The combination of breast cancer PDO and mini-PDX platform for drug screening and individualized treatment.

The majority of advanced breast cancers exhibit strong aggressiveness, heterogeneity, and drug resistance, and currently, the lack of effective treatment strategies is one of the main challenges that cancer research must face. Therefore, developing a feasible preclinical model to explore tailored treatments for refractory breast cancer is urgently needed. We established organoid biobanks from 17 patients with breast cancer and characterized them by immunohistochemistry (IHC) and next generation sequencing (NGS). In addition, we in the first combination of patient-derived organoids (PDOs) with mini-patient-derived xenografts (Mini-PDXs) for the rapid and precise screening of drug sensitivity. We confirmed that breast cancer organoids are a high-fidelity three-dimension (3D) model in vitro that recapitulates the original tumour's histological and genetic features. In addition, for a heavily pretreated patient with advanced drug-resistant breast cancer, we combined PDO and Mini-PDX models to identify potentially effective combinations of therapeutic agents for this patient who were alpelisib + fulvestrant. In the drug sensitivity experiment of organoids, we observed changes in the PI3K/AKT/mTOR signalling axis and oestrogen receptor (ER) protein expression levels, which further verified the reliability of the screening results. Our study demonstrates that the PDO combined with mini-PDX model offers a rapid and precise drug screening platform that holds promise for personalized medicine, improving patient outcomes and addressing the urgent need for effective therapies in advanced breast cancer.

Systematic identification and characterization of five transcription factors mediating the oxidative stress response in Candida albicans.

Candida albicans is an opportunistic human fungal pathogen that causes superficial and systemic infections, particularly in immunocompromised individuals. In response to C. albicans infection, innate immune cells of the host produce and accumulate reactive oxygen species (ROS), which can lead to irreversible damage and apoptosis of fungal cells. Several transcription factors involved in this oxidative stress response have been identified; however, a systematic study to identify the transcription factors that mediate the oxidative stress response has not yet been conducted. Here, we screened a comprehensive transcription factor mutant library consisting of 211 transcription factor deletion mutant strains in the presence and absence of hydrogen peroxide (H2O2), a potent ROS inducer, and identified five transcription factors (Skn7, Dpb4, Cap1, Dal81, and Stp2) that are sensitive to H2O2. Genome-wide transcriptional profiling revealed that H2O2 induces a discrete set of differentially regulated genes among the five identified transcription factor mutant strains. Functional enrichment analysis identified KEGG pathways pertaining to glycolysis/gluconeogenesis, amino sugar and nucleotide sugar metabolism, and ribosome synthesis as the most enriched pathways. GO term analysis of the top common differentially expressed genes among the transcription factor mutant strains identified hexose catabolism and iron transport as the most enriched GO terms upon exposure to H2O2. This study is the first to systematically identify and characterise the transcription factors involved in the response to H2O2. Based on our transcriptional profiling results, we found that exposure to H2O2 modulates several downstream genes involved in fungal virulence. Overall, this study sheds new light on the metabolism, physiological functions, and cellular processes involved in the H2O2-induced oxidative stress response in C. albicans.

Clinicopathological characteristics, treatment patterns and outcomes in patients with HER2-positive breast cancer based on hormone receptor status: a retrospective study.

