“
“The transcriptional repressor Rex has been implicated in the regulation of energy metabolism and fermentative growth in response to redox potential. Streptococcus mutans, the primary causative agent of human dental caries, possesses

a gene that encodes a protein with high similarity to members of the Rex family of proteins. In this study, we showed that Rex-deficiency compromised the ability of S. mutans to cope with oxidative stress and to form biofilms. The Rex-deficient mutant also accumulated less biofilm after 3 days than the wild-type strain, especially when grown in sucrose-containing Epigenetic inhibitor medium, but produced more extracellular glucans than the parental strain. Rex-deficiency caused substantial alterations in gene transcription, including those involved in heterofermentative metabolism, NAD+ regeneration and oxidative stress. Among the upregulated genes was gtfC, which encodes glucosyltransferase C, an enzyme primarily responsible for synthesis of water-insoluble glucans. These results reveal that Rex plays an important role in oxidative stress responses and biofilm formation by S. mutans. Streptococcus mutans lives CHIR99021 almost exclusively in biofilms on the tooth surface, an environment that experiences dramatic fluctuations in nutrient

availability, pH and oxygen tension. As the primary etiological agent of human dental caries, GPX6 the ability to survive various harsh challenges in the oral cavity is known to be critical to its pathogenicity (Burne, 1998). While the molecular mechanisms that govern carbohydrate utilization, acid production and low pH adaptation by this microorganism are well-studied

(Abranches et al., 2008; Lemos & Burne, 2008; Zeng & Burne, 2008), limited information is available concerning oxygen metabolism and oxidative stress and their impact on the expression of virulence traits by S. mutans. Streptococcus mutans lacks a complete respiratory chain and does not normally carry out oxidative phosphorylation, but the organism has a high capacity to metabolize oxygen (Marquis, 1995). When grown on the tooth surface, S. mutans must cope with various oxidative stress conditions, including damaging reactive oxygen species (ROS) and unfavorable cellular redox potential (Marquis, 1995). ROS, such as •O2−, HO•, and H2O2, are produced inside the bacterial cells when growing in an aerobic environment. ROS are toxic as they are highly reactive and can cleave RNA/DNA and oxidize essential proteins and lipids. It was recently shown that aeration significantly decreased the ability of S. mutans to form biofilms (Ahn & Burne, 2007; Ahn et al., 2007). Notably, growth in the presence of oxygen dramatically altered the cell surface, affecting hydrophobicity and the localization of glucosyltransferases B and C (Ahn et al., 2007).

“
“The transcriptional repressor Rex has been implicated in the regulation of energy metabolism and fermentative growth in response to redox potential. Streptococcus mutans, the primary causative agent of human dental caries, possesses

a gene that encodes a protein with high similarity to members of the Rex family of proteins. In this study, we showed that Rex-deficiency compromised the ability of S. mutans to cope with oxidative stress and to form biofilms. The Rex-deficient mutant also accumulated less biofilm after 3 days than the wild-type strain, especially when grown in sucrose-containing selleck chemical medium, but produced more extracellular glucans than the parental strain. Rex-deficiency caused substantial alterations in gene transcription, including those involved in heterofermentative metabolism, NAD+ regeneration and oxidative stress. Among the upregulated genes was gtfC, which encodes glucosyltransferase C, an enzyme primarily responsible for synthesis of water-insoluble glucans. These results reveal that Rex plays an important role in oxidative stress responses and biofilm formation by S. mutans. Streptococcus mutans lives MK-2206 nmr almost exclusively in biofilms on the tooth surface, an environment that experiences dramatic fluctuations in nutrient

availability, pH and oxygen tension. As the primary etiological agent of human dental caries, Edoxaban the ability to survive various harsh challenges in the oral cavity is known to be critical to its pathogenicity (Burne, 1998). While the molecular mechanisms that govern carbohydrate utilization, acid production and low pH adaptation by this microorganism are well-studied

