Anti-infective Drugs Research Articles

Acute Gastroenteritis in Children of the World: What Needs to Be Done?

The incidence of gastroenteritis has greatly reduced due to improved hygiene conditions in developing countries and the use of rotavirus vaccine. Still thousands of children, however, die from gastroenteritis, most of them in poor countries. Yet gastroenteritis management is simple, inexpensive, and effective and is largely the same all over the world. Universal guidelines for gastroenteritis guide the management and include simple interventions put forward early in the course of the disease. Treatment includes rehydration, continuing oral feeding, and anti-infective drugs in selected clinical conditions related to the symptoms or to host-related risk, and possible additional drug treatment to reduce the duration and severity of symptoms. There may be minor geographical differences in the treatment applied due to health care organizations that do not substantially change the standard universal recommendations. Prevention is recommended with sanitation interventions and rotavirus universal immunization. Implementation of those interventions through educational initiatives and local programs in target areas are needed. A series of recommendations for interventions, education, and research priorities are included here with the aim of reducing the burden of gastroenteritis, to be pursued by scientists, physicians, policy makers, and stakeholders involved. They include the need of recommendations for the management of gastroenteritis in malnourished children, in those with chronic conditions, in neonates, and in emergency settings. A reference system to score dehydration, the definition of optimal composition of rehydration solution and the indications for anti-infective therapy are also included. Rotavirus immunization should be actively promoted, and evidence-based guidelines should be universally implemented. Research priorities are also indicated.

Evolving spectrum of drug-induced uveitis at the era of immune checkpoint inhibitors results from the WHO's pharmacovigilance database

PurposeDrug-induced uveitis is a rare but sight-threatening condition. We seek to determine the spectrum of drug-induced uveitis at the era of immune checkpoint inhibitors (ICI). MethodsRetrospective pharmacovigilance study based on adverse drug reactions reported within VigiBase, the WHO international pharmacovigilance database. We included deduplicated individual case safety reports (ICSRs) reported as ‘uveitis’ at Preferred Term level according to the Medical Dictionary for Drug Regulatory Activities between 1967 and 04/28/2019. We performed a case/non-case analysis to study if suspected drug-induced uveitis were differentially reported for each suspected treatment compared to the full database. We excluded drugs with potential indication bias. Results1404 ICSRs corresponding to 37 drugs had a significant over-reporting signal with a median age of 57 [42–68] years and 45.7% of males. We identified five major groups of treatments: bisphosphonates (26.9%), non-antiviral anti-infectious drugs (25.4%), protein kinase inhibitors (15.5%), ICI (15.0%), and antiviral drugs (11.1%). Severe visual loss was reported in 12.1% of cases. ICI and protein kinase inhibitors were the most recently emerging signals. The time to onset between first infusion and uveitis was significantly different between groups ranging from 5 days [2–19] in the bisphosphonate group to 138.5 [47.25–263.75] in protein kinase inhibitors group (p < 0.0001). Anti-Programmed Cell death 1 represented more than 70% of ICI-induced uveitis. We identified Vogt-Koyanagi-Harada (VKH)-like syndrome as being associated with ICI use. ConclusionsThe spectrum of drug-induced uveitis has changed with the evolution of pharmacopeia and the recent emergence of ICIs. VKH-like syndrome has been reported with ICI and protein kinase inhibitors therapy.

Green synthesis of silver nanoparticles using Carum copticum: Assessment of its quorum sensing and biofilm inhibitory potential against gram negative bacterial pathogens

