodes

    USDA-ARS?s Scientific Manuscript database

    Entomopathogenic nematodes are obligate lethal parasitoids of insect larvae that navigate a chemically complex belowground environment while interacting with their insect hosts, plants, and each other. In this environment, prior exposure to volatile compounds appears to prime nematodes in a compound...

  12. Angiostrongylus vasorum in Great Britain: a nationwide postal questionnaire survey of veterinary practices.

    PubMed

    Kirk, L; Limon, G; Guitian, F J; Hermosilla, C; Fox, M T

    2014-08-02

    The lungworm, Angiostrongylus vasorum, was first reported in indigenous dogs in southwestern England in 1980 and has since been recorded in Wales, southeastern England and, more recently, in the West Midlands, northern England and Scotland. The nationwide distribution of the parasite was evaluated using a postal questionnaire sent to 3950 small animal practices during 2009. Information was sought on the location of each practice, awareness of the parasite locally, number of cases diagnosed over the past year and whether diagnosis was based on clinical signs alone or supported by additional tests. 1419 practices returned a usable response, the majority being located in a city/town. Nearly one-third of responding practices were aware of the parasite locally, 20.7 per cent had seen at least one confirmed case and 0.3 per cent >20 confirmed cases over the past year. The most widely used tests were faecal examination and any type of imaging. Existing clusters of infection were detected in southeastern England and south Wales; infection was also found to be widespread in central England, though patchy in northern England and Scotland. Using distribution of clinical cases as an indicator of parasite distribution, this study confirmed that A. vasorum has spread beyond traditional UK endemic foci. British Veterinary Association.

  13. Spatial, demographic and clinical patterns of Angiostrongylus vasorum infection in the dog population of Southern England.

    PubMed

    Blehaut, T R W; Hardstaff, J L; Chapman, P S; Pfeiffer, D U; Boag, A K; Guitian, F J

    2014-08-09

    A retrospective study was carried out to provide updated knowledge of the spatial pattern of Angiostrongylus vasorum infection in Southern England and to investigate associations between selected host characteristics (age, breed, sex), risk of infection and clinical presentation (cardiorespiratory signs v haemorrhagic diathesis). One hundred and forty-one cases diagnosed between April 1999 and July 2012 were compared with a control population of dogs referred to the same hospital. A significant association was found between haemorrhagic diathesis and breed but not for other host characteristics and clinical presentations. Younger dogs and certain breeds of dog (Jack Russell terriers, Cocker Spaniels, Springer Spaniels, Cavalier King Charles spaniels and Staffordshire Bull Terriers) had significantly higher odds of angiostrongylosis than other breeds in the study. A significant cluster of cases was found in Southern England. Animals presenting with cardiorespiratory signs or haemorrhagic diathesis in Southern England, especially if they are young or of a breed associated with angiostrongylosis, should be given special consideration with regards to possible A. vasorum infestation. Our results should be interpreted bearing in mind that they are based on the retrospective exploration of dogs seen at a referral centre.

  14. Eosinophilic meningitis attributable to Angiostrongylus cantonensis infection in Hawaii: clinical characteristics and potential exposures.

    PubMed

    Hochberg, Natasha S; Blackburn, Brian G; Park, Sarah Y; Sejvar, James J; Effler, Paul V; Herwaldt, Barbara L

    2011-10-01

    The most common infectious cause of eosinophilic meningitis is Angiostrongylus cantonensis, which is transmitted largely by consumption of snails/slugs. We previously identified cases of angiostrongyliasis that occurred in Hawaii from 2001 to 2005; the highest incidence was on the island of Hawaii. We now report symptoms, laboratory parameters, and exposures. Eighteen patients were evaluated; 94% had headache, and 65% had sensory symptoms (paresthesia, hyperesthesia, and/or numbness). These symptoms lasted a median of 17 and 55 days, respectively. Three persons recalled finding a slug in their food/drink. Case-patients on the island of Hawaii were more likely than case-patients on other islands to consume raw homegrown produce in a typical week (89% versus 0%, P < 0.001) and to see snails/slugs on produce (56% versus 0%, P = 0.03). Residents and travelers should be aware of the potential risks of eating uncooked produce in Hawaii, especially if it is from the island of Hawaii and locally grown.

  15. Eosinophilic Meningitis Attributable to Angiostrongylus cantonensis Infection in Hawaii: Clinical Characteristics and Potential Exposures

    PubMed Central

    Hochberg, Natasha S.; Blackburn, Brian G.; Park, Sarah Y.; Sejvar, James J.; Effler, Paul V.; Herwaldt, Barbara L.

    2011-01-01

    The most common infectious cause of eosinophilic meningitis is Angiostrongylus cantonensis, which is transmitted largely by consumption of snails/slugs. We previously identified cases of angiostrongyliasis that occurred in Hawaii from 2001 to 2005; the highest incidence was on the island of Hawaii. We now report symptoms, laboratory parameters, and exposures. Eighteen patients were evaluated; 94% had headache, and 65% had sensory symptoms (paresthesia, hyperesthesia, and/or numbness). These symptoms lasted a median of 17 and 55 days, respectively. Three persons recalled finding a slug in their food/drink. Case-patients on the island of Hawaii were more likely than case-patients on other islands to consume raw homegrown produce in a typical week (89% versus 0%, P < 0.001) and to see snails/slugs on produce (56% versus 0%, P = 0.03). Residents and travelers should be aware of the potential risks of eating uncooked produce in Hawaii, especially if it is from the island of Hawaii and locally grown. PMID:21976573

  16. Eosinophilic meningitis and radiculomyelitis in Thailand, caused by CNS invasion of Gnathostoma spinigerum and Angiostrongylus cantonensis.

    PubMed Central

    Schmutzhard, E; Boongird, P; Vejjajiva, A

    1988-01-01

    During the 6 year period from January 1980 to December 1985 44 patients with infection of the central nervous system by Gnathostoma spinigerum or Angiostrongylus cantonensis were admitted to the Division of Neurology, Ramathibodi Hospital, Bangkok, Thailand. In 16 patients the diagnosis could be confirmed serologically by means of ELISA techniques. In gnathostomiasis encephalitis, myelitis, radiculitis and subarachnoid haemorrhage formed the majority of clinical syndromes. Intracerebral haematoma and transitory obstructive hydrocephalus are described in this report as being caused by Gnathostoma spinigerum infection for the first time. In angiostronglyus infections the clinical syndrome of meningitis was predominant, but one patient, whose angiostrongyliasis was proved serologically, also showed bilateral paresis of abducens nerve. The main laboratory finding was eosinophilic pleocytosis in the CSF (greater than 10%) which in patients originating or returning from South-East-Asia, particularly Thailand, is highly suggestive of these parasitic infections. Increasing transcontinental travel, influx of refugees and those seeking asylum as well as importation of food from South East Asian countries demand greater awareness of these parasitic infections even in Central Europe. PMID:3351533

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

    PubMed Central

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

    2008-01-01

    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. PMID:19032790

  18. [Morphology of III stage larvae of Angiostrongylus cantonensis in Pomacea canaliculata].

    PubMed

    Zhang, Chao-Wei; Zhou, Xiao-Nong; Lv, Shan; Zhang, Yi; Liu, He-Xiang

    2008-06-30

    To observe the morphologic characteristics of III stage larvae of Angiostrongylus cantonensis from Pomacea canaliculata. P. canaliculata, the intermediate host snail of A. cantonensis, was infected with I stage larvae of A. cantonensis in laboratory. After 61 days, III stage larvae of A. cantonensis were harvested from snail's lungs and muscle of head-foot, followed by HE stain to observe morphological characteristics. The whole body of III stage larva was curling with obtuse head. Its pharyngeal canal extends from the buccal hole on the top of the head to the intestines at the pharyngeal intestine joint place, with apex cauda and clear anal tube. The tegument of the III stage larva was eosin-stained, with a transparent sheath outside of tegument. Some of the larvae cauda showed in circular cylinder, and some larvae presented ventral gland with two very short uterine which used to be the feature only showed in early IV stage larva. Morphologically characteristics of the III stage larvae is helpful to better understand the life-cycle and the control of A. cantonensis.

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

    PubMed Central

    2011-01-01

    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. PMID:22023992

  20. Existence of Angiostrongylus cantonensis in rats (Rattus norvegicus) in Grenada, West Indies.

    PubMed

    Chikweto, A; Bhaiyat, M I; Macpherson, C N L; Deallie, C; Pinckney, R D; Richards, C; Sharma, R N

    2009-05-26

    The zoonotic rat lung worm, Angiostrongylus cantonensis is endemic to Asia, North America, Africa and Australia. The parasite is expanding geographically and has recently been recorded in some of the Greater Antilles in the northern part of the Caribbean. In this study A. cantonensis is reported for the first time in the Lesser Antilles in one of the southernmost islands, Grenada. Between September 2005 and September 2006, 192 rats (Rattus norvegicus) were trapped throughout the island. The rats were anesthetized, exsanguinated, necropsied and the lungs were fixed whole in 10% buffered formalin, trimmed, processed, cut at 3microm, stained with hematoxylin and eosin and examined microscopically. A total of 45 (23.4%) of the 192 rats examined were found to be infected with A. cantonensis and adult worms were found in the cardiopulmonary system of one of the rats. Microscopically, pulmonic lesions, consisting of pulmonary thrombosis, hypertrophy of pulmonary arteries and granulomatous pneumonia were associated with intralesional adults, larvae and embryonated eggs of A. cantonensis. An incidental finding of variably sized (2-7mm) solitary to multiple cysts containing larvae of Taenia taeniaformis were seen in the livers of 57 rats. This report of A. cantonensis in Grenada provides evidence of the further global expansion of this important zoonotic parasite and the public health implications of this discovery is discussed.

  1. First report of a fatal autochthonous canine Angiostrongylus vasorum infection in Belgium.

    PubMed

    Jolly, Sandra; Poncelet, Luc; Lempereur, Laetitia; Caron, Yannick; Bayrou, Calixte; Cassart, Dominique; Grimm, Felix; Losson, Bertrand

    2015-02-01

    Canine angiostrongylosis is considered as an emergent disease in Europe and Canada. A fatal case of Angiostrongylus vasorum infection is described in a four and a half month old puppy born in Belgium. The dog was presented with marked neurological disorders, body weight loss, a profound weakness and mild respiratory signs. The dog was given antibiotics and mucolytic compounds with very little improvement and consequently was referred to a specialist for additional examinations. As the general condition of the dog was rapidly declining, the animal was euthanized shortly after on its owners' request and a necropsy was carried out. Extensive gross pulmonary lesions were observed and histopathological examination revealed the presence of numerous larvae with morphology compatible with A. vasorum. Larvae were also found in the product of a bronchoalveolar lavage but fecal material was not examined. The presence of A. vasorum circulating serum antigen was demonstrated through ELISA; additionally an A. vasorum specific PCR was performed on brain material and yielded a positive result. This case confirms that the clinical diagnosis of canine angiostrongylosis can be very challenging especially when respiratory signs are absent or very mild such in the present case. This is the first reported case of canine angiostrongylosis in Belgium. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  2. Brazilian Angiostrongylus cantonensis haplotypes, ac8 and ac9, have two different biological and morphological profiles

    PubMed Central

    Monte, Tainá CC; Gentile, Rosana; Garcia, Juberlan; Mota, Ester; Santos, Jeannie N; Maldonado, Arnaldo

    2014-01-01

    Angiostrongylus cantonensis is the etiologic agent of eosinophilic meningoencephalitis in humans. Cases have been recorded in many parts of the world, including Brazil. The aim of this study was to compare the differences in the biology and morphology of two different Brazilian haplotypes of A. : ac8 and ac9. A significantly larger number of L1 larvae eliminated in the faeces of rodents at the beginning of the patent period was observed for ac9 haplotype and compared to the total of L1 larvae eliminated, there was a significant difference between the two haplotypes. The ac9 haplotype showed a significant difference in the proportion of female and male specimens (0.6:1), but the same was not observed for ac8 (1.2:1). The morphometric analysis showed that male and female specimens isolated from ac8 haplotype were significantly larger with respect to body length, oesophagus length, spicule length (male) and distance from the anus to the rear end (female) compared to specimens from ac9. The morphological analysis by light microscopy showed little variation in the level of bifurcations at the lateral rays in the right lobe of the copulatory bursa between the two haplotypes. The biological, morphological and morphometric variations observed between the two haplotypes agree with the observed variation at the molecular level using the cytochrome oxidase subunit I marker and reinforce the possible influence of geographical isolation on the development of these haplotypes. PMID:25591110

  3. Differential proteomics analysis of female and male adults of Angiostrongylus cantonensis.

    PubMed

    Song, Zengmei; Huang, Huicong; Tan, Feng; Zhang, Erpeng; Hu, Jianwen; Pan, Changwang

    2012-06-01

    In this study, we identified the differentially expressed proteins of female and male adults of Angiostrongylus cantonensis through differential proteomics. We extracted and purified total proteins from male and female adults, separated proteins by two-dimensional difference gel electrophoresis (2D-DIGE) in pH 4-7, analyzed the gel images by DeCyder 7.0 software, and sacrificed the infected rats to count the number of male and female adults. It was found 28 protein spots that were differentially expressed; seven protein spots were then identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Five proteins were up-regulated and two proteins down-regulated in male adults compared with female adults. Three of the five up-regulated proteins with known functions ascribed to them were identified as galectin-1, proteasome alpha subunit and peroxiredoxin. The two down-regulated proteins were identified as indoleamine dioxygenase like-myoglobin and galectin. Furthermore, the female was significantly greater than male adults (P<0.01) in the rats. The findings demonstrate the differences in protein expression profiles and the ability to survive in the final host between female and male adults of A. cantonensis, and may provide a theoretical basis to study their developmental biology further.

  4. Canine angiostrongylosis in Italy: occurrence of Angiostrongylus vasorum in dogs with compatible clinical pictures.

    PubMed

    Traversa, Donato; Di Cesare, Angela; Meloni, Silvana; Frangipane di Regalbono, Antonio; Milillo, Piermarino; Pampurini, Fabrizio; Venco, Luigi

    2013-07-01

    This study evaluated the perception of veterinarians in including the emerging metastrongyloid Angiostrongylus vasorum in the differential diagnosis for dogs referred with appropriate signs. Veterinarians at teaching hospitals, private practices or kennels collected faecal samples from 606 symptomatic dogs in six different areas of Italy. The samples were examined with the Baermann technique. Fourteen dogs scored positive for A. vasorum, all showing different clinical pictures, with the most common reason for inclusion in the study being a combination of respiratory signs along with general signs. The most reported sign was cough, followed by aspecific distresses. Other respiratory signs were dyspnoea, tachypnoea and breathing sounds, while bleeding diathesis occurred in one dog. Gastrointestinal disorders were diarrhoea and vomitus, while no neurological signs were detected. Four key cases are herein described, with a special focus on their clinical description, findings at the collateral diagnostic imaging and therapeutic options with moxidectin. This survey provides new data on distribution of A. vasorum in Europe and on the clinical impact of the disease. The results confirm that clinical angiostrongylosis overlaps a series of other conditions of dogs. Awareness among vet practitioners is discussed along with the importance of including A. vasorum on the list of differential diagnoses in canine clinical practice and of performing appropriate diagnostic methods.

  5. Interactions of microfungi and plant parasitic nematodes

    USDA-ARS?s Scientific Manuscript database

    Plant parasitic nematodes and microfungi inhabit many of the same ecological habitats and interact in almost every conceivable way. Nematodes can feed on fungi, and conversely fungi can use nematodes as a food source. Fungi have been widely studied as biological controls of plant parasitic nematod...

  6. Bacteria can mobilize nematode-trapping fungi to kill nematodes

    PubMed Central

    Wang, Xin; Li, Guo-Hong; Zou, Cheng-Gang; Ji, Xing-Lai; Liu, Tong; Zhao, Pei-Ji; Liang, Lian-Ming; Xu, Jian-Ping; An, Zhi-Qiang; Zheng, Xi; Qin, Yue-Ke; Tian, Meng-Qing; Xu, You-Yao; Ma, Yi-Cheng; Yu, Ze-Fen; Huang, Xiao-Wei; Liu, Shu-Qun; Niu, Xue-Mei; Yang, Jin-Kui; Huang, Ying; Zhang, Ke-Qin

    2014-01-01

    In their natural habitat, bacteria are consumed by bacterivorous nematodes; however, they are not simply passive preys. Here we report a defensive mechanism used by certain bacteria to mobilize nematode-trapping fungi to kill nematodes. These bacteria release urea, which triggers a lifestyle switch in the fungus Arthrobotrys oligospora from saprophytic to nematode–predatory form; this predacious form is characterized by formation of specialized cellular structures or ‘traps’. The bacteria significantly promote the elimination of nematodes by A. oligospora. Disruption of genes involved in urea transport and metabolism in A. oligospora abolishes the urea-induced trap formation. Furthermore, the urea metabolite ammonia functions as a signal molecule in the fungus to initiate the lifestyle switch to form trap structures. Our findings highlight the importance of multiple predator–prey interactions in prey defense mechanisms. PMID:25514608

  7. Nematode-trapping fungi eavesdrop on nematode pheromones

    PubMed Central

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

    2013-01-01

    Summary 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 [1]. 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 [2-4]. Here we show that nematophagous fungi, natural predators of soil-dwelling nematodes [5], 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 [6]. 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 condition. Our results demonstrate that microbial predators eavesdrop on chemical communication among their metazoan prey to regulate morphogenesis, providing a striking example of predator-prey co-evolution. We anticipate that these findings will have broader implications for understanding other inter-kingdom interactions involving nematodes, which are found in almost any ecological niche on Earth. PMID:23246407

  8. Nematode-trapping fungi eavesdrop on nematode pheromones.

    PubMed

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

    2013-01-07

    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.

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

    USDA-ARS?s Scientific Manuscript database

    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...

  10. Improved Molecular Detection of Angiostrongylus cantonensis in Mollusks and Other Environmental Samples with a Species-Specific Internal Transcribed Spacer 1-Based TaqMan Assay ▿

    PubMed Central

    Qvarnstrom, Yvonne; da Silva, Ana Cristina Aramburu; Teem, John L.; Hollingsworth, Robert; Bishop, Henry; Graeff-Teixeira, Carlos; da Silva, Alexandre J.

    2010-01-01

    Angiostrongylus cantonensis is the most common cause of human eosinophilic meningitis. Humans become infected by ingesting food items contaminated with third-stage larvae that develop in mollusks. We report the development of a real-time PCR assay for the species-specific identification of A. cantonensis in mollusk tissue. PMID:20543049

  11. Nematode Chemosensilla: Form and Function

    PubMed Central

    Wright, K. A.

    1983-01-01

    As an introduction to a symposium of nematode chemoreception, the anatomy of nematode chemosensilla, their distribution on plant parasitic nematodes, and their possible functional roles is briefly reviewed. Comparison of nematode chemosensilla with those of other animals shows their greater resemblance to olfactory primary sense cells of vertebrates. Although the sensory process is obviously derived from a cilium, the absence of many ciliary features is noted. Retention of the ciliary necklace may be important functionally. A simple model is proposed, wherein binding of stimulant molecules to receptors in the membrane of the cilium-derived process results in entry of Na⁺ and Ca⁺⁺ (the latter via the ciliary necklace) to produce a receptor potential that spreads along the dendrite to the cell body where action potentials continue along the short axon to synapses. PMID:19295785

  12. Social Networks of Educated Nematodes

    PubMed Central

    Willett, Denis S.; Alborn, Hans T.; Duncan, Larry W.; Stelinski, Lukasz L.

    2015-01-01

    Entomopathogenic nematodes are obligate lethal parasitoids of insect larvae that navigate a chemically complex belowground environment while interacting with their insect hosts, plants, and each other. In this environment, prior exposure to volatile compounds appears to prime nematodes in a compound specific manner, increasing preference for volatiles they previously were exposed to and decreasing attraction to other volatiles. In addition, persistence of volatile exposure influences this response. Longer exposure not only increases preference, but also results in longer retention of that preference. These entomopathogenic nematodes display interspecific social behavioral plasticity; experienced nematodes influence the behavior of different species. This interspecific social behavioral plasticity suggests a mechanism for rapid adaptation of belowground communities to dynamic environments. PMID:26404058

  13. Social Networks of Educated Nematodes.

    PubMed

    Willett, Denis S; Alborn, Hans T; Duncan, Larry W; Stelinski, Lukasz L

    2015-09-25

    Entomopathogenic nematodes are obligate lethal parasitoids of insect larvae that navigate a chemically complex belowground environment while interacting with their insect hosts, plants, and each other. In this environment, prior exposure to volatile compounds appears to prime nematodes in a compound specific manner, increasing preference for volatiles they previously were exposed to and decreasing attraction to other volatiles. In addition, persistence of volatile exposure influences this response. Longer exposure not only increases preference, but also results in longer retention of that preference. These entomopathogenic nematodes display interspecific social behavioral plasticity; experienced nematodes influence the behavior of different species. This interspecific social behavioral plasticity suggests a mechanism for rapid adaptation of belowground communities to dynamic environments.

  14. Characterizing longitudinal changes in rabbit brains infected with Angiostrongylus Cantonensis based on diffusion anisotropy.

    PubMed

    Tsai, Hao-Hung; Shyu, Ling-Yuh; Lim, Seong Yong; Tyan, Yeu-Sheng; Weng, Jun-Cheng

    2016-05-01

    Angiostrongylus cantonensis has become a global source of infection in recent years, and the differential diagnosis and timely follow-up are crucial in the management of the infection. Magnetic resonance imaging (MRI) has been suggested as a non-invasive technique in characterizing and localizing lesions during the parasitic infections in the brain. Non-invasive diffusion tensor imaging (DTI) can be used to distinguish microscopic cerebral structures but cannot resolve the more complicated neural structure. Several methods have been proposed to overcome this limitation. One such method, generalized q-sampling imaging (GQI), can be applied to a variety of datasets, including the single shell, multi-shell or grid sampling schemes, which are believed to resolve complicated crossing fibers. This study aimed to characterize angiostrongyliasis in the rabbit brain over a 6-week period using anatomical and diffusion MRI, including DTI and GQI. Our anatomical T2WI and R2 mapping results showed that the ventricle size of the rabbit brain increased after A. cantonensis larvae infection, and the DTI and GQI indices both showed pathological changes in the corpus callosum, hippocampus and cortex over a 6-week infection period. These results were consistent with our histopathological findings. Our results demonstrated that the diagnosis of larvae infection using anatomical and diffusion MRI is possible and that follow-up characterization is informative in revealing the effects of angiostrongyliasis in various brain areas. These support the use of anatomical and diffusion MRI was helpful for diagnosis of eosinophilic meningitis caused by A. cantonensis infection. This non-invasive MRI platform could be used to improve the management of eosinophilic meningitis or eosinophilic meningoencephalitis in humans. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Angiostrongylus cantonensis eosinophilic meningitis: a clinical study of 42 consecutive cases in French Polynesia.

    PubMed

    Oehler, Erwan; Ghawche, Frédéric; Delattre, Alex; Berberian, Anthony; Levy, Marc; Valour, Florent

    2014-06-01

    In endemic areas, eosinophilic meningitis is mainly caused by Angiostrongylus cantonensis. We describe a series of this poorly-known condition. Retrospective cohort study (2000-2012) including all patients diagnosed with eosinophilic meningitis in French Polynesia. Forty-two patients (males: 61.9%, age: 22 (IQR 17-32)) were diagnosed with a serologically proven (n=13) or probable A. cantonensis meningitis, mostly during the dry season (66.6%) and following the consumption of or prolonged contact with an intermediate/paratenic host (64.3%). No differential diagnosis was found in probable cases, in whom serological tests were performed earlier (7.5 days (6.5-10)) compared to positive patients (7.5 (6.5-10) versus 11 (7-30) days, p=0.02). The most commonly reported symptom was headache (92.8%). Fever (7.1%) and biological inflammatory syndrome (14.3%) were rare. Blood eosinophil count was 1200/mm(3) (900-2548). Cerebrospinal fluid (CSF) analysis disclosed a protein level of 0.9 g/L (0.7-1.1), a CSF/plasma glucose ratio of 0.50 (0.40-0.55), and 500 leucocytes/mm(3) (292-725; eosinophils: 42.0% (29.5-60); lymphocytes: 46.5% (32.5-59.0)). Thirteen cases (31.0%) were severe, with 11 focal neurological deficits. A delayed hospital referral (OR 1.13, p=0.05) was associated with severity. A. cantonensis meningitis must be evocated in young patients with meningitic syndrome, severe headache, and CSF inflammation with predominance of eosinophils. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  16. Global decline in suitable habitat for Angiostrongylus ( = Parastrongylus) cantonensis: the role of climate change.

    PubMed

    York, Emily M; Butler, Christopher J; Lord, Wayne D

    2014-01-01

    Climate change is implicated in the alteration of the ranges of species worldwide. Such shifts in species distributions may introduce parasites/pathogens, hosts, and vectors associated with disease to new areas. The parasite Angiostrongylus ( = Parastrongylus) cantonensis is an invasive species that causes eosinophilic meningitis in humans and neurological abnormalities in domestic/wild animals. Although native to southeastern Asia, A. cantonensis has now been reported from more than 30 countries worldwide. Given the health risks, it is important to describe areas with potentially favorable climate for the establishment of A. cantonensis, as well as areas where this pathogen might become established in the future. We used the program Maxent to develop an ecological niche model for A. cantonensis based on 86 localities obtained from published literature. We then modeled areas of potential A. cantonensis distribution as well as areas projected to have suitable climatic conditions under four Representative Concentration Pathways (RCP) scenarios by the 2050s and the 2070s. The best model contained three bioclimatic variables: mean diurnal temperature range, minimum temperature of coldest month and precipitation of warmest quarter. Potentially suitable habitat for A. cantonensis was located worldwide in tropical and subtropical regions. Under all climate change RCP scenarios, the center of the projected distribution shifted away from the equator at a rate of 68-152 km per decade. However, the extent of areas with highly suitable habitat (>50%) declined by 10.66-15.66% by the 2050s and 13.11-16.11% by the 2070s. These results conflict with previous studies, which have generally found that the prevalence of tropical pathogens will increase during the 21st century. Moreover, it is likely that A. cantonensis will continue to expand its current range in the near future due to introductions and host expansion, whereas climate change will reduce the total geographic area of

  17. Retrospective evaluation of thoracic computed tomography findings in dogs naturally infected by Angiostrongylus vasorum.

    PubMed

    Coia, Mark E; Hammond, Gawain; Chan, Daniel; Drees, Randi; Walker, David; Murtagh, Kevin; Stone, Janine; Bexfield, Nicholas; Reeve, Lizzie; Helm, Jenny

    2017-09-01

    Angiostrongylus vasorum (A. vasorum) is an important emerging disease of canidae. Cardiorespiratory signs are common in affected dogs, therefore thoracic imaging is critical for diagnosing and monitoring disease. Descriptions of thoracic computed tomography (CT) findings in dogs naturally infected with A. vasorum are currently lacking. Aims of this multicenter, retrospective study were to describe thoracic CT findings in a group of dogs with confirmed disease, determine whether any changes were consistent among dogs, and propose standardized terms for describing thoracic CT findings. Nine UK-based referral centers' clinical and imaging databases were searched for dogs that had a confirmed diagnosis of A. vasorum, and had undergone thoracic CT examination. Eighteen dogs, from seven of the centers, fulfilled the inclusion criteria. The lung lobes were divided into the following three zones and the CT changes described in each: pleural (zone 1), subpleural (zone 2), and peribronchovascular (zone 3). The predominent abnormality was increased lung attenuation due to poorly defined ground-glass opacity or consolidation. There were regions of mosaic attenuation due to peripheral bronchiectasis. Nine/18 (50%) dogs showed hyperattenuating nodules of varying sizes with ill-defined margins. The distribution always affected zones 1 and 2 with varied involvement of zone 3; this resulted in clear delineation between zones 2 and 3. Tracheobronchial lymphadenomegaly was frequently noted. Findings were nonspecific and there was considerable overlap with other pulmonary conditions. However, authors recommend that A. vasorum be considered a likely differential diagnosis for dogs with a predominantly peripheral distribution of lung changes. © 2017 American College of Veterinary Radiology.

  18. Characterization of the N-glycans of female Angiostrongylus cantonensis worms.

    PubMed

    Veríssimo, Carolina M; Morassutti, Alessandra L; von Itzstein, Mark; Sutov, Grigorij; Hartley-Tassell, Lauren; McAtamney, Sarah; Dell, Anne; Haslam, Stuart M; Graeff-Teixeira, Carlos

    2016-07-01

    Glycoconjugates play a crucial role in the host-parasite relationships of helminthic infections, including angiostrongyliasis. It has previously been shown that the antigenicity of proteins from female Angiostrongylus cantonensis worms may depend on their associated glycan moieties. Here, an N-glycan profile of A. cantonensis is reported. A total soluble extract (TE) was prepared from female A. cantonensis worms and was tested by western blot before and after glycan oxidation or N- and O-glycosidase treatment. The importance of N-glycans for the immunogenicity of A. cantonensis was demonstrated when deglycosylation of the TE with PNGase F completely abrogated IgG recognition. The TE was also fractionated using various lectin columns [Ulex europaeus (UEA), concanavalin A (Con A), Arachis hypogaea (PNA), Triticum vulgaris (WGA) and Lycopersicon esculentum (LEA)], and then each fraction was digested with PNGase F. Released N-glycans were analyzed with matrix-assisted laser desorption ionization (MALDI)-time-of-flight (TOF)-mass spectrometry (MS) and MALDI-TOF/TOF-MS/MS. Complex-type, high mannose, and truncated glycan structures were identified in all five fractions. Sequential MALDI-TOF-TOF analysis of the major MS peaks identified complex-type structures, with a α1-6 fucosylated core and truncated antennas. Glycoproteins in the TE were labeled with BodipyAF558-SE dye for a lectin microarray analysis. Fluorescent images were analyzed with ProScanArray imaging software followed by statistical analysis. A total of 29 lectins showed positive binding to the TE. Of these, Bandeiraea simplicifolia (BS-I), PNA, and Wisteria floribunda (WFA), which recognize galactose (Gal) and N-acetylgalactosamine (GalNAc), exhibited high affinity binding. Taken together, our findings demonstrate that female A. cantonensis worms have characteristic helminth N-glycans.

  19. Clinical, laboratory and pathological findings in dogs experimentally infected with Angiostrongylus vasorum.

    PubMed

    Schnyder, Manuela; Fahrion, Anna; Riond, Barbara; Ossent, Pete; Webster, Pia; Kranjc, Asja; Glaus, Tony; Deplazes, Peter

    2010-11-01

    The aim of this comparative study was to investigate the development of clinical signs and accompanying haematological, coproscopic and pathological findings as a basis for the monitoring of health condition of Angiostrongylus vasorum infected dogs. Six beagles were orally inoculated with 50 (n=3) or 500 (n=3) A. vasorum third stage larvae (L3) obtained from experimentally infected Biomphalaria glabrata snails. Two dogs were treated with moxidectin/imidacloprid spot-on solution and two further dogs with an oral experimental compound 92 days post infection (dpi), and were necropsied 166 dpi. Two untreated control dogs were necropsied 97 dpi. Prepatency was 47-49 days. Dogs inoculated with 500 L3 exhibited earlier (from 42 dpi) and more severe respiratory signs. Clinical signs resolved 12 days after treatment and larval excretion stopped within 20 days in all four treated dogs. Upon necropsy, 10 and 170 adult worms were recovered from the untreated dogs inoculated with 50 and 500 L3, respectively. Adult worms were also found in two treated dogs, in the absence of L1 or eggs. Despite heavy A. vasorum infection load and severe pulmonary changes including vascular thrombosis, only mild haematological changes were observed. Eosinophilia was absent but the presence of plasma cells was observed. Neutrophilic leucocytes showed a transient increase but only after treatment. Signs for coagulopathies were slight; nevertheless coagulation parameters were inoculation dose dependent. Ten weeks after treatment pulmonary fibrosis was still present. Infections starting from 50 L3 of A. vasorum had a massive impact on lung tissues and therefore on the health of affected dogs, particularly after prepatency, although only mild haematological abnormalities were evident.

  20. [Prevalence of Angiostrongylus cantonensis infection in snails for sale in Fuzhou and Xiamen].

    PubMed

    Li, Li-Sha; Zhang, Rong-Yan; Fang, Yan-Yan; Ouyang, Rong; Xie, Han-Guo; Jiang, Dian-Wei; Xie, Xian-Liang; Chen, Zhu-Yun; Zheng, Guo-Bin

    2013-12-01

    To investigate the prevalence of Angiostrongylus cantonensis infection in snails for sale from Fuzhou and Xiamen of Fujian Province. During 2009-2012, two markets and five restaurants from each city were selected as surveillance sites. A. cantonensis infection rate in Pomacea canaliculata, Bellamya aeruginosa and Cipangopaludina cathayensis was examined two times per month. More than 50 P. canaliculata or C. cathayensis, and about 500 g B. aeruginosa were collected in each site. A. cantonensis larvae infection was determined by lung-microscopy in P. canaliculata, and by tissue homogenate method in C. cathayensis and B. aeruginosa, respectively. In markets, a total of 5,744 P. canaliculata were collected, and the infection rate of A. cantonensis larvae was 13.8% (753/5 744) with the lowest prevalence in 2009 (8.4%, 28/334) and the highest one in 2011 (16.7%, 361/2,160). The overall infection rate of A. cantonensis showed an increasing trend over the past years (P < 0.05). In restaurants, 879 P. canaliculata snails were examined in Xiamen City, and the infection rate was 12.8% (877/6 879). No significant difference was found among years (P > 0.05). A. cantonensis larvae were found from P. canaliculata for sale in different seasons with no statistical difference (P > 0.05). 19,843 B. aeruginosa snails were collected in markets from the two cities, and the infection rate was 0.2% (31/19 843). The infection rate was highest in 2011 (0.3%, 16/5,953) and lowest in 2010 (0.04%, 2/4,706). All the 361 C. cathayensis snails were negative. A. cantonensis larvae are found in P. canaliculata and B. aeruginosa from markets and restaurants of Fuzhou and Xiamen in different seasons during the years.

  1. The Geological Record of Parasitic Nematode Evolution.

    PubMed

    Poinar, George O

    2015-01-01

    This chapter discusses the evolutionary history of nematode parasites of invertebrates, vertebrates and plants based on fossil remains in amber, stone and coprolites dating from the Palaeozoic to the Holocene. The earliest parasitic nematode is a primitive plant parasite from the Devonian. Fossil invertebrate-parasitic nematodes first appeared in the Early Cretaceous, while the earliest fossil vertebrate-parasitic nematodes are from Upper Triassic coprolites. Specific examples of fossil nematode parasites over time are presented, along with views on the origin and evolution of nematodes and their hosts. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Nematode Indicators of Organic Enrichment

    PubMed Central

    Ferris, Howard; Bongers, Tom

    2006-01-01

    The organisms of the soil food web, dependent on resources from plants or on amendment from other sources, respond characteristically to enrichment of their environment by organic matter. Primary consumers of the incoming substrate, including bacteria, fungi, plant-feeding nematodes, annelids, and some microarthropods, are entry-level indicators of enrichment. However, the quantification of abundance and biomass of this diverse group, as an indicator of resource status, requires a plethora of extraction and assessment techniques. Soluble organic compounds are absorbed by bacteria and fungi, while fungi also degrade more recalcitrant sources. These organisms are potential indicators of the nature of incoming substrate, but current methods of biomass determination do not reliably indicate their community composition. Guilds of nematodes that feed on bacteria (e.g., Rhabditidae, Panagrolaimidae) and fungi (e.g., Aphelenchidae, Aphelenchoididae) are responsive to changes in abundance of their food. Through direct herbivory, plant-feeding nematodes (e.g., many species of Tylenchina) also contribute to food web resources. Thus, analysis of the nematode community of a single sample provides indication of carbon flow through an important herbivore channel and through channels mediated by bacteria and fungi. Some nematode guilds are more responsive than others to resource enrichment. Generally, those bacterivores with short lifecycles and high reproductive potential (e.g., Rhabditidae) most closely mirror the bloom of bacteria or respond most rapidly to active plant growth. The feeding habits of some groups remain unclear. For example, nematodes of the Tylenchidae may constitute 30% or more of the individuals in a soil sample; further study is necessary to determine which resource channels they portray and the appropriate level of taxonomic resolution for this group. A graphic representation of the relative biomass of bacterivorous, fungivorous, and herbivorous nematodes

  3. Basic and applied research: Entomopathogenic nematodes

    USDA-ARS?s Scientific Manuscript database

    Entomopathogenic nematodes in the genera Heterorhabditis and Steinernema kill arthropods with the aid of their bacterial symbionts. These nematodes are potent microbial control agents that have been widely commercialized for control of economically important insect pests. Biocontrol efficacy relies...

  4. Nematode neuropeptides as transgenic nematicides

    PubMed Central

    Patten, Cheryl; Fleming, Colin C.; Maule, Aaron G.

    2017-01-01

    Plant parasitic nematodes (PPNs) seriously threaten global food security. Conventionally an integrated approach to PPN management has relied heavily on carbamate, organophosphate and fumigant nematicides which are now being withdrawn over environmental health and safety concerns. This progressive withdrawal has left a significant shortcoming in our ability to manage these economically important parasites, and highlights the need for novel and robust control methods. Nematodes can assimilate exogenous peptides through retrograde transport along the chemosensory amphid neurons. Peptides can accumulate within cells of the central nerve ring and can elicit physiological effects when released to interact with receptors on adjoining cells. We have profiled bioactive neuropeptides from the neuropeptide-like protein (NLP) family of PPNs as novel nematicides, and have identified numerous discrete NLPs that negatively impact chemosensation, host invasion and stylet thrusting of the root knot nematode Meloidogyne incognita and the potato cyst nematode Globodera pallida. Transgenic secretion of these peptides from the rhizobacterium, Bacillus subtilis, and the terrestrial microalgae Chlamydomonas reinhardtii reduce tomato infection levels by up to 90% when compared with controls. These data pave the way for the exploitation of nematode neuropeptides as a novel class of plant protective nematicide, using novel non-food transgenic delivery systems which could be deployed on farmer-preferred cultivars. PMID:28241060

  5. Application and commercialization of nematodes.

    PubMed

    Peters, Arne

    2013-07-01

    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.

  6. Nematode neuropeptides as transgenic nematicides.

    PubMed

    Warnock, Neil D; Wilson, Leonie; Patten, Cheryl; Fleming, Colin C; Maule, Aaron G; Dalzell, Johnathan J

    2017-02-01

    Plant parasitic nematodes (PPNs) seriously threaten global food security. Conventionally an integrated approach to PPN management has relied heavily on carbamate, organophosphate and fumigant nematicides which are now being withdrawn over environmental health and safety concerns. This progressive withdrawal has left a significant shortcoming in our ability to manage these economically important parasites, and highlights the need for novel and robust control methods. Nematodes can assimilate exogenous peptides through retrograde transport along the chemosensory amphid neurons. Peptides can accumulate within cells of the central nerve ring and can elicit physiological effects when released to interact with receptors on adjoining cells. We have profiled bioactive neuropeptides from the neuropeptide-like protein (NLP) family of PPNs as novel nematicides, and have identified numerous discrete NLPs that negatively impact chemosensation, host invasion and stylet thrusting of the root knot nematode Meloidogyne incognita and the potato cyst nematode Globodera pallida. Transgenic secretion of these peptides from the rhizobacterium, Bacillus subtilis, and the terrestrial microalgae Chlamydomonas reinhardtii reduce tomato infection levels by up to 90% when compared with controls. These data pave the way for the exploitation of nematode neuropeptides as a novel class of plant protective nematicide, using novel non-food transgenic delivery systems which could be deployed on farmer-preferred cultivars.

  7. Impact of conservation tillage on nematode populations.

    PubMed

    Minton, N A

    1986-04-01

    Literature reporting the development of conservation tillage and the research that has been conducted on nematode control in crops grown in conservation tillage systems is reviewed. Effects of different types of conservation tillage on population densities of various nematode species in monocropping and multicropping systems, effects of tillage on nematode distribution in the soil profile, effects of conservation tillage on nematode control, and the role of nematology in conservation tillage research are discussed.

  8. 14-3-3β protein expression in eosinophilic meningitis caused by Angiostrongylus cantonensis infection.

