Isolation of thymidine-dependent and extended-spectrum-β-lactamase-producing Escherichia coli small-colony variant from urine of a septuagenarian female patient with recurrent cystitis: A case report with genetic investigation.

• 影响指数: 2.065
• 发表时间: Oct 2020
• 来源期刊: J Infect Chemother
• DOI: 10.1016/j.jiac.2020.05.013
• PMID: 32571646
• 文章类型: Case Reports
• 中科院分区: Q4
• 方向: 医学
• 作者列表: Nagano N,Kawakami Y,Matsumoto T,Tanimoto K,Kashihara M,Nagata M,Honjyo H,Yamamoto K,Takada A,Sugiura T

关键词: E. coli; ESBL; SCV; Small-colony variant; Thymidine-dependent

Mesh: Anti-Bacterial Agents / therapeutic use; Cystitis / drug therapy; Escherichia coli / genetics; Escherichia coli Infections / drug therapy; Female; Humans; Thymidine; beta-Lactamases / genetics

Abstract

Thymidine-dependent small-colony variant (TD-SCV) of Escherichia coli was isolated from urine of a septuagenarian female patient on hemodialysis suffering from recurrent cystitis. The patient had been treated with frequent administrations of trimethoprim sulfamethoxazole (SXT), every time her cystitis symptoms developed. In the TD-SCV isolate, the deletion was detected in the thyA gene associated with thymidylate synthase. Interestingly, the isolate was found to produce extended-spectrum β-lactamase (ESBL), and the experiment on conjugational transfer of the resistance trait was successful. By means of genetic analysis, the isolate was found to carry blaCTX-M-1 group. To the best of our knowledge, this is the first report of urinary tract infection caused by the transmissible ESBL-producing TD-SCV of E. coli. MICs of the TD-SCV were obtained only on the Mueller Hinton agar media supplemented with appropriate concentrations of thymidine, which might lead to the difficulty for proper chemotherapy in daily medicine. Furthermore, transmission of the ESBL gene via plasmid should be of concern.