Observations on the use of Trichostrongylus colubriformis (Nematoda) infections of guinea-pigs for laboratory experiments

Parasitology ◽  
1963 ◽  
Vol 53 (1-2) ◽  
pp. 189-199 ◽  
Author(s):  
R. F. Sturrock
Keyword(s):  
Multivariate Analysis ◽  
Guinea Pigs ◽  
Worm Burden ◽  
Laboratory Experiments ◽  
Statistical Treatment ◽  
Post Mortem ◽  
Infective Larvae ◽  
Final Weight ◽  
Cure Mechanism ◽  
Experimental Use

Four groups of guinea-pigs were infected with a range of doses of T. colubriformis. The infections were followed by egg counts and weight measurements, and the adult worms were recovered from the animals post mortem. A multivariate analysis, details of which are given in an appendix, showed that the sensitivity of the measures used was, in descending order, final weight, total egg count and worm burden. The course of the infection is discussed in view of the apparent self-cure mechanism. Precautions are outlined for the experimental use of this hostparasite relationship.The author is grateful to Professor B. G. Peters for his advice on this work, to Dr P. Silverman of Allen and Hanburys Limited for a supply of T. colubriformis infective larvae and to Dr R. E. Blackith for his advice on the statistical treatment of the data.

The effect of cortisone on the worm burdens of calves infected daily withOstertagia ostertagi

Parasitology ◽  
1969 ◽  
Vol 59 (3) ◽  
pp. 691-708 ◽  
Author(s):  
J. F. Michel ◽  
I. J. Sinclair
Keyword(s):  
Side Effects ◽  
Infection Rate ◽  
Host Resistance ◽  
Worm Burden ◽  
Limit Set ◽  
Post Mortem ◽  
Rapid Loss ◽  
Ostertagia Ostertagi ◽  
Infective Larvae ◽  
Normal Host

Of two groups of calves, one was regularly treated with the cortisone-derivative, β-methazone. This treatment greatly reduced the ability of the calves to produce antibody and gave rise to a number of side effects. Calves of both groups were given 1500 infective larvae ofOstertagia ostertagidaily. A milder régime of cortisone administrations using prednisolone was employed in a second experiment in which two comparisons were made. Worm burdens of calves infected with 1500 larvae daily and receiving cortisone were compared with those of control calves infected at the same rate and cortisone-treated calves receiving 1500 larvae per day were compared with cortisone-treated calves infected at twice this rate.By periodicpost-mortemexamination it was shown that even in cortisone-treated animals the worm burden was regulated at a level only slightly higher than in control calves, apparently by a density-dependant loss of worms. A more rapid loss of worms which occurred for a period in the control calves was prevented in cortisone-treated animals unless the infection rate was high.The limit set by the normal host to the total egg output of its worm population was raised by cortisone treatment, very greatly in the first experiment, rather less in the second in which the cortisone treatment was less severe. The effect of host resistance on the length of worms and on the incidence of females without vulval flaps was greatly reduced by cortisone. The inhibition of development was not affected.

Objective interpretation of dental disease in rabbits, guinea pigs and chinchillas

2009 ◽  
Vol 37 (04) ◽  
pp. 250-260 ◽  
Author(s):  
D. Crossley ◽  
E. Boehmer
Keyword(s):  
Guinea Pigs ◽  
Dental Disease ◽  
Post Mortem ◽  
Objective Interpretation ◽  
Skull Radiographs ◽  
Post Mortem Findings ◽  
Long Term Prognosis ◽  
Species Specific ◽  
Radiographic Changes

