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Molecular Identification by 16S rDNA Sequence of a Novel Bacterium Capable of Degrading Trichloroethylene  [PDF]
Srijata Mitra,Pranab Roy
Journal of Biological Sciences , 2010,
Abstract: Trichloroethylene (TCE) is a widely used organic solvent and metal degreasing agent, one of the most frequently detected groundwater contaminants and a potential health hazard. A novel gram positive, rod shaped bacterial strain 2479 was isolated from soil near the oil depot site at Rajbandh, West Bengal (India) and its exact taxonomic position was investigated on the basis of 16S rRNA gene sequencing and Fatty acid methyl ester analysis (FAME). This novel strain was capable of degrading Trichloroethylene (TCE) efficiently. The major fatty acids detected in the strain 2479 were iso C15::0 (24.49%) and iso C16:0 (12.12%). The 16S rRNA gene of strain 2479 was amplified by using Bacillus specific primers and obtained 1465bp amplified product. Comparison of 16S rDNA region (1465bp) of the isolate 2479 by Ribosomal Database Project II – Sequence match showed greatest similarity with genus Bacillus sp. JDM-2-1(Accession No. EF584539). Phylogenetic analysis, involved the identification of homologous sequences, their multiple alignment, phylogenetic reconstruction and the graphical representation of the inferred tree was done in Phylogeny fr. package. Phylogenetic tree showed strain 2479 had 100% similarity with Bacillus cereus group. On the basis of phylogenetic data and Fatty Acid Methyl Ester Analysis, strain 2479 should be placed within the genus Bacillus and species cereus. This is the first instance, Bacillus cereus group being used in biodegradation of Trichloroethylene.
Identification and properties of proteases from an Acanthamoeba isolate capable of producing granulomatous encephalitis
James Sissons, Selwa Alsam, Graham Goldsworthy, Mary Lightfoot, Edward L Jarroll, Naveed Khan
BMC Microbiology , 2006, DOI: 10.1186/1471-2180-6-42
Abstract: Using an encephalitis isolate belonging to T1 genotype, we observed two major proteases with approximate molecular weights of 150 KD and 130 KD on SDS-PAGE gels using gelatin as substrate. The 130 KD protease was inhibited with phenylmethylsulfonyl fluoride (PMSF) suggesting that it is a serine protease, while the 150 KD protease was inhibited with 1, 10-phenanthroline suggesting that it is a metalloprotease. Both proteases exhibited maximal activity at neutral pH and over a range of temperatures, indicating their physiological relevance. These proteases degrade extracellular matrix (ECM), which provide structural and functional support to the brain tissue, as shown by the degradation of collagen I and III (major components of collagenous ECM), elastin (elastic fibrils of ECM), plasminogen (involved in proteolytic degradation of ECM), as well as casein and haemoglobin. The proteases were purified partially using ion-exchange chromatography and their effects were tested in an in vitro model of the blood-brain barrier using human brain microvascular endothelial cells (HBMEC). Neither the serine nor the metalloprotease exhibited HBMEC cytotoxicity. However, the serine protease exhibited HBMEC monolayer disruptions (trypsin-like) suggesting a role in blood-brain barrier perturbations.Overall, these data suggest that Acanthamoeba proteases digest ECM, which may play crucial role(s) in invasion of the brain tissue by amoebae.Acanthamoeba are opportunistic protozoans that are widely distributed in the environment. Given the opportunity and the host immune status, pathogenic Acanthamoeba can invade the human central nervous system (CNS) and produce fatal granulomatous encephalitis [1-4]. Acanthamoeba granulomatous encephalitis (AGE) is characterized by headache, fever, behavioural changes, hemiparesis, lethargy, stiff neck, aphasia, ataxia, vomiting, nausea, cranial nerve palsies, increased intracranial pressure, seizures and ultimately death. Death is due to haemorrhaging
A Genetic and Pathologic Study of a DENV2 Clinical Isolate Capable of Inducing Encephalitis and Hematological Disturbances in Immunocompetent Mice  [PDF]
Jaime Henrique Amorim, Raíza Sales Pereira Bizerra, Rúbens Prince dos Santos Alves, Maria Elisabete Sbrogio-Almeida, José Eduardo Levi, Margareth Lara Capurro, Luís Carlos de Souza Ferreira
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0044984
Abstract: Dengue virus (DENV) is the causative agent of dengue fever (DF), a mosquito-borne illness endemic to tropical and subtropical regions. There is currently no effective drug or vaccine formulation for the prevention of DF and its more severe forms, i.e., dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). There are two generally available experimental models for the study of DENV pathogenicity as well as the evaluation of potential vaccine candidates. The first model consists of non-human primates, which do not develop symptoms but rather a transient viremia. Second, mouse-adapted virus strains or immunocompromised mouse lineages are utilized, which display some of the pathological features of the infection observed in humans but may not be relevant to the results with regard to the wild-type original virus strains or mouse lineages. In this study, we describe a genetic and pathological study of a DENV2 clinical isolate, named JHA1, which is naturally capable of infecting and killing Balb/c mice and reproduces some of the symptoms observed in DENV-infected subjects. Sequence analyses demonstrated that the JHA1 isolate belongs to the American genotype group and carries genetic markers previously associated with neurovirulence in mouse-adapted virus strains. The JHA1 strain was lethal to immunocompetent mice following intracranial (i.c.) inoculation with a LD50 of approximately 50 PFU. Mice infected with the JHA1 strain lost weight and exhibited general tissue damage and hematological disturbances, with similarity to those symptoms observed in infected humans. In addition, it was demonstrated that the JHA1 strain shares immunological determinants with the DENV2 NGC reference strain, as evaluated by cross-reactivity of anti-envelope glycoprotein (domain III) antibodies. The present results indicate that the JHA1 isolate may be a useful tool in the study of DENV pathogenicity and will help in the evaluation of anti-DENV vaccine formulations as well as potential therapeutic approaches.
