摘要

P菌毛，能够粘附结肠和泌尿上皮细胞，和aerobactin，一种铁螯合系统，都是人类结肠中的定植因子和尿路感染的毒力因子。建议结肠微生物群是适合转移抗生素抗性基因的位点。我们调查了来自婴幼儿的共生和尿道致病性大肠杆菌中抗生素的表型抗性是否与携带毒力基因和系统发生组来源以及在粪便菌株的情况下持续存在于肠和粪便群体水平中有关。共生菌株（n = 272）来源于出生队列研究，而尿液分离菌株（n = 205）来自门诊诊所。评估每种菌株的表型抗生素抗性和携带毒力基因（fimA，papC，sfaD / E，hlyA，iutA，kfiC和neuB），系统发育组（A，B1，B2或D）毒性克隆（CGA-D-ST69，O15：H1-D-ST393和O25b：H4-B2-ST131）。对氨苄青霉素，四环素和甲氧苄氨嘧啶的耐药性最为普遍。多变量分析显示对任何抗生素的抗性与携带编码P菌毛（papC）和aerobactin（iutA）的基因以及系统发育D组的起源显着相关。粪便中的粪便数量和长期持续存活的能力都不与粪便中的抗生素抗性有关。我们的研究证实了系统发生D组起源在大肠杆菌中对抗生素抗性的重要性，并将致病基因papC和iutA鉴定为抗生素抗性的决定因素。后者的原因目前尚不清楚。

P fimbriae, enabling adherence to colonic and urinary epithelium, and aerobactin, an iron sequestering system, are both colonization factors in the human colon and virulence factors for urinary tract infection. The colonic microbiota is suggested to be a site suitable for the transfer of antibiotic resistance genes. We investigated whether phenotypic resistance to antibiotics in commensal and uropathogenic Escherichia coli from infants and young children is associated with carriage of virulence genes and to phylogenetic group origin and, in the case of fecal strains, to persistence in the gut and fecal population levels. The commensal strains (n = 272) were derived from a birth cohort study, while the urinary isolates (n = 205) were derived from outpatient clinics. Each strain was assessed for phenotypic antibiotic resistance and for carriage of virulence genes (fimA, papC, sfaD/E, hlyA, iutA, kfiC, and neuB), phylogenetic group (A, B1, B2, or D), and markers of particular virulent clones (CGA-D-ST69, O15:H1-D-ST393, and O25b:H4-B2-ST131). Resistance to ampicillin, tetracycline, and trimethoprim was most prevalent. Multivariate analysis showed that resistance to any antibiotic was significantly associated with carriage of genes encoding P fimbriae (papC) and aerobactin (iutA), and a phylogenetic group D origin. Neither fecal population numbers nor the capacity for long-term persistence in the gut were related to antibiotic resistance among fecal strains. Our study confirms the importance of phylogenetic group D origin for antibiotic resistance in E. coli and identifies the virulence genes papC and iutA as determinants of antibiotic resistance. The reason for the latter association is currently unclear.

https://link.springer.com/article/10.1007/s10096-016-2854-y