Application of MALDI-TOF mass spectrometry for identification of Nocardia species.

BACKGROUND: Nocardiosis, despite its rarity and underreporting, is significant due to its severe impact, characterized by high morbidity and mortality rates. The development of a precise, reliable, rapid, and straightforward technique for identifying the pathogenic agent in clinical specimens is crucial to reduce fatality rates and facilitate timely antimicrobial treatment. In this study, we aimed to identify Nocardia spp. in clinical isolates, using MALDI-TOF MS as the primary method, with molecular methods as the gold standard. Clinical Nocardia isolates were identified using 16S rRNA/hsp65/gyrB/secA1/rpoB gene sequencing. Identification performance of the Bruker MALDI Biotyper 3.1 (V09.0.0.0_8468) and MBT Compass 4.1 (V11.0.0.0_10833) for Nocardia identification was evaluated. RESULTS: Seventy-six Nocardia isolates were classified into 12 species through gene sequencing. The MALDI Biotyper 3.1 (V09.0.0.0_8468) achieved 100% genus-level accuracy and 84.2% species accuracy (64/76). The MBT Compass 4.1 with the BDAL Database (V11.0.0.0_10833) improved species identification to 98.7% (75/76). The updated database enhanced species level identification with scores > 1.7, increasing from 77.6% (59/76) to 94.7% (72/76), a significant improvement (P = 0.001). The new and simplified extraction increased the proportion of strains identified to the species level with scores > 1.7 from 62.0% (18/29) to 86.2% (25/29) (P = 0.016). An in-house library construction ensured accurate species identification for all isolates. CONCLUSIONS: The Bruker mass spectrometer can accurately identify Nocardia species, albeit with some variations observed between different database versions. The MALDI Biotyper 3.1 (V09.0.0.0_8468) has limitations in identifying Nocardia brasiliensis, with some strains only identifiable to the genus level. MBT Compass 4.1 (V11.0.0.0_10833) effectively addresses this shortfall, improving species identification accuracy to 98.7%, and offering quick and reliable identification of Nocardia. Both database versions incorrectly identified the clinically less common Nocardia sputorum as Nocardia araoensis. For laboratories that have not upgraded their databases and are unable to achieve satisfactory identification results for Nocardia, employing the new and simplified extraction method can provide a degree of improvement in identification outcomes.

[Application of Rapid Detection Method Based on NG-Test® CARBA 5 in Bloodstream Infections Associated With Carbapenem-Resistant Enterobacterales].

Objective: To compare the consistency and accuracy of a rapid test method and a traditional test method for pathogen identification, antimicrobial susceptibility and carbapenemase type identification of positive blood culture samples. Methods: A total of 51 positive blood culture samples of bloodstream infection (BSI) were collected between March 2022 and May 2022. All samples were found to be "positive for Gram-negative bacilli" according to the blood smear results. The rapid method was adopted to perform rapid antimicrobial susceptibility test (RAST) and analysis of the positive blood culture samples. According to the RAST result interpretation standards, NG-Test® CARBA 5 was used for rapid carbapenemase detection of the imipenem-resistant strains and the results were confirmed by PCR. In addition, mass spectrometry, VITEK 2 Compact drug sensitivity analysis, and carbapenemase type identification were performed with the colonies cultured with positive samples according to the traditional method. Results: In the identification of bacteria, the rapid method and the traditional method had 100% consistency rate in the identification results of Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii. In the antimicrobial susceptibility test, the consistency rate between the results of the two methods was high and the consistency rate for results for susceptibility to imipenem was 100%. In the identification of carbapenemase type, 18 serinase-producing strains and 3 metal-ß-lactamase-producing strains of Enterobacterales were detected by the traditional method. With the rapid method, 18 Klebsiella pneumoniae carbapenemase (KPC)-producing strains, 2 New Delhi metallo-betalactamase (NDM)-producing strains, and 1 imipenem enzyme (IMP)-producing strain were identified in the blood culture samples by using a testing kit. Compared with the PCR results, the sensitivity and specificity of the rapid test for determining carbapenemase types were 100%. In this study, we investigated a rapid method for bacteria and carbapenemase type identification of positive blood culture specimens and found that the turnaround time (TAT) of the rapid method was reduced by 1.94 days on average in comparison with the TAT of the traditional method. Conclusion: The rapid method established in the study can effectively shorten the TAT for pathogenic microorganism identification and antimicrobial susceptibility test of blood culture samples, and the joint report of colloidal gold carbapenemase type identification results can provide a reference for clinicians to use antibiotics appropriately and accurately manage multi-drug resistant bacterial infections.

