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Oregano essential oil as an antimicrobial additive to detergent for hand washing and food contact surface cleaning

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Oregano essential oil as an antimicrobial additive to detergent for hand washing and food contact surface cleaning

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Abstract

To investigate the potential use of oregano essential oil as an antimicrobial agent in liquid soap for hand washing and for food contact surface cleaning. Oregano essential oil (O.E.O.) was emulsified in liquid detergent solution. This was challenge tested against a commercial antimicrobial soap in hand washing trials using natural flora. Soap with O.E.O. was as effective as the commercial antimicrobial soap at reducing aerobic plate count on the hands, and more effective than plain soap with no additives. Cloths wetted with soap with O.E.O. were used to clean three different surfaces contaminated with four bacterial pathogens. For three of the four pathogens, the addition of 0.5% v/v O.E.O. to the soap solution enhanced cleaning performance and also reduced bacterial survival on the cloth after cleaning. Oregano essential oil (0.5%) is effective as an antimicrobial additive to detergent solutions for hand washing and surface cleaning. This preliminary study has shown that oregano essential oil is a potential alternative to antimicrobials used in various detergents, such as chloroxylenol and triclosan, which can have adverse environmental and health effects. Further development could lead to a commercial product. This article is protected by copyright. All rights reserved.

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... Carvacrol, which is the most active ingredient in phenolic volatile oils and the most important OEO ingredient, can increase cell membrane fluidity and permeability by compressing the fatty acid chain of phospholipids; this action causes ions in the cytoplasm to flow out of the cell and results in cell death [16]. Rhoades et al. [17] showed that OEO is an effective antibacterial additive to hand-washing and surface-cleaning detergent solutions and is a potential alternative to triclosan and chloroxylenol. ...
... Nevertheless, information on the antibacterial properties of detergents remains limited. Rhoades et al. [17] reported that commercial high-efficiency antibacterial liquid dishwashing detergents containing OEO have been developed. These products contain alkyl ethoxy ether sulfate (AES), alkyl polyglycoside (APG), cocamidopropyl betaine (CAB), sodium hydroxide (NaOH), OEO, and distilled water. ...
... Raw counts were converted to lg CFU per wipe. An arbitrary value of 2.4 lg CFU per wipe was assigned to cases where no colonies were isolated (0.5 × the arithmetic assay detection limit) [17]. ...
Article
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A high-efficiency liquid dishwashing detergent was prepared by using oregano essential oil as an antibacterial agent. The surface cleaning and antibacterial property of the detergent resolved its unifunctionality problem. The antibacterial activities of the detergent were demonstrated through a disk diffusion assay and wipe experiments with Escherichia coli and Staphylococcus aureus. Results showed that the prepared detergent was highly effective against E. coli and S. aureus. The results of chemical accelerated tests indicated that the detergent would be effective for at least 1 year. The antibacterial property and detergency performance of the high-efficiency antibacterial liquid dishwashing detergent were compared with those of a commercial antibacterial detergent containing 0.02% o-phenylphenol. The detergency performance of the high-efficiency detergent reached 97.8% and was superior to that of the commercial antibacterial detergent.
... To decrease their concentrations in the UASB sludge and struvite and to ensure safe utilization of these waste products in agriculture, source control over the utilization of disinfectants is advised. The introduction of the environmentally friendly alternatives for disinfectants, e.g., utilization of essential oils instead of triclosan, is an example of such source control measures [128]. ...
... The mitigation of micropollutants in the compost produced from sludge can be achieved by source control and separate digestion of organic matter of different wastewater streams. For example, essential oils are potential alternatives that can replace triclosan as antimicrobials in personal care and household products [128]. The constituents of the washing and cleaning products and perfumes, e.g. ...
Article
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Source separated sanitation is an innovative sanitation method designed for minimizing use of energy and clean drinking water, and maximizing reuse of water, organics and nutrients from waste water. This approach is based on separate collection and treatment of toilet wastewater (black water) and the rest of the domestic wastewater (grey water). Different characteristics of wastewater streams facilitate recovery of energy, nutrients and fresh water. To ensure agricultural or ecological reuse of liquid and solid products of source separated sanitation, the quality of these materials has to meet (future) standards, i.e. for micropollutant concentrations. Therefore the objectives of this thesis included assessment of micropollutant content of source separated sanitation products intended for resource recovery and examination of post-treatment technologies for micropollutant mitigation within source separated sanitation
... Biocide-resistant L. monocytogenes strains were also isolated from different processing control points in two tilapia processing factories, and were attributed to incorrect handling of the fillets and to the incorrect application of sanitizing procedures [23]. As to potential control strategies mitigating persistence, researchers have addressed the potential effectiveness of natural antimicrobials, such as oregano essential oil (0.5%) incorporated in detergent solutions used for hand washing and food contact surface cleaning, as useful antimicrobial alternatives for reducing pathogen survival [24]. Similarly, others have looked on the reduction of E. coli O157:H7 and Salmonella when washing contaminated gloves (used for harvesting ready-to-eat produce) in levulinic acid and sodium dodecyl sulphate (SDS) solutions [25]. ...
