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The article provides a study of the antibacterial activity of nanostructured copper sulfate in Nacarboxymethyl cellulose on the example of an indigenous strain of the gram-negative bacterium Esherichia coli by the disk-diffusion method. The study revealed that the modification of the active material increases its biocidal properties by 321.34; 121.5; 369.5; 562.6 and 351.7% with an increase in the weight ratio “core : shell” to 1:2 and concentration from 0.5 to 1% in aqueous suspensions.

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.

espanolLa fiebre botonosa mediterranea, o fiebre exantematica mediterranea, es una infeccion prevalente en la cuenca mediterranea, con mayor incidencia en los meses de verano y en poblacion rural. Causada por una bacteria gramnegativa, Rickettsia conorii, se transmite al hombre tras la picadura de la garrapata del perro. Es una enfermedad de declaracion obligatoria en muchas comunidades autonomas. Se trata de la rickettsiosis mas frecuente en Europa y una alta sospecha clinica es clave en su diagnostico. EnglishBoutonneuse fever, or Mediterranean exanthematic fever, is a prevalent infection in the Mediterranean basin, with greater incidence in the summer period and in the rural population. Caused by a gram negative bacterium, Rickettsia conorii, is transmitted to human being by means of a dog’s tick bite. It is a notifiable disease in many autonomous regions. It is the most common rickettsiosis in Europe, and high clinical suspicion is the key on its diagnosis.

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.

This chapter looks briefly at the development of biological control for crown gall, discusses some of the successes and failures of its commercial application, and looks to ways in which it might be enhanced and its range extended. The causal organism, a Gram negative bacterium, Agrobacterium tumefaciens, is one of the relatively few soil-inhabiting bacterial plant pathogens. Susceptible plants are invaded only through wounds, usually at the crown or on the root system. The generally increased interest in nonpolluting and environmentally acceptable biological controls should facilitate registration of antagonistic organisms in the future, and previously fought battles for approval of strain 84 must surely have paved the way for its even more widespread registration. Strain 84 has also been maintained in 0.25% carboxymethyl cellulose for 10 months, but this leads to physiologically retarded cells that need to be used at higher than routine concentrations. The practicality of using freeze-dried cultures, having a long period of viability, has been under investigation.

Scrub typhus is also known as bus typhus inaction and it is a serious public health problem in the Asia-Pacific area. It threatens one billion peoples are effected worldwide, and causes illness in one million people for an each year. Caused by Orientia tsutsugamushi, scrub typhus can result in severe multi organ failure with a case fatality rate up to 70% without appropriate treatment. The antigenic heterogeneity of O. Tsutsugamushi precludes generic immunity and to the allows reinjection. As it is a neglected disease, there is still a large gap in our knowledge of the disease, as evidence by the sporadic epidemiologic data and others relating to the public health information regarding scrub typhus in its endemic areas. It is a gram-negative bacterium, this infection can be perfectly treated with the specific antibiotics. Early treatment gives best results those who are infected with this infection it gives better therapeutic outcomes. Oral medication is effective for mild cases, but the parenteral route is often necessary for severely ill patients. Similar to treatment for other rickettsial diseases, doxycycline is one of most effective antibiotics for treating scrub typhus infection. Key Words: Scrub typhus, threatens one billion peoples, gram-negative bacterium, Oral medication.

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 carbonic anhydrases (CAs, EC 4.2.1.1) catalyse a simple but physiologically crucial reversible reaction, the carbon dioxide hydration with the production of bicarbonate and protons. In the last years, and especially, to the rapid emergence of the bacterial antibiotic resistance that is occurring worldwide, the understanding of the function of bacterial CAs has increased significantly. Recently, a new CA-class (iota-CA) was discovered in the marine diatom T. pseudonana. It has been reported that bacterial genomes may contain genes with relevant homology to the diatom iota-class CA. Still, the catalytic activity of the enzyme encoded by the gene was not investigated. Thus, herein, for the first time, we cloned, expressed, and purified the recombinant bacterial iota-CA (acronym BteCA iota) identified in the genome of Burkholderia territorii. The recombinant BteCA iota resulted in a good catalyst for the hydration of CO2 to bicarbonate and protons, with a k(cat) of 3.0 x 10(5) s (-1) and k(cat)/K-M of 3.9 x 10(7) M (-1) s (-1), and is also sensitive to inhibition by the sulphonamide acetazolamide. Furthermore, with the aid of the protonography, it has been demonstrated that BteCA iota can be present as a dimer. This result is corroborated by the construction of a molecular model of BteCA iota, which showed that the enzyme is formed by two equivalent monomers having a structure similar to a butterfly.