Evaluation of a Cryptococcus capsular polysaccharide detection FungiXpert LFA (lateral flow assay) for the rapid diagnosis of Cryptococcosis.

Cryptococcus is an opportunistic pathogenic fungus and is the major cause of fungal meningitis. The cryptococcal antigen (CrAg) lateral flow assay (LFA) is an immunochromatographic test system that has simplified diagnosis as a point-of-care test. In this study, we evaluated the diagnostic performance of Cryptococcal capsular polysaccharide detection FungiXpert (Genobio Pharmaceutical, Tianjin, China) using serum and cerebrospinal fluid (CSF) samples for the diagnosis of cryptococcosis and investigated the cross-reaction of the assays to pathogenic fungi and bacterium by comparing it to the U.S. Food and Drug Administration (US FDA)-approved IMMY CrAg LFA. Eighty CSF and 119 serum/plasma samples from 158 patients were retrospectively collected to test for qualitative or semi-quantitative detection of CrAg. Cross-reaction of the assays was tested using 28 fungi and 1 bacterium. Compared to IMMY CrAg LFA, the FungiXpert LFA demonstrated 99.1% sensitivity and 98.9% specificity in the qualitative test. In the 96 semi-quantitative CrAg assay results, 39 (40.6%) test titers of FungiXpert LFA were 1-2 dilutions higher than those of IMMY CrAg LFA. The Intraclass Correlation Coefficient of the Semi-quantitative results of CrAg titer tests via the two assays was 0.976. Similar to IMMY CrAg LFA, FungiXpert LFA showed cross-reactivity with Trichosporon asahii. Compared with the IMMY CrAg LFA, the FungiXpert LFA showed an equal, yet, excellent performance. However, it is important to note that these two assays have potential cross-reactivity to T. asahii when diagnosing patients. FungiXpert LFA is a rapid screening method for the effective and practical diagnosis and treatment of cryptococcosis. LAY SUMMARY: The FungiXpert LFA was developed to diagnose fungal meningitis caused by Cryptococcus yeasts, by using serum or cerebrospinal fluid. It was compared to an existing lateral flow assay (LFA). The FungiXpert LFA performed well in qualitative and semi-quantitative tests.

Molecular epidemiology and antifungal susceptibilities of Cryptococcus species isolates from HIV and non-HIV patients in Southwest China.

To investigated the molecular epidemiology and in vitro antifungal susceptibility of Cryptococcus isolates from West China Hospital from HIV and non-HIV patients between 2009 and 2015. A total of 132 C. neoformans and C. gattii were subjected to antifungal susceptibility testing by E-test method. Among the 132 isolates, 42 C. neoformans and C. gattii were analyzed by mating type and URA5-RFLP. A total of 113 C. neoformans and C. gattii were subjected to multi-locus sequence typing (MLST). MLST results revealed that ST5 was the major molecular type. The wild-type (WT) phenotype was seen in 91.5-100% of C. neoformans isolates for amphotericin B, 5-flucytosine, fluconazole, and voriconazole. However, 72.3% (94/130) of C. neoformans isolates were non-wild-type (non-WT) to itraconazole by E-test method. In the sixth study year, the geometric mean, MIC50 and MIC90 of fluconazole were the highest (P < 0.001). Among 132 patients. 52 were coinfected with HIV and 80 were HIV-negative. Isolates from HIV and non-HIV patients showed no differences in susceptibility to amphotericin B (P = 0.544), 5-flucytosine (P = 0.063), fluconazole (P = 0.570), voriconazole (P = 0.542), and itraconazole (P = 0.787). Our study showed that Cryptococcus in southwest China showed a low degree of genetic diversity. The increased MIC values of fluconazole are noted. Cryptococcus isolates from HIV and non-HIV patients have shown no differences in susceptibility to five antifungal agents.

