Prevalence and Genomic Characterization of Multidrug-Resistant Salmonella enterica Serovar Kentucky Sequence Type 198 Circulating — Beijing Municipality, China, 2016–2023

Mei Qu¹; Ying Huang¹; Bing Lyu¹; Xin Zhang¹; Yi Tian¹; Zhaomin Feng¹; Zhiyong Gao¹; Daitao Zhang^1#

1. Beijing Key Laboratory of Diagnostic and Traceability Technologies for Food Poisoning, Beijing Center for Disease Prevention and Control, Beijing, China.

^# Corresponding author: Daitao Zhang, zdt016@163.com

The emergence of fluoroquinolone-resistant Salmonella Kentucky ST198, a multidrug-resistant (MDR) clone, poses a significant threat to public health globally. This study aimed to investigate the prevalence, genetic characteristics, and antimicrobial resistance profiles of S. Kentucky ST198 in Beijing Municipality, China. We performed whole-genome sequencing (WGS) and antimicrobial susceptibility testing on 54 S. Kentucky isolates recovered from food and clinical samples collected between 2016 and 2023 to analyze their genetic evolution. All 54 S. Kentucky isolates exhibited resistance to fluoroquinolones, harboring two mutations (gyrA_S83F and parC_S80I) within the quinolone resistance-determining region. Resistance to other antimicrobial classes, including folate pathway inhibitors, cephalosporins, aminoglycosides, phenicols, rifampicin, fosfomycin, macrolides, and tetracyclines, was conferred by a variety of resistance genes, such as sul1, sul2, dfrA14, bla_CTX-M, bla_TEM-1B, aac(3)-Id, aadA2, aadA7, aph(3')-I, aph(3'')-Ib, rmtB, floR, arr-2, fosA, mph(A), and tet(A), resulting in diverse resistance patterns. Phylogenetic analysis of the S. Kentucky ST198 isolates from Beijing revealed two main branches, 198.2-1 and 198.2-2. Branch 198.2-2 was further subdivided into three sub-branches: 198.2-2A, 198.2-2B, and 198.2-2C. Isolates belonging to branch 198.2-1 harbored bla_CTX-M-14b, while those in branch 198.2-2 exhibited more complex resistance phenotypes, with most isolates carrying bla_CTX-M-55, bla_TEM-1B, and the chromosomally located qnrS1 gene. Notably, two major clones, cgST236434 from branch 198.2-1 and cgST296405 from branch 198.2-2A, were responsible for outbreaks of S. Kentucky. S. Kentucky has persisted in Beijing since 2016, causing both outbreaks and sporadic infections. The circulating strains exhibit genetic diversity, comprising multiple lineages. Enhanced surveillance of S. Kentucky in both food and human populations is crucial to prevent and control the spread of antimicrobial resistance.