    PubMed

    Tsai, Hung-Chin; Huang, Yen-Lin; Chen, Yao-Shen; Yen, Chuan-Min; Tsai, Rachel; Lee, Susan Shin-Jung; Tai, Ming-Hong

    2014-02-20

    Angiostrongylus cantonensis is a parasite endemic in the Southeast Asian and Pacific regions. Humans are incidentally infected either by eating uncooked intermediate hosts or by consuming vegetables containing the living third-stage larvae. The 14-3-3β protein is a cerebrospinal fluid (CSF) marker of neuronal damage during the development of Creutzfeldt-Jakob disease. In addition, increased 14-3-3β protein is also found in CSF from patients with a variety of neurological disorders. The goal of this study is to determine the roles of serum/CSF14-3-3β protein in patients with eosinophilic meningitis. In a cohort study among nine Thai laborers with eosinophilic meningitis due to eating raw snails (Pomacea canaliculata), we examined the CSF weekly while patients were still hospitalized and followed up the serum for 6 months. The levels of 14-3-3β protein in CSF were analyzed by western blot and an in-house 14-3-3β enzyme-linked immunosorbent assay (ELISA) measurement was established and tested in an animal model of eosinophilic meningitis. The elevated 14-3-3β level was detected in the CSF from eight out of nine (81%) patients After 2 weeks of treatment, all patients showed a declined level or cleared of 14-3-3β protein in the CSF. By developing an in-house ELISA for measurement of 14-3-3β protein, it was found that the serum 14-3-3β level was significantly increased in patients during initial visit. . This finding was consistent to the animal experiment result in which there was severe blood brain barrier damage three weeks after infection and increased 14-3-3β protein expression in the CSF and serum by western blot and in house ELISA. After treatment, the serum 14-3-3β level in meningitis patients was rapidly returned to normal threshold. There was a correlation between initial CSF 14-3-3β level with severity of headache (r = 0.692, p = 0.039), CSF pleocytosis (r = 0.807, p = 0.009) and eosinophilia (r = 0.798, p = 0.01) in the

  9. 14-3-3β protein expression in eosinophilic meningitis caused by Angiostrongylus cantonensis infection

    PubMed Central

    2014-01-01

    Background Angiostrongylus cantonensis is a parasite endemic in the Southeast Asian and Pacific regions. Humans are incidentally infected either by eating uncooked intermediate hosts or by consuming vegetables containing the living third-stage larvae. The 14-3-3β protein is a cerebrospinal fluid (CSF) marker of neuronal damage during the development of Creutzfeldt-Jakob disease. In addition, increased 14-3-3β protein is also found in CSF from patients with a variety of neurological disorders. The goal of this study is to determine the roles of serum/CSF14-3-3β protein in patients with eosinophilic meningitis. Methods In a cohort study among nine Thai laborers with eosinophilic meningitis due to eating raw snails (Pomacea canaliculata), we examined the CSF weekly while patients were still hospitalized and followed up the serum for 6 months. The levels of 14-3-3β protein in CSF were analyzed by western blot and an in-house 14-3-3β enzyme-linked immunosorbent assay (ELISA) measurement was established and tested in an animal model of eosinophilic meningitis. Results The elevated 14-3-3β level was detected in the CSF from eight out of nine (81%) patients After 2 weeks of treatment, all patients showed a declined level or cleared of 14-3-3β protein in the CSF. By developing an in-house ELISA for measurement of 14-3-3β protein, it was found that the serum 14-3-3β level was significantly increased in patients during initial visit. . This finding was consistent to the animal experiment result in which there was severe blood brain barrier damage three weeks after infection and increased 14-3-3β protein expression in the CSF and serum by western blot and in house ELISA. After treatment, the serum 14-3-3β level in meningitis patients was rapidly returned to normal threshold. There was a correlation between initial CSF 14-3-3β level with severity of headache (r = 0.692, p = 0.039), CSF pleocytosis (r = 0.807, p = 0.009) and eosinophilia (r = 0

  10. Angiostrongylus cantonensis Infection on Mayotte Island, Indian Ocean, 2007-2012

    PubMed Central

    Epelboin, Loïc; Blondé, Renaud; Chamouine, Abdourahim; Chrisment, Alexandra; Diancourt, Laure; Villemant, Nicolas; Atale, Agnès; Cadix, Claire; Caro, Valérie; Malvy, Denis; Collet, Louis

    2016-01-01

    Introduction Human angiostrongyliasis (HA) is a neurological helminthic disease caused by the lung worm Angiostrongylus cantonensis. It is suspected in the combination of travel or a residence in an endemic area and eosinophilic meningitis. In Mayotte, an island in the Indian Ocean, cases are rare but regular. The main objective of our study was to describe the epidemiological and diagnosis clues of HA in Mayotte. The secondary objectives were to evaluate the contribution of Real-Time Polymerase Chain Reaction (RT- PCR) for the diagnosis of HA, delineate the characteristics of the local transmission and ascertain the presence of A. cantonensis in Achatina fulica, the potential vector of the disease. Materials and Methods Between 2007 and 2012, all cases of eosinophilic meningitis were retrospectively included and investigated by RT- PCR in the CSF. Descriptive analysis was conducted for clinical, biological and radiological features, and were analyzed for all patients together with the search for prognostic factors for mortality. Concurrently, geolocalization and temporal parameters were studied to correlate the occurrence of the cases with rainfall seasons and snails were collected to enhance a parasitic carriage with real time PCR. Results During the 6-year period of the study, 14 cases were identified (2.3 cases/year) and 9 among 10 remaining CSF were positive in PCR. Among 14 cases of EM, 13 were less than 2 year-old children. The 1 year mortality rate was 5/14 (35.7%). Among survivors, 3/7 (42.8%) presented neurological sequelae. Factors associated with mortality were dysfunction of cranial nerves, abnormal brain imaging, and CSF glucose level inferior to 2 mmol/l. Occurrence of cases was temporarily and spatially correlated to the rainy season. Among the 64 collected giant snails, 6 (9.4%) were positive with A. cantonensis PCR. The likely main route of transmission was the children licking snails, carriers of the parasite. Conclusion In Mayotte, HA was mainly

  11. Using entomopathogenic nematodes for crop insect control

    USDA-ARS?s Scientific Manuscript database

    The objective of this paper is to provide an overview on using entomopathogenic nematodes for insect pest control. Entomopathogenic nematodes (genera Steinernema and Heterorhabditis), are be used as natural biopesticides. Unlike plant parasitic nematodes, which can be serious crop pests, entomopat...

  12. In vivo production of entomopathogenic nematodes

    USDA-ARS?s Scientific Manuscript database

    In nature, entomopathogenic nematodes in the genera Heterorhabditis and Steinernema are obligate parasites of insects. The nematodes are used widely as biocontrol agents for insect pests. More than a dozen entomopathogenic nematode species have been commercialized for use as biopesticides. One of ...

  13. Therapeutic immunomodulators from nematode parasites.

    PubMed

    Harnett, William; Harnett, Margaret M

    2008-06-19

    There has been an alarming increase in the incidence of autoimmune and allergic diseases in Western countries in the past few decades. However, in countries endemic for parasitic helminth infections, such diseases remain relatively rare. Hence, it has been hypothesised that helminths may protect against the development of autoimmunity and allergy. This article reviews the evidence supporting this idea with respect to helminths of the phylum Nematoda (nematodes), considering data from human studies and animal models of inflammatory disease. The nature and mode of action of nematode-derived molecules with immunomodulatory properties are considered, and their therapeutic efficacy in models of autoimmunity and allergy described. The recent and future use of nematodes and their products in treating human disease are also discussed.

  14. Prevalence and intensity of infection with third stage larvae of Angiostrongylus cantonensis in mollusks from Northeast Thailand.

    PubMed

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

    2009-06-01

    Prevalences and intensity of infection with Angiostrongylus cantonensis third stage larvae were examined in mollusks to determine whether they are potential intermediate hosts in eight provinces, northeast Thailand. Mollusk samples were collected from 24 reservoirs (3 reservoirs/province) in close to human cases during the previous year. Six out of 24 localities and 9 (3 new record species) out of 27 species were found with the infection. The highest intensity in infected species was found to be only one or two snails, whereas the majority had very low or no infection. The highest density was found in Pila pesmei and the lowest in Pila polita. The edible snails, P. polita, P. pesmei, and Hemiplecta distincta have the potential to transmit A. cantonensis to man. The varying density levels of larvae in infected snails may reflect observed variation in symptoms of people who traditionally eat a raw snail dish.

  15. Real-Time Polymerase Chain Reaction Detection of Angiostrongylus cantonensis DNA in Cerebrospinal Fluid from Patients with Eosinophilic Meningitis.

    PubMed

    Qvarnstrom, Yvonne; Xayavong, Maniphet; da Silva, Ana Cristina Aramburu; Park, Sarah Y; Whelen, A Christian; Calimlim, Precilia S; Sciulli, Rebecca H; Honda, Stacey A A; Higa, Karen; Kitsutani, Paul; Chea, Nora; Heng, Seng; Johnson, Stuart; Graeff-Teixeira, Carlos; Fox, LeAnne M; da Silva, Alexandre J

    2016-01-01

    Angiostrongylus cantonensis is the most common infectious cause of eosinophilic meningitis. Timely diagnosis of these infections is difficult, partly because reliable laboratory diagnostic methods are unavailable. The aim of this study was to evaluate the usefulness of a real-time polymerase chain reaction (PCR) assay for the detection of A. cantonensis DNA in human cerebrospinal fluid (CSF) specimens. A total of 49 CSF specimens from 33 patients with eosinophilic meningitis were included: A. cantonensis DNA was detected in 32 CSF specimens, from 22 patients. Four patients had intermittently positive and negative real-time PCR results on subsequent samples, indicating that the level of A. cantonensis DNA present in CSF may fluctuate during the course of the illness. Immunodiagnosis and/or supplemental PCR testing supported the real-time PCR findings for 30 patients. On the basis of these observations, this real-time PCR assay can be useful to detect A. cantonensis in the CSF from patients with eosinophilic meningitis.

  16. Nonhost Root Penetration by Soybean Cyst Nematode

    PubMed Central

    Riggs, R. D.

    1987-01-01

    A total of 66 plants in 50 species were inoculated with eggs and juveniles of soybean cyst nematode, Heterodera glycines. Roots were stained and observed for penetration and development of the nematode. Twenty-six plants were not penetrated; twenty-three were penetrated, but there was no development of the nematode; eight were penetrated with some nematode development; two were penetrated and had considerable nematode development, but few nematodes, if any, matured; and seven were penetrated with many nematodes maturing. The penetration of nonhosts may imply some susceptibility and that populations eventually would build up on the penetrated plants. Plants not penetrated may be useful as rotation plants because no reproduction would occur. PMID:19290137

  17. Compatibility of soil amendments with entomopathogenic nematodes.

    PubMed

    Bednarek, A; Gaugler, R

    1997-06-01

    The impact of inorganic and organic fertilizers on the infectivity, reproduction, and population dynamics of entomopathogenic nematodes was investigated. Prolonged (10- to 20-day) laboratory exposure to high inorganic fertilizer concentrations inhibited nematode infectivity and reproduction, whereas short (1-day) exposures increased infectivity. Heterorhabditis bacteriophora was more sensitive to adverse effects than were two species of Steinernema. In field studies, organic manure resulted in increased densities of a native population of Steinernema feltiae, whereas NPK fertilizer suppressed nematode densities regardless of manure applications. Inorganic fertilizers are likely to be compatible with nematodes in tank mixes and should not reduce the effectiveness of nematodes used for short-term control as biological insecticides, but may interfere with attempts to use nematodes as inoculative agents for long-term control. Organic manure used as fertilizer may encourage nematode establishment and recycling.

  18. Free-living nematode peptides

    USDA-ARS?s Scientific Manuscript database

    All nematodes employ a wide array of peptide messengers to control nearly all aspects of the life cycle, including hatching, locomotion, feeding, defense, mating, reproduction, and other behavioral and metabolic events. There are molecular and biological similarities, as well as significant differen...

  19. Nematode Symbiont for Photorhabdus asymbiotica

    PubMed Central

    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

    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. PMID:17176572

  20. Sequence data swell for nematodes.

    PubMed

    Hertz-Fowler, Christiane; Pain, Arnab

    2008-11-01

    With more than 80,000 described species that are extremely diverse in terms of ecology and biology, the Nematoda phylum is one of the most common animal phyla. This month's Genome Watch describes genomes of several nematodes, including that of the human filarial parasite Brugia malayi.

  1. Levels of infection with the lungworm Angiostrongylus cantonensis in terrestrial snails from Thailand, with Cryptozona siamensis as a new intermediate host.

    PubMed

    Vitta, A; Polsut, W; Fukruksa, C; Yimthin, T; Thanwisai, A; Dekumyoy, P

    2016-11-01

    Angiostrongylus cantonensis is primarily considered an emerging infectious agent of eosinophilic meningitis or meningoencephalitis with a worldwide distribution. Rodents and snails are important invasive hosts for transmission and expansion of A. cantonensis. The objective of this study was to investigate infection levels of A. cantonensis in snails, the most important natural intermediate host. Our study location was Mueang Kamphaeng Phet district, Kamphaeng Phet Province, and was undertaken between October and December 2012. A total of 2228 freshwater and terrestrial snails were collected, comprising 1119 Filopaludina spp., 409 Pomacea caniculata, 275 Achatina fulica and 425 Cryptozona siamensis. Angiostrongylus larvae were isolated by artificial digestion methods following Baermann's techniques. A low prevalence and intensity of A. cantonensis were observed in A. fulica, while higher numbers were found in C. siamensis. None of the Filopaludina spp. and Pomacea caniculata were infected with A. cantonensis. Molecular characterization was performed by analysing the 264 bp of cytochrome c oxidase subunit I (COI). Three COI sequences of Angiostrongylus were identical to A. cantonensis with 91-99% identity. Cryptozona siamensis has not previously been recorded as an intermediate host for A. cantonensis in Thailand. The infection of A. cantonensis identified in the natural intermediate hosts is new and important information to assist in the prevention and control of human angiostrongyliasis.

  2. The occurrence of the rat lungworm, Angiostrongylus cantonensis, in nonindigenous snails in the Gulf of Mexico region of the United States

    USGS Publications Warehouse

    Teem, John L.; Qvarnstrom, Yvonne; Bishop, Henry S.; da Silva, Alexandre J.; Carter, Jacoby; White-McLean, Jodi; Smith, Trevor

    2013-01-01

    Nonindigenous apple snails, Pomacea maculata (formerly Pomacea insularum), are currently spreading rapidly through the southeastern United States. This mollusk serves as an intermediate host of the rat lungworm parasite (Angiostrongylus cantonensis), which can cause eosinophilic meningitis in humans who consume infected mollusks. A PCR-based detection assay was used to test nonindigenous apple snails for the rat lungworm parasite in Louisiana, Texas, Mississippi, and Florida. Only apple snails obtained from the New Orleans, Louisiana, area tested positive for the parasite. These results provide the first evidence that Angiostrongylus cantonensis does occur in nonindigenous apple snails in the southeastern United States. Additionally, Angiostrongylus cantonensis was identified in the terrestrial species Achatina fulica in Miami, Florida, indicating that rat lungworm is now established in Florida as well as Louisiana. Although the study suggests that the rat lungworm is not widespread in the Gulf States region, the infected snail population could still pose a risk to human health and facilitate the spread of the parasite to new areas.

  3. The Occurrence of the Rat Lungworm, Angiostrongylus cantonensis, in Nonindigenous Snails in the Gulf of Mexico Region of the United States

    PubMed Central

    Qvarnstrom, Yvonne; Bishop, Henry S; da Silva, Alexandre J; Carter, Jacoby; White-Mclean, Jodi; Smith, Trevor

    2013-01-01

    Nonindigenous apple snails, Pomacea maculata (formerly Pomacea insularum), are currently spreading rapidly through the southeastern United States. This mollusk serves as an intermediate host of the rat lungworm parasite (Angiostrongylus cantonensis), which can cause eosinophilic meningitis in humans who consume infected mollusks. A PCR-based detection assay was used to test nonindigenous apple snails for the rat lungworm parasite in Louisiana, Texas, Mississippi, and Florida. Only apple snails obtained from the New Orleans, Louisiana, area tested positive for the parasite. These results provide the first evidence that Angiostrongylus cantonensis does occur in nonindigenous apple snails in the southeastern United States. Additionally, Angiostrongylus cantonensis was identified in the terrestrial species Achatina fulica in Miami, Florida, indicating that rat lungworm is now established in Florida as well as Louisiana. Although the study suggests that the rat lungworm is not widespread in the Gulf States region, the infected snail population could still pose a risk to human health and facilitate the spread of the parasite to new areas. PMID:23901374

  4. Nematode.net: a tool for navigating sequences from parasitic and free-living nematodes

    PubMed Central

    Wylie, Todd; Martin, John C.; Dante, Michael; Mitreva, Makedonka Dautova; Clifton, Sandra W.; Chinwalla, Asif; Waterston, Robert H.; Wilson, Richard K.; McCarter, James P.

    2004-01-01

    Nematode.net (www.nematode.net) is a web- accessible resource for investigating gene sequences from nematode genomes. The database is an outgrowth of the parasitic nematode EST project at Washington University’s Genome Sequencing Center (GSC), St Louis. A sister project at the University of Edinburgh and the Sanger Institute is also underway. More than 295 000 ESTs have been generated from >30 nematodes other than Caenorhabditis elegans including key parasites of humans, animals and plants. Nematode.net currently provides NemaGene EST cluster consensus sequence, enhanced online BLAST search tools, functional classifications of cluster sequences and comprehensive information concerning the ongoing generation of nematode genome data. The long-term goal of nematode.net is to provide the scientific community with the highest quality sequence information and tools for studying these diverse species. PMID:14681448

  5. Detection of plant-parasitic nematode DNA in the gut of predatory and omnivorous nematodes

    USDA-ARS?s Scientific Manuscript database

    A protocol for molecular gut analysis of nematodes was developed to determine if predatory and omnivorous nematodes from five different guilds prey on Rotylenchulus reniformis, Meloidogyne incognita, and Radopholus similis. Mononchoides, Mononchus, Neoactinolaimus, Mesodorylaimus, and Aporcelaimell...

  6. Experimental Evolution with Caenorhabditis Nematodes

    PubMed Central

    Teotónio, Henrique; Estes, Suzanne; Phillips, Patrick C.; Baer, Charles F.

    2017-01-01

    The hermaphroditic nematode Caenorhabditis elegans has been one of the primary model systems in biology since the 1970s, but only within the last two decades has this nematode also become a useful model for experimental evolution. Here, we outline the goals and major foci of experimental evolution with C. elegans and related species, such as C. briggsae and C. remanei, by discussing the principles of experimental design, and highlighting the strengths and limitations of Caenorhabditis as model systems. We then review three exemplars of Caenorhabditis experimental evolution studies, underlining representative evolution experiments that have addressed the: (1) maintenance of genetic variation; (2) role of natural selection during transitions from outcrossing to selfing, as well as the maintenance of mixed breeding modes during evolution; and (3) evolution of phenotypic plasticity and its role in adaptation to variable environments, including host–pathogen coevolution. We conclude by suggesting some future directions for which experimental evolution with Caenorhabditis would be particularly informative. PMID:28592504

  7. Applying antibiotic selection markers for nematode genetics.

    PubMed

    Cornes, Eric; Quéré, Cécile A L; Giordano-Santini, Rosina; Dupuy, Denis

    2014-08-01

    Antibiotic selection markers have been recently developed in the multicellular model organism Caenorhabditis elegans and other related nematode species, opening great opportunities in the field of nematode transgenesis. Here we describe how these antibiotic selection systems can be easily combined with many well-established genetic approaches to study gene function, improving time- and cost-effectiveness of the nematode genetic toolbox. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Survey of Nematodes on Coffee in Hawaii

    PubMed Central

    Schenck, S.; Schmitt, D. P.

    1992-01-01

    Surveys of coffee fields in Hawaii during 1989-1991 indicated the presence of 10 nematode species in 8 genera. After coffee was planted in fields previously in sugarcane, populations of Criconemella sp. and Pratylenchus zeae gradually decreased, while Rotylenchulus reniformis and, in one field, Meloidogyne incognita, increased in numbers. Coffee is a poor host of R. reniformis, but weeds in coffee plantations may support this nematode. At present, nematodes pose no serious threat to Hawaii's expanding coffee industry. PMID:19283060

  9. Ecology and evolution of soil nematode chemotaxis.

    PubMed

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

    2012-06-01

    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.

  10. Preparation of nematodes for scanning electron microscopy.

    PubMed

    Green, C D; Stone, A R; Turner, R H; Clark, S A

    1975-01-01

    Nematodes from the orders Tlyenchida and Rhabditida were fixed and processed in several different ways for examination with the scanning electron microscope (SEM). Four processes produced good preparations of fixed nematodes. Drying from acetone was the simplest of these techniques and most useful for regions of the tylenchid nematodes supported by skeletal tissue. Critical point drying, a more complicated procedure, gave good preparations, but they required special care in processing. Nematodes infiltrated with glycerol and a conducting agent were the most life-like but were difficult to examine. Specimens infiltrated with an epoxy resin looked natural and this was the most promising process tried.

  11. Management of the Citrus Nematode, Tylenchulus semipenetrans

    PubMed Central

    Verdejo-Lucas, S.; McKenry, M. V.

    2004-01-01

    Of the many nematode species that parasitize citrus, Tylenchulus semipenetrans is the most important on a worldwide basis. Management of the citrus nematode remains problematic as no one tactic gives adequate control of the nematode. An overall management strategy must include such components as site selection, use of non-infected nursery stock, use of at lease one post-plant nematode control tactic, and careful management of other elements of the environment that may stress the trees. Nematicides continue to play a key role in management of this pest. Optimum results require careful attention to application techniques. PMID:19262822

  12. Optimization of protease production by the fungus Monacrosporium thaumasium and its action against Angiostrongylus vasorum larvae.

    PubMed

    Soares, Filippe Elias de Freitas; Braga, Fabio Ribeiro; Araújo, Jackson Victor de; Lima, Walter dos Santos; Mozzer, Lanuze Rose; Queiroz, José Humberto de

    2013-01-01

    The objectives of this study were to optimize protease production from the nematophagous fungus Monacrosporium thaumasium (NF34a) and evaluate its larvicidal activity and biological stability. An isolate of the nematophagous fungus Monacrosporium thaumasium (NF34a) was used to produce the enzyme. The Plackett-Burman design was used in order to scan which components of the culture medium could have a significant influence on protease production by the fungus NF34a. An in vitro assay was also performed to evaluate the larvicidal activity of NF34a. It was observed that only one component of the culture medium (yeast extract), at the levels studied, had any significant effect (p < 0.05) on protease production. There was a reduction (p < 0.01) in the mean number of larvae recovered from the treated groups, compared with the control groups. The results confirm previous reports on the efficiency of nematophagous fungi for controlling nematode larvae that are potentially zoonotic. Thus, given the importance of biological control, we suggest that further studies should be conducted on the protease produced by the fungus Monacrosporium thaumasium.

  13. Biological Control of Nematodes with Bacteria

    USDA-ARS?s Scientific Manuscript database

    Biological control of nematodes is receiving increased attention as environmental considerations with the use of nematicides have increased in importance and their high cost prohibits use on many crops. In addition, nematode resistant cultivars are not available for many crops and resistance that i...

  14. Endemic Oscheius Nematodes of Hawai'i

    USDA-ARS?s Scientific Manuscript database

    Entomopathogenic nematodes (EPNs) parasitize insects utilizing mutualistic bacteria to kill the host, allowing the nematode to feed and reproduce within the insect cadaver. Consequently EPNs are highly sought after for their biological control potential. A survey for EPNs was conducted on O’ahu and...

  15. Blends of ascarosides regulate dispersal in nematodes

    USDA-ARS?s Scientific Manuscript database

    Blends of ascarosides regulate dispersal in nematodes Presenter: Dr. Fatma Kaplan Dispersal is an important behavior for many organisms. It can easily be observed when infectious juveniles of entomopathogenic nematodes (Steinernema and Heterorhabditis) leave a consumed insect host. Dauer larvae of ...

  16. Interspecific nematode signals regulate dispersal behavior

    USDA-ARS?s Scientific Manuscript database

    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 ...

  17. Imported Infections with Mansonella perstans Nematodes, Italy

    PubMed Central

    Beltrame, Anna; Buonfrate, Dora; Staffolani, Silvia; Degani, Monica; Gobbo, Maria; Angheben, Andrea; Marocco, Stefania; Bisoffi, Zeno

    2017-01-01

    We report 74 patients in Italy infected with Mansonella perstans nematodes, a poorly described filarial parasite. M. perstans nematodes should be included in the differential diagnosis for patients with eosinophilia from disease-endemic countries. Serologic analysis is useful for screening, and testing for microfilaremia in peripheral blood should be performed for parasite-positive patients. PMID:28820369

  18. Mechanisms of host seeking by parasitic nematodes.

    PubMed

    Gang, Spencer S; Hallem, Elissa A

    2016-07-01

    The phylum Nematoda comprises a diverse group of roundworms that includes parasites of vertebrates, invertebrates, and plants. Human-parasitic nematodes infect more than one billion people worldwide and cause some of the most common neglected tropical diseases, particularly in low-resource countries [1]. Parasitic nematodes of livestock and crops result in billions of dollars in losses each year [1]. Many nematode infections are treatable with low-cost anthelmintic drugs, but repeated infections are common in endemic areas and drug resistance is a growing concern with increasing therapeutic and agricultural administration [1]. Many parasitic nematodes have an environmental infective larval stage that engages in host seeking, a process whereby the infective larvae use sensory cues to search for hosts. Host seeking is a complex behavior that involves multiple sensory modalities, including olfaction, gustation, thermosensation, and humidity sensation. As the initial step of the parasite-host interaction, host seeking could be a powerful target for preventative intervention. However, host-seeking behavior remains poorly understood. Here we review what is currently known about the host-seeking behaviors of different parasitic nematodes, including insect-parasitic nematodes, mammalian-parasitic nematodes, and plant-parasitic nematodes. We also discuss the neural bases of these behaviors. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Nematodes ultrastructure: complex systems and processes.

    PubMed

    Basyoni, Maha M A; Rizk, Enas M A

    2016-12-01

    Nematode worms are among the most ubiquitous organisms on earth. They include free-living forms as well as parasites of plants, insects, humans and other animals. Recently, there has been an explosion of interest in nematode biology, including the area of nematode ultrastructure. Nematodes are round with a body cavity. They have one way guts with a mouth at one end and an anus at the other. They have a pseudocoelom that is lined on one side with mesoderm and on the other side with endoderm. It appears that the cuticle is a very complex and evolutionarily plastic feature with important functions involving protection, body movement and maintaining shape. They only have longitudinal muscles so; they seem to thrash back and forth. While nematodes have digestive, reproductive, nervous and excretory systems, they do not have discrete circulatory or respiratory systems. Nematodes use chemosensory and mechanosensory neurons embedded in the cuticle to orient and respond to a wide range of environmental stimuli. Adults are made up of roughly 1000 somatic cells and hundreds of those cells are typically associated with the reproductive systems. Nematodes ultrastructure seeks to provide studies which enable their use as models for diverse biological processes including; human diseases, immunity, host-parasitic interactions and the expression of phylogenomics. The latter has, however, not been brought into a single inclusive entity. Consequently, in the current review we tried to provide a comprehensive approach to the current knowledge available for nematodes ultrastructures.

  20. Induction of tumour necrosis factor, interleukin-1beta and matrix metalloproteinases in pulmonary fibrosis of rats infected with Angiostrongylus cantonensis.

    PubMed

    Tu, W C; Lai, S C

    2006-09-01

    In angiostrongyliasis, chronic parasite-induced granuloma formation can lead to tissue destruction and fibrosis. Here, the histomorphology of granulomatous fibrosis and proteinase production in the lungs of Angiostrongylus cantonensis-infected Sprague-Dawley rats were investigated. The relationship between metalloproteinases and granulomatous fibrosis was investigated following infection of each rat with 60 infective larvae. Granulomata and fibrosis were marked in the lungs of rats on day 180 post-inoculation. Reverse transcriptase polymerase chain reaction of lung mRNA showed an up-expression of proinflammatory cytokine including tumour necrosis factor alpha (TNF-alpha) and interleukin-1 beta (IL-1beta). According to Western blot analysis, matrix metalloproteinase-2 (MMP-2) proenzyme was presented in the lungs of uninfected and infected rats, and partial conversion of 72 kDa proenzyme to the 64 kDa active form occurred in infected rats. In addition, increased protein levels of MMP-9 and MMP-13 were detected in infected lungs, but were undetectable in controls. The results suggest that TNF-alpha, IL-1beta, MMP-2, -9, and -13 may be associated with the granulomatous fibrosis.

  1. The influence of Angiostrongylus cantonensis (Nematoda, Metastrongylidae) infection on the aerobic metabolism of Biomphalaria straminea and Biomphalaria tenagophila (Mollusca, Gastropoda).

    PubMed

    Lima, Mariana G; Tunholi-Alves, Vinícius M; Gaudêncio, Fabrício N; Martins, Florence G; Castro, Rosane N; Thiengo, Silvana C; Garcia, Juberlan S; Maldonado, Arnaldo; Pinheiro, Jairo

    2016-12-01

    Angiostrongylus cantonensis is considered the main agent responsible for human eosinophilic meningoencephalitis. This parasite has low specificity for mollusk hosts and it can also use aquatic snails as auxiliary hosts. Studies based on the metabolic profile of Biomphalaria spp. infected by A. cantonensis have been conducted to observe parasite-host interactions. In the present study, the glucose content in the hemolymph and glycogen content in the digestive gland and cephalopedal mass of Biomphalaria tenagophila and Biomphalaria straminea experimentally infected by A. cantonensis were evaluated, along with the activity of LDH. The snails were dissected from 6 to 21days after infection to collect the hemolymph and separate the tissues. Decreases of 96% and 6.4% in the glucose content triggered a transition from aerobic to anaerobic metabolism in the two infected snail species, B. straminea and B. tenagophila, respectively. That finding was confirmed by high-performance liquid chromatography. These results indicate that when infected, these snails are able to change their metabolic profile, suggesting a strategy to maintain their homeostatic balance.

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

    PubMed

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

    2013-03-01

    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.

  3. Real-Time Polymerase Chain Reaction Detection of Angiostrongylus cantonensis DNA in Cerebrospinal Fluid from Patients with Eosinophilic Meningitis

    PubMed Central

    Qvarnstrom, Yvonne; Xayavong, Maniphet; da Silva, Ana Cristina Aramburu; Park, Sarah Y.; Whelen, A. Christian; Calimlim, Precilia S.; Sciulli, Rebecca H.; Honda, Stacey A. A.; Higa, Karen; Kitsutani, Paul; Chea, Nora; Heng, Seng; Johnson, Stuart; Graeff-Teixeira, Carlos; Fox, LeAnne M.; da Silva, Alexandre J.

    2016-01-01

    Angiostrongylus cantonensis is the most common infectious cause of eosinophilic meningitis. Timely diagnosis of these infections is difficult, partly because reliable laboratory diagnostic methods are unavailable. The aim of this study was to evaluate the usefulness of a real-time polymerase chain reaction (PCR) assay for the detection of A. cantonensis DNA in human cerebrospinal fluid (CSF) specimens. A total of 49 CSF specimens from 33 patients with eosinophilic meningitis were included: A. cantonensis DNA was detected in 32 CSF specimens, from 22 patients. Four patients had intermittently positive and negative real-time PCR results on subsequent samples, indicating that the level of A. cantonensis DNA present in CSF may fluctuate during the course of the illness. Immunodiagnosis and/or supplemental PCR testing supported the real-time PCR findings for 30 patients. On the basis of these observations, this real-time PCR assay can be useful to detect A. cantonensis in the CSF from patients with eosinophilic meningitis. PMID:26526920

  4. How do humans affect wildlife nematodes?

    USGS Publications Warehouse

    Weinstein, Sara B.; Lafferty, Kevin D.

    2015-01-01

    Human actions can affect wildlife and their nematode parasites. Species introductions and human-facilitated range expansions can create new host–parasite interactions. Novel hosts can introduce parasites and have the potential to both amplify and dilute nematode transmission. Furthermore, humans can alter existing nematode dynamics by changing host densities and the abiotic conditions that affect larval parasite survival. Human impacts on wildlife might impair parasites by reducing the abundance of their hosts; however, domestic animal production and complex life cycles can maintain transmission even when wildlife becomes rare. Although wildlife nematodes have many possible responses to human actions, understanding host and parasite natural history, and the mechanisms behind the changing disease dynamics might improve disease control in the few cases where nematode parasitism impacts wildlife.

  5. Improved nematode extraction from carrot disk culture.

    PubMed

    Kaplan, D T; Davis, E L

    1990-07-01

    Radopholus spp. were reared in carrot tissue culture via established procedures, with slight modification. Several plant tissue maceration enzymes and flotation media (salts and sucrose) were evaluated with regard to nematode toxicity and extraction efficiency. Best extraction of viable nematodes and eggs was attained when carrot tissue infested with Radopholus citrophilus or R. similis was macerated with a mixture of 0.50% driselase and 0.50% cellulysin, w/v each, with 2.5 ml of enzyme solution based for each gram of carrot tissue. Maceration slurries containing carrot tissue and nematodes were maintained in open flasks on a rotary shaker (175 rpm) at 26 C for 24 hours. Nematodes and eggs were extracted from resultant culture slurries by flotation with MgSO-7H0 (sp gr 1.1). A protocol is presented to extract large quantities of viable burrowing nematodes and their eggs from carrot disk cultures.

  6. Improved Nematode Extraction from Carrot Disk Culture

    PubMed Central

    Kaplan, David T.; Davis, Eric L.

    1990-01-01

    Radopholus spp. were reared in carrot tissue culture via established procedures, with slight modification. Several plant tissue maceration enzymes and flotation media (salts and sucrose) were evaluated with regard to nematode toxicity and extraction efficiency. Best extraction of viable nematodes and eggs was attained when carrot tissue infested with Radopholus citrophilus or R. similis was macerated with a mixture of 0.50% driselase and 0.50% cellulysin, w/v each, with 2.5 ml of enzyme solution based for each gram of carrot tissue. Maceration slurries containing carrot tissue and nematodes were maintained in open flasks on a rotary shaker (175 rpm) at 26 C for 24 hours. Nematodes and eggs were extracted from resultant culture slurries by flotation with MgSO₄-7H₂0 (sp gr 1.1). A protocol is presented to extract large quantities of viable burrowing nematodes and their eggs from carrot disk cultures. PMID:19287736

  7. Plant basal resistance to nematodes: an update.

    PubMed

    Holbein, Julia; Grundler, Florian M W; Siddique, Shahid

    2016-03-01

    Most plant-parasitic nematodes are obligate biotrophs feeding on the roots of their hosts. Whereas ectoparasites remain on the root surface and feed on the outer cell layers, endoparasitic nematodes enter the host to parasitize cells around or within the central cylinder. Nematode invasion and feeding causes tissue damage which may, in turn, lead to the activation of host basal defence responses. Hitherto, research interests in plant-nematode interaction have emphasized effector-triggered immunity rather than basal plant defence responses. However, some recent investigations suggest that basal defence pathways are not only activated but also play an important role in determining interaction outcomes. In this review we discuss the major findings and point out future directions to dissect the molecular mechanisms underlying plant basal defence to nematodes further. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  8. How do humans affect wildlife nematodes?

    PubMed

    Weinstein, Sara B; Lafferty, Kevin D

    2015-05-01

    Human actions can affect wildlife and their nematode parasites. Species introductions and human-facilitated range expansions can create new host-parasite interactions. Novel hosts can introduce parasites and have the potential to both amplify and dilute nematode transmission. Furthermore, humans can alter existing nematode dynamics by changing host densities and the abiotic conditions that affect larval parasite survival. Human impacts on wildlife might impair parasites by reducing the abundance of their hosts; however, domestic animal production and complex life cycles can maintain transmission even when wildlife becomes rare. Although wildlife nematodes have many possible responses to human actions, understanding host and parasite natural history, and the mechanisms behind the changing disease dynamics might improve disease control in the few cases where nematode parasitism impacts wildlife.

  9. Nondestructive imaging of plant-parasitic nematode development and host response to nematode pathogenesis.

    PubMed

    Dinh, Phuong T Y; Knoblauch, Michael; Elling, Axel A

    2014-05-01

    The secluded lifestyle of endoparasitic plant nematodes hampers progress toward a comprehensive understanding of plant-nematode interactions. A novel technique that enables nondestructive, long-term observations of a wide range of live nematodes in planta is presented here. As proof of principle, Pratylenchus penetrans, Heterodera schachtii, and Meloidogyne chitwoodi were labeled fluorescently with PKH26 and used to infect Arabidopsis thaliana grown in microscopy rhizosphere chambers. Nematode behavior, development, and morphology were observed for the full duration of each parasite's life cycle by confocal microscopy for up to 27 days after inoculation. PKH26 accumulated in intestinal lipid droplets and had no negative effect on nematode infectivity. This technique enabled visualization of Meloidogyne gall formation, nematode oogenesis, and nematode morphological features, such as the metacorpus, vulva, spicules, and cuticle. Additionally, microscopy rhizosphere chambers were used to characterize plant organelle dynamics during M. chitwoodi infection. Peroxisome abundance strongly increased in early giant cells but showed a marked decrease at later stages of feeding site development, which suggests a modulation of plant peroxisomes by root-knot nematodes during the infection process. Taken together, this technique facilitates studies aimed at deciphering plant-nematode interactions at the cellular and subcellular level and enables unprecedented insights into nematode behavior in planta.

  10. Current research on the major nematode problems in Japan.

    PubMed

    Ichinohe, M

    1988-04-01

    AMONG IMPORTANT NEMATODE SPECIES OCCURRING IN JAPAN, CURRENT RESEARCH ACHIEVEMENTS WITH THE FOLLOWING FOUR NEMATODES ARE REVIEWED: 1) Soybean cyst nematode (SCN), Heterodera glycines - breeding for resistance, race determination, association with Cephalosporium gregatum in azuki bean disease, and isolation of hatching stimulant. 2) Potato-cyst nematode (PCN), Globodera rostochiensis - pathotype determination (Ro 1), breeding for resistance, and control recommendations. 3) Pinewood nematode (PWN), Bursaphelenchus xylophilus - primary pathogen in pine wilt disease, life cycle exhibiting a typical symbiosis with Japanese pine sawyer, Monochamus alternatus, and project for control. 4) Rice root nematodes (RRN), Hirschmanniella imamuri and H. oryzae - distribution of species, population levels in roots, and role of these nematodes in rice culture.

  11. Parasitic nematodes - from genomes to control.

    PubMed

    Mitreva, Makedonka; Zarlenga, Dante S; McCarter, James P; Jasmer, Douglas P

    2007-08-19

    The diseases caused by parasitic nematodes in domestic and companion animals are major factors that decrease production and quality of the agricultural products. Methods available for the control of the parasitic nematode infections are mainly based on chemical treatment, non-chemical management practices, immune modulation and biological control. However, even with integrated pest management that frequently combines these approaches, the effective and long-lasting control strategies are hampered by the persistent exposure of host animals to environmental stages of parasites, the incomplete protective response of the host and acquisition of anthelmintic resistance by an increasing number of parasitic nematodes. Therefore, the challenges to improve control of parasitic nematode infections are multi-fold and no single category of information will meet them all. However, new information, such as nematode genomics, functional genomics and proteomics, can strengthen basic and applied biological research aimed to develop improvements. In this review we will, summarize existing control strategies of nematode infections and discuss ongoing developments in nematode genomics. Genomics approaches offer a growing and fundamental base of information, which when coupled with downstream functional genomics and proteomics can accelerate progress towards developing more efficient and sustainable control programs.

  12. Ascaroside Signaling is Widely Conserved Among Nematodes

    PubMed Central

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

    2012-01-01

    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. PMID:22503501

  13. [Nematodes of humans in the Primorye Territory].

    PubMed

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

    2013-01-01

    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.

  14. The FLP-side of nematodes.

    PubMed

    McVeigh, Paul; Geary, Timothy G; Marks, Nikki J; Maule, Aaron G

    2006-08-01

    The central role of FMRFamide-like peptides (FLPs) in nematode motor and sensory capabilities makes FLP signalling an appealing target for new parasiticides. Accumulating evidence has revealed an astounding level of FLP sequence conservation and diversity in the phylum Nematoda, and preliminary work has begun to identify the nematode FLP receptor complement in Caenorhabditis elegans, with a view to investigating their basic biology and therapeutic potential. However, much work is needed to clarify the functional aspects of FLP signalling and how these peptides exert their effects at the organismal level. Here, we summarize our current knowledge of nematode FLP signalling.

  15. An 8-week brain MRI follow-up analysis of rat eosinophilic meningitis caused by Angiostrongylus cantonensis infection.

