Persistence of crAssBcn phages in conditions of natural inactivation and disinfection process and their potential role as human source tracking markers.

Due to their abundance in the human gut, human specificity, and global distribution, some crAss-like phages, including the original p-crAssphage, have been proposed as indicators of human fecal pollution suitable for microbial source tracking (MST). The prevalence of crAss-like phages in water, and consequently their usefulness as MST indicators, is determined by their ability to survive various inactivation and disinfection processes. Recently, we isolated new crAss-like phages (named crAssBcn phages) capable of infecting Bacteroides intestinalis and exhibiting a wide geographical distribution.

Biofilm Prevention and Removal in Non-Target Strain by -like Coliphage.

Bacteriophages have gained significant interest as a potential solution to combat harmful bacteria, especially in the fight against antimicrobial resistance. With the rise in drug-resistant microorganisms, the medical community is increasingly exploring new alternatives to traditional antibiotics, and bacteriophages offer several advantages in this regard. However, phage applications still face some challenges, such as host specificity.

Recruitment of complete crAss-like phage genomes reveals their presence in chicken viromes, few human-specific phages, and lack of universal detection.

The order Crassvirales, which includes the prototypical crAssphage (p-crAssphage), is predominantly associated with humans, rendering it the most abundant and widely distributed group of DNA phages in the human gut. The reported human specificity and wide global distribution of p-crAssphage makes it a promising human fecal marker. However, the specificity for the human gut as well as the geographical distribution around the globe of other members of the order Crassvirales remains unknown.

CrAss-like phages are suitable indicators of antibiotic resistance genes found in abundance in fecally polluted samples.

Antibiotic resistance genes (ARGs) have been extensively observed in bacterial DNA, and more recently, in phage particles from various water sources and food items. The pivotal role played by ARG transmission in the proliferation of antibiotic resistance and emergence of new resistant strains calls for a thorough understanding of the underlying mechanisms. The aim of this study was to assess the suitability of the prototypical p-crAssphage, a proposed indicator of human fecal contamination, and the recently isolated crAssBcn phages, both belonging to the Crassvirales group, as potential indicators of ARGs.

Adapted methods for monitoring influenza virus and respiratory syncytial virus in sludge and wastewater.

Wastewater-based surveillance constitutes a valuable methodology for the continuous monitoring of viral circulation, with the capacity to function as an early warning system. It holds particular significance in scenarios where respiratory viruses exhibit overlapping clinical presentations, as occurs with SARS-CoV-2, influenza virus (IV), and respiratory syncytial virus (RSV), and allows seasonal virus outbreaks to be distinguished from COVID-19 peaks. Furthermore, sewage sludge, given it harbors concentrated human waste from a large population, serves as a substantial reservoir for pathogen detection.

Monitoring influenza and respiratory syncytial virus in wastewater. Beyond COVID-19.

Wastewater-based surveillance can be a valuable tool to monitor viral circulation and serve as an early warning system. For respiratory viruses that share similar clinical symptoms, namely SARS-CoV-2, influenza, and respiratory syncytial virus (RSV), identification in wastewater may allow differentiation between seasonal outbreaks and COVID-19 peaks. In this study, to monitor these viruses as well as standard indicators of fecal contamination, a weekly sampling campaign was carried out for 15 months (from September 2021 to November 2022) in two wastewater treatment plants that serve the entire population of Barcelona (Spain).

The Prophage and Us-Shiga Toxin Phages Revisited.

The authors first met in 1998 at the University of Würzburg, Germany, at the Institute of Hygiene and Microbiology, in Helge Karch's lab, where Herbert Schmidt worked as a PostDoc and Maite Muniesa visited the lab for a postdoctoral research stay to work on phages encoding Shiga toxin 2e (Stx2e) [...

Identification of a virulent phage infecting species of Nitrosomonas.

In the first and limiting step of nitrification, ammonia (NH) is oxidised to nitrite (NO) by the action of some prokaryotes, including bacteria of the Nitrosomonas genus. A potential approach to nitrification inhibition would be through the application of phages, but until now this method has been unexplored and no virulent phages that infect nitrifying bacteria have been described. In this study, we report the isolation of the first phage infecting some Nitrosomonas species.

Dominance of phage particles carrying antibiotic resistance genes in the viromes of retail food sources.