ST198型多重耐药肯塔基沙门菌流行情况及基因组特征 — 中国北京市，2016-2023年

曲梅¹；黄瑛¹；吕冰¹；张新¹；田祎¹；冯兆民¹；高志勇¹；张代涛^1#

1 食物中毒诊断溯源技术北京市重点实验室，北京疾控中心，北京，中国；

#通讯作者：张代涛，zdt016@163.com。

氟喹诺酮类耐药的ST198型肯塔基沙门菌已成为全球性的多重耐药克隆株，对公共卫生构成威胁。了解北京市ST198型肯塔基沙门菌流行情况、遗传特性及耐药特征。采用全基因组测序和抗生素药物敏感性检测，对2016～2023年来自食品和临床样本分离到的54株肯塔基沙门菌进行遗传进化分析。54株肯塔基沙门菌全部对喹诺酮类药物耐药，喹诺酮耐药决定区携带2个突变位点（gyrA_S83F 和 parC_S80I）。对其他类抗生素（叶酸途径抑制剂、头孢菌素类、氨基糖苷类、酚类、利福霉素、磷霉素、大环内酯类和四环素类）的耐药，由 sul1、sul2、dfrA14、bla_CTX-M、bla_{TEM_1B}、aac(3)-Id、aadA2、aadA7、aph(3')-I、aph(3'')-Ib、rmtB、floR、arr-2、fosA、mph(A) 和 tet(A)等耐药基因介导，存在多种耐药组合。北京市ST198 型肯塔基沙门菌系统发育树显示存在 198.2-1 和 198.2-2 两个分支，198.2-2进一步分化为198.2-2A、198.2-2B 和 198.2-2C 三个亚分支。198.2-1分支的菌株携带 bla_CTX-M-14b ；而198.2-2 分支的菌株则表现出更复杂的耐药表型，大多数菌株携带bla_CTX-M-55 和 bla_TEM-1B，以及位于染色体上的 qnrS1基因。肯塔基沙门菌暴发菌株主要有两个克隆来源：198.2-1 分支 cgST236434和198.2-2A分支 cgST296405。自2016 年以来肯塔基沙门菌在北京一直持续存在，引起暴发和流行，由多个谱系组成，具有遗传多样性。加强对食品和人类的肯塔基沙门菌的监测将有助于预防和控制耐药性的传播。

For more information: https://weekly.chinacdc.cn/en/article/doi/10.46234/ccdcw2024.179

Post-Marketing Surveillance of Adverse Events Following Immunization with Haemophilus Influenzae Type b Conjugate Vaccine — China, 2010–2021

Minrui Ren¹; Keli Li^1#; Yan Li¹; Chunxiang Fan¹; Yuyang Xu^1,2; Lina Zhang¹; Yuan Li¹; Lei Cao¹; Wenzhou Yu¹; Zundong Yin¹

1. National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases (NITFID), National Immunization Program, Chinese Center for Disease Control and Prevention, Beijing, China;

2. Department of Expanded Program on Immunization, Hangzhou Center for Disease Control and Prevention, Hangzhou City, Zhejiang Province, China.

^# Corresponding author: Keli Li, likl@chinacdc.cn.

The Haemophilus influenzae type b (Hib) conjugate vaccine is widely administered in China. This study extracted data on Hib vaccine doses administered and adverse events following immunization (AEFI) reported between 2010 and 2021 from the Chinese National Immunization Information System (CNIIS). A descriptive analysis was conducted to examine the characteristics and incidence rates of AEFI associated with the Hib vaccine. In China, between 2010 and 2021, a total of 52,910 AEFI associated with the Hib vaccine were reported, resulting in an overall AEFI reporting rate of 38.10 per 100,000 doses. Common (typically minor) and rare (potentially serious) vaccine reactions occurred at rates of 34.71 and 2.78 per 100,000 doses, respectively. Among the common reactions, the incidences of severe fever (axillary temperature ≥38.6℃), injection site redness and swelling (>2.5cm in diameter), and injection site induration (>2.5cm in diameter) were 11.93, 9.69, and 3.38 per 100,000 doses, respectively. Rare vaccine reactions included anaphylactic rash, angioedema, and febrile convulsion with reported incidences of 2.42, 0.10, and 0.05 per 100,000 doses, respectively. The incidence of severe rare vaccine reactions was 0.16 per 100,000 doses. The reported incidence of Hib vaccine-associated AEFI was low, with the occurrence of serious, rare adverse reactions also being markedly low throughout the period 2010–2021 in China. Enhanced surveillance of AEFI is recommended.

