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Background Elizabethkingia spp. are emerging as nosocomial pathogens causing various infections. These pathogens express resistance to a broad range of antibiotics, thus requiring antimicrobial combinations for coverage. However, possible antagonistic interactions between antibiotics have not been thoroughly explored. This study aimed to evaluate the effectiveness of antimicrobial combinations against Elizabethkingia infections, focusing on their impact on pathogenicity, including biofilm production and cell adhesion. Methods Double-disc diffusion, time–kill, and chequerboard assays were used for evaluating the combination effects of antibiotics against Elizabethkingia spp. We further examined the antagonistic effects of antibiotic combinations on biofilm formation and adherence to A549 human respiratory epithelial cells. Further validation of the antibiotic interactions and their implications was performed using ex vivo hamster precision-cut lung sections (PCLSs) to mimic in vivo conditions. Results Antagonistic effects were observed between cefoxitin, imipenem and amoxicillin/clavulanic acid in combination with vancomycin. The antagonism of imipenem toward vancomycin was specific to its effects on the genus Elizabethkingia. Imipenem further hampered the bactericidal effect of vancomycin and impaired its inhibition of biofilm formation and the adhesion of Elizabethkingia meningoseptica ATCC 13253 to human cells. In the ex vivo PCLS model, vancomycin exhibited dose-dependent bactericidal effects; however, the addition of imipenem also reduced the effect of vancomycin. Conclusions Imipenem reduced the bactericidal efficacy of vancomycin against Elizabethkingia spp. and compromised its capacity to inhibit biofilm formation, thereby enhancing bacterial adhesion. Clinicians should be aware of the potential issues with the use of these antibiotic combinations when treating Elizabethkingia infections. [ABSTRACT FROM AUTHOR]

Directed bonding with Al and Al2O3 was achieved using a transient liquid phase (TLP) method after annealing at the low melting point of Al, which deposited Ni, Cu, Ge, and Si on the Al2O3 substrate. Al/Al2O3 microstructures were evaluated using a scanning electron microscopy and transmission electron microscopy. A reaction layer was absent at the Al/Al2O3 interface, and all deposited metal films dissolved into the Al foil and reacted with Al to form an eutectic liquid phase near the interface to wet and join with the Al2O3. Al9Fe2 and Al3Fe intermetallic compounds were formed in the Al substrate because of Fe precipitation, which is an impurity of Al foil, and the reaction with Al at the grain boundaries of Al. The bonding area percentage, shear strength, and thermal conductivity for Al and Al2O3 were assessed using scanning acoustic tomography (SAT), the ISO 13 124 shear strength test, and the laser flash method, respectively. The Al/Al2O3 specimen deposited with the Ni film had the highest shear strength (33.74 MPa), thermal conductivity (42.3 W/mK), and bonding area percentage (96.78%). The Al/Al2O3 specimens deposited with Ge and Si exhibited relatively poor bonding because of the oxidation of Ge and Si at the surface of Al2O3 before bonding with Al. [ABSTRACT FROM AUTHOR]