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1.
葡萄球菌感染是家禽养殖中一种常见的细菌性传染疾病,鸡养殖中的葡萄球菌感染通常是致病性金黄色葡萄球菌感染的一种慢性或急性传染性疾病,通常慢性疾病感染会导致鸡只出现关节炎症或者足部疾病,急性型感染会导致鸡只出现急性败血症病变。葡萄球菌感染疾病所导致的鸡只死亡率较高,尤其在雏鸡和育成阶段,对于成年鸡的死亡率相对较低,但是会对其生产性能和机体健康状况造成严重的损伤,进而影响鸡养殖的经济效益。该文主要对鸡养殖中葡萄球菌感染的临床症状,解剖检查变化及相关的防治措施进行论述。  相似文献   

2.
Day-old chickens were vaccinated with the SA2 strain of infectious laryngotracheitis vaccine using a coarse spray and 14-day-old chickens were vaccinated using a coarse or a fine (Turbair Vaccinair 240) spray. The Conjunctiva was the most common site of infection in all cases but this almost invariably led to involvement of the nasolacrimal ducts. Other sites in the nasal cavity were affected less frequently. The clinical consequences of infection in day-old chickens were too severe for field use but the mortality (0 to 1.4% in different experiments) in 14-day-old chickens may be acceptable in some circumstances although about 9% developed infection of the trachea. It is concluded that a less pathogenic vaccine is needed if spray vaccination with ILT is to be recommended as a routine procedure particularly for day-old chickens.  相似文献   

3.
雏鸡感染传染性法氏囊病病毒后红细胞免疫功能的观察   总被引：2，自引：0，他引：2  
用经传染性法氏囊病(IBD)弱毒苗免疫和未免疫的蛋鸡为试验动物,检测了感染IBDV后雏鸡的红细胞C3b受体(RBC-C3bR)花环率和红细胞免疫复合物(RBC-IC)花环率。试验结果表明,雏鸡在感染IBDV后红细胞C3bR花环率显著(P<0.01或P<0.05)低于B组,红细胞免疫复合物(IC)花环率极显著(P<0.01)高于B组,说明感染IBDV后雏鸡红细胞的免疫调节功能受到明显抑制。  相似文献   

4.
Chickens from lines selectively bred for either a high (HH) or low (LL) antibody response to sheep erythrocytes were challenged intravenously with avian adenovirus group II (AA). Spleen size was determined 6 days later. In some experiments the responses of chickens to AA and Escherichia coli infections were compared. The level of corticosterone in the feed (15 mg/kg) which resulted in the lowest incidence of pericarditis in response to E. coli resulted in the greatest incidence of large spleens in response to AA infection. Incidence of enlarged spleens in response to AA infection was increased in fasted chickens and reduced in socialized LL-line chickens. Among ignored chickens harshly treated for 2 weeks before challenge, LL-line chickens had a higher incidence of enlarged spleens than HH-line chickens. Socialized HH-line chickens subjected to social stress 1 day before challenge had more severely affected spleens than socialized LL-line chickens. The HL cross was more severely affected by AA than the LH cross but was less severely affected by E. coli. Antibody responsiveness to sheep erythrocytes did not affect the severity of AA infection. Factors that increased the severity of AA infection seemed to result in a decreased severity of E. coli infection.  相似文献   

5.
This is a comparative study on seroconversion to chicken infectious anemia virus (CIAV) in a closed flock of specific-pathogen-free chickens undergoing a natural outbreak and after vaccination of some of these flocks with a commercial, live vaccine. The N2a strain (B21B21 haplotype) had the highest seroconversion after natural infection (94%) or vaccination (100%), followed by the P2a strain (B19B19) at 75%-82% seroconversion after natural infection and 85% seroconversion after vaccination. The S13 (B13B13) chickens were 26% seropositive after natural infection and 75% seropositive after vaccination. N2a chickens with polymerase chain reaction (PCR)-positive tissues were 97% seropositive compared to 80%-83% PCR-positive and seropositive for the P2a chickens and only 8% seropositive and PCR-positive for the S13 chickens. Seroconversion occurred at or near sexual maturity after natural infection in seven flocks studied.  相似文献   

