Role of Ttca of Citrobacter werkmanii in bacterial growth, biocides resistance, biofilm formation and swimming motility

Abstract

To screen, identify and study the genes involved in isothiazolone resistance and biofilm formation in Citrobacter werkmanii strain BF-6. A Tn5 transposon library of approximately 900 mutants of C. werkmanii strain BF-6 was generated and screened to isolate 1,2-benzisothiazolin-3-one (BIT) resistant strains. In addition, the tRNA 2-thiocytidine (32) synthetase gene (ttcA) was deleted through homologous recombination and the resulting phenotypic changes of the ∆ttcA mutant were studied. A total of 3 genes were successfully identified, among which ∆ttcA mutant exhibited a reduction in growth rate and swimming motility. On the other hand, an increase in biofilms formation in ∆ttcA were observed but not with a significant resistance enhancement to BIT. This work, for the first time, highlights the role of ttcA gene of C. werkmanii strain BF-6 in BIT resistance and biofilm formation.