Search

Burkholderia territorii, a Gram-negative bacterium, encodes for the ι-class carbonic anhydrase (CA, EC 4.2.1.1) BteCAι, which was recently characterised. It acts as a good catalyst for the hydration of CO2 to bicarbonate and protons, with a kcat value of 3.0 × 105 s−1 and kcat/KM value of 3.9 × 107 M−1 s−1. No inhibition data on this new class of enzymes are available to date. We report here an anion and small molecules inhibition study of BteCAι, which we prove to be a zinc(II)- and not manganese(II)-containing enzyme, as reported for diatom ι-CAs. The best inhibitors were sulphamic acid, stannate, phenylarsonic acid, phenylboronic acid and sulfamide (KI values of 6.2–94 µM), whereas diethyldithiocarbamate, tellurate, selenate, bicarbonate and cyanate were submillimolar inhibitors (KI values of 0.71–0.94 mM). The halides (except iodide), thiocyanate, nitrite, nitrate, carbonate, bisulphite, sulphate, hydrogensulfide, peroxydisulfate, selenocyanate, fluorosulfonate and trithiocarbonate showed KI values in the range of 3.1–9.3 mM.

Introduction: Helicobacter pylori (H. pylori) is a Gram negative bacterium considered to be the etiologic agent of various gastric diseases. The prevalence of bacterial infection varies according to age, geographic location, ethnicity and socioeconomic status. The chronic infection caused by microorganism can favor the development of severe pathologies such as gastric adenocarcinoma. In this sense, early diagnosis is essential for a better prognosis and therapeutic success. Several diagnostic methods performed using invasive and non-invasive techniques, with different sensitivity and specificity, have been used in the detection of H. pylori. Objective: To compare the performance of the molecular and histopathological technique used in the diagnosis of H. pylori infection. Methods: 76 gastric tissue samples were collected from dyspeptic patients who underwent molecular and histopathological diagnosis. Molecular detection was performed using the ribosomal gene (16S rRNA) using the polymerase chain reaction (PCR) technique. Results: The PCR-based molecular diagnostic method detected the bacterium in 63.1% of the samples, while the histopathological test identified the microorganism in only 38.1% of gastric biopsies. The data demonstrated that the PCR technique was about 1.6 times more sensitive than the histopathological technique. Conclusion: The PCR technique was the most efficient diagnostic method for detecting H. pylori and can be implemented in the laboratory routine as a complementary test for the early detection of H. pylori. RESUMEN Introducción: Helicobacter pylori (H. pylori) es una bacteria Gram negativa considerada agente etiológico de diversas enfermedades gástricas. La prevalencia de la infección bacteriana varía según la edad, la ubicación geográfica, la etnia y el nivel socioeconómico. La infección crónica provocada por esos microorganismos puede favorecer el desarrollo de patologías graves como el adenocarcinoma gástrico. Por esa razón, el diagnóstico precoz es fundamental para un mejor pronóstico y éxito terapéutico. En la detección de H. pylori se han utilizado varios métodos de diagnóstico realizados mediante técnicas invasivas y no invasivas, con diferentes sensibilidad y especificidad. Objetivo: Comparar el desempeño de las técnicas moleculares e histopatológicas utilizadas en el diagnóstico de la infección por H. pylori. Métodos: Se recolectaron 76 muestras de tejido gástrico de pacientes dispépticos y se las sometieron a diagnóstico molecular e histopatológico. La detección molecular se realizó mediante el gen ribosómico (ARNr 16S) mediante la técnica de reacción en cadena de la polimerasa (PCR). Resultados: El método molecular de diagnóstico basado en PCR detectó la bacteria en el 63,1% de las muestras, mientras que la prueba histopatológica identificó el microorganismo en solo el 38,1% de las biopsias gástricas. Los datos demostraron que la técnica de PCR era aproximadamente 1,6 veces más sensible que la técnica histopatológica. Conclusión: La técnica de PCR fue el método diagnóstico más eficaz para la detección de H. pylori y puede implementarse en la rutina del laboratorio como prueba complementaria para la detección precoz de H. pylori. RESUMO Introdução: Helicobacter pylori (H. pylori) é uma bactéria Gram negativa considerada o agente etiológico de várias doenças gástricas. A prevalência da infecção bacteriana varia de acordo com idade, localização geográfica, etnia e status socioeconômico. A infecção crônica ocasionada por esse microrganismo pode favorecer o desenvolvimento de patologias severas, como o adenocarcinoma gástrico. Nesse sentido, o diagnóstico precoce é essencial para um melhor prognóstico e o sucesso terapêutico. Vários métodos de diagnóstico realizados com técnicas invasivas e não invasivas, com diferentes sensibilidade e especificidade, têm sido utilizados na detecção de H. pylori. Objetivo: Comparar o desempenho das técnicas molecular e histopatológica utilizadas no diagnóstico da infecção por H. pylori. Métodos: Setenta e seis amostras de tecido gástrico foram coletadas de pacientes dispépticos e submetidas ao diagnóstico molecular e histopatológico. A detecção molecular foi realizada utilizando o gene ribossomal (rRNA 16S) por meio da técnica de reação em cadeia da polimerase (PCR). Resultados: O método molecular de diagnóstico com base na PCR detectou a bactéria em 63,1% das amostras, enquanto o teste histopatológico identificou o microrganismo em apenas 38,1% das biópsias gástricas. Os dados demonstram que a técnica de PCR apresentou cerca de 1,6 vezes mais sensibilidade que a técnica histopatológica. Conclusão: A técnica de PCR foi o método de diagnóstico mais eficiente para detecção de H. pylori e pode ser implementada na rotina laboratorial como teste complementar para detecção precoce de H. pylori.

