Potential of citrus extract as disinfectant in SARS-CoV-2 prevention

<p>SARS-CoV-2 is the virus that causes the COVID-19 disease, responsible for the second pandemic of the 21st century. This virus has caused a health emergency due to its rapid transmission and high mortality rate. The use of disinfectants of chemical origin has increased considerably to avoid contamination by SARS-CoV-2 but when used incorrectly they can pose a health risk. Citrus-based extracts have shown effectiveness in controlling the development of fungi and bacteria in<em> in vitro</em> and <em>in situ</em> studies. In <em>in vitro</em> cell assays, citrus extracts are effective in controlling the replication of disease-causing viruses. The objective of this review is to describe the problem of COVID-19, its transmission mechanisms, the use of chemical disinfectants and citrus extracts to control microorganisms and its suggested use as a complement in COVID-19 prevention. The use of citrus extracts has certain advantages such as biodegradability and low health risks. Thus, they could be a viable alternative to be used as a complement in the management and prevention of the spread of SARS-CoV-2.</p>

The in vitro and in vivo anti-virulent effect of organic acid mixtures against Eimeria tenella and Eimeria bovis

Eimeria tenella and Eimeria bovis are complex parasites responsible for the condition of coccidiosis, that invade the animal gastrointestinal intestinal mucosa causing severe diarrhoea, loss of appetite or abortions, with devastating impacts on the farming industry. The negative impacts of these parasitic infections are enhanced by their role in promoting the colonisation of the gut by common foodborne pathogens. The aim of this study was to test the anti-Eimeria efficacy of maltodextrin, sodium chloride, citric acid, sodium citrate, silica, malic acid, citrus extract, and olive extract individually, in vitro and in combination, in vivo. Firstly, in vitro infection models demonstrated that antimicrobials reduced (p < 0.05), both singly and in combination (AG), the ability of E. tenella and E. bovis to infect MDBK and CLEC-213 epithelial cells, and the virulence reduction was similar to that of the anti-coccidial drug Robenidine. Secondly, using an in vivo broiler infection model, we demonstrated that AG reduced (p = 0.001) E. tenella levels in the caeca and excreted faeces, reduced inflammatory oxidative stress, improved the immune response through reduced ROS, increased Mn-SOD and SCFA levels. Levels of IgA and IgM were significantly increased in caecal tissues of broilers that received 0.5% AG and were associated with improved (p < 0.0001) tissue lesion scores. A prophylactic approach increased the anti-parasitic effect in vivo, and results indicated that administration from day 0, 5 and 10 post-hatch reduced tissue lesion scores (p < 0.0001) and parasite excretion levels (p = 0.002). Conclusively, our in vitro and in vivo results demonstrate that the natural antimicrobial mixture (AG) reduced parasitic infections through mechanisms that reduced pathogen virulence and attenuated host inflammatory events.

Antilisterial Effect of a Natural Formulation Based on Citrus Extract in Ready-To-Eat Foods

Controlling Listeria in food is a major challenge, especially because it can persist for years in food processing plants. The best option to control this pathogen is the implementation of effective cleaning and disinfection procedures that guarantee the safety and quality of the final products. In addition, consumer trends are changing, being more aware of the importance of food safety and demanding natural foods, minimally processed and free of chemical additives. For this reason, the current consumption model is focusing on the development of preservatives of natural origin, from plants or microorganisms. In sum, this study aimed to evaluate the antimicrobial effectiveness of a citrus extract formulation rich in flavonoids against several L. monocytogenes and L. innocua strains, using in vitro test (agar diffusion test, minimum bactericidal concentration (MBC), and time-kill curves) and challenge test in food trials (carne mechada, salami, fresh salmon, lettuce, brine, and mozzarella cheese). The results presented in this work show that citrus extract, at doses of 5 and 10%, had a relevant antimicrobial activity in vitro against the target strains tested. Besides this, citrus extract applied on the surface of food had a significant antilisterial activity, mainly in carne mechada and mozzarella cheese, with reductions of up to eight logarithmic units with respect to the control. These results suggest that citrus extract can be considered a promising tool to improve the hygienic quality of ready-to-eat foods.

158 Effect of Mootral™ and Forage Amount on Methane Emissions, Growth and Carcass Characteristics of Feedlot Steers

One hundred and forty-four Angus x Simmental steers were allotted by body weight (BW; 363 kg, breed composition, and farm origin to a 3 x 2 factorial arrangement of 6 treatments (4 pens per treatment) to determine the effect of Mootral (garlic + citrus extract; 0.25% of the diet DM vs. 0.0%) on methane emissions, growth and carcass characteristics of feedlot cattle. During the first 84 days, cattle were fed three different diets (forage content of 15, 41.5, or 68% corn silage). From day 85 to slaughter, corn silage was included at only 15% of the diet DM. Data were analyzed using the MIXED procedure of SAS. There was an interaction (P = 0.03) between forage content and Mootral for DMI from d 0 to 84, where Mootral decreased DMI of steers fed 15% corn silage, but did not affect DMI of steers fed 41.5 or 68% corn silage. There were no effects (P ≥ 0.22) of forage content or Mootral on BW or average daily gain at any time, or on DMI from d 84 to slaughter and overall. Gain-feed ratio from d 0 to 84 and overall was greater (P = 0.04) for steers fed 68% compared to 15 or 41.5% corn silage. On d 41, steers fed 41.5 and 68% corn silage had increased (P ≤ 0.02) methane emissions compared to steers fed 15% corn silage. There tended to be an interaction (P ≤ 0.09) between forage content and Mootral for methane emissions (g/d) on d 41 and 203, where steers fed Mootral showed lesser methane emissions with 15% corn silage, but not with the 41.5 and 68% corn silage diets. Steers fed Mootral showed lesser (P ≤ 0.03) methane emissions on d 203. Mootral tended to decrease (P &lt; 0.10) fat thickness and yield grade. In conclusion, Mootral decreased methane production in 15% corn silage diets and improved carcass leanness.

Effect of Physical and Chemical Treatments on Viability, Sub-Lethal Injury, and Release of Cellular Components from Bacillus clausii and Bacillus coagulans Spores and Cells

Bacterial spores are of concern to the food industry due to their ability to survive processing and their potential to subsequently germinate and grow in food. In this paper, two strains belonging to the genus Bacillus (B. clausii DSM 8716 and B. coagulans DSM 1) were studied under in vitro conditions after the application of essential oils, and physical treatments; cells and spores’ susceptibility, the extent of sub-lethal injury and the release of cellular components as a function of treatment and targets (cells, spores, old or activated spores) were studied. The highest antimicrobial effect was found for cells treated through citrus extract, while both essential oils and physical treatments could cause a sub-lethal injury on the surviving cells and spores; in addition, the spores of B. coagulans released dipicolinic acid (DPA) and proteins. Sub-lethal injury should be considered when designing a food processing treatment, because injured microorganisms could either repair the damage or be inactivated with a different effect on microbial stability of foods.