6.
Inbred chickens SC (B2B2) and TK (B15B21) display different levels of susceptibility to Eimeria acervulina infection. Following primary and secondary infections, SC chickens showed significantly lower oocyst production compared to TK chickens. Both strains produce significantly fewer oocysts during secondary infection (si) indicating that a protective host immune response had developed subsequent to primary infection (pi). To elucidate the immunologic differences between SC and TK chickens that may account for their different levels of disease susceptibility, cellular and molecular parameters of intestinal immunity were compared. CD4 T-lymphocytes increased significantly and more rapidly post-pi and si in SC relative to TK chickens during the later stages of infections. However, later during the infections, CD4 cells were higher in TK compared to SC chickens. Although the percentage of CD8 lymphocytes increased in both strains after pi, following si the percentage of these cells continued to increase in SC chickens but showed a marked decrease in TK chickens. Contrary to the effects on CD4 cells, the percentage of TCR1 cells was higher in TK chickens early after pi while the same cell subset was higher in SC chickens later following infection. The percentages of TCR2 cells were significantly higher in both strains following pi. At the molecular level, IFN-gamma mRNA expression in caecal tonsils and splenic lymphocytes was generally higher in SC compared to TK chickens following E. acervulina infection, while intraepithelial lymphocytes from the duodenum demonstrated reduced levels of this cytokine in both the strains, particularly following pi. TGF-beta4 mRNA levels generally increased in lymphocytes from the caecal tonsils, spleen and duodenum from both the strains. These differences in lymphocyte subpopulations and cytokine mRNA expression between SC and TK chickens following E. acervulina infection indicate a complex genetic control of the native immune response to coccidiosis.  相似文献   

7.
The present study is the first demonstration of an association of the genetic serum Mannan-binding lectin (MBL) concentration with bacterial infections in chickens. The genetic serum MBL concentration was determined in two chicken breeds, and the association with the specific Pasteurella multocida humoral immune response during an experimental infection was examined. Furthermore, we examined the association of the genetic serum MBL concentration with systemic infection. The chickens with systemic infection had a statistically significant lower mean serum MBL concentration than the rest of the chickens, suggesting that MBL plays an important role against P. multocida. A statistically significant negative correlation was found between the specific antibody response and the genetic serum MBL concentration for both breeds. This indicates that MBL in chickens is capable of acting as the first line of defence against P. multocida by diminishing the infection before the adaptive immune response takes over.  相似文献   

8.
试验旨在从免疫遗传学的角度初步探讨藏鸡（TC）和隐性白羽鸡（RWC）对柔嫩艾美耳球虫（Eimeria tenella）易感性差异的分子机制,分别用1×105个柔嫩艾美耳球虫孢子化卵囊感染对球虫具有抗性的藏鸡和易感的隐性白羽鸡。应用实时荧光定量PCR检测藏鸡和隐性白羽鸡感染前0 d和感染后第2、4、6和8天脾脏、盲肠、胸腺、法氏囊中γ-干扰素（IFN-γ）、白细胞介素-2（IL-2）、IL-16、Toll样受体（TLR3）和TLR15免疫相关基因的转录水平变化。结果显示,藏鸡脾脏IFN-γ、IL-2、IL-16及TLR3、TLR15免疫相关基因转录水平于感染后第4和8天明显上调,隐性白羽鸡则无明显变化。藏鸡盲肠IFN-γ转录水平在感染后第2天显著上调（P<0.05）,TLR3在感染后第4天起显著上调（P<0.05）,其余免疫相关基因变化幅度不大;隐性白羽鸡盲肠IFN-γ转录水平在感染后第8天显著上调（P<0.05）,IL-2在感染后第2天起显著上调（P<0.05）,IL-16在感染后第6天起显著上调（P<0.05）,TLR3在感染后第2和8天显著上调（P<0.05）,TLR15变化幅度不大。各免疫相关基因在2个品种鸡胸腺和法氏囊中均出现上调或下调,但除藏鸡法氏囊TLR3和TLR15转录水平变化幅度相对较大外,其余免疫相关基因与感染前相比变化幅度不大。以上结果显示,球虫感染主要导致藏鸡和隐性白羽鸡脾脏和盲肠中的各免疫相关基因出现显著变化,表明宿主的遗传背景在一定程度上可影响球虫感染的免疫应答。  相似文献   