New silver(I) 5,5-diethylbarbiturate (barb) complexes with a series of bis(diphenylphosphino)alkanes such as 1,1-bis(diphenylphosphino)methane (dppm), 1,2-bis(diphenylphosphino)ethane (dppe), 1,3-bis-(diphenylphosphino)propane (dppp) and 1,4-bis(diphenylphosphino)butane (dppb) were synthesized and characterized. [Ag-2(barb)(2)(mu-dppm)(2) (1), [Ag-2(barb)(2)(mu-dppe)(DMSO)(2)] (2) and [Ag-2(barb)(2)( dppp)2](3) were binuclear, while [Ag(barb)(mu-dppb)] (4) was a coordination polymer. 1-4 effectively bind to the G/C rich region of the major groove of DNA and interact with BSA via hydrophobic interactions in accordance with molecular docking studies. All complexes displayed significant DNA cleavage in the presence of H2O2. 1-4 exhibited more specificity against Gram-positive bacteria than Gram-negative bacteria, but 2 targets both bacterial strains, being comparable to AgNO3 and silver sulfadiazine. Complex 1 has a strong growth inhibitory effect on A549 cells, while 2 and 3 exhibit considerable cytotoxicity against MCF-7 cells. The complexes showed high accumulation in the cytosol fraction of the cells. Mechanistic studies showed that 1 and 2 display effective cell growth inhibition by triggering S and G2/M phase arrest, induce apoptosis via mitochondrial pathways and also damage to DNA due to the overproduction of ROS. (C) 2017 Elsevier Masson SAS. All rights reserved.

Bu çalışma, 22-24 Kasım 2012 tarihleri arasında İstanbul[Türkiye]’da düzenlenen 16. Annual Meeting of the European-Society-of-Surgery (ESS)’da bildiri olarak sunulmuştur. Background: Laparoscopic cholecystectomy (LC) is the gold standard for the treatment of symptomatic gallbladder stones. As infections are rare in uncomplicated LC, it is widely accepted that prophylactic antibiotics need not be administered, and guidelines do not support routine antibiotic prophylaxis during elective LC. However, routine antibiotic prophylaxis for elective LC is still popular in many clinical settings. We investigated this situation in our department. Method: This randomized double-blind controlled study included 570 patients who underwent LC between March 2007 and February 2010. The exclusion criteria were antibiotic intake before surgery, steroid treatment, and the presence of pancreatitis, cholangitis, obstructive jaundice, cephalosporin allergy, or pregnancy. The patients were randomized into three groups. Group 1 (n = 193) received physiologic saline as placebo, Group 2 (n = 191) received a first-generation cephalosporin (cefazolin; 1 g), and Group 3 (n = 186) received a second-generation cephalosporin (cefuroksim aksetil; 750mg). Bile and epigastric and umbilical port tissue samples were harvested for culture. All patients were observed until the end of the fourth week after surgery. Patient age, sex, weight, American Society of Anesthesiologists (ASA) score, diabetes mellitus, smoking history, history of biliary colic in the past month, length of the hospital stay before the operation, operational findings (acute or chronic cholecystitis), operation duration, use of drainage, type of prophylaxis administered if any, culture results, surgical site infection (SSI) development, and time to SSI development along with associated treatments were evaluated. Results: There was no statistically significant difference between the groups with respect to any of the demographic and clinical features analyzed in this study. The SSI rate was 1.2% in total, and in Groups 1, 2, and 3, it was 1.5%, 1.04%, and 1.07%, respectively. There was no statistical difference regarding SSI among the groups (p = 1.00). Superficial SSI was observed in all groups, and in all patients, the site of infection was the entrance to the epigastric port through which the gallbladder had been removed. Conclusions: Surgical site infection is rare after LC, and antibiotic prophylaxis does not appear to affect the outcome significantly. Moreover, factors such as positive bile cultures, history of biliary attack, ASA score, diabetes, obesity, and smoking do not have any effect on SSI development. Thus, we conclude that antibiotic prophylaxis is not needed for elective LC. European Soc Surgery

The number of new antibiotics being developed has plateaued, particularly compared to the sharp increase in antibiotic-resistant bacteria plaguing humanity. Many current antibiotics target the bact...

Bacteria have evolved numerous pathways to sense and respond to changing environmental conditions, including, within Gram-positive bacteria, the stressosome complex that regulates transcription of general stress response genes. However, the signalling molecules recognized by Gram-positive stressosomes have yet to be identified, hindering our understanding of the signal transduction mechanism within the complex. Furthermore, an analogous pathway has yet to be described in Gram-negative bacteria. Here we characterize a putative stressosome from the Gram-negative bacterium Vibrio brasiliensis. The sensor protein RsbR binds haem and exhibits ligand-dependent control of the stressosome complex activity. Oxygen binding to the haem decreases activity, while ferrous RsbR results in increased activity, suggesting that the V. brasiliensis stressosome may be activated when the bacterium enters anaerobic growth conditions. The findings provide a model system for investigating ligand-dependent signalling within stressosome complexes, as well as insights into potential pathways controlled by oxygen-dependent signalling within Vibrio species., The stressosome is a multiprotein complex that regulates the expression of stress response genes in Gram-positive bacteria. Here the authors characterize a stressosome from a Gram-negative bacterium, showing that one of the protein components senses oxygen through a bound haem.

Due to economic, environmental and geopolitical issues, the development of permanent magnets with a composition free of rare earth elements and with acceptable magnetic properties has been considered a priority by the international community, being MnAl based alloys amongst the most promising candidates. The aim of this work was to evaluate the toxicity of powders of two forms of newly developed MnAl(C) permanent magnets through exposure experiments applying three model organisms, using as a benchmark powders of a commercial rare-earth-containing magnet (Nd2Fe14B). For this purpose, the direct exposure to the different particles suspensions as well as to magnets leachates was evaluated. Both viability and oxidative stress assays were applied in an adenocarcinomic human alveolar basal epithelial cell line (A549) and in the yeast Saccharomyces cerevisiae, together with the bioluminescent inhibition assay in the Gram negative bacterium Vibrio fischeri. The obtained results indicate that MnAl(C) permanent magnets, in general terms, presented similar toxicity than the Nd magnet for the selected biological models under the studied conditions. Overall, the presented data provide, for the first time, an in vitro toxicity analysis of MnAl based magnets., European Union’s Horizon 2020 NOVAMAG project (NMBP 23-2015, grant agreement N 686056) and from the Junta de Castilla y Leon and the European Social Fund-Youth European Initiative grant UBU-15-A.

