So there was this clickbaitey article I came across the other day about how kitchen sponges are so utterly filthy that you shouldn't be cleaning them at all. Instead, you should be throwing them into the fires of mount doom and replacing them with a new one from the Shire at least every week.

They explained that of the vast number of bacteria residing in a sponge after even just a single use, the toughest and most dangerous tend to survive when you microwave or dish wash the sponge under high temperatures. All you're doing is killing off the weak ones, giving room for the bad stuff to re-colonize and make you sick such as Salmonella and Campylobacter.

I was skeptical, so I decided, what better time to get out the old laser and have a look for myself? My sponge has been used for numerous weeks for washing dishes and surfaces and it's been left on the side since, so I figure it would be a hot bed for all kinds of deadly stuff.

I looked up a typical list of types of bacteria from wikicommons in an attempt to identify what I was going to find:

And, in case I see anything distinct, I grabbed myself this specific water-borne bacteria infographic:

I should say now that this is not the most fool-proof look at bacteria. There's a whole scientific process of bacteria identification that involves more than shining a laser at a drop of water.

But ain't nobody got time for that, so I whipped out the laser and syringe, filled it with juice from the sponge and had a look. Once again I was not disappointed; I saw some weird stuff in there that I didn't see even in saliva, toilet water or the cat's drinking water in previous experiments.

Here's a 2 minute, summarized video of what I found. Images below:

So first up, there's a whole bunch of circular, or 'coccos' bacteria. This has been a running theme in everything I look at, so clearly that's the most ubiquotous type out there.

But then at 5 seconds, 11 seconds and 20 seconds, we see things like this:

There's nothing in the first image that seems to relate, but in the second image, I feel it has a striking resemblance to L, thiospillum, which according to Google should actually be thiospirillum

Definition:

' sulfur bacteria (family Thiorhodaceae) motile by means of polar flagella and common in mud and stagnant water'

Flagella are basically protein structures used as an engine to get the bacteria traveling around, like the tail of a sperm cell.

This sounds right being in stagnant water but I'm not really sure what the lump in the polar regions of my example is, but this is my closest comparison, anyway. There's surprisingly little information here, so I'm going to assume:

NOT DANGEROUS

Next up, at 36 seconds we have what looks like a diplococcus:

Bacteria in this form is quite common and I discovered quite a few that are dangerous, such as Neisseria which includes N. meningitidis and N. gonorrhoeae; Moraxella catarrhalis which can cause a variety of infections and problems; Streptococcus pneumoniae which was 'a major cause of pneumonia in the late 19th century'; and Enterococcus which can cause a range of things like UTI's and meningitis.

So I can't distinguish exactly what this bacteria is, but I'm going to go ahead and consider it:

DANGEROUS, KINDA MAYBE

Moving on to 51 seconds, we start to see some weird-ass stuff:

In the video you can better see that this appears to have a bunch of centipede-like hairs all over it, which is very close in appearance to H, proteus:

##Definition:

'Proteus bacilli are widely distributed in nature as saprophytes, being found in decomposing animal matter, sewage, manure soil, the mamallian intestine, and human and animal feces. They are opportunistic pathogens, commonly responsible for urinary and septic infections, often nosocomial.'

Well, that doesn't sound good does it? But the key work here is 'nosociomial' which means 'acquired in the hospital'. Usually, this only targets those with immunosuppressive conditions already; those very weak to infection to begin with. If that happens, you might get a UTI or some other non-fatal infection.

NOT DANGEROUS (unless you're already very sick)

at 1 minute, we get what seems to be a classic bacilos

The best I can do here is suggest 'proteobacteria' which, according to wikipedia, is such a wide phylum that it doesn't even have a proposed genus. Some of these are of course pathogenic, but I can't say for certain with its overly-generic appearance:

UNKNOWN

Immediately after at 1 minute 2 and another, even bigger one at 1 minute 23, we get some huge, long twisty bacteria:

You can only truly appreciate the length of this one in the video, but I believe this fits nicely into filamentosa bacteria.

Definition:

'Filamentous bacteria are normal components of activated sludge biomass. The existence of some filamentous bacteria is important and helpful for good floc formation to a biomass'

This is simply the definition I found most amusing to be found in a sponge, which you can read more about here. Typically, it seems most filamentous bacteria are not harmful, with some triggering some immune responses in mice but not much else.

To read more about identifying filamentous bacteria you can check here

NOT DANGEROUS, POSSIBLY HELPFUL

So there you have it, almost everything I found in my sponge.

What about the click bait?

Well, if you look at the actual study, it does point out that a sponge is indeed riddled with bacteria in this way, but there's no suggestion that the dangerous pathogenic bacteria thrives and spreads when you wash them. Generally, food bacteria is pretty weak which is why we cook things; it kills them.

Along with the helpful and harmless bacteria on your sponge, the dangerous typically don't survive on a plate after a rinse under some clean water, and microwaving or dishwashing under high temperatures will pretty much knock any dangers out. This is obviously true, or billions of sponge-utilizing humans would be falling ill every week.

Basically, unless you are outrageously immuno-compromised, you have nothing to worry about and just keep doing what you do... maybe replace the sponge more often than I do.

Image Sources:

Types of bacteria: Wiki commons
Bacteria found in Water