[First finding of the Centrorhynchus aluconis (Muller, 1780) (Giganthorhynchidae) and Moniliformis moniliformis bremser, 1811 (Moniliformidae) larvae in shrews (Insectivora: Soricidae) of the fauna of Russia].

The larvae of acanthocephalans Centrorhynchus aluconis (Muller, 1780) and Moniliformis moniliformis Bremser, 1811 are recorded for the first time from shrews in Russia (Samarskaya Luka National Park, Samara Region). Taxonomic descriptions and figures of the specimens examined are presented.

Red fox (Vulpes vulpes) a new host species for acanthocefalan Moniliformis moniliformis (Bremser, 1811) in Poland.

Acanthocephalan Moniliformis moniliformis is a parasite of rodents, rarely also reported from carnivorous mammals. One female specimen of this parasite has been found in the small intestine of red fox Vulpes vulpes. It is the first report about this species invading the red fox in Poland.

Helminth fauna of Talpa spp. in the Palaearctic Realm.

The helminth fauna of the genus Talpa in the Palaearctic Realm is reviewed. Several helminth species reported in Talpa spp. by a number of authors are discussed, with reference to host specificity, parasite biology, and host ethology, ecology and phylogeny. Twelve species of cestodes were found, two of which exhibit stenoxenous specificity (Staphylocystis bacillaris and Multitesticulata filamentosa). Only three species of trematodes, Ityogonimus lorum, Ityogonimus ocreatus and Combesia macrobursata, are exclusive parasites of Talpa spp. The largest group are nematodes, with 37 species. Species of Tricholinstowia are parasites of holarctic talpids and several species of distinct genera, such as Capillaria, Soboliphyme and Trichuris, are found only in Talpa spp. Only acanthocephalans of the genus Moniliformis have been reported in moles of the genus Talpa. On the basis of these helminthological findings, the close phylogenetic relationship between moles (Talpidae) and shrews (Soricidae) supports the separation of the ordinal levels Soricomorpha and Erinaceomorpha.

The effect of parasitism on host fecundity is dependent on temperature in a cockroach-acanthocephalan system.

The fitness of infected organisms can vary greatly depending on the temperature at which they find themselves. Understanding the role of temperature in the fitness of infected organisms can be crucial to population studies, epidemiological studies, and when screening for biological control agents. We measured the effect of parasitism on host survival and reproduction at 4 constant temperatures using the acanthocephalan parasite Moniliformis moniliformis and its intermediate host, the cockroach Supella longipalpa. Infection did not affect cockroach survival at any temperature. Infection had a negative impact on cockroach fecundity but only at higher temperatures (28 and 31 C) and only later in infection (>20 days postinfection). At lower temperatures, infected and uninfected cockroaches had similar fecundities throughout the duration of the experiment (120 days). This study, along with previous studies, suggests that researchers would do well to consider environmental variables when exploring the effects of parasitism.

A comparison of biological performances among a laboratory-isolated population and two wild populations of Moniliformis moniliformis.

Divergence of biological performance of a laboratory-reared population of Moniliformis moniliformis (Acanthocephala) was investigated after 31 yr, or approximately 60 generations, of genetic isolation. An isolate of the laboratory-reared population and isolates of 2 wild populations were used to begin 3 independent life cycles that were maintained for 1 generation for interbreeding and life history trait comparison. Both wild population isolates represented populations with open gene flow. One wild population isolate represented a present-day sample of descendants of the parent population of the laboratory isolate. All 3 populations hybridized, and egg production occurred in all mixed-sex pairs of different populations. The 3 populations did not differ significantly in prepatent period, mean daily egg production, or establishment within the definitive host Rattus norvegicus. The 3 populations varied in patent period, but the laboratory-isolated worms differed from the 2 wild population isolates no more than they did from each other. A positive correlation between mean daily egg production and duration of patent period resulted in different cumulative egg productions. A 31-yr period of isolation did not produce greater divergence in a laboratory population of M. moniliformis than occurs between wild populations with respect to the biological parameters measured.

Worm kinetics and serum IgE in hooded lister rats infected with the acanthocephalan Moniliformis moniliformis and the nematode Nippostrongylus brasiliensis.

