Antibiotic resistance pattern of multidrug-resistant Enterobacterales from a rectal surveillance study in northern Nigeria.

Abstract

Background: Multidrug-resistant organisms (MDROs) are important in clinical practice worldwide. As whole genome sequencing (WGS) technologies are adopted, it is key to understand the nature of MDROs before the introduction of WGS in resource-poor settings.

Methods: A hospital-based surveillance study was conducted in the largest referral health facility in northern Nigeria. A rectal swab sample was collected from each patient and samples were investigated for extended spectrum beta-lactamases and carbapenemase-resistant Enterobacterales (i.e. ESBL-PE and CRE, respectively). These MDROs were subjected to antimicrobial susceptibility testing and multiplex PCR. Statistical analyses were used to identify any associations between MDROs and selected antibiotics.

Results: The prevalence of MDROs among participants (N=168) was 87.5% (n=147) for ESBL-PE and 4.2% (n=7) for CRE. All isolates were resistant to tetracycline and co-trimoxazole; however, most MDROs were susceptible to meropenem, ceftazidime-avibactam and fosfomycin (≥70%). blaSHV (33.3%; n=49) was the predominant ESBL gene carried by the isolates, followed by combinations of blaSHV, blaCTX and blaTEM. Although no carbapenemase genes were found, all CRE isolates had the blaOXA-48 gene, which may not be associated with phenotypic carbapenem resistance observed (χ2=0.056, p=0.81).

Conclusions: Research utilising WGS and bioinformatics will elucidate more of the molecular landscape of MDROs in resource-poor settings.