Breaking News
August 14, 2018 - Rethinking the stroke rule ‘time is brain’
August 14, 2018 - Incidence of coronary artery compression in children may be more common than previously thought
August 14, 2018 - Study helps to better understand disease caused by Alpha-1 antitrypsin deficiency
August 14, 2018 - AI platform identifies acute neurological illnesses faster than human diagnosis
August 14, 2018 - American College of Rheumatology receives grants to support development of lupus clinical trials
August 14, 2018 - American Heart Association Urges Screen Time Limits for Youth
August 14, 2018 - Brief interventions during routine care reduce alcohol use among men with HIV
August 14, 2018 - New genome analysis could identify people at higher risk of common deadly diseases
August 14, 2018 - NIH grant for Mount Sinai to study use of inhaled corticosteroids for treatment of sickle cell disease
August 14, 2018 - Daicel supplies free nanodiamond samples to international researchers
August 14, 2018 - Switching anti-psychotic drugs in first-episode schizophrenia patients does not improve clinical outcomes
August 14, 2018 - Study to examine whether modulating gut bacteria can improve cardiac function in heart failure patients
August 14, 2018 - AI technology could hold key to improving health services
August 14, 2018 - One out of two children not getting enough nutrients needed for their health
August 14, 2018 - Mono-antiplatelet therapy after aortic heart valve replacements may work as well as two drugs
August 14, 2018 - Aid-in-dying patient chooses his last day
August 14, 2018 - Exercise Really Can Chase Away the Blues, to a Point
August 14, 2018 - Surgical mesh implants may cause autoimmune disorders
August 14, 2018 - Researchers develop revolutionary zebrafish model to gain more insight into bone diseases
August 14, 2018 - Researchers discover secret communication hotline between breast cancers and normal cells
August 14, 2018 - Study examines how a person adapts to visual field loss after stroke
August 14, 2018 - Researchers show how specialized nucleic acid-based nanostructures could help target cancer cells
August 14, 2018 - Reducing opioid prescriptions for one operation can also spill over to other procedures
August 14, 2018 - E-cigarettes not so safe but still better than cigarettes
August 14, 2018 - Researchers find link between common ‘harmless’ virus and cardiovascular damage
August 14, 2018 - Initiation of PIMs associated with higher risk of fracture-specific hospitalizations and mortality
August 14, 2018 - Genetically modified mosquitoes and special bed nets help tackle deadly diseases
August 14, 2018 - Advances in treating hep C lead to new option for transplant patients
August 14, 2018 - Study finds quality of doctor-patient discussions about lung cancer screening to be ‘poor’
August 14, 2018 - MSU researchers uncover the effects of aging on regenerative ability of kidneys
August 14, 2018 - Better conditioning, throwing mechanics can help reduce elbow injuries in young baseball pitchers
August 14, 2018 - Brain game doesn’t offer brain gain
August 14, 2018 - Reproductive choices facing women with disabilities require careful consideration
August 14, 2018 - Scientists pinpoint the cause of a rare childhood seizure disorder
August 14, 2018 - Lumpectomy plus radiation associated with reduced risk of breast cancer death, study finds
August 14, 2018 - UAB study shows how ion channel differentiates newborn and mature neurons in the brain
August 14, 2018 - Experts highlight key knowledge gaps that need to be addressed in Ebola vaccine research
August 14, 2018 - Discovery could lead to new drugs against infection and inflammation
August 14, 2018 - Infection Prevention Differs Between Small, Large Hospitals
August 14, 2018 - Mom still matters—In study, young adults tended to prioritize parents over friends
August 14, 2018 - Deep brain stimulation might benefit those with severe alcoholism, preliminary studies show
August 14, 2018 - Study finds increased rate of repeat pregnancies in women with intellectual and developmental disabilities
August 14, 2018 - Lighter sedation fails to reduce risk of postoperative delirium in older patients
August 13, 2018 - Asking better questions about person’s memory could improve doctors’ understanding of patients
August 13, 2018 - U.S. Trauma Doctors Push for Stricter Gun Controls
August 13, 2018 - Asthma and flu: a double whammy
August 13, 2018 - 5 Questions: Donna Zulman on engaging high-need patients in intensive outpatient programs | News Center
August 13, 2018 - Behavioral Nudges Lead to Drop in Prescriptions of Potent Antipsychotic
August 13, 2018 - Potential New Class of Drugs May Reduce Cardiovascular Risk by Targeting Gut Microbes
August 13, 2018 - How to get your kids to eat better
August 13, 2018 - The importance of hearing your patients
August 13, 2018 - Transmission of F. tularensis unlikely to happen through the food chain
August 13, 2018 - Researchers discover epigenetic mechanism underlying ischemic cardiomyopathy
August 13, 2018 - Adolescent health programs receive only a tiny share of international aid, finds research
August 13, 2018 - Fracture risk increases by 30% after gastric bypass, study shows
August 13, 2018 - Quality-improvement project to standardize feeding practices helps micro preemies gain weight
August 13, 2018 - Long-term cannabinoid exposure impairs memory, study shows
August 13, 2018 - New intervention to reduce risk of HIV in young transgender women
August 13, 2018 - Japan human trial tests iPS cell treatment for Parkinson’s
August 13, 2018 - Altered nitrogen metabolism may contribute to emergence of new cancer mutations
August 13, 2018 - Cycling provides greatest health benefits, study finds
August 13, 2018 - Scientists discover biomarker for kidney cancer
August 13, 2018 - New test predicts the risk of serious disease before symptoms appear
August 13, 2018 - Cianna Medical receives FDA 510(k) clearance to extend indication of SCOUT reflector for use in soft tissue localization
August 13, 2018 - Ground-breaking discovery offers new hope for treatment of Alzheimer’s, other neurological diseases
August 13, 2018 - Medical nutrition therapy provided by RDNs benefits patients with chronic kidney disease
August 13, 2018 - Prenatal Tdap vaccination not linked with increased risk of autism in children, study shows
August 13, 2018 - One-Third of Canadian Patients Get Hip Fx Repair Within 24 Hours
August 13, 2018 - ANA (Antinuclear Antibody) Test: MedlinePlus Lab Test Information
August 13, 2018 - Traffic jams in the brain
August 13, 2018 - NIH awards $6.5 million to establish multi-institution biomedical technology resource center
August 13, 2018 - New marker in the blood could help predict person’s risk of developing kidney cancer
August 13, 2018 - New biomarker may provide clues to create diagnostic tool for hypoglycemia-associated autonomic failure
August 13, 2018 - Oxidative Stress Hampers Blood Vessel Dilation in Men
August 13, 2018 - Parents’ Religious Beliefs May Affect Kids’ Suicide Risk: Study
August 13, 2018 - Measure of belly fat in older adults is linked with cognitive impairment
August 13, 2018 - FDA permits marketing of first mobile medical app for contraceptive use to prevent pregnancy
August 13, 2018 - NUS scientists develop new technology to customize optimal drug ‘cocktail’ for myeloma patients
August 13, 2018 - Disordered eating behaviors up for overweight young adults
August 13, 2018 - Connection between Alzheimer’s disease and degenerative eye diseases
Reducing use of antibiotics not sufficient to reverse drug resistance