Two dimensional materials beyond graphene such as MoS2 and WS2 are novel and interesting class of materials whose unique physico-chemical properties can be exploited in applications ranging from leading edge nanoelectronics to the frontiers between biomedicine and biotechnology. To unravel the potential of TMD crystals in biomedicine, control over their production through green and scalable routes in biocompatible solvents is critically important. Furthermore, considering multiple applications of eco-friendly 2D dispersions and their potential impact onto live matter, their toxicity and antimicrobial activity still remain an open issue. Herein, we focus on the current demands of 2D TMDs and produce high-quality, few-layered and defect-free MoS2 nanosheets, exfoliated and dispersed in pure water, stabilized up to three weeks. Hence, we studied the impact of this material on human cells by investigating its interactions with three cell lines: two tumoral, MCF7 (breast cancer) and U937 (leukemia), and one normal, HaCaT (epithelium). We observed novel and intriguing results, exhibiting evident cytotoxic effect induced in the tumor cell lines, absent in the normal cells in the tested conditions. The antibacterial action of MoS2 nanosheets is then investigated against a very dangerous gram negative bacterium, such as two types of Salmonellas: ATCC 14028 and wild-type Salmonella typhimurium. Additionally, concentration and layer-dependent modulation of cytotoxic effect is found both on human cells and Salmonellas.

Clostridial neurotoxins, including botulinum and tetanus neurotoxins, are among the deadliest known bacterial toxins. Until recently, the horizontal mobility of this toxin gene family appeared to be limited to the genus Clostridium . We report here the closed genome sequence of Chryseobacterium piperi , a Gram-negative bacterium containing coding sequences with homology to clostridial neurotoxin family proteins.

O-Antigen polysaccharides constitute the outer protective layer of most Gram-negative bacteria, important for the bacterium's survival and adaption within its host. Although important for many functions, the three-dimensional structure of the dense polysaccharide coat remains to be elucidated. In this study, we present a systematic numerical investigation of O-antigen polysaccharide chains of Shigella flexneri serotype Y composed of one up to four tetrasaccharide repeat units. To bridge the gap between atomistic and coarse-grained levels of description, we employ a genuine multiscale modeling approach. It reveals that even for a few repeat units polymer-like flexibility emerges, which is furthermore complemented by extreme, hairpin-like conformations. These can facilitate the formation of metastable compact states, but this conclusion depends sensitively on the force field used to model the carbohydrates. Thus, our computational analysis represents an essential prerequisite for developing reliable coarse- grained models that may help visualizing changes in O-antigen coat morphology upon variations in chain length distribution or chemical composition of the polysaccharide characterizing a certain serotype.

Chryseobacterium meningosepticum, a gram negative bacterium predominantly found in soil and water is a nosocomial pathogen which is responsible for causing opportunistic infection and meningitis in children in hospital has become area of concern. We have described a case report of 64 year patient with Cholangitis who acquired the bacterium nosocomially.

Catheter-associated bloodstream infections (CABSIs) are common complications encountered with cancer treatment. The aims of this study were to analyze the factors associated with recurrent infection and catheter removal in pediatric hematology-oncology patients. All cases of CABSIs in patients attending the Department of Pediatric Hematology-Oncology between January 2008 and December 2010 were reviewed. A total of 44 episodes of CABSIs, including multiple episodes involving the same catheter, were identified in 31 children with cancer. The overall CABSIs rate was 7.4 infections per 1000 central venous catheter (CVC) days. The most frequent organism isolated was coagulase-negative Staphylococcus (CONS). The CVC was removed in nine (20.4%) episodes. We found that hypotension, persistent bacteremia, Candida infection, exit-side infection, neutropenia, and prolonged duration of neutropenia were the factors for catheter removal. There were 23 (52.2%) episodes of recurrence or reinfection. Mortality rate was found to be 9.6% in children with CABSIs. In this study, we found that CABSIs rate was 7.4 infections per 1000 catheter-days. CABSIs rates in our hematology-oncology patients are comparable to prior reports. Because CONS is the most common isolated microorganism in CABSIs, vancomycin can be considered part of the initial empirical regimen.

Two new pentaketides, including a new benzofuran-1-one derivative (1) and a new isochromen-1-one (5), and seven new benzoic acid derivatives, including two new benzopyran derivatives (2a, b), a new benzoxepine derivative (3), two new chromen-4-one derivatives (4b, 7) and two new benzofuran derivatives (6a, b), were isolated, together with the previously reported 2,3-dihydro-6-hydroxy-2,2-dimethyl-4H-1-benzopyran-4-one (4a), from the culture of the marine sponge-associated fungus Neosartorya quadricincta KUFA 0081. The structures of the new compounds were established based on 1D and 2D NMR spectral analysis, and in the case of compounds 1, 2a, 4b, 5, 6a and 7, the absolute configurations of their stereogenic carbons were determined by an X-ray crystallographic analysis. None of the isolated compounds were active in the tests for antibacterial activity against Gram-positive and Gram-negative bacteria, as well as multidrug-resistant isolates from the environment (MIC > 256 μg/mL), antifungal activity against yeast (Candida albicans ATTC 10231), filamentous fungus (Aspergillus fumigatus ATTC 46645) and dermatophyte (Trichophyton rubrum FF5) (MIC > 512 μg/mL) and in vitro growth inhibitory activity against the MCF-7 (breast adenocarcinoma), NCI-H460 (non-small cell lung cancer) and A375-C5 (melanoma) cell lines (GI50 > 150 μM) by the protein binding dye SRB method. © 2016 by the authors; licensee MDPI. This work was developed in the Natural Products Research Laboratory of the Department of Chemistry, Instituto de Ciências Biomédicas Abel Salazar (ICBAS), of the University of Porto and partially supported through national funds provided by FCT-Foundation for Science and Technology and European Regional Development Fund (ERDF) and COMPETE, under the projects PEst-C/MAR/LA0015/2013, PTDC/MAR-BIO/4694/2014, as well as by the project INNOVMAR (Innovation and Sustainability in the Management and Exploitation of Marine Resources) (Reference NORTE-01-0145-FEDER-000035, within Research Line NOVELMAR/INSEAFOOD/ECOSERVICES), supported by the North Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). We thank Mrs. Júlia Bessa and Sara Cravo for technical support.