9.
Avian intestinal spirochaetosis (AIS) is a disease complex affecting adult laying and breeding chickens associated with infection by anaerobic intestinal spirochaetes of the genus Brachyspira. Options for control of AIS are limited, as few effective antimicrobial agents are registered for use in laying chickens. One of the two most commonly encountered pathogenic species in AIS is B. intermedia, and the aim of the current study was to determine whether a B. intermedia bacterin vaccine would help control AIS caused by this species. An autogenous bacterin was prepared from B. intermedia strain HB60 and given twice intramuscularly at a 3-week interval to 12 laying chickens housed in individual cages. Twelve non-vaccinated control chickens were placed in adjacent cages in the same room. Two weeks after the second vaccination all the chickens were experimentally challenged with B. intermedia HB60 by crop tube. Subsequently faeces were cultured for spirochaetes every 2-3 days, faecal water content and chicken weight were measured weekly, and egg numbers and weights were recorded daily. Serum was taken prior to both vaccinations, at the time of challenge and at euthanasia. The chickens were killed 6 weeks post-challenge. The vaccinated chickens showed seroconversion to the vaccine, but antibody levels declined significantly post-infection. In comparison, the non-vaccinated chickens showed seroconversion post-infection. The reason for the reduction in the antibody levels in the vaccinated chickens after infection was not explained. At some point all the chickens excreted spirochaetes in their faeces, and the duration of excretion was not different between vaccinated and non-vaccinated chickens. There were no differences in faecal water content, chicken weights, egg production, or gross and microscopic caecal lesions between vaccinated and non-vaccinated chickens. In conclusion, an autogenous bacterin vaccine did not prevent infection with B. intermedia in laying chickens.  相似文献   

10.
The role of cell-mediated immunity (CMI) in pathogenesis of infectious bursal disease virus (IBDV) was investigated. One-day-old specific pathogen-free chickens were treated with 3mg of cyclophosphamide (Cy) per chicken for 4 consecutive days and, 3 weeks later, infected with the IBDV-IM strain. Chickens were examined for: (a) mitogenic response of splenocytes to ConA, as an indicator of T-cell functions in vitro, (b) antibody against IBDV by ELISA, (c) IBDV genome in various tissues by RT-PCR and (d) immunological memory. At the time of IBDV infection, Cy-treated chickens had depleted bursal tissue (an avian primary B-cell lymphoid organ), severely compromised antibody-producing ability, but normal T-cell response to ConA. In primary infection, no detectable antibody against IBDV antigen in Cy-treated, IBDV-infected chickens was observed up to 28 days post-infection (PI), while IBDV genome was detected by RT-PCR in spleen, thymus, liver and blood until 10 days PI. Like intact control chickens infected with IBDV, Cy-treated, IBDV-infected chickens suppressed splenocytes responses to ConA from 5 to 10 days PI, suggesting that intact control as well as Cy-treated chickens responded similarly to IBDV infection in the early phase. Following re-infection with IBDV, no detectable secondary antibody response to IBDV as well as IBDV genome in tissues were observed in Cy-treated chickens, while intact control chickens developed vigorous secondary antibody response. Similar to intact control chickens infected with IBDV, Cy-treated chickens after second infection with IBDV did not suppress splenocyte response to ConA. These results suggested that in the absence of detectable anti-IBDV antibodies, protection of Cy-treated chickens from IBDV infection may occur via immunological memory mediated by CMI. We concluded that under normal conditions, IBDV induces a protective antibody response, however, in the absence of antibody, CMI alone is adequate in protecting birds against virulent IBDV.  相似文献   

11.
Avian leukosis virus subgroup J has a high tropism for myeloid lineage cells and frequently induces neoplastic transformation of myelocytes. The impact of congenital avian leukosis virus subgroup J infection on the function of circulating heterophils and susceptibility to staphylococcal infection was investigated. Six-week-old broiler chickens negative for exogenous avian leukosis viruses or congenitally infected with avian leukosis virus subgroup J were inoculated intravenously with 10(6) colony-forming units of Staphylococcus aureus, and pre- and postinoculation heterophil function was assessed. All chickens developed a leukocytosis with heterophilia after inoculation, but total leukocyte and heterophil counts were significantly higher in leukosis-negative chickens than in virus-infected chickens. Tenosynovitis was more severe in leukosis-negative chickens, and 2/10 (20%) of the virus-infected chickens had no histologic evidence of tenosynovitis. Osteomyelitis in the tibiotarsus or tarsometatarsus developed in 5/10 (50%) of the chickens in each group. S. aureus was recovered from the hock joint of 6/10 (60%) of the chickens in each group. Heterophils from all chickens exhibited similar phagocytic ability pre- and postinoculation. Heterophils from virus-infected chickens exhibited less bactericidal ability preinoculation than did heterophils from leukosis-negative chickens. However, postinoculation bactericidal ability was similar in both groups. Avian leukosis virus subgroup J provirus was present in heterophils isolated from congenitally infected chickens. Heterophils isolated from broiler chickens congenitally infected with avian leukosis virus subgroup J exhibit no significant functional deficits, and infected and uninfected chickens exhibit similar susceptibility to staphylococcal infection.  相似文献   

