Bacteriophages can be used successfully to treat pathogenic bacteria in the food chain including zoonotic pathogens that colonize the intestines of farm animals. However, harsh gastric conditions of low pH and digestive enzyme activities affect phage viability, and accordingly reduce their effectiveness. We report the development of a natural protective barrier suitable for oral administration to farm animals that confers acid stability before functional release of bead-encapsulated phages. Escherichia coli bacteriophage ZSEC5 is rendered inactive at pH 2.0 but encapsulation in chitosan–alginate bead with a honey and gelatin matrix limited titer reductions to 1 log10 PFU mL−1. The encapsulated phage titers were stable upon storage in water but achieved near complete release over 4–5 h in a simulated intestinal solution (0.1% bile salt, 0.4% pancreatin, 50 mM KH2PO4 pH 7.5) at 37 °C. Exposure of E. coli O157:H7 to the bead-encapsulated phage preparations produced a delayed response, reaching a maximal reductions of 4.2 to 4.8 log10 CFU mL−1 after 10 h at 37 °C under simulated intestinal conditions compared to a maximal reduction of 5.1 log10 CFU mL−1 at 3 h for free phage applied at MOI = 1. Bead-encapsulation is a promising reliable and cost-effective method for the functional delivery of bacteriophage targeting intestinal bacteria of farm animals.

The high frequency of using engineered nanoparticles in various medical applications entails a deep understanding of their interaction with biological macromolecules. Molecular docking simulation is now widely used to study the binding of different types of nanoparticles with proteins and nucleic acids. This helps not only in understanding the mechanism of their biological action but also in predicting any potential toxicity. In this review, the computational techniques used in studying the nanoparticles interaction with biological macromolecules are covered. Then, a comprehensive overview of the docking studies performed on various types of nanoparticles will be offered. The implication of these predicted interactions in the biological activity and/or toxicity is also discussed for each type of nanoparticles.

Antibiotic-resistant Pseudomonas aeruginosa (P. aeruginosa) is one of the most critical pathogens in wound infections, causing high mortality and morbidity in severe cases. However, bacteriophage therapy is a potential alternative to antibiotics against P. aeruginosa. Therefore, this study aimed to isolate a novel phage targeting P. aeruginosa and examine its efficacy in vitro and in vivo. The morphometric and genomic analyses revealed that ZCPA1 belongs to the Siphoviridae family and could infect 58% of the tested antibiotic-resistant P. aeruginosa clinical isolates. The phage ZCPA1 exhibited thermal stability at 37 °C, and then, it decreased gradually at 50 °C and 60 °C. At the same time, it dropped significantly at 70 °C, and the phage was undetectable at 80 °C. Moreover, the phage ZCPA1 exhibited no significant titer reduction at a wide range of pH values (4–10) with maximum activity at pH 7. In addition, it was stable for 45 min under UV light with one log reduction after 1 h. Also, it displayed significant lytic activity and biofilm elimination against P. aeruginosa by inhibiting bacterial growth in vitro in a dose-dependent pattern with a complete reduction of the bacterial growth at a multiplicity of infection (MOI) of 100. In addition, P. aeruginosa-infected wounds treated with phages displayed 100% wound closure with a high quality of regenerated skin compared to the untreated and gentamicin-treated groups due to the complete elimination of bacterial infection. The phage ZCPA1 exhibited high lytic activity against MDR P. aeruginosa planktonic and biofilms. In addition, phage ZCPA1 showed complete wound healing in the rat model. Hence, this research demonstrates the potential of phage therapy as a promising alternative in treating MDR P. aeruginosa.