(Abranches et al., 2008; Lemos & Burne, 2008; Zeng & Burne, 2008), limited information is available concerning oxygen metabolism and oxidative stress and their impact on the expression of virulence traits by S. mutans. Streptococcus mutans lacks a complete respiratory chain and does not normally carry out oxidative phosphorylation, but the organism has a high capacity to metabolize oxygen (Marquis, 1995). When grown on the tooth surface, S. mutans must cope with various oxidative stress conditions, including damaging reactive oxygen species (ROS) and unfavorable cellular redox potential (Marquis, 1995). ROS, such as •O2−, HO•, and H2O2, are produced inside the bacterial cells when growing in an aerobic environment. ROS are toxic as they are highly reactive and can cleave RNA/DNA and oxidize essential proteins and lipids. It was recently shown that aeration significantly decreased the ability of S. mutans to form biofilms (Ahn & Burne, 2007; Ahn et al., 2007). Notably, growth in the presence of oxygen dramatically altered the cell surface, affecting hydrophobicity and the localization of glucosyltransferases B and C (Ahn et al., 2007).

difficile protein similar to the VirR toxin gene regulator of C. perfringens. Comparative phylogenomic analysis of C. difficile strains, by Stabler et al. (2009), showed that the deletion of five specific genes, including CD0590, was characteristic of a toxin A−/B+ subclade of C. difficile strains;

therefore, it may be hypothesized that the protein encoded by CD0590 is in some way important for toxin A production by C. difficile. However, under the conditions of our study, neither toxin A nor toxin B was detected. In a previous study of cell-surface proteins (as distinct from the insoluble proteins reported here) from C. difficile, Wright et al. (2005) identified a total of 11 proteins from a glycine extract of whole cells and a further 42 proteins from a lysozyme digest of their peptidoglycan layer, resulting in a total of 47 uniquely identified proteins. It is to be expected that different experimental selleck chemicals approaches, including sample types and extraction

methods, will lead to the identification of different proteomic data for the same organism. For example, the hypothetical proteins identified by us were distinct from those detected by Lawley et al. (2009) in the C. difficile spore proteome. When we compared data from our current investigation with the previous work of Wright et al. (2005), 20 proteins were common to both studies, 27 were unique to Wright and colleagues and 87 were unique to our work. The larger number of proteins identified by our Dasatinib price bottom-up geLC-MS

approach confirms that this experimental strategy can yield significant and important biological information to further our understanding of a microorganism. An important step towards understanding the function of a protein is the determination of its subcellular localization, and in recent years, a number of bioinformatic tools have been developed to assist with this (Emanuelsson et al., 2007). Knowledge of Gram-positive bacterial protein targeting/secretion is essentially restricted to the model organism Bacillus subtlis (Tjalsma et al., 2000, 2004), and indeed, Desvaux et al. (2005) state that protein secretion by clostridia in general is ‘poorly understood’. As the insoluble proteome might be expected to contain proteins associated with, or targeted to, either the cell membrane or the extracellular DNA Synthesis inhibitor milieu, and that could thus play a role in virulence, we therefore used psortb (Gardy et al., 2005), signalp (Bendtsen et al., 2004) and secretomep (Bendtsen et al., 2005) to guide our efforts to assign a subcellular location for each protein. All 107 proteins identified in this study were analysed and assigned a putative or a predicted cellular localization as shown in the workflow depicted in Fig. 2. Within the subset of proteins predicted to be secreted, 23 were identified as possessing an N-terminal signal peptide (Table 2).

Only one in 10 children who reported a problem with using an asthma medication asked a medication question during their consultations. None of the 79 children who had problems using their medications at school asked about school use during their consultation An important finding was that if providers asked Veliparib mouse more questions about asthma control medications, both children

and caregivers who reported at least one medication problem were significantly more likely to ask one or more medication questions. Also, among children who reported a medication problem, those with higher asthma management self-efficacy were twice as likely to ask at least one medication question during consultations

than children with lower self-efficacy. The study is limited in generalizability in that NVP-BEZ235 it was conducted in five paediatric clinics in non-urban areas of North Carolina. Another limitation is that we do not know how many patients that the clinic staff referred chose not to talk with the research assistant. However, we could not ask the clinic staff to track these numbers because of the busyness of the clinic and our promise not to interrupt clinic flow. Providers, children, and caregivers knew they were being recorded and may have changed their communication style and/or content, but they did not know the study hypotheses. Another limitation is that we do not know if caregivers and patients had asked their medication-related questions in prior visits. Also, we did not use a validated scale to assess adherence and we did not assess if patients went to more provider visits in between their audiotaped visits and the 1-month follow-up Nintedanib (BIBF 1120) home visits. We did not examine if the caregivers had asthma or if more than one caregiver was helping manage the child’s asthma. Despite the limitations of the study, it presents new information on the extent to which caregivers and children ask questions during medical visits about asthma medication areas that they

