並列タイトル等泌尿器科患者由来のST131は、他菌種からプラスミド媒介性に基質特異性拡張型βラクタマーゼを高頻度で獲得する
授与機関名Nagasaki University (長崎大学)
一般注記Objectives: To investigate the prevalence of the clonal group Escherichia coli ST131 in urologic patients, and to clarify the mechanisms underlying the high prevalence of the antimicrobial resistant genes in ST131.Methods: We used 65 Escherichia coli strains collected from the Department of Urology, Nagasaki University Hospital, between January 2018 and December 2018. All of them underwent multilocus sequence typing and were analyzed for genes associated with quinolone resistance and extended-spectrum β-lactamases. To compare ST131 and non-ST131 strains, bacterial conjugation experiments and intestinal colonization evaluations were performed.Results: ST131 was the most dominant among all the strains, along with levofloxacin resistant strains, and extended-spectrum β-lactamases positive strains (32%, 63%, and 73%, respectively). 12 out of 15 extended-spectrum β-lactamases-producing Escherichia coli strains harbored CTX-M-9. In particular, all extended-spectrum β-lactamases-producing ST131 strains possessed CTX-M-9. The proportions of ST131 strains with or without quinolone resistance-determining region mutations were significantly higher and lower, respectively, than that of non-ST131 strains (P = 0.0002 and P < 0.0001, respectively). When Klebsiella pneumoniae was used as a donor, three ST131 strains acquired extended-spectrum β-lactamases a total of 16 times (six, four, and six times each), which was significantly more than that in one of the non-ST131 strains (two times). The amount of bacteria was significantly lower in the ST131 strains than in the non-ST131 strains administered to mice. Both the ST131 and non-ST131 strains increased again after the administration of vancomycin, even after the colony was not detected.Conclusions:These results support the mechanisms underlying the prevalence of ST131 strains in hospitals, particularly in urologic patients.
長崎大学学位論文 学位記番号:博(医歯薬)甲第1450号 学位授与年月日:令和4年6月1日
Author: Tsubasa Kondo, Kei Sakamoto, Yoshitomo Morinaga, Yasuyoshi Miyata, Katsunori Yanagihara, Hideki Sakai
Citation: International Journal of Urology, 29(6), pp. 587-594; 2022
identifier:Nagasaki University (長崎大学), 博士(医学) (2022-06-01)
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