He Hong, Wei Cong, Wheeler Diana E
College of Forestry, Northwest A&F University, Yangling, 712100, Shaanxi, China,
Curr Microbiol. 2014 Sep;69(3):292-302. doi: 10.1007/s00284-014-0586-8. Epub 2014 Apr 20.
Camponotus is the second largest ant genus and known to harbor the primary endosymbiotic bacteria of the genus Blochmannia. However, little is known about the effect of diet and environment changes on the gut bacterial communities of these ants. We investigated the intestinal bacterial communities in the lab-raised and field-collected ants of Camponotus fragilis which is found in the southwestern United States and northern reaches of Mexico. We determined the difference of gut bacterial composition and distribution among the crop, midgut, and hindgut of the two types of colonies. Number of bacterial species varied with the methods of detection and the source of the ants. Lab-raised ants yielded 12 and 11 species using classical microbial culture methods and small-subunit rRNA genes (16S rRNAs) polymerase chain reaction-restriction fragment-length polymorphism analysis, respectively. Field-collected ants yielded just 4 and 1-3 species using the same methods. Most gut bacterial species from the lab-raised ants were unevenly distributed among the crop, midgut, and hindgut, and each section had its own dominant bacterial species. Acetobacter was the prominent bacteria group in crop, accounting for about 55 % of the crop clone library. Blochmannia was the dominant species in midgut, nearly reaching 90 % of the midgut clone library. Pseudomonas aeruginosa dominated the hindgut, accounting for over 98 % of the hindgut clone library. P. aeruginosa was the only species common to all three sections. A comparison between lab-raised and field-collected ants, and comparison with other species, shows that gut bacterial communities vary with local environment and diet. The bacterial species identified here were most likely commensals with little effect on their hosts or mild pathogens deleterious to colony health.
弓背蚁属是第二大蚂蚁属，已知其体内携带着布洛赫曼氏菌属的主要内共生细菌。然而，关于饮食和环境变化对这些蚂蚁肠道细菌群落的影响，人们了解甚少。我们调查了在美国西南部和墨西哥北部发现的脆弱弓背蚁在实验室饲养和野外采集的蚂蚁的肠道细菌群落。我们确定了这两种蚁群的嗉囊、中肠和后肠中肠道细菌组成和分布的差异。细菌种类的数量因检测方法和蚂蚁来源而异。使用经典微生物培养方法和小亚基核糖体RNA基因（16S rRNAs）聚合酶链反应-限制性片段长度多态性分析，实验室饲养的蚂蚁分别产生了12种和11种细菌。使用相同方法，野外采集的蚂蚁仅产生了4种和1 - 3种细菌。实验室饲养的蚂蚁的大多数肠道细菌种类在嗉囊、中肠和后肠中的分布不均匀，每个部分都有自己的优势细菌种类。醋杆菌是嗉囊中突出的细菌群，约占嗉囊克隆文库的55%。布洛赫曼氏菌是中肠中的优势物种，几乎占中肠克隆文库的90%。铜绿假单胞菌在后肠中占主导地位，占后肠克隆文库的98%以上。铜绿假单胞菌是所有三个部分共有的唯一物种。实验室饲养和野外采集的蚂蚁之间的比较，以及与其他物种的比较表明，肠道细菌群落随当地环境和饮食而变化。这里鉴定出的细菌种类很可能是共生菌，对其宿主影响很小，或者是对蚁群健康有害的轻度病原体。
