In Ontario, numbers for August show there were 319 cases of C.difficile, a deadly form of infectious diarrhea, found among the 228 hospital sites in Ontario. The provincial C.diff rate was 0.39 per 1,000 patient days.
Information from patientsafetyontario.net.
Monday, October 6, 2008
Disinfectants Can Make Bacteria Resistant To Treatment
Chemicals used in the environment to kill bacteria could be making them stronger, according to a paper published in the October issue of the journal Microbiology. Low levels of these chemicals, called biocides, can make the potentially lethal bacterium Staphylococcus aureus remove toxic chemicals from the cell even more efficiently, potentially making it resistant to being killed by some antibiotics.
Biocides are used in disinfectants and antiseptics to kill microbes. They are commonly used in cleaning hospitals and home environments, sterilizing medical equipment and decontaminating skin before surgery. At the correct strength, biocides kill bacteria and other microbes. However, if lower levels are used the bacteria can survive and become resistant to treatment.
"Bacteria like Staphylococcus aureus make proteins that pump many different toxic chemicals out of the cell to interfere with their antibacterial effects," said Dr Glenn Kaatz from the Department of Veterans Affairs Medical Center in Detroit, USA. "These efflux pumps can remove antibiotics from the cell and have been shown to make bacteria resistant to those drugs. We wanted to find out if exposure to biocides could also make bacteria resistant to being killed by the action of efflux pumps."
The researchers exposed S. aureus taken from the blood of patients to low concentrations of several biocides and dyes, which are also used frequently in hospitals. They looked at the effect of exposure on the bacteria and found that mutants that make more efflux pumps than normal were produced.
"We found that exposure to low concentrations of a variety of biocides and dyes resulted in the appearance of resistant mutants," said Dr Kaatz. "The number of efflux pumps in the bacteria increased. Because the efflux pumps can also rid the cell of some antibiotics, pathogenic bacteria with more pumps are a threat to patients as they could be more resistant to treatment."
If bacteria that live in protected environments are exposed to biocides repeatedly, for example during cleaning, they can build up resistance to disinfectants and antibiotics. Such bacteria have been shown to contribute to hospital-acquired infections.
"Scientists are trying to develop inhibitors of efflux pumps. Effective inhibitors would reduce the likelihood of additional resistance mechanisms emerging in bacteria," said Dr Kaatz. "Unfortunately, inhibitors evaluated to date do not work on a wide range of pathogens so they are not ideal to prevent resistance."
"Careful use of antibiotics and the use of biocides that are not known to be recognised by efflux pumps may reduce the frequency at which resistant strains are found," said Dr Kaatz. "Alternatively, the combination of a pump inhibitor with an antimicrobial agent or biocide will reduce the emergence of such strains and their clinical impact."
--------------------------------------------------------------------------------
Adapted from materials provided by Society for General Microbiology, via EurekAlert!, a service of AAAS.
Source - Science Daily
Biocides are used in disinfectants and antiseptics to kill microbes. They are commonly used in cleaning hospitals and home environments, sterilizing medical equipment and decontaminating skin before surgery. At the correct strength, biocides kill bacteria and other microbes. However, if lower levels are used the bacteria can survive and become resistant to treatment.
"Bacteria like Staphylococcus aureus make proteins that pump many different toxic chemicals out of the cell to interfere with their antibacterial effects," said Dr Glenn Kaatz from the Department of Veterans Affairs Medical Center in Detroit, USA. "These efflux pumps can remove antibiotics from the cell and have been shown to make bacteria resistant to those drugs. We wanted to find out if exposure to biocides could also make bacteria resistant to being killed by the action of efflux pumps."
The researchers exposed S. aureus taken from the blood of patients to low concentrations of several biocides and dyes, which are also used frequently in hospitals. They looked at the effect of exposure on the bacteria and found that mutants that make more efflux pumps than normal were produced.
