Profile cover photo
Profile photo
Vincent Racaniello
10,157 followers -
Professor, virus guru, science podcaster and blogger
Professor, virus guru, science podcaster and blogger

10,157 followers
About
Posts

Post has attachment
On the latest episode of the science podcast This Week in Virology, we continue our monthly series on the viruses that you can see in the Smithsonian's Outbreak Exhibit. Today we discuss Ebola viruses, covering their nomenclature and molecular biology. Next, Rich is pumped to cover a paper on his beloved vaccinia virus. The topic are the many membrane proteins of the virus particle. Some are needed for attachment to cells, others are needed for fusion with cell. membranes. Using super-resolution microscopy and computational methods, the authors can identify the location of these glycoproteins on single virus particles. The big surprise: the proteins required for fusion are located on the tips of the virus particles (which are pillow-shaped), and the attachment proteins are on the sides. Form follows function at nanoscale.
Add a comment...

Post has attachment
On the latest episode of the science podcast Immune, Cindy and I reveal the construction of a gene network that programs mammalian cells to detect and eliminate bacterial infections. The authors introduce into cells a series of genes that detect the presence of Staphylococcus aureus (via toll-like receptors). When bacteria are present, TLR sensing leads to the production of lysostaphin, a protein that kills the bacteria. The authors show that this system works perfectly in cells, and then move on to mice, where it also eliminates the infection. As antibiotic-resistant S. aureus infections are a growing problem, this approach might provide a novel alternative to therapy. To use it in humans would like require insertion of the gene network into cells recovered from the patient, then infusing these back. Not a simple protocol and likely expensive. As S. aureus infections often compromise implants, perhaps the approach could be used together with the implant to prevent colonization.
Add a comment...

Post has attachment
On the latest episode of the science podcast This Week in Evolution, Nels and I take on a recent science paper that asks the question, when mammals went back into the sea, which genes did they lose? Whales, dolphins, manatees and more are all examples of marine mammals. The authors looked at the genomes of cetaceans, pinnipeds, and sirenians, and found a set of genes that no longer function. The top hit is a gene that encodes paraoxonase I, an enzyme involved in lipid metabolism that is apparently not needed for life in the oceans. Unfortunately, and unpredictably, this enzyme is a defense against human made organophosphorus pesticides like chlorpyrifos and diazinon, which can cause neurotoxicity. These compounds wash into the oceans after application on farms, and the lack of paraoxonase I makes the animals susceptible to disease. Just in Florida, the manatee habitats are near areas of agricultural land use. The solution? Dickson would recommend indoor farming which does not require pesticides, but for now we'll have to monitor marine mammal habitats to determine if these compounds pose a threat.
Add a comment...

Post has attachment
On the latest episode of the science podcast This Week in Virology, we review the recently solved structure of the giant virus Cafeteria roenbergensis virus. The particle is large, composed of over 29,000 proteins, a real challenge for cryo-electron microscopy. It required 3 million hours of CPU time to solve this structure! Also of great interest, the structure suggests a new mode of particle assembly by a spiral mechanism - great movies to explain this on the author's website (see the show notes for a link). Next, apparently dengue fever has been eliminated from a city in Australia by the release of Aedes aegypti mosquitoes harboring Wolbachia bacteria. The bacteria prevent dengue virus replication in the mosquito and hence interrupt transmission. Over 4 million mosquitoes were released and the A. aegypti mosquito population is nearly 100% Wolbachia positive. Amazingly, there have been no cases of dengue fever in this region in the past four years. Previously, there were about 100 cases per year. An amazing success story.
Add a comment...

Post has attachment
On the latest episode of the science podcast This Week in Microbiology, we begin with an amazing development - how to test antimicrobial susceptibility in 30 minutes! It involves a microfluidic chamber that is loaded with urine, and the bacteria line up in the narrow grooves. As they multiply, bacteria are pushed out of the end. Presumably to come to your doctor's office soon. Next, the finding of a carbonate-sensitive phytotransferrin in diatoms that controls iron uptake. It's essential for growth of diatoms, which are a key component of marine ecosystems. The key here: acidification-driven declines in the concentration of seawater carbonate ions will have a negative effect on this globally important eukaryotic iron acquisition mechanism. Yes, the oceans are becoming more acidic.
Add a comment...