BACKGROUND: Different hormone receptor (HR) expression patterns have significant biological and therapeutic implications in patients with human epidermal growth factor receptor 2 (HER2)-positive breast cancer. However, the distinction between HR-positive /HER2-positive (HR+/HER2+) and HR-negative/HER2-positive (HR-/HER2+) subtypes remains unclear. METHODS: This retrospective study analyzed 828 patients with HER2-positive breast cancer at the First Affiliated Hospital of Xi'an Jiaotong University from 2012 to 2022. Baseline characteristics were compared by chi-square test. Survival outcomes were estimated by Kaplan-Meier method. RESULTS: In total, 56.3% (n = 466) had HR-positive and 43.7% (n = 362) had HR-negative disease. Comparatively, HR+/HER2 + breast cancers presented favorable clinicopathological features. At a median follow-up of 49 months, 199 disease-free survival (DFS) events and 99 deaths were observed. HR+/HER2 + patients had significantly better survival outcomes than HR-/HER2 + patients. HR-positive status was an independent protective factor for overall survival (OS) [P = 0.032; hazard ratio, 0.61; 95% confidence interval (CI), 0.39-0.96] and DFS (P = 0.001; hazard ratio, 0.61; 95% CI, 0.46-0.81). HR+/HER2 + patients were significantly less sensitive to neoadjuvant therapy than HR-/HER2 + patients. In the first-line treatment for HR+/HER2 + advanced breast cancer, receiving endocrine therapy significantly improved advanced-OS (P < 0.001; hazard ratio, 0.33; 95% CI, 0.18-0.59) and progression-free survival (PFS) (P < 0.001; hazard ratio, 0.38; 95% CI, 0.25-0.58) compared with not receiving endocrine therapy. Moreover, maintenance endocrine therapy after HER2-targeted therapy and chemotherapy is associated with significant advanced-OS and PFS benefits compared with no maintenance endocrine therapy (advanced-OS: P < 0.001; hazard ratio, 0.05; 95% CI, 0.03-0.12; PFS: P < 0.001; hazard ratio, 0.35; 95% CI, 0.21-0.57). CONCLUSIONS: This study reveals the high heterogeneity of HER2-positive breast cancer related to HR status in clinicopathological features, metastasis patterns, and outcomes. Large randomized controlled trials are warranted to optimize treatment strategies for the HER2-positive breast cancer population.

The regulatory subunits of CK2 complex mediate DNA damage response and virulence in Candida Glabrata.

BACKGROUND: Candida glabrata which belongs to normal microbiota, has caused significant concern worldwide due to its high prevalence and drug resistance in recent years. C. glabrata has developed many strategies to evade the clearance of the host immune system, thereby causing persistent infection. Although coping with the induced DNA damage is widely acknowledged to be important, the underlying mechanisms remain unclear. RESULTS: The present study provides hitherto undocumented evidence of the importance of the regulatory subunits of CgCK2 (CgCkb1 and CgCkb2) in response to DNA damage. Deletion of CgCKB1 or CgCKB2 enhanced cellular apoptosis and DNA breaks and led to cell cycle delay. In addition, deficiencies in survival upon phagocytosis were observed in Δckb1 and Δckb2 strains. Consistently, disruption of CgCKB1 and CgCKB2 attenuated the virulence of C. glabrata in mouse models of invasive candidiasis. Furthermore, global transcriptional profiling analysis revealed that CgCkb1 and CgCkb2 participate in cell cycle resumption and genomic stability. CONCLUSIONS: Overall, our findings suggest that the response to DNA damage stress is crucial for C. glabrata to survive in macrophages, leading to full virulence in vivo. The significance of this work lies in providing a better understanding of pathogenicity in C. glabrata-related candidiasis and expanding ideas for clinical therapies.

Altered intestinal microbiome and metabolome correspond to the clinical outcome of sepsis.

BACKGROUND: The gut microbiome plays a pivotal role in the progression of sepsis. However, the specific mechanism of gut microbiota and its metabolites involved in the process of sepsis remains elusive, which limits its translational application. METHOD: In this study, we used a combination of the microbiome and untargeted metabolomics to analyze stool samples from patients with sepsis enrolled at admission, then microbiota, metabolites, and potential signaling pathways that might play important roles in disease outcome were screened out. Finally, the above results were validated by the microbiome and transcriptomics analysis in an animal model of sepsis. RESULTS: Patients with sepsis showed destruction of symbiotic flora and elevated abundance of Enterococcus, which were validated in animal experiments. Additionally, patients with a high burden of Bacteroides, especially B. vulgatus, had higher Acute Physiology and Chronic Health Evaluation II scores and longer stays in the intensive care unit. The intestinal transcriptome in CLP rats illustrated that Enterococcus and Bacteroides had divergent profiles of correlation with differentially expressed genes, indicating distinctly different roles for these bacteria in sepsis. Furthermore, patients with sepsis exhibited disturbances in gut amino acid metabolism compared with healthy controls; namely, tryptophan metabolism was tightly related to an altered microbiota and the severity of sepsis. CONCLUSION: Alterations in microbial and metabolic features in the gut corresponded with the progression of sepsis. Our findings may help to predict the clinical outcome of patients in the early stage of sepsis and provide a translational basis for exploring new therapies.

