Systematic Review and Geospatial Modeling of Molecular Markers of Resistance to Artemisinins and Sulfadoxine-Pyrimethamine in Plasmodium falciparum in India

Surveillance for genetic markers of resistance can provide valuable information on the likely efficacy of antimalarials but needs to be targeted to ensure optimal use of resources. We conducted a systematic search and review of publications in seven databases to compile resistance marker data from studies in India. The sample collection from the studies identified from this search was conducted between 1994 and 2020, and these studies were published between 1994 and 2022. In all, Plasmodium falciparum Kelch13 (PfK13), P. falciparum dihydropteroate synthase, and P. falciparum dihydrofolate reductase (PfDHPS) genotype data from 2,953, 4,148, and 4,222 blood samples from patients with laboratory-confirmed malaria, respectively, were extracted from these publications and uploaded onto the WorldWide Antimalarial Resistance Network molecular surveyors. These data were fed into hierarchical geostatistical models to produce maps with a predicted prevalence of the PfK13 and PfDHPS markers, and of the associated uncertainty. Zones with a predicted PfDHPS 540E prevalence of >15% were identified in central, eastern, and northeastern India. The predicted prevalence of PfK13 mutants was nonzero at only a few locations, but were within or adjacent to the zones with >15% prevalence of PfDHPS 540E. There may be a greater probability of artesunate-sulfadoxine-pyrimethamine failures in these regions, but these predictions need confirmation. This work can be applied in India and elsewhere to help identify the treatments most likely to be effective for malaria elimination.

A randomised controlled trial to compare the efficacy, safety, and tolerability of low dose, short course primaquine in adults with uncomplicated P. vivax malaria in two hospitals in India

BACKGROUND

Plasmodium vivax remains a major challenge for malaria control and elimination due to its ability to cause relapsing illness. To prevent relapses the Indian National Center for Vector Borne Diseases Control (NCVBDC) recommends treatment with primaquine at a dose of 0.25 mg/kg/day provided over 14 days. Shorter treatment courses may improve adherence and treatment effectiveness.

METHODS

This is a hospital-based, randomised, controlled, open-label trial in two centres in India. Patients above the age of 16 years, with uncomplicated vivax malaria, G6PD activity of ≥ 30% of the adjusted male median (AMM) and haemoglobin levels ≥ 8 g/dL will be recruited into the study and randomised in a 1:1 ratio to receive standard schizonticidal treatment plus 7-day primaquine at 0.50 mg/kg/day or standard care with schizonticidal treatment plus 14-day primaquine at 0.25 mg/kg/day. Patients will be followed up for 6 months. The primary endpoint is the incidence risk of any P. vivax parasitaemia at 6 months. Safety outcomes include the incidence risk of severe anaemia (haemoglobin < 8 g/dL), the risk of blood transfusion, a > 25% fall in haemoglobin and an acute drop in haemoglobin of > 5 g/dL during primaquine treatment.

DISCUSSION

This study will evaluate the efficacy and safety of a 7-day primaquine regimen compared to the standard 14-day regimen in India. Results from this trial are likely to directly inform national treatment guidelines.

TRIAL REGISTRATION

Trial is registered on CTRI portal, Registration No: CTRI/2022/12/048283.

ICARUS at the Fermilab Short-Baseline Neutrino program: initial operation

The ICARUS collaboration employed the 760-ton T600 detector in a successful 3-year physics run at the underground LNGS laboratory, performing a sensitive search for LSND-like anomalous ν e appearance in the CERN Neutrino to Gran Sasso beam, which contributed to the constraints on the allowed neutrino oscillation parameters to a narrow region around 1 eV2 . After a significant overhaul at CERN, the T600 detector has been installed at Fermilab. In 2020 the cryogenic commissioning began with detector cool down, liquid argon filling and recirculation. ICARUS then started its operations collecting the first neutrino events from the booster neutrino beam (BNB) and the Neutrinos at the Main Injector (NuMI) beam off-axis, which were used to test the ICARUS event selection, reconstruction and analysis algorithms. ICARUS successfully completed its commissioning phase in June 2022. The first goal of the ICARUS data taking will be a study to either confirm or refute the claim by Neutrino-4 short-baseline reactor experiment. ICARUS will also perform measurement of neutrino cross sections with the NuMI beam and several Beyond Standard Model searches. After the first year of operations, ICARUS will search for evidence of sterile neutrinos jointly with the Short-Baseline Near Detector, within the Short-Baseline Neutrino program. In this paper, the main activities carried out during the overhauling and installation phases are highlighted. Preliminary technical results from the ICARUS commissioning data with the BNB and NuMI beams are presented both in terms of performance of all ICARUS subsystems and of capability to select and reconstruct neutrino events.

