Sangeetha Balakrishnan Geetha, Jayaprakas Cheruvandasseri Arumughan, Siji Jinachandrannair Vijayakumari, Rajitha Moochattil, Shyni Basheerkutty, Mohandas Chellappan
Division of Crop Protection, Central Tuber Crops Research Institute, Sreekariyam, Trivandrum, Kerala, India.
3 Biotech. 2016 Jun;6(1):32. doi: 10.1007/s13205-015-0326-1. Epub 2016 Jan 14.
Bacterial strains associated with entomopathogenic nematodes (EPNs) Rhabditis (Oscheius) spp. were isolated from infected cadavers of Galleria mellonella. The obtained 18 isolates were subdivided into nine phylogenetically different genera based on comparative sequence analysis of their 16S rRNA genes. The isolates were affiliated to three different class namely γ-proteobacteria (Enterobacter, Proteus, Providencia, Pseudomonas, Stenotrophomonas), β-proteobacteria (Alcaligenes) and Bacilli (Bacillus, Enterococcus, Lysinibacillus). It was observed that Gram-positive strains (Bacilli) were more frequently associated with the EPN, whereas Gram-negative isolates were affiliated to six different genera with more genotypic diversity. Subsequently, all bacterial isolates used in this study were analyzed by amplified ribosomal DNA restriction analysis (ARDRA). Eight restriction endonucleases (CfoI, HinfI, RsaI, DdeI, Sau3AI, AluI, HaeIII, and MspI) were examined and a total of 15 different genotypes were obtained, forming two heterogenous main clusters after analysis by un-weighted pair-group method using arithmetic averages.
从感染的大蜡螟尸体中分离出与昆虫病原线虫（EPNs）小杆线虫（奥氏小杆线虫属）相关的细菌菌株。根据对其16S rRNA基因的比较序列分析，将获得的18个分离株细分为9个系统发育不同的属。这些分离株隶属于三个不同的类别，即γ-变形菌纲（肠杆菌属、变形杆菌属、普罗威登斯菌属、假单胞菌属、嗜麦芽窄食单胞菌属）、β-变形菌纲（产碱菌属）和芽孢杆菌纲（芽孢杆菌属、肠球菌属、赖氨酸芽孢杆菌属）。观察到革兰氏阳性菌株（芽孢杆菌纲）更频繁地与EPN相关，而革兰氏阴性分离株隶属于六个不同的属，具有更多的基因型多样性。随后，通过扩增核糖体DNA限制性分析（ARDRA）对本研究中使用的所有细菌分离株进行了分析。检测了八种限制性内切酶（CfoI、HinfI、RsaI、DdeI、Sau3AI、AluI、HaeIII和MspI），共获得15种不同的基因型，采用算术平均非加权配对组法分析后形成两个异质的主要聚类。