"We found that exposure to low concentrations of a variety of biocides and dyes resulted in the appearance of resistant mutants," said Dr Kaatz. "The number of efflux pumps in the bacteria increased. Because the efflux pumps can also rid the cell of some antibiotics, pathogenic bacteria with more pumps are a threat to patients as they could be more resistant to treatment."
If bacteria that live in protected environments are exposed to biocides repeatedly, for example during cleaning, they can build up resistance to disinfectants and antibiotics. Such bacteria have been shown to contribute to hospital-acquired infections.
"Scientists are trying to develop inhibitors of efflux pumps. Effective inhibitors would reduce the likelihood of additional resistance mechanisms emerging in bacteria," said Dr Kaatz. "Unfortunately, inhibitors evaluated to date do not work on a wide range of pathogens so they are not ideal to prevent resistance."
"Careful use of antibiotics and the use of biocides that are not known to be recognised by efflux pumps may reduce the frequency at which resistant strains are found," said Dr Kaatz. "Alternatively, the combination of a pump inhibitor with an antimicrobial agent or biocide will reduce the emergence of such strains and their clinical impact."
--------------------------------------------------------------------------------
Adapted from materials provided by Society for General Microbiology, via EurekAlert!, a service of AAAS.
Source - Science Daily
HIV/AIDS Emerged as Early as 1880s
October 1, 2008
The AIDS pandemic in humans originated at least three decades earlier than previously thought, and it may have been triggered by rapid urbanization in west-central Africa during the early 20th century, according to an international team of researchers.
A better understanding of the conditions that helped fuel the pandemic could be key in controlling the disease and preventing future outbreaks of other emerging viruses.
"Rapid urbanization was the turning point that allowed the pandemic to start," said Michael Worobey, an evolutionary biologist at the University of Arizona, Tucson, and lead author of the study.
"We as human beings made some changes that took a virus that could not exist on its own and turned it into a successful epidemic," he added.
Birth of AIDS
Until now it was thought that HIV-1 Group M, the strain of HIV that causes the most infections worldwide, originated in 1930 in Cameroon.
Epidemic levels of AIDS and HIV-1 infections started appearing in Leopoldville, Belgian Congo (now Kinshasa, Democratic Republic of the Congo), around 1960.
Findings from the new study, however, suggest that the virus most likely started circulating among humans in sub-Saharan Africa sometime between 1884 and 1924.
Worobey and his colleagues made the discovery while analyzing tissue samples collected between 1958 and 1960 from Kinshasa. One of them, acquired in 1960, contained bits of HIV-1 RNA, the virus's genetic material.
The researchers compared the 1960 virus with the oldest known HIV-1 strain, which was obtained in 1959 and evolved independently of the 1960 variant. They found that the 1960 version was significantly different.
Next the researchers constructed an evolutionary family tree of the HIV-1 virus, made up of both the 1959 and 1960 strains along with more than a hundred modern viral sequences.
Using a mathematical model, Worobey and his colleagues discovered that the 1960 strain must have been evolving for at least 40 years to account for the number of differences from the 1959 strain.
The model also traced the most recent common ancestor of both strains to 1908.
The team's findings appear today in the journal Nature.
Lurking Danger
"This confirms that this was a virus that was lurking around for many decades before it exploded into the human population to become a noticeable pandemic, as opposed to something that started in the '70s or '80s," said Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases (NIAID), in Maryland.
NIAID funded the study along with the National Institutes of Health.
"It solidifies our understanding of the timetable of how this virus emerged from the chimpanzees to establish itself as a human infection," Fauci added.
"[HIV-1] flew below the radar level for decades until social conditions such as the end of colonization, migration of people to cities, increase in prostitution, and promiscuous sexual activity made it much easier for the disease to explode into a pandemic," Fauci explained.
More Mutations
Robert Garry is a microbiologist at New Orleans's Tulane University who was not involved with the study.
In the late 1980s, Garry was the first scientist to examine tissues samples taken from the U.S.'s first confirmed AIDS patient, who died in 1969.