Post has attachment
On the latest episode of the science podcast This Week in Parasitism, we begin by solving the case of the Ecuadorian with Immunodeficiency and Chronic Diarrhea. As always, those who submit guesses are entered into a contest to win a signed copy of Parasitic Diseases, 6th Edition. Next, a paper on oral transmission of Chagas disease. While triatomine bugs are a known vector for transmission of T. cruzi, the infection can also be acquired by eating the bugs or contaminated food. This study uses imaging to address the question of whether the pathogenesis of disease in mice differs depending on whether the parasites are given orally or inoculated by needle. Bottom line: there is no difference.
Add a comment...

Post has attachment
On the latest episode of the science podcast This Week in Virology, we begin with a case report on persistence of Ebola virus near the end of 2015, after the outbreak was declared finished in Liberia. The case involves a mother was contracted disease in 2014, recovered, gave birth a year later and then became ill again with Ebola virus disease. She transmitted the infection to several members of her family. With thousands of individuals in west Africa who have recovered from infection, there may be other harboring virus with the potential for recrudescence. Next, a massive paper suggesting that two herpesviruses, human herpesvirus 6A and 7, might be associated with the development of Alzheimer's disease. While there is no proof of causation, the results suggest that these ubiquitous human viruses - most of the population is infected at an early age and the viruses remain within us for our lives - could be triggers for the neurodegenerative disease.
Add a comment...

Post has attachment
TWiV returns to the studio after eight straight weeks on the road! In the latest episode of the science podcast This Week in Virology, we review Nipah virus in light of the current outbreak in India. Seemingly over, it comprised 19 cases with an astounding 17 deaths. The epidemic occurred on the western gulf state of Kerala, far from West Bengal and Bangladesh where other outbreaks have taken place. Nipah virus is one of the subjects of the Smithsonian Exhibit Outbreak: Epidemics in a Connected World. We also tackle the recent case of polio in Papua New Guinea - the first in 18 years. It happened in an unvaccinated child and was caused by circulating vaccine-derived poliovirus. Vaccination coverage in this region had dropped due to complaency - reason why eradication is going to be very difficult.
Add a comment...

Post has attachment
On the latest episode of the science podcast This Week in Microbiology, I sit down for a chat with John Warhol (apparently related to Andrew) at ASM Microbe in Atlanta. John is President of Warhol Institute, which is dedicated to spreading the word about microbes and their importance in our lives. John has written a wonderful book, Dr. Warhol's Periodic Table of the Microbes, and an actual periodic table. The book, based on the periodic table of elements, describes 118 microorganisms in 300 words or less; each organism is keyed out by its microbial characteristics, and all the organisms are described in terms of popular culture and recent history. The Periodic Table is available separately. John has also been deeply involved in getting a state microbe named for New Jersey - Streptomyces griseus. Why is John doing all this? You'll have to listen to find out, but here's a hint: he thinks that microbiology is cooler than astrophysics, but they have better TV shows.
Add a comment...

Post has attachment
On the latest episode of the science podcast This Week in Evolution, Nels and I review a paper about a virus in a fungus in a fly. The fungus, Entomophthora muscae, is a pathogen of flies. It modifies their behavior - causes them to climb high in plants where they spread their wings, allowing the fungal spores to shoot out and find new hosts! While studying the genome and transcriptome of this fungus, the authors found evidence for a virus that infects the fungus. It's a novel picornavirus, the first of fungi, and most likely crossed over from insects. It's possible, given other examples (like baculoviruses manipulating caterpillar behavior, and iflaviruses manipulating ladybug behavior) that this virus could manipulate the fungus which in turn controls the fly host. Microbial control of behavior rules!
Add a comment...
Wait while more posts are being loaded