Davis Michael J, Mondal Sachindra N, Chen Huiqin, Rogers Michael E, Brlansky Ronald H
University of Florida, Institute of Food and Agricultural Sciences, Citrus Research and Education Center, Lake Alfred 33850.
Plant Dis. 2008 Nov;92(11):1547-1550. doi: 10.1094/PDIS-92-11-1547.
Huanglongbing (HLB), also known as citrus greening disease, is a devastating disease of citrus caused by phloem-limited bacteria that have not been grown in culture. Three species, 'Candidatus Liberibacter asiaticus', 'Ca. L. africanus', and 'Ca. L. americanus', are known. 'Ca. L. asiaticus' and its insect vector, the psyllid Diaphorina citri, have been recently introduced into Florida. We attempted to isolate 'Ca. L. asiaticus' using media formulations developed in response to the growth of another bacterium that appears to be related to the liberibacters based on 16S rRNA gene identities. Cultures were obtained that were polymerase chain reaction (PCR) positive for 'Ca. L. asiaticus'. However, transmission electron microscope examination of the culture, PCR using generic primers, and sequencing of the PCR products revealed the presence of other bacteria in the cultures. These were actinobacteria related to Propionibacterium acnes based on 16S rRNA identities. The co-cultures remained after attempts to purify the cultures by single-colony isolation, suggesting that the bacteria might be mutually beneficial to each other in culture. The co-cultures have survived more than 10 weekly passages to fresh medium. PCR using P. acnes-specific primers indicated that actinobacteria are common inhabitants of citrus and psyllids, whether or not 'Ca. L. asiaticus' is present.
黄龙病（HLB），也被称为柑橘黄龙病，是一种由尚未在培养基中培养的韧皮部限制性细菌引起的毁灭性柑橘病害。已知有三个种，即“亚洲韧皮杆菌”（‘Candidatus Liberibacter asiaticus’）、“非洲韧皮杆菌”（‘Ca. L. africanus’）和“美洲韧皮杆菌”（‘Ca. L. americanus’）。“亚洲韧皮杆菌”及其昆虫传播媒介——柑橘木虱（Diaphorina citri）最近已传入佛罗里达州。我们尝试使用针对另一种基于16S rRNA基因同源性似乎与韧皮杆菌相关的细菌生长而开发的培养基配方来分离“亚洲韧皮杆菌”。获得了对“亚洲韧皮杆菌”聚合酶链反应（PCR）呈阳性的培养物。然而，对培养物进行透射电子显微镜检查、使用通用引物进行PCR以及对PCR产物进行测序后发现培养物中存在其他细菌。基于16S rRNA同源性，这些细菌是与痤疮丙酸杆菌相关的放线菌。通过单菌落分离法纯化培养物的尝试后，共培养物仍然存在，这表明这些细菌在培养中可能对彼此互利。共培养物在每周转接至新鲜培养基的情况下已存活超过10次。使用痤疮丙酸杆菌特异性引物进行的PCR表明，无论是否存在“亚洲韧皮杆菌”，放线菌都是柑橘和柑橘木虱的常见栖息菌。
