Microbiology Group

Salisbury, United Kingdom

Microbiology Group

Salisbury, United Kingdom
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Mahboubi M.,Microbiology Group | Kazempour N.,Microbiology Group | Nazar A.R.B.,Agricultural Group
Jundishapur Journal of Natural Pharmaceutical Products | Year: 2013

Background: Scrophularia striata (Scrophulariaceae family) is an herbaceous plant that is traditionally used for treatment of microbial infections. Objectives: Antimicrobial and antioxidant activity of different extracts (methanolic, ethanolic, aqueous and ethyl acetate) from S. striata aerial parts was evaluated. Materials and Methods: The antimicrobial activity of different extracts from S. striata was evaluated against a large number of bacteria and fungi by micro broth dilution. Total phenolic and flavonoid contents were measured and their antioxidant activities evaluated by DPPH assay and beta carotene linoleic acid test. Results: Antimicrobial screening exhibited the positive relation between the total phenolic content and its antimicrobial activity but their antioxidant activity had a negative relation. Conclusions: Further studies are recommended against clinical isolate of sensitive bacteria and deep investigation on flavonoid and phenolic compounds of S. striata and detecting the antioxidant portion in aqueous extract. © 2013, School of Pharmacy, Ahvaz Jundishapur University of Medical Sciences; Published by Kowsar Corp.


Amziane M.,Microbiology Group | Metiaz F.,Microbiology Group | Darenfed-Bouanane A.,Microbiology Group | Djenane Z.,Microbiology Group | And 4 more authors.
Current Microbiology | Year: 2013

A novel, Gram-positive, moderately halophilic bacterium, oxidase- and catalase-positive designated FarDT was isolated from sediments of a saline lake located in Taghit, 93 km from Bechar, southwest of Algeria. Cells were rod-shaped, endospore forming, and motile. Growth occurred at 15-40 C (optimum, 35 C), pH 6.0-12.0 (optimum, 7.0) and in the presence of 1-20 % NaCl (optimum, 10 %). Strain FarDT used glucose, mannitol, melibiose, d-mannose, and 5 ketogluconate. The polar lipids comprised diphosphatidylglycerol, phosphatidylglycerol, and three phospholipids; MK-7 is the predominant menaquinone. The predominant cellular fatty acids were anteiso C15:0, anteiso C17:0, C20:0, and anteiso C 19:0. The DNA G+C content was 42.1 mol%. Phylogenetic analysis of the small-subunit ribosomal RNA gene sequence indicated that strain FarD T had as its closest relative Virgibacillus salinus (similarity of 96.3 %). Based on phenotypic, phylogenetic, and taxonomic characteristics, strain FarDT is proposed as a novel species of the genus Virgibacillus within the order Clostridiales, for which the name V. natechei is proposed. The type strain is FarDT (=DSM 25609T = CCUG 62224T). © 2013 Springer Science+Business Media New York.


Bukowska-Faniband E.,Microbiology Group | Hederstedt L.,Microbiology Group
Molecular Microbiology | Year: 2017

Endospore cortex peptidoglycan synthesis is not required for bacterial growth but essential for endospore heat resistance. It therefore constitutes an amenable system for research on peptidoglycan biogenesis. The Bacillus subtilis sporulation-specific class B penicillin-binding protein (PBP) SpoVD and many homologous PBPs contain two conserved cysteine residues of unknown function in the transpeptidase domain - one as residue x in the SxN catalytic site motif and the other in a flexible loop near the catalytic site. A disulfide bond between these residues blocks the function of SpoVD in cortex synthesis. With a combination of experiments with purified proteins and B. subtilis mutant cells, it was shown that in active SpoVD the two cysteine residues most probably interact by hydrogen bonding and that this is important for peptidoglycan synthesis in vivo. It was furthermore demonstrated that the sporulation-specific thiol-disulfide oxidoreductase StoA reduces SpoVD and that requirement of StoA for cortex synthesis can be suppressed by two completely different types of structural alterations in SpoVD. It is concluded that StoA plays a critical role mainly during maturation of SpoVD in the forespore outer membrane. The findings advance our understanding of essential PBPs and redox control of extra-cytoplasmic protein disulfides in bacterial cells. © 2017 John Wiley & Sons Ltd.


