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Objective The purpose of this study was to evaluate the in vitro antibacterial effects of a p‐Cymene‐based bis(pyrazolyl)methane derivative (SC‐19) to advance in developing alternative therapeutic compounds to fight against bacterial isolates from patients with otitis externa (OE). Methods Eighteen swab specimens were collected from patients aged over 18 years diagnosed with OE within at least 7 days of symptom onset, contaminated by only one bacterium type: Pseudomonas aeruginosa (n = 5); Staphylococcus aureus (n = 8); Klebsiella aerogenes (n = 2); Serratia marcescens (n = 1); Morganella morganii (n = 2). To appraise antibacterial activity, minimal inhibitory concentration (MIC), minimal bactericidal concentration (MBC), minimum biofilm inhibitory concentration (MBIC), and minimum biofilm eradication concentration (MBEC) assays were run at different SC‐19 concentrations. Results When using SC‐19, S. aureus strains showed less bacterial growth, but no bactericidal effect was observed. The MIC and MBC of SC‐19 were 62.5 and 2000 μg/ml against S. aureus and were >2000 μg/ml against the other isolates obtained from OE, respectively. In addition, the MBICs and MBECs of SC‐19 against S. aureus were 125 and >2000 μg/ml, respectively. Conclusion Nowadays the acquired antibiotic resistance phenomenon has stimulated research into novel and more efficient therapeutic agents. Hence, we report that, helped by the structural diversity fostered herein by a range of bis(pyrazolyl)methane derivatives, SC‐19 can be a promising alternative therapeutic option for treating OE caused by S. aureus given the observed effects on both planktonic state and biofilm. Level of Evidence IV

Infection is one of the most common causes that leads to joint prosthesis failure. In the present work, biodegradable sol-gel coatings were investigated as a promising controlled release of antibiotics for the local prevention of infection in joint prostheses. Accordingly, a sol-gel formulation was designed to be tested as a carrier for 8 different individually loaded antimicrobials. Sols were prepared from a mixture of MAPTMS and TMOS silanes, tris(tri-methylsilyl)phosphite, and the corresponding antimicrobial. In order to study the cross-linking and surface of the coatings, a battery of examinations (Fourier-transform infrared spectroscopy, solid-state 29Si-NMR spectroscopy, thermogravimetric analysis, SEM, EDS, AFM, and water contact angle, thickness, and roughness measurements) were conducted on the formulations loaded with Cefoxitin and Linezolid. A formulation loaded with both antibiotics was also explored. Results showed that the coatings had a microscale roughness attributed to the accumulation of antibiotics and organophosphites in the surface protrusions and that the existence of chemical bonds between antibiotics and the siloxane network was not evidenced. This research was funded by the Regional Government of Madrid through the program ADITIMAT (ref. P2018/NMT-4411) and CIBERINFEC-CIBER of Infectious Diseases (CB21/13/00043). B.T. would like to thank the Spanish Ministry of Education, Culture, and Sports for the support through FPU grant (FPU17/05977).

The purpose of this study was to evaluate the in vitro antibacterial effects of aEighteen swab specimens were collected from patients aged over 18 years diagnosed with OE within at least 7 days of symptom onset, contaminated by only one bacterium type:When using SC-19,Nowadays the acquired antibiotic resistance phenomenon has stimulated research into novel and more efficient therapeutic agents. Hence, we report that, helped by the structural diversity fostered herein by a range of bis(pyrazolyl)methane derivatives, SC-19 can be a promising alternative therapeutic option for treating OE caused byIV.