Assessment of patient based real-time quality control on comparative assays for common clinical analytes.

BACKGROUND: It is critical for laboratories to conduct multianalyzer comparisons as a part of daily routine work to strengthen the quality management of test systems. Here, we explored the application of patient-based real-time quality controls (PBRTQCs) on comparative assays to monitor the consistency among clinical laboratories. METHODS: The present study included 11 commonly tested analytes that were detected using three analyzers. PBRTQC procedures were set up with exponentially weighted moving average (EWMA) algorithms and evaluated using the AI-MA artificial intelligence platform. Comparative assays were carried out on serum samples, and patient data were collected. Patients were divided into total patient (TP), inpatient (IP), and outpatient (OP) groups. RESULTS: Optimal PBRTQC protocols were evaluated and selected with appropriate truncation limits and smoothing factors. Generally, similar comparative assay performance was achieved using both the EWMA and median methods. Good consistency between the results from patients' data and serum samples was obtained, and unacceptable bias was detected for alkaline phosphatase (ALP) and gamma-glutamyl transferase (GGT) when using analyzer C. Categorizing patients' data and applying specific groups for comparative assays could significantly improve the performance of PBRTQCs. When monitoring the inter- and intraanalyzer stability on a daily basis, EWMA was superior in detecting very small quality-related changes with lower false-positive alarms. CONCLUSIONS: We found that PBRTQCs have the potential to efficiently assess multianalyzer comparability. Laboratories should be aware of population variations concerning both analytes and analyzers to build more suitable PBRTQC protocols.

Inhibition of Ras protein activator like 2 produces antitumor effects in gastric cancer via the suppression of YAP1 activation.

Ras protein activator like 2 (RASAL2) has a cancer-related function, but plays inconsistent roles in different malignancies. This project was designed to determine the role of RASAL2 in carcinogenesis in gastric cancer. The Cancer Genome Atlas data revealed high levels of RASAL2 in gastric cancer tissue, which was confirmed in clinical specimens of gastric cancer via real-time quantitative PCR and western blotting assays. High RASAL2 was correlated with a reduced survival rate in gastric cancer patients. In gastric cancer cell lines, the silencing of RASAL2 restrained cellular proliferation, invasion and epithelial-to-mesenchymal transition, while enhancing chemosensitivity to cisplatin. Mechanistically, the silencing of RASAL2 was found to inhibit the activation of Yes-associated protein 1 (YAP1), a pro-oncogenic protein in gastric cancer, and decrease the expression of YAP1 target genes. The re-expression of constitutively active YAP1 substantially reversed RASAL2-silencing-produced antitumor effects. Moreover, treatment with YAP1 inhibitors could diminish RASAL2-overexpression-evoked oncogenic effects in gastric cancer cells. Additionally, gastric cancer cells with RASAL2 silencing exhibited a reduced ability to form xenograft tumors in nude mice. Collectively, our data demonstrate that the silencing of RASAL2 has noteworthy antitumor effects in gastric cancer cells via the suppression of YAP1 activation. This project underscores a vital role of the RASAL2/YAP1 axis in gastric progression and indicates that targeting this oncogenic axis may be applied as a potential therapeutic option for gastric cancer.

Clophosome alleviate dextran sulphate sodium-induced colitis by regulating gut immune responses and maintaining intestinal integrity in mice.

