Comparison of antimicrobial susceptibility between mucoid and non-mucoid and its guiding value for antibiotic therapy.

UNLABELLED

The aim of the study was to compare antimicrobial susceptibility between mucoid and non-mucoid and its guiding value for antibiotic therapy. A retrospective review was conducted on the sources of isolates, patient information, antimicrobial susceptibility results, and antimicrobial usage records for mucoid and non-mucoid isolates spanning from 2021 to 2023, comparing the differences between the two types. Additionally, infection cases of mucoid and non-mucoid were selected for in-depth analysis of their treatment courses, evaluating the guiding value of antimicrobial susceptibility results for antimicrobial therapy. We collected 1,443 non-mucoid and 342 mucoid . Our findings revealed that mucoid was predominantly found in respiratory tract specimens, while non-mucoid was primarily isolated from a broader range of specimen sources. Regarding antimicrobial susceptibility, mucoid exhibited notably lower levels of resistance compared to their non-mucoid counterparts, except for ciprofloxacin, levofloxacin, and cefepime. The most frequently prescribed drugs for mucoid were levofloxacin and ceftazidime, whereas for non-mucoid ceftazidime and meropenem were more frequently used. A total of 42 non-mucoid cases and 36 mucoid cases were further analyzed, which were isolated from hospitalized patients with a confirmed diagnosis of monomicrobial infection. The analysis of case information revealed that 90.2% of non-mucoid infections and 94.4% of mucoid infections showed consistency between antimicrobial susceptibility and outcomes. Our results revealed differences in demographic and clinical characteristics, antimicrobial susceptibility, and selection of antimicrobial agents between mucoid and non-mucoid . The findings will help optimize prognosis and combat the challenges posed by infections.

IMPORTANCE

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 . infections in terms of gender, antimicrobial susceptibility test, and the selection of antimicrobial agents. Specifically, mucoid 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 were levofloxacin and ceftazidime, whereas for non-mucoid , ceftazidime and meropenem were more frequently used. The analysis of case information revealed that no matter whether in mucoid or non-mucoid , the in vitro antimicrobial susceptibility test results were in good agreement with the therapeutic outcomes.