Reducing use of antibiotics not sufficient to reverse drug resistance

image_pdfDownload PDFimage_print

Researchers have discovered that reducing the use of antibiotics will not be enough to reverse the growing prevalence of antibiotic resistance for some types of bacteria.

Besides passing along the genes bestowing antibiotic resistance to their offspring, many bacteria can also swap genes amongst themselves through a process called conjugation. There has long been a debate, however, as to whether this process occurs fast enough to spread through a population that is not under attack by antibiotics.

In a new study, researchers from Duke University believe they have found a definitive answer to that question. Through a series of experiments with bacteria capable of conjugation, they show that all of the bacteria tested share genes fast enough to maintain resistance. They also show, however, that there are ways to disrupt the process and reverse antibiotic resistance.

The results appear online on Nov. 22 in the journal Nature Communications.

“The results came as a surprise to me when I first saw the data,” said Lingchong You, the Paul Ruffin Scarborough Associate Professor of Engineering at Duke University and corresponding author on the paper. “For all of the bacteria we tested, their conjugation rate is sufficiently fast that, even if you don’t use antibiotics, the resistance can be maintained –even if the genes carry a high cost.”

Most resistance to antibiotics arises and spreads through natural selection. If a few lucky bacteria have genes that help them survive a round of antibiotics, they quickly parent the next generation and pass on those genes.

Many of these genes, however, come at a cost. For example, a mutation may allow a bacterium to build a thicker membrane to survive a particular antibiotic, but that mutation might also make it more difficult for the cell to reproduce. Without the selective pressure of antibiotics killing off the competition, bacteria with this mutation should disappear over time.

But when the genes responsible for resistance can also be swapped between cells, the equation gets more complicated. In favor of maintaining the resistance is the rate at which the genes are shared. Working against it is the previously mentioned biological cost of the genes, and the natural error rate in genes when they are passed on.

“There have been some studies on how critical conjugation is to maintaining resistance despite its cost, but there has been a lack of careful and well-defined experiments to come to definitive conclusions,” said You. “That’s where Allison has made a central contribution. Her incredibly thorough measurements allow us to draw our conclusions with high confidence.”

Allison Lopatkin, a doctoral student in You’s laboratory and first author of the paper, carefully measured the rate of conjugation and antibiotic resistance in pathogens for more than a month. The strains were obtained through a parallel project with Duke Health, in which You is trying to determine just how common conjugation is amongst pathogens.

So far, You has found that more than 30 percent of the bacterial pathogens he has tested spread resistance through conjugation. And of those, nine were further tested by Lopatkin to see how well they would maintain their resistance in the abscence of antibiotics.

“Every single clinical strain we tested maintained its resistance through conjugation even without the selective pressure of antibiotics,” said Lopatkin.

The results indicate that — at least for bacteria that swap resistance genes — simply managing the amount of antibiotics being used will not turn the tide on the growing problem of resistance. To make any headway, according to You and Lopatkin, drugs will also be needed that both stop the sharing of genes and decrease the rate at which they are passed on through reproduction.

Luckily, such drugs already exist, and there may be many more out there waiting to be discovered.

“We did the same experiments with one drug that is known to inhibit conjugation and another that encourages resistance genes to be lost,” Lopatkin said. “We found that without the presence of antibiotics we could reverse the bacteria’s resistance in four of the pathogens we tested and could stop it from spreading in the rest.”

One of the drugs is a benign natural product and the second is an FDA-approved antipsychotic. While the team has filed a provisional patent for the use of the combination to reverse antibiotic resistance, they hope future work will reveal even better options.

“As a next step, we’re interested in identifying additional chemicals that can fill these roles more effectively,” said You. “Historically, when researchers screened huge libraries for medicines, they focused on drugs that can kill the bacteria. But what our studies suggest is that there is a whole new universe where you can now screen for other functions, like the ability to block conjugation or to induce the loss of resistance genes. These chemicals, once proven safe, can serve as adjuvants of the standard antibiotic treatment, or they can be applied in an environmental setting as a way of generally managing of the spread of antibiotic resistance.”

Tagged with:

About author

Related Articles