A study from the Centre for Phage Technology, part of Texas A&M’s College of Agriculture and Life Sciences and Texas A&M AgriLife Research, shows how the “hidden” genes in bacteriophages – types of viruses that infect and destroy bacteria – may be key to the development of a new class of antibiotics for human health.

The study has been published in Nature Communications and Current Science Daily, as well as featured in a recent Nature Research Microbiology Community blog post.

Antibiotic-resistant bacteria pose an increasing threat to human health, creating an urgent need for the development of novel antibiotics.

“There has been an increased interest in bacteriophages and their potential as antibacterial agents to fight pathogenic bacteria,” said Centre for Phage Technology director Ryland Young, Ph.D., who supervised the study research. “This is in large part due to the ability of the ‘lysis genes’ of the phage to cause a cellular breakdown in the bacterial host.”

The need for new and more effective antibiotics has increased interest in bacteriophages as possible agents to fight pathogenic bacteria.

Most phages can cause their host cell to rupture, a process called lysis. They also release new “progeny” phage virions that are genetically and structurally identical to the parent virus.

“Small phages, such as the ones this study focuses on, make a single protein which causes host lysis,” Young said. “Basically, the virus produces a ‘protein antibiotic’ that causes lysis in the same way antibiotics like penicillin do – by disrupting the multistage process of cell wall biosynthesis. When the infected cell tries to divide, it blows up because it can’t create the new cell wall between the daughter cells.”

He said these small lysis proteins can be the model for a completely new class of antibiotics.

The study focuses on characterizing the lysis genes of leviviruses, bacteriophages containing small single-stranded RNA genomes with only three to four genes. Tens of thousands of leviviruses have been discovered. Among the known levivirus genes is Sgl, which stands for ‘single gene lysis.’ Sgl encodes a protein that induces the cellular breakdown of bacteria.

“We wanted to discover these ‘hidden’ lysis genes in single-stranded RNA phages, as well as understand how their structure and evolution could benefit development of new, more effective antibiotics,” said Karthik Chamakura, Ph.D., a postdoctoral research associate at the centre and the study’s first author. “We also wanted to investigate how certain molecular targets within bacteria could be identified and exploited for antibiotic development.”

Reference:

https://doi.org/10.1038/s41467-020-19860-0

By Samuel Boova, Director Alliance Development, High Burden HIV Global Markets, Beckman Coulter Life Sciences Despite significant progress in its prevention and treatment, human immunodeficiency virus (HIV) remains a serious public health threat across the globe. The United Nations programme UNAIDS has led the global effort to address the HIV/AIDS crisis and has set out […]

The MedTech company Hologic, with a primary focus on women’s health, has acquired SOMATEX Medical Technologies, a leader in biopsy site markers and localization technologies, for approximately $64 million. The company was previously owned by E-Med Solutions, Berlin, a group of investors led by German private equity company Westlake Partners.

Proton therapy, a type of external beam radiation therapy, is a safe and effective treatment for prostate cancer, according to two new studies.
In the first study, researchers at the University of Florida in Jacksonville, Fla., prospectively studied 211 men with low-, intermediate-, and high-risk prostate cancer. The men were treated with proton therapy, a specialised type of external beam radiation therapy that uses protons instead of X-rays. After a two year follow-up, the research team led by Nancy Mendenhall, MD, of the University of Florida Proton Therapy Institute, reported that the treatment was effective and that the gastrointestinal and genitourinary side effects were generally minimal.
‘This study is important because it will help set normal tissue guidelines in future trials,’ Dr. Mendenhall, said.
In the second study, researchers from Massachusetts General Hospital in Boston, Loma Linda University Medical Center in Loma Linda, Calif., and the Radiation Therapy Oncology Group in Philadelphia performed a case-matched analysis comparing high-dose external beam radiation therapy using a combination of photons (X-rays) and protons with brachytherapy (radioactive seed implants).
Over three years, 196 patients received the external beam treatments. Their data was compared to 203 men of similar stages who received brachytherapy over the same time period. Researchers then compared the biochemical failure rates (a statistical measure of whether the cancer relapses) and determined that men who received the proton/photon therapy had the same rate of recurrence as the men who received brachytherapy.
‘For men with prostate cancer, brachytherapy and external beam radiation therapy using photons and protons are both highly effective treatments with similar relapse rates,’ John J. Coen, MD, a radiation oncologist at Massachusetts General Hospital in Boston, said. ‘Based on this data, it is our belief that men with prostate cancer can reasonably choose either treatment for localised prostate cancer based on their own concerns about quality of life without fearing they are compromising their chance for a cure.’ EurekAlert

Dr. Fritz EilberResearchers from UCLA’s Jonsson Comprehensive Cancer Center have found that by administering a PET scan to individuals with soft-tissue sarcomas after just a single cycle of neoadjuvant chemotherapy, they can predict increased survival in these patients.

Prior research by this multidisciplinary team of physician-scientists had shown that a combined PET/CT scan using a glucose uptake probe called FDG allowed them to determine the pathologic response of patients’ tumours after the first dose of chemotherapy drugs. They then wondered if the patients who showed a significant PET response after the first round of chemotherapy also were surviving longer.

‘We did find that patients who experienced an early PET response to treatment had significantly increased survival,’ said the study’s senior author, Dr. Fritz Eilber, an associate professor of surgical oncology and director of the Jonsson Cancer Center’s sarcoma program. ‘This is vital because patients want to know if the drugs are working and what that says about their ultimate outcome.’
In the study, 39 patients with soft-tissue sarcoma underwent a PET scan to measure their tumour