Antimicrobial resistance among pathogenic bacteria has become a global threat to human health. Due to poor progress in development of new antimicrobial drugs, there is a need for the development of novel alternative strategies to combat the problem of multidrug resistance. Moreover, there is focus on ecofriendly approach for the synthesis nanoparticles having efficient medicinal properties including antivirulence properties to tackle the emergence of multi-drug resistance. Targeting quorum sensing controlled virulence factors and biofilms has come out to be a novel anti-infective drug target. The silver nanoparticles (Ag@CC-NPs) were synthesized from aqueous extract of Carum copticum and characterized using UV–vis absorption spectroscopy, fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). Ag@CC-NPs were checked for its ability to inhibit quorum sensing-mediated virulence factors and biofilms against three test pathogens at sub-MIC values. There was ~75% inhibition of violacein production by Ag@CC-NPs against C. violaceum. The P. aeruginosa virulence factors such as pyocyanin production, pyoverdin production, exoprotease activity, elastase activity, swimming motility and rhamnolipid production were inhibited by 76.9, 49.0, 71.1, 53.3, 89.5, and 60.0% at sub-MIC. Moreover, virulence factors of S. marcescens viz. prodigiosin production, exoprotease activity, and swarming motility was reduced by 78.4, 67.8, and 90.7%. Ag@CC-NPs also exhibited broad-spectrum antibiofilm activity with 77.6, 86.3, and 75.1% inhibition of biofilms of P. aeruginosa, S. marcescens, and C. violaceum respectively. The biofilm formation on glass coverslip was reduced remarkably as evident from SEM and CLSM analysis. The findings revealed the in vitro efficacy of Ag@CC-NPs against bacterial pathogens and can be exploited in the development of alternative therapeutic agent in management of bacterial infections for topical application, mainly wound infection, or coating of surfaces to prevent bacterial adherence on medical devices.

Determination of free clindamycin, flucloxacillin or tedizolid in plasma: Pay attention to physiological conditions when using ultrafiltration.

Pharmacokinetic/pharmacodynamic indices of anti-infective drugs should be referenced to free drug concentrations. In the present study, clindamycin, flucloxacillin and tedizolid have been determined in human plasma by HPLC-UV. The drugs were separated isocratically within 3-6 min on a C18 column using mixtures of phosphate buffer-acetonitrile of pH 7.1-7.2. Sample treatment for the determination of total drug concentrations in plasma included extraction/back-extraction (clindamycin) or protein precipitation (flucloxacillin, tedizolid). The free drug concentrations were determined after ultrafiltration. An ultrafiltration device with a membrane consisting of regenerated cellulose proved to be suitable for all drugs. Maintaining a physiological pH was crucial for clindamycin, whereas maintaining body temperature was essential for tedizolid. The methods were applied to the analysis of total and free drug concentrations in clinical samples and were sufficiently sensitive for pharmacokinetic studies and therapeutic drug monitoring.

Adverse Drug Events Detected by Clinical Pharmacists in an Emergency Department: A Prospective Monocentric Observational Study.

Adverse drug events (ADEs) are a major public health issue in hospitals. They are difficult to detect because of incomplete or unavailable medication history. In this study, we aimed to assess the rate and characteristics of ADEs identified by pharmacists in an emergency department (ED) to identify factors associated with ADEs. In this prospective observational study, we included consecutive adult patients presenting to the ED of a French 2600-bed tertiary care university hospital from November 2011 to April 2015. Clinical pharmacists conducted structured interviews and collected the medication history to detect ADEs (i.e., injuries resulting directly or indirectly from adverse drug reactions and noncompliance to medication prescriptions). Unsure ADE cases were reviewed by an expert committee. Relations between patient characteristics, type of ED visit, and ADE risk were analyzed using logistic regression. Among the 8275 included patients, 1299 (15.7%) presented to the ED with an ADE. The major ADE symptoms were bleeding, endocrine problems, and neurologic disorders. Moreover, ADEs led to the ED visit, hospitalization, and death in 87%, 49.3%, and 2.2% of cases, respectively. Adverse drug event risk was independently associated with male sex, ED visit for neurological symptoms, visit to the ED critical care unit, or ED short stay hospitalization unit, use of blood, anti-infective, antineoplastic, and immunomodulating drugs. This study improves the knowledge about ADE characteristics and on the patients at risk of ADE. This could help ED teams to better identify and manage ADEs and to improve treatment quality and safety.

