Dados do Trabalho

Título

MOLECULAR DETECTION OF exoU+ Pseudomonas aeruginosa HIGH-RISK CLONES ST235 AND ST357 AT HEALTHCARE INSTITUTIONS IN THE STATE OF PARÁ, BRAZIL

Introdução

Several outbreaks in clinical settings caused by Pseudomonas aeruginosa have been associated with the global dissemination of high-risk clones presenting multi-drug resistant (MDR) phenotypes and specific virulence markers. Among the various virulence factors produced by P. aeruginosa, the detection of cytotoxic/exoU+ virulotype has been recommended due to its impact on patient’s clinical outcomes.

Objetivo(s)

The present study describes the presence of P. aeruginosa high-risk clones ST235 and ST357 harboring the exoU virulence marker at healthcare institutions in the state of Pará, Brazil. The five (5) investigated P. aeruginosa isolates were available at the Bacteriology and Mycology Section of the Evandro Chagas Institute (IEC), a referral center for resistance mechanisms surveillance, and recovered in 2019 (4/80.0%) and 2021 (1/10.0%) at four (4) distinct healthcare institutions.

Material e Métodos

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 conventional PCR, and genotyping by means of multilocus sequence typing (MLST).

Resultados e Conclusão

All exoU+ isolates were positive for exoS, exoT, aprA, lasA and lasB (5/100.0%), while exoY was negative in one isolate only (20.0%). MLST genotyping revealed three (3) isolates belonging to ST235, of which two (2) isolated within a 20 days period in September/2019 and one (1) isolated in April/2021, and two (2) isolates related to ST357, which were recovered within a five days period in October/2019. To conclude, the presented findings highlight the importance of surveillance and detection of high lethality potential strains, and the circulation of international high-risk clones with the rare exoS+/exoU+ virulotype.

Palavras-chave

Keywords: Virulence, Molecular typing, exoU, ST235, ST357.