The colonization factor CS6 of enterotoxigenic Escherichia coli contributes to host cell invasion.

Enterotoxigenic Escherichia coli (ETEC) is one of the main causes of diarrhea in children and travelers in low-income regions. The virulence of ETEC is attributed to its heat-labile and heat-stable enterotoxins, as well as its colonization factors (CFs). CFs are essential for ETEC adherence to the intestinal epithelium. However, its invasive capability remains unelucidated. In this study, we demonstrated that the CS6-positive ETEC strain 4266 can invade mammalian epithelial cells. The invasive capability was reduced in the 4266 ΔCS6 mutant but reintroduction of CS6 into this mutant restored the invasiveness. Additionally, the laboratory E. coli strain Top 10, which lacks the invasive capability, was able to invade Caco-2 cells after gaining the CS6-expressing plasmid pCS6. Cytochalasin D inhibited cell invasion in both 4266 and Top10 pCS6 cells, and F-actin accumulation was observed near the bacteria on the cell membrane, indicating that CS6-positive bacteria were internalized via actin polymerization. Other cell signal transduction inhibitors, such as genistein, wortmannin, LY294002, PP1, and Ro 32-0432, inhibited the CS6-mediated invasion of Caco-2 cells. The internalized bacteria of both 4266 and Top10 pCS6 strains were able to survive for up to 48 h, and 4266 cells were able to replicate within Caco-2 cells. Immunofluorescence microscopy revealed that the internalized 4266 cells were present in bacteria-containing vacuoles, which underwent a maturation process indicated by the recruitment of the early endosomal marker EEA-1 and late endosomal marker LAMP-1 throughout the infection process. The autophagy marker LC3 was also observed near these vacuoles, indicating the initiation of LC-3-associated phagocytosis (LAP). However, intracellular bacteria continued to replicate, even after the initiation of LAP. Moreover, intracellular filamentation was observed in 4266 cells at 24 h after infection. Overall, this study shows that CS6, in addition to being a major CF, mediates cell invasion. This demonstrates that once internalized, CS6-positive ETEC is capable of surviving and replicating within host cells. This capability may be a key factor in the extended and recurrent nature of ETEC infections in humans, thus highlighting the critical role of CS6.

A review of clinical trials registered in India from 2008 to 2022 to describe the first-in-human trials.

Aim: This analysis was conducted to review the number, and describe the characteristics of first-in-human (FIH) Phase 1 clinical trials registered in India from 2008 to 2022. Materials and Methods: The data were extracted from the Clinical Trials Registry - India database for all FIH Phase 1 clinical trials registered between 2008 and 2022. Early-phase trials that were not FIH trials (e.g., pharmacokinetic studies and drug-drug interaction studies) were excluded from the study. Results: A total of 1891 trials were retrieved and 220 were included in the analysis. Most of the investigational products were drugs (55%) followed by vaccines (38.2%). The most common therapeutic class of drugs was cancer chemotherapy (19.8%), followed by antimicrobial chemotherapy and endocrinology (18.2% each). The most common vaccine was the influenza vaccine (21.4%), followed by the measles-mumps-rubella vaccine (15.5%). The pharmaceutical industry was the predominant sponsor for most (91%) of the Phase 1 trials. Of the top five sites where most of the Phase 1 trials were conducted, three were private nonacademic centers (cumulatively 31%) and two were tertiary care medical colleges (cumulatively 9%). Conclusion: Phase 1 clinical trials seem to be conducted in India predominantly with industry sponsorship. There is a need to have an alternate ecosystem to take forward molecules that do not receive adequate attention from the industry and molecules that are of national health priority other than areas such as chemotherapy, antimicrobials, and endocrinology. The Indian Council of Medical Research is setting up Phase 1 clinical trial capacity for molecules that predominantly may arise from nonindustry channels.

Prescription-based cost analysis of medicines for cardiovascular risk factors at Indian Council of Medical Research-Rational Use of Medicine Centre Hospitals of India.

OBJECTIVES: India has taken several initiatives to provide health care to its population while keeping the related expenditure minimum. Since cardiovascular diseases are the most prevalent chronic conditions, in the present study, we aimed to analyze the difference in prices of medicines prescribed for three cardiovascular risk factors, based on (a) listed and not listed in the National List of Essential Medicines (NLEM) and (b) generic and branded drugs. MATERIALS AND METHODS: Outpatient prescriptions for diabetes mellitus, hypertension, and dyslipidemia were retrospectively analyzed from 12 tertiary centers. The prices of medicines prescribed were compared based on presence or absence in NLEM India-2015 and prescribing by generic versus brand name. The price was standardized and presented as average price per medicine per year for a given medicine. The results are presented in Indian rupee (INR) and as median (range). RESULTS: Of the 4,736 prescriptions collected, 843 contained oral antidiabetic, antihypertensive, and/or hypolipidemic medicines. The price per medicine per year for NLEM oral antidiabetics was INR 2849 (2593-3104) and for non-NLEM was INR 5343 (2964-14364). It was INR 806 (243-2132) for generic and INR 3809 (1968-14364) for branded antidiabetics. Antihypertensives and hypolipidemics followed the trend. The price of branded non-NLEM medicines was 5-22 times higher compared to generic NLEM which, for a population of 1.37 billion, would translate to a potential saving of 346.8 billion INR for statins. The variability was significant for sulfonylureas, angiotensin receptor blockers, beta-blockers, diuretics, and statins (P < 0.0001). CONCLUSION: The study highlights an urgent need for intervention to actualize the maximum benefit of government policies and minimize the out-of-pocket expenditure on medicines.