Ramsey Kyle H, Sigar Ira M, Schripsema Justin H, Townsend Kathryn E, Barry Randall J, Peters Jan, Platt Kenneth B
Microbiology and Immunology Department, Midwestern University, Downers Grove, Illinois, 60515, USA
Microbiology and Immunology Department, Midwestern University, Downers Grove, Illinois, 60515, USA.
Pathog Dis. 2016 Apr;74(3). doi: 10.1093/femspd/ftv129. Epub 2016 Jan 4.
To determine if Chlamydia muridarum, or other chlamydiae, are enzootic in rodents, we probed a serum bank of wild Peromyscus spp. mice for immunoglobulin G-antibody reactivity to ultraviolet light-inactivated C. muridarum elementary bodies (EBs) using an enzyme-linked immunoassay. Applying a cut-off for a positive reaction of OD(405) nm = 0.1 at a 1:20 dilution, we found titratable antibody reactivity in 190 of 247 specimens surveyed (77%, mean OD(405) = 0.33 ± 0.26, range = 0.11-1.81, median = 0.25). In addition, serum samples were obtained from a colony of specific pathogen-free Peromyscus spp. maintained at the University of South Carolina and six of 12 samples were reactive (50%, mean OD(405) = 0.19 +/- 0.08, range = 0.1-0.32, median = 0.18). Lastly, 40 additional wild Peromyscus spp. were captured in a disparate region of Midwestern USA and 22 serum specimens were reactive (55%, mean OD(405) = 0.22 +/- 0.11, range = 0.1-0.48, median = 0.2). Specificity of selected reactive sera for chlamydial antigen was confirmed on Western blot using resolved purified EBs as the detecting antigen. From tissues removed from several mice at necropsy, the gene for chlamydial 16S ribosomal ribonucleic acid (rRNA) was amplified by polymerase chain reaction (PCR). Positive samples of 16S rRNA were subjected to additional PCR for the major outer membrane protein gene (ompA). The amplicons of three select ompA positive samples were sequenced with ≥99% homology with C. muridarum. Our findings indicate that chlamydial infection is enzootic for Peromyscus spp., and that C. muridarum, or a closely related species or strain, is likely the agent in the tested rodent species.
为了确定鼠衣原体或其他衣原体是否在啮齿动物中呈地方流行性，我们使用酶联免疫测定法，检测了野生鹿鼠属小鼠血清库中针对紫外线灭活的鼠衣原体原体（EBs）的免疫球蛋白G抗体反应性。以1:20稀释时OD(405) nm = 0.1作为阳性反应的临界值，我们在所检测的247个标本中的190个中发现了可滴定的抗体反应性（77%，平均OD(405) = 0.33±0.26，范围 = 0.11 - 1.81，中位数 = 0.25）。此外，从南卡罗来纳大学饲养的无特定病原体鹿鼠属群体中获取血清样本，12个样本中有6个呈反应性（50%，平均OD(405) = 0.19 +/- 0.08，范围 = 0.1 - 0.32，中位数 = 0.18）。最后，在美国中西部一个不同区域捕获了另外40只野生鹿鼠属小鼠，并对22份血清标本进行检测，其中12份呈反应性（55%，平均OD(405) = 0.22 +/- 0.11，范围 = 0.1 - 0.48，中位数 = 0.2）。使用分离的纯化EBs作为检测抗原，通过蛋白质印迹法确认了所选反应性血清对衣原体抗原的特异性。在尸检时从几只小鼠身上取下的组织中，通过聚合酶链反应（PCR）扩增了衣原体16S核糖体核糖核酸（rRNA）基因。对16S rRNA阳性样本进行额外的主要外膜蛋白基因（ompA）PCR检测。对三个选择的ompA阳性样本的扩增子进行测序，与鼠衣原体的同源性≥99%。我们的研究结果表明，衣原体感染在鹿鼠属中呈地方流行性，并且鼠衣原体或密切相关的物种或菌株可能是所检测啮齿动物物种中的病原体。
