Flesh-Eating Bacterium by beyondandabove

@JackTsuchiyam: Think it might have been this: http://www.ted.com/talks/rob_knight_how_our_microbes_make_us_who_we_are It would mostly shape the early human microbiome. I’m not talking about the gut microbiome, by the way. But the skin flora. When delivering a baby via C-section, it will be in an environment that’s as sterile as possible. Natural childbirth will cover the baby in some of the mum’s microbiota. So that would make sense. (:

Atm I am looking for anything that is remotely related and would give me some experience. I don’t need to be in the lab, tbh, and I lost interest in pursuing a PhD because I want to turn my back to academia. Good luck getting into grad school!
Anyway, a little something on necrotising fasciitis:

Necrotising fasciitis This is what the so-called “flesh-eating” bacteria are generally known for. It is a rare, but life-threatening disease that mostly affects the extremities (hands, feet), perineum and truncal areas. However, any part of the body can be affected.

Most commonly patients present with signs of inflammation, pain and swelling at the site of infection. These are non-specific symptoms, and therefore can lead to a misdiagnosis. In later stages, the skin might become more tense and change its colour to a darkish blue. Then it will progress to necrosis and become haemorrhagic, meaning that the skin at the site of infection will be dead and practically torn open (better not look up pictures if you’re squeamish. They showed us a couple of pictures in our lectures, of course right before lunch).

Thankfully it’s rare and in the UK about 500 cases are reported every year.

When looking at the microbiological nature, most studies show that more than one species of bacteria seem to be involved in necrotising fasciitis. Most cultures result in a mixture of aerobic and anaerobic organisms, this can also depend on the site of infection. For example, the perineum might have a higher proportion of anaerobic bacteria (you could see why). Single pathogen infections can also occur (roughly 15% of the cases).

The most common causative organism is the streptococcus, more specifically M types 1 and 3 (which produce exotoxin A and streptolyisin O). Another variety is toxic shock strains (Group A streptococci, aka GAS, so something like Strep pyogenes). They can result in organ dysfunction along with fasciitis.

– Streptolysin O causes an immune response and is one of the bases of this organism’s beta-haemolytic property (complete lysis of red blood cells).

– Exotoxin A is a superantigen, responsible for the rash in scarlet fever and many of the symptoms related to toxic shock syndrome.

– M proteins of M types 1 and 3 prevent phagocytosis, so white blood cells can’t swoop in and get rid of the bacteria through this process.

There are actually quite a lot of bacteria and organisms in general identified in necrotising soft tissue infections, including GAS, Group B streptococci,Staphylococcus aureus, Bacillus species (think of gangrene), Escherichia coli, and more. The matter can be even more complicated if antibiotic-resistant bacteria are involved.

I read this:

Hasham, Saiidy et al. “Necrotising Fasciitis.” BMJ : British Medical Journal 330.7495 (2005): 830–833. Print.

Sadly, since I’m not a student anymore, my sources are limited thanks to a lot of articles being behind a paywall. Yay.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s