水产科学
水產科學
수산과학
FISHERIES SCIENCE
2014年
3期
171-174
,共4页
大鳍鳠%病原菌鉴定%鲇爱德华氏菌%药敏试验
大鰭鳠%病原菌鑒定%鲇愛德華氏菌%藥敏試驗
대기화%병원균감정%점애덕화씨균%약민시험
Mystus macropterus Bleeker%pathogen identification%Edwardsiella ictaluri%drug susceptibility test
自患头顶溃疡症的大鳍鳠内脏组织中分离出致病菌株MM-A ，对该菌进行了鉴定。人工感染试验证实，MM-A菌株为大鳍鳠的病原菌，其半致死量（LD50）为5．3×107 cfu/mL。根据菌株形态学特点、生理生化指标和16S rDNA序列确定其为鲇爱德华氏菌。16S rDNA序列分析显示MM-A菌珠与鲇爱德华氏菌的亲缘关系最近，同源性达99．4％；系统进化树分析表明该菌与鲇爱德华氏菌聚为一支。14种药物敏感性试验结果显示，该菌对土霉素、链霉素、氧氟沙星和庆大霉素均敏感，对四环素等5种抗生素及中草药柯子和秦皮比较敏感。
自患頭頂潰瘍癥的大鰭鳠內髒組織中分離齣緻病菌株MM-A ，對該菌進行瞭鑒定。人工感染試驗證實，MM-A菌株為大鰭鳠的病原菌，其半緻死量（LD50）為5．3×107 cfu/mL。根據菌株形態學特點、生理生化指標和16S rDNA序列確定其為鲇愛德華氏菌。16S rDNA序列分析顯示MM-A菌珠與鲇愛德華氏菌的親緣關繫最近，同源性達99．4％；繫統進化樹分析錶明該菌與鲇愛德華氏菌聚為一支。14種藥物敏感性試驗結果顯示，該菌對土黴素、鏈黴素、氧氟沙星和慶大黴素均敏感，對四環素等5種抗生素及中草藥柯子和秦皮比較敏感。
자환두정궤양증적대기화내장조직중분리출치병균주MM-A ，대해균진행료감정。인공감염시험증실，MM-A균주위대기화적병원균，기반치사량（LD50）위5．3×107 cfu/mL。근거균주형태학특점、생리생화지표화16S rDNA서렬학정기위점애덕화씨균。16S rDNA서렬분석현시MM-A균주여점애덕화씨균적친연관계최근，동원성체99．4％；계통진화수분석표명해균여점애덕화씨균취위일지。14충약물민감성시험결과현시，해균대토매소、련매소、양불사성화경대매소균민감，대사배소등5충항생소급중초약가자화진피비교민감。
Bacterial pathogen strain MM-A was isolated from largefin longbarbel catfish ( Mystus macropterus) , suffered from a kind of disease with typical head-ulcerative symptom . The bacterial pathogen strain MM-A was confirmed to be the causative agent of the epidemic by artificial infection test and the LD50 was about 5 .3 × 107 cfu/mL .According to physiological feature ,biochemical indexes and 16s rDNA sequence ,the MM-A was further proved to be Edwardsiella ictaluri .The comparison of 16S rDNA molecule in Enterobacteriaceae showed that the strain MM-A shared the highest level of similarity (99 .4% ) with that of the E .ictaluri ,and they had the same position in the molecular phylogenetic tree based on 16S rDNA sequence in Enterobacteriaceae .The drug susceptibility test revealed that the isolated strain MM-A was susceptible to oxyteracycline ,streptomicinum ,ofloxacin and other antibiotics ,lowly susceptible to tetracycline and other antibiotics and Chinese medicinal herbs including Terminalia chebula , and Fraxinus rhynchophylla .