reported having problems with. The study examined actual transcripts of audiotaped paediatric asthma visits so we knew what actual questions caregivers and children asked their providers. We also knew what medication problems children and caregivers reported to the research assistant, so we could compare what problems they stated having to what types of questions they asked their providers. Pharmacists could help caregivers by asking them if they would like a demonstration of how to correctly use their child’s asthma medication devices. Pharmacists could also ask questions like ‘Is your child experiencing side effects when using their asthma medications?’ or ‘Is your child having any problems with their asthma medications?’ to encourage caregivers to discuss side effects.

Outliers presenting after longer durations of ART had been on other

NRTI drugs prior to a substitution to d4T (n=3). Univariate analysis showed that cases were more likely to be female, have a higher baseline weight and gain weight more rapidly in the first 3 months on ART (Table 1). The overwhelming majority of cases were female (94.4%), compared with 66.2% of the controls [odds ratio (OR) 10.0; 95% CI 3.0–33.2]. Where height measurements were available (52 cases and 49 controls), 51.0% of the cases had a BMI (kg/m2) ≥30 (obese), while only 12.2% of the controls were in the same category

(OR 17.7; 95% CI 2.3–134.8). Compared with controls, a higher proportion of cases started ART Pexidartinib mw with a weight above 75 kg (44.8%vs. 15.4%; OR 4.2; 95% CI 2.1–8.5). During the first 3 months on ART, 38.5% of cases gained more than 6 kg compared with 25.2% of the controls (OR 1.8 per 10 kg; 95% CI 1.0–3.5). There were no routine baseline laboratory results that were found to be associated with SHLA during crude analysis. Clinical stage and baseline age were also not associated with SHLA; cases started ART at a median age of 34.1 years (IQR 30.5–41.2 years) compared Selleckchem NVP-BEZ235 with 36.7 years (IQR 32.4–43.2 years) in controls (OR 0.8 per 10 years; 95% CI 0.6–1.2). The first multivariate model contains data that describe the time period

before the onset of signs or symptoms related to SHLA, identifying characteristics of patients who may at the outset be at a greater risk of developing SHLA (Table 2). Very strong associations with SHLA persisted for women and patients with high initial body weight. The adjusted odds ratio (AOR) for women compared with men was 23.4 (95% CI 4.0–136.6). Compared with a body weight of below 60 kg, the AOR was 4.5 (95% CI 1.4–14.1) for those with an initial weight of 60–74.9 kg, and 19.4 (95% CI 4.6–82.6) for those with an initial weight ≥75 kg. During the first 3 months on ART, cases were at 3.5 times greater odds of having gained at least 6 kg in comparison to controls (95% CI 1.3–9.5). Table 3 explores associations between patient PAK6 characteristics during follow-up and subsequent diagnosis of SHLA. All patients who presented with SHLA during the 27-month study period had been or were currently exposed to d4T for >100 days in comparison to 87% of the controls. Altogether, eight of the cases were on a 60 mg total daily dosage of d4T for >100 days. Of these eight cases, four remained on this dosage for their entire time on ART prior to diagnosis while the remaining four were on the 80 mg dosage at some point during their treatment. In univariate analysis, cases with SHLA were more likely to have a rise in ALT of ≥10 U/L between baseline and their peak measurements (OR 4.1; 95% CI 1.8–9.1, in 47 cases and 84 controls who had serial ALT measurements).

