scholarly journals Helminth species richness in wild wood mice,Apodemus sylvaticus, is enhanced by the presence of the intestinal nematodeHeligmosomoides polygyrus

Parasitology ◽  
2009 ◽  
Vol 136 (7) ◽  
pp. 793-804 ◽  
Author(s):  
J. M. BEHNKE ◽  
C. EIRA ◽  
M. ROGAN ◽  
F. S. GILBERT ◽  
J. TORRES ◽  
...  
Keyword(s):  
Species Richness ◽  
A Priori ◽  
Apodemus Sylvaticus ◽  
Helminth Species ◽  
Intestinal Helminth ◽  
Heligmosomoides Polygyrus ◽  
Wood Mice ◽  
Intestinal Nematode ◽  
Firm Evidence

SUMMARYWe analysed 3 independently collected datasets of fully censused helminth burdens in wood mice,Apodemus sylvaticus, testing thea priorihypothesis of Behnkeet al.(2005) that the presence of the intestinal nematodeHeligmosomoides polygyruspredisposes wood mice to carrying other species of helminths. In Portugal, mice carryingH. polygyrusshowed a higher prevalence of other helminths but the magnitude of the effect was seasonal. In Egham, mice withH. polygyrusshowed a higher prevalence of other helminth species, not confounded by other factors. In Malham Tarn, mice carryingH. polygyruswere more likely to be infected with other species, but only among older mice. Allowing for other factors, heavy residualH. polygyrusinfections carried more species of other helminths in both the Portugal and Egham data; species richness in Malham was too low to conduct a similar analysis, but asH. polygyrusworm burdens increased, so the prevalence of other helminths also increased. Our results support those of Behnkeet al.(2005), providing firm evidence that at the level of species richness a highly predictable element of co-infections in wood mice has now been defined: infection withH. polygyrushas detectable consequences for the susceptibility of wood mice to other intestinal helminth species.

scholarly journals Structure in parasite component communities in wild rodents: predictability, stability, associations and interactions .... or pure randomness?

Parasitology ◽  
2008 ◽  
Vol 135 (7) ◽  
pp. 751-766 ◽  
Author(s):  
J. M. BEHNKE
Keyword(s):  
Species Richness ◽  
Published Data ◽  
Data Sets ◽  
Wild Rodents ◽  
Heligmosomoides Polygyrus ◽  
Wood Mice ◽  
Core Species ◽  
Helminth Communities ◽  
Immune Mediated ◽  
Concurrent Infections

SUMMARYExperimental data establish that interactions exist between species of intestinal helminths during concurrent infections in rodents, the strongest effects being mediated through the host's immune responses. Detecting immune-mediated relationships in wild rodent populations has been fraught with problems and published data do not support a major role for interactions in structuring helminth communities. Helminths in wild rodents show predictable patterns of seasonal, host age-dependent and spatial variation in species richness and in abundance of core species. When these are controlled for, patterns of co-infection compatible with synergistic interactions can be demonstrated. At least one of these, the positive relationship betweenHeligmosomoides polygyrusand species richness of other helminths has been demonstrated in three totally independent data-sets. Collectively, they explain only a small percentage of the variance/deviance in abundance data and at this level are unlikely to play a major role in structuring helminth communities, although they may be important in the more heavily infected wood mice. Current worm burdens underestimate the possibility that earlier interactions through the immune system have taken place, and therefore interactions may have a greater role to play than is immediately evident from current worm burdens. Longitudinal studies are proposed to resolve this issue.

Ecological aspects influencing the helminth community of the wood mouse Apodemus sylvaticus in Dunas de Mira, Portugal

2006 ◽  
Vol 51 (4) ◽  
Author(s):  
Catarina Eira ◽  
Jordi Torres ◽  
José Vingada ◽  
Jordi Miquel
Keyword(s):  
Species Richness ◽  
Sand Dune ◽  
Sand Dunes ◽  
Wood Mouse ◽  
Apodemus Sylvaticus ◽  
Habitat Characteristics ◽  
Helminth Community ◽  
Heligmosomoides Polygyrus ◽  
Ecological Aspects ◽  
Host Sex

