Table 4.
Selected Antimicrobial Resistance Characteristics of H30Rx, H30-Non-Rx, and Non-H30 Isolates Stratified by Extended-Spectrum Cephalosporin Resistance Status
| Characteristic | ESC-R (n = 278) | ESC-S (n = 1008) | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| H30 (n = 83) | P Value vs Non-H30a | H30 (n = 47) | P Value vs Non-H30a | |||||||
| Rx (n = 64) | Non-Rx (n = 19) | Non-H30 (n = 195) | Rx | Non-Rx | Rx (n = 5) | Non-Rx (n = 42) | Non-H30 (n = 961) | Rx | Non-Rx | |
| Co-resistance | ||||||||||
| Ciprofloxacin | 62 (96.9) | 18 (94.7) | 76 (39.0) | <.001* | <.001* | 5 (100) | 36 (85.7) | 25 (2.6) | <.001* | <.001* |
| Gentamicin | 28 (43.8) | 6 (31.6) | 73 (37.4) | .453 | .798 | 0 (…) | 13 (31.0) | 34 (3.5) | 1.00 | <.001* |
| TMP/SMX | 43 (67.2) | 15 (78.9) | 121 (62.1) | .555 | .226 | 1 (20.0) | 26 (61.9) | 240 (25.0) | 1.00 | <.001* |
| TMP/SMX & ciprofloxacin | 41 (64.1) | 15 (78.9) | 64 (32.8) | <.001* | <.001* | 1 (20.0) | 23 (54.8) | 15 (1.6) | .080 | <.001* |
| All 3 | 19 (29.7) | 5 (26.3) | 36 (18.5) | .084 | .374 | 0 (…) | 8 (19.0) | 2 (0.2) | 1.00 | <.001* |
| ESC-R type | <.001* | .007* | ||||||||
| ESBL only | 64 (100)c | 17 (89.5) | 102 (52.6) | … | … | … | … | … | ||
| AmpC only | 0 (…) | 2 (5.4) | 88 (45.4) | … | … | … | … | … | ||
| ESBL & AmpC | 0 (…) | 0 (…) | 4 (2.06) | … | … | … | … | … | ||
| Undetermined | 0 (…) | 0 (…) | 1 (0.5) | … | … | … | … | … | ||
| ESBL determinantsc | n = 64 | n = 17 | n = 106 | |||||||
| CTX-M-15 | 60 (93.8)b | 3 (17.6) | 48 (45.3) | <.001* | .060 | … | … | … | … | … |
| CTX-M-14 | 0 (…) | 2 (11.8) | 44 (41.5) | <.001* | .037* | … | … | … | … | … |
| CTX-M-27 | 1 (1.6) | 10 (58.8) | 1 (0.9) | 1.000 | <.001* | … | … | … | … | … |
| CTX-M others | 0 (…) | 1 (5.3) | 7 (6.6) | .046* | 1.000 | … | … | … | … | … |
| ESBL SHV | 0 (…) | 0 (…) | 3 (2.8) | .292 | 1.000 | … | … | … | … | … |
| ESBL TEM | 0 (…) | 0 (…) | 0 (…) | … | … | … | … | … | … | … |
| None identified | 3 (4.7) | 1 (5.3) | 4 (3.8) | 1.000 | .531 | … | … | … | … | … |
| AmpC determinantsc | n = 0 | n = 2 | n = 92 | |||||||
| CMY-2 | … | 1 (50.0) | 79 (96.3) | … | .277 | … | … | … | … | … |
| DHA | … | 0 (…) | 2 (2.2) | … | 1.000 | … | … | … | … | … |
| FOX | … | 0 (…) | 2 (2.2) | … | 1.000 | … | … | … | … | … |
| None identified | … | 1 (50.0) | 10 (10.9) | … | 1.000 | … | … | … | … | … |
Abbreviations: AmpC, AmpC-type-beta-lactamase; ESBL, extended-spectrum β-lactamase; ESC-R, extended-spectrum cephalosporin-resistant; ESC-S, extended-spectrum cephalosporin-susceptible; TMP/SMX, trimethoprim/sufamethoxazole.
a P values generated via χ2 test; Fisher exact test was used when expected frequencies were <5.
bOne of these isolates had both a CTX-M-15 gene identified as well as a KPC-3 carbapenemase gene, and was resistant to meropenem.
cTotal exceeds 100% as isolates could have >1 determinant identified.
*P value <.05.