The rapid emergence and spread of antibiotic-resistant bacteria continues to be an issue difficult to deal with, especially in the clinical, animal husbandry, and food fields. The occurrence of multidrug-resistant bacteria renders treatment with antibiotics ineffective. Therefore, the development of new therapeutic methods is a worthwhile research endeavor in treating infections caused by antibiotic-resistant bacteria. Recently, bacterial membrane vesicles (BMVs) have been investigated as a possible approach to drug delivery and vaccine development. The BMVs are released by both pathogenic and non-pathogenic Gram-positive and Gram-negative bacteria, containing various components originating from the cytoplasm and the cell envelope. The BMVs are able to transform bacteria with genes that encode enzymes such as proteases, glycosidases, and peptidases, resulting in the enhanced antibiotic resistance in bacteria. The BMVs can increase the resistance of bacteria to antibiotics. However, the biogenesis and functions of BMVs are not fully understood in association with the bacterial pathogenesis. Therefore, this review aims to discuss BMV-associated antibiotic resistance and BMV-based therapeutic interventions.

The global problem of antibiotic resistance in bacteria is quickly developing in most antibiotics used in hospitals and livestock. Recently, the infections with multi-drug resistant (MDR) bacteria become a major cause of death worldwide. Current antibiotics are not very effective in treating MDR Salmonella infections, which have become a public health threat. Therefore, novel approaches are needed to rapidly detect and effectively control antibiotic-resistant pathogens. Bacteriophages (phages) have seen renewed attention for satisfying those requirements due to their host-specific properties. Therefore, this review aims to discuss the possibility of using phages as a detection tool for recognizing bacterial cell surface receptors and an alternative approach for controlling antibiotic-resistant pathogens in food systems.

This study aimed to assess the β-lactamase- and efflux pump-mediated antibiotic resistance in Typhimurium (WT-ST), ciprofloxacin-induced antibiotic-resistant. Typhimurium (CI-ST), and clinically-acquired antibiotic-resistant . Typhimurium (CA-ST). The β-lactamase activities were significantly increased up to 63 μmol/min/mL in CA-ST and 24 μmol/min/mL in CI-ST when compared to WT-ST (13 μmol/min/mL). The highest efflux pump activity was observed in CI-ST and CA-ST, showing more than 45%. The antibiotic susceptibilities of WT-ST, CI-ST, and CA-ST were increased in the presence of β-lactamase and efflux pump inhibitors. CA-ST showed the highest activity in AcrD, MdtABC, EmrAB, MdtK, and MacAB efflux pumps. The repressed were responsible for the decreased susceptibility of CA-ST to ampicillin (MIC > 512 μg/mL). This study would provide useful information for better understating of the development of multidrug resistance in association with β-lactamase and efflux pump activities and designing new antibiotic chemotherapy in combination with inhibitors.

The improvement in current standards is essential to accurately detect methicillin-resistant Staphylococcus aureus in consideration of various resistance phenotypes and genotypes. The varied and distinctive expression patterns of antibiotic resistance-related genes were observed in S. aureus exposed to oxacillin and ciprofloxacin. It is worth noting the relationship between resistance phenotype and resistance genotype in terms of MIC values and expression of antibiotic resistance determinants. This study provides useful information for understanding the mechanisms of methicillin resistance in S. aureus in association with phenotypic and genotypic resistance determinants.

Drought tolerance is a complex trait controlled by many metabolic pathways and genes and identifying a solution to increase the resilience of plants to drought stress is one of the grand challenges in plant biology. This study provided compelling evidence of increased drought stress tolerance in two sugar beet genotypes when treated with exogenous putrescine (Put) at the seedling stage. Morpho-physiological and biochemical traits and gene expression were assessed in thirty-day-old sugar beet seedlings subjected to drought stress with or without Put (0.3, 0.6, and 0.9 mM) application. Sugar beet plants exposed to drought stress exhibited a significant decline in growth and development as evidenced by root and shoot growth characteristics, photosynthetic pigments, antioxidant enzyme activities, and gene expression. Drought stress resulted in a sharp increase in hydrogen peroxide (H2O2) (89.4 and 118% in SBT-010 and BSRI Sugar beet 2, respectively) and malondialdehyde (MDA) (35.6 and 27.1% in SBT-010 and BSRI Sugar beet 2, respectively). These changes were strongly linked to growth retardation as evidenced by principal component analysis (PCA) and heatmap clustering. Importantly, Put-sprayed plants suffered from less oxidative stress as indicated by lower H2O2 and MDA accumulation. They better regulated the physiological processes supporting growth, dry matter accumulation, photosynthetic pigmentation and gas exchange, relative water content; modulated biochemical changes including proline, total soluble carbohydrate, total soluble sugar, and ascorbic acid; and enhanced the activities of antioxidant enzymes and gene expression. PCA results strongly suggested that Put conferred drought tolerance mostly by enhancing antioxidant enzymes activities that regulated homeostasis of reactive oxygen species. These findings collectively provide an important illustration of the use of Put in modulating drought tolerance in sugar beet plants.