[Rational use of antibiotics]

Sinigrin reduces the virulence of Staphylococcus aureus by targeting coagulase

Multi-resistant Staphylococcus aureus (S. aureus) infection is a significant global health concern owing to its high mortality and morbidity rates. Coagulase (Coa), a key enzyme that activates prothrombin to initiate host coagulation, has emerged as a promising target for anti-infective therapeutic approaches. This study identified sinigrin as a potent Coa inhibitor that significantly inhibited S. aureus-induced coagulation at concentration as low as 32 mg/L. Additionally, at a higher concentration of 128 mg/L, sinigrin disrupted the self-protection mechanism of S. aureus. Thermal shift and fluorescence-quenching assays confirmed the direct binding of sinigrin to the Coa protein. Molecular docking analysis predicted specific binding sites for sinigrin in the Coa molecule, and point mutation experiments highlighted the importance of Arg-187 and Asp-222 as critical binding sites for both Coa and sinigrin. In vivo studies demonstrated that the combination of sinigrin with oxacillin exhibited greater antibacterial efficacy than oxacillin alone in the treatment of S. aureus-induced pneumonia in mice. Furthermore, sinigrin was shown to reduce bacterial counts and inflammatory cytokine levels in the lung tissues of S. aureus-infected mice. In summary, sinigrin was shown to directly target Coa, resulting in the attenuation of S. aureus virulence, which suggests the potential of sinigrin as an adjuvant for future antimicrobial therapies.

Over-the-counter sale of antibiotics during COVID-19 outbreak by community pharmacies in Saudi Arabia: a simulated client study

Background

Recent studies have reflected increased global concern regarding the possible acceleration of bacterial resistance secondary to the reported overuse and misuse of antibiotics during the COVID-19 pandemic. Therefore, this study aimed to investigate the nonprescribed sale of antibiotics by community pharmacies in Saudi Arabia during the COVID-19 outbreak and the pharmacists’ skills in triaging COVID-19 suspects.

Methods

Herein, 120 pharmacies were randomly selected and surveyed by simulated clients who presented gradual demands to convince the encountered pharmacists to agree to the over-the-counter sale of antibiotics. The pharmacists’ responses and counseling skills were documented in addition to their effectiveness in triaging suspected COVID-19 cases.

Results

Nineteen pharmacists (15.8%) were convinced to sell nonprescribed antibiotics after various levels of demand by clients. Moreover, twenty pharmacists (16.7%), who refused to sell nonprescribed antibiotics, referred the clients to clinics where they could easily obtain prescriptions, or to other pharmacies that violate the system. In addition, 29 pharmacists (24.2%) were not concerned about possible COVID-19 suspects, and 47–66 (39.2–55%) of them demonstrated different responses and recommendations. Moreover, 12 pharmacists of the 19 who violated the law did not offer any counseling regarding the use of the antibiotics.

Conclusions

The nonprescribed sale of antibiotics is still prevalent and may have increased during the COVID-19 outbreak in Saudi Arabia, thereby increasing the risk of accelerated bacterial resistance. The pharmacists’ skills in triaging COVID-19 suspects and patient education and counseling were below expectations. Further follow-up studies are highly recommended.

Antibiotic Intervention Affects Maternal Immunity During Gestation in Mice

Background

Pregnancy is a portentous stage in life, during which countless events are precisely orchestrated to ensure a healthy offspring. Maternal microbial communities are thought to have a profound impact on development. Although antibiotic drugs may interfere in these processes, they constitute the most frequently prescribed medication during pregnancy to prohibit detrimental consequences of infections. Gestational antibiotic intervention is linked to preeclampsia and negative effects on neonatal immunity. Even though perturbations in the immune system of the mother can affect reproductive health, the impact of microbial manipulation on maternal immunity is still unknown.

Aim

To assess whether antibiotic treatment influences maternal immunity during pregnancy.

Methods

Pregnant mice were treated with broad-spectrum antibiotics. The maternal gut microbiome was assessed. Numerous immune parameters throughout the maternal body, including placenta and amniotic fluid were investigated and a novel machine-learning ensemble strategy was used to identify immunological parameters that allow distinction between the control and antibiotic-treated group.

Results

Antibiotic treatment reduced diversity of maternal microbiota, but litter sizes remained unaffected. Effects of antibiotic treatment on immunity reached as far as the placenta. Four immunological features were identified by recursive feature selection to contribute to the most robust classification (splenic T helper 17 cells and CD5⁺ B cells, CD4⁺ T cells in mesenteric lymph nodes and RORγT mRNA expression in placenta).

Conclusion

In the present study, antibiotic treatment was able to affect the carefully coordinated immunity during pregnancy. These findings highlight the importance of inclusion of immunological parameters when studying the effects of medication used during gestation.

[Antibiotic stewardship (ABS). Part 2: Application]

Antibiotic stewardship (ABS) is an important measure to counteract the spread of resistant pathogens and multidrug resistance. The most important ABS tools include the implementation of local guidelines, the development of a house-related list of anti-infective agents, regular ABS visits and practice-oriented internal training events. Effective strategies for therapy optimization include indication testing and therapy evaluation, dose optimization as well as determining an appropriate duration of therapy. Oralization of anti-infectives (sequence therapy) should be supported by consistent clinical criteria in in-house guidelines. The incidence of Clostridioides difficile infections (CDI) can be more than halved by restricting the so-called "4C antibiotics". Point-of-care tests help to minimize the use of antibiotics in the outpatient setting. Vaccination reduces the need for antibiotic therapy.