A team of biologists and biomedical researchers at UC San Diego has developed a new method to determine if bacteria are susceptible to antibiotics within a few hours, an advance that could slow the appearance of drug resistance and allow doctors to more rapidly identify the appropriate treatment for patients with life threatening bacterial infections.
In a paper published online this week in the journal EBioMedicine, the scientists reported the development of a rapid susceptibility test for Staphylococcus aureus, a bacterium that causes some 60 percent of hospital-acquired infections and which has spread in communities, causing pneumonia and a variety of skin and tissue infections in both healthy and immune-compromised individuals.
The development is important, say biomedical scientists, because of the critical need for physicians to rapidly discriminate between drug resistant strains (commonly termed MRSA for methicillin-resistant S. aureus) and drug sensitive strains, since these infections can progress rapidly, especially MRSA strains with additional resistance to newer antibiotics designed to treat pathogens that are now appearing in hospitals.
According to the Centers for Disease Control and Prevention, antibiotic resistance causes two million illnesses and 23,000 deaths annually, costing the U.S. economy approximately $20-billion a year in direct health care costs and nearly eight million extra days in the hospital. Indeed, bacteria are evolving resistance to antibiotics much more quickly than global biomedical research efforts are delivering new drugs to market, leading to the appearance of infections caused by bacteria that are now resistant to every therapy.
Rapid antimicrobial susceptibility testing allows doctors to discriminate between infections caused by drug sensitive bacteria, which can be treated with safe and effective antibiotics developed in what scientists call the golden age of drug discovery (the mid-20th century) such as penicillin, and those caused by drug resistant bacteria, which might require newer antibiotics, such as daptomycin or cubicin. This approach will decrease the emergence of resistance by reserving the newest drugs for those infections where they are most needed.
The interdisciplinary team at UC San Diego was comprised of two infectious-disease specialists in the School of Medicine, Victor Nizet, MD, and George Sakoulas, MD; two biologists in the Division of Biological Sciences, Kit and Joe Pogliano; and Diana Quach, a bioengineering graduate student. The scientists applied a method previously developed in the Pogliano laboratories for drug discovery to antibiotic susceptibility testing.
“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,” said Kit Pogliano, a professor of biology at UC San Diego who headed the research team. “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.”
Examining single cells has two key advantages over other testing methods, say the researchers. First, it is rapid, cutting days off the time for typical culture-based assays. It often takes days for a doctor to receive information on resistance, and this means that patients with life-threatening infections are often treated with the assumption that the infection is drug-resistant. Second, this method does not rely on having any detailed understanding of the bacterium causing the infection, or of the genes that convey resistance. This is particularly important in this case, since resistance to the drugs used to treat MRSA infections arise by several evolutionary pathways via different combinations of mutations, and it could also provide rapid treatment information for newly emerging bacterial pathogens, such as that which caused the infections transmitted by endoscopes.
“Regardless of the type of bacterium, a healthy and growing bacterium looks different from a dead bacterium, so whenever we detect a difference in how the cells look, we know that the bacterium is sensitive to the antibiotic we have applied. When we combine careful culture conditions, cutting edge imaging methods and a detailed quantitative analysis, we can turn this simple approach into a reliable test,” said Joe Pogliano, a professor of biology.
“Rapid and precise identification of antibiotic sensitivity patterns allows the most potent and effective drug to be administered,” said Nizet, a professor of pediatrics and pharmacy. “Equally important, more specific antibiotic therapy can help preserve the normal bacteria living in our gut microbiome that play an important role in our health and immune system function.”
The UC San Diego biologists say their new method has the potential to be applied to many different types of bacteria. “Our new method worked surprising well at rapidly detecting antibiotic resistant strains of S. aureus,” said Diana Quach, a graduate student and lead author on the study. “We are now optimizing it to provide a more accurate test for other types of antibiotic resistant bacteria, such as Pseudomonas aeruginosa.”
The Latest on: Antibiotic susceptibility testing
via Google News
The Latest on: Antibiotic susceptibility testing
- Aperture Bio Invited to Present at Antimicrobial Resistance World Congress on May 13, 2019 at 5:52 pm
The speed and accuracy of the test will reduce turn-around-times, with actionable results, from days to hours when compared to current screen, culture and reflexed Antibiotic Susceptibility Testing ... […]
- Global Antimicrobial Susceptibility Testing Instrument Market Demonstrate Growth, Pharmaceuticals, Experiments, Research, Analysis 2025 on May 8, 2019 at 7:24 am
The market size of Antimicrobial Susceptibility Testing Instrument is million US$ and it will reach million US$ in 2025, growing at a CAGR of from 2019; while in China, the market size is valued at xx ... […]
- Rapid bacterial analysis and testing for antibiotic sensitivity demonstrated on May 6, 2019 at 12:10 pm
detects polymicrobial samples and identifies antimicrobial susceptibility directly from clinical samples at the single cell level." The system is 100 percent sensitive to the presence of bacteria ... […]
- Can antibiotics treat endometriosis? on May 3, 2019 at 7:31 am
In mice, treatment with an antibiotic reduces the size of lesions from endometriosis, researchers report. The researchers are planning a large, multicenter clinical trial to test the drug ... and ... […]
- Antimicrobial Susceptibility Testing Instrument Market to Reach at High CAGR in Forecast Period 2019 to 2026 on May 3, 2019 at 1:19 am
May 03, 2019 (Global QYResearch via COMTEX) -- The Exhaustive Study for "Antimicrobial Susceptibility Testing Instrument Market " is added on Global QYResearch. The report covers the market aspect and ... […]
- Practical Guide to Interpretation of Antimicrobial Susceptibility Test on April 30, 2019 at 11:31 pm
Department of Medicine & Epidemiology, University of California-Davis, Davis, CA, USA In recent years, there has been a frightening rise in the prevalence of multidrug-resistant bacterial infections ... […]
- Researchers find antibiotic resistant mcr-1 gene in Salmonella from mussels on April 23, 2019 at 9:06 pm
Of the 19 Salmonella strains analyzed, four were isolated from cooked mussels. Antimicrobial susceptibility-resistance testing was positive for resistance to at least four of the antibiotics tested. ... […]
- On-chip drug screening for identifying antibiotic interactions in eight hours on April 19, 2019 at 5:28 am
Antibiotic susceptibility testing, which determines types and doses of antibiotics that can effectively inhibit bacterial growth, has become more critical in recent years with the emergence of ... […]
- Wanted: New Strategies for Antibiotic-Resistant H. pylori on April 18, 2019 at 12:30 pm
pylori to many currently used antibiotics." Among the report's reconciled proposals ... the review proposed the following: Make susceptibility testing more widely available and establish ... […]
- Bringing Antimicrobial Susceptibility Testing (AST) to the Community on February 13, 2019 at 5:20 am
Thought LeadersDr. Ester SegalAssociate Professor of Biotechnology and Food TechnologyThe Technion – Israel Institute of Technology An interview with Dr. Ester Segal from the Technion (Israel ... […]
via Bing News