The growth of antibiotic resistance has stimulated interest in understanding the mechanisms by which antibiotic resistance genes (ARG) are mobilized. Among them, studies analyzing the presence of ARGs in the viral fraction of environmental, food and human samples, and reporting bacteriophages as vehicles of ARG transmission, have been the focus of increasing research. However, it has been argued that in these studies the abundance of phages carrying ARGs has been overestimated due to experimental contamination with non-packaged bacterial DNA or other elements such as outer membrane vesicles (OMVs).

Chicken liver is a potential reservoir of bacteriophages and phage-derived particles containing antibiotic resistance genes.

Poultry meat production is one of the most important agri-food industries in the world. The selective pressure exerted by widespread prophylactic or therapeutic use of antibiotics in intensive chicken farming favours the development of drug resistance in bacterial populations. Chicken liver, closely connected with the intestinal tract, has been directly involved in food-borne infections and found to be contaminated with pathogenic bacteria, including Campylobacter and Salmonella.

Essential Topics for the Regulatory Consideration of Phages as Clinically Valuable Therapeutic Agents: A Perspective from Spain.

Antibiotic resistance is one of the major challenges that humankind shall face in the short term. (Bacterio)phage therapy is a valuable therapeutic alternative to antibiotics and, although the concept is almost as old as the discovery of phages, its wide application was hindered in the West by the discovery and development of antibiotics in the mid-twentieth century. However, research on phage therapy is currently experiencing a renaissance due to the antimicrobial resistance problem.

Bacteriophages in sewage: abundance, roles, and applications.

The raw sewage that flows through sewage systems contains a complex microbial community whose main source is the human gut microbiome, with bacteriophages being as abundant as bacteria or even more so. Phages that infect common strains of the human gut bacteriome and transient bacterial pathogens have been isolated in raw sewage, as have other phages corresponding to non-sewage inputs. Although human gut phages do not seem to replicate during their transit through the sewers, they predominate at the entrance of wastewater treatment plants, inside which the dominant populations of bacteria and phages undergo a swift change.

Antibiotic resistance in the viral fraction of dairy products and a nut-based milk.

Phages, the most abundant biological entities in the biosphere, can carry different bacterial genes, including those conferring antibiotic resistance. In this study, dairy products were analyzed by qPCR for the presence of phages and phage particles containing antibiotic resistance genes (ARGs). Eleven ARGs were identified in 50 samples of kefir, yogurt, milk, fresh cheese and nut-based milk (horchata), purchased from local retailers in Barcelona.

Modeling human pollution in water bodies using somatic coliphages and bacteriophages that infect Bacteroides thetaiotaomicron strain GA17.

The ability to detect human fecal pollution in water is of great importance when assessing the associated health risks. Many microbial source tracking (MST) markers have been proposed to determine the origin of fecal pollution, but their application remains challenging. A range of factors, not yet sufficiently analyzed, may affect MST markers in the environment, such as dilution and inactivation processes.

Bacteriophages as Fecal Pollution Indicators.

Bacteriophages are promising tools for the detection of fecal pollution in different environments, and particularly for viral pathogen risk assessment. Having similar morphological and biological characteristics, bacteriophages mimic the fate and transport of enteric viruses. Enteric bacteriophages, especially phages infecting (coliphages), have been proposed as alternatives or complements to fecal indicator bacteria.

Population genomics and antimicrobial resistance dynamics of Escherichia coli in wastewater and river environments.

Aquatic environments are key niches for the emergence, evolution and dissemination of antimicrobial resistance. However, the population diversity and the genetic elements that drive the dynamics of resistant bacteria in different aquatic environments are still largely unknown. The aim of this study was to understand the population genomics and evolutionary events of Escherichia coli resistant to clinically important antibiotics including aminoglycosides, in anthropogenic and natural water ecosystems.

Bacteriophages of Shiga Toxin-Producing and Their Contribution to Pathogenicity.

Shiga toxins (Stx) of Shiga toxin-producing (STEC) are generally encoded in the genome of lambdoid bacteriophages, which spend the most time of their life cycle integrated as prophages in specific sites of the bacterial chromosome. Upon spontaneous induction or induction by chemical or physical stimuli, the genes are co-transcribed together with the late phase genes of the prophages. After being assembled in the cytoplasm, and after host cell lysis, mature bacteriophage particles are released into the environment, together with Stx.

Bacteriophages immunomodulate the response of monocytes.

Bacteriophages are present in fluids from cirrhosis patients. However, their effect on the immune response is unknown. In this work, we explore the role of phages in the phenotype, function, and cytokine production of monocytes.