pathogenicity

buzzfeed.com
Top Pathogens To Watch Out For and What They Do
The World Health Organization (WHO) brought together experts in human and animal health, epidemiology, applied mathematics as well as relevant researchers and clinicians to identify severe emerging diseases with potential to generate a public health emergency just like what Ebola did in 2014. Do you know which ones made it to the list?
By Dr Melvin Sanicas

You’ve heard a lot about Ebola and Zika but these are the other dangerous emerging pathogens, according to WHO. You may not know their names, but health officials and experts are concerned about the epidemic potential of these viruses. 

nature.com
Collapse of Aztec society linked to catastrophic salmonella outbreak
DNA of 500-year-old bacteria is first direct evidence of an epidemic — one of humanity's deadliest — that occurred after Spanish conquest.

One of the worst epidemics in human history, a sixteenth-century pestilence that devastated Mexico’s native population, may have been caused by a deadly form of salmonella from Europe, a pair of studies suggest.

In one study, researchers say they have recovered DNA of the stomach bacterium from burials in Mexico linked to a 1540s epidemic that killed up to 80% of the country’s native inhabitants. The team reports its findings in a preprint posted on the bioRxiv server on 8 February1.

This is potentially the first genetic evidence of the pathogen that caused the massive decline in native populations after European colonization, says Hannes Schroeder, an ancient-DNA researcher at the Natural History Museum of Denmark in Copenhagen who was not involved in the work. “It’s a super-cool study.”

Dead bodies and ditches

In 1519, when forces led by Spanish conquistador Hernando Cortés arrived in Mexico, the native population was estimated at about 25 million. A century later, after a Spanish victory and a series of epidemics, numbers had plunged to around 1 million.

The largest of these disease outbreaks were known as cocoliztli (from the word for ‘pestilence’ in Nahuatl, the Aztec language). Two major cocoliztli, beginning in 1545 and 1576, killed an estimated 7 million to 18 million people living in Mexico’s highland regions.

“In the cities and large towns, big ditches were dug, and from morning to sunset the priests did nothing else but carry the dead bodies and throw them into the ditches,” noted a Franciscan historian who witnessed the 1576 outbreak.

There has been little consensus on the cause of cocoliztli — although measles, smallpox and typhus have all been mooted. In 2002, researchers at the National Autonomous University of Mexico (UNAM) in Mexico City proposed that a viral haemorrhagic fever, exacerbated by a catastrophic drought, was behind the carnage2. They compared the magnitude of the 1545 outbreak to that of the Black Death in fourteenth-century Europe.

Bacterial genomics

In an attempt to settle the question, a team led by evolutionary geneticist Johannes Krause at the Max Planck Institute for the Science of Human History in Jena, Germany, extracted and sequenced DNA from the teeth of 29 people buried in the Oaxacan highlands of southern Mexico. All but five were linked to a cocoliztli that researchers think ran from 1545 to 1550.

Ancient bacterial DNA recovered from several of the people matched that of Salmonella, based on comparisons with a database of more than 2,700 modern bacterial genomes.

Further sequencing of short, damaged DNA fragments from the remains allowed the team to reconstruct two genomes of a Salmonella enterica strain known as Paratyphi C. Today, this bacterium causes enteric fever, a typhus-like illness, that occurs mostly in developing countries. If left untreated, it kills 10–15% of infected people.

It’s perfectly reasonable that the bacterium could have caused this epidemic, says Schroeder. “They make a really good case.” But María Ávila-Arcos, an evolutionary geneticist at UNAM, isn’t convinced. She notes that some people suggest that a virus caused the cocoliztli, and that wouldn’t have been picked up by the team’s method.

The question of origin

Krause and his colleagues’ proposal is helped by another study posted on bioRxiv last week, which raises the possibility that Salmonella Paratyphi C arrived in Mexico from Europe3.

A team led by Mark Achtman, a microbiologist at the University of Warwick in Coventry, UK, collected and sequenced the genome of the bacterial strain from the remains of a young woman buried around 1200 in a cemetery in Trondheim, Norway. It is the earliest evidence for the now-rare Salmonella strain, and proof that it was circulating in Europe, according to the study. (Both teams declined to comment on their research because their papers have been submitted to a peer-reviewed journal.)

“Really, what we’d like to do is look at both strains together,” says Hendrik Poinar, an evolutionary biologist at McMaster University in Hamilton, Canada. And if more ancient genomes can be collected from Europe and the Americas, it should be possible to find out more conclusively whether deadly pathogens such as Salmonella arrived in the New World from Europe.

