Transcriptomic analysis of Campylobacter jejuni following exposure to gaseous chlorine dioxide reveals an oxidative stress response

Authors: DYKES, GRETCHEN - Former ARS Employee; He, Yiping; Jin, Zhonglin; Fan, Xuetong; Lee, Joseph; REED, SUE - Former ARS Employee; Capobianco Jr, Joseph

Submitted to: International Journal of Molecular Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/26/2025
Publication Date: 4/1/2025
Citation: Dykes, G., He, Y., Jin, Z.T., Fan, X., Lee, J., Reed, S., Capobianco Jr, J.A. 2025. Transcriptomic analysis of Campylobacter jejuni following exposure to gaseous chlorine dioxide reveals an oxidative stress response. International Journal of Molecular Sciences. https://doi.org/10.3390/ijms26073254.
DOI: https://doi.org/10.3390/ijms26073254

Interpretive Summary: The molecular basis for the bactericidal action of gaseous chlorine dioxide (ClO2; released from a sodium chlorite pad) was investigated with the bacteria Campylobacter jejuni, an important foodborne pathogen and a common cause of bacterial gastroenteritis worldwide. We found that C. jejuni was extremely sensitive to gaseous ClO2, with complete killing of 10^8 CFU/ml cells after 2 hr of exposure to 0.4 mg/L dissolved gaseous ClO2. A comprehensive RNA sequencing study showed molecular evidence that the antimicrobial mechanism of gaseous ClO2 is consistent with induction of oxidative stress in bacteria. The rapid and lethal effect of gaseous ClO2 on Campylobacter at low concentrations implies a potential use of the NaClO2 pad in food packages to control this and other pathogens. The understanding of the molecular basis of gaseous ClO2 action in bacteria could lead to the development of more powerful but less toxic antimicrobial agents for food safety operations.

Technical Abstract: Gaseous chlorine dioxide (ClO2) is a potent antimicrobial agent used to control microbial contamination in food and water. In this study, the bactericidal activity of gaseous ClO2 released from a NaClO2 pad was investigated on Campylobacter jejuni. After exposure to a low level (0.4 mg/L) of dissolved ClO2 for 2 hrs, over 99% of fresh C. jejuni cells (108 CFU/ml) were killed, indicating C. jejuni was extremely sensitive to gaseous ClO2. To investigate the molecular basis of ClO2 bactericidal action on bacteria, we performed genome-wide RNA sequencing (RNA-seq) of C. jejuni following exposure to ClO2. Our results show that cells induced an oxidative stress response by upregulating genes (sodB, ahpC, katA, msrP, and trxB) for detoxifying reactive oxygen species (ROS) and repairing damage caused by oxidation. Furthermore, a number of genes associated with oxidative stress responses, including iron transport systems (ceuBCD, cfbpABC, and chuBCD), a phosphate transport system (pstSCAB), and DNA repair and protection genes (rdgB and mutY), were upregulated following exposure to gaseous ClO2. Consistent with the results from RNA-Seq, reverse transcription-quantitative PCR (RT-qPCR) confirmed that C. jejuni exposed to gaseous ClO2 had increased expression of genes involved in oxidative stress response (sodB, ahpC, katA, and cfbpA) but not involved in general stress responses (spoT, dnaK, and groES). Together, these results assist elucidation of the antibacterial mechanism of induced oxidative damage of essential cellular components by gaseous ClO2 resulting in cell death.