Tweet
:format(webp)/cloudfront-us-east-1.images.arcpublishing.com/grupoclarin/3PTHDL4L5BFEVHWN5OHHPXBTXI.jpg)
Spanish to English translation
Findings on antibiotic-resistant bacteria
One group studied pneumococci Cordoba, one of the pathogens with the highest incidence in children. Discovered a new clue as to why bacteria persist even in areas where antibiotic use is not high. Could lead to better drugs.
21/02/2011 00:01 by Lucas Viano
When her group got the results of the experiment, Jos? Echenique realized there was something more than novelty. 14 years studying pneumococci, a type of bacteria that cause various infections such as pneumonia and meningitis. But I never saw a rod-shaped (bacillus). Precisely, the suffix "coconut" refers to its spherical shape.
That was the "eureka" the work of his group at the Faculty of Chemistry, National University of Cordoba (UNC) and CONICET which was published last Friday in the journal Plos Pathongens , a publication with high impact on biomedical research community. Her research found a mechanism that allows the spread of antibiotic resistant pneumococci. The group was formed by Andrea Albarracin Orio, Germain Pi?as, and Melina Cortes Paulo Cian.
The basis of this work began in 2004, but Echenique pneumococci studied since 1997, when it initiated a post-doctoral stay at the University Paul Sabatier, Toulouse. In 2001 she returned to France and formed a team at UNC. The group's first published work was a study of molecular epidemiology of pneumococcal strains isolated from pediatric patients. They found that in Argentina runs a type of pneumonia (a group of strains or subclone) with characteristics different from those described internationally. Of this group of strains, about 25 percent were resistant to antibiotics of the penicillin family.
The pneumococcus is one of the bacterial pathogens of greatest impact on human health. Cause common infections such as otitis and sinusitis, and more serious such as pneumonia and meningitis. For years, causes more than two million deaths in children in developing countries only.
The following Echenique work focused on studying a protein involved in forming the wall of the bacteria and cell division. "What makes penicillin is to block this protein, called PBP (acronym for penicillin-binding proteins , in English). The bacteria can not flourish and die, "says Echeverri.
While penicillin is very effective in treating these infections, over the years pneumococci were accumulating mutations that changed in part three of the PBP to prevent penicillin can block them. This generated strains resistant to antibiotics.
But this evolutionary advantage brought a disadvantage, according to previous studies. The downside is that antibiotic-resistant bacteria grow more slowly than those that are not. "In an individual treated with antibiotic-resistant pneumococci survive unlike the susceptible strains. In individuals without antibiotic treatment the opposite happens. Susceptible strains spread more rapidly than resistant, "says
Pneumococcus Argentine . What the group found is that the rate of resistant pneumococci circulating in Argentina does not respect this rule described in studies of other countries. Resistant bacteria "Argentina" grow at the same pace as the strains susceptible to penicillin.
So scientists wanted to go further and describe why this was happening with pneumococcal Argentina. Succeeded in creating genetically engineered pneumococci were only one of the three PBP involved in resistance to antibiotics. Just found that separate each protein reduced the growth of bacteria. One in particular did so dramatically and caused the bacteria to lose its spherical shape to become a bacillus, which drew much attention from Echenique.
"We found that the three proteins are cleared to create a mechanism that allows the resistant bacteria spread on an equal footing with non-resistant in the absence of antibiotics," says Echeverri.
He adds: "This would be one of the reasons why, although in some countries reduced the supply of antibiotics, the rate of infection with resistant pneumococci was not reduced. Resistant bacteria survived, although there was no antibiotic pressure. "
Then, Echenique focused on the mysterious pneumonia-shaped stick. "So far there has been described as a pneumococcus bacillus," he said. The fault was in the process of cell division proteins are also involved with other PBP. Understanding this mechanism is essential for designing compounds that can block this process, kill bacteria and prevent infection.
This finding is of interest to the pharmaceutical industry to focus on new designs of antibiotics. However, the work is basic science, to achieve a new drug to block this mechanism can take years.
The circulation of pneumococcus in C?rdoba
Relevance. Echenique 20 years researching and says he does not know if he could publish a work of such importance as this. The importance of research is measured by the impact of the magazine that is published.
To do this, bibliometrics uses what is called "impact factor."
Impact. journals such as Science and Nature famous over 30 points. PLoS Pathogens reaches nine points, a figure that doubles with the magazines which regularly publish the work of Argentine scientists.
Money. To be published in the journal, the scientist must pay. But the costs are commensurate with the subsidies that are received in Europe and the U.S.. When he sent his work Echenique said he could not pay the usual and proposed a figure proportional to the 40 thousand dollars a year it receives to investigate. The editors agreed.
Times . The job was sent to the magazine in December 2009. He returned in January to conduct new experiments. It took another year and forward the work performed by.
Internet. The publication can be read online at http://www.plospathogens.org/article/info% 3Adoi% 2F10.1371% 2Fjournal.ppat ...