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Streptococcus species are a natural part of the microflora: its ability to survive under a variety of conditions allow it to colonize several niches on the human body. Some of these species live as mostly harmless commensals, while some of these are potential pathogens that can cause disease under the right circumstances. Group B Streptococcus (GBS), or Streptococcus agalactiae, falls under both categories, as healthy adults rarely present GBS disease symptoms, but those with immunocompromised immune systems – especially the very young and the elderly – can be susceptible to invasive disease.
Should infectious disease researchers be allowed to generate lab strains that are more pathogenic than naturally occurring microbes?
Lignocellulosic plant biomass is one of the most available and renewable materials on earth. It serves as a potent source of energy, being comprised of several polysaccharide sugars crosslinked to lignin. Sugars fermented into bioethanol can be used as a fuel source or additive.  But removing the polysaccharides and breaking them down into smaller sugar subunits requires heat, chemical, and enzymatic treatment, and is energetically and financially expensive.  Research on a wide variety of lignocellulose-degrading microbes, from archaea to bacteria to fungi, is therefore focused on finding a more efficient way to degrade these materials.
Friday, 14 August 2015 13:50

A role for histidine in influenza HA

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HA is a glycoprotein found in the viral envelope of influenza A virus as a trimer (see schematic at left). HA is required for the first step of the viral life cycle: attachment of the virus to its new host cell. After HA binds its sialic acid receptor, the host takes up the virus via endocytosis. As the endosome becomes acidic, HA changes shape to insert into the lipid membrane, fusing viral and endosomal membranes to release viral genomic contents into the cytoplasm (see schematic below). Because HA is so important for these steps in viral replications, understanding how it…
Wednesday, 12 August 2015 13:41

Special (drug) delivery

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Targeted drug delivery is the ultimate goal: imagine fewer side effects, more selective killing, and lower drug concentration needed to reach a desired effect. Toward that end, microbes are well ahead of us (as usual), having developed several targeted delivery systems.
Thursday, 06 August 2015 13:40

Learning what Listeria likes about lox

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Do you enjoy lox on your bagel? A refreshing ceviche in the hot summer weather?  New research published this week in Applied and Environmental Microbiology highlights the importance of proper storage of salmon and other meats that require no cooking prior to eating.
Thursday, 30 July 2015 13:34

Rethinking the cell wall

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Budding microbiologists learn that the cell wall of bacteria and fungi plays an vital structural role. Indeed, spheroplasts (cells that have had their walls removed) are easily lysed with water, unable to maintain osmotic stability. Part of the cell wall duty is to remain rigid and provide the cell shape – this is most obvious when seeing the round spheroplasts from a rod-shaped cell (pictured).
Tuesday, 28 July 2015 13:31

CF Microbes Survive with Little to No Oxygen

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On sabbatical four years ago, Dianne K. Newman, PhD, came up with an idea to apply geochemistry tools to infectious diseases. At that point Newman, a professor of biology and geobiology at the California Institute of Technology, already had been working in Pseudomonas biology for a decade, and her laboratory work suggested that some findings may be relevant in infectious diseases of the lungs, like cystic fibrosis (CF).
The doctor enters the patient’s room for the fourth visit in three days. Her immunosuppressed patient was transferred from a small local clinic to this large research facility to provide more intensive treatment. Despite this, the patient is deteriorating, and suffering from multiple infections. A culture has just come back from the microbiology lab, which shows the Klebsiella pneumoniae isolated from the patient is resistant to ertapenem, imipenem, and meropenem – the isolate is a carbapenem-resistant Enterobacteriaceae (CRE). The drug susceptibility testing directs therapeutic decisions, but an important question remains: did the patient pick up this resistant strain in this…
Thursday, 23 July 2015 12:53

