Prevalence and molecular characterization of ESBL-producing Enterobacterales in clinical samples from the Boucle du Mouhoun region in Burkina Faso

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Résumé

Background: Extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli and
Klebsiella pneumoniae represent a major clinical and public health concern due to their
ability to confer resistance to multiple classes of antibiotics. Data on the molecular
epidemiology of ESBL-producing Escherichia coli and Klebsiella pneumoniae remain limited
in many regions of Burkina Faso, particularly outside the Ouagadougou and Bobo Dioulasso.
This study aimed to determine the frequency of ESBL-producing Escherichia coli and
Klebsiella pneumoniae and to characterize the ESBL resistance genes circulating in the
Boucle du Mouhoun region.
Methods: A total of 1,845 clinical samples (urine, pus, blood, and semen) collected from
patients attending two major healthcare facilities in Dédougou were processed during the
study period. From these samples, 247 non-duplicate Escherichia coli and Klebsiella
pneumoniae isolates were recovered and identified using API 20E and confirmed by MALDITOF mass spectrometry. Other Enterobacterales species identified during routine culture
were excluded from subsequent analyses. Antimicrobial susceptibility testing was performed
using the disk diffusion method. ESBL-encoding genes and Escherichia coli phylogenetic
groups were characterized by polymerase chain reaction.
Results: Among the 247 Enterobacterales isolates, Escherichia coli accounted for 78.1 %
(193/247) and Klebsiella pneumoniae for 21.86 % (54/247). Overall, 55.0 % (136/247) of the
isolates were ESBL-producing, including 58.03% (112/193) of Escherichia coli and 44.44 %
(24/54) of Klebsiella pneumoniae. High levels of co-resistance were observed with
fluoroquinolones (90.4%), trimethoprim-sulfamethoxazole (91.9%), and aminoglycosides
(55.9%). Molecular analysis revealed a predominance of CTX-M-1-group genes (88.7%),followed by CTX-M-9-group genes (10.3%). Of the 112 ESBL-producing Escherichia coli
isolates, 47.3% (53/112) belonged to phylogroup B2 and 42.9% (48/112) to phylogroup A.
Conclusions: This study provides the first molecular evidence of ESBL-producing
Escherichia coli and Klebsiella pneumoniae in the Boucle du Mouhoun region of Burkina
Faso. The high prevalence of blaCTX-M genes underscores the urgent need to strengthen
antimicrobial stewardship programs, enhance infection prevention and control measures,
and implement regular regional surveillance to curb the spread of multidrug-resistant
Enterobacterales

Mots-clés

Escherichia coli; Klebsiella pneumoniae; Antimicrobial resistance; ESBLproducing; Burkina Faso