After infection with the intestinal helminths Moniliformis moniliformis or Nippostrongylus brasiliensis, worm-specific IgE first appeared in the serum rats between days 10 and 24 p.i., varying with host age, worm species and worm dose used. The rate of increase in specific IgE was comparable regardless of the worm species, infection dose or host age and a peak response was observed about 1 month after the sera turned positive. In the M. moniliformis infections, these events took place long before the beginning of worm expulsion on day 63 in high-dose (50 worms) infections, and potentiation of heterologous IgE was not observed. In contrast, IgE stimulation by N. brasiliensis infections was detected as potentiation of anti-ovalbumin IgE, anti-M. moniliformis IgE and total IgE. Most of the total IgE in the serum of M. moniliformis-infected rats was likely to be the worm-specific IgE. Anthelminthic removal of M. moniliformis revealed that the presence of residual worms was necessary to maintain worm-specific IgE production.

Altered behavior in two species of blattid cockroaches infected with Moniliformis moniliformis (Acanthocephala).

Moniliformis moniliformis-infected Periplaneta australasiae and Blatta orientalis were less active than uninfected controls in behavioral arena tests under both red and white light regimes. There was a strong interaction between light regime and parasitism for substrate use by P. australasiae. Under red light, parasitism decreased the use of black horizontal surfaces, whereas under white light, parasitism increased the use of black horizontal surfaces. In contrast, B. orientalis substrate use was unaffected by parasitism, although infected animals were less active than uninfected conspecifics under both light regimes. For both species, parasitism did not change the percentage of time spent in light, the freeze time, or the directional response to light.

Moniliformis moniliformis infection has no effect on some behaviors of the cockroach Diploptera punctata.

The behavior of the cockroach Diploptera punctata parasitized with the acanthocephalan Moniliformis moniliformis was examined for parasite-induced alterations. No significant difference in behavior was found between parasitized and unparasitized animals in the following behavioral tests: (1) choice of white/black, horizontal/vertical substrate under light and dark conditions; (2) temporal and directional response to a bright light source; (3) choice between light and dark (photophilia); and (4) activity (time spent moving, distance, and velocity). A comparison of uninfected animals under 2 light conditions showed that light affected the activity of uninfected animals and their response to substrate. Diploptera punctata is the first nondomestic cockroach to be examined for behavioral responses to Moniliformis infection. This is the first report of an arthropod in which acanthocephalan infection has failed to alter behavior under at least some common test conditions.

A comparison of behavioral alterations in the brown cockroach, Periplaneta brunnea, and the American cockroach, Periplaneta americana, infected with the acanthocephalan, Moniliformis moniliformis.

We examined behavioral alterations in the brown cockroach, Periplaneta brunnea, infected with the acanthocephalan, Moniliformis moniliformis. The responses of infected and uninfected P. brunnea to light, substrate choice, and activity were compared. Infected brown cockroaches spent more time on white horizontal substrates under red and white light. Infected brown cockroaches also had a shorter freeze time than uninfected cockroaches after being presented with a light source. There was no difference in photophilia or activity of infected and uninfected brown cockroaches. These behavioral alterations in brown cockroaches were compared to those in Periplaneta americana, the American cockroach, infected with the same parasite. American and brown cockroaches differed in some responses to substrate, phototaxis, and activity.

Localization of phenoloxidase in the midgut of Periplaneta americana parasitized by larvae of Moniliformis moniliformis (Acanthocephala).

In cockroaches infected with Moniliformis moniliformis, the melanogenic enzyme phenoloxidase (PO) was histochemically localized in the posterior midgut and in haemocytes. Midguts were incubated with either 3-hydroxytyramine-HCl (dopamine) or 3-(3,4-dihydroxyphenyl)-L-alanine (dopa), and the resulting electron-dense reaction products of PO activity were found to be homogeneously distributed in the cytoplasm of both midgut cells and haemocytes. Following experimental infection, the first acanthors that reached the outer surface of the gut elicited a haemocyte response similar to that observed during wound healing. Larvae that remained attached to the gut became melanized or developed successfully. PO activity gradually decreased as the course of infection proceeded (10-50 days post-infection) but was apparently not inhibited in either midgut cells or haemocytes that were closely associated with the parasites. PO was lacking in the midgut cells of uninfected cockroaches. The results of the present study are discussed with respect to the defence reactions of the host and the survival mechanisms of the parasite.

