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PubMed1982

Effects of carbon dioxide, temperature, pH and the number of worms on the in vitro survival, histology and histochemistry of Paramphistomum cervi (Paramphistomatidae: Digenea).

Survival of immature and mature stages of Paramphistomum cervi, collected from the intestine and the rumen of sheep has been studied in in vitro using Tyrode's, Hank's, Eagle's, Stephenson's saline and Hedon--Fleig media. Twenty-five ml quantities of carbon dioxide (CO2)-rich Hedon--Fleig solution at pH 6.7, at 37 degrees C supported the maximum survival of 5 worms of both immature and mature flukes for periods of 9 and 10 days, respectively. Alterations to the pH of the medium, the incubation temperature and the number of worms significantly affected the period of their in vitro survival. The tissues of immature and mature worms did not show any marked histological and histochemical change until 24 h of in vitro survival in Hedon--Fleig solution when the testes of adult worms started undergoing degeneration. There was a progressive depletion of stored lipids and carbohydrates in the parenchymatous tissue during the course of in vitro survival. After the second day of in vitro maintenance, the maturation of the worms' vitelline follicles was affected, and thereafter they started to degenerate. On Day 4, degeneration of some gastrodermal cells, and a ruptured body wall were observed in some worms. Though the degenerative changes in the tissues of worms appeared at 24 h and continued to increase during in vitro maintenance, the worms survived for 9-10 days.

Animals↗

PubMed2004

Comparison of social ranks based on worm-running and aggressive behaviour in young domestic fowl.

Worm-running is behaviour in which a chick runs carrying a worm-like object while flock mates follow and attempt to grab the object from its beak. We hypothesised that social ranks based on worm-running frequency are stable over time and are positively correlated with social ranks based on success in aggressive interactions when older. At 8-12 days of age, we scored worm-running in 17 groups of 12 female White Leghorn chicks during three 10-min tests. Based on instantaneous scans at 5-s intervals, the bird carrying the 'worm' most often was placed in rank one and so on down the rank order. These tests were repeated at 68-70 days of age. An aggression index for each bird was calculated as the number of aggressive acts given, divided by the number given and received, during three 1-h observation periods when the birds were 68-70 days. Ranks obtained in worm-running tests were positively correlated over the two age periods (P < 0.05) but were not correlated with ranks based on the aggression index (P > 0.05). Our results indicate that worm-running ranks are not predictive of success in aggressive interactions. Instead, worm-running fits some criteria for play.

Aggression↗

PubMed2006

A new reactor concept for sludge reduction using aquatic worms.

Biological waste water treatment results in the production of waste sludge. The final treatment option in The Netherlands for this waste sludge is usually incineration. A biological approach to reduce the amount of waste sludge is through predation by aquatic worms. In this paper we test the applicability of a new reactor concept for sludge reduction by the aquatic worm Lumbriculus variegatus. In this reactor concept the worms are immobilized in a carrier material. In sequencing batch experiments, the sludge breakdown in the predation reactor is compared to sludge breakdown in a blank reactor (i.e. without worms). Predation by the worms results in a distinct sludge reduction, which is almost three times higher than in the blank experiment. The worm faeces that are produced after sludge predation have a sludge volume index (SVI) that is approximately half that of the initial waste sludge. Due to the configuration of the predation reactor, waste sludge, worm faeces and worms are separated, which is beneficial to further processing. The obtained results show that the proposed reactor concept has a high potential for use in large-scale sludge processing.

Animals↗

PubMed2003

Infestation of the clam Chione fluctifraga by the burrowing worm Polydora sp. nov. in laboratory conditions.

