笼养绿尾虹雉源肠球菌的分离鉴定及耐药性分析

Isolation, identification, and drug resistance of Enterococcus from captive Chinese monal (Lophophorus lhuysii)

摘要:

【背景】绿尾虹雉(Lophophorus lhuysii)是我国特有的一级重点保护野生鸟类，长期以来由于受人类活动及疾病等因素的影响，其种群数量不断减少。肠球菌(Enterococcus sp.)是一类广泛存在于自然界中的条件性致病菌，其耐药性强，治疗困难，对野生动物的保护带来挑战。【目的】更好地保护绿尾虹雉，关注其肠球菌感染或携带情况并对肠球菌特性的相关研究很有必要，这对绿尾虹雉种群的生存与保护有重要意义。【方法】采集了蜂桶寨国家级自然保护区的笼养绿尾虹雉1年中4个不同月份的粪便，对其中的细菌进行分离纯化，再通过形态学鉴定、生化鉴定、分子生物学鉴定确定分离菌株种类，最后进行药敏试验探究其耐药性。【结果】共分离出17株菌株，其菌落在培养基上均呈现出灰白色不透明、表面光滑、直径1 mm内的圆形，菌株的糖发酵试验、胆汁七叶苷水解试验呈阳性，接触酶试验和产气试验呈阴性，所有结果均符合肠球菌的基本特征，16S rRNA基因测序进一步验证了该结果。药敏试验结果表明绿尾虹雉源肠球菌具有较强的耐药性，其中对四环素、环丙沙星、诺氟沙星、左氧氟沙星等药物的耐药性最高。【结论】成功分离出绿尾虹雉源肠球菌，并对其耐药情况进行了研究，为绿尾虹雉携带肠球菌的现状及其耐药情况提供了初步数据分析，同时对其疾病防控提供了参考。

关键词:绿尾虹雉;肠球菌;分离鉴定;耐药性

Abstract:

[Background] The Chinese monal (Lophophorus lhuysii) is a protected wild bird endemic to China, with a declining population due to human activities and diseases. Enterococcus, a genus of common conditional pathogenic bacteria in the nature, is known for strong drug resistance and difficult treatment, posing challenges to wildlife conservation. [Objective] Therefore, it is necessary to pay attention to the enterococcal infection or carrier status and study the characteristics of enterococci in order to better protect the Chinese monal population, which is of great significance to the survival and protection of Chinese monal population. [Methods] Fecal samples were collected from captive Chinese monal at the Fengtongzhai National Nature Reserve in four different months of a year. The bacteria were isolated and then identified by morphological observation and biochemical and molecular analyses. Additionally, drug susceptibility tests were conducted to assess the resistance patterns of the isolated strains. [Results] A total of 17 strains were successfully isolated. These strains exhibited grayish opaque colonies with smooth surfaces and diameters not exceeding 1 mm on the culture media. Positive results were obtained for the sugar fermentation test, and bile esculin hydrolysis test. Negative results were observed for the catalase test and gas production test. All these characteristics aligned with those of Enterococcus, and 16S rRNA gene sequencing further validated the result. The strains of Enterococcus from Chinese monal showed strong resistance to tetracycline, ciprofloxacin, norfloxacin, and levofloxacin. [Conclusion] We successfully isolated Enterococcus strains from Chinese monal and comprehensively analyzed their drug resistance. The findings reveal the current status and drug resistance profile of Enterococcus carried by Chinese monal, giving insights into the disease prevention and protection of Chinese monal.

Key words:Lophophorus lhuysii;Enterococcus;isolation and identification;drug resistance