绿海龟背甲坏死病病原真菌的鉴定及其药敏特性

人工饲养的绿海龟(Chelonia mydas)患背甲坏死病的背甲整体呈现"灰白甲"症状,用伍德灯检查有荧光现象,即疑似真菌感染;从绿海龟背甲边缘病变坏死处分离纯化得到1株优势真菌,编号为SDABAI,通过形态学观察、分生孢子形态并结合ITS 18S rDNA序列分析对疑似致病菌株进行鉴定,进而构建系统发育树进行分析。结果表明:SDABAI菌株(登录号为:MK583351)与Fusarium solani(登录号为:KU377470.1)基因相似性达99%,判定SDABAI菌株为腐皮镰刀菌(Fusarium solani),真菌菌丝形态、分生孢子产生和形态也符合该菌。将患病绿海龟背甲病灶处分离得到的SDABAI菌株,接种到4 mL离心管中,斜面培养生长4～5 d长出白色絮状菌苔后,用光固化型树脂封闭在2只健康绿海龟(A1、A2)的背甲上各2只带菌离心管(A1-1;A1-2;A2-1;A2-2)内,攻毒感染第24天,A1出现被感染症状,有荧光现象,产生了和自然发病一样的症状,并于背甲边缘生长纹处分离到了和SDABAI菌株一样的腐皮镰刀菌。A2较A1症状较弱。根据绿海龟背甲整体呈现"灰白甲"症状和腐皮镰刀菌病原,定名为绿海龟背甲坏死病。选用大蒜油、艾叶油和茶树油进行腐皮镰刀菌药敏试验,结果表明,三者均可起到一定抑制该菌生长的效果,还可以抑制次生菌生长,大蒜油的抑菌效果最佳。特比萘芬、克霉唑、咪康唑、制霉菌素、两性霉素5种药对腐皮镰刀菌药敏试验结果显示咪康唑和制霉菌素的抑菌效果较佳。

Identification of etiological agent for necrotizing scute disease and sensitivity in green sea turtle

Green sea turtle (Chelonia mydas) in captivity that suffered from necrotizing scute disease showed the symptoms of "grey-white scute", Wood lamp fluorescence phenomenon, suspected of the presence of fungal infection;One dominant fungus was isolated and purified from the edge necrosis of the carapace of the green turtles, which was numbered SDABAI. The pathogenic strain was identified by morphological observation, conidia morphology, and combined with ITS 18S rDNA sequence analysis, and the phylogenetic analysis was constructed. The results showed that the SDABAI strain(accession number:MK583351) and Fusarium solani(accession number:KU377470.1) had 99% genetic similarity, so SDABAI was determined to be F. solani, and the fungal morphology and conidia morphology were also consistent.The SDABAI strain was inoculated into a 4 mL centrifuge tube and cultured on an inclined plane for 4-5 days. After growing white flocculent fungi, the fungus was sealed on the dorsal plates of 2 healthy green sea turtles (A1 and A2) using light-curable composite resin. Each turtle had 2 germ-bearing centrifuge tubes (A1-1; A1-2; A2-1; A2-2). On the 24th day of infection, the infected symptoms of A1 appeared, with fluorescence, which produced the same symptoms as the natural disease, and Fusarium solani similar to SDABAI were isolated at the edge of shell of A1.A2 had weaker symptoms than A1.According to the whole dorsal shell of green sea turtles showing "grey-and-white scute" symptoms and the pathogen of Fusarium solani, it was named green sea turtle necrotizing scute disease.Garlic oil, wormwood oil and tea tree oil were selected for drug sensitivity test. The results showed that all of them could inhibit growth to a certain extent, and also inhibit the growth of secondary bacteria, with the best antifungal effect of garlic oil. The results showed that five drugs, including terbinafine, clomazole, miconazole, nystatin and amphotericin, had better antifungal effect on SDABAI.