In vitro evaluation of metal chelators as potential metallo- ß -lactamase inhibitors.

AIMS: This study aimed at investigating the use of metal chelators as potential metallo-ß-lactamase inhibitors (MBL). METHODS AND RESULTS: The minimum inhibitory concentration (MIC) of meropenem was ascertained alone and in combination with various concentrations of macrocyclic (1,4,7- triazacyclononane-1-glutaric acid-4,7-diacetic acid = NODAGA) peptide derivatives and acyclic (N,N,N',N'-Tetrakis(2-pyridylmethyl)ethylenediamine = TPEN and di-(2-picolyl)amine = DPA) metal chelators using the broth microdilution method. MICs of meropenem against carbapenem-resistant enterobacteriaceae (CRE) producing MBLs were decreased to concentrations as low as 0·06 mg l(-1) in the presence of some metal chelators. TPEN at 4 and 8 mg l(-1) showed the best activity by decreasing meropenem MICs to 0·5 and 0·06 mg l(-1) , respectively, for some New Delhi Metallo-beta-lactamase (NDM) and Verona integron-encoded metallo-ß-lactamase (VIM) -producing enterobacteriaceae. DPA at 8 and 16 mg l(-1) was also able to decrease meropenem MICs to 1 and 0·125 mg l(-1) , respectively, for these CREs. NODAGA peptide derivatives showed the least inhibition as 32 mg l(-1) was required for meropenem MICs to be decreased to 0·06 mg l(-1) against an NDM-1 producing isolate. CONCLUSION: The various metal chelators, TPEN, DPA and NODAGA peptide derivatives were able to inhibit the MBLs in decreasing order of activity, rendering CREs susceptible to meropenem. SIGNIFICANCE AND IMPACT OF THE STUDY: In the absence of new antibiotics, this study evaluated metal chelators as potential MBL inhibitors.

First Report of Nigrospora Leaf Blight on Tea Caused by Nigrospora sphaerica in India.

Tea [Camellia sinensis (L.) O. Kuntze] is an economically important non-alcoholic caffeine-containing beverage crop widely cultivated for leaves in India, especially in the Darjeeling district of West Bengal. In May 2012, distinct blight symptoms were observed on leaves of popular tea cultivars AV-2, Tukdah 78, Rungli Rungliot 17/144, and Bannockburn 157 in commercial tea estates of the Darjeeling district. This disease reduces yield and quality of the leaves. The initial symptoms were frequently observed on the young leaf margins and apices. Foliar symptoms are characterized by grayish to brown, semicircular or irregular shaped lesions, often surrounded by pale yellow zones up to 9 mm in diameter. The lesions later expand and the affected leaves turn grayish to dark brown and eventually the dried tissue falls, leading to complete defoliation of the plant. The disease causes damage to leaves of all ages and is severe in young leaves. A portion of the symptomatic leaf tissues were surface sterilized in 70% ethanol for 30 s, then in 2% NaClO for 3 min, rinsed three times in sterile distilled water, and plated onto potato dextrose agar (PDA). The fungal colonies were initially white and then became grayish to brown with sporulation. Conidia were spherical to sub spherical, single-celled, black, 19 to 21 µm in diameter, and were borne on a hyaline vesicle at the tip of each conidiophore. Morphological characteristics of the isolates were concurring to those of Nigrospora sphaerica (1). Moreover, the internal transcribed spacer (ITS) region of the ribosomal RNA was amplified by using primers ITS1 and ITS4 and sequenced (GenBank Accession No. KJ767520). The sequence was compared to the GenBank database through nucleotide BLAST search and the isolate showed 100% similarity to N. sphaerica (KC519729.1). On the basis of morphological characteristics and nucleotide homology, the isolate was identified as N. sphaerica. Koch's postulates were fulfilled in the laboratory on tea leaves inoculated with N. sphaerica conidial suspension (106 conidia ml-1) collected from a 7-day-old culture on PDA. Six inoculated 8-month-old seedlings of tea cultivars AV-2 and S.3/3 were incubated in a controlled environment chamber at 25°C and 80 to 85% humidity with a 12-h photoperiod. In addition, three plants of each cultivar were sprayed with sterile distilled water to serve as controls. Twelve to 14 days after inoculation, inoculated leaves developed blight symptoms similar to those observed on naturally infected tea leaves in the field. No symptoms were observed on the control leaves. The pathogen was re-isolated from lesions and its identity was confirmed by morphological characteristics. It was reported that N. sphaerica is frequently encountered as a secondary invader or as a saprophyte on many plant species and also as a causative organism of foliar disease on several hosts worldwide (2,3). To our knowledge, this is first report of N. sphaerica as a foliar pathogen of Camellia sinensis in Darjeeling, West Bengal, India, or worldwide. References: (1) M. B. Ellis. Dematiaceous Hyphomycetes. CMI, Kew, Surrey, UK, 1971. (2) D. F. Farr and A. Y. Rossman. Fungal Databases, Syst. Mycol. Microbiol. Lab., ARS, USDA. Retrieved from http://nt.ars-grin.gov/fungaldatabases/ July 01, 2013. (3) E. R. Wright et al. Plant Dis. 92:171, 2008.

