大熊猫精液和包皮菌群组成及潜在致病菌调查

Investigation on the bacterial community composition of the semen and prepuce and potentially pathogenic bacteria of giant pandas

摘要:

[目的] 大熊猫是我国国家一级保护动物，其种群面临着传染病和栖息地破碎化等持续威胁，其中生殖系统的细菌感染和菌群失衡会影响大熊猫生殖健康，严重者可导致流产，是引起大熊猫繁殖障碍的原因之一。本研究对精液与包皮分泌物样本的菌群组成情况及分离培养潜在致病菌开展研究。[方法] 通过采集13份大熊猫包皮分泌物和12份精液样本，采用16S rRNA扩增子测序技术、细菌培养及PCR鉴定的方法，确定样本中的细菌种类。[结果] 菌群组成分析结果显示，在门水平上，厚壁菌门（Firmicutes）的细菌丰度在大熊猫包皮与精液中均为最高；在属水平上，不同时期的雄性大熊猫包皮的菌群可能会发生改变，棒状杆菌属（Corynebacterium）和Dolosicoccus是Ⅰ期包皮样本中最丰富的微生物菌群，相对丰度分别为15.45%和12.40%；链球菌属（Streptococcus）和埃希氏菌属（Escherichia）是Ⅱ期包皮样本中最丰富的微生物菌群，相对分度分别为37.94%和9.68%；拟杆菌属（Bacteroides）和普雷沃氏菌属（Prevotella）是精液样本中最丰富的微生物菌群，相对丰度分别为14.40%和12.88%。菌群多样性分析结果显示，精液样品高于Ⅰ期包皮样品和Ⅱ期包皮样品，Ⅰ期包皮样品和Ⅱ期包皮样品之间无显著差异。通过细菌分离培养得到肺炎克雷伯菌（Klebsiella pneumonia）在内的多种潜在性致病菌。[结论] 本研究分析了大熊猫精液和不同时期包皮分泌物的菌群组成，其优势菌属存在差异，大熊猫包皮与精液中存在潜在性致病菌，这可能对大熊猫的生殖系统健康带来威胁，其致病性有待进一步研究。

Abstract:

[Objective] Giant panda is one of the first-class protected animals in China, which the population is facing continuous threats such as infectious diseases and habitat fragmentation. Bacterial infection and imbalance of bacterial community in the genitourinary system of giant panda could affect the reproductive health, in severe cases, it can also lead to abortion, which is one of the causes of reproductive disorders in giant panda. In this study, our aim was to examine the bacterial community composition of semen and prepuce secretion and isolate potential pathogenic bacteria of giant panda.[Methods] 13 of prepuce secretions and 12 of semen samples of giant panda were used to determine the bacteria species by 16S rRNA amplicon sequencing technique, bacterial separation and PCR methods.[Results] The results showed that the abundance of Firmicutes was the highest in the samples of prepuce and semen of giant panda at phylum level. Moreover, at the genus level, the bacterial community composition of prepuce was changed in different periods, Corynebacterium and Dolosicoccus were the most abundant microbiome in preputial samples at phase I with relative abundances of 15.45% and 12.40%, respectively. Streptococcus and Escherichia were the most abundant microbiome in preputial samples at phase II, with relative abundance of 37.94% and 9.68%, respectively. Bacteroides and Prevotella were the most abundant microbiome in seminal samples, with relative abundance of 14.40% and 12.88%, respectively. The results of bacterial diversity showed that the diversity in seminal samples was higher than that in preputial samples; there were no significant difference between preputial samples at stages I and stage II. Klebsiella pneumonia and other potential pathogenic bacteria were obtained by bacterial isolation and culture.[Conclusion]] In this study, we analyzed the bacterial community composition of the prepuce secretions in different periods and semen of male giant pandas, and the dominant microbiome were different. It was hypothesized that potential pathogenic bacteria were in the prepuce and semen of giant pandas, which may pose a threat to the reproductive system health of giant panda, and the pathogenicity needs further research.