Distribution of Carbapenemase Genes Associated With Global High‐Risk Sequence Types in <i>Pseudomonas aeruginosa</i> Isolates From Chronic Leg Ulcer Patients in Northern Tanzania

Carbapenem-resistant Pseudomonas aeruginosa exacerbates the healing of chronic leg ulcer among patients. Further, production and dissemination of the carbapenemase genes are associated with P. aeruginosa high-risk sequence types. Hence, understanding the population structure of these organisms is essential for healthcare personnel to establish effective leg ulcers care management, prevention interventions and control strategies particularly in regions with poor diagnosis. A cross-sectional study included inpatients and outpatients with chronic leg ulcers was conducted from August 2022 to April 2023 in 2 hospitals in Kilimanjaro region. Antimicrobial susceptibility testing was done by using the disc diffusion method. Further, whole genome sequencing was performed to study the genotypic characteristics of the isolates. Ten of 92 participants were positive for genus Pseudomonas isolates upon culture during the study period. Ambler class D carbapenemase genes were carried in all 8 isolates, and class B ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:semantics> <mml:mrow><mml:msub><mml:mi>bla</mml:mi> <mml:mrow><mml:mi>VIM</mml:mi> <mml:mo>-</mml:mo> <mml:mn>2</mml:mn></mml:mrow> </mml:msub> </mml:mrow> <mml:annotation>$$ {\mathrm{bla}}_{\mathrm{VIM}-2} $$</mml:annotation></mml:semantics> </mml:math> , <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:semantics> <mml:mrow><mml:msub><mml:mi>bla</mml:mi> <mml:mrow><mml:mi>DIM</mml:mi> <mml:mo>-</mml:mo> <mml:mn>1</mml:mn></mml:mrow> </mml:msub> </mml:mrow> <mml:annotation>$$ {\mathrm{bla}}_{\mathrm{DIM}-1} $$</mml:annotation></mml:semantics> </mml:math> ) in 2 isolates. The tree topology showed that all 8 P. aeruginosa isolates that carried any of the Ambler carbapenemase genes were in one clade with the reference strain PAO1. This study sheds light on different carbapenemase gene types (VIM-2, DIM-1, and OXA-types) harboured in the denominated global high-risk and endemic sequence types in 2 tertiary hospitals in northern Tanzania, alarming the possibility of a prolonged healing process and a high risk of treatment failure among patients because of the increased spread of antimicrobial resistance. Further, the findings underscore the need for antimicrobial surveillance to guide healthcare personnel in managing chronic leg ulcers for better patient outcomes and the implementation of antimicrobial stewardship programs.