DUT-67 and tubular polypyrrole formed a cross-linked network for electrochemical detection of nitrofurazone and ornidazole

The cross-linked network of DUT-67/tubular polypyrrole (T-PPY) composites was first synthesized by in-situ growth zirconium - based metal-organic frameworks (DUT-67) with T-PPY. The introduction of T-PPY effectively increases conductivity of DUT-67/T-PPY composites, weakens accumulation of the DUT-67, and exposes more active sites of DUT-67. DUT-67/T-PPY/GCE manifests increased electrocatalytic activity toward reduction of nitrofurazone and ornidazole compared with DTU-67. A novel electrochemical sensor based on DUT-67/T-PPY was established to effectively detect two anti-infective drugs, respectively. Under optimized experimental conditions, the proposed sensor shows a wider linear range for nitrofurazone that is composed by two line segments (9.08–354.08 μM and 354.08–1004.04 μM). Meanwhile, the sensor also displays a linear response to ornidazole in the range of (0.7–100.5 μM and 100.5–250.4 μM) as well as a low LOD as 0.25 μM (S/N = 3). The proposed sensor was used for the detection of nitrofurazone and ornidazole in actual samples, and the satisfactory results were acquired. This research provides an efficient strategy for fabricating novel electrochemical sensor based on cross-linked network structure of T-PPY and MOFs.

Assessment of anti-infective medication adherence in pediatric outpatients.

The objective of this pilot study was to assess the overall adherence rate of the pediatric population to anti-infective drugs prescribed for acute infection at hospital discharge and to identify risk factors for non-adherence behavior. Pediatric patients discharged from a French university hospital with at least one oral drug prescription for acute infection were included for 3months. Medication adherence and antibiotic knowledge were assessed through data collected by calling the parents. Overall adherence was assessed according to seven items: medication order filling, administered dose, time of intake, frequency of doses, medication omission, dose modification, and length of treatment. Seventy-five patients were included, and 63 interviews were exploited. The median age was 1.4years, IQR = [0.7; 3.3]. Overall adherence to anti-infective agents concerned 34.9% of patients. The most frequently prescribed antibiotics were amoxicillin (29.3%), amoxicillin associated with clavulanic acid (25.3%), cotrimoxazole (18.7%), and cefixime (12.0%). A lack of parents' anti-infective knowledge was associated with non-adherence to anti-infective drugs.Conclusion: Two-thirds of outpatients were non-adherent to anti-infectives in acute infectious diseases. The misunderstanding of anti-infective treatment could be a risk factor for non-adherence. Implementation of preventive actions such as therapeutic education or pharmaceutical counseling at hospital discharge could improve adherence to anti-infective agents. What Is Known: • Non-adherence to anti-infective drugs involves the emergence and spread of antibiotic resistance. • Very few studies have assessed medication adherence in acute infectious diseases in pediatrics after hospital discharge. What Is New: • Only 35% of children were overall adherent to anti-infective drugs in acute infectious disease after hospital discharge. • Most patients (89%) had a good primary adherence but very few (40%) had good secondary adherence mainly due to dose omission and dose modification.

Hospital based Intensive Medication Safety Monitoring; an Observational Prospective Study in a North Indian Private Tertiary Care Teaching Institute

Objective: To identify and characterize adverse drug reactions (ADRs) in patients admitted in intensive care units and wards of a private tertiary care hospital. Materials and Methods: This prospective, observational study was conducted on inpatients. During their hospital stay, whenever a new symptom unrelated to disease or change in laboratory values was observed; ADR was identified using World Health Organisation's definition and recorded in the patient's case sheet. ADRs were classified based on Naranjo's probability scale, Modified Hartwig's criteria of severity and Schumock–Thornton preventability scale. Further, ADRs were analyzed in terms of age, gender, organ system involved, number of medications, and length of stay. Results: Of the 1000 study patients, 35 patients developed 43 ADRs (reported incidence: 3.5%). Twenty-seven patients developed one ADR, while eight patients developed 2 ADRs each. Anti-infective drugs were suspected to have caused the majority (44%) of the ADRs. The most affected organ systems were the gastrointestinal system (44%) and hematological system (26%). On the causality scale, 81.39% ADRs were probably related to suspected medications. About 91% ADRs were probably preventable and 58% ADRs were moderately severe. Number of patients with ADRs was significantly more (P 11 medications. Further, the number of patients with ADRs was significantly more (P 6 days); suggesting, polypharmacy and length of patient's stay as important contributors to developing ADRs. Conclusion: Medication use is majorly associated with the occurrence of ADRs in inpatients. Such surveys on a larger scale would be a useful effort in making medication use safer.

The French reporting system for drug shortages: description and trends from 2012 to 2018: an observational retrospective study

ObjectivesThe aim was to provide figures for drug shortages in France and describe their characteristics, causes and trends between 2012 and 2018.MethodsData from the national reporting system from the Agency...

