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Sample records for bacteria modulates infections

  1. Modulation of Stat-1 in Human Macrophages Infected with Different Species of Intracellular Pathogenic Bacteria

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    Giuditta Fiorella Schiavano

    2016-01-01

    Full Text Available The infection of human macrophages by pathogenic bacteria induces different signaling pathways depending on the type of cellular receptors involved in the microorganism entry and on their mechanism(s of survival and replication in the host cell. It was reported that Stat proteins play an important role in this process. In the present study, we investigate the changes in Stat-1 activation (phosphorylation in p-tyr701 after uptake of two Gram-positive (Listeria monocytogenes and Staphylococcus aureus and two Gram-negative bacteria (Salmonella typhimurium and Legionella pneumophila characterized by their varying abilities to enter, survive, and replicate in human macrophages. Comparing the results obtained with Gram-negative and Gram-positive bacteria, Stat-1 activation in macrophages does not seem to be related to LPS content. The p-tyr701Stat-1 expression levels were found to be independent of the internalized bacterial number and IFN-γ release. On the contrary, Jak/Stat-1 pathway activation only occurs when an active infection has been established in the host macrophage, and it is plausible that the differences in the expression levels of p-tyr701Stat-1 could be due to different survival mechanisms or to differences in bacteria life cycles within macrophages.

  2. Chronic oral infection with major periodontal bacteria Tannerella forsythia modulates systemic atherosclerosis risk factors and inflammatory markers.

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    Chukkapalli, Sasanka S; Rivera-Kweh, Mercedes F; Velsko, Irina M; Chen, Hao; Zheng, Donghang; Bhattacharyya, Indraneel; Gangula, Pandu R; Lucas, Alexandra R; Kesavalu, Lakshmyya

    2015-04-01

    Tannerella forsythia is a Gram-negative anaerobic organism that inhabits the subgingival cavity and initiates connective tissue destruction and alveolar bone resorption in periodontal disease (PD). PD is a chronic immunoinflammatory disease and has been linked to several systemic diseases including atherosclerosis. This study evaluated the effects of a chronic oral infection with T. forsythia ATCC 43037 on the induction of PD, inflammatory markers and atherosclerosis risk factors in hyperlipidemic ApoE(null) mice. Mice were orally infected for 12 and 24 weeks prior to euthanasia. Bacterial colonization of the oral cavity and bacteremia was confirmed via isolation of genomic DNA from oral plaque and tissues. Oral infection elicited significantly elevated levels of serum IgG and IgM antibodies and alveolar bone resorption compared to control mice. Tannerella forsythia-infected mice had increased serum amyloid A, and significantly reduced serum nitric oxide when compared to controls. Tannerella forsythia chronic infection also significantly increased serum lipoproteins suggesting altered cholesterol metabolism and potential for aortic inflammation. Despite enhanced acute phase reactants and altered lipid profiles, T. forsythia infection was associated with decreased aortic plaque. This study investigates the potential of a known periodontal bacterial pathogen found in atherosclerotic plaque in humans to accelerate atherosclerosis in hyperlipdemic mice.

  3. Extract of Pelargonium sidoides (EPs 7630) displays anti-infective properties by enhanced phagocytosis and differential modulation of host-bacteria interactions.

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    Conrad, Andreas; Frank, Uwe

    2008-05-01

    EPs 7630 is an aqueous-ethanolic extract of the roots of PELARGONIUM SIDOIDES that displays well-documented benefits in the treatment of upper respiratory tract infections (URTI). IN VITRO and animal investigations have revealed various anti-infective properties of EPs 7630. The present review sums up recently published IN VITRO investigations that have shown positive effects on the activity of human peripheral blood phagocytes (PBP) and differential modulation of the interactions between group A streptococci and the host's epithelial barrier.