Burrowing worms that belong to Polydora spp. infest marine mollusks cultured worldwide, causing problems for production and marketing. The clam Chione fluctifraga is semi-cultured in Bahía Falsa, Baja California, NW Mexico, and some clams harbor burrowing worms. The present study was carried out to determine the identity of the worm species infesting the clam, the infesting process by cohabitation of infested and non-infested clams in aquaria with a variety of substrates (fine sand, gross sand, plastic bag used for clam culture, and aquarium without substrate) and turbulence conditions, and the occurrence of architomy phenomena in connection with infestation of the clam. The burrowing worm was considered as a nova species due to its singular limbate neurosetae and notosetae in the setiger 5, hooks in the setiger 6, eyes not present, and general pigmentation, among other characteristics. Infestation was similar in all substrates and turbulence conditions, but it was more abundant on clams previously infested than on those free of worms, showing a preferential settlement of worm infesting stages on pre-infested clams. Regeneration was observed in all segments of the worm: anterior (metastomium), medium, and posterior (prostomium); the complete regeneration time occurred in 40 days. This is the first record of architomy in a species of Polydora and this phenomenon could account for the increase of infestation intensity in pre-infested clams at the end of the study period. Infestation of clams by settling polichaete in the conditions studied, and the architomy process in this worm species, shows its great infesting capacity.

Animals↗

PubMed1979

The uptake in vitro of dyes, monosaccharides and amino acids by the filarial worm Brugia pahangi.

The uptake in vitro of various substances by Brugia pahangi was investigated using infective larvae obtained from Aedes aegypti and worms removed from Meriones unguiculatus at 2, 3, 10, 20 and 90 days post-infection. Worms incubated in growth medium 199 containing 1% Trypan blue possessed demonstrable dye in the oral orifice, the anterior oesophageal lumen and the external openings of the vulva and the cloaca or anus but the dye was not found in the gut lumen even after incubation for 24 h. No uptake of ferritin particles into the intestine of the worms was found and no fluorescence could be demonstrated in the gut lumen of worms incubated in medium containing 50% (v/v) fluorescein isothiocyanate-conjugated calf serum for up to 24 h. Trypan blue uptake by the gut of Aspiculuris tetraptera was clearly observed after incubation for several hours. The uptake of D-glucose and L-leucine by B. pahangi was demonstrated using autoradiographic and scintillation counting techniques and incorporation into worm tissues was detected. Glucose was found to be readily incorporated in the apical, glycogen-rich areas of the myocytes of worms of all ages studied and in the uterine epithelium of the adult female. In contrast, a lower incorporation of D-glucose was found in the eggs, embryos and vas deferens and especially in the gut. The incorporation of L-leucine occurred throughout the tissue of the worms during a 30 min incubation. Labelling was also located over the surface of the cuticle of the worms, when incubated for a period of 15 to 60 min in L-[H]leucine. Scintillation counting techniques demonstrated that there was no uptake of 14C-labelled L-glucose or sucrose by B. pahangi. The data presented on the uptake in vitro of nutrients or other compounds by infective larvae and adult stages of B. pahangi did not demonstrate an intestinal route of uptake but indicated that the transcuticular route of uptake may be employed.

Animals↗

PubMed1979

Hymenolepis diminuta: the role of the tail in determining the position of the worm in the intestine of the rat.

One-worm infections of Hymenolepis diminuta in rats had their strobila severed surgically, in the neck region, on day 14 of an infection. The scolex and remaining strobila survived but were recovered from a more posterior region of the intestine where small worms are attached during development. The movement to the new region was usually not complete in 24 h, but was complete by 72 h, and probably by 48 h. The operation, involving laparotomy and an incision in the duodenal wall which avoided severing the strobila, had no effect on the position of the worm but did depress the growth of the worm during the ensuing 24 h. It is suggested that (1) the preferred site for H. diminuta is 30-50% down the small intestine, (2) the worm monitors information about its position from all over its strobila and (3) as the worm grows, its position is determined by balancing the input of adverse information from its tail and head ends. The slowness with which surgically shortened worms return to the preferred site may be due either to delay in the worm "realising" it has no tail, or to the location stimuli in the intestine being disturbed for 24 h by the operation.

Animals↗

PubMed1982

Distribution of exposed and hidden carbohydrates of Schistosoma mansoni adult worms demonstrated by selective binding of fluorochrome-conjugated lectins.

