烏魚革蘭氏陽性鏈狀球菌之鑑定及調查

Identification and Survey on Gram-Positive Streptococcus-Like Organisms Isolated from Grey Mullet(Mugil cephalus Linnaeus)

李建霖(Jlan-Lin Lee) ； 邱淑雍(Shu-Yung Chu) ； 余贊生(Zan-Sheng Yu) ； 李建裕(Chien-Yu Lee) ； 賴金鞠(Chin-Chu Lai) ； 洪崇順(Chung-Shun Hung) ； 王建雄(Jlann-Hsiunq Wang) ； 吳宗炳(Zong-Bing Wu) ； 陳石柱(Shih-Chu Chen) ； 張聰洲(Tsunq-Chou Chang) ； 蔡信雄(Shinn-Shyong Tsai)

《臺灣獸醫學雜誌》 32卷2期 (2006/06) Pp. 136-145

https://doi.org/10.7009/TVJ.200606.0136

摘要

鏈球菌症（streptococcosis）在鳥魚（Mugil cephalus Linnaeus）養殖期間是相當重要的細菌性疾病，其危害常造成嚴重的經濟損失。本研究由1997年至2004年，收集嘉雲南地區養殖烏魚感染革蘭氏陽性鏈狀球菌病例共51例，進行病理學、病原學及分子生物學檢查。病理學檢查方面，發現病魚有嚴重程度不等之體表充、出血，伴隨有凸眼、角膜混濁或出血，體腔內有乾酪樣物質附著及腹水蓄積，組織切片下以多發性漿膜炎及腦膜炎為主要病變。微生物學檢查方面，本病病原為革蘭氏陽性鏈狀球菌，Oxidase及Catalase反應均為陰性，可生長於0~5％ NaCI及4~40℃環境中。分子生物學檢查方面，以革蘭氏陽性鏈狀球菌共同引子對進行聚合酶鏈鎖反應，皆可增幅出750bp之預期產物，經16S rDNA 基因序列比對，其中Lactococcus garvieae佔90%（45/51）、Streptococcus agalactiae佔5%（3/51）、Streptococcus dysgalactiae亦佔5%（3/51）。由此調查結果得知，乳酸球菌（L. garvieae）是台灣養殖鳥魚中主要細菌性病原之一，尤其流行在每年的5~9月。

關鍵字

烏魚 ； 鏈球菌症 ； 乳酸球菌

並列摘要

Streptococcosis was an important bacterial disease in cultured grey mullet (Mugil cephalus Linnaeus) and caused serious economic losses. Fifty-one cases of grey mullet infected with Gram-positive streptococcus-like organisms were collected from cultured farms in central Taiwan from 1997 to 2004. For diagnosis, gross pathological evaluation, histopathological examination, microbiological testing and molecular identification were used. All diseased fish had congestion and hemorrhage on the body surface, and showed exophthalmia with or without conjunctival hemorrhage and corneal opacity. Pathologically, they showed ascites, polyserositis and meningitis. The bacterial isolates from the diseased fish, were Gram-positive streptococcus-like bacteria, catalase negative, oxidase negative and grew in 0-5% NaCI broth. All these isolates grew over a wide temperature ranges (4-40°C). Identification of all isolates was confirmed by a PCR assay for Gram positive cocci that gave the expected amplicon of 750 bp, The pathogens from diseased fish were identified as Lactococccus garvieae 90%(45/51), Streptococcus agalactiae 5%(3/51) and Streptococcus dysgalactiae 5%(3/51) by Rapid ID 32 Strep, biochemical tests and the sequence of a PCR product from the 16S rDNA and phylogenetic analysis. Epidemiologically, L. garvieae is the major pathogen in bacterial infection of cultured grey mullet, occurred highly from May to September in Taiwan.

並列關鍵字

Grey mullet ； Mugil cephalus ； streptococcosis ； Lactococcus garvieae