A virus within a bacteria, isn’t life incredible or what?
A bacteriophage (/ˈbækˈtɪərioʊˌfeɪdʒ/), also known informally as a phage (/feɪdʒ/), is a virus that infects and replicates within Bacteria and Archaea. The term was derived from “bacteria” and the Greek: φαγεῖν (phagein), “to devour”. Bacteriophages are composed of proteins that encapsulate a DNA or RNA genome, and may have relatively simple or elaborate structures. Their genomes may encode as few as four genes, and as many as hundreds of genes. Phages replicate within the bacterium following the injection of their genome into its cytoplasm. Bacteriophages are among the most common and diverse entities in the biosphere. Bacteriophages are ubiquitous viruses, found wherever bacteria exist. It is estimated there are more than 1031 bacteriophages on the planet, more than every other organism on Earth, including bacteria, combined.
Phages are widely distributed in locations populated by bacterial hosts, such as soil or the intestines of animals. One of the densest natural sources for phages and other viruses is sea water, where up to 9×108 virions per milliliter have been found in microbial mats at the surface, and up to 70% of marine bacteria may be infected by phages. They have been used for over 90 years as an alternative to antibiotics in the former Soviet Union and Central Europe, as well as in France. They are seen as a possible therapy against multi-drug-resistant strains of many bacteria (see phage therapy). Nevertheless, phages of Inoviridae have been shown to complicate biofilms involved in pneumonia and cystic fibrosis, and shelter the bacteria from drugs meant to eradicate disease and promote persistent infection.
by: Edsel Cook
Saturday, April 07, 2018
Researchers from the Yale School of Medicine (YSM) in New Haven, Connecticut reported that the naturally-occurring virus succeeded in treating Pseudomonas aeruginosa, which resisted conventional antibiotic treatment.
They believed the results indicate the suitability of bacteriophage therapy for treating antibiotic-resistant infections. They also called for larger studies to determine the full extent of effectiveness and potential side effects.
The researchers published their exploratory report in the online journal Evolution, Medicine, and Public Health.
According to their study, the patient underwent heart surgery in 2012. Doctors replaced a damaged part of his aorta with a graft, a synthetic tube that performs the same purpose
Shortly after the surgery, the man developed a P. aeruginosa infection in his graft. A fairly widespread bacterium, it is often associated with infections in hospital environments.
For the next few years, the patient undertook a long-term antibiotic course to deal with the unexpected complication. However, the P. aeruginosa infection resisted treatment and eventually threatened the man’s life. (Related: Bacteria-eating viruses may be effective at eliminating foodborne pathogens; could be used to prevent food poisoning.)
OMKO1 uses bacterial defenses against bacteria
Eventually, the man’s physician came into contact with the YSM research team, who were investigating naturally-occurring bacteriophages at the time. They recommended trying an OMK01-based treatment based on their earlier experiments.
OMKO1 was first found in a sample from Dodge Pond, some 40 miles (64 kilometers) north of New Haven. The YSM researchers discovered its bactericidal properties against P. aeruginosa during experiments in lab dishes.
According to the researchers, P. aeruginosa possessed proteins on its cellular surface that pumped out any antibiotics before the medicine could damage them. These pumps gave the bacteria its high resistance to conventional treatment.
However, OMKO1 used that defensive system against its owner. The virus bound itself to those proteins, allowing it to bypass the bacteria’s anti-viral defenses and kill its target.
Furthermore, while P. aeruginosa could evolve to resist OMKO1’s attacks, doing so required alteration of its protein pumps. When that happened, the bacteria became vulnerable to antibiotics.
“The bacteria are backed into an evolutionary corner,” stated Paul Turner, a professor of ecology and evolutionary biology at Yale University (Yale) who co-authored the study.
Experimental bacteriophage treatment successfully eliminates infection
Based on their earlier experiments, Turner and his fellow researchers believed the OMKO1 virus could be used to eliminate the patient’s persistent infection.
After obtaining clearance from the patient, his physicians, and the Food and Drug Administration (FDA), the YSM researchers implemented an experimental procedure in January 2016.
In a surgical operation, they injected large numbers of OMKO1 into the patient’s chest to hunt down any instance of P. aeruginosa. Afterward, the patient took antibiotics for a brief period.
Turner and his team reported that the bacteriophage treatment successfully eliminated the infection. The patient remained free of P. aeruginosa for 18 months even without antibiotic protection.
“We argue that the phage therapy played a significant role in contributing to the eradication of the P. aeruginosa infection,” he and his co-author Benjamin Chan stated in their published study.
The authors hoped that their exploratory study served as initial evidence regarding the way OMKO1 could bolster the effectiveness of antibiotics in removing P. aeruginosa infections.
Chan said the next step is to look for bacteriophages that could be employed against E. coli, Klebsiella pneumoniae, and other antibiotic-resistant bacteria.
Find out more novel medical discoveries in Medicine.News.