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1.
Cellular changes in spleens of mature fowl in relation to both the primary and secondary humoral antibody response following experimental EDS'76 virus infection were studied. The influence of splenectomy on humoral antibody response was also examined. Experimental fowl had been naturally infected with fowl adenovirus (FAV) but did not possess precipitins to these viruses at the time of EDS'76 virus infection. Since EDS'76 infection provokes a recall of the group antibody to FAV, this infection simultaneously induces a primary response against EDS'76 virus and a secondary response due to the recall of the group antibody to FAV. HI and precipitating antibody to EDS'76 virus (primary response) were first detected at 6 and 8 days p.i. respectively. Curves of HI, precipitating and neutralising antibody titres were biphasic; the first peak (IgM peak) occurred at 10-11 days p.i., the second (IgG peak) at 16-28 days p.i. Precipitating antibodies to FAV (secondary response) were demonstrated from 4 days p.i. The curve of these antibody titres was also biphasic, with peaks at the same times as in the primary response. Based on HI and AGP testing of primary and secondary immune response in both splenectomised and non-splenectomised fowl it is concluded that in the primary response the spleen of the adult fowl is involved significantly in only IgM secretion, while in the secondary response it is likely that both IgM and IgG are secreted in considerable amounts. Clusters of lymphoblasts and plasmablasts were observed at 3 days p.i. in the red pulp. It is very likely that antigen-antibody complexes are formed from that time and circulate bound to the surface of lymphocytes. These antigen-loaded lymphocytes are 'picked up' from the blood stream by -red pulp macrophages, leading to enhanced formation of lymphoblasts in the red pulp. Great numbers of these cells (which are very probably IgM secreting cells) were present on days 6 and 7 p.i., but were no longer detectable after day 10 p.i. -macrophages of the macrophagal ellipsoidal corona (MEC), leading to significant enlargement of the periellipsoidal lymphoid tissue (PELT) by an increase of the number of lymphocytes observed from days 4-12 p.i. The MEC was significantly enlarged from 7-12 days p.i., very likely due to an increased number of macrophages. Following deposition of antigen in the white pulp, formation of follicles begins. The number of small, intact follicles including follicle precursors increased from 6 days p.i.(ABSTRACT TRUNCATED AT 400 WORDS) 相似文献
2.
The effects of a simultaneous and/or a subsequent coinfection with chicken anemia virus (CAV) isolate 10343 and fowl adenovirus (FAV) isolate 341 in specific-pathogen-free light chickens were evaluated. The simultaneous coinfection was conducted by the intramuscular route, whereas the subsequent coinfection trial considered FAVs administered orally. In trial 1, 20-day-old chickens simultaneously coinfected with CAV (10343) and FAV (341) intramuscularly (i.m.) showed 55% mortality and characteristic signs and lesions of inclusion body hepatitis/hydropericardium (IBH/HPS). In contrast, birds singly infected with FAV i.m. showed 10% mortality due to IBH/HPS. Trial 2 showed that birds receiving FAV 341 orally at day 7 post-CAV intramuscular infection (group A) developed a mild form of IBH/HPS with presence of inclusion bodies (INIBs) in 60% of the group and virus-neutralizing antibodies against FAV 341. Group B (FAV orally 14 days after CAV) showed significant decreased weight gain, nonspecific microscopic lesions in the liver, spleen, bursa, and thymus, and an antibody response against FAV 341. However, no INIBs could be detected in the hepatocytes of these chickens. Group C (FAV orally 35 days after CAV) showed nonspecific histopathologic changes in the liver and no antibody response to FAV. The oral single infection with FAV isolate 341 induced neither mortality nor macroscopic lesions of IBH/HPS in the birds. The present results corroborate previous reports on pathogenicity of Chilean FAV isolates, which suggest that synergism with other viruses or prior immunosuppression is necessary to produce IBH/HPS in chickens. These results also suggest that the susceptibility of chickens to FAV oral infection resulting in IBH/HPS varies throughout the course of CAV infection. 相似文献
3.