  4. Bacteria Isolated from Post-Partum Infections

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    Nahid Arianpour

    2009-06-01

    Full Text Available Objective: This study was undertaken with an aim to determine bacterial species involved in post partum infections and also their abundance in patients admitted to at Khanevadeh hospital. In this study out of three different kinds of postpartum infections (i.e. genital, breast and urinary tract, only genital infection is considered.Materials and Methods: Post partum infection among 6077 patients (inpatients and re-admitted patients of Khanevadeh hospital from 2003 till 2008 was studied in this descriptive study. Samples were collected from patients for laboratory diagnosis to find out the causative organisms.Results: Follow up of mothers after delivery revealed 7.59% (461 patients had post partum infection, out of which 1.03% (63 patients were re-hospitalized. Infection was more often among younger mothers. Bacteria isolated and identified were both aerobic and anaerobic cocci and bacilli, majority of which were normal flora of the site of infection. Though, some pathogenic bacteria like Staphylococcus aureus, Neisseria gonorrhea, Chlamydia trachomatis,were also the causative agents. The commonest infection was infection at the site of episiotomy. Conclusion: Puerperal infection was detected in of 7.59% mothers. Bacteria isolated were both aerobic and anaerobic cocci and bacilli, majority of which were normal flora. However; some pathogenic bacteria were isolated.

  5. Bacteria and protozoa differentially modulate the expression of Rab proteins.

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    Elsa Seixas

    Full Text Available Phagocytic cells represent an important line of innate defense against microorganisms. Uptake of microorganisms by these cells involves the formation of a phagosome that matures by fusing with endocytic compartments, resulting in killing of the enclosed microbe. Small GTPases of the Rab family are key regulators of vesicular trafficking in the endocytic pathway. Intracellular pathogens can interfere with the function of these proteins in order to subvert host immune responses. However, it is unknown if this subversion can be achieved through the modulation of Rab gene expression. We compared the expression level of 23 distinct Rab GTPases in mouse macrophages after infection with the protozoan Plasmodium berghei, and the bacteria Escherichia coli and Salmonella enterica. We found that P. berghei induces an increase in the expression of a different set of Rab genes than E. coli and S. enterica, which behaved similarly. Strikingly, when one of the Rab proteins whose expression was increased by P. berghei, namely Rab14, was silenced, we observed a significant increase in the phagocytosis of P. berghei, whereas Rab14 overexpression led to a decrease in phagocytosis. This suggests that the parasite might induce the increase of Rab14 expression for its own advantage. Similarly, when Rab9a, whose expression was increased by E. coli and S. enterica, was silenced, we observed an increase in the phagocytosis of both bacterial species, whereas Rab9a overexpression caused a reduction in phagocytosis. This further suggests that the modulation of Rab gene expression could represent a mechanism of immune evasion. Thus, our study analyzes the modulation of Rab gene expression induced by bacteria and protozoa and suggests that this modulation could be necessary for the success of microbial infection.

  6. Bacteria-Targeting Nanoparticles for Managing Infections

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    Radovic-Moreno, Aleksandar Filip

    Bacterial infections continue to be a significant concern particularly in healthcare settings and in the developing world. Current challenges include the increasing spread of drug resistant (DR) organisms, the side effects of antibiotic therapy, the negative consequences of clearing the commensal bacterial flora, and difficulties in developing prophylactic vaccines. This thesis was an investigation of the potential of a class of polymeric nanoparticles (NP) to contribute to the management of bacterial infections. More specifically, steps were taken towards using these NPs (1) to achieve greater spatiotemporal control over drug therapy by more targeted antibiotic delivery to bacteria, and (2) to develop a prophylactic vaccine formulation against the common bacterial sexually transmitted disease (STD) caused by Chlamydia trachomatis. In the first part, we synthesized polymeric NPs containing poly(lactic-co-glycolic acid)-block-poly(L-histidine)-block-poly(ethylene glycol) (PLGA-PLH-PEG). We show that these NPs are able to bind to bacteria under model acidic infection conditions and are able to encapsulate and deliver vancomycin to inhibit the growth of Staphylococcus aureus bacteria in vitro. Further work showed that the PLGA-PLH-PEG-based NPs demonstrated the potential for competition for binding bacteria at a site of infection from soluble protein and model phagocytic and tissue-resident cells in a NP composition dependent manner. The NPs demonstrated low toxicity in vitro, were well tolerated by mice in vivo, and circulated in the blood on timescales comparable to control PLGA-PEG NPs. In the second part, we used PLGA-PLH-PEG-based NPs to design a prophylactic vaccine against the obligate intracellular bacterium Chlamydia trachomatis, the most common cause of bacterial STD in the world. Currently, no vaccines against this pathogen are approved for use in humans. We first formulated NPs encapsulating the TLR7 agonist R848 conjugated to poly(lactic acid) (R848-PLA

  7. Bacteria in surface infections of neonates.

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    Ghosh, S; Chatterjee, B D; Chakraborty, C K; Chakravarty, A; Khatua, S P

