Dam enzyme participates in the regulation of biofilm production in Salmonella enterica serovar Typhimurium

M.DEL ROSARIO AYA C; SEBASTIAN H. SARNACKI; MARIANGELES NOTO LLANA; MONICA N GIACOMODONATO; M CRISTINA CERQUETTI

Jena

Conferencia; 5th International Student Conference on Microbial Communication; 2015

Jena School - MiCom 2015

On the bacterial world, existence within surface-associated structured multicellular communities may be the rule, rather than the exception [1]. It has been demonstrated that several serovars of S. enterica, including Typhimurium, are able to attach to and form biofilms on a variety of surfaces, and this ability has been implicated in the persistence of non-typhoidal Salmonella in the environment and in industrial, veterinary and medical settings [2]. Non-typhoidal salmonellosis is an important foodborne disease of worldwide economic significance. Salmonella Typhimurium (ST) can be found in some laying flocks in the European Union (EU) and in earlier years, has been associated with outbreaks involving contamination of egg contents [3]. Here, we studied the involvement of Dam methylations in biofilm production in S.T strains. The ability to generate biofilms and the expression of curli and cellulose was analyzed in wild type and mutant strains. Also, the expression of five main genes that are involved on biofilm production -csgD, csgA, bcsA, adrA and bapA- were determined by qPCR, in different culture conditions. We observed that dam-defective strains of S.T are affected in their capacity to develop biofilms and the production of cellulose and curli are affected, mainly curli. Ours results suggest that changes in gene expression required for biofilm production are finely regulated by Dam methylation. Thus, methylations could modulate csgD expression and up regulate the expression of factors related with biofilm production, including biofilm-associated proteins, curli and cellulose. The biofilm capacity production play an important role in bacterial infectious process and this study contributes to the understanding of biofilm regulation in Salmonella. References [1] Branda, S., Chu, F., Kearns, D., Losick, R., & Kolter, R. (2006). A major protein component of the Bacillus subtilis biofilm matrix. Molecular Microbiology, 59(4), 1229-1238. [2] Vestby, L., Møretrø, T., Langsrud, S., Heir, E., & Nesse, L. (2009). Biofilm forming abilities of Salmonella are correlated with persistence in fish meal- and feed factories. BMC Veterinary Research, 5, 20-20. [3] EFSA-ECDC (European Food Safety Authority-European Centre for Disease Prevention and Control). (2012). The European Union summary report on trends and sources of zoonoses, zoonotic agents and food-borne outbreaks in 2010. EFSA J. 10, 442?2597.