Following BCI4 (EDS'76) virus infection of brown layer hens at 33 weeks of age, production of normally shelled eggs dropped from 87 per cent to 49 per cent within 3 weeks. The production of soft shelled and shell‐less eggs attained a maximum of 33 per cent 3 weeks after infection (p.i.). Shell quality recovered completely within 5 weeks p.i. Egg production problems in White Leghorns infected with BCI4 virus were less severe and of shorter duration than in brown layers. Both in brown layers and in White Leghorns total egg production, mean weight of normally shelled eggs, and internal egg quality were not affected following BCI 4 virus infection at 33 and 28 weeks of age, respectively. Besides shell abnormalities no clinical disease symptoms were observed. Vaccination with a commercial EDS'76 vaccine (Nobivac EDS'76 ®) at 17 weeks of age had no adverse effects on laying performance and provoked adequate immunity against challenge at 33 weeks of age. The same observations were made following BCI4 virus infection at 17 weeks of age. After infectious bronchitis virus (IBV) (H52 virus) infection of laying fowl the percentage of eggs with shell aberrations (rough, misshapen and/ or soft shells) increased to a maximum of 8 per cent, total egg production was depressed, mean egg weight was reduced I to 2 grams, and up to 10 Per cent of normally shelled eggs showed watery, not ropy thin albumen. This abnormally thin albumen was observed in a considerably higher proportion of eggs with shell defects than in normally shelled eggs. No turbidity of the thick albumen was observed and no symptoms of respiratory disease were noticed. The severity and duration of adverse effects of IBV infection on laying performance depend very much on the stage of production in which the infection occurs. Following IBV infection at the onset of production a much severer drop in total production and in production of normally shelled eggs, a greater increase in the number of abnormally shelled eggs, and more lasting adverse effects on egg weight and internal egg quality were observed, in comparison with infection after peak production. Compared with single infections, a combined BC14 virus and IBV infection of brown layers at 33 weeks of age resulted in greatly potentiated adverse effects on total egg production, number of eggs with aberrant internal quality, and duration of production problems. Following a combined BC14 virus and IBV infection, in a great proportion of eggs with shell defects and watery thin albumen, turbidity of the thick albumen was observed also, probably due to combined effects on the uterus of both IBV and BC14 virus. BC14 virus infection did not reinforce the adverse influence of IBV infection on egg weight. The same observations as described for the combined BC14 virus and IBV infection were made following BC14 virus infection of fowl previously infected with IBV. It is concluded that changes of internal egg quality in field cases of EDS'76 are most likely due to subclinical IBV infections. After infection of brown layers at 33 weeks of age with fowl adenovirus 66 (FA V 66) neither symptoms of clinical disease were observed nor effects on egg production, egg weight, and egg quality. Also, in a combined infection with FA V66, IBV, and BCI4 virus, no pathogenic significance could be attributed to the FAV. 相似文献
4.
1. The primary antibody response to sheep erythrocytes was determined by haemagglutination test in guinea fowl. The effects of various genetic and non‐genetic factors on immune response to sheep RBCs in guinea fowl were also estimated. 2. The immune response to sheep RBCs was normally distributed in guinea fowl with mean titre at 1.534 ± 0.014. 3. In guinea fowl, effects on titre values of sire and variety (feather colour) were significant whereas sex and sex × variety interaction effects were non‐significant. 4. The estimate of heritability for immune response to sheep RBCs in guinea fowl was 0.35 ±0.17. 相似文献
5.
Pathogenicity of a fowl adenovirus (FAV), JM1/1 strain of serotype 1 derived from gizzard erosions of a broiler chicken, was examined to specific pathogen-free (SPF) chickens pre-treated with infectious bursal disease viruses (IBDVs) or cyclophosphamide (CY). Virulent IBDVs, classical type, were inoculated orally at 3 days of age of SPF chickens. CY was treated subcutaneously for 3 days after hatch. FAV was given orally at 30 days of age. At 40 days of age, all chickens were bled and autopsied for serology and gross observation. Gizzard lesions were ranked by the scores depending on their severities. IBDV- or CY-treated chickens showed significantly higher gizzard lesion scores than non treated birds. There were no gross lesions in any other organs except for bursal atrophy. Serologically, antibody production against FAV was highly suppressed by IBDV infection or CY treatment. 相似文献
6.
1. The effect of acute heat exposure on triglyceride (TG) transfer to preovulatory follicles was studied in the laying fowl. 2. Heat exposure of laying fowl resulted in a 1.1°C rise in body temperature, a 10‐fold increase in respiration frequency and mild hypocapnia and hypoxaemia. 3. Plasma and follicular tissue TG concentrations were not significandy affected by heat exposure, but plasma TG specific radioactivity decreased significantly and was negatively correlated with body temperature. 4. The transfer rate of TG to the preovulatory follicles was not affected significantly by hyperthermia. 5. We conclude that nutrient supply to the developing follicles is not compromised in acutely heat‐exposed laying fowl. 相似文献
7.
