Deciphering miRNA-lncRNA-mRNA interaction through experimental validation of miRNAs, lncRNAs, and miRNA targets on mRNAs in Cajanus cajan

Pigeon pea (Cajanus cajan) is widely cultivated for its nutritional and medicinal value yet remains an orphan crop as productivity has not been improved because of a lack of genome and non-coding genome information. Non-coding RNAs, like miRNAs and long non-coding RNAs (lncRNAs), are involved in regulation of growth, metabolism, development, and stress response, and have a critical role in post-transcriptional gene regulation (PTGR). We attempted to elucidate the roles of miRNAs and lncRNAs in pigeon pea through experimental validation of computationally predicted miRNAs and lncRNAs and targets of miRNAs on mRNAs. We experimentally validated 20 miRNAs and 11 lncRNAs. We predicted cleavage sites of three miRNA targets: serine/threonine-protein kinase, polygalacturonase, beta-galactosidase. We identified 469 targets of 265 miRNAs and their functional annotations using computational methods. We built a miRNA-mRNA-lncRNA network model, with the miRNAs targeting both mRNAs and lncRNAs, to obtain information on the interplay of these three molecules. A confirmed interaction through experimental validation was established between miRNA, namely cca-miR1535a targeting the mRNA for beta-galactosidase, as well as the lncRNA cca-lnc-020033. Our findings increase knowledge of the non-coding genome of pigeon pea and their roles in PTGR and in improving agronomic traits of this pulse crop.

Phenolic composition and bioactivity of Ribes magellanicum fruits from southern Patagonia

Eight Ribes magellanicum collections from three different places in southern Patagonia were compared for content of different groups of phenolics, antioxidant capacity and inhibition of enzymes related to metabolic syndrome (α-amylase, α-glucosidase and pancreatic lipase). The sample with the highest antioxidant capacity was assessed for glutathione (GSH) synthesis stimulation in human gastric adenocarcinoma (AGS) cells. The chemical profile was determined by high performance liquid chromatography with tandem mass spectrometry detection (HPLC-MS/MS) and the main phenolics were quantified. The samples from Navarino Island and Reserva Nacional Magallanes showed higher content of anthocyanins and caffeoylquinic acid, with better activity towards α-glucosidase and antioxidant capacity. A sample from Omora (Navarino Island), significantly increased intracellular GSH content in AGS cells. Some 70 compounds were identified in the fruit extracts by HPLC-MS/MS. The glucoside and rutinoside from delphinidin and cyanidin and 3-caffeoylquinic acid were the main compounds. Different chemical profiles were found according to the collection places.

Endoscopic Endonasal Trans-Sphenoidal Minimally Invasive Pituitary Surgery with Image Guided Navigation System (Igns): Learning Experience of Ent Surgeon: First Author

Introduction- Endoscopic minimally invasive pituitary surgery (MIPS) is advantageous over microscopic technique, as it provides superior close up, wide angle view of surgical target area. Image guided navigation system (IGNS) guides the surgeon to localize the lesion. In the present study we analyzed the Image Guided Surgical procedure and outcome of Endoscopic minimally invasive pituitary surgery and shared our experiences regarding disease clearance.

MATERIALS AND METHODS

During the period of April 2015 to August 2022 a total 104 patients, diagnosed with pituitary adenoma underwent surgery and further followed up in a multidisciplinary team approach in a tertiary care hospital of Kolkata, India. The data obtained were reviewed statistically to satisfy the study objectives.

RESULTS

Total 104 operations were done on 98 patients and total cases taken for calculation and analysis was 98, which consist of 11 microadenomas, 81 macroadenomas. Among 35 patients with normal preoperative hormonal assay, one patient developed postoperative hypopituitarism. Among 6 patients with preoperative hypopituitarism 4 patients (66.6%) recovered after surgery. Overall, 85 cases had total disease clearance as detected on post-operative MRI. In functioning pituitary adenoma (FPA) clinical and endocrinological improvement occurred after primary surgery in 85.36% (n = 35) and after revision surgery it was 84.44% (n = 38). Macroadenomas, giant adenomas were found to have statistically significant higher risk of incomplete disease clearance but large adenomas do not have statistically higher risk of incomplete clearance.

CONCLUSION

IGNS requires extra time for setup, but with proper registration of tracker instruments it adds precision to the surgery. IGNS supplements endoscopic visualization with localization of target lesion by real time stereotactic feedback using preset preoperative imaging data, thus increasing accuracy, safety and effectiveness of minimally invasive surgery.

Tests of Light-Lepton Universality in Angular Asymmetries of B^{0}→D^{*-}ℓν Decays

We present the first comprehensive tests of the universality of the light leptons in the angular distributions of semileptonic B^{0}-meson decays to charged spin-1 charmed mesons. We measure five angular-asymmetry observables as functions of the decay recoil that are sensitive to lepton-universality-violating contributions. We use events where one neutral B is fully reconstructed in ϒ(4S)→BB[over ¯] decays in data corresponding to 189  fb^{-1} integrated luminosity from electron-positron collisions collected with the Belle II detector. We find no significant deviation from the standard model expectations.

Field-Based Planetary Protection Operations for Melt Probes: Validation of Clean Access into the Blood Falls, Antarctica, Englacial Ecosystem

Subglacial environments on Earth offer important analogs to Ocean World targets in our solar system. These unique microbial ecosystems remain understudied due to the challenges of access through thick glacial ice (tens to hundreds of meters). Additionally, sub-ice collections must be conducted in a clean manner to ensure sample integrity for downstream microbiological and geochemical analyses. We describe the field-based cleaning of a melt probe that was used to collect brine samples from within a glacier conduit at Blood Falls, Antarctica, for geomicrobiological studies. We used a thermoelectric melting probe called the IceMole that was designed to be minimally invasive in that the logistical requirements in support of drilling operations were small and the probe could be cleaned, even in a remote field setting, so as to minimize potential contamination. In our study, the exterior bioburden on the IceMole was reduced to levels measured in most clean rooms, and below that of the ice surrounding our sampling target. Potential microbial contaminants were identified during the cleaning process; however, very few were detected in the final englacial sample collected with the IceMole and were present in extremely low abundances (∼0.063% of 16S rRNA gene amplicon sequences). This cleaning protocol can help minimize contamination when working in remote field locations, support microbiological sampling of terrestrial subglacial environments using melting probes, and help inform planetary protection challenges for Ocean World analog mission concepts.

