Identification of an extracellular infection-induced glyceraldehyde-3-phosphate dehydrogenase of the phytopathogenic proteobacterium Pseudomonas syringae pv tomato DC3000

According to molecular biology, genomic and proteo- mic data, the phytopathogenic gamma-proteobacte- rium Pseudomonas syringae pv. tomato DC3000 pro-duces a number of proteins that may promote infec- tion and draw nutrients from plants. Remarkably, P. syringae DC3000 strain possesses three paralogous gap genes encoding glyceraldehyde-3-phosphate dehy- drogenase (GAPDH) enzymes with different predic- ted molecular sizes and metabolic functions. As GAPDH was shown to be a virulence factor in other microbial pathogens, in the current study, we analyzed the ex-pression levels of each paralogous gap gene by real- time PCR to understand the actual impact of their protein products on P. syringae virulence. We found that all of them were strongly induced during the in-fection process. Nevertheless, proteomic analysis of cul- ture supernatants revealed that only Class I GAPDH1 encoded by the gap1 gene was identified as an extra-cellular protein in infective cells. These results strongly suggest that this GAPDH should play a role in the infective process, including its well-know en-zymatic function in the glycolytic metabolic pathway.España AECID (MAEC) A1/043076/1

Identification of an extracellular infection-induced glyceraldehyde-3-phosphate dehydrogenase of the phytopathogenic proteobacterium Pseudomonas syringae pv tomato DC3000

According to molecular biology, genomic and proteo- mic data, the phytopathogenic gamma-proteobacte- rium Pseudomonas syringae pv. tomato DC3000 pro-duces a number of proteins that may promote infec- tion and draw nutrients from plants. Remarkably, P. syringae DC3000 strain possesses three paralogous gap genes encoding glyceraldehyde-3-phosphate dehy- drogenase (GAPDH) enzymes with different predic- ted molecular sizes and metabolic functions. As GAPDH was shown to be a virulence factor in other microbial pathogens, in the current study, we analyzed the ex-pression levels of each paralogous gap gene by real- time PCR to understand the actual impact of their protein products on P. syringae virulence. We found that all of them were strongly induced during the in-fection process. Nevertheless, proteomic analysis of cul- ture supernatants revealed that only Class I GAPDH1 encoded by the gap1 gene was identified as an extra-cellular protein in infective cells. These results strongly suggest that this GAPDH should play a role in the infective process, including its well-know en-zymatic function in the glycolytic metabolic pathway.Peer Reviewe

Purificación y caracterización de deshidrogenasa gliceraldehído-3- fosfato de Pseudomonas syringae pv. tomato DC3000

1 página.Pseudomonas syringae pv. tomato causa frecuentemente una enfermedad en el tomate llamada técnicamente mancha bacteriana. Pero su mecanismo de infección sigue siendo muy poco conocido.Peer reviewe

Solubilization of inorganic phosphate and production of organic acids by bacteria isolated from a Moroccan mineral phosphate deposit

Three efficient inorganic-phosphate solubilizing bacteria (PSB) were isolated from a phosphate rock deposit of a Moroccan mine. The phosphate solubilization index of these isolates, determined in National Botanical Research Institute's phosphate (NBRIP) medium supplemented with tribasic calcium phosphate, ranging from 2.8 to 4.4. The medium pH dropped from 7.0 to 3.5 units after growth under continuous agitation for seven days. PSB6, the most efficient PSB, closely related to Enterobacter hormaechei subsp. steigerwaltii strain NM23-1, permitted the recovery of the maximum soluble orthophosphate concentration in the medium (505 mg/L) after a growth period of 60 to 72 h. PSB4 and PSB5 strains were identified as Enterobacter sp. Strain TSSAS2-48 and Bacterium DR172. The capacity to solubilize inorganic phosphate by these PSB can be attributed to the secretion of organic acids, to determine their presence in the cultures supernatant, reverse-phase high performance liquid chromatography was performed. The presence of 9 identified and three unidentified organic acids was consequently demonstrated. Gluconic acid was strongly produced by all strains, extending to 55.4 mM by PSB6, 46.4 mM by PSB5, and 44.9 mM by PSB4. Besides succinic, acetic, glutamic, oxaloacetic, pyruvic, malic and fumaric acids, a newly detected and identified organic acid was the alpha-ketoglutaric acid. To the best of our knowledge this is the first report mentioning alpha-ketoglutaric acid production by PSB strain