Two experiments were conducted in which the effect of carrageenan (CGN) on humoral immune response of chicks selected on either high (H) or low (L) antibody production to sheep red blood cells (SRBC) was determined. H and L line chicks were injected i.p. with different doses of CGN prior to immunization with SRBC or Brucella abortus (BA). Four weeks later chicks were reimmunized with the same antigens. In general, control H and L chicks had significantly higher total anti-SRBC titers than CGN-treated chicks in primary response. Also, total anti-BA titers were significantly higher in control chicks than CGN-treated chicks on days 3 and 5 following primary immunization and on days 0 and 7 of the secondary response. Overall, the 2-mercaptoethanol (2ME)-resistant anti-SRBC titers did not differ significantly among the CGN-treated groups. However, control chicks tended to have higher anti-BA 2ME-resistant titers from day 14 p.i. of primary response on. Regardless of antigen or CGN treatment, the H line chicks had significantly higher titers than L line chicks. However, the CGN treatments did not affect the antibody response to BA nor to SRBC differently between L and H line chicks. It would appear that since CGN is cytotoxic for macrophages, selection for antibody production did not result in different abilities of the macrophages of these chicken lines to respond to an antigenic challenge. 相似文献
8.
The effect of aqueous lead acetate given per os to chickens for 35 consecutive days and the effect of lead on interferon and antibody production was investigated. Chickens were found to tolerate levels of lead as high as 160 mg/kg/day without exhibiting clinical signs or hematological changes in spite of very high levels of lead in the blood (6.2 ppm). It is apparent from these findings that chickens are more resistant to lead poisoning than humans, horses, dogs and wild fowl such as ducks. Subclinical lead doses did not affect interferon induction in response to statolon and Newcastle Disease virus (NDV)-B1. Interferon concentrations and duration in serum were markedly decreased in chickens which received lead at the 320 mg/kg level. Long time lead exposure had no marked effect on antibody production to NDV in chickens. No consistent correlation was observed between blood lead concentration and antibody titer. The results of these studies indicate that long term subclinical lead intake suppresses neither interferon nor antibody production in chickens. 相似文献
9.
Bluetongue virus, a member of the genus Orbivirus of the family Reoviridae, is the causative agent of bluetongue, which is a non-contagious Culicoides mediated blood-borne disease. The present study characterizes the pathogenicity of a Taiwan prototype BTV2/KM/2003 in Corriedale sheep inoculated subcutaneously into the ear pinna. Histologically, multifocal petechiated hemorrhage, with mild to moderate inflammation and edema, were present in the contralateral ear pinna, tongue, and facial skin, without remarkable lesions in lymphoid organs. By days post-infection (DPI) 7, viral VP7 antigen, detected by immunohistochemistry, presented in the spleen, chiefly located in the outer rim of <3 cell thickness of marginal zone macrophages bordering the marginal zone and red pulp, and T lymphocytes of the red pulp. By DPI 11, viral signals shifted from the marginal zone to macrophages and small lymphocytes within follicles of the spleen. In situ hybridization with VP7 gene probe detected strong signals in the spleen, chiefly spanning the whole width of 5-10 cell thickness of the marginal zone, including the marginal zone macrophages and marginal zone B cells, as well as macrophages of sheathed capillaries in the red pulp. This study demonstrates molecular as well as morphologic evidence of the presence of bluetongue virus in the marginal zone of the spleen, most likely associated with viremia in acute infection, as previously demonstrated by the authors. 相似文献
10.
Summary The pathogenicity and pathogenesis of Lelystad virus was studied in six 6‐day‐old SPF piglets. A third passage of the agent was propagated on porcine alveolar macrophages and intranasally inoculated into pigs. Pigs were killed at hours 24, 48, 60, and 72, and on days 6 and 8 after inoculation. From day 2 on pigs developed diffuse interstitial pneumonia with focal areas of catarrhal pneumonia, and from this day on splenic red pulp macrophages were enlarged and vacuolated. Lelystad virus was re‐isolated from the lungs of infected pigs from day 2 after inoculation. Lelystad virus antigens were detected by immunohistochemical techniques in bronchiolar epithelium and alveolar cells, and in spleen cells of infected pigs from day 2 after inoculation. Ultrastructural examination of tissues by electron microscopy revealed degenerating alveolar macrophages and epithelial cells in lungs and nasal mucosa, with excessive vacuolation of the endoplasmic reticulum. Although the respiratory tract seems to be the target organ for this virus, macrophages in other organs, such as the spleen, can also be infected. This preference for macrophages may impair immunological defences. 相似文献
11.
