Evaluation of biofilm formation, antimicrobial pattern, and typing of Stenotrophomonas maltophilia isolated from clinical sources in Brazil.

Abstract

This study aimed to evaluate the biofilm formation and disinfectant tolerance of Stenotrophomonas maltophilia strains originated from hospitalized patients during the COVID-19 pandemic. Nine strains were isolated from different clinical departments at a hospital in Brazil, were identified by VITEK®2, Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry, 16S rRNA sequencing, and 23S rRNA PCR. Enterobacterial Repetitive Intergenic Consensus-Polymerase Chain Reaction (ERIC-PCR), Fourier-transform infrared (FTIR) spectroscopy, antimicrobial susceptibility testing, and biofilm formation and disinfectant tolerance tests were applied. ERIC-PCR, FTIR, and VITEK®2 results exhibited no correlation between the strains, indicating different origins in the Hospital. Most strains expressed resistance to several antibiotics but minocycline and cefiderocol, which were therefore regarded as optimistic therapy options. All strains produced biofilms on polystyrene and most of them (n = 7) on stainless-steel surfaces. The sodium hypochlorite 0.5% was shown to be the most efficient disinfectant for biofilm eradication. Biofilm formation and tolerance to disinfectants analysis indicated the requirement for efficient cleaning protocols to eliminate S. maltophilia contamination.