Efficient isolation of Campylobacter bacteriophages from chicken skin, analysis of several isolation protocols

Application of bacteriophages in biopolymer-based functional food packaging films

Recently, food spoilage caused by pathogens has been increasing. Therefore, applying control strategies is essential. Bacteriophages can potentially reduce this problem due to their host specificity, ability to inhibit bacterial growth, and extend the shelf life of food. When bacteriophages are applied directly to food, their antibacterial activity is lost. In this regard, bacteriophage-loaded biopolymers offer an excellent option to improve food safety by extending their shelf life. Applying bacteriophages in food preservation requires comprehensive and structured information on their isolation, culturing, storage, and encapsulation in biopolymers for active food packaging applications. This review focuses on using bacteriophages in food packaging and preservation. It discusses the methods for phage application on food, their use for polymer formulation and functionalization, and their effect in enhancing food matrix properties to obtain maximum antibacterial activity in food model systems.

Bacteriophages in nature: recent advances in research tools and diverse environmental and biotechnological applications

Bacteriophages infect and replicate within bacteria and play a key role in the environment, particularly in microbial ecosystems and bacterial population dynamics. The increasing recognition of their significance stems from their wide array of environmental and biotechnological uses, which encompass the mounting issue of antimicrobial resistance (AMR). Beyond their therapeutic potential in combating antibiotic-resistant infections, bacteriophages also find vast applications such as water quality monitoring, bioremediation, and nutrient cycling within environmental sciences. Researchers are actively involved in isolating and characterizing bacteriophages from different natural sources to explore their applications. Gaining insights into key aspects such as the life cycle of bacteriophages, their host range, immune interactions, and physical stability is vital to enhance their application potential. The establishment of diverse phage libraries has become indispensable to facilitate their wide-ranging uses. Consequently, numerous protocols, ranging from traditional to cutting-edge techniques, have been developed for the isolation, detection, purification, and characterization of bacteriophages from diverse environmental sources. This review offers an exploration of tools, delves into the methods of isolation, characterization, and the extensive environmental applications of bacteriophages, particularly in areas like water quality assessment, the food sector, therapeutic interventions, and the phage therapy in various infections and diseases.

Bacteriophages Isolation and Efficacy Testing

Bacteriophages (phages) are viruses that infect bacteria and are the most abundant biological entity on the planet. Phages have gained popularity as an alternative to antibiotics due to their specificity and ability to efficiently lyse antimicrobial resistant bacterial pathogens. Before using phages, they must be isolated from the environment and tested to ensure purity and lytic ability against various hosts. This protocol walks through the entire multi-day procedure of enriching and processing raw environmental samples (seawater, primary sludge, and soil), testing for lytic activity, selecting and picking potential phage plaques, verifying phage purity, and finally, propagation (liquid and solid) of phages to obtain high-titer crude phage lysates.

Bacteriophage therapy in aquaculture: current status and future challenges

The escalation of antibiotic resistance has revitalized bacteriophage (phage) therapy. Recently, phage therapy has been gradually applied in medicine, agriculture, food, and environmental fields due to its distinctive features of high efficiency, specificity, and environmental friendliness compared to antibiotics. Likewise, phage therapy also holds great promise in controlling pathogenic bacteria in aquaculture. The application of phage therapy instead of antibiotics to eliminate pathogenic bacteria such as Vibrio, Pseudomonas, Aeromonas, and Flavobacterium and to reduce fish mortality in aquaculture has been frequently reported. In this context, the present review summarizes and analyzes the current status of phage therapy in aquaculture, focusing on the key parameters of phage application, such as phage isolation, selection, dosage, and administration modes, and introducing the strategies and methods to boost efficacy and restrain the emergence of resistance. In addition, we discussed the human safety, environmental friendliness, and techno-economic practicability of phage therapy in aquaculture. Finally, this review outlines the current challenges of phage therapy application in aquaculture from the perspectives of phage resistance, phage-mediated resistance gene transfer, and effects on the host immune system.

Bacteriophage Therapy for Critical and High-Priority Antibiotic-Resistant Bacteria and Phage Cocktail-Antibiotic Formulation Perspective

Phage therapy is revolving to address the issues mainly dealing with antibiotic resistance in the pathogenic bacteria. Among the drug-resistant microbial populations, the bacterial species have been categorized as high-priority or critical-priority bacteria. This review summarizes the efficiency and development in phage therapy used against these drug-resistant bacteria in the past few years mainly belonging to the critical- and high-priority list. Phage therapy is more than just an alternative to antibiotics as it not only kills the target microbial population directly but also leads to the chemical and physical modifications in bacterial cell structures. These phage-mediated modifications in the bacterial cell may make them antibiotic sensitive. Application of phage therapy in antibiotic-resistant foodborne bacteria and possible modulation in gut microbes has also been explored. Further, the phage cocktail antibiotic formulation, containing more than one type of phage with antibiotics, has also been discussed.

Isolation, host specificity and genetic characterization of Campylobacter specific bacteriophages from poultry and swine sources

The isolation and characterization of 304 Campylobacter specific bacteriophage isolates from broiler and swine sources is reported in this study. Genome size characterization determined by PFGE classified these isolates,called CAM1-CAM304, within the campylophages group II (n = 18) and group III (n = 286). Host range analyses showed a high host specificity and similar lytic spectrum among isolates of the same group. Campylophages of group II infected C. jejuni, C. coli and even a C. fetus strain whereas those of group III only infected C. jejuni strains. The most promising 59 campylophage candidates were selected according to their lytic activity and their genetic diversity was analyzed by RFLP using SmiI and HhaI endonucleases for group II and III campylophages, respectively. Moreover, RAPD-PCR technique was for the first time assessed in the genetic characterization of campylophages and it was shown to be effective only for those of group II. Bacteriophage isolates grouped in a same genotype displayed different host ranges, therefore, 13 campylophages of group II and eight of group III were differentiated considering all the approaches assayed. An in-depth analysis of these bacteriophages will be performed to confirm their promising potential for the biocontrol of Campylobacter within the farm to fork process.