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...

Mannheimia haemolytica (M. haemolytica) is a gram negative bacterium which can infect humans and animals. It’s commensal as a normal flora of the nasopharynx and tonsils in cattle, sheep and goats, pneumonic pasteurellosis is one of the most economically important infectious disease in goats worldwide prevalence. This study aimed to investigate the incidence of M. haemolytica by bacteriological and molecular characterization in goats. One hundred nasopharyngeal swabs were collected from apparently healthy field goats, seven lung tissue specimens and five nasal mucus swabs from slaughtered goats in Baghdad. All samples were cultured on Blood and MacConky agars. Biochemical tests and EPI20E kit were used for identification of the suspected colonies. 5 (4.46%) isolates of M. haemolytica were identified phenotypicaly and confirmed diagnosis by polymerase chain reaction (PCR) technique using two primers 16s rRNA and 12s rRNA genes .The results of this study concluded that identification of M. haemolytica by PCR was in accordance with those of phenotypic tests and it providing the basis for effective preventative strategies through epidemiological studies performance.

A Gram-stain-negative, rod-shaped strain, Braz8T, isolated from larvae of Anopheles darlingi was investigated using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain Braz8T was related most closely to species of the genus Thorsellia , with 95.6, 96.5 and 96.6 % similarity to the type strains of Thorsellia anophelis , Thorsellia kandunguensis and Thorsellia kenyensis , respectively, and formed a separate branch in the phylogenetic tree next to the monophyletic cluster of the genus Thorsellia . Chemotaxonomic data supported the allocation of the strain to the family Thorselliaceae . The major fatty acids were C18 : 1 ω7c, C16 : 0 and C14 : 0. The quinone system was composed of ubiquinones Q-8 and Q-7 (1 : 0.3), the predominant polar lipids were diphosphatidylglycerol and phosphatidylglycerol, and the polyamine pattern showed the major compound putrescine. However, qualitative and quantitative differences in the major polyamine, polar lipid profile and fatty acid patterns distinguished strain Braz8T from species of the genus Thorsellia . Phylogenetic analysis based on 16S rRNA gene sequences, average nucleotide identity, DNA–DNA hybridization, multilocus sequence analysis as well as physiological and biochemical tests distinguished strain Braz8T both genotypically and phenotypically from the three Thorsellia species but also showed its placement in the family Thorselliaceae . Thus, strain Braz8T is considered to represent a novel species of a new genus most closely related to the genus Thorsellia, for which the name Coetzeea brasiliensis gen. nov., sp. nov. is proposed. The type strain of Coetzeea brasiliensis is Braz8T (=LMG 29552T=CIP 111088T).

Salmonella typhi, a Gram negative bacterium, has become multidrug resistant (MDR) to wide classes of antibacterials which necessitate an alarming precaution. This study focuses on the binding potential and therapeutic insight of Nano-Fullerene C60 towards virulent targets of Salmonella typhi by computational prediction and preliminary in vitro assays. The clinical isolates of Salmonella typhi were collected and antibiotic susceptibility profiles were assessed. The drug targets of pathogen were selected by rigorous literature survey and gene network analysis by various metabolic network resources. Based on this study, 20 targets were screened and the 3D structures of few drug targets were retrieved from PDB and others were computationally predicted. The structures of nanoleads such as Fullerene C60, ZnO and CuO were retrieved from drug databases. The binding potential of these nanoleads towards all selected targets were predicted by molecular docking. The best docked conformations were screened and concept was investigated by preliminary bioassays. This study revealed that most of the isolates of Salmonella typhi were found to be MDR (p .05). The theoretical models of selected drug targets showed high stereochemical validity. The molecular docking studies suggested that Fullerene C60 showed better binding affinity towards the drug targets when compared to ZnO and CuO. The preliminary in vitro assays suggested that 100 μg/L Fullerene C60 posses significant inhibitory activities and absence of drug resistance to this nanoparticle. This study suggests that Fullerene C60 can be scaled up as probable lead molecules against the major drug targets of MDR Salmonella typhi.

