Predisposition of mice to Heligmosomoides polygyrus and Aspiculuris tetraptera (Nematoda)

Parasitology ◽  
1988 ◽  
Vol 97 (1) ◽  
pp. 101-114 ◽  
Author(s):  
Marilyn E. Scott
Keyword(s):  
Count Data ◽  
Egg Production ◽  
Intensity Of Infection ◽  
Heligmosomoides Polygyrus ◽  
Mouse Population ◽  
Pyrantel Pamoate ◽  
Population Prevalence ◽  
Positive Correlations ◽  
Aspiculuris Tetraptera ◽  
Old Mice

SUMMARYThe purpose of this study was to determine whether predisposition to Heligmosomoides polygyrus and Aspiculuris tetraptera (Nematoda) exists within a naturally infected population of mice. A breeding mouse population was housed in a spacious arena in which endemic infections of H. polygyrus and A. tetraptera were present. H. polygyrus were over-dispersed in the mouse population. Prevalence reached 100% by the age of 3 weeks; intensity of infection increased to a peak in the 10 to 15-week-old mice, and remained high throughout life. A group of 73 mice was treated with pyrantel pamoate, and the expelled worms were counted. Mice were returned to the arena. Daily egg production was monitored 4, 8, 12 and 14 weeks after treatment. Mice were then killed and numbers of H. polygyrus and A. tetraptera were counted. Significant positive correlations were detected between numbers of H. polygyrus at first treatment and at necropsy, indicating the existence of predisposition. Similar results were obtained for A. tetraptera. Correlations improved when data were analysed by age class of mice. Analyses based on egg-count data during reinfection did not support the hypothesis of predisposition, however. A. tetraptera and H. polygyrus burdens were significantly correlated only in 3 to 4-week-old mice at the time of the treatment.

Epidemiology of Heligmosomoides polygyrus in mice: experiments on natural transmission

Parasitology ◽  
1986 ◽  
Vol 93 (1) ◽  
pp. 177-187 ◽  
Author(s):  
A. F. G. Slater ◽  
A. E. Keymer
Keyword(s):  
Community Dynamics ◽  
Laboratory Mouse ◽  
High Protein Diet ◽  
Experimental System ◽  
Protein Diet ◽  
Acquired Immunity ◽  
Intensity Of Infection ◽  
Heligmosomoides Polygyrus ◽  
Mouse Population ◽  
Frequency Distributions

SUMMARYAn experimental system is described for the study of the community dynamics of helminth–host populations, using Heligmosomoides polygyrus in the laboratory mouse. The results of a preliminary experiment using closed populations of 50 mice revealed that coexistence of host and parasite occurs for at least 4 months in the absence of immigration, with the generation of epidemiological patterns similar to those observed in the real world. In well-nourished mice the prevalence and intensity of infection initially increased with time and then declined, probably as a result of acquired immunity. The prevalence and intensity of infection increased less rapidly among hosts fed on a low protein diet, but continued to rise over the entire duration of the experiment. This continued rise is interpreted as evidence of a negative effect of protein malnutrition on host immunocompetence. The frequency distributions of parasite numbers/host were over-dispersed in each mouse population. No density dependence in parasite fecundity was detected. Aspiculuris tetraptera was also found to be present in the mouse populations. This parasite was not transmitted between mice fed on a high protein diet, but rose to a prevalence of 80 % in protein malnourished animals. No association between the intensity of A. tetraptera and H. polygyrus could be detected in individual hosts. The results are discussed in terms of the future potential of the system for the investigation of the role of acquired immunity (and its genetic control) in the generation of epidemiological patterns.

The regulation ofOstertagia ostertagipopulations in calves: density-dependent control of fecundity

Parasitology ◽  
1987 ◽  
Vol 95 (2) ◽  
pp. 373-388 ◽  
Author(s):  
G. Smith ◽  
B. T. Grenfell ◽  
R. M. Anderson
Keyword(s):  
Worm Burden ◽  
Egg Production ◽  
Inverse Function ◽  
Single Infection ◽  
Intensity Of Infection ◽  
Density Dependent ◽  
Helminth Infections ◽  
Model Predictions ◽  
Initial Peak ◽  
Infection Experiments

SUMMARYThe decline in faecal egg counts, characteristic of calves which have been experimentally infected withOstertagia ostertagi, is analysed using a mathematical model in which parasite fecundity is assumed to be an inverse function of both the duration and intensity of infection. The model incorporates a description of the frequency distribution of mature parasites between hosts (which is less over-dispersed than is usual for many other helminth infections). The model provides a good overall description of the decline in faecal egg production observed during trickle and single infection experiments. The main discrepancy between a comparison of the model predictions and the results of the most detailed available series of trickle infection experiments occurs at the initial peak of egg production. The magnitude of this difference appears to be related to the worm burden at the peak of egg production. The possible mechanisms underlying density-dependent regulation of the fecundity ofO. ostertagiaare discussed.

scholarly journals Dynamics of Salmonella Shedding and Welfare of Hens in Free-Range Egg Production Systems