According to Peleg et al. (2008), even if species of this genus do not necessarily have their habitat

in the environment, no systematic study has been performed concerning the occurrence of the different species and their natural habitats still remain to be determined. In a hospital environment, on the other hand, it has been conclusively proven that a water system can be a reservoir for this bacterium (Huang et al., 2008). Improved understanding of the reservoirs and routes of transmission of this bacterium is indeed needed in the effective operation of prevention and control. On the other hand, it is now well known that check details some protozoa, including free-living amoebae of the Acanthamoeba genus, may support bacterial growth in aquatic ecosystems and serve as reservoirs and vehicles PLX3397 in vitro for a number of pathogenic microorganisms (Greub & Raoult, 2004). Their life cycle consists of two stages: an actively feeding, dividing trophozoite and a dormant cyst. They colonize domestic and institutional water systems such as domestic tap water, hospital water networks, swimming pools, dental unit waterlines and cooling towers (Sanden et al.,

1992; Rohr et al., 1998; Thomas et al., 2008, 2009). Interactions between free-living amoebae and Legionella pneumophila have been studied extensively (Marciano-Cabral & Cabral, 2003; Bouyer et al., 2007; Dey et al., 2009), but numerous other bacteria can also interact with these GBA3 protozoa (Greub & Raoult, 2004), including Mycobacterium sp. (Steinert et al., 1998; Sharbati-Tehrani et al., 2005), Pseudomonas sp. (Marciano-Cabral & Cabral, 2003), Vibrio sp. (Sandstrom

et al. 2010; Abd et al., 2005, 2010), Campylobacter sp. (Axelsson-Olsson et al., 2010), Francisella tularensis (Greub & Raoult, 2004) or Listeria monocytogenes (Akya et al., 2009). The objective of our study is to analyze the relationships between two strains of Acanthamoeba (Acanthamoeba castellanii and Acanthamoeba culbertsoni) and two strains of A. baumanii in order to investigate whether Acanthamoeba could influence the growth and/or survival of this bacterium. Acanthamoeba castellanii ATCC 30234 and A. culbertsoni ATCC 30171 were grown in 150-cm2 tissue culture flasks in PYG broth at 27 °C (Schuster, 2002). When cells formed a monolayer, the trophozoites were harvested by tapping the flasks and washed three times in Page’s modified Neff’s amoeba saline (PAS, containing in 1 L of distilled water, 120 mg NaCl, 4 mg MgSO4·7H2O, 4 mg CaCl2·2H2O, 142 mg Na2HPO4 and 36 mg KH2PO4). For experiments carried out in 96-well microtiter plates, amoebae were used at a final cell concentration of 5 × 105 mL−1 in PAS or in filtered tap water (0.22 μm). Two antibiotic-sensitive strains of A. baumanii (named Ab1 and Ab2) were isolated from water of Poitiers Teaching Hospital (France).

, 2005; Miot & Betton, 2007). CpxP has no obligatory function for the induction of the Cpx response (Raivio et al., 1999; DiGiuseppe & Silhavy, 2003). However, the cpxP gene was identified as a CpxR target involved in inhibiting the expression of toxic envelope proteins, including misfolded pilus subunits of P-pili that are crucial for uropathogenic E. coli (UPEC) during kidney colonization (Jones et al., 1997; Danese et al., 1998; Hung et al., 2001; Isaac et al., 2005). In agreement with its function selleck chemicals llc in quality control for subunits of surface appendages, CpxP is also involved in the early steps of biofilm

formation (Beloin et al., 2004; Yang et al., 2008). Biochemical analysis of the reconstituted CpxAR phosphorylation cascade demonstrated that CpxP, incorporated into the lumen of the proteoliposomes, inhibits the autophosphorylation of CpxA (Fleischer et al., 2007). As the reconstituted system excludes the involvement of other factors, this finding indicates a direct protein–protein interaction between CpxP and CpxA (Fleischer et al., 2007; Zhou et al., 2011). In support of this, peptide library

screens showed that the purified PSD of CpxA directly interacts with CpxP (Zhou et al., PLX4032 mouse 2011). Interestingly, the interaction of purified CpxP with peptides derived from the PSD of CpxA depends on negative charges within this domain (Zhou et al., 2011). The crystal structure of CpxP gave further insight into this interaction (Thede et al., 2011; Zhou et al., 2011). CpxP consists of a dimer, the monomers of which are interwined like ‘left hands’ (Thede et al., 2011; Zhou et al., 2011). Thereby, each monomer is strengthened by double hydrogen bonds between two highly conserved LTxxQ repeat motifs. Based on the structural and biochemical analysis, CpxP-mediated Cpx inhibition results from