b型流感嗜血杆菌结合疫苗疑似预防接种异常反应监测分析 — 中国，2010-2021年

任敏睿¹; 李克莉^1#; 李燕¹; 樊春祥¹; 许玉洋^1，2; 张丽娜¹; 李媛¹; 曹雷¹; 余文周¹; 尹遵栋¹

1. 传染病溯源预警与智能决策全国重点实验室，中国疾病预防控制中心免疫规划中心，北京，中国；

2. 杭州市疾控中心免疫预防所，杭州市，浙江省，中国。

#通讯作者：李克莉, likl@chinacdc.cn。

b型流感嗜血杆菌（Hib）结合疫苗在中国广泛使用。本研究通过中国免疫规划信息系统收集2010-2021年Hib疫苗接种剂次数据和疑似预防接种异常反应（AEFI）报告数据，描述性分析AEFI分布特征和报告发生率。2010-2021年中国共报告52,910例Hib疫苗AEFI，AEFI报告发生率为38.10/10万剂。一般反应和异常反应报告发生率分别为34.71/10万和2.78/10万。一般反应中，高热（腋温≥38.6℃）、局部红肿（直径>2.5cm）、局部硬结（直径>2.5cm）报告发生率分别为11.93/10万、9.69/10万和3.38/10万。异常反应中，过敏性皮疹、血管性水肿和热性惊厥报告发生率分别为2.42/10万、0.10/10万和0.05/10万。严重异常反应报告发生率为0.16/10万。结果表明中国2010-2021年Hib疫苗AEFI报告发生率较低，严重异常反应报告发生率极低；需继续加强Hib疫苗AEFI监测。

For more information: https://weekly.chinacdc.cn/en/article/doi/10.46234/ccdcw2024.180

Risk Factors for Norovirus Outbreaks in Schools and Kindergartens — Beijing Municipality, China, July 2017–June 2022

Baiwei Liu¹; Yu Wang¹; Mengdi Tan²; Boran E³; Dongxue Zhang⁴; Hanqiu Yan¹; Quanyi Wang¹; Daitao Zhang¹; Lei Jia^1#; Zhiyong Gao^1,2#

1. Institute for Infectious Disease and Endemic Disease Control, Beijing Center for Disease Prevention and Control, Beijing, China;

2. School of Public Health, China Medical University, Shenyang City, Liaoning Province, China;

3. School of Public Health, Capital Medical University, Beijing, China;

4. Department of Endocrinology, Beijing Shijitan Hospital, Capital Medical University, Beijing, China.

^# Corresponding author: Lei Jia, Lailajia@126.com; Zhiyong Gao, zhiyonggao1@163.com

The study analyzing norovirus outbreaks in Beijing schools and kindergartens from 2017 to 2022 has identified the risk factors contributing to these events. The research examined 1,163 norovirus clusters and outbreaks caused by person-to-person transmission, and conditional logistic regression showed that students vomiting at school, case activity in public areas, and classrooms located less than 5 meters from toilets increased the risk of outbreaks. The study emphasizes the importance of dealing with vomit in a standardized way, immediate isolation of sick individuals and timely toilet disinfection to prevent norovirus outbreaks. In China, nearly 90% of norovirus outbreaks occur in schools and kindergartens, and it is necessary to take targeted prevention and control measures in these institutions to reduce the burden of disease and protect public health.

学校及托幼机构中诺如病毒暴发疫情的危险因素分析 — 北京，2017年6月至2022年7月

刘白薇¹；王宇¹；谭梦迪²；鄂博然³；张冬雪⁴；严寒秋¹；王全意¹；张代涛¹；贾蕾^1#；高志勇^1,2#

1 北京市疾病预防控制中心传染病地方病控制所，北京，中国；

2 中国医科大学公共卫生学院，沈阳市，辽宁省，中国；

3 首都医科大学公共卫生学院，北京，中国；

4 北京世纪坛医院内分泌科，北京，中国。

#通讯作者：贾蕾，Lailajia@126.com；高志勇，zhiyonggao1@163.com。

这项研究分析了2017年至2022年北京市学校和幼儿园发生的诺如病毒疫情，探讨了发生诺如病毒暴发疫情的危险因素。该研究纳入了1,163起人-人传播引起的诺如病毒聚集性和暴发疫情，应用条件logistic回归分析发现学生在学校呕吐、病例在公共场所活动和教室距离厕所不到5米增加了诺如病毒暴发疫情的发生风险。该研究强调了规范处理呕吐物、立即隔离病例和及时消毒公共厕所对预防诺如病毒暴发疫情的重要性。我国90%的诺如病毒暴发疫情发生在学校和幼儿园，有必要在这些机构采取针对性的防控措施，以减轻疾病负担，保护公众健康。