Article
Farms and food industries rely to a large extent on the use of biocides as disinfectants and other antimicrobial agents and preservatives with antimicrobial properties in order to provide food of high microbiological quality and safe for consumers. However, in the last decades it has become apparent that long-term sub-lethal exposure to these antimicrobial agents can exert a selective pressure leading to the emergence and spread of microbial strains with a reduced susceptibility to the used antimicrobials, which can persistently colonize food-processing environments and recurrently contaminate food. In addition, it may induce resistance to unrelated and clinically relevant antibiotics, in a phenomenon known as cross-resistance. This review aims to provide insights on how antimicrobial resistance emergence and spread can be affected by certain food processing activities and to discuss recent research focused on different pathways through which biocides and other antimicrobials could co-select for bacteria resistant to clinically relevant antibiotics.
... Among the various alternatives are plant-derived compounds such as essential oils (EOs). EOs are natural, volatile, complex compounds known for their antibacterial, antifungal, antiviral, antioxidant and medicinal properties (Kim et al., 2008;Rhoades et al., 2013;Gilling et al., 2014;Talibi et al., 2014;Sivakumar and Bautista-Banos, 2014). The development of resistant strains of fungi against essential oils may be less likely as it is for many synthetic fungicides because several active components are often present in the EOs and synergistic interactions may exist between the different components of the oils (Tripathi and Dubey, 2003;Tripathi et al., 2004). ...
... Dense growth was observed on the control plates devoid of AgNPs, while no growth was recorded on the AgNPstreated toothpaste plate (Figure 8). Though there are very little or no information on applications of AgNPs as antimicrobial additives in detergents and toothpastes, but there exist studies on enhancements of their antimicrobial qualities using natural plant extracts (Verkaik et al. 2011, Rhoades et al. 2013, Rossi et al. 2014). However, most recently, Ahmed et al. (2019) reported a high antibacterial efficacy induced by nanosilvercontaining toothpaste against a strain of Streptococcus mutans. ...
... The mitigation of micropollutants in the compost produced from sludge can be achieved by source control and separate digestion of organic matter of different wastewater streams. For example, essential oils are potential alternatives that can replace triclosan as antimicrobials in personal care and household products [43]. The constituents of the washing and cleaning products and perfumes, e.g., alkylphenols and synthetic musks, are one of the major groups of organic compounds present in domestic wastewater [44]. ...
Article
Full-text available
The excess sludge from Up-flow anaerobic sludge bed (UASB) reactor operated on source separated toilet wastewater is a potential source of nutrients and organic matter. It can be further stabilized and dried by composting and applied as a soil amendment. Presence of pathogens, heavy metals and micropollutants in the compost derived from anaerobic sludge is thus undesirable. This paper focuses on removal of micropollutants, typically present in domestic wastewater, via composting of UASB sludge with waste wood. Estrone, diclofenac, ibuprofen, metoprolol, carbamazepine, galaxolide and triclosan were spiked to a mixture of UASB sludge and waste wood. Their concentrations were monitored during 92 days of composting at controlled temperature conditions. All studied micropollutants were removed at various rates with overall removal ranging from 99.9% for ibuprofen, diclofenac and estrone to 87.8% for carbamazepine. Accumulation of methyltriclosan as by-product of triclosan degradation was observed. The prospects and limitations of the integration of a composting process into Source Separated Sanitation concepts are discussed.
... In daily activities, hands are often contaminated with microbes as it constantly in contact with the environment. 1 In other words, hands are one of the media for entry of microbes into the body. The generally accepted ways to maintain hand hygiene is by hand washing. 2 Hand washing is a simple activity that aims to remove dirt and minimize the number of germs in the hands and palms by using water and an additional substance, where the substance can be antiseptic. ...
... In Mediterranean countries, grapes products are highly contaminated with OTA and A. carbonarius which is regarded as the prominent ochratoxigenic fungi on vines due to its highest ochratoxin-producing isolates incidence within the Aspergillus group, and to its great OTA production potential (Lasram et al., , 2012b; Melki oils (EOs) seems to bring up a solution to the problem. EOs are known for their antifungal, antibacterial, antioxidant, antiviral and medicinal properties (Gilling et al., 2014;Rhoades et al., 2013;Talibi et al., 2014). Their applications as natural preservatives in food are widely studied (Holley and Patel, 2005). ...
