Pseudomonas syringae is a plant-associated bacterial species that has been divided into more than 60 pathovars, with the Pseudomonas syringae pv. syringae being the main causative agent of diseases in a wide variety of fruit trees. The most common treatments for biocontrol of P. syringae pv. syringae infections has involved copper derivatives and/or antibiotics. However, these treatments should be avoided due to their high toxicity to the environment and promotion of bacterial resistance. Therefore, it is essential to search for new approaches for controlling P. syringae pv. syringae. Phage therapy can be a useful alternative tool to the conventional treatments to control P. syringae pv. syringae infections in plants. In the present study, the efficacy of bacteriophage (or phage) φ6 (a commercially available phage) was evaluated in the control of P. syringae pv. syringae. As the plants are exposed to the natural variability of physical and chemical parameters, the influence of pH, temperature, solar radiation and UV-B irradiation on phage φ6 viability was also evaluated in order to develop an effective phage therapy protocol. The host range analysis revealed that the phage, besides its host (P. syringae pv. syringae), also infects the Pseudomonas syringae pv. actinidiae CRA-FRU 12.54 and P. syringae pv. actinidiae CRA-FRU 14.10 strains, not infecting strains from the other tested species. Both multiplicities of infection (MOIs) tested, 1 and 100, were effective to inactivate the bacterium, but the MOI 1 (maximum reduction of 3.9 log CFU/mL) was more effective than MOI 100 (maximum reduction of 2.6 log CFU/mL). The viability of phage φ6 was mostly affected by exposure to UV-B irradiation (decrease of 7.3 log PFU/mL after 8 h), exposure to solar radiation (maximum reduction of 2.1 PFU/mL after 6 h), and high temperatures (decrease of 8.5 PFU/mL after 6 days at 37 °C, but a decrease of only 2.0 log PFU/mL after 67 days at 15 °C and 25 °C). The host range, high bacterial control and low rates of development of phage-resistant bacterial clones (1.20 × 10−3) suggest that this phage can be used to control P. syringae pv. syringae infections in plants, but also to control infections by P. syringae pv. actinidiae, the causal agent of bacterial canker of kiwifruit. Although the stability of phage φ6 was affected by UV-B and solar radiation, this can be overcome by the application of phage suspensions at the end of the day or at night.

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Prostate cancer is the third most diagnosed cancer worldwide, and the second cause of cancer death in men. The treatments currently available are not always effective. For that reason, new treatment options need to be explored, which can include the use of drugs, already clinically available, used for the treatment of other conditions, such as -blockers. The present study aimed to explore the effects of several -blockers and cytostatic drugs in prostate cancer cell lines (22Rv1, LNCaP and PC3) and a normal prostate cell line (PNT-2). Cells were exposed up to 72 h to increasing concentrations of propranolol, carvedilol (both nonselective -blockers), atenolol, metoprolol (both 1-blockers), cisplatin (a cytostatic drug) and flutamide (an androgen receptor blocker) and cell viability was assessed. The non-selective blockers selected, propranolol and carvedilol and cytostatic drugs displayed cytotoxic effect on all cell lines, while the 1-blockers, metoprolol and atenolol did not alter significantly cells viability. Of the tested cell lines, 22Rv1 was the most sensitive to propranolol, carvedilol and cisplatin and PC3 was the most resistant. Therefore, sensitive line 22Rv1, resistant line PC3 and normal cell line PNT-2 were chosen for combined treatment between propranolol and cytostatic cisplatin and flutamide. Overall, the combined exposures revealed concentration dependent interactions between the cytostatic drugs and propranolol.