Loop-Mediated isothermal amplification in human Cytomegalovirus diagnostic

The pathogenicity and the consequences of human cytomegalovirus (HCMV) infection in immunocompromised persons are reported in the literature and, HCM Viral DNA detection is the reliable indicator of infection especially to study its reactivation after organ transplantation in the recipient patients. Congenital infections in pregnant women cause opportunistic diseases of the central nervous system in new-born.  HCMV increases suffering and death in patients with chronic diseases like diabetes, tuberculosis, hepatitis C or patients with immunodeficient HIV/AIDS. Diagnostic methods are present in medical analysis laboratories either by immunofluorescence, Chemiluminescence, immunochromatography, western blot or by molecular biology techniques such as PCR are used to detect qualitatively and/or quantitatively IgG and IgM antibodies in the organism using serum or plasma as samples. The follow-up and treatment of patients are carried out in case the clinical data correlate with specific pathologies and symptoms, thus, the analysis of cytomegalovirus by PCR is requested to be sure of the cause of this pathology and to eliminate other doubts because this virus shares genetic and pathological similarity with Epstein-Barr virus (EBV), Varicella-Zoster virus (VZV) and Herpes Simplex Virus (HSV) as they are all of the same family of the Herpesviridae. The viral load quantified by PCR is a key element for monitoring and treatment. Molecular biology researchers have developed different PCR amplification techniques to answer the question of sensitivity, efficiency, and speed of this technique, and more recently in 2000, Notomi and the EIKEN Chemical Co. Ltd. developed a method of amplification under isothermal conditions named LAMP (Loop-mediated isothermal amplification) which combines speed and easy access for all laboratories that want to use only the less expensive equipment like those used with real-time PCR, later this technique was validated by the World Health Organization (WHO) and the organization recommended it to be used as an alternative in research and diagnostics. In this bibliographic study, we will exploit the contribution of the LAMP method in the diagnosis of human cytomegalovirus

Widespread occurrence of non-phosphorylating glyceraldehyde-3-phosphate dehydrogenase among gram-positive bacteria

The non-phosphorylating glyceraldehyde 3-phosphate dehydrogenase (GAPDHN, NADP+-specific, EC 1.2.1.9) is present in green eukaryotes and some Streptococcus strains. The present report describes the results of activity and immunoblot analyses, which were used to generate the first survey of bacterial GAPDHN distribution in a number of Bacillus, Streptococcus and Clostridium strains. Putative gapN genes were identified after PCR amplification of partial 700-bp sequences using degenerate primers constructed from highly conserved protein regions. Alignment of the amino acid sequences of these fragments with those of known sequences from other eukaryotic and prokaryotic GAPDHNs, demonstrated the presence of conserved residues involved in catalytic activity that are not conserved in aldehyde dehydrogenases, a protein family closely linked to GAPDHNs. The results confirm that the basic structural features of the members of the GAPDHN family have been conserved throughout evolution and that no identity exists with phosphorylating GAPDHs. Furthermore, phylogenetic trees generated from multiple sequence alignments suggested a close relationship between plant and bacterial GAPDHN families. [Int Microbiol 2005; 8(4):251-258

Marine biomolecules: a promising approach in therapy and biotechnology

The marine environment is characterized by a wide diversity of microorganisms among which marine bacteria. To insure their survival in hostile conditions where they face high competition with pathogenic microorganisms, they produce various kinds of bioactive molecules within biofilms with unique structural and functional features. As example: marine peptides which provide a broad spectrum of antimicrobial, antitumoral, antiviral and anti-inflammatory activities, in addition to marine exopolysaccharides showing antifouling and antifungal activities, immunomodulatory properties, emulsion stabilization capacity with other various potentials. Some biofilms have shown a beneficial role for aquaculture, among which enhancement of growth performance and improvement of water quality, while others are threatening not only aquaculture and maritime fields, but also medicine and food industry. Thus, marine bioactive compounds are promising preventing agents for the establishment and growth of fouling microorganisms, which may be useful in different fields in order to decrease economic losses and avoid foodborne illnesses. DOI: http://dx.doi.org/10.5281/zenodo.438415

