RESUMEN
Objectives. Anti-fungal agents are increasingly becoming less effective due to the development of resistance. In addition, it is difficult to treat Candida organisms that form biofilms due to a lack of ability of drugs to penetrate the biofilms. We are attempting to assess the effect of a new therapeutic agent, N-acetylcysteine (NAC), on adhesion and biofilm formation in Candida parapsilosis clinical strains. Meanwhile, to detect the transcription level changes of adhesion and biofilm formation-associated genes (CpALS6, CpALS7, CpEFG1 and CpBCR1) when administrated with NAC in C. parapsilosis strains, furthermore, to explore the mechanism of drug interference on biofilms.Hypothesis/Gap statement. N-acetylcysteine (NAC) exhibits certain inhibitory effects on adhesion and biofilm formation in C. parapsilosis clinical strains from CRBSIs through: (1) down-regulating the expression of the CpEFG1 gene, making it a highly potential candidate for the treatment of C. parapsilosis catheter-related bloodstream infections (CRBSIs), (2) regulating the metabolism and biofilm -forming factors of cell structure.Methods. To determine whether non-antifungal agents can exhibit inhibitory effects on adhesion, amounts of total biofilm formation and metabolic activities of C. parapsilosis isolates from candidemia patients, NAC was added to the yeast suspensions at different concentrations, respectively. Reverse transcription was used to detect the transcriptional levels of adhesion-related genes (CpALS6 and CpALS7) and biofilm formation-related factors (CpEFG1 and CpBCR1) in the BCR1 knockout strain, CP7 and CP5 clinical strains in the presence of NAC. To further explore the mechanism of NAC on the biofilms of C. parapsilosis, RNA sequencing was used to calculate gene expression, comparing the differences among samples. Gene Ontology (GO) enrichment analysis helps to illustrate the difference between two particular samples on functional levels.Results. A high concentration of NAC reduces the total amount of biofilm formation in C. parapsilosis. Following co-incubation with NAC, the expression of CpEFG1 in both CP7 and CP5 clinical strains decreased, while there were no significant changes in the transcriptional levels of CpBCR1 compared with the untreated strain. GO enrichment analysis showed that the metabolism and biofilm-forming factors of cell structure were all regulated after NAC intervention.Conclusions. The non-antifungal agent NAC exhibits certain inhibitory effects on clinical isolate biofilm formation by down-regulating the expression of the CpEFG1 gene, making it a highly potential candidate for the treatment of C. parapsilosis catheter-related bloodstream infections.
Asunto(s)
Acetilcisteína , Biopelículas , Candida parapsilosis , Candidemia , Infecciones Relacionadas con Catéteres , Biopelículas/efectos de los fármacos , Biopelículas/crecimiento & desarrollo , Acetilcisteína/farmacología , Humanos , Candida parapsilosis/efectos de los fármacos , Candida parapsilosis/genética , Candida parapsilosis/fisiología , Infecciones Relacionadas con Catéteres/microbiología , Candidemia/microbiología , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Antifúngicos/farmacologíaRESUMEN
We analyzed the clinical features and risk factors of candidemia due to C. parapsilosis (n=104) in the intensive care unit of a tertiary hospital over six years. This was a monocentric, retrospective study of candidemia, conducted from January 2013 to March 2019. Epidemiological characteristics, clinical features, invasive procedures, laboratory data and outcomes of 267 patients with candidemia were analyzed to determine risk factors of candidemia due to C. parapsilosis. Sixty-three cases of C. albicans and 204 cases of non-C. albicans Candida (NCAC) species were included, the latter was composed of 104 cases of C. parapsilosis and 100 cases of non-C. albicans species (46 cases of C. tropicalis, 22 cases of C. glabrata, 23 cases of C. guilliermondii, 5 cases of C. krusei and 4 cases of C. lusitaniae), suggesting that C. parapsilosis was the predominant Candida species isolated from cases of candidemia. A binary multivariate logistic regression analysis showed that APACHE II scores, central venous catheterization and the use of broad-spectrum antibiotics were closely related to C. parapsilosis candidemia, with OR values of 1.159, 3.913 and 2.217, respectively. In conclusion, we found that C. parapsilosis was the main pathogen among the NCAC candidemia in the ICU patients. APACHE II scores, central venous catheterization and the use of broad-spectrum antibiotics were independent risk factors for the occurrence of C. parapsilosis candidemia, which may provide data to support the early introduction of anti-fungal therapy.