[Antibiotic Resistance and Risk Factors for Mortality of Blood Stream Infections (BSIs) with Escherichia coli in Patients with Hematological Malignancies].

OBJECTIVE: To analyze the risk factors for mortality of blood stream infections (BSIs) caused by Escherichia coli in the patients with hematological malignancies. METHODS: There were 110 Escherichia coli BSIs patients with hematological malignancies included in recent five years. Among them,77 cases had BSIs caused by extended-spectrum-beta-lactamase (ESBL)-producing Escherichia coli (ESBL-EC group),while 33 cases had BSIs with non-ESBL-producing Escherichia coli (non-ESBL-EC group). The antibiotic resistance and clinical features were compared between the two groups,and the risk factors for death within 30 d were analyzed. RESULTS: Less than 10% of the isolates were resistant to carbapenems and amikacin. Between ESBL-EC group and non-ESBL-EC group,the clinical symptoms,prior use of antibiotics or antifungal agents,risk factors for infection,30 d mortality rates were not significantly different (P>0.05). A logistic regression analysis confirmed that non remission of hematologic malignancies (odds ratio=9.575,95% confidence interval 1.546-59.312,P=0.015) and inappropriate initial antibiotic therapy (odds ratio=8.806,95% confidence interval 1.527-50.772, P=0.015) were independent risk factors for 30 d mortality. CONCLUSION: The use of effective antimicrobial treatment as early as possible could reduce the risk of death for hematological malignancies patients suffering Escherichia coli BSIs.

Enhancing pili assembly and biofilm formation in Acinetobacter baumannii ATCC19606 using non-native acyl-homoserine lactones.

BACKGROUND: Quorum Sensing (QS) systems influence biofilm formation, an important virulence factor related to the bacterial survival and antibiotic resistance. In Acinetobacter baumannii, biofilm formation depends on pili biosynthesis, structures assembled via the csuA/BABCDE chaperone-usher secretion system. QS signaling molecules are hypothesized to affect pili formation; however, the mechanism behind this remains unclear. This study aimed to demonstrate the possible role of QS signaling molecules in regulating pili formation and mediating the ability to form biofilms on abiotic surfaces. RESULTS: Real-time quantitative PCR analysis showed the expression of the csuA/BABCDE genes distinctly increased when co-cultured with C6-HSL (P < 0.05). Under the same experimental conditions, expression of BfmS and BfmR was significantly higher than the control strain (P < 0.05). A subsurface twitching assay showed a switch from a small to a large and structured clone that may result from enhanced twitching motility (P < 0.05). Transmission electron microscopy analysis of cells lifted from a MH broth co-cultured with C6-HSL showed more abundant pili-like structures than the control strain. We then tested the idea that the addition of a QS signal, and therefore induction of chaperone-usher secretion system genes, provides a greater benefit at higher biofilm densities. An assay for the total fluorescence intensity of the biofilm using Confocal Laser Scanning Microscopy revealed an obvious increase. CONCLUSION: Our study demonstrated that, increased transcription of the BfmS and BfmR genes, QS signaling molecules enhance the expression of the chaperone-usher secretion system, and this expression is required for twitching motility in A. baumannii. The concomitant pili expression and strain twitching allowed A. baumannii to attach easily to abiotic surfaces and form biofilms at an earlier timepoint.