The existence of Salmonella Paratyphi C in Norway 300 years before it appeared in Mexico doesn’t prove that Europeans spread enteric fever to native Mexicans, says Schroeder, but that hypothesis is reasonable. A small percentage of people infected with Salmonella Paratyphi C carry the bacterium without falling ill, so apparently healthy Spaniards could have infected Mexicans who lacked natural resistance.

Paratyphi C is transmitted through faecal material, and a collapse of social order during the Spanish conquest might have led to the poor sanitary conditions that are ripe for Salmonella spread, Krause and his team note in the paper.

Krause’s study offers a blueprint for identifying the pathogens behind ancient outbreaks, says Schroeder. His own team plans to look for ancient pathogens in Caribbean burial sites that seem to be linked to catastrophic outbreaks, and that were established after the Europeans arrived. “The idea that some of them might have been caused by Salmonella is now a distinct possibility,” he says.

Today I learned that one of the toxin gene names (mcf) of the bioluminescent insect pathogen Photorhabdus luminescens stands for “makes caterpillars floppy”

The drug-resistant bacteria that pose the greatest health threats

The World Health Organization (WHO) has for the first time released a list of drug-resistant bacteria that pose the greatest threat to human health — and for which new antibiotics are desperately needed. The agency’s aim in listing these ‘priority pathogens’ is to steer funds towards development of the most crucial antimicrobials. Researchers say the list is a useful reminder of the danger of bacteria that are becoming resistant to antibiotics.

The list ranks 12 bacteria or bacterial families and is topped by carbapenem-resistant Acinetobacter baumannii. This obscure bacterium causes a severe infection for which almost no treatments exist, and mainly affects people who are already critically ill. (It is resistant to carbapenem antibiotics, a ‘last resort’ antibiotic used only when all other treatments have failed.) The ranking also includes well-known bacteria, such as those that cause  pneumonia and gonorrhoea (see ’Threat list’).

Antibiotic resistance kills an estimated 700,000 people each year worldwide, and some experts predict that number to reach 10 million by 2050 if efforts are not made to curtail resistance or develop new antibiotics. Despite an urgent need for these drugs, the once-robust development pipeline for antibiotics now produces little more than a trickle of compounds. As of September 2016, about 40 new antibiotics were in clinical development for the US market, compared with hundreds of cancer drugs.

Carbapenem-resistant Acinetobacter baumannii tops the the World Health Organization’s 'priority pathogens’ list. CDC/Science Photo Library

let’s play a game called Why is Bones on the Bridge?

  • an actual medical emergency
  • he was bored
  • he wanted to make sure Jim was behaving
  • he needed his daily dose of argue with Spock time
  • to see a first contact
  • to show off his awesome juggling skills
  • a pathogen that turns people blue has swept the ship and the bridge is the only place not contaminated
  • to stab Jim with hypos
  • to gossip
  • he’s just there to look pretty

subversivegrrl  asked:

Is there actually any correlation between exposure and illness? Like, if a healthy person was out in the elements (let's say overnight temperatures in the 40s) without adequate clothing or gear, what's the likelihood of developing pneumonia or bronchitis?

Hey there! Your question is a really good one, and it’s a trope we see a lot in fiction.

The short answer is basically no, your character cannot develop pneumonia or bronchitis from being outside in the cold for a few hours. They’ll have a pretty rough night, but you won’t die of pneumonia.

The long answer is: these are pathogens. Bronchitis is usually viral, pneumonia is usually bacterial. Your character has to come into contact with the virus / bacteria in order to become infected with them.

However, there is some evidence that cold exposure in the short term suppresses the immune system in the nasal passages, but only while the person is exposed to the cold. So it’s possible that if they come into contact with a rhinovirus (that causes the common cold) during this time, it may get a chance to take a foothold in the nasal passages.

But bronchitis and pneumonia work much deeper down in the chest, where it’s a lot warmer.

So the odds of them developing a crappy night? 100%.

The odds of them developing pneumonia? Practically nil.

Hope this helped!

xoxo, Aunt Scripty

disclaimer    

Space Australia

you know that post that goes around talking about how alien life would be afraid of earth and its crazy oxygen breathing lifeforms?

I need to write a one-shot about Hal Jordan explaining to a young Superman that earth is actually an extremely gross hella toxic hell world for alot of other alien life forms out there. Sure,alien invasions are happening all the time, but no one wants this pathogenic shit hole. Nah.

“Okay,” Supes would say, “but if we’re such a lousy planet, why do we have like two Green Lanterns? How come so many threats end up out here?”

And Hal gets all cagey like “Look, man, don’t be mad but 99% of the reason bad dudes come to this planet is because its like space Australia. Lanterns think it’s funny to like… trick bad guys into coming out here so they either get wiped out by some mutated super virus or a tropical storm or something.”

Supes just like, “Lobo doesn’t seem like he’d be bothered by a storm.”

