Detection of aac3IIc, aac(6)Ib and armA gene encoding aminoglycoside resistance in Klebsiella pneumoniae in Burkina Faso.

Background: Klebsiella pneumoniae is the second most frequently isolated bacterium in medical bacteriology laboratory 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 aminoglycoside-modifying 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 FindingsA 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 (MH) medium to obtain pure colonies, antibiotic susceptibility testing was performed with aminoglycosides, β-lactams, fluoroquinolones and sulfonamides. PCR testing for the phoE gene allowed genotypic identification of Klebsiella 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 one 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. Among the 16S rRNA genes, the armA gene was present in 19.04% of the strains (12/63).ConclusionAminoglycoside resistance in K. pneumoniae strains in this study is primarily due to aac(3)-IIc and aac(6')-Ib acetyltransferases. Although armA RNA methylases genes are less frequent, increased surveillance is necessary due to the high level of aminoglycoside resistance conferred by this gene.