Article
This investigation is performed to evaluate the antifungal and anti-ochratoxigenic activities of Salvia officinalis, Lavandula dentata and Laurus nobilis essential oils (EOs), and their major constituent 1,8-cineole. The evaluation of these activities was performed by two assays, contact assay with application of different concentrations of each tested EO as well as 1,8-cineole (0, 0.1, 0.2, 0.3, 0.4 and 0.5%) in Czapek Yeast Agar medium (CYA) and volatile assay by application of one concentration of each EO equal to 0.025% of CYA. The chemical composition of tested EOs was determined through gas chromatographic-mass spectrometry analysis and their antioxidant capacity was assessed by DPPH assay. Obtained results showed that L. nobilis EO exhibited better antioxidant activity (IC50=0.35 ± 0.05mg/mL) than S. officinalis (IC50=11.12 ± 0.09mg/mL) and L. dentate (IC50=14.03 ± 0.16mg/mL) and it possessed the highest phenolic content (15.15 ± 1.64 mg gallic acid equivalent/g EO). Statistical analyses of volatile assay showed that L. nobilis EO inhibited the growth rate much more than L. dentata and S. officinalis with a percentage equal to 47.82, 37.92 and 31.71%, respectively, and reduced the production of OTA with a percentage of 88.87%. While, on contact assay L. nobilis and L. dentata EOs exhibited a higher antifungal and anti-ochratoxigenic activities than S. officinalis, with a minimum inhibitory concentration (MIC) of about 0.3, 0.3 and 0.5%, respectively. The MIC of 1,8-cineole (0.5%) was approximately double to that of L. nobilis and L. dentata EOs. Hence, its powerful biological activities were assured by the synergism between the major component and the other existing ones
... In Mediterranean countries, grapes products are highly contaminated with OTA and A. carbonarius which is regarded as the prominent ochratoxigenic fungi on vines due to its highest ochratoxin-producing isolates incidence within the Aspergillus group, and to its great OTA production potential (Lasram et al., , 2012b; Melki oils (EOs) seems to bring up a solution to the problem. EOs are known for their antifungal, antibacterial, antioxidant, antiviral and medicinal properties (Gilling et al., 2014;Rhoades et al., 2013;Talibi et al., 2014). Their applications as natural preservatives in food are widely studied (Holley and Patel, 2005). ...
Article
This investigation is performed to evaluate the antifungal and anti-ochratoxigenic activities of Salvia officinalis, Lavandula dentata and Laurus nobilis essential oils (EOs), and their major constituent 1,8-cineole. The evaluation of these activities was performed by two assays, contact assay with application of different concentrations of each tested EO as well as 1,8-cineole (0, 0.1, 0.2, 0.3, 0.4 and 0.5%) in Czapek Yeast Agar medium (CYA) and volatile assay by application of one concentration of each EO equal to 0.025% of CYA. The chemical composition of tested EOs was determined through gas chromatographic-mass spectrometry analysis and their antioxidant capacity was assessed by DPPH assay. Obtained results showed that L. nobilis EO exhibited better antioxidant activity (IC50=0.35 ± 0.05mg/mL) than S. officinalis (IC50=11.12 ± 0.09mg/mL) and L. dentate (IC50=14.03 ± 0.16mg/mL) and it possessed the highest phenolic content (15.15 ± 1.64 mg gallic acid equivalent/g EO). Statistical analyses of volatile assay showed that L. nobilis EO inhibited the growth rate much more than L. dentata and S. officinalis with a percentage equal to 47.82, 37.92 and 31.71%, respectively, and reduced the production of OTA with a percentage of 88.87%. While, on contact assay L. nobilis and L. dentata EOs exhibited a higher antifungal and anti-ochratoxigenic activities than S. officinalis, with a minimum inhibitory concentration (MIC) of about 0.3, 0.3 and 0.5%, respectively. The MIC of 1,8-cineole (0.5%) was approximately double to that of L. nobilis and L. dentata EOs. Hence, its powerful biological activities were assured by the synergism between the major component and the other existing ones.
... In another study, the potential use of oregano EO as an antimicrobial agent was investigated in liquid soap for stainless steel food contact surfaces. After wiping with water, the count of E. coli (inoculated at 7Á70 AE 0Á20 log CFU per ml) on the surface was found to be approximately 2Á4 log CFU per 6 9 6 cm, while the numbers decreased to an undetectable level after wiping with soap containing 0Á5% oregano EO (Rhoades et al. 2013). These studies demonstrated that various EOs or EO combinations may act as potential antimicrobial agents for the disinfection of various surfaces such as laboratory equipment and food preparation areas. ...
Article
In this study, it was aimed to develop a novel disinfectant from various essential oils containing active components with antimicrobial activity. The mixture of oregano, cinnamon, and clove oils (1:1:1) with 10% oil concentration (SOM) was used as potential disinfectant on various areas and showed the highest antimicrobial activity among oil combinations tested. SOM reduced the numbers of total mesophilic aerobic bacteria (TMAB) (2.27 log CFU 25 cm‐2) and Escherichia coli (4.60 log CFU 25 cm‐2) under the detection limits. Application of SOM (1%, 2%, 3%, 4%, and 6%) into incubators reduced TMAB and mold‐yeast counts of incubator air by 82.9% and 100%, respectively. SOM application (3%) into ambient air also reduced its TMAB and mold‐yeast counts by 92% and 84.6%, respectively. While ethanol is commonly used for the disinfection of environments, equipment, and surfaces, SOM is an important alternative that may also be used for the disinfection of various surfaces as well as air.
