Surveillance and epidemiology of Clostridioides difficile infection using the national health surveillance network criteria: A 7-year study from Mumbai, India.

INTRODUCTION: Clostridioides difficile (CD) is a significant cause of morbidity and mortality. While considerable data is available in the developed world regarding Clostridioides difficile infection (CDI), Indian data is sparse especially using the standardized surveillance systems. AIM AND OBJECTIVES OF THE STUDY: To identify the incidence, risk factors, and mortality rate associated with CDI in a tertiary care hospital based on the Laboratory-Identified (LabID) event criteria of the Centers for Disease Control and Prevention (CDC) National Health Surveillance Network (NHSN). MATERIALS AND METHODS: During a 7- year prospective observational study, CDI was diagnosed using CD polymerase chain reaction (PCR). CDI Laboratory-Identified (LabID) events were classified using the CDC NHSN surveillance definition, and CDI incidence was calculated per 10,000 Patient Days (PDs). Clinical details were collected as part of healthcare-associated infection (HCAI) surveillance. Healthcare Facility-Onset (HO) and Community-Onset Healthcare Facility-Associated (CO-HCFA) incident CDI events were analyzed further. RESULTS: Among 898 tested stool samples, 77 CDI LabID events were observed, with 68 being Incident events. Of 68 events, 76.5% (52/68), 19.1% (13/68), and 4.4% (3/68) were HO, Community-Onset (CO), and CO-HCFA CDI events respectively. The overall incidence of CDI events was 1.66 per 10,000 PDs. Risk factors observed were antibiotics exposure (100%), comorbidities (87.3%), antacids exposure (87.3%), age over 60 years (80%), and hospitalization within the past 6 months (67.3%). The crude mortality rate was 25.5% (14/55). CONCLUSION: These findings highlight the predominance of HO-CDI and the need for further investigation into CO-CDI in the Indian context to identify at-risk populations. Utilizing standardized surveillance methods such as NHSN definitions can facilitate accurate disease burden estimation, trend monitoring, and meaningful comparisons with global data.

Nuclear Receptor 4A2 (NR4A2/NURR1) Regulates Autophagy and Chemoresistance in Pancreatic Ductal Adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive cancer with poor prognosis and chemotherapy with gemcitabine has limited effects and is associated with development of drug resistance. Treatment of Panc1 and MiaPaca2 pancreatic cancer cells with gemcitabine induced expression of the orphan nuclear receptor 4A2 (NURR1) and analysis of the cancer genome atlas indicated the NURR1 is overexpressed in pancreatic tumors and is a negative prognostic factor for patient survival. Results of NURR1 knockdown or treatment with the NURR1 antagonist 1,1-bis(3΄-indolyl)-1-(p-chlorophenyl)methane (C-DIM 12) demonstrated that NURR1 was pro-oncogenic in pancreatic cancer cells and regulated cancer cell and tumor growth and survival. NURR1 is induced by gemcitabine and serves as a key drug-resistance factor and is also required for gemcitabine-induced cytoprotective autophagy. NURR1 regulated genes were determined by RNA sequencing of mRNAs expressed in MiaPaCa2 cells expressing NURR1 and in CRISPR/Cas9 gene edited cells for NURR1 knockdown and KEGG enrichment analysis of the differentially expressed genes showed that autophagy was the major pathway regulated by NURR1. Moreover, NURR1 regulated expression of two major autophagic genes ATG7 and ATG12 which are also overexpressed in pancreatic tumors and like NURR1 are negative prognostic factors for patient survival. Thus, gemcitabine-induced cytoprotective autophagy is due to the NURR1 - ATG7/ATG12 axis and this can be targeted and disrupted by NURR1 antagonist C-DIM12 demonstrating the potential clinical applications for combination therapies with gemcitabine and NURR1 antagonists.

MITF is a driver oncogene and potential therapeutic target in kidney angiomyolipoma tumors through transcriptional regulation of CYR61.

Tuberous sclerosis complex (TSC) is an autosomal dominant tumor suppressor syndrome, characterized by tumor development in multiple organs, including renal angiomyolipoma. Biallelic loss of TSC1 or TSC2 is a known genetic driver of angiomyolipoma development, however, whether an altered transcriptional repertoire contributes to TSC-associated tumorigenesis is unknown. RNA-seq analyses showed that MITF A isoform (MITF-A) was consistently highly expressed in angiomyolipoma, immunohistochemistry showed microphthalmia-associated transcription factor nuclear localization, and Chromatin immuno-Precipitation Sequencing analysis showed that the MITF-A transcriptional start site was highly enriched with H3K27ac marks. Using the angiomyolipoma cell line 621-101, MITF knockout (MITF.KO) and MITF-A overexpressing (MITF.OE) cell lines were generated. MITF.KO cells showed markedly reduced growth and invasion in vitro, and were unable to form xenografted tumors. In contrast, MITF.OE cells grew faster in vitro and as xenografted tumors compared to control cells. RNA-Seq analysis showed that both ID2 and Cysteine-rich angiogenic inducer 61 (CYR61) expression levels were increased in the MITF.OE cells and reduced in the MITF.KO cells, and luciferase assays showed this was due to transcriptional effects. Importantly, CYR61 overexpression rescued MITF.KO cell growth in vitro and tumor growth in vivo. These findings suggest that MITF-A is a transcriptional oncogenic driver of angiomyolipoma tumor development, acting through regulation of CYR61.

Tumors with TSC mutations are sensitive to CDK7 inhibition through NRF2 and glutathione depletion.

Tuberous sclerosis complex (TSC) is characterized by tumor development in the brain, heart, kidney, and lungs. In TSC tumors, loss of the TSC1/TSC2 protein complex leads to activation of mTORC1 with downstream effects on anabolism and cell growth. Because mTORC1 activation enhances mRNA transcription, we hypothesized that aberrant mTORC1 activation might confer TSC-null cell dependence on transcriptional regulation. We demonstrate that TSC1- or TSC2-null cells, in contrast to their wild-type counterparts, are sensitive to pharmacological inhibition of CDK7. Mechanistic studies revealed that CDK7 inhibition markedly reduces glutathione levels and increases reactive oxygen species due to reduced expression of NRF2 and glutathione biosynthesis genes. Treatment of both Tsc2+/ - mice and a TSC1-null bladder cancer xenograft model with a CDK7 inhibitor showed marked reduction in tumor volume and absence of regrowth in the xenograft model. These results suggest that CDK7 inhibition is a promising therapeutic approach for treatment of TSC-associated tumors and cancers with mutations in either TSC1 or TSC2.