    PubMed

    Shyu, L Y; Tsai, H H; Lin, D P; Chang, H H; Tyan, Y S; Weng, J C

    2014-09-01

    Early differential diagnosis and timely follow-up are advantageous in the management of Angiostrongylus cantonensis infection. This study aimed to characterize angiostrongyliasis in the rat brain for an 8-week period using magnetic resonance imaging (MRI) with contrast-enhanced T1-weighted images (T1WI), T2-weighted imaging (T2WI), fluid attenuation inversion recovery (FLAIR) and R2 mapping sequences. The data were analysed with Mathematica and Matlab software programs for weekly changes in each brain following the infection of 20, 50, 100 and 300 third-stage larvae (L3), respectively. The results showed that the average subarachnoid space detected by T2WI technique was peaked up to 10% increase of original size on day 35 after 100 or 300 larvae infection, while those infected with 20 or 50 larvae showed less than 4% increase during the entire course of observation. This increase was relevant to the mortality of the infected rats, because those with 100 or 300 larvae infections showed a sharp decrease in survival rate before day 40. After day 40, the average subarachnoid space was decreased, but the average ventricle size was persistently increased, with the highest increase observed in the group infected with 300 larvae on day 56. Furthermore, the R2 mapping mean and R2 mapping size were significantly different between the brains with severe infection (100 and 300 larvae groups together) and those with mild infection (20 and 50 larvae groups together) on day 49, but not on day 35. Our results showed that diagnosis for different quantity of larvae infection using MRI is possible and follow-up characterization is informative in revealing the effects of angiostrongyliasis on different brain areas. In conclusion, our results support the use of MRI as a non-invasive diagnostic technique for eosinophilic meningitis caused by A. cantonensis infection. © 2013 Blackwell Verlag GmbH.

  16. Nematode endogenous small RNA pathways

    PubMed Central

    Hoogstrate, Suzanne W; Volkers, Rita JM; Sterken, Mark G; Kammenga, Jan E; Snoek, L Basten

    2014-01-01

    The discovery of small RNA silencing pathways has greatly extended our knowledge of gene regulation. Small RNAs have been presumed to play a role in every field of biology because they affect many biological processes via regulation of gene expression and chromatin remodeling. Most well-known examples of affected processes are development, fertility, and maintenance of genome stability. Here we review the role of the three main endogenous small RNA silencing pathways in Caenorhabditis elegans: microRNAs, endogenous small interfering RNAs, and PIWI-interacting RNAs. After providing an entry-level overview on how these pathways function, we discuss research on other nematode species providing insight into the evolution of these small RNA pathways. In understanding the differences between the endogenous small RNA pathways and their evolution, a more comprehensive picture is formed of the functions and effects of small RNAs. PMID:25340013

  17. Galactosylated Fucose Epitopes in Nematodes

    PubMed Central

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

    2012-01-01

    The modification of α1,6-linked fucose residues attached to the proximal (reducing-terminal) core N-acetylglucosamine residue of N-glycans by β1,4-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 α1,6-fucosylation and β1,4-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 α1,3-fucosylation of the proximal N-acetylglucosamine was abolished, the degree of galactosylation of core α1,6-fucose increased, and a novel Galα1,2Fucα1,3 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 α1,3-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. PMID:22733825

  18. WormBase: Annotating many nematode genomes.

    PubMed

    Howe, Kevin; Davis, Paul; Paulini, Michael; Tuli, Mary Ann; Williams, Gary; Yook, Karen; Durbin, Richard; Kersey, Paul; Sternberg, Paul W

    2012-01-01

    WormBase (www.wormbase.org) has been serving the scientific community for over 11 years as the central repository for genomic and genetic information for the soil nematode Caenorhabditis elegans. The resource has evolved from its beginnings as a database housing the genomic sequence and genetic and physical maps of a single species, and now represents the breadth and diversity of nematode research, currently serving genome sequence and annotation for around 20 nematodes. In this article, we focus on WormBase's role of genome sequence annotation, describing how we annotate and integrate data from a growing collection of nematode species and strains. We also review our approaches to sequence curation, and discuss the impact on annotation quality of large functional genomics projects such as modENCODE.

  19. Nematode molecular diagnostics: from bands to barcodes.

    PubMed

    Powers, Tom

    2004-01-01

    Nematodes are considered among the most difficult animals to identify. DNA-based diagnostic methods have already gained acceptance in applications ranging from quarantine determinations to assessments of biodiversity. Researchers are currently in an information-gathering mode, with intensive efforts applied to accumulating nucleotide sequence of 18S and 28S ribosomal genes, internally transcribed spacer regions, and mitochondrial genes. Important linkages with collateral data such as digitized images, video clips and specimen voucher web pages are being established on GenBank and NemATOL, the nematode-specific Tree of Life database. The growing DNA taxonomy of nematodes has lead to their use in testing specific short sequences of DNA as a "barcode" for the identification of all nematode species.

  20. How cellular slime molds evade nematodes.

    PubMed Central

    Kessin, R H; Gundersen, G G; Zaydfudim, V; Grimson, M

    1996-01-01

    We have found a predator-prey association between the social amoeba Dictyostelium discoideum and the free soil living nematode Caenorhabditis elegans. C. elegans feeds on the amoebae and multiplies indefinitely when amoebae are the sole food source. In an environment created from soil, D. discoideum grows and develops, but not in the presence of C. elegans. During development, C. elegans feeds on amoebae until they aggregate and synthesize an extracellular matrix called the slime sheath. After the sheath forms, the aggregate and slug are protected. Adult nematodes ingest Dictyostelium spores, which pass through the gut of the worm without loss of structure and remain viable. Nematodes kill the amoebae but disperse the spores. The sheath that is constructed when the social amoebae aggregate and the spore coats of the individual cells may protect against this predator. Individual amoebae may also protect themselves by secreting compounds that repel nematodes. Images Fig. 1 Fig. 3 Fig. 4 Fig. 5 Fig. 6 PMID:8643493

  1. Conserving and Enhancing Biological Control of Nematodes

    PubMed Central

    Timper, Patricia

    2014-01-01

    Conservation biological control is the modification of the environment or existing practices to protect and enhance antagonistic organisms to reduce damage from pests. This approach to biological control has received insufficient attention compared with inundative applications of microbial antagonists to control nematodes. This review provides examples of how production practices can enhance or diminish biological control of plant-parasitic nematodes and other soilborne pests. Antagonists of nematodes can be enhanced by providing supplementary food sources such as occurs when organic amendments are applied to soil. However, some organic amendments (e.g., manures and plants containing allelopathic compounds) can also be detrimental to nematode antagonists. Plant species and genotype can strongly influence the outcome of biological control. For instance, the susceptibility of the plant to the nematode can determine the effectiveness of control; good hosts will require greater levels of suppression than poor hosts. Plant genotype can also influence the degree of rhizosphere colonization and antibiotic production by antagonists, as well the expression of induced resistance by plants. Production practices such as crop rotation, fallow periods, tillage, and pesticide applications can directly disrupt populations of antagonistic organisms. These practices can also indirectly affect antagonists by reducing their primary nematode host. One of the challenges of conservation biological control is that practices intended to protect or enhance suppression of nematodes may not be effective in all field sites because they are dependent on indigenous antagonists. Ultimately, indicators will need to be identified, such as the presence of particular antagonists, which can guide decisions on where it is practical to use conservation biological control. Antagonists can also be applied to field sites in conjunction with conservation practices to improve the consistency, efficacy, and

  2. Conserving and enhancing biological control of nematodes.

    PubMed

    Timper, Patricia

    2014-06-01

    Conservation biological control is the modification of the environment or existing practices to protect and enhance antagonistic organisms to reduce damage from pests. This approach to biological control has received insufficient attention compared with inundative applications of microbial antagonists to control nematodes. This review provides examples of how production practices can enhance or diminish biological control of plant-parasitic nematodes and other soilborne pests. Antagonists of nematodes can be enhanced by providing supplementary food sources such as occurs when organic amendments are applied to soil. However, some organic amendments (e.g., manures and plants containing allelopathic compounds) can also be detrimental to nematode antagonists. Plant species and genotype can strongly influence the outcome of biological control. For instance, the susceptibility of the plant to the nematode can determine the effectiveness of control; good hosts will require greater levels of suppression than poor hosts. Plant genotype can also influence the degree of rhizosphere colonization and antibiotic production by antagonists, as well the expression of induced resistance by plants. Production practices such as crop rotation, fallow periods, tillage, and pesticide applications can directly disrupt populations of antagonistic organisms. These practices can also indirectly affect antagonists by reducing their primary nematode host. One of the challenges of conservation biological control is that practices intended to protect or enhance suppression of nematodes may not be effective in all field sites because they are dependent on indigenous antagonists. Ultimately, indicators will need to be identified, such as the presence of particular antagonists, which can guide decisions on where it is practical to use conservation biological control. Antagonists can also be applied to field sites in conjunction with conservation practices to improve the consistency, efficacy, and

  3. Interactions between Nematodes and Earthworms: Enhanced Dispersal of Steinernema carpocapsae

    PubMed Central

    Shapiro, D. I.; Berry, E. C.; Lewis, L. C.

    1993-01-01

    Dispersal of the nematode Steinernema carpocapsae (All strain), applied on the top or the bottom of soil columns, was tested in the presence or absence of two earthworm species, Lumbricus terrestris or Aporrectodea trapezoides. Nematode dispersal was estimated after a 2-week period with a bioassay against the greater wax moth, Galleria mellonella. Vertical dispersal of nematodes was increased in the presence of earthworms. When nematodes were placed on the surface of soil columns, significantly more nematodes dispersed to the lower half of the columns when either earthworm species was present than when earthworms were not present. When nematodes were placed on the bottom of soil columns, significantly more nematodes dispersed to the upper half of the columns when L. terrestris was present than when A. trapezoides was present or in the absence of earthworms. Because nematodes were found on the exterior and in the interior of earthworms, nematode dispersal may be enhanced by direct contact with the earthworms. PMID:19279757

  4. Nematode parasites of animals are more prone to develop xenobiotic resistance than nematode parasites of plants.

    PubMed

    Silvestre, A; Cabaret, J

    2004-06-01

    In this paper, we concentrate on a comparison of plant and animal-parasitic nematodes, to gain insight into the factors that influence the acquisition of the drug resistance by nematodes. Comparing nematode parasite of domestic animals and cultivated plants, it appears that drug resistance threatens only domestic animal production. Does the paucity of report on nematicide field resistance reflect reality or, is nematicide resistance bypassed by other management practices, specific to cultivated plants (i.e. agricultural control)? First, it seems that selection pressure by treatments in plants is not as efficient as selection pressure in ruminants. Agronomic practices (i.e. sanitation, early planting, usage of nematodes resistant cultivar and crop rotation) are frequently used to control parasitic-plant nematodes. Although the efficiency of such measures is generally moderate to high, integrated approaches are developing successfully in parasitic-plant nematode models. Secondly, the majority of anthelmintic resistance cases recorded in animal-parasitic nematodes concern drug families that are not used in plant-parasitic nematodes control (i.e. benzimidazoles, avermectines and levamisole). Thirdly, particular life traits of parasitic-plant nematodes (low to moderate fecundity and reproductive strategy) are expected to reduce probability of appearance and transmission of drug resistance genes. It has been demonstrated that, for a large number of nematodes such as Meloidogyne spp., the mode of reproduction by mitotic parthenogenesis reduced genetic diversity of populations which may prevent a rapid drug resistance development. In conclusion, anthelmintic resistance develops in nematode parasite of animals as a consequence of an efficient selection pressure. Early detection of anthelmintic resistance is then crucial: it is not possible to avoid it, but only to delay its development in farm animal industry.

  5. Biocontrol: Fungi as Nematode Control Agents

    PubMed Central

    Mankau, R.

    1980-01-01

    The fungal antagonists of nematodes consist of a great variety of organisms belonging to widely divergent orders and families of fungi. They include the nematode-trapping fungi, endoparasitic fungi, parasites of nematode eggs and cysts, and fungi which produce metabolites toxic to nematodes. The diversity, adaptations, and distribution of nematode-destroying fungi and taxonomic problems encountered in their study are reviewed. The importance of nemato-phagous fungi in soil biology, with special emphasis on their relationship to populations of plant-parasitic nematodes, is considered. While predacious fungi have long been investigated as possible biocontrol agents and have often exhibited spectacular results in vitro, their performance in field studies has generated little enthusiasm among nematologists. To date no species has demonstrated control of any plant pest to a degree achieved with nematicides, but recent studies have provided a much clearer concept of possibilities and problems in the applied use of fungal antagonists. The discovery of new species, which appear to control certain pests effectively under specific conditions, holds out some promise that fungi may be utilized as alternatives to chemical control after a more thorough and expanded study of their biology and ecology. PMID:19300699

  6. Molecular mechanisms of nematode-nematophagous microbe interactions: basis for biological control of plant-parasitic nematodes.

    PubMed

    Li, Juan; Zou, Chenggang; Xu, Jianping; Ji, Xinglai; Niu, Xuemei; Yang, Jinkui; Huang, Xiaowei; Zhang, Ke-Qin

    2015-01-01

    Plant-parasitic nematodes cause significant damage to a broad range of vegetables and agricultural crops throughout the world. As the natural enemies of nematodes, nematophagous microorganisms offer a promising approach to control the nematode pests. Some of these microorganisms produce traps to capture and kill the worms from the outside. Others act as internal parasites to produce toxins and virulence factors to kill the nematodes from within. Understanding the molecular basis of microbe-nematode interactions provides crucial insights for developing effective biological control agents against plant-parasitic nematodes. Here, we review recent advances in our understanding of the interactions between nematodes and nematophagous microorganisms, with a focus on the molecular mechanisms by which nematophagous microorganisms infect nematodes and on the nematode defense against pathogenic attacks. We conclude by discussing several key areas for future research and development, including potential approaches to apply our recent understandings to develop effective biocontrol strategies.

  7. Influence of Metalaxyl on Three Nematodes of Citrus

    PubMed Central

    Kaplan, David T.

    1983-01-01

    Metalaxyl significantly reduced population of Pratylenchus coffeae, Radopholus similis, and Tylenchulus semipenetrans in roots of Citrus limon (rough lemon) under greenhouse conditions. Postinoculation treatment of rough lemon seedlings was not as effective i n reducing nematode populations as was treatment before inoculation. Fewer nematodes infected metalaxyl-treated roots than nontreated roots. However, incubation of nematodes in metalaxyl did not inhibit nematode motility or their ability to locate and infect roots. Cellular responses to nematode injection differed between treated and nontreated tissues. Metalaxyl appeared to confer nematode contraol by modifying citrus roots such that a normally susceptible rootstock became tolerant. PMID:19295833

  8. Influence of metalaxyl on three nematodes of citrus.

    PubMed

    Kaplan, D T

    1983-07-01

    Metalaxyl significantly reduced population of Pratylenchus coffeae, Radopholus similis, and Tylenchulus semipenetrans in roots of Citrus limon (rough lemon) under greenhouse conditions. Postinoculation treatment of rough lemon seedlings was not as effective i n reducing nematode populations as was treatment before inoculation. Fewer nematodes infected metalaxyl-treated roots than nontreated roots. However, incubation of nematodes in metalaxyl did not inhibit nematode motility or their ability to locate and infect roots. Cellular responses to nematode injection differed between treated and nontreated tissues. Metalaxyl appeared to confer nematode contraol by modifying citrus roots such that a normally susceptible rootstock became tolerant.

  9. Nematode Trophic Structure in Conventional and No-Tillage Agroecosystems

    PubMed Central

    Parmelee, Robert W.; Alston, Diane G.

    1986-01-01

    The effect of tillage intensity on nematode community trophic structure and the role of nematodes in the regulation of decomposition rates in agroecosystems were examined. Conventional (CT) and no-tillage (NT) agroecosystems were sampled monthly for 1 year. Tillage affected nematode trophic structure and total abundance. Monthly mean densities of bacterivorous, fungivorous, and total nematodes were greater in CT than in NT plots. In the summer, however, fungivorous and plant parasitic nematodes were more abundant in NT. No difference was detected for omnivore-predator nematodes. PMID:19294199

  10. Induced resistance to nematodes in cotton: a novel contribution to nematode management.

    USDA-ARS?s Scientific Manuscript database

    Induced resistance against plant-parasitic nematodes has not previously been shown in cotton. We tested whether co-infection of cotton by Meloidogyne incognita and Rotylenchulus reniformis affected population levels of either nematode compared to single-species infection. In split-root experiments, ...

  11. Interspecific Nematode Signals Regulate Dispersal Behavior

    PubMed Central

    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

    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. PMID:22701701

  12. Clinical manifestations of eosinophilic meningitis caused by Angiostrongylus cantonensis: 18 years' experience in a medical center in southern Taiwan.

    PubMed

    Tseng, Yu-Ting; Tsai, Hung-Chin; Sy, Cheng Len; Lee, Susan Shin-Jung; Wann, Shue-Ren; Wang, Yung-Hsing; Chen, Jei-Kuang; Wu, Kuan-Sheng; Chen, Yao-Shen

    2011-10-01

    With the improvement of public health, eosinophilic meningitis associated with Angiostrongylus cantonensis infection is now seldom reported in Taiwan. Eosinophilic meningitis typically occurred sporadically in children. This study aims to analyze the clinical manifestations and change in the contemporary epidemiology of eosinophilic meningitis in Taiwan. This is a retrospective study of patients diagnosed with eosinophilic meningitis at Kaohsiung Veterans General Hospital, from December 1991 to September 2009. The demographic characteristics, clinical presentations, laboratory data, radiographic imaging, and treatment and clinical outcome were analyzed. A PubMed search with the keywords of eosinophilic meningitis, A cantonensis, and Taiwan was performed to retrieve cases of eosinophilic meningitis caused by A cantonensis since 1960. Thirty-seven patients were diagnosed to have eosinophilic meningitis during a period of 18 years. The median age was 32 years (range, 2-80 years). Ninety five percent (35/37) of the patients were adults. The median incubation period was 10.5 days (range, 3-80 days). Most of the patients presented with headache (29, 78%), fever (25, 68%), and 11(30%) had hyperesthesia. Patients with hyperesthesia had longer incubation period (55 vs. 7 days, p=0.004), lower serum immunoglobulin E levels (127.5 vs. 1295 IU/mL, p<0.001), and longer duration between symptom onset and spinal taps (14 vs. 5 days, p=0.011). Three patients presented initially with lymphocytic meningitis, and eosinophilia only appeared on a second lumbar puncture. Magnetic resonance imaging of the brain disclosed leptomeningeal enhancement (17/26, 65%) and increased signal intensity (10/26, 38%) on T2-weighted and fluid-attenuated inversion recovery images. There were eight relapses and two patients died. No sequela was noted except in one 2-year-old toddler, who had weakness of both lower limbs. The epidemiology of eosinophilic meningitis has changed during the past two decades

  13. Larvicidal effect of imidacloprid/moxidectin spot-on solution in dogs experimentally inoculated with Angiostrongylus vasorum.

    PubMed

    Schnyder, M; Fahrion, A; Ossent, P; Kohler, L; Webster, P; Heine, J; Deplazes, P

    2009-12-23

    A controlled, randomized, blinded dose confirmation study was conducted to evaluate the larvicidal efficacy and safety of imidacloprid 10 mg/kg/moxidectin 2.5 mg/kg body weight spot-on solution in dogs experimentally inoculated with 200 infective third stage larvae (L3) of Angiostrongylus vasorum. Twenty-four adult dogs were randomly allocated to three study groups of 8 dogs each. Animals in group 1 were treated 4 days post-inoculation (dpi), those in group 2 at 32 dpi, and the dogs in group 3 were left untreated. All dogs were euthanized and necropsied 56-59 dpi. In order to determine the worm burdens in the arterial lung vessels a method of reverse lung perfusion with phosphate buffered solution after inhibition of coagulation with heparin was applied. In the control group, excretion of first stage larvae (L1) of A. vasorum started 47-55 dpi and all dogs excreted L1 at least on one sample day before euthanasia (0.1-32.5 larvae per gram of faeces). A mean of 99 (SD 42.8) adult parasites were recovered in the post-mortem examinations in these eight control dogs. In contrast, no L1 at all were found in the faeces of dogs of groups 1 and 2, nor were any adult parasites detected at necropsy. Respiratory symptoms were observed in dogs of groups 2 and 3. Pathological findings in the lungs correlated with the treatment groups: in the animals of group 1, no or minimal lesions were found, while in all those of group 2 dispersed patterns of pale pink, slightly raised and consolidated foci were present in all lung lobes. In contrast, the lungs of the dogs from group 3 were severely affected: large confluent areas were hardened, raised and discoloured, with frequent haemorrhagic patches. Pneumonia, thrombi and parasites were histologically confirmed. The lung lymph nodes were regularly enlarged. Hence, imidacloprid/moxidectin spot-on effectively eliminated fourth stage larvae (L4) and immature adult A. vasorum in experimentally infected dogs and prevented patent infections

  14. Activation of the hypothalamic-pituitary-adrenal (HPA) axis contributes to the immunosuppression of mice infected with Angiostrongylus cantonensis.

    PubMed

    Chen, Ai-Ling; Sun, Xi; Wang, Wei; Liu, Jin-Feng; Zeng, Xin; Qiu, Jing-Fan; Liu, Xin-Jian; Wang, Yong

    2016-10-12

    Immunosuppression has been described as a consequence of brain injury and infection by different mechanisms. Angiostrongylus cantonensis can cause injury to the central nervous system and eosinophilic meningitis to human. Both T cell and B cell immunity play an essential role in the resistance of the infection. However, whether brain injury caused by A. cantonensis infection can lead to immunosuppression is not clear. Therefore, the present study sought to observe the alteration of immune responses in mice infected with A. cantonensis. Mice were infected with 20 third-stage A. cantonensis larvae. The messenger RNA (mRNA) expression of inflammatory mediators in brain tissues was observed by qRT-PCR. Cell surface markers including CD3, CD4, CD8, CD19, B220, 7-AAD, annexin-V, IgM, AA4.1, and CD23 were evaluated by using flow cytometry. The immune functions of T and B lymphocytes were detected upon stimulation by ConA and antibody responses to a nonself antigen OVA, respectively. Activation of the hypothalamic-pituitary-adrenal axis was evaluated by analyzing the concentration of plasma corticosterone and levels of mRNA for corticotropin-releasing hormone, tyrosine hydroxylase, and c-fos. A. cantonensis infection results in obvious immunosuppression evidenced as progressive spleen and thymus atrophy and significant decrease in the number of lymphocyte subsets including B cells, CD3(+) T cells, CD4(+) T cells, and CD8(+) T cells, as well as reduced T cell proliferation at 21 days post-infection and antibody reaction to exogenous protein after infection. However, the sharp decrease of splenic and thymic cells was not due to cell apoptosis but to B cell genesis cessation and impairing thymocyte development. In addition, helminthicide treatment with albendazole on infected mice at 7 days post-infection could prevent immunosuppressive symptoms. Importantly, infected mice displayed hypothalamic-pituitary-adrenal axis activation, with peak responses occurring at 16

  15. Pepsin is a positive regulator of Ac-cathB-2 involved in the rat gut penetration of Angiostrongylus cantonensis.

    PubMed

    Long, Ying; Cao, Binbin; Wang, Yinan; Luo, Damin

    2016-05-17

    Angiostrongyliasis caused by the rat lungworm, Angiostrongylus cantonensis (A. cantonensis), has globally spread from the traditional epidemic areas. The small intestine is the site where the third-stage larvae (L3) of this worm entered the host body, and parasite proteases are involved in this process. Ac-cathB-2, a cathepsin B-like cysteine of A. cantonensis, was formerly isolated from the insoluble part of fragmentised Escherichia coli without activity. The unplanned low activity of prokaryotic expression proteins and difficulties in genetic modification hindered understanding the function of this protein. The recombinant Ac-cathB-2 was expressed and harvested from 293 T cells and the enzymatic property and the effects of processing on the activity of the recombinant protease were investigated in vitro. The expression of Ac-cathB-2 in response to external stimulation was assessed, and the function of this protease during host gut penetration was observed by using antiserum for inhibition. Of the life-cycle stages studied, L3 expressed the highest level of Ac-cathB-2 gene and released the corresponding gene product from the body. The expression of this gene was rapidly upregulated after incubating L3 in small intestine homogenate of rat. Recombinant Ac-cathB-2 was harvested from 293 T cell culture medium. This protease was activated by pepsin-HCl and the enabled Ac-cathB-2 could subsequently digest laminin and fibronectin readily. Moreover, the small intestine isolated from rat was disrupted after incubating with the activated Ac-cathB-2, resulting in the detachment of epithelial cells. Antiserum treatment inhibited the hydrolytic ability of recombinant Ac-cathB-2 by 82.7 %, and also reduced the tissue penetration of activated L3 by 41.2 %. Additionally, pre-incubation of L3 with artificial gastric acid increased the number of penetrating larvae by 53.2 %, and this alteration could be partly blocked by antiserum treatment. We believe that Ac-cathB-2 from A

  16. Embryological variation during nematode development.

    PubMed

    Schierenberg, Einhard

    2006-01-02

    Early cell lineages and arrangement of blastomeres in C. elegans are similar to the pattern found in Ascaris and other studied nematodes leading to the assumption that embryonic development shows little variation within the phylum Nematoda. However, analysis of a larger variety of species from various branches of the phylogenetic tree demonstrate that prominent variations in crucial steps of early embryogenesis exist among representatives of this taxon. So far, most of these variations have only been studied on a descriptive level and thus essentially nothing is known about their molecular or genetic basis. Nevertheless, it is obvious that the limited morphological diversity of the freshly hatched juvenile and the uniformity of the basic body plan contrast with the many modifications in the way a worm is generated from the egg cell. This chapter focuses on the initial phase between egg activation and gastrulation and deals with the following aspects: reproduction and diploidy, polarity, cleavage and germ line, cell lineages; cell cycles and maternal contribution, cell-cell communication and cell specification, gastrulation.

  17. Parameters affecting plant defense pathway mediated recruitment of entomopathogenic nematodes

    USDA-ARS?s Scientific Manuscript database

    Entomopathogenic nematodes are natural enemies and effective biological control agents of subterranean insect herbivores. Interactions between her bivores, plants, and entomopathogenic nematodes are mediated by plant defense pathways that can induce release of volatiles that recruit entomopathogenic...

  18. Two new species of soil nematodes from Manipur, India.

    PubMed

    Chanu, Loukrakpam Bina; Meitei, N Mohilal; Shah, M Manjur

    2016-09-01

    Survey for soil nematodes associated with mulberry plants in valley districts of Manipur revealed the presence of two new species of soil nematodes of the genus Tylenchus sp. and Telotylenchus sp. The two new species are described and illustrated here.

  19. Nematodes associated with blackberry in arkansas.

    PubMed

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

    1991-10-01

    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.

  20. Molecular Transfer of Nematode Resistance Genes

    PubMed Central

    Williamson, V. M.; Ho, J.-Y.; Ma, H. M.

    1992-01-01

    Recombinant DNA techniques have been used to introduce agronomically valuable traits, including resistance to viruses, herbicides, and insects, into crop plants. Introduction of these genes into plants frequently involves Agrobacterium-mediated gene transfer. The potential exists for applying this technology to nematode control by introducing genes conferring resistance to nematodes. Transferred genes could include those encoding products detrimental to nematode development or reproduction as well as cloned host resistance genes. Host genes that confer resistance to cyst or root-knot nematode species have been identified in many plants. The best characterized is Mi, a gene that confers resistance to root-knot nematodes in tomato. A map-based cloning approach is being used to isolate the gene. For development of a detailed map of the region of the genome surrounding Mi, DNA markers genetically linked to Mi have been identified and analyzed in tomato lines that have undergone a recombination event near Mi. The molecular map will be used to identify DNA corresponding to Mi. We estimate that a clone of Mi will be obtained in 2-5 years. An exciting prospect is that introduction of this gene will confer resistance in plant species without currently available sources of resistance. PMID:19282989

  1. Nematode feeding sites: unique organs in plant roots.

    PubMed

    Kyndt, Tina; Vieira, Paulo; Gheysen, Godelieve; de Almeida-Engler, Janice

    2013-11-01

    Although generally unnoticed, nearly all crop plants have one or more species of nematodes that feed on their roots, frequently causing tremendous yield losses. The group of sedentary nematodes, which are among the most damaging plant-parasitic nematodes, cause the formation of special organs called nematode feeding sites (NFS) in the root tissue. In this review we discuss key metabolic and cellular changes correlated with NFS development, and similarities and discrepancies between different types of NFS are highlighted.

  2. Nature and Inheritance of Nematode Resistance in Cereals

    PubMed Central

    Cook, R.

    1974-01-01

    Resistance to a number of nematodes is present in varieties of temperate and tropical cereals. The occurrence, nature, and inheritance of varietal resistance in cereals is reviewed. Evaluation of the practical significance of nematode resistance in a particular host-nematode combination is discussed in relation to host efficiency, host sensitivity, genetic control of resistance, and presence of virulence in the nematode population. PMID:19308117

  3. Biocontrol: the potential of entomophilic nematodes in insect management.

    PubMed

    Webster, J M

    1980-10-01

    A review of the development of entomophilic nematology and a commentary on the potential of entomophilic nematodes in controlling insect pests. The paper considers some of the major contributions to our knowledge of entomophilic nematology; factors involved in insect pest management and how they are applicable to the use of nematodes; nematodes which are most promising as biological control agents; and problems to be solved to facilitate the use of entomophilic nematodes in insect management.

  4. Biocontrol: The Potential of Entomophilic Nematodes in Insect Management

    PubMed Central

    Webster, John M.

    1980-01-01

    A review of the development of entomophilic nematology and a commentary on the potential of entomophilic nematodes in controlling insect pests. The paper considers some of the major contributions to our knowledge of entomophilic nematology; factors involved in insect pest management and how they are applicable to the use of nematodes; nematodes which are most promising as biological control agents; and problems to be solved to facilitate the use of entomophilic nematodes in insect management. PMID:19300702

  5. Characterization of biocontrol traits in the entomopathogenic nematode Heterorhabditis georgiana (Kesah strain), and phylogenetic analysis of the nematode's symbiotic bacteria.

    USDA-ARS?s Scientific Manuscript database

    Our objective was to estimate the biocontrol potential of the recently discovered entomopathogenic nematode species, Heterorhabditis georgiana (Kesha strain). Virulence and environmental tolerance were tested among several nematode species. Heterorhabditis georgiana expressed low or intermediate c...

  6. Site-Specific Detection and Management of Nematodes

    USDA-ARS?s Scientific Manuscript database

    Nematode distribution varies significantly throughout a field and is highly correlated to soil texture and other edaphic factors. Field-wide application results in nematicides being applied to areas without nematodes and the application of sub-effective levels in areas with high nematode densities. ...

  7. Bacterial microbiome and nematode occurrence in different potato agricultural soils

    USDA-ARS?s Scientific Manuscript database

    Pratylenchus neglectus and Meloidogyne chitwoodi are the main plant-parasitic nematodes in potato crops of the San Luis Valley, Colorado. Bacterial microbiome (16S rRNA copies per gram of soil) and nematode communities (nematodes per 200 gr of soil) from five different potato farms were analyzed to ...

  8. Ecology of the Pinewood Nematode in Southern Pine Chip Piles

    Treesearch

    L. David Dwinell

    1986-01-01

    The optimum temperature range for pinewood nematodes in southern pine chips was 35 to 40° C. Nematode populations declined at temperatures of -20°C. at temperatures above 45°C. and in anaerobic environments. Wood moisture content and presence of bluestain fungus also influenced nematode populations.

  9. Opportunity to use native nematodes for pest control

    USDA-ARS?s Scientific Manuscript database

    We have surveyed wild cranberry bogs in WI and found three isolates of native nematodes. We have been testing these nematodes as potential biological control agents in for cranberry insect pests including sparganothis fruitworm and flea beetle. The nematodes seem to be effective at finding and killi...

  10. Towards a genome sequence for reniform nematode (Rotylenchulus reniformis)

    USDA-ARS?s Scientific Manuscript database

    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...

  11. Nematode CLE signaling in Arabidopsis requires CLAVATA2 and CORYNE

    USDA-ARS?s Scientific Manuscript database

    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...

  12. A novel flavivirus in the soybean cyst nematode

    USDA-ARS?s Scientific Manuscript database

    Heterodera glycines, the soybean cyst nematode (SCN) is a subterranean root pathogen that causes the most damaging disease of soybean in the United States. A novel nematode virus genome, soybean cyst nematode virus 5 (SbCNV5), was identified in RNASeq data from SCN eggs and second-stage juveniles. T...

  13. The Apple Snail Pomacea canaliculata, a Novel Vector of the Rat Lungworm, Angiostrongylus cantonensis: its Introduction, Spread, and Control in China

    PubMed Central

    Wu, Zhong-Dao; Lun, Zhao-Rong

    2013-01-01

    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

  14. Alteration of antibodies against the fifth-stage larvae and changes in brain magnetic resonance images in experimentally infected rabbits with Angiostrongylus cantonensis.

    PubMed

    Wang, Lian-Chen; Wan, Yung-Liang

    2004-10-01

    Magnetic resonance (MR) imaging has been suggested to be helpful in delineating the lesions during the acute phase of angiostrongyliasis caused by Angiostrongylus cantonensis. In this study, antibody titers in serum samples of 3 rabbits were determined by enzyme-linked immunosorbent assay, and brain MR images were obtained from 6 rabbits. The antibody titer elevated rapidly in the first 4 wk postinfection (PI) before reaching a plateau. However, suspicious changes in brain MR images near the left lateral ventricle and hippocampus were found only in 1 rabbit on day 28 PI. These findings indicate that immunologic responses in the central nervous system at the early stage of angiostrongyliasis are not sufficient to be observed by image studies.

  15. Nematode Problems Affecting Agriculture in the Philippines

    PubMed Central

    Davide, R. G.

    1988-01-01

    Nematodes are considered major pests on most economic crops in the Philippines, particularly on banana, pineapple, citrus, tomato, ramie, and sugarcane. Radopholus similis is the most destructive nematode on banana, while Meloidogyne spp. are more serious on various vegetable crops such as tomato, okra, and celery and on fiber crops such as ramie. Tylenchulus semipenetrans is a problem on citrus and Rotylenchulus reniformis on pineapple and some legume crops. Hirschmanniella oryzae and Aphelenchoides besseyi are becoming serious on rice, and Pratylenchus zeae is affecting corn in some areas. Lately, Globodera rostochiensis has been causing serious damage on potato in the highlands. Control measures such as crop rotation, planting resistant varieties, chemical nematicide application, and biological control have been recommended to control these nematodes. PMID:19290204

  16. Remote Sensing of Parasitic Nematodes in Plants

    NASA Technical Reports Server (NTRS)

    Lawrence, Gary W.; King, Roger; Kelley, Amber T.; Vickery, John

    2007-01-01

    A method and apparatus for remote sensing of parasitic nematodes in plants, now undergoing development, is based on measurement of visible and infrared spectral reflectances of fields where the plants are growing. Initial development efforts have been concentrated on detecting reniform nematodes (Rotylenchulus reniformis) in cotton plants, because of the economic importance of cotton crops. The apparatus includes a hand-held spectroradiometer. The readings taken by the radiometer are processed to extract spectral reflectances at sixteen wavelengths between 451 and 949 nm that, taken together, have been found to be indicative of the presence of Rotylenchulus reniformis. The intensities of the spectral reflectances are used to estimate the population density of the nematodes in an area from which readings were taken.

  17. Nematode problems affecting agriculture in the Philippines.

    PubMed

    Davide, R G

    1988-04-01

    Nematodes are considered major pests on most economic crops in the Philippines, particularly on banana, pineapple, citrus, tomato, ramie, and sugarcane. Radopholus similis is the most destructive nematode on banana, while Meloidogyne spp. are more serious on various vegetable crops such as tomato, okra, and celery and on fiber crops such as ramie. Tylenchulus semipenetrans is a problem on citrus and Rotylenchulus reniformis on pineapple and some legume crops. Hirschmanniella oryzae and Aphelenchoides besseyi are becoming serious on rice, and Pratylenchus zeae is affecting corn in some areas. Lately, Globodera rostochiensis has been causing serious damage on potato in the highlands. Control measures such as crop rotation, planting resistant varieties, chemical nematicide application, and biological control have been recommended to control these nematodes.

  18. Nematode taxonomy: from morphology to metabarcoding

    NASA Astrophysics Data System (ADS)

    Ahmed, M.; Sapp, M.; Prior, T.; Karssen, G.; Back, M.

    2015-11-01

    Nematodes represent a species rich and morphologically diverse group of metazoans inhabiting both aquatic and terrestrial environments. Their role as biological indicators and as key players in nutrient cycling has been well documented. Some groups of nematodes are also known to cause significant losses to crop production. In spite of this, knowledge of their diversity is still limited due to the difficulty in achieving species identification using morphological characters. Molecular methodology has provided very useful means of circumventing the numerous limitations associated with classical morphology based identification. We discuss herein the history and the progress made within the field of nematode systematics, the limitations of classical taxonomy and how the advent of high throughput sequencing is facilitating advanced ecological and molecular studies.

  19. Theory of the locomotion of nematodes

    PubMed Central

    Niebur, Ernst; Erdös, Paul

    1991-01-01

    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. PMID:19431807

  20. Immunological control of gastrointestinal nematode infections.

    PubMed

    Klei, T R

    1997-11-01

    Control of nematode parasitism by an active manipulation of the host immune response has been a goal of veterinary and medical parasitologists for decades. The reality of achieving this goal has been questioned vigorously and demonstrations of the feasibility of using immunological control under field conditions are minimal. Nevertheless, with the rapid growth of modern biotechnology and the identification of novel parasite molecules as vaccine targets, the potential for success in this area has recently generated considerable excitement. The induction and regulation of the ruminant immune response against nematode parasites can be controlled either by management programs which include anthelmintic treatment or by vaccination. Both approaches will be discussed in this session.

  1. Detecting Nematode Features from Digital Images

    PubMed Central

    de la Blanca, N. Pérez; Fdez-Valdivia, J.; Castillo, P.; Gómez-Barcina, A.

    1992-01-01

    Procedures for estimating and calibrating nematode features from digitial images are described and evaluated by illustration and mathematical formulae. Technical problems, such as capturing and cleaning raw images, standardizing the grey level range of images, and the detection of characteristics of the body habitus, presence or absence of stylet knobs, and tail and lip region shape are discussed. This study is the first of a series aimed at developing a set of automated methods to permit more rapid, objective characterizations of nematode features than is achievable by cumbersome conventional methods. PMID:19282998

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

    USDA-ARS?s Scientific Manuscript database

    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...

  3. [Soil nematode as a bioindicator of environment pollution].

    PubMed

    Zhang, Wei; Song, Yufang; Sun, Tieheng; Song, Xueying; Zhou, Qixing

    2004-10-01

    As a part of mesofauna in soil ecosystem, nematode plays an important role in essential soil processes. Because of its unique attributes, nematode was widely used in the study of soil health indication. Based on the current studies at home and abroad, this paper discussed the function and application of nematode in indicating and diagnosing soil pollution, and the indices (maturity index, diversity index, similarity index, key species, N/C ratio, and physiological index) and their characteristics of nematode communities used as indicators. As a useful index of bioindicators in ecotoxicological diagnosis, the prospect of soil nematode application was of potential.

  4. Unravelling parasitic nematode natural history using population genetics.

    PubMed

    Gilabert, Aude; Wasmuth, James D

    2013-09-01

    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. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Mining nematode genome data for novel drug targets.

    PubMed

    Foster, Jeremy M; Zhang, Yinhua; Kumar, Sanjay; Carlow, Clotilde K S

    2005-03-01

    Expressed sequence tag projects have currently produced over 400 000 partial gene sequences from more than 30 nematode species and the full genomic sequences of selected nematodes are being determined. In addition, functional analyses in the model nematode Caenorhabditis elegans have addressed the role of almost all genes predicted by the genome sequence. This recent explosion in the amount of available nematode DNA sequences, coupled with new gene function data, provides an unprecedented opportunity to identify pre-validated drug targets through efficient mining of nematode genomic databases. This article describes the various information sources available and strategies that can expedite this process.

  6. The evolution of spliced leader trans-splicing in nematodes.

    PubMed

    Pettitt, Jonathan; Harrison, Neale; Stansfield, Ian; Connolly, Bernadette; Müller, Berndt

    2010-08-01

    Spliced leader trans-splicing occurs in many primitive eukaryotes including nematodes. Most of our knowledge of trans-splicing in nematodes stems from the model organism Caenorhabditis elegans and relatives, and from work with Ascaris. Our investigation of spliced leader trans-splicing in distantly related Dorylaimia nematodes indicates that spliced-leader trans-splicing arose before the nematode phylum and suggests that the spliced leader RNA gene complements in extant nematodes have evolved from a common ancestor with a diverse set of spliced leader RNA genes.