The gram negative bacterium Stenotrophomonas is rapidly evolving as a nosocomial pathogen in immuno-compromised patients. Treatment of Stenotrophomonas maltophilia infections is problematic because of their increasing resistance to multiple antibiotics. This article aims to review the multi-disciplinary role of Stenotrophomonas in our environment with special focus on their metabolic and genetic potential in relation to bioremediation and phytoremediation. Current and emerging treatments and diagnosis for patients infected with S. maltophilia are discussed besides their capability of production of novel bioactive compounds. The plant growth promoting characteristics of this bacterium has been considered with special reference to secondary metabolite production. Nano-particle synthesis by Stenotrophomonas has also been reviewed in addition to their applications as effective biocontrol agents in plant and animal pathogenesis.

In this study, Gram negative bacterium,Sphingomonas paucimobilis, was used to test its ability to decolourise two triphenylmethane dyes: malachite green (MG) and crystal violet (CV) in mineral salts medium (MSM). Decolourisation was examined with dye concentrations (2.5, 5, 15, 25, 30 and 50 mg/l), glucose (0, 1.4, 2.8, 4.2, 5.6 and 7 mM) and yeast extract concentrations (0, 0.05, 0.10, 0.15% w/v). Our results showed thatSphingomonas paucimobilis used at 1 OD (λ 600 nm), equivalent to 14×107 CFU/ml cell concentration, remove MG and CV colour with 35 and 55%, respectively, for 2.5 mg/l dye concentration in MSM. The best removal efficiencies for decolourisation were 93.43% for MG and 71.29% for CV at 50 mg/l dye concentration, obtained with 7 mM of glucose used as source of carbon. Whereas the optimum concentration of yeast extract which allowed high value on decolourisation was determined at 0.1% for MG and 0.05% for CV. We obtained the high percentage of decolourisation which reaches 100% within 10 h. Moreover, at the same conditions the source of nitrogen yeast extract enhanced more rapidly the decolourisation of dyes colour removal by a new natural isolatesSphingomonas paucimobilis which was significantly affected by adding nutrient sources.

Agaricus bisporus mushrooms are commercially produced on a microbe rich compost. Here, fungal and bacterial biomass was quantified in compost with and without colonization by A. bisporus. Chitin content, indicative of total fungal biomass, increased during a 26-day period from 576 to 779 nmol N-acetylglucosamine g−1 compost in the absence of A. bisporus (negative control). A similar increase was found in the presence of this mushroom forming fungus. The fungal phospholipid-derived fatty acid (PLFA) marker C18:2ω6, indicative of the living fraction of the fungal biomass, decreased from 575 to 280 nmol g−1 compost in the negative control. In contrast, it increased to 1200 nmol g−1 compost in the presence of A. bisporus. Laccase activity was absent throughout culturing in the negative control, while it correlated with the fungal PLFA marker in the presence of A. bisporus. PLFA was also used to quantify living bacterial biomass. In the negative control, the bacterial markers remained constant at 3000–3200 nmol PLFA g−1 compost. In contrast, they decreased to 850 nmol g−1 compost during vegetative growth of A. bisporus, implying that bacterial biomass decreased from 17.7 to 4.7 mg g−1 compost. The relative amount of the Gram positive associated PLFA markers a15:0 and a17:0 and the Gram negative PLFA associated markers cy17:0 and cy19:0 increased and decreased, respectively, suggesting that Gram negative bacteria are more suppressed by A. bisporus. Together, these data indicate that fungal biomass can make up 6.8% of the compost after A. bisporus colonization, 57% of which being dead. Moreover, results show that A. bisporus impacts biomass and composition of bacteria in compost. Electronic supplementary material The online version of this article (doi:10.1186/s13568-016-0304-y) contains supplementary material, which is available to authorized users.

A glycosyldiacylglycerol was isolated from the marine bacterium Deleya marina (ATCC 25374). The structure was determined, mainly by spectral data, to be 1, 2-diacyl-3-O-[alpha-2-amino-2-deoxy-glucopyranose-(1--4)-O-alpha-idu ronopyranuronic acid]-glycerol. This is, to our knowledge, the first isolation of diglycosyldiacylglycerol containing both iduronopyranuronic acid and 2-amino-2-deoxy-glucopyranose from Gram-negative bacteria.

4-Imino-3,4-dihydro-2H-pyrimido[2,1-b][1,3] benzothiazole-2-one (3) was synthesized by the reaction of 2-aminobenzothiazole with ethyl cyanoacetate in solvent free conditions at 150°C. A series of pyrimido benzothiazole-based azo dyes 4( a-m) were obtained by the coupling of carbocyclic amine-based diazonium chloride with compound (3). The synthesized dyes were purified and characterized by elemental analysis, FT-IR, 1 H NMR, and high-resolution mass spectral data. The solvatochromic behaviors of dyes in various solvents were examined. All the azo dyes exhibited pronounced in vitro antibacterial activities against Gram-positive and Gram-negative bacteria, as well as fungi. The results revealed that most of the compounds exhibited good levels of antibacterial activity. Compounds 4d and 4h showed excellent levels of antimicrobial activity with MIC values of 8.25 µg/mL. © Springer Science+Business Media 2014.