Differential Response to Mechanical Cues in Uterine Fibroid Versus Paired Myometrial Cells

Uterine leiomyomas, or fibroids, are common, benign tumors for which hysterectomy is the only definitive treatment. The extracellular matrix of fibroids is disorganized and stiffer than the surrounding myometrial tissue. To understand how stiffness affects fibroid cells, patient-matched fibroid and myometrial cells were cultured on substrates with stiffnesses varying from 0.2 to 150 kPa. Fibroid cells grew more slowly than myometrial cells overall, and only the myometrial cells altered their growth rate in response to stiffness. In both cell types, cell proliferation decreased with inhibition of PI3K and increased with inhibition of IGF-1. The cellular area was greater for the fibroid cells. The only significant effect of stiffness on the cell area was between the 0.2 and 64 kPa substrates, and this was true for both cell types. To investigate intracellular stiffness, intracellular particle tracking microrheology was used. Fibroid cells exhibited a more than 100-fold increase in elastic modulus at a frequency of 1 Hz in response to the addition of external stress, while myometrial cells showed little change in elastic modulus. Overall, the responses of both cells followed similar trends in response to stiffness and inhibitors, although the response was attenuated in the fibroid cells. The changes that were demonstrated by the change in intracellular stiffness with response to compression suggest that other mechanical forces may provide insight into differences in the two cell types.

Precise Measurement of the D_{s}^{+} Lifetime at Belle II

We measure the lifetime of the D_{s}^{+} meson using a data sample of 207  fb^{-1} collected by the Belle II experiment running at the SuperKEKB asymmetric-energy e^{+}e^{-} collider. The lifetime is determined by fitting the decay-time distribution of a sample of 116×10^{3} D_{s}^{+}→ϕπ^{+} decays. Our result is τ_{D_{s}^{+}}=(499.5±1.7±0.9)  fs, where the first uncertainty is statistical and the second is systematic. This result is significantly more precise than previous measurements.

Search for a τ^{+}τ^{-} Resonance in e^{+}e^{-}→μ^{+}μ^{-}τ^{+}τ^{-} Events with the Belle II Experiment

We report the first search for a nonstandard-model resonance decaying into τ pairs in e^{+}e^{-}→μ^{+}μ^{-}τ^{+}τ^{-} events in the 3.6-10  GeV/c^{2} mass range. We use a 62.8  fb^{-1} sample of e^{+}e^{-} collisions collected at a center-of-mass energy of 10.58 GeV by the Belle II experiment at the SuperKEKB collider. The analysis probes three different models predicting a spin-1 particle coupling only to the heavier lepton families, a Higgs-like spin-0 particle that couples preferentially to charged leptons (leptophilic scalar), and an axionlike particle, respectively. We observe no evidence for a signal and set exclusion limits at 90% confidence level on the product of cross section and branching fraction into τ pairs, ranging from 0.7 to 24 fb, and on the couplings of these processes. We obtain world-leading constraints on the couplings for the leptophilic scalar model for masses above 6.5  GeV/c^{2} and for the axionlike particle model over the entire mass range.

Measurement of CP Violation in B^{0}→K_{S}^{0}π^{0} Decays at Belle II

We report a measurement of the CP-violating parameters C and S in B^{0}→K_{S}^{0}π^{0} decays at Belle II using a sample of 387×10^{6}  BB[over ¯] events recorded in e^{+}e^{-} collisions at a center-of-mass energy corresponding to the ϒ(4S) resonance. These parameters are determined by fitting the proper decay-time distribution of a sample of 415 signal events. We obtain C=-0.04_{-0.15}^{+0.14}±0.05 and S=0.75_{-0.23}^{+0.20}±0.04, where the first uncertainties are statistical and the second are systematic.

Foreign Body Aspiration in Children and Emergency Rigid Bronchoscopy: A Retrospective Observational Study

Foreign body aspiration is potentially life-threatening in paediatric age group. Early recognition and emergency intervention by Rigid bronchoscopy is life-saving. To highlight various difficulties in emergency paediatric bronchoscopy and discuss our experience in 138 patients. < 12 years children with suspected foreign body aspiration were included. Data of 138 patients < 12 years of age were studied. The most common foreign body found was peanut and organic foreign bodies constituted of total foreign bodies removed. Choking, Cough and sudden onset breathlessness were common symptoms. Tachypnoea, asymmetric breath sound, rhonchi, stridor, reduced chest movements were common signs. Obstructive emphysema was commonest radiological findings. Majority of the patients were discharged within 72 h & only two patients expired. History, clinical and radiological findings are highly indicative of foreign body in the airway. Inspite of being a high risk procedure, Rigid bronchoscopy when performed with necessary expertise,trained anaesthesia team and a paediatric ICU, saves majority of lives of children with tracheobronchial foreign bodies.

CuII-Catalyzed cis-Selective Synthesis of Ketoepoxides from Phenacyl Bromides and Water

A verity of α,β-ketoepoxides was synthesized using a Cu^II-catalyzed oxidative C-C/O-C coupled cyclization strategy with high yield and cis-selectivity. Water is used as the source of oxygen and phenacyl bromide as the carbon in the valuable epoxides. The self-coupling method was extended to cross-coupling between phenacyl bromides with benzyl bromides. A high cis-diastereoselectivity was observed in all the synthesized ketoepoxides. Control experiments and density functional theory (DFT) study were performed to understand the Cu^II-Cu^I transition mechanism.

Water-based efficient alkyne transformation towards α-acetoxy/imido-ketones via oxidative coupling reactions using an alkylamine catalyst

A novel approach is unveiled for the expedited synthesis of valuable α-substituted ketones, utilising aliphatic amine catalysis to drive the oxidative C-O/C-N coupling reaction between alkynes and an appropriate nucleophile. This one-pot synthesis employs hypervalent iodine as both the oxidant and coupling agent. A fast, metal-free, and environmentally benign method is developed for synthesising α-acetoxyketones and α-imidoketones in an aqueous medium. To demonstrate the potential for larger-scale production, a gram-scale reaction is conducted. Moreover, the newly developed methodology has successfully enabled the direct synthesis of cathinone, a psychoactive drug. Overall, this work holds significant promise for the efficient and sustainable synthesis of α-substituted ketones and the potential development of novel biologically active compounds.

Post-COVID-19 Cardiovascular Sequelae and Myocarditis

BACKGROUND AND AIM

Post coronavirus disease 2019 (COVID-19) cardiovascular (CV) pathological changes, myocarditis, and myocardial infarctions (MIs) are major public health issues. This review discusses acute and chronic COVID-19 cardiac manifestations.

METHODS

The devastating impact of COVID-19 on global healthcare and economies has likely been one of humanity's deadliest calamities in recent decades, as multiple literature and databases were searched from 2020 to 2022.