The distribution of exposed and hidden lectin-binding glycoconjugates in adult Schistosoma mansoni worms was studied. Fluorochrome-conjugated lectins were allowed to react both with intact worms and with frozen sections of worms. The results show a selective reactivity of lectins with tegumental surface structures, the intestine, eggs and basement membranes. Strong binding of wheat germ agglutinin (WGA) was seen to the exposed surface of intact worms. Peanut agglutinin (PNA), Ricinus communis agglutinin (RCA) and concanavalin A (Con A) gave a weaker reaction. There was a preferential affinity of PNA and RCA to the spikes covering the tubercles of male worms whereas Con A gave a more uniform staining pattern. Internal structures exposed in frozen sections of worms gave distinct staining reactions. Binding sites for Con A were widely distributed throughout the worm. PNA produced a more selective binding and was the only lectin staining basement membranes as distinct structures. There was a strong selective staining of the gut with soybean agglutinin (SBA) and RCA. Eggs seen in large quantitites inside female parasites reacted strongly with SBA and PNA and less intensely with RCA and WGA. The observed selectivity of lectin binding may reflect physiological function. The results may be important as a basis for using lectin affinity-chromatography for purification and characterization of worm constituents.

Animals↗

PubMed1987

Immunological relationships during primary infection with Heligmosomoides polygyrus (Nematospiroides dubius): the capacity of adult worms to survive following transplantation to recipient mice.

Chronic primary infections with Heligmosomoides polygyrus (Nematospiroides dubius) are still relatively poorly documented, particularly in relation to the role of host resistance in limiting worm survival. In the present work the duration of infection with H. polygyrus was studied in CFLP mice given doses of infective larvae ranging from 50 to 500 L3. The least heavily infected (50 L3) group ceased egg production earliest (week 36) whereas eggs were still detected in the faeces of mice given 500 larvae in week 42. At autopsy (week 42) mice given 50 larvae had virtually lost their entire worm burden with 5 out of 11 mice still harbouring a single worm each. However, all the mice in the group given 500 larvae were still infected, the highest worm burden being 93. The concentration of serum IgG1 and specific antibody was highest in mice given 500 larvae, but sera taken from mice with declining worm burdens 19-38 weeks post-infection did not contain detectable host-protective antibody. During the course of infection in CFLP mice, H. polygyrus sustained irreversible changes in its capacity for subsequent survival. Thus, adult worms transferred to naive mice 2, 7, 14, 30 or 36 weeks post-infection did not live longer than worms of a comparable age in the respective donor group. In contrast, primary infection worms taken from jirds in which expulsion is usually completed by 6 weeks post-infection, re-established in mice and survived considerably longer than in the group of donor jirds. These results were discussed in relation to the possible interactions between parasite senility and immunomodulation, and host resistance in limiting primary infections with H. polygyrus in mice and jirds.

Animals↗

PubMed2006

Influence of substrate on bioaccumulation of 14C-paraquat in compost worms Eisenia foetida.

Contamination of soil with pesticides can be evaluated using toxicity tests with worms because their ecological niche makes them good bioindicators. Bioaccumulation in compost worms of [methyl-14C] paraquat (1,1'-dimethyl-4,4'-bipyridinium dichloride) was measured after three-month exposure in two substrates with differing physicochemical characteristics, in particular their organic matter and clay contents. The treatments were 1.2, 12, and 120 microg paraquat g(-1) substrate. The action of the worms did not influence the loss of 14C from the substrates, as the 14C-recovered was essentially quantitative at the end of the study in both the presence and absence of the worms. The organic matter and clay contents of the substrates determined the extent of the paraquat uptake by the worms; worms from the substrate with smaller amounts of clay and organic matter had the higher values of the bioconcentration factor (BCF), these being about 5 (fresh-weight basis) and independent of the application rate. The BCF values in the substrate containing more organic matter and clay were smaller but increased from 1.1 to 3.8 with the increasing rates of application. However, in both substrates the amounts of paraquat bioaccumulated in the worms was always less than 1% of that applied, indicating the very strong binding of paraquat to the substrates and hence low availability to the worms.

Animals↗

PubMed2000

Protein folds in the worm genome.

