Regulation of Nicotine Tolerance by Quorum Sensing and High Efficiency of Quorum Quenching Under Nicotine Stress in Pseudomonas aeruginosa PAO1

Abstract

Quorum sensing (QS) regulates the behavior of bacterial populations and promotes their adaptation and survival under stress. As QS is responsible for the virulence of vast majority of bacteria, quorum quenching (QQ), the interruption of QS, has become an attractive therapeutic strategy. However, the role of QS in stress tolerance and the efficiency of QQ under stress in bacteria are seldom explored. In this study, we demonstrated that QS-regulated catalase (CAT) expression and biofilm formation help Pseudomonas aeruginosa PAO1 resist nicotine stress. CAT activity and biofilm formation in wild type (WT) and ΔrhlR strains are significantly higher than those in the ΔlasR strain. Supplementation of ΔlasI strain with 3OC12-HSL showed similar CAT activity and biofilm formation as those of the WT strain. LasIR circuit rather than RhlIR circuit is vital to nicotine tolerance. Acylase I significantly decreased the production of virulence factors, namely elastase, pyocyanin, and pyoverdine under nicotine stress compared to the levels observed in the absence of nicotine stress. Thus, QQ is more efficient under stress. To our knowledge, this is the first study to report that QS contributes to nicotine tolerance in P. aeruginosa. This work facilitates a better application of QQ for the treatment of bacterial infections, especially under stress.

Nicotine promotes Mycobacterium tuberculosis H37Rv growth and overexpression of virulence genes

“…20 Our results showed that nicotine has a toxic effect on PAO depending on the concentration. Other reports have shown that nicotine modifies the composition and structure of the biofilms produced by PAO and also regulates the quorum sensing and quorum quenching, 3 nonetheless, the growth rates remained the same, suggesting that the growth induction effect induced by nicotine is specific for Mtb.…”

“…For instance, the presence of nicotine in Pseudomonas aeruginosa (PAO) cultures promotes the formation of biofilms and the expression of other virulence factors. 3 Other studies have demonstrated that the presence of nicotine promotes virulence factors including those related to resistance to antimicrobial peptides (AMPs) in methicillin-resistant Staphylococcus aureus (MRSA); 4 however, there is scarce information regarding the effect that nicotine might have on Mycobacterium tuberculosis.…”

“…These effects are not only limited to pulmonary and immune cells, since once the inhaled cigarette smoke enters the lung, it also interacts with commensal and pathogenic pulmonary bacteria, inducing stress and promoting changes in the expression of several genes including those related to virulence factors. For instance, the presence of nicotine in Pseudomonas aeruginosa ( PAO ) cultures promotes the formation of biofilms and the expression of other virulence factors 3 . Other studies have demonstrated that the presence of nicotine promotes virulence factors including those related to resistance to antimicrobial peptides (AMPs) in methicillin‐resistant Staphylococcus aureus (MRSA); 4 however, there is scarce information regarding the effect that nicotine might have on Mycobacterium tuberculosis .…”

Herbicides Tolerance in a Pseudomonas Strain Is Associated With Metabolic Plasticity of Antioxidative Enzymes Regardless of Selection

“…CAT is an important antioxidant enzyme in bacteria exposed to xenobiotics. The activity of this enzyme has been observed in freshwater bacterial biofilms exposed to the herbicide oxyfluorfen ( Bonnineau et al, 2013 ), and P. aeruginosa PAO1 WT exposed to nicotine ( Tang et al, 2018 ). Despite the importance of CAT, other enzymes participate in the metabolism of H 2 O 2 , such as glutathione peroxidases ( Gebicka and Krych-Madej, 2019 ).…”

Construction, analysis and validation of co-expression network to understand stress adaptation in Deinococcus radiodurans R1

“…The Tan module was enriched with 1 KEGG pathway and 5 biological processes (Table 1 and S5B Fig). Quorum sensing pathway enriched in Tan module is known to enhance stress responses in various organisms like V. cholerae [47], Pseudomonas aeruginosa PAO1 [48,49] as well as in D. radiodurans [50]. Besides this, the Tan module was also found to be enriched with the genes and proteins crucial for both gamma radiation and desiccation stress such as DR_0423 (Single-stranded DNA binding protein/DdrA) and DR_A0282.…”