RESULTS

As of April 2022, we identified 73 articles in various electronic databases that discussed the details of COVID-19 and cardiac manifestations. Cardiometabolic risk factors should now, more than ever, be a top priority for clinicians, as their potent role in exacerbating COVID-19 illness severity has been conclusively demonstrated.

CONCLUSION

This review discusses cardiac pathology changes, CV consequences of acute COVID-19, microvascular injury and cardiac complications linked with SARS-CoV2, COVID-19 linked with chronic CV disease, therapeutic drug effects on heart used in COVID-19, and possible investigational approaches and management strategies for post-COVID-19 CV consequences. Highlights Cardiac pathology changes: Effect of COVID-19. Mechanism of development of CV consequences in acute COVID-19: Including autopsy studies. Microvascular injury and cardiac complications: Linked with SARS-CoV2. COVID-19 linked with chronic CV disease. Therapeutic drug effects on heart used in COVID-19. Possible investigational approaches and management strategies for post-COVID-19 CV consequences.

Cu(I)-catalysed cross-coupling reaction of in situ generated azomethine ylides towards easy construction of fused N-heterocycles

In this study, we have devised a new method for synthesizing highly valuable 5,6,7,8a-tetrahydropyrrolo[2,1-b]thiazoles using a decarboxylative C-N coupling reaction between phenyl glyoxal and proline or its analogue, which is catalyzed by CuI in the presence of K₂CO₃. This reaction is followed by a regiospecific C-C and C-S coupling cyclization with dialkyl trithiocarbonate. Furthermore, we have demonstrated that this cross-coupling method can also be extended to imines, leading to the formation of fused symmetrical and unsymmetrical 6,7-dihydro-5H-pyrrolo[1,2-a]imidazoles. This finding greatly expands the scope and versatility of the synthetic approach. Therefore, this work represents a significant contribution to the field of organic synthesis, providing a novel and efficient method for the preparation of fused N-heterocyclic compounds that could have useful applications in areas such as material science and pharmaceuticals.

Fundoplication in laparoscopic Heller's cardiomyotomy for achalasia

BACKGROUND

Laparoscopic Heller's cardiomyotomy (LHC) is the preferred treatment of achalasia. It improves dysphagia by dividing muscles of the lower oesophageal sphincter, but this intervention can result in debilitating gastro-oesophageal reflux symptoms in some patients. To prevent these reflux symptoms, most surgeons add a fundoplication to Heller's cardiomyotomy, but there is no consensus regarding this or the type of fundoplication which is best suited for the purpose.

OBJECTIVES

To assess how the addition of a fundoplication affects postoperative reflux and dysphagia in people undergoing LHC and compare the different types of fundoplications used in combination with LHC to determine which is better at controlling reflux without worsening the dysphagia.

SEARCH METHODS

We searched three databases (CENTRAL, MEDLINE and Embase) on 31 October 2021 and trial registers to identify all published and unpublished randomised controlled trials (RCTs) in any language, comparing different fundoplications used in combination with LHC to treat achalasia. We also included RCTs where LHC with a fundoplication is compared with LHC without any fundoplication.

SELECTION CRITERIA

We only included RCTs which recruited adult participants with achalasia undergoing LHC with minimal hiatal dissection. We excluded non-randomised studies or studies involving paediatric participants. We also excluded studies where the procedure was done by open surgery and where circumferential hiatal dissection of the oesophagus was carried out, unless it was necessary to reduce a hiatus hernia or to facilitate a Toupet or Nissen fundoplication.

DATA COLLECTION AND ANALYSIS

Two review authors independently identified studies to be included, assessed risk of bias using the Cochrane RoB 1 tool, and extracted the data. We calculated the risk ratio (RR) with 95% confidence interval (CI) using both fixed-effect and random-effect models with Review Manager (RevMan) software.

MAIN RESULTS

We included eight studies in this review, with a total of 571 participants with an average age of 45 years (range 33.5 to 50). LHC without any fundoplication was performed in 65 (11.3%) participants, 298 (52.1%) had Dor fundoplication, 81 (14.1%) had Toupet fundoplication, 72 (12.6%) had Nissen's fundoplication, and 55 (9.6%) participants had angle of His accentuation. Three studies with a total of 143 participants compared LHC + Dor to LHC without fundoplication. We found that the evidence is very uncertain as to whether the addition of a Dor fundoplication made any difference to the outcome of postoperative pathological acid reflux (RR 0.37, 95% CI 0.07 to 1.89; I² = 56%; 2 studies, 97 participants; very low-certainty evidence) and uncertain for severe postoperative dysphagia (RR 3.00, 95% CI 0.34 to 26.33; I² = 0%; 3 studies, 142 participants; low-certainty evidence). Three studies with 174 participants compared LHC + Dor to LHC + Toupet. The evidence suggests that there may be little to no difference in the outcomes of postoperative pathological acid reflux (RR 0.75, 95% CI 0.23 to 2.43; I² = 60%; 3 studies, 105 participants; low-certainty evidence) and severe postoperative dysphagia (RR 0.78, 95% CI 0.19 to 3.15; I² = 0%; 3 studies, 123 participants; low-certainty evidence) between the two interventions, but the certainty of the evidence is low. One study with 138 participants compared LHC + Dor to LHC + Nissen. Nissen fundoplication caused increased severe postoperative dysphagia (RR 0.19, 95% CI 0.04 to 0.83; 1 study, 138 participants; high-certainty evidence) when compared to Dor fundoplication. This study did not show a difference in postoperative pathological acid reflux (RR 4.72, 95% CI 0.23 to 96.59; 1 study, 138 participants; low-certainty evidence), but the certainty of evidence is low. One study with 110 participants compared LHC + Dor with LCH + angle of His accentuation, and reported that severe postoperative dysphagia was similar between the two interventions (RR 1.56, 95% CI 0.27 to 8.95; 1 study, 110 participants; moderate-certainty evidence), with moderate certainty of evidence. This study did not report on postoperative pathological acid reflux.

AUTHORS' CONCLUSIONS

When LHC was performed with minimal hiatal dissection, we were very uncertain whether the addition of a Dor fundoplication made a difference in controlling postoperative reflux, and we were uncertain if it increased the risk of severe postoperative dysphagia. There may be little to no difference in the outcomes of postoperative pathological acid reflux or severe dysphagia between Dor and Toupet fundoplications when used in combination with LHC, but the certainty of the evidence is low. Nissen (total) fundoplication used in combination with LHC for achalasia increased the risk of severe postoperative dysphagia. The angle of His accentuation and Dor fundoplication had a similar effect on severe postoperative dysphagia when combined with LHC, but their effect on postoperative pathological acid reflux was not reported.

