2010—2025年宁夏蜡样芽孢杆菌分布趋势及毒力基因、耐药特征研究

Study on the distribution trend, virulence genes and drug resistance characteristics of Bacillus cereus in Ningxia from 2010 to 2025

中文关键词:  蜡样芽孢杆菌  毒力基因，药物敏感性试验

英文关键词:Bacillus cereus  virulence genes  drug sensitivity test

中文摘要:

      目的 了解宁夏地区蜡样芽孢杆菌分布流行特征、毒力基因携带情况、耐药趋势及多重耐药形势。方法 本研究针对2010—2025年各监测点分离的312株蜡样芽孢杆菌进行生化和质谱复核鉴定、毒力基因多重荧光定量聚合酶链式反应和微量肉汤稀释法药物敏感性实验, 并进行分析。结果 2010—2025年共检出蜡样芽孢杆菌312株, 食品样本来源284株, 食物中毒来源28株, 其中早期分离78株, 中期112株, 末期122株。银川、石嘴山、吴忠、固原和中卫5市之间存在地域差异, 银川市最高, 吴忠市次之, 石嘴山市最低。蜡样芽孢杆菌毒力基因携带率超97%。优势基因型为nheB基因和hblC基因双阳性, 占比52.82%。对氨苄西林(ampicillin, AMP)、青霉素(penicillin, PEN)、头孢西丁(cefoxitin, CFX)及苯唑西林(oxacillin, OXA)的耐药率均超90%, 对环丙沙星(ciprofloxacin, CIP)、氯霉素(chloramphenicol, CHL)、庆大霉素(gentamicin, GEN)、万古霉素(vancomycin, VAN)、亚胺培南(imipenem, IMP) 100%敏感, 耐药谱AMP-PEN-OXA-CFX占比最高(60.90%)。结论 宁夏蜡样芽孢杆菌检出数量稳步上升, 在时间、来源、地域等方面呈现多样性, 毒力基因携带率高, 耐药形势严峻, 应持续对食品和病人加强监测, 采取有效措施进行控制, 以更好地保障食品安全和公众健康。

英文摘要:

      Objective To understand the distribution and prevalence characteristics, virulence gene carriage, drug resistance trends and multi-drug resistance situation of Bacillus cereus in Ningxia Region. Methods This study conducted biochemical and mass spectrometry re-identification, multiple fluorescence quantitative polymerase chain reaction for virulence genes and microbroth dilution method for drug sensitivity tests on 312 isolates of Bacillus cereus obtained from monitoring points from 2010 to 2025, and analyzed the results. Results A total of 312 strains of Bacillus cereus were detected from 2010 to 2025, including 284 strains from food samples and 28 strains from food poisoning. Among them, 78 strains were isolated in the early period, 112 in the middle period, and 122 in the late period. There were regional differences among the 5 cities of Yinchuan, Shizuishan, Wuzhong, Guyuan and Zhongwei. Yinchuan had the highest rate, followed by Wuzhong City, and the lowest was Shizuishan City. The carriage rate of virulence genes in Bacillus cereus exceeded 97%. The dominant genotype was double positive for gene nheB and gene hblC accounted for 52.82%. The resistance rates to ampicillin (AMP), penicillin (PEN), cefoxitin (CFX) and oxacillin (OXA) all exceeded 90%. The strains were 100% sensitive to ciprofloxacin (CIP), chloramphenicol (CHL), gentamicin (GEN), vancomycin (VAN) and imipenem (IMP). The most common resistance pattern was AMP-PEN-OXA-CFX, accounting for 60.90%. Conclusion The number of Bacillus cereus detected in Ningxia has been steadily increasing. It showes diversity in terms of time, source and region. The carriage rate of virulence genes is high, and the drug resistance situationwas is severe. Continuous monitoring of food and patients should be carried out, and effective measures should be taken for control to better ensure food safety and public health.