Theileria orientalis Buffeli pathotype in cows in a theileriosis-endemic region of India

Oriental theileriosis caused by Theileria orientalis is a growing health concern of lactating cows in its endemic areas. Rapid and sensitive diagnostic tests are demand areas for appropriate and effective prophylactic and therapeutic measures. Quantitative polymerase chain reaction (qPCR) is the answer for both detection and quantification of parasites. Present study deals with qPCR for detection of parasitemia level of T. orientalis in apparently healthy and clinically affected cows. Major piroplasm surface protein (MPSP) gene present in T. orientalis was cloned in pUC57 vector and transformed into E. coli Top 10 cells. Single and mixed infections of hemoprotozoa other than T. orientalis, causing anemia were differentiated through blood smear examination and PCR tests. T. orientalis was detected in 108 (63.15%) ill and 48 (26.66%) healthy cows. Piroplasms detected per 1000 red blood cells (RBCs) was 0-1 in the healthy group as compared to 3-22 in those showing clinical signs. Parasitemia in ill cows ranged between 6.9 × 102 and 4.5 × 103 parasites / µl of blood which was significantly higher (p<0.05) than healthy group (2.6 × 102 - 5.7 × 102 parasites / µl of blood). Phylogenetic study of the isolates showed similarity with Buffeli type that unfolded its pathogenic form in apparently healthy and ill cows.

Scintillation light detection in the 6-m drift-length ProtoDUNE Dual Phase liquid argon TPC

DUNE is a dual-site experiment for long-baseline neutrino oscillation studies, neutrino astrophysics and nucleon decay searches. ProtoDUNE Dual Phase (DP) is a 6  ×  6  ×  6 m 3 liquid argon time-projection-chamber (LArTPC) that recorded cosmic-muon data at the CERN Neutrino Platform in 2019-2020 as a prototype of the DUNE Far Detector. Charged particles propagating through the LArTPC produce ionization and scintillation light. The scintillation light signal in these detectors can provide the trigger for non-beam events. In addition, it adds precise timing capabilities and improves the calorimetry measurements. In ProtoDUNE-DP, scintillation and electroluminescence light produced by cosmic muons in the LArTPC is collected by photomultiplier tubes placed up to 7 m away from the ionizing track. In this paper, the ProtoDUNE-DP photon detection system performance is evaluated with a particular focus on the different wavelength shifters, such as PEN and TPB, and the use of Xe-doped LAr, considering its future use in giant LArTPCs. The scintillation light production and propagation processes are analyzed and a comparison of simulation to data is performed, improving understanding of the liquid argon properties.

Thalidomide and steroid in the management of erythema nodosum leprosum

OBJECTIVE

The objective of the study was to assess the efficacy and safety profiles of combined treatment of prednisolone with thalidomide (Gr-A) and prednisolone with clofazimine (Gr. B) in patients with erythema nodosum leprosum (ENL) or type 2 lepra reactions.

MATERIALS AND METHODS

Efficacy of both regimens was assessed on the basis of clinical recovery of recurrent ENL measured by reaction severity score (RSS), Visual Analog Scale (VAS), and recurrence of type 2 lepra reaction. The causality assessment of adverse drug reactions was done using the WHO UMC causality assessment scale.

RESULTS

The average age of patients with recurrent ENL was 42.8 years (male) and 51.8yrs (female) and had mean duration of leprosy and recurrent ENL 2.4 years and 2.09 years, respectively. 80% of nonrecurrence was observed in Gr-A versus 66% in Gr-B. Significant (P < 0.05) lower RSS and VAS was found in both the treatment groups as compared to pretreatment value. The reduction in RSS and VAS was statistically significant (P < 0.05) in Gr-A compared to Gr-B treatment.

CONCLUSION

Thalidomide combination with steroid was found to be more efficacious than clofazimine combination with steroid in the treatment of ENL both the treatment regimens showed few tolerable side effects. Improved strategies for the treatment and management of these reactions need to be developed.

