魚類立克次體症

與水生動物疾病召集人陳媺玫副教授聯絡

友善列印

魚類立克次體症

建立日期：

2008/12/22

更新日期：

2009/09/04

作者：

涂堅

中文病名：

魚類立克次體症

英文病名：

Piscirickettsiosis

疾病描述：

1.病原概述
病原型別：細菌
病原環境：淡水及鹹水
學名：Piscirickettsia salmonis
病名(及俗名)：Salmonid rickettsial septicemia (SRS), Coho salmon syndrome
最早發現者： Bravo等(1989).在智利發現本症，Fryer 等(1990, 1992)分離及正式命名。
ＯＩＥ狀況：未表列(Not listed)
病原摘要：革蘭氏陰性、營養需求高、絕對魚類細胞質內生長的細菌。親緣關係上，它與Coxiella 及 Francisella 有些微親緣關係。.
病原分類：
變形菌門 (Proteobacteria)、γ變形菌綱 (Garmmaproteobacteria)、硫髮菌目(Thiotrichales)、魚立克次體科(Piscirickettsiaceae)。
別名：無
命名沿革：最早由Fryer 等(1992) 命名。
2.疾病特性：
（感染組織及器官：感染路徑、好發組織器官、宿主）
目前證實水平感染。主要發生在鱒鮭類海水魚；宿主為銀鮭coho salmon (Oncorhynchus kisutch), chinook salmon (O. tshawytscha), 櫻鱒sakura salmon (O. masou), 虹鱒rainbow trout ( O.Mykiss), 粉紅鮭pink salmon (O. gorbuscha) 、大西洋鮭 Atlantic salmon (Salmo salar) , 有名錘形石首魚white sea bass (Atractoscion nobilis )。歐洲海鱸European sea bass (Dicentrarchus labrax)。
本菌主要感染表淺的皮膚、肝、腎臟、脾、胃、鰾、及肌肉。

疾病型態及流行病學：（急性或慢性型態、器官傳播分佈情形）
本病為、全身性炎症疾病。病地理分佈在智利、蘇格蘭、挪威、及加拿大。
臨床症狀及病理學：
臨床症狀：嚴重感染者體色變黑、食欲廢絕、無力游動。靠近岸邊或水面游動。輕微感染者並無外表症狀。感染到腦的魚會出現無目的的游動。有些魚皮膚會出現白色斑點，甚至演變為潰瘍。最常見的症狀為由於貧血引起的灰色的鰓。
病理學：
剖檢
呈現慢性炎症病變。可見腎臟腫大、變色；脾臟腫大。腹腔內可見腹水，出血遍佈內臟脂肪、胃、鰾、肌肉。最明顯的病變出現在肝臟，呈現腫大、顏色變成白色或黃色、多發性局部、融合在一起的化膿性肉芽腫結節；嚴重時結節會迸裂，導致肝臟表面出現火山口樣的凹陷。
組織病理病變
主要發現在肝、腎、脾及小腸；但是腦、心、卵巢及鰓也可看到。肝臟可見多發局部性肝細胞壞死，伴隨慢性炎症單核細胞浸潤； H& E染色，高倍鏡檢查時，可在變性的肝細胞及巨噬細胞胞質內發現許多嗜鹼性或多染性直徑約 1 µm 的橢圓形細菌。另外肝臟亦可見血管內及血管週圍壞死，甚至由於主要血管內凝血造成的纖維素血栓都很常見。較急性感染時，壞死區域的融合會造成一片雜色的區域，而不是呈現結節狀區域。腎臟及脾臟的間質及實質也會出現肉芽腫病變，血管的病變則與肝臟類似。腦膜炎、心內膜炎、腹膜炎、鰓炎均會出現類似於肝腎的病變。卵巢亦有出現病變的報告。

病原致病性意義：（實際魚場及田間發病、抗藥性等情形）
通常發生在小魚放養於海上箱網後一個月後發生。箱網鮭魚感染後死亡率界於30-90 %。任何年齡的魚都有感受性。