Asunto(s)
Candida parapsilosis/aislamiento & purificación , Candidemia/epidemiología , Unidades de Cuidados Intensivos/estadística & datos numéricos , Adulto , Anciano , Anciano de 80 o más Años , Antifúngicos/uso terapéutico , Candidemia/diagnóstico , Candidemia/tratamiento farmacológico , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Resultado del TratamientoRESUMEN
BACKGROUND: To compare the adhesion properties and biofilm-forming capabilities of 27 Candida isolates obtained from catheter-related candidemia patients and to evaluate the inhibitory effects of antifungal agents on different Candida species. MATERIAL AND METHODS: Seven C. albicans, six C. parapsilosis, five C. guilliermondii, five C. tropicalis, and four C. glabrata clinical isolates were investigated. We quantified the adherence of these Candida species by flow cytometric method and evaluated the formation of biofilms by XTT reduction and crystal violet methods. Actions of micafungin (MF), fluconazole (FZ), and N-acetylcysteine (NAC) on the adhesion and biofilm formation of different Candida species were determined. RESULTS: Non-albicans Candida species were demonstrated to have stronger adhesion abilities compared with C. albicans. The biofilm-forming capabilities of different Candida species were varied considerably, and the degree of biofilm formation might be affected by different assay approaches. Interestingly, C. parapsilosis displayed the highest biofilm formation abilities, while C. glabrata exhibited the lowest total biomass and metabolic activity. Furthermore, the inhibitory activities of MF, FZ, and NAC on fungal adhesion and biofilm formation were evaluated, and the results indicated that MF could reduce the adhesion ability and biofilm metabolism more significantly (p < 0.05), and its antifungal activity was elevated in a dose-dependent manner. CONCLUSION: Non-albicans Candida species, especially C. guilliermondii, C. tropicalis, and C. parapsilosis, exhibited higher adhesion ability in catheter-related candidemia patients. However, these Candida species had varied biofilm-forming capabilities. MF tended to have stronger inhibitory effects against both adhesion and biofilm formation of different Candida species.
Asunto(s)
Antifúngicos/farmacología , Candida , Candidemia/microbiología , Infecciones Relacionadas con Catéteres/microbiología , Adhesión Celular/efectos de los fármacos , Biopelículas/efectos de los fármacos , Candida/efectos de los fármacos , Candida/patogenicidad , Candida/fisiología , HumanosRESUMEN
Thymol, a naturally occurring phenol isolated from thyme, has been known to exhibit anti-inflammatory and anti-oxidative effects. The aim of this study was to determine the effect of thymol on acute lung injury (ALI) within an lipopolysaccharide (LPS)-induced mouse model. ELISA and western blotting were performed to detect the pro-inflammatory cytokines and signaling pathways. The myeloperoxidase (MPO) activity and MDA content in lung tissues, lung wet/dry (W/D) ratio and histopathological examination were detected. The results showed that thymol inhibit LPS-induced TNF-α, IL-6 and IL-1ß production in BALF. Furthermore, thymol significantly reduced the MPO activity, MDA content, lung wet/dry weight ratio and histopathological changes induced by LPS. In addition, thymol inhibited LPS-induced NF-κB signaling pathway and up-regulated the expression of Nrf2 and HO-1. In conclusion, we found that thymol had anti-inflammatory and anti-oxidative effects against LPS-induced ALI and the mechanism was through suppressed NF-κB signaling pathway and activating Nrf2 signaling pathway.
Asunto(s)
Lesión Pulmonar Aguda/inducido químicamente , Lesión Pulmonar Aguda/prevención & control , Antiinflamatorios/administración & dosificación , Lipopolisacáridos/toxicidad , Timol/administración & dosificación , Lesión Pulmonar Aguda/patología , Animales , Líquido del Lavado Bronquioalveolar/química , Citocinas/análisis , Modelos Animales de Enfermedad , Ensayo de Inmunoadsorción Enzimática , Histocitoquímica , Pulmón/patología , Masculino , Ratones Endogámicos BALB CRESUMEN
MicroRNAs play critical roles in regulating cell survival under multiple pathological conditions of heart diseases. Oxidative stress-induced apoptosis contributes greatly to heart ischemia-reperfusion injury. Herein, we describe a novel regulatory role of miR-28 on the survival of cardiomyocytes. We show that miR-28 was upregulated in cardiomyocytes treated with hydrogen peroxide (H2O2). MiR-28 gain of function sensitized cell apoptosis, whereas miR-28 loss of function partially rescued cell apoptosis induced by H2O2. Importantly, we observed a significant reduction in Akt/mammalian target of rapamycin (mTOR) signaling activity after miR-28 treatment. Luciferase activity assay and western blot analysis both revealed that, phosphoinositide-dependent kinase-1 (PDK1), which is critical for Akt activation, was directly and negatively modulated by miR-28. Our results therefore indicate that miR-28 regulates oxidative stress-induced cell apoptosis in heart muscle cells, which possibly involves a PDK1/Akt/mTOR-dependent mechanism. MIR-28 could serve as a critical therapeutic target to diminish oxidative stress-induced cell death in the heart.