... So far, some well characterized EOs or their main active compounds have been directly applied as flavoring agents in food, used in washing solutions for vegetables, or incorporated in packaging materials to control foodborne pathogens (Irkin & Esmer, 2015). Furthermore, the application of well-characterized EOs to sanitize food contact surfaces has also been investigated (Giaouris et al., 2014;Rhoades et al., 2013;Valeriano et al., 2012). ...
Article
Chemical sanitizers continue to be widely used by the food industry to disinfect food contact surfaces. However, as some chemical disinfectants have been reported to produce unhealthy by-products, alternative and natural compounds need to be investigated. To this end, nine essential oils (EOs) were screened to develop a natural sanitizing solution (SAN) for disinfecting food contact surfaces. Once extracted, their antimicrobial activity and chemical composition were determined. An exploratory multivariate approach was used to investigate the relationships between the chemical and microbiological data sets. Among the tested EOs, Thymbra capitata EO, containing up to 93.31% oxygenated monoterpenes (mainly carvacrol), showed the strongest antimicrobial activity and thus was assayed as a potential SAN for food contact surfaces. To this end, a SAN consisting of 1% T. capitata EO was first validated according to the AOAC standard, which showed about 8 log reduction for Escherichia coli and Salmonella enterica after 30 and 60 s of contact time, respectively. Then, the SAN was evaluated at various concentrations, cleanliness conditions, and contact times on stainless steel, glass, and polypropylene surfaces for sanitizing purposes. The results showed that the SAN containing 2.5% of T. capitata EO applied for 10 min, reduced the levels of E. coli by >3 log and S. enterica by 1 log under clean working conditions on the three tested surfaces. These findings indicate that EOs can be used as natural disinfectants to decontaminate food contact surfaces, thus lowering the risk of the indirect transfer of bacterial pathogens to food or persons.
... Among the various sources available for natural compounds, plant products especially essential oils (EOs) outperform others in having many medicinal and antimicrobial properties [9,10]. Many EOs have been reported for their antibacterial, antiviral and antifungal properties [11][12][13]. ...
Article
The present investigation for the first time explains the anti biofilm and anti virulence potential of Kaffir lime oil (KLO) and its major constituent, Citronellal (3,7-dimethyloct-6-enal) against Xanthomonas oryzae pv. oryzae, causal organism of bacterial blight disease of rice. KLO at 500 ppm showed potential activity against X. oryzae pv. oryzae. Among the major components identified, citronellal (CIT) at 75 μM concentration was found to significantly inhibit biofilm along with the swimming and swarming potential of X. oryzae pv. oryzae. In contrary, CIT did not affectthe metabolic status and growth kinetics of the bacterial cells. Gene expression analysis showed down regulation in motA, cheD, cheY, flgF, gumC, xylanase, endogluconase, cellulose, cellobiosidase, virulence and rpfF transcript levels by citronellal treatment. However, insignificant effect of 75 μM CIT treatment was observed on motB, flgE, pilA, estY, pglA, protease and lytic genes expression. Finally, the observations recorded were in confirmity with the virulence leaf clip test as lesion length was significantly decreased (39%) in CIT treatment as compared to the control leaves inoculated with only X. oryzae pv. oryzae. Overall, the findings obtained advocate the use of CIT for promising anti biofilm and anti virulence activity which in turn can be used for managing the blight disease in rice.
... The NIR heating technique can, when based on predictive modeling of microbial killing, be used in inactivating microbes in slicing of, for example, deli ham (Ha and Kang, 2014). The efficacy of disinfectants used in food processing and in hand hygiene rubs can be improved by using compounds from essential oils (Lang and Buchbauer, 2011;Rhoades et al., 2013). Improvements in hygienic design can be carried out using new materials and new techniques based on, for example, 3D printing. ...