    1995-04-01

    A bacteriological work on surface infections was done among live births (study group I) and neonates admitted in hospital (study group II). Out of 134 cases of conjunctivitis in group I Gram-negative bacilli predominated (48.5%) with Escherichia coli accounting for 29 (14.9%) cases, Klebsiella species 15 (11.2%) cases, Citrobacter freundii 3 (2.2%) cases, Pseudomons aeruginosa 18 (13.4%) cases and Aeromonas hydrophila 3 (2.2%) amongst pure isolates (73.9%). Gonococcus was noted in 2 (1.5%) cases. In group II, 41.7% were Staphylococcus aureus in pure growth (75%), compared to only 9.0% in group I. Skin infections were caused by both Staphylococcus aureus and Staphylococcus epidermidis. Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa were the principal insolates from umbilical sepsis. Pseudomonas aeruginosa was isolated as pure growth from local site of noma neonatorum. Anaerobic cultures were negative in all except in 2 cases of umbilical sepsis with tetanus neonatorum revealing Clostridium tetani which however proved to be non-toxigenic. Blood cultures were positive in 4 out of 14 cases bearing 50% correlation with bacteria from surface infections. A source study established partial correlation with the cases of pseudomonas conjunctivitis. Phage typing of Staphylococcus aureus and biochemical typing failed to detect any definite marker of clinical entities, except that the skin infections were caused by group III phages predominantly (65.0%).

  8. AZF Microdeletions in Human Semen Infected with Bacteria

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    Hayfa H Hassani

    2011-11-01

    Full Text Available Bacterial infections are associated with infertility in men. This study was aimed to investigate microdeletions on Yq chromosome in semen infected with bacteria by using bacteriological, biochemical, and serological assays. The investigation showed that 107 of 300 (84.80% semen samples collected from infertile men with primary or secondary infertility were infected with different species of bacteria. Chlamydia trachomatis and Neisseria gonorrheae were the most frequently diagnosed bacteria in the infected semen samples. The percentages of infections of semen samples with C. trachomatis and N. gonorrhea were 42.31% and 35.28% respectively. Genomic DNA from each semen sample infected with predominant bacteria was analyzed for AZF deletions by using multiplex PCR. Different patterns of AZF microdeletions were obtained. It can be concluded that sexually transmitted bacteria may contribute in microdeletions of Yq chromosome by indirectly producing reactive oxygen species and causing gene defect in AZF regions.

  9. The interplay between Entamoeba and enteropathogenic bacteria modulates epithelial cell damage.

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    José Manuel Galván-Moroyoqui

    : The in vitro system presented here provides evidence that the Entamoeba/enteropathogenic bacteria interplay modulates epithelial cell responses to the pathogens. In mixed intestinal infections, where such interactions are possible, they could influence the outcome of disease. The results offer insights to continue research on this phenomenon.

  10. Parasitic infection improves survival from septic peritonitis by enhancing mast cell responses to bacteria in mice.

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    Rachel E Sutherland

    Full Text Available Mammals are serially infected with a variety of microorganisms, including bacteria and parasites. Each infection reprograms the immune system's responses to re-exposure and potentially alters responses to first-time infection by different microorganisms. To examine whether infection with a metazoan parasite modulates host responses to subsequent bacterial infection, mice were infected with the hookworm-like intestinal nematode Nippostrongylus brasiliensis, followed in 2-4 weeks by peritoneal injection of the pathogenic bacterium Klebsiella pneumoniae. Survival from Klebsiella peritonitis two weeks after parasite infection was better in Nippostrongylus-infected animals than in unparasitized mice, with Nippostrongylus-infected mice having fewer peritoneal bacteria, more neutrophils, and higher levels of protective interleukin 6. The improved survival of Nippostrongylus-infected mice depends on IL-4 because the survival benefit is lost in mice lacking IL-4. Because mast cells protect mice from Klebsiella peritonitis, we examined responses in mast cell-deficient Kit(W-sh/Kit(W-sh mice, in which parasitosis failed to improve survival from Klebsiella peritonitis. However, adoptive transfer of cultured mast cells to Kit(W-sh/Kit(W-sh mice restored survival benefits of parasitosis. These results show that recent infection with Nippostrongylus brasiliensis protects mice from Klebsiella peritonitis by modulating mast cell contributions to host defense, and suggest more generally that parasitosis can yield survival advantages to a bacterially infected host.