Critical Parameters for the Development of Novel Therapies for Severe and Resistant Infections-A Case Study on CAL02, a Non-Traditional Broad-Spectrum Anti-Virulence Drug.

Background: Poor outcomes in severe and resistant infections, together with the economic struggles of companies active in the field of anti-infective development, call for new solutions and front runners with novel approaches. Among “non-traditional” approaches, blocking virulence could be a game changer. Objectives: This review offers a perspective on parameters that have determined the development path of CAL02, a novel anti-virulence agent, with a view to steering clear of the obstacles and limitations that impede market sustainability for new anti-infective drugs. Conclusions and implications of key findings: This case study highlights four pillars that may support the development of other non-traditional drugs and, concurrently, provide a new model that could reshape the field. Therapeutic triggers, study designs, and economic parameters are discussed.

Aseptic meningitis as an atypical manifestation of neuromyelitis optica spectrum disorder flare

BackgroundInflammatory demyelinating disease of the central nervous system characterized by aseptic meningitis is rare and can be easily confused with intracranial infection. Here, we investigated the clinical features of neuromyelitis optica spectrum disorder (NMOSD) patients with a meningitis-like presentation. MethodsFrom a total of six attacks, five patients were identified. Their demographic, clinical, and magnetic resonance imaging (MRI) findings, as well as treatments and prognoses were retrospectively analyzed. ResultsFive patients (two males with myelin oligodendrocyte glycoprotein [MOG] antibody and three females with aquaporin-4 [AQP4] antibody) experienced six attacks. Average age at onset was 31.5 ± 3.5 years-old. The earliest clinical manifestations included fever (6/6), headache (5/6), and meningeal irritation (6/6) accompanied by leukocytosis and elevated protein levels (6/6) in cerebrospinal fluid. Two attacks initially manifested as meningitis alone. Meanwhile, following the onset of meningitis-like symptoms, four attacks were accompanied by transverse myelitis on the same day. One attack was associated with leptomeningeal enhancement on MRI, four attacks with spinal meninges enhancement, and one with both leptomeningeal and spinal meninges enhancement. All patients were considered to have an intracranial infection at onset and consequently treated with anti-infective drugs. As the symptoms continuously deteriorated, flare-up of NMOSD was considered a more reasonable diagnosis. Application of glucocorticoids (with or without intravenous immunoglobulin therapy) quickly relieved the symptoms. Subsequent re-examination of cerebrospinal fluid and MRI showed significant improvements. ConclusionAseptic meningitis may be an atypical phenotype of NMOSD flare that is easily confused with specific infection. Comprehensive evaluation to exclude an infective etiology and enable accurate diagnosis and timely immunotherapy are critical to prognosis.

Formulation and Characterization of Moxifloxacin Nanoparticles with Ion Exchange Resin

Moxifloxacin (MOX) is a fluoroquinolone anti-infective drug, indicated for the treatment of bacterial conjunctivitis. The drug is soluble in water but still produces low ocular bioavailability due to biological barriers and so it requires dosing for two/three times a day. The present study was designed to formulate, optimize and characterize polymeric Nanoparticles MOX for ocular administration using Ion Exchange Resin (IER). IER-nanoparticles were prepared by media milling method, formulation/process parameters were optimized based on evaluation parameters such as color of nanosuspension, sedimentation behaviour, particle size and zeta potential. MOX-IER nanosuspensions were prepared at different stoichiometric ratio of MOX and IER and characterized by entrapment efficiency, pH, particle size and zeta potential of nanosuspension. In vitro release study of optimized batch MNIER3 exhibited sustained release pattern which follows Korsmeyer-Peppas model with Fickian diffusion mechanism for drug release. Based on these results optimized batch of MOX-IER nanosuspension formulated in the laboratory was found suitable for ocular delivery.&#x0D; Keywords: Moxifloxacin; nanoparticles, nanosuspension; media milling; stoichiometric ratio; sedimentation behaviour.

