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. 2021 Feb 18;59(3):e01870-20. doi: 10.1128/JCM.01870-20

TABLE 4.

Overall performance of Enterobacterales and P. aeruginosa

Organism Total isolates, n EA, n EA, % CA, n CA, % R, n Major,a n Major, % Very major, n Very major, %
C. freundii 57 49 86.0 57 100.0 5 0 0 0 0
C. koseri 44 43 97.7 44 100.0 0 0 0 0 0
E. tarda 1 1 100.0 1 100.0 0 0 0 0 0
K. (E.) aerogenes 47 43 91.5 46 97.9 1 1 2.2 0 0
E. cloacae 43 43 100.0 43 100.0 9 0 0 0 0
E. cloacae subsp. cloacae 24 20 83.3 24 100.0 0 0 0 0 0
E. cloacae complex 19 19 100.0 19 100.0 0 0 0 0 0
E. coli 169 163 96.4 168 99.4 7 1 0.6 0 0
K. oxytoca 48 46 95.8 48 100.0 3 0 0 0 0
K. pneumoniae subsp. pneumoniae 103 97 94.2 103 100.0 1 0 0 0 0
K. pneumoniae 65 63 96.9 64 98.5 7 1 1.7 0 0
Morganella morganii subsp. morganii 18 18 100.0 18 100.0 0 0 0 0 0
M. morganii 12 11 91.7 12 100.0 0 0 0 0 0
P. mirabilis 59 57 96.6 59 100.0 0 0 0 0 0
P. vulgaris 29 25 86.2 29 100.0 0 0 0 0 0
P. stuartii 25 23 92.0 23 92.0 3 2 9.1 0 0
Salmonella Enteritidis 7 7 100.0 7 100.0 0 0 0 0 0
Salmonella Typhi 4 3 75.0 4 100.0 0 0 0 0 0
S. marcescens 76 69 90.8 74 97.4 1 2 2.7 0 0
S. flexneri 1 1 100.0 1 100.0 0 0 0 0 0
S. sonnei 15 15 100.0 15 100.0 0 0 0 0 0
P. aeruginosa 207 198 95.7 200 96.6 38 7 4.1 0 0
All species combined 1,073 1,014 94.5 1,059 98.7 75 14b 1.4 0 0
a

The overall categorical major error rate for Enterobacterales and P. aeruginosa combined was 1.4% (14/998). Nine major errors were one dilution apart from the reference method and, as such, fall within essential agreement. Based on the essential agreement and the lack of an intermediate breakpoint for ceftazidime-avibactam, the adjusted categorical major error rate for FDA criteria was 0.5% (5/998).

b

Adjusted major error rate for P. aeruginosa was calculated due to lack of an intermediate category. Before adjustment, major error rate as presented in the table was 4.1% (7/169). After adjustment, the major error rate for FDA criteria was 1.2% (2/169). Five P. aeruginosa isolates were within essential agreement compared to the reference method. Out of seven major errors for Enterobacterales, four major errors were one dilution apart from the reference method and, as such, fall within essential agreement. For resolved errors per ISO standards, refer to Table S4.