  11. Activation of type III interferon genes by pathogenic bacteria in infected epithelial cells and mouse placenta.

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    Hélène Bierne

    Full Text Available Bacterial infections trigger the expression of type I and II interferon genes but little is known about their effect on type III interferon (IFN-λ genes, whose products play important roles in epithelial innate immunity against viruses. Here, we studied the expression of IFN-λ genes in cultured human epithelial cells infected with different pathogenic bacteria and in the mouse placenta infected with Listeria monocytogenes. We first showed that in intestinal LoVo cells, induction of IFN-λ genes by L. monocytogenes required bacterial entry and increased further during the bacterial intracellular phase of infection. Other Gram-positive bacteria, Staphylococcus aureus, Staphylococcus epidermidis and Enterococcus faecalis, also induced IFN-λ genes when internalized by LoVo cells. In contrast, Gram-negative bacteria Salmonella enterica serovar Typhimurium, Shigella flexneri and Chlamydia trachomatis did not substantially induce IFN-λ. We also found that IFN-λ genes were up-regulated in A549 lung epithelial cells infected with Mycobacterium tuberculosis and in HepG2 hepatocytes and BeWo trophoblastic cells infected with L. monocytogenes. In a humanized mouse line permissive to fetoplacental listeriosis, IFN-λ2/λ3 mRNA levels were enhanced in placentas infected with L. monocytogenes. In addition, the feto-placental tissue was responsive to IFN-λ2. Together, these results suggest that IFN-λ may be an important modulator of the immune response to Gram-positive intracellular bacteria in epithelial tissues.

  12. Immune regulation of a chronic bacteria infection and consequences for pathogen transmission

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    Pathak Ashutosh K

    2010-08-01

    Full Text Available Abstract Background The role of host immunity has been recognized as not only playing a fundamental role in the interaction between the host and pathogen but also in influencing host infectiousness and the ability to shed pathogens. Despite the interest in this area of study, and the development of theoretical work on the immuno-epidemiology of infections, little is known about the immunological processes that influence pathogen shedding patterns. Results We used the respiratory bacterium Bordetella bronchiseptica and its common natural host, the rabbit, to examine the intensity and duration of oro-nasal bacteria shedding in relation to changes in the level of serum antibodies, blood cells, cytokine expression and number of bacteria colonies in the respiratory tract. Findings show that infected rabbits shed B. bronchiseptica by contact up to 4.5 months post infection. Shedding was positively affected by number of bacteria in the nasal cavity (CFU/g but negatively influenced by serum IgG, which also contributed to the initial reduction of bacteria in the nasal cavity. Three main patterns of shedding were identified: i- bacteria were shed intermittently (46% of individuals, ii- bacteria shedding fell with the progression of the infection (31% and iii- individuals never shed bacteria despite being infected (23%. Differences in the initial number of bacteria shed between the first two groups were associated with differences in the level of serum antibodies and white blood cells. These results suggest that the immunological conditions at the early stage of the infection may play a role in modulating the long term dynamics of B. bronchiseptica shedding. Conclusions We propose that IgG influences the threshold of bacteria in the oro-nasal cavity which then affects the intensity and duration of individual shedding. In addition, we suggest that a threshold level of infection is required for shedding, below this value individuals never shed bacteria

  13. Modulation of Intestinal Epithelial Defense Responses by Probiotic Bacteria.

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    Wan, L Y M; Chen, Z J; Shah, N P; El-Nezami, H

    2016-12-09

    Probiotics are live microorganisms, which when administered in food confer numerous health benefits. In previous studies about beneficial effects of probiotic bacteria to health, particularly in the fields of intestinal mucosa defense responses, specific probiotics, in a strain-dependent manner, show certain degree of potential to reinforce the integrity of intestinal epithelium and/or regulate some immune components. The mechanism of probiotic action is an area of interest. Among all possible routes of modulation by probiotics of intestinal epithelial cell-mediated defense responses, modulations of intestinal barrier function, innate, and adaptive mucosal immune responses, as well as signaling pathways are considered to play important role in the intestinal defense responses against pathogenic bacteria. This review summarizes the beneficial effects of probiotic bacteria to intestinal health together with the mechanisms affected by probiotic bacteria: barrier function, innate, and adaptive defense responses such as secretion of mucins, defensins, trefoil factors, immunoglobulin A (IgA), Toll-like receptors (TLRs), cytokines, gut associated lymphoid tissues, and signaling pathways.

