Biologists and biomedical researchers in San Diego have developed a new method to quickly determine if bacteria are resistant to antibiotics. The advance could slow the appearance of drug-resistant infections and allow doctors to more rapidly identify the appropriate treatment for patients with life-threatening bacterial infections.
The team from the University of California – San Diego (UC San Diego) has developed a rapid susceptibility test for Staphylococcus aureus, a bacterium that causes some 60 per cent of hospital-acquired infections. It will enable physicians to quickly discriminate between drug-resistant strains (commonly termed MRSA for methicillin-resistant S. aureus), which might require newer antibiotics, such as daptomycin or cubicin; and drug-sensitive strains which can be treated with traditionally prescribed antibiotics such as penicillin. This approach will decrease the emergence of resistance by reserving the newest drugs for those infections where they are most needed, as well as allowing the most potent and effective drug to be administered.
Bacteria are evolving resistance to antibiotics much more quickly than global biomedical research efforts can deliver new drugs to market, leading to infections resistant to every therapy. The study was funded by the National Institutes of Health and conducted by aninterdisciplinary team at UC San Diego comprised of two infectious-disease specialists in the School of Medicine; two biologists in the Division of Biological Sciences, and a bioengineering graduate student.
The life sciences sector is a major driver of the innovation economy in San Diego, with a total economic impact of more than $31.8 billion. The region is home to more than 1,100 life sciences companies and more than 80 research institutes, alongside key universities including UC San Diego and San Diego State University. Disease prevention and immunology are major themes, with key knowledge centres in the region including La Jolla Institute for Allergy & Immunology based in UC San Diego’s Science Research Park, one of the top five research institutes of its type in the world; and The Scripps Research Institute (TSRI), a private, non-profit research organisation internationally recognised for its research into areas including immunology, virology, and synthetic vaccine development.
Major pharmaceutical companies including Pfizer, Johnson & Johnson, GlaxoSmithKline and Merck maintain a presence in San Diego to foster collaboration with these knowledge centres. In addition, San Diego County higher education institutions produce more than 7,000 STEM graduates annually, fuelling the growth of the industry.
According to the Centers for Disease Control and Prevention, antibiotic resistance causes two million illnesses and 23,000 deaths annually, costing the US economy approximately $20 billion a year in direct healthcare costs and nearly eight million extra days in the hospital.
Research leader Kit Pogliano, a professor of biology at UC San Diego, said: “Previously we developed a microscopy-based method that performs an autopsy on bacterial cells that allows us to determine how each cell died, and we have shown that this method can identify new antibiotics and help understand how these antibiotics work. We tested to see if this method could be applied to antibiotic susceptibility testing. Surprisingly, we not only found that our method was able to accurately differentiate sensitive S. aureus strains from resistant MRSA strains, but that we were able to identify two subgroups of MRSA strains, one of which is susceptible to combinations of antibiotics that could be used in the hospital. We are excited by the accuracy and speed of this test, as well as by its unanticipated ability to identify these two types of MRSA infections, which would have been missed by other tests.”
The UC San Diego biologists are now optimising the test for other types of antibiotic-resistant bacteria, such as Pseudomonas aeruginosa. The method is now being commercialised by Linnaeus Bioscience Inc so that it can enter clinical use.
