| Congresso Brasileiro de Microbiologia 2023 | Resumo: 87-1 | ||||
Resumo:Antimicrobial resistance threatens the effective prevention and treatment of an ever-increasing range of infections caused by bacteria. During the COVID-19 pandemic, the incidence of bacterial infection in hospitalized COVID-19 patients was high, especially those caused by multidrug-resistant Gram-negative bacteria such as Pseudomonas aeruginosa, Acinetobacter baumannii, and Stenotrophomonas maltophilia. S. maltophilia is an emerging opportunistic pathogen, commonly associated with respiratory infections in humans. This study aimed to characterize S. maltophilia strains (n=9) isolated from hospitalized patients during the COVID-19 pandemic in a hospital localized in the municipality of Rio de Janeiro from February to September 2021. Nine strains were isolated from seven patients (eight males and one female): two with COVID-19 co-infection and five only with S. maltophilia; with ages varying from 64 to 86 years. The clinical specimens were tracheal swabs (n=4), blood (n=2), sputum (n=1), lung mass (n=1), and soft tissue fragment (n=1). The strains were characterized by a semi-automatic VITEK 2 systems, Matrix Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS), polymerase chain reaction (PCR) targeting 23S rRNA gene and typing by Enterobacterial Repetitive Intergenic Consensus (ERIC). Antimicrobial susceptibility test (AST) was evaluated using the disc diffusion agar method (Kirby-Bauer) or ETEST and results were interpreted according to the Clinical and Laboratory Standards Institute (CLSI). Biofilm formation assay was performed in 96-well polystyrene plates at two different temperatures (22.5 and 37.0°C). All strains were identified as S. maltophilia with 99% of confidence by VITEK 2 and showed five different phenotypic profiles. MALDI-TOF MS also identified all strains as S. maltophilia with confidence varying from 80.1-99.9% and were positive using 23S PCR. Nine distinct band profiles were obtained by ERIC-PCR (Figure 1) and similarity varying from 14.65 to 72.73%. All strains were susceptible to cefiderocol, and minocycline and resistant to ceftazidime. Five (55.5%) were resistant to ticarcillin-clavulanate and four (44.5%) were susceptible, increased exposure. Three (33.3%) were resistant to chloramphenicol and six (66.7%) were susceptible, increased exposure. One (11.1%) strain was resistant to trimethoprim-sulfamethoxazole and one (11.1%) to levofloxacin. The AST was similar between strains, neither whether they were from patients co-infected with COVID-19 or not. Six (66.7%) strains were classified as strongly adherent and three were weakly adherent at 22.5°C. Four (44.5%) strains were classified as strongly adherent, three (33.3%) as moderately, one weakly, and one non-adherent at 37.0°C. All strains presented different ERIC-PCR profiles, indicating that they were not clonal, and possibly have different origins. Considering the necessity to use broad-spectrum antibiotics in cases of bacterial infections, especially in cases of co-infection with COVID-19, the resistance found to four classes of antimicrobial agents (&beta-lactam, cephems, folate pathway antagonists, and fluoroquinolones) is worrisome. In conclusion, the continuous monitoring of the antimicrobial susceptibility profile and clonality of S. maltophilia is important to understand the epidemiology of this bacteria.
CNPq. Palavras-chave: Stenotrophomonas maltophilia, Antimicrobial susceptibility test, ERIC-PCR, Biofilm, MALDI-TOF MS Agência de fomento:Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) | |||||