Results

The study analyzed 260 Enterobacterales isolates obtained from 260 patients. In the cohort, the sex distribution was almost equal, with 131 of 260 patients being male (50.4%) and 129 of 260 being female (49.6%). Saudi nationals were 199 of 260 patients (76.5%), while 61 of 260 (23.5%) were non-Saudi nationals. The patients were divided among the age groups as follows: ≥ 60 years (119/260, 45.8%), adults 18-59 years (109/260, 41.9%), children 0-12 years old (24/260, 9.2%), and adolescents 13-17 years old (8/260, 3.1%). Their mean age was 55.6 years, with a median of 63 years.

Of the 260 isolates, 26 (10.0%) met the CRE definition by demonstrating phenotypic resistance to at least one of the two carbapenems tested; the remaining 234 isolates (90.0%) did not meet the CRE definition. The main CRE species included Klebsiella pneumoniae (approximately 81%), the E. cloacae complex (approximately 11%), Escherichia coli (approximately 4%), and Klebsiella oxytoca (approximately 4%). Of the carbapenemase-producing isolates, the majority were NDM-positive (approximately 58%), followed by those with OXA-48 and NDM (approximately 23%), and those with OXA-48 alone (approximately 19%). None had KPC, VIM, or IMP. CRE isolates were distributed almost equally between blood (11/26, 42.3%) and urine (10/26, 38.5%); the remaining five isolates (19.2%) were recovered from other specimen types (see Table 1).

In the bivariate analyses (Table 2), several device- and care-related variables showed strong quantitative associations with CRE isolation. Use of a central venous catheter was associated with nearly a sevenfold increased odds of CRE isolation (odds ratio [OR] 6.80, 95% confidence interval [CI] 2.84–16.27; χ2 = 23.834; p < 0.001; post-hoc power = 0.99). Foley catheterization was associated with more than a fourfold increased odds (OR 4.49, 95% CI 1.84–10.96; χ2 = 11.162; p = 0.004; power = 0.93). Critical care unit admission was also associated with higher odds of CRE (OR 2.83, 95% CI 1.22–6.55; χ2 = 7.821; p = 0.020), although post-hoc power was modest (0.69), reflecting limited event numbers.

Characteristic | N (%)
Age
Child | 24 (9.2%)
Adolescent | 8 (3.1%)
Adult | 109 (41.9%)
Older adult | 119 (45.8%)
Mean (years) | 55.58
Median (years) | 63
Gender
Male | 131 (50.4%)
Female | 129 (49.6%)
Nationality
Saudi | 199 (76.5%)
Non-Saudi | 61 (23.5%)

Risk factor | Chi-Square Value | P-value | ORa (95% CIb) | Post Hoc Power
Critical care unit admission | 7.821 | 0.02 | 2.83 (1.22-6.55) | 0.69
Central venous line catheter | 23.834 | 0.000 | 6.80 (2.84-16.27) | 0.99
Foley catheter | 11.162 | 0.004 | 4.49 (1.84-10.96) | 0.93
Endotracheal intubation | 4.711 | 0.095 | 2.24 (0.93-5.39) | 0.42
Solid organ malignancy | 0.101 | 0.951 | NC | NAc
Hematological malignancy | 5.246 | 0.073 | NC | 0.82
Hemoglobinopathy | 0.628 | 0.731 | NC | NAc
Diabetes mellitus | 3.844 | 0.206 | NC | NAc
Hypertension | 3.16 | 0.146 | NC | NAc

The other factors did not achieve conventional statistical significance. For endotracheal intubation, the OR was 2.24 (95% CI 0.93–5.39; χ2 = 4.711; p = 0.095; post-hoc power = 0.42). For hematologic malignancy, solid organ malignancy, hemoglobinopathy, diabetes, and hypertension, ORs were not calculated because zero cell counts precluded valid uncorrected estimation; these entries were therefore reported as NC rather than 0.00. Given that only 26 CRE cases were identified, these nonsignificant or non-estimable findings should be interpreted as imprecise and should not be interpreted as protective effects or evidence of no association.