Emergence of a unique O3:K6 clone of Vibrio parahaemolyticus in Calcutta, India, and isolation of strains from the same clonal group from Southeast Asian travelers arriving in Japan
Emergence of a unique O3:K6 clone of Vibrio parahaemolyticus in Calcutta, India, and isolation of strains from the same clonal group from Southeast Asian travelers arriving in Japan
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DOI：
10.1128/jcm.35.12.3150-3155.1997
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发表时间：
1997-12-01
影响因子：
9.4
通讯作者：
Nishibuchi, M
中科院分区：
文献类型：
--
作者：
Okuda, N;Ishibashi, M;Nishibuchi, M
1994年1月开始对印度加尔各答住院病人中的副溶血性弧菌感染进行积极监测。1996年2月，副溶血性弧菌感染病例突然增加，此后一直居高不下。对1994年1月至1996年8月分离的134株副溶血性弧菌进行了血清型、耐热直接溶血素基因（tdh）和tdh相关溶血素基因（trh 1和trh 2）的存在、尿素酶的产生和酶谱检查。O3：K6血清型菌株于1996年2月首次出现。在高发期（1996年2 ~ 8月），O_3：K_6型占50 ~ 80%，所有O_3：K_6型菌株均携带tdh基因，不携带trh基因，不产尿素酶。除两株外，所有分离株对所有测试的抗生素均敏感。这些以及任意引发PCR方法的分析结果表明，O3：K6血清型菌株属于一个独特的克隆。当O3：K6血清型菌株，从旅行者抵达日本从东南亚国家，进行了比较，由任意引物PCR方法，1982年和1993年之间分离的菌株是不同的加尔各答O3：K6，而在1995年和1996年分离的菌株是无法区分的加尔各答O3：K6菌株。结果表明，这种独特的O3：K6克隆可能不仅在加尔各答流行，而且最近在东南亚国家也很流行。不仅O3：K6菌株，而且1996年分离的非O3：K6、tdh-bearing菌株也产生高水平的热稳定性直接溶血素，因此产生的溶血素水平似乎没有影响血清型O3：K6菌株的高发病率。
Active surveillance of Vibrio parahaemolyticus infection among hospitalized patients in Calcutta, India, was initiated in January 1994. The incidence of cases of V. parahaemolyticus infection suddenly increased in February 1996 and has remained high since then. One hundred thirty-four strains of V. parahaemolyticus isolated from January 1994 to August 1996 were examined for serovar, the presence of the thermostable direct hemolysin gene (tdh) and tdh-related hemolysin genes (trh1 and trh2), production of urease, and antibiogram. Strains of the O3:K6 serovar appeared for the first time in February 1996. The O3:K6 serovar strains accounted for 50 to 80% of the strains isolated during the high-incidence period (February to August 1996), All of the serovar O3:K6 strains carried the tdh gene but not the trh genes and did not produce urease. All of the isolates except two were sensitive to all of the antibiotics tested. These and the results of analysis by an arbitrarily primed PCR method indicated that the O3:K6 serovar strains belong to a unique clone. When the O3:K6 serovar strains, isolated from travelers arriving in Japan from Southeast Asian countries, were compared by the arbitrarily primed PCR method, the strains isolated between 1982 and 1993 were distinct from Calcutta O3:K6 while the strains isolated in 1995 and 1996 were indistinguishable from the Calcutta O3:K6 strains. The results suggest that this unique O3:K6 clone may have become prevalent not only in Calcutta but also in Southeast Asian countries very recently. Not only the O3:K6 strains but also the non-O3:K6, tdh-bearing strains isolated in 1996 produced thermostable direct hemolysin at high levels, and thus the level of hemolysin produced does not appear to have influenced the high incidence of serovar O3:K6 strains.