Detection of Haemophilus parasuis isolates from South China by loop-mediated isothermal amplification and isolate characterisation  [cached]
Jian-min Zhang,Hai-yan Shen,Ming Liao,Tao Ren
Onderstepoort Journal of Veterinary Research , 2012, DOI: 10.4102/ojvr.v79i1.383
Abstract: Haemophilus parasuis is the etiological agent of Gl sser’s disease, which is characterised by brinous polyserositis, meningitis and polyarthritis, causing severe economic losses to the swine industry. In this study, a loop-mediated isothermal ampli cation (LAMP) test was developed to improve the speci city, facility and speed of diagnosis of H. parasuis isolates. The LAMP assay rapidly ampli ed the target gene within 50 min incubation at 63 °C in a laboratory water bath. The LAMP amplicon could be visualised directly in the reaction tubes following the addition of SYBR Green I dye. The detection limit of this LAMP method was 10 CFU/mL, which was 10 times more sensitive than the earlier 16S rRNA polymerase chain reaction (PCR) test conducted by Oliveira, Galina and Pijoan (2001), and no cross-reactivity was observed from other non-H. parasuis strains. This LAMP test was evaluated further on 187 clinical specimens from pigs suspected of being infected with H. parasuis. Forty-three were found positive by bacterial isolation of H. parasuis, as well as by the 16S rRNA PCR and LAMP tests. The 43 H. parasuis isolates were classi ed into 9 serovars and had 37 genetic patterns when analysed by pulsed- eld gel electrophoresis (PFGE). This displayed that various H. parasuis serovars and genotypes were widely distributed in South China. Therefore, the speed, speci city and sensitivity of the LAMP test, the lack of a need for expensive equipment, and the visual readout showed great potential for a correct clinical diagnosis of H. parasuis in favour of controlling Gl sser’s disease. How to cite this article: Zhang, J., Shen, H., Liao, M., Ren, T., Guo, L., Xu, C. et al., ‘Detection of Haemophilus parasuis isolates from South China by loop-mediated isothermal amplification and isolate characterisation’, Onderstepoort Journal of Veterinary Research 79(1), Art. #383, 6 pages. http://dx.doi.org/10.4102/ojvr.v79i1.383
Isolation, Identification and Characteristics of a Trichloroethylene Degrading Bacterium FT17
三氯乙烯降解菌FT17的分离、鉴定及其降解特性研究

WANG Xin-Xin,ZHANG Ying,LI Hui,WANG Yuan-Fen,
王新新
,张 颖,李 慧,王元芬

微生物学通报 , 2009,
Abstract: The bacterium FT17, capable of degrading trichloroethylene, was isolated from trichloroethylene contaminated sediments from the Liaohe River using the water-silicon oil biphasic system. Biochemical, physiological characteristics and phylogenetic study based on the 16S rRNA gene sequences all indicated that strain FT17 should be placed in the Sporosarcina ginsengisoli. The experiment of single factor optimization about the growth of strain FT17 was carried out, and the results showed that the optimum temperature was 34.0°C and the optimum pH value was 7.8. The degradation ratio of trichloroethylene could be enhanced at the present of 100 mg/L phenol. Intracellular and extracellular degrading enzymes were both important to the degradation of trichloroethylene. Two methods were applied to extract plasmids from strain FT17, yet none of plasmids were detected. So it was presumed that the degrading gene may locate on the chromosomes instead of on the plasmids.