  7. An improved method for generating axenic entomopathogenic nematodes.

    PubMed

    Yadav, Shruti; Shokal, Upasana; Forst, Steven; Eleftherianos, Ioannis

    2015-09-19

    Steinernema carpocapsae are parasitic nematodes that invade and kill insects. The nematodes are mutualistically associated with the bacteria Xenorhabdus nematophila and together form an excellent model to study pathogen infection processes and host anti-nematode/antibacterial immune responses. To determine the contribution of S. carpocapsae and their associated X. nematophila to the successful infection of insects as well as to investigate the interaction of each mutualistic partner with the insect immune system, it is important to develop and establish robust methods for generating nematodes devoid of their bacteria. To produce S. carpocapsae nematodes without their associated X. nematophila bacteria, we have modified a previous method, which involves the use of a X. nematophila rpoS mutant strain that fails to colonize the intestine of the worms. We confirmed the absence of bacteria in the nematodes using a molecular diagnostic and two rounds of an axenicity assay involving appropriate antibiotics and nematode surface sterilization. We used axenic and symbiotic S. carpocapsae to infect Drosophila melanogaster larvae and found that both types of nematodes were able to cause insect death at similar rates. Generation of entomopathogenic nematodes lacking their mutualistic bacteria provides an excellent tool to dissect the molecular and genetic basis of nematode parasitism and to identify the insect host immune factors that participate in the immune response against nematode infections.

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

    PubMed

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

    2009-08-24

    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. 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. 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

  9. A Trojan horse mechanism of bacterial pathogenesis against nematodes

    PubMed Central

    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

    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. PMID:20733068

  10. Cryopreservation of roe deer abomasal nematodes for morphological identification.

    PubMed

    Beraldo, Paola; Pascotto, Ernesto

    2014-02-01

    Conventional methods to preserve adult nematodes for taxonomic purposes involve the use of fixative or clearing solutions (alcohol, formaldehyde, AFA and lactophenol), which cause morphological alterations and are toxic. The aim of this study is to propose an alternative method based on glycerol-cryopreservation of nematodes for their subsequent identification. Adults of trichostrongylid nematodes from the abomasum of roe deer (Capreolus capreolus Linnaeus) were glycerol-cryopreserved and compared with those fixed in formaldehyde, fresh and frozen without cryoprotectans. Morphology, transparency and elasticity of the anterior and posterior portion of male nematodes were compared, especially the caudal cuticular bursa and genital accessories. The method presented is quick and easy to use, and the quality of nematode specimens is better than that of nematodes fixed by previously used fixatives. Moreover, glycerol cryopreserved nematodes can be stored for a long time at -20 degrees C in perfect condition and they could be suitable for further analyses, such as histological or ultrastructural examinations.

  11. Cuticle surface coat of plant-parasitic nematodes.

    PubMed

    Davies, Keith G; Curtis, Rosane H C

    2011-01-01

    The surface coat (SC) of the plant-parasitic nematode cuticle is an understudied area of current research, even though it likely plays key roles in both nematode-plant and nematode-microbe interactions. Although in several ways Caenorhabditis elegans is a poor model for plant-parasitic nematodes, it is a useful starting point for investigations of the cuticle and its SC, especially in the light of recent work using this species as a model for innate immunity and the generic biology underpinning much host-parasite biology. We review the research focused on the involvement of the SC of plant-parasitic nematodes. Using the insights gained from animal-parasitic nematodes and other sequenced nematodes, we discuss the key roles that the SC may play.

  12. Potato cyst nematodes: pests of national importance

    USDA-ARS?s Scientific Manuscript database

    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...

  13. The Future of Nematode Management in Cotton

    PubMed Central

    Starr, J. L.; Koenning, S. R.; Kirkpatrick, T. L.; Robinson, A. F.; Roberts, P. A.; Nichols, R. L.

    2007-01-01

    The importance of plant-parasitic nematodes as yield-limiting pathogens of cotton has received increased recognition and attention in the United States in the recent past. This paper summarizes the remarks made during a symposium of the same title that was held in July 2007 at the joint meeting of the Society of Nematologists and the American Phytopathological Society in San Diego, California. Although several cultural practices, including crop rotation, can be effective in suppressing the populations of the important nematode pathogens of cotton, the economic realities of cotton production limit their use. The use of nematicides is also limited by issues of efficacy and economics. There is a need for development of chemistries that will address these limitations. Also needed are systems that would enable precise nematicide application in terms of rate and placement only in areas where nematode population densities warrant application. Substantial progress is being made in the identification, characterization and mapping of loci for resistance to Meloidogyne incognita and Rotylenchulus reniformis. These data will lead to efficient marker-assisted selection systems that will likely result in development and release of nematode-resistant cotton cultivars with superior yield potential and high fiber quality. PMID:19259500

  14. Meloidogyne incognita nematode resistance QTL in carrot

    USDA-ARS?s Scientific Manuscript database

    Root-knot nematodes (Meloidogyne spp.) are major pests attacking carrots (Daucus carota) worldwide, causing galling and forking of the storage roots, rendering them unacceptable for market. Genetic resistance could significantly reduce the need for broad-spectrum soil fumigants in carrot production....

  15. Diverse CLE peptides from cyst nematode species

    USDA-ARS?s Scientific Manuscript database

    Plant CLAVATA3/ESR (CLE)-like peptides play diverse roles in plant growth and development including maintenance of the stem cell population in the root meristem. Small secreted peptides sharing similarity to plant CLE signaling peptides have been isolated from several cyst nematode species including...

  16. Dolichodorus aestuarius n. sp. (Nematode: Dolichodoridae)

    PubMed Central

    Chow, F. H.; Taylor, A. L.

    1978-01-01

    Dolichodorus aestuarius n. sp. from an estuarine habitat near Cedar Key, Florida is described. This nematode has a stylet range of 62-76 μm in females and 60-72 μm in males. The stylet is shorter than those of all described species except D. brevistilus. The probable host plant is Juncus roemerianus. PMID:19305840

  17. Molecular analysis of plant-parasitic nematodes

    USDA-ARS?s Scientific Manuscript database

    In addition to traditional morphology-based taxonomic approaches, molecular methods are often required to confirm diagnoses or to establish phylogenetic relationships among plant-parasitic nematodes. Current challenges, including limitations of existing methods, and new research directions will be d...

  18. Nematodes: Model Organisms in High School Biology

    ERIC Educational Resources Information Center

    Bliss, TJ; Anderson, Margery; Dillman, Adler; Yourick, Debra; Jett, Marti; Adams, Byron J.; Russell, RevaBeth

    2007-01-01

    In a collaborative effort between university researchers and high school science teachers, an inquiry-based laboratory module was designed using two species of insecticidal nematodes to help students apply scientific inquiry and elements of thoughtful experimental design. The learning experience and model are described in this article. (Contains 4…

  19. Key to nematodes reported in waterfowl

    USGS Publications Warehouse

    McDonald, Malcolm E.

    1974-01-01

    This key, covering 171 species and subspecies of nematodes in 49 genera, is based on the the listings in the author's "Catalogue of Helminths of Waterfowl" (McDonald, 1969b), but includes 19 additional forms from his continuing survey of new literature.

  20. Nematode modulation of inflammatory bowel disease.

    PubMed

    Whelan, Rose A K; Hartmann, Susanne; Rausch, Sebastian

    2012-10-01

    Inflammatory bowel disease (IBD) is a chronic disease arising due to a culmination of genetic, environmental, and lifestyle-associated factors and resulting in an excessive pro-inflammatory response to bacterial populations in the gastrointestinal tract. The prevalence of IBD in developing nations is relatively low, and it has been proposed that this is directly correlated with a high incidence of helminth infections in these areas. Gastrointestinal nematodes are the most prevalent parasitic worms, and they efficiently modulate the immune system of their hosts in order to establish chronic infections. Thus, they may be capable of suppressing unrelated inflammation in disorders such as IBD. This review describes how nematodes, or their products, suppress innate and adaptive pro-inflammatory immune responses and how the mechanisms involved in the induction of anti-nematode responses regulate colitis in experimental models and clinical trials with IBD patients. We also discuss how refinement of nematode-derived therapies should ultimately result in the development of potent new therapeutics of clinical inflammatory disorders.

  1. Survival of Chlorophyceae Ingested by Saprozoic Nematodes

    PubMed Central

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

    1970-01-01

    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

  2. Mermithid Nematodes: In Vitro Culture Attempts

    PubMed Central

    Finney, Jean R.

    1981-01-01

    Few attempts at in vitro culture of mermithids have been undertaken. The various methods used to initiate cultures are described. The capacity of a range of media to promote growth and development of the nematodes has been evaluated and current approaches to in vitro outlined. PMID:19300762

  3. The Pinewood Nematode: Regulation and Mitigation

    Treesearch

    L. David Dwinell

    1997-01-01

    In North America, the native pinewood nematode (PWN), Bursaphelenchus xylophilus, kills exotic pines. When inadvertently introduced to Japan and other Asian countries, PWN became a destructive pest of pines. The PWN has been intercepted in pine shipments from North America to Europe, where there is concern that it may also kill pines and other conifers. To protect...

  4. Considering field physical characteristics in assessing risk and delineating nematode management zones

    USDA-ARS?s Scientific Manuscript database

    Site-specific management (SSM) of nematodes requires identifying factors affecting nematode distribution, nematode population density, and nematode-induced yield losses, and then using that information to predict where nematode management will cost-effectively reduce yield loss. Using cotton (Gossy...

  5. Top 10 plant-parasitic nematodes in molecular plant pathology.

    PubMed

    Jones, John T; Haegeman, Annelies; Danchin, Etienne G J; Gaur, Hari S; Helder, Johannes; Jones, Michael G K; Kikuchi, Taisei; Manzanilla-López, Rosa; Palomares-Rius, Juan E; Wesemael, Wim M L; Perry, Roland N

    2013-12-01

    The aim of this review was to undertake a survey of researchers working with plant-parasitic nematodes in order to determine a 'top 10' list of these pathogens based on scientific and economic importance. Any such list will not be definitive as economic importance will vary depending on the region of the world in which a researcher is based. However, care was taken to include researchers from as many parts of the world as possible when carrying out the survey. The top 10 list emerging from the survey is composed of: (1) root-knot nematodes (Meloidogyne spp.); (2) cyst nematodes (Heterodera and Globodera spp.); (3) root lesion nematodes (Pratylenchus spp.); (4) the burrowing nematode Radopholus similis; (5) Ditylenchus dipsaci; (6) the pine wilt nematode Bursaphelenchus xylophilus; (7) the reniform nematode Rotylenchulus reniformis; (8) Xiphinema index (the only virus vector nematode to make the list); (9) Nacobbus aberrans; and (10) Aphelenchoides besseyi. The biology of each nematode (or nematode group) is reviewed briefly. © 2013 BSPP AND JOHN WILEY & SONS LTD.

  6. Microbiota from Rhabditis regina may alter nematode entomopathogenicity.

    PubMed

    Jiménez-Cortés, Jesús Guillermo; Canales-Lazcano, Jorge; Lara-Reyes, Nancy; Rosenblueth, Mónica; Martínez-Romero, Esperanza; Contreras-Garduño, Jorge

    2016-11-01

    Here we report the presence of the entomopathogenic nematode Rhabditis (Rhabditoides) regina affecting white grubs (Phyllophaga sp. and Anomala sp.) in Mexico and R. regina-associated bacteria. Bioassays were performed to test the entomopathogenic capacity of dauer and L2 and L3 (combined) larval stages. Furthermore, we determined the diversity of bacteria from laboratory nematodes cultivated for 2 years (dauer and L2-L3 larvae) and from field nematodes (dauer and L2-L3 larvae) in addition to the virulence in Galleria mellonella larvae of some bacterial species from both laboratory and field nematodes. Dauer and non-dauer larvae of R. regina killed G. mellonella. Bacteria such as Serratia sp. (isolated from field nematodes) and Klebsiella sp. (isolated from larvae of laboratory and field nematodes) may explain R. regina entomopathogenic capabilities. Different bacteria were found in nematodes after subculturing in the laboratory suggesting that R. regina may acquire bacteria in different environments. However, there were some consistently found bacteria from laboratory and field nematodes such as Pseudochrobactrum sp., Comamonas sp., Alcaligenes sp., Klebsiella sp., Acinetobacter sp., and Leucobacter sp. that may constitute the nematode microbiome. Results showed that some bacteria contributing to entomopathogenicity may be lost in the laboratory representing a disadvantage when nematodes are cultivated to be used for biological control.

  7. The Bacterial Community of Entomophilic Nematodes and Host Beetles

    PubMed Central

    Koneru, Sneha L.; Salinas, Heilly; Flores, Gilberto E.; Hong, Ray L.

    2016-01-01

    Insects form the most species-rich lineage of Eukaryotes and each is a potential host for organisms from multiple phyla, including fungi, protozoa, mites, bacteria, and nematodes. In particular, beetles are known to be associated with distinct bacterial communities and entomophilic nematodes. While entomopathogenic nematodes require symbiotic bacteria to kill and reproduce inside their insect hosts, the microbial ecology that facilitates other types of nematode-insect associations is largely unknown. To illuminate detailed patterns of the tritrophic beetle-nematode-bacteria relationship, we surveyed the nematode infestation profiles of scarab beetles in the greater Los Angeles area over a five-year period and found distinct nematode infestation patterns for certain beetle hosts. Over a single season, we characterized the bacterial communities of beetles and their associated nematodes using high-throughput sequencing of the 16S rRNA gene. We found significant differences in bacterial community composition among the five prevalent beetle host species, independent of geographic origin. Anaerobes Synergistaceae and sulfate-reducing Desulfovibrionaceae were most abundant in Amblonoxia beetles, while Enterobacteriaceae and Lachnospiraceae were common in Cyclocephala beetles. Unlike entomopathogenic nematodes that carry bacterial symbionts, insect-associated nematodes do not alter the beetles’ native bacterial communities, nor do their microbiomes differ according to nematode or beetle host species. The conservation of Diplogastrid nematodes associations with Melolonthinae beetles and sulfate-reducing bacteria suggests a possible link between beetle bacterial communities and their associated nematodes. Our results establish a starting point towards understanding the dynamic interactions between soil macroinvertebrates and their microbiota in a highly accessible urban environment. PMID:26992100

  8. The bacterial community of entomophilic nematodes and host beetles.

    PubMed

    Koneru, Sneha L; Salinas, Heilly; Flores, Gilberto E; Hong, Ray L

    2016-05-01

    Insects form the most species-rich lineage of Eukaryotes and each is a potential host for organisms from multiple phyla, including fungi, protozoa, mites, bacteria and nematodes. In particular, beetles are known to be associated with distinct bacterial communities and entomophilic nematodes. While entomopathogenic nematodes require symbiotic bacteria to kill and reproduce inside their insect hosts, the microbial ecology that facilitates other types of nematode-insect associations is largely unknown. To illuminate detailed patterns of the tritrophic beetle-nematode-bacteria relationship, we surveyed the nematode infestation profiles of scarab beetles in the greater Los Angeles area over a five-year period and found distinct nematode infestation patterns for certain beetle hosts. Over a single season, we characterized the bacterial communities of beetles and their associated nematodes using high-throughput sequencing of the 16S rRNA gene. We found significant differences in bacterial community composition among the five prevalent beetle host species, independent of geographical origin. Anaerobes Synergistaceae and sulphate-reducing Desulfovibrionaceae were most abundant in Amblonoxia beetles, while Enterobacteriaceae and Lachnospiraceae were common in Cyclocephala beetles. Unlike entomopathogenic nematodes that carry bacterial symbionts, insect-associated nematodes do not alter the beetles' native bacterial communities, nor do their microbiomes differ according to nematode or beetle host species. The conservation of Diplogastrid nematodes associations with Melolonthinae beetles and sulphate-reducing bacteria suggests a possible link between beetle-bacterial communities and their associated nematodes. Our results establish a starting point towards understanding the dynamic interactions between soil macroinvertebrates and their microbiota in a highly accessible urban environment. © 2016 John Wiley & Sons Ltd.

  9. Small RNAs and extracellular vesicles in filarial nematodes: From nematode development to diagnostics.

    PubMed

    Quintana, J F; Babayan, S A; Buck, A H

    2017-02-01

    Parasitic nematodes have evolved sophisticated mechanisms to communicate with their hosts in order to survive and successfully establish an infection. The transfer of RNA within extracellular vesicles (EVs) has recently been described as a mechanism that could contribute to this communication in filarial nematodes. It has been shown that these EVs are loaded with several types of RNAs, including microRNAs, leading to the hypothesis that parasites could actively use these molecules to manipulate host gene expression and to the exciting prospect that these pathways could result in new diagnostic and therapeutic strategies. Here, we review the literature on the diverse RNAi pathways that operate in nematodes and more specifically our current knowledge of extracellular RNA (exRNA) and EVs derived from filarial nematodes in vitro and within their hosts. We further detail some of the issues and questions related to the capacity of RNA-mediated communication to function in parasite-host interactions and the ability of exRNA to enable us to distinguish and detect different nematode parasites in their hosts. © 2016 The Authors. Parasite Immunology published by John Wiley & Sons Ltd.

  10. Rolling Circle Amplification of Complete Nematode Mitochondrial Genomes

    PubMed Central

    Tang, Sha; Hyman, Bradley C.

    2005-01-01

    To enable investigation of nematode mitochondrial DNA evolution, methodology has been developed to amplify intact nematode mitochondrial genomes in preparative yields using a rolling circle replication strategy. Successful reactions were generated from whole cell template DNA prepared by alkaline lysis of the rhabditid nematode Caenorhabditis elegans and a mermithid nematode, Thaumamermis cosgrovei. These taxa, representing the two major nematode classes Chromodorea and Enoplea, maintain mitochondrial genomes of 13.8 kb and 20.0 kb, respectively. Efficient amplifications were conducted on template DNA isolated from individual or pooled nematodes that were alive or stored at -80°C. Unexpectedly, these experiments revealed that multiple T. cosgrovei mitochondrial DNA haplotypes are maintained in our local population. Rolling circle amplification products can be used as templates for standard PCR reactions with specific primers that target mitochondrial genes or for direct DNA sequencing. PMID:19262866

  11. How nematodes manipulate plant development pathways for infection.

    PubMed

    Gheysen, Godelieve; Mitchum, Melissa G

    2011-08-01

    Sedentary plant-parasitic nematodes establish long term relationships with their hosts. Root vascular cells are transformed into large multinucleate feeding cells from which the nematodes feed for more than one month. Recent transcriptome analyses suggest that feeding cells are different from other plant cell types. Their development, however, remains poorly understood, despite new evidence that appears to confirm previously proposed models, such as the important role of auxin. From the analysis of nematode effector proteins that interact with plant proteins, it has become clear that nematodes manipulate many aspects of plant development, including auxin transport and plant cell differentiation pathways. These studies are also revealing roles for effectors in the inhibition of plant stress and defense responses to establish feeding cells. In the coming years breakthroughs can be expected in our understanding of plant-nematode interactions from the functional analysis of nematode effector genes as well as the involved plant genes. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. Plant actin cytoskeleton re-modeling by plant parasitic nematodes.

    PubMed

    Engler, Janice de Almeida; Rodiuc, Natalia; Smertenko, Andrei; Abad, Pierre

    2010-03-01

    The cytoskeleton is an important component of the plant's defense mechanism against the attack of pathogenic organisms. Plants however, are defenseless against parasitic root-knot and cyst nematodes and respond to the invasion by the development of a special feeding site that supplies the parasite with nutrients required for the completion of its life cycle. Recent studies of nematode invasion under treatment with cytoskeletal drugs and in mutant plants where normal functions of the cytoskeleton have been affected, demonstrate the importance of the cytoskeleton in the establishment of a feeding site and successful nematode reproduction. It appears that in the case of microfilaments, nematodes hijack the intracellular machinery that regulates actin dynamics and modulate the organization and properties of the actin filament network. Intervening with this process reduces the nematode infection efficiency and inhibits its life cycle. This discovery uncovers a new pathway that can be exploited for the protection of plants against nematodes.

  13. Rolling circle amplification of complete nematode mitochondrial genomes.

    PubMed

    Tang, Sha; Hyman, Bradley C

    2005-06-01

    To enable investigation of nematode mitochondrial DNA evolution, methodology has been developed to amplify intact nematode mitochondrial genomes in preparative yields using a rolling circle replication strategy. Successful reactions were generated from whole cell template DNA prepared by alkaline lysis of the rhabditid nematode Caenorhabditis elegans and a mermithid nematode, Thaumamermis cosgrovei. These taxa, representing the two major nematode classes Chromodorea and Enoplea, maintain mitochondrial genomes of 13.8 kb and 20.0 kb, respectively. Efficient amplifications were conducted on template DNA isolated from individual or pooled nematodes that were alive or stored at -80 degrees C. Unexpectedly, these experiments revealed that multiple T. cosgrovei mitochondrial DNA haplotypes are maintained in our local population. Rolling circle amplification products can be used as templates for standard PCR reactions with specific primers that target mitochondrial genes or for direct DNA sequencing.

  14. RNAi and functional genomics in plant parasitic nematodes.

    PubMed

    Rosso, M N; Jones, J T; Abad, P

    2009-01-01

    Plant nematology is currently undergoing a revolution with the availability of the first genome sequences as well as comprehensive expressed sequence tag (EST) libraries from a range of nematode species. Several strategies are being used to exploit this wealth of information. Comparative genomics is being used to explore the acquisition of novel genes associated with parasitic lifestyles. Functional analyses of nematode genes are moving toward larger scale studies including global transcriptome profiling. RNA interference (RNAi) has been shown to reduce expression of a range of plant parasitic nematode genes and is a powerful tool for functional analysis of nematode genes. RNAi-mediated suppression of genes essential for nematode development, survival, or parasitism is revealing new targets for nematode control. Plant nematology in the genomics era is now facing the challenge to develop RNAi screens adequate for high-throughput functional analyses.

  15. Immunity to gastrointestinal nematodes: mechanisms and myths.

    PubMed

    Grencis, Richard K; Humphreys, Neil E; Bancroft, Allison J

    2014-07-01

    Immune responses to gastrointestinal nematodes have been studied extensively for over 80 years and intensively investigated over the last 30-40 years. The use of laboratory models has led to the discovery of new mechanisms of protective immunity and made major contributions to our fundamental understanding of both innate and adaptive responses. In addition to host protection, it is clear that immunoregulatory processes are common in infected individuals and resistance often operates alongside modulation of immunity. This review aims to discuss the recent discoveries in both host protection and immunoregulation against gastrointestinal nematodes, placing the data in context of the specific life cycles imposed by the different parasites studied and the future challenges of considering the mucosal/immune axis to encompass host, parasite, and microbiome in its widest sense.

  16. All the microbiology nematodes can teach us

    PubMed Central

    Bulgheresi, Silvia

    2016-01-01

    Be it their pervasiveness, experimental tractability or their impact on human health and agriculture, nematode–bacterium associations are far-reaching research subjects. Although the omics hype did not spare them and helped reveal mechanisms of communication and exchange between the associated partners, a huge amount of knowledge still awaits to be harvested from their study. Here, I summarize and compare the kind of research that has been already performed on the model nematode Caenorhabditis elegans and on symbiotic nematodes, both marine and entomopathogenic ones. The emerging picture highlights how complementing genetic studies with ecological ones (in the case of well-established genetic model systems such as C. elegans) and vice versa (in the case of the yet uncultured Stilbonematinae) will deepen our understanding of how microbial symbioses evolved and how they impact our environment. PMID:26839382

  17. Mucocutaneous manifestations of helminth infections: Nematodes.

    PubMed

    Lupi, Omar; Downing, Christopher; Lee, Michael; Pino, Livia; Bravo, Francisco; Giglio, Patricia; Sethi, Aisha; Klaus, Sidney; Sangueza, Omar P; Fuller, Claire; Mendoza, Natalia; Ladizinski, Barry; Woc-Colburn, Laila; Tyring, Stephen K

    2015-12-01

    In the 21st century, despite increased globalization through international travel for business, medical volunteerism, pleasure, and immigration/refugees into the United States, there is little published in the dermatology literature regarding the cutaneous manifestations of helminth infections. Approximately 17% of travelers seek medical care because of cutaneous disorders, many related to infectious etiologies. This review will focus on the cutaneous manifestations of helminth infections and is divided into 2 parts: part I focuses on nematode infections, and part II focuses on trematode and cestode infections. This review highlights the clinical manifestations, transmission, diagnosis, and treatment of helminth infections. Nematodes are roundworms that cause diseases with cutaneous manifestations, such as cutaneous larval migrans, onchocerciasis, filariasis, gnathostomiasis, loiasis, dracunculiasis, strongyloidiasis, ascariasis, streptocerciasis, dirofilariasis, and trichinosis. Tremadotes, also known as flukes, cause schistosomiasis, paragonimiasis, and fascioliasis. Cestodes (tapeworms) are flat, hermaphroditic parasites that cause diseases such as sparganosis, cysticercosis, and echinococcus.

  18. Immunity to gastrointestinal nematodes: mechanisms and myths

    PubMed Central

    Grencis, Richard K; Humphreys, Neil E; Bancroft, Allison J

    2014-01-01

    Immune responses to gastrointestinal nematodes have been studied extensively for over 80 years and intensively investigated over the last 30–40 years. The use of laboratory models has led to the discovery of new mechanisms of protective immunity and made major contributions to our fundamental understanding of both innate and adaptive responses. In addition to host protection, it is clear that immunoregulatory processes are common in infected individuals and resistance often operates alongside modulation of immunity. This review aims to discuss the recent discoveries in both host protection and immunoregulation against gastrointestinal nematodes, placing the data in context of the specific life cycles imposed by the different parasites studied and the future challenges of considering the mucosal/immune axis to encompass host, parasite, and microbiome in its widest sense. PMID:24942690

  19. Caenorhabditis Elegans—Applications to Nematode Genomics

    PubMed Central

    Parkinson, John

    2003-01-01

    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. PMID:18629128

  20. Reniform Nematode Resistance in Selected Soybean Cultivars

    PubMed Central

    Robbins, R. T.; Rakes, L.; Jackson, L. E.; Dombek, D. G.

    1999-01-01

    Two hundred eighty-two soybean cultivars from the variety testing programs of Arkansas and Mississippi were tested in greenhouse pot experiments during summer 1998 to identify soybean cultivars with resistance to the reniform nematode, Rotylenchulus reniformis. Also included in the tests were the resistant cultivars Forrest and Hartwig, the susceptible control Braxton, and fallow infested soil, which were used as controls. Numbers of reniform nematode extracted from the soil and roots and the ratio of the numbers reproducing on each cultivar compared to the number reproducing on Forrest are reported. Cultivars with reproduction not significantly different from Forrest were classified resistant, whereas those with greater reproductive indices were considered susceptible. One of the 18 cultivars of relative maturity group (RMG) ≤4.4 was classified as resistant. For the 86 cultivars of RMG 4.5-4.9, 18 were found to be resistant. Of the 43 cultivars of RMG 5.0-5.4, 16 were resistant, while 43 of the 91 cultivars of RMG 5.5-5.9 were resistant. Fifteen of the cultivars with an RMG of ≥6.0 were classed as resistant. These data will be useful in the selection of soybean cultivars to use in rotation with cotton to help control the reniform nematode. PMID:19270934

  1. Nematode locomotion in unconfined and confined fluids

    NASA Astrophysics Data System (ADS)

    Bilbao, Alejandro; Wajnryb, Eligiusz; Vanapalli, Siva A.; Blawzdziewicz, Jerzy

    2013-08-01

    The millimeter-long soil-dwelling nematode Caenorhabditis elegans propels itself by producing undulations that propagate along its body and turns by assuming highly curved shapes. According to our recent study [V. Padmanabhan et al., PLoS ONE 7, e40121 (2012), 10.1371/journal.pone.0040121] all these postures can be accurately described by a piecewise-harmonic-curvature model. We combine this curvature-based description with highly accurate hydrodynamic bead models to evaluate the normalized velocity and turning angles for a worm swimming in an unconfined fluid and in a parallel-wall cell. We find that the worm moves twice as fast and navigates more effectively under a strong confinement, due to the large transverse-to-longitudinal resistance-coefficient ratio resulting from the wall-mediated far-field hydrodynamic coupling between body segments. We also note that the optimal swimming gait is similar to the gait observed for nematodes swimming in high-viscosity fluids. Our bead models allow us to determine the effects of confinement and finite thickness of the body of the nematode on its locomotion. These effects are not accounted for by the classical resistive-force and slender-body theories.

  2. Association of Nematodes and Dogwood Cankers

    PubMed Central

    Self, Louann H.; Bernard, Ernest C.

    1994-01-01

    Dogwood canker is a serious production problem of unknown etiology. From May 1985 through April 1989, cankers from 290 flowering dogwood trees in 15 separate nurseries were sampled for nematodes. Seventy-three percent (213) of the cankers contained nematodes. Panagrolaimus rigidus (Schneider) Thorne (115/290) and Aphelenchoides spp. (91/290) were the most frequently collected taxa. Panagrolaimus rigidus was reared on 2% water agar with unidentified bacteria as the food source. Aphelenchoides spp. were reared in antibiotic-amended agar culture with the fungus Glomerella cingulata (Stoneman) Spauld. &Schrenk as a food source. Repeated attempts to culture Aphelenchoides spp. on dogwood callus tissue were unsuccessful. Artificially created stem wounds inoculated with combinations of Aphelenchoides spp. and P. rigidus callused completely in 60 days with no indication of canker development. Very low numbers of nematodes were recovered from inoculated trees, but P. rigidus and one Aphelenchoides sp. were efficient dispersers and occurred in treatments other than those in which they were inoculated. PMID:19279869

  3. Association of nematodes and dogwood cankers.

    PubMed

    Self, L H; Bernard, E C

    1994-03-01

    Dogwood canker is a serious production problem of unknown etiology. From May 1985 through April 1989, cankers from 290 flowering dogwood trees in 15 separate nurseries were sampled for nematodes. Seventy-three percent (213) of the cankers contained nematodes. Panagrolaimus rigidus (Schneider) Thorne (115/290) and Aphelenchoides spp. (91/290) were the most frequently collected taxa. Panagrolaimus rigidus was reared on 2% water agar with unidentified bacteria as the food source. Aphelenchoides spp. were reared in antibiotic-amended agar culture with the fungus Glomerella cingulata (Stoneman) Spauld. &Schrenk as a food source. Repeated attempts to culture Aphelenchoides spp. on dogwood callus tissue were unsuccessful. Artificially created stem wounds inoculated with combinations of Aphelenchoides spp. and P. rigidus callused completely in 60 days with no indication of canker development. Very low numbers of nematodes were recovered from inoculated trees, but P. rigidus and one Aphelenchoides sp. were efficient dispersers and occurred in treatments other than those in which they were inoculated.

  4. Entomopathogenic Nematode Production and Application Technology

    PubMed Central

    Shapiro-Ilan, David I.; Han, Richou; Dolinksi, Claudia

    2012-01-01

    Production and application technology is critical for the success of entomopathogenic nematodes (EPNs) in biological control. Production approaches include in vivo, and in vitro methods (solid or liquid fermentation). For laboratory use and small scale field experiments, in vivo production of EPNs appears to be the appropriate method. In vivo production is also appropriate for niche markets and small growers where a lack of capital, scientific expertise or infrastructure cannot justify large investments into in vitro culture technology. In vitro technology is used when large scale production is needed at reasonable quality and cost. Infective juveniles of entomopathogenic nematodes are usually applied using various spray equipment and standard irrigation systems. Enhanced efficacy in EPN applications can be facilitated through improved delivery mechanisms (e.g., cadaver application) or optimization of spray equipment. Substantial progress has been made in recent years in developing EPN formulations, particularly for above ground applications, e.g., mixing EPNs with surfactants or polymers or with sprayable gels. Bait formulations and insect host cadavers can enhance EPN persistence and reduce the quantity of nematodes required per unit area. This review provides a summary and analysis of factors that affect production and application of EPNs and offers insights for their future in biological insect suppression. PMID:23482883

  5. Assaying environmental nickel toxicity using model nematodes

    USGS Publications Warehouse

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

    2013-01-01

    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. elegansand 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.

  6. Assaying environmental nickel toxicity using model nematodes.

    PubMed

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

    2013-01-01

    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.

  7. Evolution of plant parasitism among nematodes.

    PubMed

    Baldwin, J G; Nadler, S A; Adams, B J

    2004-01-01

    Despite extraordinary diversity of free-living species, a comparatively small fraction of nematodes are parasites of plants. These parasites represent at least three disparate clades in the nematode tree of life, as inferred from rRNA sequences. Plant parasites share functional similarities regarding feeding, but many similarities in feeding structures result from convergent evolution and have fundamentally different developmental origins. Although Tylenchida rRNA phylogenies are not fully resolved, they strongly support convergent evolution of sedentary endoparasitism and plant nurse cells in cyst and root-knot nematodes. This result has critical implications for using model systems and genomics to identify and characterize parasitism genes for representatives of this clade. Phylogenetic studies reveal that plant parasites have rich and complex evolutionary histories that involve multiple transitions to plant parasitism and the possible use of genes obtained by horizontal transfer from prokaryotes. Developing a fuller understanding of plant parasitism will require integrating more comprehensive and resolved phylogenies with appropriate choices of model organisms and comparative evolutionary methods.

  8. Condensed tannins act against cattle nematodes.

    PubMed

    Novobilský, Adam; Mueller-Harvey, Irene; Thamsborg, Stig Milan

    2011-12-15

    The use of natural plant anthelmintics was suggested as a possible alternative control of gastrointestinal nematodes (GIN) in ruminants. Direct anthelmintic effects of tannin-containing plants have already been shown in sheep and goat GIN. These anthelmintic properties are mainly associated with condensed tannins. In the present study, we evaluated possible in vitro effects of three tannin-containing plants against bovine GIN. Effects of Onobrychis viciifolia, Lotus pedunculatus and Lotus corniculatus condensed tannin (CT) extracts on Cooperia oncophora and Ostertagia ostertagi were determined by a larval feeding inhibition assay (LFIA) and a larval exsheathment assay (LEA). In the LFIA, all three plant extracts significantly inhibited larval feeding behaviour of both C. oncophora and O. ostertagi first stage larvae in a dose-dependent manner. The L. pedunculatus extract, based on EC(50) (effective concentration for 50% inhibition), was the most effective against both nematodes, followed by O. viciifolia and L. corniculatus. The effect of CT extracts upon larval feeding behaviour correlates with CT content and procyanidin/prodelphidin ratio. Larval exsheathment of C. oncophora and O. ostertagi L3 larvae (third stage larvae) was also affected by CT extracts from all three plants. In both in vitro assays, extracts with added polyvinylpolypyrrolidone, an inhibitor of tannins, generated almost the same values as the negative control; this confirms the role of CT in the anthelmintic effect of these plant extracts. Our results, therefore, indicated that tannin-containing plants could act against cattle nematodes. Copyright © 2011 Elsevier B.V. All rights reserved.

  9. A White Paper on Nematode Comparative Genomics

    PubMed Central

    Bird, David McK.; Blaxter, Mark L.; McCarter, James P.; Mitreva, Makedonka; Sternberg, Paul W.; Thomas, W. Kelley

    2005-01-01

    In response to the new opportunities for genome sequencing and comparative genomics, the Society of Nematology (SON) formed a committee to develop a white paper in support of the broad scientific needs associated with this phylum and interests of SON members. Although genome sequencing is expensive, the data generated are unique in biological systems in that genomes have the potential to be complete (every base of the genome can be accounted for), accurate (the data are digital and not subject to stochastic variation), and permanent (once obtained, the genome of a species does not need to be experimentally re-sampled). The availability of complete, accurate, and permanent genome sequences from diverse nematode species will underpin future studies into the biology and evolution of this phylum and the ecological associations (particularly parasitic) nematodes have with other organisms. We anticipate that upwards of 100 nematode genomes will be solved to varying levels of completion in the coming decade and suggest biological and practical considerations to guide the selection of the most informative taxa for sequencing. PMID:19262884

  10. A white paper on nematode comparative genomics.

    PubMed

    Bird, David McK; Blaxter, Mark L; McCarter, James P; Mitreva, Makedonka; Sternberg, Paul W; Thomas, W Kelley

    2005-12-01

    In response to the new opportunities for genome sequencing and comparative genomics, the Society of Nematology (SON) formed a committee to develop a white paper in support of the broad scientific needs associated with this phylum and interests of SON members. Although genome sequencing is expensive, the data generated are unique in biological systems in that genomes have the potential to be complete (every base of the genome can be accounted for), accurate (the data are digital and not subject to stochastic variation), and permanent (once obtained, the genome of a species does not need to be experimentally re-sampled). The availability of complete, accurate, and permanent genome sequences from diverse nematode species will underpin future studies into the biology and evolution of this phylum and the ecological associations (particularly parasitic) nematodes have with other organisms. We anticipate that upwards of 100 nematode genomes will be solved to varying levels of completion in the coming decade and suggest biological and practical considerations to guide the selection of the most informative taxa for sequencing.

  11. Assaying Environmental Nickel Toxicity Using Model Nematodes

    PubMed Central

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

    2013-01-01

    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. PMID:24116204

  12. On the Methodology of Nematode Extraction from Field Samples: Density Flotation Techniques

    PubMed Central

    Viglierchio, David R.; Yamashita, Tom T.

    1983-01-01

    Density flotation has been frequently used for the extraction of nematodes from field samples. Density flotation curves for four nematode species and five solutes have been prepared. The curves confirm that flotation was governed by several factors: solute density, solute osmotic activity, and physiological properties of the nematode species. Nematode viability and function can be adversely affected by improper selection of solute for density extraction of nematodes; nevertheless, some nematode species can be enriched from mixtures by density and solute selection. PMID:19295831

  13. Detection and description of soils with specific nematode suppressiveness.

    PubMed

    Westphal, Andreas

    2005-03-01

    Soils with specific suppressiveness to plant-parasitic nematodes are of interest to define the mechanisms that regulate population density. Suppressive soils prevent nematodes from establishing and from causing disease, and they diminish disease severity after initial nematode damage in continuous culturing of a host. A range of non-specific and specific soil treatments, followed by infestation with a target nematode, have been employed to identify nematode-suppressive soils. Biocidal treatments, soil transfer tests, and baiting approaches together with observations of the plant-parasitic nematode in the root zone of susceptible host plants have improved the understanding of nematode-suppressive soils. Techniques to demonstrate specific soil suppressiveness against plant-parasitic nematodes are compared in this review. The overlap of studies on soil suppressiveness with recent advances in soil health and quality is briefly discussed. The emphasis is on methods (or criteria) used to detect and identify soils that maintain specific soil suppressiveness to plant-parasitic nematodes. While biocidal treatments can detect general and specific soil suppressiveness, soil transfer studies, by definition, apply only to specific soil suppressiveness. Finally, potential strategies to exploit suppressive soils are presented.

  14. Entomopathogenic and plant pathogenic nematodes as opposing forces in agriculture.

    PubMed

    Kenney, Eric; Eleftherianos, Ioannis

    2016-01-01

    Plant-parasitic nematodes are responsible for substantial damages within the agriculture industry every year, which is a challenge that has thus far gone largely unimpeded. Chemical nematicides have been employed with varying degrees of success, but their implementation can be cumbersome, and furthermore they could potentially be neutralising an otherwise positive effect from the entomopathogenic nematodes that coexist with plant-parasitic nematodes in soil environments and provide protection for plants against insect pests. Recent research has explored the potential of employing entomopathogenic nematodes to protect plants from plant-parasitic nematodes, while providing their standard degree of protection against insects. The interactions involved are highly complex, due to both the three-organism system and the assortment of variables present in a soil environment, but a strong collection of evidence has accumulated regarding the suppressive capacity of certain entomopathogenic nematodes and their mutualistic bacteria, in the context of limiting the infectivity of plant-parasitic nematodes. Specific factors produced by certain entomopathogenic nematode complexes during the process of insect infection appear to have a selectively nematicidal, or at least repellant, effect on plant-parasitic nematodes. Using this information, an opportunity has formed to adapt this relationship to large-scale, field conditions and potentially relieve the agricultural industry of one of its most substantial burdens.

  15. Nematodes Associated with Plants from Naturally Acidic Wetlands Soil

    PubMed Central

    Cox, Robert John; Smart, Grover C.