We survey the protein folds in the worm genome, using pairwise and multiple-sequence comparison methods (i.e. FASTA and PSI-blast). Overall, we find that approximately 250 folds match approximately 8000 domains in approximately 4500 ORFs, about 32 matches per fold involving a quarter of the total worm ORFs. We compare the folds in the worm genome to those in other model organisms, in particular yeast and E. coli, and find that the worm shares more folds with the phylogenetically closer yeast than with E. coli. There appear to be 36 folds unique to the worm compared to these two model organisms, and many of these are obviously implicated in aspects of multicellularity. The most common fold in the worm genome is the immunoglobulin fold, and many of the common folds are repeated in various combinations and permutations in multidomain proteins. In addition, an approach is presented for the identification of "sure" and "marginal" membrane proteins. When applied to the worm genome, this reveals a much greater relative prevalence of proteins with seven transmembrane helices in comparison to the other completely sequenced genomes, which are not of metazoans. Combining these analyses with some other simple filters allows one to identify ORFs that potentially code for soluble proteins of unknown fold, which may be promising targets for experimental investigation in structural genomics. A regularly updated worm fold analysis will be available from bioinfo.mbb.yale.edu/genome/worm.

Animals↗

PubMed1981

Influence of an experimental infection of nodular worms (Oesophagostomum spp.) on performance of pigs.

Four trials were conducted to determine the effect of different levels of nodular worm (Oesophagostomum spp.) infection on the performance of growing-finishing swine and on digestion and absorption of nutrients by the growing pig. In each of two growing-finishing trials, 48 crossbred pigs (average body weight 26.6 kg in trial 1 and 24.4 kg in trial 2) were individually housed and given a single infection of nodular worms (0, 550, 1,100 or 1,650 infective larvae/kg body weight in trial 1 and 0, 1,500, 3,000 or 4,500 infective larvae/kg body weight in trial 2). At 21 days postinfection, pigs given either 1,100 or 1,650 nodular worm larvae/kg body weight required more feed (P less than .05) per unit gain than pigs not infected, but for the 77-day test period, as a whole, nodular worms did not significantly affect performance. in trial 2, pigs given either 3,000 or 4,500 nodular worm larvae/kg body weight were lighter (P less than .05) and gained weight slower (P less than .05) for the first 21 days postinfection than pigs not infected, while pigs given 4,500 larvae gained slower (P less than .05) than pigs on the other three treatments. During the first 21 days after infection, pigs given 4,500 larvae/kg body weight consumed less feed (P less than .05 than pigs given either 0 or 1,500 larvae. Even at the higher levels of infection, nodular worms did not significantly affect performance over the entire 77-day test period. In each of the two other trials, eight crossbred barrows (average body weight 28.8 kg in trial 1 and 28.4 kg body weight in trials 2) were examined for the effects of two levels of nodular worm infection (0 and 4,950 larvae/kg body weight) on digestion and absorption of nutrients and on N balance. Pigs experimentally infected had a lower digestion coefficient for dry matter (P less than .01), ash (P less than .05), crude fiber (P less than .01), N free extract (P less than .05) and N (P less than .05) than noninfected pigs. Pigs not infected with nodular worms had a higher (P less than .05) N balance.

Animals↗

PubMed1985

Prevalence, worm burden and other epidemiological parameters of Ascaris lumbricoides infection in rural communities in Korea.

The epidemiological status of ascariasis was analyzed in 8 rural villages in Korea, through observation of its epidemiological parameters such as prevalence, worm burden and basic reproductive rate. Total 978 inhabitants were subjected to stool examination and recovery of worms after chemotherapy with pyrantel pamoate. The results were as follows: The worm positive rate in each village was 16.5~79.5%, while the egg positive rate was 9~18% lower, 3.3~66.7%. The average worm burden(among all inhabitants) ranged from 0.21 to 8.44 by villages and the frequency of cases with each worm burden showed negative binomial distributions with 'k' values of 0.38-0.54. The prevalence rates (worm) in each village was almost identical with the theoretical ones from Anderson and May's equation; p=1-(1+M(*)/k)**(-k), where 'p' is worm prevalence and 'M(*)' equilibrium average worm burden. The basic reproductive rate 'R' was calculated from 1.03 to 2.11. It is suggested that, although 'R' in lower endemic areas is approaching to the breakpoint of reinfection (R=1), control programs of ascariasis in Korea should be continued until it becomes below the level nationwidely.

