Chatzidaki-Livanis Maria, Hubbard Michael A, Gordon Katrina, Harwood Valerie J, Wright Anita C
University of Florida, Department of Food Science and Human Nutrition, P.O. Box 110370, Gainesville, FL 32611, USA.
Appl Environ Microbiol. 2006 Sep;72(9):6136-41. doi: 10.1128/AEM.00341-06.
Vibrio vulnificus causes rare but frequently fatal septicemia associated with raw oyster consumption by persons with underlying hepatic or immune system dysfunction. The virulence potential of environmental reservoirs appears widely distributed, because most strains are virulent in animal models; however, several investigations recently demonstrated genetic divergence among strains from clinical versus environmental origin at independent genetic loci. The present study used PCR to screen DNA polymorphisms in strains from environmental (n = 35) or clinical (n = 33) sources, and genomic relationships were determined by repetitive extragenic palindromic DNA PCR (rep-PCR) typing. Significant (P < 0.01) association was observed for typical "clinical" or "environmental" polymorphism profiles based on strain origin. Most oyster isolates (88%), including all of those with the "environmental" profile, also formed a single rep-PCR genogroup. Clinical isolates within this group did not have the typical "clinical" profile. On the other hand, clinical isolates with the typical polymorphism profile were distributed among multiple rep-PCR genogroups, demonstrating greater genetic diversity than was evident by profiling genetic polymorphisms. Wound isolates were genetically distinct from typical blood isolates by all assays. Strains from an outbreak of wound infections in Israel (biotype 3) were closely related to several U.S. strains by rep-PCR, indicating potential reservoirs of emerging disease. Strains genetically related to blood isolates appeared to be relatively rare in oysters, as only one had the "clinical" polymorphism profile or clustered by rep-PCR. However, this study was not an extensive survey, and more sampling using rep-PCR for sensitive genetic discrimination is needed to determine the virulence potential of environmental reservoirs.
创伤弧菌可引发罕见但往往致命的败血症，与潜在肝脏或免疫系统功能障碍者食用生牡蛎有关。环境宿主的致病潜力似乎分布广泛，因为大多数菌株在动物模型中具有致病性；然而，最近的几项研究表明，临床来源与环境来源的菌株在独立基因位点存在基因差异。本研究使用聚合酶链反应（PCR）筛选环境来源（n = 35）或临床来源（n = 33）菌株中的DNA多态性，并通过重复外源性回文DNA PCR（rep-PCR）分型确定基因组关系。基于菌株来源，观察到典型的“临床”或“环境”多态性谱之间存在显著关联（P < 0.01）。大多数牡蛎分离株（88%），包括所有具有“环境”谱的分离株，也形成了一个单一的rep-PCR基因组群。该组中的临床分离株没有典型的“临床”谱。另一方面，具有典型多态性谱的临床分离株分布在多个rep-PCR基因组群中，表明其遗传多样性比通过基因多态性分析所显示的更为明显。通过所有检测方法，伤口分离株在基因上与典型血液分离株不同。以色列一次伤口感染暴发（生物型3）的菌株通过rep-PCR与几株美国菌株密切相关，表明存在新兴疾病的潜在宿主。与血液分离株基因相关的菌株在牡蛎中似乎相对较少，因为只有一株具有“临床”多态性谱或通过rep-PCR聚类。然而，本研究并非广泛调查，需要更多使用rep-PCR进行敏感基因鉴别采样，以确定环境宿主的致病潜力。