Doxorubicin-loaded glycyrrhetinic acid modified recombinant human serum albumin nanoparticles for targeting liver tumor chemotherapy.

Due to overexpression of glycyrrhetinic acid (GA) receptor in liver cancer cells, glycyrrhetinic acid modified recombinant human serum albumin (rHSA) nanoparticles for targeting liver tumor cells may result in increased therapeutic efficacy and decreased adverse effects of cancer therapy. In this study, doxorubicin (DOX) loaded and glycyrrhetinic acid modified recombinant human serum albumin nanoparticles (DOX/GA-rHSA NPs) were prepared for targeting therapy for liver cancer. GA was covalently coupled to recombinant human serum albumin nanoparticles, which could efficiently deliver DOX into liver cancer cells. The resultant GA-rHSA NPs exhibited uniform spherical shape and high stability in plasma with fixed negative charge (∼-25 mV) and a size about 170 nm. DOX was loaded into GA-rHSA NPs with a maximal encapsulation efficiency of 75.8%. Moreover, the targeted NPs (DOX/GA-rHSA NPs) showed increased cytotoxic activity in liver tumor cells compared to the nontargeted NPs (DOX/rHSA NPs, DOX loaded recombinant human serum albumin nanoparticles without GA conjugating). The targeted NPs exhibited higher cellular uptake in a GA receptor-positive liver cancer cell line than nontargeted NPs as measured by both flow cytometry and confocal laser scanning microscopy. Biodistribution experiments showed that DOX/GA-rHSA NPs exhibited a much higher level of tumor accumulation than nontargeted NPs at 1 h after injection in hepatoma-bearing Balb/c mice. Therefore, the DOX/GA-rHSA NPs could be considered as an efficient nanoplatform for targeting drug delivery system for liver cancer.

Molecular characterisation of clinical Cryptococcus neoformans and Cryptococcus gattii isolates from Sichuan province, China.

Previous reports on the molecular characteristics of clinical isolates of Cryptococcus species in China have focused on isolates from southeast China. To obtain a more detailed molecular epidemiology, a total of 92 cryptococcal isolates were collected from Sichuan province. A total of 24 isolates from 12 other provinces were collected for comparative study. Genotypes and mating types of 116 Cryptococcus isolates were determined. Among the 116 isolates, 43 isolates (19 isolates from Sichuan and 24 isolates outside of Sichuan) were analysed by multi-locus sequence typing (MLST). All 116 clinical isolates were mating type α. Most isolates (114/116) were molecular type VNI and the remaining two isolates were VGI and VGII respectively. MLST results revealed five sequence types (STs) of C. neoformans including two novel STs, with most isolates identified as ST5. The two C. gattii isolates identified in our study were ST44 and ST159. Based on our report and previous studies, there are 15 C. neoformans STs in China which can be divided into three subgroups. The C. gattii isolate from Sichuan could be a scattered subtype of VGII (ST44). Our findings demonstrated that C. neoformans isolates in Sichuan are genetically homogeneous, and ST5 is the epidemic clone of C. neoformans in China.

[Genotypes and in vitro antifungal susceptibility of Cryptococcus isolates in Sichuan Province].

