Infections / 28.10.2024
Newly Discovered Toxins Made by Bacteria May Lead to New Antibiotics and Antifungals
MedicalResearch.com Interview with:
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Dr. Levy[/caption]
Dr. Asaf Levy
Senior Lecturer, Assistant Professor
Plant Pathology and Microbiology
The Robert H Smith Faculty of Agriculture, Food and Environment
Hebrew University of Jerusalem
MedicalResearch.com: What is the background for this study?
Response: Bacteria encode many compounds used to target neighboring microbes or cause disease in hosts, including humans. Classic antibiotics (small molecules) are one well-studied group of antimicrobials encoded by bacteria. A less-studied group consists of short protein toxins. These proteins are produced by bacteria and injected into target cells to kill them. In this study, we focused on a group of protein toxins called polymorphic toxins, which carry a short toxin domain at their end, which we termed “PTs” (an acronym for polymorphic toxins) and are roughly 100 amino acid long.
We developed a new algorithm to scan 107,000 bacterial genomes and discover novel PTs encoded by these bacteria. We then experimentally confirmed 9 new PT families that can kill bacteria and pathogenic fungi, including human pathogens, such as Candida auris and Aspergillus fumigatus. We saw that two of the toxins kill cells by degrading their DNA.
Dr. Levy[/caption]
Dr. Asaf Levy
Senior Lecturer, Assistant Professor
Plant Pathology and Microbiology
The Robert H Smith Faculty of Agriculture, Food and Environment
Hebrew University of Jerusalem
MedicalResearch.com: What is the background for this study?
Response: Bacteria encode many compounds used to target neighboring microbes or cause disease in hosts, including humans. Classic antibiotics (small molecules) are one well-studied group of antimicrobials encoded by bacteria. A less-studied group consists of short protein toxins. These proteins are produced by bacteria and injected into target cells to kill them. In this study, we focused on a group of protein toxins called polymorphic toxins, which carry a short toxin domain at their end, which we termed “PTs” (an acronym for polymorphic toxins) and are roughly 100 amino acid long.
We developed a new algorithm to scan 107,000 bacterial genomes and discover novel PTs encoded by these bacteria. We then experimentally confirmed 9 new PT families that can kill bacteria and pathogenic fungi, including human pathogens, such as Candida auris and Aspergillus fumigatus. We saw that two of the toxins kill cells by degrading their DNA.












Dr. Debra Silverman[/caption]
Dr. Debra Silverman Sc.D
Branch Chief and Senior Investigator in the Occupational and Environmental Epidemiology Branch, Division of Cancer Epidemiology & Genetics
National Cancer Institute
MedicalResearch.com: What is the background for this study? What are the main findings?
Dr. Silverman: We know that bladder cancer mortality rates have been elevated in northern New England for at least five decades. Incidence patterns in Maine, New Hampshire and Vermont are similar—about 20% higher than those for the United States overall. Elevated rates have been observed in both men and women, suggesting the role of a shared environmental etiologic factor.
A unique feature of northern New England is that a high proportion of the population uses private wells as their primary source of drinking water. The well water may contain low-to-moderate levels of arsenic. There are two possible sources of this arsenic contamination:
Dr. Steven Hicks[/caption]
Steven Daniel Hicks, M.D., Ph.D.
Penn State Hershey Medical Group Hope Drive, Pediatrics
Hershey, PA 17033
MedicalResearch.com: What is the background for this study? What are the main findings?
Dr. Hicks: This research was inspired by results of the CHARGE study (examining environmental influences on autism) which showed that specific pesticides (including pyrethroids) increased the risk of autism and developmental delay, particularly when mothers were exposed in the 3rdtrimester.
We recognized that the department of health sprayed pyrethroids from airplanes in a specific area near our regional medical center every summer to combat mosquito borne illnesses. We asked whether children from those areas had increased rates of autism and developmental delay. We found that they were about 25% more likely to be diagnosed with a developmental disorder at our medical center than children from control regions without aerial spraying of pyrethroids.


Dr. Braun[/caption]
MedicalResearch.com Interview with:
Joseph M. Braun PhD
Assistant Professor
Department of Epidemiology in the Program in Public Health
Brown University
Medical Research: What is the background for this study?
Dr. Braun: Perfluoroalkyl substances are a class of chemicals used to produce stain/water repellent textiles, fire fighting foams, and non-stick coatings. Virtually all people in the US have measurable levels of several different perfluoroalkyl substances in their blood. There is concern that early life exposure to these chemicals can increase the risk of obesity by reducing fetal growth or promoting adipogenesis.
What are the main findings?
Dr. Braun: Pregnant women in our study had perfluorooctanoic acid (PFOA) concentrations in their blood that were over 2-fold higher than pregnant women in the United States (median: 5.3 vs. 2.3 ng/mL) during the same time period (2003-2006).
Children born to women with higher serum PFOA concentrations during pregnancy had a higher body mass index, greater waist circumference, and more body fat at 8 years of age compared to children born to women with lower serum PFOA concentrations
