Bacteria strains mapped in Lebanon could lead to more targeted treatment
Published online 23 June 2014
Researchers sequence genome of a certain bacteria strain for the first time as fears grow over antibiotic resistance.
Scientists in Lebanon have sequenced the full genome of bacteria that cause skin and nosocomial infections and food-borne illnesses and claim the breakthrough should help curb the spread of antibiotic resistance in the region.
Sima Tokajian, associate professor of microbiology at the Lebanese American University (LAU), says mapping the genome will allow physicians to narrow the spectrum of drugs for treatment and therefore curb antibiotic resistance.
“In the future we will be able to limit the spread and emergence of antibiotic resistance by determining the best treatment regimen instead of resorting to empirical treatment,” she says.
Tokajian and her colleagues analysed 40 strains of bacteria collected from patients in Lebanon, including Staphylococcus aureus, Streptococcus pyogenes and Escherichia coli. The aim was to determine resistance mechanisms, identify strains and determine whether the strains causing disease were new.
Tokajian says: “Through whole genome sequencing and using the same experimental procedure regardless of the type of pathogen, I can sequence the whole genome within two days and get a detailed overview.” She adds that this was the first time that the full genome of bacteria taken from local patients had been sequenced in the region.
Dennis Russell, from the department of biology and chemistry at the American University of Sharjah in the UAE, says that while the genomes of many organisms had been previously sequenced, knowing the DNA sequence of a particular strain would differentiate toxic from non-toxic bacteria in the same species.
“Knowing the sequences of DNA that code for specific proteins will help identify critical proteins that we could find chemicals (medicines or antibiotics) that could block them and thus kill the bacteria,” he says.
The sequencing comes amid concerns of growing antibiotic resistance, as recently highlighted by the World Health Organisation’s (WHO) Antimicrobial Resistance Global Report on Surveillance.
“Increasingly, governments around the world are beginning to pay attention to a problem so serious that it threatens the achievements of modern medicine,” the report says. “A post-antibiotic era in which common infections and minor injuries can kill – far from being an apocalyptic fantasy – is instead a very real possibility for the 21st century.”
Russell says the over-prescribing of antibiotics in the region for minor illnesses is fuelling the problem. “This can lead to individual people harboring bacteria strains that are antibiotic resistant."
The report acknowledges that a lack of surveillance systems in the Middle East meant there was insufficient data available to comprehensively combat antibiotic and antimicrobial resistance. It says adequate legislation was lacking in some places and poor enforcement of hygiene standards in others. A focus on conflict meant the issue was overshadowed and neglected.
Tokajian adds that she hopes her research would lead to better control measures over outbreaks in the region. “This is a big and severe problem and we cannot even estimate the magnitude due to the lack of the continuity of studies targeting this important aspect,” she says.