Mallonga Zoe, Tokuda Maho, Yamazaki Rin, Tsuruga Shunta, Nogami Isana, Sato Yuka, Tarrayo Ann Gelanie, Fuentes Rolly, Parilla Richard, Kimbara Kazuhide, Suzuki Masato, Shintani Masaki
Division of Natural Sciences and Mathematics, University of the Philippines Tacloban College, Tacloban City, Philippines.
Faculty of Engineering, Shizuoka University, Shizuoka, Japan.
J Glob Antimicrob Resist. 2025 Mar;41:287-289. doi: 10.1016/j.jgar.2025.01.017. Epub 2025 Feb 3.
The clinical effectiveness of carbapenem and tigecycline, which are last-resort antimicrobials used to treat multidrug-resistant bacterial infections, faces challenges due to emerging plasmid-borne resistance mechanisms, including the enzymatic inactivation of antimicrobials. Here, we investigate and report the co-occurrence of bla and tet(X7) genes in an Acinetobacter towneri isolate from hospital wastewater in the Philippines.
An A. towneri isolate PT23-B2 was obtained from a hospital wastewater treatment plant in Tacloban, Philippines in 2023. Whole-genome sequencing of PT23-B2 was performed and antimicrobial resistance genes (ARGs), plasmids, and mobile genetic elements were detected using custom sequence databases.
Whole-genome sequencing analysis of A. towneri PT23-B2 resulted in the complete genome sequence consisting of one chromosome and five putative plasmids. One of the five plasmids identified, the 134-kb plasmid named pPT23-B2_1 (of which replicon was classified as R3-T45 or GR31), contained multiple ARGs, including bla and tet(X7). The bla was flanked by ISAba125, and tet(X7) was associated with one IS26 family insertion sequence (IS), indicating probable transpositions into the plasmid via these mobile genetic elements. Antimicrobial susceptibility tests showed that PT23-B2 is resistant to tigecycline, in addition to meropenem.
This is the first report on an environmental bacterial isolate from the Philippines harbouring both carbapenem-resistance gene (bla) and tigecycline-resistance gene [tet(X7)]. This study highlights the potential dissemination of clinically important ARGs, such as bla and tet(X), in environmental reservoirs, necessitating continuous monitoring and urgent intervention strategies.
碳青霉烯类和替加环素是用于治疗多重耐药细菌感染的最后手段抗菌药物，由于新出现的质粒介导耐药机制，包括抗菌药物的酶促失活，其临床有效性面临挑战。在此，我们调查并报告了在一株从菲律宾医院废水中分离出的陶氏不动杆菌中bla和tet(X7)基因的共现情况。
2023年从菲律宾塔克洛班的一家医院污水处理厂获得了一株陶氏不动杆菌分离株PT23 - B2。对PT23 - B2进行了全基因组测序，并使用定制序列数据库检测了抗菌耐药基因（ARGs）、质粒和移动遗传元件。
对陶氏不动杆菌PT23 - B2的全基因组测序分析得到了由一条染色体和五个推定质粒组成的完整基因组序列。鉴定出的五个质粒之一，即134 kb的质粒pPT23 - B2_1（其复制子被归类为R3 - T45或GR31），包含多个ARGs，包括bla和tet(X7)。bla两侧是ISAba125，tet(X7)与一个IS26家族插入序列（IS）相关，表明可能通过这些移动遗传元件转座到质粒中。药敏试验表明，PT23 - B2除对美罗培南耐药外，还对替加环素耐药。
这是关于菲律宾环境细菌分离株同时携带碳青霉烯耐药基因（bla）和替加环素耐药基因[tet(X7)]的首次报道。本研究强调了临床重要ARGs，如bla和tet(X)，在环境库中的潜在传播，需要持续监测和紧急干预策略。