The possible influence of male worm age on the fecundity of Moniliformis moniliformis (Acanthocephala) in laboratory rats.

During the course of a primary infection of Moniliformis moniliformis in rats, involving an experimentally structured population of worms derived from infective doses of 10 male and 10 female cystacanths per rat, the fecundity of the female worms appeared to be influenced by the age of the males. The experimental design ensured that all the female worms were 35 days old when fecundity was assessed. On average, the number of eggs in females recovered from rats containing 28-day-old males was 20,930 +/- 2,143, that from rats containing 35-day-old males was 7,434 +/- 937, and that from 42-day-old males was 14,396 +/- 1,704; these values were found to be significantly different (least significant difference, P less than or equal to 0.01). The results suggest that the variable age of the worms would be likely to favor fecundity in naturally occurring infections.

A simple method for the oral transfer of Moniliformis moniliformis (Acanthocephala) between rats.

A technique is described whereby young adult Moniliformis moniliformis, aged up to 7 days, can be transferred via the oral route from one rat to another. The method is dependent on giving the recipient rats a dose of Cimetidine (0.25 ml/250 g body weight of a solution containing 950 mg/ml) 1 h before transfer. Cimetidine functions as an H2-receptor antagonist and gastric acid secretion in the rat is inhibited temporarily. The technique does not appear to interfere with the reproductive biology of the parasite.

Survival of shelled acanthors of Moniliformis moniliformis (Acanthocephala) under laboratory conditions.

Shelled acanthors (= eggs) of two isolates of Moniliformis moniliformis (Acanthocephala) were tested for their capacity to respond to a hatching stimulus in vitro and for their retention of infectivity to a natural intermediate host (Periplaneta americana). The shelled acanthors were stored for more than 120 weeks (Australian isolate) and for 104 weeks (Texan isolate) together with rat faeces in an incubator maintained at 22.2 +/- 0.1 degrees C. In both cases, infectivity to P. americana was shown to have been retained. In vitro tests of the hatching response were carried out on many occasions during this period of faecal storage. Shelled acanthors continued to respond and no differences were detected either between isolates or within an isolate through time.

Effects of cholinergic drugs on muscle contraction in Moniliformis moniliformis (Acanthocephala).

In whole Moniliformis moniliformis spontaneous muscle contractions were rhythmic; longitudinal contractions were measured with a force transducer. The cholinergic agonists levamisole and nicotine significantly increased muscle tension in whole worms; these contractions were tonic and were antagonised by the ganglionic blocker pentolinium and by piperazine. In addition, levamisole-induced contractions were inhibited by gallamine, hexamethonium, and norepinephrine. In worm segments, where drugs in solution were injected through the worms, acetylcholine (ACh) and nicotinic agonists were effective in causing contractions, whereas muscarinic agonists in concentrations up to 1 mM had no effect. Although muscle contraction in M. moniliformis was induced by nicotinic agonists, these contractions were effectively antagonised by a range of chemicals that block ganglionic, skeletal, and muscarinic sites in vertebrates. The presence of ACh in M. moniliformis and the effects of nicotinic agonists on muscle contraction suggest that ACh is a putative excitatory neurotransmitter.

Inequalities in the individual reproductive success of parasites.

Two simple methods of measuring the levels of inequality in reproductive success of different individuals in parasite populations are presented. These techniques are then applied to a number of sets of data for cestodes and acanthocephalans. The analysis suggests that both population density and host nutrition are important in determining the observed degree of inequality in reproductive success and body size. Cestodes, with a more flexible growth form, are shown to exhibit higher levels of inequality than acanthocephalans. The discussion outlines the evolutionary importance of considering variation in the reproductive success of different individuals.

Investigating over-dispersion; Moniliformis (Acanthocephala) and rats.

