Altered gene expression of cold shock proteins under antibiotic exposure.

Stressors like translational inhibitors stall protein synthesis and produce a response specific to temperature extremes. Yet, little is known about the expression of temperature-related proteins, particularly the cold shock proteins (Csps), under antibiotic stress. Here, we demonstrate the expression pattern of all nine Csps of Escherichia coli to a sub-lethal concentration of chloramphenicol, tetracycline, gentamicin, kanamycin, and ampicillin. The five antibiotics represent different classes that target different areas of the translational apparatus and the cell wall. To investigate whether all nine csps are expressed in response to antibiotics, we measured the survival of E. coli across the antibiotics and further analyzed expression by qPCR. We find that the expression pattern of csps varies between the Csp groups, and within a Csp group, certain members are more prominently expressed than the rest. The C-group antibiotics, which include chloramphenicol and tetracycline, upregulated the expression of cold-inducible and uncharacterized Csp groups. The H-group antibiotic, kanamycin, along with the uncharacterized antibiotics gentamicin and ampicillin, induced csps as well as heat shock proteins (hsps). To the best of our knowledge, this study is the first to demonstrate the expression pattern of all nine csps in response to antibiotics. Moreover, our study has implications for understanding the triggers of Csps and, in a broader context, their role in stress tolerance, virulence, and pathogenesis.