Through the shake-flask method, the solubility of p-nitrobenzamide in 12 pure solvents including n-propanol, ethanol, isopropanol, n-butanol, water, isobutanol, ethyl acetate, acetonitrile, dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), N-methyl-2-pyrrolidinone (NMP), and ethylene glycol (EG) was acquired over a temperature range from 283.15 to 328.15 K at ambient pressure p = 101.2 kPa. The mole fractions of p-nitrobenzamide in the equilibrium liquid phase increased as the temperature increased and had the following order in various solvents: DMSO > DMF > NMP > EG > ethyl acetate > ethanol > isopropanol > n-propanol > isobutanol > acetonitrile > n-butanol > water. They were fitted through the Wilson model, modified Apelblat equation, λh equation, and NRTL model. The maximum root-mean-square deviation value and relative average deviation value gained through the four models were, respectively, 56.69 × 10–4 and 6.55 × 10–2. The relative average deviation values achieved were smaller through the modified Apelblat equation than through the other equations for a given solvent. The mixing properties, infinitesimal concentration activity coefficient, and reduced excess enthalpy were derived. Additionally, using the relationship analysis of the Kamlet and Taft linear solvation energy of the solvent effect, the degree and type of interactions of solute–solvent and solvent–solvent were recognized.

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Sulbactam is a plausible option for treating infections because of its intrinsic antibacterial activity against the members of the genus, but the mechanisms of sulbactam resistance have not been fully studied in In this study, a total of 2,197 clinical isolates were collected from 27 provinces in China. Eighty-eight isolates with various MICs for sulbactam were selected on the basis of their diverse clonality and underwent multilocus sequence typing (MLST), antimicrobial susceptibility testing, and resistance gene screening. The copy number and relative expression of and were measured via quantitative PCR and quantitative reverse transcription-PCR, respectively. The genetic structure of multicopy was determined using the whole-genome sequencing technology. The cefoperazone-sulbactam resistance rate of the 2,197 isolates was 39.7%. The rate of positivity for or IS in the sulbactam-nonsusceptible group (64.91% and 78.95%, respectively) was significantly higher than that in the sulbactam-susceptible group (0% and 0%, respectively; < 0.001). The MIC of sulbactam ( < 0.001) varied considerably between the groups expressing with or without upstream IS Notably, the genetic structure of the multicopy gene in strain ZS3 revealed that was embedded within four tandem copies of the cassette IS-Tn-IS Therefore, and IS represent the prevalent mechanism underlying sulbactam resistance in clinical isolates in China. The structure of the four tandem copies of first identified may increase sulbactam resistance.