• Parasites, Hosts and Diseases
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• v.45 no.3
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• pp.225-228
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• 2007

We observed the time gap between oocyst shedding and antibody responses in mice (3-week-old C57BL/6J females) infected with Cryptosporidium parvum. Oocyst shedding was verified by modified acid-fast staining. The individually collected mouse sera were assessed for C. parvum IgM and IgG antibodies by enzyme-linked immunosorbent assay from 5 to 25 weeks after infection. The results showed that C. parvum oocysts were shed from day 5 to 51 post-infection (PI). The IgM antibody titers to C. parvum peaked at week 5 PI, whereas the IgG antibody titers achieved maximum levels at week 25 PI. The results revealed that IgM responses to C. parvum infection occurred during the early stage of infection and overlapped with the oocyst shedding period, whereas IgG responses occurred during the late stage and was not correlated with oocyst shedding. Hence, IgM antibody detection may prove helpful for the diagnosis of acute cryptosporidiosis, and IgG antibody detection may prove effective for the detection of past infection and endemicity.

• Korean Journal of Veterinary Research
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• v.51 no.3
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• pp.249-252
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• 2011

Cell culture systems for the protozoan Eimeria are not yet available. The present study was conducted to develop an animal model system by inoculating animals with a live Eimeria vaccine. This study was conducted on 3-day-old chickens (n = 20) pretreated with cyclophosphamide. The chickens were divided into 2 groups: the control group (n = 10) and the inoculated group that received the live Eimeria vaccine (n = 10). During the study period, we compared the clinical signs, changes in body weight, and number of oocysts shed in the feces of the control and inoculated group. This study showed that oocyst shedding was significantly higher in the chickens inoculated with live Eimeria oocysts than in the control chickens. Moreover, body weight gain was lesser in the animals in the inoculated group than in the control animals. Fecal oocyst shedding was observed in the inoculated animals. On the basis of these findings, we suggest that live Eimeria vaccination with cyclophosphamide pretreatment may be used to obtain an effective animal model for studying protozoan infections. This animal study model may eliminate the need for a tedious continuous animal inoculation process every 6 months because the live coccidiosis vaccine contains live oocysts.

• Parasites, Hosts and Diseases
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• v.34 no.4
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• pp.255-258
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• 1996

Eight 2-day-old SPF Chickens were each inoculated Orally With 3 Sing1e dose Of 5 × 105 oocysts of Cryptosporinium boilevi. and immunoglobulin G (IgG) antibody responses were chronologically measured by indirect immunofluorescent antibody (IFA) assay. Anti-C. bcileyi IgG antibody levels remained high (1 : 106.67 to 1:512.00) for at least 4 months with 330 days of a detectable period. Ten days after the negative conversion, each chicken was re-challenged with 1 × 107 oocysts of the same species. Subsequent infection in 340-day-old individuals caused sudden elevated IgG antibody levels and the titer peaked on day 28 postchallenge inoculation (PCI), at 1:1.024 with a 65 days of detection period. Chickens in primary infection showed oocyst shedding profiles. but did not exhibit any oocyst shedding before or after experimental reinfection.

• Korean Journal of Veterinary Service
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• v.35 no.1
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• pp.25-31
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• 2012

This study examined the efficacy of natural ingredient formulated herbal medicine as feed additives against coccidiosis in broiler chicken. Medicinal herbs used in this study were Artemisia annua, Pulsatilla chinensis, Clematis chinensis and Scutellaria baicalensis. Two week old chicks were administered with 1% ingredient formulated herbal medicine. Observations of the efficacy were confirmed by examining the lesion score, histopathological appearance of cecum, shedding of fecal oocyst and production index in farm. S. baicalensis of the most effective substance were analyzed by UPLC. The results are as follows; among various types of Chinese medicine, the most efficacious ingredient was found to be pure bicalein. The major index substance is bicalein and $13{\mu}g/ml$ per gram was found. Feeding of chickens with S. baicalensis induced the coccidiostat effect and reduced the fecal shedding of E. tenella oocyst by 14%. Experimental results on a farm, feed conversion ratio and weight gain and production rate in the group with natural ingredient formulated additives than in control group increased. The rate of weight gain (%) in each experimental group showed 108% and 126% increase while the mortality rate was 1.4% lower than the control group. The investigation showed that the most efficacious ingredient was found to be S. baicalensis among herbal medicine products for coccidiostats. However, as it was found in the farm experiment that pure S. baicalensis alone is economically unviable. The additives with cocktailed of efficacious ingredient are suggested to be implemented for effective protection against coccidiosis.

• Parasites, Hosts and Diseases
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• v.59 no.4
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• pp.403-408
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• 2021

Avian coccidiosis has a major economic impact on the poultry industry, it is caused by 7 species of Eimeria, and has been primarily controlled using chemotherapeutic agents. Due to the emergence of drug-resistant strains, alternative control strategies are needed. We assessed anticoccidial effects of berberine-based diets in broiler chickens following oral infection with 5 Eimeria species (E. acervulina, E. maxima, E. tenella, E. mitis, and E. praecox). When 0.2% berberine, a concentration that does not affect weight gain, was added to the diet, the 4 groups infected with E. acervulina, E. tenella, E. mitis, or E. praecox showed significant reductions in fecal oocyst shedding (P<0.05) compared to their respective infected and untreated controls. In chickens treated 0.5% berberine instead of 0.2% and infected with E. maxima, fecal oocyst production was significantly reduced, but body weight deceased, indicating that berberine treatment was not useful for E. maxima infection. Taken together, these results illustrate the applicability of berberine for prophylactic use to control most Eimeria infections except E. maxima. Further studies on the mechanisms underlying the differences in anticoccidial susceptibility to berberine, particularly E. maxima, are remained.