  14. Current taxonomy of phages infecting lactic acid bacteria

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    Jennifer eMahony

    2014-01-01

    Full Text Available Phages infecting lactic acid bacteria have been the focus of significant research attention over the past three decades. Through the isolation and characterization of hundreds of phage isolates, it has been possible to classify phages of the dairy starter and adjunct bacteria Lactococus lactis, Streptococcus thermophilus, Leuconostoc spp. and Lactobacillus spp. Among these, phages of L. lactis have been most thoroughly scrutinized and serve as an excellent model system to address issues that arise when attempting taxonomic classification of phages infecting other LAB species. Here, we present an overview of the current taxonomy of phages infecting LAB genera of industrial significance, the methods employed in these taxonomic efforts and how these may be employed for the taxonomy of phages of currently underrepresented and emerging phage species.

  15. Secular Trends in Nosocomial Bloodstream Infections : Antibiotic-Resistant Bacteria Increase the Total Burden of Infection

    NARCIS (Netherlands)

    Ammerlaan, H. S. M.; Harbarth, S.; Buiting, A. G. M.; Crook, D. W.; Fitzpatrick, F.; Hanberger, H.; Herwaldt, L. A.; van Keulen, P. H. J.; Kluytmans, J. A. J. W.; Kola, A.; Kuchenbecker, R. S.; Lingaas, E.; Meessen, N.; Morris-Downes, M. M.; Pottinger, J. M.; Rohner, P.; dos Santos, R. P.; Seifert, H.; Wisplinghoff, H.; Ziesing, S.; Walker, A. S.; Bonten, M. J. M.

    2013-01-01

    Background. It is unknown whether rising incidence rates of nosocomial bloodstream infections (BSIs) caused by antibiotic-resistant bacteria (ARB) replace antibiotic-susceptible bacteria (ASB), leaving the total BSI rate unaffected. Methods. We investigated temporal trends in annual incidence densit

  16. Modulation of host responses by oral commensal bacteria

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    Deirdre A. Devine

    2015-02-01

    Full Text Available Immunomodulatory commensal bacteria are proposed to be essential for maintaining healthy tissues, having multiple roles including priming immune responses to ensure rapid and efficient defences against pathogens. The default state of oral tissues, like the gut, is one of inflammation which may be balanced by regulatory mechanisms and the activities of anti-inflammatory resident bacteria that modulate Toll-like receptor (TLR signalling or NF-κB activation, or influence the development and activities of immune cells. However, the widespread ability of normal resident organisms to suppress inflammation could impose an unsustainable burden on the immune system and compromise responses to pathogens. Immunosuppressive resident bacteria have been isolated from the mouth and, for example, may constitute 30% of the resident streptococci in plaque or on the tongue. Their roles in oral health and dysbiosis remain to be determined. A wide range of bacterial components and/or products can mediate immunomodulatory activity, raising the possibility of development of alternative strategies for therapy and health promotion using probiotics, prebiotics, or commensal-derived immunomodulatory molecules.

  17. Lactic acid bacteria protect human intestinal epithelial cells from Staphylococcus aureus and Pseudomonas aeruginosa infections.

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    Affhan, S; Dachang, W; Xin, Y; Shang, D

    2015-12-16

    Staphylococcus aureus and Pseudomonas aeruginosa are opportunistic pathogens that cause nosocomial and food-borne infections. They promote intestinal diseases. Gastrointestinal colonization by S. aureus and P. aeruginosa has rarely been researched. These organisms spread to extra gastrointestinal niches, resulting in increasingly progressive infections. Lactic acid bacteria are Gram-positive bacteria that produce lactic acid as the major end-product of carbohydrate fermentation. These bacteria inhibit pathogen colonization and modulate the host immune response. This study aimed to investigate the effects of Lactobacillus acidophilus and Lactobacillus rhamnosus on enteric infections caused by the paradigmatic human pathogens S. aureus ATCC25923 and P. aeruginosa ATCC27853. The effect of whole cells and neutralized cell-free supernatant (CFS) of the lactobacilli on LoVo human carcinoma enterocyte (ATCC CCL-229) infection was analyzed by co-exposure, pre-exposure, and post-exposure studies. Simultaneous application of whole cells and CFS of the lactobacilli significantly eradicated enterocyte infection (P cells and CFS were added after or prior to the infection (P > 0.05). This result could be attributed to interference by extracellular polymeric substances and cell surface hydrophobicity, which resulted in the development of a pathogen that did not form colonies. Furthermore, results of the plate count and LIVE/ DEAD BacLight bacterial viability staining attributed this inhibition to a non-bacteriocin-like substance, which acted independently of organic acid and H2O2 production. Based on these results, the cell-free supernatant derived from lactobacilli was concluded to restrain the development of S. aureus and P. aeruginosa enteric infections.