Prospects for beyond the Standard Model physics searches at the Deep Underground Neutrino Experiment: DUNE Collaboration

The Deep Underground Neutrino Experiment (DUNE) will be a powerful tool for a variety of physics topics. The high-intensity proton beams provide a large neutrino flux, sampled by a near detector system consisting of a combination of capable precision detectors, and by the massive far detector system located deep underground. This configuration sets up DUNE as a machine for discovery, as it enables opportunities not only to perform precision neutrino measurements that may uncover deviations from the present three-flavor mixing paradigm, but also to discover new particles and unveil new interactions and symmetries beyond those predicted in the Standard Model (SM). Of the many potential beyond the Standard Model (BSM) topics DUNE will probe, this paper presents a selection of studies quantifying DUNE's sensitivities to sterile neutrino mixing, heavy neutral leptons, non-standard interactions, CPT symmetry violation, Lorentz invariance violation, neutrino trident production, dark matter from both beam induced and cosmogenic sources, baryon number violation, and other new physics topics that complement those at high-energy colliders and significantly extend the present reach.

Evaluating the harvesting efficiency of inorganic coagulants on native microalgal consortium enriched with human urine

Flocculation is a common technique to harvest microalgae, where the negatively charged algal cells coalesce together to form larger flocs that settle under gravity. Although several inorganic flocculants have been applied for algal biomass recovery, the dosage varies depending on the algal strain-specific features. Thus, the selection of inorganic coagulant that can be applied at a low dosage for achieving the maximal biomass recovery under normal physiological conditions is necessary. The present study analyses the influence of different inorganic flocculants like ferric chloride (FeCl₃), alum, calcium hydroxide, ferrous sulphate and copper sulphate on the biomass removal efficiency of a mixed microalgal consortium isolated from the open ponds of the National Institute of Technology Rourkela and further enriched with diluted human urine. Flocculation experiments were carried out with varying coagulant dosages, pH between 7.5 and 7.8, and 0.5 g L^-1 algal concentration. The results revealed that FeCl₃ at the dosage of 0.05 g L^-1 and KAl(SO₄)₂ with the dosage of 0.04 g L^-1 could be utilized to achieve the biomass recovery efficiency of 99.5% and 97.9%, respectively, within a duration of 5 min. An economic evaluation of the harvesting process showed KAl(SO₄)₂ to be the cheapest coagulant that could be feasibly used to recover algae at a large scale.

Accurate Base Pair Energies of Artificially Expanded Genetic Information Systems (AEGIS): Clues for Their Mutagenic Characteristics

Recently, several artificial nucleobases, such as B, S, J, V, X, K, P, and Z, have been proposed to help in the expansion of the genetic information system and diagnosis of diseases. Among these bases, P and Z were identified to form stable DNA and to participate in the replication. However, the stabilities of P:Z and other artificial base pairs are not fully understood. The abilities of these unnatural nucleobases in mispairing with themselves and with natural bases are also not known. Here, the ωB97X-D dispersion-corrected density functional theoretical and complete basis set (CBS-QB3) methods are used to obtain accurate structural and energetic data related to base pair interactions involving these unnatural nucleobases. The roles of protonation and deprotonation of certain artificial bases in inducing mutations are also studied. It is found that each artificial purine has a complementary artificial pyrimidine, the base pair interactions between which are similar to those of the natural Watson-Crick base pairs. Hence, these base pairs will function naturally and would not impart mutagenicity. Among these base pairs, the J:V complex is found to be the most stable and promising artificial base pair. Remarkably, the noncomplementary artificial nucleobases are found to form stable mispairs, which may generate mutagenic products in DNA. Similarly, the misinsertions of natural bases opposite artificial bases are also found to be mutagenic. The mechanisms of these mutations are explained in detail. These results are in agreement with earlier biochemical studies. It is thus expected that this study would aid in the advancement of the synthetic biology to design more robust artificial nucleotides.