OBJECTIVE: To determine the genotypes and in vitro antifungal susceptibility of Cryptococcus strains isolated from Sichuan Province. METHODS: Ninety two clinical isolates of Cryptococcus spp. were collected from West China Hospital. Genotyping of the URA5 gene was accomplished by restriction fragment length polymorphism. The minimum inhibitory concentrations (MIC) of the isolates to 5 antifungals, including amphotericin B, flucytosine, fluconazole, itraconazole and voriconazole were determined by agar-based E-test method. The MIC50 and MIC90 were calculated based on MICs. RESULTS: Among the 92 clinical isolates, 91 were molecular type VN I and one was VG II. The susceptibility range, MIC50 and MICW, of the isolates to five antifungals were as follows: (<0.002-2) microg/mL, 0.19 microg/mL and 0.75 microg/mL for amphotericin B; (0.5-> 32) microg/mL, 4 microg/mL and 8 microg/mL for flucytosine; (0.5-32) microg/mL, 3 microg/mL and 8 microg/mL for uconazole; (0.064-2) microg/mL, 0.5 microg/mL and 1.5 microg/mL for itraconazole; (0.004-0.19) microg/mL, 0.047 microg/mL and 0.094 microg/mL for voriconazole. Three (3.3%) isolates were resistant to amphotericin B, 4 (4.3%) to flucytosine and 25 (27.2%) to itraconazole. No isolate was resistant to fluconazole and all isolates were susceptible to voriconazole. The isolate Cryprococcus gattii was resistant to flucytosine, while S-DD was resistant to fluconazole. There were significant differences in the MICs of the strains isolated from different periods. The MICs of the isolates to amphotericin B and flucytosine increased over time. CONCLUSION: VNI molecular type is the major genotype of Cryprococcus in Sichuan. All the agents have good in vitro activities against the tested strains except itraconazole. A few stains are resistant to amphotericin B and flucytosine.

Thermo-immune synergy: Camrelizumab plus microwave ablation in preoperative early-stage breast cancer.

Immunotherapy has enhanced breast cancer outcomes, but optimizing combination therapies is crucial. Integrating additional treatment modalities, like physical therapies, holds promise for optimizing efficacy. Pan et al. recently reported that combining preoperative immunotherapy with microwave ablation is safe and feasible in early-stage breast cancer, effectively sensitizing peripheral CD8+ T cells.1.

Effects of dietary intervention on human diseases: molecular mechanisms and therapeutic potential.

Diet, serving as a vital source of nutrients, exerts a profound influence on human health and disease progression. Recently, dietary interventions have emerged as promising adjunctive treatment strategies not only for cancer but also for neurodegenerative diseases, autoimmune diseases, cardiovascular diseases, and metabolic disorders. These interventions have demonstrated substantial potential in modulating metabolism, disease trajectory, and therapeutic responses. Metabolic reprogramming is a hallmark of malignant progression, and a deeper understanding of this phenomenon in tumors and its effects on immune regulation is a significant challenge that impedes cancer eradication. Dietary intake, as a key environmental factor, can influence tumor metabolism. Emerging evidence indicates that dietary interventions might affect the nutrient availability in tumors, thereby increasing the efficacy of cancer treatments. However, the intricate interplay between dietary interventions and the pathogenesis of cancer and other diseases is complex. Despite encouraging results, the mechanisms underlying diet-based therapeutic strategies remain largely unexplored, often resulting in underutilization in disease management. In this review, we aim to illuminate the potential effects of various dietary interventions, including calorie restriction, fasting-mimicking diet, ketogenic diet, protein restriction diet, high-salt diet, high-fat diet, and high-fiber diet, on cancer and the aforementioned diseases. We explore the multifaceted impacts of these dietary interventions, encompassing their immunomodulatory effects, other biological impacts, and underlying molecular mechanisms. This review offers valuable insights into the potential application of these dietary interventions as adjunctive therapies in disease management.

Label-free and ultrasensitive detection of environmental lead ions based on spatially localized DNA nanomachines driven by hyperbranched hybridization chain reaction.

A label-free fluorescent sensing strategy for the rapid and highly sensitive detection of Pb2+ was developed by integrating Pb2+ DNAzyme-specific cleavage activity and a tetrahedral DNA nanostructure (TDN)-enhanced hyperbranched hybridization chain reaction (hHCR). This strategy provides accelerated reaction rates because of the highly effective collision probability and enriched local concentrations from the spatial confinement of the TDN, thus showing a higher detection sensitivity and a more rapid detection process. Moreover, a hairpin probe based on a G-triplex instead of a G-quadruplex or chemical modification makes hybridization chain reaction more controlled and flexible, greatly improving signal amplification capacities and eliminating labeled DNA probes. The enhanced reaction rates and improved signal amplification efficiency endowed the biosensors with high sensitivity and a rapid response. The label-free detection of Pb2+ based on G-triplex combined with thioflavin T can be achieved with a detection limit as low as 1.8 pM in 25 min. The proposed Pb2+-sensing platform was also demonstrated to be applicable for Pb2+ detection in tap water, river water, shrimp, rice, and soil samples, thus showing great potential for food safety and environmental monitoring.