2016 ◽  
Vol 83 (5) ◽  
Author(s):  
Vaibhav C. Gole ◽  
Rebecca Woodhouse ◽  
Charles Caraguel ◽  
Talia Moyle ◽  
Jean-Loup Rault ◽  
...  
Keyword(s):  
Production System ◽  
Salmonella Enterica ◽  
Egg Production ◽  
Production Systems ◽  
Most Probable Number ◽  
Probable Number ◽  
Content Type ◽  
Free Range ◽  
Phage Types ◽  
Positive Correlations

ABSTRACT The current study investigated the effect of environmental stressors (i.e., weather changes) on Salmonella shedding in free-range production systems and the correlations with behavioral and physiological measures (i.e., fecal glucocorticoid metabolites). This involved longitudinal and point-in-time surveys of Salmonella shedding and environmental contamination on four commercial free-range layer farms. The shedding of Salmonella was variable across free-range farms and in different seasons. There was no significant effect of season on the Salmonella prevalence during this investigation. In this study, the combined Salmonella most probable number (MPN) counts in environmental (including feces, egg belt, dust, nest box, and ramp) samples were highest in samples collected during the summer season (4th sampling, performed in February). The predominant serovars isolated during this study were Salmonella enterica serovar Mbandaka and Salmonella enterica serovar Typhimurium phage types 135 and 135a. These two phage types were involved in several egg product-related Salmonella outbreaks in humans. Multilocus variable-number tandem-repeat analysis (MLVA) results indicated that MLVA types detected from human food poisoning cases exhibited MLVA patterns similar to the strains isolated during this study. All Salmonella isolates (n = 209) were tested for 15 different genes involved in adhesion, invasion, and survival of Salmonella spp. We also observed variations for sopA, ironA, and misL. There were no positive correlations between fecal corticosterone metabolite (FCM) and Salmonella prevalence and/or shedding in feces. Also, there were no positive correlations between Salmonella prevalence and Salmonella count (log MPN) and any of the other welfare parameters. IMPORTANCE In this study, the welfare of laying hens and Salmonella shedding were compared over a prolonged period of time in field conditions. This study investigated the long-term shedding of Salmonella serovars in a free-range egg production system. Given that there is increasing demand for free-range eggs, it is essential to understand the risks associated with such a production system.

Opisthorchis viverrini: relationships between egg counts, worms recovered and antibody levels within an endemic community in Northeast Thailand

Parasitology ◽  
1991 ◽  
Vol 102 (2) ◽  
pp. 283-288 ◽  
Author(s):  
D. B. Elkins ◽  
P. Sithithaworn ◽  
M. Haswell-Elkins ◽  
S. Kaewkes ◽  
P. Awacharagan ◽  
...  
Keyword(s):  
Relative Intensity ◽  
Worm Burden ◽  
Egg Production ◽  
Epidemiological Studies ◽  
Opisthorchis Viverrini ◽  
Northeast Thailand ◽  
Intensity Of Infection ◽  
Antibody Levels ◽  
Serum Igg Levels ◽  
Total Worm Burden

SUMMARYThree techniques for estimating the intensity of Opisthorchis viverrini infection in individuals from a Northeast That community are compared. Egg counts were determined using a quantitative formalin/ethyl acetate technique, worm burdens were estimated by expulsion chemotherapy and antibody levels were measured by ELISA. Log-transformed worm and egg counts were closely correlated (r = 0·80), suggesting that both measurements provide good assessments of relative intensity of infection. However, no Opisthorchis worms were recovered from 34 people with high egg counts; probably due to problems with the expulsion technique in some individuals. Examination of egg production per fluke indicated that each fluke contributed an average of 180 eggs per gram (epg) of faeces and fecundity was negatively associated with total worm burden. Serum IgG levels correlated significantly with Opisthorchis egg count (r = 0·61) at two independent assessments. Although significant associations were observed between antibody levels and echinostome infection, analysis suggested that these reflected independent associations between these two variables and Opisthorchis infection and age. We conclude that all three measurements are useful for epidemiological studies.

Plasmodium yoelii nigeriensis: the effect of high and low intensity of infection upon the egg production and bloodmeal size of Anopheles stephensi during three gonotrophic cycles

Parasitology ◽  
1995 ◽  
Vol 111 (5) ◽  
pp. 555-562 ◽  
Author(s):  
J. C. Hogg ◽  
H. Hurd
Keyword(s):  
Egg Production ◽  
Anopheles Stephensi ◽  
Plasmodium Yoelii ◽  
Infected Mosquito ◽  
Intensity Of Infection ◽  
Related Factors ◽  
Low Intensity ◽  
Mosquito Mortality ◽  
Fecundity Reduction

SUMMARYAnopheles stephensi mosquitoes showed a reduction in fecundity over 3 successive gonotrophic cycles, after becoming infected with Plasmodium yoelii nigeriensis. This effect could be observed at high oocyst burdens (> 75) or at low oocyst burdens (mean of 4·36). Mean bloodmeal size of the infected mosquitoes was significantly reduced only when feeding upon a mouse with a high gametocytaemia and the conversion of the bloodmeal into eggs by the infected mosquitoes was disrupted. Patterns of infected mosquito mortality, over the 3 gonotrophic cycles, varied with severity of infection. Although in 1 case increased mortality and decreased bloodmeal size may have affected fecundity, this could not have accounted for all of the observed fecundity reduction. We propose that other, unknown parasite related factors, are involved.