Huanglongbing (HLB), previously citrus greening disease, is the most destructive of citrus species causing major threat to the world citrus industry. The disease was reported from China in 1919 and now known to occur in more than 40 different countries of Asia, Africa, South and North America. Three species of gram negative bacterium namely Candidatus Liberibacter asiaticus, Candidatus Liberibacter africanus and Candidatus Liberibacter americanus are the casual organisms of HLB, respectively prevailing in the continent of Asia, Africa and South America. It is one of the most extensively researched subjects in citriculture world. HLB was detected in 2004 and 2005, respectively in San Paulo of Brazil and Florida of USA: the two leading citrus production hub of the world causing huge economic loss within 5 years of first detection. Since then research on HLB detection and management was further accelerated in American continents. This paper presents the scientific advancement made on detection, spread, economic losses caused by HLB in different parts of the world and controlling management strategies. Remarkable achievements have been made on HLB detection techniques including iodine test, qPCR and more recently in spectroscopy. While efforts are being made to develop resistance varieties using conventional and biotechnological tools management strategy which includes reduction of inoculums source, vector control and replant with disease-free planting materials still remains major option for HLB control. Citrus intercropping with guava have shown promising results for vector reduction.Journal of Nepal Agricultural Research Council Vol.1 2015, pp.41-50

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.

Melioidosis is an infection caused by a gram negative bacterium .We report a case of FUO which upon investigation revealed muscle abscess and subsequent pus culture revealed melioidosis.

Here, we report the full-genome sequence of an NAD-hemin-independent Avibacterium paragallinarum serovar C-2 strain, FARPER-174, isolated from layer hens in Peru. This genome contained 12 potential genomic islands that include ribosomal protein-coding genes, a nadR gene, hemocin-coding genes, sequences of fagos, an rtx operon, and drug resistance genes.

The aim of this work is to study the freezing process of water molecules surrounding Antarctic Gram-negative bacterium Marinomonas primoryensis antifreeze protein (MpAFP) and the MpAFP interactions to the surface of ice crystals under various marine environments (at different NaCl concentrations of 0.3, 0.6, and 0.8 mol/l). Our result indicates that activating temperature region of MpAFPs reduced as NaCl concentration increased. Specifically, MpAFP was activated and functioned at 0.6 mol/l with temperatures equal or larger 278 K, and at 0.8 mol/l with temperatures equal or larger 270 K. Additionally, MpAFP was inhibited by ice crystal network from 268 to 274 K and solid-liquid hybrid from 276 to 282 K at 0.3 mol/l concentration. Our results shed lights on structural dynamics of MpAFP among different marine environments.

The interaction of a single bacterial species (Burkholderia fungorum) with basaltic rocks from the ICDP HSDP2 drill core and synthetic basaltic glasses was investigated in batch laboratory experiments to better understand the role of microbial activity on rock alteration and Fe mobilization. Incubation experiments were performed with drill core basaltic rock samples to investigate differences in the solution chemistry during biotic and abiotic alteration. Additionally, colonization experiments with synthetic basaltic glasses of different Fe redox states and residual stresses were performed to evaluate their influence on microbial activity and surface attachment of cells. In biotic incubation experiments bacterial growth was observed and the release of Fe and other major elements from drill core basaltic rocks to solution exceeded that of abiotic controls only when the rock sample assay was nutrient depleted. The concentration of dissolved major elements in solution in biotic colonization experiments with synthetic basaltic glasses increased with increasing residual stress and Fe(II) content. Furthermore, the concentration of dissolved Fe and Al increased similarly in biotic colonization experiments indicating that their dissolution might be triggered by microbial activity. Surface morphology imaging by SEM revealed that cells on basaltic rocks in incubation experiments were most abundant on the glass and surfaces with high roughness and almost absent on minerals. In colonization experiments, basaltic glasses with residual stress and high Fe(II) content were intensely covered with a cellular biofilm. In contrast, glasses with high Fe(III) content and no residual stress were sparsely colonized. We therefore conclude that structurally bound Fe is most probably used by B. fungorum as a nutrient. Furthermore, we assume that microbial activity overall increased rock dissolution as soon as the environment becomes nutrient depleted. Our results show that besides compositional effects, other factors such as redox state and residual stress can control microbial alteration of basaltic glasses.

Pseudomonas aeruginosa is an opportunistic human pathogen with huge medical relevance worldwide, since it is associated to both acute and chronic infections with impressive morbidity and mortality rates [1]. This Gram negative bacterium has ubiquitous distribution, being able to colonize a vast diversity of habitats with distinct physicochemical characteristics, such as soil, water, plants, animals and humans [1]. This versatility can be assigned, at least in part, to P. aeruginosa genome plasticity, which reflects in its ability to quickly modulate the metabolic repertoire in order to adapt to the changes in environmental conditions [2]. For all these reasons, P. aeruginosa might cause a wide variety of human infections, with special clinic emphasis in immunocompromised patients.

