Introduction: The continuous increase in the incidence of bacterial resistance to existing antibiotics represents a worldwide health burden. A surrogate strategy to combat such crisis is to find compounds that restore the antimicrobial activity of the already existing antibiotics against multidrug resistant bacteria. Metformin is a commonly used antidiabetic medication. It has proven benefits in other diseases including cancer, aging-related and infectious diseases. In this study, the potential effect of metformin as an adjuvant therapy to antibiotics was investigated. Methods: Two multidrug resistant bacterial strains were used; methicillin-resistant Staphylococcus aureus (MRSA; ATCC 33,591) and multidrug resistant Pseudomonas aeruginosa (ATCC BAA-2114). To assess its efficacy, metformin was combined with several antibiotics: levofloxacin, chloramphenicol, rifampicin, ampicillin, and doxycycline. The antibacterial effect of metformin was tested using the micro broth dilution method. The minimum inhibitory concentration (MIC) was also measured. Cytotoxicity studies were also performed on mammalian cells to assess its safety. Results: Metformin exhibited an antibacterial effect when combined with the antibiotics on the two tested strains. It also showed low toxicity on the mammalian cells. Moreover, synergetic studies showed that metformin enhanced the effect of the combined antibiotics, as these combinations provide either a synergistic or additive effect with significant reduction in the MIC. Conclusion:Metformin exerts an adjuvant antibacterial effect; thus, it could be a possible candidate as an adjuvant therapy to reduce antimicrobial resistance.

Vaccines are important to improve immunity against pathogens and diseases. The current COVID-19 disease is rapidly evolving and spreading among people; therefore, it is important to utilize a proper vaccination strategy against it. Currently, many approved vaccines are available and accessible; however, there is a reported hesitancy against taking them among the public and even the health care workers. Mainly, this is attributed to the fear of the possible side effects and complications. Moreover, inaccurate knowledge disseminated through the media/social media especially by those who lack proper expertise adds confusion and more fear that affects the vaccination decision. For such reasons, it is essential to find strategies to increase the acceptability of vaccines and to enhance confidence in the vaccination process. This should be accompanied by sufficient efforts and proper clinical studies to confirm the value and the safety of the vaccines. Those strategies are important to avoid the further spread of the COVID-19 disease and to abort the pandemic worldwide, especially when considering the likely approach towards a COVID-19 booster vaccination program, in which booster vaccines are re-taken along intervals to adequately contain the rapidly evolving nature of the virus. This review article highlights the factors influencing the acceptability of the COVID-19 vaccination and enrollment in clinical trials among the public and some specific populations. Furthermore, it summarizes the suggested strategies and recommendations that can improve the attitudes towards COVID-19 vaccination programs.

Background: Ciprofloxacin is an antimicrobial that is commonly used to treat several types of infections. It exerts its antimicrobial activity through interfering with bacterial DNA replication and transcription, leading to increase oxidative stress and eventually bacterial death. Vitamin D, on the other hand, has been found to have DNA protective and antioxidant effects. In the current study, the possible interactive effect of vitamin D on ciprofloxacininduced cytotoxicity was investigated in various standard bacterial strains. Methods: The bacterial strains that were used include Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Staphylococcus epidermidis, Acinetobacter baumannii, Proteus mirabilis, and Klebsiella pneumoniae. The antibacterial effect of ciprofloxacin with and without vitamin D treatment of the bacteria was assessed using disc diffusion method and by measuring the minimum inhibitory concentration (MIC) and zones of inhibition of bacterial growth. Moreover, reactive oxygen species (ROS) generation after pretreatment of E. Coli cells with ciprofloxacin and/or vitamin D was measured as a function of as a function of hydrogen peroxide generation. Results: Ciprofloxacin demonstrated a potent antibacterial effect against the tested strains of bacteria. Moreover, pretreatment with vitamin D resulted in protecting the bacteria from the cytotoxicity of ciprofloxacin, this was indicated by the significantly smaller zones of inhibition and higher MIC values compared to ciprofloxacin alone as well as reduced ciprofloxacin-induced ROS generation after treatment with vitamin D. Conclusion: Results revealed the possible reduction in the activity of ciprofloxacin when used in combination with vitamin D. This could be explained by the ability of vitamin D to reduce oxidative stress in the bacterial cells.