Summary Objective: Objective interpretation of dental disease in rabbits, guinea pigs and chinchillas with the use of anatomical reference lines. Material and methods: Skull radiographs (laterolateral and dorsoventral view) of 528 small mammals (204 rabbits, 151 guinea pigs and 173 chinchillas) were measured and analysed exactly in connection with a thorough intra- and extraoral clinical examination. 464 animals showed variable signs of malocclusion whereas 64 animals had a normocclusion. The clinical and radiographic changes of 224 individuals (52 rabbits, 41 guinea pigs and 131 chinchillas) were additionally compared with post mortem findings. Results: Particularly the comparison of the prepared skulls with the radiographs of the identical animals enabled the acquirement of species specific anatomical reference lines, that facilitate the objectice assessment of severity of dental disease in elodont species. Conclusion and clinical relevance: Using these reference lines the extent of malocclusion in rabbits, guinea pigs and chinchillas can be acquired more exactly and the results are reproducible by different examiners (staging). In addition to this these special lines facilitate to accurately monitor the progress of dental changes and thus to predict a probable long-term prognosis. The reference lines are absolutely applicable for daily use in practice.

Experimental infections withCooperia oncophora(Railliet, 1918) in calves. Results of single infections with two graded dose levels of larvae

Parasitology ◽  
1979 ◽  
Vol 78 (3) ◽  
pp. 331-342 ◽  
Author(s):  
F. H. M. Borgsteede ◽  
J. Hendriks
Keyword(s):  
Small Intestine ◽  
Weight Gain ◽  
Worm Burden ◽  
Great Part ◽  
Clinical Signs ◽  
Larval Stages ◽  
Infective Larvae ◽  
Cooperia Oncophora ◽  
Dose Levels ◽  
Haematological Data

SUMMARYTwo experiments were carried out in which calves reared parasite-free were infected with a single dose of 3rd-stage larvae ofCooperia oncophora. In the first experiment the calves received 20000 or 200000 infective larvae and they were autopsied 28 or 56 days after the infection. In the second experiment the doses were the same but the animals were killed 14, 84 or 140 days after infection. If a dose of 20000 was given, clinical signs were never observed, while at a dose level of 200000 the weight gain was less on 56 and 84 days after the infection compared with the low-infected groups or the control animals. After 140 days the differences in weight gain were compensated. Faecal egg output was higher in the 200000 groups only in the first period of patency, thereafter the calves in the 20000 groups produced more. No obvious differences between the two infection levels were observed with regard to the haematological data. In the low-infected groups worm counts were only slightly lower when the results after 28 days were compared with those after 56 days. Also, the worm numbers after 14 days were almost equal to those after 84 days, while at 140 days 1 animal still had the same number, the other one had lost its worm burden. In the high-infected groups the worm loss was much quicker. After 28 days a great part of the population had already been lost. Obviously, at the 200000 level the reaction of the host against the parasite was much stronger. Adult worms were expelled at a higher rate than early 4th-larval stages. In the first experiment worm measurements revealed differences between the length of females, males and spicules of males, these being significantly longer in the low-infected groups. Analysis of the distribution of worms over the small intestine showed that in the low-infected groups worms were mainly restricted to the first 6 metres. In the high-infected groups the worm population was distributed more evenly over the whole small intestine.

scholarly journals Serological evidence of rotavirus infection in guinea pig colony

1988 ◽  
Vol 83 (4) ◽  
pp. 411-413 ◽  
Author(s):  
L. de Castro ◽  
H. P. de Araújo ◽  
A. M. Fialho ◽  
V. S. Gouvea ◽  
H. G. Pereira
Keyword(s):  
Guinea Pig ◽  
Western Blot ◽  
Enzyme Immunoassay ◽  
Guinea Pigs ◽  
Serological Evidence ◽  
Western Blot Assay ◽  
Antibody Titres ◽  
Group A Rotaviruses ◽  
Group A ◽  
Experimental Use

Antibodies reacting with simian rotavirus SAII were detected by enzyme immunoassay (EIA) and Western blot assay (WBA) in sera from guinea pigs bred for experimental use at the Fundação Oswaldo Cruz, Rio de Janeiro, Brazil. The proportion of antibody-positive animals and the antibody titres rose sharply in 1985, were maintained at a high levels in 1986 and declined in 1987. There were no obvious signs of disease coinciding with serological evidence of infection. Results of WBA suggest that the virus involved belongs to subgroup 1 of group A rotaviruses.