Journal Article↗

PubMed2004

Schistosoma mansoni worms induce anergy of T cells via selective up-regulation of programmed death ligand 1 on macrophages.

Infectious pathogens can selectively stimulate activation or suppression of T cells to facilitate their survival within humans. In this study we demonstrate that the trematode parasite Schistosoma mansoni has evolved with two distinct mechanisms to suppress T cell activation. During the initial 4- to 12-wk acute stages of a worm infection both CD4(+) and CD8(+) T cells are anergized. In contrast, infection with male and female worms induced T cell anergy at 4 wk, which was replaced after egg laying by T cell suppression via a known NO-dependent mechanism, that was detected for up to 40 wk after infection. Worm-induced anergy was mediated by splenic F4/80(+) macrophages (Mphi) via an IL-4-, IL-13-, IL-10-, TGF-beta-, and NO-independent, but cell contact-dependent, mechanism. F4/80(+) Mphi isolated from worm-infected mice were shown to induce anergy of naive T cells in vitro. Furthermore, naive Mphi exposed to live worms in vitro also induced anergy in naive T cells. Flow cytometry on in vivo and in vitro worm-modulated Mphi revealed that of the family of B7 costimulatory molecules, only programmed death ligand 1 (PD-L1) was selectively up-regulated. The addition of inhibitory mAb against PD-L1, but not PD-L2, to worm-modulated Mphi completely blocked the ability of these cells to anergize T cells. These data highlight a novel mechanism through which S. mansoni worms have usurped the natural function of PD-L1 to reduce T cell activation during early acute stages of infection before the subsequent emergence of egg-induced T cell suppression in the chronic stages of infection.

Animals↗

PubMed1979

Kinetics of Dipetalonema viteae infections established by surgical implantation of adult worms into hamsters.

Native LVG strain hamsters were infected with Dipetalonema viteae by the surgical implantation of adult worms. Groups of hamsters received either 50 male, 50 female, 50 male plus 50 female or 25 male plus 25 female worms per hamster. Approximately 50% of the transferred worms became established in the recipient hosts regardless of the number or sex of the worms implanted. Microfilaremia occurred in recipient hamsters within 1 week after the transfer of female or male plus female worms. This microfilaremia became negative on week 9 post-transfer and no microfilaremia developed in these hamsters following a secondary challenge infection of male plus female worms. Hamsters whose primary infection consisted solely of male worms developed a microfilaremia when challenged with male plus female worms.

Animals↗

PubMed1983

The antigens of Paragonimus westermani, Schistosoma mansoni, and Fasciola hepatica adult worms. Evidence for the presence of cross-reactive antigens and for cross-protection to Schistosoma mansoni infection using antigens of Paragonimus westermani.

The presence of cross-reacting antigens between Paragonimus westermani, Schistosoma mansoni, and Fasciola hepatica adult worms was demonstrated by Ouchterlony immunodiffusion and enzyme-linked immunosorbent assay (ELISA). A serum bank was developed against the three trematode genera to serve as probes to determine the presence of cross-reacting antibodies to P. westermani worm extracts. In this manner, it was possible to demonstrate that antigens common to F. hepatica and S. mansoni tegument were also present in P. westermani worm extracts. Likewise, it was possible to demonstrate that the F. hepatica antigens which bind to Concanavalin A, as well as the subfraction which in isoelectric focusing has a pI of 4.2, were also found in P. westermani worms. Also, a monospecific polyclonal serum to a Fasciola/Schistosoma cross-reacting antigen and the anti-P. westermani serum both reacted in Ouchterlony immunodiffusion with the P. westermani antigenic extract, each producing a line which linked with each other indicating common antigenic determinants and suggesting a common antigen among the digenetic trematodes. Finally, the P. westermani antigenic extracts induced in mice the production of antibodies which reacted with S. mansoni adult worm antigens by ELISA. As all of the Fasciola and Schistosoma sera were prepared against antigenic preparations which induced in mice protection to challenge infection with S. mansoni, this suggested that the P. westermani worms also contain protective antigens against S. mansoni. Immunity to Schistosoma mansoni infection was induced in mice by vaccination with Paragonimus westermani whole worm extracts (PwWWE). Immunized mice showed as high as a 67% worm burden reduction over controls. High doses of PwWWE did not confer protection to S. mansoni infection. Thus, in this study, immunity in heterologous systems was demonstrated and the existence of a common protective antigen shared by the digenetic trematodes was suggested.

