| Congresso Brasileiro de Microbiologia 2023 | Resumo: 1093-1 | ||||
Resumo:ABSTRACT:
Multidrug-resistant Pseudomonas aeruginosa is one of the most common causes of nosocomial infections, especially in immunocompromised patients, including infections in the lungs of patients with cystic fibrosis, in skin wounds, in the urinary system, causing prolonged hospital stay and high morbidity and mortality rates. To treat this type of infection, aminoglycosides such as tobramycin (TOB) can be used, however, the oral use of this drug becomes limited due to the impossibility of crossing the intestinal barrier and the high toxicity. To overcome these limitations, encapsulating TOB in zein nanoparticles becomes a promising alternative in the use of oral particles for the controlled release of antimicrobials in the treatment of infections caused by P. aeruginosa. Thus, this study aimed to evaluate the antibacterial activity of zein nanoparticles encapsulating TOB (TOB-ZNP). TOB-ZNP were prepared by the nanoprecipitation method and characterized by measuring the particle size (Ø), polydispersion index (PDI), zeta potential (ξ), pH and encapsulation efficiency (EE%). The determination of the minimum inhibitory concentration (MIC) of TOB and TOB-ZNP against clinical isolates of P. aeruginosa (PA 19, PA 56, and PA 69) was performed using the broth microdilution method according to the Clinical and Laboratory Standards Institute. The minimum bactericidal concentration (MBC) was determined from the well in which the MIC did not show bacterial growth, whose aliquot was seeded in Müeller Hinton agar and incubated at 35 ± 2 ºC for 24h. After this period, MBC was determined as the lowest concentration at which there is no microbial growth. TOB-ZNP presented a Ø of 317.7 nm, PDI of 0.274, ξ of +45.1±0.7 mV, pH 4.5 and EE% of 63.38%. The MICs for PA 19, PA 56, and PA 69 of TOB were 6.25 µg/ml, 12.5 µg/ml, and 6.25 µg/ml, and of TOB-ZNP were 1.56 µg/ml, 3.12 µg/ml, and 1.56 µg/ml, respectively. The CBMs for PA 19, PA 56, and PA 69 from TOB were 12.5 µg/ml, 50 µg/ml, and 25 µg/ml, and from TOB-ZNP were 3.12 µg/ml, 12.5 µg/ml, and 6.25 µg/ml, respectively. Tobramycin encapsulated in zein nanoparticles has greater antibacterial activity when compared to unencapsulated tobramycin, demonstrating the therapeutic potential for the treatment of infections caused by multidrug-resistant strains of P. aeruginosa.
Keywords: Bacterial resistance, infection, nanocarriers, Pseudomonas aeruginosa.
Development Agency: National Council for Scientific and Technological Development (CNPq), Coordination for the Improvement of Higher Education Personnel (CAPES) and Foundation for the Support of Science and Technology of the State of Pernambuco (FACEPE). Palavras-chave: Bacterial resistance, infection, nanocarriers, Pseudomonas aeruginosa Agência de fomento:National Council for Scientific and Technological Development (CNPq), Coordination for the Improvement of Higher Education Personnel (CAPES) and Foundation for the Support of Science and Technology of the State of Pernambuco (FACEPE). | |||||