AbstractThis paper presents the first extensive data on the helminth community of the wood mouse Apodemus sylvaticus in a coastal sand dune area in Portugal. The 557 hosts analysed in this study were trapped seasonally between autumn 2002 and summer 2005 across 6 habitat types. Twelve helminth species were detected among which, Taenia parva larvae, Angiostrongylus dujardini, Heligmosomoides polygyrus, Syphacia stroma and S. frederici constitute the component species, accounting for 98.7% of all worms. H. polygyrus was the most prevalent helminth parasite. Species richness varied according to habitat and season. The highest species richness was found in sand dunes during winter whereas the lowest was detected along lake margins also during the winter. Some differences in prevalence and mean intensity values were found in relation to year (T. parva larvae and H. polygyrus), habitat (A. dujardini), season (T. parva larvae, H. polygyrus, A. dujardini and S. stroma) and host sex (T. parva larvae and S. stroma). These differences are discussed both in view of the host’s biology and habitat characteristics.

Sexual transmission of a nematode parasite of Wood Mice (Apodemus sylvaticus)?

Parasitology ◽  
2004 ◽  
Vol 128 (5) ◽  
pp. 561-568 ◽  
Author(s):  
J. R. CLARKE ◽  
T. J. C. ANDERSON ◽  
C. BANDI
Keyword(s):  
18S Rdna ◽  
Reproductive Tract ◽  
Sexual Transmission ◽  
Molecular Data ◽  
Apodemus Sylvaticus ◽  
Nematode Parasite ◽  
Sequence Comparisons ◽  
Heligmosomoides Polygyrus ◽  
Sexually Transmitted ◽  
Wood Mice

Sexual transmission occurs commonly in microparasites such as viruses and bacteria, but this is an unusual transmission route for macroparasites. Here we present evidence which suggests that a nematode parasite of Wood Mice (Apodemus sylvaticus) may be sexually transmitted and we have classified the nematode using molecular data. Wood Mice were collected annually in the course of work on their reproductive physiology. Larval nematodes were found in the epididymides of 19·6% of males. It seems likely that they would be transmitted to females at ejaculation. To identify these larval nematodes, which we were unable to do using morphological features, we sequenced the 18S rDNA. Sequence comparisons with the molecular phylogeny of Blaxteret al. (1998) demonstrated that they were bursate nematodes (Order Strongylida). The relationships between strongylid taxa were poorly resolved by 18S rDNA. However, both distance and parsimony analyses grouped the nematode with the superfamily Metastrongylidea in a clade containingFilaroidesandAngiostrongylussp. Importantly, the sequences were distinct from those ofHeligmosomoides polygyrusandAngiostrongylus dujardini, two common strongylid nematodes ofApodemus. We were therefore unable positively to identify these worms by matching their sequences with those from morphologically identifiable adult strongylid nematodes infectingApodemus. These results demonstrate that an as yet unidentified strongylid is quite commonly found in large numbers in the male reproductive tract of Wood Mice. Further work is required to understand the biology and transmission dynamics of this interesting system.

scholarly journals The helminth infracommunities of the wood mouse (Apodemus sylvaticus) two years after the fire in Mediterranean forests

2013 ◽  
Vol 50 (1) ◽  
pp. 27-38 ◽  
Author(s):  
I. Torre ◽  
A. Arrizabalaga ◽  
C. Feliu ◽  
A. Ribas
Keyword(s):  
Species Richness ◽  
Life Cycle ◽  
Wood Mouse ◽  
Final Host ◽  
Life Cycles ◽  
Helminth Species ◽  
Mediterranean Forests ◽  
Intermediate Hosts ◽  
Wood Mice ◽  
Short Period

