Antimikrobna aktivnost etarskih ulja na Listeria monocytogenes

Ružica Tomičić,Zorica Tomičić,Ana Varga,Ivana Čabarkapa

doi:10.5937/ffr1801037t

Abstract

Food poisoning caused by Listeria monocytogenes leads to a 30% rate of mortality among patients. The application of essential oils (EOs) to food products is a suitable strategy to control pathogens and to extend their shelf life by reducing microbial levels. The objective of this study was to evaluate the antimicrobial potential of essential oils (EOs) against L. monocytogenes. The EOs used in this study were caraway (Carum carvi), cinnamon (Cinnamomum zeylanicum), dill (Anethum graveolens), clove (Syzygium aromaticum), mentha (Menthae piperitae aetheroleum), red thyme (Thymus vulgaris), rosemary (Rosmarinus officinalis), common sage (Salvia officinalis), clary sage (Salvia sclarea) and summer savory (Satureja hortensis). The minimal inhibitory concentrations (MICs) of EOs were determined using the broth microdilution method. According to the MIC values, all essential oils were effective in the inhibition of L. monocytogenes strains, with MICs varying from 256 μg/ml to 4096 μg/ml. The results showed that cinnamon EO had the highest antimicrobial activity, while dill and mentha EOs were the least effective against the L. monocytogenes. In addition, two different procedures were carried out to test the effect of antibiotics gentamycin and streptomycin against the L. monocytogenes strains, the broth microdilution method and the MIC Test Strip. Our results indicated that the reference strain L. monocytogenes ATCC 19111 was much more sensitive to antibiotics than L. monocytogenes strains isolated from meat, highlighting that gentamycin was the more effective in comparison to streptomycin.

Highlights

Listeria monocytogenes is an important gram-positive foodborne pathogen which can cause the serious illness, listeriosis (Magalhães and Nitschke, 2012), which leads to a 30% rate of mortality among patients (Abdollahzadeh et al, 2014).One of its remarkable features is the ability to survive and grow in adverse conditions, such as high salt concentration, and low pH and temperature
An exhaustive review of the literature shows that there is a lack of studies on the antibacterial activity of the essential oils (EOs) against L. monocytogenes
The effect of the ten EOs was examined against the foodborne pathogenic bacteria L. monocytogenes by the broth microdilution methods (Tables 1)

Summary

Introduction

Listeria monocytogenes is an important gram-positive foodborne pathogen which can cause the serious illness, listeriosis (Magalhães and Nitschke, 2012), which leads to a 30% rate of mortality among patients (Abdollahzadeh et al, 2014).One of its remarkable features is the ability to survive and grow in adverse conditions, such as high salt concentration, and low pH and temperature. L. Monocytogenes has been found in a wide variety of food products as raw meat, raw vegetables, dairy products and read-to-eat food (Liu et al, 2017; McLauchlin et al, 2004; Tomičić et al, 2016; White et al, 2002). Monocytogenes has been found in a wide variety of food products as raw meat, raw vegetables, dairy products and read-to-eat food (Liu et al, 2017; McLauchlin et al, 2004; Tomičić et al, 2016; White et al, 2002) This bacteria is often linked to ready-to-eat food because it is able to grow at refrigeration temperatures and many outbreaks are associated with the consumption of these products In spite of the various modern technologies and safety concepts such as HACCP, the control of this pathogen remains a major problem in food industry (Kramarenko et al, 2016; Liu et al, 2017)

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