背景:近年来,全球对各种沙门氏菌血清型多药耐药性(MDR)增加的关注显著增加.然而,关于MDR乙型副伤寒沙门氏菌的报告仍然很少,更不用说广泛耐药(XDR)菌株了。
方法:在这项回顾性研究中,调查了江苏省近10年来的乙型副伤寒沙门菌分离株,然后对菌株进行测序和生物信息学分析。
结果:共鉴定出27株乙型副伤寒沙门菌,其中主要的STS是ST42(11),ST86(10),和ST2814(5)。在这些菌株中,我们发现了4株以前未报道的XDR乙型副伤寒沙门氏菌ST2814株(4/5)。这些令人震惊的耐药分离株对沙门氏菌治疗甚至最后的替加环素治疗的所有三种主要抗生素类别均具有耐药性。生物信息学分析显示,这些XDR菌株所携带的质粒与来自中国及周边地区的不同沙门氏菌血清型和大肠杆菌之间具有高度相似性。值得注意的是,这四个质粒通过调节AcrAB-TolC泵携带负责多种抗生素抗性的ramAp基因,主要来自中国。此外,还鉴定了染色体上具有ICE的独特的MDRST42(1/11)菌株。此外,全球ST42/ST2814分离株的系统发育分析强调了这些菌株的区域特异性,江苏分离株与国内分离株聚集在一起,XDRST2814形成了一个独特的分支,表明适应当地的抗生素压力。
结论:这项研究强调了密切监测MDR/XDR副伤寒沙门氏菌B的迫切需要,特别是江苏省新兴的ST2814菌株,有效遏制其传播,保护公众健康。此外,在“一个健康”的概念下,应加强对不同生态位和属的监测,以跟踪抗性基因和水平基因转移元件。
BACKGROUND: In recent years, global concern over increasing multidrug resistance (MDR) among various Salmonella serotypes has grown significantly. However, reports on MDR Salmonella Paratyphi B remain scarce, let alone the extensively drug-resistant (
XDR) strains.
METHODS: In this retrospective study, we investigated the isolates of Salmonella Paratyphi B in Jiangsu Province over the past decade and carried out antimicrobial susceptibility tests, then the strains were sequenced and bioinformatics analyses were performed.
RESULTS: 27 Salmonella Paratyphi B strains were identified, of which the predominant STs were ST42 (11), ST86 (10), and ST2814 (5). Among these strains, we uncovered four concerning
XDR Salmonella Paratyphi B ST2814 strains (4/5) which were previously unreported. These alarmingly resistant isolates showed resistance to all three major antibiotic classes for Salmonella treatment and even the last resort treatment tigecycline. Bioinformatics analysis revealed high similarity between the plasmids harbored by these
XDR strains and diverse Salmonella serotypes and Escherichia coli from China and neighboring regions. Notably, these four plasmids carried the ramAp gene responsible for multiple antibiotic resistance by regulating the AcrAB-TolC pump, predominantly originating from China. Additionally, a distinct MDR ST42(1/11) strain with an ICE on chromosome was also identified. Furthermore, phylogenetic analysis of global ST42/ST2814 isolates highlighted the regional specificity of these strains, with Jiangsu isolates clustering together with domestic isolates and
XDR ST2814 forming a distinct branch, suggesting adaptation to local antibiotic pressures.
CONCLUSIONS: This research underscores the pressing need for closely monitoring the MDR/
XDR Salmonella Paratyphi B, particularly the emerging ST2814 strains in Jiangsu Province, to effectively curb its spread and protect public health. Moreover, surveillance should be strengthened across different ecological niches and genera to track resistance genes and horizontal gene transfer elements under the concept of \"ONE HEALTH\".