Analogues of P and Z as Efficient Artificially Expanded Genetic Information System

To artificially expand the genetic information system and to realize artificial life, it is necessary to discover new functional DNA bases that can form stable duplex DNA and participate in error-free replication. It is recently proposed that the 2-amino-imidazo[1,2- a]-1,3,5-triazin-4(8 H)one (P) and 6-amino-5-nitro-2(1 H)-pyridone (Z) would form a base pair complex, which is more stable than that of the normal G-C base pair and would produce an unperturbed duplex DNA. Here, by using quantum chemical calculations in aqueous medium, it is shown that the P and Z molecules can be modified with the help of electron-withdrawing and -donating substituents mainly found in B-DNA to generate new bases that can produce even more stable base pairs. Among the various bases studied, P3, P4, Z3, and Z5 are found to produce base pairs, which are about 2-15 kcal/mol more stable than the P-Z base pair. It is further shown that these base pairs can be stacked onto the G-C and A-T base pairs to produce stable dimers. The consecutive stacking of these base pairs is found to yield even more stable dimers. The influence of charge penetration effects and backbone atoms in stabilizing these dimers are also discussed. It is thus proposed that the P3, P4, Z3, and Z5 would form promiscuous artificial genetic information system and can be used for different biological applications. However, the evaluations of the dynamical effects of these bases in DNA-containing several nucleotides and the efficacy of DNA polymerases to replicate these bases would provide more insights.

Blue- and Red-Shifting Hydrogen Bonding: A Gas Phase FTIR and Ab Initio Study of RR'CO···DCCl3 and RR'S···DCCl3 Complexes

Blue-shifting H-bonded (C-D···O) complexes between CDCl₃ and CH₃HCO, (CH₃)₂CO, and C₂H₅(CH₃)CO, and red-shifting H-bonded (C-D···S) complexes between CDCl₃ with (CH₃)₂S and (C₂H₅)₂S have been identified by Fourier transform infrared spectroscopy in the gas phase at room temperature. With increasing partial pressure of the components, a new band appears in the C-D stretching region of the vibrational spectra. The intensity of this band decreases with an increase in temperature at constant pressure, which provides the basis for identification of the H-bonded bands in the spectrum. The C-D stretching frequency of CDCl₃ is blue-shifted by +7.1, +4, and +3.2 cm^-1 upon complexation with CH₃HCO, (CH₃)₂CO, and C₂H₅(CH₃)CO, respectively, and red-shifted by -14 and -19.2 cm^-1 upon complexation with (CH₃)₂S and (C₂H₅)₂S, respectively. By using quantum chemical calculations at the MP2/6-311++G** level, we predict the geometry, electronic structural parameters, binding energy, and spectral shift of H-bonded complexes between CDCl₃ and two series of compounds named RCOR' (H₂CO, CH₃HCO, (CH₃)₂CO, and C₂H₅(CH₃)CO) and RSR' (H₂S, CH₃HS, (CH₃)₂S, and (C₂H₅)₂S) series. The calculated and observed spectral shifts follow the same trends. With an increase in basicity of the H-bond acceptor, the C-D bond length increases, force constant decreases, and the frequency shifts to the red from the blue. The potential energy scans of the above complexes are done, which show that electrostatic attraction between electropositive D and electron-rich O/S causes bond elongation and red shift, and the electronic and nuclear repulsions lead to bond contraction and blue shifts. The dominance of the two opposing forces at the equilibrium geometry of the complex determines the nature of the shift, which changes both in magnitude and in direction with the basicity of the hydrogen-bond acceptor.

A randomized, open-label clinical trial to evaluate immunogenicity and safety of an indigenously developed DTwP-Hib tetravalent combination vaccine (Easyfour®-TT) with Quadrovax® in Indian infants

An open-label, randomized, multi-center trial was conducted to compare the immunogenicity and safety of an indigenously developed tetravalent DTwP-Hib vaccine, Easyfour®-TT with a commercially available vaccine, Quadrovax®. A total of 244 infants in good health, aged 6-10 weeks, were randomized in a 1:1 allocation to receive three doses of the test or comparator vaccine. Immunogenicity of the vaccines was determined by measuring the baseline and post-vaccination antibody response against the vaccine antigens; safety was evaluated in terms of local and systemic reactions (solicited and unsolicited) reported during the trial. Similar levels of seroprotection/seroresponse were achieved, 4 weeks after receiving 3 doses of Easyfour®-TT and Quadrovax®, and the antibody response of Easyfour®-TT was found non-inferior to Quadrovax®, against all four vaccine antigens. Both vaccines were well tolerated and had similar reactogenicity profiles, with a significantly lower occurrence of local (redness at injection site) and systemic reactions (irritability post-vaccination) with Easyfour®-TT vaccine as compared to Quadrovax® (p < 0.05). All adverse events resolved completely with no sequelae. All through the study, only one serious adverse event was observed that completely resolved upon treatment and was deemed unrelated to the vaccine administered. This study demonstrated that Easyfour®-TT vaccine was safe and immunogenic.

