This week in Biofilms and Microbiomes: Monday September 19, 2016

A round-up of what we read last week in the media's coverage of biofilms and microbiomes research.

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Bacteriophage therapy can be used to eradicate Clostridium difficile infection, reports a new study published online in the journal Frontiers in Microbiology. Clostridium difficile is a notorious nosocomial pathogen causing fatalities in the immunocompromised. A limiting factor to the control of the disease is the lack of treatment options, and complications from antibiotic resistance, leading to relapse, increased health care-associated costs and death in 10% cases. In this study, funded by AmpliPhi Biosciences Corporation, a global leader in the development of bacteriophage-based antibacterial therapies to treat drug-resistant infections, researchers from the University of Leicester examined the impact of an optimized phage combination on C. difficile biofilms and tested their efficacy both as a stand-alone treatment and as adjunct to vancomycin in wax moth, G. mellonella larva CDI model. Bacteriophages are naturally occurring viruses that develop high selectivity for certain bacteria. When they acquire their target, they rapidly kill the host and replicate to locally amplify their presence, resulting in a powerful local response to an infection. In the study, the phages were applied before or after biofilm establishment in vitro, and the impact was analyzed according to turbidity, viability counts and topography as observed using scanning electron and confocal microscopy. The infectivity profiles and efficacies of orally administered phages and/or vancomycin were ascertained by monitoring colonization levels and larval survival rates. It was observed that phages prevented biofilm formation, and penetrated established biofilms, thus demonstrating that C. difficile phages are particularly effective when used to prevent infection, but they are also good at targeting harmful bacterial infections once biofilms have formed. “The results suggest that it may be possible to reduce the threat of C. difficile, and potentially other bacterial infections, through the use of phage, both prophylactically to prevent infection and therapeutically once an infection is established. Phage therapy targets specific pathogenic bacterial populations while sparing the beneficial microbiome,” said Prof. Martha Clokie from the Department of Infection, Immunity and Inflammation at the University of Leicester. The paper was widely publicized by the scientific media, including coverage by Business Wire, Science Codex, and Scicasts.

Another hot paper of the week was a new study on infant microbiome published in Nature Medicine. According to this research the microbes living in a baby’s gut during its first month of life may directly impact the developing immune system, leading to a higher risk of allergies and asthma later in childhood. To examine this relationship, the study’s senior authors Christine Johnson of the Henry Ford Health System in Detroit, Susan Lynch of the University of California, and their colleagues analyzed stool samples from 130 babies around their 1-month birthday and from 168 infants around 6 months of age, as well as health information including the children’s responses to 10 food and aeroallergens at 2 years. Interestingly, the team found that the children had one of three distinct patterns of bacteria and fungi in their guts. Infants with a neonatal microbiota state characterized by lower levels of common gut bacteria—specifically, Bifidobacteria, Lactobacillus, Faecalibacterium, and Akkermansia, and higher levels of some fungi including Candida tended to be allergy prone at age 2. A further analysis of the microbes' metabolic byproducts -- molecules in the stool samples revealed a distinct metabolite profile that lacked anti-inflammatory fatty acids and breast milk–derived oligosaccharides that were found in children who possessed the two lower-risk gut microbiota states. In contrast, the researchers identified a specific lipid, called 12,13-DiHOME, that was enriched in the high-risk neonate samples. This lipid alone was sufficient to suppress “the group of T-cells necessary to prevent allergic response,” explained Lynch. A careful study of the socioeconomic and environmental factors to learn why some children developed a high-risk gut microbiome profile suggested only two major factors — dog ownership and gender, with boys being more likely to lack a healthy gut. The researchers are continuing to follow the children on study, including evaluating their lung function at age 11 when a definitive asthma diagnosis is possible. But, the current findings underscore the importance of developing early interventions to improve microbial health in young infants. Read the press release by Science Daily, Genome Web, GEN News and Quartz.

We’d love to hear what you’ve been reading this week. Please comment below.

Richa Dandona

Partnerships and Operations Manager, Nature Partner Journals, Nature Research