Silver nanoparticle synthesis and their potency against multidrug-resistant bacteria: a green approach from tissue-cultured Coleus forskohlii

Drug resistance is a major concern nowadays, and finding alternatives of the well-known antibiotic is necessary. Green nanoparticles are emerging as a tenable alternative to this with a large spectrum of activity. The present manuscript describes an eco-friendly approach for green synthesis of silver nanoparticles from both in vitro and in vivo leaf extract of Coleus forskohlii. Leaf extracts were used in synthesis of nanoparticles which were further analyzed through UV-Vis, dynamic light scattering, energy-dispersive spectroscopy, and transmission electron microscopy. Antimicrobial activity of silver nanoparticles alone, as well as crude extract of the plant itself, was carried out against eight multidrug-resistant respiratory tract infecting pathogenic strains. Satisfactory antimicrobial activities were found with nanoparticles, in vitro and in vivo leaf extracts. However, gradually higher to lower inhibition potential against pathogenic bacterial strains was found in silver nanoparticles, in vitro and in vivo leaf extracts. Seven bioactive compounds were detected in the crude extract through gas chromatography-mass spectroscopy analysis. Results revealed that nanoparticle formation occurred in a wide range of sizes (10-50 nm) and shapes (trigonal, hexagonal, spherical, rod). The diversity in size and shape of the nanoparticles makes them biologically active. Silver nanoparticle exhibits significantly better antimicrobial activities as compared to the plant extract in case of nearly all pathogens with a maximum zone of inhibition of 15.33 ± 0.94 mm where more than 12 well-known antibiotics failed to respond. Because of this broad-spectrum activity of nanoparticles as well as the leaf extracts against life-threatening microbes, it can be used as future generation drugs.

Serum Zinc Level and Glycemic Status in Newly Diagnosed Type 2 Diabetes Mellitus Patients in a Tertiary Care Hospital of Bangladesh

Background: Reduced level of serum zinc has been observed in patients with type 2 diabetes mellitus (T2DM). Objectives: Estimation of serum zinc level and HbA1c in newly detected T2DM. Materials and methods: This cross-sectional study encompassed 100 newly detected non-pregnant T2DM subjects diagnosed on basis of ADA 2015 criteria (n=100; age: 44.74±11.34 years, mean+SD; Sex: 56/44, M/F) from the department of Endocrinology, BSMMU consecutively. Study period was March, 2015 to April, 2016. Blood sample was collected for measurement of zinc and HbA1c. Height, weight, waist circumference, hypertension, dyslipidaemia, ischemic heart disease (IHD), cerebrovascular disease (CVD), retinopathy, neuropathy, nephropathy, serum creatinine were recorded as confounding variables. HbA1c was measured using the NGSP certified Bio-Rad D-10TM Hemoglobin A1C Program while Zinc by using Atomic Absorption Spectrometric Analysis. Result: There was no statistically significant difference for zinc level in gender groups (M vs. F: 0.91±0.02 vs. 0.88±0.02 mg/L, p= 0.580; M±SEM), age groups (age <25 years: 0.89±0.82, 25 – 34 years: 0.90±0.03, 35 – 44 years: 0.90±0.32, 45 – 54 years: 0.91±0.03, and 55 years: 85±0.03 mg/L, M±SEM; F= 0.379, p= 0.823), body mass index (BMI) groups (BMI <25 vs. 25 kg/m2: 0.92±0.02vs. 87±0.02, p= 0.107), socioeconomic groups (low vs. middle vs. high socioeconomic status: 0.90±0.02 vs. 0.91±0.02 vs. 0.86±0.03 mg/L, M±SEM; F= 0.548, p= 0.580) as well as with and without family history of diabetes (0.90±0.01 vs. 0.89±0.02 mg/L, M±SEM; p= 0.705). Also zinc level was statistically similar among glycemic status groups (HbA1c < 6.5% vs. 6.5-9% vs. > 9%: 0.89±0.40 vs. 0.87±0.02 vs. 0.91±0.02 mg/L, F= 0.568, p= 0.569). Comparisons between groups with or without risk factors like: smoking (0.93±0.10 vs. 0.89±0.10 mg/L, p=0.724), hypertension (0.87±0.02 vs. 0.91±0.02 mg/L, p= 0.237), dyslipidemia (0.87±0.02 vs. 0.90±0.02 mg/L, p=0.393) and also co morbidities like: .......

Role of animal models in biomedical research: a review

The animal model deals with the species other than the human, as it can imitate the disease progression, its’ diagnosis as well as a treatment similar to human. Discovery of a drug and/or component, equipment, their toxicological studies, dose, side effects are in vivo studied for future use in humans considering its’ ethical issues. Here lies the importance of the animal model for its enormous use in biomedical research. Animal models have many facets that mimic various disease conditions in humans like systemic autoimmune diseases, rheumatoid arthritis, epilepsy, Alzheimer’s disease, cardiovascular diseases, Atherosclerosis, diabetes, etc., and many more. Besides, the model has tremendous importance in drug development, development of medical devices, tissue engineering, wound healing, and bone and cartilage regeneration studies, as a model in vascular surgeries as well as the model for vertebral disc regeneration surgery. Though, all the models have some advantages as well as challenges, but, present review has emphasized the importance of various small and large animal models in pharmaceutical drug development, transgenic animal models, models for medical device developments, studies for various human diseases, bone and cartilage regeneration model, diabetic and burn wound model as well as surgical models like vascular surgeries and surgeries for intervertebral disc degeneration considering all the ethical issues of that specific animal model. Despite, the process of using the animal model has facilitated researchers to carry out the researches that would have been impossible to accomplish in human considering the ethical prohibitions.

Mathematical Analysis of a COVID-19 Epidemic Model by Using Data Driven Epidemiological Parameters of Diseases Spread in India

This paper attempts to describe the outbreak of Severe Acute Respiratory Syndrome Coronavirus 2 (COVID-19) via an epidemic model. This virus has dissimilar effects in different countries. The number of new active coronavirus cases is increasing gradually across the globe. India is now in the second stage of COVID-19 spreading, it will be an epidemic very quickly if proper protection is not undertaken based on the database of the transmission of the disease. This paper is using the current data of COVID-19 for the mathematical modeling and its dynamical analysis. We bring in a new representation to appraise and manage the outbreak of infectious disease COVID-19 through SEQIR pandemic model, which is based on the supposition that the infected but undetected by testing individuals are send to quarantine during the incubation period. During the incubation period if any individual be infected by COVID-19, then that confirmed infected individuals are isolated and the necessary treatments are arranged so that they cannot taint the other residents in the community. Dynamics of the SEQIR model is presented by basic reproduction number R ₀ and the comprehensive stability analysis. Numerical results are depicted through apt graphical appearances using the data of five states and India.