Chapter
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This study was performed in order to determine the level of bacterial contamination on the hands of food handlers (n=30) who work in the kitchen of a military training hospital. A total of 180 samples were collected from bare and gloved hands before and during food preparation.A total of 16 different bacteria were isolated, of which the most common was Staphylococcus aureus (126/180; 70%), followed by coagulase-negative staphylococci (102/180; 56.7%), diphtheroid bacilli (39/180; 21.7%), Bacillus spp. (19/180; 10.5%), and Escherichia coli (14/180; 7.8%). Fifty-one of 60 (85%) gloved hand samples were collected during work, 57 (95%) of the bare hand samples were collected before work all of the bare hand samples collected during work were positive. Poor hand hygiene was indicated by high levels of S. aureus and E. coli on samples taken from bare and gloved hands. Although bacterial loads on gloved hand samples were found to be significantly lower (p<0.05) than ungloved hand samples, these loads were not within acceptable limits. These results show that the hands of food handlers are an important contamination source in this establishment. In this study, 203 bacterial isolates were from right hand samples while 166 bacterial isolates were from left hand samples (χ2=1.913; p<0.05). All of the food handlers were right-handed. Bacterial load isolated from the inexperienced food handlers was higher than those from experienced ones (χ2=2.024; p<0.05).As a result, the poor hand hygiene and improper glove use by the food handlers was emphasized and we concluded that the training in personal hygiene and food safety should be improved, and inexperienced personnel should not be employed in kitchens without being well trained. On the other hand, if glove use principles are performed correctly, it may be efficacious for decreasing of bacterial load on hands, particularly, establishments where hand hygiene control can not performed properly or inexperienced personnel are employed.
Article
To confirm the importance of washing food sediments from the surface of food-related environments, we examined resistances against benzalkonium chloride of pathogenic bacterial (Escherichia coli O26, Pseudomonas aeruginosa and Staphylococcus aureus) cells dried and adhered on stainless steel dishes with milk, beef gravy or tuna gravy. Suspensions (0.1 ml) of these bacteria (8–9 log cfu/ml) were put on a 5 cm ϕ stainless steel dish and dried at room temperature (20–24 °C) for 90 min in a bio-clean bench with ventilation. Though these bacteria suspended with distilled water decreased 30–40 fold during the drying period, milk and the gravies protected the bacteria. Without the food elements, the adhered E. coli and Stap. aureus were decreased from 6 to<2 log cfu/dish by 0.5 mg/ml benzalkonium chloride (BKC) for 10 min treatment. Although Ps. aeruginosa showed resistance to BKC, the adhered cells were inactivated by 2.0 mg/ml BKC. However, the bactericidal effect disappeared by the food elements, particularly with milk, even at 1.0 and/or 2.0 mg/ml BKC levels. The protective efficiency of milk on bacteria disappeared if washed with water.
Article
Herbs and spices containing essential oils (EOs) in the range of 0.05–0.1% have demonstrated activity against pathogens, such as Salmonella typhimurium, Escherichia coli O157:H7, Listeria monocytogenes, Bacillus cereus and Staphylococcus aureus, in food systems. Application of herbs, spices and EOs with antimicrobial effects comparable to synthetic additives is still remote for three major reasons: limited data about their effects in food, strong odor, and high cost. Combinations of techniques have been successfully applied in several in-food and in vitro experiments. This paper aims to review recent in-food applications of EOs and plant-origin natural antimicrobials and recent techniques for screening such compounds.
Article
Despite an increase in the number of food handlers receiving food hygiene training, a high number of food poisoning outbreaks still occur as a result of improper food handling practices in the retail industry. In this study, samples were collected from the hands and aprons of food handlers in the delicatessen sections of a prominent South African retail group and analysed for the presence of total viable counts (TVC), total coliforms, Escherichia coli, members of the family Enterobacteriaceae and Staphylococcus aureus in order to assess the levels of contamination and to establish possible relationships. Noteworthy TVC were present on 98% of hands and 84% of aprons sampled and conformed to the national standard of 1 × 102 cfu cm−2 without exception. Coliforms were present on 40% of food handler’s hands and on 26% of aprons and when compared to the literature which suggests a target value of <2.5 cfu cm−2, 32% of food handlers exceeded the target with regard to hands and 8% with regard to aprons. E. coli was found to only exceed the limit in the case of one food handler. Enterobacteriaceae were present on the hands of food handlers (44%) and on aprons (16%), ranging between 5 and 1.8 × 101 cfu cm−2 on hands and between 5 and 2.9 × 101 cfu cm−2 on aprons. S. aureus counts were present on 88% of hands and 48% of aprons and ranged between negligible and 9.8 × 101 cfu cm−2 for hands and up to 6.2 × 101 cfu cm−2 for aprons. No significant statistical correlation occurred between the organisms on hands and aprons, indicating that the latter were not likely to be cross-contaminated by hands.
Article
To simulate the persistence of Salmonella typhimurium on food preparation surfaces, survival was assessed on 25 cm2 wood and plastic chopping boards both new and after heavy scoring. Survival was assessed by counting the numbers of S. typhimurium recovered after rinsing the inoculum off the board surface followed by contact plates. Recovery of the board inoculum from the rinse diluent was significantly greater from plastic than wood, and from untreated than scored boards. S. typhimurium was recovered, using contact plates, on scored wood boards up to 120 min after the initial rinsing procedure, up to 60 min on scored plastic and up to 30 min on untreated wood or plastic. On boards with food residues, there was significant recovery from scored boards, although there was no difference between wood or plastic. Disinfection was more readily carried out on plastic than both types of wood boards. The results of this study suggest that wooden boards (especially those that are scored through use) present a greater potential hazard for cross contamination than plastic chopping boards.
