Govan J R, Hughes J E, Vandamme P
Department of Medical Microbiology, University of Edinburgh Medical School.
J Med Microbiol. 1996 Dec;45(6):395-407. doi: 10.1099/00222615-45-6-395.
The increasing challenge posed by multiresistant saprophytes in medical microbiology is strikingly demonstrated by the emergence of Burkholderia (formerly Pseudomonas) cepacia as an opportunist pathogen in immunocompromised patients, particularly individuals with chronic granulomatous disease and cystic fibrosis (CF). Best known previously as a phytopathogen and the cause of soft rot of onions, B. cepacia presents three major problems for the CF community: innate multiresistance to antimicrobial agents; person-to-person transmission of epidemic strains through nosocomial or social contacts; and 'cepacia syndrome', a fulminating fatal pneumonia, sometimes associated with septicaemia, that occurs in approximately 20% of colonised patients, including those with previously mild disease. Accumulated evidence to dispel earlier suggestions that the organism is avirulent and merely a marker of existing lung disease includes: case-controlled studies in CF patients; reports of serious infections in non-CF patients; in-vitro and in-vivo evidence that B. cepacia induces production of pro-inflammatory markers, including the major cytokine TNFalpha; and histopathological evidence that exposure of transgenic CF mice to B. cepacia results in pneumonia. By the early 1990s, the use of selective culture media and DNA-based bacterial fingerprinting confirmed suspicions of epidemic person-to-person spread of B. cepacia. This evidence provided scientific justification for draconian and controversial measures for infection control, in particular, segregation of B. cepacia-colonised patients during treatment at CF centres and their exclusion from social gatherings and national conferences. Recently, molecular analyses of type strains and clinical isolates have revealed that isolates identified previously as B. cepacia belong to at least three distinct species and have increased concern regarding the reliability of current laboratory detection and identification systems. Clarification of the taxonomy of B. cepacia-like organisms and the pathogenic potential of environmental isolates remains a high priority, particularly when the organism's antifungal and degradative properties have created interest in its potential use as a biological control agent to improve crop yields and its use for the bioremediation of contaminated soils.
在医学微生物学中，多重耐药腐生菌带来的挑战日益增加，洋葱伯克霍尔德菌（以前称为洋葱假单胞菌）作为免疫功能低下患者，尤其是患有慢性肉芽肿病和囊性纤维化（CF）的个体中的机会致病菌的出现，就显著地证明了这一点。洋葱伯克霍尔德菌以前最为人所知的是作为一种植物病原体以及洋葱软腐病的病因，它给CF群体带来了三个主要问题：对抗菌药物的固有多重耐药性；流行菌株通过医院内或社会接触在人与人之间传播；以及“洋葱伯克霍尔德菌综合征”，一种暴发性致命肺炎，有时与败血症相关，约20%的定植患者会发生，包括那些之前病情较轻的患者。越来越多的证据驳斥了早期认为该菌无致病性且仅仅是现有肺部疾病标志物的观点，这些证据包括：CF患者的病例对照研究；非CF患者严重感染的报告；体外和体内证据表明洋葱伯克霍尔德菌可诱导促炎标志物的产生，包括主要细胞因子肿瘤坏死因子α；以及组织病理学证据表明转基因CF小鼠接触洋葱伯克霍尔德菌会导致肺炎。到20世纪90年代初，使用选择性培养基和基于DNA的细菌指纹图谱证实了对洋葱伯克霍尔德菌在人与人之间流行传播的怀疑。这一证据为严厉且有争议的感染控制措施提供了科学依据，特别是在CF中心治疗期间将洋葱伯克霍尔德菌定植患者隔离，并禁止他们参加社交聚会和全国性会议。最近，对模式菌株和临床分离株的分子分析表明，之前鉴定为洋葱伯克霍尔德菌的分离株至少属于三个不同的物种，这增加了人们对当前实验室检测和鉴定系统可靠性的担忧。明确洋葱伯克霍尔德菌样生物的分类学以及环境分离株的致病潜力仍然是一个高度优先事项，特别是当该菌的抗真菌和降解特性引发了人们对其作为提高作物产量的生物防治剂以及用于污染土壤生物修复潜在用途的兴趣时。