Mathematical Analysis of a COVID-19 Epidemic Model by Using Data Driven Epidemiological Parameters of Diseases Spread in India

This paper attempts to describe the outbreak of Severe Acute Respiratory Syndrome Coronavirus 2 (COVID-19) via an epidemic model. This virus has dissimilar effects in different countries. The number of new active coronavirus cases is increasing gradually across the globe. India is now in the second stage of COVID-19 spreading, it will be an epidemic very quickly if proper protection is not undertaken based on the database of the transmission of the disease. This paper is using the current data of COVID-19 for the mathematical modeling and its dynamical analysis. We bring in a new representation to appraise and manage the outbreak of infectious disease COVID-19 through SEQIR pandemic model, which is based on the supposition that the infected but undetected by testing individuals are send to quarantine during the incubation period. During the incubation period if any individual be infected by COVID-19, then that confirmed infected individuals are isolated and the necessary treatments are arranged so that they cannot taint the other residents in the community. Dynamics of the SEQIR model is presented by basic reproduction number R 0 and the comprehensive stability analysis. Numerical results are depicted through apt graphical appearances using the data of five states and India.

Optimal control design incorporating vaccination and treatment on six compartment pandemic dynamical system

In this paper, a mathematical model of the COVID-19 pandemic with lockdown that provides a more accurate representation of the infection rate has been analyzed. In this model, the total population is divided into six compartments: the susceptible class, lockdown class, exposed class, asymptomatic infected class, symptomatic infected class, and recovered class. The basic reproduction number (R0) is calculated using the next-generation matrix method and presented graphically based on different progression rates and effective contact rates of infective individuals. The COVID-19 epidemic model exhibits the disease-free equilibrium and endemic equilibrium. The local and global stability analysis has been done at the disease-free and endemic equilibrium based on R0. The stability analysis of the model shows that the disease-free equilibrium is both locally and globally stable when R0<1, and the endemic equilibrium is locally and globally stable when R0>1 under some conditions. A control strategy including vaccination and treatment has been studied on this pandemic model with an objective functional to minimize. Finally, numerical simulation of the COVID-19 outbreak in India is carried out using MATLAB, highlighting the usefulness of the COVID-19 pandemic model and its mathematical analysis.

AB0399 COMPARISON OF RITUXIMAB VERSUS LEFLUNOMIDE IN COMBINATION WITH METHOTREXATE IN PATIENTS WITH ACTIVE RHEUMATOID ARTHRITIS DESPITE METHOTREXATE TREATMENT- AN OPEN LABEL, RANDOMISED CONTROLLED TRIAL

Background

Active rheumatoid arthritis (RA) despite methotrexate monotherapy is seen in about 43% of patients1. The current American College of Rheumatology (ACR) guidelines recommend adding a biologic or targeted synthetic Disease Modifying Anti-rheumatic Drug (DMARD) to methotrexate (MTX) therapy in such cases. The European Alliance of Associations for Rheumatology (EULAR) guidelines recommend combination DMARDs but the most commonly used combination is that of MTX with sulphasalazine and hydroxychloroquine. In a resource limited country like ours, it is not always possible to give a biological or a targeted synthetic DMARD, and a more cost effective method needs to be implemented. Often, leflunomide (LEF) is added in such cases and is effective.

Objectives

We aimed to study if LEF with MTX combination is non inferior to rituximab (RTX) and MTX combination in patients with active RA despite MTX.

Methods

This open label, randomised controlled trial, carried out on patients with moderate to high disease activity despite MTX therapy for atleast 3 months (Clinical Trials Registry- India - REF/2021/04/042755) was conducted in a tertiary care centre in India. Patients were randomised to receive either LEF (10-20mg/day) or RTX (2 doses of 1gm, 2 weeks apart) along with background MTX (10-25mg/week) and followed up at 12, 18 and 24 weeks. The primary outcome ACR20 response at 24 weeks and secondary outcomes were ACR50 and 70 responses at 24 weeks.

Results

There were 21 patients in each arm. At baseline, all patients in both groups had seropositive RA and had high disease activity according to Disease Activity Score (DAS)28 scores. The ACR20 response at 24 weeks was achieved by 14 (66.6%) and 16 (76.19%) patients respectively in the LEF and RTX arms. The ACR50 response was achieved by 11 (52.38%) patients in both groups and ACR70 response by 4 (19%) and 7 (33.3%) in the LEF and RTX arms respectively (Figure 1). The mean dose of LEF at week 24 was 17.6 mg/day. Improvement of various parameters at week 24 as compared to the baseline values were similar in both groups (Table 1). No major adverse events were noted. Two patients receiving RTX had a mild infusion reaction. Elevation in liver enzymes (<3 times the upper limit of normal) were noted in 4 patients in the LEF arm which normalised subsequently. No patient required drug withdrawal.

Table 1.

Responses in both groups at week 24 (p= Not significant for all)

Leflunomide, n=21Rituximab, n=21Mean ±SD reduction in SJC-4.57 ± 3.4-5.43 ± 4.6Mean ±SD reduction in TJC-6.2 ± 3.9-7.1 ± 6.1Mean ±SD reduction in PhGA-3.42 ± 1.8-4.04 ± 2.5Mean ±SD reduction in PGA-3.05 ± 1.8-3.42 ± 2.4Mean ±SD reduction in pain VAS-33.57 ± 23.2-38.57 ± 24.4Mean ±SD reduction in DAS28-ESR-1.95 ± 1.2-2.08 ± 1.4Mean ±SD reduction in DAS28-CRP-1.81 ± 1.2-2.07 ± 1.4Mean ±SD reduction in HAQ-DI-0.65 ± 0.5-0.82 ± 0.6EULAR good response (%)1 (4.76%)1 (4.76%)EULAR moderate response (%)15 (71.43%)14 (66.6%)EULAR non-responders (%)5 (23.81%)6 (28.57%)

CRP, C- Reactive Protein; DAS, Disease Activity Score; ESR, Erythrocyte Sedimentation Rate; HAQ-DI, Healthy Assessment Questionnaire-Disability Index; PGA, Patient’s global assessment of disease activity; PhGA, Physician’s global assessment of disease activity; SJC, Swollen Joint Count; TJC, Tender Joint Count; VAS, Visual analogue scale.

Figure 1.

