Vaughn L E, Holt P S, Moore R W, Gast R K, Anderson K E
Egg Safety & Quality Research Unit, Russell Research Center, USDA-ARS, 950 College Station Road, Athens, GA 30605, USA.
Avian Dis. 2008 Mar;52(1):79-87. doi: 10.1637/7982-040907-Reg.
The crop immune response against Salmonella Enteritidis (SE) challenge in eight commercial egg-layer strains (five white-egg layer and three brown-egg layer) and specific-pathogen-free (SPF) White Leghorn (WL) hens was investigated. Pre- and post-SE challenge mucosal immune responses within the crops were evaluated. Commercial layers and SPF WL hens were orally challenged with 10(8) CFU/ml SE PT13a and SE nalR PT13, respectively. Crop lavage samples were collected at weekly intervals from day 0 (pre-challenge) to day 25-27 postinfection (PI), and bacteriological examination was performed to monitor progression of SE infection. Crop lavage samples were analyzed for SE-lipopolysaccharide (LPS)-specific IgA using enzyme-linked immunosorbent assay (ELISA). H&E-stained slides of crop sections from day 34 PI and uninfected controls were assessed for lymphoid tissue via light microscopy. Lymphoid areas were graded based on morphology, size, and cellularity using a score 0 to 5 scale. The 0 to 5 (low to high) numerical values represented progressive increases in size and cellular density of lymphoid tissue. Bacterial culture results showed the highest percentage of SE-positive crop lavage samples from all hen groups at day 5-6 PI and day 11-12 PI. A progressive decline in percentage of SE-positive crop lavage samples did occur as time PI lengthened; however, at day 25-27 PI SE persisted in crop lavage samples from SPF WL hens and three commercial white-egg layer strains. A marked increase in SE-LPS-specific IgA was measured in crop lavage samples between day 0 and day 11-12 PI for all hen groups. Crop SE-LPS-specific IgA response remained elevated above day 0 baseline for the duration of the experiment. Well-defined score 3 to 5 lymphoid tissue aggregates were observed in crop tissue sections harvested at day 34 PI. Comparison of crop sections determined a 1.2-4.0 times increase in ratio of lymphoid tissue in day 34 PI SE-challenged hens vs. uninfected control hens.
研究了8种商业蛋鸡品系（5种白壳蛋鸡和3种褐壳蛋鸡）以及无特定病原体（SPF）白来航鸡（WL）对肠炎沙门氏菌（SE）攻击的嗉囊免疫反应。评估了SE攻击前后嗉囊内的黏膜免疫反应。分别用10(8) CFU/ml SE PT13a和SE nalR PT13对商业蛋鸡和SPF WL母鸡进行口服攻击。从感染前第0天到感染后（PI）第25 - 27天，每周采集嗉囊灌洗样本，并进行细菌学检查以监测SE感染的进展。使用酶联免疫吸附测定（ELISA）分析嗉囊灌洗样本中的SE - 脂多糖（LPS）特异性IgA。通过光学显微镜对感染后第34天的嗉囊切片和未感染对照的苏木精 - 伊红（H&E）染色玻片进行淋巴组织评估。根据形态、大小和细胞性，使用0至5分的评分标准对淋巴区域进行分级。0至5（低至高）的数值表示淋巴组织大小和细胞密度的逐渐增加。细菌培养结果显示，在感染后第5 - 6天和第11 - 12天，所有母鸡组的SE阳性嗉囊灌洗样本百分比最高。随着感染后时间延长，SE阳性嗉囊灌洗样本的百分比确实逐渐下降；然而，在感染后第25 - 27天，SPF WL母鸡和3种商业白壳蛋鸡品系的嗉囊灌洗样本中仍存在SE。在感染后第0天至第11 - 12天期间，所有母鸡组的嗉囊灌洗样本中SE - LPS特异性IgA均显著增加。在整个实验期间，嗉囊SE - LPS特异性IgA反应一直高于感染前第0天的基线水平。在感染后第34天采集的嗉囊组织切片中观察到明确的3至5分的淋巴组织聚集。对嗉囊切片的比较确定，感染后第34天受SE攻击的母鸡与未感染对照母鸡相比，淋巴组织比例增加了1.2至4.0倍。