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.

Helicobacter pylori is spiral shaped Gram negative bacterium, colonizes the stomach and can persist for a lifetime if not completely eradicated. Infection caused by this bacterium is the most common in the world and it is much widespread in developing countries. Prevalence of Helicobacter pylori antibiotic resistance is increasing. It is the main factor displeasing efficacy of current treatment regimens. The epidemiology of Helicobacter pylori resistance to antibiotics is poorly documented in developing countries with many reasons. Therefore, this review aims to assess the prevalence and drug resistance pattern of Helicobacter pylori. Different literature was searched with different electronic databases and reviewed systematically to get tangible findings. This review tries to include recent articles across the world by giving more emphasis for Africa performed on prevalence and drug resistance patterns of Helicobacter pylori. According to this review there is a need to embark on more studies to draw attention to the clinical and epidemiological significance of this pathogens.

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.

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.

5-Amino-3-methyl-4-phenylazo-1H-pyrazole and ethyl cyanoacetate reacted in solvent-free media at 150°C to produce 7-amino-3-phenylazo-2-methyl-4H-pyrazolo[1,5-a]pyrimidine-5-one (3). A series of aromatic amines was coupled using this compound (3) and nitrous acid to produce new pyrazolo[1,5-a] pyrimidine derivatives with two arylazo groups 4(a-m). The structures of these dyes were determined via UV–vis, Fourier transform infrared, proton nuclear magnetic resonance, high-resolution mass spectral data, and elemental analysis. After synthesis, the solvent and acid–base effects of the dyes were investigated within the UV–vis region. The antimicrobial properties of the dyes were also studied. All dyes exhibited activity against Gram-positive and Gram-negative bacteria, and even against fungi. The results were compared to conventional reference results from the antibiotics ciprofloxacin and ketoconazole. Antioxidant potentials were analyzed using in vitro antioxidant models on the basis of DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activities. Most of the compounds exhibited excellent antioxidant activities. In particular, compound 4b had a higher activity than Vitamin C. © 2017 Wiley Periodicals, Inc.

Chiral secondary alcohols are valuable intermediates for many important enantiopure pharmaceuticals and biologically active molecules. In this work, we studied asymmetric reduction of aromatic ketones to produce the corresponding chiral secondary alcohols using lactic acid bacteria (LAB) as new biocatalysts. Seven LAB strains were screened for their ability to reduce acetophenones to their corresponding alcohols. Among these strains, Lactobacillus paracasei BD101 was found to be the most successful at reducing the ketones to the corresponding alcohols. The reaction conditions were further systematically optimized for this strain and high enantioselectivity (99%) and very good yields were obtained. These secondary alcohols were further tested for their antimicrobial activities against important pathogens and significant levels of antimicrobial activities were observed although these activities were altered depending on the secondary alcohols as well as their enantiomeric properties. The current methodology demonstrates a promising and alternative green approach for the synthesis of chiral secondary alcohols of biological importance in a cheap, mild, and environmentally useful process. © 2017 Wiley-VHCA AG, Zurich, Switzerland

Helicobacter pylori (H. pylori) is a Gram negative bacterium that colonizes the stomach of almost half human population. It has evolved to escape immune surveillance, establishes lifelong inflammation, predisposing to genomic instability and DNA damage, notably Double Strand Breaks (DSBs). The epithelial host cell responds by activation of DNA Damage Repair (DDR) machinery that seems to be compromised by the infection. It is therefore now accepted that genetic damage is a major mechanism operating in cases of H. pylori induced carcinogenesis. Here we review the data on the molecular pathways involved in DNA damage and DDR activation during H. pylori infection.

Hafnia alvei is a Gram negative bacterium that belongs to the family Enterobacteriaceae. It is part of the intestinal flora of humans and animals, moreover it has been described from natural environments and foodstuffs. In human medicine is considered an opportunistic bacterium that causes different infections associated to underlying illnesses or predisposing factors as immunocompromised patients. The knowledge and literature about this bacterium in veterinary medicine is scarce, highlighting its importance in gastropods and bees, and it has also been described in poultry, mares, fish and ruminants producing various clinicopathologic signs.

