Allice T, Scutera S, Chirillo M G, Savoia D
Department of Clinical and Biological Sciences, University of Torino at S. Luigi Gonzaga Hospital, 10043 Orbassano, Torino, Italy.
J Infect. 2006 Sep;53(3):159-65. doi: 10.1016/j.jinf.2005.11.005. Epub 2006 Jan 10.
To characterize by molecular techniques Burkholderia strains responsible for respiratory tract infections in cystic fibrosis (CF) patients (children and adults), to assign the Burkholderia cepacia complex (Bcc) isolates to a genomovar and to assess the presence of cblA and esmR genes in bacteria. Unique or sequential Burkholderia isolates (n=48) that had been collected from eight CF children and 17 adults over several (4-6) years were investigated; moreover 11 reference strains were analyzed.
The microorganisms were identified by using biochemical methods, genotyped by pulse field gel electrophoresis (PFGE) and random-amplified polymorphic DNA fingerprinting-PCR (RAPD-PCR), and assessed by PCR assays for the genomovar and cblA and esmR genes of Bcc.
Among isolates 70.8% were identified as Bcc genomovar III-A; one child was infected by Burkholderia ambifaria and four adults were colonized with Burkholderia gladioli. The cblA gene was not detected in any of the isolates, while the esmR gene was detected in the 52.1% of the strains, all belonging to genomovar III-A.
Molecular analysis of strains revealed in CF patients a colonization with a persistent Burkholderia flora with strains of one genotype. The prevalence of Bcc of genomovar III-A in the two categories of patients and of B. gladioli in four adults demonstrated that transmission may have occurred between subjects. Moreover the B. ambifaria infection demonstrated in a child may be environmentally derived.
采用分子技术对囊性纤维化（CF）患者（儿童和成人）呼吸道感染相关的伯克霍尔德菌菌株进行特征分析，将洋葱伯克霍尔德菌复合体（Bcc）分离株归类到基因变种，并评估细菌中cblA和esmR基因的存在情况。对在4至6年期间从8名CF儿童和17名成人中收集的48株独特或连续的伯克霍尔德菌分离株进行了研究；此外，还分析了11株参考菌株。
采用生化方法鉴定微生物，通过脉冲场凝胶电泳（PFGE）和随机扩增多态性DNA指纹图谱-PCR（RAPD-PCR）进行基因分型，并通过PCR检测评估Bcc的基因变种以及cblA和esmR基因。
在分离株中，70.8%被鉴定为Bcc基因变种III-A；一名儿童感染了歧义伯克霍尔德菌，四名成人定植了唐菖蒲伯克霍尔德菌。在任何分离株中均未检测到cblA基因，而在52.1%的菌株中检测到esmR基因，所有这些菌株均属于基因变种III-A。
对菌株的分子分析显示，CF患者中存在一种由单一基因型菌株组成的持续性伯克霍尔德菌菌群定植。两类患者中基因变种III-A的Bcc以及四名成人中唐菖蒲伯克霍尔德菌的流行表明，可能在个体之间发生了传播。此外，一名儿童中显示的歧义伯克霍尔德菌感染可能源自环境。
