State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, AMMS, Beijing 100071, China.
Department of Pediatrics, Peking University First Hospital, Beijing, 100034, China.
Anaerobe. 2019 Feb;55:1-7. doi: 10.1016/j.anaerobe.2018.06.015. Epub 2018 Jul 2.
Infant botulism was rarely reported in China. The second reported event of the disease including three cases occurred in 2015. In the present study, one (the third case) of the three cases was identified and investigated to trace the sources of transmission. Samples from feces and foodstuffs were used to isolate Clostridium botulinum strains. Each isolate was obtained from the baby's feces and opened powdered infant rice cereal, respectively. In this case, the C. botulinum strains were identified and characterized by combined mouse bioassay, Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and high-throughput sequencing including single nucleotide polymorphisms (SNP). Results showed that the disease was caused by a type B strain of C. botulinum. Strains associated with this case as well as isolates from stored and historical samples were phylogenetically analyzed and compared. C. botulinum type B isolates from the infant feces and from an opened container of infant rice cereal were indistinguishable, suggesting that opened container of infant rice cereal is likely to be the source of transmission of spores to the infant. It is not clear that how the opened container was contaminated and the child was exposed since environmental testing was not performed. This study provides detailed information about usage of the three methods and references for dealing with other associated cases.
婴儿肉毒中毒在中国很少见。该疾病的第二起报告事件包括 2015 年发生的三例。在本研究中，对这三例中的一例（第三例）进行了鉴定和调查，以追踪传播源。使用粪便和食品样本分离出肉毒梭菌菌株。每个分离株分别从婴儿粪便和已开封的婴儿米粉中获得。在这种情况下，通过结合小鼠生物测定法、基质辅助激光解吸/电离飞行时间质谱（MALDI-TOF MS）和包括单核苷酸多态性（SNP）在内的高通量测序对 C. botulinum 菌株进行了鉴定和特征分析。结果表明，该疾病是由 B 型 C. botulinum 菌株引起的。与该病例相关的菌株以及来自储存和历史样本的分离株进行了系统发育分析和比较。从婴儿粪便和已开封的婴儿米粉容器中分离出的 B 型 C. botulinum 分离株无法区分，表明已开封的婴儿米粉容器很可能是孢子传播给婴儿的来源。由于未进行环境测试，因此尚不清楚打开的容器是如何污染的，以及孩子是如何暴露的。本研究提供了有关三种方法的详细信息，为处理其他相关病例提供了参考。
