| Congresso Brasileiro de Microbiologia 2023 | Resumo: 1093-2 | ||||
Resumo:ABSTRACT:
Multidrug-resistant Klebsiella pneumoniae is a worldwide public health problem, as infections caused by this bacterium cause high rates of morbidity and mortality. This pathogen has caused about one-third of all Gram-negative bacterial infections and approximately 14 to 20% of nosocomial infections related to the respiratory tract, lower bile duct, surgical wounds, and urinary tract. The treatment of infections caused by K. pneumoniae MDR is a challenge, therefore, new therapeutic alternatives are sought, including molecules of natural origin such as quercetin (QUER) to eliminate K. pneumoniae. QUER is a flavonoid of the polyphenolic class with several biological properties, including antioxidant, anti-inflammatory, cardioprotective, neuroprotective, hepatoprotective, and antimicrobial properties. However, the use of QUER becomes limited due to low water solubility and low bioavailability. To overcome these limitations, encapsulating QUER in zein nanoparticles becomes a promising alternative for the controlled release of antimicrobials in the treatment of infections caused by K. pneumoniae. Thus, this work aimed to evaluate the antibacterial and antibiofilm activity of zein nanoparticles encapsulating QUER (QUER-ZNP). QUER-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 QUER and QUER-ZNP against clinical isolates of K. pneumoniae (K A2 26, K A2 29, K A2 31) 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. QUER-ZNP had a Ø of 205.4 nm, PDI of 0.071, ξ of -47.1±0.7 mV, pH 7.1, and EE% of 99.72%. The MIC and MBC for K A2 26, K A2 29, and K A2 31 of QUER were >2000 µg/ml for all strains tested. QUER-ZNP MICs were 250 µg/ml for all strains tested, and QUER-ZNP MICs for K A2 26, K A2 29, and K A2 31 were 1000 µg/ml, 500 µg/ml and 250 µg /ml, respectively. Quercetin encapsulated in zein nanoparticles has greater antibacterial activity when compared to non-encapsulated quercetin, demonstrating therapeutic potential for the treatment of infections caused by multidrug-resistant strains of Klebsiella pneumoniae.
Keywords: Infection, Klebsiella pneumoniae Palavras-chave: Infection, Klebsiella pneumoniae, microbial resistance, nanostructure 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). | |||||