Narayanan S, Nagaraja T G, Wallace N, Staats J, Chengappa M M, Oberst R D
Department of Animal Sciences, Kansas State University, Manhattan 66506, USA.
Am J Vet Res. 1998 Mar;59(3):271-6.
To isolate Actinomyces pyogenes and A pyogenes-like (APL) organisms from the ruminal wall and ruminal contents of cattle and compare them with isolates from liver abscesses from the same animals, using ribosomal DNA restriction fragment length polymorphism analysis or ribotyping.
Specimens of liver abscesses, ruminal walls, and ruminal contents were collected from 59 cattle at slaughter. All beta-hemolytic, pinpoint colonies that were gram positive, pleomorphic rod-shaped, and catalase negative, and that hydrolyzed casein and gelatin were presumptively identified as A pyogenes and were characterized biochemically, using an identification kit. The isolates that resembled A pyogenes but fermented mannitol or raffinose, or both, were called APL organisms. Isolates from the ruminal wall and ruminal contents were compared with liver abscess isolates from the same animal by use of ribotyping.
Actinomyces pyogenes and APL organisms were isolated more frequently from the ruminal wall than from ruminal contents. Ruminal isolates of A pyogenes and APL had biochemical characteristics similar to those of the isolates from liver abscesses. Among 6 sets of isolates (4 A pyogenes and 2 APL), 2 isolates from liver abscesses had ribopatterns identical to the corresponding ruminal wall isolates. Also, the APL organisms isolated from the ruminal content matched with the corresponding liver abscess isolates for both sets of specimens tested.
The ruminal wall may be the niche for A pyogenes and APL organisms in the rumen. The genetic similarity, on the basis of ribotyping among isolates from liver abscesses, the ruminal wall, and ruminal contents of the same animal suggests that A pyogenes and APL organisms that cause liver abscesses originate from the rumen.
从牛的瘤胃壁和瘤胃内容物中分离化脓放线菌和类化脓放线菌（APL），并使用核糖体DNA限制性片段长度多态性分析或核糖体分型，将它们与同一动物肝脓肿的分离株进行比较。
从59头屠宰牛中采集肝脓肿、瘤胃壁和瘤胃内容物的样本。所有β-溶血、针尖大小的菌落，若革兰氏阳性、多形杆状、过氧化氢酶阴性，且能水解酪蛋白和明胶，则初步鉴定为化脓放线菌，并使用鉴定试剂盒进行生化特征鉴定。那些类似化脓放线菌但发酵甘露醇或棉子糖，或两者都发酵的分离株被称为APL菌。通过核糖体分型，将瘤胃壁和瘤胃内容物的分离株与同一动物的肝脓肿分离株进行比较。
化脓放线菌和APL菌从瘤胃壁中分离出来的频率高于瘤胃内容物。瘤胃中的化脓放线菌和APL菌的分离株具有与肝脓肿分离株相似的生化特征。在6组分离株（4株化脓放线菌和2株APL菌）中，2株肝脓肿分离株的核糖体图谱与相应的瘤胃壁分离株相同。此外，在两组测试样本中，从瘤胃内容物中分离出的APL菌与相应的肝脓肿分离株相匹配。
瘤胃壁可能是瘤胃中化脓放线菌和APL菌的生态位。基于同一动物肝脓肿、瘤胃壁和瘤胃内容物分离株的核糖体分型的遗传相似性表明，引起肝脓肿的化脓放线菌和APL菌起源于瘤胃。