診斷方法：

一級初步診斷：肉眼觀察臟器多發局部性肉芽腫病變。
二級初步診斷：直接取臟器壓片或抹片Giemsa染色鏡檢可見胞內有球狀、成對菌體直徑約0.5-1.5 µm.。
三級初步診斷：無

一級確定診斷：無
二級確定診斷：組織病理檢查，臟器中的巨噬細胞胞質內發現許多嗜鹼性或多染性(H&E)，或是暗藍色(Giemsa)直徑約 1 µm 的橢圓形小體。
三級確定診斷：以CHSE-214或EPC細胞進行分離或以特異ＰＣＲ進行增幅，出現特異性產物。進一步將產物定序、進行基因庫比對
PCR條件如下（產物為467 bp）：
PS2S (223F) : 5'-CTA-GGA-GAT-GAG-CCC-GCG-TTG-3'
PS2AS (690R) : 5'-GCT-ACA-CCT-GAA-ATT-CCA-CTT-3
反應液： 5 µl 10x PCR buffer (10 mM Tris/HCl, pH 9, 1.5 mM MgCl2, 50 mM KCl, and 0.1% Trition X-100), 200 µM each of dATP, dCTP, dTTP and dGTP, 2 µM each of PS2S primer and PS2AS primer, and 2.5 units Taq DNA polymerase, 5 µl of the DNA preparation, 最後加水至50 µl。
反應條件： 94°C for 2 minutes，然後進行35循環( 94°C for 1 minute, 50°C for 2 minutes, and 72°C for 3 minutes).

治療方法：

依藥物敏感試驗結果決定

預防控制方法：

1.勿引進汙染的魚苗及種魚。

相關圖片：

參考文獻：

1.Alday-Sanz V., Rodger H., Turnbull T., Adams A. & Richards R.H. (1994). An immunohistochemical diagnostic test for rickettsial disease. J. Fish Dis., 17, 189-191.

2.Branson E.J. & Nieto Diaz-Munoz D. (1991). Description of a new disease condition occurring in farmed coho salmon, Oncorhynchus kisutch (Walbaum), in South America. J. Fish Dis., 14, 147-156.

3.Bravo S. (1994). Piscirickettsiosis in freshwater. Bull. Eur. Assoc. Fish. Pathol., 14, 137-138.

4.Bravo S. & Campos M. (1989). Coho salmon syndrome in Chile. AFS/FHS Newsletter, 17, 3.

5.Brocklebank J.R., Speare D.J., Armstrong R.D. & Evelyn T. (1992). Septicemia suspected to be caused by a rickettsia-like agent in farmed Atlantic salmon. Can. Vet. J., 33, 407-408.

6.Chen M.F., Yun S., Marty G.D., McDowell T.S., House M.L., Appersen J.A., Guenther T.A., Arkush K.D. & Hedrick R.P. (2000). A Piscirickettsia salmonis-like bacterium associated with mortality of white seabass Atractoscion nobilis. Dis. Aquat. Org., 43, 117-126.

7.Chen S.C., Tung M.C., Chen S.P., Tsai J.F., Wang P.C., Chen R.S., Lin S.C. & Adams A. (1994). Systemic granulomas caused by a rickettsia-like organism in Nile tilapia, Oreochronuis niloticus (L.), from southern Taiwan. J. Fish Dis., 17, 591-599.

8.Chen S.C., Wang P.C., Tung M.C., Thompson K.D. & Adams A. (2000). A Pisicirickettsia salmonis-like organism in grouper, Epinephelus melanostigma, in Taiwan. J. Fish Dis., 23, 415-418.

9.Cvitanich J.D., Garate N.O. & Smith C.E. (1991). The isolation of a rickettsia-like organism causing disease and mortality in Chilean salmonids and its confirmation by Koch's postulate. J. Fish Dis., 14, 121-145.