(Background): Multi-drug-resistant Klebsiella pneumoniae (MDR-KP) has steadily grown beyond antibiotic control. Wound infection kills many patients each year, due to the entry of multi-drug resistant (MDR) bacterial pathogens into the skin gaps. However, a bacteriophage (phage) is considered to be a potential antibiotic alternative for treating bacterial infections. This research aims at isolating and characterizing a specific phage and evaluate its topical activity against MDR-KP isolated from infected wounds. (Methods): A lytic phage ZCKP8 was isolated by using a clinical isolate KP/15 as a host strain then characterized. Additionally, phage was assessed for its in vitro host range, temperature, ultraviolet (UV), and pH sensitivity. The therapeutic efficiency of phage suspension and a phage-impeded gel vehicle were assessed in vivo against a K. pneumoniae infected wound on a rat model. (Result): The phage produced a clear plaque and was classified as Siphoviridae. The phage inhibited KP/15 growth in vitro in a dose-dependent pattern and it was found to resist high temperature (˂70 °C) and was primarily active at pH 5; moreover, it showed UV stability for 45 min. Phage-treated K. pneumoniae inoculated wounds showed the highest healing efficiency by lowering the infection. The quality of the regenerated skin was evidenced via histological examination compared to the untreated control group. (Conclusions): This research represents the evidence of effective phage therapy against MDR-KP.

The emergence and evolution of antibiotic-resistant bacteria is considered a public health concern. Salmonella is one of the most common pathogens that cause high mortality and morbidity rates in humans, animals, and poultry annually. In this work, we developed a combination of silver nanoparticles (AgNPs) with bacteriophage (phage) as an antimicrobial agent to control microbial growth. The synthesized AgNPs with propolis were characterized by testing their color change from transparent to deep brown by transmission electron microscopy (TEM) and Fourier-Transform Infrared Spectroscopy (FTIR). The phage ZCSE2 was found to be stable when combined with AgNPs. Both minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were evaluated for AgNPs, phage, and their combination. The results indicated that MIC and MBC values were equal to 23 µg/mL against Salmonella bacteria at a concentration of 10⁷ CFU/mL. The combination of 0.4× MIC from AgNPs and phage with Multiplicity of Infection (MOI) 0.1 showed an inhibitory effect. This combination of AgNPs and phage offers a prospect of nanoparticles with significantly enhanced antibacterial properties and therapeutic performance.

Background: Bacteriophages (phages) are one of the most promising alternatives to traditional antibiotic therapies, especially against multidrug-resistant bacteria. Klebsiella pneumoniae is considered to be an opportunistic pathogen that can cause life-threatening infections. Thus, this study aims at the characterization of a novel isolated phage vB_Kpn_ZC2 (ZCKP2, for short). Methods: The phage ZCKP2 was isolated from sewage water by using the clinical isolate KP/08 as a host strain. The isolated bacteriophage was purified and amplified, followed by testing of its molecular weight using Pulse-Field Gel Electrophoresis (PFGE), transmission electron microscopy, antibacterial activity against a panel of other Klebsiella pneumoniae hosts, stability studies, and whole genome sequencing. Results: Phage ZCKP2 belongs morphologically to siphoviruses as indicated from the Transmission Electron Microscopy microgram. The Pulsed Field Gel Electrophoresis and the phage sequencing estimated the phage genome size of 48.2 kbp. Moreover, the absence of lysogeny-related genes, antibiotic resistance genes, and virulence genes in the annotated genome suggests that phage ZCKP2 is safe for therapeutic use. Genome-based taxonomic analysis indicates that phage ZCKP2 represents a new family that has not been formally rated yet. In addition, phage ZCKP2 preserved high stability at different temperatures and pH values (-20 − 70 °C and pH 4 – 9). For the antibacterial activity, phage ZCKP2 maintained consistent clear zones on KP/08 bacteria along with other hosts, in addition to effective bacterial killing over time at different MOIs (0.1, 1, and 10). Also, the genome annotation predicted antibacterial lytic enzymes. Furthermore, the topology of class II holins was predicted in some putative proteins with dual transmembrane domains that contribute significantly to antibacterial activity. Phage ZCKP2 characterization demonstrates safety and efficiency against multidrug-resistant K. pneumoniae, hence ZCKP2 is a good candidate for further in vivo and phage therapy clinical applications.