McNeilly F, Walker I, Allan G M, Foster J C, Linne T, Merza M, Hernandez P, Kennedy S, Adair B
Department of Agriculture for Northern Ireland, Veterinary Sciences Division, Belfast.
J Vet Diagn Invest. 1997 Jan;9(1):3-9. doi: 10.1177/104063879700900102.
La Piedad Michoacan paramyxovirus (LPMV) is newly recognized paramyxovirus that has been associated with neurologic and reproductive disorders in pigs in Mexico. To date, no comparative study of methods for the diagnosis of infection with this virus has been published. In this study, we identified tissues containing maximum virus load to optimize virus isolation procedures, and we compared this method to a rapid diagnostic test employing immunostaining of impression smears for LPMV antigens. In addition, several of the available tests for detecting LPMV antibodies were compared for their sensitivity in detecting seroconversion. Pigs used for the study of virus load in tissues and serologic studies were inoculated at 17 days of age with 10(7.00) TCID50 of LPMV. Serial blood samples were collected from selected pigs, and selected pigs were necropsied over a 14-day period. Pigs used in the investigation comparing standard virus isolation techniques to immunostaining of impression smears were inoculated at 3 days of age as described above and necropsied over an 8-day period. The results demonstrate that in the 17-day-old pigs maximum virus titers were detected in olfactory bulb at 5 days postinoculation (PI) and in midbrain at 9 days PI. In addition, the most consistent recovery of high titer virus was from tonsil (3-9 days PI) and olfactory bulb (4-9 days PI). Immunostaining of impression smears was as sensitive as virus isolation when selected tissues (lung, midbrain, olfactory bulb) were compared, with virus detected by both methods in 11/13 samples and in 1 sample each by immunostaining and virus isolation, respectively. All of the serology tests investigated detected seroconversion in pigs by 8 days PI. The identification of target organs where highest virus titers are found combined with immunofluorescent methods for the detection of LPMV antigens and a comparative study of the available serologic tests should facilitate the selection of techniques suitable for any laboratory to diagnose LPMV infection in pigs.
米却肯州拉皮德德副粘病毒（LPMV）是一种新发现的副粘病毒，与墨西哥猪的神经和生殖系统疾病有关。迄今为止，尚未发表关于该病毒感染诊断方法的比较研究。在本研究中，我们确定了病毒载量最高的组织，以优化病毒分离程序，并将该方法与采用免疫染色检测LPMV抗原的快速诊断试验进行比较。此外，还比较了几种现有的检测LPMV抗体的试验在检测血清转化方面的敏感性。用于组织病毒载量研究和血清学研究的猪在17日龄时接种10(7.00) TCID50的LPMV。从选定的猪身上采集系列血样，并在14天内对选定的猪进行剖检。用于比较标准病毒分离技术与印片免疫染色的猪在3日龄时按上述方法接种，并在8天内进行剖检。结果表明，在17日龄的猪中，接种后5天在嗅球中检测到最高病毒滴度，接种后9天在中脑检测到最高病毒滴度。此外，高滴度病毒最一致的回收部位是扁桃体（接种后3 - 9天）和嗅球（接种后4 - 9天）。当比较选定的组织（肺、中脑、嗅球）时，印片免疫染色与病毒分离一样敏感，两种方法在13个样本中的11个样本中都检测到了病毒，免疫染色和病毒分离分别在1个样本中检测到了病毒。所有研究的血清学试验在接种后8天均检测到猪的血清转化。确定发现最高病毒滴度的靶器官，结合检测LPMV抗原的免疫荧光方法以及对现有血清学试验的比较研究，应有助于选择适合任何实验室诊断猪LPMV感染的技术。
