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Real‐time PCR based analysis of metal resistance genes in metal resistant Pseudomonas aeruginosa strain J007
Author(s) -
Choudhary Sangeeta,
Sar Pinaki
Publication year - 2016
Publication title -
journal of basic microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.58
H-Index - 54
eISSN - 1521-4028
pISSN - 0233-111X
DOI - 10.1002/jobm.201500364
Subject(s) - pseudomonas aeruginosa , bacteria , microbiology and biotechnology , efflux , strain (injury) , gene , real time polymerase chain reaction , periplasmic space , gene expression , superoxide dismutase , biology , chemistry , metal , downregulation and upregulation , enzyme , biochemistry , genetics , escherichia coli , anatomy , organic chemistry
A uranium (U)‐resistant and ‐accumulating Pseudomonas aeruginosa strain was characterized to assess the response of toxic metals toward its growth and expression of metal resistance determinants. The bacterium showed MIC (minimum inhibitory concentration) values of 6, 3, and 2 mM for Zn, Cu, and Cd, respectively; with resistance phenotype conferred by periplasmic Cu sequestering copA and RND type heavy metal efflux czcA genes. Real‐time PCR‐based expression analysis revealed significant upregulation of both these genes upon exposure to low concentrations of metals for short duration, whereas the global stress response gene sodA encoding superoxide dismutase enzyme was upregulated only at higher metal concentrations or longer exposure time. It could also be inferred that copA and czcA are involved in providing resistance only at low metal concentrations, whereas involvement of “global stress response” phenomenon (expression of sodA ) at higher metal concentration or increased exposure was evident. This study provides significant understanding of the adaptive response of bacteria surviving in metal and radionuclide contaminated environments along with the development of real‐time PCR‐based quantification method of using metal resistance genes as biomarker for monitoring relevant bacteria in such habitats.