The pattern of antibody response to vaccination with Brucella abortus, strain 19, was studied in two sheep. Agglutinative activity was detected by the third and fifth days and complement - fixing activity by the fifth and seventh days post-vaccination. Density gradient centrifugation and DEAE cellulose column chromatography showed the 19S antibody developed first, followed soon after by 7S antibody. The former had disappeared by the 25th day but the latter persisted longer in both sheep. A small amount of 19S antibody was detected in sheep 1 following a booster dose of vaccine but 7S antibody constituted the major secondary response. The standard tube agglutination test was found to be more efficient than the complement-fixation test for titration of 19S antibody. An increase in the salt concentration to 10% in tube agglutination test rendered it more sensitive in demonstrating 7S antibody. 相似文献
12.
The hypothesis that an effective protection of progeny chickens against inclusion body hepatitis/hydropericardium syndrome (IBH/HP) can be achieved by dual vaccination of breeders with fowl adenovirus (FAV) serotype 4 and chicken anemia virus (CAV) was tested. Thus, 17-wk-old brown leghorn pullet groups were vaccinated by different schemes including single FAV (inactivated), single CAV (attenuated), FAV and CAV dually, or were not vaccinated (controls). Subsequent progenies of these breeders were challenged with the virulent strains FAV-341 and CAV-10343 following three strategies: 1) FAV-341 intramuscularly (i.m.) at day 10 of age (only FAV-vaccinated and control progenies); 2) FAV + CAV i.m. simultaneously at day 10 of age (all progenies); 3) CAV i.m. at day 1 and FAV orally at day 10 of age (all progenies). The induction of IBH/HP in these progenies was evaluated throughout a 10-day period. Both breeder groups vaccinated against FAV and those vaccinated against CAV increased virus neutralizing specific antibodies. Challenge strategy 1 showed 26.6% mortality in control progeny chickens and 13.3% in the progeny of FAV-vaccinated breeders. Presence of lesions in the liver of these groups showed no significant differences (P > 0.05), suggesting a discreet protective effect of the vaccine. Challenge strategy 2 showed 29.4% mortality in controls and 94% of chickens showed hepatic inclusion bodies (HIB). Single CAV vaccination of breeders did not demonstrate a beneficial effect, with both mortality and liver lesions resembling the nonvaccinated controls. FAV vaccination of breeders significantly reduced both mortality (7.4%) and liver lesions (26% HIB) (P < 0.05), providing protection against this challenge strategy. Dual vaccination of breeders with FAV and CAV proved to be necessary to achieve maximum protection of the progeny (no mortality and 7% HIB). Challenge strategy 3 produced no mortality but consistent liver damage in controls (96% HIB). In this case, both CAV and FAV + CAV-vaccinated breeders showed best protection results in terms of liver histopathology (8% and 0% HIB, respectively). FAV vaccination alone produced 24% HIB, similar to challenge strategy 2, demonstrating a lower protective effect. 相似文献
13.
The study was designed to investigate the replication of a re-assortant H9N2 avian influenza virus (AIV) and induction of the interferon (IFNγ) response after aerosol or intranasal inoculation with the virus in guinea fowl. To determine virus shedding pattern, oropharyngeal and cloacal swabs and tissue specimens of trachea, lungs, spleen and caecal tonsils were collected post-inoculation (pi). Infected guinea fowl showed mild clinical signs, while negative control guinea fowl remained healthy and active throughout the experiment irrespective of the inoculation route. However, the clinical signs were more prominent in guinea fowl infected through the aerosol route. Virus was detected in all oropharyngeal and cloacal swabs up to 7 d pi in guinea fowl from both inoculation groups. However, virus was detected more frequently and in higher titres in oropharyngeal swabs and specimens of trachea and lungs from the group exposed to aerosols than in the group given intranasal drops. In accordance with viral replication findings, expression of IFNγ was up-regulated on 1, 2 and 4 d pi to a significantly higher level in lung tissue specimens from the group exposed to virus aerosol than from controls treated with PBS intranasally. On the other hand, IFNγ was up-regulated above that of controls in lung tissue specimens from the group treated with intranasal drops of virus only on 4 d pi. These findings indicate that virus administered in aerosols was more efficient in infecting the lower respiratory tract and in inducing activity of the IFNγ gene than virus administered as intranasal drops. The results of this study suggest that virus aerosols cause more intense respiratory infection and increase the shedding of the H9N2 AIV in guinea fowl, highlighting the potential role of guinea fowl as a mixing bowl for transmission and maintenance of H9N2 AIV between poultry premises.