Transmission of methicillin-resistant Staphylococcus aureus via deceased donor liver transplantation confirmed by whole genome sequencing.

Donor-derived bacterial infection is a recognized complication of solid organ transplantation (SOT). The present report describes the clinical details and successful outcome in a liver transplant recipient despite transmission of methicillin-resistant Staphylococcus aureus (MRSA) from a deceased donor with MRSA endocarditis and bacteremia. We further describe whole genome sequencing (WGS) and complete de novo assembly of the donor and recipient MRSA isolate genomes, which confirms that both isolates are genetically 100% identical. We propose that similar application of WGS techniques to future investigations of donor bacterial transmission would strengthen the definition of proven bacterial transmission in SOT, particularly in the presence of highly clonal bacteria such as MRSA. WGS will further improve our understanding of the epidemiology of bacterial transmission in SOT and the risk of adverse patient outcomes when it occurs.

Demonstration of side coupling to cladding modes through zinc oxide nanorods grown on multimode optical fiber.

A novel concept is introduced that utilizes the scattering properties of zinc oxide nanorods to control light guidance and leakage inside optical fibers coated with nanorods. The effect of the hydrothermal growth conditions of the nanorods on light scattering and coupling to optical fiber are experimentally investigated. At optimum conditions, 5% of the incident light is side coupled to the cladding modes. This coupling scheme could be used in different applications such as distributed sensors and light combing. Implementation of the nanorods on fiber provides low cost and controllable nonlithography-based solutions for free space to fiber coupling. Higher coupling efficiencies can be achieved with further optimization.

Progress in antimicrobial activities of chitin, chitosan and its oligosaccharides: a systematic study needs for food applications.

In recent years, active biomolecules such as chitosan and its derivatives are undergoing a significant and very fast development in food application area. Due to recent outbreaks of contaminations associated with food products, there have been growing concerns regarding the negative environmental impact of packaging materials of antimicrobial biofilms, which have been studied. Chitosan has a great potential for a wide range of applications due to its biodegradability, biocompatibility, antimicrobial activity, nontoxicity and versatile chemical and physical properties. It can be formed into fibers, films, gels, sponges, beads or nanoparticles. Chitosan films have been used as a packaging material for the quality preservation of a variety of foods. Chitosan has high antimicrobial activities against a wide variety of pathogenic and spoilage microorganisms, including fungi, and Gram-positive and Gram-negative bacteria. A tremendous effort has been made over the past decade to develop and test films with antimicrobial properties to improve food safety and shelf-life. This review highlights the preparation, mechanism, antimicrobial activity, optimization of biocide properties of chitosan films and applications including biocatalysts for the improvement of quality and shelf-life of foods.

First report of porcine respirovirus 1 in South America.

