A guide to the use of bioassays in exploration of natural resources.

Bioassays are the main tool to decipher bioactivities from natural resources thus their selection and quality are critical for optimal bioprospecting. They are used both in the early stages of compounds isolation/purification/identification, and in later stages to evaluate their safety and efficacy. In this review, we provide a comprehensive overview of the most common bioassays used in the discovery and development of new bioactive compounds with a focus on marine bioresources.

Molecular structures mediating adhesion of Campylobacter jejuni to abiotic and biotic surfaces.

Microaerophilic, Gram-negative Campylobacter jejuni is the causative agent of campylobacteriosis, the most common bacterial gastrointestinal infection worldwide. Adhesion is the crucial first step in both infection or interaction with the host and biofilm formation, and is a critical factor for bacterial persistence. Here we describe the proteins and other surface structures that promote adhesion to various surfaces, including abiotic surfaces, microorganisms, and animal and human hosts.

SIMBA Method-Simultaneous Detection of Antimicrobial and Anti-biofilm Activity of New Compounds Using Infantis.

The development of antimicrobial resistance and the formation of biofilms are serious public health problems. For this reason, new natural compounds with antimicrobial and anti-biofilm activity are being sought, and wild fungi represent an untapped potential. Various extraction agents, including organic solvents and aqueous buffers, can be used to obtain bioactive compounds from natural sources.

Isolation and characterization of novel phages for therapeutic applications.

is an important opportunistic pathogen causing chronic prosthetic joint infections associated with biofilm growth. Increased tolerance to antibiotic therapy often requires prolonged treatment or revision surgery. Phage therapy is currently used as compassionate use therapy and continues to be evaluated for its viability as adjunctive therapy to antibiotic treatment or as an alternative treatment for infections caused by to prevent relapses.

Biofilm Assay Using NanoLuc Luciferase.

Biofilms serve as a bacterial survival strategy, allowing bacteria to persist under adverse environmental conditions. The non-pathogenic Listeria innocua is used as a surrogate organism for the foodborne pathogen Listeria monocytogenes, because they share genetic and physiological similarities and can be used in a Biosafety Level 1 laboratory. Several methods are used to evaluate biofilms, including different approaches to determine biofilm biomass or culturability, viability, metabolic activity, or other microbial community properties.

Characterisation of a new cell wall teichoic acid produced by Listeria innocua ŽM39 and analysis of its biosynthesis genes.

Listeria innocua is genetically closely related to the foodborne human pathogen Listeria monocytogenes. However, as most L. innocua strains are non-pathogenic, it has been proposed as a surrogate organism for determining the efficacy of antimicrobial strategies against L.

The role of the Listeria monocytogenes surfactome in biofilm formation.

Listeria monocytogenes is a highly pathogenic foodborne bacterium that is ubiquitous in the natural environment and capable of forming persistent biofilms in food processing environments. This species has a rich repertoire of surface structures that enable it to survive, adapt and persist in various environments and promote biofilm formation. We review current understanding and advances on how L.

Expression of NanoLuc Luciferase in for Development of Biofilm Assay.

Studies of biofilm formation by bacteria are crucial for understanding bacterial resistance and for development of novel antibacterial strategies. We have developed a new bioluminescence biofilm assay for , which is considered a non-pathogenic surrogate for was transformed with a plasmid for inducible expression of NanoLuc luciferase (Nluc). Concentration-dependent bioluminescence signals were obtained over a concentration range of more than three log units.

Introduction of Phage Genome into Escherichia coli by Electroporation.

Electroporation has been an established tool for DNA delivery into prokaryotic and eukaryotic cells, thus facilitating basic research studies and improving medical treatments. Here we describe its use for introduction of phage genomic DNA into Escherichia coli cells, including preparation of electrocompetent cells, electric pulse optimization and recovery of electrotransformed cells. The technique can also be adapted for other bacterial species.

The lytic Myoviridae of Enterobacteriaceae form tight recombining assemblages separated by discontinuities in genome average nucleotide identity and lateral gene flow.

In Bacteria, a working consensus of species circumscription may have been reached and one of the most prominent criteria is high average nucleotide identity (ANI). ANI in effect groups strains that may recombine more or less frequently, depending on their biology, as opposed to rare interspecies gene transfer. For bacteriophages, which show various lifestyles, the nature of the fundamental natural unit, if it exists in a biological sense, is not well understood and defined.

Complete Genome Sequences of Group III Campylobacter Bacteriophages PC5 and PC14.

Here, we present the whole-genome sequences of bacteriophages PC5 and PC14 specific for Campylobacter jejuni, a leading cause of gastroenteritis in developed countries. Their genomes are syntenic to those of group III Campylobacter bacteriophages and share more than 90% identity at the nucleotide level with members of this group.

Identification and characterisation of new Campylobacter group III phages of animal origin.

Campylobacter-specific bacteriophages (phages) are considered as an alternative intervention strategy to decrease the level of poultry contamination with Campylobacter, a leading cause of gastroenteritis worldwide. Eradication efficiency depends primarily on phage-host interaction mediated by phage tail-spike proteins and bacterial receptors. Here, this interaction was characterised using tail-spike gene sequence analysis, phage neutralisation by antiserum and host range analysis of newly isolated group III Campylobacter phages with 68 Campylobacter jejuni and Campylobacter coli strains.

Use of phages to control Campylobacter spp.

The use of phages to control pathogenic bacteria has been investigated since they were first discovered in the beginning of the 1900s. Over the last century we have slowly gained an in-depth understanding of phage biology including which phage properties are desirable when considering phage as biocontrol agents and which phage characteristics to potentially avoid. Campylobacter infections are amongst the most frequently encountered foodborne bacterial infections around the world.