  18. [Modulation of inflammatory cells in helminth infections].

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    Bruschi, F

    1997-01-01

    In this review, different mechanisms by which helminthic parasites modulate the activities of inflammatory cells are considered. Examples are presented of parasitic products interfering with lymphocytes and their products such as antibodies, then modifying both regulation and effector response of the immune system. Furthermore, examples of interference on the complement system are illustrated. Parasites such as Ancylostoma caninum produce factors such as the neutrophil inhibitory factor (NIF) capable of inhibiting the neutrophil-endothelium adhesion, whereas Trichinella spiralis produces a glycoprotein, the 45gp, which inhibits different neutrophil functions. Parasites are also able to modulate the function of the monocytes-macrophages which in some infections play a crucial role; the modulation of NO synthesis is also relevant to the host-parasite relationship. Finally, the different anti-oxidant systems of helminthic parasites are described. The comprehension of such evasion mechanisms of the immune response is necessary to develop vaccines and new drugs, but it is also useful to clarify the contribution of parasites to immune system evolution.

  19. Anti-infective potential of hot-spring bacteria

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    Pallavi Pednekar

    2011-01-01

    Full Text Available Aim and Background: Antibiotic resistance currently spans most of the known classes of natural and synthetic antibiotics; limiting our options for treatment of infections and demanding discovery of new classes of antibiotics. Much effort is being directed towards developing new antibiotics to overcome this problem. Success in getting novel chemical entities from microbial sources depends essentially on novelty of its habitat. The diversity of geographical location decides the type of micro-flora. In the past various terrestrial and aqueous microorganisms have provided several novel bioactive secondary metabolites of pharmaceutical importance. Hot-springs have not been as extensively exploited as other terrestrial resources. However, perseverance with such microbes augment the probability of getting novel bioactive compounds. Materials and Methods: Hot-springs soil samples were collected from Hot-springs in Maharashtra. Actinomycetes and other eubacteria were isolated from these soil samples by selective methods and purified. They were classified based on gram′s nature and morphology. Six representative morphological strains were screened for their anti-infective potential by agar well diffusion method as reported by Nathan P. et al (1974. The bioactivity of the active microbes was confirmed. Results: Seventy three strains of bacteria encompassing eight actinomycetes, and 65 eubacteria were isolated and purified. Among the actives eubacteria PPVWK106001 showed broad spectrum antibacterial activity encompassing both gram positive and gram negative bacterial test models. The extract was active against resistant bacteria such as MRSA and VREs. Activity was very specific as there was no activity against fungi even at 100 fold concentration. The active principle was extractable in butanol. Conclusions: The study showed that Hot-springs exhibit diverse bacteria and it serves as potential reservoirs for bacteria of antimicrobial importance with

  20. Analysis on the infections change and measures for the multiple drug-resistant bacteria of neurology.

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    Zang, Wenju

    2016-05-01

    To analyze the bacterial infection situations and the separation situations of multiple drug-resistant bacteria of the neurology of Zhengzhou People's hospital from Feb. 2012 to Dec. 2014. The patients data of neurology were retrieved by means of the doctor workstation system. The infection sites, the classification and drug-resistant feature of bacteria were classified and summarized in Excel. Finally, Compared with the infection sites, the classification and drug-resistant feature of bacteria at different year. The data obtained use SPSS 19.0 software to do statistical analysis. The infection rate of bacteria in neurology from Year 2012 to 2014 declined from 4.99% to 3.41%. But the constitution of the infection sites of bacteria had no significant changes. Staphylococcus aureus still was the majority in the infections of gram-positive bacteria, and Escherichia coli was the majority in the infections of gram-negative bacteria, and there were no significant changes in the ranking of the past three years. The separation rate of Acihetobacter baumanii and Pseudomonas aeruginosa in gram-negative bacteria gradually escalated. There were definite efficiencies in the prevention and control of the bacterial infections in neurology in the past three years. But the situation of prevention and control was still severe at the same time.

  1. