Carbapenem-Resistant Gram-Negative Pathogens in Brazil: Analysis from Patients in a Laboratory Network

OBJECTIVES: Treatment of gram-negative infections has become increasingly complicated by the emergence of carbapenem-resistant (CR) Enterobacterales, Pseudomonas aeruginosa (Pa) and Acinetobacter baumannii. Despite their clinical and economic impact, there is a lack of robust national data in Brazil. Our objective was to determine the frequency of Enterobacterales and Pa in Brazil from 2018-2020.

METHODS: Cross-sectional study using a database composed of national private laboratory information. Enterobacterales and Pa were collected from patient samples aged ≥18 years during hospitalization from January 01, 2018 to June 30, 2020. Antimicrobial susceptibility for samples from intensive care unit was determined by broth microdilution, and by disk diffusion for other samples. Susceptibility was interpreted using BRCAST/EUCAST. Carbapenem resistance was defined as resistance to imipenem or meropenem for Pa, and resistance to ertapenem for Enterobacterales.

RESULTS: A total of 18,753 samples were included in the analysis, 5,975 (31.9%) Pa, 11,169 (59.5%) non-Morganellaceae Enterobacterales (NME), and 1,609 (8.6%) a combination of Morganella, Proteus and Providencia spp. Almost 50% of the Pa samples were CR, while only 6% of the NME showed the same trait. Nonetheless, 54% of K. pneumoniae samples were CR. CR was most frequently observed among Pa samples from the northeast and southeast (52% and 47%, respectively), when compared to the south and midwest regions (39% and 35%, respectively). Regarding NME, CR was more prevalent in the midwest and northeast regions (22% and 15%, respectively). Finally, 55% and 14% of CR Pa and NME came from samples from the lower respiratory tract.

CONCLUSIONS: We observed a high prevalence of CR gram-negative pathogens among hospitalized patients in Brazil. These data should reinforce the urgency of having strategies to fight against antimicrobial resistance.