    1994-01-01

    Four plants, Cyperus ochraceus, Eriocaulon compressum, Lythrum alatum, and Xyris jupicai, growing along the shoreline of an oligotrophic lake in north central Florida were sampled for nematodes. The nematodes recovered were placed in four trophic groups: bacterivores, herbivores, omnivores, and predators. When the nematodes on all plants were considered, 27% were bacterivores, 23% were herbivores, 7% were omnivores, and 43% were predators. Tripyla was the dominant predator and the dominant genus of all nematodes, and Malenchus was the dominant herbivore. Dominance was not clearly pronounced in the other trophic groups. PMID:19279927

  16. Distribution patterns of entomopathogenic nematodes applied through drip irrigation systems.

    PubMed

    Wennemann, L; Cone, W W; Wright, L C; Perez, J; Conant, M M

    2003-04-01

    The distribution of entomopathogenic nematodes applied by drip irrigation was evaluated by injecting small volumes of Steinernema carpocapsae (Weiser) All strain, Steinernema feltiae (Filipjev) SN strain, Steinernema glaseri Steiner, and Heterorhabditis bacteriophora HP 88 strain Poinar suspensions into drip irrigation lines. Additionally, Steinernema riobrave Cabanillas, Poinar, & Raulston, and S. carpocapsae were injected in a 10-liter volume of water with an injection pump. Overall, the nematodes were evenly distributed along the drip lines. The total number of nematodes recovered from drip emitters was variable ranging from 42 to 92%. However, drip irrigation lines have potential to deliver entomopathogenic nematodes efficiently into pest habitats.

  17. Detection and Description of Soils with Specific Nematode Suppressiveness

    PubMed Central

    Westphal, Andreas

    2005-01-01

    Soils with specific suppressiveness to plant-parasitic nematodes are of interest to define the mechanisms that regulate population density. Suppressive soils prevent nematodes from establishing and from causing disease, and they diminish disease severity after initial nematode damage in continuous culturing of a host. A range of non-specific and specific soil treatments, followed by infestation with a target nematode, have been employed to identify nematode-suppressive soils. Biocidal treatments, soil transfer tests, and baiting approaches together with observations of the plant-parasitic nematode in the root zone of susceptible host plants have improved the understanding of nematode-suppressive soils. Techniques to demonstrate specific soil suppressiveness against plant-parasitic nematodes are compared in this review. The overlap of studies on soil suppressiveness with recent advances in soil health and quality is briefly discussed. The emphasis is on methods (or criteria) used to detect and identify soils that maintain specific soil suppressiveness to plant-parasitic nematodes. While biocidal treatments can detect general and specific soil suppressiveness, soil transfer studies, by definition, apply only to specific soil suppressiveness. Finally, potential strategies to exploit suppressive soils are presented. PMID:19262851

  18. Dynamic expression of miR-132, miR-212, and miR-146 in the brain of different hosts infected with Angiostrongylus cantonensis.

    PubMed

    Yu, Liping; Liao, Qi; Chen, Xiaoguang; Xu, Lian; Zeng, Xin; Lv, Zhiyue; Sun, Xi; Zhen, Huanqin; Wu, Zhongdao

    2014-01-01

    Increasing evidence shows that microRNAs (miRNAs) are a family of regulatory molecules involved in many physiological processes, including the inflammation in central nervous system (CNS) and neurological disorders. Angiostrongylus cantonensis (A. cantonensis) is the major cause of human infectious eosinophilic meningitis and can induce CNS injury. In the present study, we investigated the expression of miRNAs involved in neuronal functions such as miR-132-3p/212-3p, and miR-146a-5p, inflammation-related miRNA, in the modulation of inflammation of CNS of mice and rats induced by A. cantonensis. The functions of differentially expressed miRNAs were analyzed through bioinformatics methods, and the expression of chosen target genes were investigated by quantitative reverse transcription polymerase chain reaction. The results showed that miR-146a-5p upregulated in the brain of rats after 21 days; A. cantonensis infection and the expression of miR-132-3p and miR-146a-5p upregulated in the brain of mice model infected by A. cantonensis. The expression of the target genes of mmu-miR-146a-5p such as Irak1 and Traf6 downregulated in 14 days and 21 days after A. cantonensis infection. Our results supply more information about the involvement of the miRNAs in the regulation of inflammation of CNS induced by A. cantonensis.

  19. Dexamethasone downregulated the expression of CSF 14-3-3β protein in mice with eosinophilic meningitis caused by Angiostrongylus cantonensis infection.

    PubMed

    Tsai, Hung-Chin; Lee, Bi-Yao; Yen, Chuan-Min; Wann, Shue-Ren; Lee, Susan Shin-Jung; Chen, Yao-Shen; Tai, Ming-Hong

    2014-03-01

    Angiostrongylus cantonensis is the main causative agent of human eosinophilic meningitis in Southeast Asia and the Pacific Islands. A previous study demonstrated that the 14-3-3β protein is a neuropathological marker in monitoring neuronal damage in meningitis. Steroids are commonly used in patients with eosinophilic meningitis caused by A. cantonensis infection. However, the mechanism by which steroids act in eosinophilic meningitis is unknown. We hypothesized that the beneficial effect of steroids on eosinophilic meningitis is partially mediated by the down-regulation of 14-3-3β protein expression in the cerebrospinal fluid (CSF). In this animal study, we determined the dynamic changes of 14-3-3β protein in mice with eosinophilic meningitis. The 14-3-3β protein in serum and CSF was increased in week 2 and 3 after infections. Dexamethasone administration significantly decreased the amounts of CSF 14-3-3β protein. By developing an in-house ELISA to measure 14-3-3β protein, it was found that the amounts of 14-3-3β protein in the CSF and serum increased over a three-week period after infection. There was a remarkable reduction of 14-3-3β protein in the CSF after 2 weeks of dexamethasone treatment. In conclusion, the administration of corticosteroids in mice with eosinophilic meningitis decreased the expression of 14-3-3β protein in the CSF. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Anti-apoptotic effects of Sonic hedgehog signalling through oxidative stress reduction in astrocytes co-cultured with excretory-secretory products of larval Angiostrongylus cantonensis.

    PubMed

    Chen, Kuang-Yao; Chiu, Cheng-Hsun; Wang, Lian-Chen

    2017-02-07

    Angiostrongylus cantonensis, the rat lungworm, is an important aetiologic agent of eosinophilic meningitis and meningoencephalitis in humans. Co-culturing astrocytes with soluble antigens of A. cantonensis activated the Sonic hedgehog (Shh) signalling pathway and inhibited the apoptosis of astrocytes via the activation of Bcl-2. This study was conducted to determine the roles of the Shh signalling pathway, apoptosis, and oxidative stress in astrocytes after treatment with excretory-secretory products (ESP) from A. cantonensis fifth-stage larvae. Although astrocyte viability was significantly decreased after ESP treatment, the expression of Shh signalling pathway related proteins (Shh, Ptch-1 and Gli-1) was significantly increased. However, apoptosis in astrocytes was significantly decreased after activation of the Shh signalling pathway. Moreover, superoxide and hydrogen superoxide levels in astrocytes were significantly reduced after the activation of Shh pathway signalling due to increasing levels of the antioxidants catalase and superoxide dismutase. These findings indicate that the anti-apoptotic effects of the Shh signalling pathway in the astrocytes of mice infected with A. cantonensis are due to reduced levels of oxidative stress caused by the activation of antioxidants.

  1. Anti-apoptotic effects of Sonic hedgehog signalling through oxidative stress reduction in astrocytes co-cultured with excretory-secretory products of larval Angiostrongylus cantonensis

    PubMed Central

    Chen, Kuang-Yao; Chiu, Cheng-Hsun; Wang, Lian-Chen

    2017-01-01

    Angiostrongylus cantonensis, the rat lungworm, is an important aetiologic agent of eosinophilic meningitis and meningoencephalitis in humans. Co-culturing astrocytes with soluble antigens of A. cantonensis activated the Sonic hedgehog (Shh) signalling pathway and inhibited the apoptosis of astrocytes via the activation of Bcl-2. This study was conducted to determine the roles of the Shh signalling pathway, apoptosis, and oxidative stress in astrocytes after treatment with excretory-secretory products (ESP) from A. cantonensis fifth-stage larvae. Although astrocyte viability was significantly decreased after ESP treatment, the expression of Shh signalling pathway related proteins (Shh, Ptch-1 and Gli-1) was significantly increased. However, apoptosis in astrocytes was significantly decreased after activation of the Shh signalling pathway. Moreover, superoxide and hydrogen superoxide levels in astrocytes were significantly reduced after the activation of Shh pathway signalling due to increasing levels of the antioxidants catalase and superoxide dismutase. These findings indicate that the anti-apoptotic effects of the Shh signalling pathway in the astrocytes of mice infected with A. cantonensis are due to reduced levels of oxidative stress caused by the activation of antioxidants. PMID:28169282

  2. Unexpected Variation in Neuroanatomy among Diverse Nematode Species

    PubMed Central

    Han, Ziduan; Boas, Stephanie; Schroeder, Nathan E.

    2016-01-01

    Nematodes are considered excellent models for understanding fundamental aspects of neuron function. However, nematodes are less frequently used as models for examining the evolution of nervous systems. While the habitats and behaviors of nematodes are diverse, the neuroanatomy of nematodes is often considered highly conserved. A small number of nematode species greatly influences our understanding of nematode neurobiology. The free-living species Caenorhabditis elegans and, to a lesser extent, the mammalian gastrointestinal parasite Ascaris suum are, historically, the primary sources of knowledge regarding nematode neurobiology. Despite differences in size and habitat, C. elegans and A. suum share a surprisingly similar neuroanatomy. Here, we examined species across several clades in the phylum Nematoda and show that there is a surprising degree of neuroanatomical variation both within and among nematode clades when compared to C. elegans and Ascaris. We found variation in the numbers of neurons in the ventral nerve cord and dye-filling pattern of sensory neurons. For example, we found that Pristionchus pacificus, a bacterial feeding species used for comparative developmental research had 20% fewer ventral cord neurons compared to C. elegans. Steinernema carpocapsae, an insect-parasitic nematode capable of jumping behavior, had 40% more ventral cord neurons than C. elegans. Interestingly, the non-jumping congeneric nematode, S. glaseri showed an identical number of ventral cord neurons as S. carpocapsae. There was also variability in the timing of neurodevelopment of the ventral cord with two of five species that hatch as second-stage juveniles showing delayed neurodevelopment. We also found unexpected variation in the dye-filling of sensory neurons among examined species. Again, sensory neuron dye-filling pattern did not strictly correlate with phylogeny. Our results demonstrate that variation in nematode neuroanatomy is more prevalent than previously assumed and

  3. Soybean Cyst Nematode in North America - 55 Years Later

    USDA-ARS?s Scientific Manuscript database

    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...

  4. [Resistance to anthelmintics in nematodes in sheep and goats].

    PubMed

    Praslicka, J; Corba, J

    1995-08-01

    The article offers a brief view on the most important theoretical knowledge of resistance of gastrointestinal nematodes to anthelmintic drugs in sheep and goats. Besides the definition and basic terms, factors of development and occurrence of resistance on farm are analyzed. Furthermore, methods for detection of resistant nematodes as well as complex of recommended preventive measures are given.

  5. Native nematodes as new bio-insecticides for cranberries

    USDA-ARS?s Scientific Manuscript database

    In the summer of 2015, an effort was made in central Wisconsin to find an entomopathogenic nematode capable controlling Wisconsin’s cranberry pests. Using a standard baiting method, a nematode of the Oscheius genus was collected from the mossy, sandy, peat-filled soils of a wild cranberry marsh. Thi...

  6. Correlations of Nematodes and Soil Properties in Soybean Fields

    PubMed Central

    Norton, D. C.; Frederick, L. R.; Ponchillia, P. E.; Nyhan, J. W.

    1971-01-01

    Soil samples from 40 soybean fields were collected in 1967 and 1968 and analyzed for nematodes and soil properties. Correlations o f total nematodes, non-stylet nematodes, Dorylaimoidea (excluding Xiphinema americanum), X. americanum, Helicotylenchus pseudorobustus, Tylenchus spp., Aphelenchus avenae, and other groupings of nematodes were made with pH; percentage sand, silt, and clay; percentage organic matter; cation exchange capacity; saturation percentage, and percentage saturation. Organic matter, pH, and cation exchange capacity were most consistently highly correlated with the nematodes. H. pseudorobustus had the most consistently significant correlations with the soil factors. Correlations of nematodes were with more soil factors and were stronger in a wet than in a dry year. The highest numbers of nematodes were usually found in the lighter soils, except in the loamy sand where moisture probably was limiting. In general, soil moisture levels below 20% saturation were probably limiting for most nematodes studied, except for the dorylaims which survived in large numbers in soils with less than 20% saturation. PMID:19322361

  7. Pineapple Nematode Research in Hawaii: Past, Present, and Future

    PubMed Central

    Caswell, E. P.; Apt, W. J.

    1989-01-01

    The first written record of pineapple in Hawaii is from 1813. In 1901 commercial pineapple production started, and in 1924 the Experiment Station for pineapple research was established. Nematode-related problems were recognized in the early 1900s by N. A. Cobb. From 1920 to approximately 1945 nematode management in Hawaiian pineapple was based on fallowing and crop rotation. During the 1920s and 1930s G. H. Godfrey conducted research on pineapple nematode management. In the 1930s and 1940s M. B. Linford researched biological control and described several new species of nematodes including Rotylenchulus reniformis. In 1941 nematology and nematode management were advanced by Walter Carter's discovery of the first economical soil fumigant for nematodes, D-D mixture. Subsequently, DBCP was discovered and developed at the Pineapple Research Institute (PRI). Since 1945 soil fumigation has been the main nematode management strategy in Hawaiian pineapple production. Recent research has focused on the development of the nonvolatile nematicides, their potential as systemic nematicides, and their application via drip irrigation. Current and future research addresses biological and cultural alternatives to nematicide-based nematode management. PMID:19287592

  8. Granite rock outcrops: an extreme environment for soil nematodes?

    PubMed

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

    2009-03-01

    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.

  9. Conserved nematode signaling molecules elicit plant defenses and pathogen resistance

    USDA-ARS?s Scientific Manuscript database

    Nematodes, which are ubiquitous in soil and are estimated to cause $100 B of agricultural damage annually, produce novel, highly conserved small sugar-based molecules call ascarosides. Ascarosides play critical roles in nematode development and behavior. We report here that plants recognize these un...

  10. Nematode resistance and agronomic performance of LONREN and NEMSTACK lines

    USDA-ARS?s Scientific Manuscript database

    LONREN lines have resistance to reniform nematodes that was obtained from Gossypium longicalyx. The NEMSTACK lines have the same resistance recombined with the rkn-1 gene for resistance to root knot nematode from 'Acala NemX.' Different LONREN lines vary depending on whether the resistance gene was...

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

    USDA-ARS?s Scientific Manuscript database

    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...

  12. Development of Reniform Nematode Resistance in Upland Cotton

    USDA-ARS?s Scientific Manuscript database

    The purpose of this review is to assess development of resistance to the reniform nematode (Rotylenchulus reniformis) in Upland Cotton (Gossypium hirsutum). Cotton cultivars with reniform nematode resistance are needed. The development of resistant cultivars appears possible but presents a signifi...

  13. Control of the peachtree borer using beneficial nematodes

    USDA-ARS?s Scientific Manuscript database

    The peachtree borer, Synanthedon exitiosa, is a major pest of peaches and other stone fruits. Our research indicates that entomopathogenic nematodes, also known as beneficial nematodes, can be used effectively to control the insect. We conducted replicated experiments in randomized block designs ov...

  14. Nematode effector proteins: an emerging paradigm of parasitism

    USDA-ARS?s Scientific Manuscript database

    Phytonematodes use a stylet and secreted effectors to invade host tissues and extract 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 ...

  15. Harmful Effects of Mustard Bio-fumigants on Entomopathogenic Nematodes

    USDA-ARS?s Scientific Manuscript database

    Green manures, particularly mustards 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. It is not known if mustard green manures also kill beneficial entomopathogenic nematodes (EPNs) tha...

  16. 76 FR 60357 - Golden Nematode; Removal of Regulated Areas

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-29

    ... nematode (Globodera rostochiensis) is a destructive pest of potatoes and other solanaceous plants. Potatoes... no longer required. From 1977 until 2010, potato production fields in the townships of Elba and Byron... nematode quarantine. In 2007, there were 13 farms in Genesee County that harvested potatoes. These farms...

  17. Characterization of reniform nematode genome through shotgun sequencing

    USDA-ARS?s Scientific Manuscript database

    The reniform nematode (RN), a major agricultural pest particularly on cotton in the United States(U.S.), is among the major plant parasitic nematodes for which limited genomic information exists. In this study, over 380 Mb of sequence data were generated from four pooled adult female RN and assembl...

  18. Anthelmintics Are Substrates and Activators of Nematode P Glycoprotein▿

    PubMed Central

    Kerboeuf, Dominique; Guégnard, Fabrice

    2011-01-01

    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. PMID:21300828

  19. Soybean lines evaluated for resistance to reniform nematode

    USDA-ARS?s Scientific Manuscript database

    Seventy-four wild and domestic soybean (Glycine max and G. soja) lines were evaluated for resistance to reniform nematode (Rotylenchulus reniformis) in growth chamber tests with a day length of 16 hours and temperature held constant at 28 C. Several entries for which reactions to reniform nematode w...

  20. High Sensitivity NMR and Mixture Analysis for Nematode Behavioral Metabolomics

    USDA-ARS?s Scientific Manuscript database

    Nematodes are the most abundant animal on earth, and they parasitize virtually all plants and animals. Caenorhabditis elegans is a free-living nematode that lives in soil and composting material. We have shown that C. elegans releases at least 40 small molecules into its environment including many...

  1. Transgenic Strategies for Enhancement of Nematode Resistance in Plants

    PubMed Central

    Ali, Muhammad A.; Azeem, Farrukh; Abbas, Amjad; Joyia, Faiz A.; Li, Hongjie; Dababat, Abdelfattah A.

    2017-01-01

    Plant parasitic nematodes (PPNs) are obligate biotrophic parasites causing serious damage and reduction in crop yields. Several economically important genera parasitize various crop plants. The root-knot, root lesion, and cyst nematodes are the three most economically damaging genera of PPNs on crops within the family Heteroderidae. It is very important to devise various management strategies against PPNs in economically important crop plants. Genetic engineering has proven a promising tool for the development of biotic and abiotic stress tolerance in crop plants. Additionally, the genetic engineering leading to transgenic plants harboring nematode resistance genes has demonstrated its significance in the field of plant nematology. Here, we have discussed the use of genetic engineering for the development of nematode resistance in plants. This review article also provides a detailed account of transgenic strategies for the resistance against PPNs. The strategies include natural resistance genes, cloning of proteinase inhibitor coding genes, anti-nematodal proteins and use of RNA interference to suppress nematode effectors. Furthermore, the manipulation of expression levels of genes induced and suppressed by nematodes has also been suggested as an innovative approach for inducing nematode resistance in plants. The information in this article will provide an array of possibilities to engineer resistance against PPNs in different crop plants. PMID:28536595

  2. Transgenic Strategies for Enhancement of Nematode Resistance in Plants.

    PubMed

    Ali, Muhammad A; Azeem, Farrukh; Abbas, Amjad; Joyia, Faiz A; Li, Hongjie; Dababat, Abdelfattah A

    2017-01-01

    Plant parasitic nematodes (PPNs) are obligate biotrophic parasites causing serious damage and reduction in crop yields. Several economically important genera parasitize various crop plants. The root-knot, root lesion, and cyst nematodes are the three most economically damaging genera of PPNs on crops within the family Heteroderidae. It is very important to devise various management strategies against PPNs in economically important crop plants. Genetic engineering has proven a promising tool for the development of biotic and abiotic stress tolerance in crop plants. Additionally, the genetic engineering leading to transgenic plants harboring nematode resistance genes has demonstrated its significance in the field of plant nematology. Here, we have discussed the use of genetic engineering for the development of nematode resistance in plants. This review article also provides a detailed account of transgenic strategies for the resistance against PPNs. The strategies include natural resistance genes, cloning of proteinase inhibitor coding genes, anti-nematodal proteins and use of RNA interference to suppress nematode effectors. Furthermore, the manipulation of expression levels of genes induced and suppressed by nematodes has also been suggested as an innovative approach for inducing nematode resistance in plants. The information in this article will provide an array of possibilities to engineer resistance against PPNs in different crop plants.

  3. Pineapple nematode research in hawaii: past, present, and future.

    PubMed

    Caswell, E P; Apt, W J

    1989-04-01

    The first written record of pineapple in Hawaii is from 1813. In 1901 commercial pineapple production started, and in 1924 the Experiment Station for pineapple research was established. Nematode-related problems were recognized in the early 1900s by N. A. Cobb. From 1920 to approximately 1945 nematode management in Hawaiian pineapple was based on fallowing and crop rotation. During the 1920s and 1930s G. H. Godfrey conducted research on pineapple nematode management. In the 1930s and 1940s M. B. Linford researched biological control and described several new species of nematodes including Rotylenchulus reniformis. In 1941 nematology and nematode management were advanced by Walter Carter's discovery of the first economical soil fumigant for nematodes, D-D mixture. Subsequently, DBCP was discovered and developed at the Pineapple Research Institute (PRI). Since 1945 soil fumigation has been the main nematode management strategy in Hawaiian pineapple production. Recent research has focused on the development of the nonvolatile nematicides, their potential as systemic nematicides, and their application via drip irrigation. Current and future research addresses biological and cultural alternatives to nematicide-based nematode management.

  4. The cyst nematodes Heterodera and Globodera species in Egypt

    USDA-ARS?s Scientific Manuscript database

    Information concerning the occurrence and distribution of the cyst nematodes (Heterodera spp. and Globodera spp.) in Egypt is important to assess their potential to cause economic damage to many crop plants. A nematode survey was conducted in Alexandria, El Behera and Sohag governorates during 2012-...

  5. A SURVEY OF CYST NEMATODES (HETERODERA SPP.) IN NORTHERN EGYPT

    USDA-ARS?s Scientific Manuscript database

    Information concerning the occurrence and distribution of cyst nematodes (Heterodera spp.) in Egypt is important to assess their potential to cause economic damage to crop plants. A nematode survey was conducted in Alexandria and El-Behera Governorates in northern Egypt to identify the species of cy...

  6. Aggregative group behavior in insect parasitic nematode disperal

    USDA-ARS?s Scientific Manuscript database

    Movement behavior is critical to determination of spatial ecology and success of foraging in predators and parasites. In this study movement behavior of entomopathogenic nematodes was explored. Movement patterns in sand were investigated when nematodes were applied to a specific locus or when the ne...

  7. Viability and virulence of entomopathogenic nematodes exposed to ultraviolet radiation

    USDA-ARS?s Scientific Manuscript database

    Entomopathogenic nematodes can be highly effective biocontrol agents, but their efficacy can be reduced due to exposure environmental stress such as from ultraviolet radiation. Our objective was to compare UV tolerance among a broad array of nematode species. We compared 9 different EPN species and ...

  8. Sex-specific mating pheromones in the nematode Panagrellus redivivus

    USDA-ARS?s Scientific Manuscript database

    Despite advances in medicine and crop genetics, nematodes remain significant human pathogens and agricultural pests. This warrants investigation of alternative strategies for pest control, such as interference with pheromone-mediated reproduction. Because only two nematode species have had their phe...

  9. Nematodes from terrestrial and freshwater habitats in the Arctic.

    PubMed

    Holovachov, Oleksandr

    2014-01-01

    WE PRESENT AN UPDATED LIST OF TERRESTRIAL AND FRESHWATER NEMATODES FROM ALL REGIONS OF THE ARCTIC, FOR WHICH RECORDS OF PROPERLY IDENTIFIED NEMATODE SPECIES ARE AVAILABLE: Svalbard, Jan Mayen, Iceland, Greenland, Nunavut, Northwest territories, Alaska, Lena River estuary, Taymyr and Severnaya Zemlya and Novaya Zemlya. The list includes 391 species belonging to 146 genera, 54 families and 10 orders of the phylum Nematoda.

  10. Antagonists of Plant-parasitic Nematodes in Florida Citrus

    PubMed Central

    Walter, David Evans; Kaplan, David T.

    1990-01-01

    In a survey of antagonists of nematodes in 27 citrus groves, each with a history of Tylenchulus semipenetrans infestation, and 17 noncitrus habitats in Florida, approximately 24 species of microbial antagonists capable of attacking vermiform stages of Radopholus citrophilus were recovered. Eleven of these microbes and a species of Pasteuria also were observed attacking vermiform stages of T. semipenetrans. Verticillium chlamydosporium, Paecilomyces lilacinus, P. marquandii, Streptomyces sp., Arthrobotrys oligospora, and Dactylella ellipsospora were found infecting T. semipenetrans egg masses. Two species of nematophagous amoebae, five species of predatory nematodes, and 29 species of nematophagous arthropods also were detected. Nematode-trapping fungi and nematophagous arthropods were common inhabitants of citrus groves with a history of citrus nematode infestation; however, obligate parasites of nematodes were rare. PMID:19287759

  11. Antagonists of Plant-parasitic Nematodes in Florida Citrus.

    PubMed

    Walter, D E; Kaplan, D T

    1990-10-01

    In a survey of antagonists of nematodes in 27 citrus groves, each with a history of Tylenchulus semipenetrans infestation, and 17 noncitrus habitats in Florida, approximately 24 species of microbial antagonists capable of attacking vermiform stages of Radopholus citrophilus were recovered. Eleven of these microbes and a species of Pasteuria also were observed attacking vermiform stages of T. semipenetrans. Verticillium chlamydosporium, Paecilomyces lilacinus, P. marquandii, Streptomyces sp., Arthrobotrys oligospora, and Dactylella ellipsospora were found infecting T. semipenetrans egg masses. Two species of nematophagous amoebae, five species of predatory nematodes, and 29 species of nematophagous arthropods also were detected. Nematode-trapping fungi and nematophagous arthropods were common inhabitants of citrus groves with a history of citrus nematode infestation; however, obligate parasites of nematodes were rare.

  12. Survey of nematodes associated with terrestrial slugs in Norway.

    PubMed

    Ross, J L; Ivanova, E S; Hatteland, B A; Brurberg, M B; Haukeland, S

    2016-09-01

    A survey of nematodes associated with terrestrial slugs was conducted for the first time in Norway. A total of 611 terrestrial slugs were collected from 32 sample sites. Slugs were identified by means of morphological examination, dissection of genitalia and molecular analysis using mitochondrial DNA. Twelve slug species were identified, representing four different slug families. Internal nematodes were identified by means of morphological analysis and the sequencing of the 18S rRNA gene. Of the sample sites studied, 62.5% were found to be positive for nematode parasites, with 18.7% of all slugs discovered being infected. Five nematode species were identified in this study: Alloionema appendiculatum, Agfa flexilis, Angiostoma limacis, Angiostoma sp. and Phasmarhabditis hermaphrodita. Of these species, only one nematode was previously undescribed (Angiostoma sp.). This is the first record of the presence of A. appendiculatum, A. flexilis and A. limacis in Norway.

  13. Multifaceted effects of host plants on entomopathogenic nematodes.

    PubMed

    Hazir, Selcuk; Shapiro-Ilan, David I; Hazir, Canan; Leite, Luis G; Cakmak, Ibrahim; Olson, Dawn

    2016-03-01

    The success of parasites can be impacted by multi-trophic interactions. Tritrophic interactions have been observed in parasite-herbivore-host plant systems. Here we investigate aspects of multi-trophic interactions in a system involving an entomopathogenic nematode (EPN), its insect host, and host plant. Novel issues investigated include the impact of tritrophic interactions on nematode foraging behavior, the ability of EPNs to overcome negative tritrophic effects through genetic selection, and interactions with a fourth trophic level (nematode predators). We tested infectivity of the nematode, Steinernema riobrave, to corn earworm larvae (Helicoverpa zea) in three host plants, tobacco, eggplant and tomato. Tobacco reduced nematode virulence and reproduction relative to tomato and eggplant. However, successive selection (5 passages) overcame the deficiency; selected nematodes no longer exhibited reductions in phenotypic traits. Despite the loss in virulence and reproduction nematodes, first passage S. riobrave was more attracted to frass from insects fed tobacco than insects fed on other host plants. Therefore, we hypothesized the reduced virulence and reproduction in S. riobrave infecting tobacco fed insects would be based on a self-medicating tradeoff, such as deterring predation. We tested this hypothesis by assessing predatory success of the mite Sancassania polyphyllae and the springtail Sinella curviseta on nematodes reared on tobacco-fed larvae versus those fed on greater wax moth, Galleria mellonella, tomato fed larvae, or eggplant fed larvae. No advantage was observed in nematodes derived from tobacco fed larvae. In conclusion, our results indicated that insect-host plant diet has an important effect on nematode foraging, infectivity and reproduction. However, negative host plant effects, might be overcome through directed selection. We propose that host plant species should be considered when designing biocontrol programs using EPNs.

  14. Soil microorganisms control plant ectoparasitic nematodes in natural coastal foredunes.

    PubMed

    Piśkiewicz, Anna M; Duyts, Henk; Berg, Matty P; Costa, Sofia R; van der Putten, Wim H

    2007-06-01

    Belowground herbivores can exert important controls on the composition of natural plant communities. Until now, relatively few studies have investigated which factors may control the abundance of belowground herbivores. In Dutch coastal foredunes, the root-feeding nematode Tylenchorhynchus ventralis is capable of reducing the performance of the dominant grass Ammophila arenaria (Marram grass). However, field surveys show that populations of this nematode usually are controlled to nondamaging densities, but the control mechanism is unknown. In the present study, we first established that T. ventralis populations are top-down controlled by soil biota. Then, selective removal of soil fauna suggested that soil microorganisms play an important role in controlling T. ventralis. This result was confirmed by an experiment where selective inoculation of microarthropods, nematodes and microbes together with T. ventralis into sterilized dune soil resulted in nematode control when microbes were present. Adding nematodes had some effect, whereas microarthropods did not have a significant effect on T. ventralis. Our results have important implications for the appreciation of herbivore controls in natural soils. Soil food web models assume that herbivorous nematodes are controlled by predaceous invertebrates, whereas many biological control studies focus on managing nematode abundance by soil microorganisms. We propose that soil microorganisms play a more important role than do carnivorous soil invertebrates in the top-down control of herbivorous ectoparasitic nematodes in natural ecosystems. This is opposite to many studies on factors controlling root-feeding insects, which are supposed to be controlled by carnivorous invertebrates, parasitoids, or entomopathogenic nematodes. Our conclusion is that the ectoparasitic nematode T. ventralis is potentially able to limit productivity of the dune grass A. arenaria but that soil organisms, mostly microorganisms, usually prevent the

  15. Identification and functional analysis of secreted effectors from phytoparasitic nematodes.

    PubMed

    Rehman, Sajid; Gupta, Vijai K; Goyal, Aakash K

    2016-03-21

    Plant parasitic nematodes develop an intimate and long-term feeding relationship with their host plants. They induce a multi-nucleate feeding site close to the vascular bundle in the roots of their host plant and remain sessile for the rest of their life. Nematode secretions, produced in the oesophageal glands and secreted through a hollow stylet into the host plant cytoplasm, are believed to play key role in pathogenesis. To combat these persistent pathogens, the identity and functional analysis of secreted effectors can serve as a key to devise durable control measures. In this review, we will recapitulate the knowledge over the identification and functional characterization of secreted nematode effector repertoire from phytoparasitic nematodes. Despite considerable efforts, the identity of genes encoding nematode secreted proteins has long been severely hampered because of their microscopic size, long generation time and obligate biotrophic nature. The methodologies such as bioinformatics, protein structure modeling, in situ hybridization microscopy, and protein-protein interaction have been used to identify and to attribute functions to the effectors. In addition, RNA interference (RNAi) has been instrumental to decipher the role of the genes encoding secreted effectors necessary for parasitism and genes attributed to normal development. Recent comparative and functional genomic approaches have accelerated the identification of effectors from phytoparasitic nematodes and offers opportunities to control these pathogens. Plant parasitic nematodes pose a serious threat to global food security of various economically important crops. There is a wealth of genomic and transcriptomic information available on plant parasitic nematodes and comparative genomics has identified many effectors. Bioengineering crops with dsRNA of phytonematode genes can disrupt the life cycle of parasitic nematodes and therefore holds great promise to develop resistant crops against plant

  16. Chemical signals from plants previously infected with root knot nematodes affect behavior of infective juvenile root knot nematodes

    USDA-ARS?s Scientific Manuscript database

    Nematodes are a worldwide problem in agriculture, with losses estimated to $100 billion per year in the US. Damage caused by root-knot nematodes (Meloidogyne spp.) (RKN) disrupts the flow of water and nutrients to the plant and increases the plant’s vulnerability to other pathogens. While studies ...

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

    PubMed

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

    2009-09-01

    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, seven 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.

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

    PubMed Central

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

    2009-01-01

    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. PMID:19383517

  19. First report of the root-lesion nematode, Pratylenchus scribneri, infecting potato in North Dakota

    USDA-ARS?s Scientific Manuscript database

    Root-lesion nematodes (Pratylenchus spp.) are the most common nematode pests of potato. Five soil samples were collected from a harvested potato field near Cogswell (Sargent County), ND in October 2014 to investigate the occurrence of root-lesion nematodes. Plant-parasitic nematodes were extracted, ...

  20. First report of the spiral nematode Helicotylenchus microlobus infecting soybean in North Dakota

    USDA-ARS?s Scientific Manuscript database

    Spiral nematodes (Helicotylenchus spp.) are common plant-parasitic nematodes in fields of many crops. In June 2015, two soil samples were collected from a soybean field in Richland County, ND. Nematodes were extracted from soil using the sugar centrifugal flotation method. Plant-parasitic nematodes ...

  1. [Nematodes (Nematoda) from bats (Chiroptera) of the Samarskaya Luka Peninsula (Russia)].

    PubMed

    Kirillova, N Iu; Kirillov, A A; Vekhnik, V P

    2008-01-01

    Fauna of parasitic nematodes from Chiroptera of the Samarskaya Luka has been studied. Seven nematode species has been recorded. Numbers of host specimens, indices of extensiveness and intensiveness of the invasion, parasite abundance, and brief characteristics of the nematode species are given. Some nematode species were for the first time recorded in bats of Russia.

  2. Vertebrate herbivores influence soil nematodes by modifying plant communities.

    PubMed

    Veen, G F; Olff, Han; Duyts, Henk; van der Putten, Wim H

    2010-03-01

    Abiotic soil properties, plant community composition, and herbivory all have been reported as important factors influencing the composition of soil communities. However, most studies thus far have considered these factors in isolation, whereas they strongly interact in the field. Here, we study how grazing by vertebrate herbivores influences the soil nematode community composition of a floodplain grassland while we account for effects of grazing on plant community composition and abiotic soil properties. Nematodes are the most ubiquitous invertebrates in the soil. They include a variety of feeding types, ranging from microbial feeders to herbivores and carnivores, and they perform key functions in soil food webs. Our hypothesis was that grazing affects nematode community structure and composition through altering plant community structure and composition. Alternatively, we tested whether the effects of grazing may, directly or indirectly, run via changes in soil abiotic properties. We used a long-term field experiment containing plots with and without vertebrate grazers (cattle and rabbits). We compared plant and nematode community structure and composition, as well as a number of key soil abiotic properties, and we applied structural equation modeling to investigate four possible pathways by which grazing may change nematode community composition. Aboveground grazing increased plant species richness and reduced both plant and nematode community heterogeneity. There was a positive relationship between plant and nematode diversity indices. Grazing decreased the number of bacterial-feeding nematodes, indicating that in these grasslands, top-down control of plant production by grazing leads to bottom-up control in the basal part of the bacterial channel of the soil food web. According to the structural equation model, grazing had a strong effect on soil abiotic properties and plant community composition, whereas plant community composition was the main determinant of

  3. Entomopathogenic nematodes in agricultural areas in Brazil

    PubMed Central

    de Brida, Andressa Lima; Rosa, Juliana Magrinelli Osório; Oliveira, Cláudio Marcelo Gonçalves de; Castro, Bárbara Monteiro de Castro e; Serrão, José Eduardo; Zanuncio, José Cola; Leite, Luis Garrigós; Wilcken, Silvia Renata Siciliano

    2017-01-01

    Entomopathogenic nematodes (EPNs) (Steinernematidae and Heterorhabditidae) can control pests due to the mutualistic association with bacteria that kill the host by septicemia and make the environment favorable for EPNs development and reproduction. The diversity of EPNs in Brazilian soils requires further study. The identification of EPNs, adapted to environmental and climatic conditions of cultivated areas is important for sustainable pest suppression in integrated management programs in agricultural areas of Brazil. The objective was to identify EPNs isolated from agricultural soils with annual, fruit and forest crops in Brazil. Soil samples were collected and stored in 250 ml glass vials. The nematodes were isolated from these samples with live bait traps ([Galleria mellonella L. (Lepidoptera: Pyralidae) larvae]. Infective juveniles were collected with White traps and identified by DNA barcoding procedures by sequencing the D2/D3 expansion of the 28S rDNA region by PCR. EPNs identified in agricultural areas in Brazil were Heterorhabditis amazonensis, Metarhabditis rainai, Oscheios tipulae and Steinernema rarum. These species should be considered pest biocontrol agents in Brazilian agricultural areas. PMID:28382937

  4. Entomopathogenic nematodes in agricultural areas in Brazil.

    PubMed

    de Brida, Andressa Lima; Rosa, Juliana Magrinelli Osório; Oliveira, Cláudio Marcelo Gonçalves de; Castro, Bárbara Monteiro de Castro E; Serrão, José Eduardo; Zanuncio, José Cola; Leite, Luis Garrigós; Wilcken, Silvia Renata Siciliano

    2017-04-06

    Entomopathogenic nematodes (EPNs) (Steinernematidae and Heterorhabditidae) can control pests due to the mutualistic association with bacteria that kill the host by septicemia and make the environment favorable for EPNs development and reproduction. The diversity of EPNs in Brazilian soils requires further study. The identification of EPNs, adapted to environmental and climatic conditions of cultivated areas is important for sustainable pest suppression in integrated management programs in agricultural areas of Brazil. The objective was to identify EPNs isolated from agricultural soils with annual, fruit and forest crops in Brazil. Soil samples were collected and stored in 250 ml glass vials. The nematodes were isolated from these samples with live bait traps ([Galleria mellonella L. (Lepidoptera: Pyralidae) larvae]. Infective juveniles were collected with White traps and identified by DNA barcoding procedures by sequencing the D2/D3 expansion of the 28S rDNA region by PCR. EPNs identified in agricultural areas in Brazil were Heterorhabditis amazonensis, Metarhabditis rainai, Oscheios tipulae and Steinernema rarum. These species should be considered pest biocontrol agents in Brazilian agricultural areas.

  5. Osmoregulation in the parasitic nematode Pseudoterranova decipiens.

    PubMed

    Fusé, M; Davey, K G; Sommerville, R I

    1993-02-01

    When subjected to hyper- or hypo-osmotic stress at 5 degrees C for 24 h, third-stage larvae of the parasitic nematode Pseudoterranova decipiens do not exhibit changes in mass or in the osmotic pressure of the pseudocoelomic fluid. Immersion in solutions containing 3H2O demonstrates that exchange with the water in the pseudocoelomic fluid is substantially complete within 24 h. Sacs composed of cylinders of body wall without the intestine and pseudocoelomic fluid do not gain weight when immersed for 24 h in hypotonic medium. Metabolic poisons abolish the ability of whole worms and sacs to maintain their weight when immersed in hypotonic media. These observations support the conclusion that the nematode is capable of at least short-term osmoregulation and that the site of osmoregulation is the body wall. The observations that more fluid is passed from the anus in some hypo-osmotically stressed worms and that worms ligatured at the tail exhibit a small increase in mass when exposed to hypo-osmotic conditions may indicate that the intestine plays a minor and subsidiary role in osmoregulation.

  6. Arrested larval development in cattle nematodes.

    PubMed

    Armour, J; Duncan, M

    1987-06-01

    Most economically important cattle nematodes are able to arrest their larval development within the host - entering a period of dormancy or hypobiosis. Arrested larvae have a low death rate, and large numbers can accumulate in infected cattle during the grazing season. Because of this, outbreaks of disease caused by such nematodes can occur at times when recent infection with the parasites could not have occurred, for example during winter in temperature northern climates when cattle are normally housed. The capacity to arrest is a heritable trait. It is seen as an adaptation by the parasite to avoid further development to its free-living stages during times when the climate is unsuitable for free-living survival. But levels of arrestment can vary markedly in different regions, in different cattle, and under different management regimes. Climatic factors, previous conditioning, host immune status, and farm management all seem to affect arrestment levels. In this article, James Armour and Mary Duncan review the biological basis of the phenomenon, and discuss the apparently conflicting views on how it is controlled.

  7. Resistance of Grape Rootstocks to Plant-parasitic Nematodes

    PubMed Central

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

    2012-01-01

    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

  8. Resistance of Grape Rootstocks to Plant-parasitic Nematodes.

    PubMed

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

    2012-12-01

    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.

  9. Assaying Predatory Feeding Behaviors in Pristionchus and Other Nematodes

    PubMed Central

    Okumura, Misako; Sommer, Ralf J.

