Malassezia: a fungus among us

Hypopigmentation caused by Malassezia (Photo: astrium.com)

A group of clinical researchers from the School of Biochemistry and Pharmacy at the National University of Rosario received the Best Scientific Work Award for their work in the assessment of culture media for studies on Malassezia growth and drug sensitivity. The ceremony took place during the Argentine Meeting on Micology in Posadas, Misiones.

According to Silvana Ramadán, the researcher who presented the work, “I believe that more than the methodology applied, our dedication, the bench work and our efforts to obtain the yeast isolates were considered”.

Along with Silvana Ramadán, authors  Maximiliano Sortino , Lucía Bulacio, Clara López  and Laura Ramos were interested in a kind of yeast that produces human mycoses, known as Malassezia. Formerly known as Pitirosporum, name we have heard in many commercial ads refering to anti dandruff shampoos against Pitirosporum ovale, this fungus is currently considered to be the same as Malazzesia. This yeast species is very difficult to propagate since its nutritional requirements are very specific and heavily-dependent on lipids. At the same time, the development of appropriate culture media is absolutely neccesary if we are to determine this fungus sensitivity to different antifungal drugs used in the treatment of patients.

Malassezia is usually present on normal human skin (and in dogs) but under some conditions may overgrow leading to skin manifestations and folliculitis. In hospitalized patients, Malassezia may display a more agressive behaviour leading to catheter-associated sepsis, especially in those cases where patients receive lipid-based parenteral nutrition.

“When I was a student, Malassezia furfur was the only species we had knowledge of. Now, we know that there are more than 15 species and it is hard to distinguish between them, especially because they are hard to grow in regular culture media and also very difficult to maintain in the lab since they require lipid-rich media. That is the reason why these yeasts are found in patients with sebhorreic skin and in body areas such as chest and face”, added Ramadán.

Antifungal sensitivity tests are neccesary to determine drugs and concentrations required to treat patients. This becomes a problem when no standard methods are available to grow Malassezia in optimal conditions. The two methods employed by the researchers yielded results comparable to previously published data. The next steps include the standardization of the different variables as well as correlation studies between both techniques. The aim is to provide new approaches to determine antifungal resistance for Malassezia at the hospital and community levels.

Source:
http://www.unr.edu.ar/noticia/3738/premio-al-mejor-trabajo-cientifico-sobre-micologia-clinica/

Let there be (UV) light

Vinchucas (Triatoma infestans) are carriers of Trypanosoma cruzi, the parasite causing Chagas-Mazza disease, an endemic pathology affecting different countries in Latin America. Mainly affected areas in Argentina include the north and northwest parts of the country. Also known as American trypanosomiasis, the disease is one of Argentina’s main health problems for which no cure is available although different treatments have been developed to lessen its effects. Parasites may cause heart disease and lesions affecting the digestive and nervous systems and in view of the current status, prevention is key.

Now, a group of researchers at the Regional Center for Scientific Research and Technology Transfer (CRILAR) from the province of La Rioja, report the results of a study aimed at the early detection of vinchucas. Methods to clearly determine the risk of the spread of disease as well as the presence of these insects are crucial for the successful design and evaluation of programs to control the malady.
Researchers point to the use of ultraviolet (UV) light to expose vinchuca´s feces as an easy way for the early detection of these vectors. “Vinchuca detection through the use of UV light is based in the fluorescent properties of these insects’ droppings when exposed to that light wavelength”, said Silvia Catalá, researcher at the CRILAR and the paper’s main author (see Sources).

Vinchuca’s feces vary in color (yellow, black, white or colorless) and the study showed that, except when black, all other colors display different fluorescent intensities. Fluorescence is higher in more recent depositions and in materials such as ordinary and adobe bricks, wood, paper and plastic. Droppings on certain fabrics and cardboard showed weaker fluorescence. According to Catalá “if we consider brick and wood as the two most common materials found in humble rural homes, this technique would allow us for an efficient detection of these insects”. According to the paper, colorless urine can also be detected by this method.

The technique would also provide with a quick way for the early detection of vinchuca infestation, since it can estimate number of insects and date of depositions (fluorescence decreases over time).
Dr. Catalá indicated the existence of portable UV flashlights which are commercially available and would permit the early detection of vinchuca infestation before their number becomes harder to handle.

Sources:
www.agenciacyta.org.ar
Paper in Acta Tropica

The sooner the better: detecting hepatitis C and HIV

The research group (left to right): Taborda, Giri, Perez and Gardiol.

Current methods to screen blood donors include a questionnaire and tests to detect a disease. But all those precautions cannot rule out the existence of the so-called window period. This is the period of time during which no antibody against an infection can be detected. Considering the hepatitis C and Human Immunodeficiency viruses this is a worrying situation when we think that for 22 (HIV) or 69 days (HCV) a
person can be considered suitable as a donor while they are actually infected. That is why proper detection methods are key when a blood transfusion is required.

A group of researchers at the Institute of Molecular and Cell Biology in Rosario are currently working to develop a method that will allow the detection of genetic material from any of these viruses. Such material is already present in the blood right after the infection unlike antibodies, which appear several days after the event, originating the window period.

Researchers, who are also faculty members at the School of Biochemistry and Pharmacy, National University of Rosario, are currently conducting a pilot study at one of the local public hospitals. Depending on the results, authorities will be notified in order to consider a large-scale implementation of the new test.