12.
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13.
Serofibrinous pleuropneumonia in a piglet was examined microbiologically and immunohistopathologically. Large numbers of Morganella morganii were isolated from the pneumonic lesion, but no other pathogens were identified. A large amount of M. morganii antigen was demonstrated, and its distribution was closely associated with the histologic lesion. This finding suggests that pleuropneumonia in piglets might be caused by M. morganii.  相似文献   

14.
内源性NO在雏鸡球虫感染中的作用   总被引：3，自引：0，他引：3  
以腹腔注射途径给予感染柔嫩艾美耳球虫 (E.tenella)雏鸡细菌脂多糖 (L PS)和地塞米松 (Dex) ,用铜离子活化镉还原法检测血清 NO- 2 水平 ,并通过测定 NBT阳性细胞百分率、雏鸡增重、免疫器官的脏器系数、OPG值以及盲肠病变记分等指标 ,探讨了 NO在雏鸡感染球虫过程中的作用。试验结果表明 ,与空白对照组相比 ,给予 L PS可使 NBT阳性细胞百分率明显升高 (P<0 .0 1) ,并使盲肠病变及球虫感染引起的增重下降有所减轻 ,这提示 L PS对雏鸡具一定的保护作用 ;而给予 Dex不仅降低了感染雏鸡血清 NO- 2 的水平、NBT阳性细胞百分率、增重和胸腺的脏器系数 ,还增加了 OPG值和盲肠病变记分 ,说明在雏鸡感染球虫过程中 ,Dex会减少 NO的生成 ,并使雏鸡抗球虫免疫力下降。  相似文献   

15.
To study effects of experimental cryptosporidiosis, broiler chickens were infected per os with 5 x 10(5) oocysts of Cryptosporidium baileyi and Cryptosporidium meleagridis. In the first experiment, chickens were infected with oocysts of C. baileyi at the age of 7, 14, and 21 days. In the second experiment, chickens were infected with oocysts of C. baileyi, C. meleagridis, or both cryptosporidial species at the age of 7 days. Although clinical signs of infection were apparent, neither final live weight nor mortality was significanty influenced in chickens infected with a single Cryptosporidium species. In chickens infected with C. meleagridis, the growth retardation was observed in the 2-wk period after infection. The compensatory growth, however, started when the oocyst shedding had ceased. The number of oocysts in excreta specimens of chickens infected with C. meleagridis was two to three times lower than in excreta of chickens infected with C. baileyi. Chickens infected with both C. baileyi and C. meleagridis (5 x 10(5) oocysts of each) had significantly lower final live weight and worse feed efficiency than chickens of other groups. Concurrent infection did not influence individual C. baileyi or C. meleagridis oocyst shedding.  相似文献   

16.
Broiler chickens free of maternal immunity to reticuloendotheliosis virus (REV) were used in the experiment. Two groups of 25 chickens were inoculated with REV at one day of age. One of these groups and another group of 25 chickens were inoculated with Eimeria tenella sporulated oocysts at 7 days of age. Chickens inoculated with E. tenella showed bloody diarrhoea from 12 to 14 days of age. Six out of 25 chickens died (P less than 0.05) at 13 and 14 days of age in the dual infected group. At 14 days of age, when chickens were killed, the lesion score in the combined infection group, was statistically different from that in the chickens inoculated with E. tenella alone. Also the weights of the bursa of Fabricius and thymus were lower in the two REV infected groups than in the controls. Although REV infection alone adversely affected the weight gain and feed conversion, with combined infection this effect was much greater. Following REV inoculation most of the chickens showed feathering defects and all the examined chickens were viraemic at 21 days of age. At the same age, all but one chicken failed to show precipitating antigenaemia and about one-half of these chickens showed a very low serum neutralisation titre. None of these chickens showed precipitating antibodies.  相似文献   

17.
Various parasite- and host-related factors influencing disease susceptibility and development of protective immunity against Eimeria tenella infection were investigated in two inbred strains of chickens. Chickens that received a primary inoculation of 10(3), 10(4), or 10(5) oocysts showed a significant reduction in packed cell volume and produced significantly more oocysts than chickens inoculated with fewer oocysts. Younger chickens were as susceptible as older chickens to identical parasite doses. However, upon a secondary inoculation 5 weeks following primary inoculation, FP chickens 1 to 21 days old at the time of primary inoculation developed resistance to reinfection, whereas SC chickens less than 3 weeks old at the time of primary inoculation were highly susceptible to secondary infection. Flow cytometric analysis of spleen lymphocytes showed a substantial reduction in T-cell number in 1-day-old SC but not FP chickens. Furthermore, 1-week-old SC chickens showed depressed mitogenic responses to concanavalin A compared with 1-week-old FP chickens. There was no significant difference between SC and FP chickens in speen B-cell number, regardless of age.  相似文献   