The most important mechanism for combating infection using larval therapy depends on larval excretions and secretions (ES). The present work was aimed at evaluating Sarconesiopsis magellanica (Diptera: Calliphoridae) ES antibacterial activity in six bacterial strains (three Gram-positive and three Gram-negative) and comparing this to the effect of Lucilia sericata-derived ES. Antibacterial activity at 50. ?g/mL minimum inhibitory concentration (MIC) was observed for Staphylococcus epidermidis ATCC-12228 and Staphylococcus aureus ATCC-29213 strains, when the turbidimetry test involving S. magellanica ES was used; the rest of the bacterial strains (Staphylococcus aureus ATCC-6538, Pseudomonas aeruginosa ATCC-10145, Pseudomonas aeruginosa ATCC-9027 and Pseudomonas aeruginosa ATCC-27853) were inhibited at a 100. ?g/mL MIC. Twice the amount was required to inhibit the aforementioned bacteria with L. sericata-derived ES using this same technique; a similar trend was observed when the agar diffusion method was used instead. Furthermore, when the previously established MIC for each bacterial strain was used, their colonies became reduced following 1-6. h incubation with S. magellanica derived ES, whilst the reduction occurred from 2 to 6. hours with those from L. sericata. Although the MIC for each strain obtained with ciprofloxacin was lower than those established when using either blowfly derived-ES, the gradual reduction of the colonies occurred at a longer incubation time (6. h or more). The results showed that S. magellanica ES antibacterial activity was more potent and effective, compared to that of L. sericata-derived ES. © 2014 Elsevier B.V.

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.

Escherichia coli é um micro-organismo altamente adaptativo e sua habilidade em formar biofilmes pode ser fundamental na resistência a tratamentos com antimicrobianos. A avaliação da concentração mínima inibitória (CMI) vem sendo utilizada para verificar a sensibilidade dos micro-organismos aos antimicrobianos. Entretanto, quando se avaliam células sésseis, a concentração do antimicrobiano requerido para erradicação do biofilme é maior do que a determinada pela CMI. Objetivou-se comparar as CMI com as concentrações mínimas de erradicação de biofilmes (CMEB) de antimicrobianos usados no tratamento da mastite em 27 isolados de E. coli produtores de biofilmes provenientes de mastite. Os isolados foram submetidos a testes de sensibilidade a antimicrobianos usados no tratamento da mastite, tanto para células planctônicas, por meio da CMI, quanto para células sésseis, pela avaliação da CMEB. Os resultados revelaram uma alta sensibilidade: apenas quatro (14,8%) isolados obtiveram valores da CMI elevados, variando de 4 a 10µg/mL, sendo classificados como resistentes. Para os demais isolados (85,2%), os valores foram menores, variando de 0,125 a 2µg/mL, classificados como sensíveis. A avaliação de CMEB indicou que a concentração dos antimicrobianos necessária para eliminar as células sésseis variou de 100µg/mL a 500µg/mL. Os valores de CMEB foram significativamente maiores nos isolados grandes e moderados produtores de biofilmes em relação aos isolados fracos produtores de biofilmes (p0,05). A escolha da terapêutica antimicrobiana correta para o tratamento de infecções intramamárias em bovinos relacionadas com a produção de biofilmes parece exigir a aplicação de testes mais específicos. Testes de susceptibilidade antimicrobiana baseados apenas em valores de CMI mostraram-se ineficazes em determinar com precisão a susceptibilidade das células bacterianas sésseis. Escherichia coli is a highly adaptive microorganism. Its ability to form biofilms may be critical for resistance to antimicrobial treatments. Evaluation of minimum inhibitory concentration (MIC) has been used to check the sensitivity of microorganisms to antibiotics, however, when evaluating sessile cells, the required antibiotic concentration to eradicate biofilm is greater than determined by MIC. This study aimed to compare MIC with minimum biofilm eradication concentration (MBEC) of antimicrobials used in mastitis treatment in 27 E. coli biofilm producers isolates from mastitis. Isolates were tested for sensitivity to antimicrobials used in mastitis treatment, for both planktonic cells (by CMI) and sessile cells (by MBEC). The results revealed high sensitivity: only four (14.8%) isolates showed high MIC values, ranging from 4 to 10g/mL and they were classified as resistant. All other isolates (85.2%) showed lower values, ranging from 0.125 to 2mg/mL, and they were classified as sensitive. Evaluation of MBEC indicated that concentration of antimicrobial needed to remove sessile cells ranged from 100mg/mL to 500mg/mL. MBEC values were significantly higher in large and moderate biofilm producers isolates regarding weak biofilm producers isolates (p0.05). The correct choice of antimicrobial therapy for treatment of mammary infections in cattle related to biofilm production seems to require application of more specific tests. Antimicrobial susceptibility testing based only on MIC values proved ineffectiveness to accurately determination the susceptibility of sessile bacterial cells.