Another advantage of the new analysis is that it will allow for the detection of HIV and Hepatitis C virus strains circulating in the region. This, in turn, will favor better detection methods and treatments. “Many molecular diagnostic systems use kits made in the USA and Europe and may not consider strains circulating in our country leading to inaccuracies when making a diagnosis”, explained Project Director Adriana Giri.

The research group is formed by Adriana Giri, Daniela Gardiol y Miguel Taborda (PhDs), PhD-student Germán Perez and the Hemotherapy Service at the Hospital Provincial del Centenario leaded by Dr. Marcela Ruzzini.

Source:
Distéfano, S. Diseñan un test para detección temprana de virus de Hepatitis C y HIV. www.unr.edu.ar. 06/27/2011. www.unr.edu.ar/noticia/3715/disenan-un-test-para-deteccion-temprana-de-virus-de-hepatitis-c-y-hiv

Eureka time for Argentinean physicists

Sepliarsky and Stachiotti relaxed after their paper´s publication

Two researchers from the Rosario Institute of Physics recently published a breakthrough in the prestigious Physical Review Letters. The paper entitled "Toroidal ferroelectricity in PbTiO3 nanoparticles" was published by Marcelo Stachiotti and Marcelo Sepliarsky, both Professors at the National University of Rosario and members of the National Council of Scientific and Technological Research from Argentina.

Stachiotti and Sepliarsky obtained surprising results regarding a new ordering of ferroelectric materials considering the shape of tiny particles. This discovery in the fascinating field of nanomaterials, more specifically in nanoelectronics, paves the way for the design of smaller devices and the development of power sources for a wide variety of techno gadgets.

The researchers found that a stable ferroelectric state can be reached for nanoparticles smaller than 10 nm when their height-width ratio is considered. Previous studies suggested that ferroelectricity faded when particles became smaller until this work was published.

A ferroelectric material can be considered as the electrical version of a magnet, where a spontaneous polarization is created as a result of the alignment of electric dipoles in a certain direction when an electric field is applied.

In a press release from their institute, Stachiotti explained that "the ability to invert the polarization direction of a ferroelectric material between two stable states represents the basis of a new technology to develop non-volatile memories for binary codification, which is used in smart cards and high-density memories employed in aerospace computers".

"The possibility to use these materials for biomechanical generation of electric power is currenty being explored. This will allow for our cell phone or portable player to be charged while we are walking, running or dancing which leads to energy savings" Sepliarsky added.

The phenomenon of ferroelectricity was discovered in 1920 and since it is similar to ferromagnetism, where iron represents one of its classic examples, the term "ferro" remained although most ferroelectric materials do not contain iron.

Source:
Grecco, N. Investigadores de IFIR-CONICET-UNR descubrieron un nuevo ordenamiento de los materiales ferroeléctricos en la nano-escala. www.unr.edu.ar. April, 2011. www.unr.edu.ar/noticia/3562/investigadores-de-ifir-conicet-unr-descubrieron-un-nuevo-ordenamiento-de-los-materiales-ferroelectricos-en-la-nano-escala

For more info on the city of Rosario, click here and here.

A big step for Science, a huge step for Argentina

Claudio Pairoba

 

Dr. Claudio Fernández and his research team at the IBR

Claudio Fernández returned to Argentina in 2006 with a clear goal in mind: to continue his research on neurodegenerative disorders in the country where he was born, grew up and studied.

A graduate from the University of Buenos Aires, Fernández is a Biochemist, Pharmacist and PhD from that institution. After spending more than 10 years doing research at different international laboratories, including the world renowned Max Planck Institute in Göttingen, Germany, Fernández decided it was time for him to go back to Argentina. The task ahead was not a minor one: to set up a state of the art laboratory in a country that has distinguished itself academically and in the scientific research field (three Argentinean researchers were awarded Nobel Prizes) but has also been struggling to recover from several decades of uncertain scientific policies and military governments.

A Nuclear Magnetic Resonance equipment, one of the key tools Fernández and his team use to carry out his research, was provided by the National Agency for the Promotion of Science and Technology and the National Council of Scientific and Technological Research from Argentina (both dependent from the national government). This was the kickoff for Fernández’s voyage back home, to the city of Rosario in the province of Santa Fe.

Fernández is currently working at the Institute of Molecular and Cell Biology of Rosario. He and his team have continued to publish scientific papers in top science journals. The most recent elucidates the interaction between molecules of the protein α-sinuclein to produce insoluble aggregates that lead to neuron malfunction, a mechanism underlying the development of several neurodegenerative disorders.

But the good news faced new challenges. The development of new drugs required a 5-million dollar investment, which was prohibitive in terms of economic resources. The Argentinean pharmaceutical business was not interested and those who were interested were not Argentinean. Fernández received a tempting offer: returning to Germany and getting funding for the next step of his research project: drug development.

It would be a road definitely easy to follow but not the one Fernández had in mind. As a graduate from the public university system, he feels responsible for contributing to society in return for the opportunity society gave him: to study at the university tuition-free.

After knocking on many doors, giving countless interviews and calling every influential person he could get ahold of, that is, showing people what he was doing, he has finally received the much needed political and institutional support. As a result of this, the national and provincial governments as well as the National University of Rosario will join efforts to build a new center where an interdisciplinary team will do the research and design of new drugs aimed at treating neurological disorders such as Parkinson’s and Alzheimer’s diseases. Not only that: this effort paves the way for the discovery of new drugs and the subsequent patent applications in Argentina, with all their obvious implications.

Fernández´s story is a clear example that excellent scientific research and valuable results are undoubtedly required but not enough if a country is to grow based on science. Researchers who are devoted to communicate their research to politicians, government officials, the media and society in general are equally needed.