Bidirectional crosstalk between therapeutic cancer vaccines and the tumor microenvironment: Beyond tumor antigens.

Immunotherapy has rejuvenated cancer therapy, especially after anti-PD-(L)1 came onto the scene. Among the many therapeutic options, therapeutic cancer vaccines are one of the most essential players. Although great progress has been made in research on tumor antigen vaccines, few phase III trials have shown clinical benefits. One of the reasons lies in obstruction from the tumor microenvironment (TME). Meanwhile, the therapeutic cancer vaccine reshapes the TME in an ambivalent way, leading to immune stimulation or immune escape. In this review, we summarize recent progress on the interaction between therapeutic cancer vaccines and the TME. With respect to vaccine resistance, innate immunosuppressive TME components and acquired resistance caused by vaccination are both involved. Understanding the underlying mechanism of this crosstalk provides insight into the treatment of cancer by directly targeting the TME or synergizing with other therapeutics.

[Multilocus sequence typing of Candida albicans bloodstream isolates in an intensive care unit].

OBJECTIVE: Investigate the molecular epidemiological characteristics of bloodstream infections (BSI) due to Candida albicans (C. albicans) in the intensive care unit (ICU) of West China Hospital, Sichuan University. METHODS: C. albicans isolates recovered from blood cultures in West China Hospital, Sichuan University between 2009 and 2011 were collected. Multilocus sequence typing (MLST) was performed to assess the genetic relationships among BSI isolates of C. albicans collected from the ICU. RESULTS: 135 BSI isolates of Candida species were obtained from 2009 to 2011. C. albicans was the leading pathogen (51 isolates, 37.8%). 17 C. albicans BSI isolates from 15 patients of ICU were analyzed by MLST. Among the 17 isolates, 15 were recovered from peripheral blood and 2 from central venous catheters (CVC) (Peripheral blood and CVC were sent for culture and both had positive results for 2 patients). The 17 isolates yielded 15 unique sequence types (STs) by MLST. While 14 STs were each derived from a single isolate, 1 STs were shared by 3 isolates. 5 (29.4%) isolates were clustered within Group 46, 2 (11.8%) isolates were clustered within Group 47, and 10 isolates (58.8%) typed as singletons. The strains (Calb-36 and Calb-40) recovered from one blood sample and one CVC from one patient were indistinguishable by MLST, while two distinct strains were found in one blood sample and one CVC from another patient. CONCLUSION: C. albicans was the most frequently isolated species of candidemia in West China Hospital. Predominant strains of C. albicans caused BSI in the ICU belonged to Group 46 and Group 47. There was not yet an outbreak of BSI caused by C. albicans, but catheter-related candidemia was confirmed by our research.

Integrated analysis reveals the molecular features of fibrosis in triple-negative breast cancer.

