#bactera

Study determines structure of toxin in respiratory infections

Researchers from the School of Medicine at The University of Texas Health Science Center at San Antonio today revealed the molecular structure of the cytotoxin from Mycoplasma pneumoniae, a widespread, highly contagious bacterium that infects the lungs.

The determination of the structure of the protein, called Community Acquired Respiratory Distress Syndrome (CARDS) toxin, will facilitate drug and vaccine development in asthma and other airway diseases, two members of the research team said. According to the U.S. Centers for Disease Control and Prevention (CDC), 2 million new cases of Mycoplasma pneumoniae infections occur each year in the U.S., but the true extent of the health problem is not known and is probably underestimated.

The finding is in this week's Proceedings of the National Academy of Sciences (PNAS). "We know a lot about how the toxin works, but we did not have its 3-D structure," said corresponding author Joel B. Baseman, Ph.D., professor of microbiology and immunology and director of the Center for Airway Inflammation Research at the UT Health Science Center San Antonio. "The structure shows us the molecular architecture of the protein, which permits the rational design of effective drugs and vaccines to neutralize the injurious effects of CARDS toxin."

A research team has discovered a complex and diverse microbial ecosystem of bacteria and archaea in the waters and sediments of sub-glacial Lake Whillans, lying 800 meters beneath the surface of the West Antarctic ice sheet.

Researcher Dr. Brent Christner says of this discovery: “It is the first definitive evidence that there is not only life, but active ecosystems underneath the Antarctic ice sheet, something that we have been guessing about for decades. Given the prevalence of subglacial water in Antarctica, our data lead us to contend that aquatic microbial systems are common features of the subsurface environment that exists beneath the Antarctic ice sheet.”

This microbial community is dominated by Betaprotoebacteria, Thaumarchaeota, Gammaproteobacteria, Deltaproteobacteria, Actinobacteria, Chloroflexi, and Bacteriodetes, among many others.

14th-century plague bodies unearthed at London station:

The newly discovered Farringdon bodies, just 2.5 metres below the surface, are neatly oriented and were probably wrapped in shrouds and interred: the Crossrail team have found shroud pins but no fabric remains and no sign of coffins. Pottery found at the same depth as the bodies has been dated to before 1350.

The skeletons will now be removed to the Museum of London Archaeology, where radiocarbon dating will determine the approximate age of the bodies. Skeletons discovered in a plague pit in nearby Smithfield yielded DNA markers identifying the plague bacterium Yersinia pestis.

A piece of research (PDF) [was] released Friday morning in the journal Clinical Infectious Diseases 

A team of researchers from Arizona bought meat and poultry in five cities across the United States, tested them for bacteria, and found this: 47 percent of the samples contained the very common pathogen Staphylococcus aureus, and 96 percent of those isolates were resistant to at least one antibiotic. Of more concern: 52 percent of those staph isolates were resistant to at least three antibiotics that are commonly used in both veterinary and human medicine.

That is, roughly one in four packages of meat and poultry from across the United States contained multidrug resistant staph.

Among the types of meat tested, turkey carried the most resistance, with 77 percent of the meat samples showing at least some; that was followed by pork (42 percent), chicken (41 percent) and beef (37 percent). Interestingly, it wasn’t all the same staph. Though there was a great diversity of staph types, each animal species seemed to carry mostly one sequence type or strain of staph: ST1 in pigs, ST5 in chickens and ST398 in turkey. (More on that below.)

We found that each of the meat and poultry types had their own distinctive staph on them. That provides strong evidence that food animals were the primary source of the resistant staph. The source wasn’t human contamination of the meat at slaughter, or when it was packaged for retail sale.”

hat surveillance system doesn’t look for MRSA, and in the past few years, because of those pig findings, there has been a lot of pressure to add MRSA to the list.

But even if we did perform nationwide testing for MRSA in meat, that would not have found the multi-drug resistant strains revealed in Price’s work today — because most of them were not MRSA.

More from the original study:

A new multidrug-resistant S. aureus strain, ST398,has emerged that predominantly colonizes people working in food animal production. First discovered in 2003, ST398 now makes up a substantial proportion of the community-acquired methicillin-resistant S. aureus (MRSA) cases in the Netherlands. Multiple studies have demonstrated the high prevalence of multidrug-resistant S. aureus, including ST398, among intensively raised swine in the European Union, Canada, and the United States, but few studies have been conducted to measure its prevalence in US food products. 

 All isolates were screened against antibiotics that are commonly used to treat severe MRSA infections. We identified 1 vancomycin-intermediate-resistant isolate and 1 daptomycinresistant isolate. Vancomycin, daptomycin, and their analogs were never approved for US food animal production; therefore, these findings were unexpected and may suggest origins other than US food animals.

European and North American studies indicate that ST398 can successfully colonize and infect humans.

Conventional concentrated animal feeding operations (CAFOs) provide all the necessary components for the emergence and proliferation of multidrug-resistant zoonotic pathogens. In the United States, billions of food animals are raised in densely stocked CAFOs, where antibiotics are routinely administered in feed and water for extended periods to healthy animals.