For more information: https://weekly.chinacdc.cn/en/article/doi/10.46234/ccdcw2024.181

Infection and Genomic Characteristics of Campylobacter jejunifrom a Patient Without Diarrhea — China, 2018

Xiangdong Yang^1,2; Wen Wang¹; Chajin Cui³; Binbin Yu²; Qing Zhang²; Yanhua Wang^1#

1. Ecological Medicine Research Center, National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China

2. Department of Zoonotic Disease Control and Prevention, Yunnan Institute of Endemic Diseases Control & Prevention, Dali Bai Autonomous Prefecture, Yunnan Province, China

3. Medical Laboratory Department, Yunnan Luxi County People’s Hospital, Honghe Hani-Yi Autonomous Prefecture, Yunnan Province, China

^#Corresponding author: Yanhua Wang, wangyanhua@icdc.cn.

A child with Campylobacter jejuni infection manifested high fever and convulsions, deviating from the typical diarrheal symptoms. This study aims to investigate the genetic characteristics responsible for this unique phenotype. The L8 strain isolated from the patient underwent whole-genome sequencing, followed by phylogenetic analyses using Bayesian Analysis of Population Structure (BAPS) with a representative set of 83 strains. Subsequently, this isolate was compared with reference strains to assess the distribution of common virulence factors and identify specific virulence factors. Additionally, analyses were conducted on the Type VI Secretion System (T6SS) and C. jejuni Integrated Element 3 (CJIE3). L8 hosted a T6SS-containing CJIE3, notably featuring insertion of two long segments and multiple consecutive or scattered mutations were exhibited in the C-terminal VgrG, a key effector of the T6SS. The complete cytolethal distending toxin (CDT) gene was present in L8, and the CdtA sequence significantly differed from other strains. L8 contained 83 virulence factors crucial for maintaining C. jejuni's virulence traits, with the highest similarity to NCTC11168. In comparison to NCTC 11168, L8 harboured 90 additional genes, 55 of which had functional annotations, including the 13 major components of T6SS. The sequence type of L8 was ST-464, classified within the widely distributed BAPS cluster 1. Our study suggests that the C-terminal VgrG domain of T6SS probably altered to a virulence protein that could be a major factor, contributing to the specific clinical phenotype of this case. Furthermore, we wish to focus on the potential effect of T6SS in the pathogenesis, in studying the genetic feature of the patient’s clinical phenotypes.