Inflammatory bowel disease (IBD) is a chronic progressive disorder characterized by complicated gastrointestinal inflammation. Research on therapeutic agents is still urgent due to the lack of satisfactory treatments. Gut macrophages are considered to be predominant in excessive inflammatory responses. Thus, we aimed to investigate whether depletion of macrophages would have a beneficial effect on IBD and could be a potential therapeutic strategy. In this study, we established a 12-day Dextran sodium sulphate (DSS)-induced colitis mouse model and determined the effect of the macrophage depletion agent Clophosome (neutral clodronate liposomes; CNC). The results showed that CNC significantly alleviated the symptoms of colitis, as demonstrated by greater weight gain, decreased disease activity index (DAI) scores, and lower histopathological damage scores, as well was reduced levels of the proinflammatory cytokines interleukin (IL)-6 and tumour necrosis factor (TNF)-α. To investigate T cell subsets, cells were isolated from the lamina propria and cultured to analyse the expression of IL-17A, interferon (IFN)-γ and Foxp3 in CD4+ cells by flow cytometry. The data showed that during the process of colitis, the frequencies of CD4+ IL-17A+ T cells were significantly increased. Notably, CNC treatment markedly reduced the population of CD4+ IL-17A+ T cells, especially CD4+ IL-17A+ IFN-γ+ T cells. Furthermore, intestinal barrier integrity, as assessed by immunostaining of mucin and tight junction proteins, was severely disrupted in colitis. CNC improved the intestinal barrier by enhancing the expression of muc-2 and occludin. In summary, our findings demonstrated that CNC successfully ameliorated DSS-induced colitis and that its effect may be associated with inhibiting inflammatory responses and maintaining intestinal integrity.

α-Mangostin suppresses the de novo lipogenesis and enhances the chemotherapeutic response to gemcitabine in gallbladder carcinoma cells via targeting the AMPK/SREBP1 cascades.

High rates of de novo lipid synthesis have been discovered in certain kinds of tumours, including gallbladder cancer (GBC). Unlike several other tumours, GBC is highly insensitive to standard adjuvant therapy, which makes its treatment even more challenging. Although several potential targets and signalling pathways underlying GBC chemoresistance have been revealed, the precise mechanisms are still elusive. In this study, we found that α-Mangostin, as a dietary xanthone, repressed the proliferation and clone formation ability, induced cell cycle arrest and the apoptosis, and suppressed de novo lipogenesis of gallbladder cancer cells. The underlying mechanisms might involve the activation of AMPK and, therefore, the suppression of SREBP1 nuclear translocation to blunt de novo lipogenesis. Furthermore, SREBP1 silencing by siRNA or α-mangostin enhanced the sensitivity of gemcitabine in gallbladder cancer cells. In vivo studies also displayed that MA or gemcitabine administration to nude mice harbouring NOZ tumours can reduce tumour growth, and moreover, MA administration can significantly potentiate gemcitabine-induced inhibition of tumour growth. Corroborating in vitro findings, tumours from mice treated with MA or gemcitabine alone showed decreased levels of proliferation with reduced Ki-67 expression and elevated apoptosis confirmed by TUNEL staining, furthermore, the proliferation inhibition and apoptosis up-regulation were obviously observed in MA combined with gemcitabine treatment group. Therefore, inhibiting de novo lipogenesis via targeting the AMPK/SREBP1 signalling by MA might provide insights into a potential strategy for sensitizing GBC cells to chemotherapy.

A nomogram for predicting survival in patients with de novo metastatic breast cancer: a population-based study.

BACKGROUND: 5-10% of patients are diagnosed with metastatic breast cancer (MBC) at the initial diagnosis. This study aimed to develop a nomogram to predict the overall survival (OS) of these patients. METHODS: de novo MBC patients diagnosed in 2010-2016 were identified from the Surveillance, Epidemiology, and End Results (SEER) database. They were randomly divided into a training and a validation cohort with a ratio of 2:1. The best subsets of covariates were identified to develop a nomogram predicting OS based on the smallest Akaike Information Criterion (AIC) value in the multivariate Cox models. The discrimination and calibration of the nomogram were evaluated using the Concordance index, the area under the time-dependent receiver operating characteristic curve (AUC) and calibration curves. RESULTS: In this study, we included 7986 patients with de novo MBC. The median follow-up time was 36 months (range: 0-83 months). Five thousand three-hundred twenty four patients were allocated into the training cohort while 2662 were allocated into the validation cohort. In the training cohort, age at diagnosis, race, marital status, differentiation grade, subtype, T stage, bone metastasis, brain metastasis, liver metastasis, lung metastasis, surgery and chemotherapy were selected to create the nomogram estimating the 1-, 3- and 5- year OS based on the smallest AIC value in the multivariate Cox models. The nomogram achieved a Concordance index of 0.723 (95% CI, 0.713-0.733) in the training cohort and 0.719 (95% CI, 0.705-0.734) in the validation cohort. AUC values of the nomogram indicated good specificity and sensitivity in the training and validation cohort. Calibration curves showed a favorable consistency between the predicted and actual survival probabilities. CONCLUSION: The developed nomogram reliably predicted OS in patients with de novo MBC and presented a favorable discrimination ability. While further validation is needed, this may be a useful tool in clinical practice.

