What do you think is the most common place in your home to grow microbes? Is it a toilet that hasn't been cleaned in a long time, or a dirty laundry that hasn't been washed for a week, or ...... Garbage in a garbage basket for days?
You probably can't imagine the real answer - the dishwashing sponge that you use almost every day may be the petri dish with the most microorganisms living in your home.
The structure of the kitchen sponge
A dishwashing sponge that has been used in the kitchen for a long time can contain hundreds of bacteria, and up to 54 billion bacteria can be hidden per cubic centimeter.
A wide variety of bacteria are found almost everywhere in the sponge; The red color in the figure represents the bacterial colony, and the cyan color is the autofluorescence of the sponge.
A number of studies have concluded that used kitchen sponges are the items with the highest number of bacteria in the entire home environment. In other words, if you are used to wiping the dishes and stove with a sponge every time you wash the dishes, although it looks clean to the naked eye, it is actually ...... You're probably spreading bacteria evenly all over the surface.
Note: This comparison is for all inanimate objects in the home, and does not include living animals or humans themselves - after all, there are more than 100 trillion microorganisms on our bodies and bodies. In particular, the microorganisms in the gut are an important part of our human body and assume important functions.
So, why does a dishwashing sponge that seems harmless to humans and animals become a microbial petri dish?
This is all thanks to its unique loose and porous structure, which not only allows us to absorb and squeeze water quickly when using, but also foams quickly when using dish soap, creating excellent conditions for bacteria to survive.
This loose and porous structure is like creating a "livable community" for bacteria. Bacteria of the same kind or who prefer to live together in "groups" can survive in close proximity; Microorganisms that may inhibit each other, or prefer to "live alone", can also survive in more distant areas. In short, both E and I can find their own suitable growth environment, be safe with each other, and vigorously grow their families.
The microorganisms in the dishwashing sponge are not only abundant, but also quite diverse. In a dishwashing sponge alone, there are more than 362 bacteria in 118 genera.
This is because the dishwashing sponge, which is a loose and porous environment with its own spatial segmentation effect, can also avoid the vicious competition between microbial populations and the demise of one party, and everyone can find a small corner of the "huge" space to thrive.
According to relevant research, environments such as sponges, with medium spatial segmentation, can grow the most abundant and diverse bacterial communities. Compared with the pure and single agar petri dish in the laboratory, this environment that can be dispensed in multiple stages can be described as a real "natural choice petri dish".
Frequency of use and
A suitable placement environment for bacteria to multiply
In addition to the structure itself is very suitable for the life of bacteria, we frequently use a dishwashing sponge to provide a continuous supply of "food and water" for the bacteria in it.
Even if we squeeze the dishwashing sponge hard and squeeze it again, there will still be some moisture left inside. And this condition of always being slightly moist is simply too suitable for the growth of bacteria. Every time we wash dishes, some of the food residue enters the sponge when we wipe and scrub it, and it becomes food for bacteria.
The "terrain" is suitable for growth, and the "survival resources" are quite abundant, so it's no wonder that the dishwashing sponge can become a base camp for kitchen bacteria. Once a dishwashing sponge is contaminated in use, microorganisms can multiply rapidly on its surface and inside. Wait, if an unused dishwashing sponge must be clean, then where does the pollution source come from?
The answer may make you uncomfortable – you and the variety of foods you handle in your kitchen, are sources.
Every day in the environment, we are exposed to a large number of microorganisms that attach to the surface of our skin and are transmitted to the various places we touch through contact. Especially in the kitchen environment, raw meat and fresh food will also introduce a lot of microorganisms in and out. When we come into contact with these items and then touch the dishwashing sponge, we pass on microorganisms to it.
For example, if you have a raw egg in your hand, the salmonella on it may get on your hand, and when you pick up the kitchen sponge and are ready to wipe the countertop, the salmonella may use it to burrow into the sponge and establish its own large family in a small room inside.
In addition, when we wash all kinds of food and utensils with microorganisms, splashing water droplets will also spread microorganisms to the entire kitchen environment, and dishwashing sponges are usually placed next to the sink, and the splashed droplets often land on it, so that the bacterial community inside adds another resident.
So, the biggest microbial load in our homes is not the bathroom you think it is, but ...... Kitchen.
When a kitchen sponge becomes a haven for microbes, it not only produces odors, but also transfers various microorganisms to the kitchen surface with each use. Thankfully, most of the bacteria in the dishwashing sponge are not disease-threatening.
But in the rich and large microbial community, there are inevitably a few bad bacteria that can cause bad guys, such as Salmonella, E. coli, Pseudomonas aeruginosa and other harmful bacteria that may affect our health. If the dishwashing sponge is not used properly, these microorganisms may be transmitted to the surface of the food, and if there are pregnant women, the elderly, and children with poor immunity in the family, foodborne diseases may occur.
Clean the dishwashing sponge regularly
Does it really work?
So can regularly cleaning the dishwashing sponge effectively reduce the microbial load inside? It can only be said that the effect is better than nothing.
Researchers have conducted a series of experiments on used kitchen sponges with antibacterial detergents on the market, and the results have been found to ...... Applying dish soap to the surface of a dishwashing sponge on a regular basis, as recommended by the vendor, is not effective in reducing the microbial load in the dishwashing sponge.
The porous structure of the sponge not only provides a good environment for the attachment and growth of bacteria, but also becomes a natural "safe haven". In particular, a long-term dishwashing sponge will form a biofilm on the surface of a dishwashing sponge that inactivates the antimicrobial component when it is regularly replenished with food residues.
In addition, even if we can continue to soak and disinfect with a high concentration of dish soap or alcohol for a long time, or use hot water or microwave oven for high temperature sterilization, it is difficult to reduce the microbial load in the dishwashing sponge to less than half. Once the dishwashing sponge returns to its normal environment, the remaining microorganisms inside will soon grow again.
Do we have to coexist with microbes that may pose a risk? Can't our dishes and chopsticks be "cleaned"?
The easiest and most efficient way is to use the dishwasher directly, so that the dishwasher is no longer needed in the kitchen, and the problem is solved at the root. The process of washing and drying in the dishwasher at high temperature can effectively remove stains and sterilize efficiently.
But if the conditions don't allow it, or you just don't like to use it, you can replace it with the following cleaning products that are relatively less easy to breed bacteria.
- A dishwashing brush is a good choice. The structure of the dishwashing brush is simple, it is not easy to attach microorganisms, and it is easier to dry and clean, which is not so friendly to the reproduction of microorganisms. A comparative experiment found that the levels of bacteria observed in used brushes were lower than in sponges, and that salmonella died faster in brushes.
- Disposable kitchen rags are also good, every time it is a clean cloth, throw it away when it is used up, there is no cross-infection. Even if the traditional cotton rag is not as complex as a dishwashing sponge, it is still a good breeding ground for microorganisms.
- There is also a wood pulp sponge that looks very similar to a dishwashing sponge. The sponge dries quickly after each use – straight to a hard patch, and its large pores and quick-drying properties make it less easy for microorganisms to thrive inside. Even if it's just laid flat, a wood pulp sponge will dry much faster than a regular sponge.
But in any case, as long as it involves reusable cleaning products, no matter how powerful it is, the most important thing is to change it frequently.
Source: Popular Science China, CCTV news client