Sludge Watch ==> 2 stories - bacteria get sick after sex - flies and spread of disease

[maureen.reilly at sympatico.ca]

Sludgewatch Admin:

You see, the sex life of bacteria is far more interesting than you may have 
imagined.
The promiscuous Salmonella bacterium acquires foreign DNA through 'sex' with 
other bacteria.
The sewage treatment plant is a hot bed of promiscuous sex with antibiotic 
resistant bacteria
from hospitals, vet clinics, etc.

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How bugs avoid getting sick after sex
18.aug.06
Institute of Food Research Media Release
Norwich and Oxford, UK, - Scientists at the Institute of Food Research
in Norwich revealed today how the promiscuous Salmonella bacterium protects 
itself from getting ill after acquiring foreign DNA through "sex" with other 
bacteria. This discovery could lead to the design of new antibiotics to 
fight this killer disease.

Salmonella causes food poisoning and kills around 1 million people worldwide 
every year; it is becoming more difficult to treat with drugs because it 
quickly evolves resistance to antibiotics by swapping genes with other bugs 
during "bacterial sex". These foreign genes help the bacterium because they 
make it infectious and resistant to antibiotics.

Professor Jay Hinton's group at the Institute of Food Research in 
collaboration
withOxford Gene Technology, have discovered that a protein called H-NS 
switches off these incoming genes until they need to be activated - a 
process called gene silencing.
This study, published today in the respected online journal PLoS Pathogens 
shows that without proper control the incoming genes make proteins that are 
toxic for the bacterium. Without H-NS, the bacterium has problems growing 
and can't function properly.

H-NS allows the bacteria to evolve by determining how new pieces of DNA are 
used in Salmonella.
"We may have found the Achilles' Heel for Salmonella bacteria because they 
need this H-NS protein to acquire new skills and become infectious" says Jay 
Hinton, "Salmonella still kills a huge number of people. Discoveries like 
this will help us find new ways of attacking these dangerous bacteria; if we 
can inactivate H-NS, we could discover urgently-needed new antibiotics."
Hinton's team found that H-NS works by coating stretches of the foreign DNA, 
which can be distinguished from Salmonella DNA because it contains a higher 
amount of the molecules adenine and thymine (A and T). H-NS binding stops 
foreign genes producing protein unnecessarily. Once the bacterium has 
invaded a human, the effect of H-NS is blocked and the genes can be switched 
on.
"Gene silencing is well known in plants and animals, but has never been seen 
before in bacteria" Jay Hinton adds, "It looks like H-NS has helped 
Salmonella to evolve to infect humans over the last 10 million years."
The researchers hope that this discovery could lead to a new strategy in the 
fight against drug-resistant "superbugs".


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Sludgewatch Admin:

This story has sludge implications ... since it documents the movement 
offsite from sludge spreading and open air sludge composting sites.

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Flies and cattle blamed for food poisoning rate
18.aug.06
New Zealand Herald
Errol Kiong
http://www.nzherald.co.nz/section/story.cfm?c_id=5&objectid=10396817
A new study which appears in the New Zealand Medical Journal today was cited 
as finding that flies and the proximity of most New Zealand cities to cattle 
are to sblame for the country's astoundingly high rate of campylobacter food 
poisonings, and eating chicken is also a "significant risk factor."
The study warns that takeaway chicken meals are particularly risky if food 
is eaten without washing hands.
However the paper concludes that the sporadic nature of campylobacter 
illnesses and the seasonal pattern of infection, which peaks in warmer 
months, indicate that chicken meat itself is not the major source of 
infection.
The story explains that last month an Otago University study suggested that 
90 per cent of fresh chicken sold was contaminated with campylobacter.
New Zealand has a high rate of campylobacteriosis with up to 14,000 reported 
cases annually.
Laboratory scientist Ben Harris, who co-wrote the paper with research 
consultant Warrick Nelson, were cited as reporting that the occurrence of 
the illness is between 10 and 20 times higher than reported because most 
people don't report food poisoning.
Mr Harris was quoted as saying, "As soon as the temperature increases, the 
human campylobacter rates increase ... too."
The bacteria is transferred through fly faecal deposits on common surfaces 
such as hand rails and door handles. Campylobacter deposited on fingertips 
can survive for at least an hour, and have been recovered from dry surfaces 
24 hours after being deposited.
Mr Harris was further cited as saying poisonings are also caused by poor 
food preparation practices or improperly cooked chicken, adding, "Many 
people actually don't cook it all the way through, or if it's a stuffed 
chicken, it's harder to cook it all the way through. So you often think, if 
you can have a rare steak, why can't you have a rare chicken? The reason is 
the steak does not have an intestine. There is no campylobacter in the 
middle of the steak ... There is in the middle of the chicken. The poultry 
industry will say if you cook it properly you won't have any campylobacter. 
That's quite true, but in practice ... preparation methods are not good 
enough to handle something that's got large numbers of campylobacter on it."

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