an interaction between the concave polar surface of CpxP and the negatively charged sensor domain of CpxA (Fig. 3a; Zhou et al., 2011). The CpxP dimer acts as a patch to shield the CpxA sensor domain from inducing signals, maintaining Thiamet G the SK in an ‘off’ mode. Moreover, the structure of CpxP provides explanations of how CpxP might act as a sensor for salt (Zhou et al., 2011), pH (Thede et al., 2011) and misfolded pilus subunits (Zhou et al., 2011) for the Cpx system. Physicochemical and chemical stimuli inducing the Cpx response include alkaline pH, salt (Raivio & Silhavy, 1997), depletion of the major lipid phosphatidylethanolamine (Mileykovskaya & Dowhan, 1997), attachment to hydrophobic surfaces (Otto & Silhavy, 2002), intermediates of the acetyl-CoA pathway (Wolfe et al., 2008; Lima et al., 2011), low cAMP levels (Strozen et al., 2005), carbon monoxide (Davidge et al., 2009), metals (Lee et al., 2005; Yamamoto & Ishihama, 2006), indole (Raffa & Raivio, 2002), alcohols, acetone and the anaesthetics procaine and phenethyl alcohol (Clarke & Voigt, 2011; Table 1).

For the purpose of predicting candidate sRNAs, both strands of the 1396 intergenic regions (IGs) at least 50 nucleotides in length in the N. europaea genome (Chain et al., 2003) were analyzed using a computational approach that integrates primary sequence information and comparative genomics analysis (Tjaden, 2008a, b). In summary, candidate ρ-independent transcription terminators in the N. europaea genome were predicted using the program transtermhp (Kingsford et RO4929097 clinical trial al., 2007). For the comparative genomics analysis, evidence of base-pair substitutions that conserve the sRNA secondary structure was identified by comparing both strands

of each of the 1396 IGs of the N. europaea genome with the following betaproteobacterial genomes: Acidovorax JS42, Bordetella bronchiseptica, Burkholderia pseudomallei K96243, Herminiimonas arsenicoxydans, Methylobacillus flagellatus KT, Neisseria meningitidis MC58, Nitrosomonas eutropha C91, Nitrosospira multiformis ATCC 25196, Polaromonas JS666, and Ralstonia solanacearum. For the 15 IGs predicted to contain likely sRNAs, alignments and covarying residues evincing the conserved

selleck chemicals RNA secondary structure (Supporting Information, Fig. S1). The 15 predicted sRNA sequences were then searched against the Rfam model library (Griffiths-Jones et al., 2005). Following the Rfam search methodology, each sequence was scanned against the library of Rfam sequences using wu-blast with an E-value threshold of 1.0. Any matches were then scanned against the corresponding covariance model using the Rfam threshold for that family of sequences. Data from 42 N. europaea Affymetrix Bupivacaine microarrays were obtained from the Gene Expression Omnibus (Edgar et al., 2002). The experimental data for these microarrays were derived from cells exposed to chloroform, chloromethane (Gvakharia et al., 2007),

zinc, cadmium, cyanide (Park & Ely, 2008, 2009), benzene, or toluene (Radniecki et al., 2008), and from all the corresponding controls. Tiled oligonucleotide probes on the arrays assayed each of the 2461 protein-coding genes as well as one strand of 1042 IGs of the N. europaea genome. Data from all microarray experiments were normalized so that the median intensities are the same across all arrays. GeneRacer® Core Kit from Invitrogen (Carlsbad, CA) was used to confirm the expression and the full length of the transcripts of the two selected psRNAs (psRNA5 and psRNA11). RNA extracted from chloromethane-treated cells was used to map the transcripts’ 5′- and 3′-ends. The cDNA was generated by reverse transcription of the RNA with SuperScript Reverse Transcriptase (Invitrogen). To distinguish the primary transcript 5′-ends from internal 5′-processing sites, we analyzed the RNAs with 5′-rapid amplification of cDNA ends (RACE), with and without treatment with tobacco acid pyrophosphatase (TAP).

