Antibiotic resistance is a growing global problem that affects people, animals, the environment, and the economy. Many clinically relevant bacteria have become resistant to antibiotics, and this fact is emerging as one of the major threats to public health. The lack of new antibiotics, which is due to their time-consuming and costly development, exacerbates the problem. Therefore, it is necessary to identify new antimicrobial agents to treat bacterial and fungal infections. Plant extracts, which are valuable sources of bioactive compounds, mainly polyphenols, play an important role as a new strategy to combat pathogenic microorganisms. There is an extensive body of supporting evidence for the potent antibacterial and antifungal activities of polyphenols. Furthermore, some polyphenols show a synergistic effect when combined with antibiotics and antifungals, suggesting a promising alternative for therapeutic strategies against antibiotic resistance. However, only a few articles are found when searching the antibacterial or antifungal activities of polyphenols employing clinical isolates. Hence, this review focuses on the antimicrobial activity of polyphenols and extracts rich in polyphenols on clinical isolates, organized according to the World Health Organization priority pathogens classification.

Background: Hepatitis delta virus (HDV) is a defective agent that only replicates in the presence of the hepatitis B virus. Accordingly, HDV acquisition may occur as superinfection of HBsAg+ carriers or following acute dual HDV and hepatitis B virus exposure. Herein, we examined the global and incident rates of HDV infections in Spain. Patients and methods: The presence of anti-HDV antibody and new HDV superinfections was examined in all HBsAg+ patients who attended one large tertiary outclinic in Spain since year 2000. Anti-HDV antibodies were tested repeatedly every 5 years in those previously negative. Results: During a median follow-up of 12 years, 478 individuals were diagnosed as HBsAg+. Overall, 64.4% were male, median age was 55 years, 88.1% were native Spaniards, 6.5% were coinfected with HIV, and 7.3% were reactive for hepatitis C virus (HCV) antibodies. A total of 19 (4%) patients had anti-HDV antibody at first diagnosis. There were no further HDV seroconversions. Most anti-HDV+ patients were male (n=12), former injection drug users (n=13), and native Spaniards (n=16). Coinfection with HIV was found in six, and 12 had HCV antibodies. Interestingly, three of seven women with delta hepatitis were foreigners (Asian or African), denied injection drug use, were younger than 40 years old, and negative for both HCV and HIV. Conclusion: The prevalence of chronic hepatitis delta is currently very low (<5%) among chronic HBsAg+ carriers in Spain, with lower rates in recent years. Moreover, new incident HDV infections were not seen in 478 chronic hepatitis B carriers since year 2000, following drastic declines in injection drug use.

Infections caused by multidrug-resistant bacteria are becoming increasingly frequent and sometimes difficult to treat due to the limited number of antibiotics active against them. In addition, they can spread between countries and/or continents, which is a problem of great relevance worldwide. It is, therefore, urgent to find alternatives to treat infections caused by multidrug-resistant bacteria. This study aimed at exploring a possible therapeutic alternative in the fight against antibiotic resistance. Based on the known antibacterial capacity of polyphenols, we tested the antimicrobial activity of a polyphenolic extract of Albariño white grape marc on clinical strains since research on such bacteria has been very scarce until now. First, the extract was obtained using a medium-scale ambient temperature (MSAT) system, which is an efficient and sustainable extractive method. The determinations of the polyphenolic content of the extract and its antioxidant capacity showed good results. Using chromatographic and mass spectrometric tools, 13 remarkable polyphenols were detected in the extract. The antibacterial activity of our grape marc extract against nineteen clinical strain isolates, some of which are multidrug-resistant, was evaluated by means of the calculation of half of the maximum inhibitory concentration (IC50) and the value of the minimum bactericidal concentrations (MBCs). In conclusion, the extract showed effectiveness against all clinical strains tested, regardless of their level of antibiotic resistance, and shows promise in the fight against antibiotic resistance.