Vibrio vulnificus-like bacteria in seawater from the coast of northern Taiwan

• Main Authors: ChingHuei Chou, 周青慧
• Other Authors: Wung Yang Shieh
• Format: Others
• Language: zh-TW
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/00150232622437032009

碩士 === 國立臺灣大學 === 海洋研究所 === 88 === Vibrio vulnificus is an autochthonous marine bacterium which is widely distributed in estuarine and coastal ecosystems; seafood and water can be vectors for transmission of this pathogenic species to humans. Its infection might result in a variety of clinical syndromes, including gastroenteritis, cellulitis, and septicemia. There are many reports for abundance of V. vulnificus in shellfish, but rare studies for its distribution in seawater. V. vulnificus, Vibrio cholerae and Vibrio parahaemolyticus are the only species in the genus Vibrio, which are known to be resistant to both polymyxin B and colistin. Among the three species only V. vulnificus can ferment cellobiose and salicin. According to the characteristics found in V. vulnificus, we used a modified cellobiose-polymyxin B-colistin medium ( CPC medium ) and developed a salicin-polymyxin B-colistin medium ( SPC medium ) for cultivation, enumeration, isolation and identification of V. vulnificus-like bacteria in seawater samples from the coast of northern Taiwan. Most MPN counting values of these bacteria were in the range of 100 to 103 cells / ml for coastal water samples from Shalun, Paishawan, Chinshan and Fetsueiwan, and for estuarine water samples from Kuantu and Chuwei. The counting values on CPC and SPC media were not significantly different. Sixty-six strains of V. vulnificus-like bacteria isolated in this study were divided into six groups according to their phenotypic characteristics. All the isolated bacteria fermented glucose while only four groups included halophilic isolates. Only the representative strains included in the greatest group ( 21 isolates ) showed levels of 16S rDNA sequence similarity more than 97% with V. vulnificus. Higher incidence of V. vulnificus were observed on coastal water than on estuarine water samples ( 60-100% : 0-40% ) by using the present cultivation methods. Appropriate modifications of the concentration of polymyxin B and colistin in CPC and SPC media would enhance the selectivity of these media for V. vulnificus.