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Diseases

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Jenny
46026.  Mon Jan 16, 2006 12:58 pm Reply with quote

What's in it for disease-causing microbes?

The same as for everything else - reproduction. Symptoms like vomiting, sneezing and diarrhoea are excellent methods of spreading itself from one host to another.

The well-being of their hosts is only of concern to them when they kill you too efficiently. Many a careless microbe has found itself disappearing when this happens - Jared Diamond cites the English sweating sickness that raged from 1485 to 1552, killing thousands, and then disappeared.

 
Jenny
46027.  Mon Jan 16, 2006 1:01 pm Reply with quote

Do we dare talk about antibiotic-resistant bacteria at this point? Such as the streptococcus bacteria that normally do no more than give us a sore throat but when they get into the bloodstream can cause the dreadful necrotising fasciitis, which is completely resistant to antibiotics. There are about a thousand cases a year in the USA.

 
garrick92
46241.  Tue Jan 17, 2006 10:22 am Reply with quote

Never mind that, why are they protecting the identity of this mass-murderer 'Mrs A' who I keep reading about?

It's a disgrace.

 
garrick92
46258.  Tue Jan 17, 2006 10:55 am Reply with quote

Oooh, I can feel my inoculation rant coming on ...

 
Tas
46259.  Tue Jan 17, 2006 10:56 am Reply with quote

Ooh....rant for us Garrick92!!!! Rant for us!

:-)

Tas

 
Stressed parent
48149.  Sat Jan 28, 2006 5:33 pm Reply with quote

I found this:

Quote:
While microbes that cause infectious diseases are virulent, opportunistic diseases may also be caused by normally benign microbes. Opportunistic infections occur when the host defense mechanisms are impaired, microbes are present in large numbers, or when microbes reach vulnerable body sites. A striking example is HIV which impairs the host's defenses to multiple microbes. Because death or severe impairment of an infected host compromises the survival of the infecting microbe, natural selection favors a predominance of less virulent microorganisms, except when microbial transmission depends on disease manifestations (e.g., coughing and sneezing


Source: http://gsbs.utmb.edu/microbook/

Another site :
http://www.slic2.wsu.edu:82/hurlbert/micro101/pages/Chap13.html#Virulence_determinants


It seems that some pathogens are more virulent in space to...
http://www.nasa.gov/vision/earth/livingthings/01dec_yeast.html

 
Celebaelin
48162.  Sat Jan 28, 2006 7:49 pm Reply with quote

Jenny wrote:
Do we dare talk about antibiotic-resistant bacteria at this point? Such as the streptococcus bacteria that normally do no more than give us a sore throat but when they get into the bloodstream can cause the dreadful necrotising fasciitis, which is completely resistant to antibiotics. There are about a thousand cases a year in the USA.

I think the problem with necrotising fasciitis is that its onset is so rapid (hours) that antibiotics are of little use, the dosage required to halt bacterial reproduction would be lethal to the patient as well. Amputation/excision of infected areas is the only answer currently. It is not necessarily anti-biotic resistant, not that it would currently make much difference if it was.

It's caused by a normally quite harmless bacterium getting into an unusual place through a skin breach. IIRC it breaks down the connective layer between two tissue types (the fascia) and spreads rapidly along the gap thus created breaking down the surrounding tissue, hence the name.

Quote:
FASCIA [fascia] , fibrous tissue network located between the skin and the underlying structure of muscle and bone. Fascia is composed of two layers, a superficial layer and a deep layer. Superficial fascia is attached to the skin and is composed of connective tissue containing varying quantities of fat. It is especially dense in the scalp, the back of the neck, and the palms of the hands, where it serves to anchor the skin firmly to underlying tissues. In other areas of the body it is loose and the skin may be moved freely back and forth. Deep fascia underlies the superficial layers, to which it is loosely joined by fibrous strands. It is thin but strong and densely packed, and serves to cover the muscles and to partition them into groups.

http://www.encyclopedia.com/html/f1/fascia.asp

 
gerontius grumpus
48195.  Sun Jan 29, 2006 7:33 am Reply with quote

Not only is the loathsome Mrs A. protectedby anonymity, there is also a widespread campaign to cloud the issue with irrelevant precautions and general misunderstanding.

The advice from the microbiologists is that MRSA bacteria do not survive for long on dry, non-living surfaces, however dirty they may be but they thrive and remain infective on hands and moist areas of skin such as under wrist watch straps.

Before Christmas, hospitals banned decorations "because they could harbour MRSA"

In the summer nurses were disciplined for being seen sitting on the grass outside where they could come into contact with the soil "and carry MRSA into the hospital".

Just a few weeks ago there was a big news item about angry members of the public who went into hospitals without permission and cleaned corridors and waiting areas "to help beat MRSA".

Whilst it is essential to maintain high standards of hygiene and keep hospitals clean, none of these example have anything to do with MRSA.

Oh yes and while I'm in rant mode, when will newsreaders stop talking about the "MRSA virus"?

 
Caradoc
48288.  Sun Jan 29, 2006 6:48 pm Reply with quote

gerontius grumpus wrote:
Oh yes and while I'm in rant mode, when will newsreaders stop talking about the "MRSA virus"?


At least they are not calling them germs or bugs.

 
gerontius grumpus
48289.  Sun Jan 29, 2006 6:53 pm Reply with quote

In a way germs or bugs would be better because they would just be dumbing down instead of getting it wrong.

this opens up the question; is it better to dumb down or to be wrong?

 
Caradoc
48300.  Sun Jan 29, 2006 7:43 pm Reply with quote

I think on balance wrong is better than dumbed down, I'd rather someone say Bull instead of cow than moo-cow.

 
gerontius grumpus
48301.  Sun Jan 29, 2006 7:49 pm Reply with quote

Hmm.. moo cow is a bit too dumb, I'm not sure about germ though. Bug is, of course, right out.

I still think virus is too wrong to be better than dumb.

 
Celebaelin
48304.  Sun Jan 29, 2006 10:50 pm Reply with quote

As someone with a fair amount of microbiological experience if I want to call a bacterium a bug in order to sound non-technical then I damn well will (and often do). If there's any confusion about what is intended then that's easily addressed but in context it's not a mistake anyone could easily make - it's comparable to leaving the apostrophe out in its', by convention if there isn't one before the s then it must be possessive (its as a plural is not considered, and in fairness is very rare).

On the one hand we are criticised for making science inaccessible and on the other we're berated for terminological inexactitude. Stuff that for a lark; I know damn well what it is, and how it works come to that, but in a situation where youíre communicating an idea it's the approach that's of importance not the jargon. Iíd far rather someone understood a general principle than knew the difference between Saccharomyces and Saccharopolyspora. If itís technical information you want you can look that up in a book, comprehension is a bit rarer.

I agree with gg about the misuse of 'virus'. Vehemently so in fact.

 
gerontius grumpus
48435.  Mon Jan 30, 2006 6:18 pm Reply with quote

In last week's episode of Eleventh hour, Captain Piccard...sorry, Patrick Stewart was looking at viruses through a microscope.

 
Gray
48486.  Tue Jan 31, 2006 5:44 am Reply with quote

Heh - one for the 'Things That Only Happen In Movies' thread. It could have been a portable scanning electron microscope, maybe?

 

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