The ciliate protist tetrahymena pyriformis as a cellular adhesion model for the pathogenic bacterium staphylococcus aureus

Staphylococcus aureus is one of the main pathogenic agents responsible for nosocomial and community-acquired bacterial infections. The pathogenicity of this Gram-positive bacterium is ensured by its different adhesion factors. Collagen and the extracellular glycoprotein adhesin are among the Staphylococcus most important virulence factors. It has been shown that most of the S. aureus strains carry the ica operon, responsible for biofilm production. However, the coexpression of the icaA and the icaD genes is necessary for complete biofilm synthesis. The aim of our study was to study a collection of 15 clinical strains of S. aureus from different sources for the presence of cna and icaD genes coding intercellular adhesion proteins. We also intended to estimate the strains¿ ability to form biofilms by the red Cong method and to test the adhesion ability of S. aureus to the ciliated protist Tetrahymena pyriformis, which we used as a novel cellular adhesion model. Finally, we checked the adhesion¿s inhibition capacity of some plants extracts. The molecular detection of adhesion genes revealed that 80% of strains are cna positive, and 73% are icaD positive. Qualitative biofilm production of S. aureus revealed that 66.6% of strains were slime producers. The adhesion test revealed that 20% of strains are strongly adhering to T. pyriformis and that the Clematis cirrhosa extract has an anti-adhering effect of S. aureus to the ciliate T. pyriformis

Assessment of the electrochemical behaviour of Nickel-Titanium-based orthodontic wires : effect of some natural corrosion inhibitors in comparison with fluoride

The aim of this study is to assess the corrosion resistance behaviour of Nickel-Titanium-based orthodontic wires (NiTi) in different concentrations of Sodium Fluoride (NaF) and the corrosion?s inhibitory effect of the extracts of some medicinal plants (essential oils, hydrosols and extract). In this study we used NiTi (3M) and CuNiTi (ORMCO, 35°C, California) orthodontic wires. The following electrolytes were prepared: Lactate Ringer solution with additions of 0.1%, 0.5% or 1% of Sodium Fluoride and the extracts of different plants: Artemisia, Syzygium aromaticum (Clove) and Celtis australis. Corrosion resistance was studied using anodic potentiodynamic polarisation and electrochemical impedance spectroscopy measurements. At the end of the experiment, microscopic images of wires were performed. ANOVA test with the comparison of Bonferroni and Tukey tests were performed to elucidate comparisons among all groups. The higher sodium fluoride concentration is related to negative corrosion potential for both NiTi and CuNiTi orthodontic wire. Hydrosols are associated to positive values of corrosion potential. CuNiTi has a lower corrosion resistance than NiTi. The prescription of toothpastes containing sodium fluoride should be reduced especially for patients wearing fixed orthodontic appliances. Eugenol may be considered as alternative of sodium fluoride for orthodontic patients for its anti-microbial and anti-corrosive effects

Investigation of antioxidant activity of some bis-benzimidazole in Tetrahymena thermophila stressed cells

In this paper, we present experimental findings on the protective effect of some bis-benzimidazole molecules against oxidative (H2O2) and nitrosative (SNP) stress using the protozoan T. thermophila as a cellular model. The results of this article show that the molecules 2,2’-Benzendiyl-1,4-Bis-(5-amino-1H-benzimidazole) and 2,2’-Octandiyl-1,8-Bis-(quinolin-8-ol-5-azo-1H-benzimidazole) have a protective effect against stress important than the molecule 2,2’-Benzendiyl-1,4-Bis-(1H-benzimidazole)