Density-dependent regulation of the growth of the hookworms Necator americanus and Ancylostoma ceylanicum

Parasitology ◽  
1994 ◽  
Vol 109 (1) ◽  
pp. 119-128 ◽  
Author(s):  
S. M. B. Norozian-Amiri ◽  
J. M. Behnke
Keyword(s):  
Worm Burden ◽  
Infection Intensity ◽  
Dry Weight ◽  
Ancylostoma Ceylanicum ◽  
Density Dependent ◽  
Necator Americanus ◽  
Infective Larvae ◽  
Length Width ◽  
Negative Relationships ◽  
Dependent Processes

SUMMARYLaboratory bred DSN hamsters were exposed to varying doses of infective larvae of Ancylostoma ceylanicum (orally) or Necator americanus (percutaneously) and were autopsied at times which corresponded to a period immediately before cessation of growth of worms or soon afterwards. A total of 829 (404 male and 425 female) A. ceylanicum and 1582 (781 male and 801 female) N. americanus were measured. At worm burdens of fewer than 100, the length of A. ceylanicum appeared to increase with infection intensity and no evidence was found that growth was retarded under crowded conditions. In an experiment comparing directly low (mean worm burden = 22) and heavy infections (mean worm burden = 180) significant negative associations between both weight and width, and worm burden were detected, but length again increased with worm burden. In contrast, 5 experiments with N. americanus indicated negative relationships between measures of worm size (length, width, wet and dry weight) and worm burden. It was concluded that N. americanus is subject to regulation by density-dependent processes within the host while A. ceylanicum is not sensitive to the same degree.

Distribution of Ascaris suum in experimentally and naturally infected pigs and comparison with Ascaris lumbricoides infections in humans

Parasitology ◽  
1998 ◽  
Vol 117 (6) ◽  
pp. 589-596 ◽  
Author(s):  
J. BOES ◽  
G. F. MEDLEY ◽  
L. ERIKSEN ◽  
A. ROEPSTORFF ◽  
P. NANSEN
Keyword(s):  
Worm Burden ◽  
Ascaris Suum ◽  
Natural Infection ◽  
Distribution Patterns ◽  
Human Populations ◽  
Suitable Model ◽  
Post Mortem ◽  
Intensity Of Infection ◽  
Low Intensity ◽  
Low Prevalence

This paper describes the distribution of Ascaris suum in experimentally and naturally infected pigs, and offers a comparison with A. lumbricoides infections in humans. In the first study, worms were recovered post-mortem from a group of 38 pigs that had been trickle inoculated with 10000 infective A. suum eggs twice weekly for 12 weeks. In the second study, worms were collected from a group of 49 pigs that had been kept on a pasture contaminated with infective A. suum eggs for 10 weeks, after which they received treatment with an anthelmintic; they then were turned out on the same pasture for a second 10-week period before slaughter. The worm burdens of the naturally infected pigs were recorded both at treatment and post-mortem. Mean worm counts were similar at all occasions but the prevalence of infection was higher in the trickle infected and naturally reinfected pigs. Furthermore, the prevalence in naturally infected pigs increased significantly over the study period. Worm burden distributions in all groups were heavily overdispersed, but the distribution patterns differed significantly between groups: lower exposure (initial natural infection) gave a low prevalence and an almost uniform distribution of worm burdens among infected hosts. Continued or higher exposure (trickle and natural reinfection) resulted in increased prevalence and a reduction in the proportion of hosts with increasing worm load. A positive correlation was found between initial and reinfection worm burdens in the naturally infected pig population, suggesting that individual pigs are predisposed to a high or low intensity of infection. The prevalence and intensity as well as the distribution observed for A. suum infection in pigs were comparable to those reported for A. lumbricoides in endemic areas, and there is evidence for predisposition to A. suum in pigs, with an estimated correlation coefficient similar to that found in humans. It is concluded that A. suum infections in pigs are a suitable model to study the population dynamics of A. lumbricoides in human populations.