Risk factors and intestinal microbiota: Clostridioides difficile infection in patients receiving enteral nutrition at Intensive Care Units.

BACKGROUND: Clostridioides difficile infection (CDI) is a leading cause of nosocomial diarrhea. Patients receiving enteral nutrition (EN) in the intensive care unit (ICU) are potentially at high risk of CDI. In the present study, we assessed the risk factors and intestinal microbiome of patients to better understand the occurrence and development of CDI. METHODS: Patients were screened for C. difficile every week after starting EN, and their clinical records were collected for risk factor identification. Fecal samples were analyzed using 16S rRNA sequencing to evaluate the intestinal microbiota. RESULTS: Overall incidence of CDI was 10.7% (18/168 patients). History of cerebral infarction was significantly associated with CDI occurrence (OR, 9.759; 95% CI, 2.140-44.498), and treatment with metronidazole was identified to be protective (OR, 0.287; 95% CI, 0.091-0.902). Patients with EN had lower bacterial richness and diversity, accompanied by a remarkable decrease in the abundance of Bacteroides, Prevotella_9, Ruminococcaceae, and Lachnospiraceae. Of these patients, acquisition of C. difficile resulted in a transient increase in microbial diversity, along with consistent alterations in the proportion of some bacterial taxa, especially Ruminococcaceae and Lachnospiraceae. Upon initiation of EN, patients who were positive for C. difficile later showed an enhanced load of Bacteroides, which was negatively correlated with the abundance of C. difficile when CDI developed. CONCLUSION: ICU patients receiving EN have a high prevalence of CDI and a fragile intestinal microbial environment. History of cerebral infarction and prior treatment with metronidazole are considered as vital risk and protective factors, respectively. We propose that the emergence of CDI could cause a protective alteration of the intestinal microbiota. Additionally, Bacteroides loads seem to be closely related to the occurrence and development of CDI.

BRD4 promotes glioma cell stemness via enhancing miR-142-5p-mediated activation of Wnt/ß-catenin signaling.

The bromodomain protein BRD4 exerts carcinogenic effects in many cancers. However, its roles in glioma occurrence are still confused. Here, it is found that BRD4 expression is increased in glioma tissues and negatively correlated with the overall survival of glioma patients. We construct cellular experiments indicating that BRD4 promotes glioma cell stemness by analyzing ALDH1 activity, master stemness regulator expression, and sphere formation ability. Mechanistically, BRD4 knockdown triggers a switch of miR-142-5p promoter methylation, which targets Wnt3a and thus further inactivates Wnt/ß-catenin signaling. Importantly, inhibition of miR-142-5p or reactivation of Wnt/ß-catenin signaling rescues the inhibition of BRD4 knockdown on glioma cell stemness. As a result, these results not only indicate an unforeseen connection between BRD4, miR-142-5p, and Wnt/ß-catenin signaling, but also reveal a promising epigenetic-based therapeutic strategy that might be explored for glioma patients.

Risk factors for Clostridioides difficile infection and colonization among patients admitted to an intensive care unit in Shanghai, China.