Antimicrobial Effect of Drug Incorporated Nanoparticles Against Oral Pathogens

Last few years antibiotics resistance known a major problem that concerns the specialists in the dentistry field due to the improper usage of anti-infectious drugs. Administration of third generation quinolones, levofloxacin (Lev), in dental practice is preferred since has few nonhazardous adverse effects, is used once daily and can be successfully applied as intra-pocket films.This study investigated the possibility of preparing levofloxacin loaded layered double hydroxides nanoparticles in order to enhance antibiotic efficacy against oral pathogens. The nanoparticles obtained under optimal conditions were physico-chemically analyzed and intercalation efficiency was tested. The results of this work revealed that the use of these nanoparticles type levofloxacin loaded layered double hydroxides has the major advantage of prolonged release of the drug, thus allowing an increase of the period between administration and the diminution of side effects of the antibiotic. Further researches should focus on biocompatible properties and antibacterial effect as these nanomaterials supposed to be a sustainable drug delivery system. Keywords: nanoparticles, drug carriers, antibacterial properties, public health dentistry, oral infections

Design, Synthesis and In vitro Biological Activity of Some New 1,3- thiazolidine-4-one Derivatives as Chemotherapeutic Agents using Virtual Screening Strategies

Designing of a new series of derivatives possessing thiazolidine-4-one moiety, their virtual screening using various computational tools, synthesis of prioritized compounds, spectral characterization and biological evaluation along with the comparison of in silico & in vitro results. WHO has come up with a list of antibiotic-resistant "priority pathogens" i.e. families of bacteria, that pose the greatest threat to human health. Some virulent bacteria are focused in the present study namely Mycobacterium tuberculosis (multi drug resistant), Staphylococcus aureus (methicillin-resistant) Streptococcus pneumoniae, (penicillin-non-susceptible) and Pseudomonas aeruginosa (Carbapenem-resistant) One of the neglected pathogenic disease which needs an urgent attention is Leishmaniasis which has a major burden among the poorest segments of populations in Asia, Africa, and South America. 1. To design of a series of new heteroaryl-1,3-thiazolidin-4-one derivatives. 2. To prioritize the molecules for synthesis using virtual screening techniques. 3. To synthesize the virtually predicted molecules via different synthetic schemes. 4. To characterize the synthesized molecules by spectroscopic analysis. 5. To evaluate the synthesized compounds for in vitro biological activity. A series of new heteroaryl thiazolidine-4-one derivatives was designed and subjected to in silico prioritization using various virtual screening strategies. The prioritized thiazolidinone derivatives were synthesized and screened for their in vitro antitubercular, anticancer, antileishmanial and antibacterial (Staphylococcus aureus; Streptococcus pneumonia; Escherichia coli; Pseudomonas aeruginosa) activities. The compounds with electronegative substitutions exhibited positive antitubercular activity, the derivatives possessing a methyl substitution exhibited good inhibitory response against breast cancer cell line MCF-7 while the compounds possessing a hydrogen bond acceptor site like hydroxyl and methoxy substitution in their structures exhibited good in vitro antileishmanial activity. Some compounds exhibited potent activity against gram positive bacteria Pseudomonas aeruginosa as compared to the standards. The designed compounds exhibited good in vitro anti-infective potential which was in good agreement with the in silico predictions and they can be developed as important lead molecules for anti-infective and chemotherapeutic drug research.

Fluorescent Detection of the Ubiquitous Bacterial Messenger 3',5' Cyclic Diguanylic Acid by Using a Small Aromatic Molecule.

3′,5′ Cyclic diguanylic acid (c-di-GMP) has been shown to play a central role in the regulation of bacterial physiological processes such as biofilm formation and virulence production, and is regarded as a potential target for the development of anti-infective drugs. A method for the facile detection of the bacterial level of cellular c-di-GMP is required to explore the details of c-di-GMP signaling and design drugs on the basis of this pathway. Current methods of c-di-GMP detection have limited sensitivity or difficultly in probe preparation. Herein a new fluorescent probe is reported for the detection of c-di-GMP at concentrations as low as 500 nM. The probe was developed on the basis of the G-quadruplex formation of c-di-GMP induced by aromatic molecules. When used on crude bacterial cell lysates, it can effectively distinguish between the low c-di-GMP levels of bacteria in plankton and the high c-di-GMP levels in biofilm. The method described here is simple, inexpensive, sensitive, and suitable for practical applications involving the rapid detection of cellular c-di-GMP levels in vitro after simple bacterial lysis and filtration.