The evolution of bacterial resistance is generating a serious public health problem due to the indiscriminate use of antibiotics, the application of non-optimal doses, the irregularity in the taking of medicines sent by the health professional, factors that have affected the increase in the rate of antimicrobial resistance; It is important to generate strategies that contribute to diminishing it, including the rational use of antibiotics and the constant research of new therapeutic alternatives such as teixobactin, which is a product of the Gram negative bacterium called Eleftheria terrae, related to the genus Aquabacterium, is a microorganism that presents extremophile conditions, for which, a multichannel system of semipermeable membranes called Ichip was developed for its isolation. Eravacycline is a new fully synthetic bacteriostatic antibiotic of the tetracycline family, is a potent inhibitor based on the mechanism of the bacterial ribosome and exerts potent activity against a broad spectrum of susceptible and multiresistant bacteria.

Sphingomonas paucimobilis is a gram negative bacterium usually an opportunistic pathogen. It is known to cause infections among immunocompromised individuals. Rarely it causes infections among immunocompetent individuals. We report a case of sphingomonas paucimobilis sepsis in a ten year old male child.

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.

Melioidosis is caused by the Gram negative bacterium Burkholderia pseudomallei. The gold standard for diagnosis is culture, which requires at least 3-4 days obtaining a result, hindering successful treatment of acute disease. The existing indirect haemagglutination assay (IHA) has several disadvantages, in that approximately half of patients later confirmed culture positive are not diagnosed at presentation and a subset of patients are persistently seronegative. We have developed 2 serological assays, an enzyme-linked immunosorbent assay (ELISA), and a 2-dimensional immunoarray (2DIA), capable of detecting antibodies in patient sera from a greater proportion of IHA-negative patient subsets. The 2DIA format can distinguish between different LPS serotypes. Currently, the 2DIA has a sensitivity and specificity of 100% and 87.1%, respectively, with 100% of culture-positive, IHA-negative samples detected. The ELISA has a sensitivity and specificity of 86.2% and 93.5%, respectively, detecting 67% of culture-positive, IHA-negative samples. The ELISA and 2DIA tests described here are more rapid and reliable for serological testing compared to the existing IHA.

Highlights • In vitro screens have very low success rate in follow up preclinical trials. • In vitro systems do not reflect the complexity of the host. • The main advantage of Drosophila is its significant similarity with humans. • Drug screens in Drosophila may increase the success of preclinical trials., Following an expansion in the antibiotic drug discovery in the previous century, we now face a bottleneck in the production of new anti-infective drugs. Traditionally, chemical libraries are screened either using in vitro culture systems or in silico to identify and chemically modify small molecules with antimicrobial properties. Nevertheless, almost all compounds passing through in vitro screening fail to pass preclinical trials. Drug screening in Drosophila offers to fill the gap between in vitro and mammalian model host testing by eliminating compounds that are toxic or have reduced bioavailability and by identifying others that may boost innate host defence or selectively reduce microbial virulence in a whole-organism setting. Such alternative screening methods in Drosophila, while low-throughput, may reduce the cost and increase the success rate of preclinical trials.

Currently, there is a global interest in propolis research due to its various biological activities. In vitro methods are useful for preliminary investigation of the antibacterial activity of propolis extracts. The disk diffusion method and broth macrodilution method recommended by the Clinical and Laboratory Standards Institute were used in this study, with some modifications, to evaluate the antibacterial activity of propolis. Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27853 and Streptococcus pneumoniae ATCC 49619 were used. A standardized extract of Brazilian propolis was evaluated. The methods were precise and showed 100% accuracy. Gram positive bacteria were more sensitive to propolis extract than Gram negative bacterium. The validations demonstrated that the disk diffusion method and broth macrodilution method are appropriate for the evaluation of the antibacterial activity of propolis extracts. Therefore, the methodologies validated in this study may be useful tools in propolis research. Key words: Methodologies, validation, antibacterial activity, propolis.

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.