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.

Daily egg production of Ascaris lumbricoides: the distribution of eggs in the faeces and the variability of egg counts

Parasitology ◽  
1982 ◽  
Vol 84 (1) ◽  
pp. 167-175 ◽  
Author(s):  
B. Sinniah
Keyword(s):  
Stool Sample ◽  
Ascaris Lumbricoides ◽  
Egg Production ◽  
Female Worm ◽  
The Other ◽  
Egg Load ◽  
Intensity Of Infection ◽  
Direct Smear ◽  
Daily Average ◽  
Thick Smear

SUMMARYFifteen children aged from 6 to 12 years who were infected with Ascaris lumbricoides were selected for the study. The number of eggs/g (e.p.g.) of stool was determined using Beaver's direct smear technique, Stoll's dilution egg count technique and Katz's modified thick smear technique. Beaver's direct smear method consistently gave a higher e.p.g. than the other two methods. Results of this study show that Katz's modified thick smear technique was the best of the three methods used. The e.p.g. depends on several factors: the amount of stool passed daily, the concentration of eggs within a stool sample, the daily egg output, the worm load, the age of the worm and the technique used for determining the egg load. The daily average egg output/female A. lumbricoides was estimated to be 238722 (range 134462–358 750) with an average e.p.g. of 3540. The estimation of worm load based on egg count is useful in determining the intensity of infection in an individual. The male/female worm ratio was estimated to be 1: 1·4.

scholarly journals Estimated egg production of Fasciola gigantica (Japanese strain) in goats experimentally infected with 50 metacercariae

2010 ◽  
Vol 47 (4) ◽  
pp. 199-203 ◽  
Author(s):  
K. Taira ◽  
Y. Saitoh
Keyword(s):  
Single Dose ◽  
Experimental Infection ◽  
Count Data ◽  
Egg Production ◽  
Production Capacity ◽  
Fasciola Gigantica ◽  
Confidence Limits ◽  
Japanese Strain ◽  
The Mean

AbstractEgg production capacity in Fasciola gigantica (Japanese strain) was estimated from egg count data obtained by the experimental infection of two goats. The goats were inoculated with a single dose of 50 metacercariae. The first goat was necropsied 132 days after infection (DAI) and the second goat 732 DAI. After patency, daily faecal production was collected and weighed and number of eggs per gram was counted. At necropsy, 23 flukes were recovered from the liver of the first goat, and five from the second goat. The mean number of eggs produced per day per worm (± 95 % confidence limits) was 9 477.9 (± 764.92) for the first goat at 106 to 132 DAI, and 8,064.1 (± 416.49) at 195 to 561 DAI for the second goat. The number of eggs produced per day per worm in F. gigantica (Japanese strain) has thus reached values ranged from approximately 8 000 to 10 000 eggs.

scholarly journals Helminth fauna of Mus musculus Linnaeus, 1758 from the suburban area of Belgrade, Serbia

2008 ◽  
Vol 60 (4) ◽  
pp. 609-617 ◽  
Author(s):  
D.S. Kataranovski ◽  
Olivera Vukicevic-Radic ◽  
Milena Kataranovski ◽  
Dusica Radovic ◽  
Ivana Mirkov
Keyword(s):  
Mus Musculus ◽  
Infection Intensity ◽  
Nematode Species ◽  
Helminth Fauna ◽  
Suburban Area ◽  
Trichuris Muris ◽  
Heligmosomoides Polygyrus ◽  
Syphacia Obvelata ◽  
Aspiculuris Tetraptera ◽  
Taenia Taeniaeformis

The helminth fauna of the house mouse (Mus musculus Linnaeus, 1758) was studied on the basis of 429 host individuals from the suburban area of Belgrade. Eleven helminth species were recorded: three cestode species - Catenotaenia pusilla, Rodentolepis fraterna, and Cysticercus (= Strobilocercus) fasciolaris [larval stage of Taenia taeniaeformis (Batsch, 1821)]; and eight nematode species - Heligmosomoides polygyrus, Syphacia sp., Aspiculuris tetraptera, Syphacia obvelata, Heterakis spumosa, Trichuris muris, Mastophorus muris, and Gongylonema sp. Within the general helminth fauna, H. polygyrus was found to be the most prevalent species (39.2%) and caused the highest infection intensity. Prevalences of A. tetraptera, C. pusilla, and S. obvelata ranged from 12.8% to 6.1%, while the remaining species showed prevalences ranging from 4.9% (for Syphacia sp.) to 0.2% (for Gongylonema sp.). All the species found in males were also present in females, with the exceptions of M. muris and Gongylonema sp. No significant differences were found between males and females regarding prevalence (P%), mean infection intensity (MI), or mean abundance (MA).

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