    2016-01-01

    This protocol provides multiple methods for the analysis and quantification of predatory feeding behaviors in nematodes. Many nematode species including Pristionchus pacificus display complex behaviors, the most striking of which is the predation of other nematode larvae. However, as these behaviors are absent in the model organism Caenorhabditis elegans, they have thus far only recently been described in detail along with the development of reliable behavioral assays 1. These predatory behaviors are dependent upon phenotypically plastic but fixed mouth morphs making the correct identification and categorization of these animals essential. In P. pacificus there are two mouth types, the stenostomatous and eurystomatous morphs 2, with only the wide mouthed eurystomatous containing an extra tooth and being capable of killing other nematode larvae. Through the isolation of an abundance of size matched prey larvae and subsequent exposure to predatory nematodes, assays including both "corpse assays" and "bite assays" on correctly identified mouth morph nematodes are possible. These assays provide a means to rapidly quantify predation success rates and provide a detailed behavioral analysis of individual nematodes engaged in predatory feeding activities. In addition, with the use of a high-speed camera, visualization of changes in pharyngeal activity including tooth and pumping dynamics are also possible. PMID:27684744

  10. Pack hunting by a common soil amoeba on nematodes.

    PubMed

    Geisen, Stefan; Rosengarten, Jamila; Koller, Robert; Mulder, Christian; Urich, Tim; Bonkowski, Michael

    2015-11-01

    Soils host the most complex communities on Earth, including the most diverse and abundant eukaryotes, i.e. heterotrophic protists. Protists are generally considered as bacterivores, but evidence for negative interactions with nematodes both from laboratory and field studies exist. However, direct impacts of protists on nematodes remain unknown. We isolated the soil-borne testate amoeba Cryptodifflugia operculata and found a highly specialized and effective pack-hunting strategy to prey on bacterivorous nematodes. Enhanced reproduction in presence of prey nematodes suggests a beneficial predatory life history of these omnivorous soil amoebae. Cryptodifflugia operculata appears to selectively impact the nematode community composition as reductions of nematode numbers were species specific. Furthermore, we investigated 12 soil metatranscriptomes from five distinct locations throughout Europe for 18S ribosomal RNA transcripts of C. operculata. The presence of C. operculata transcripts in all samples, representing up to 4% of the active protist community, indicates a potential ecological importance of nematophagy performed by C. operculata in soil food webs. The unique pack-hunting strategy on nematodes that was previously unknown from protists, together with molecular evidence that these pack hunters are likely to be abundant and widespread in soils, imply a considerable importance of the hitherto neglected trophic link 'nematophagous protists' in soil food webs.

  11. Reciprocal Interactions between Nematodes and Their Microbial Environments

    PubMed Central

    Midha, Ankur; Schlosser, Josephine; Hartmann, Susanne

    2017-01-01

    Parasitic nematode infections are widespread in nature, affecting humans as well as wild, companion, and livestock animals. Most parasitic nematodes inhabit the intestines of their hosts living in close contact with the intestinal microbiota. Many species also have tissue migratory life stages in the absence of severe systemic inflammation of the host. Despite the close coexistence of helminths with numerous microbes, little is known concerning these interactions. While the environmental niche is considerably different, the free-living nematode Caenorhabditis elegans (C. elegans) is also found amongst a diverse microbiota, albeit on decaying organic matter. As a very well characterized model organism that has been intensively studied for several decades, C. elegans interactions with bacteria are much more deeply understood than those of their parasitic counterparts. The enormous breadth of understanding achieved by the C. elegans research community continues to inform many aspects of nematode parasitology. Here, we summarize what is known regarding parasitic nematode-bacterial interactions while comparing and contrasting this with information from work in C. elegans. This review highlights findings concerning responses to bacterial stimuli, antimicrobial peptides, and the reciprocal influences between nematodes and their environmental bacteria. Furthermore, the microbiota of nematodes as well as alterations in the intestinal microbiota of mammalian hosts by helminth infections are discussed. PMID:28497029

  12. Evolution of Parasitism in Insect-transmitted Plant Nematodes

    PubMed Central

    Giblin-Davis, R. M.; Davies, K. A.; Morris, K.; Thomas, W. K.

    2003-01-01

    Nematode-insect associations have evolved many times in the phylum Nematoda, but these lineages involve plant parasitism only in the Secernentean orders Aphelenchida and Tylenchida. In the Aphelenchida (Aphelenchoidoidea), Bursaphelenchus xylophilus (Pine wood nematode), B. cocophilus (Red ring or Coconut palm nematode) (Parasitaphelenchidae), and the many potential host-specific species of Schistonchus (fig nematodes) (Aphelenchoididae) nematode-insect interactions probably evolved independently from dauer-forming, mycophagous ancestors that were phoretically transmitted to breeding sites of their insect hosts in plants. Mycophagy probably gave rise to facultative or obligate plant-parasitism because of opportunities due to insect host switches or peculiarities in host behavior. In the Tylenchida, there is one significant radiation of insect-associated plant parasites involving Fergusobia nematodes (Fergusobiinae: Neotylenchidae) and Fergusonina (Fergusoninidae) flies as mutualists that gall myrtaceous plant buds or leaves. These dicyclic nematodes have different phases that are parasitic in either the insect or the plant hosts. The evolutionary origin of this association is unclear. PMID:19265987

  13. Changes in soil nematode communities under the impact of fertilizers

    NASA Astrophysics Data System (ADS)

    Gruzdeva, L. I.; Matveeva, E. M.; Kovalenko, T. E.

    2007-06-01

    Changes taking place in the communities of soil nematodes of an artificially sown meadow under the impact of annually applied mineral fertilizers have been studied in a field experiment for nine years. It is shown that changes in the species composition, trophic structure, and numbers of nematodes from different genera depend on the fertilizer applied and on the competitiveness of the plant species grown. The spectra of nematode genera sensitive to the complete mineral fertilizer (NPK) and to the particular nutrients have been identified with the use of a number of parameters, including the maturity index of nematode communities, the biotope preferences of the particular nematode genera, and the general pattern of nematode habitats. The results obtained in this study can be used to assess the effect of mineral fertilizers on the soil fauna and to suggest optimum application rates of mineral fertilizers ensuring the sustainable development of meadow herbs. The use of the data on the trophic structure of nematode communities for predicting the ways of organic matter decomposition in the soil is discussed.

  14. Susceptibility of the Plum Curculio, Conotrachelus nenuphar, to Entomopathogenic Nematodes

    PubMed Central

    Shapiro-Ilan, David I.; Mizell, Russell F.; Campbell, James F.

    2002-01-01

    The plum curculio, Conotrachelus nenuphar, is a major pest of pome and stone fruit. Our objective was to determine virulence and reproductive potential of six commercially available nematode species in C. nenuphar larvae and adults. Nematodes tested were Heterorhabditis bacteriophora (Hb strain), H. marelatus (Point Reyes strains), H. megidis (UK211 strain), Steinernema riobrave (355 strain), S. carpocapsae (All strain), and S. feltiae (SN strain). Survival of C. nenuphar larvae treated with S. feltiae and S. riobrave, and survival of adults treated with S. carpocapsae and S. riobrave, was reduced relative to non-treated insects. Other nematode treatments were not different from the control. Conotrachelus nenuphar larvae were more susceptible to S. feltiae infection than were adults, but for other nematode species there was no significant insect-stage effect. Reproduction in C. nenuphar was greatest for H. marelatus, which produced approximately 10,000 nematodes in larvae and 5,500 in adults. Other nematodes produced approximately 1,000 to 3,700 infective juveniles per C. nenuphar with no significant differences among nematode species or insect stages. We conclude that S. carpocapsae or S. riobrave appears to have the most potential for controlling adults, whereas S. feltiae or S. riobrave appears to have the most potential for larval control. PMID:19265940

  15. Assaying Predatory Feeding Behaviors in Pristionchus and Other Nematodes.

    PubMed

    Lightfoot, James W; Wilecki, Martin; Okumura, Misako; Sommer, Ralf J

    2016-09-04

    This protocol provides multiple methods for the analysis and quantification of predatory feeding behaviors in nematodes. Many nematode species including Pristionchus pacificus display complex behaviors, the most striking of which is the predation of other nematode larvae. However, as these behaviors are absent in the model organism Caenorhabditis elegans, they have thus far only recently been described in detail along with the development of reliable behavioral assays (1). These predatory behaviors are dependent upon phenotypically plastic but fixed mouth morphs making the correct identification and categorization of these animals essential. In P. pacificus there are two mouth types, the stenostomatous and eurystomatous morphs (2), with only the wide mouthed eurystomatous containing an extra tooth and being capable of killing other nematode larvae. Through the isolation of an abundance of size matched prey larvae and subsequent exposure to predatory nematodes, assays including both "corpse assays" and "bite assays" on correctly identified mouth morph nematodes are possible. These assays provide a means to rapidly quantify predation success rates and provide a detailed behavioral analysis of individual nematodes engaged in predatory feeding activities. In addition, with the use of a high-speed camera, visualization of changes in pharyngeal activity including tooth and pumping dynamics are also possible.

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

    PubMed

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

    2011-08-01

    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.

  17. Nematode Assemblages in Native Plant Communities of Molokai, Hawaii

    PubMed Central

    Bernard, E. C.; Schmitt, D. P.

    2005-01-01

    Four native plant community types (in decreasing elevation: montane bog, rain forest, wet mesic forest, drier forest) on Molokai were sampled for nematodes. Six samples of 10 cores each were gathered from each community. Nematodes were extracted from 200 cm³ soil by elutriation. All extracted nematodes were counted and identified to species-level taxa. Sixty-seven species were identified among the four plant communities; only eight species occurred in all four communities. Species diversity and evenness were greater in the rain forest and mesic forest than in the bog and the drier forest, but the drier forest and mesic forest had similar species communities. The bog nematode community was not similar to the other three sites. In a presence/absence cluster analysis, all six bog sample assemblages clustered together. The rain forest samples also clustered together but were associated with the mesic forest sample closest to the rain forest edge. Of 11 nematode orders collected, Tylenchida accounted for 40% to 73% of all individuals, followed by Dorylaimida (5% to 17%). Diplogasterida were absent. No plant-parasitic nematodes of known Hawaiian agricultural importance or occurrence were collected in these native plant communities. Calculated nematode densities (76,000 to 321,300/m²) were comparable to those reported for some other Pacific tropical forests. PMID:19262867

  18. Current Surveys of the Seroprevalence of Borrelia burgdorferi, Ehrlichia canis, Anaplasma phagocytophilum, Leishmania infantum, Babesia canis, Angiostrongylus vasorum and Dirofilaria immitis in Dogs in Bulgaria.

    PubMed

    Pantchev, Nikola; Schnyder, Manuela; Vrhovec, Majda Globokar; Schaper, Roland; Tsachev, Ilia

    2015-08-01

    Canine vector-borne diseases (CVBDs) have increasingly become a focus of interest in recent years. Some of the CVBDs are zoonotic and may therefore also represent a risk for the human population. Different factors are in discussion to explain the expansion of vectors and pathogens into formerly unaffected areas. Knowledge of the prevalence and distribution of CVBDs in Bulgaria is scant overall and most data rely on single case descriptions. The aim of the present study was to determine the seroprevalence of important CVBDs in 167 dogs from central-southern Bulgaria (Stara Zagora), with special emphasis on hitherto uninvestigated babesiosis and angiostrongylosis, on poorly investigated Lyme borreliosis and canine granulocytic anaplasmosis, and on the potentially zoonotic dirofilariosis and leishmaniosis. Relatively high prevalence rates were documented for anti-Babesia canis antibodies, Dirofilaria immitis antigen (16.2 %; 27/167 each), anti-Ehrlichia canis (21 %; 35/167) and anti-Anaplasma phagocytophilum antibodies (30.5 - 46.1 %; 51 - 77/167), while Borrelia burgdorferi seroprevalence was low (2.4 %; 4/167). All samples were negative for Leishmania infantum antibodies and Angiostrongylus vasorum antigen and antibodies. In total, 64.7 % (108/167) of the samples indicated infection or exposure to at least one agent and a high proportion of dual infections (39.8 %; 43/108) was demonstrated. Multiple infections with up to four different organisms were also detected. Our data underline the importance of CVBDs and especially of co-infections which could influence the clinical outcome in dogs.

  19. Efficacy and safety of imidacloprid/moxidectin spot-on solution and fenbendazole in the treatment of dogs naturally infected with Angiostrongylus vasorum (Baillet, 1866).

    PubMed

    Willesen, J L; Kristensen, A T; Jensen, A L; Heine, J; Koch, J

    2007-07-20

    A randomized, blinded, controlled multicentre field trial study was conducted to evaluate the efficacy and safety of imidacloprid 10%/moxidectin 2.5% spot-on solution and fenbendazole in treating dogs naturally infected with Angiostrongylus vasorum. Dogs were randomly treated either with a single dose of 0.1 ml/kg bodyweight of imidacloprid 10%/moxidectin 2.5% spot-on solution or with 25 mg/kg bodyweight fenbendazole per os for 20 days. The study period was 42 days with dogs being examined on days 0, 7 and 42. The primary efficacy parameter was the presence of L1 larvae in faecal samples evaluated by a Baermann test from three consecutive days. Thoracic radiographs performed on each visit were being taken as a paraclinical parameter to support the results of the Baermann test. Twenty-seven dogs in the imidacloprid/moxidectin group and 23 dogs in the fenbendazole group completed the study according to protocol. The efficacies of the two treatment protocols were 85.2% (imidacloprid/moxidectin) and 91.3% (fenbendazole) with no significant difference between treatment groups. On radiographic evaluation pulmonary parenchyma showed similar improvement in each group. No serious adverse effects to treatment were recorded: most of the minor adverse effects were gastrointestinal such as diarrhea (nine dogs), vomitus (eight dogs) and salivation (three dogs). In general, these adverse effects were of short duration (1-2 days) within the first few days after treatment start and required little or no treatment. This prospective study demonstrates that both treatment protocols used are efficacious under field conditions, that treatment of mildly to moderately infected dogs with either of these protocols is safe and yields an excellent prognosis for recovering from the infection.

  20. Unraveling flp-11/flp-32 dichotomy in nematodes.

    PubMed

    Atkinson, Louise E; Miskelly, Iain R; Moffett, Christy L; McCoy, Ciaran J; Maule, Aaron G; Marks, Nikki J; Mousley, Angela

    2016-10-01

    FMRFamide-like peptide (FLP) signalling systems are core to nematode neuromuscular function. Novel drug discovery efforts associated with nematode FLP/FLP receptor biology are advanced through the accumulation of basic biological data that can reveal subtle complexities within the neuropeptidergic system. This study reports the characterisation of FMRFamide-like peptide encoding gene-11 (flp-11) and FMRFamide-like peptide encoding gene-32 (flp-32), two distinct flp genes which encode the analogous peptide, AMRN(A/S)LVRFamide, in multiple nematode species - the only known example of this phenomenon within the FLPergic system of nematodes. Using bioinformatics, in situ hybridisation, immunocytochemistry and behavioural assays we show that: (i) flp-11 and -32 are distinct flp genes expressed individually or in tandem across multiple nematode species, where they encode a highly similar peptide; (ii) flp-11 does not appear to be the most widely expressed flp in Caenorhabditis elegans; (iii) in species expressing both flp-11 and flp-32, flp-11 displays a conserved, restricted expression pattern across nematode clades and lifestyles; (iv) in species expressing both flp-11 and flp-32, flp-32 expression is more widespread and less conserved than flp-11; (v) in species expressing only flp-11, the flp-11 expression profile is more similar to the flp-32 profile observed in species expressing both; and (vi) FLP-11 peptides inhibit motor function in multiple nematode species. The biological significance and evolutionary origin of flp-11 and -32 peptide duplication remains unclear despite attempts to identify a common ancestor; this may become clearer as the availability of genomic data improves. This work provides insight into the complexity of the neuropeptidergic system in nematodes, and begins to examine how nematodes may compensate for structural neuronal simplicity. From a parasite control standpoint, this work underscores the importance of basic biological data, and has

  1. Intestinal Enterobacteriaceae that Protect Nematodes from the Effects of Benzimidazoles

    PubMed Central

    Whittaker, John H; Robertson, Alan P; Kimber, Michael J; Day, Tim A; Carlson, Steve A

    2016-01-01

    The objective of this study was to investigate an interaction between nematodes and gut Enterobacteriaceae that use benzimidazoles as a carbon source. By addressing this objective, we identified an anthelmintic resistance-like mechanism for gastrointestinal nematodes. We isolated 30 gut bacteria (family Enterobacteriaceae) that subsist on and putatively catabolize benzimidazole-class anthelmintics. C. elegans was protected from the effects of benzimidazoles when co-incubated with these Enterobacteriaceae that also protect adult ascarids from the effects of albendazole. This bacterial phenotype represents a novel mechanism by which gastrointestinal nematodes are potentially spared from the effects of benzimidazoles, without any apparent fitness cost to the parasite. PMID:28066686

  2. Suppression of plant parasitic nematodes in the chinampa agricultural soils.

    PubMed

    Zuckerman, B M; Dicklow, M B; Coles, G C; Garcia-E, R; Marban-Mendoza, N

    1989-06-01

    Soil from the chinampa agricultural system in the Valley of Mexico suppressed damage by plant-parasitic nematodes to tomatoes and beans in greenhouse and growth chamber trials. Sterilization of the chinampa soil resulted in a loss of the suppressive effect, thereby indicating that one or more biotic factors were responsible for the low incidence of nematode damage. Nine organisms were isolated from chinampa soil, which showed antinematodal properties in culture. Naturally occurring populations of plant-parasitic nematodes were of lower incidence in chinampa soil than in Chapingo soil.

  3. Biocontrol: Bacillus penetrans and Related Parasites of Nematodes

    PubMed Central

    Sayre, R. M.

    1980-01-01

    Bacillus penetrans Mankau, 1975, previously described as Duboscqia penetrans Thorne 1940, is a candidate agent for biocontrol of nematodes. This review considers the life stages of this bacterium: vegetative growth phase, colony fragmentation, sporogenesis, soil phase, spore attachment, and penetration into larvae of root-knot nematodes. The morphology of the microthallus colonies and the unusual external features of the spore are discussed. Taxonomic affinities with the actinomycetes, particularly with the genus Pasteuria, are considered. Also discussed are other soil bacterial species that are potential biocontrol agents. Products of their bacterial fermentation in soil are toxic to nematodes, making them effective biocontrol agents. PMID:19300701

  4. Effects of catechin polyphenols and preparations from the plant-parasitic nematode Heterodera glycines on protease activity and behavior in three nematode species

    USDA-ARS?s Scientific Manuscript database

    Protease activities in preparations from the plant-parasitic nematodes Heterodera glycines and Meloidogyne incognita and the free-living nematode Panagrellus redivivus were inhibited by exposure to a series of 8 catechin polyphenol analogs, (+)-catechin, (-)- epicatechin (EC), (-)-gallocatechin (GC)...

  5. Advancing nematode barcoding: a primer cocktail for the cytochrome c oxidase subunit I gene from vertebrate parasitic nematodes.

    PubMed

    Prosser, Sean W J; Velarde-Aguilar, Maria G; León-Règagnon, Virginia; Hebert, Paul D N

    2013-11-01

    Although nematodes are one of the most diverse metazoan phyla, species identification through morphology is difficult. Several genetic markers have been used for their identification, but most do not provide species-level resolution in all groups, and those that do lack primer sets effective across the phylum, precluding high-throughput processing. This study describes a cocktail of three novel primer pairs that overcome this limitation by recovering cytochrome c oxidase I (COI) barcodes from diverse nematode lineages parasitic on vertebrates, including members of three orders and eight families. Its effectiveness across a broad range of nematodes enables high-throughput processing. © 2013 John Wiley & Sons Ltd.

  6. Robustness and flexibility in nematode vulva development.

    PubMed

    Félix, Marie-Anne; Barkoulas, Michalis

    2012-04-01

    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. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. MSP Dynamics and Retraction in Nematode Sperm

    NASA Astrophysics Data System (ADS)

    Wolgemuth, Charles W.

    2005-03-01

    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.

  8. MSP dynamics and retraction in nematode sperm

    NASA Astrophysics Data System (ADS)

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

    2005-03-01

    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.

  9. Are nematode collections in danger of extinction?

    PubMed

    Hockland, S; Hoestra, H

    2003-01-01

    The correct identification of pest organisms, including plant-parasitic nematodes, is the essential foundation for integrated pest programmes and government policy decisions involving trade. A plethora of identification methods have been developed but the basis for identification remains essentially morphological in nature, with invertebrate collections forming the ultimate reference facility. However, a continuing decline in funds for the preservation and curation of collections and for the development of taxonomists is leading to a deterioration in the quality of standards. The development of computer technology associated with digital images and their analysis provides the possibility of not only attracting resources but also of exposing collections to international use in ways not previously possible. The time is right to develop a European strategy to save and develop collections and taxonomy.

  10. A Nematode Growth Factor from Baker's Yeast

    PubMed Central

    Buecher, E. J.; Hansen, E. L.; Gottfried, T.

    1970-01-01

    An extract prepared from commercially available yeast supported maturation of the free-living nematode Caenorhabditis briggsae. The extract can be used to supplement a chemically defined medium or, after a limited dialysis, as a complete medium. Several biologically active fractions were prepared; those containing larger amounts of ribonucleic acid (RNA) had greater biological activity, the most active being a pellet resuspended after centrifugation at 30,000 × g for 30 min. This fraction could be substituted for serum in a medium which supports the maturation of the animal parasites Trichinella spiralis and Hymenolepis nana. Addition of protamine sulfate decreased the RNA content, leaving inactive protein fractions which could be reactivated by specific treatments that caused protein precipitation. It is postulated that biological activity is associated with protein sedimented with ribosomes. PMID:19322277

  11. OX40 interactions in gastrointestinal nematode infection.

    PubMed

    Ierna, Michelle X; Scales, Hannah E; Schwarz, Herbert; Bunce, Campbell; McIlgorm, Anne; Garside, Paul; Lawrence, Catherine E

    2006-01-01

    The immune expulsion of gastrointestinal nematode parasites is usually associated with T helper type 2 (Th2) responses, but the effector mechanisms directly responsible for parasite loss have not been elucidated. The intestinal inflammatory response accompanying infection with gastrointestinal helminths is thought to be a contributory factor leading to the expulsion of the parasite. However, we have shown that the intestinal inflammation, which is controlled by interleukin (IL)-4, is not required for parasite expulsion. OX40-OX40 ligand (L) signals have been shown to be important for the development of Th2 immune responses but are also involved in a number of inflammatory diseases including those of the intestine. Here, we have investigated the effect of OX40 and OX40L fusion protein treatment on the induction of protective Th2 responses and enteropathy following infection with the gastrointestinal nematode Trichinella spiralis. Treatment with an OX40-immunoglobulin (Ig) blocking fusion protein resulted in enhanced expulsion of the parasite and an increase in the accompanying mastocytosis, despite unaltered levels of Th2 cytokines. Furthermore, there was a delay in the villus atrophy and crypt hyperplasia usually associated with this infection. In contrast, levels of Th2 cytokines were greatly up-regulated in mice treated with an OX40L-Ig activating fusion protein, yet the expulsion of the parasite and the enteropathy were unaffected. Therefore, OX40 ligation potentiates the Th2 response without enhancing host protective immune responses, whereas blocking the OX40-OX40L interaction enhances host protection without promoting Th2 cytokine responses during Trichinella spiralis infection.

  12. OX40 interactions in gastrointestinal nematode infection

    PubMed Central

    Ierna, Michelle X; Scales, Hannah E; Schwarz, Herbert; Bunce, Campbell; McIlgorm, Anne; Garside, Paul; Lawrence, Catherine E

    2006-01-01

    The immune expulsion of gastrointestinal nematode parasites is usually associated with T helper type 2 (Th2) responses, but the effector mechanisms directly responsible for parasite loss have not been elucidated. The intestinal inflammatory response accompanying infection with gastrointestinal helminths is thought to be a contributory factor leading to the expulsion of the parasite. However, we have shown that the intestinal inflammation, which is controlled by interleukin (IL)-4, is not required for parasite expulsion. OX40–OX40 ligand (L) signals have been shown to be important for the development of Th2 immune responses but are also involved in a number of inflammatory diseases including those of the intestine. Here, we have investigated the effect of OX40 and OX40L fusion protein treatment on the induction of protective Th2 responses and enteropathy following infection with the gastrointestinal nematode Trichinella spiralis. Treatment with an OX40–immunoglobulin (Ig) blocking fusion protein resulted in enhanced expulsion of the parasite and an increase in the accompanying mastocytosis, despite unaltered levels of Th2 cytokines. Furthermore, there was a delay in the villus atrophy and crypt hyperplasia usually associated with this infection. In contrast, levels of Th2 cytokines were greatly up-regulated in mice treated with an OX40L–Ig activating fusion protein, yet the expulsion of the parasite and the enteropathy were unaffected. Therefore, OX40 ligation potentiates the Th2 response without enhancing host protective immune responses, whereas blocking the OX40–OX40L interaction enhances host protection without promoting Th2 cytokine responses during Trichinella spiralis infection. PMID:16423046

  13. Soil Organic Matter and Management of Plant-Parasitic Nematodes

    PubMed Central

    Widmer, T. L.; Mitkowski, N. A.; Abawi, G. S.

    2002-01-01

    Organic matter and its replenishment has become a major component of soil health management programs. Many of the soil's physical, chemical, and biological properties are a function of organic matter content and quality. Adding organic matter to soil influences diverse and important biological activities. The diversity and number of free-living and plant-parasitic nematodes are altered by rotational crops, cover crops, green manures, and other sources of organic matter. Soil management programs should include the use of the proper organic materials to improve soil chemical, physical, and biological parameters and to suppress plant-parasitic nematodes and soilborne pathogens. It is critical to monitor the effects of organic matter additions on activities of major and minor plant-parasitic nematodes in the production system. This paper presents a general review of information in the literature on the effects of crop rotation, cover crops, and green manures on nematodes and their damage to economic crops. PMID:19265946

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

    PubMed

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

    1984-01-01

    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.

  15. SCREENING OF TRANSGENIC ANTHURIUMS FOR BACTERIAL BLIGHT AND NEMATODE RESISTANCE

    USDA-ARS?s Scientific Manuscript database

    Anthuriums exhibit limited resistance to bacterial blight caused by Xanthomonas axonopodis pv. dieffenbachiae and to the nematodes Radopholus simile and Meloidogyne javanica. Agrobacterium tumefaciens transformation of embryogenic calli with strains LBA4404, EHA105, and AGLO resulted in transgenic p...

  16. Human gastrointestinal nematode infections: are new control methods required?

    PubMed Central

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

    2006-01-01

    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. PMID:16965561

  17. Nematodes Attacking Cultivars of Peach in North Carolina

    PubMed Central

    Barker, K. R.; Clayton, C. N.

    1973-01-01

    Criconemoides xenoplax and Meloidogyne incognita were the nematode species most frequently associated with peach in North Carolina. Other nematodes often found in high numbers on that crop were Pratylenehus vulnus, Helicotylenchus spp., Trichodorus christiei, Xiphinema amerieanum and Tylenchorhynchus claytoni. P. vulnus and P. penetrans reproduced well on rootstocks of 21 peach cultivars tested in the greenhouse. P. zeae, P. brachyurus, P. coffeae and P. scribneri decreased or increased only slightly in most instances. C. xenoplax increased as much as 330-fold and reproduced on all cultivars tested. In a field experiment with six peach cultivars and moderate numbers of P. brachyurus, P. vulnus, C. xenoplax, and M. incognita, only M. incognita caused significant stunting in 30 months. This nematode increased only on root-knot susceptible cultivars, whereas the other nematodes followed the same patterns observed in the greenhouse. In a second field experiment, seedlings were stunted significantly by high numbers of C. xenoplax during an 18-month period. PMID:19319348

  18. The draft genome of the parasitic nematode Trichinella spiralis

    PubMed Central

    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

    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. PMID:21336279

  19. A comparison of two methods for quantifying parasitic nematode fecundity

    USDA-ARS?s Scientific Manuscript database

    Accurate measures of nematode fecundity can provide important information for investigating parasite life history evolution, transmission potential, and effects on host health. Understanding differences among fecundity assessment protocols and standardizing methods, where possible, will enable compa...

  20. Breeding a super nematode for enhanced insect pest suppression

    USDA-ARS?s Scientific Manuscript database

    Entomopathogenic nematodes in the genera Heterorhabditis and Steinernema are important regulators of natural insect populations, and are used commercially as biological control agents for pest suppression. Successful biocontrol applications depend on the introduced organism having an array of benef...

  1. Excretory/secretory products from the gastrointestinal nematode Trichuris muris.

    PubMed

    Tritten, Lucienne; Tam, Mifong; Vargas, Mireille; Jardim, Armando; Stevenson, Mary M; Keiser, Jennifer; Geary, Timothy G

    2017-07-01

    To better control gastrointestinal nematode infections in humans and animals, it is important to understand the strategies used by these parasites to modulate the host immune system. In this regard, molecules released by parasites have been attributed crucially important roles in host-parasite negotiations. We characterized the excretory/secretory (E/S) microRNA (miRNA) and protein profiles from the mouse gastrointestinal nematode parasite Trichuris muris. Released miRNAs were subjected to miRNA sequencing and E/S proteins were analysed by mass spectrometry. Fourteen miRNAs were identified in T. muris exosome-like vesicles, as well as 73 proteins of nematode origin, 11 of which were unique to this study. Comparison with published nematode protein secretomes revealed high conservation at the functional level. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Nematode parasites of waterfowl (Anseriformes) from western United States

    USGS Publications Warehouse

    McDonald, M.E.

    1974-01-01

    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).

  3. Ecological Biogeography of the Terrestrial Nematodes of Victoria Land, Antarctica

    PubMed Central

    Adams, Byron J.; Wall, Diana H.; Virginia, Ross A.; Broos, Emma; Knox, Matthew A.

    2014-01-01

    Abstract The terrestrial ecosystems of Victoria Land, Antarctica are characteristically simple in terms of biological diversity and ecological functioning. Nematodes are the most commonly encountered and abundant metazoans of Victoria Land soils, yet little is known of their diversity and distribution. Herein we present a summary of the geographic distribution, habitats and ecology of the terrestrial nematodes of Victoria Land from published and unpublished sources. All Victoria Land nematodes are endemic to Antarctica, and many are common and widely distributed at landscape scales. However, at smaller spatial scales, populations can have patchy distributions, with the presence or absence of each species strongly influenced by specific habitat requirements. As the frequency of nematode introductions to Antarctica increases, and soil habitats are altered in response to climate change, our current understanding of the environmental parameters associated with the biogeography of Antarctic nematofauna will be crucial to monitoring and possibly mitigating changes to these unique soil ecosystems. PMID:25061360

  4. Potential Nematode Alarm Pheromone Induces Acute Avoidance in Caenorhabditis elegans.

    PubMed

    Zhou, Ying; Loeza-Cabrera, Mario; Liu, Zheng; Aleman-Meza, Boanerges; Nguyen, Julie K; Jung, Sang-Kyu; Choi, Yuna; Shou, Qingyao; Butcher, Rebecca A; Zhong, Weiwei

    2017-07-01

    It is crucial for animal survival to detect dangers such as predators. A good indicator of dangers is injury of conspecifics. Here we show that fluids released from injured conspecifics invoke acute avoidance in both free-living and parasitic nematodes. Caenorhabditis elegans avoids extracts from closely related nematode species but not fruit fly larvae. The worm extracts have no impact on animal lifespan, suggesting that the worm extract may function as an alarm instead of inflicting physical harm. Avoidance of the worm extract requires the function of a cGMP signaling pathway that includes the cGMP-gated channel TAX-2/TAX-4 in the amphid sensory neurons ASI and ASK. Genetic evidence indicates that the avoidance behavior is modulated by the neurotransmitters GABA and serotonin, two common targets of anxiolytic drugs. Together, these data support a model that nematodes use a nematode-specific alarm pheromone to detect conspecific injury. Copyright © 2017 by the Genetics Society of America.

  5. Transgenesis in parasitic nematodes: building a better array

    PubMed Central

    Lok, James B.

    2011-01-01

    In spite of recent progress in the development of transgenesis in parasitic nematodes, several impediments remain before this methodology can become a practical and widely employed tool in parasitology. Recently published studies on transgenesis in the necromenic nematode Pristionchus pacificus from the laboratory of Ralf Sommer highlight several leads that might be valuable as efforts to refine current systems in obligate parasites go forward. PMID:19617000

  6. Exploring the transcriptome of the burrowing nematode Radopholus similis.

    PubMed

    Jacob, Joachim; Mitreva, Makedonka; Vanholme, Bartel; Gheysen, Godelieve

    2008-07-01

    Radopholus similis is an important nematode pest on fruit crops in the tropics. Unraveling the transcriptome of this migratory plant-parasitic nematode can provide insight in the parasitism process and lead to more efficient control measures. For the first high throughput molecular characterization of this devastating nematode, 5,853 expressed sequence tags from a mixed stage population were generated. Adding 1,154 tags from the EST division of GenBank for subsequent analysis, resulted in a total of 7,007 ESTs, which represent approximately 3,200 genes. The mean G + C content of the nucleotides at the third codon position (GC3%) was calculated to be as high as 64.8%, the highest for nematodes reported to date. BLAST-searches resulted in about 70% of the clustered ESTs having homology to (DNA and protein) sequences from the GenBank database, whereas one-third of them did not match to any known sequence. Roughly 40% of these latter sequences are predicted to be coding, representing putative novel protein coding genes. Functional annotation of the sequences by GO annotation revealed the abundance of genes involved in reproduction and development, which reflects the nematode population biology. Genes with a role in the parasitism process are identified, as well as genes essential for nematode survival, providing information useful for parasite control. No evidence was found for the presence of trans-spliced leader sequences commonly occurring in nematodes, despite the use of various approaches. In conclusion, we found three different sources for the EST sequences: the majority has a nuclear origin, approximately 1% of the EST sequences are derived from the mitochondrial transcriptome, and interestingly, 1% of the tags are with high probability derived from Wolbachia, providing the first molecular indication for the presence of this endosymbiont in a plant-parasitic nematode.

  7. [Effects of phytase transgenic corn planting on soil nematode community].

    PubMed

    Zhao, Zong-Chao; Su, Ying; Mou, Wen-Ya; Liu, Man-Qiang; Chen, Xiao-Yun; Chen, Fa-Jun

    2014-04-01

    A healthy soil ecosystem is essential for nutrient cycling and energy conversion, and the impact of exogenous genes from genetically modified crops had aroused wide concerns. Phytase transgenic corn (i. e., the inbred line BVLA430101) was issued a bio-safety certificate on 27 September 2009 in China, which could improve the efficiency of feed utilization, reduce environmental pollution caused by animal manure. In this study, the abundance of trophic groups, community structure and ecological indices of soil nematodes were studied over the growing cycle of phytase transgenic corn (ab. transgenic corn) and control conventional parental corn (ab. control corn) in the field. Totally 29 and 26 nematode genera were isolated from transgenic corn and control corn fields, respectively. The abundances of bacterivores and omnivores-predators, the total number of soil nematodes, and the Shannon index (H) were significantly greater under transgenic corn than under control corn, while the opposite trend was found for the relative abundance of herbivores and the maturity index (Sigma MI) of soil nematodes. Repeated-measures analysis of variance (ANOVA) did not detect any significant effects of transgenic corn on the composition and abundance of nematode trophic groups and ecological indices of soil nematodes. Furthermore, the Student-T test showed that the abundances of bacterivores and omnivores-predators and the total number of soil nematodes during the milk-ripe stage were significant higher in the transgenic corn field than in the control corn field. The effects of transgenic corn planting on soil nematodes might be related to the increase in the nitrogen content of field soil under transgenic corn compared to control corn.

  8. Nematodes from terrestrial and freshwater habitats in the Arctic

    PubMed Central

    2014-01-01

    Abstract We present an updated list of terrestrial and freshwater nematodes from all regions of the Arctic, for which records of properly identified nematode species are available: Svalbard, Jan Mayen, Iceland, Greenland, Nunavut, Northwest territories, Alaska, Lena River estuary, Taymyr and Severnaya Zemlya and Novaya Zemlya. The list includes 391 species belonging to 146 genera, 54 families and 10 orders of the phylum Nematoda. PMID:25197239

  9. Sandy beaches: state of the art of nematode ecology.

    PubMed

    Maria, Tatiana F; Vanaverbeke, Jan; Vanreusel, Ann; Esteves, André M

    2016-01-01

    In this review, we summarize existing knowledge of the ecology of sandy-beach nematodes, in relation to spatial distribution, food webs, pollution and climate change. We attempt to discuss spatial scale patterns (macro-, meso- and microscale) according to their degree of importance in structuring sandy-beach nematode assemblages. This review will provide a substantial background on current knowledge of sandy-beach nematodes, and can be used as a starting point to delineate further investigations in this field. Over decades, sandy beaches have been the scene of studies focusing on community and population ecology, both related to morphodynamic models. The combination of physical factors (e.g. grain size, tidal exposure) and biological interactions (e.g. trophic relationships) is responsible for the spatial distribution of nematodes. In other words, the physical factors are more important in structuring nematodes communities over large scale of distribution while biological interactions are largely important in finer-scale distributions. It has been accepted that biological interactions are assumed to be of minor importance because physical factors overshadow the biological interactions in sandy beach sediments; however, the most recent results from in-situ and ex-situ experimental investigations on behavior and biological factors on a microscale have shown promise for understanding the mechanisms underlying larger-scale patterns and processes. Besides nematodes are very promising organisms used to understand the effects of pollution and climate changes although these subjects are less studied in sandy beaches than distribution patterns.

  10. Conserved nematode signalling molecules elicit plant defenses and pathogen resistance.

    PubMed

    Manosalva, Patricia; Manohar, Murli; von Reuss, Stephan H; Chen, Shiyan; Koch, Aline; Kaplan, Fatma; Choe, Andrea; Micikas, Robert J; Wang, Xiaohong; Kogel, Karl-Heinz; Sternberg, Paul W; Williamson, Valerie M; Schroeder, Frank C; Klessig, Daniel F

    2015-07-23

    Plant-defense responses are triggered by perception of conserved microbe-associated molecular patterns (MAMPs), for example, flagellin or peptidoglycan. However, it remained unknown whether plants can detect conserved molecular patterns derived from plant-parasitic animals, including nematodes. Here we show that several genera of plant-parasitic nematodes produce small molecules called ascarosides, an evolutionarily conserved family of nematode pheromones. Picomolar to micromolar concentrations of ascr#18, the major ascaroside in plant-parasitic nematodes, induce hallmark defense responses including the expression of genes associated with MAMP-triggered immunity, activation of mitogen-activated protein kinases, as well as salicylic acid- and jasmonic acid-mediated defense signalling pathways. Ascr#18 perception increases resistance in Arabidopsis, tomato, potato and barley to viral, bacterial, oomycete, fungal and nematode infections. These results indicate that plants recognize ascarosides as a conserved molecular signature of nematodes. Using small-molecule signals such as ascarosides to activate plant immune responses has potential utility to improve economic and environmental sustainability of agriculture.

  11. Conserved nematode signalling molecules elicit plant defenses and pathogen resistance

    PubMed Central

    Manosalva, Patricia; Manohar, Murli; von Reuss, Stephan H.; Chen, Shiyan; Koch, Aline; Kaplan, Fatma; Choe, Andrea; Micikas, Robert J.; Wang, Xiaohong; Kogel, Karl-Heinz; Sternberg, Paul W.; Williamson, Valerie M.; Schroeder, Frank C.; Klessig, Daniel F.

    2015-01-01

    Plant-defense responses are triggered by perception of conserved microbe-associated molecular patterns (MAMPs), for example, flagellin or peptidoglycan. However, it remained unknown whether plants can detect conserved molecular patterns derived from plant-parasitic animals, including nematodes. Here we show that several genera of plant-parasitic nematodes produce small molecules called ascarosides, an evolutionarily conserved family of nematode pheromones. Picomolar to micromolar concentrations of ascr#18, the major ascaroside in plant-parasitic nematodes, induce hallmark defense responses including the expression of genes associated with MAMP-triggered immunity, activation of mitogen-activated protein kinases, as well as salicylic acid- and jasmonic acid-mediated defense signalling pathways. Ascr#18 perception increases resistance in Arabidopsis, tomato, potato and barley to viral, bacterial, oomycete, fungal and nematode infections. These results indicate that plants recognize ascarosides as a conserved molecular signature of nematodes. Using small-molecule signals such as ascarosides to activate plant immune responses has potential utility to improve economic and environmental sustainability of agriculture. PMID:26203561

  12. Nematode Communities in Organically and Conventionally Managed Agricultural Soils

    PubMed Central

    Neher, Deborah A.

