Comparison of <i>in vitro</i> antimicrobial susceptibility between mucoid and non-mucoid <i>Pseudomonas aeruginosa</i> and its guiding value for antibiotic therapy

This study represents a large-scale comparative research conducted over two years at a tertiary hospital in China, involving 1,443 non-mucoid and 342 mucoid strains. We found significant differences between mucoid and non-mucoid <i>P</i>. <i>aeruginosa</i> infections in terms of gender, antimicrobial susceptibility test, and the selection of antimicrobial agents. Specifically, mucoid <i>P. aeruginosa</i> infections were predominantly observed in females and were mainly associated with respiratory tract infections. Moreover, the isolates with mucoid phenotype exhibited higher susceptibility to most antimicrobial agents compared to non-mucoid isolates. According to the data of the pharmacy department, we found the most frequently prescribed drugs for mucoid <i>P. aeruginosa</i> were levofloxacin and ceftazidime, whereas for non-mucoid <i>P. aeruginosa</i>, ceftazidime and meropenem were more frequently used. The analysis of case information revealed that no matter whether in mucoid or non-mucoid <i>P. aeruginosa</i>, the in vitro antimicrobial susceptibility test results were in good agreement with the therapeutic outcomes.