Porcine respirovirus 1 (PRV1) is an emerging virus in pigs that has been previously described in the USA and China. There are no reports of its presence in the rest of the world. The objective of this study was to determine the occurrence of PRV1 in Chile and to determine its phylogeny. Thus, we collected samples (oral fluids, nasal swabs, and lungs) from a swine influenza A virus (IAV) surveillance program, most of which belonged to pigs with respiratory disease. The samples were analyzed by RT-PCR, and the viral sequencing was obtained using RNA whole-genome sequencing approach. Maximum likelihood phylogeny was constructed with the available references. Thirty-one of 164 samples (18.9 %) were RT-PCR positive for PRV1: 62.5 % oral fluids, 19.0 % nasal swabs, and 8.6 % lungs. All 6 farms in this study had at least one positive sample, with 6-40 % of positive results per farm, which suggests that PRV1 is disseminated in Chilean swine farms. Twenty-one of 31 (677%) PRV1-positive samples were also positive for IAV, so the role of PRV1 as secondary pathogen in respiratory disease needs to be further evaluated. Near to complete genome of two PRV1s were obtained from two farms. The phylogenies, in general, showed low bootstrap support, except the concatenated genome and the L gene trees which showed clustering of the Chilean PRV1 with Asian sequences, suggesting a close genetic relationship. This is the first report of PRV1 in the Southern Hemisphere. Further studies are necessary to determine the genetic diversity of this virus in Chile.

Nanocomposite functionalized membranes based on silica nanoparticles cross-linked to electrospun nanofibrous support for arsenic(v) adsorption from contaminated underground water.

Nanocomposite functionalized membranes were synthesized using surface functionalized mesoporous silica nanoparticles (MCM-NH2 or MCM-PEI) cross-linked to a modified polyacrylonitrile (mPAN) nanofibrous substrate for the removal of 1 mg L-1 of As(v); a concentration much higher than what has been reported for underground water in Argentina. Adsorption studies were carried out in batch mode at pH 8 with nanoparticles in colloidal form, as well as the nanoparticles supported on the modified PAN membranes (mPAN/MCM-NH2 and mPAN/MCM-PEI). Results indicate a twenty-fold improvement in As(v) adsorption with supported nanoparticles (nanocomposite membranes) as opposed to their colloidal form. The adsorption efficiency could be further enhanced by modifying the nanocomposite membrane surface with Fe3+ (mPAN/MCM-NH2-Fe3+ and mPAN/MCM-PEI-Fe3+) which resulted in more than 95% arsenic being removed within the first 15 minutes and a specific arsenic adsorption capacity of 4.61 mg g-1 and 5.89 mg g-1 for mPAN/MCM-NH2-Fe3+ and mPAN/MCM-PEI-Fe3+ nanocomposite membranes, respectively. The adsorption characteristics were observed to follow a pseudo-first order behavior. The results suggest that the synthesized materials are excellent for quick and efficient reduction of As(v) concentrations below the WHO guidelines and show promise for future applications.

Current insights into the regulation of programmed cell death by NF-kappaB.

The nuclear factor-kappaB (NF-kappaB) transcription factors have emerged as major regulators of programmed cell death (PCD) whether via apoptosis or necrosis. In this context, NF-kappaB's activity has important ramifications for normal tissue development, homoeostasis and the physiological functions of various cell systems including the immune, hepatic, epidermal and nervous systems. However, improper regulation of PCD by NF-kappaB can have severe pathologic consequences, ranging from neurodegeneration to cancer, where its activity often precludes effective therapy. Although NF-kappaB generally protects cells by inducing the expression genes encoding antiapoptotic and antioxidizing proteins, its role in apoptosis and necrosis can vary markedly in different cell contexts, and NF-kappaB can sensitize cells to death-inducing stimuli in some instances. This article describes our current knowledge of the role of NF-kappaB in apoptosis and necrosis, and focuses on the many advances since we last reviewed this rapidly evolving topic in Oncogene 3 years ago. There has been substantial progress in understanding NF-kappaB's mode of action in apoptosis and necrosis and the mechanisms that regulate its anti- vs proapoptotic activities. These recent developments shed new light on the role of NF-kappaB in many disease conditions including tumor development, tumor progression and anticancer treatment.

Prospects for the use of ornamental fishes for mosquito control: a laboratory investigation.

