Chironomid egg masses as a natural reservoir of Vibrio cholerae non-O1 and non-O139 in freshwater habitats
Chironomid egg masses as a natural reservoir of Vibrio cholerae non-O1 and non-O139 in freshwater habitats
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DOI：
10.1007/s00248-003-2007-6
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发表时间：
2004-05-01
影响因子：
3.6
通讯作者：
Broza, M
中科院分区：
文献类型：
--
作者：
Halpern, M;Broza, YB;Broza, M
霍乱是一种由革兰氏阴性菌霍乱弧菌引起的腹泻疾病，据估计，全球每年有12万人死于霍乱。细菌的天然宿主是环境。最近的一份报告表明霍乱弧菌与卵团之间存在关联。手摇蚊，即“不咬人的蠓”（双翅目；手摇蚊科），是淡水中分布最广泛、数量最多的昆虫。雌性将含有数百个卵的卵团，包裹在一层明胶中，附着在细菌丰富的水边，可能会遇到营养丰富的基质。本文报道了从以色列、印度和非洲不同淡水水体的卵团中分离出的非o1型和非o139型霍乱弧菌。在以色列的一项年度调查中，人们发现摇尾虫的数量每两年达到一次高峰，似乎在这些高峰之后，地中海地区的细菌会在冬季生长和消失。水温超过25度时，细菌数量增加。从手拟虫分离的细菌中鉴定出35个不同的霍乱弧菌血清群，显示出群体异质性。从桑给巴尔岛鸡卵群中分离到的霍乱弧菌O37和O201均为NAG-ST阳性。我们的研究结果支持了一种假设，即手拟虫与霍乱细菌之间的联系并非罕见的巧合，表明手拟虫卵团可能是霍乱弧菌的另一个潜在宿主。
Cholera is a diarrheal disease caused by the gram-negative bacterium Vibrio cholerae, and an estimated 120,000 deaths from cholera occur globally every year. The natural reservoir of the bacterium is environmental. A recent report indicated an association between V. cholerae and chironomid egg masses. Chironomids, the "non-biting midges" (Diptera; Chironomidae), are the most widely distributed and frequently the most abundant insects in freshwater. Females attach egg masses, each containing hundreds of eggs encased in a layer of gelatin, to the water's edge where bacteria are abundant and may encounter the nutrient-rich substrate. Here we report the isolation of non-O1 and non-O139 V. cholerae from chironomid egg masses from different freshwater bodies in Israel, India, and Africa. In a yearly survey in Israel, chironomid populations were found to peak biannually, and it seemed that those peaks were followed by subsequent bacterial growth and disappearance during the winter in the Mediterranean region. The bacterial population rose as water temperature surpassed 25degreesC. Thirty-five different serogroups of V. cholerae were identified among the bacteria isolated from chironomids, demonstrating population heterogeneity. Two strains of V. cholerae O37 and O201 that were isolated from chironomid egg masses in Zanzibar Island were NAG-ST positive. Our findings support the hypothesis that the association found between chironomids and the cholera bacteria is not a rare coincidence, indicating that chironomid egg masses may serve as yet another potential reservoir for V cholerae.