Porous SBA-15/cellulose membrane with prolonged anti-microbial drug release characteristics for potential wound dressing application

A sustained release of anti-infection drugs is beneficial for the reduction of required dressing change times and the protection of the granulation tissue against further infection. In this work, the strategy of encapsulating mesoporous SBA-15 particles in a permeable cellulose membrane (CM) was used in the preparation of antibacterial cellulose based composite membranes to depot store and deliver drugs with prolonged anti-microbial drug release characteristics. It was found that SBA-15 with the protection of phosphate buffered saline prefilled in SBA-15 mesoporous channel could resist strong alkali environment during composite membranes preparation and its mesoporous structure remained intact, which was verified by SEM, TEM and BET results. The resultant cellulose based composite membrane containing 30 wt% SBA-15 (denoted as P-CM-SBA (30%)) had achieved 3.6 wt% drug loading and demonstrated the sustained release of chloramphenicol for 250 h, which was resulted from SBA-15/cellulose structure-inducing two-stage release behavior. Strong antibacterial activity of P-CM-SBA (30%) against S. aureus and E. coli. could last 144 h. In addition, the tensile strength, water vapor transmission rate and swelling properties of P-CM-SBA (30%) conformed to the primary requirements of wound dressing materials. Therefore, cellulose based composite membrane with 30 wt% SBA-15 particles possesses the potential for the application of wound healing.

Kikuchi-Fujimoto Disease with Hemophagocytic Syndrome and Pleural Effusion in an Elder Man: A Case Report and Literature Review

Background: Kikuchi-Fujimoto disease (KFD), also named Histiocytic necrotizing lymphadenitis (HNL), is a rare and self-limited necrotizing lymphadenitis, most commonly affects young Asian female. KFD is characterized by lymphadenopathy, cytopenia, fever, rashes, and weight loss, however, hemophagocytic syndrome and pleural effusion are rarely reported. Case Presentation: We present the case of a 61-year-old man with clinical features including fever, lymphadenopathy, purpura, arthralgia, pleural effusion and pulmonary infection. He had cervical lymphnodebiopsy and the pathology is consistent with KFD, laboratory tests and clinical manifestations were consistent with hemophagocytic syndrome (HLH). After initial treatment including corticosteroid and anti-infection drugs, the patient showed improvement but soon deteriorated. Conclusion: KFD is a self-limited disease with spontaneous resolution. However, the cases of KFD with HLH may have a fatal course. Early appropriate intensive immunosuppressive therapy and strong anti-infection therapy could be beneficial for the treatment outcome.

ROLE OF UNANI MEDICINE IN THE PREVENTION OF CORONAVIRUS DISEASE-2019 (COVID-19): A REVIEW AND RESEARCH PERSPECTIVE

In December 2019 some patients with symptoms very much similar to SARS and MERS emerged in Wuhan city of China. In January 2020 a new type of coronavirus was isolated and name as 2019-nCoV, which later termed 'SARSCoV-2'. WHO declared the Covid-19 outbreak a Public Health Emergency of International Concern, and on March 11, the epidemic was upgraded to the pandemic. As on 02.04.2020, 827,419 confirmed cases are officially reported in more than 200 countries or territories with 40,777 deaths. The history of epidemiology typically starts with 'Hippocrates' in about 400 BC; he in his valuable book, Of the Epidemics introduced several concepts of epidemiology. In Unani Classical texts, both epidemics and pandemics have been described under a common term 'Waba'. Unani medicine have described Nazla Haar by the name of Nazla-e-Wabaiya (epidemic influenza) which is characterized by body ache, sore throat, nasal irritation, burning sensation in eyes sneezing &amp; cough, and fever. Unexplained general weakness is an early feature of Nazla-e-Wabaiya and the disease is often complicated by pneumonia and pleurisy, therefore, Nazla-e-Wabaiya (Nazla Haar) is very much similar to that of Covid-19. In such conditions Ibn Sina advised that houses should be sanitized daily by spraying different arqiyat, he recommended the use of Bukhoor(incense) of some anti-infective drugs. Zakariya Razi has prescribed several aromatic Unani drugs for prevention of Waba. For prophylaxis of epidemic diseases, Unani scholars also prescribed several drugs to augment the immunity (Quwwat-e-Mudabbira Badan). There is a long list of drugs suggested by Unani scholars to be used in different ways to combat epidemic and pandemic situations that need to be validated on current scientific parameters.