18.
Anticoccidial effects of green tea (GT)-based diets were evaluated in chickens following oral infection with Eimeria maxima an ubiquitous intestinal parasite of poultry that impairs the growth and feed efficiency of infected birds. Five-week-old chickens were assigned to four groups (GT 0.5%, GT 2.0%, untreated/infected and non-infected control) and each group consisted of 15 chickens. Chickens were fed a standard diet supplemented with ground green tea for 2 weeks prior to infection with E. maxima (10,000 sporulated oocysts per bird). The effects of green tea on E. maxima infection were assessed by two parameters, fecal oocyst shedding and body weight gain. The green tea-fed chickens produced significantly reduced fecal oocysts (P<0.05) when compared to the E. maxima-infected group fed standard diet. The green tea-based diet, however, did not improve body weight loss caused by E. maxima infection. This study is the first to demonstrate anticoccidial effect of green tea on Eimeria parasites.  相似文献   

19.
Han MG  Kim SJ 《Avian diseases》2003,47(2):261-271
The efficacy of four different commercial live vaccines (vaccines A, B, C, and D) against the infectious laryngotracheitis virus (ILTV) was assessed in specific-pathogen-free (SPF) chickens. SPF chickens were vaccinated intraocularly at 6 wk old with ILTV live vaccines and were challenged intratracheally with the N91B01 strain of virulent Korean ILTV 2 wk after vaccination. The immunity against ILTV live vaccines was assessed by the incidence of latent infection by the challenge virus in the chickens' tracheas and trigeminal ganglia, the reisolation rate of the challenge virus, and the clinical signs in the chickens challenged with the N91B01 strain of ILTV. The latent infection in chickens was assessed by nested polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Our data showed that the clinical signs and challenge virus isolation were negative in all chickens receiving four difference commercial ILTV live vaccines. The viral DNA of the vaccine strain, but not that of the challenge virus, was detected in chickens vaccinated with vaccine A by nested PCR-RFLP. The viral DNAs of both the vaccine and challenge strains were detected from chickens vaccinated with vaccines B, C, and D. This study showed that only vaccine A can protect chickens from latent infection with the field virulent ILTV. We speculate that the efficacy of infectious laryngotracheitis live vaccines to protect chickens from latent infection with virulent ILTVs can be assessed by nested PCR-RFLP analysis.  相似文献   

20.
The effects of oral administration of sugar cane extracts (SCE) on Eimeria tenella oocysts infection in chickens were studied with 2 different experiments. In Experiment 1, 3-week-old inbred chickens (MHC; H.B15) were inoculated into the crop with SCE (500 mg/kg/day) for 1 day or 3 consecutive days, and then challenged with E. tenella sporulated oocysts (2 x 10(4) cells/chicken). In Experiment 2, 1-week-old chickens were orally administered SCE at the same dose for 3 consecutive days, and then initially infected with E. tenella sporulated oocysts (2 x 10(3) cells/chicken). At 2 and 3 weeks of age, these chickens were immunized intravenously with the mixed antigens of sheep red blood cells (SRBC) and Brucella abortus (BA). At 4 weeks of age, chickens were challenged with E. tenella sporulated oocysts (1 x 10(5)/chicken). Challenged chickens with E. tenella oocysts showed markedly decreased body weight gain/day, severe hemorrhage and great number of shedding oocysts in feces and high lesion scores. Oral administration of SCE and initial infection with oocysts (2 x 10 (3)/chicken) resulted in a remarkable improvement in body weight gain/day, hemorrhage, the number of shedding oocysts and lesion score, compare to other infected groups. In addition, SCE-inoculated chickens with the initial infection showed a significant increase in antibody responses against SRBC and BA and also improvement in decreased relative proportions of Bu-1a(+) and CD4( )cells in cecal tonsil lymphocytes of E. tenella-challenged chickens. Cecal tissues of chickens administered SCE and initially infected with E. tenella oocysts showed lower numbers of schizonts, gametocytes and oocysts than those of infected control chickens. These results suggest that SCE have immunostimulating and protective effects against E. tenella infection in chickens.  相似文献   

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