Ramsay Kay A, Butler Claire A, Paynter Stuart, Ware Robert S, Kidd Timothy J, Wainwright Claire E, Bell Scott C
Queensland Children's Medical Research Institute, The University of Queensland, Brisbane, Queensland, Australia.
J Clin Microbiol. 2013 Dec;51(12):3975-80. doi: 10.1128/JCM.01360-13. Epub 2013 Sep 18.
Burkholderia cepacia complex organisms are important transmissible pathogens found in cystic fibrosis (CF) patients. In recent years, the rates of cross-infection of epidemic strains have declined due to effective infection control efforts. However, cases of sporadic B. cepacia complex infection continue to occur in some centers. The acquisition pathways and clinical outcomes of sporadic B. cepacia complex infection are unclear. We sought to determine the patient clinical characteristics, outcomes, incidence, and genotypic relatedness for all cases of B. cepacia complex infection at two CF centers. We also sought to study the external conditions that influence the acquisition of infection. From 2001 to 2011, 67 individual organisms were cultured from the respiratory samples of 64 patients. Sixty-five percent of the patients were adults, in whom chronic infections were more common (68%) (P = 0.006). The incidence of B. cepacia complex infection increased by a mean of 12% (95% confidence interval [CI], 3 to 23%) per year. The rates of transplantation and death were similar in the incident cases who developed chronic infection compared to those in patients with chronic Pseudomonas aeruginosa infection. Multilocus sequence typing revealed 50 individual strains from 65 isolates. Overall, 85% of the patients were infected with unique strains, suggesting sporadic acquisition of infection. The yearly incidence of nonepidemic B. cepacia complex infection was positively correlated with the amount of rainfall in the two sites examined: subtropical Brisbane (r = 0.65, P = 0.031) and tropical Townsville (r = 0.82, P = 0.002). This study demonstrates that despite strict cohort segregation, new cases of unrelated B. cepacia complex infection continue to occur. These data also support an environmental origin of infection and suggest that climate conditions may be associated with the acquisition of B. cepacia complex infections.
洋葱伯克霍尔德菌复合体是在囊性纤维化（CF）患者中发现的重要可传播病原体。近年来，由于有效的感染控制措施，流行菌株的交叉感染率有所下降。然而，一些中心仍有散发性洋葱伯克霍尔德菌复合体感染病例持续出现。散发性洋葱伯克霍尔德菌复合体感染的获得途径和临床结局尚不清楚。我们试图确定两个CF中心所有洋葱伯克霍尔德菌复合体感染病例的患者临床特征、结局、发病率和基因型相关性。我们还试图研究影响感染获得的外部条件。2001年至2011年，从64例患者的呼吸道样本中培养出67株个体菌株。65%的患者为成年人，其中慢性感染更为常见（68%）（P = 0.006）。洋葱伯克霍尔德菌复合体感染的发病率平均每年增加12%（95%置信区间[CI]，3%至23%）。与慢性铜绿假单胞菌感染患者相比，发生慢性感染的新发病例的移植率和死亡率相似。多位点序列分型从65株分离株中鉴定出50个个体菌株。总体而言，85%的患者感染的是独特菌株，表明感染为散发性获得。在所检查的两个地点，非流行型洋葱伯克霍尔德菌复合体感染的年发病率与降雨量呈正相关：亚热带的布里斯班（r = 0.65，P = 0.031）和热带的汤斯维尔（r = 0.82，P = 0.002）。这项研究表明，尽管进行了严格的队列隔离，但无关的洋葱伯克霍尔德菌复合体感染新病例仍在继续出现。这些数据也支持感染的环境起源，并表明气候条件可能与洋葱伯克霍尔德菌复合体感染的获得有关。