    1999-01-01

    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

  13. Alternatives to anthelmintics for the control of nematodes in livestock.

    PubMed

    Stear, M J; Doligalska, M; Donskow-Schmelter, K

    2007-02-01

    Efficient and welfare-friendly livestock production demands the control of nematode infection. Current control measures rely upon anthelmintic treatment but are threatened by the widespread evolution of drug-resistance in parasite populations. Several methods have been advocated to control nematodes without relying on effective anthelmintics. These include grazing management, biological control, nutritional supplementation, vaccination, and genetic approaches. Each method has its advantages and disadvantages. There are several grazing management schemes that can reduce the severity of infection but they are insufficient on their own to control infection. Biological control includes the use of predatory fungi to control nematode populations and the use of pasture species that can reduce the intensity of infection. Fungi can control nematodes but the current requirement for daily feeding means that this approach will be most useful for animals that are handled daily. Feeding supplementary protein can control nematode infection. The method is simple but can be expensive and may not be cost-effective for some marginal enterprises. Genetic approaches include the use of resistant breeds and selective breeding. Some breeds will thrive in conditions that kill animals from other breeds but substitution of resistant breeds is not always feasible. Selective breeding is effective and inexpensive but requires a high level of expertise. The most appropriate method or set of methods to minimize the adverse consequences of nematode infection may vary among farms.

  14. The host immune response to gastrointestinal nematode infection in sheep.

    PubMed

    McRae, K M; Stear, M J; Good, B; Keane, O M

    2015-12-01

    Gastrointestinal nematode infection represents a major threat to the health, welfare and productivity of sheep populations worldwide. Infected lambs have a reduced ability to absorb nutrients from the gastrointestinal tract, resulting in morbidity and occasional mortality. The current chemo-dominant approach to nematode control is considered unsustainable due to the increasing incidence of anthelmintic resistance. In addition, there is growing consumer demand for food products from animals not subjected to chemical treatment. Future mechanisms of nematode control must rely on alternative, sustainable strategies such as vaccination or selective breeding of resistant animals. Such strategies take advantage of the host's natural immune response to nematodes. The ability to resist gastrointestinal nematode infection is considered to be dependent on the development of a protective acquired immune response, although the precise immune mechanisms involved in initiating this process remain to be fully elucidated. In this study, current knowledge on the innate and acquired host immune response to gastrointestinal nematode infection in sheep and the development of immunity is reviewed. © 2015 John Wiley & Sons Ltd.

  15. Checklist of nematode parasites of amphibians from Argentina.

    PubMed

    González, Cynthya Elizabeth; Inés, Hamann Monika

    2015-07-01

    This review includes information about 47 taxa of nematode parasites reported from 34 species of Argentinean amphibians, all belonging to order Anura (33 native species and 1 introduced species). Thirty four nematode species have been reported as adults and 13 species were reported as larvae (10 taxa) or juveniles (3 taxa). Two species, Cosmocerca parva and C. podicipinus (Cosmocercidae), collected as adults, are the most commonly occurring adult nematodes in Argentinean amphibians; each of them parasitize 14 amphibian species. The bufonid Rhinella schneideri and the leptodactylid Leptodactylus bufonius present the highest species richness of parasitic nematodes (9 species); followed by Rhinella fernandezae, R. arenarum and Leptodactylus chaquensis, each of which is parasitized by 8 nematode species. Mean species richenss was highest for the family Bufonidae (4.5±3.4; range: 1-9); followed by the Leptodactylidae (3.5±2.8; range: 1-9). Data on hosts, geographical distribution, site of infection, location of deposited materials, and information about life cycles are provided. This is the first compilation of information on nematode parasites of amphibians in Argentina.

  16. Temperature-based bioclimatic parameters can predict nematode metabolic footprints.

    PubMed

    Bhusal, Daya Ram; Tsiafouli, Maria A; Sgardelis, Stefanos P

    2015-09-01

    Nematode metabolic footprints (MFs) refer to the lifetime amount of metabolized carbon per individual, indicating a connection to soil food web functions and eventually to processes supporting ecosystem services. Estimating and managing these at a convenient scale requires information upscaling from the soil sample to the landscape level. We explore the feasibility of predicting nematode MFs from temperature-based bioclimatic parameters across a landscape. We assume that temperature effects are reflected in MFs, since temperature variations determine life processes ranging from enzyme activities to community structure. We use microclimate data recorded for 1 year from sites differing by orientation, altitude and vegetation cover. At the same sites we estimate MFs for each nematode trophic group. Our models show that bioclimatic parameters, specifically those accounting for temporal variations in temperature and extremities, predict most of the variation in nematode MFs. Higher fungivorous and lower bacterivorous nematode MFs are predicted for sites with high seasonality and low isothermality (sites of low vegetation, mostly at low altitudes), indicating differences in the relative contribution of the corresponding food web channels to the metabolism of carbon across the landscape. Higher plant-parasitic MFs were predicted for sites with high seasonality. The fitted models provide realistic predictions of unknown cases within the range of the predictor's values, allowing for the interpolation of MFs within the sampled region. We conclude that upscaling of the bioindication potential of nematode communities is feasible and can provide new perspectives not only in the field of soil ecology but other research areas as well.

  17. Soil sampling and isolation of entomopathogenic nematodes (Steinernematidae, Heterorhabditidae).

    PubMed

    Orozco, Rousel A; Lee, Ming-Min; Stock, S Patricia

    2014-07-11

    Entomopathogenic nematodes (a.k.a. EPN) represent a group of soil-inhabiting nematodes that parasitize a wide range of insects. These nematodes belong to two families: Steinernematidae and Heterorhabditidae. Until now, more than 70 species have been described in the Steinernematidae and there are about 20 species in the Heterorhabditidae. The nematodes have a mutualistic partnership with Enterobacteriaceae bacteria and together they act as a potent insecticidal complex that kills a wide range of insect species. Herein, we focus on the most common techniques considered for collecting EPN from soil. The second part of this presentation focuses on the insect-baiting technique, a widely used approach for the isolation of EPN from soil samples, and the modified White trap technique which is used for the recovery of these nematodes from infected insects. These methods and techniques are key steps for the successful establishment of EPN cultures in the laboratory and also form the basis for other bioassays that consider these nematodes as model organisms for research in other biological disciplines. The techniques shown in this presentation correspond to those performed and/or designed by members of S. P. Stock laboratory as well as those described by various authors.

  18. Allelopathy in the Management of Plant-Parasitic Nematodes

    PubMed Central

    Halbrendt, J. M.

    1996-01-01

    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

  19. Communities of terrestrial nematodes after different approaches to heathland restoration

    NASA Astrophysics Data System (ADS)

    Radochova, Petra; Frouz, Jan

    2016-04-01

    Since the 20th century, the distribution of European heathlands rapidly decreased due to agricultural intensification, heavy use of artificial fertilizers or acidification (Aerts & Heil, 1993). Therefore, various attempts of heathland restoration are under way in these days. Analysis of nematode community composition can be one of the tools suitable for succession evaluation (Ferris et al., 2001). In 2011, 2013 and 2014, soil samples were collected from heathland restoration experiment (launched in 2011) where different restoration methods were applied in a 3 × 3 factorial experiment; existing heathlands were also sampled to identify the target community both in dry and wet heathland. A total of 60 samples of extracted nematodes were analysed for absolute abundance, trophic groups, and genera dominance. Various indices were calculated to describe the nematode community. We were able to prove faster development of wet heathlands towards the target community. However, because of large data variability, there was no significant difference between treatments. Development of wet and dry heathlands differed also in increased proportion of omniphagous nematodes in 2013 and predators in 2014 in dry heathlands. After three years of heathland restoration, nematode community has not yet reached parameters of the target community. References Aerts, R., Heil, G. W., 1993. Heathlands: patterns and processes in a changing environment, 1st ed, Geobotany: 20. Springer Netherlands, Dordrecht, p. 229. Ferris, H., Bongers, T., De Goede, R. G. M., 2001. A framework for soil food web diagnostics: Extension of the nematode faunal analysis oncept. Appl. Soil Ecol. 18, 13-29.

  20. Diverse Host-Seeking Behaviors of Skin-Penetrating Nematodes

    PubMed Central

    Castelletto, Michelle L.; Gang, Spencer S.; Okubo, Ryo P.; Tselikova, Anastassia A.; Nolan, Thomas J.; Platzer, Edward G.; Lok, James B.; Hallem, Elissa A.

    2014-01-01

    Skin-penetrating parasitic nematodes infect approximately one billion people worldwide and are responsible for some of the most common neglected tropical diseases. The infective larvae of skin-penetrating nematodes are thought to search for hosts using sensory cues, yet their host-seeking behavior is poorly understood. We conducted an in-depth analysis of host seeking in the skin-penetrating human parasite Strongyloides stercoralis, and compared its behavior to that of other parasitic nematodes. We found that Str. stercoralis is highly mobile relative to other parasitic nematodes and uses a cruising strategy for finding hosts. Str. stercoralis shows robust attraction to a diverse array of human skin and sweat odorants, most of which are known mosquito attractants. Olfactory preferences of Str. stercoralis vary across life stages, suggesting a mechanism by which host seeking is limited to infective larvae. A comparison of odor-driven behavior in Str. stercoralis and six other nematode species revealed that parasite olfactory preferences reflect host specificity rather than phylogeny, suggesting an important role for olfaction in host selection. Our results may enable the development of new strategies for combating harmful nematode infections. PMID:25121736

  1. Cryopreservation of Radopholus similis, a tropical plant-parasitic nematode.

    PubMed

    Elsen, Annemie; Vallterra, Salvador Ferrandis; Van Wauwe, Tom; Thuy, Trinh Thi Thu; Swennen, Rony; De Waele, Dirk; Panis, Bart

    2007-10-01

    For obligate plant-parasitic nematodes, cryopreservation has advantages over the usual preservation methods on whole plants or axenic culture systems, because the latter two are labourious and time and space consuming. In addition, cross contamination among different isolates can occur easily. Moreover, specific genetic studies require maintenance of the original population. The nematode under investigation, Radopholus similis, is a plant-parasitic nematode from the humid tropics. Therefore, any treatment at low temperatures is likely to add extra stress to the nematode, making the development of a cryopreservation protocol extremely difficult. In this paper, we describe experiments to achieve a successful cryopreservation protocol for the tropical nematode R. similis using vitrification solution-based methods based on a well defined mixture of cryoprotectants in combination with ultra-rapid cooling and thawing rates. A two-step treatment was used consisting of an incubation in glycerol followed by the application of a vitrifying mixture of methanol, glycerol and glucose. After cryopreservation, the pathogenicity of the nematodes was not altered, since they could infect and reproduce on carrot discs after recovery in the Ringer solution. The cryopreservation method described can be used for routine cryopreservation of R. similis lines from different origins.

  2. Directional movement of entomopathogenic nematodes in response to electrical fields: Effects of species, magnitude of voltage, and infective juvenile age

    USDA-ARS?s Scientific Manuscript database

    Entomopathogenic nematodes respond to a variety of stimuli when foraging. Previously, we reported a directional response to electrical fields for two entomopathogenic nematode species; specifically, when electrical fields were generated on agar plates Steinernema glaseri (a nematode that utilizes a...

  3. Plant-parasitic Nematode Acetylcholinesterase Inhibition by Carbamate and Organophosphate Nematicides.

    PubMed

    Opperman, C H; Chang, S

    1990-10-01

    The sensitivity of acetylcholinesterases (ACHE) isolated from the plant-parasitic nematodes Meloidogyne arenaria, M. incognita, and Heterodera glycines and the free-living nematode Caenorhabditis elegans to carbamate and organophosphate nematicides was examined. The AChE from plant-parasitic nematode species were more sensitive to carbamate inhibitors than was AChE from C. elegans, but response to the organophosphates was approximately equivalent. The sulfur-containing phosphate nematicides were poor inhibitors of nematode acetylcholinesterase, but treatment with an oxidizing agent greatly improved inhibition. Behavioral bioassays with living nematodes revealed a poor relationship between enzyme inhibition and expression of symptoms in live nematodes.

  4. Tomato transgenic plants expressing hairpin construct of a nematode protease gene conferred enhanced resistance to root-knot nematodes

    PubMed Central

    Dutta, Tushar K.; Papolu, Pradeep K.; Banakar, Prakash; Choudhary, Divya; Sirohi, Anil; Rao, Uma

    2015-01-01

    Root-knot nematodes (Meloidogyne incognita) cause substantial yield losses in vegetables worldwide, and are difficult to manage. Continuous withdrawal of environmentally-harmful nematicides from the global market warrants the need for novel nematode management strategies. Utility of host-delivered RNAi has been demonstrated in several plants (Arabidopsis, tobacco, and soybean) that exhibited resistance against root-knot and cyst nematodes. Herein, a M. incognita-specific protease gene, cathepsin L cysteine proteinase (Mi-cpl-1), was targeted to generate tomato transgenic lines to evaluate the genetically modified nematode resistance. In vitro knockdown of Mi-cpl-1 gene led to the reduced attraction and penetration of M. incognita in tomato, suggesting the involvement of Mi-cpl-1 in nematode parasitism. Transgenic expression of the RNAi construct of Mi-cpl-1 gene resulted in 60–80% reduction in infection and multiplication of M. incognita in tomato. Evidence for in vitro and in vivo silencing of Mi-cpl-1 was confirmed by expression analysis using quantitative PCR. Our study demonstrates that Mi-cpl-1 plays crucial role during plant-nematode interaction and plant-mediated downregulation of this gene elicits detrimental effect on M. incognita development, reinforcing the potential of RNAi technology for management of phytonematodes in crop plants. PMID:25883594

  5. Pan-phylum Comparison of Nematode Metabolic Potential

    PubMed Central

    Tyagi, Rahul; Rosa, Bruce A.; Lewis, Warren G.; Mitreva, Makedonka

    2015-01-01

    Nematodes are among the most important causative pathogens of neglected tropical diseases. The increased availability of genomic and transcriptomic data for many understudied nematode species provides a great opportunity to investigate different aspects of their biology. Increasingly, metabolic potential of pathogens is recognized as a critical determinant governing their development, growth and pathogenicity. Comparing metabolic potential among species with distinct trophic ecologies can provide insights on overall biology or molecular adaptations. Furthermore, ascertaining gene expression at pathway level can help in understanding metabolic dynamics over development. Comparison of biochemical pathways (or subpathways, i.e. pathway modules) among related species can also retrospectively indicate potential mistakes in gene-calling and functional annotation. We show with numerous illustrative case studies that comparisons at the level of pathway modules have the potential to uncover biological insights while remaining computationally tractable. Here, we reconstruct and compare metabolic modules found in the deduced proteomes of 13 nematodes and 10 non-nematode species (including hosts of the parasitic nematode species). We observed that the metabolic potential is, in general, concomitant with phylogenetic and/or ecological similarity. Varied metabolic strategies are required among the nematodes, with only 8 out of 51 pathway modules being completely conserved. Enzyme comparison based on topology of metabolic modules uncovered diversification between parasite and host that can potentially guide therapeutic intervention. Gene expression data from 4 nematode species were used to study metabolic dynamics over their life cycles. We report unexpected differential metabolism between immature and mature microfilariae of the human filarial parasite Brugia malayi. A set of genes potentially important for parasitism is also reported, based on an analysis of gene expression in

  6. Pan-phylum Comparison of Nematode Metabolic Potential.

    PubMed

    Tyagi, Rahul; Rosa, Bruce A; Lewis, Warren G; Mitreva, Makedonka

    2015-05-01

    Nematodes are among the most important causative pathogens of neglected tropical diseases. The increased availability of genomic and transcriptomic data for many understudied nematode species provides a great opportunity to investigate different aspects of their biology. Increasingly, metabolic potential of pathogens is recognized as a critical determinant governing their development, growth and pathogenicity. Comparing metabolic potential among species with distinct trophic ecologies can provide insights on overall biology or molecular adaptations. Furthermore, ascertaining gene expression at pathway level can help in understanding metabolic dynamics over development. Comparison of biochemical pathways (or subpathways, i.e. pathway modules) among related species can also retrospectively indicate potential mistakes in gene-calling and functional annotation. We show with numerous illustrative case studies that comparisons at the level of pathway modules have the potential to uncover biological insights while remaining computationally tractable. Here, we reconstruct and compare metabolic modules found in the deduced proteomes of 13 nematodes and 10 non-nematode species (including hosts of the parasitic nematode species). We observed that the metabolic potential is, in general, concomitant with phylogenetic and/or ecological similarity. Varied metabolic strategies are required among the nematodes, with only 8 out of 51 pathway modules being completely conserved. Enzyme comparison based on topology of metabolic modules uncovered diversification between parasite and host that can potentially guide therapeutic intervention. Gene expression data from 4 nematode species were used to study metabolic dynamics over their life cycles. We report unexpected differential metabolism between immature and mature microfilariae of the human filarial parasite Brugia malayi. A set of genes potentially important for parasitism is also reported, based on an analysis of gene expression in

  7. Effects of albendazole combined with TSII-A (a Chinese herb compound) on optic neuritis caused by Angiostrongylus cantonensis in BALB/c mice.

    PubMed

    Feng, Feng; Feng, Ying; Liu, Zhen; Li, Wei-Hua; Wang, Wen-Cong; Wu, Zhong-Dao; Lv, Zhiyue

    2015-11-25

    Angiostrongylus cantonensis (A. cantonensis) infection can lead to optic neuritis, retinal inflammation, damage to ganglion cells, demyelination of optic nerve and visual impairment. Combined therapy of albendazole and dexamethasone is a common treatment for the disease in the clinic, but it plays no role in vision recovery. Therefore, it has been necessary to explore alternative therapies to treat this disease. Previous studies reported the neuro-productive effects of two constituents of Danshen (a Chinese herb)-tanshinone II-A (TSII-A) and cryptotanshinone (CPT), and this study aims to evaluate the impacts of TSII-A or CPT combined with albendazole on optic neuritis caused by A. cantonensis infection in a murine model. To assess the effects of TSII-A or CPT combined with albendazole on optic neuritis due to the infection, mice were divided into six groups, including the normal control group, infection group and four treatment groups (albendazole group, albendazole combined with dexamethasone group, albendazole combined with CPT group and albendazole combined with TSII-A group). The infection group and treatment groups were infected with A. cantonensis and the treatment groups received interventions from 14 dpi (days post infection), respectively. At 21 dpi, the visual acuity of mice in each group was examined by visual evoked potential (VEP). The pathologic alteration of the retina and optic nerve were observed by hematoxylin and eosin (H&E) staining and transmission electronic microscopy (TEM). Infection of A. cantonensis caused prolonged VEP latency, obvious inflammatory cell infiltration in the retina, damaged retinal ganglions and retinal swelling, followed by optic nerve fibre demyelination and a decreasing number of axons at 21 dpi. In treatment groups, albendazole could not alleviate the above symptoms; albendazole combined with dexamethasone lessened the inflammation of the retina, but was futile for the other changes; however, albendazole combined with

  8. The nematode story: Hox gene loss and rapid evolution.

    PubMed

    Aboobaker, Aziz; Blaxter, Mark

    2010-01-01

    The loss in some taxa of conserved developmental control genes that are present in the vast majority of animal lineages is an understudied phenomenon. It is likely that in those lineages in which loss has occurred it may be a strong signal of the mode, tempo and direction of developmental evolution and thus identify ways of generating morphological novelties. Intuitively we might expect these novelties to be particularly those associated with morphological simplifications. One striking example of this has occurred within the nematodes. It appears that over half the ancestral bilaterian Hox cluster has been lost from the model organism Caenorhabditis elegans and its closest related species. Studying the Hox gene complement of nematodes across the phylum has shown that many, if not all these losses occurred within the phylum. Other nematode clades only distantly related to C. elegans have additional Hox genes orthologous to those present in the ancestral bilaterian but absent from the model nematode. In some of these cases rapid sequence evolution of the homeodomain itself obscures orthology assignment until comparison is made with sequences from multiple nematode clades with slower evolving Hox genes. Across the phylum the homeodomains of the Hox genes that are present are evolving very rapidly. In one particular case the genomic arrangement of two homeodomains suggests a mechanism for gene loss. Studying the function in nematodes of the Hox genes absent from C. elegans awaits further research and the establishment of new nematode models. However, what we do know about Hox gene functions suggests that the genetic circuits within which Hox genes act have changed significantly within C. elegans and its close relatives.

  9. Enzymes involved in the biogenesis of the nematode cuticle.

    PubMed

    Page, Antony P; Winter, Alan D

    2003-01-01

    Nematodes include species that are significant parasites of man, his domestic animals and crops, and cause chronic debilitating diseases in the developing world; such as lymphatic filariasis and river blindness caused by filarial species. Around one third of the World's population harbour parasitic nematodes; no vaccines exist for prevention of infection, limited effective drugs are available and drug resistance is an ever-increasing problem. A critical structure of the nematode is the protective cuticle, a collagen-rich extracellular matrix (ECM) that forms the exoskeleton, and is critical for viability. This resilient structure is synthesized sequentially five times during nematode development and offers protection from the environment, including the hosts' immune response. The detailed characterization of this complex structure; it's components, and the means by which they are synthesized, modified, processed and assembled will identify targets that may be exploited in the future control of parasitic nematodes. This review will focus on the nematode cuticle. This structure is predominantly composed of collagens, a class of proteins that are modified by a range of co- and post-translational modifications prior to assembly into higher order complexes or ECMs. The collagens and their associated enzymes have been comprehensively characterized in vertebrate systems and some of these studies will be addressed in this review. Conversely, the biosynthesis of this class of essential structural proteins has not been studied in such detail in the nematodes. As with all morphogenetic, functional and developmental studies in the Nematoda phylum, the free-living species Caenorhabditis elegans has proven to be invaluable in the characterization of the cuticle and the cuticle collagen gene family, and is now proving to be an excellent model in the study of cuticle collagen biosynthetic enzymes. This model system will be the main focus of this review.

  10. Evolution of early embryogenesis in rhabditid nematodes

    PubMed Central

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

    2009-01-01

    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. PMID:19643102

  11. The nematode Caenorhabditis elegans and its genome.

    PubMed

    Hodgkin, J; Plasterk, R H; Waterston, R H

    1995-10-20

    Over the past two decades, the small soil nematode Caenorhabditis elegans has become established as a major model system for the study of a great variety of problems in biology and medicine. One of its most significant advantages is its simplicity, both in anatomy and in genomic organization. The entire haploid genetic content amounts to 100 million base pairs of DNA, about 1/30 the size of the human value. As a result, C. elegans has also provided a pilot system for the construction of physical maps of larger animal and plant genomes, and subsequently for the complete sequencing of those genomes. By mid-1995, approximately one-fifth of the complete DNA sequence of this animal had been determined. Caenorhabditis elegans provides a test bed not only for the development and application of mapping and sequencing technologies, but also for the interpretation and use of complete sequence information. This article reviews the progress so far toward a realizable goal--the total description of the genome of a simple animal.

  12. GABA localization in the nematode Ascaris

    SciTech Connect

    Guastella, J.

    1988-01-01

    A histochemical approach was used to examine the distribution of GABA-associated neurons in the nematode Ascaris, an organism whose small number of morphologically simple neurons make it an excellent preparation for analyzing neuronal phenotypes. Two GABAergic markers were examined: GABA-like immunoreactivity (GLIR), a marker for endogenous stores of GABA; and ({sup 3}H)-GABA uptake, a marker for GABA uptake sites. Strong GLIR was present in the cell bodies, neurites and commissures of dorsal and ventral inhibitory motorneurons present in this region. Strong GLIR was also present in the cell bodies and processes of the four RME neurons in the nerve ring and in several other ganglionic neurons. Staining was absent in excitatory motorneurons, in ventral cord interneurons and in muscle cells and hypodermis. GABA uptake sites were found in single neural processes in both the ventral and dorsal nerve cords. ({sup 3}H)-GABA labeling was also observed in the other two RME cells and several other cephalic neurons. Four putative cholinergic excitatory motorneurons in the retrovesicular ganglion (RVG) were heavily labeled. Ventral and dorsal nerve cord inhibitory motorneurons did not take up ({sup 3}H)-GABA. Labeling of the ventral cord excitatory motorneuron somata and cell bodies was at or slightly above background. Heavy labeling of muscle cells was also observed.

  13. BACTERIAL PREFERENCES OF THE BACTERIVOROUS SOIL NEMATODE CEPHALOBUS BREVICAUDA (CEPHALOBIDAE): 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...

  14. BACTERIAL PREFERENCES OF THE BACTERIVOROUS SOIL NEMATODE CEPHALOBUS BREVICAUDA (CEPHALOBIDAE): 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...

  15. Susceptibility of the Strawberry Crown Moth Synanthedon bibionipennis (Lepidoptera: Sesiidae) to Entomopathogenic Nematodes

    USDA-ARS?s Scientific Manuscript database

    The objective of this study was to determine the susceptibility of the strawberry crown moth, Synanthedon bibionipennis (Lepidoptera: Sesiidae) larvae to two species of entomopathogenic nematodes(Steinernema carpocapsae (Weiser) Agriotos and Heterorhabditis bacteriophora (Steiner) Oswego). Nematodes...

  16. Taxonomy, morphology and phylogenetics of coffee-associated root-lesion nematodes, Pratylenchus spp

    USDA-ARS?s Scientific Manuscript database

    Technical Abstract: Although lesion nematodes (Pratylenchus species) can reduce coffee yield worldwide, methods for their identification are often difficult to implement. This review summarizes the diagnostic morphological features for distinguishing the eight previously described lesion nematode sp...

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

    USDA-ARS?s Scientific Manuscript database

    The cellular mechanisms that mediate resistance of allotetraploid cotton (Gossypium spp.) to root-knot nematode (Meloidogyne incognita) and reniform nematode (Rotylenchulus reniformis) are poorly understood. Here, Agrobacterium rhizogenes-induced hairy roots were investigated as a possible research...

  18. Precision and Selection of Extraction Methods of Aphelenchid Nematodes from Maritime Pine Wood, Pinus pinaster L.

    PubMed Central

    Penas, Ana C.; DIias, Luis S.; Mota, Manuel M.

    2002-01-01

    Four extraction methods for Bursaphelenchus xylophilus and other aphelenchid nematodes were compared on the number of nematodes per gram recovered, and on the precision of the mean number of nematodes per gram of pine wood. The number of nematodes per gram recovered by each method, in addition to its inherent shortcomings when the actual number of nematodes is unknown, failed to provide clear rankings among the extraction methods. The precision of the mean number of nematodes per gram did provide clear guidelines for selection. Selection of the method may be based on prior knowledge about the range of nematodes to be expected or the independence of precision from the mean number of nematodes. PMID:19265909

  19. A quick tour of nematode diversity and the backbone of nematode phylogeny.

    PubMed

    De Ley, Paul

    2006-01-25

    Contrary to textbook dogma, nematodes are not only highly diverse, but often also complex and biologically specialized metazoans. Just a few of the many fascinating adaptations are reviewed in this chapter, as a prelude to a quick tour through phylogenetic relationships within the phylum. Small Subunit rDNA sequences have confirmed several controversial prior hypotheses, as well as revealing some unexpected relationships, resulting in a recent proposal for revised classification. Three major lineages exist within the phylum: Chromadoria, Enoplia and Dorylaimia. The exact order of appearance of these lineages is not yet resolved, which also leaves room for uncertainty about the biology and morphology of the exclusive common ancestor of nematodes. Enoplia and Dorylaimia differ considerably in many respects from C. elegans, which is a member of Chromadoria. The latter group is extremely diverse in its own right, for example in ecological range, in properties of the cuticle and in structure of the pharynx. The formerly relatively widely accepted class Secernentea is deeply nested within Chromadoria, and has therefore recently been relegated to the rank and name of order Rhabditida. Within this order, closer relatives of C. elegans include strongylids, diplogasterids and bunonematids. Tylenchs, cephalobs and panagrolaimids are also members of Rhabditida, albeit probably more distantly related to C. elegans.

  20. 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)

    USDA-ARS?s Scientific Manuscript database

    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...

  1. The dual effects of root-cap exudates on nematodes: from quiescence in plant-parasitic nematodes to frenzy in entomopathogenic nematodes.

    PubMed

    Hiltpold, Ivan; Jaffuel, Geoffrey; Turlings, Ted C J

    2015-02-01

    To defend themselves against herbivores and pathogens, plants produce numerous secondary metabolites, either constitutively or de novo in response to attacks. An intriguing constitutive example is the exudate produced by certain root-cap cells that can induce a state of reversible quiescence in plant-parasitic nematodes, thereby providing protection against these antagonists. The effect of such root exudates on beneficial entomopathogenic nematodes (EPNs) remains unclear, but could potentially impair their use in pest management programmes. We therefore tested how the exudates secreted by green pea (Pisum sativum) root caps affect four commercial EPN species. The exudates induced reversible quiescence in all EPN species tested. Quiescence levels varied with the green pea cultivars tested. Notably, after storage in root exudate, EPN performance traits were maintained over time, whereas performances of EPNs stored in water rapidly declined. In sharp contrast to high concentrations, lower concentrations of the exudate resulted in a significant increase in EPN activity and infectiousness, but still reduced the activity of two plant-parasitic nematode species. Our study suggests a finely tuned dual bioactivity of the exudate from green pea root caps. Appropriately formulated, it can favour long-term storage of EPNs and boost their infectiousness, while it may also be used to protect plants from plant-parasitic nematodes. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  2. The dual effects of root-cap exudates on nematodes: from quiescence in plant-parasitic nematodes to frenzy in entomopathogenic nematodes

    PubMed Central

    Hiltpold, Ivan; Jaffuel, Geoffrey; Turlings, Ted C. J.

    2015-01-01

    To defend themselves against herbivores and pathogens, plants produce numerous secondary metabolites, either constitutively or de novo in response to attacks. An intriguing constitutive example is the exudate produced by certain root-cap cells that can induce a state of reversible quiescence in plant-parasitic nematodes, thereby providing protection against these antagonists. The effect of such root exudates on beneficial entomopathogenic nematodes (EPNs) remains unclear, but could potentially impair their use in pest management programmes. We therefore tested how the exudates secreted by green pea (Pisum sativum) root caps affect four commercial EPN species. The exudates induced reversible quiescence in all EPN species tested. Quiescence levels varied with the green pea cultivars tested. Notably, after storage in root exudate, EPN performance traits were maintained over time, whereas performances of EPNs stored in water rapidly declined. In sharp contrast to high concentrations, lower concentrations of the exudate resulted in a significant increase in EPN activity and infectiousness, but still reduced the activity of two plant-parasitic nematode species. Our study suggests a finely tuned dual bioactivity of the exudate from green pea root caps. Appropriately formulated, it can favour long-term storage of EPNs and boost their infectiousness, while it may also be used to protect plants from plant-parasitic nematodes. PMID:25165149

  3. [Intestinal nematodes of the Aythyini ducks in Western Pomerania].

    PubMed

    Kavetska, Katarzyna M

    2005-01-01

    Intestinal nematodes of the Aythyini ducks in Western Pomerania. Biology, including ecology, of the Aythyini renders them particularly attractive subjects of parasitological studies. The tribe is represented in Poland by 4 nesting species; two of them, Aythya fuligula and A. ferina, are very abundant game birds. However, their helminth fauna, including nematodes, is still very poorly known. This study was aimed at quantifying the structure of parasitic intestinal nematodes of the Western Pomeranian Aythyini. The study, performed in 1999-2004, involved a total of 71 ducks representing 3 species: A. ferina, A. fuligula, and A. marila. The nematodes, isolated from the intestines, were fixed in 75% ethyl alcohol and cleared in lactic acid. Among the 9668 helminth individuals found, 589 (6.1%) represented the phylum Nematoda. They were found in 57 ducks (80.3% of all the ducks examined). The nematodes belonged to the following 4 families: Amidostomatidae, Tetrameridae, Acuariidae, and Trichuridae. They were identified as representing 8 species, 2 genera (Amidostomoides sp. and Tetrameres sp.), and 1 subfamily (Capillariinae gen. sp.); in addition, 1 damaged individual could be identified as a nematode only. The highest prevalence (57.8%), at mean intensity (4.8 inds), was typical of Amidostomoides petrovi (Shakhtahtinskaya, 1956) Lomakin, 1991, while Tetrameres fissispina (Diesing, 1861) Travassos, 1914 occurred with the highest intensity (15.1 inds) and 12.7% prevalence. Nematodes of the subfamily Capillariinae occurred with a fairly high intensity (averaging 10.0 inds) as well, although their prevalence was not high, either (4.2% of all ducks were infected). The nematofauna studied was clearly dominated by A. petrovi, T. fissispina, and Capillaria anatis (Schrank, 1790). The total frequency of occurrence of those species was close to 80%; their dominance indices exceeded the threshold value of 0.1 and amounted to 1.6 (the dominant A. petrovi), 0.2, and 0.5 (the

  4. Experimental Studies with Nematodes in Ecotoxicology: An Overview

    PubMed Central

    Hägerbäumer, Arne; Höss, Sebastian; Heininger, Peter; Traunspurger, Walter

    2015-01-01

    With respect to their high abundances, their role as intermediaries between microorganisms and higher trophic levels, and their ubiquitous occurrence in all habitats, nematodes are of strong potential interest as environmental indicators. Ecotoxicological methods to evaluate the risk of anthropogenic pollutants on ecosystems require both in vitro and in vivo toxicity tests to investigate either mechanisms or pathways of toxicity and to set accurate toxicity thresholds. For this, the interest in nematodes as model organisms in ecotoxicology increased over the past few decades and existing appropriate experimental methods are reviewed in this manuscript. An overview of the various existing ecotoxicological tools for nematodes, ranging from molecular laboratory methods to experimental model ecosystem approaches, and their role as indicator organisms is given. The reviewed studies, approaches that range from species-based to community-based methods, reveal exciting possibilities for the future use of nematodes in ecotoxicological studies. Suitable ecotoxicological tools and ecological indices for nematodes should be integrated in weight-of-evidence approaches for assessing the ecological risk of contamination. PMID:25861113

  5. Heme acquisition in the parasitic filarial nematode Brugia malayi

    PubMed Central

    Luck, Ashley N.; Yuan, Xiaojing; Voronin, Denis; Slatko, Barton E.; Hamza, Iqbal; Foster, Jeremy M.

    2016-01-01

    Nematodes lack a heme biosynthetic pathway and must acquire heme from exogenous sources. Given the indispensable role of heme, this auxotrophy may be exploited to develop drugs that interfere with heme uptake in parasites. Although multiple heme-responsive genes (HRGs) have been characterized within the free-living nematode Caenorhabditis elegans, we have undertaken the first study of heme transport in Brugia malayi, a causative agent of lymphatic filariasis. Through functional assays in yeast, as well as heme analog, RNAi, and transcriptomic experiments, we have shown that the heme transporter B. malayi HRG-1 (BmHRG-1) is indeed functional in B. malayi. In addition, BmHRG-1 localizes both to the endocytic compartments and cell membrane when expressed in yeast cells. Transcriptomic sequencing revealed that BmHRG-1, BmHRG-2, and BmMRP-5 (all orthologs of HRGs in C. elegans) are down-regulated in heme-treated B. malayi, as compared to non–heme-treated control worms. Likely because of short gene lengths, multiple exons, other HRGs in B. malayi (BmHRG-3–6) remain unidentified. Although the precise mechanisms of heme homeostasis in a nematode with the ability to acquire heme remains unknown, this study clearly demonstrates that the filarial nematode B. malayi is capable of transporting exogenous heme.—Luck, A. N., Yuan, X., Voronin, D., Slatko, B. E., Hamza, I., Foster, J. M. Heme acquisition in the parasitic filarial nematode Brugia malayi. PMID:27363426

  6. Efficacy of Methionine Against Ectoparasitic Nematodes on Golf Course Turf

    PubMed Central

    Cuda, James P.; Stevens, Bruce R.

    2009-01-01

    Plant-parasitic nematodes are important pathogens of intensely-managed turf used on golf courses. Two of these nematodes that are common in the southeastern US are Belonolaimus longicaudatus and Mesocriconema ornata. Currently, there is a lack of effective treatments that can be used to manage these important pests. Turfgrass field trials evaluated DL-methionine as a turfgrass nematicide against B. longicaudatus and M. ornata. One trial was on a bermudagrass putting green, the other was on zoysiagrass maintained under putting-green conditions. Two rates of methionine, 1120 kg/ha in a single application, and 112 kg/ha applied twice four weeks apart, were compared with untreated control and fenamiphos treatments. Measurements collected included soil nematode counts, turf density, and root lengths. In both trials, 1120 kg/ha of methionine reduced numbers of both nematode species (P ≤ 0.1), and 112 kg/ha of methionine reduced numbers of both nematode species after two applications. Bermudagrass turf density responded favorably to both methionine rates and root lengths were improved by the 1120 kg/ha rate. Zoysiagrass showed short-term phytotoxicity to methionine, but quickly recovered and treated plots were improved compared to the untreated controls by the end of the trial. These trials indicated that methionine has potential for development as a turfgrass nematicide, but further research is needed to determine how it can best be used. PMID:22736817

  7. Sequential Decision Rules for Managing Nematodes with Crop Rotations

    PubMed Central

    Burt, O. R.; Ferris, H.

    1996-01-01

    A dynamic model of nematode populations under a crop rotation that includes both host and nonhost crops is developed and used to conceptualize the problem of economic control. The steady state of the dynamic system is used to devise an approximately optimal decision policy, which is then applied to cyst nematode (Heterodera schachtii) control in a rotation of sugarbeet with nonhost crops. Long-run economic returns from this approximately optimal decision rule are compared with results from solution of the exact dynamic optimization model. The simple decision rule based on the steady state provides long-run average returns that are similar to the fully optimal solution. For sugarbeet and H. schachtii, the simplified rule can be calculated by maximizing a relatively simple algebraic expression with respect to the number of years in the sequence of nonhost crops. Maximization is easy because only integers are of interest and the number of years in nonhost crops is typically small. Solution of this problem indirectly yields an approximation to the optimal dynamic economic threshold density of nematodes in the soil. The decision rule requires knowledge of annual nematode population change under host and nonhost crops, and the relationship between crop yield and nematode population density. PMID:19277164

  8. Non-target effects of herbicides on soil nematode assemblages.

    PubMed

    Zhao, Jie; Neher, Deborah A; Fu, Shenglei; Li, Zhi'an; Wang, Kelin

    2013-06-01

    Herbicides are used extensively to control weeds. However, little is known about the non-target effects of herbicides on soil nematode assemblages. The objective of this study was to determine whether herbicides affect the abundance of nematodes in specific trophic groups. Meta-analysis was performed, and the calculated effect size, lr, quantified the impact of herbicides on the abundance of total nematodes and five trophic groups (bacterivores, fungivores, plant parasites, omnivores and predators). Measurements of lr indicated that herbicides decreased abundance of both fungivores and predators; however, abundance of bacterivores, plant parasites and omnivores increased. Overall, total nematode abundance tended to increase in response to herbicide application. The decrease in predator abundance suggests that herbicide application disturbs soil food webs. The increase in bacterivore and decrease in fungivore abundance suggest that bacterivores are more tolerant and both fungivores and predators more sensitive to herbicide applications. Herbicides also have non-target effects on omnivores, which may be due to the increased amount of food resources for omnivores after weed control. Additionally, the use of herbicides may result in a risk of an increase in plant-parasitic nematode abundance. © 2013 Society of Chemical Industry.

  9. The FMRFamide-Like Peptide Family in Nematodes

    PubMed Central

    Peymen, Katleen; Watteyne, Jan; Frooninckx, Lotte; Schoofs, Liliane; Beets, Isabel

    2014-01-01

    In the three decades since the FMRFamide peptide was isolated from the mollusk Macrocallista nimbosa, structurally similar peptides sharing a C-terminal RFamide motif have been identified across the animal kingdom. FMRFamide-like peptides (FLPs) represent the largest known family of neuropeptides in invertebrates. In the phylum Nematoda, at least 32 flp-genes are classified, making the FLP system of nematodes unusually complex. The diversity of the nematode FLP complement is most extensively mapped in Caenorhabditis elegans, where over 70 FLPs have been predicted. FLPs have shown to be expressed in the majority of the 302 C. elegans neurons including interneurons, sensory neurons, and motor neurons. The vast expression of FLPs is reflected in the broad functional repertoire of nematode FLP signaling, including neuroendocrine and neuromodulatory effects on locomotory activity, reproduction, feeding, and behavior. In contrast to the many identified nematode FLPs, only few peptides have been assigned a receptor and there is the need to clarify the pathway components and working mechanisms of the FLP signaling network. Here, we review the diversity, distribution, and functions of FLPs in nematodes. PMID:24982652

  10. A bioassay to estimate root penetration by nematodes.

    PubMed

    Kaplan, D T; Davis, E L

    1991-10-01

    An in vitro bioassay with a 96-well microtiter plate was used to study the effect of lectins on burrowing nematode penetration of citrus roots. In each well, one 4-mm root segment, excised from the zone of elongation of rough lemon roots, was buried in 0.88 g dry sand. Addition of a Radopholus citrophilus suspension containing ca. 300 nematodes in 50 mu1 test solution completely moistened the sand in each well. The technique assured uniform treatment concentration throughout the medium. Within 16-24 hours, burrowing nematodes penetrated citrus root pieces, primarily through the cut ends. The lectins (100 mug/ml) Concanavalin A (Con A), soybean agglutinin (SBA), wheat germ agglutinin (WGA), and Lotus tetragonolobus agglutinin (LOT) stimulated an increase in penetration of citrus root segments by Radopholus citrophilus. Concentrations as low as 12.5 mug/ml Con A, LOT, and WGA stimulated burrowing nematode penetration of citrus roots. Heat denaturation of the lectins reversed their effect on penetration; however, incubation of nematodes in lectin (25 mug/ml) with 25 mM competitive sugars did not. The reason for enhanced penetration associated with lectins is unclear.