BACKGROUND: Clostridioides difficile is considered the main pathogen responsible for hospital-acquired infections. This prospective study determined the prevalence, molecular epidemiological characteristics, and risk factors for C. difficile infection (CDI) and C. difficile colonization (CDC) among patients in the intensive care unit (ICU) of a large-scale tertiary hospital in China, with the aim of providing strategies for efficient CDI and CDC prevention and control. METHODS: Stool samples were collected and anaerobically cultured for C. difficile detection. The identified isolates were examined for toxin genes and subjected to multilocus sequence typing. Patients were classified into CDI, CDC, and control groups, and their medical records were analyzed to determine the risk factors for CDI and CDC. RESULTS: Of the 800 patients included in the study, 33 (4.12%) and 25 (3.12%) were identified to have CDI and CDC, respectively. Associations with CDI were found for fever (OR = 13.993), metabolic disorder (OR = 7.972), and treatment with fluoroquinolone (OR = 42.696) or combined antibiotics (OR = 2.856). CDC patients were characterized by prolonged hospital stay (OR = 1.137), increased number of comorbidities (OR = 36.509), respiratory diseases (OR = 0.043), and treatment with vancomycin (OR = 18.168). Notably, treatment with metronidazole was found to be a protective factor in both groups (CDI: OR = 0.042; CDC: OR = 0.013). Eighteen sequence types (STs) were identified. In the CDI group, the isolated strains were predominantly toxin A and toxin B positive (A + B+) and the epidemic clone was genotype ST2. In the CDC group, the dominant strains were A + B+ and the epidemic clone was ST81. CONCLUSIONS: The prevalences of CDC and CDI in our ICU were relatively high, suggesting the importance of routine screening for acquisition of C. difficile. Future prevention and treatment strategies for CDC and CDI should consider hospital stay, enteral nutrition, underlying comorbidities, and use of combined antibiotics. Moreover, metronidazole may be a protective factor for both CDI and CDC, and could be used empirically.

The role of radiotherapy in patients with resected ampullary carcinoma: findings based on the SEER database.

BACKGROUND: The role of adjuvant radiotherapy for resected ampullary carcinoma (AC) remains controversial. The aim of this study was to assess the effect of adjuvant radiotherapy on survival in patients who underwent resection for AC. METHODS: The Surveillance, Epidemiology and End Results (SEER) database was used to identify patients diagnosed with AC from 2004 to 2012. Kaplan-Meier survival curve and multivariable Cox proportional hazards analyses were conducted to determine the effect of adjuvant radiotherapy on overall survival (OS) and disease-specific survival (DSS). Propensity score matching (PSM) method was used to balance the differences of clinicopathological characteristics between groups. RESULTS: A total of 1227 patients were included. Patients who received adjuvant radiotherapy were younger, had more advanced T stage and N stage tumors and were more likely to receive chemotherapy (p < 0.001). Adjuvant radiotherapy failed to improve either OS (p = 0.119) or DSS (p = 0.188) in PSM cohorts. In subgroup analysis, no subgroup benefited from adjuvant radiotherapy and in patients older than 70 years, radiotherapy was associated with a worse OS and DSS. CONCLUSION: Patients with resected AC do not benefit from adjuvant radiotherapy.

Sequence modification of the master regulator Pdr1 interferes with its transcriptional autoregulation and confers altered azole resistance in Candida glabrata.

The transcriptional regulator Pdr1 plays a positive role in regulating azole drug resistance in Candida glabrata. Previous studies have shown the importance of the carboxyl (C)-terminal sequence of Pdr1 in fulfilling its function, as this region mediates interactions between Pdr1 and the co-activator Gal11A and is crucial for activation of Pdr1 targets. However, mechanisms of how Pdr1 is regulated, especially implication of its C-terminus in the regulatory activity, remain uncharacterized. In this study, we unexpectedly observed that the C-terminal modification of Pdr1 in an azole-resistant clinical isolate harboring a single GOF mutation, resulted in adverse effects such as decreased expression levels of Pdr1, downregulation of Pdr1 targets and azole hypersensitivity. Importantly, the C-terminal 3 × FLAG tagging significantly decreased the binding of Pdr1 to the pleiotropic drug response elements in its own promoter, promoted an irregular cellular mislocalization and thereby disrupted the transcriptional autoregulation of this master regulator. Unexpectedly, the aberrant cytoplasmic localization caused a non-functional interaction with Gal11A, a co-activator involved in drug resistance. Based on these findings, we proposed that C-terminal sequence of Pdr1 is vital for its stability and functionality, and targeting regulation of this region may represent a promising future strategy for combating C. glabrata infection and drug resistance.