AbstractParasites have been recognized as indicators for natural or man-induced environmental stress and perturbation. In this article, we investigated the role of two non-exclusive hypotheses on the response of helminths of wood mice to fire perturbation: 1) a reduction of the helminth infracommunity (species richness) in post-fire areas due to the temporal lack of worms with indirect (complex) life cycles linked to intermediate hosts that are more specialized than the final host, and 2) an increase of the abundance of helminths with direct (simple) life cycles as a response of increasing abundances of the final host, may be in stressful conditions linked to the post-fire recolonization process.We studied the helminth infracommunities of 97 wood mice in two recently burned plots (two years after the fire) and two control plots in Mediterranean forests of NE Spain. Species richness of helminths found in control plots (n = 14) was twice large than in burned ones (n = 7). Six helminth species were negatively affected by fire perturbation and were mainly or only found in unburned plots. Fire increased the homogeneity of helminth infracommunities, and burned plots were characterised by higher dominance, and higher parasitation intensity. We found a gradient of frequency of occurrence of helminth species according to life cycle complexity in burned areas, being more frequent monoxenous (66.6 %), than diheteroxenous (33.3 %) and triheteroxenous (0 %), confirming the utility of helminths as bioindicators for ecosystem perturbations. Despite the short period studied, our results pointed out an increase in the abundance and prevalence of some direct life cycle helminths in early postfire stages, whereas indirect life cycle helminths were almost absent. A mismatch between the final host (that showed a fast recovery shortly after the fire), and the intermediate hosts (that showed slow recoveries shortly after the fire), was responsible for the loss of half of the helminth species.

Rhythmicity of egg production by Heligmosomoides polygyrus in wild wood mice, Apodemus sylvaticus

1994 ◽  
Vol 68 (2) ◽  
pp. 105-108 ◽  
Author(s):  
E.D. Brown ◽  
D.W. Macdonald ◽  
T.E. Tew ◽  
I.A. Todd
Keyword(s):  
Egg Production ◽  
Apodemus Sylvaticus ◽  
Heligmosomoides Polygyrus ◽  
Wood Mice ◽  
Faecal Weight

AbstractThe rhythmicity of egg production by Heligmosomoides polygyrus (Nematoda) in wild caught wood mice (Apodemus sylvaticus) was studied. Faecal production followed a 24 h cycle, with peaks at 0400 h and troughs at 1300–1900 h. The patterns in eggs per gram of faeces (EPG) and total eggs were similar to each other, though the former was more accentuated. Both of these followed a 24 h cycle, with peaks coinciding with troughs in faecal production and vice versa. Faecal weight was inversely correlated with EPG, but was not significantly correlated with total eggs. The pattern in EPG presumably reflected the effect of faecal production on the total eggs excreted in each 3 h period. The observed cycle in total eggs probably describes the pattern of egg production by the worm, although other factors, such as the host's intestinal rhythms, may contribute to this cycle.

Levels of helminth infection in the flat lizard Tropidurus semitaeniatus from north-eastern Brazil

2015 ◽  
Vol 90 (6) ◽  
pp. 779-783 ◽  
Author(s):  
C.H. Bezerra ◽  
R.W. Ávila ◽  
D.C. Passos ◽  
D. Zanchi-Silva ◽  
C.A.B. Galdino
Keyword(s):  
Body Size ◽  
Helminth Infection ◽  
Helminth Species ◽  
Intestinal Helminth ◽  
Helminth Parasites ◽  
Intestinal Nematode ◽  
Eastern Brazil ◽  
Host Sex ◽  
North Eastern ◽  
First Time

AbstractParasites represent a great, unknown component of animal biodiversity. Recent efforts have begun to uncover patterns of infection by helminth parasites in several Neotropical lizards. The present study reports, for the first time, levels of helminth infection in a population of the flat lizard Tropidurus semitaeniatus. One hundred and thirty-nine lizards were examined and evidence of five intestinal helminth species was found, comprising four species of nematodes, one species of cestode and an unidentified encysted larval nematode. The most frequently occurring species was the intestinal nematode Parapharyngodon alvarengai, which did not exhibit differences in prevalence and intensity of infection relative to host sex or age/body size. Furthermore, helminth species richness was not related to host body size.

The role of positive and negative interspecific associations in the organization of communities of intestinal helminths of bats

Parasitology ◽  
1991 ◽  
Vol 103 (1) ◽  
pp. 127-138 ◽  
Author(s):  
J. M. Lotz ◽  
W. F. Font
Keyword(s):  
Species Richness ◽  
Frequency Distribution ◽  
Host Population ◽  
Helminth Species ◽  
Positive Interactions ◽  
Intestinal Helminth ◽  
Number Of Species ◽  
Interspecific Associations ◽  
Species Pairs ◽  
The Mean

Twelve populations of bats were examined to determine the extent of interspecific associations in determining the species richness of intestinal helminth infracommunities. The pool of helminth species which was available to individual bats ranged from 2 to 21. The ‘summed binomial’ distribution was determined to underlie the host frequency distribution of the number of helminth species per host. Overall covariation in occurrences of species in replicated communities can be detected by testing for the equality of the observed variance of the host frequency distribution to the variance expected when species are allocated to hosts at random. Where statistically significant the covariance was indicative of a majority of positive rather than negative interspecific associations. As the mean number of species per host in a host population increases not only does the number of positive associations increase but so does the proportion of species pairs which exhibit positive associations. Although there is an increase in the proportion of species pairs which exhibit positive associations as the number of species increases, the magnitude of the associations (as indicated by the mean positive or the mean negative pairwise covariances) does not. Therefore, we concluded that positive interactions are more common than negative interactions in determining the species richness of helminth infracommunities of bats. Further, positive associations become even more important as the community becomes more complex. However, the increased importance is derived from the number rather than the strength of the associations.

scholarly journals Spatial interactions between two nematode species along the intestine of the wood mouse Apodemus sylvaticus from woodland and grassland sites in southern England

2021 ◽  
Vol 95 ◽  
Author(s):  
J.W. Lewis ◽  
N.J. Morley ◽  
J.M. Behnke
Keyword(s):  
Wood Mouse ◽  
Nematode Species ◽  
Apodemus Sylvaticus ◽  
Middle Section ◽  
Heligmosomoides Polygyrus ◽  
Wood Mice ◽  
Nematode Parasites ◽  
Study Sites ◽  
Dose Dependent ◽  
Species Being

Abstract The distributions of the nematode parasites Heligmosomoides polygyrus and Syphacia stroma were quantified in three equal-length sections along the intestine of wood mice (Apodemus sylvaticus) trapped in three different locations in the south of England. The distribution of H. polygyrus did not change in the presence of S. stroma, this species being largely confined to the anterior third of the intestine, whether S. stroma was or was not present. However, while in single infections with S. stroma, worms were equally distributed in the anterior and middle sections of the intestine, in the presence of H. polygyrus, a higher percentage of worms was located in the middle section. This was a dose-dependent response by S. stroma to increasing worm burdens with H. polygyrus, and even relatively low intensities of infection with H. polygyrus (e.g. ≤10 worms) were sufficient to cause a posterior redistribution of S. stroma into the middle section. A similar posterior shift in the percentage distribution of S. stroma in the intestine was evident in juvenile and mature mice of both sexes, and in mice from all three study sites. The ecological significance of these results is discussed.

scholarly journals Long-term trends in helminth infections of wood mice (Apodemus sylvaticus) from the vicinity of Malham Tarn in North Yorkshire, England

Parasitology ◽  
2020 ◽  
pp. 1-13
Author(s):  
Jerzy M. Behnke ◽  
Michael T. Rogan ◽  
Philip S. Craig ◽  
Joseph A. Jackson ◽  
Geoff Hide
Keyword(s):  
Species Richness ◽  
Wood Mouse ◽  
Heligmosomoides Polygyrus ◽  
Mouse Population ◽  
Wood Mice ◽  
Higher Taxa ◽  
Helminth Infections ◽  
Underlying Causes ◽  
Long Term Trends

Abstract Helminth infections in wood mice (n = 483), trapped over a period of 26 years in the woods surrounding Malham Tarn in North Yorkshire, were analysed. Although 10 species of helminths were identified, the overall mean species richness was 1.01 species/mouse indicating that the helminth community was relatively depauperate in this wood mouse population. The dominant species was Heligmosomoides polygyrus, the prevalence (64.6%) and abundance (10.4 worms/mouse) of which declined significantly over the study period. Because of the dominance of this species, analyses of higher taxa (combined helminths and combined nematodes) also revealed significantly declining values for prevalence, although not abundance. Helminth species richness (HSR) and Brillouin's index of diversity (BID) did not show covariance with year, neither did those remaining species whose overall prevalence exceeded 5% (Syphacia stroma, Aonchotheca murissylvatici and Plagiorchis muris). Significant age effects were detected for the prevalence and abundance of all higher taxa, H. polygyrus and P. muris, and for HSR and BID, reflecting the accumulation of helminths with increasing host age. Only two cases of sex bias were found; male bias in abundance of P. muris and combined Digenea. We discuss the significance of these results and hypothesize about the underlying causes.

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