犬貓胃螺旋桿菌的研究

外文標題: 
Study of Gastric Helicobacters in Dogs and Cats
校院系所: 
國立臺灣大學 獸醫學研究所
指導教授: 
黃慧璧
張本恆
出版年份: 
2001年
主題類別: 
摘要: 

近年來Helicobacter pylori已被證實與人的胃炎、消化性潰瘍、胃癌及淋巴瘤等有密切關聯性,其他動物例如貂、印度豹與豬的胃病,也發現與胃螺旋桿菌的感染有關。犬貓的胃螺旋桿菌屬細菌(gastric Helicobacter-like organism, 簡稱GHLO)盛行率極高,但是至今仍無法確切了解GHLO與犬貓消化道疾病的關係。本研究的目的為比較犬貓GHLO的診斷技術,包括抹片細胞學、組織病理學及聚合脢鏈反應,也探討GHLO與犬、貓胃組織病理變化以及與年齡之間的相關性。共有50隻犬與9隻貓參與本研究,這些犬貓在臨床上皆無消化道症狀,且在進行採樣前二週無投與任何藥物。實驗為利用胃內視鏡進行胃黏膜組織的生檢採樣,採樣部位包括胃賁門部、胃底部與胃幽門部,分別進行抹片細胞學、組織病理學與聚合脢鏈反應檢查。研究結果指出抹片細胞學、組織病理學及聚合脢鏈反應診斷GHLO的陽性率,在犬分別是68%、66%與60%,在貓三種診斷方法的GHLO陽性率皆為77.8%,不論犬或貓,此三種診斷方法的陽性結果在統計上無顯著差異。組織病理學結果顯示,犬貓GHLO細菌量的多寡與胃組織炎症細胞浸潤的程度在統計上無相關性﹔在犬隻,胃組織浸潤的細胞以淋巴球和漿性球為主,在貓則是淋巴球。組織切片下,GHLO常聚集成叢狀分布,其存在位置為於胃黏膜表面的黏液中或於胃線窩中。此外,GHLO盛行率與犬隻年齡在統計學上無顯著相關性。在聚合脢鏈反應部分,進行400bp與1200bp產物的基因序列分析,結果顯示本實驗所選用的部分16S rRNA基因與數個不同種別的胃螺旋桿菌屬細菌,包括H. felis、H. salomonis、H. bizzozeronii、H. heilmannii、H. bilis與H. pylori的相似性高達95%以上,而且與其他屬別無相似性,顯示本實驗所選用的聚合脢鏈反應起始子確實具有螺旋桿菌屬細菌專一性,但無法鑑定GHLO 的種別。本研究證實本地犬貓確實有感染螺旋桿菌屬細菌,雖然本地犬貓有高的GHLO陽性率,但是這些犬貓皆無消化道症狀,而且與胃組織炎症細胞浸潤程度之間無相關性,因此欲探討GHLO與胃疾病的關係,有必要對出現消化道症狀的犬貓進行調查與研究,以釐清胃螺旋桿菌屬細菌在臨床上的意義。

外文摘要: 

The association of Helicobacter pylori with gastritis, peptic ulcer, gastric carcinoma and lymphoma has been proved in humans. The relationship of gastric diseases to gastric helicobacters in animals, for example ferrets, cheetahs and pigs has also been reported. Gastric Helicobacter-like organisms (GHLO) are highly prevalent in dogs and cats, however the relationship between GHLO and peptic disease in dogs and cats is currently unclear. The purposes of present study were to compare different diagnostic methods (smear cytology, histopathology and polymerase chain reaction) for detecting GHLO, and to clarify the relationship between GHLO and histopathologic changes, and between GHLO prevalence and age. Fifty dogs and 9 cats without any episodes of gastrointestinal signs, or without administering medicine 2 weeks prior to biopsy were included in the study. The gastric biopsy specimens were obtained of the mucosa of the cardia, fundus and pylorus, using endoscopic forceps. The GHLO positive rate in dogs was 68%, 66%, and 60% detected by smear cytology, histopathology, and polymerase chain reaction respectively. In cats, the GHLO positive rate was identically 77.8% detected by 3 different diagnostic methods. No statistically significant differences were found in 3 diagnostic methods in detecting GHLO in either dogs or cats. No correlation was found between the degree of GHLO colonization and infiltration of inflammatory cells. The major inflammatory cells were lymphocytes and plasma cells in dogs whereas lymphocytes in cats. Histologic evaluation revealed GHLOs often aggregated patchily and localized in the mucous covering the surface epithelium and in gastric pits. The prevalence of GHLO was not varied statistically by age in dogs. The DNA sequences of 400bp and 1200bp polymerase chain reaction products revealed the selected partial 16S rRNA sequences were more than 95% similarity to various Helicobacter spp., including H. felis, H. salomonis, H. bizzozeronii, H. heilmannii, H. bilis and H. pylori and the sequences were not compatible to any other genus of organisms. This clearly indicated that the polymerase chain reaction primers used were Helicobacter genus-specific. However they were not able to differentiate the species between Helicobacter genus. This study confirmed the presence of Helicobacter spp. in dogs and cats in this area. Although the incidence of GHLO in dogs and cats was high, none of the animals were presented with any signs of gastrointestinal upset. Infiltration of inflammatory cells in gastric mucosa was not correlated to presence of GHLO. Future studies concerning investigation of relationship between GHLO and gastricism, and clarification of the clinical importance of GHLO were necessary in dogs and cats with gastrointestinal signs.