Involvement of toxin–antitoxin modules in Burkholderia cenocepacia biofilm persistence

In this study, we investigated whether TA modules contribute to persistence toward antibiotics in Burkholderia cenocepacia J2315. Sixteen pairs of genes were identified based on their apparent similarity to TA modules. Overexpression of the putative toxins had various effects on growth, persistence, and biofilm formation. Toxins, whose overexpression resulted in growth inhibition, often increased the number of surviving persisters; in contrast, overexpression of putative toxins showing no effects on growth had no positive influence on the number of surviving persisters. Furthermore, the expression of the TA modules was compared between treated and untreated sessile and planktonic wild‐type cultures. For 10 toxin‐encoding genes, the expression was higher in untreated sessile cells than in untreated planktonic cells. Nine toxin‐encoding genes were upregulated after treatment with tobramycin, but none after treatment with ciprofloxacin. These results indicate that most, but not all TA modules contribute to persistence in B. cenocepacia J2315 and that this contribution depends on the mode of growth and the antibiotic used. Several toxin–antitoxin modules contribute to persistence in Burkholderia cenocepacia J2315; this contribution depends on the mode of growth and the antibiotic used.
Source: FEMS Immunology and Medical Microbiology - Category: Microbiology Authors: Tags: Research Article Source Type: research