Triple-negative breast cancer (TNBC) is an aggressive type of breast cancer. High fibrosis, marked by increased collagen fibers, is widespread in TNBC and correlated with tumor progression. However, the molecular features of fibrosis and why it results in a poor prognosis remain poorly understood. Based on multiomics datasets of TNBC, we evaluated the pathological fibrosis grade of 344 samples for further analysis. Genomic, transcriptomic, and immune changes were analyzed among different subgroups of fibrosis. High fibrosis was an independent adverse prognosis predictor and had interactions with low stromal tumor-infiltrating lymphocytes. Genomic analysis identified copy number gains of 6p22.2-6p22.1 (TRIM27) and 20q13.33 (CDH4) as genomic hallmarks of tumors with high fibrosis. Transcriptome analysis revealed the transforming growth factor-beta pathway and hypoxia pathway were key pro-oncogenic pathways in tumors with high fibrosis. Moreover, we systematically evaluate the relationship between fibrosis and different kinds of immune and stromal cells. Tumors with high fibrosis were characterized by an immunosuppressive tumor microenvironment with limited immune cell infiltration and increased fibroblasts. This study proposes new insight into the genomic and transcriptomic alterations potentially driving fibrosis. Moreover, fibrosis is related to an immunosuppressive tumor microenvironment that contributes to the poor prognosis.

Persistence of an epidemic cluster of Rhodotorula mucilaginosa in multiple geographic regions in China and the emergence of a 5-flucytosine resistant clone.

Rhodotorula mucilaginosa, an environmental yeast widely used in industry and agriculture, is also an opportunistic pathogen resistant to multi-antifungals. During the national surveillance in China, R. mucilaginosa has been documented from various hospitals and regions. At present, the molecular epidemiology of invasive infections caused by R. mucilaginosa and their resistance profiles to antifungals were unknown. Here we collected 49 strains from four hospitals located in different geographic regions from 2009 to 2019 in China, determined their genotypes using different molecular markers and quantified susceptibilities to various antifungals. Sequencing of ITS and D1/D2 regions in rDNA indicated that 73.5% (36/49) of clinical strains belong to same sequence type (rDNA type 2). Microsatellite (MT) genotyping with 15 (recently developed) tandem repeat loci identified 5 epidemic MT types, which accounted for 44.9% (22/49) of clinical strains, as well as 27 sporadic MT types. Microsatellite data indicated that the presence of an epidemic cluster including 35 strains (71.4%) repeatedly isolated in four hospitals for eight years. Single nucleotide variants (SNVs) from the whole genome sequence data also supported the clustering of these epidemic strains due to low pairwise distance. In addition, phylogenetic analysis of SNVs from these clinical strains, together with environmental and animal strains showed that the closely related epidemic cluster strains may be opportunistic, zoonotic pathogens. Also, molecular data indicated a possible clonal transmission of pan echinocandins-azoles-5-flucytosine resistant R. mucilaginosa strains in hospital H01. Our study demonstrated that R. mucilaginosa is a multi-drug resistant pathogen with the ability to cause nosocomial infection.

Antifungal susceptibility profiles and drug resistance mechanisms of clinical Candida duobushaemulonii isolates from China.

Candida duobushaemulonii, type II Candida haemulonii complex, is closely related to Candida auris and capable of causing invasive and non-invasive infections in humans. Eleven strains of C. duobushaemulonii were collected from China Hospital Invasive Fungal Surveillance Net (CHIF-NET) and identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF), VITEK 2 Yeast Identification Card (YST), and internal transcribed spacer (ITS) sequencing. Whole genome sequencing of C. duobushaemulonii was done to determine their genotypes. Furthermore, C. duobushaemulonii strains were tested by Sensititre YeastOne™ and Clinical and Laboratory Institute (CLSI) broth microdilution panel for antifungal susceptibility. Three C. duobushaemulonii could not be identified by VITEK 2. All 11 isolates had high minimum inhibitory concentrations (MICs) to amphotericin B more than 2 µg/ml. One isolate showed a high MIC value of ≥64 µg/ml to 5-flucytosine. All isolates were wild type (WT) for triazoles and echinocandins. FUR1 variation may result in C. duobushaemulonii with high MIC to 5-flucytosine. Candida duobushaemulonii mainly infects patients with weakened immunity, and the amphotericin B resistance of these isolates might represent a challenge to clinical treatment.

Aesculetin-induced apoptosis through a ROS-mediated mitochondrial dysfunction pathway in human cervical cancer cells.