GCMS analysis &amp; assessment of antimicrobial potential of rhizospheric Actinomycetes of AIA3 isolate

Plants have been used for medicine to support human health in many regions in the world by researchers since ancient times. Plants and soil organisms have been found to have very high therapeutic potential as they produce many natural products. Evolving drug resistance towards nearly all anti-infection drugs, lead to the fast development of new drugs. Many natural products or secondary metabolites have been used for animal and human health. Recently, many new secondary metabolites from actinomycetes have been isolated and reported as important compounds with different activities like anti-microbial, anti-oxidant, anti-inflammatory, anti-androgenic and anticancer agents, etc. In this study isolation of actinomycetes was carried out on actinomycetes isolation agar media (AIA). Characterization and biochemical tests were performed and followed by fermentation and solvent extraction by four solvents for example- Benzene, pet ether, ethyl acetate, chloroform. GCMS was performed for identification of compounds present in culture broth. Major compounds present were Octanal,Pyrrolo[1,2-a]pyrazine-1,4-dione,hexahydro-3-(2-methylpropyl), Dibutyl phthalate, N-hexadecanoic acid, 1-nonadecene, Heptadecane, Octadecanoic acid, 3,7,11,15-tetramethyl-2-hexadecene, Dihydroergotamine, Hexadecanoic acid, 2-hydroxy-1-(hydroxymethyl) ethyl ester, Octadecanoic acid, 2,3-dihydroxypropyl ester, 13-docosenamide, and 4-tert-butylcalix[4]arene. Crude obtained was checked for their antimicrobial activity and inhibition zones (IZ) were noted on Mullar Hinton agar (MHA) media against indicator organisms like Staphylococcus aureus (MTCC-3160) (IZ=Ben-18 mm, E.A-25 mm), Pseudomonas aeruginosa (MTCC 1688) (IZ=Ben-11 mm, Chl-14 mm, E.A-24 mm), Klebsiella pneumonia (MTCC-432) (IZ=Ben-19 mm, Chl-20 mm, E.A-34 mm), Proteus vulgaris (MTCC-7306) (IZ=Benzene-10 mm, E.A-30 mm), Bacillus subtilis (MTCC-441). Identification of compounds was carried out by NIST 14 library.

Uncovering the functional residues of Arabidopsis isoprenoid biosynthesis enzyme HDS

The methylerythritol phosphate (MEP) pathway is responsible for producing isoprenoids, metabolites with essential functions in the bacterial kingdom and plastid-bearing organisms including plants and Apicomplexa. Additionally, the MEP-pathway intermediate methylerythritol cyclodiphosphate (MEcPP) serves as a plastid-to-nucleus retrograde signal. A suppressor screen of the high MEcPP accumulating mutant plant (ceh1) led to the isolation of 3 revertants (designated Rceh1-3) resulting from independent intragenic substitutions of conserved amino acids in the penultimate MEP-pathway enzyme, hydroxymethylbutenyl diphosphate synthase (HDS). The revertants accumulate varying MEcPP levels, lower than that of ceh1, and exhibit partial or full recovery of MEcPP-mediated phenotypes, including stunted growth and induced expression of stress response genes and the corresponding metabolites. Structural modeling of HDS and ligand docking spatially position the substituted residues at the MEcPP binding pocket and cofactor binding domain of the enzyme. Complementation assays confirm the role of these residues in suppressing the ceh1 mutant phenotypes, albeit to different degrees. In vitro enzyme assays of wild type and HDS variants exhibit differential activities and reveal an unanticipated mismatch between enzyme kinetics and the in vivo MEcPP levels in the corresponding Rceh lines. Additional analyses attribute the mismatch, in part, to the abundance of the first and rate-limiting MEP-pathway enzyme, DXS, and further suggest MEcPP as a rheostat for abundance of the upstream enzyme instrumental in fine-tuning of the pathway flux. Collectively, this study identifies critical residues of a key MEP-pathway enzyme, HDS, valuable for synthetic engineering of isoprenoids, and as potential targets for rational design of antiinfective drugs.