一位无腹泻症状空肠弯曲菌患者的感染及基因组特征 — 中国, 2018年

杨向东^1，2；王文¹；崔茶进³；于彬彬²；张青²；王艳华^1#

1． 传染病溯源预警与智能决策全国重点实验室，中国疾病预防控制中心传染病预防控制所，生态医学中心，北京，中国；

2． 云南省地方病防治所，人兽共患病防治科，大理白族自治州，云南省，中国；

3． 云南省泸西县人民医院，医学检验科，红河哈尼族彝族自治州，云南省，中国。

#通讯作者：王艳华，wangyanhua@icdc.cn。

一名感染空肠弯曲菌的患儿没有典型的腹泻症状，而是出现高烧和抽搐。本研究旨在探究引起这一独特表型的遗传特征。从患儿体内分离的L8菌株进行全基因组测序后，采用贝叶斯种群结构分析法（BAPS），对有代表性的83个菌株进行了系统发育分析。随后将L8菌株与参考菌株通过基因组比较，以评估常见毒力因子的分布并鉴定特殊的毒力因子。此外，还对VI型分泌系统（T6SS）和空肠弯曲菌整合元件3（CJIE3）进行了分析。L8包含一个带有T6SS 的CJIE3，其显著特点是插入了两个长片段。并且，在T6SS的关键效应因子VgrG的C端，出现了多个连续或散在的突变。L8中含有完整的细胞致死膨胀毒素（CDT）基因，其CdtA序列与其他菌株存在显著差异。L8含有83个维持空肠弯曲菌毒力特征的关键因子，与NCTC11168的相似度最高。与NCTC 11168相比，L8多了90个基因，其中55个有功能注释，包括T6SS的13个主要成分。L8的序列型为ST-464，属于广泛分布的BAPS-1簇。我们的研究提示，T6SS中VgrG的C端结构域可能已经转变为一种毒力蛋白，这一改变可能是导致该病例出现特殊临床表型的主要因素。此外，我们希望在研究患者临床表型的遗传特征时，重点关注T6SS在发病机制中的潜在作用。

For more information: https://weekly.chinacdc.cn/en/article/doi/10.46234/ccdcw2024.182

A Review of the Latest Control Strategies for Mosquito-Borne Diseases

Jing Ni^1&; Jinna Wang^2&; Chunfu Fang^3&; Wenrong Zhang¹; Zhenyu Gong^2# 

1. School of Public Health, Hangzhou Medical College, Hangzhou City, Zhejiang Province, China;

2. Institute of Infectious Disease Prevention and Control, Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou City, Zhejiang Province, China.

3. Institute of Infectious Disease Prevention and Control, Quzhou Center for Disease Control and Prevention, Quzhou City, Zhejiang Province, China.

^& Joint first authors.

Corresponding author: Zhenyu Gong, zhygong@cdc.zj.cn.

Mosquito-borne diseases are persistent and easily severe diseases that are a crisis to global pandemic health. Moreover, the risk of transmission of mosquito-borne disease viruses is rapidly increasing with the unprecedented spread of mosquito-borne diseases viruses such as dengue and chikungunya viruses, disruption of the global mosquito-borne diseases control process due to the Corona Virus Disease 2019 (COVID-19) emergence in 2019, global warming and human activities. To address this global challenge, various innovative mosquito control technologies are currently being developed in various countries. Therefore, this paper will summarize the latest mosquito vector control advances, with a focus on China's latest control strategies for mosquito, to provide experience for subsequent implementation of the latest mosquito-borne diseases control measures.

最新的蚊媒传染病防控策略

倪静^1&；王金娜^2&；方春福^3&；张文蓉¹；龚震宇^2#

1. 杭州医学院公共卫生学院，杭州市，浙江省，中国；

2. 浙江省疾病预防控制中心传染病预防控制所，杭州市，浙江省，中国；

3. 衢州市疾病预防控制中心，衢州市，浙江省，中国。

&共同第一作者。

#通讯作者：龚震宇，zhygong@cdc.zj.cn。

本文总结最新的蚊媒传染病防控进展，重点介绍中国最新的蚊虫控制策略，为后续实施最新的蚊媒疾病控制措施提供经验。文章从蚊媒传染病的全球展望、全球防蚊策略与挑战、中国浙江“无蚊村”最新进展三方面来介绍，分析总结全球最新蚊媒传染病防治策略。从全球展望到策略与挑战、再到中国无蚊村最新进展，防治策略始终强调的是“环境-宿主媒介-人类健康”，始终实施监测指导下的媒介生物综合控制和管理，将媒介生物长期控制在不足为害的水平。全球最新蚊媒传染病防治策略始终遵循“2017-2030全球病媒控制对策”的理念，坚持对蚊媒传染病进行综合管理和可持续控制，是实现健康效益、社会效益、经济效益及生态环境综合效益的完美举措。

For more information: https://weekly.chinacdc.cn/en/article/doi/10.46234/ccdcw2024.183