METHODS
The aim of this study was to develop a CFA at a single pediatric CF care center, Children’s Mercy Kansas City (CMKC). IRB approval was obtained at CMKC. Data from all respiratory isolates from individuals with a diagnosis of CF obtained between 01 January 2015 and 31 December 2019 at CMKC were reviewed for study inclusion. Demographic information collected included the sex and age of the patient. Culture source was coded as sputum or oropharyngeal swab and were differentiated through a microbiology report. The microorganisms included in analysis for the CFA included: methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-resistant Staphylococcus aureus (MRSA),Pseudomonas aeruginosa (PA), Achromobacter species,Stenotrophomonas maltophila , and Burkholderia cepaciacomplex including Burkholderia multivorans, B. cenocepacia, B. gladioloi , and B. vietnamiensis species. Per CLSI guidelines, only species with a minimum of 30 isolates during the study period were included in the CFA.11 No other isolates were included. Antimicrobial susceptibility information was collected for all CF isolates. Each culture represents a distinct patient encounter. For people with CF with multiple isolates growing the same microorganism during the same year, only the first chronological isolate was included in the antibiogram. This methodology was based on CLSI guidance for handling multiple isolates within the same year.11
The CF antibiogram was compared to the HWA each year. The HWA is an annual compilation of system-wide susceptibility results from cultures from all sources. These HWA are published in June of each year. Cultures from people with CF are excluded from the HWA.
Descriptive statistics included mean and percentages. Additional statistical analyses of antibiogram data and susceptibility information were performed using X2 or Fisher’s exact test for categorical data, as appropriate, and t-test for non-categorical data. All tests of significance were two-tailed and p -values of ≤0.05 were considered statistically significant.