Detection of aac(3)IIc, aac(6)Ib and armA gene encoding aminoglycoside resistance in Klebsiella pneumoniae in Burkina Faso

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Résumé

Background. Klebsiella pneumoniae is the second most frequently isolated bacterium in medical bacteriology laboratories after
Escherichia coli. It can be responsible for many infections, including urinary tract infections and pneumonia. The treatment of
these infections is often prolonged because of the resistance of this bacterium to antibiotics. The production of aminoglycosidemodifying enzymes and the production of RNA methylases confer resistance to aminoglycosides. In Burkina Faso, studies on
bacterial resistance to aminoglycosides, an antibiotic regularly prescribed and consumed by patients, are limited; hence, the
purpose of this study was to determine the prevalence of aminoglycoside resistance genes in K. pneumoniae isolated from urine
and pus samples.
Methods and Findings. A total of 150 Klebsiella strains from pus and urine cultures were collected from October 2018 to
June 2019 in two hospitals in Ouagadougou and were included in this study. After plating on Muller–Hinton medium to
obtain pure colonies, antibiotic susceptibility testing was performed with aminoglycosides, β-lactams, fluoroquinolones
and sulphonamides. PCR testing for the phoE gene allowed genotypic identification of K. pneumoniae. PCRs were then
performed on strains with at least one aminoglycoside resistance for identification of the aac(6′)-Ib, aac(3)-IIc and armA
resistance genes.
Antibiotic susceptibility testing showed that 38.67% (58/150) of the strains were resistant to tobramycin, 28.67% (43/150) to
gentamicin, 10.00% (15/150) to netilmicin, 8.67% (13/150) to kanamycin, 4.67% (7/150) to amikacin and 0.67% (1/150) to neomycin. Of the 63 strains (42.66%) with at least 1 aminoglycoside resistance, the resistance genes, aac(3)-IIc and aac(6′)-Ib, were
detected in 49 strains (77.77%) and 39 strains (61.90%), respectively, and 34 strains (53.97%) had both genes. The armA gene
was present in 19.04% of the strains (12/63).
Conclusion. Aminoglycoside resistance in K. pneumoniae strains in this study is primarily due to aac(3)-IIc and aac(6′)-Ib acetyltransferases. Although armA RNA methylase genes are less frequent, increased surveillance is necessary due to the high level
of aminoglycoside resistance conferred by this gene.

Mots-clés

Klebsiella pneumoniae; aminoglycoside resistance; aac(3)-IIc; aac(6′)Ib; armA; Burkina Faso.