Cellulitis Images with Lymphedema
Wednesday, December 26, 2012
Saturday, December 22, 2012
A Novel Function of MUC18: Amplification of Lung Inflammation during .
Correlation between bacterial L-form infection, expression of HIF-1α/MMP-9 and vasculogenic mimicry in epithelial ovarian cancer
Correlation between L-form , expression of HIF-1α/MMP-9 and vasculogenic mimicry in epithelial ovarian cancer
Pattern Recognition and Host Defense Response to Cryptococcus neoformans.
Friday, December 14, 2012
Review of streptococcal bloodstream at a comprehensive cancer care center, 2000-2011.
Bacterial DNA sequence used to map an infection outbreak
|November 14, 2012 05:51 PM|
For the first time, researchers have used DNA sequencing to help bring an infectious disease outbreak in a hospital to a close.
Researchers from the Wellcome Trust Sanger Institute, the University of Cambridge and Cambridge University Hospitals used advanced DNA sequencing technologies to confirm the presence of an ongoing outbreak of methicillin-resistantStaphylococcus aureus (MRSA) in a Special Care Baby Unit in real time. This assisted in stopping the outbreak earlier, saving possible harm to patients. This approach is much more accurate than current methods used to detect hospital outbreaks.
Using this technology, the team revealed that the outbreak had extended into the wider community, a conclusion that could not be reached with available methods. They also used sequencing to link the outbreak to an unsuspecting carrier, who was treated to eradicate MRSA.
"We are always seeking ways to improve our patient care and wanted to explore the role that the latest sequencing technologies could play in the control of infections in hospitals," says Dr Nick Brown, author, consultant microbiologist at the Health Protection Agency and infection control doctor at Addenbrooke's Hospital Cambridge. "Our aim is to prevent outbreaks, and in the event that they occur to identify these rapidly and accurately and bring them under control.
"What we have glimpsed through this pioneering study is a future in which new sequencing methods will help us to identify, manage and stop hospital outbreaks and deliver even better patient care."
Over a six month period, the hospital infection control team used standard protocols to identify 12 patients who were carrying MRSA. However, this standard approach alone could not give enough information to confirm or refute whether or not an ongoing outbreak was actually taking place.
In this study, the researchers analysed MRSA isolates from these 12 patients with DNA sequencing technology and demonstrated clearly that all the MRSA bacteria were closely related and that this was an outbreak. They also revealed that the outbreak was more extensive than previously realised, finding that over twice as many people were carrying or were infected with the same outbreak strain. Many of these additional cases were people who had recent links to the hospital but were otherwise healthy and living in the community when they developed a MRSA infection.
While this sequencing study was underway, the infection control team identified a new case of MRSA carriage in the Special Care Baby Unit, which occurred 64 days after the last MRSA-positive patient had left the same unit. The team used advanced DNA sequencing to show in real time that this strain was also part of the outbreak, despite the lack of apparent links between this case and previous patients. This raised the possibility that an individual was unknowingly carrying and transmitting the outbreak MRSA strain.
The infection control team screened 154 healthcare workers for MRSA and found that one staff member was carrying MRSA. Using DNA sequencing, they confirmed that this MRSA strain was linked to the outbreak. This healthcare worker was quickly treated to eradicate their MRSA carriage and thus remove the risk of further spread.
"Our study highlights the power of advanced DNA sequencing used in real time to directly influence infection control procedures," says Dr Julian Parkhill, lead author from the Wellcome Trust Sanger Institute. "There is a real health and cost burden from hospital outbreaks and significant benefits to be gained from their prevention and swift containment. This technology holds great promise for the quick and accurate identification of bacterial transmissions in our hospitals and could lead to a paradigm shift in how we manage infection control and practice."
In this instance, DNA sequencing was a key step in bringing the outbreak to a close, saving possible harm to patients and potentially saving the hospital money.
