Multidrug-resistant microorganisms are a well-known global problem, and gram-negative bacilli are top-ranking. When these pathogens are associated with bloodstream infections (BSI), outcomes become even worse. Here we applied whole-genome sequencing to access information about clonal distribution, resistance mechanism diversity and other molecular aspects of gram-negative bacilli (GNB) isolated from bloodstream infections in Brazil. It was possible to highlight international high-risk clones circulating in the Brazilian territory, such as CC258 for Klebsiella pneumoniae, ST79 for Acinetobacter baumannii and ST233 for Pseudomonas aeruginosa. Important associations can be made such as a negative correlation between CRISPR-Cas and K. pneumoniae CC258, while the genes bla TEM, bla KPC and bla CTX-M are highly associated with this clone. Specific relationships between A. baumannii clones and bla OXA-51 variants were also observed. All P. aeruginosa ST233 isolates showed the genes bla VIM and bla OXA486. In addition, some trends could be identified, where a new P. aeruginosa MDR clone (ST3079), a novel A. baumannii clonal profile circulating in Brazil (ST848), and important resistance associations in the form of bla VIM-2 and bla IMP-56 being found together in one ST233 strain, stand out. Such findings may help to develop approaches to deal with BSI and even other nosocomial infections caused by these important GNB.
Keywords: Brazil; bloodstream infections; gram-negative bacilli; multidrug-resistance; surveillance; whole-genome sequencing.
Copyright © 2021 Silveira, Rocha-de-Souza, de Oliveira Santos, Pontes, Oliveira, Tavares-Teixeira, Cossatis, Pereira, da Conceição-Neto, da Costa, Rodrigues, Albano, da Silva, Marques, Leão and Carvalho-Assef.