Tetracycline-Containing MCM-41 Mesoporous Silica Nanoparticles for the Treatment of Escherichia coli.

Tetracycline (TC) is a well-known broad spectrum antibiotic, which is effective against many Gram positive and Gram negative bacteria. Controlled release nanoparticle formulations of TC have been reported, and could be beneficial for application in the treatment of periodontitis and dental bone infections. Furthermore, TC-controlled transcriptional regulation systems (Tet-on and Tet-off) are useful for controlling transgene expression in vitro and in vivo for biomedical research purposes; controlled TC release systems could be useful here, as well. Mesoporous silica nanomaterials (MSNs) are widely studied for drug delivery applications; Mobile crystalline material 41 (MCM-41), a type of MSN, has a mesoporous structure with pores forming channels in a hexagonal fashion. We prepared 41 ± 4 and 406 ± 55 nm MCM-41 mesoporous silica nanoparticles and loaded TC for controlled dug release; TC content in the TC-MCM-41 nanoparticles was 18.7% and 17.7% w/w, respectively. Release of TC from TC-MCM-41 nanoparticles was then measured in phosphate-buffered saline (PBS), pH 7.2, at 37 °C over a period of 5 h. Most antibiotic was released from both over this observation period; however, the majority of TC was released over the first hour. Efficacy of the TC-MCM-41 nanoparticles was then shown to be superior to free TC against Escherichia coli (E. coli) in culture over a 24 h period, while blank nanoparticles had no effect.

Patient and provider characteristics and outcomes associated with outpatient antibiotic overuse in acute adult bronchitis.

Nonbacterial acute bronchitis leads to many outpatient clinic visits in the US that result in an antibiotic prescription. Understanding antibiotic prescribing patterns and their clinical consequences will help improve antimicrobial stewardship efforts. A retrospective chart review was conducted to identify any correlations between patient and provider characteristics with antibiotic use in adult acute bronchitis (AAB) and to compare the clinical outcomes and rates of health care utilization between those who did and did not receive antibiotics. Study participants included adults with uncomplicated AAB seen by family medicine or internal medicine, specialty, and mid-level practitioners in a Baylor Scott & White Health outpatient facility. Phase 1 investigated whether prescribing rates varied by provider- or patient-level characteristics. Phase 2 compared clinical outcomes and health care utilization between patients who received an antibiotic versus those who did not receive an antibiotic for AAB. Among 35,383 visits for AAB, 81.4% resulted in a prescription for an antibiotic. Physicians >35 years of age and internal and family medicine physicians were more likely to prescribe antibiotics. Health care utilization rates did not differ between cohorts. The number of Clostridium difficile events was negligible.