Nelson M.,Microbiology Group | Nunez A.,Animal Plant and Health Agency | Ngugi S.A.,Microbiology Group | Sinclair A.,Microbiology Group | Atkins T.P.,Microbiology Group
International Journal of Experimental Pathology | Year: 2015

Summary: The marmoset model of melioidosis was used to explore whether there was any difference in the disease presentation and/or the lesion formation following inhalational challenge with one of four strains of Burkholderia pseudomallei (K96243, 1026b, HBPUB10303a and HBPUB10134a). Marmosets were challenged with a range of bacterial doses and bacterial load, histological and physiological features were determined temporally following lethal disease. Melioidosis presented as an acute, febrile disease with bacteraemia, bacterial dissemination, necrotizing hepatitis, splenitis and pneumonia which was independent of the challenge strain. Generally, there were no major differences in the manifestation of melioidosis following challenge by the different strains of B. pseudomallei; however, there were some differences in the time to death and the severity of the pathological features. The pathological features observed in the liver and spleen of animals challenged with B. pseudomallei strain 1026b were statistically less severe (P < 0.05) and less frequent. However, more severe foci of disease were evident in the lungs of animals challenged with strain 1026b. In all cases, the lesions developed from small areas of bacteria-infected macrophages surrounded by non-infected neutrophils into large lesions with both immune cell types infected. The marmoset model was a useful tool enabling the distinction of subtle difference in the pathological response to B. pseudomallei. © 2015 International Journal of Experimental Pathology.


Janeczek A.A.,University of Southampton | Tare R.S.,University of Southampton | Scarpa E.,University of Southampton | Moreno-Jimenez I.,University of Southampton | And 5 more authors.
Stem Cells | Year: 2016

Activation of the canonical Wnt signaling pathway is an attractive anabolic therapeutic strategy for bone. Emerging data suggest that activation of the Wnt signaling pathway promotes bone mineral accrual in osteoporotic patients. The effect of Wnt stimulation in fracture healing is less clear as Wnt signaling has both stimulatory and inhibitory effects on osteogenesis. Here, we tested the hypothesis that transient Wnt stimulation promotes the expansion and osteogenesis of a Wnt-responsive stem cell population present in human bone marrow. Bone marrow mononuclear cells (BMMNCs) were isolated from patients undergoing hip arthroplasty and exposed to Wnt3A protein. The effect of Wnt pathway stimulation was determined by measuring the frequency of stem cells within the BMMNC populations by fluorescence-activated cell sorting and colony forming unit fibroblast (CFU-F) assays, before determining their osteogenic capacity in in vitro differentiation experiments. We found that putative skeletal stem cells in BMMNC isolates exhibited elevated Wnt pathway activity compared with the population as whole. Wnt stimulation resulted in an increase in the frequency of skeletal stem cells marked by the STRO-1bright/Glycophorin A- phenotype. Osteogenesis was elevated in stromal cell populations arising from BMMNCs transiently stimulated by Wnt3A protein, but sustained stimulation inhibited osteogenesis in a concentration-dependent manner. These results demonstrate that Wnt stimulation could be used as a therapeutic approach by transient targeting of stem cell populations during early fracture healing, but that inappropriate stimulation may prevent osteogenesis. Stem Cells 2016;34:418-430 Therapeutic approaches to modulate Wnt signaling in fracture healing should consider the complexity of Wnt signaling requirements for successful differentiation of osteoblasts from progenitors present at injury sites. Transient exposure of fresh bone marrow cells to a canonical Wnt stimulus increases CFU-O potential and osteogenic differentiation of stem/progenitor cell populations. © 2015 AlphaMed Press.


Mahboubi M.,Microbiology Group | Kazempour N.,Microbiology Group
Iranian Journal of Microbiology | Year: 2011

Background and Objectives: The aim of this study was to evaluate the chemical composition and antimicrobial activity of Satureja hortensis and Trachyspermum copticum essential oils against different kinds of microorganisms in vitro. Material and Methods: The antimicrobial activity was evaluated by micro broth dilution assay and the chemical composition of essential oils was analyzed by GC and GC/MS. Results: Thymol, p-cymene, γ-terpinene and carvacrol were the main components of S. hortensis oil while thymol, γ-terpinene, and o-cymene were the major components of T. copticum oil. Two essential oils exhibited strong antimicrobial activity but the antimicrobial activity of T. copticum oil was higher than that of S. hortensis oil. Conclusion: Thymol as a main component of oils plays an important role in antimicrobial activity.


Kan J.,University of Southern California | Kan J.,Microbiology Group | Chellamuthu P.,University of Southern California | Obraztsova A.,University of Southern California | And 2 more authors.
Journal of Applied Microbiology | Year: 2011