CLINICAL TRIAL REGISTRATION NUMBER

CTRI/2014/12/005326 (registered with the Clinical Trial Registry of India (CTRI)).

Measurement of the Neutrino Mixing Angle θ_{23} in NOvA

This Letter reports new results on muon neutrino disappearance from NOvA, using a 14 kton detector equivalent exposure of 6.05×10^{20} protons on target from the NuMI beam at the Fermi National Accelerator Laboratory. The measurement probes the muon-tau symmetry hypothesis that requires maximal θ_{23} mixing (θ_{23}=π/4). Assuming the normal mass hierarchy, we find Δm_{32}^{2}=(2.67±0.11)×10^{-3}  eV^{2} and sin^{2}θ_{23} at the two statistically degenerate values 0.404_{-0.022}^{+0.030} and 0.624_{-0.030}^{+0.022}, both at the 68% confidence level. Our data disfavor the maximal mixing scenario with 2.6σ significance.

The mysterious Zika virus: Adding to the tropical flavivirus mayhem

Until now, known as the demure cousin of dengue virus (DENV) inhabiting Africa, Zika virus (ZIKV) has reinvented itself to cause explosive epidemics captivating the Western hemisphere. The outbreak causing potential for ZIKV was realized when it made its way from Africa to Yap Island Micronesia in 2007, and in French Polynesia in 2013. From there, it moved on to Brazil in 2015. Now ZIKV has infected people in more than 33 countries in Central and South America and the Caribbean. Moreover the epidemiological and subsequent virological association with microcephaly cases in Brazil has prompted the World Health Organization to declare a public health emergency of International Concern. ZIKV shares not only its vector Aedes aegypti with dengue and chikungunya but also the geographic distribution and clinical features, which makes the laboratory confirmation mandatory for definitive diagnosis. The serological cross-reactivity with other Flavivirus, particularly with DENV makes laboratory confirmation challenging and will place additional burden on health systems to establish molecular diagnostic facilities. The evidence of additional nonvector modes of transmission, such as perinatal, sexual as well as transfusion has made preventative strategies more difficult. As ZIKV disease continues to mystify us with several unanswered questions, it calls for coordinated effort of global scientific community to address the ever growing arboviral threat to mankind.

Genipin-Crosslinked Gelatin-Based Emulgels: an Insight into the Thermal, Mechanical, and Electrical Studies

The present study discusses about the preparation and characterization (thermal, mechanical, and electrical) of the genipin-crosslinked gelatin emulgels. Emulgels have gained importance in recent years due to their improved stability than emulsions and ability to control the drug release. Mustard oil was used as the representative oil. A decrease in the enthalpy and entropy of the formulations was observed with the increase in the oil fraction. The mechanical studies suggested formation of softer emulgels as the oil fraction was increased. As the proportion of the oil fraction was increased in the emulgels, there was a corresponding increase in the impedance. The drug release properties from the emulgels were also studied. Ciprofloxacin was used as the model antimicrobial drug. The drug release was higher from the emulgels whose electrical conductivity was higher.

Catalyst-Free Synthesis of ZnO Nanowires on Oxidized Silicon Substrate for Gas Sensing Applications

In the present work, we report the synthesis of nanostructured ZnO by oxidation of zinc film without using a seed or catalyst layer. The zinc films were deposited on oxidized Si substrates by RF magnetron sputtering process. These were oxidized in dry and wet air/oxygen ambient. The optimized process yielded long nanowires of ZnO having diameter of around 60-70 nm and spread uniformly over the surface. The effect of oxidation temperature, time, Zn film thickness and the ambient has strong influence on the morphology of resulting nanostruxctured ZnO film. The films were characterized by scanning electron microscopy for morphological studies and X-ray diffraction (XRD) analysis to study the phase of the nanostructured ZnO. Room temperature photoluminescence (PL) measurements of the nanowires show UV and green emission. A sensor was designed and fabricated using nanostructured ZnO film, incorporating inter-digital-electrode (IDE) for the measurement of resistance of the sensing layer. The gas sensing properties were investigated from the measurement of change in resistance when exposed to vapours of different volatile organic compound (VOC) such as acetone, ethanol, methanol and 2-propanol. The results suggest that ZnO nanowires fabricated by this method have potential application in gas sensors.

