Molecular characterisation of the first New Delhi metallo-β-lactamase 1-producing Acinetobacter baumannii from Tanzania

• Published in: Transactions of the Royal Society of Tropical Medicine and Hygiene 2021-09, Vol.115 (9), p.1080-1085
• Main Authors: Moyo, Sabrina J, Manyahi, Joel, Hubbard, Alasdair T M, Byrne, Rachel L, Masoud, Nahya Salim, Aboud, Said, Manji, Karim, Blomberg, Bjørn, Langeland, Nina, Roberts, Adam P
• Format: Article
• Language: English
• Subjects: Original
• ISSN: 0035-9203; 1878-3503
• DOI: 10.1093/trstmh/traa173

Abstract Background We aimed to characterise the genetic determinants and context of two meropenem-resistant clinical 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.