Editorial: Evolution of Genetic Mechanisms of Antibiotic Resistance

Harnessing Efficient ROS Generation in Carbon Dots Derived from Methyl Red for Antimicrobial Photodynamic Therapy

The emergence of drug-resistant pathogenic microorganisms has become a public health concern, with demand for strategies to suppress their proliferation in healthcare facilities. The present study investigates the physicochemical and antimicrobial properties of carbon dots (CD-MR) derived from the methyl red azo dye. The morphological and structural analyses reveal that such carbon dots present a significant fraction of graphitic nitrogen in their structures, providing a wide emission range. Based on their low cytotoxicity against mammalian cells and tunable photoluminescence, these carbon dots are applied to bioimaging in vitro living cells. The possibility of using CD-MR to generate reactive oxygen species (ROS) is also analyzed, and a high singlet oxygen quantum efficiency is verified. Moreover, the antimicrobial activity of CD-MR is analyzed against pathogenic microorganisms Staphylococcus aureus, Candida albicans, and Cryptococcus neoformans. Kirby-Bauer susceptibility tests show that carbon dots synthesized from methyl red possess antimicrobial activity upon photoexcitation at 532 nm. The growth inhibition of C. neoformans from CD-MR photosensitization is investigated. Our results show that N-doped carbon dots synthesized from methyl red efficiently generate ROS and possess a strong antimicrobial activity against healthcare-relevant pathogens.

Knowledge and Awareness of Physicians About Rational Antibiotic Use and Antimicrobial Resistance Before and After Graduation: A Cross-Sectional Study Conducted in Malatya Province in Turkey

BACKGROUND

We aimed to evaluate the level of theoretical knowledge of rational antibiotic use and awareness about emergence of multidrug resistance (MDR) among the senior students at a medical school and the actively-working family physicians.

METHODS

This cross-sectional research was carried out between 1 February and 30 April 2019 in Malatya province. Two-hundred twenty-five senior students in the Inonu University Medical School (Group 1) and 230 actively-working family physicians in Malatya primary health care services who were found to be eligible (Group 2) were included in this study. Power analysiscalculated the minimum of 240 participants with a proportion difference of 0.18 between the groups, a type I error of 0.05 and a type II error of 0.20. A questionnaire including seven sections and 28 questions was applied to the participants.

RESULTS

Doctors were more hesitant in pre-graduation and more self-confident in the post-graduation period for the decision to start antibiotic treatment. In addition, doctors forget their theoretical knowledge of antibiotics over time and are unable to follow current developments after graduation. The most important concern in the pre-graduation period was the choice of antibiotics from the wrong group, while in the post-graduation period it is the fear of the presence of unproven infection.

CONCLUSION

Physicians' antibiotic prescribing habits, attitudes and behaviors vary before and after graduation. Sustainable education for antibiotic use for physicians after graduation can contribute positively to reduce of antimicrobial resistance rates and to increase awareness about the use of rational antibiotics.

Performance of the VITEK®2 advanced expert system™ for the validation of antimicrobial susceptibility testing results

Time to reporting antimicrobial susceptibility testing (AST) results to physicians plays an essential role in antibiotic stewardship programs. Expert software has been developed for facilitating the microbiologists' AST review process. The reliability of the VITEK®2 Advanced Expert™ software to effectively alert the microbiologist in detection of atypical and inconsistent AST results was assessed at the Labor Berlin-Charité Vivantes services. The results demonstrated a confidence rate of 99.3% in reporting fully consistent AST results to physicians.

Carbon Nanodots in Photodynamic Antimicrobial Therapy: A Review

Antibiotic resistance development in bacteria is an ever-increasing global health concern as new resistant strains and/or resistance mechanisms emerge each day, out-pacing the discovery of novel antibiotics. Increasingly, research focuses on alternate techniques, such as antimicrobial photodynamic therapy (APDT) or photocatalytic disinfection, to combat pathogens even before infection occurs. Small molecule "photosensitizers" have been developed to date for this application, using light energy to inflict damage and death on nearby pathogens via the generation of reactive oxygen species (ROS). These molecular agents are frequently limited in widespread application by synthetic expense and complexity. Carbon dots, or fluorescent, quasi-spherical nanoparticle structures, provide an inexpensive and "green" solution for a new class of APDT photosensitizers. To date, reviews have examined the overall antimicrobial properties of carbon dot structures. Herein we provide a focused review on the recent progress for carbon nanodots in photodynamic disinfection, highlighting select studies of carbon dots as intrinsic photosensitizers, structural tuning strategies for optimization, and their use in hybrid disinfection systems and materials. Limitations and challenges are also discussed, and contemporary experimental strategies presented. This review provides a focused foundation for which APDT using carbon dots may be expanded in future research, ultimately on a global scale.