Antimicrobial resistance is a significant threat to human health worldwide, forcing scientists to explore non-traditional antibacterial agents to support rapid interventions and combat the emergence and spread of drug resistant bacteria. Many new antibiotic-free approaches are being developed while the old ones are being revised, resulting in creating unique solutions that arise at the interface of physics, nanotechnology, and microbiology. Specifically, physical factors (e.g., pressure, temperature, UV light) are increasingly used for industrial sterilization. Nanoparticles (unmodified or in combination with toxic compounds) are also applied to circumvent in vivo drug resistance mechanisms in bacteria. Recently, bacteriophage-based treatments are also gaining momentum due to their high bactericidal activity and specificity. Although the number of novel approaches for tackling the antimicrobial resistance crisis is snowballing, it is still unclear if any proposed solutions would provide a long-term remedy. This review aims to provide a detailed overview of how bacteria acquire resistance against these non-antibiotic factors. We also discuss innate bacterial defense systems and how bacteriophages have evolved to tackle them.

2Aims: Ten rhizobial isolates obtained from different locations in Egypt were examined for their ability to survive under stress conditions and their growth response to increasing levels of NaCl (1±8% w/v), pH (4±10), CaCO 3 (1±10% w/v) and 12 antibiotics. Methods and Results: All the rhizobial isolates tolerated a NaCl concentration up to 5% and were divided into two groups with respect to NaCl tolerance. The rhizobial isolates from group two showed signi®cantly (P < 0á05) better survival under high NaCl concentration. All the tested isolates survived acidic (pH 4±5) and alkaline conditions (pH 9±10) and CaCO 3 (up to 10% w/v) in liqued YEM medium. Conclusions: Antibiotic resistance patterns did not correlate to NaCl, pH or CaCO 3 tolerance.Variations among different strains showed that there is potential to improve strain performance under stress conditions. Signi®cance and Impact of the Study: The results suggest that selection of adapted strains under stress conditions is possible and can be used as inoculants for successful lupin growth.

Phages are efficient in diagnosing, treating, and preventing various diseases, and as sensing elements in biosensors. Phage display alone has gained attention over the past decade, especially in pharmaceuticals. Bacteriophages have also found importance in research aiming to fight viruses and in the consequent formulation of antiviral agents and vaccines. All these applications require control over the stability of virions. Phages are considered resistant to various harsh conditions. However, stability-determining parameters are usually the only additional factors in phage-related applications. Phages face instability and activity loss when preserved for extended periods. Sudden environmental changes, including exposure to UV light, temperature, pH, and salt concentration, also lead to a phage titer fall. This review describes various formulations that impart stability to phage stocks, mainly focusing on polymer-based stabilization, encapsulation, lyophilization, and nano-assisted solutions.