"Our study indicates the considerable potential of sequencing for the rapid identification of MRSA outbreaks," says Professor Sharon Peacock, lead author from the University of Cambridge and clinical specialist at the Health Protection Agency. "What we need before this can be introduced into routine care is automated tools that interpret sequence data and provide readily understandable information to healthcare workers. We are currently working on such a system.
"If we have a robust system of this type in operation when the outbreaks occur, we predict that we will be able to stop them after the first few cases, as we will rapidly find clear connections."
In their next step, the team will study all MRSA carriers and infected patients over the next year in Addenbrooke's Hospital and surrounding hospitals and the community to understand transmission events with the aim of improving infection management.
Sir Mark Walport, Director of the Wellcome Trust, says: "This is a dramatic demonstration that medical genomics is no longer a technology of the future - it is a technology of the here and now. By collaborating with NHS doctors, geneticists have shown that sequencing can have extremely important applications in healthcare today, halting an outbreak of a potentially deadly disease."
Source : Wellcome Trust Sanger Institute
Battling bacteria: Research shows iron's importance in infection, suggests new therapies
The collaborative research—led by Phillip Klebba, professor and head of the department of biochemistry—clarifies how microorganisms colonize animal hosts and how scientists may block them from doing so. The findings suggest new approaches against bacterial disease and new strategies for antibiotic development. The study—in collaboration with Tyrrell Conway, director of the Microarray and Bioinformatics Core Facilities at the University of Oklahoma, and Salete M. Newton, Kansas State University research professor of biochemistry—recently appeared in PLOS ONE. It shows how iron acquisition affects the ability of bacteria to colonize animals, which is the first stage of microbial disease. "This paper establishes that iron uptake in the host is a crucial parameter in bacterial infection of animals," said Klebba, the senior author on the publication. "The paper explains why discrepancies exist about the role of iron, and it resolves them." Iron plays a key role in metabolism, leading bacteria and animals to battle each other to obtain it. Klebba's team found that E. coli must acquire iron from the host to establish a foothold and colonize the gut—a concept that was often debated by scientists. "For years it was theorized that iron is a focal point of bacterial pathogenesis and infectious disease because animals constantly defend the iron in their bodies," Klebba said. "Animal proteins bind iron and prevent microorganisms from obtaining it. This is called nutritional immunity, and it's a strategy of the host defense system to minimize bacterial growth. But successful pathogens overcome nutritional immunity and get the iron." Little was known about what forms of iron enteric bacteria—which are bacteria of the intestines—use when growing in the host, but this study shows that the native Gram-negative bacterial iron uptake systems are highly effective. Scientists questioned whether prevention of iron uptake could block bacterial pathogenesis. This article leaves no doubt about the importance of iron when E. coli colonizes animals because bacteria that were systematically deprived of iron became 10,000-fold less able to grow in host tissues, Klebba said.
"This is the first time our experiments unambiguously verified the indispensability of iron in infection, because here we created the correct combination of mutations to study the problem," Klebba said. Enteric bacteria have so many iron transport systems that it's difficult to eliminate them all. For example, E. coli has at least eight iron acquisition systems. "These transporters are redundant because iron is essential," Klebba said. "Bacteria are resilient. If one system is blocked, then another one takes over." These findings suggest strategies to block microorganisms from creating diseases in animals and humans, including the potential for antibiotic development and for therapeutic antibodies. "It gives us insight," Klebba said. "Now we know that iron deprivation protects against disease, but we must be comprehensive and inhibit multiple systems to completely shut down the microorganisms' ability to obtain the metal." The researchers are using their findings to isolate antibodies that block bacterial iron uptake. This may help animals and humans defend themselves against microbial diseases. "We would like to apply this research and protect people from bacterial infection," Klebba said. "That's one of the focal points of our laboratory." Klebba's research was supported by a $1.25 million grant from the National Institutes of Health. The study was led by Hualiang Pi, Klebba's student at his former institution, the University of Oklahoma. Another Kansas State University collaborator on the project was Lorne Jordan, doctoral student in biochemistry, Toledo, Ohio.