Development of Immunity in Broilers Continuously Exposed to Eimeria sp.

Stiff, Mary I.; Bafundo, Kenneth W.

doi:10.2307/1591652

Cited by 19 publications

(8 citation statements)

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“…Continuous low-level infection with oocysts, termed trickleimmunization, will induce solid protection against clinical coccidiosis (21,22,53). Although some permutations on this general phenomenon have been reported (12,14,35), this natural model has not been studied adequately with the objective of developing a more thorough understanding of the underlying host immune mechanisms associated with protection, particularly in young chickens.…”

Section: Discussionmentioning

confidence: 99%

Characterization of immune response to Eimeria tenella antigens in a natural immunity model with hosts which differ serologically at the B locus of the major histocompatibility complex

et al. 1997

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A model to simulate natural immunity to Eimeria tenella was developed in three chicken lines which differ at the B locus of the major histocompatibility complex. Homozygous, 1-day-old chicks of the B 19 B 19 , B 24 B 24 , or B 30 B 30 genotype were trickle immunized by being orally fed a small infectious dose of E. tenella oocysts for 5 consecutive days. These naturally exposed birds were then challenged at different times between 5 and 24 days after the final dose, and the level of protection was assessed 6 days after challenge, using body weight gain and intestinal lesion scores. The duration of immunity in naturally exposed birds differed among the major histocompatibility complex lines. Trickle immunization of the B 19 B 19 haplotype afforded the longest and strongest level of protection compared to the other two haplotypes tested. In addition, in vitro splenic and peripheral blood lymphocyte proliferative responses in trickle-immunized birds were measured against sporozoite, merozoite, and tissue culture-derived E. tenella parasite antigens isolated from the recently described SB-CEV-1/F7 established cell line. The lymphocytes obtained from B 19 B 19 birds trickle immunized responded in vitro to the E. tenella-infected SB-CEV-1/F7 tissue culture-derived parasite antigen. Furthermore, antigen-specific immune responses appeared earlier in immune, challenged B 19 B 19 birds than in their naive, challenged counterparts. The development of a model simulating natural immunization will serve as a foundation to further characterize both humoral and cell-mediated responses to E. tenella tissue culture-derived parasite antigens and to better understand host protective immune responses to avian coccidiosis.

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Section: Discussionmentioning

confidence: 99%

Characterization of immune response to Eimeria tenella antigens in a natural immunity model with hosts which differ serologically at the B locus of the major histocompatibility complex

et al. 1997

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“…of oocysts have been shown to induce immunity (Eimeria hungaryensis, Higgs and Nowell 1988;Eimeria tenella, Lillehoj 1988; Eimeria sp., Stiff and Bafundo 1993). Although it is unclear how many oocysts naturally infected deer mice ingested, it is clear that they were repeatedly exposed because they were repeatedly infected (Fig.…”

Section: Discussionmentioning

confidence: 99%

“…First, large numbers of oocysts (uninfective parasite eggs) are shed during infections (often > lo6 oocysts per day; Long 1982), thus infections are easy to detect. Second, fecal oocyst output decreases from one infection to the next as animals become immune (Higgs and Nowell 1988;Lillehoj 1988;Stiff and Bafundo 1993). An absence of oocysts during a second infection can be used to document complete immunity; a drop in fecal oocyst output from one infection to the next can be used to assess the degree of partial immunity.…”

Section: Nized: (I) Microparasites (Viruses and Bacteria) Go Throughmentioning

confidence: 99%

Variable levels of immunity to experimental Eimetia arizonensis infections in natural, seminatural, and laboratory populations of deer mice (Peromyscus maniculatus)

Fuller¹

1996

Can. J. Zool.

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Acquired immunity to parasites may affect both host and parasite population dynamics. Although immunity has been studied experimentally in laboratory-reared hosts, less attention has focused on free-living animals. I examined acquired immunity of free-living deer mice (Peromyscus maniculatus) to naturally occurring and experimental infections of Eimeria arizonensis (Protozoa: Coccidia). In a mark-recapture study, I found evidence of complete immunity to natural infections in only 1 of 3 years and evidence of partial immunity in all years. I subsequently examined partial immunity to experimental infections by giving laboratory-reared, free-living, and enclosure populations of deer mice two or three consecutive E. arizonensis infections. Greater than 90% (13 of 14) of laboratory-reared animals developed immunity after only one exposure, suggesting that E. arizonensis is immunogenic. However, significantly fewer animals living under natural and seminatural conditions developed immunity after one exposure in two of three experiments. These observational and experimental results suggest that immunocompetence of free-living deer mice to E. arizonensis may be variable and may differ with respect to that of laboratory-reared animals.RCsumC : L'immunitC aux parasites acquise au cours de la vie peut affecter la dynamique des populations, aussi bien celle des populations d'h6tes que des populations de parasites. L'immunitC est un phCnomkne qui a CtC assez bien CtudiC experimentalement chez des h6tes ClevCs en laboratoire, mais peu CtudiC chez des animaux libres en nature. J'ai CtudiC I'immunitC acquise chez des Souris a pattes blanches (Peromyscus maniculatus) en nature, contre des infections naturelles et expkrimentales d'Eimeria arizonensis (Protozoa : Coccidia). Au cours d'une Ctude de marquage-recapture, j'ai pu reconnaitre une immunitC totale aux infections naturelles au cours de 1 des 3 annCes et une immunitC partielle au cours des 3 annCes. J'ai ensuite examink 1'immunitC partielle a des infections expCrimentales chez des populations de souris ClevCes en laboratoire, des populations libres et des populations en enceintes, aprks deux ou trois infections consCcutives d'E. arizonensis. Plus de 90% (13 sur 14) des animaux ClevCs en laboratoire ont acquis 1'immunitC aprks seulement une exposition au parasite, ce qui semble indiquer qu'E. arizonensis est immunogkne. Cependant, significativement moins des animaux vivant dans des conditions naturelles et semi-naturelles ont acquis 1'immunitC aprks une seule infection, dans deux des trois experiences. Les rCsultats de ces observations et de ces expkriences indiquent que I'immunitC des souris en libertC contre les infections d'E. arizonensis peut ttre variable et peut diffCrer de celle des animaux ClevCs en laboratoire. [Traduit par la RCdaction]