Signaling a stop to biofilm formation

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Many reports focus on bacterial growth in water (especially nutrient-rich waste water), but bacteria also grow well – if not better – on surfaces, where they can form a biofilm community. Biofilms are surface-dwelling microbes growing in a single- or multispecies mixture, encased in an extracellular matrix. Scientists study many characteristics of biofilms – nutrient and oxygen gradation, gene expression patterns, adherence capabilities – but important to healthcare systems is the resilience of biofilms. Biofilms are extremely resistant to antibiotic treatment, and thus a common problem of hospital-acquired infections.
While many people think of the flu (influenza) as just a pesky illness, it can be lethal. The 1918 Spanish flu killed an estimated 50 to 100 million people. To protect against the morbidity and mortality from seasonal flu, each year scientists develop a vaccine to protect against the specific influenza strains that are predicted to cause the most problems for that year. Since future pandemics or outbreaks cannot be predicted, it has not been possible to make a protective pre-pandemic vaccine with current vaccine strategies. Now researchers say they have developed a strategy that may lead to a practical…
It started around this time last year, in August 2014. Young children with respiratory distress were arriving in unusual numbers to Kansas City’s Childrens Mercy Hospital. Soon the Comer Children’s Hospital at the University of Chicago had a similar report. By mid-October, 691 people, mostly young children, were associated with the outbreak, which was diagnosed as Entervirus D-68 (EV-D68) infection. Recent data counts at least 1153 confirmed cases that have resulted in 14 deaths, with the total number of infected individuals unknown (since most people with colds don’t go to the doctor, let alone have their cold-causing microbe sequenced).
Clyde (Chip) Manuel and Dr. Lee Ann Jaykus are excited about their results. “I’m very proud of this story. It’s going to have pretty immediate benefits,” says Manuel, a senior graduate student in Dr. Jaykus’ lab at NC State. “This is a great example of applied research that has a basic science component,” says Jaykus. The results they are excited about are published in the August issue of Applied and Environmental Microbiology.
Diet and environment are two of the biggest influences on gut microbiota. So maybe it’s only appropriate that gut microbiota researcher Patrick Schloss often uses food and gardening analogies to describe his research problem.
Friday, 08 July 2016 12:07

New drug shows promise in silencing HIV

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When asked what inspired her to test a derivative compound from a saltwater sponge against HIV replication, investigator Dr. Susana Valente laughed.
The changing weather reminds us that influenza season is around the corner, which means it’s nearly time to get your annual vaccine. This year’s vaccine is updated to protect against influenza A viruses H1N1 + H3N2 and influenza B virus Victoria lineage. These strains are included in vaccine production after intensive epidemiological work predicted these to be circulating strains for the year. But what if the circulating strains vary slightly from the vaccine strains? Even worse, what if the circulating subtype is one not contained in the vaccine at all?
Scott Hultgren is that rare biologist who has tracked the problem of uropathogenic Escherichia coli (UPEC)—the bacteria responsible for the vast majority of urinary tract infections—from the atomic level to the clinic. In a quarter century of study, he and his collaborators have attacked the problem by crystallizing protein structures, analyzing binding pockets, mutating genes, tinkering with cell adhesion, and rigorously testing their ideas in a mouse model of urinary tract infections (UTIs).
Although hantaviruses cause significant human diseases worldwide, no specific antiviral treatments are available, in part because gaps in the understanding of how the viruses enter human cells have hampered the search for therapeutics. In Europe and Asia, hantavirus strains have caused hemorrhagic fever with kidney failure, while in the Americas the viruses have caused hantavirus cardiopulmonary syndrome, a severe, sometimes fatal respiratory disease.
This past weekend, the New York Times ran an article addressing the connection between the microbiome and mood. Evidence is increasing that resident microbes can affect host systems such as the immune system, the digestive system, and, more and more, the nervous system. However, the human microbiome is very complex, with over 1000 different species (and that’s just bacteria!). There are a number of hard-to-control variables when conducting human microbiome studies, such as diet and other potentially confounding factors. These can complicate drawing strong conclusions in human microbiome studies.
The war on invasive fungal infections has not been going well. Despite state-of-the art therapy, roughly 50% of individuals with invasive fungal infections will die. Now, a new study has identified a new therapeutic attack strategy and a new class of antifungal agents. The research demonstrates that compounds that target the synthesis of lipid glucosylceramide on the surface of fungal cells can kill fungal infections.