Article
Various bacteria including food spoilage bacteria and pathogens can form biofilms on different food processing surfaces, leading to potential food contamination or spoilage. Therefore, the survival of foodborne pathogens (Escherichia coli O157:H7, Listeria monocytogenes, Salmonella typhimurium, Staphylococcus aureus, Cronobacter sakazakii) in different forms (adhered cells, biofilm producing in TSB, biofilm producing at RH 100%) on the surface of stainless steel and stored at various relative humidities (RH 23%, 43%, 68%, 85%, and 100%) at room temperature for 5 days was investigated in this study. Additionally, the efficacy of chemical sanitizers (chlorine-based and alcohol-based commercial sanitizers) on inhibiting various types of biofilms of E. coli O157:H7 and S. aureus on the surface of stainless steel was investigated. The number of pathogens on the surface of stainless steel in TSB stored at 25°C for 7 days or RH 100% at 25°C for 7 days was significantly increased and resulted in the increase of 3 log(10) CFU/coupon after 1 day, and these levels were maintained for 7 days. When stainless steel coupons were stored at 25°C for 5 days, the number of pathogens on the surface of stainless steel was significantly reduced after storage at RH 23%, 43%, 68%, and 85%, but not at 100%. When the bacteria formed biofilms on the surface of stainless steel in TSB after 6 days, the results were similar to those of the attached form. However, levels of S. aureus and C. sakazakii biofilms were more slowly reduced after storage at RH 23%, 43%, 68%, and 85% for 5 days than were those of the other pathogens. Formation of biofilms stored at RH 100% for 5 days displayed the highest levels of resistance to inactivation. Treatment with the alcohol sanitizer was very effective at inactivating attached pathogens or biofilms on the surface of stainless steel. Reduction levels of alcohol sanitizer treatment ranged from 1.91 to 4.77 log and from 4.35 to 5.35 log CFU/coupon in E. coli O157:H7 and S. aureus, respectively. From these results, the survival of pathogens contaminating the surfaces of food processing substrates such as stainless steel varied depending on RH and attachment form. Also, alcohol-based sanitizers can be used as a potential method to remove microbial contamination on the surfaces of utensils, cooking equipment, and other related substrates regardless of the microbial attached form.
Article
This study evaluated the effect of blood on the antimicrobial activity of several agents used for handwashing. Seventy-one healthy adult volunteers used 1 of 6 products (70% isopropyl alcohol [IPA]; liquid hand rinse containing 70% ethyl alcohol and 0.5% chlorhexidine gluconate [EA]; detergent containing 7.5% povidone-iodine [PI]; detergent containing 4% chlorhexidine gluconate [CHG]; a nonantimicrobial soap; and a control group that used no product) in two tests: with and without 1.2 mL of dried sterile sheeps' blood on the hands. In the presence of blood, the two alcohol products (IPA and EA) resulted in significantly greater reductions in numbers of colony-forming units than other products (P less than 0.001). When no blood was present, IPA was associated with significantly greater reductions, whereas soap and control groups had significantly lower reductions (P = 0.008). We conclude that hands are effectively degermed with a variety of products in the presence of blood, and that alcohols give greater initial reductions in colonizing flora. This is of particular relevance in emergency situations during which contamination with blood is likely and handwashing facilities are inaccessible.
Article
The retention of bacteria on food contact surfaces increases the risk of cross-contamination of these microorganisms to food. The risk has been considered to be lowered when the surfaces are dry, partly because bacterial growth and survival would be reduced. However, some non-spore-forming bacteria might be able to withstand dry conditions on surfaces for an extensive period of time. In this study the survival of Salmonella enteritidis, Staphylococcus aureus and Campylobacter jejuni on stainless steel surfaces at different initial levels was determined at room temperature. The transfer rates of these pathogens from kitchen sponges to stainless steel surfaces and from these surfaces to foods were also investigated. Staph. aureus was recovered from the surfaces for at least 4 days when the contamination level was high (10 5 CFU/cm2) or moderate (103 CFU/cm 2). At low levels (10 CFU/cm2), the surviving numbers decreased below the detection limit (4 CFU/100 cm2) within 2 days. S. enteritidis was recovered from surfaces for at least 4 days at high contamination levels, but at moderate level, the numbers decreased to the detection limit within 24 h and at low level within 1 h. C. jejuni was the most susceptible to slow-air-drying on surfaces; at high contamination levels, the numbers decreased below the detection limit within 4 h. The test microorganisms were readily transmitted from the wet sponges to the stainless steel surfaces and from these surfaces to the cucumber and chicken fillet slices, with the transfer rates varied from 20% to 100%. This study has highlighted the fact that pathogens remain viable on dry stainless steel surfaces and present a contamination hazard for considerable periods of time, dependent on the contamination levels and type of pathogen. Systematic studies on the risks of pathogen transfer associated with surface cleaning using contaminated sponges provide quantitative data from which a model of risks assessment in domestic setting could lead.
