Detection of New Delhi metallo-β-lactamase (bla NDM) and oxacillinase (bla OXA-48) genes among carbapenem-resistant Enterobacteriaceae (CRE) in Jazan Region, Saudi Arabia

Abstract Carbapenem-resistant Enterobacteriaceae (CRE) are critical priority pathogens due to their resistance to carbapenems, the last-resort antibiotics, and their rapid spread in healthcare facilities. The study investigates the epidemiological and molecular characteristics of CRE isolates in the Jazan region, Saudi Arabia. Clinical specimens were collected from patients admitted to Jazan General Hospital between December 2023 and May 2024. Identification of the isolates was done by the VITEK 2 system, and their susceptibility to antibiotics was determined on the MicroScan WalkAway platform according to the EUCAST guidelines. The E-test was used to confirm the CRE isolates. Molecular detection of carbapenemase genes (bla IMP, bla VIM, bla NDM, bla KPC and bla OXA-48) was conducted using the GeneXpert Carba-R assay using the GeneXpert®. A total of 426 Enterobacterial clinical isolates were collected from patients; among them, 53 (12.4%) were phenotypically found to be CRE; among such isolates, 14 (26.4%) were found to be carbapenemase-positive Enterobacteriaceae (CPE), and 39 (73.6%) were carbapenemase-negative Enterobacteriaceae (CNE). Among the CPE strains, Klebsiella pneumoniae was the predominant organism (42.9%), followed by Escherichia coli (28.6%), Enterobacter cloacae (21.4%), and Serratia marcescens (7.1%). Molecular analysis revealed a high prevalence of the bla NDM gene (71.4%), with bla OXA-48 detected in 42.9% of isolates. The bla VIM was identified in only 7.1%, while neither the bla KPC nor bla IMP is detected. For the CNE strains, K. pneumoniae was most common (62%), of which 15% produced extended-spectrum β-lactamase (ESBL). The isolates were all highly resistant to penicillin and β-lactam/β-lactamase inhibitors, moderately susceptible to fluoroquinolone (33%) and aminoglycosides (49%), and most susceptible to tigecycline (79%). The bla NDM was mainly found among ICU patients, while bla OXA-48 was most frequently identified among pediatric patients. The ICU admission with invasive devices, and prior broad-spectrum antibiotic exposure emerged as the main risk factors for the evolution of CPE. Multiple comorbidities; particularly malignancy, diabetes, and surgery; further increased vulnerability to CPE infections. Jazan city has a lower prevalence of CPE, while non-carbapenemase resistance is most predominant, reflecting regional epidemiological heterogeneity, which is important for regional stewardship and control.