Drosophila has been the invertebrate model organism of choice for the study of innate immune responses during the past few decades. Many Drosophila-microbe interaction studies have helped to define innate immunity pathways, and significant effort has been made lately to decipher mechanisms of microbial pathogenesis. Here we catalog 68 bacterial, fungal, and viral species studied in flies, 43 of which are relevant to human health. We discuss studies of human pathogens in flies revealing not only the elicitation and avoidance of immune response but also mechanisms of tolerance, host tissue homeostasis, regeneration, and predisposition to cancer. Prominent among those is the emerging pattern of intestinal regeneration as a defense response induced by pathogenic and innocuous bacteria. Immunopathology mechanisms and many microbial virulence factors have been elucidated, but their relevance to human health conventionally necessitates validation in mammalian models of infection. © 2014 Landes Bioscience. 5 253 269 Cited By :19

International audience; Sponges and bacteria have lived together in complex consortia for 700 million years. As filter feeders, sponges prey on bacteria. Nevertheless, some bacteria are associated with sponges in symbiotic relationships. To enable this association, sponges and bacteria are likely to have developed molecular communication systems. These may include molecules such as N-acyl-L-homoserine lactones, produced by Gram-negative bacteria also within sponges. In this study, we examined the role of N-3-oxododecanoyl-L-homoserine lactone (3-oxo-C12-HSL) on the expression of immune and apoptotic genes of the host sponge Suberites domuncula. This molecule seemed to inhibit the sponge innate immune system through a decrease of the expression of genes coding for proteins sensing the bacterial membrane: a Toll-Like Receptor and a Toll-like Receptor Associated Factor 6 and for an anti-bacterial perforin-like molecule. The expression of the pro-apoptotic caspase-like 3/7 gene decreased as well, whereas the level of mRNA of anti-apoptotic genes Bcl-2 Homolog Proteins did not change. Then, we demonstrated the differential expression of proteins in presence of this 3-oxo-C12-HSL using 3D sponge cell cultures. Proteins involved in the first steps of the endocytosis process were highlighted using the 2D electrophoresis protein separation and the MALDI-TOF/TOF protein characterization: α and β subunits of the lysosomal ATPase, a cognin, cofilins-related proteins and cytoskeleton proteins actin, α tubulin and α actinin. The genetic expression of some of these proteins was subsequently followed. We propose that the 3-oxo-C12-HSL may participate in the tolerance of the sponge apoptotic and immune systems towards the presence of bacteria. Besides, the sponge may sense the 3-oxo-C12-HSL as a molecular evidence of the bacterial presence and/or density in order to regulate the populations of symbiotic bacteria in the sponge. This study is the first report of a bacterial secreted molecule acting on sponge cells and regulating the symbiotic relationship.

Aeromonas hydrophila is a Gram-negative bacterium of considerable importance in both clinical, especially nosocomial infections, and zoonotic respects, both aquatic and terrestrial infections. In addition to the ability to thrive in a wide range of conditions, A. hydrophila is resistant to numerous antibiotics and antimicrobials. In conjunction with Kansas State University and the Kansas Water Office, water samples from various locations within Kansas were screened for organisms resistant to chlorhexidine. Chlorhexidine is the active agent in many surgical scrubs, prescription mouthwashes, and other bactericidal and bacteriostatic substances. Aeromonas hydrophila capable of growth in therapeutic levels of chlorhexidine was detected in one of the water samples. The isolate was determined not to be harboring a plasmid, lending to a course of inquiry founded on the premise that the source of chlorhexidine resistance resides within the chromosome. Investigation into efflux pumps (EP) is underway with select resistance-nodulation-cell division (RND) pumps, especially the AheABC EP, being exculpated of responsibility for chlorhexidine resistance following testing with a select EP inhibitor. Inquiry into the major facilitator superfamily (MFS) EPs is underway with specific examination of the EmrB/QacA EPs, as chlorhexidine resistance in Staphylococcus aureus carrying the QacA gene has been observed.

The aim of this study was to assess the interaction of a series of well characterised nano-objects with the Gram negative bacterium Salmonella typhimurium, and how such an interaction may relate to the potential mutagenicity of nano-objects. Transmission electron microscopy showed that nano-objects (Au-PMA-ATTO NPs, CeO₂ NPs, SWCNTs and MWCNTs), as well as CAFs entered S. typhimurium. Only DEPs did not penetrate/enter the bacteria, however, were the only particle stimulus to induce any significant mutagenicity through the Ames test. Comparison with a sophisticated 3D in vitro cell model showed CAFs, DEPs, SWCNTs and MWCNTs to cause a significant increase in mammalian cell proliferation, whilst both the Au-PMA-ATTO NPs and CeO₂ NPs had not significant adverse effects. In conclusion, these results indicate that various of different nano-objects are able to penetrate the double-lipid bilayer of Gram negative bacteria, although the Ames test may not be a good indicator for nano-object mutagenicity.

The microbiology of the spacecraft assembly process is of paramount importance to planetary exploration, as the biological contamination that can result from remote-enabled spacecraft carries the potential to impact both life-detection experiments and extraterrestrial evolution. Accordingly, insights into the mechanisms and range of extremotolerance of Acinetobacter radioresistens 50v1, a Gram-negative bacterium isolated from the surface of the preflight Mars Odyssey orbiter, were gained by using a combination of microbiological, enzymatic, and proteomic methods. In summary, A. radioresistens 50v1 displayed a remarkable range of survival against hydrogen peroxide and the sequential exposures of desiccation, vapor and plasma phase hydrogen peroxide, and ultraviolet irradiation. The survival is among the highest reported for non-spore-forming and Gram-negative bacteria and is based upon contributions from the enzyme-based degradation of H(2)O(2) (catalase and alkyl hydroperoxide reductase), energy management (ATP synthase and alcohol dehydrogenase), and modulation of the membrane composition. Together, the biochemical and survival features of A. radioresistens 50v1 support a potential persistence on Mars (given an unintended or planned surface landing of the Mars Odyssey orbiter), which in turn may compromise the scientific integrity of future life-detection missions.