Aesculetin (1) is an important coumarin found in various plant materials. It has been shown to have antiproliferative effects on several types of human cancer cells, but its effect on cervical cancer cells in vitro is unknown. In this study, we investigated that the cytotoxic effect of 1 on a non-cancer cell line (293) was smaller than on a tumor cell line (HeLa). This is the first report showing the possible mechanism of antiproliferative effect of 1 for the prevention of cervical cancer in cell culture models. It was found that 1 inhibited cell viability by inducing apoptosis, as evidenced by the formation of apoptotic bodies, generation of reactive oxygen species (ROS), and the accumulation of cells in the sub-G1 phase. Treatment with compound 1 decreased the cell growth in a dose-dependent manner with an IC(50) value of 37.8 microM. Aesculetin-induced apoptosis was correlated with mitochondrial dysfunction (DeltaPsi(m)), leading to the release of cytochrome c from the mitochondria to the cytosol, as well as the proteolytic activation of caspases in HeLa cells. These results indicate that 1 induces apoptosis in HeLa cells through a ROS-mediated mitochondrial dysfunction pathway.

Time lasting S-nitrosoglutathione polymeric nanoparticles delay cellular protein S-nitrosation.

Physiological S-nitrosothiols (RSNO), such as S-nitrosoglutathione (GSNO), can be used as nitric oxide (NO) donor for the treatment of vascular diseases. However, despite a half-life measured in hours, the stability of RSNO, limited by enzymatic and non-enzymatic degradations, is too low for clinical application. So, to provide a long-lasting effect and to deliver appropriate NO concentrations to target tissues, RSNO have to be protected. RSNO encapsulation is an interesting response to overcome degradation and provide protection. However, RSNO such as GSNO raise difficulties for encapsulation due to its hydrophilic nature and the instability of the S-NO bound during the formulation process. To our knowledge, the present study is the first description of the direct encapsulation of GSNO within polymeric nanoparticles (NP). The GSNO-loaded NP (GSNO-NP) formulated by a double emulsion process, presented a mean diameter of 289 ± 7 nm. They were positively charged (+40 mV) due to the methacrylic acid and ethylacrylate polymer (Eudragit® RL) used and encapsulated GSNO with a satisfactory efficiency (i.e. 54% or 40 mM GSNO loaded in the NP). In phosphate buffer (37 °C; pH 7.4), GSNO-NP released 100% of encapsulated GSNO within 3h and remained stable still 6h. However, in contact with smooth muscle cells, maximum protein nitrosation (a marker of NO bioavailability) was delayed from 1h for free GSNO to 18h for GSNO-NP. Therefore, protection and sustained release of NO were achieved by the association of a NO donor with a drug delivery system (such as polymeric NP), providing opportunities for vascular diseases treatment.

Improving Efficiency of Multicrystalline Silicon and CIGS Solar Cells by Incorporating Metal Nanoparticles.

This work studies the use of gold (Au) and silver (Ag) nanoparticles in multicrystalline silicon (mc-Si) and copper-indium-gallium-diselenide (CIGS) solar cells. Au and Ag nanoparticles are deposited by spin-coating method, which is a simple and low cost process. The random distribution of nanoparticles by spin coating broadens the resonance wavelength of the transmittance. This broadening favors solar cell applications. Metal shadowing competes with light scattering in a manner that varies with nanoparticle concentration. Experimental results reveal that the mc-Si solar cells that incorporate Au nanoparticles outperform those with Ag nanoparticles. The incorporation of suitable concentration of Au and Ag nanoparticles into mc-Si solar cells increases their efficiency enhancement by 5.6% and 4.8%, respectively. Incorporating Au and Ag nanoparticles into CIGS solar cells improve their efficiency enhancement by 1.2% and 1.4%, respectively. The enhancement of the photocurrent in mc-Si solar cells is lower than that in CIGS solar cells, owing to their different light scattering behaviors and material absorption coefficients.