Comparative Transcriptomic and Phenotypic Analysis of the Responses ofBacillus cereusto Various Disinfectant Treatments

Abstract

Antimicrobial chemicals are widely applied to clean and disinfect food-contacting surfaces. However, the cellular response of bacteria to various disinfectants is unclear. In this study, the physiological and genome-wide transcriptional responses of Bacillus cereus ATCC 14579 exposed to four different disinfectants (benzalkonium chloride, sodium hypochlorite, hydrogen peroxide, and peracetic acid) were analyzed. For each disinfectant, concentrations leading to the attenuation of growth, growth arrest, and cell death were determined. The transcriptome analysis revealed that B. cereus, upon exposure to the selected concentrations of disinfectants, induced common and specific responses. Notably, the common response included genes involved in the general and oxidative stress responses. Exposure to benzalkonium chloride, a disinfectant known to induce membrane damage, specifically induced genes involved in fatty acid metabolism. Membrane damage induced by benzalkonium chloride was confirmed by fluorescence microscopy, and fatty acid analysis revealed modulation of the fatty acid composition of the cell membrane. Exposure to sodium hypochlorite induced genes involved in metabolism of sulfur and sulfur-containing amino acids, which correlated with the excessive oxidation of sulfhydryl groups observed in sodium hypochlorite-stressed cells. Exposures to hydrogen peroxide and peracetic acid induced highly similar responses, including the upregulation of genes involved in DNA damage repair and SOS response. Notably, hydrogen peroxide-and peracetic acid-treated cells exhibited high mutation rates correlating with the induced SOS response.

Impact of UV and Peracetic Acid Disinfection on the Prevalence of Virulence and Antimicrobial Resistance Genes in Uropathogenic Escherichia coli in Wastewater Effluents

“…In previous studies, UV was shown to induce the expression of SOS response genes in E. coli, which is consistent with DNA damage (33,57). Furthermore, exposure to PAA reduced the expression of membrane proteins but increased the expression of chaperone proteins, of oxidative stress response genes, and of sulfur-containing amino acid metabolism genes in different species (58)(59)(60)(61). All these effects are consistent with the oxidative reaction with proteins as the chemical diffuses into the cell.…”

“…Demple and Halbrook (62) reported that hydrogen peroxide induced DNA damage repair systems in E. coli. In another study with Bacillus cereus, PAA and hydrogen peroxide have been found to induce DNA damage repair systems and SOS response genes, but quaternary ammonium compounds (QAC) or hypochlorous acid did not provoke the same effects (61). Similarly to hydrogen peroxide or PAA, UV irradiation also induces the DNA repair mechanisms in the E. coli cell (63).…”

Microbial Community Degradation of Widely Used Quaternary Ammonium Disinfectants

“…Sterol carrier proteins transfer steroids across cellular membranes (37), and enoyl-acyl carrier reductase is involved in the fatty acid elongation cycle (38); thus, both genes modulate membrane fluidity, permeability, and thickness and could play a role in alleviating BAC toxicity by enhancing cell membrane integrity. Cell membrane biosynthesis represents an important cellular response to BACs, which are membrane disruption agents (39,40). Hence, the genes identified here might contribute to the fitness advantage of P. nitroreducens related to maintaining cell membrane integrity in the presence of BAC toxicity, although this hypothesis awaits experimental verification.…”

Effect of peracetic acid on biofilms formed by Listeria monocytogenes strains isolated from a Brazilian cheese processing plant

“…Peracetic acid (PAA) is a common sanitizer used in the dairy industry (Ceragioli et al, 2010) and is normally used in food industries in Brazil at concentrations of 300 -700 mg/L (Quarentei et al, 2011). PAA has a broad spectrum and is a strong oxidizing agent that is decomposed into safe waste products (Van der Veen, Abee, 2011).…”