10.Evelyn T.P.T. (1992). Salmonid rickettsial septicemia. In: Diseases of Seawater Netpen-reared Salmonid Fishes in the Pacific Northwest, Kent M.L., ed. Can. Spec. Pub. Fish. Aquat. Sci. 116. Dept. Fisheries and Oceans, Nanaimo, British Colombia, Canada, 18-19.

11.Fryer J.L., Lannan C.N., Garces L.H., Larenas J.J. & Smith P.A. (1990). Isolation of a rickettsiales-like organism from diseased coho salmon Oncorhynchus kisutch in Chile. Fish Pathol., 25, 107-114.

12.Fryer J.L., Lannan C.N., Giovannoni S.J. & Wood N.D. (1992). Piscirickettsia salmonis gen. nov., sp. nov., the causative agent of an epizootic disease in salmonid fishes. Int. J. Syst. Bacteriol., 42, 120-126.

13.Gaggero A., Castro H. & Sandino A.M. (1995). First isolation of Piscirickettsia salmonis from coho salmon, Oncorhynchus kisutch (Walbaum), and rainbow trout, Oncorhynchus mykiss (Walbaum), during the freshwater stage of their life cycle. J. Fish Dis., 18, 277-279.

14.Garces L.H., Larenas J.J., Smith P.A., Sandino S., Lannan C.N. & Fryer J.L. (1991). Infectivity of a rickettsia isolated from coho salmon (Oncorhynchus kisutch). Dis. Aquat. Org., 11, 93-97.

15.Jones S.R.M., Markham R.J.F., Groman D.B. & Cusack R.R. (1998). Virulence and antigenic characteristics of a cultured Rickettsiales-like organism isolated from farmed Atlantic salmon Salmo salar in eastern Canada. Dis. Aquat. Org., 33, 25-31.

16.Lannan C.N., Ewing S.A. & Fryer J.L. (1991). A fluorescent antibody test for detection of the rickettsia causing disease in Chilean salmonids. J. Aquat. Anim. Health, 3, 229-234.

17.Lannan C.N. & Fryer J.L. (1991). Recommended methods for inspection of fish for the salmonid rickettsia. Bull. Eur. Assoc. Fish Pathol., 11, 135-136.

18.Marshall S., Heath S., Henriquez V. & Orrego C. (1998). Minimally invasive detection of Piscirickettsia salmonis in cultivated salmonids via the PCR. Appl. Environ. Microbiol., 64, 3066-3069.

19.Mauel M. J., Giovannoni S.J. & Fryer J.L. (1996). Development of polymerase chain reaction assays for detection, identification, and differentiation of Piscirickettsia salmonis. Dis. Aquat. Org., 26, 189-195.

20.Olsen A.B., Melby H.P., Speilberg L., Evensen O. & Hastein T. (1997). Piscirickettsia salmonis infection in Atlantic salmon Salmo salar in Norway - epidemiological, pathological and microbiological findings. Dis. Aquat. Org., 31, 35-48.

21.Palmer R., Ruttledge M., Callanan K. & Drinan E. (1997). A Piscirickettsiosis-like disease in farmed Atlantic salmon in Ireland - isolation of the agent. Bull. Eur. Assoc. Fish Pathol., 17, 68-72.

22.Rodger H.D. & Drinan E.M. (1993). Observation of a rickettsia-like organism in Atlantic salmon, Salmo salar L., in Ireland. J. Fish Dis., 16, 361-369.

23.Schafer J.W., Alvarado V., Enriquez R. & Monras M. (1990). The 'coho salmon syndrome' (CSS): a new disease in Chilean salmon, reared in sea water. Bull. Eur. Assoc. Fish Pathol., 10, 130.

24.Skarmeta A.M., Henriquez, V., Zahr M., Orrego C. & Marshall S.H. (2000). Isolation of a virulent Piscirickettsia salmonis from the brain of naturally infected coho salmon. Bull. Eur. Assoc. Fish Pathol., 20, 261-264.

參考連結：

1 . http://www.oie.int/eng/normes/fmanual/A_00030.htm

檔案下載：