• Parasites, Hosts and Diseases
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• v.33 no.4
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• pp.377-382
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• 1995

Three-week-old ICR SPF mice were orally inoculated with one of 5 doses ranging from $2{\;}\times{\;}10^2{\;}to{\;}2{\;}\times{\;}10^6$ oocysts of Crwptosporidium tsuris (strain MCR) per mouse. Oocyst inoculation was directly proportional to the amount of oocysts shed and was inversely proportional to the period required for peals oocyst production and to the prepatent period. Peak oocyst production occurred between fifteen and thirty-one days with a patent period from 61 to 64 days. Three days after all mice stopped shedding oocysts, they were orally challenged with a single dose of $2{\;}\times{\;}10^6$ oocysts or the same species. Marked seroconversion for IgG antibody accompanied recovery from mice inoculated with $5{\;}\times{\;}10^5$ oocysts. Mice administered with carrageenan excreted a small number of oocysts for 49.0 days on the average after challenge inoculation (ACI) and control mice for 14.2 days in a dose-independent fashion. Just before challenge infection, phagocytic activity of peritoneal macrophages ($M{\phi}$) and the number of peripheral $M{\phi}$ were dramatically decreased. Mild challenge infection implies that the immunogenicity of C. nuris (strain MCR) is very strong, despite $M{\phi}$ blocker carrageenan administration.

• Parasites, Hosts and Diseases
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• v.35 no.4
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• pp.245-250
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• 1997

The responses of gastric mucosal mast cells (GMMCS) to infection with coccid- ian protozoa, Clptosporinium muris, in mice were examined during primary and challenge infections. Each of three-week-old ICR SPF mice was orally inoculated with a single dose of 2 × 106 oocysts of C. muffs (strain MCR). After oocyst shedding ceased, the mice were orally challenged with a single dose of 2×106 oocysts of the same species. GMMCS reached a peak on days 20-30 postinoculation (Pl) in number, and decreased thereafter. An increase on days 20-30 post-challenge-infection (PCI) was also observed. The mice showed, on the whole, normal profiles of oocyst shedding in droppings. The number of the cells of uninfected control mice remained constant. .Tudging from the above results, it is suggested that mastocytosis correlate with expulsion of C. mans in primary infection and the defense mechanism of challenge infection.

• Korean Journal of Veterinary Research
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• v.51 no.2
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• pp.101-105
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• 2011

We investigate the resistance of Cryptosporidium (C.) parvum oocysts to commercial bleach treatment. The viability and infectivity of C. parvum oocysts suspended in 100, 50, 25, 12.5, 6.3 or 3.2% aqueous commercial bleach for 10, 30, 60, 120 or 180 min at room temperature were assessed by nucleic acid Syto-9 staining, histologic examination of ileum and infectivity to immunosuppressed neonatal C57BL/6N mice. Although the viability was decreased compared with normal oocysts, all oocysts in contact with serially diluted commercial bleach for 180 min were alive by nucleic acid dye Syto-9 staining. And, microscopic examination of ileum sections revealed developmental stages of C. parvum in all mice. The oocyst shedding patterns between mice infected with oocysts contacted with commercial bleach and normal control mice were not significantly different each other. Although commercial bleach is widely used as a bacterial and viral disinfectant, the present findings indicate that it is not an effective disinfectant for C. parvum oocysts under practical conditions. Authors conclude that, therefore, it is undesirable to recommend commercial bleach as a disinfectant for C. parvum oocysts.

• Journal of Veterinary Science
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• v.23 no.6
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• pp.91.1-91.9
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• 2022

Three parameters, body weight gain (BWG), intestinal lesion score (LS) and fecal oocyst shedding, were compared in broilers infected with major parasitic species; Eimeria acervulina, E. maxima, and E. tenella. First, two- and three-week-old chickens with Eimeria infection showed LS of approximately 3, but two-week-old chickens were more correlated with BWG. Second, significant differences in BWG were observed between male and female broilers challenged with Eimeria. Finally, E. maxima-infected broilers among three Eimeria species showed a higher relationship between BWG and LS, suggesting three considerations such as genders, age and Eimeria species for Eimeria experiments.

• Journal of Veterinary Clinics
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• v.23 no.3
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• pp.243-250
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• 2006

The chickens fed with the feeds supplemented with green tea(GT) and lactic acid bacteria(LB) were infected orally with 10,000 oocysts per chicken of E. maxima. The groups administered with the feeds supplemented with GT by 0.5% and 2.0% of feed showed the significant levels of decreasing in the number of oocysts shed for 5 days after E. maxima infection. The feeds supplemented with LB by 0.1% and 0.5% of feed were less effective in reducing the number of the fecal oocyst, compared with the groups administered with GT. To evaluate the immunoregulatory effects of the feed additives, the expression patterns of IL-2 and IFN-r in spleen cells were studied by RT-PCR and ELISA. The higher levels of IL-2 transcripts after E. maxima infection were observed in the groups with n, compared with the groups with LB and the mixture of GT and LB. The $IFN-\gamma$ mRNA bands were observed in the all of experimental groups except the uninfected control. The culture supernatants of Con A-stimulated spleen cells($5{\times}10^6cells/ml$) were measured for the concentration of IL-2 and $IFN-\gamma$ by ELISA. The levels of IL-2 and $IFN-\gamma$ on days 3 and 7 after E. maxima infection were significantly augmented in the groups with n. These results indicated that GT-supplemented feeds resulted in higher reduction of oocyst-shedding and more enhanced immune responses in the chicken infected with E. maxima, as compared with LB-supplemented feeds. According to the results, it was implicative that the supplements could be utilized for development of feed additives for anti-coccidiosis.