Volume 25, Number 7—July 2019
Dispatch
Carbapenem and Cephalosporin Resistance among Enterobacteriaceae in Healthcare-Associated Infections, California, USA1
, Sam Horwich-Scholefield, and Erin Epson
Table 1
Carbapenem and cephalosporin resistance among Enterobacteriaceae reported in healthcare-associated infections by California hospitals, 2014–2017*
| Antimicrobial agent | 2014 |
2015 |
2016 |
2017 |
Change |
|||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| No. (%) isolates† | % R | No. (%) isolates† | % R | No. (%) isolates† | % R | No. (%) isolates† | % R | Risk ratio (95% CI) | p value | |||||
| Enterobacteriaceae | ||||||||||||||
| Carbapenems | 2,747 (60.2) | 3.1 | 3,310 (64.2) | 3.1 | 3,409 (64.2) | 3.5 | 3,247 (65.1) | 3.0 | 1.00 (0.92–1.09) | 0.98 | ||||
| Cephalosporins | 3,303 (74.3) | 24.0 | 3,837 (76.2) | 27.7 | 4,020 (77.4) | 27.5 | 3,885 (79.6) | 28.0 | 1.04 (1.02–1.07) | 0.001 | ||||
| DTR | 2,298 (50.0) | 2.2 | 2,786 (53.5) | 2.0 | 2,916 (54.5) | 2.1 | 2,856 (56.6) | 1.6 | 0.92 (0.81–1.04) | 0.16 | ||||
| MDR |
4,500 (98.0) |
38.8 |
5,129 (98.5) |
43.3 |
5,228 (97.6) |
43.8 |
4,942 (97.9) |
44.0 |
1.04
(1.02–1.05) |
<0.001 |
||||
| Escherichia coli | ||||||||||||||
| Carbapenems | 1,623 (59.9) | 0.7 | 1,969 (64.9) | 0.7 | 1,969 (64.6) | 1.1 | 1,893 (66.7) | 1.2 | 1.24 (1.00–1.56) | 0.05 | ||||
| Cephalosporins | 1,890 (71.1) | 22.9 | 2,158 (72.4) | 28.0 | 2,229 (74.2) | 27.1 | 2,147 (76.8) | 29.7 | 1.07 (1.04–1.11) | <0.001 | ||||
| DTR | 1,323 (48.6) | 0.5 | 1,577 (51.7) | 0.3 | 1,615 (52.7) | 0.5 | 1,613 (56.3) | 0.4 | 0.99 (0.69–1.42) | 0.95 | ||||
| MDR |
2,669 (98.0) |
42.8 |
3,004 (98.4) |
47.0 |
2,998 (97.8) |
47.1 |
2,812 (98.2) |
49.2 |
1.04
(1.02–1.06) |
<0.001 |
||||
| Enterobacter spp. | ||||||||||||||
| Carbapenems | 489 (62.1) | 3.7 | 550 (62.9) | 6.9 | 602 (63.7) | 5.2 | 559 (63.0) | 5.4 | 1.06 (0.90–1.24) | 0.51 | ||||
| Cephalosporins | 701 (94.1) | 29.8 | 786 (94.5) | 30.9 | 855 (94.9) | 33.6 | 811 (94.5) | 30.8 | 1.02 (0.97–1.07) | 0.47 | ||||
| DTR | 488 (60.6) | 0.2 | 554 (61.8) | 0.5 | 608 (63.1) | 0.5 | 564 (61.2) | 0 | 0.79 (0.38–1.57) | 0.50 | ||||
| MDR |
789 (98.0) |
43.5 |
883 (98.5) |
53.0 |
940 (97.5) |
55.6 |
897 (97.3) |
50.3 |
1.04
(1.01–1.07) |
0.01 |
||||
| Klebsiella spp. | ||||||||||||||
| Carbapenems | 635 (59.7) | 8.8 | 791 (63.2) | 6.6 | 838 (63.8) | 7.9 | 795 (63.3) | 5.7 | 0.90 (0.80–1.01) | 0.07 | ||||
| Cephalosporins | 712 (68.3) | 21.4 | 893 (73.1) | 24.2 | 936 (72.6) | 22.8 | 927 (75.5) | 21.5 | 0.99 (0.94–1.05) | 0.76 | ||||
| DTR | 487 (45.7) | 8.8 | 655 (52.1) | 7.2 | 693 (52.4) | 7.2 | 679 (53.8) | 5.7 | 0.88 (0.77–1.00) | 0.06 | ||||
| MDR | 1,042 (97.8) | 25.1 | 1,242 (98.7) | 27.7 | 1,290 (97.5) | 27.2 | 1,233 (97.7) | 27.8 | 1.03 (0.99–1.07) | 0.21 | ||||
*Carbapenem-resistant Enterobacteriaceae were resistant to imipenem, meropenem, doripenem, or ertapenem. Enterobacteriaceae resistant to ceftriaxone, ceftazidime, cefepime, or cefotaxime were cephalosporin-resistant. MDR Enterobacteriaceae were nonsusceptible to >3 antimicrobial categories; XDR Enterobacteriaceae were nonsusceptible to all but 1 or 2 antimicrobial categories and pandrug-resistant Enterobacteriaceae were nonsusceptible to all antimicrobial categories (n = 15). DTR Enterobacteriaceae were intermediate or resistant to all reported agents within carbapenem, cephalosporin, and fluoroquinolone categories, as well as piperacillin-tazobactam and aztreonam when results were available. DTR, difficult-to-treat; MDR, multidrug-resistant; % R, percentage resistant.
†The number and percentage of Enterobacteriaceae with antimicrobial susceptibility test results as a proportion of the overall number reported (i.e., with or without antimicrobial susceptibility test results).
1Preliminary data from this analysis were presented in a poster at IDWeek 2018 in San Francisco, California, USA, October 5, 2018.