Molecular characterization of carbapenem-resistant Enterobacterales in thirteen tertiary care hospitals in Saudi Arabia

Abstract

Background: Carbapenems are the antibiotics of last-resort for the treatment of bacterial infections caused by multidrug-resistant organisms. The emergence of resistance is a critical and worrisome problem for clinicians and patients. Carbapenem-resistant Enterobacterales (CRE) are spreading globally, are associated with an increased frequency of reported outbreaks in many regions, and are becoming endemic in many others.

Objectives: Determine the molecular epidemiology of CRE isolates from various regions of Saudi Arabia to identify the genes encoding resistance and their clones for a better understanding of the epidemio-logical origin and national spread.

Design: Multicenter, cross-sectional, laboratory-based study.

Setting: Samples were collected from 13 Ministry of Health tertiary-care hospitals from five different regions of Saudi Arabia.

Methods: Isolates were tested using the GeneXpert molecular platform to classify CRE.

Main outcome measures: Prevalence of various types of CRE in Saudi Arabia.

Sample size: 519 carbapenem-resistant isolates.

Result: Of 519 isolates, 440 (84.7%) were positive for CRE, with Klebsiella pneumoniae (410/456, 90%) being the most commonly isolated pathogen. The distribution of the CRE-positive K pneumoniae resistance genes was as follows: OXA-48 (n=292, 71.2%), NDM-1 (n=85, 20.7%), and NDM+OXA-48 (n=33, 8%). The highest percentage of a single blaOXA-48 gene was detected in the central and eastern regions (77%), while the bla_NDM-gene was the predominant type in the northern region (27%). The southern regions showed the lowest percentages for harboring both blaOXA-48 and bla_NDM genes (4%), while the western region isolates showed the highest percentage of harboring both genes (14%).

Conclusion: The results illustrate the importance of molecular characterization of CRE isolates for patient care and infection prevention and control. Larger multicenter studies are needed to critically evaluate the risk factors and trends over time to understand the dynamics of spread and effective methods of control.

Limitations: Lack of phenotypic susceptibility and clinical data.

Conflict of interest: None.

Figure 1.. Participating regions and molecular classification of the 436 carbapenem-resistant Enterobacterales isolates by region (percentage for region shown above bars).