Acinetobacter baumannii analysis by core genome MLST in two hospitals in Bolivia: endemicity of international clone 7 isolates (CC25).

ABSTRACT In total, 95 Acinetobacter baumannii isolates recovered from patients from two hospitals in Cochabamba, Bolivia were studied. The presence of class D and B β-lactamases was investigated using polymerase chain reaction, and antimicrobial susceptibility testing was performed by agar dilution and broth microdilution. The resistance rate to carbapenems was 53.7%. All carbapenem-resistant A. baumannii (CRAb, n =51) and four carbapenem-susceptible isolates were further analysed by whole-genome sequencing. The resulting genome assemblies were used to identify the acquired resistome, and core genome multi-locus sequence typing (cgMLST) was used to determine their molecular epidemiology. All but one of the CRAb isolates ( n =50) belonged to international clone (IC) 7 and they clustered into five sequence types; on cgMLST, they were found to be separated by ≥40 alleles. All CRAb isolates carried bla OXA-23 on transposon Tn 2008. Metallo-β-lactamases were not detected . These data show that dissemination of several IC7 A. baumannii clones harbouring the carbapenem resistance determinant bla OXA-23 is occurring in these two hospitals in Cochambamba.