Schoeb T R, Dybvig K, Davidson M K, Davis J K
Department of Comparative Medicine, University of Alabama at Birmingham 35294.
J Clin Microbiol. 1993 Oct;31(10):2751-7. doi: 10.1128/jcm.31.10.2751-2757.1993.
Cilia-associated respiratory (CAR) bacillus, an unclassified gliding bacterium associated with respiratory disease in rats, mice, and rabbits, has previously been cultivated only in embryonated chicken eggs, cell culture, or cell culture medium supplemented with conditioned medium from cultured tracheas. A reference strain of CAR bacillus, originally isolated in eggs, grew in cell culture flasks as adherent individual bacilli and ropy, whorled fascicles in cell culture media supplemented only with fetal calf serum. Using Dulbecco's minimal essential medium, we isolated CAR bacillus from naturally infected rats and a naturally infected rabbit and from experimentally inoculated mice and rats. Isolates were maintained for up to 20 passages. Isolates from rats were similar in morphology to the reference strain, but most were more actively motile and formed pincushion-like aggregates. The rabbit bacilli were smaller and formed fewer aggregates. DNAs of rat isolates differed only slightly in restriction fragment patterns from that of the reference strain, whereas that of the rabbit isolate was distinctly different. Cultures of CAR bacilli of all strains from rats contained Mycoplasma fermentans, Mycoplasma pulmonis, or both, and cultures of the CAR bacillus from the rabbit contained an unidentified arginine-utilizing mycoplasma. The sequence of the 16S rRNA gene of the reference strain was determined by amplification by polymerase chain reaction, cloning of the product, and sequencing by the dideoxynucleotide chain termination method. Comparison of the sequence with sequences in the GenBank data base indicated that CAR bacillus is a unique organism most closely related to Flavobacterium ferrugineum and Flexibacter sancti.
纤毛相关呼吸道（CAR）杆菌是一种与大鼠、小鼠和家兔呼吸道疾病相关的未分类滑行细菌，此前仅在鸡胚、细胞培养或添加了来自培养气管的条件培养基的细胞培养基中培养。一株最初从鸡蛋中分离出的CAR杆菌参考菌株，在仅添加胎牛血清的细胞培养基中，以贴壁的单个杆菌和绳状、螺旋状束状形态在细胞培养瓶中生长。我们使用杜尔贝科改良伊格尔培养基，从自然感染的大鼠和一只自然感染的家兔以及实验接种的小鼠和大鼠中分离出了CAR杆菌。分离株传代培养多达20次。来自大鼠的分离株在形态上与参考菌株相似，但大多数运动更为活跃，并形成针垫状聚集体。家兔杆菌较小，形成的聚集体较少。大鼠分离株的DNA在限制性片段模式上与参考菌株仅略有不同，而家兔分离株的DNA则明显不同。来自大鼠的所有菌株的CAR杆菌培养物中都含有发酵支原体、肺支原体或两者都有，而来自家兔的CAR杆菌培养物中含有一种未鉴定的利用精氨酸的支原体。通过聚合酶链反应扩增、产物克隆和双脱氧核苷酸链终止法测序，确定了参考菌株的16S rRNA基因序列。将该序列与GenBank数据库中的序列进行比较表明，CAR杆菌是一种独特的生物体，与铁锈色黄杆菌和圣洁屈挠杆菌关系最为密切。