Use of larvivorous fishes Gambusia and Poecilia for mosquito control has been a well established option. The study evaluated the larvivorous potential of some ornamental fish vis-a-vis Gambusia and Poecilia in the laboratory settings using standard testing protocol. Gold fish and Blue Gourami were found to be as effective larvivores as Gambusia affinis, the mosquito fish. The study recommends introduction of Goldfish and Blue Gourami in ornamental tanks for control of mosquito breeding as well as providing aesthetic beauty.

Hybrid Pixel-Waveform (HPWF) Enabled CdTe Detectors for Small Animal Gamma-Ray Imaging Applications.

This paper presents the design and preliminary evaluation of small-pixel CdTe gamma ray detectors equipped with a hybrid pixel-waveform (HPWF) readout system for gamma ray imaging applications with additional discussion on CZT due to its similarity. The HPWF readout system utilizes a pixelated anode readout circuitry which is designed to only provide the pixel address. This readout circuitry works in coincidence with a high-speed digitizer to sample the cathode waveform which provides the energy, timing, and depth-of-interaction (DOI) information. This work focuses on the developed and experimentally evaluated prototype HPWF-CdTe detectors with a custom CMOS pixel-ASIC to readout small anode pixels of 350 µm in size, and a discrete waveform sampling circuitry to digitize the signal waveform induced on the large cathode. The intrinsic timing, energy, and spatial resolution were experimentally evaluated in this paper in conjunction with methods for depth of interaction (DOI) partitioning of the CdTe crystal. While the experimental studies discussed in this paper are primarily for evaluating HPWF detectors for small animal PET imaging, these detectors could find their applications for ultrahigh-resolution SPECT and other imaging modalities.

Evaluation of specific humoral immune response in pigs vaccinated with cell culture adapted classical swine fever vaccine.

AIM: To determine an efficient vaccination schedule on the basis of the humoral immune response of cell culture adapted live classical swine fever virus (CSFV) vaccinated pigs and maternally derived antibody (MDA) in piglets of vaccinated sows. MATERIALS AND METHODS: A cell culture adapted live CSFV vaccine was subjected to different vaccination schedule in the present study. Serum samples were collected before vaccination (day 0) and 7, 14, 28, 42, 56, 180, 194, 208, 270, 284 and 298 days after vaccination and were analyzed by liquid phase blocking enzyme-linked immunosorbent assay. Moreover, MDA titre was detected in the serum of piglets at 21 and 42 days of age after farrowing of the vaccinated sows. RESULTS: On 28 days after vaccination, serum samples of 83.33% vaccinated pigs showed the desirable level of antibody titer (log10 1.50 at 1:32 dilution), whereas 100% animals showed log10 1.50 at 1:32 dilution after 42 days of vaccination. Animals received a booster dose at 28 and 180 days post vaccination showed stable high-level antibody titre till the end of the study period. Further, piglets born from pigs vaccinated 1 month after conception showed the desirable level of MDA up to 42 days of age. CONCLUSION: CSF causes major losses in pig industry. Lapinised vaccines against CSFV are used routinely in endemic countries. In the present study, a cell culture adapted live attenuated vaccine has been evaluated. Based on the level of humoral immune response of vaccinated pigs and MDA titer in piglets born from immunized sows, it may be concluded that the more effective vaccination schedule for prevention of CSF is primary vaccination at 2 months of age followed by booster vaccination at 28 and 180 days post primary vaccination and at 1 month of gestation.

Field performance of cyphenothrin: an integrated insecticide strategy against German cockroaches (Dictyoptera: Blatellidae).

BACKGROUND & OBJECTIVES: Resistance to organophosphorous and carbamate insecticides amongst German cockroaches is widely reported. Cyphenothrin EC, a new synthetic pyrethroid was evaluated in cookhouses in an urban area, with the aim of exploring alternate control option against the German cockroach Blatella germanica. METHODS: Three cookhouses were selected by simple random sampling method, two for treatment and one as control. The impact of treatment on cockroach infestation was monitored weekly by visual assessment sampling technique. RESULTS: Cyphenothrin brought about 95 to 97.5% reduction in cockroach infestation by the end of six weeks post-treatment. INTERPRETATION & CONCLUSION: The study reports the efficacy of cyphenothrin in the control of German cockroaches and recommends an "Integrated insecticide strategy" for the control of cockroaches in urban cookhouses.