scholarly journals The proportional frequency of the human and bovine types of tubercle bacilli in human pulmonary tuberculosis in the middle and south of Scotland

1940 ◽  
Vol 40 (3) ◽  
pp. 365-376 ◽  
Author(s):  
A. Stanley Griffith
Keyword(s):  
Pulmonary Tuberculosis ◽  
Thoracic Spine ◽  
Guinea Pigs ◽  
Direct Contact ◽  
Spinal Tuberculosis ◽  
Raw Milk ◽  
Tubercle Bacillus ◽  
Post Mortem ◽  
Cervical Gland ◽  
Gland Enlargement

1. The types of tubercle bacilli have been determined in the sputum of 515 cases of pulmonary tuberculosis occurring in the middle and south of Scotland.2. Of the 515 cases 484 were human (476 eugonic and eight dysgonic) and thirty-one were bovine infections.3. With the exception of the strains from one case (case 28) all the bovine strains, seventy in number, were typical culturally and fully virulent for rabbits.4. The attenuated strains, two in number, from case 28 were slightly less virulent than typical bovine strains for rabbits and (one strain) for guinea-pigs.5. The percentage of bovine infections found in this series, including the Cumberland case, during the years 1931–9 was 6·0, but excluding that case it was 5·8.6. The percentage of bovine infections found by Munro during about the same period and covering the same regions was 5·0%.7. In Munro's series strains of bovine tubercle bacilli were obtained from fifty-eight out of 1165 persons (5·0%). Five of his cases yielded attenuated bovine strains and in one of these the pulmonary tuberculosis was preceded by tuberculosis of the thoracic spine.8. In my series the attenuated tubercle bacilli came from a case (case 28) of pulmonary tuberculosis which was preceded nearly 20 years previously by tuberculosis of the lower dorsal spine.Dr Munro and others have made post-mortem examinations on cases of phthisis pulmonalis due to bovine bacilli, but I wish to defer reference to these until we can review them altogether.In this series there are seven instances of cervical gland enlargement and one instance (case 28) of spinal tuberculosis occurring previous to the development of phthisis pulmonalis. These, I think, are examples of alimentary infection with the bovine tubercle bacillus. Thus, with the three autopsies previously mentioned, there are eleven cases, or about one-third, which are almost certainly alimentary in origin. As for the rest of the cases, 20 in number, no glandular enlargements in neck or abdomen were detected but the majority, if not all, were probably alimentary in origin, since all the persons drank a lot of raw milk and only five came into direct contact with cattle in their employment.

Immune response of guinea-pigs to chemically abbreviated prepatent Metastrongylus apri infection

Parasitology ◽  
1976 ◽  
Vol 72 (1) ◽  
pp. 13-18 ◽  
Author(s):  
V. Kumar ◽  
J. Mortelmans
Keyword(s):  
Guinea Pigs ◽  
Gamma Globulin ◽  
Immune Status ◽  
Clinical Manifestations ◽  
Control Group ◽  
Infection Dose ◽  
Infective Larvae ◽  
Worm Recovery ◽  
The Status ◽  
Experimental Group

The effect of chemical abbreviation of the primary infection dose (PID) of 160 infective larvae of Metastrongylus apri on the immune status of the guinea-pig host was studied. The criteria used for assessing the status of immunity consisted of clinical manifestations following administration of a challenge infection dose (CID) of 800 infective larvae of M. apri, the rate of worm recovery 15 days post-CID and the rate of mortality following administration of CID.Among the guinea-pigs of the main experimental group, where 15-day-old PID was abbreviated by two parenteral doses of levamisole*, a strong immunity to CID given 35 days post-PID was built-up. Against this, all the guinea-pigs of a control group, which did not receive PID, died between 16 and 22 days post-CID.The increase in serum gamma-globulin level of the guinea-pigs, where the PID was abbreviated chemically, suggested that the rise of this globulin fraction in the serum could be in some way related to the resistant state of guinea-pigs.

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