Kaufman G E, Myers M L, Pass C L, Bej A K, Kaysner C A
Department of Biology, University of Alabama at Birmingham, 35294-1170, USA.
Lett Appl Microbiol. 2002;34(3):155-61. doi: 10.1046/j.1472-765x.2002.01076.x.
The objective of this study was to investigate the occurrence and distribution of haemolysin genes, plasmid profile, serogroup analysis and cellular urease activity for Vibrio parahaemolyticus isolates from infected human patients and oysters from the Pacific north-western United States between 1988 and 1997.
All of the clinical and environmental isolates tested in this study exhibited the presence of the thermolabile haemolysin gene, tl, confirming that all of the isolates were V. parahaemolyticus. Furthermore, the V. parahaemolyticus isolates that contained either the thermostable direct haemolysin gene, tdh, or the thermostable direct haemolysin-related gene, trh, or both, were also positive for urease. Isolates from infected human patients belong to serogroups O1 and O4, whereas, the isolates from oysters belong to serogroups O1, O4 and O5. These results suggest that the presence of a V. parahaemolyticus serogroup O1 and O4 could indicate the presence of a virulent strain of this pathogen. In this study, the presence of the haemolysin genes, serogroup profiles and urease production in V. parahaemolyticus isolated from human patients correlated with the oysters collected during the outbreaks. However, no significant correlation of the plasmid profiles was detected, based on their distribution and molecular weights, between V. parahaemolyticus isolated from infected human patients and from oysters collected during this outbreak.
CONCLUSIONS, SIGNIFICANCE AND IMPACT OF STUDY: It is apparent from this study that the identification of the haemolysin genes by multiplex PCR amplification, in conjunction with serogroup analysis and urease production, can be used to monitor shellfish for the presence of potentially pathogenic strains of V. parahaemolyticus.
本研究的目的是调查1988年至1997年期间从美国西北太平洋地区受感染的人类患者和牡蛎中分离出的副溶血性弧菌分离株的溶血素基因的发生和分布、质粒图谱、血清群分析和细胞脲酶活性。
本研究中测试的所有临床和环境分离株均显示存在不耐热溶血素基因tl，证实所有分离株均为副溶血性弧菌。此外，含有耐热直接溶血素基因tdh或耐热直接溶血素相关基因trh或两者的副溶血性弧菌分离株脲酶也呈阳性。来自受感染人类患者的分离株属于O1和O4血清群，而来自牡蛎的分离株属于O1、O4和O5血清群。这些结果表明，副溶血性弧菌O1和O4血清群的存在可能表明该病原体的有毒菌株的存在。在本研究中，从人类患者分离出的副溶血性弧菌中的溶血素基因、血清群谱和脲酶产生与疫情期间采集的牡蛎相关。然而，根据其分布和分子量，在从受感染人类患者分离出的副溶血性弧菌与本次疫情期间采集的牡蛎中的副溶血性弧菌之间未检测到质粒图谱的显著相关性。
研究的结论、意义和影响：从本研究中可以明显看出，通过多重PCR扩增鉴定溶血素基因，结合血清群分析和脲酶产生，可用于监测贝类中潜在致病性副溶血性弧菌菌株的存在。