Number of patients achieving ACR20, 50 and 70 responses at week 24

Conclusion

In our study, LEF was comparable to RTX for achievement of ACR20/50/70 responses at 24 weeks. LEF can be considered as an add-on option to MTX instead of more expensive biologic agents in MTX refractory RA. Larger studies are needed to confirm this hypothesis.

References

[1]Sergeant JC, Hyrich KL, Anderson J, et al. Prediction of primary non-response to methotrexate therapy using demographic, clinical and psychosocial variables: results from the UK Rheumatoid Arthritis Medication Study (RAMS). Arthritis Res Ther. 2018;20(1):147. Published 2018 Jul 13.

Disclosure of Interests

None declared

A discrete-time epidemic model for the analysis of transmission of COVID19 based upon data of epidemiological parameters

The forecasting of the nature and dynamics of emerging coronavirus (COVID-19) pandemic has gained a great concern for health care organizations and governments. The efforts aim to to suppress the rapid and global spread of its tentacles and also control the infection with the limited available resources. The aim of this work is to employ real data set to propose and analyze a compartmental discrete time COVID-19 pandemic model with non-linear incidence and hence predict and control its outbreak through dynamical research. The Basic Reproduction Number ( R 0 ) is calculated analytically to study the disease-free steady state ( R 0 < 1 ), and also the permanency case ( R 0 > 1 ) of the disease. Numerical results show that the transmission rates α > 0 and β > 0 are quite effective in reducing the COVID-19 infections in India or any country. The fitting and predictive capability of the proposed discrete-time system are presented for relishing the effect of disease through stability analysis using real data sets.

Surgical Outcome of CSF Drainage in Paediatric Obstructive Hydrocephalus

Hydrocephalus (HCP) is occurred when there is inequality in the formation and absorption of CSF to such a level which causes accumulation of fluid and causing raised intracranial pressure. Hydrocephalus is the most frequent neurosurgical problem encountered in the paediatric age group. CSF diversion surgically is needed as treatment for certain condition. Endoscopic third ventriculostomy (ETV) and Ventriculo-peritoneal shunt (VPS) are most widely used CSF diversion procedure. Therefore, this study was conducted for comparing the surgical outcome of ETV and VP shunt in obstructive hydrocephalus. This is a prospective experimental study conducted in the Department of Neurosurgery, Dhaka Medical College and Hospital (DMCH) and Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh from January 2017 to December 2019. Paediatric patients of both sex and 6 months to 18 years of age with obstructive hydrocephalus undergone endoscopic third ventriculostomy (ETV) or ventriculo-peritoneal shunt (VP shunt) were included after fulfilling inclusion and exclusion criteria. The patients divided into two groups (Group A and Group B). The Group A included 30 patients who treated by Endoscopic third ventriculostomy and the Group B include 30 patients, who was treated by Ventriculo-peritoneal shunt. Surgical outcome was analyzed in two procedures separately. In Group A (ETV group) symptomatic improvement, GCS score improves earlier and post-operative complications relatively less than Group B (VP shunt group). But in VP shunt group 3 months follow up reveals- improvement of papilledema, Occipital frontal circumference (OFC) regression and fontanelle size improvement was more than that of ETV group. This study concluded with suggesting that Endoscopic third ventriculostomy (ETV) is technologically superior surgical technique than VP shunt. Though ETV showed relatively more immediate procedural failure and intraventricular hemorrhage but long-term outcome is better and also associated with lower incidence of infection and re-operation in comparison to VP shunt.

Micro-CT imaging of Onchocerca infection of Simulium damnosum s.l. blackflies and comparison of the peritrophic membrane thickness of forest and savannah flies

Onchocerciasis is a neglected tropical disease (NTD) caused by Onchocerca Diesing 1841 (Spirurida: Onchocercidae) nematodes transmitted by blackflies. It is associated with poverty and imposes a significant health, welfare and economic burden on many tropical countries. Current methods to visualize infections within the vectors rely on invasive methods. However, using micro-computed tomography techniques, without interference from physical tissue manipulation, we visualized in three dimensions for the first time an L1 larva of an Onchocerca species within the thoracic musculature of a blackfly, Simulium damnosum s.l. Theobald 1903 (Diptera: Simuliidae), naturally infected in Ghana. The possibility that thicker peritrophic membranes in savannah flies could account for their lower parasite loads was not supported, but there were limits to our analysis. While there were no statistically significant differences between the mean thicknesses of the peritrophic membranes, in the anterior, dorsal and ventral regions, of forest and savannah blackflies killed 34-48 min after a blood-meal, the thickness of the peritrophic membrane in the posterior region could not be measured. Micro-computed tomography has the potential to provide novel information on many other parasite/vector systems and impactful images for public engagement in health education.

A comprehensive characterization of novel CYP-BM3 homolog (CYP-BA) from Bacillus aryabhattai

Functionalizing C-H bond poses one of the most significant challenges for chemists providing them with very few substrate-specific synthetic routes. Despite being incredibly plastic in their enzymatic ability, they are confined with deficient enzymatic action and limited explicitness of the substrates. In this study, we have endeavored to characterize novel cytochrome P450 from Bacillus aryabhattai (CYP-BA), a homolog of CYP P450-BM3, by taking interdisciplinary approaches. We conducted structure and sequence comparison to understand the conservation pattern for active site residues, conserved fold, evolutionary relationships among others. Molecular dynamics simulations were performed to understand the dynamic nature and interaction with the substrates. CYP-BA was successfully cloned, purified, and characterized. The enzyme's stability toward various physicochemical parameters was evaluated by UV-vis spectroscopy and Circular Dichroism (CD) spectroscopy. Various saturated fatty acids being the natural cytochrome P450 substrates were evaluated as catalytic efficiency of substrate oxidation by CYP-BA. The binding affinity of these natural substrates was monitored against CYP-BA by isothermal titration calorimetry (ITC). The catalytic performance of CYP-BA was satisfactory enough to proceed to the next step, that is, engineering to expand the substrate range to include polycyclic aromatic hydrocarbons (PAH). This is the first evidence of cloning, purifying and characterizing a novel homolog of CYP-BM3 to enable a better understanding of this novel biocatalyst and to provide a platform toward expanding its catalytic process through enzyme engineering.