Animals↗

PubMed1998

Bancroftian filariasis in Egypt: visualization of adult worms and subclinical lymphatic pathology by scrotal ultrasound.

The purpose of this study was to explore the value of scrotal ultrasound as a means of evaluating Bancroftian filariasis. Color Doppler ultrasound examinations were performed to look for subclinical hydroceles and motile adult filarial worms (dancing worms) in dilated lymphatics. Sixty-one male subjects from a filariasis-endemic area in Egypt were studied including 19 clinically normal microfilaria (MF) carriers (seven with dancing worms and eight with subclinical hydroceles), 13 MF-negative subjects with positive filarial antigen test results (three with dancing worms and seven with subclinical hydroceles), 22 exposed subjects with no MF and negative antigen test results (no dancing worms, four subclinical hydroceles), and seven subjects with clinical filariasis (no dancing worms, seven hydroceles). Thus, all men tested with clinical filariasis and most clinically normal subjects with either microfilaremia or filarial antigenemia had abnormal ultrasound examination results. Ultrasound findings often changed after therapy with diethylcarbamazine, with disappearance of dancing worms and development of new scrotal calcifications or hydroceles. This study confirms the value of scrotal ultrasound as a means of noninvasively visualizing adult filarial worms and assessing subclinical lymphatic damage in Bancroftian filariasis.

Adult↗

PubMed1975

Nippostrongylus brasiliensis in young rats. Lymphocytes expel larval infections but not adult worms.

Young rats were not able to expel adult N. brasiliensis infections even when the worms were damaged by antibodies and the young rats were given all the cellular components (sensitized lymphocytes and bone marrow cells) shown to be necessary for the expulsion of antibody-damaged worms from adult rats. In contrast, most of the worms were expelled from young rats given sensitized lymph node cells on the day of a larval infection. These results show that the reduced ability of young rats to respond to infection by producing sensitized lymphocytes only partly explains their inability to expel the worms. It was not possible to explain the failure of young rats to expel adult worms by hypothesizing that they develop an active factor which prevents the cells from acting on the worms. It is also unlikely that worms persist in young rats because they differ in their susceptibility to cells compared with antibody-damaged worms from mature rats. This work suggests that the immune mechanism which affects the immature stages of this nematode may differ from that which controls the adult stages.

Aging↗

PubMed1986

Eosinophil responses of permissive and nonpermissive hosts to the young adult worms of Angiostrongylus cantonensis.

Blood and bone marrow eosinophilia was assessed in nonpermissive (guinea pigs) and permissive (rats) hosts following the pulmonary arterial transfers of live or dead young adult worms of Angiostrongylus cantonensis. Guinea pigs showed a marked eosinophilic response to live worms but only a slight response to dead worms. Neither IgE nor haemagglutinating antibodies correlated with the induction of this eosinophilia. In contrast, the rat responded to neither form of the young adult worm. When the guinea pig and the rat were injected with whole worm extract (WWE) of the young adult worms either by an osmotic mini-pump connected to the jugular vein or by intermittent intravenous injections, the former animal showed blood eosinophilia but the latter failed to do so. Guinea pigs also developed blood eosinophilia after continuous exposure to the excretory and secretory products of the young adult worms, administered by the mini-pump. Eosinophil responses to WWE could be induced both in athymic CD-1 (ICR) nude mice and in its heterozygous litter mates, suggesting that T cell-independent mechanism(s) could be involved in the induction of blood eosinophilia in the nonpermissive, mouse host. These data clearly indicate that the eosinophilia-inducing factor(s) and the mechanism of eosinophilia are different in permissive and nonpermissive hosts.

Angiostrongylus↗