“Right, well, if the storms don’t get them, then the statistically improbable Kryptonian roided out on yellow sunlight certainly will…”

“Do not send dangerous criminals to Earth to fight me! And I am not ‘roided out’. Is that what you’re telling people?!”

“They never see it coming. It’s like intergalactic Thunder Dome.”

“Hal!”

WHY DON'T THEY SAY ANYTHING?!

Okay, so I work at a golf course and I am one of the 2 female employees, so I use the women’s bathroom. (yay cleaner facilities and less traffic.) 99.9% of our customers are male. So, I have been job hunting and got bloodborne pathogen training for a job I was applying for. Unfortunately, I did not get the job.

However!!

The other day, I was working the closing shift and male customers had been in and out of the bathroom all day, so at the end of the day, I go in to clean it.

THERE IS BLOOD EVERYWHERE.

I mean, the sink, the floor, and in the trash can…

I was taken by surprise because I normally have the standard unflushed urinal, pubes, and the sanitizing to do.

I rushed out, grabbed proper equipment to clean it and wondered why NONE OF THE CUSTOMERS SAID ANYTHING.

All the men that had walked past me to get to the bathroom had no apparent injuries. So they used a bloodied bathroom and didn’t bother reporting it to me so I could clean it!

2

The Raising of Chicago

During the early history of Chicago, the city was often plagued by epidemic diseases such as typhoid fever, yellow fever, cholera, and dysentery.  The main cause of this was due to the fact that the elevation of the city was not that much higher than the shoreline of Lake Michigan. As a result, the city suffered from poor drainage and sewage systems as water could not flow downhill, causing Chicago streets to be filled with large pools of standing water which harbored pathogens and parasites.  Flooding was also very common.  By the late 1850’s, it was clear that something had to be done as the city continued to grow, worsening the problem.

In 1856 an engineer named Ellis S. Chesbrough submitted a plan to solve the problem by building a new sewage and drainage system.  An ambitious project, the key to the new plan was to literally raise the entire city around 4-7 feet, working systematically, building by building, block by block.  Work began in early 1858 with the lifting of a four story, 750 ton brick building to a new elevation of 6 feet, 2 inches with the aid of 200 jackscrews. Over the next year, 50 other buildings were likewise lifted, with hundreds of thousands of tons of soil and concrete laid to form a new foundation for the city. In 1861 the 1 acre large Tremont House Hotel was raised six feet using 5,000 jackscrews (top picture).  The Hotel continued to operate throughout the work, housing many guests including several VIP’s and a US Senator.  The following year the 27,000 ton Robbins Building was lifted more than two feet, all the while businesses and shops continued to operate out of the building.  The most impressive feat was the lifting of half of a city block located between Clark Street and LaSalle Street.  This included several 4 and 5 story brick buildings as well as the streets and sidewalk. Conducted by a team of six engineers (including Brown Hollingsworth and George Pullman) directing a crew of six hundred men, the entire half block was lifted 4 feet 8 inches using 6,000 jackscrews (bottom picture).

Work continued throughout the 1860’s, by the end of the decade it was mostly completed, with hundreds of buildings raised or moved completely.  The new sewage and drainage system mostly solved Chicago’s health and sanitation problems.  However pollution and sewage from the rapidly growing industrial city devastated Lake Michigan.

Pascale Cossart (b. 1948) is a French bacteriologist, working for the Pasteur Institute of Paris. She is a world authority on the deadly pathogen Listeria monocytogenes, the cause of diseases such as meningitis and encephalitis.

She obtained a PhD from the University of Paris, and went on to become a Professor there. Her research analysed the behaviour of the Listeria bacteria in different conditions, and has also led to the development of important biological tools.

2

When some young lovers walk along the trail in a park, they might have the urge to carve their names/initials and a heart within as a cute expression of their love that could outlast their lifetime. Sometimes cut a little too deep and remove the bark entirely when tracing a heart. In hiking culture, this is considered a dick move who believe in “Leave No Trace Behind”. It damages the tree by disrupting its flow of nutrients and expose itself to insects who could carry pathogens. As a complete ‘homebody’, I found this information new and influenced to rethink trees as flesh. Delicious flesh trees.

my madding thoughts

the falling of the sienna sky
into a cauterized tomb
of sleeping
souls
is
the
thought
that i am
here & now
while the future
stirs my mornings into
an alignment
of a path of
a modern
poet as
this
is
a
strut
where reality
dissipates into
the bridal suite
and
sparks
will
fly
into the
lunacy
of the
pathogens
of the
murmurations
of a kindred
ghost (that i am)
as demons echo
through hot undercurrents
of burning feet & timid eyes -

… and the asylum walks towards me …