Article
In this study, the survival of Salmonella, Campylobacter and Escherichia coli O157: H7, when exposed to a range of constant temperatures (47-60 degrees C), in hard or soft water, in the presence/absence of detergent (0-0.3%) and organic matter, and during drying, was investigated. Further experiments used a washing-up process simulation, where soiled dishes contaminated with bacteria were washed in a bowl of warm water containing detergent. In addition, this study considered the risk of bacterial transfer onto (1) sterile dishes and sponges via contaminated water, (2) kitchen surfaces wiped with a contaminated sponge, (3) items placed in direct contact with a contaminated kitchen surface, (4) food placed on a contaminated dish or (5) dishes from contaminated food. A proportion of dishes remained contaminated with all pathogen types after a typical washing-up. Water hardness did not appear to affect survival. E. coli, and to a lesser extent Salmonella, survived towel- or air-drying on dishes and after towel-drying the cloth became contaminated on every occasion, regardless of the test organism. A proportion of sterile dishes washed after contaminated dishes became contaminated with pathogens but transfer from dishes onto food was rare. Washing-up sponges frequently became contaminated with pathogens. The results of this study highlight the potential for survival and cross contamination of food borne pathogens in the kitchen environment.
Article
This prevalence study was conducted to compare the counts, types and antimicrobial resistance profiles of bacterial flora on the hands of individuals in the community to that of nurses at a nearby university teaching hospital, with an intense hand hygiene regimen. Hand cultures were obtained from 204 individuals during a home visit and 119 nurses in two neonatal intensive care units (NICUs). The mean total log counts of organisms were 5.73 and 5.24 for the homemakers [defined as the person (usually the mother) who is the primary person responsible for arranging childcare, cooking, cleaning etc] and nurse hands, respectively (P<0.0001). Significantly more homemakers had Acinetobacter lwoffii, Enterobacter cloacae, Klebsiella pneumoniae, Pseudomonas aeruginosa, P. fluorescens/putida, and Staphylococcus aureus on their hands compared with the nurses (all P<0.05). However, significantly more nurses had Enterococcus faecalis, S. epidermidis, and S. warneri on their hands (P<0.05). Of note, the hands of nurses harboured significantly more S. epidermidis strains resistant to amoxicillin/clavulanate, cefazolin, clindamycin, erythromycin, and oxacillin and S. warneri resistant to amoxicillin/clavulanate, cefazolin, clindamycin, and oxacillin (P<0.05). Surprisingly, significantly more trimethoprim/sulfamethoxazole-resistant S. epidermidis and ciprofloxacin-resistant S. warneri was recovered from the hands of homemakers (P<0.05). This study demonstrates differences in prevalence, bacterial composition and antimicrobial resistance of hand flora of hospital personnel compared with homemakers. Moreover, the hands of homemakers may serve as community reservoirs for antimicrobial resistant strains of clinical importance.
Article
In vitro studies have demonstrated antibacterial activity of essential oils (EOs) against Listeria monocytogenes, Salmonella typhimurium, Escherichia coli O157:H7, Shigella dysenteria, Bacillus cereus and Staphylococcus aureus at levels between 0.2 and 10 microl ml(-1). Gram-negative organisms are slightly less susceptible than gram-positive bacteria. A number of EO components has been identified as effective antibacterials, e.g. carvacrol, thymol, eugenol, perillaldehyde, cinnamaldehyde and cinnamic acid, having minimum inhibitory concentrations (MICs) of 0.05-5 microl ml(-1) in vitro. A higher concentration is needed to achieve the same effect in foods. Studies with fresh meat, meat products, fish, milk, dairy products, vegetables, fruit and cooked rice have shown that the concentration needed to achieve a significant antibacterial effect is around 0.5-20 microl g(-1) in foods and about 0.1-10 microl ml(-1) in solutions for washing fruit and vegetables. EOs comprise a large number of components and it is likely that their mode of action involves several targets in the bacterial cell. The hydrophobicity of EOs enables them to partition in the lipids of the cell membrane and mitochondria, rendering them permeable and leading to leakage of cell contents. Physical conditions that improve the action of EOs are low pH, low temperature and low oxygen levels. Synergism has been observed between carvacrol and its precursor p-cymene and between cinnamaldehyde and eugenol. Synergy between EO components and mild preservation methods has also been observed. Some EO components are legally registered flavourings in the EU and the USA. Undesirable organoleptic effects can be limited by careful selection of EOs according to the type of food.
