Prevalence and Molecular Characterization of Extended Spectrum β-Lactamase, Plasmid-Mediated Quinolone Resistance, and Carbapenemase-Producing Gram-Negative Bacilli in Burkina Faso

The spreading of carbapenemase-producing gram-negative bacilli (GNB) must be considered as an urgent threat. The aim of this study was to determine the prevalence of extended spectrum beta-lactamase (ESBL), plasmid-mediated quinolone resistance (PMQR), and carbapenemase-producing GNB and to characterize the supporting genes in GNB specimens isolated from patients and healthy volunteers in Burkina Faso. From April to June 2016, carbapenemase-producing GNB screening was performed in 1,230 consecutive clinical specimens, and 158 fecal samples from inpatients and healthy volunteers without digestive pathology at Souro Sanou University Hospital, Bobo Dioulasso. Strains were identified by matrix-assisted laser desorption ionization-time of flight and antimicrobial susceptibility was tested with the disk diffusion method on Muller-Hinton agar. The presence of carbapenemase, ESBL, and PMQR genes was assessed by multiplex PCR. The molecular epidemiological study was performed using multilocus sequence typing analysis. From the 1,230 clinical samples, 443 GNB strains were isolated among which 4 (0.9%) were carbapenemase-producing isolates (Escherichia coli,n = 1;Acinetobacter baumannii,n = 3). Among the 158 fecal samples tested for carbapenemase-producing Enterobacteriaceae carriage, 13 (8.2%) were carbapenemase-producing isolates (E. coli, n = 4;Klebsiella pneumoniae,n = 6;A. baumannii, n = 2;Acinetobacter nosocomialis, n = 1;Acinetobacter bereziniae, n = 1). The strains from the two groups were resistant to broad-spectrum cephalosporins (100% for both), gentamicin (100% and 64.3%), levofloxacin (100% and 85.7%), and to amikacin (0% and 7.1%). The carbapenemase-encoding genesbla(NDM-1),bla(Oxa-58),bla(Oxa-181), andbla(VIM-2)were detected in clinical and in fecal samples. The majority (10/11) of the enterobacterial strains carried alsobla(CTX-M-15). The majority of the strains belonged to ST692 forE. coli, to ST147 forK. pneumoniaeand to ST2 forA. baumannii. This study confirms the presence of carbapenemase-producing GNB in samples from patients and healthy volunteers. More effective active surveillance activities are needed.

Automated summary

The study confirmed the presence of carbapenemase-producing gram-negative bacilli (GNB) in samples from patients and healthy volunteers, indicating the need for more effective active surveillance activities.