Electronic databases were searched

and duplicate articles were removed. All articles were reviewed manually by title, abstract and/or full text for relevance. The reference lists of retrieved articles and relevant review articles were manually examined for further applicable studies. The key journals were also manually screened for further relevant articles. Full-text manuscripts were retrieved either electronically or as hard copy for assessment. Information was extracted into a pro forma which included: primary author name and date of publication, study design and study duration, participants’ age, setting, sample, type(s) and possible cause(s) of MRPs, intervention or recommendations to address the problems or to support ethnic minorities MK0683 in the use of medicines. Studies of MRPs experienced by ethnic minority patients in the UK are shown in Table 2. Communication and language barriers;

problems with interpretation provided; problems with non-prescription medicine; limited knowledge of the medical and healthcare system; lack of belief in the treatment they received. Lip (2002)[21] Some patients had limited knowledge of atrial fibrillation as well as its consequences and therapy; problems with not taking medicines as advised. Ethnic, cultural and religious differences; communication and language barriers; poor amount of counselling and information given to patients by healthcare professionals. Horne Trichostatin A chemical structure (2004)[33] High risk of not taking medicines as advised. Students of South Asian Resminostat origin had higher General Harm score

than those of European origin (i.e. they perceived medicines as being intrinsically harmful, addictive substances that should be avoided (P < 0.001) and they were significantly (P < 0.001) less likely to endorse the benefits of modern medication). Cultural beliefs; current and previous experience of taking medication. Indo-Asians and Afro-Caribbeans were less aware of CHF as well as its consequences and therapy; problems with not taking medicines as advised. Ethnic, cultural and religious differences; communication and language barriers; poor amount of counselling and information given to patients. South Asians were less aware of diabetes as well as its consequences; problems with not taking medicines as advised and missing clinical appointments. Cultural and religious influences; language and communication barriers; problems with interpretation provided. Using pictorial flashcards to provide information for illiterate people instead of providing written information in a native language; providing bilingual link-workers.

The absence of metabolically favorable carbon sources in the chitin-containing media could trigger

the negative regulation of the gpdh1 gene to the detriment of the positive regulation of genes encoding the enzymes required for the use of metabolically less favorable carbon sources. The complexity of the exoskeleton that was added to the culture medium is difficult to determine. This could explain the positive regulation of the GAPDH gene in the exoskeleton-containing media, in addition to the possible host-adhesion role of GAPDH (Dutra et al., 2004; Mogensen et al., 2006). Immunofluorescence microscopy was performed to elucidate JQ1 the subcellular protein localization. Conidia, appressoria, mycelia, blastospores and germinated blastospores were analyzed and both cytosolic and surface forms of the GAPDH protein were observed in vesicular-like structures, as reported before (Rodrigues et al., 2007, 2008; De Jesus et al., 2009). Cell-surface GAPDH localization was corroborated by Triton X-100 surface removal of the protein and the measurement of specific GAPDH activity. Surface GAPDH was also quantified by fluorescence using

a polyclonal antibody. Both methods corroborated the presence of GAPDH on the cell surface. This ‘unexpected’ localization of cytosolic enzymes is increasingly being recognized in

both eukaryotic and prokaryotic cells (Barbosa et al., 2006; Egea et al., 2007). The presence of GAPDH on the external cell surface of M. anisopliae Alectinib in vitro raises some questions, such as how incorporation into the cell wall occurs in the absence of a conventional N-terminal signal sequence that is responsible for targeting the protein in the secretory pathway. The vesicular-like structures presented by GAPDH would lead us to hypothesize that there is a vesicle-secretion pathway across the cell wall (Rodrigues et al., Ponatinib research buy 2007); however, more studies will be needed to verify this possibility. The blastospore pole migration pattern evidenced after a 64-h cultivation and the almost complete GAPDH migration to the poles of germinated blastospore are remarkable events in GAPDH localization in M. anisopliae cells. One simple explanation for this recruitment is the increased metabolic activity in these regions of the germinating cells. On the other hand, the surface localization at the blastospore pole could have another function: inhibition of the host immune system through a molecular mimicry mechanism, because the fungal and host GAPDH share high identity, leading to a lack of recognition of the pathogen by the host immune system (Goudot-Crozel et al., 1989; Terao et al., 2006). The possible involvement of M.