Progress Made in Creating 'Good' Bacteria to Fight 'Bad' Bacteria in Eye Infections

There were three major components to the study. The first established that isolates of two antibiotic-resistant ocular pathogens, Pseudomonas aeruginosa and Serratia marcescens, were all susceptible to being attacked and killed by at least one of two other bacteria , Micavibrio aeruginosavorus and Bdellovibrio baceriovorus, which act as predators against the pathogens but are believed to be "good," or non-infectious, bacteria when they exist within the human body.

In the second phase, human corneal-limbic epithelial cells that are native to the eye were exposed in vitro to M. aeruginosavorus and B. baceriovorus to test whether those "good" predator bacteria would cause either toxicity or inflammation in those cells. They did not.

In the third phase, the two "good" predator bacteria were injected into live worms from the species Galleria mellonella, which is well established as a suitable model to test the toxicity of various microbes as well as a live organism's innate immunity to those microbes.

Where injection of the pathogenic bacterium P. aeruginosa as a positive control was one hundred percent fatal to the worms, other worms injected with the two "good" predator bacteria had 11-day survival rates between 93.3 and 100 percent, a strong sign that the "good" bacteria were not toxic to the worms.

In addition a lack of change in larval pigmentation following injection suggested that the "good" bacteria also did not provoke an aggressive innate immune response in the worms.

Lead author of the study Daniel Kadouri, PhD, an assistant professor of oral biology the University of Medicine and Dentistry of New Jersey-New Jersey Dental School, said their findings leave them confident that, in isolation, pathogenic bacteria are susceptible to successful attack by predator bacteria, predator bacteria do not appear inherently harmful to ocular cells when applied topically, and a live organism can tolerate the predator bacteria well.

He said that the time to test all three phenomena simultaneously in the eye tissue of a live organism may now be at hand.

The current study builds on another recent paper published in PLoS ONE, which also described research led by Kadouri. That study used the predatory bacteria Bdellovibrio baceriovorus 109J, B. bacteriovorus HD100, and Micavibrio aeruginosavorus strain ARL-13, in targeting 14 strains of dangerous bacteria that are known to be multidrug resistant (MDR). Species targeted in that earlier research included Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae, and Pseudomas spp., all of which are commonly encountered in health care settings.

After predator bacteria and MDR strains were co-cultured in the laboratory, the researchers found that cell viability had diminished to varying degrees in all 14 MDR strains, suggesting that while the MDR strains are strongly resistant to current antibiotics, they may have no innate defenses that would protect them against one or more of the predator bacteria.

The study has been published in the online journal PLoS ONE.

Source-ANI

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Scientists Make New Discovery in Fight Against Deadly Meningococcal Disease

"Until now we have not known how it attaches to the human host. It has been a long-standing mystery how it attaches to the airway to colonise "People can be carriers of the bug and not get any symptoms, while some people progress to invasive disease.

To understand why, we need to know the detail of how the bacterium colonises the airway. Now that the pathway has been identified we can study this process to understand how invasive disease occurs. This is especially important considering the rapidly progressing and serious outcomes of meningococcal disease."If you understand how the bug first attaches and how it first signals its attachment then we may identify new risk factors or treatment procedures," Professor Jennings said.

The findings were published Friday in the highly regard PLOS Pathogens journal as featured research "Dual Pili Post-translational Modifications Synergize to Mediate Meningococcal Adherence to Platelet Activating Factor Receptor on Human Airway Cells." The paper states: There is no fully protective vaccine against this pathogen in current use and the key processes that dictate the transition from harmless carriage of the bacterium in the airway (the case for the vast majority of colonised hosts) to invasive disease are largely undefined.

A key missing link in this organism's interaction with the human host is the identity of the receptor that is the first point of contact for the organism within the airway.Professor Jennings said the receptor is used by a range of airway pathogens and the bacterium mimics a human structure to attach to this receptor."It's not actually protein that attaches to the receptor but decorations on the protein that are known as post-translational modifications. One of these is a sugar structure, which of course is of great interest to our work here at Glycomics," he said.The Institute of Glycomics is a world leader in the study of glycans and carbohydrates (sugars) and how they behave in terms of disease prevention and cure.

Source-Eurekalert

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Study Shows How Frog Embryos Could Help Fight Disease

Scientists at Northwestern University and the Karlsruher Institut fur Technologie in Germany, in collaboration with the Advanced Photon Source at the U.S. Department of Energy's Argonne National Laboratory, X-rayed an embryo during gastrulation, the period when its hundreds of cells start to organize into differentiated tissues that eventually form the nervous system, muscles and internal organs.

The study titled "X-ray phase-contrast in vivo microtomography probes new aspects of Xenopus gastrulation."

Studies of African clawed frog embryos can provide clues to the evolution of vertebrates and how human genes turn on or off to create diseases.

Until now, however, it has been difficult to study these embryos. Classical absorption imaging requires a contrast agent and large X-ray dose that can harm living organisms.

Researchers from the German synchrotron ANKA proposed a new method of nondestructive analysis using X-ray diffraction.

In the experiment, Xianghui Xiao, a scientist at the APS who collaborated on the work, and his colleagues took regular 15-second exposures separated by periods of 10 minutes over the course of two hours of different gastrulas.

The resulting 13 time-lapse scans provided a detailed portrait of the transfiguration of the frog cells.

The scientists discovered new morphological structures and clarified the process for redistributing fluid in the embryo. They also were able to locate the areas of the embryo that were driving the migration of tissues and cells during gastrulation.

The findings have been published in the journal Nature.

Source-ANI

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