Abstract：
The urgent need for comprehensive and systematic analyses of Shigella as the key pathogen led us to meticulously explore the epidemiology and molecular attributes of Shigella isolates. Accordingly, we procured 24 isolates (10 from Xinjiang and 14 from Wuhan, China) and performed serotype identification and antimicrobial susceptibility testing. Resistance gene detection and homology analysis by polymerase chain reaction and pulsed-field gel electrophoresis (PFGE), respectively, were performed for genetic diversity analysis. All isolates were identified as Shigella flexneri, with 70% (35.4-91.9%) and 30% (8.1-64.6%) of the Xinjiang isolates and 85.7% (56.2-97.5%) and 14.3% (2/14, 2.5-43.9%) of the Wuhan isolates belonging to serotype 2a and serotype 2b, respectively. All isolates displayed resistance to at least two antibiotics and complete resistance to ampicillin. Multidrug resistance (MDR) was recorded in 70.8% (48.8-86.6%) of isolates, with Xinjiang isolates exhibiting relatively higher resistance to ampicillin-sulbactam, piperacillin, ceftriaxone, and aztreonam. Conversely, Wuhan isolates displayed higher MDR and resistance to tetracycline, ciprofloxacin, levofloxacin, and cefepime relative to Xinjiang isolates. Molecular scrutiny of antibiotic-resistance determinants revealed that blaTEM was the main mechanism of ampicillin resistance, blaCTX-M was the main gene for resistance to third- and fourth-generation cephalosporins, and tetB was the predominant gene associated with tetracycline resistance. Four Xinjiang and seven Wuhan isolates shared T1-clone types (>85%), and two Xinjiang and one Wuhan isolates were derived from the T6 clone with a high similarity of 87%. Six PFGE patterns (T1, T2, T5, T6-3, T8, and T10) of S. flexneri were associated with MDR. Thus, there is a critical need for robust surveillance and control strategies in managing Shigella infections, along with the development of targeted interventions and antimicrobial stewardship programs tailored to the distinct characteristics of Shigella isolates in different regions of China.
摘要：
迫切需要对志贺氏菌作为关键病原体进行全面和系统的分析，这使我们精心探索志贺氏菌分离株的流行病学和分子特征。因此，我们采购了24个分离株(10个来自新疆，14个来自武汉，中国）并进行了血清型鉴定和抗菌药物敏感性试验。通过聚合酶链反应和脉冲场凝胶电泳（PFGE）进行抗性基因检测和同源性分析，分别,进行遗传多样性分析。所有分离株都被鉴定为福氏志贺氏菌，新疆分离株的70％（35.4-91.9％）和30％（8.1-64.6％），武汉分离株的85.7％（56.2-97.5％）和14.3％（2/14，2.5-43.9％）属于血清型2a和血清型2b，分别。所有分离株都显示出对至少两种抗生素的抗性和对氨苄青霉素的完全抗性。在70.8%（48.8-86.6%）的分离株中记录到多药耐药（MDR），新疆分离株对氨苄西林-舒巴坦的耐药性相对较高，哌拉西林,头孢曲松,还有氨曲南.相反，武汉分离株表现出较高的MDR和对四环素的耐药性，环丙沙星,左氧氟沙星,和头孢吡肟相对于新疆分离株。对抗生素抗性决定因素的分子审查表明，blaTEM是氨苄青霉素抗性的主要机制，blaCTX-M是对第三代和第四代头孢菌素耐药的主要基因，tetB是与四环素抗性相关的主要基因。4个新疆和7个武汉分离株共有T1克隆型(>85%)，2个新疆和1个武汉分离株来自T6克隆，相似度高达87%。福氏链球菌的六个PFGE模式（T1，T2，T5，T6-3，T8和T10）与MDR相关。因此，在管理志贺氏菌感染时，迫切需要强有力的监测和控制策略，随着针对中国不同地区志贺氏菌分离株的独特特征，针对性干预措施和抗菌药物管理计划的发展。
