Avian Metapneumovirus Subgroup C Infection in Chickens,China

Avian metapneumovirus causes acute respiratory tract infection and reductions in egg production in various avian species. We isolated and characterized an increasingly prevalent avian metapneumovirus subgroup C strain from meat-type commercial chickens with severe respiratory signs in China. Culling of infected flocks could lead to economic consequences.     

Involvement of the PKC–NF–κB signaling pathway in the regulation of T lymphocytes proliferation of chickens by conjugated linoleic acids

The involvement of protein kinase C (PKC) and nuclear factor-κB (NF-κB) signaling pathway in immunoregulatory actions of conjugated linoleic acid (CLA) in chicken T lymphocyte was investigated. T lymphocytes in peripheral blood were isolated and cultured. The PKC and NF–κB inhibitors, staurosporine (SP) and pyrrolidine dithiocarbamate (PDTC), were used. SP inhibited the production of PKC, and PDTC partly blocked the NF–κB mRNA relative expression. Data suggested compared with c9, t11-CLA and t10, c12-CLA groups, the attenuated effects were showed in SP or PDTC treatment with the application of CLA, which suggested PKC and NF–κB mediated in the immunity of CLA. Furthermore, SP and PDTC inhibited the IL-2 secretion and T lymphocyte proliferation. SP or PDTC induced reduction of IL-2 secretion and T-lymphocytes proliferation were greatly or partially attenuated by CLA isomers. In conclusion, CLA was a potent immunomodulator for T lymphocytes through targeting the PKC–NF–κB pathway.     

加味升降散对鸡传染性支气管炎体内模型的影响

目的了解加味升降散对鸡传染性支气管炎病鸡的治疗效果。方法1日龄雏鸡先适应性饲养2天后,以华农传代的IBV M41株第3继代株滴鼻、滴眼,之后随机分为6个组（正常组除外）,攻毒10小时后予以相应药物治疗,正常对照组及模型组灌等体积蒸馏水,共观察9天,期间主要观察雏鸡的症状、大小便、死亡等指标。结果模型组雏鸡发病数比其他组多,用药后症状有所改善,大剂量组与模型组比较有统计学差异,P〈0．05,中剂量组喷嚏及甩鼻症状改善和模型组有显著统计学差异,P〈0．05。其它症状虽有所改善,但和模型组比较,无统计学上差异。模型组死亡率很高,用药后可以减少死亡率,动物死亡高峰在第3～4天。结论加味升降散能有效抑制病毒,提高雏鸡抵抗力,增强抗病毒能力,能较好地改善症状,减少死亡率,对养禽业有一定保护作用。     

Staphylococcus simulans associated with endocarditis in broiler chickens

This report suggests a strong association between coagulase-negative Staphylococcus simulans and endocarditis in broiler chickens of a single flock. Clinical signs included increased mortality and lameness, and some dead chickens were found on their backs. Lesions included cauliflower-like, fibrinous vegetative lesions on the left atrioventricular valve; cream-coloured, necrotic foci of varying size in the liver; and necrosis of the femoral head. Histopathological examination of the heart revealed multifocal conglomerates of bacterial colonies attached to the valvular endocardium, threads of fibrin, and inflammatory cells with the presence of heterophils. S. simulans strains were first identified by API ID32, and then confirmed with Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry and by partial sequencing of the rpoB and dnaJ genes. These bacteria were resistant to methicillin but sensitive to vancomycin and characterized by slime production and protease activity.     

Total IgA in spleen,bursa and intestine of chickens pretreated with E. faecium AL41 and challenged with Salmonella Enteritidis PT4

The concentration of secretory IgA (sIgA) in intestine flush and solid organs (spleen, bursa) in chickens pretreated with probiotic strain Enterococcus faecium AL41 (EF) and challenged with Salmonella Enteritidis PT4 (SE) was assessed. Forty 1-day-old chickens Cobb 500 were divided into four groups: control, EFAL41, SE and combined EFAL41+SE. The increased concentration of sIgA was determined on day 4 after salmonella infection in the intestine flush in EFAL41group. In combined EFAL41+SE group significant increase of sIgA in the intestine flush was found 7 days post-infection. Pre-treatment of chickens with E. faecium AL41 also showed beneficial effect in bursa in EFAL41 and EFAL41+SE groups. In spleen, total IgA was increased only in SE group. The results demonstrated positive effect of E. faecium AL41 on IgA production in chickens' intestine and solid organs after S. Enteritidis PT4 challenge. Validity of method using for IgA evaluation in solid organ was proved.     

Eitneria tenella: immunological diversity between asexual generations

In the development of a normal strain, WIS, of Eimeria tenella there are three generations of schizogony whereas in an attenuated line, WIS-F-96, derived from WIS, the second and third are absent. Chickens immunized by infection with WIS-F-96, however, were highly resistant to oral challenge with sporulated oocysts of WIS, and histological studies indicated that the immune response was directed against the sporozoites from that challenge inoculum. When challenge of the WIS-F-96-primed chickens consisted of second generation merozoites of WIS (inoculated intracaecally), immunity was less pronounced and the histological data indicated that the merozoites proceeded to develop normally in these birds. These indications of immunological diversity between the merozoites of the first and second generations of schizogony of E. tenella WIS correlated with the results of preliminary studies of the antigenic composition of these developmental stages.     

Leukocytic response and composition of enteral microbiota in chickens fed a sage extract supplemented diet and infected with Salmonella Enteritidis PT4

The effects of sage on the enteral microbiota and leukocytic response of chickens challenged with Salmonella Enteritidis (SE) PT4 were studied. Chickens were divided into four groups: control, sage (S), SE and sage+S. Enteritidis (SSE). Groups S and SSE were fed sage extract (8.2 g kg^?1) for 21 days. Groups SE and SSE were challenged with SE (10⁸ CFU) on day 4. The administration of the sage extract to the SSE group confirmed the selective antibacterial activity on SE, and resulted in an increased number of leukocytes, lymphocytes, heterophils and phagocytic activity index at day 3 post-infection. In the early phase of the infection, there was a tendency to increase the numbers of CD3+, CD8+ and IgM+ cells in the SSE group. The later phase led to a decrease of IgM+, CD3+ and CD4+ cells, but an increase in influx of macrophages, which suggested their movement into inflammatory regions.     

不同品系养殖鸡弯曲菌感染调查

目的了解规模化养殖鸡弯曲菌感染现状。方法随机采集北京市某规模化养殖场蛋鸡(养殖时间大于120d)和肉鸡(养殖时间小于42d)肛拭子标本,采用两种分离培养方案(80份蛋鸡和200份肉鸡标本直接经选择性培养基划线培养,150份肉鸡标本经24h增菌后采用选择性培养基划线培养)进行弯曲菌的微需氧(5%O2、10%CO2和85%N2)培养。从肉鸡标本中随机选取50份,提取病原菌DNA,进行弯曲菌荧光定量PCR检测,并对相同培养条件下生长菌落进行质谱鉴定。结果 80份蛋鸡标本中分离到24株空肠弯曲菌,阳性率为30%;350份肉鸡标本未检测到弯曲菌。通过质谱菌落鉴定,205份标本检测到奇异变形杆菌,检出率为58.6%;145份标本检测到大肠埃希菌,检出率为41.4%。50份肉鸡粪便标本弯曲菌荧光定量PCR检测结果均为阴性,与分离培养结果一致。结论北京市规模化养殖蛋鸡弯曲菌感染率较高,饲养时间较短的肉鸡未发现弯曲菌感染。