Early neonatal meningitis with non-fermenting Gram negative bacilli (NFGNB) is rare, and whenever it occurrs, inanimate environment is usually implicated as the source. The authors report a case of neonatal meningitis and sepsis with Chryseobacterium indologenes, a rare non fermenting Gram negative bacterium with unusual antimicrobial susceptibility. Despite resistance to all the beta lactams, carbapenems and aminoglycosides, therapy with ciprofloxacin led to a favorable outcome.

Escherichia coli is used for eco-friendly extra cellular synthesis of metallic silver and gold nanoparticles. This is achieved by reducing AgNO 3 and HAuCl 4 solutions respectively under ambient conditions by using the extra cellular protein produced by the microorganism. The proteins act as reducing as well as capping agent. The nanoparticles were characterized by UV-Visible spectroscopy, X-Ray diffraction (XRD), Fourier transform infra-red spectroscopy (FT-IR) and transmission electron microscopy (TEM). Both the nanoparticles are polydisperse. Gold particles predominantly exhibit flat and plate like morphology. These nanoparticles are stable in water for more than three months. The silver nanoparticles are able to inhibit the growth of several Gram positive and negative microorganisms, and the gold nanoparticles exhibit good antioxidant activity. This approach is simple, does not use toxic chemicals and is amenable for large scale commercial production. Copyright � 2012 American Scientific Publishers All rights reserved.

Streptomyces venezuelae ISP5230 is recognized for the production of chloramphenicol and the jadomycin family of natural products. The jadomycins are angucycline natural products containing a unique oxazolone ring incorporating an amino acid present in the minimal culture media. Substitution of different amino acids results in products of varying biological activity. Analysis of cultures of S. venezuelae ISP5230 incubated with l- and d-norvaline and l- and d-norleucine indicated that only the d-configured amino acids were incorporated into the natural products. Subsequently, jadomycin DNV and jadomycin DNL were isolated and characterized (titers 4 and 9 mg L -1, respectively). The compounds were evaluated in the National Cancer Institute cell line cancer growth inhibition and cytotoxicity screens, for antimicrobial activity against selected Gram-positive and Gram-negative bacteria, and as DNA-cleavage agents in vitro. © Published 2011 by the American Chemical Society.

[EN] Although several strains of B. subtilis with antifungal activity have been isolated worldwide, to date there are no published reports regarding the isolation of a native B. subtilis strain from strawberry plants in Mexico. A native bacterium (Bacillus subtilis 21) demonstrated in vitro antagonistic activity against different plant pathogenic fungi. Under greenhouse conditions, it was shown that plants infected with Rhizoctonia solani and Fusarium verticillioides and treated with B. subtilis 21 produced augment in the number of leaves per plant and an increment in the length of healthy leaves in comparison with untreated plants. In addition, B. subtilis 21 showed activity against pathogenic bacteria. Secreted proteins by B. subtilis 21 were studied, detecting the presence of proteases and bacteriocin-like inhibitor substances that could be implicated in its antagonistic activity. Chitinases and zwittermicin production could not be detected. Then, B. subtilis 21 could potentially be used to control phytopathogenic fungi that infect strawberry plants., This research was supported by grants from the Universidad de Guanajuato (52/07) and SEP-CONACYT (44990) to M. G. L. Basurto-Cadena and J. E. Barboza-Corona, respectively. The authors are grateful to Norma Margarita de la Fuente-Salcido, Karla Villaverde, Ana Perez, and Rosario Razo for their technical assistance. The authors are thankful for the essential material provided by Jorge Ibarra, Irais Sanches-Ortega and Ma. Alejandra Chavira-Zuniga and Departamento de Produccion Vegetal, Universidad Politecnica de Valencia.

Aims: To isolate and characterize the biosurfactant-producing micro-organism from petroleum-contaminated soil as well as to determine the biochemical properties of the biosurfactant. Methods and Results: A novel rhamnolipid-producing Pseudomonas aeruginosa (GenBank accession number) strain was isolated from a petroleum-contaminated soil. Surface active compound was separated by solvent extraction of the acidified culture supernatant. The extract was able to reduce the surface tension of water from 72 to 44 mN m -1 at a critical micelle concentration of 11�27 � 1�85 mg l-1. It showed better activity (based on microdilution method) against Gram-positive (? 31 mg ml-1) bacteria and filamentous fungi (? 50 mg ml-1) than Gram-negative bacteria (? 125 mg ml-1) with mild toxicity (HC50-38 � 8�22 ?g ml-1) to red blood cells. Fourier transform infrared spectroscopy revealed the presence of aliphatic chain, hydroxyl groups, ester and glycosidic bonds. Presence of nineteen rhamnolipid homologues with variation in chain length and saturation was revealed from liquid chromatography coupled to mass spectrometry with electrospray ionization. Conclusion: The results indicate that the isolated biosurfactant has a novel combination of rhamnolipid congeners with unique properties. Significance and Impact of the Study: This study provides a biosurfactant, which can be used as a biocontrol agent against phytopathogens (Fusarium proliferatum NCIM 1105 and Aspergillus niger NCIM 596) and exploited for biomedical applications. � 2010 The Society for Applied Microbiology.

Klebsiella oxytoca BAS-10 is a Gram-negative micro-organism capable of growing on high concentrations of heavy metals. This bacterium produces large amounts of an iron-binding exopolysaccharide that, in the presence of metallic cations, precipitates as a dense gel. The primary and secondary structure of the repeating unit of such polysaccharide has been characterised by chemical and spectroscopic methods, resulting in the following heptasaccharide: 2)-α-Rha-(13)-β-Gal-(12)-α-Rha-(14)-β-GlcA-[β-GlcA-(14)]-(13)-α-Rha-(13)-α-Rha-(1. The absolute configurations for the Rha units are L, while those for the GlcA and Gal residues are D. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

Klebsiella oxytoca BAS-10 is a Gram-negative micro-organism capable of growing on high concentrations of heavy metals. This bacterium produces large amounts of an iron-binding exopolysaccharide that, in the presence of metallic cations, precipitates as a dense gel. The primary and secondary structure of the repeating unit of such polysaccharide has been characterised by chemical and spectroscopic methods, resulting in the following heptasaccharide: 2)-α-Rha-(13)-β-Gal-(12)-α-Rha-(14)-β-GlcA-[β-GlcA-(14)]-(13)-α-Rha-(13)-α-Rha-(1. The absolute configurations for the Rha units are L, while those for the GlcA and Gal residues are D. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

Summary Capnocytophaga canimorsus is a Gram negative bacterium, that belongs to the normal oral flora of dogs and cats. Human infections, usually following dog bites, are associated with underlying conditions and alcoholism in most cases. The authors report a new case of septicemia complicated by meningitis that developped in an alcohol-addict, but had a favorable outcome.