Biodegradation of 2 - methoxyethanol by a new bacterium isolate Pseudomonas sp. Strain VB under aerobic conditions
FO Ekhaise, O Meyer
Journal of Applied Sciences and Environmental Management , 2010,
Abstract: Microbial biodegradation of 2-methoxyethanol also known as Methyl glycol (MG) under anaerobic conditions has received much attention during the past decade. However, not much is known about the aerobic degradation of 2-methoxyethanol. Samples from various environmental niches were enriched to isolate and determine bacterial isolates capable of utilizing 2-methoxyethanol as a sole source of carbon and energy under aerobic conditions. A 2-methoxyethanol degrading bacterium was isolated from anaerobic sludge of a municipal sewage from a treatment plant in Bayreuth, Germany, by selective enrichment techniques. The isolate was designated strain VB after it was shown by the 16S rRNA phylogenetic sequence analysis as belonging to the genus Pseudomonas. Under aerobic conditions Pseudomonas sp. strain VB was capable of mineralizing 2-methoxyethanol and its intermediary metabolites. Stoichiometrically, the strain utilized one mole of oxygen per one mole of 2-methoxyethanol instead of four mole oxygen per one mole of 2-methoxythanol for the total oxidative metabolism
Biodegradation of Trichloroethylene (TCE) in the Presence of Phenolic Compound  [PDF]
Muhammad Ferhan
Journal of Biological Sciences , 2003,
Abstract: Experimental bioreactors operated as closed recirculation systems were inoculated with aerobic bacterial cultures that utilized tryptone–yeast extract as carbon and energy sources. These were inoculated with the bacterial culture, which degraded trichloroethylene (TCE) and was observed after 5 days of incubation. Each bioreactor consisted of an expanded bed column through which the liquid phase was recirculated. TCE degradation was also observed with the metabolism of aromatic hydrocarbons established for indigenous microbial population in soil and ground water, in which TCE removal has been shown to be stimulated by the addition of phenol. So co-metabolism occurred when a non-specific enzyme or co-factor was used to transform the growth supporting carbon source, also capable of degrading non-growth supporting compounds. Gas chromatography was use to monitor TCE and their metabolites which compare to run their standards and to check their retention time (tr) values. The retention time (tr) values of phenol, catechol, TCA, TCE were 7.22, 8.82, 8.55 and 2.25.
Optimization of Cultural Conditions for Production of Chitinase by a Soil Isolate of Massilia timonae  [PDF]
M.A. Faramarzi,M. Fazeli,M. Tabatabaei Yazdi,S. Adrangi
Biotechnology , 2009,
Abstract: The aim of this study was to characterize chitinase-producing bacteria isolated from environmental samples and to investigate conditions affecting chitinase production by these bacteria. Ninety-eight isolates recovered from 20 soil samples were screened for chitinase production. Eighteen isolates showed chitinolytic activity, among which isolate U2 was selected for further study based on dinitrosalisylic acid assay results. The isolate U2 was identified as Massilia timonae through phenotypic characterization and 16S rDNA sequencing and the optimal conditions for chitinase production were determined to be 25-30°C, initial pH 6.0-6.5 and chitin concentration of 1% (w/v). The maximum chitinolytic activity was achieved after 36 h of incubation. The addition of different nitrogen sources to the production medium had no significant effect on chitinase production. Among various carbon sources tested, N-acetylglucosamine (GlcNAc), fructose, lactose, maltose and glucose showed modest inhibitory effect while arabinose did not affect enzyme production by M. timonae isolate U2. The addition of Triton X100 increased chitinase production by 12.4%. The enzyme was reasonably stable in the pH range 5-7 and at temperatures up to 50°C. These results indicate that M. timonae is capable of producing chitinase in relatively simple media containing colloidal chitin as the sole carbon and nitrogen source.
Identification and Characterisation of a Hyper-Variable Apoplastic Effector Gene Family of the Potato Cyst Nematodes  [PDF]
Sebastian Eves-van den Akker,Catherine J. Lilley,John T. Jones,Peter E. Urwin
PLOS Pathogens , 2014, DOI: doi/10.1371/journal.ppat.1004391
Abstract: Sedentary endoparasitic nematodes are obligate biotrophs that modify host root tissues, using a suite of effector proteins to create and maintain a feeding site that is their sole source of nutrition. Using assumptions about the characteristics of genes involved in plant-nematode biotrophic interactions to inform the identification strategy, we provide a description and characterisation of a novel group of hyper-variable extracellular effectors termed HYP, from the potato cyst nematode Globodera pallida. HYP effectors comprise a large gene family, with a modular structure, and have unparalleled diversity between individuals of the same population: no two nematodes tested had the same genetic complement of HYP effectors. Individuals vary in the number, size, and type of effector subfamilies. HYP effectors are expressed throughout the biotrophic stages in large secretory cells associated with the amphids of parasitic stage nematodes as confirmed by in situ hybridisation. The encoded proteins are secreted into the host roots where they are detectable by immunochemistry in the apoplasm, between the anterior end of the nematode and the feeding site. We have identified HYP effectors in three genera of plant parasitic nematodes capable of infecting a broad range of mono- and dicotyledon crop species. In planta RNAi targeted to all members of the effector family causes a reduction in successful parasitism.
Painful Glomangioma On Sole  [cached]
Chakravarty K,Chanda M,Pal D
Indian Journal of Dermatology , 1996,
Abstract: A child of 8 years developed multiple painful conglomerated mass on sole. Excision was done and there was no recurrence after 6 months of excision. Diagnosis was made on histopathological examination. Multiple glomus tumour is a rare condition and is therefore reported.
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