Creutzfeldt-Jakob disease.

Cruetzfeldt-Jakob disease is a prion protein disease causing a transmissible, subacute, fatal neurodegenerative disease characterized by a spongiform encephalopathy. Though rare, ever since Pruisner described the pathogenesis in 1982, this disease kept the clinicians as well as biologists spellbound, because of its distinct clinical picture and the novel mechanism of transmission. There was a further quantum leap in the interest in the disease with the establishment of its new clinical variant, the so called 'mad cow disease' in the late 1990s and had led to more stringent measures to ensure the quality of cattle-feeds and cattle-derived food products. The sporadic genetic variants, the commonest form of the disease, continue to challenge the genetic scientists. Advances in neuroimaging, cerebrospinal fluid marker proteins and genetic linkage studies now offer excellent diagnostic methods, while advances in therapeutic medicine which use products from cadaveric extracts such as growth hormone for treatment of hypopituitarism, dural grafts for neurosurgical procedures and cornea for transplantation etc. have thrown new challenges in controlling this serious disease.

Indium metal as a reducing agent. Selective reduction of the carbon-carbon double bond in highly activated conjugated alkenes.

[reaction: see text] Indium metal in aqueous ethanolic ammonium chloride reduces the C=C bond in highly activated conjugated alkenes such as alpha,alpha-dicyano olefins, beta-arylenones, and enone esters.

Co-amplification of dhfr and a homologue of hmsh3 in a Chinese hamster methotrexate-resistant cell line correlates with resistance to a range of chemotherapeutic drugs.

PURPOSE: To characterize a methotrexate-resistant Chinese hamster cell line, designated as M5, which had previously been shown to be resistant to gamma radiation, at the cellular and molecular levels. METHODS: Sensitivity towards a number of chemotherapeutic drugs was determined by colony-forming ability and compared with that of parental V79 cells. Expression of the hamster homologue of the human mismatch repair gene hmsh3 was also determined by RT-PCR. RESULTS: Induced killing by chemotherapeutic agents cis-diamminedichloroplatinum II (cisplatin). the antimetabolite 6-thioguanine (6-TG), camptothecin, a topoisomerase I inhibitor, and 4-(9-acridinyl-amino)-methanesulfon-m-anisidide (mAMSA), an inhibitor of topoisomerase II, was less in M5 cells than in the parental V79 cells. The IC50 values, defined as the concentration of the drug that reduced the survival to 50% that of the untreated control, in V79 cells for mAMSA and camptothecin treatment were 0.35 +/- 0.02 microg/ml and 84.3 +/- 16.0 ng/ml, respectively. For M5 cells, equivalent values were 0.52 +/- 0.10 microg/ml and 186 +/- 40.8 ng/ml. Treatment with 30 microM cisplatin reduced the survival of V79 cells to 0.09 +/- 0.07, whereas the same treatment reduced the survival of M5 cells to 0.67 +/- 0.16. Treatment of M5 cells with 6-TG did not induce appreciable killing up to the concentrations studied. However, for V79 cells, 6-TG was very toxic. We further observed that the dihydrofolate reductase (dhfr) gene as well as the hamster homologue of the human mismatch repair gene hmsh3 was amplified in the methotrexate-resistant M5 cells. CONCLUSION: Resistance to this group of chemotherapeutic drugs observed in M5 cells could be due to the amplification of the hamster homologue of hMSH3, which in turn possibly sequesters all the hMSH2 making M5 cells functionally deficient in the mismatch repair system.

Effect of trimethoprim-sulphamethoxazole on vibrio clearance in cholera (El Tor): a comparative study.