An analysis of the frequency distribution of numbers of Moniliformis dubius in rats of an outbred strain of Wistar origin (CFHB) and feeding ad libitum on Oxoid 41B diet, showed that over-dispersion occurred regardless of the age and sex of the rats and the infective dose given (12, 20 or 40 cystacanths/rat). Over-dispersion was also shown to be independent of variability in the age and sex of the cystacanths given. The analysis demonstrated that the over-dispersion declined as the course of the infection proceeded. As expected, parasite survival was found to be age-dependent with female worms living longer, on average, than males, and both male and female worms living longer in rats given 12 as opposed to 20 cystacanths. Possible mechanisms for generating the over-dispersion observed during this work are discussed and a tentative hypothesis, invoking host heterogeneity with regard to carbohydrate availability in the small intestine, is proposed for further experimental investigation.

Parasite population biology and host nutrition: dietary fructose and Moniliformis (Acanthocephala).

Experiments were carried out to investigate the possible influence of host-dietary fructose concentration on the relationship between worm burden and the fecundity of Moniliformis dubius. Worm length was found to be dependent both on the fructose concentration of the host's diet and on worm burden. The number of free ovaries/female worm was found to increase linearly with increasing dietary fructose concentration but was independent of worm burden. The length of the ovaries increased with increasing dietary fructose concentration and decreased in response to increases in worm density. The magnitude of the density-dependent reduction in the volume of ovarian tissue/female was decreased in worms from rats fed on diets containing low concentrations of fructose. The numbers of eggs present in the body cavities of the female worms was found to be positively correlated with dietary fructose concentration. At 5 weeks post-infection, mature eggs (containing fully developed acanthor larvae) were found in the body cavities of female worms from rats whose diets contained 3 and 12% fructose, but not in those from rats whose diets contained 1 and 2% fructose (w/w). The experimental results are discussed in the wider context of the influence of host nutrition on parasite population biology.

Mucosal lesions in the rat associated with the attachment of Moniliformis (Acanthocephala).

By means of scanning electron microscopy, aspects of the attachment of Moniliformis dubius (Acanthocephala) to the intestinal wall of the rat are described together with various changes in the structure and form of the mucosa. Attachment of the parasite results in the formation of a distinct pit around the everted proboscis and a crater around the neck. Contact between the anterior region of the trunk of the worm and the intestine of the host appears to lead to villous fusion so that characteristic grooves are formed in the mucosal tissue. Evidence was also obtained to suggest that host goblet cells may become exhausted during the course of an infection with Moniliformis.

Observations on the development of the ovarian balls of Moniliformis (Acanthocephala).

Observations have been made on the ultrastructure of objects identified as ovarian balls from female Moniliformis after 1, 3, 5, 7 and 9 days in the rat. Similar objects are present in the body cavity of female cystacanths from cockroaches. The ovarian balls from 1-day-old worms are formed of several cells which are enclosed within a surface coat. During development, the ovarian balls increase in size and cell number and the interval organization appears to become more complex. After 9 days of development in the rat, the surface coat of the ovarian balls can no longer be observed and microvilli are present. It also appears that the supporting syncytium has been formed by this time.

[Contribution to the knowledge of the biology of Moniliformis moniliformis Bremser, 1811 (Acanthocephala). Influence of host resistance of Rattus norvegicus Berkenhout, 1769, on the parasite (author's transl)]. / Contribution a la connaissance de la biologie de Moniliformis moniliformis Bremser, 1811 (Acanthocephala). Influence de la résistance de l'hôte, Rattus norvegicus Berkenhout, 1769, sur le parasite.

Acquired resistance in rats (SIV 50) during infection with 30 Moniliformis moniliformis has an effect on survival, growth and behaviour of the parasite. We observe an expulsion of worms during infection, starting in the 4th week for female worms but usually after 8 weeks for the males. The density of parasites determines the beginning of the self-cure. Comparing our results with the works of Andreassen (1974a) and Burlingame et Chandler (1941), we observe that the self-cure occurs earlier with doses of 100 larvae than with 30 or 20. Rats with a primary infection show immunity against reinfection. Two weeks after reinfection we observe that only 26% of the parasites are fixed compared to 66% in primary infections. A major effect of immunity is retardation of worm growth. Parasites from reinfections are shorter than those of primary infections. During infection the worm migrate. After the first 3 weeks the male migrate posteriorly and female anteriorly and posteriorly. In reinfections parasites become localized after only 2 weeks. We hypothize that M. moniliformis migrates due to an immunological reaction and inflammatory response of the intestinal mucus but also as a part of its own normal development.