Phenotypic and Genotypic Characterization of Extended Spectrum Beta-Lactamase-Producing Clinical Isolates of and in Two Kenyan Facilities: A National Referral and a Level Five Hospital.

BACKGROUND

The emergence of antimicrobial resistance (AMR) and multidrug resistance (MDR) among and , especially through the production of extended spectrum -lactamases (ESBLs), limits therapeutic options and poses a significant public health threat.

OBJECTIVE

The aim of this study was to assess the phenotypic and genetic determinants of antimicrobial resistance of ESBL-producing and isolates from patient samples in two Kenyan Hospitals.

METHODS

We collected 138 and 127 isolates from various clinical specimens at the two health facilities from January 2020 to February 2021. The isolates' ESBL production and antibiotic susceptibility were phenotypically confirmed using a standard procedure. Molecular analysis was done through conventional polymerase chain reaction (PCR) with appropriate primers for A, B, , , , , , , and genes, sequencing and BLASTn analysis.

RESULTS

Most (82.6%) and (92.9%) isolates were ESBL producers, with the highest resistance was against ceftriaxone (69.6% among and 91.3% among ) and amoxicillin/clavulanic acid (70.9% among ). The frequency of MDR was 39.9% among and 13.4% among isolates. The commonest MDR phenotypes among the isolates were CRO-FEP-AZM-LVX and CRO-AZM-LVX, while the FOX-CRO-AMC-MI-TGC-FM, FOX-CRO-FEP-AMC-TZP-AZM-LVX-MI and CRO-AMC-TZP-AZM-MI were the most frequent among isolates. Notably, the FOX-CRO-FEP-AMC-TZP-AZM-LVX-MI phenotype was observed in ESBL-positive and ESBL-negative isolates. The most frequent ESBL genes were (42%), (40.6%), and (36.2%) among , and (89%), (82.7%), (76.4%), and (72.5%) were most frequent ESBL genes among isolates. The and and genotypes were predominantly associated with FOX-CRO-FEP-MEM and CRO-FEP multidrug resistance (MDR) and CRO antimicrobial resistance (AMR) phenotypes, among isolates from Embu Level V (16.7%) and Kenyatta National Hospital (7.0%), respectively.

CONCLUSIONS

The high proportion of ESBL-producing and isolates increases the utilization of last-resort antibiotics, jeopardizing antimicrobial chemotherapy. Furthermore, the antimicrobial resistance patterns exhibited towards extended-spectrum cephalosporins, beta-lactam/beta-lactamase inhibitor combinations, fluoroquinolones, and macrolides show the risk of co-resistance associated with ESBL-producing isolates responsible for MDR. Hence, there is a need for regular surveillance and implementation of infection prevention and control strategies and antimicrobial stewardship programs.