Kitchens, along with bathrooms, are usually the most polluted domestic environments. It is common to isolate pathogens from countertops, utensils, complex appliances such as food processors and blenders, can openers, sink drains, cloths, cutting boards, sponges, and scouring pads.
In particular, wooden utensils –whether they are spoons, forks, cutting boards, or some other piece of equipment–, highly appreciated and used in the domestic environment, are prohibited in the restaurant sector, as they are not considered sufficiently safe to microbiological level. Moreover, in 1991 the US Department of Agriculture published a recommendation so college-bound students cooking for the first time wouldn’t use wooden cutting boards either.
The reason, in both cases, is that wood is a porous material that retains moisture, necessary for microbial growth. To make matters worse, it usually deteriorates forming cracks in which an endless number of microorganisms can be lodged. For this reason it is advisable to use items made of plastic, metal or silicone. Also at home.
However, the debate is not without controversy. Because there are also studies that suggest that the rough surface of wood is hostile to bacteria. Some analyzes even indicate that the wood has properties antibacterial.
Although the consumer’s perception of the risk of contracting foodborne illnesses in the domestic environment is very low, the truth is that cross-contamination in household kitchens represents an important domestic source of infection. In 2014, 37.3% of foodborne outbreaks in the European Union germinated in domestic settings. Similarly, according to one of the latest surveillance reports from the US Center for Disease Control (CDC)in 2016 there were 76 outbreaks (10%) and 895 cases of illness (7%) in that country that were attributed to food prepared in private homes.
In recent years, reports from the European Union indicate that several foodborne illnesses are related to sources of domestic infection. Improper food handling, not washing hands before preparing food, and handling food and unhygienic practices are considered the main factors in episodes of foodborne illness.
The list is extensive, but the bacterial genera Salmonella, Campylobacter, Listeria Y Brucellathe bacteria Escherichia coli verocytotoxigenic (VTEC), noroviruses, hepatitis A virus, and parasites such as Taenia solium, Echinococcus, Ascaris, Cryptosporidium, Entamoeba histolytica either Giardia They top the list of common foodborne pathogens that affect millions of people each year.
Scouring pads, the main source of contamination
Among the potential microbiological sources in domestic environments, scouring pads stand out. They are often used not only to clean dishes and kitchen utensils, but also different surfaces or even refrigerator shelves, which increases the risk of cross-contamination.
Thanks to the high surface area to volume ratio of scouring pads, the usual constant humidity they present, the porous and airy structure and the nutrients for bacterial growth they contain (from food scraps), scouring pads are an ideal habitat for microorganisms . It is estimated that they are capable of holding 54.000 million bacteria per cubic centimeter.
Various studies on the microbiological quality of scouring pads warn that they usually contain a high level of contamination and that pathogens such as Salmonella spp., Acinetobacter spp., Moraxella spp., Staphylococcus aureus, Campylobacter spp., Listeria monocytogenes, Enterobacter cloacae, Klebsiella oxytoca either Cronobacter sakazakii. An analysis carried out in 1997 in 10 kitchens in the USA found that 33% of the scourers analyzed were positive for Escherichia coli and 67% for fecal coliforms.
A study carried out in 2020 on the microbiological quality of the scouring pads used in University residences.) revealed that students used scouring pads to wash items such as cutlery, plates, and glasses, but also to clean the oven (32%), the sink (26%), the refrigerator (10%), and even spills on the floor ( 4 %).
Analysis showed that the used scouring pads contained high counts of mesophilic aerobic bacteria (79 billion bacteria per cubic centimeter), coliforms (72 billion bacteria per cubic centimeter), Enterobacteriaceae (73 billion bacteria per cubic centimeter), and yeasts and filamentous fungi. (70,000 million cells per cubic centimeter). The most frequently isolated Enterobacteriaceae were Enterobacter cloacae (56%) and Klebsiella oxytoca (16%), both human pathogens. All the isolates of Enterobacter cloacae were resistant to antibiotics such as amoxicillin, cephalothin, cefoxitin and cefuroxime-axetil.
In short, there is no doubt that, for what it brings us, it is convenient to regularly renew our scouring pads.
Raul Rivas Gonzalez He is Professor of Microbiology at the University of Salamanca.
Disclosure Clause: Raúl Rivas González does not receive a salary, does not perform consultancy work, does not own shares, or receives funding from any company or organization that may benefit from this article, and has declared that he has no relevant links beyond the academic position cited. .
This article was originally published on The Conversation. here you can read the original.
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