Evolutionary optimisation of antibiotic dosing regimens for bacteria with different levels of resistance

Reflecting on Fleming's caveat: the impact of stakeholder decision-making on antimicrobial resistance evolution

Antimicrobial resistance poses one of the greatest and most imminent threats to global health, environment and food security, for which an urgent response is mandated. Evolutionary approaches to tackling the crisis tend to focus on proximate issues including the mechanisms and pathways to resistance, with associated calls to action for infection control and antimicrobial stewardship. This is of clear benefit but overlooks the fundamental influence of policy and stakeholder decision-making on resistance evolution. In 1945, Fleming issued a stark warning on the irresponsible use of penicillin and its potential to cause death due to penicillin-resistant infections. Attention to resistance evolution theory and heeding Fleming's advice could have allowed for a vastly different reality. Embedding evolutionary theory within policy, industry and regulatory bodies is not only essential but is now a race against time. Hence, critical appraisal of historical behaviour and attitudes at a global scale can inform a paradigm of anticipatory and adaptive policy. To undertake this exercise, we focused on the largest group of antibiotics with the greatest clinical and economic footprint, the beta-lactams. We examined historical case studies that affected how beta-lactams were developed, produced, approved and utilized, in order to relate stakeholder decision-making to resistance evolution. We derive lessons from these observations and propose sustainable approaches to curb resistance evolution. We set a position that actively incorporates an evolutionary theory of antimicrobial resistance into decision-making within antimicrobial development, production and stewardship.

Assessment of endocarditis prophylaxis knowledge and attitudes among healthcare practitioners in Tehran and Hamadan

BACKGROUND

Having knowledge of the dental procedures that necessitate endocarditis prophylaxis is of high importance. Therefore, the aim of the present study was to determine the knowledge level and attitudes of general medical and dental practitioners, dental specialists, and cardiologists in Tehran and Hamadan about endocarditis.

METHODS

This cross-sectional study was carried out on 420 general medical and dental practitioners, dental specialists, and cardiologists in Tehran and Hamadan provinces in 2015. The questionnaire used in this research consisted of three parts as follows: part one: information on cardiac diseases; part two: dental procedures requiring endocarditis prophylaxis; part three: antibiotic diet in endocarditis prophylaxis. Independent t-test, one-way ANOVA, and chi-square tests were conducted to analyze the data. All the analyses were performed in SPSS version 16.

RESULTS

The results showed that 86.7 had a relatively favorable and 10.5% of subjects had a favorable level of knowledge about endocarditis. Also, 58.6% of subjects had a poor attitude toward endocarditis prophylaxis. There was a significant relationship between knowledge and attitude, age, gender, and work experience (P < 0.001). There was a significant relationship between knowledge and attitude, and job groups; dental specialists had a more favorable knowledge and positive attitude than others (P < 0.001).

CONCLUSION

We recommended developing more practical training programs in dental schools on cardiac diseases, and dental procedures requiring endocarditis prophylaxis and antibiotic diets.

Dosage Optimisation of Trimethoprim and Sulfamethoxazole for the Treatment of an Avian Pathogenic Strain of Escherichia coli in Broiler Chickens

Based on pharmacokinetic studies carried out according to the methodologies defined by the European Medicines Agency (EMA) using mass spectrometry analysis, a new formulation of a veterinary drug for the treatment of broiler chickens is proposed. Currently, the traditional trimethoprim-sulfamethoxazole drug used for broilers is applied in a 1:5 ratio, and the recommended dose is 45 mg kg-1 of live weight administered at 24 h intervals for 3 to 5 days. In this study, we propose a novel combination containing similar active substances in a newly established ratio of 1:4, with a recommended dosage of 20 mg kg-1 of live weight administered at 24 h intervals for 3 to 5 days. With this method, the currently recommended dose of the traditional trimethoprim-sulfamethoxazole drug used for broilers can be reduced by more than half. The efficacy of the newly designed formulation and dosage of the drug was verified in a bioassay for the treatment of broilers experimentally infected with an avian pathogenic strain of Escherichia coli. In the experiment, we compared the newly designed dosage with the traditional dosage in terms of efficacy and dosage. There were no statistically significant differences between the two drugs in efficacy regarding the survival of chickens after experimental infection or changes in their health status. The experimental results suggest that a significant reduction in the recommended daily dose of drugs containing trimethoprim and sulfamethoxazole for the treatment of bacterial infections in broilers is possible and can support the prudent use of antimicrobials, including the limitation of their overuse.

Optimizing Antimicrobial Treatment Schedules: Some Fundamental Analytical Results

This work studies fundamental questions regarding the optimal design of antimicrobial treatment protocols, using pharmacodynamic and pharmacokinetic mathematical models. We consider the problem of designing an antimicrobial treatment schedule to achieve eradication of a microbial infection, while minimizing the area under the time-concentration curve (AUC), which is equivalent to minimizing the cumulative dosage. We first solve this problem under the assumption that an arbitrary antimicrobial concentration profile may be chosen, and prove that the ideal concentration profile consists of a constant concentration over a finite time duration, where explicit expressions for the optimal concentration and the time duration are given in terms of the pharmacodynamic parameters. Since antimicrobial concentration profiles are induced by a dosing schedule and the antimicrobial pharmacokinetics, the 'ideal' concentration profile is not strictly feasible. We therefore also investigate the possibility of achieving outcomes which are close to those provided by the 'ideal' concentration profile, using a bolus+continuous dosing schedule, which consists of a loading dose followed by infusion of the antimicrobial at a constant rate. We explicitly find the optimal bolus+continuous dosing schedule, and show that, for realistic parameter ranges, this schedule achieves results which are nearly as efficient as those attained by the 'ideal' concentration profile. The optimality results obtained here provide a baseline and reference point for comparison and evaluation of antimicrobial treatment plans.

Prevalence of antibiotic misuse in cases of pneumonia and diarrhea in Saudi Arabia

Background

Antibiotic misuse is a major public health issue with long-term repercussions.

Objective

The purpose of this investigation was to evaluate the effects of pneumonia and diarrhea, with an emphasis on antibiotic misuse.

Methodology

This study included 410 participants (217 fathers and 193 mothers), of whom 239 purchased antibiotics for their children without a prescription, whereas 171 had a prescription or were unsure if one was required.

Results

Antibiotics were used incorrectly by 58.1% of respondents. About 51.2% of participants said they were taking two antibiotics at the same time. Around 30% of people admitted to using antibiotics inefficiently. The most prevalent reason for use was "viral and bacterial," followed by "viral," and then "bacterial," with 35%, 21%, and 20%, respectively. In addition, 22.4% of patients have used antibiotics for an unknown reason.

Conclusion

Saudi parents of children with pneumonia and diarrhea abuse antibiotics. Saudi legislation banning medications without a prescription has helped reduce antibiotic abuse, but more community-based education and awareness are needed.