Replicon typing of plasmids carrying bla CTX-M or bla CMY β-lactamase genes indicates a predominance of I1 and A/C replicons among bla CMY -carrying plasmids and five different plasmid scaffolds associated with the different types of bla CTX-M genes (I1, FII, HI2, K, and N). These results demonstrate the association of certain β-lactamase genes with specific plasmid backbones.

Because they contain covalently attached hemes, c-type cytochromes, especially those with multi-heme, are difficult to over-express. The gram negative bacterium Shewanella oneidensis MR-1 has been successfully used for over-expression of multi-heme c-type cytochromes...

Parsley (Coriandrum sativum) plants exhibited a sudden yellowing and death that included a soft rot of the roots and the basal parts of the petioles. A rod shaped, facultatively anaerobic, Gram negative bacterium was isolated that infected healthy parsley plants, reproducing the original symptoms. Biochemical, biological, staining and morphological studies suggested that the bacterium was most closely related to Erwinia carotovora subsp. betavasculorum. As E. carotovora has not been reported from parsley (in Brazil) (Robbs et al., 1981), this appears to be a new disease in Brazil.

Acidaminococcus intestini belongs to the family Acidaminococcaceae , order Selenomonadales , class Negativicutes , phylum Firmicutes . Negativicutes show the double-membrane system of Gram-negative bacteria, although their chromosomal backbone is closely related to that of Gram-positive bacteria of the phylum Firmicutes . The complete genome of a clinical A. intestini strain is here presented.

This article is free to read on the publishers website An anaerobic, extremely thermophilic xylanolytic, non-spore-forming bacterium was isolated from a sediment sample taken from Owens Lake, California, and designated strain OLT (T = type strain). Strain OLT had a Gram-negative reaction and occurred as short rods which sometimes formed long chains containing a few coccoid cells. It grew at 50--80 °C, with an optimum at 75 °C. The pH range for growth was 5·5--9·0 with an optimum at about pH 7·5. When grown on glucose at optimal conditions, its doubling time was 7·3 h. In addition to glucose, the isolate utilized sucrose, xylose, fructose, ribose, xylan, starch, pectin and cellulose. Yeast extract stimulated growth on carbohydrates but was not obligately required. The end products from glucose fermentation were lactate, acetate, ethanol, H2 and CO2. The G+C content of strain OLT was 36·6 mol%. The 16S rDNA sequence analysis indicated that strain OLT was a member of the subdivision containing Gram-positive bacteria with DNA G+C content of less than 55 mol% and clustered with members of the genus Caldicellulosiruptor. Because strain OLT is phylogenetically and phenotypically different from other members of this genus, it is proposed to designate this isolate Caldicellulosiruptor owensensis sp. nov. Strain OLT is the type strain (=ATCC700167T).

Several organisms are known to cause outbreaks of meningitis in pigs, with Haemophilus species being the most frequently implicated. We report such an outbreak in which necropsied pigs manifested an unusual combination of meningitis, tracheitis, and bronchitis. The causative agent appeared to be an asaccharolytic gram-negative nonfermentative bacterium whose classification has yet to be determined. The organism was isolated from the brain and was extremely capnophilic, growing in air only after several serial subcultures.

The occurrence of thermophilic, halophilic anaerobic bacteria in the sediment of a Tunisian salted lake was tested in samples collected at 20-cm intervals down to a depth of 1.20 m. A long rod, present only in the 40- to 60-cm layer, was isolated at 60 degrees C in a medium containing 100 g of NaCl per liter and designated strain H168. This strain produced acetate, ethanol, H2, and CO2 from glucose metabolism. Fructose, xylose, ribose, cellobiose, and starch were also oxidized. The optimum temperature for growth was 60 degrees C. No growth was obtained at 42 or 70 degrees C. Strain H168 grew optimally in NaCl concentrations ranging from 50 to 100 g per liter, with the upper and lower limits of growth around 200 and 40 g per liter, respectively. The G+C ratio of the DNA was 39.6 mol%. Although halophilic, moderately thermophilic bacteria have been characterized among anaerobes, particularly within methanogens, strain H168 is the first true thermophilic (growing above 60 degrees C) halophilic anaerobic bacterium described so far. The phylogeny, physiology, morphology, lipid content, and high G+C content of strain H168 are sufficiently different from those of genera belonging to the family Haloanaerobiaceae to justify the definition of a new genus.

Plasmid pKYM isolated from a Gram-negative bacterium encodes a Rep protein that is essential for plasmid replication. A comparison of Rep protein from pKYM to Rep proteins encoded by other plasmids shows that it has homology to Rep proteins of the pUB110 plasmid family from Gram-positive bacteria. These plasmids replicate by a rolling-circle mechanism in which a tyrosine residue in the Rep protein acts as the acceptor for the 5' end of the single-strand break introduced by the Rep protein. A Tyr----Phe substitution in the pKYM Rep protein abolishes its activity. Strand-specific single-stranded circular plasmid DNA can be recovered from the cells carrying pKYM and thus we propose that the plasmid pKYM replicates by a rolling-circle mechanism.