Effects of intestinal colonization by Clostridium difficile and Staphylococcus aureus on microbiota diversity in healthy individuals in China.

BACKGROUND: Intestinal colonization by pathogenic bacteria is a risk factor for infection, and contributes to environmental contamination and disease dissemination. Alteration of gut microbiota also plays a pivotal role in the development of disease. Although Clostridium difficile and Staphylococcus aureus are well-recognized pathogens causing nosocomial and community infections, the intestinal colonization was not fully investigated. Herein, we explored their overall carriage rates in healthy adults from the community, and characterized the gut microbiomes of C. difficile and S. aureus carriers. METHODS: Fecal samples were collected from 1709 healthy volunteers from communities in Shanghai, China, and tested for the presence of C. difficile, methicillin-sensitive S. aureus (MSSA), and methicillin-resistant S. aureus (MRSA) using culture-based techniques. To explore differences in the gut microbiome, 16S rRNA gene sequencing was conducted using samples from non-carriers (CH), C. difficile carriers (CCD), MRSA carriers (CM), and MSSA carriers (CS). RESULTS: Overall, we detected 12 C. difficile and 60 S. aureus isolates, accounting for 0.70% and 3.51% of total isolates, respectively. Eight isolates were determined to be MRSA, accounting for 13.3% of the S. aureus population. Sequencing data revealed that the microbial diversity and richness were similar among the four groups. However, at the phylum level, carriage of C. difficile or MRSA was associated with a paucity of Bacteroidetes and an overabundance of Proteobacteria compared with non-carriers. At the genus level, the prevalence of the genera Bacteroides, Prevotella, Faecalibacterium, and Roseburia was decreased in C. difficile-positive samples compared with the controls, while the proportion of Clostridium cluster XIVa species was increased. MRSA carriers exhibited a higher proportion of the genera Parasutterella and Klebsiella, but a decreased prevalence of Bacteroides. Compared with MSSA carriers, Klebsiella was the only genus found to be significantly enriched in MRSA carriers. CONCLUSIONS: In healthy adults, colonization by C. difficile or S. aureus did not significantly affect gut microbiota diversity. However, the alteration of the gut microbiota composition in C. difficile carriers could indicate a predisposition to further infection. Our study provides essential data on the prevalence and effects of C. difficile and S. aureus colonization on gut microbiota composition in healthy adults.

CgPDR1 gain-of-function mutations lead to azole-resistance and increased adhesion in clinical Candida glabrata strains.

Recently, Candida glabrata has emerged as a health-threatening pathogen and the rising resistance to antifungal agent in C. glabrata often leads to clinical treatment failure. To investigate the evolution of drug resistance and adherence ability in four paired clinical isolates collected before and after antifungal treatment. Sequence analysis, gene disruption, drug-susceptibility, adhesion tests and real-time quantitative PCR were performed. The azole-susceptible strains acquired azole resistance after antifungal therapy. Four gain-of-function (GOF) mutations in CgPDR1 were revealed by sequence analysis, namely G1099D, G346D, L344S and P927S, the last being reported for the first time. CDR1, CDR2 and SNQ2 efflux pump gene expression levels were elevated in strains harbouring GOF mutations in CgPDR1, resulting in decreased azole susceptibility. CgPDR1 alleles with distinct GOF mutations displayed different expression profiles for the drug-related genes. CgPDR1GOF mutations led to increased efflux pumps expression levels in a strain background independent way. Hyperactive Pdr1G1099D and Pdr1P927S displayed strain background-dependent increased adherence to host cells via upregulation of EPA1 transcription. Interestingly, the drug transporter gene expression levels did not always correspond with that of the adhesin EPA1 gene. GOF mutations in CgPDR1 conferred drug resistance and increased adherence in the clinical strains, possibly endowing C. glabrata with increased viability and pathogenicity.