  11. Plant genes involved in harbouring symbiotic rhizobia or pathogenic nematodes.

    PubMed

    Damiani, Isabelle; Baldacci-Cresp, Fabien; Hopkins, Julie; Andrio, Emilie; Balzergue, Sandrine; Lecomte, Philippe; Puppo, Alain; Abad, Pierre; Favery, Bruno; Hérouart, Didier

    2012-04-01

    The establishment and development of plant-microorganism interactions involve impressive transcriptomic reprogramming of target plant genes. The symbiont (Sinorhizobium meliloti) and the root knot-nematode pathogen (Meloidogyne incognita) induce the formation of new root organs, the nodule and the gall, respectively. Using laser-assisted microdissection, we specifically monitored, at the cell level, Medicago gene expression in nodule zone II cells, which are preparing to receive rhizobia, and in gall giant and surrounding cells, which play an essential role in nematode feeding and constitute the typical root swollen structure, respectively. We revealed an important reprogramming of hormone pathways and C1 metabolism in both interactions, which may play key roles in nodule and gall neoformation, rhizobia endocytosis and nematode feeding. Common functions targeted by rhizobia and nematodes were mainly down-regulated, whereas the specificity of the interaction appeared to involve up-regulated genes. Our transcriptomic results provide powerful datasets to unravel the mechanisms involved in the accommodation of rhizobia and root-knot nematodes. Moreover, they raise the question of host specificity and the evolution of plant infection mechanisms by a symbiont and a pathogen.

  12. Signatures of adaptation to plant parasitism in nematode genomes.

    PubMed

    Bird, David McK; Jones, John T; Opperman, Charles H; Kikuchi, Taisei; Danchin, Etienne G J

    2015-02-01

    Plant-parasitic nematodes cause considerable damage to global agriculture. The ability to parasitize plants is a derived character that appears to have independently emerged several times in the phylum Nematoda. Morphological convergence to feeding style has been observed, but whether this is emergent from molecular convergence is less obvious. To address this, we assess whether genomic signatures can be associated with plant parasitism by nematodes. In this review, we report genomic features and characteristics that appear to be common in plant-parasitic nematodes while absent or rare in animal parasites, predators or free-living species. Candidate horizontal acquisitions of parasitism genes have systematically been found in all plant-parasitic species investigated at the sequence level. Presence of peptides that mimic plant hormones also appears to be a trait of plant-parasitic species. Annotations of the few genomes of plant-parasitic nematodes available to date have revealed a set of apparently species-specific genes on every occasion. Effector genes, important for parasitism are frequently found among those species-specific genes, indicating poor overlap. Overall, nematodes appear to have developed convergent genomic solutions to adapt to plant parasitism.

  13. Organic and Inorganic Nitrogen Amendments to Soil as Nematode Suppressants

    PubMed Central

    Rodríguez-Kábana, R.

    1986-01-01

    Inorganic fertilizers containing ammoniacal nitrogen or formulations releasing this form of N in the soil are most effective for suppressing nematode populations. Anhydrous ammonia has been shown to reduce soil populations of Tylenchorhynchus claytoni, Helicotylenchus dihystera, and Heterodera glycines. The rates required to obtain significant suppression of nematode populations are generally in excess of 150 kg N/ha. Urea also suppresses several nematode species, including Meloidogyne spp., when applied at rates above 300 kg N/ha. Additional available carbon must be provided with urea to permit soil microorganisms to metabolize excess N and avoid phytotoxic effects. There is a direct relation between the amount of "protein" N in organic amendments and their effectiveness as nematode population suppressants. Most nematicidal amendments are oil cakes, or animal excrements containing 2-7% (w:w) N; these materials are effective at rates of 4-10 t/ha. Organic soil amendments containing mucopolysaccharides (e.g., mycelial wastes, chitinous matter) are also effective nematode suppressants. PMID:19294153

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

    USDA-ARS?s Scientific Manuscript database

    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 ...

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

    PubMed

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

    2008-06-01

    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.

  16. 7 CFR 301.85-9 - Movement of live golden nematodes.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 5 2012-01-01 2012-01-01 false Movement of live golden nematodes. 301.85-9 Section... INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES Golden Nematode Quarantine and Regulations § 301.85-9 Movement of live golden nematodes. Regulations requiring a permit for and...

  17. 7 CFR 301.85-9 - Movement of live golden nematodes.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 5 2014-01-01 2014-01-01 false Movement of live golden nematodes. 301.85-9 Section... INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES Golden Nematode Quarantine and Regulations § 301.85-9 Movement of live golden nematodes. Regulations requiring a permit for and...

  18. 7 CFR 301.85-9 - Movement of live golden nematodes.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 5 2011-01-01 2011-01-01 false Movement of live golden nematodes. 301.85-9 Section... INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES Golden Nematode Quarantine and Regulations § 301.85-9 Movement of live golden nematodes. Regulations requiring a permit for and...

  19. 7 CFR 301.85-9 - Movement of live golden nematodes.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 5 2013-01-01 2013-01-01 false Movement of live golden nematodes. 301.85-9 Section... INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES Golden Nematode Quarantine and Regulations § 301.85-9 Movement of live golden nematodes. Regulations requiring a permit for and...

  20. Management Options for Control of a Stunt and Needle Nematode in Southern Forest Nurseries

    Treesearch

    Michelle M. Cram; Stephen W. Fraedrich

    2005-01-01

    Crop rotation and fallow are management options that can be used to control plant parasitic nematodes in forest tree nurseries. Before these options can be put into practice, it is important to determine the host range and survivability under fallow of the parasitic nematode to be controlled. The results of host range tests on a needle nematode (Longidorus...

  1. A SNARE-like protein and biotin are implicated in soybean cyst nematode virulence

    USDA-ARS?s Scientific Manuscript database

    Some phytoparasitic nematodes have the ability to infect and reproduce on plants that are normally considered resistant to nematode infection. Such nematodes are referred to as virulent and the mechanisms they use to evade or suppress host plant defenses are not well understood. Here, we report the ...

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

    NASA Astrophysics Data System (ADS)

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

    2011-11-01

    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.

  3. [Effect of agrochemicals and bio-control productions on soil nematode community dynamics].

    PubMed

    Zhang, Wanmin; Duan, Yuxi; Chen, Lijie; Liang, Chen

    2002-05-01

    Dynamics of soil nematode communities amended with agrochemicals and bio-control preparations were investigated in a soybean field. The results showed that the frequency of plant non-parasitic nematodes were obviously higher in soil amended with bio-control preparations (Doufeng 1) than with urea and herbicide, however, that of plant parasitic nematodes exhibited an inverse trend.

  4. Occurence of phytoparasitic nematodes associated with some crop plants in Northern Egypt

    USDA-ARS?s Scientific Manuscript database

    Information concerning the occurrence and distribution of phytoparasitic nematodes in Egypt is very important for agricultural production. A nematode survey was conducted in northern Egypt to identify the genera and species of phytoparasitic nematodes associated with some crop plants. A total of 240...

  5. First report of the root-lesion nematode Pratylenchus neglectus on wheat in North Dakota

    USDA-ARS?s Scientific Manuscript database

    Root-lesion nematodes (Pratylenchus spp.) are important nematode pests that invade roots of plants and restrict productivity of wheat. In August 2015, a soil sample was collected from a harvested wheat field in Walsh County, ND and was found to contain 1,044 root-lesion nematodes per kg of soil usin...

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

    PubMed Central

    Félix, Marie-Anne

    2008-01-01

    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

  7. First Report of the new root-lesion nematode Pratylenchus sp. on soybean in North Dakota

    USDA-ARS?s Scientific Manuscript database

    Root-lesion nematodes (Pratylenchus spp.) are important nematode pests on soybean. In 2015, two soil samples were collected from a soybean field in Richland County, ND. Nematodes were extracted from soil using a sugar centrifugal flotation method, revealing these two samples contained 125 and 350 ro...

  8. 78 FR 1713 - Golden Nematode; Removal of Regulated Areas in Livingston and Steuben Counties, NY

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-09

    ... The golden nematode (Globodera rostochiensis) is a destructive pest of potatoes and other solanaceous plants. Potatoes cannot be economically grown on land that contains large numbers of the nematode. The... total of 262,847 acres. Golden nematode is a major pest of potato plants and also attacks eggplant...

  9. Root knot nematode effects on metabolic profiles of susceptible and resistant grapevine rootstocks

    USDA-ARS?s Scientific Manuscript database

    Root knot nematodes (Meloidogyne spp.) can negatively impact newly planted and stressed vineyards. Nematode infestations also may increase grapevine susceptibility to other stresses such as water deficit or various diseases. However, little is known about direct or indirect effects of nematode feedi...

  10. Molecular and morphological characterization of the corn cyst nematode, Heterodera zeae, from Greece

    USDA-ARS?s Scientific Manuscript database

    The corn cyst nematode Heterodera zeae was first detected in India, where it has wide distribution. This nematode has also been reported from Pakistan, Egypt, Thailand, Nepal, the United States, and Portugal. There is limited information regarding nematodes attacking cereals in Greece, and thus far ...

  11. Chemical ecology and isolation of biologically active compounds from parasitic nematodes

    USDA-ARS?s Scientific Manuscript database

    Root knot nematodes (Meloidogyne spp) are possibly the economically most important and best-studied species of plant parasitic nematodes. However, for Meloidogyne spp and the intensely studied nematode, Caenorhabditis elegans, very little is known about signaling within and in-between species. It h...

  12. Galling problems – the Fergusobia nematode/Fergusonina fly mutualism on Myrtaceous hosts

    USDA-ARS?s Scientific Manuscript database

    Fergusobia (Sphaerularioidea, Tylenchidae) is the only known nematode to have a dicyclic life cycle with a generation in a plant (a myrtaceous host) followed by one in an insect (a Fergusonina fly). The nematode and fly have a mutualistic association, with the nematode inducing a plant gall on which...

  13. 7 CFR 301.85-9 - Movement of live golden nematodes.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Movement of live golden nematodes. 301.85-9 Section... Regulations § 301.85-9 Movement of live golden nematodes. Regulations requiring a permit for and otherwise governing the movement of live golden nematodes in interstate or foreign commerce are contained in the...

  14. New germplasm lines with high yield and fiber quality combined with nematode resistance

    USDA-ARS?s Scientific Manuscript database

    The lines BAR-8, -11, -13, -25, -33, -41, and -48 were developed to have both resistance to nematodes and superior yield and quality. All have resistance to reniform nematodes derived from G. barbadense GB 713 and several carry the DNA marker for Mi1, the gene for resistance to root-knot nematodes....

  15. Discovery and virulence-screening of native nematodes in Wisconsin cranberries

    USDA-ARS?s Scientific Manuscript database

    Three newly discovered entomopathogenic nematodes have been recovered from wild Wisconsin cranberry marshes. All three nematode strains have been shown to attack Sparganothis Fruitworm (SFW), and all seem similar in their virulence (ability to kill the host). Only one nematode line, however, has bee...

  16. First report of a new, unnamed lesion nematode Pratylenchus sp. infecting soybean in North Dakota

    USDA-ARS?s Scientific Manuscript database

    Lesion nematodes (Pratylenchus spp.) are important pests on soybean. In 2015 and 2016, nematodes in 11 soil samples from a soybean field in Richland County, ND were extracted by sugar centrifugal flotation method (Jenkins 1964). Ten samples contained lesion nematodes from 150 to 875/kg of soil. One ...

  17. Mechanisms Involved in Nematode Control by Endophytic Fungi.

    PubMed

    Schouten, Alexander

    2016-08-04

    Colonization of plants by particular endophytic fungi can provide plants with improved defenses toward nematodes. Evidently, such endophytes can be important in developing more sustainable agricultural practices. The mechanisms playing a role in this quantitative antagonism are poorly understood but most likely multifactorial. This knowledge gap obstructs the progress regarding the development of endophytes or endophyte-derived constituents into biocontrol agents. In part, this may be caused by the fact that endophytic fungi form a rather heterogeneous group. By combining the knowledge of the currently characterized antagonistic endophytic fungi and their effects on nematode behavior and biology with the knowledge of microbial competition and induced plant defenses, the various mechanisms by which this nematode antagonism operates or may operate are discussed. Now that new technologies are becoming available and more accessible, the currently unresolved mechanisms can be studied in greater detail than ever before.

  18. The development of RNA interference (RNAi) in gastrointestinal nematodes.

    PubMed

    Selkirk, Murray E; Huang, Stanley C; Knox, David P; Britton, Collette

    2012-04-01

    Despite the utility of RNAi for defining gene function in Caenorhabditis elegans and early successes reported in parasitic nematodes, RNAi has proven to be stubbornly inconsistent or ineffective in the animal parasitic nematodes examined to date. Here, we summarise some of our experiences with RNAi in parasitic nematodes affecting animals and discuss the available data in the context of our own unpublished work, taking account of mode of delivery, larval activation, site of gene transcription and the presence/absence of essential RNAi pathway genes as defined by comparisons to C. elegans. We discuss future directions briefly including the evaluation of nanoparticles as a means to enhance delivery of interfering RNA to the target worm tissue.

  19. Natural Occurrence of Entomogenous Nematodes in Tennessee Nursery Soils

    PubMed Central

    Rueda, L. M.; Osawaru, S. O.; Georgi, L. L.; Harrison, R. E.

    1993-01-01

    To isolate potential insect biocontrol agents, entomogenous nematodes were surveyed in Tennessee plant nurseries in 1991. Soil samples from 113 nursery sites were baited with greater wax moth (Galleria mellonella) larvae, house cricket (Acheta domesticus) adults, lesser mealworm (Alphitobius diaperings) adults, and house fly (Musca domestica) larvae. Heterorhabditis bacteriophora and Steinernema carpocapsae were each recovered from 17 soil samples. Heterorhabditis bacteriophora was more common in habitats with crape myrtle (Lagerstroemia indica) and Chinese juniper (Juniperus chinensis) than other nursery plants, and S. carpocapsae was more frequently recovered from habitats with juniper and Southern magnolia (Magnolia grandiflora). Bulk density, electrical conductivity, organic matter, pH, temperature, and moisture content of the entomogenous-nematode positive soil samples were compared. Other nematode genera recovered with insect baits included Rhabditis sp., Pelodera sp., Cryptaphelenchoides sp., and Mesodiplogaster sp., which was recovered from a greater percentage of soil samples than the other five genera. PMID:19279756

  20. Meningomyelitis due to nematode infection in four cats.

    PubMed

    Gómez, M; Mieres, M; Moroni, M; Mora, A; Barrios, N; Simeone, C; Lindsay, D S

    2010-06-24

    Spinal cord parasitic migrations in cats are uncommon. This report describes four cases of chronic hindlimb paraparesis in cats associated with nematode infection. Complete neurologic, hematologic, serum chemistry and radiographic examination was performed on all animals. Computed tomographic (CT)-myelographic examination at the lumbar area in one cat showed a slight swelling of the spinal cord. Necropsy examination of the spinal cord revealed generalized edema and marked submeningeal hemorrhage at the thoracic region in three cats. On histopathologic examination, numerous sections of adult nematodes and eggs were present in histological sections of the affected spinal cord segments in all cats. The morphologic features of the nematode, location and appearance of the lesions suggest that the parasite responsible for the paralysis in these cats is Gurltia paralysans.

  1. New Insights into the Mechanism of Fertilization in Nematodes

    PubMed Central

    Singaravelu, Gunasekaran; Singson, Andrew

    2012-01-01

    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. PMID:21749902

  2. Plant-Parasitic Nematodes in Maine Agricultural Soils

    PubMed Central

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

    1990-01-01

    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

  3. Report on anisakid nematodes in polar regions - Preliminary results

    NASA Astrophysics Data System (ADS)

    Dzido, Joanna; Kijewska, Agnieszka; Rokicka, Magdalena; Świątalska-Koseda, Agnieszka; Rokicki, Jerzy

    2009-11-01

    The aim of this study is to extend our knowledge of the distribution of anisakid nematode parasites in Arctic and Antarctic polar regions. We examined vertebrate (fish) taxa characteristic of the faunas in both polar regions for the presence of parasitic nematodes. The material was collected from Svalbard (Arctic) between July and August 2008 and from King George Island (South Shetland Islands, Antarctic Peninsula) between November 2007 and January 2008. In addition, faecal, bird, and invertebrate samples were collected and examined for the presence of anisakid nematodes or eggs. Anisakis simplex s.s. was found in the body cavity of Arctic cod, and Contracaecum sp. and Pseudoterranova sp. were found in Antarctic notothenioids. Eggs of Anisakis sp. and Contracaecum sp. were recovered from the faeces of Mirounga leonina. We present the first record of the occurrence of A. simplex C in the Antarctic fishes Notothenia coriiceps and Notothenia rossii.

  4. Efficacy of extracts of immature mango on ovine gastrointestinal nematodes.

    PubMed

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

    2012-12-01

    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.

  5. Caenorhabditis elegans: A Genetic Guide to Parasitic Nematode Biology.

    PubMed

    Bird, D M; Opperman, C H

    1998-09-01

    The advent of parasite genome sequencing projects, as well as an increase in biology-directed gene discovery, promises to reveal genes encoding many of the key molecules required for nematode-host interactions. However, distinguishing parasitism genes from those merely required for nematode viability remains a substantial challenge. Although this will ultimately require a functional test in the host or parasite, the free-living nematode Caenorhabditis elegans can be exploited as a heterologous system to determine function of candidate parasitism genes. Studies of C. elegans also have revealed genetic networks, such as the dauer pathway, that may also be important adaptations for parasitism. As a more directed means of identifying parasitism traits, we developed classical genetics for Heterodera glycines and have used this approach to map genes conferring host resistance-breaking phenotypes. It is likely that the C. elegans and H. glycines genomes will be at least partially syntenic, thus permitting predictive physical mapping of H. glycines genes of interest.

  6. Evolution of the control of sexual identity in nematodes.

    PubMed

    Pires-daSilva, Andre

    2007-06-01

    Most animals are male/female species and reproduce sexually. Variation in this pattern of reproduction has arisen many times during animal evolution, particularly in nematodes. Little is known about the evolutionary forces and constraints that influenced the origin of self-fertilization, for instance, a type of reproduction that seems to have evolved many times in the phylum Nematoda. Caenorhabditis elegans, a very well known nematode, provides the framework for comparative studies of sex determination. The relative ease with which nematodes can be studied in the laboratory and the fact that many recently developed techniques can be applied to many species make them attractive for comparative research. It is relatively poorly understood how the evolution of new types of sex determination and mode of reproduction results in changes in genome structure, ecology and population genetics. Here, I review the evolution of sex determination and mating types in the phylum Nematoda with the objective of providing a framework for future research.

  7. Small-molecule pheromones and hormones controlling nematode development.

    PubMed

    Butcher, Rebecca A

    2017-05-17

    The existence of small-molecule signals that influence development in Caenorhabditis elegans has been known for several decades, but only in recent years have the chemical structures of several of these signals been established. The identification of these signals has enabled connections to be made between these small molecules and fundamental signaling pathways in C. elegans that influence not only development but also metabolism, fertility, and lifespan. Spurred by these important discoveries and aided by recent advances in comparative metabolomics and NMR spectroscopy, the field of nematode chemistry has the potential to expand dramatically in the coming years. This Perspective will focus on small-molecule pheromones and hormones that influence developmental events in the nematode life cycle (ascarosides, dafachronic acids, and nemamides), will cover more recent work regarding the biosynthesis of these signals, and will explore how the discovery of these signals is transforming our understanding of nematode development and physiology.

  8. Infection with parasitic nematodes confounds vaccination efficacy.

    PubMed

    Urban, Joseph F; Steenhard, Nina R; Solano-Aguilar, Gloria I; Dawson, Harry D; Iweala, Onyinye I; Nagler, Cathryn R; Noland, Gregory S; Kumar, Nirbhay; Anthony, Robert M; Shea-Donohue, Terez; Weinstock, Joel; Gause, William C

    2007-08-19

    T helper (Th) cells produce signature cytokine patterns, induced largely by intracellular versus extracellular pathogens that provide the cellular and molecular basis for counter regulatory expression of protective immunity during concurrent infections. The production of IL-12 and IFN-gamma, for example, resulting from exposure to many bacterial, viral, and protozoan pathogens is responsible for Th1-derived protective responses that also can inhibit development of Th2-cells expressing IL-4-dependent immunity to extracellular helminth parasites and vice versa. In a similar manner, concurrent helminth infection alters optimal vaccine-induced responses in humans and livestock; however, the consequences of this condition have not been adequately studied especially in the context of a challenge infection following vaccination. Demands for new and effective vaccines to control chronic and emerging diseases, and the need for rapid deployment of vaccines for bio security concerns requires a systematic evaluation of confounding factors that limit vaccine efficacy. One common albeit overlooked confounder is the presence of gastrointestinal nematode parasites in populations of humans and livestock targeted for vaccination. This is particularly important in areas of the world were helminth infections are prevalent, but the interplay between parasites and emerging diseases that can be transmitted worldwide make this a global issue. In addition, it is not clear if the epidemic in allergic disease in industrialized countries substitutes for geohelminth infection to interfere with effective vaccination regimens. This presentation will focus on recent vaccination studies in mice experimentally infected with Heligmosomoides polygyrus to model the condition of gastrointestinal parasite infestation in mammalian populations targeted for vaccination. In addition, a large animal vaccination and challenge model against Mycoplasma hyopneumonia in swine exposed to Ascaris suum will provide

  9. Leucocyte recruitment during enteric nematode infection.

    PubMed

    McDermott, J R; Grencis, R K; Else, K J

    2001-08-01

    Resolution of infection with the intestinal nematode Trichinella spiralis depends on the host mounting a T helper 2 (Th2) response. It is known that both mast cells and T cells play a crucial role. We have previously shown that efficient migration of mast cells to the gut during infection depends on their expression of the integrin beta 7. beta 7 forms a heterodimer complex with either alpha E or alpha 4 integrin chains, alpha E beta 7 binding to E-cadherin expressed by epithelial cells and alpha 4 beta 7 binding to mucosal addressin cell adhesion molecule (MAdCAM-1) on the endothelium. We were interested to know whether dysfunctional mast cell localization to the gut in the absence of beta 7 was due to the failure of alpha 4 beta 7 to bind to MAdCAM-1 or the failure of alpha E beta 7 to bind to E-cadherin. We used blocking monoclonal antibodies against alpha E (M290) or alpha 4 (PS2) or beta 7 (HB293) during T. spiralis infection of C57BL/6 mice and found that all antibody treatments reduced mastocytosis. In contrast, none of the antibody treatments prevented the migration of CD3(+) T cells into the intestine. These results indicate that during inflammation (a) there is integrin redundancy for lymphocytes but not for mast cells and (b) both alpha E beta 7 and alpha 4 beta 7 are crucial either for the entry of mast cells into the gut or for their maturation once they have entered.

  10. Leucocyte recruitment during enteric nematode infection

    PubMed Central

    McDermott, Jacqueline R; Grencis, Richard K; Else, Kathryn J

    2001-01-01

    Resolution of infection with the intestinal nematode Trichinella spiralis depends on the host mounting a T helper 2 (Th2) response. It is known that both mast cells and T cells play a crucial role. We have previously shown that efficient migration of mast cells to the gut during infection depends on their expression of the integrin β7. β7 forms a heterodimer complex with either αE or α4 integrin chains, αEβ7 binding to E-cadherin expressed by epithelial cells and α4β7 binding to mucosal addressin cell adhesion molecule (MAdCAM-1) on the endothelium. We were interested to know whether dysfunctional mast cell localization to the gut in the absence of β7 was due to the failure of α4β7 to bind to MAdCAM-1 or the failure of αEβ7 to bind to E-cadherin. We used blocking monoclonal antibodies against αE (M290) or α4 (PS2) or β7 (HB293) during T. spiralis infection of C57BL/6 mice and found that all antibody treatments reduced mastocytosis. In contrast, none of the antibody treatments prevented the migration of CD3+ T cells into the intestine. These results indicate that during inflammation (a) there is integrin redundancy for lymphocytes but not for mast cells and (b) both αEβ7 and α4β7 are crucial either for the entry of mast cells into the gut or for their maturation once they have entered. PMID:11529942

  11. Nematicidal Bacteria Associated to Pinewood Nematode Produce Extracellular Proteases

    PubMed Central

    Francisco, Romeu; Verissimo, Paula; Santos, Susana S.; Fonseca, Luís; Abrantes, Isabel M. O.; Morais, Paula V.

    2013-01-01

    Bacteria associated with the nematode Bursaphelenchus xylophilus, a pathogen of trees and the causal agent of pine wilt disease (PWD) may play a role in the disease. In order to evaluate their role (positive or negative to the tree), strains isolated from the track of nematodes from infected Pinus pinaster trees were screened, in vitro, for their nematicidal potential. The bacterial products, from strains more active in killing nematodes, were screened in order to identify and characterize the nematicidal agent. Forty-seven strains were tested and, of these, 21 strains showed capacity to produce extracellular products with nematicidal activity. All Burkholderia strains were non-toxic. In contrast, all Serratia strains except one exhibited high toxicity. Nematodes incubated with Serratia strains showed, by SEM observation, deposits of bacteria on the nematode cuticle. The most nematicidal strain, Serratia sp. A88copa13, produced proteases in the supernatant. The use of selective inhibitors revealed that a serine protease with 70 kDa was majorly responsible for the toxicity of the supernatant. This extracellular serine protease is different phylogenetically, in size and biochemically from previously described proteases. Nematicidal assays revealed differences in nematicidal activity of the proteases to different species of Bursaphelenchus, suggesting its usefulness in a primary screen of the nematodes. This study offers the basis for further investigation of PWD and brings new insights on the role bacteria play in the defense of pine trees against B. xylophilus. Understanding all the factors involved is important in order to develop strategies to control B. xylophilus dispersion. PMID:24244546

  12. Nematode Spatial and Ecological Patterns from Tropical and Temperate Rainforests

    PubMed Central

    Porazinska, Dorota L.; Giblin-Davis, Robin M.; Powers, Thomas O.; Thomas, W. Kelley

    2012-01-01

    Large scale diversity patterns are well established for terrestrial macrobiota (e.g. plants and vertebrates), but not for microscopic organisms (e.g. nematodes). Due to small size, high abundance, and extensive dispersal, microbiota are assumed to exhibit cosmopolitan distributions with no biogeographical patterns. This assumption has been extrapolated from local spatial scale studies of a few taxonomic groups utilizing morphological approaches. Recent molecularly-based studies, however, suggest something quite opposite. Nematodes are the most abundant metazoans on earth, but their diversity patterns are largely unknown. We conducted a survey of nematode diversity within three vertical strata (soil, litter, and canopy) of rainforests at two contrasting latitudes in the North American meridian (temperate: the Olympic National Forest, WA, U.S.A and tropical: La Selva Biological Station, Costa Rica) using standardized sampling designs and sample processing protocols. To describe nematode diversity, we applied an ecometagenetic approach using 454 pyrosequencing. We observed that: 1) nematode communities were unique without even a single common species between the two rainforests, 2) nematode communities were unique among habitats in both rainforests, 3) total species richness was 300% more in the tropical than in the temperate rainforest, 4) 80% of the species in the temperate rainforest resided in the soil, whereas only 20% in the tropics, 5) more than 90% of identified species were novel. Overall, our data provided no support for cosmopolitanism at both local (habitats) and large (rainforests) spatial scales. In addition, our data indicated that biogeographical patterns typical of macrobiota also exist for microbiota. PMID:22984536

  13. Management of root-knot nematode, Meloidogyne incognita in carrot.

    PubMed

    Pedroche, Nordalyn B; Villanueva, Luciana M; De Waele, Dirk

    2009-01-01

    The root-knot nematode, Meloidogyne incognito, remains to be one of the most important constraints in agricultural production worldwide. However, reports showed that root-knot nematode (RKN) population can be suppressed by addition of organic amendments. A greenhouse microplot experiment was conducted to determine if locally available organic amendments would reduce RKN population and improve the growth and yield of more susceptible and less susceptible carrot cultivars in comparison with the farmers' practice. Residues of broccoli, chicken manure and Trichoderma inoculant were incorporated into the soil artificially infested with root-knot nematodes. Untreated microplots were provided as controls. Three months after transplanting, nematodes were recovered from the soil using the modified Baermann-tray technique and from the roots using staining technique. The number of root-knot nematodes was counted under the stereoscopic microscope. In the more susceptible cultivar New Kuroda, significantly lowest number of second stage juveniles (J2's) was recovered from the soil incorporated with broccoli left-over materials and Trichoderma inoculant while chicken manure-amended soil had the most number of J2's. Galls and egg masses in secondary roots were highest in unamended-inoculated soil which was significantly different from broccoli-amended soil with solarisation and Trichoderma inoculant. No significant differences were obtained among the treatments in the less susceptible cultivar Chunhong. The yield was significantly highest in broccoli-amended soil with solarisation and Trichoderma inoculant but no significant difference existed between the two cultivars tested. In general, the treatments with broccoli residues and Trichoderma inoculant were able to decrease root-knot nematode population and significantly increase the yield relative to untreated soil, however, differences between the two cultivars were not significant.

  14. [Screening endophytic bacteria against plant-parasitic nematodes].

    PubMed

    Peng, Shuang; Yan, Shuzhen; Chen, Shuanglin

    2011-03-01

    Plant-parasite nematode is one of the most important pathogens in plant. Our objective is to screen endophytic bacteria against plant-parasitic nematodes from plant. Endophytic bacteria were isolated and screened by testing their metabolite against Bursaphelenchus xylophilus in vitro. Those strains inhibiting B. xylophilus were selected to culture in liquid medium and fermentation conditions were optimized by orthogonal test. The stability of the antinematode substances was evaluated by various. In addition, four strains were identified by 16SrDNA sequence analysis. In total 13 strains of endophytic bacteria secreting antinematode metabolite were isolated from 6 species of plant. The supernatant of the fermentation broth of these endophytic bacteria gave 100% mortality of nematodes after treated as the follows: 1 ml each was mixed with 0.2 ml of the suspension of nematodes (2000 nematodes/ml) then incubated at 250C for 24 h, some of which could led to leakage or dissolution of nematodes. Among them, four strains, BCM2, SZ5, CCM7 and DP1, showed stronger activity than others. The supernatants diluted three times also gave not less than 95% mortality after 24 h treatment, and those from DP1 and SZ5 even gave 100% mortality. The fermentation conditions of the four strains were optimized and the antinematode activity grew up four times after optimization. The antinematode substances of these strains were found stable when treated with protease or heating or stored at 4 degrees C after 100 days, while instable when treated with acid or alkali. DP1 and CCM7 were identified to be Bacillus subtilis, while SZ5 and BCM2 to be Bacillus cereus. Endophytic bacteria secreting antinematode metabolite were found in economic crops. The metabolite of some strains showed strong and stable antinematode activity. Our results indicate the real potential of biocontrol by endophytic bacteria.

  15. Viability and Virulence of Entomopathogenic Nematodes Exposed to Ultraviolet Radiation

    PubMed Central

    Shapiro-Ilan, David I.; Hazir, Selcuk; Lete, Luis

    2015-01-01

    Entomopathogenic nematodes (EPNs) can be highly effective biocontrol agents, but their efficacy can be reduced due to exposure to environmental stress such as from ultraviolet (UV) radiation. Our objectives were to 1) compare UV tolerance among a broad array of EPN species, and 2) investigate the relationship between reduced nematode viability (after exposure to UV) and virulence. Nematodes exposed to a UV radiation (254 nm) for 10 or 20 min were assessed separately for viability (survival) and virulence to Galleria mellonella. We compared 9 different EPN species and 15 strains: Heterorhabditis bacteriophora (Baine, fl11, Oswego, and Vs strains), H. floridensis (332), H. georgiana (Kesha), H. indica (HOM1), H. megidis (UK211), Steinernema carpocapsae (All, Cxrd, DD136, and Sal strains), S. feltiae (SN), S. rarum (17C&E), and S. riobrave (355). In viability assessments, steinernematids, particularly strains of S. carpocapsae, generally exhibited superior UV tolerance compared with the heterorhabditids. However, some heterorhabditids tended to be more tolerant than others, e.g., H. megidis and H. bacteriophora (Baine) were most susceptible and H. bacteriophora (Vs) was the only heterorhabditid that did not exhibit a significant effect after 10 min of exposure. All heterorhabditids experienced reduced viability after 20 min exposure though several S. carpocapsae strains did not. In total, after 10 or 20 min exposure, the viability of seven nematode strains did not differ from their non-UV exposed controls. In virulence assays, steinernematids (particularly S. carpocapsae strains) also tended to exhibit higher UV tolerance. However, in contrast to the viability measurements, all nematodes experienced a reduction in virulence relative to their controls. Correlation analysis revealed that viability among nematode strains is not necessarily related to virulence. In conclusion, our results indicate that the impact of UV varies substantially among EPNs, and viability alone

  16. An evolutionary perspective on gastrointestinal nematodes of sheep.

    PubMed

    Stear, M J; Singleton, D; Matthews, L

    2011-06-01

    The purpose of this paper was to discuss from an evolutionary perspective the interaction between domestic sheep (Ovis aries) and their gastrointestinal nematodes. Although evolution is the central theme of biology, there has been little attempt to consider how evolutionary forces have shaped and continue to shape the relationships between domestic animals and their parasite community. Mathematical modelling of the host-parasite relationship indicated that the system is remarkably robust to perturbations in its parameters. This robustness may be a consequence of the long coevolution of host and parasites. Although nematodes can potentially evolve faster than the host, coevolution is not dominated by the parasite and there are several examples where breeds of cattle or sheep have evolved high levels of resistance to disease. Coevolution is a more equal partnership between host and nematode than is commonly assumed. Coevolution between parasites and the host immune system is often described as an arms race where both host immune response genes and parasite proteins evolve rapidly in response to each other. However, initial results indicate that nematode antigens are not evolving rapidly; the arms race between the immune system and nematodes, if it exists, is happening very slowly. Fisher's fundamental theorem of natural selection states that genes with positive effects on fitness will be fixed by natural selection. Consequently, heritable variation in fitness traits is expected to be low. Contrary to this argument, there is considerable genetic variation in resistance to nematode infection. In particular, the heritabilities of nematode-specific IgA and IgE activity are moderate to high. The reasons for this apparent violation of the fundamental theorem of natural selection are not clear but several possible explanations are explored. Faecal nematode egg counts increase at the beginning of the grazing season - a phenomenon known as the periparturient rise. This

  17. Stacking resistance to crown gall and nematodes in walnut rootstocks.

    PubMed

    Walawage, Sriema L; Britton, Monica T; Leslie, Charles A; Uratsu, Sandra L; Li, YingYue; Dandekar, Abhaya M

    2013-10-01

    Crown gall (CG) (Agrobacterium tumefaciens) and the root lesion nematodes (RLNs) (Pratylenchus vulnus) are major challenges faced by the California walnut industry, reducing productivity and increasing the cost of establishing and maintaining orchards. Current nematode control strategies include nematicides, crop rotation, and tolerant cultivars, but these methods have limits. Developing genetic resistance through novel approaches like RNA interference (RNAi) can address these problems. RNAi-mediated silencing of CG disease in walnut (Juglans regia L.) has been achieved previously. We sought to place both CG and nematode resistance into a single walnut rootstock genotype using co-transformation to stack the resistance genes. A. tumefaciens, carrying self-complimentary iaaM and ipt transgenes, and Agrobacterium rhizogenes, carrying a self-complimentary Pv010 gene from P. vulnus, were used as co-transformation vectors. RolABC genes were introduced by the resident T-DNA in the A. rhizogenes Ri-plasmid used as a vector for plant transformation. Pv010 and Pv194 (transgenic control) genes were also transferred separately using A. tumefaciens. To test for resistance, transformed walnut roots were challenged with P. vulnus and microshoots were challenged with a virulent strain of A. tumefaciens. Combining the two bacterial strains at a 1:1 rather than 1:3 ratio increased the co-transformation efficiency. Although complete immunity to nematode infection was not observed, transgenic lines yielded up to 79% fewer nematodes per root following in vitro co-culture than untransformed controls. Transgenic line 33-3-1 exhibited complete crown gall control and 32% fewer nematodes. The transgenic plants had thicker, longer roots than untransformed controls possibly due to insertion of rolABC genes. When the Pv010 gene was present in roots with or without rolABC genes there was partial or complete control of RLNs. Transformation using only one vector showed 100% control in some lines

  18. Commercial Development and Future Prospects for Entomogenous Nematodes

    PubMed Central

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

    1981-01-01

    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. PMID:19300763

  19. Stacking resistance to crown gall and nematodes in walnut rootstocks

    PubMed Central

    2013-01-01

    Background Crown gall (CG) (Agrobacterium tumefaciens) and the root lesion nematodes (RLNs) (Pratylenchus vulnus) are major challenges faced by the California walnut industry, reducing productivity and increasing the cost of establishing and maintaining orchards. Current nematode control strategies include nematicides, crop rotation, and tolerant cultivars, but these methods have limits. Developing genetic resistance through novel approaches like RNA interference (RNAi) can address these problems. RNAi-mediated silencing of CG disease in walnut (Juglans regia L.) has been achieved previously. We sought to place both CG and nematode resistance into a single walnut rootstock genotype using co-transformation to stack the resistance genes. A. tumefaciens, carrying self-complimentary iaaM and ipt transgenes, and Agrobacterium rhizogenes, carrying a self-complimentary Pv010 gene from P. vulnus, were used as co-transformation vectors. RolABC genes were introduced by the resident T-DNA in the A. rhizogenes Ri-plasmid used as a vector for plant transformation. Pv010 and Pv194 (transgenic control) genes were also transferred separately using A. tumefaciens. To test for resistance, transformed walnut roots were challenged with P. vulnus and microshoots were challenged with a virulent strain of A. tumefaciens. Results Combining the two bacterial strains at a 1:1 rather than 1:3 ratio increased the co-transformation efficiency. Although complete immunity to nematode infection was not observed, transgenic lines yielded up to 79% fewer nematodes per root following in vitro co-culture than untransformed controls. Transgenic line 33-3-1 exhibited complete crown gall control and 32% fewer nematodes. The transgenic plants had thicker, longer roots than untransformed controls possibly due to insertion of rolABC genes. When the Pv010 gene was present in roots with or without rolABC genes there was partial or complete control of RLNs. Transformation using only one vector showed 100

  20. ORGANIC VS CONVENTIONAL: SOIL NEMATODE COMMUNITY STRUCTURE AND FUNCTION.

    PubMed

    Kapp, C; Storey, S G; Malan, A P

    2014-01-01

    Global increases in human population are creating an ever-greater need for food production. Poor soil management practices have degraded soil to such an extent that rapidly improved management practices is the only way to ensure future food demands. In South Africa, deciduous fruit producers are realising the need for soil health, and for an increased understanding of the benefits of soil ecology, to ensure sustainable fruit production. This depends heavily on improved orchard management. Conventional farming relies on the addition of artificial fertilizers, and the application of chemicals, to prevent or minimise, the effects of the soil stages of pest insects, and of plant-parasitic nematodes. Currently, there is resistance toward conventional farming practices, which, it is believed, diminishes biodiversity within the soil. The study aimed to establish the soil nematode community structure and function in organically, and conventionally, managed deciduous fruit orchards. This was done by determining the abundance, the diversity, and the functionality of the naturally occurring free-living, and plant-parasitic, nematodes in deciduous fruit orchards in the Western Cape province of South Africa. The objective of the study was to form the basis for the use of nematodes as future indicators of soil health in deciduous fruit orchards. Orchards from neighbouring organic, and conventional, apricot farms, and from an organic apple orchard, were studied. All the nematodes were quantified, and identified, to family level. The five nematode-classified trophic groups were found at each site, while 14 families were identified in each orchard, respectively. Herbivores were dominant in all the orchards surveyed. Organic apples had the fewest herbivores and fungivores, with the highest number of carnivores. When comparing organic with conventional apricot orchards, higher numbers of plant-parasitic nematodes were found in the organic apricot orchards. The Maturity Index (MI