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“…Immune responses, developed after (repeated) infection with parasites such as Eimeria spp. affect the susceptibility and infectivity of individual birds (Rose, 1987;Lillehoj, 1988;Stiff and Bafundo, 1993;Williams, 1995;Claerebout and Vercruysse, 2000). As a result of differences in the exposure of birds to infectious oocysts from the environment, birds in a group are likely to differ in their infection history, which will result in a heterogeneous population with respect to infectivity and immunity.…”

Section: Introductionmentioning

confidence: 99%

“…Most studies carried out in the last decades focused either on immunity (Lillehoj, 1988;Stiff and Bafundo, 1993;Williams, 1995) or epidemiology (Graat et al, 1998;Williams, 1998), but it is the mutual interaction between host and pathogen ("within-host dynamics"), and between infectious and susceptible hosts in a flock and the environment ("between-host dynamics") that determines the dynamics of the infection with the pathogen in a flock. Although this seems straightforward, the outcome of these interactions may give rise to non-linear effects, which may result in a counterintuitive and an unpredictable course of the infection Heesterbeek, 1995, 1998;Graat et al, 1996;Klinkenberg and Heesterbeek, 2007).…”

Section: Introductionmentioning

confidence: 99%

Effect of Eimeria acervulina infection history on the immune response and transmission in broilers

Velkers

Swinkels

Rebel³

et al. 2010

Veterinary Parasitology

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Heterogeneity in exposure to Eimeria spp. of chickens in a flock will result in differences between individual birds in oocyst output and acquired immunity, which subsequently affects transmission of the parasite in the population. The aim of this study was to quantify effects of previous infection of broilers with Eimeria acervulina on immune responses, oocyst output and transmission. A transmission experiment was carried out with pair-wise housed broilers, that differed in infection history. This "infection history" was achieved by establishment of a primary infection by inoculation of birds with 50,000 sporulated E. acervulina oocysts at day 6 of age ("primed"); the other birds did not receive a primary infection ("naïve"). The actual transmission experiment started at day 24 of age: one bird (I) was inoculated with 50,000 sporulated oocysts and was housed together with a non-inoculated contact bird (C). Oocyst excretion and parameters describing transmission, i.e. the number of infected C birds and time passed before start of excretion of C birds, were determined from day 28 to day 50 for six pairs of four different combinations of I and C birds (I-C): naïve-naïve, naïve-primed, primed-naïve and primed-primed. Immune parameters, CD4(+), CD8(+), αβTCR(+) and γδTCR(+) T cells and macrophages in duodenum, were determined in an additional 25 non-primed, non-inoculated control birds, and in the naïve-naïve and naïve-primed groups, each group consisting of 25 pairs. Although the numbers of CD4(+) T cells and γδTCR(+) T cells increased after primary infection, none of the immunological cell types provided an indication of differences in infectivity, susceptibility or transmission between birds. Oocyst output was significantly reduced in primed I and C birds. Transmission was reduced most in the primed-primed group, but nonetheless transmission occurred in all groups. This study also showed that acquired immunity significantly reduced oocyst output after inoculation and contact-infection, but not sufficiently to prevent transmission to contact-exposed birds.

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Development of Immunity in Broilers Continuously Exposed to Eimeria sp.

Cited by 19 publications

References 0 publications

Characterization of immune response to Eimeria tenella antigens in a natural immunity model with hosts which differ serologically at the B locus of the major histocompatibility complex

Characterization of immune response to Eimeria tenella antigens in a natural immunity model with hosts which differ serologically at the B locus of the major histocompatibility complex

Variable levels of immunity to experimental Eimetia arizonensis infections in natural, seminatural, and laboratory populations of deer mice (Peromyscus maniculatus)

Effect of Eimeria acervulina infection history on the immune response and transmission in broilers

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