Aims: This study applied culture-dependent and molecular approaches to examine the bacterial communities at corrosion sites at Granite Mountain Record Vault (GMRV) in Utah, USA, with the goal of understanding the role of microbes in these unexpected corrosion events. Methods and Results: Samples from corroded steel chunks, rock particles and waters around the corrosion pits were collected for bacterial isolation and molecular analyses. Bacteria cultivated from these sites were identified as members of Alphaproteobacteria, Gammaproteobacteria, Firmicutes and Actinobacteria. In addition, molecular genetic characterization of the communities via nested-polymerase chain reaction-denaturing gradient gel electrophoresis (DGGE) indicated the presence of a broad spectrum of bacterial groups, including Alphaproteobacteria, Betaproteobacteria, Deltaproteobacteria, Actinobacteria, Firmicutes and Bacteroidetes. However, neither cultivation nor molecular approaches identified sulfate-reducing bacteria (SRB), the bacteria commonly implicated as causative organisms were found associated with corrosive lesions in a process referred to as microbially influenced corrosion (MIC). The high diversity of bacterial groups at the corrosion sites in comparison with that seen in the source waters suggested to us a role for the microbes in corrosion, perhaps being an expression of a redox-active group of microbes transferring electrons, harvesting energy and producing biomass. Conclusions: The corrosion sites contained highly diverse microbial communities, consistent with the involvement of microbial activities along the redox gradient at corrosion interface. We hypothesize an electron transport model for MIC, involving diverse bacterial groups such as acid-producing bacteria (APB), SRB, sulfur-oxidizing bacteria (SOB), metal-reducing bacteria (MRB) and metal-oxidizing bacteria (MOB). Significance and Impact of the Study: The characterization of micro-organisms that influence metal-concrete corrosion at GMRV has significant implications for corrosion control in high-altitude freshwater environments. MIC provides a potential opportunity to further our understandings of extracellular electron transfer and interspecies communications. © 2011 The Authors. Journal of Applied Microbiology © 2011 The Society for Applied Microbiology.


PubMed | University of Southampton and Microbiology group
Type: Journal Article | Journal: Stem cells (Dayton, Ohio) | Year: 2016

Activation of the canonical Wnt signaling pathway is an attractive anabolic therapeutic strategy for bone. Emerging data suggest that activation of the Wnt signaling pathway promotes bone mineral accrual in osteoporotic patients. The effect of Wnt stimulation in fracture healing is less clear as Wnt signaling has both stimulatory and inhibitory effects on osteogenesis. Here, we tested the hypothesis that transient Wnt stimulation promotes the expansion and osteogenesis of a Wnt-responsive stem cell population present in human bone marrow. Bone marrow mononuclear cells (BMMNCs) were isolated from patients undergoing hip arthroplasty and exposed to Wnt3A protein. The effect of Wnt pathway stimulation was determined by measuring the frequency of stem cells within the BMMNC populations by fluorescence-activated cell sorting and colony forming unit fibroblast (CFU-F) assays, before determining their osteogenic capacity in in vitro differentiation experiments. We found that putative skeletal stem cells in BMMNC isolates exhibited elevated Wnt pathway activity compared with the population as whole. Wnt stimulation resulted in an increase in the frequency of skeletal stem cells marked by the STRO-1(bright) /Glycophorin A(-) phenotype. Osteogenesis was elevated in stromal cell populations arising from BMMNCs transiently stimulated by Wnt3A protein, but sustained stimulation inhibited osteogenesis in a concentration-dependent manner. These results demonstrate that Wnt stimulation could be used as a therapeutic approach by transient targeting of stem cell populations during early fracture healing, but that inappropriate stimulation may prevent osteogenesis.


PubMed | Animal Plant and Health Agency and Microbiology Group
Type: Comparative Study | Journal: International journal of experimental pathology | Year: 2016

The marmoset model of melioidosis was used to explore whether there was any difference in the disease presentation and/or the lesion formation following inhalational challenge with one of four strains of Burkholderia pseudomallei (K96243, 1026b, HBPUB10303a and HBPUB10134a). Marmosets were challenged with a range of bacterial doses and bacterial load, histological and physiological features were determined temporally following lethal disease. Melioidosis presented as an acute, febrile disease with bacteraemia, bacterial dissemination, necrotizing hepatitis, splenitis and pneumonia which was independent of the challenge strain. Generally, there were no major differences in the manifestation of melioidosis following challenge by the different strains of B. pseudomallei; however, there were some differences in the time to death and the severity of the pathological features. The pathological features observed in the liver and spleen of animals challenged with B. pseudomallei strain 1026b were statistically less severe (P < 0.05) and less frequent. However, more severe foci of disease were evident in the lungs of animals challenged with strain 1026b. In all cases, the lesions developed from small areas of bacteria-infected macrophages surrounded by non-infected neutrophils into large lesions with both immune cell types infected. The marmoset model was a useful tool enabling the distinction of subtle difference in the pathological response to B. pseudomallei.


PubMed | Microbiology Group
Type: Journal Article | Journal: Iranian journal of microbiology | Year: 2012

The aim of this study was to evaluate the chemical composition and antimicrobial activity of Satureja hortensis and Trachyspermum copticum essential oils against different kinds of microorganisms in vitro.The antimicrobial activity was evaluated by micro broth dilution assay and the chemical composition of essential oils was analyzed by GC and GC/MS.Thymol, p-cymene, -terpinene and carvacrol were the main components of S. hortensis oil while thymol, -terpinene, and o-cymene were the major components of T. copticum oil. Two essential oils exhibited strong antimicrobial activity but the antimicrobial activity of T. copticum oil was higher than that of S. hortensis oil.Thymol as a main component of oils plays an important role in antimicrobial activity.

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