Botryomycosis

Botryomycosis is a rare chronic bacterial granulomatous disease that usually involves skin and rarely viscera. Main etiological agent is Staphylococcus aureus and less commonly Pseudomonas spp., Escherichia coli, Proteus spp., Streptococcus spp. We here report a case of 32-year-old male with polymicrobial botryomycosis on forehead and on frontal scalp. Culture from lesions revealed growth of S. aureus initially. Partial resolution was achieved with cefadroxyl and clavulanic acid, rifampicin, and linezolid. Subsequent repeat culture revealed E. coli sensitive to netilmycin. Slow and steady resolution was achieved with surgical debridement and combination therapy of injectable netilmycin and oral sufomethoxazole and trimethoprim for a prolonged period.

Bacterial vaginosis: Etiology and modalities of treatment-A brief note

A large women population of the world is suffering from a vaginal infection commonly known as bacterial vaginosis. The disease is associated with the decrease in the lactobacilli count in the vagina. Till date, there is a lack of full proof treatment modalities for the cure of the disease. The treatment includes the use of antimicrobials and/or acidifying agents and probiotics, either separately or in combination. This note discusses about the etiology and the various present-day modalities of treatment of bacterial vaginosis.

Search for a dark matter annihilation signal from the galactic center halo with H.E.S.S

A search for a very-high-energy (VHE; ≥100  GeV) γ-ray signal from self-annihilating particle dark matter (DM) is performed towards a region of projected distance r∼45-150  pc from the Galactic center. The background-subtracted γ-ray spectrum measured with the High Energy Stereoscopic System (H.E.S.S.) γ-ray instrument in the energy range between 300 GeV and 30 TeV shows no hint of a residual γ-ray flux. Assuming conventional Navarro-Frenk-White and Einasto density profiles, limits are derived on the velocity-weighted annihilation cross section (σv) as a function of the DM particle mass. These are among the best reported so far for this energy range and in particular differ only little between the chosen density profile parametrizations. In particular, for the DM particle mass of ∼1  TeV, values for (σv) above 3×10(-25)  cm(3) s(-1) are excluded for the Einasto density profile.

Ertapenem susceptibility of extended spectrum beta-lactamase-producing Enterobacteriaceae at a tertiary care centre in India

INTRODUCTION

Infections caused by multidrug-resistant organisms such as extended spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae have come to assume widespread proportions. Carbapenems (imipenem and meropenem) are the drugs of choice for the treatment of infections caused by ESBL-producing organisms. There is limited clinical data regarding the efficacy of the latest carbapenem, called ertapenem, against these organisms in the Indian subcontinent. In this study, ertapenem susceptibility in ESBL-producing clinical isolates was evaluated. The in vitro activities of the three carbapenems were compared in ertapenem-resistant isolates.

METHODS

A total of 205 ESBL-producing Enterobacteriaceae collected from inpatients and outpatients at the All India Institute of Medical Sciences, were identified and tested for antimicrobial susceptibility by the disc diffusion method and Vitek 2 advanced expert system. Ertapenem susceptibility was performed by disc diffusion and Vitek 2 in all the isolates and by E-test in 100 isolates.

RESULTS

191 (93 percent) of the ESBL-producing isolates tested were susceptible to ertapenem. All ertapenem-susceptible isolates were also susceptible to imipenem and meropenem. Isolates with low-level ertapenem resistance retained their susceptibility to imipenem and meropenem, whereas those with high-level ertapenem resistance were resistant to both imipenem and meropenem.

CONCLUSION

Our results suggest that ertapenem may be a viable alternative to other carbapenems for the treatment of infections caused by ESBL-producing clinical isolates. Clinical outcome studies are required to determine if ertapenem is effective for the treatment of infections caused by these organisms.

Energy spectrum of cosmic-ray electrons at TeV energies

The very large collection area of ground-based gamma-ray telescopes gives them a substantial advantage over balloon or satellite based instruments in the detection of very-high-energy (>600 GeV) cosmic-ray electrons. Here we present the electron spectrum derived from data taken with the High Energy Stereoscopic System (H.E.S.S.) of imaging atmospheric Cherenkov telescopes. In this measurement, the first of this type, we are able to extend the measurement of the electron spectrum beyond the range accessible to direct measurements. We find evidence for a substantial steepening in the energy spectrum above 600 GeV compared to lower energies.