Antibacterial and antibiofilm activity of carvacrol against Salmonella enterica serotype Typhimurium

Daliah Alves Coelho Trevisan,Jane Martha Graton Mikcha,Melyssa Negri,Benício Alves De Abreu Filho,Paula Aline Zanetti Campanerut-Sá,Eliana Valéria Patussi,Alex Fiori Da Silva,Miguel Machinski Junior

doi:10.1590/s2175-97902018000117229

Daliah Alves Coelho Trevisan, Jane Martha Graton Mikcha + Show 6 more

Open Access

https://doi.org/10.1590/s2175-97902018000117229

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Abstract

The present study evaluated the antibacterial and antibiofilm activity of carvacrol against Salmonella Typhimurium. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined and the time-kill curve and scanning electron microscopy (SEM) were performed to evaluate antibacterial activity. Antibiofilm activity was evaluated by quantifying total biomass using crystal violet assay, and metabolic activity was determined using MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. The action of carvacrol against preformed biofilm on polypropylene and stainless steel was also evaluated by colony counting and SEM. The MIC and MBC was 312 µg mL-1. Carvacrol at MIC and 2 x MIC eliminated cells after 6 and 1 h of treatment, respectively, as exhibited in the time-kill curve. The greatest reduction in biofilm biomass and metabolic activity was 1,719 OD550 and 0,089 OD550 respectively, both at 4 x MIC of carvacrol. In carvacrol treated biofilms of S. Typhimurium on polypropylene, a reduction of 5.12 log was observed with 4 x MIC, while on stainless steel, carvacrol at 4 x MIC reduced bacterial counts by 5 log. The results showed that carvacrol exhibits antibacterial activity and can be used as an alternative for the control of S. Typhimurium biofilms.

Highlights

Food contamination by pathogenic bacteria is a public health problem and an important cause of mortality worldwide (WHO, 2015)
Polypropylene and stainless steel are commonly used in the food processing industries, and some studies have shown the formation of Salmonella Typhimurium biofilm on these surfaces (Bayoumi et al, 2012; Soni et al, 2013; Amaral et al, 2015)
Results obtained from the minimum inhibitory concentration (MIC) tests were used to evaluate the effects of carvacrol in biofilm

Summary

INTRODUCTION

Food contamination by pathogenic bacteria is a public health problem and an important cause of mortality worldwide (WHO, 2015). It is estimated that 48 million cases of foodborne diseases, 128,000 hospitalizations, and 3,000 deaths occur in the USA each year (CDC, 2015) Of these 48 million, Salmonella spp. is responsible for over 1 million, causing more than 19,000 hospitalizations and around 380 deaths Polypropylene and stainless steel are commonly used in the food processing industries, and some studies have shown the formation of Salmonella Typhimurium biofilm on these surfaces (Bayoumi et al, 2012; Soni et al, 2013; Amaral et al, 2015). Biofilms can be source of cross-contamination, as food can come into contact with contaminated surfaces (Cappitelli, Polo, Villa, 2014) Another problem is that the biofilms are more resistant than bacteria in planktonic form (Simões, Simões, Vieira, 2010; Nguyen, Yuk, 2013).

MATERIAL AND METHODS

RESULTS AND DISCUSSION

CONCLUSION