Hines Murray E, Stiver Shane, Giri Dipak, Whittington Lisa, Watson Cindy, Johnson Jill, Musgrove Julie, Pence Mel, Hurley David, Baldwin Charles, Gardner Ian A, Aly Sharif
University of Georgia, Tifton Veterinary Diagnostic and Investigational Laboratory, Tifton, GA 31793, USA.
Vet Microbiol. 2007 Mar 10;120(3-4):261-83. doi: 10.1016/j.vetmic.2006.10.030. Epub 2006 Oct 29.
A Mycobacterium avium subspecies paratuberculosis (MAP) vaccine that reduced the incidence of clinical disease or reduced fecal shedding of MAP would aid control of Johne's disease (JD). The objective of the present study was to evaluate the efficacy of four MAP vaccine combinations, including cell-wall competent (CWC) alum adjuvant, CWC-QS21 adjuvant, cell-wall deficient (CWD) alum adjuvant and CWD-QS21 adjuvant vaccines. Eighty baby goats were vaccinated at 1 and 4 weeks of age with one of these vaccines or a sham control vaccine consisting of alum adjuvant. Kids were challenged orally with approximately 6.0x10(9) organisms in four divided doses of 1.5x10(9) organisms using a goat isolate of MAP. Vaccinated challenged and challenged control groups had 10 and 6 kids per group, respectively. Half of the kids within each group were necropsied at either 6 or 9 months post-challenge. Gross and microscopic lesions and relative number of acid-fast bacilli were evaluated and scored at necropsy. Results indicated all challenged kids had some lesions compatible with JD suggesting none of the vaccines prevented infection. Three vaccines (CWC-alum, CWC-QS21 and CWD-QS21) reduced lesion scores by 46-51% at 9 months. CWD-alum vaccine resulted in a more severe (+33.5%) lesion score than sham-vaccinated challenged control. Lesion scores were greater at 9 months than at 6 months post-challenge in the sham-vaccinated challenged group and CWD-alum vaccinated group, while lesion scores were generally stable with remaining vaccines. Mean fecal CFU/g were significantly different across time from challenge to 9-month necropsy (p=0.043) and the CWC-QS21 vaccine group had a marked reduction in fecal CFU/g at all time points post-challenge. A reduction in MAP CFU/g was also detected in necropsy tissues from kids given the CWC-alum, CWC-QS21 and CWD-QS21 vaccines, and increased CFU/g were detected in tissues from kids given the CWD-alum vaccine. Immunological tests evaluated included, humoral response evaluation by AGID, ELISA and Western blot, and cell mediated response by comparative PPD skin testing (M. avium, Old Johnin, M. bovis and Lot 2 Johnin PPD's), and production of MAP induced gamma-interferon. Vaccination also resulted in false-positive PPD skin test reactions for M. avium PPD, Old Johnin PPD and gamma-interferon tests. When a 2-mm cutoff above normal skin thickness was used to define positive skin test reactions, false-positive reactions for M. bovis were detected in only 2 of 32 kids given a vaccine with QS21 adjuvant.
一种能降低副结核分枝杆菌（MAP）临床疾病发病率或减少MAP粪便排出量的疫苗，将有助于控制约内氏病（JD）。本研究的目的是评估四种MAP疫苗组合的效力，包括细胞壁活性（CWC）明矾佐剂、CWC-QS21佐剂、细胞壁缺陷（CWD）明矾佐剂和CWD-QS21佐剂疫苗。80只小山羊在1周龄和4周龄时用这些疫苗之一或由明矾佐剂组成的假对照疫苗进行接种。使用MAP山羊分离株，以四个1.5x10⁹个菌体的分剂量，给小羊口服接种约6.0x10⁹个菌体。接种后攻毒组和攻毒对照组每组分别有10只和6只小羊。每组一半的小羊在攻毒后6个月或9个月进行剖检。在剖检时评估大体和显微镜下病变以及抗酸杆菌的相对数量并进行评分。结果表明，所有攻毒的小羊都有一些与JD相符的病变，这表明没有一种疫苗能预防感染。三种疫苗（CWC-明矾、CWC-QS21和CWD-QS21）在9个月时使病变评分降低了46%-51%。CWD-明矾疫苗导致的病变评分比假接种攻毒对照组严重（+33.5%）。在假接种攻毒组和CWD-明矾接种组中，攻毒后 nine months时的病变评分高于6个月时，而其余疫苗的病变评分总体稳定。从攻毒到9个月剖检期间，粪便CFU/g的平均值在不同时间有显著差异（p=0.043），并且CWC-QS21疫苗组在攻毒后的所有时间点粪便CFU/g都有显著降低。在接种CWC-明矾、CWC-QS21和CWD-QS21疫苗的小羊的剖检组织中也检测到MAP CFU/g的减少，而在接种CWD-明矾疫苗的小羊的组织中检测到CFU/g增加。所评估的免疫学检测包括通过AGID、ELISA和Western印迹评估体液反应，以及通过比较PPD皮肤试验（鸟分枝杆菌、旧结核菌素、牛分枝杆菌和批次2结核菌素PPD）评估细胞介导反应，以及检测MAP诱导的γ-干扰素的产生。接种疫苗还导致鸟分枝杆菌PPD、旧结核菌素PPD和γ-干扰素检测出现假阳性PPD皮肤试验反应。当使用比正常皮肤厚度高2毫米的截断值来定义阳性皮肤试验反应时，在接种QS21佐剂疫苗的32只小羊中，只有2只检测到牛分枝杆菌的假阳性反应。