相似文献
14.
The antibody response in serum and nasal secretions of groups of ponies vaccinated or infected with Myxovirus influenzae A-equi 2 was examined. Following infection by aerosol with live virus, a weak antibody response was recorded in both serum and secretions. Antibody levels were undetectable in secretions at 31 days after infection. After primary intramuscular vaccination with killed virus, using sodium alginate as an adjuvant, antibody was detected only in the serum. However, following revaccination, a pronounced antibody response was demonstrated in both serum and secretions. Antibody was still detectable in all four ponies when tested 135 days later. Only a serum antibody response was detected in ponies after primary intramuscular vaccination with a commercial vaccine. Upon revaccination nasal antibody occurred in all ponies but this only persisted for about 30 days. Neither serum nor nasal antibody response occurred following intranasal vaccination and revaccination with a killed virus vaccine. 相似文献
15.
1. Hens from White Leghorn lines selected for high (HA) or low (LA) antibody response to sheep red blood cells (SRBC) were inoculated with 0.1 ml of either 0.25% or 2.50% SRBC suspension. Eggs laid over the next 15 d were grouped into 5, 3‐d collection periods and incubated. Maternal antibody titres were determined in chicks at hatch and 7 d after hatch. 2. In a subsequent experiment, hens of the 2 lines were inoculated with 0.1 ml of 2.50% suspension of SRBC, and eggs laid on days 10 to 13 after inoculation were incubated. Maternal antibody titres were determined in 15 and 18‐d embryos as well as in chicks at 0, 5, 10, 15, 20, and 25 d after hatch. 3. Dosage of SRBC had no effect on the antibody titres in line HA; however, the higher dosage elicited greater antibody titres than the lower dosage in line LA. 4. Maternal antibodies were detected earlier in chicks of line HA (eggs laid on days 7 to 9) than those of line LA (eggs laid on days 10 to 12) regardless of dosage administered to the hens. 5. In both lines, antibodies specific to SRBC were observed on day 15 of incubation, with the frequency of responders greatest at hatch. The high frequency of HA responders was maintained for 15 d after hatch, whereas there was an immediate decline with age in LA responders. 6. It was concluded that lines HA and LA have diverged in the pattern of maternal antibody levels as a result of the divergent selection for antibody response to SRBC. 相似文献
16.
Three fowl adenovirus (FAV) isolates (341, 344, and 215) obtained during 1996-97 from field outbreaks of inclusion body hepatitis/hydropericardium syndrome (IBH/HPS) affecting broilers and broiler breeders in Chile were characterized by virus neutralization tests (VNTs) and restriction enzyme analysis of a DNA fragment. Furthermore, the pathologic characteristics of one of these FAV isolates (FAV 341) was studied in experimentally infected chickens. The VNTs conducted with isolates 341 and 344 against reference strains and antisera belonging to each of 12 FAV serotypes demonstrated a close antigenic relationship with strain KR5 of the FAV serotype 4. Polymerase chain reaction using the primers H3/H4 and subsequent HpaII digestion was used for serotype identification of isolates 341 and 215. The length of the PCR products and the restriction profiles of isolates 341, 215, and the reference strain KR5 (FAV4) were identical. The present results confirmed the classification of all three isolates as FAV4. The pathogenicity test with 1000 mean tissue infectious dose of isolate 341 inoculated intramuscularly in 20-day-old specific-pathogen-free chickens resulted in the death of 9% (two birds) six days postinoculation (PI). Both birds showed characteristic IBH/HPS gross and microscopic lesions; the remaining birds, sacrificed at day 10 PI, showed less severe lesions. On the basis of epidemiologic and experimental data of the virulence of Chilean FAV isolates, and the pathogenicity results with isolate 341, we speculate that Chilean FAV strains may require an association with other agents (immunosuppressive agents) to induce IBH/HPS outbreaks in the field. 相似文献
17.