"This study is very important, and what they are finding here is when the human virus started circulating in people," he said. "We still don't know when exactly the virus jumped from chimpanzees to humans, but it may be pushed back even further with this study.
"There will be other emerging viruses in the future, and what we learn about the conditions that help viruses spread, be it social changes or changes within the virus itself, will make us better prepared for other epidemics," he said.
Garry also argues that, though the rapid growth of cities in west-central Africa may have sparked the spread of infections, the virus itself underwent some sort of genetic change to facilitate transmission.
"We have to figure out what that change was," he cautioned.
Source:Amitabh Avasthi - National Geographic News
The AIDS pandemic in humans originated at least three decades earlier than previously thought, and it may have been triggered by rapid urbanization in west-central Africa during the early 20th century, according to an international team of researchers.
A better understanding of the conditions that helped fuel the pandemic could be key in controlling the disease and preventing future outbreaks of other emerging viruses.
"Rapid urbanization was the turning point that allowed the pandemic to start," said Michael Worobey, an evolutionary biologist at the University of Arizona, Tucson, and lead author of the study.
"We as human beings made some changes that took a virus that could not exist on its own and turned it into a successful epidemic," he added.
Birth of AIDS
Until now it was thought that HIV-1 Group M, the strain of HIV that causes the most infections worldwide, originated in 1930 in Cameroon.
Epidemic levels of AIDS and HIV-1 infections started appearing in Leopoldville, Belgian Congo (now Kinshasa, Democratic Republic of the Congo), around 1960.
Findings from the new study, however, suggest that the virus most likely started circulating among humans in sub-Saharan Africa sometime between 1884 and 1924.
Worobey and his colleagues made the discovery while analyzing tissue samples collected between 1958 and 1960 from Kinshasa. One of them, acquired in 1960, contained bits of HIV-1 RNA, the virus's genetic material.
The researchers compared the 1960 virus with the oldest known HIV-1 strain, which was obtained in 1959 and evolved independently of the 1960 variant. They found that the 1960 version was significantly different.
Next the researchers constructed an evolutionary family tree of the HIV-1 virus, made up of both the 1959 and 1960 strains along with more than a hundred modern viral sequences.
Using a mathematical model, Worobey and his colleagues discovered that the 1960 strain must have been evolving for at least 40 years to account for the number of differences from the 1959 strain.
The model also traced the most recent common ancestor of both strains to 1908.
The team's findings appear today in the journal Nature.
Lurking Danger
"This confirms that this was a virus that was lurking around for many decades before it exploded into the human population to become a noticeable pandemic, as opposed to something that started in the '70s or '80s," said Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases (NIAID), in Maryland.
NIAID funded the study along with the National Institutes of Health.
"It solidifies our understanding of the timetable of how this virus emerged from the chimpanzees to establish itself as a human infection," Fauci added.
"[HIV-1] flew below the radar level for decades until social conditions such as the end of colonization, migration of people to cities, increase in prostitution, and promiscuous sexual activity made it much easier for the disease to explode into a pandemic," Fauci explained.
More Mutations
Robert Garry is a microbiologist at New Orleans's Tulane University who was not involved with the study.
In the late 1980s, Garry was the first scientist to examine tissues samples taken from the U.S.'s first confirmed AIDS patient, who died in 1969.
"This study is very important, and what they are finding here is when the human virus started circulating in people," he said. "We still don't know when exactly the virus jumped from chimpanzees to humans, but it may be pushed back even further with this study.
"There will be other emerging viruses in the future, and what we learn about the conditions that help viruses spread, be it social changes or changes within the virus itself, will make us better prepared for other epidemics," he said.
Garry also argues that, though the rapid growth of cities in west-central Africa may have sparked the spread of infections, the virus itself underwent some sort of genetic change to facilitate transmission.
"We have to figure out what that change was," he cautioned.
Source:Amitabh Avasthi - National Geographic News
Subscribe to:
Posts (Atom)
