Phytopathology. 2007 Feb;97(2):195-201. doi: 10.1094/PHYTO-97-2-0195.
ABSTRACT Burkholderia cenocepacia (genomovar III of B. cepacia complex), the causal agent of banana finger-tip rot, is a common plant-associated bacterium but also an important opportunistic pathogen of humans. To better understand the nature of B. cenocepacia from banana, the genetic variation among B. cenocepacia isolates from various banana-growing regions in southern Taiwan was examined. Forty-four serial isolates recovered from diseased banana stigmata from three banana-growing regions during the periods ranging from 2002 to 2004 were investigated. All B. cenocepacia isolates picked from quinate-yeast extract tetracycline-polymyxin semiselective medium could cause onion maceration and were polymerase chain reaction (PCR) positive for bcscV, which is a type III secretion gene present in all members of the B. cepacia complex except B. cepacia (formerly genomovar I). Genetic diversity was assessed using recA PCR restriction fragment length polymorphism, recA nucleotide sequence analysis, and pulsed-field gel electrophoresis assays. The assays revealed the genetic variability among the isolates and also allowed us to trace the relationship among isolates. The isolates all were assigned to genomovar III and consisted of two groups, A and B, which corresponded to recA lineage IIIA and IIIB. The group B strains were separated into B1 and B2 subgroups and the B1 strains were further divided into distinct lineages. The B1 strains were the most frequently detected and occurred in all regions tested. There was no significant difference between strains from each subgroup in the virulence on banana fingers of cv. Cavendish. PCR assays were further used to determine whether B. cenocepacia from banana contained the cable pilus subunit gene (cblA), IS1356, and B. cepacia epidemic strain marker (BCESM), which are DNA markers associated with epidemic B. cepacia clinic strains. The results indicated that cblA and IS1356 were absent but the BCESM was found in all isolates. The present study revealed that banana is a natural reservoir of genetically diversified B. cenocepacia strains.
摘要 洋葱伯克霍尔德菌（鲍曼不动杆菌复合群的基因组变种 III）是导致香蕉指尖腐烂的病原体，它是一种常见的植物相关细菌，但也是人类重要的机会致病菌。为了更好地了解香蕉中的洋葱伯克霍尔德菌，本研究检测了来自台湾南部不同香蕉种植区的洋葱伯克霍尔德菌分离株之间的遗传变异。从 2002 年至 2004 年期间，从三个香蕉种植区患病香蕉柱头中连续分离出 44 株分离株。从喹啉酵母提取物四环素多粘菌素半选择性培养基中挑取的所有洋葱伯克霍尔德菌分离株都可以引起洋葱浸渍，并且聚合酶链反应（PCR）均为 bcscV 阳性，bcscV 是一种 III 型分泌基因，存在于除鲍曼不动杆菌（前基因组变种 I）以外的所有鲍曼不动杆菌复合群成员中。使用 recA PCR 限制性片段长度多态性、recA 核苷酸序列分析和脉冲场凝胶电泳检测评估遗传多样性。这些检测结果显示了分离株之间的遗传变异性，并使我们能够追踪分离株之间的关系。分离株均被分配到基因组变种 III 中，由 A 和 B 两个组组成，分别对应于 recA 谱系 IIIA 和 IIIB。B 组菌株被分为 B1 和 B2 亚群，B1 菌株进一步分为不同的谱系。B1 菌株是最常检测到的菌株，存在于所有测试的地区。来自每个亚组的菌株在香蕉手指上的毒力没有显著差异。Cavendish 香蕉。进一步使用 PCR 检测来确定香蕉中的洋葱伯克霍尔德菌是否含有电缆菌毛亚基基因（cblA）、IS1356 和鲍曼不动杆菌流行株标记（BCESM），这些是与流行的鲍曼不动杆菌临床株相关的 DNA 标记。结果表明，cblA 和 IS1356 缺失，但所有分离株均存在 BCESM。本研究表明，香蕉是遗传多样化的洋葱伯克霍尔德菌菌株的天然宿主。