The present study describes the cellular, cultural, and biochemical properties of 5 isolates of a bacterium from reproductive tract exudates of hamsters in a breeding colony with a clinical history of abortions and infertility. Although defined cultural and biochemical test methodologies were used to determine the phenotypic properties of this gram-negative bacillus, the organism could not be identified to either genus or species based on the descriptions of currently classified organisms in the family Pasteurellaceae or similar organisms.

This article is free to read on the publishers website A new extremely halophilic chemoorganotrophic bacterium (strain H200T [T = type strain]) was isolated from the hypersaline sediments of Retba Lake in Senegal. This organism was a sluggishly motile, rod-shaped, non-spore-forming, gram-negative, obligate anaerobe that grew optimally at 40°C in the presence of 180 to 200 g of NaCl per liter. The DNA base composition was 32 mol% guanine plus cytosine. The fermentation products from glucose were ethanol, acetate, H2, and CO2. Yeast extract was required for growth. The fermentable substrates included d-fructose, galactose, d-xylose, cellobiose, lactose, maltose, sucrose, starch, d-mannitol, glycerol, and Casamino Acids. On the basis of the results of a 16S rRNA sequence analysis, strain H200T was found to be related to Haloanaerobium species. The 16S rRNA sequence of strain H200T differed from the sequences of the three previously described Haloanaerobium species, and strain H200T also differed from these organisms in its NaCl range for growth (60 to 340 g/liter); strain H200T grew in the presence of the highest NaCl concentration recorded for any halophilic anaerobic organism, including the three previously described Haloanaerobium species. We propose that strain H200T (= DSM 10165) belongs to a new Haloanaerobium species, Haloanaerobium lacusroseus.

A pink, obligately themophilic (60 C), gram-negative, nonmotile, nonsporeforming, rod-shaped bacterium with a deoxyribonucleic acid base ratio of 64 to 65 mol% guanine plus cytosine has been repeatedly isolated from slightly alkaline, man-made and natural thermal aquatic environments. This bacterium (K-2 isolate) does not appear to have been described previously and it has been deposited with the American Type Culture Collection as an unidentified bacterium with the accession no. 27599.

Several clinical and laboratory studies have demonstrated the risk of sepsis in connection with encapsulated bacteria. The importance of clearing these organisms by the spleen is now well accepted. In contrast, the present work deals with the clearance of non-encapsulated gram-negative bacteria (Escherichia coli). The animals used for the experiments (a heterogeneous population of rabbits) were divided into a control group, a splenectomized group, and an autotransplanted group. The histological examination of the splenic transplants revealed typical splenic tissue including lymphatic follicles with germinal activity 42 days after transplantation. For estimation of the clearance capacity different amounts of bacteria were injected i.v. into the rabbits, and colony-forming bacterial cells in the blood were counted at certain intervals. In the control group no bacteria could be detected in the blood after 7 min. All animals of the splenectomized and autotransplanted groups showed a remarkable decrease in clearance efficiency (no bacteria in the blood after 19 min). No difference in the clearance kinetics could be shown between splenectomized and autotransplanted animals. Measuring the uptake of bacterial cells into different organs elicited low incorporation in the spleen as compared to non-immunocompetent organs, but no difference between normal spleen and splenic replants. However, saturation with E. coli cells reached higher limits in the normal spleen than in autotransplants. The immunologic capacity with respect to IgM-producing lymphocytes was measured by the hemolytic plaque assay. The results showed a severe malfunction of the autotransplants as compared to the normal spleen (only 2% of the activity of the control group). Vaccination against E. coli increased the clearance efficiency in all three groups. The data presented in this paper point out that several functions of the spleen cannot be carried out by autotransplants. The reasons, therefore, may be limited transplant mass and/or decreased specific functions.

SUMMARY: The nutritional requirements of the Gram-negative Bacterium NCIB 8250 (formerly referred to as ‘Vibrio 01’) have been determined. Growth was tested on almost 450 compounds, of which over 100 served as carbon+energy sources and almost 50 as nitrogen sources. The effects of various factors such as pH value, temperature and aeration on the growth rate and cell yield of organism have also been measured.

SUMMARY: The original strain of Vibrio 01 (Happold&Key, 1932) appears to have been lost. The Bacterium NCIB 8250, which is frequently referred to as ‘Vibrio 01’, has different properties from those of the original isolate and is a Gramnegative non-motile oxidase-negative coccobacillus.

lungs were clear to percussion and ausculta­ tion. The heart was enlarged, with the point of maximal intensity in the sixth left inter­ costal space 2 cm. lateral to the midclavicular line. There was a grade IV/VI harsh sys­ tolic murmur at the apex which was trans­ mitted to the axilla. The tender edge of the liver was palpable 3 cm. below the right costal margin. The spleen was not palpable. Any movement of the trunk or lower ex­ tremities elicited pain in the sacral region. A trace of edema was present in the ankles. No embolic lesions were noted in the ex­ tremities and there was no clubbing of the fingers.

A gram-negative bacterium, probably Pasteurella haemolytica, was found to support the growth of Acanthamoeba spp. This provides a useful means for initial isolation of Acanthamoeba spp. and for culturing these parasites to high cell densities.

A new, extremely thermophilic, anaerobic, chemo-organotrophic bacterium was isolated from intertidal habitats where seepage of geothermally heated water occurs. The antibiotic sensitivity pattern and the presence of muramic acid strongly suggest an eubacterial nature of the novel isolate. Growth was measured between pH 4.8–8.2 (optimal pH 7.0) and at temperatures up to 90°C with a doubling time of 50 min at optimal temperatures of 80–85°C. This is the highest optimal growth temperature for an eubacterium described so far. The Gram-negative, non-motile, non-sporulating, short rod to coccal shaped cells were enclosed in a sphere-like cell envelope protruding from either end. A wide range of carbohydrates, including xylose, glucose, fructose, maltose, starch, carboxymethylcellulose, and amylopectin were used in an obligately fermentative metabolism. Morphological, physiological and molecular properties (mol% G + C = 46) are distinct from other known extremely thermophilic eubacterial genera.