Porcine otitis is a novel mycoplasmal disease

对8个商品猪场479头1日龄~ 1岁龄猪的耳道进行了病理学和微生物学检查。479头猪中有364头（76.0%）患耳炎。咽鼓管炎是最常见的，并且先于耳部其他部位的炎症，并且早在出生后1周就发生急性咽鼓管炎。上呼吸道常见的细菌栖息地，如多杀性巴氏杆菌和化脓放线菌是最常见的分离物，从渗出液在鼓室或在鼓室泡。免疫组织化学检查冷冻切片显示支原体hyorhinis（Mhr）抗原的耳咽管上皮的管腔表面上的14（50.0%）的28头仔猪检查。从28头仔猪中分别有19头（67.9%）和16头（57.1%）的咽鼓管和鼓室中分离出MHR。所有Mhr阳性的猪均患有急性咽鼓管炎。使用17头17- 22日龄SPF仔猪进行耳炎的实验性繁殖。接种于中耳的Mhr大量繁殖，并诱发耳部的短暂性化脓性卡他炎。结果表明，猪中耳炎可能主要由Mhr感染引起，是一种新的支原体病。

The ear of 479 pigs from 8 commercial farms, ranging age from 1 day to 1 year old were pathologically and microbiologically examined. 364(76.0%) of 479 pigs were affected wit otitis. Eustachitis was the most common and preceded an inflammation of other sites of the ear, and an acute eustachitis occurred from as early as 1 week of life. Common bacterial habitants of the upper respiratory tracts such as Pasteurella multocida and Actinomyces pyogenes were the most frequent isolates from the exudate in the tympanic cavity or in the tympanic bulla. Immunohistochemical examination of frozen cryostat sections revealed Mycoplasma hyorhinis (Mhr) antigens on the luminal surface of the eustachian epithelia in 14 (50.0%) of 28 piglets examined. Mhr was isolated from the auditory tubes and tympanic cavities of 19 (67.9%) and 16 (57.1%) of 28 piglets, respectively. All the pigs positive for Mhr had an acute eustachitis. Experimental reproduction of otitis was performed using seventeen, 17- to 22-day-old, SPF piglets. Mhr inoculated in the middle ear multiplied and induced transient, purulent-catarrhal inflammation of the ear. From these results, it was concluded that porcine otitis media might be caused primarily by Mhr infection and be a novel mycoplasmal disease.