Dados do Trabalho

Título

VIRULENCE PROPERTIES OF SPM-PRODUCING Pseudomonas aeruginosa ISOLATED AT HEALTHCARE INSTITUTIONS IN NORTHERN BRAZIL DURING THE PRE- AND POST-PANDEMIC PERIOD

Introdução

Pseudomonas aeruginosa stands as critical priority pathogen, particularly due to the spread of carbapenem-resistant (CRPA) and high virulent strains. Among the multiple resistance mechanisms in P. aeruginosa, the production of metallo-beta-lactamases (MBL), particularly the São Paulo metallo-ß-lactamase (SPM), which is endemic in Brazil, severely limits therapeutic options. Also, strains presenting certain virulotypes, such as exoS+/exoU+ and exoS-/exoU+, are related to severe clinical conditions and poor prognostic of patients.

Objetivo(s)

The present study investigated the virulence features of P. aeruginosa isolates recovered at healthcare institutions in Northern Brazil during the pre- and post-pandemic period.

Material e Métodos

A total of 50 non-repetitive SPM-producing P. aeruginosa isolates available at the Bacteriology and Mycology Section of the Evandro Chagas Institute (IEC), a referral surveillance center, were evaluated. Included isolates were recovered from 2018 to 2022 in their respective institutions, and sent to the IEC for molecular detection by PCR of resistance mechanisms. The detection of the virulence genes related to the type 1 (T1SS/aprA gene), type 2 (T2SS/lasA, lasB and toxA genes), and type 3 secretion systems (T3SS/exoS, exoU, exoT and exoY) was performed by PCR.

Resultados e Conclusão

The virulence genes were detected at the following frequencies: aprA (n = 50/100.0%), lasA (n = 50/100.0%), lasB (n = 49/98.0%), toxA (n = 50/100.0%), exoS (n = 50/100.0%), exoT (49/98.0%) and exoY (n = 50/100.0%). Interestingly, the exoU+ virulotype was not detected. It is also worthy mentioning that most of the isolates were from the pandemic period (2020-2022) (39/78.0%), which may be related with the high burden of critically ill patients, leading to wide antibiotic usage and selective pressure on healthcare institutions during this period. Finally, the presented data highlight the presence of strains demonstrating both resistance and virulence potential, and an ongoing outbreak of SPM-producing strains potentially related to the pandemic situation.

Palavras-chave

Virulence, exoS, Resistance mechanisms, Carbapenem resistance, SPM.