OMICS Laboratory, Department of Biotechnology, University of North Bengal, Siliguri, India.
OMICS Laboratory, Department of Biotechnology, University of North Bengal, Siliguri, India; Department of Botany, Prasannadeb Women's College, Jalpaiguri, India.
Clin Microbiol Infect. 2021 Mar;27(3):472.e1-472.e5. doi: 10.1016/j.cmi.2020.10.032. Epub 2020 Nov 4.
This study aims to investigate ampicillin catabolism in a pandrug-resistant strain, Pseudomonas sp. MR 02 of P. putida lineage.
The characterization of carbapenem resistance was done following the standard protocol. The broth macrodilution method was used to determine the MIC values of antimicrobial agents both in the presence and in the absence of phenylalanine-β-naphthylamide. High MIC values (>10 000 mg/L) of ampicillin led to speculation that it may serve as a growth substrate, and thus minimal medium was used to evaluate ampicillin as a nutrient. The growth of MR 02 was measured in minimal medium in the presence or absence of 0.4 mM EDTA, supplemented with ampicillin as sole carbon, nitrogen and energy source. RNA-seq was used to generate expression profiles of genes in ampicillin or glucose-grown cells. The bla gene of MR 02 was cloned in the pHSG398 vector and expressed in Escherichia coli DH5α.
Phenotypic analysis along with genome sequence data identifies Pseudomonas sp. MR 02 as a pandrug-resistant strain. Transcriptome data has revealed that bla was among the top 50 differentially expressed genes in ampicillin grown cells compared to the glucose grown cells in the minimal medium. Heterologous expression of bla gene in E. coli DH5α enabled its growth and subsistence on ampicillin as the sole source of carbon and energy.
The ability of a pandrug-resistant Pseudomonas sp. MR 02 to consume ampicillin for growth has a huge implication in the bioremediation of β-lactam residues in the environment.
本研究旨在探究假单胞菌属 MR 02 对氨苄青霉素的分解代谢，该菌属于铜绿假单胞菌谱系，对多种药物具有耐药性。
采用标准方案对碳青霉烯类耐药性进行特征描述。采用肉汤微量稀释法测定抗菌药物的 MIC 值，包括有无苯丙氨酸-β-萘酰胺的情况下。氨苄青霉素的 MIC 值较高（>10000mg/L），推测其可能作为生长基质，因此使用基础培养基来评估氨苄青霉素作为营养物质的作用。在含有或不含有 0.4mM EDTA 的基础培养基中，以氨苄青霉素作为唯一碳源、氮源和能源，测量 MR 02 的生长情况。采用 RNA-seq 技术生成氨苄青霉素或葡萄糖生长细胞中基因的表达谱。将 MR 02 的 bla 基因克隆到 pHSG398 载体中，并在大肠杆菌 DH5α 中表达。
表型分析结合基因组序列数据将假单胞菌属 MR 02 鉴定为一种多药耐药菌株。转录组数据显示，与葡萄糖生长细胞相比，bla 在氨苄青霉素生长细胞中是前 50 个差异表达基因之一。bla 基因在大肠杆菌 DH5α 中的异源表达使其能够以氨苄青霉素作为唯一碳源和能源生长和存活。
多药耐药假单胞菌属 MR 02 消耗氨苄青霉素进行生长的能力对环境中β-内酰胺残留的生物修复具有重要意义。