The efficacy of trimethoprim-sulphamethoxazole (TMP-SMX) has been compared with that of tetracycline and chloramphenicol in 175 bacteriologically confirmed cases of cholera admitted to the Infectious Diseases Hospital Delhi. Vibrio cholerae, biotype El Tor, serotype ogawa, were isolated from all the patients. TMP-SMX showed greater in vitro inhibition and earlier eradication from the intestinal tract and is recommended as a suitable vibriocidal agent against cholera.

Treatment of clinical rabies in man: drug therapy and other measures.

The treatment of symptomatic rabies is a challenging problem; no specific drug is yet available. Isolation in intensive care unit with symptomatic and supportive measures is the mainstay of treatment at present. Antiviral drugs, particularly interferon and interferon-inducers, have been employed with variable results. Corticosteroid is not effective. Anti-rabies vaccine has no proven efficacy in treatment. Effective treatment of systemic complications during survival period with appropriate therapy is essential.

Comparison of the effects of dietary fish oils with different n-3 polyunsaturated fatty acid compositions on plasma and liver lipids in rats.

The effects of dietary fish oils with different n-3 polyunsaturated fatty acid compositions on plasma lipid profiles in rats have been studied. Forty-eight male rats, previously maintained on a cholesterol-free diet for 15 days, were fed for 60 days with diets supplemented with 10% fat of either marine hilsa fish (Hilsa ilisa, family clupeidae) or fresh-water chital fish (Notopterus chitala, family notopteridae). The diets had similar levels of total saturated (35-41%), monounsaturated (43-47%) and n-3 polyunsaturated (9-10%) fatty acids. Cholesterol contents of the diets were adjusted to 0.85%; gamma-linolenic acid (3.3%) in chital oil and eicosapentaenoic acid (4.9%) in hilsa oil diets were the major n-3 contributors. The percentage of eicosapentaenoic acid in the chital oil diet was 0.57 times that of the hilsa oil diet, but the eicosapentaenoic (EPA) to arachidonic acid (AA) ratio in the latter (4.08) was 3.2 times that of the former (1.27). Sixty days of hilsa oil diet feeding decreased the levels of cholesterol (53.3 +/- 2.9 to 50.0 +/- 1.1 mg/dL), triacylglycerol (75.7 +/- 3.8 to 64.3 +/- 2.6 mg/dL) and phospholipid (55.8 +/- 1.5 to 51.7 +/- 3.1 mg/dL) in rat plasma. Similar treatment with chital oil diet elevated the plasma cholesterol level (53.3 +/- 2.9 to 62.3 +/- 7.6 mg/dL) while triacylglycerol and phospholipid contents remained unaltered. Both the dietary treatments decreased the levels of linoleic and arachidonic acids in liver but only under the hilsa oil diet did the eicosapentaenoic acid percentage increase markedly (0.8 +/- 0.06% to 5.5 +/- 0.06%) at the expense of arachidonic acid.(ABSTRACT TRUNCATED AT 250 WORDS)

Preparation ofcis,cis,cis-5,8,11-eicosatrienoic acid from arachidonic acid.

Arachidonic acid was reduced by hydrazine to yield isomeric eicosatrienoic acids with other products. Methylcis,cis,cis-5,8,11-eicosatrienoate was isolated from the products by silver ion chromatography and preparative gas liquid chromatography in 8% yield. The structure was confirmed by spectral studies and oxidative degradation.

Effects of bacteriophage M13 infection upon phospholipid and fatty acid compositions of Escherichia coli.

Escherichia coli K38 were grown and infected with wild type and amber mutants of bacteriophage M13 in the early log phase. Lipid compositions of the infected and healthy cultures, grown under identical conditions, were determined 2 hr after infection. From the results, it was observed that total lipid and total phospholipid content remained nearly constant, suggesting that the cell membrane which contained the maximum phospholipids was not damaged by the infection. Moreover, the percentage of diphosphatidylglycerol and lyso- compounds corresponding to phosphatidylethanolamine and phosphatidylglycerol increased, while phosphatidylethanolamine and phosphatidylglycerol decreased. The increase in lyso- compounds may be due to the relase of phospholipase A2 (a periplasmic enzyme) from the cell wall after damage by the infection. Bacteriophage M13 infection had no effect on the fatty acid compostion of the phospholipids.