Studies on the changes of biochemical, microbiological and sensory parameters of sauerkraut and fermented mix vegetables

Fermentation is one of the safest and most economical means of producing foods acceptable to human beings. It improves the nutritional quality of foods by increasing the bioavailability and thus, renders the food safe palatable and easily acceptable to mankind. The present study showed the effects of fermentation on the nutritional quality and safety of fermented foods with respect to nutrient composition and digestibility measures. Sauerkraut and fermented mixed vegetable were selected for study and the effects of fermentation on nutrient were observed. Digestibility, shelf-life and biochemical aspects were also studied. Level of all principle nutrients was significantly increased. In course of fermentation, total sugar and reducing sugar in the brine increased slowly to 3% and 2%, respectively up to 8th day and then decreased in sauerkraut fermentation. The maximum total acidity (1.98-2.22%) was observed on 15th day in fermented mixed vegetables. The pH of the shredded cabbage was 6.9 and decreased to around 4 after 15 days and then remained constant.

A Zn(II)-Coordination Polymer for the Instantaneous Cleavage of Csp3-Csp3 Bond and Simultaneous Reduction of Ketone to Alcohol

Two coordination polymers of Zn(II) and Cu(II) with n-butylmalonic acid have been achieved in this work. The crystallographic structural descriptions along with the sedimentary rock-type microstructural morphology of these two coordination polymers (CPs) have been explored. The reactivity of β-hydroxy ketones with these two CPs has also been investigated. The Zn(II)-CP shows a specific reactivity with β-hydroxy ketone at room temperature and in open air conditions. Through a microcolumn-based filtration technique, the Zn(II)-CP shows the capability to break the C_sp³-C_sp³ σ bonds of β-hydroxy ketone and simultaneously reduce the associated ketone to alcohol. Such conversion has been progressed without the use of any additional external reducing agent and any chemical workup or column chromatographic purification protocol. Other similar type CPs of Cu(II) and Mn(II) with n-butylmalonic acid completely failed to show similar reactivity with β-hydroxy ketone. On the basis of much experimental evidence, the most possible mechanistic pathway of the reactivity between β-hydroxy ketone and Zn(II)-CP has also been proposed through this work.

Endoscopic ossiculoplasty: Is there any edge over the microscopic technique?

OBJECTIVES/HYPOTHESIS

To compare endoscopic ossiculoplasty with conventional microscopic technique in terms of postoperative hearing outcomes and complications.

STUDY DESIGN

Randomized controlled trial.

METHODS

One hundred eighteen patients diagnosed with ossicular chain discontinuity were randomly assigned into two groups, one undergoing endoscopic ossiculoplasty and the other undergoing ossiculoplasty by the microscopic technique, with the operating surgeon being same for both groups. The two groups were compared in terms of operative time, postoperative air-bone gap, mean air-bone gap closure, and incidence of complications. Teflon prostheses (partial ossicular chain replacement prosthesis [PORP] and total ossicular chain replacement prosthesis [TORP]) were used for reconstruction in all cases.

RESULTS

Endoscopic ossiculoplasty with PORP rendered a statistically significant mean postoperative air-bone gap and air-bone gap closure at 1 month when compared to that of microscopic PORP ossiculoplasty. However, there was no significant difference between the two techniques in terms of mean postoperative air-bone gap and air-bone gap closure at 3 and 6 months. In the TORP ossiculoplasty cases, there was no significant difference in mean postoperative air-bone gap and air-bone gap closure at 1, 3, and 6 months. In terms of operative time and incidence of complications, no statistical significance was found between the two groups.

CONCLUSIONS

Endoscopic ossiculoplasty appears to provide superior visualization and better early audiological outcome (in PORP ossiculoplasty cases) when compared to microscopic technique. However, long-term audiological outcomes and incidence of complications remain comparable.

LEVEL OF EVIDENCE

1 Laryngoscope, 130:797-802, 2020.

Triethylenetetramine-Based Semiconducting Fe(III) Metallogel: Effective Catalyst for Aryl-S Coupling

A fascinating way to originate a mechanically stable metallogel of ferric ions with metal-coordinating organic ligand triethylenetetramine through direct mixing of their water solutions in a stoichiometric ratio is achieved under ambient conditions. The rheological study established the mechanical property of the Fe(III) metallogel. A cashew-shaped microstructure of the metallogel was observed by FESEM analysis. The electrical property of the Fe(III) metallogel was also carefully scrutinized. The semiconducting features like the Schottky barrier diode property of the Fe(III) metallogel were explored. The catalytic role of the Fe(III) metallogel was also critically explored. The Fe(III) metallogel shows an excellent catalytic property toward the synthesis of aryl thioethers via a C-S coupling reaction under mild reaction conditions without the use of any organic solvent.

Endoscopic Stapedotomy: Overcoming Limitations of Operating Microscope

The study is aimed to assess the scope of endoscopic stapedotomy in overcoming technical challenges faced during conventional stapedotomy using operating microscope. Sixty-four patients with clinical and audiological diagnosis of otosclerosis were randomly assigned into one of the 2 groups-one underwent conventional stapedotomy using operating microscope, while the other group underwent endoscopic stapedotomy, the operating surgeon being the same for both groups, for all cases. The 2 groups were observed in terms of extent of the postero-superior canal bone curettage/drilling, chorda tympani repositioning, visualization of footplate area, surgical time from first incision to ear packing, post-operative morbidity in terms of post-operative pain, vertigo, hearing outcome, and changes in taste sensation. It was observed that irrespective of the width of the external auditory canal, endoscopic approach offered better access to the footplate area requiring lesser bone removal and chorda tympani repositioning. The operating time, post-operative pain, and changes in taste sensation were significantly less in the endoscopic group. However, no difference was noted in terms of the post-operative hearing outcome and incidence of vertigo. Endoscopic stapedotomy has clear advantages in terms of the technicality and accessibility to the working area as well as faster recovery.

Risk Categorization with Different Grades of Cervical Pre-Neoplastic Lesions - High Risk HPV Associations and Expression of p53 and RARβ

Objective:

To identify high risk HPV associations by evaluating linked p16 overexpression and also the expression of p53 and RARβ together with histopathology for risk categorization of cervical pre-neoplastic lesions.

Materials and Methods:

Immunohistochemical staining was performed on 100 cases of cervical pre- neoplastic lesions for expression of biomarkers like p16, p53 and RARβ for comparison with haematoxylin/eosin (HE) findings. All the experimentally generated data were statistically analyzed.

Results:

In this study 70% cases showed overexpression of p16INK4A increasing progressively from CIN I to CIN II but reduced in CIN III (p <0.01). p53 oncoprotein expression was seen in 51% cases, again with increments from CIN I to CIN II with slight reduction in CIN III (p<0.01). Some 24% cases showed negative immunoreactivity for the putative tumor suppressor gene RARβ (p>0.05).