1. The course of infection by exogenous avian leukosis virus was followed in a commercial strain of White Leghorn domestic fowls by measuring viral antigen in feather pulp and egg albumin. Ten days after hatching, 2 out of 360 birds tested positive and at 286 days of age about 60% of the birds had been antigen positive at least once. 2. Among the antigen positive birds, two groups could be distinguished: those which permanently and those which transiently expressed viral antigen. Permanent antigen expression was associated with low antibody titres, while transient antigen expression was associated with high antibody titres. 3. The strain segregated for the two endogenous viral genes ev6 and ev9, both of which express endogenous viral envelope protein, and have been implicated in affecting immune‐responsiveness. The antibody titre in individuals positive for both ev6 and ev9, was significantly lower than in those which had none or only one of the two ev‐genes. In addition, individuals positive for both ev‐genes occurred more frequently in the group permanently positive for viral antigen than in the group transiently antigen positive. 4. The results indicate that there was a strong synergism between ev6 and ev9 in reducing the antibody response to exogenous avian leukosis virus infection, perhaps by inducing immune tolerance or interfering with antibody formation. 相似文献
18.
To investigate the pathogens that racing pigeons in Taiwan are exposed to, a total of 3764 pigeons from 90 lofts were analysed by collection of blood samples in the period between October 2000 and September 2001. The haemagglutination inhibition (HI) test was performed to detect antibodies against Newcastle disease virus (NDV), type 2 avian paramyxovirus (APMV-2), and egg drop syndrome '76 virus (EDS-76V). The agar-gel precipitin (AGP) test was used to detect antibodies against fowl adenovirus (FAV), goose parvovirus (GPV), and avian reovirus (REO). The virus neutralisation (VN) test was applied to detect antibodies against the serotypes FAV-1 and FAV-8. A rapid serum agglutination test was applied for the detection of antibodies against Mycoplasma spp. Antibodies to several infectious agents were found, including NDV (43.3%), EDS-76V (19.2%), FAV (0.8%), REO (0.5%), APMV-2 (0.2%), Mycoplasma columbinum (10.3%), M. columborale (7.1%), M. synoviae (1.8%) and M. gallisepticum (1.3%). Antibodies against GPV, FAV-1, and FAV-8 were not detected in any serum sample. NDV seroprevalence was significantly higher in pigeons of more than one year of age than in pigeons younger than one year. ND or EDS-76 seroprevalence of pigeons vaccinated with ND vaccine or EDS-76 vaccine was significantly higher than that of pigeons that did not receive any vaccination. 相似文献
19.
Ten fowl adenoviruses (FAVs), isolated from suspected cases of inclusion body hepatitis (IBH) in quails and broilers, were characterized by a hexon-based polymerase chain reaction (PCR) combined with restriction enzyme analysis (REA) of the amplified DNA fragments. All the isolates could be detected using H1/H2 and H3/H4 primer sets. Amplification of DNA with H1/H2 and H3/H4 primer sets resulted in fragments of approximately 1219 bp and 1319 bp, respectively. HaeII digestion of the H1/H2 PCR products and HpaII digestion of the H3/H4 PCR products characterized all the isolates in FAV groups, known from genomic typing using the whole DNA. For some of the isolates, neutralization tests were used to confirm these results. The results revealed that, as well as FAV serotype 1, which is the sole member of DNA group A, FAVs of DNA group E are also associated with IBH in poultry in northern India. The FAV specific PCR combined with REA was found to be very useful in investigating the epidemiological situation in the field. It was even possible to define mixed infections with more than one FAV. 相似文献
20.
Gizzard lesions were formed in specific-pathogen-free (SPF) white leghorn chickens inoculated with fowl adenovirus (FAV). The virus, serotype 1 FAV 99ZH strain (FAV-99ZH), was originally isolated from the gizzard mucosa of commercial broiler chickens exhibiting gizzard erosion with intranuclear inclusion bodies. Five-day-old and 53-day-old SPF white leghorn chickens were inoculated with FAV-99ZH by both oral and ocular routes and then examined at necropsy on days 3, 5, 7, 10, 14, and 21 postinoculation (PI). There were no clinical signs in any of the chickens after the inoculation. Focal gizzard lesions occurred macroscopically, however, in inoculated chickens at several experimental periods. FAV was recovered from tissue samples of the proventriculus, gizzard, pancreas, and rectum by day 10 or 7 PI but was not recovered from liver samples of any of the chickens. These results indicate that FAV isolated from gizzard erosion is able to reproduce gizzard lesions as necrosis and erosion in SPF white leghorn chickens and that it may have a greater degree of tissue tropism in gizzards and other digestive organs than in the liver. 相似文献
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