Vázquez Xenia, Fernández Javier, Rodríguez-Lozano Jesús, Calvo Jorge, Rodicio Rosaura, Rodicio M Rosario
Área de Microbiología, Departamento de Biología Funcional, Universidad de Oviedo (UO), 33006 Oviedo, Spain.
Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), 33011 Oviedo, Spain.
Antibiotics (Basel). 2022 Jun 9;11(6):786. doi: 10.3390/antibiotics11060786.
serovar Infantis (. Infantis) is a broiler-associated pathogen which ranks in the fourth position as a cause of human salmonellosis in the European Union. Here, we report a comparative genomic analysis of two clinical . Infantis isolates recovered in Spain from children who just returned from Peru. The isolates were selected on the basis of resistance to cefotaxime, one of the antibiotics of choice for treatment of infections. Antimicrobial susceptibility testing demonstrated that they were resistant to eight classes of antimicrobial agents: penicillins, cephalosporins, phenicols, aminoglycosides, tetracyclines, inhibitors of folate synthesis, (fluoro)quinolones and nitrofurans, and one of them was also resistant to fosfomycin. As shown by whole-genome sequence analysis, each isolate carried a pESI-like megaplasmid of ca. 300 kb harboring multiple resistance genes [, , , , , , , (A), ± ], as well as genes for resistance to heavy metals and disinfectants (, and ). These genes were distributed in two complex regions, separated by DNA belonging to the plasmid backbone, and associated with a wealth of transposable elements. The two isolates had a D87Y amino acid substitution in the GyrA protein, and truncated variants of the nitroreductase genes and , accounting for chromosomally encoded resistances to nalidixic acid and nitrofurantoin, respectively. The two . Infantis isolates were assigned to sequence type ST32 by in silico multilocus sequence typing (MLST). Phylogenetic analysis revealed that they were closely related, differing only by 12 SNPs, although they were recovered from different children two years apart. They were also genetically similar to -positive ± isolates obtained from humans and along the poultry production chain in the USA, South America, as well as from humans in several European countries, usually associated with a travel history to America. However, this is the first time that the . Infantis ± MDR clone has been reported in Spain.
婴儿血清型（Infantis）是一种与肉鸡相关的病原体，在欧盟导致人类沙门氏菌病的病原体中排名第四。在此，我们报告了对从刚从秘鲁返回的儿童中分离出的两株西班牙临床婴儿血清型菌株的比较基因组分析。这些菌株是根据对头孢噻肟的耐药性选择的，头孢噻肟是治疗感染的首选抗生素之一。抗菌药敏试验表明，它们对八类抗菌药物耐药：青霉素类、头孢菌素类、酚类、氨基糖苷类、四环素类、叶酸合成抑制剂、（氟）喹诺酮类和硝基呋喃类，其中一株还对磷霉素耐药。全基因组序列分析表明，每株菌株都携带一个约300 kb的类似pESI的大质粒，含有多个耐药基因[，，，，，，，（A），±]，以及重金属和消毒剂耐药基因（，和）。这些基因分布在两个复杂区域，由属于质粒主干的DNA分隔，并与大量转座元件相关。这两株菌株在GyrA蛋白中有一个D87Y氨基酸取代，以及硝基还原酶基因和的截短变体，分别解释了对萘啶酸和呋喃妥因的染色体编码耐药性。通过计算机多位点序列分型（MLST），这两株婴儿血清型菌株被归为序列型ST32。系统发育分析表明，它们密切相关，仅相差12个单核苷酸多态性（SNP），尽管它们是在相隔两年的不同儿童中分离得到的。它们在基因上也与从美国、南美洲家禽生产链以及几个欧洲国家的人类中获得的阳性±菌株相似，这些菌株通常与有美国旅行史相关。然而，这是首次在西班牙报道婴儿血清型±多重耐药克隆。