Article
This study involved observation of hand-hygiene behaviour and evaluation of the effect of alcohol-based hand disinfection and handwashing with plain liquid soap on microbial flora. The study was performed in a combined medical and surgical intensive care unit. We demonstrated a crude compliance of hand hygiene of 50.4%, which was only performed adequately in 20.8% of cases. Of this group, handwashing and hand-disinfection procedures were performed properly 34.0% and 71.6% of the time, respectively. Hand samples for bacteriological examinations with the glove juice method demonstrated that whilst handwashing was sensitive to the way in which hand hygiene was performed, alcohol-based hand disinfection was less sensitive to such performance. Our study demonstrated that alcohol-based hand disinfection is a robust hand-hygiene method with many advantages in a practical setting. It is very feasible for use in hospital wards.
Article
The efficacy of formulations containing tea tree oil (TTO) has been assessed in vitro in previous studies. Products that passed the European suspension test guidelines were investigated further in this study, in vivo with volunteers using the European handwashing method (EN 1499) and ex vivo using freshly excised human skin samples. The activity of 5% TTO in 0.001% Tween 80, in a hygienic skin wash (HSW) and in an alcoholic hygienic skin wash (AHSW) was investigated and compared with that of a non-medicated soft soap (SS, control). These formulations were assessed against Escherichia coli K12 as recommended by the European standard. In-vivo results showed that 5% TTO in Tween 80 and the AHSW were significantly more active than the SS after 1 min of handwashing. When assessed ex vivo, these two products were also significantly more active than the reference soap after 1 min of rubbing. Both methods showed that 5% TTO in Tween 80 was generally, although not always, more active than a handwash formulation, and that the AHSW was generally more active than the HSW, although this difference was not significant. The formulations tested, as well as the SS, were more active when assessed in vivo than ex-vivo against E. coli, although only the SS and the HSW were significantly more active in vivo. There appeared to be a pattern in the comparison between ex vivo and in vivo results. The antiseptics tested were, on average, 1.28+/-0.06 times more active when assessed in-vivo than when assessed ex vivo. Nevertheless, the main outcome of the European handwashing method is for the formulation tested to be significantly more active than the SS; both 5% TTO in Tween 80 and the AHSW achieved this both in-vivo and ex-vivo. TTO in Tween 80 and in formulations met the European in-vivo method requirements.
Article
Healthcare workers are required to disinfect the hands several times a day using hand disinfectants, which leads to chronic hand exposure to high levels of antimicrobials contained in the disinfectants, which could compromise the skin integrity. This problem may be addressed by developing hand disinfectants containing synergistic combinations of small amounts of antimicrobials and other agents. The synergistic effect of farnesol and essential oils with several antimicrobials was studied in vitro to select an effective antimicrobial system in preservative concentration for use in healthcare hand rub. Farnesol and lemon oil showed synergistic activity against S. aureus, in combination with benzalkonium chloride and benzethonium chloride, but not with other antimicrobials studied. All essential oils studied showed synergy with benzethonium chloride against Staphylococcus aureus and Escherichia coli. An alcohol-based healthcare hand rub (ZBF hand rub) containing this unique synergistic combination of farnesol and benzethonium chloride was then developed and its efficacy as a healthcare hand rub was evaluated in human volunteers according to the US FDA-TFM protocol using Serratia marcescens as a marker organism. The ZBF hand rub showed a 3.22 log(10) reduction in the microbial count after the first application and a 5.49 log(10) reduction after the tenth application in vivo and exceeds the US FDA-TFM criteria for healthcare hand rub. The ZBF hand rub did not irritate the hands when tested on human volunteers when applied 10 times everyday for five consecutive days. The ZBF hand rub exhibits more than 5.5 log(10) reduction in the microbial count within 15s and more than 2.8 log(10) reduction in the two types of viruses tested within 30s in vitro. When evaluated in an in vitro pig skin model, the ZBF hand rub shows better prolonged activity (20-35 min post-application) against transient bacteria (S. aureus and E. coli) compared to other alcohol-based hand rubs. These findings suggest that the use of the ZBF hand rub amongst health care workers may lower the risk of chronic hand exposure to high levels of antimicrobials without compromising the efficacy.
Side Effects of Drugs: The International Encyclopedia of Adverse Drug Reactions and Interactions
  • Anon
Anon. (2006) Chloroxylenol. In Meyler's Side Effects of Drugs: The International Encyclopedia of Adverse Drug Reactions and Interactions, 15th edn ed. Aronson, J.K. pp. 731-732. Amsterdam: Elsevier B.V.
United States Patent number US 6,884,763 B2. Waterless hand cleaner containing plant derived natural essential oil
  • D M Willard
  • G Barraza
  • J D Zook
Willard, D.M., Barraza, G. and Zook, J.D. (2005) United States Patent number US 6,884,763 B2. Waterless hand cleaner containing plant derived natural essential oil. April 26.
Waterless hand cleaner containing plant derived natural essential oil
  • D M Willard
  • G Barraza
  • J D Zook