The risk and survival outcome of subsequent primary colorectal cancer after the first primary colorectal cancer: cases from 1973 to 2012.

BACKGROUND: Among colorectal cancer (CRC) survivors, how the prior tumor location affects the risk of subsequent primary colorectal cancer (SPCRC) and the outcome of those suffering from SPCRC remain unknown. METHODS: CRC cases diagnosed from 1973 to 2012 were screened for SPCRC development using the Surveillance, Epidemiology, and End Results database. The relative risk of SPCRC was estimated using the standardized incidence ratio. Survivals were analyzed using the Kaplan-Meier and Cox regression model. RESULTS: The overall risk of SPCRC increased by 27% in CRC survivors compared to that of the general population. The risk increased in patients with both prior right colon cancer (RCC) and left colon cancer (LCC), and was concentrated in the first 5 years after the prior diagnosis, and among young patients. Among the 6701 SPCRC patients identified, patients with prior RCC were more likely to be elderly, female, and with more low or undifferentiated disease than those with prior LCC or rectal cancer (ReC). The overall survivals differed by both prior tumor location (P < 0.0001) and age (P < 0.0001), and the difference by tumor location remained significant when adjusted or stratified by any other potential prognostic factor except age. The cancer specific survivals differed by age (P < 0.0001) rather than by prior tumor location (P = 0.455). CONCLUSIONS: The overall risk of SPCRC increased among patients with both prior RCC and LCC, but not among those with ReC. The different survival outcomes in CRC survivors suffering from SPCRC were largely explained by the patient age but not by the prior tumor location.

The Role of UPC2 Gene in Azole-Resistant Candida tropicalis.

Azole resistance of Candida tropicalis has, in recent years, become a serious issue in hospitals; however, there is limited knowledge of the mechanisms underlying this resistance. We have previously demonstrated that ERG11 plays a vital role in azole resistance in C. tropicalis. Here, we describe the expression and sequence variation of UPC2, which encodes a transcription factor of ERG11. Quantitative real-time RT-PCR showed that 31 azole-resistant C. tropicalis strains significantly overexpressed UPC2. Those isolates resistant to all three azole antifungals upregulated UPC2 expression to a greater degree than those resistant to only fluconazole or itraconazole. The UPC2 promoter contains mutations -118T-G and -155G-A in azole-resistant strains of C. tropicalis. Meanwhile, the mutation G392E was also detected twice in UPC2 gene in azole-resistant C. tropicalis and was demonstrated to mediate azole antifungal susceptibility by using Saccharomyces cerevisiae as an expression host, particularly for fluconazole and itraconazole.

The Correlation Between Candida Colonization of Distinct Body Sites and Invasive Candidiasis in Emergency Intensive Care Units: Statistical and Molecular Biological Analysis.

Both statistical and molecular biological methods were used to evaluate the association between Candida colonization of different body sites and invasive candidiasis (IC) and analyse the potential infection sources of IC. Candida surveillance cultures from the urine, sputum, rectum and skin were performed on patients admitted to an emergency intensive care units (EICU) of a tertiary care hospital in Shanghai, China, from February 2014 to January 2015. Specimens were collected once a week at admission and thereafter. The patients' clinical data were collected, and Candida isolates were genotyped using polymorphic microsatellite markers. A total of 111 patients were enrolled. Patients with positive urine (23.3 vs. 2.5 %, p = 0.001) and rectal swab (13.6 vs. 0 %, p = 0.010) cultures were more likely to develop IC. However, the risk for IC was not significantly different among patients with and without respiratory (10.0 vs. 5.8 %, p = 0.503) and skin (33.3 vs. 6.5 %, p = 0.056) colonization. Gene microevolution frequently occurred at rectal swab and urine sites, and IC with possible source of infection was caused by rectal isolates (2/7), urine isolates (4/7) and sputum isolate (1/7).The colonization of gut and urinary tract maybe more relevant indicators of IC, which should be taken into consideration when selecting practical body sites for Candida surveillance cultures.