Genomic and Clinical Characterization of IMP-1-Producing Multidrug-Resistant Acinetobacter bereziniae Isolates from Bloodstream Infections in a Brazilian Tertiary Hospital.

Acinetobacter baumannii is the main species of the Acinetobacter genus; however, non-baumannii Acinetobacter (NBA) species causing infections have been described for the past years, as well as antimicrobial resistance. In this study, we describe the occurrence of two multidrug-resistant (MDR) IMP-1-producing Acinetobacter bereziniae isolates recovered from bloodstream infections in different patients but in the same intensive care unit among 134 carbapenem-resistant Acinetobacter screened. Antimicrobial susceptibility testing revealed resistance to carbapenems, extended spectrum, and antipseudomonad cephalosporins, amikacin, and trimethoprim-sulfamethoxazole. Both A. bereziniae isolates shared the same ApaI-pulsed-field gel electrophoresis (PFGE) pattern. Whole-genome sequencing of both isolates revealed that blaIMP-1 was embedded into an In86 Class I integron carrying also sul1, aac(6')-31, and aadA genes. A new sequence type (ST1309 Pasteur) was deposited. The virulence genes lpxC and ompA, seen in A. baumannii, were detected in the A. bereziniae strains. Recognition of A. bereziniae causing invasive MDR infection underscores the role of NBA species as human pathogens especially in at-risk patients.