Conclusion:

Our study provides support for the idea that p16 can be used to identify associations with HPV , as well as having potential along with p53 and RARβ for categorizing cervical pre-neoplastic cases having a higher risk of neoplastic conversion. Thus it may be concluded that accurate risk categorization can be achieved with the help of genetic markers as well as histopathology.

Postoperative Systemic Acyclovir in Juvenile-Onset Recurrent Respiratory Papillomatosis: The Outcome

A prospective observational study was conducted consisting of 21 patients of Juvenile-onset recurrent respiratory papillomatosis, attending the Department of Otorhinolaryngology and Head Neck Surgery at our institution, who underwent surgical excision of the papillomas followed by oral acyclovir postoperatively. The study was aimed to observe the effect of systemic acyclovir on postoperative outcomes in children having recurrent respiratory papillomatosis undergoing primary surgical excision. It was observed that the mean interval between surgeries as well as the number of surgical interventions required was significantly lesser when acyclovir was used as a postoperative adjuvant than when surgery was done alone. Hence, the interval between successive surgeries, or in other words, the time interval between relapse of the disease could be prolonged significantly with the use of postoperative systemic acyclovir. Thus, the disease could be controlled for longer periods and repeated surgeries avoided.

Selective amidation by a photocatalyzed umpolung reaction

Herein, a metal-catalyzed organic transformation merged with another organophotocatalyst has been developed under mild conditions for the production of α-ketoamides.

Systematic review of methodologies used to assess mastectomy flap viability

BACKGROUND

Accurate prediction of mastectomy skin flap viability is vital as necrosis causes significant morbidity, potentially compromising results and delaying oncological management. Traditionally assessed by clinical judgement, a more objective evaluation can be provided using intraoperative imaging modalities. This systematic review aimed to compare all intraoperative techniques for assessment of mastectomy flap viability.

METHODS

A systematic literature review was performed using MEDLINE and Embase databases. Primary outcomes reported included specificity, sensitivity and predictive values of each test, and mean rates of mastectomy flap necrosis and reoperation. Secondary outcomes included cost analysis.

RESULTS

Some 18 studies were included. Designs were prospective cohort study (8), retrospective case series (4), prospective case series (3), retrospective case-control study (1), prospective pilot trial (1) and cost analysis study (1). The studies compared indocyanine green angiography (ICGA) (16 studies) and fluorescein dye angiography (FA) (3 studies) with clinical judgement. Sensitivity and specificity were highest for ICGA (5 studies) ranging from 38 to 100 and 68 to 91 per cent respectively. Both methods overpredicted necrosis. Mean rates of flap necrosis and reoperation decreased with ICGA (7·9 and 5·5 per cent respectively) and FA (3 and 0 per cent) compared with clinical judgement (19·4 and 12·9 per cent). Two studies were designed to define numerical parameters corresponding to perfusion using intraoperative techniques. Two studies performed a cost analysis for ICGA; one claimed a cost benefit and the other advocated its use in high-risk patients only.

CONCLUSION

ICGA and FA are potentially useful tools for mastectomy flap assessment. However, the predictive accuracy is subject to the specific settings and model of equipment used. Current recommendations support their use in high-risk patients.

The utility of monitoring trimellitic anhydride (TMA)-specific IgG to predict IgE-mediated sensitization in an immunosurveillance program

BACKGROUND

Workplace exposure to trimellitic anhydride (TMA) can elicit TMA-specific IgE (sIgE), which may lead to occupational asthma (OA). An occupational immunosurveillance program (OISP) has been implemented to monitor TMA exposure and immunologic outcomes. The purpose of this study was to determine whether TMA-specific IgG (sIgG) responses can discriminate between TMA-exposed workers with and without sIgE responses.

METHODS

Serum TMA-specific antibody (IgG, IgG4, and IgE) levels were estimated longitudinally (years 2006 to 2014) in TMA-exposed workers recruited in low, medium, and high exposure areas. sIgG and sIgE titers plotted against exposure duration were compared between workers with (a) sIgG only and (b) with sIgG who developed sIgE.

RESULTS

Among 92 TMA-exposed workers continuously monitored for sIgG and sIgE, 38 developed sIgG; 11 developed a sIgE response 342.38 ± 186.03 days posthire and were removed from exposure. The average detection time of sIgG in removed workers (159 ± 92 days) was significantly shorter than for actively exposed workers with only sIgG (346 ± 187 days). Workers with earlier sIgG responses of higher titer (mean value 42.25 μg/mL) compared to delayed responders with lower sIgG titers (mean value 14.79 μg/mL) more frequently developed sIgE responses. Hierarchical clustering showed the initial magnitude and exposure time required for detectable sIgG production discriminated between workers with only sIgG from workers who subsequently produced sIgE.

CONCLUSIONS

This study demonstrates the utility of longitudinally monitoring TMA-specific antibodies in an OISP as exposed workers with early sIgG responses and of higher magnitude are more likely to develop TMA sIgE sensitization.

Antibacterial activity of polyphenolic fraction of Kombucha against Vibrio cholerae: targeting cell membrane

The present study was undertaken to determine the mechanism of antibacterial activity of a polyphenolic fraction, composed of mainly catechin and isorhamnetin, previously isolated from Kombucha, a 14-day fermented beverage of sugared black tea, against the enteropathogen Vibrio cholerae N16961. Bacterial growth was found to be seriously impaired by the polyphenolic fraction in a dose-dependent manner. Scanning Electron Microscopy demonstrated morphological alterations in bacterial cells when exposed to the polyphenolic fraction in a concentration-dependent manner. Permeabilization assays confirmed that the fraction disrupted bacterial membrane integrity in both time- and dose-dependent manners, which were proportional to the production of intracellular reactive oxygen species (ROS). Furthermore, each of the polyphenols catechin and isorhamnetin showed the ability to permeate bacterial cell membranes by generating oxidative stress, thereby suggesting their role in the antibacterial potential of Kombucha. Thus, the basic mechanism of antibacterial activity of the Kombucha polyphenolic fraction against V. cholerae involved bacterial membrane permeabilization and morphological changes, which might be due to the generation of intracellular ROS. To the best of our knowledge, this is the first report on the investigation of antibacterial mechanism of Kombucha, which is mostly attributed to its polyphenolic content.

SIGNIFICANCE AND IMPACT OF THE STUDY

The emergence of multidrug-resistant Vibrio cholerae strains has hindered an efficient anti-Vibrio therapy. This study has demonstrated the membrane damage-mediated antibacterial mechanism of Kombucha, a popular fermented beverage of sugared tea, which is mostly attributed to its polyphenolic content. This study also implies the exploitation of Kombucha as a potential new source of bioactive polyphenols against V. cholerae.