Abstract:
ackground: We aimed to characterise the genetic determinants and context of two meropenem-resistant clin ical isolates of Acinetobacter baumannii isolated from children hospitalised with bloodstream infections in Dar
es Salaam, Tanzania.
Methods: Antimicrobial susceptibility was determined by disc diffusion E-test and broth microdilution. Genomes
were completed using a hybrid assembly of Illumina and Oxford Nanopore Technologies sequencing reads and
characterisation of the genetic context of resistance genes, multi-locus sequence types (STs) and phylogenetic
analysis was determined bioinformatically.
Results: Twelve A. baumannii were isolated from 2226 blood cultures, two of which were meropenem-resistant.
The two meropenem-resistant isolates, belonging to distinct STs, ST374 and ST239, were found to harbour
blaNDM-1, which was chromosomally located in isolate DT0544 and plasmid-located in isolate DT01139. The
genetic environment of blaNDM-1 shows the association of insertion sequence ISAba125 with blaNDM-1 in both
isolates. Both isolates also harboured genes conferring resistance to other β-lactams, aminoglycosides and
cotrimoxazole.
Conclusions: This is the first report of New Delhi metallo-β-lactamase-producing isolates of A. baumannii from
Tanzania. The genetic context of blaNDM-1 provides further evidence of the importance of ISAba125 in the spread
of blaNDM-1 in A. baumannii. Local surveillance should be strengthened to keep clinicians updated on the incidence
of these and other multidrug-resistant and difficult-to-treat bacteria.
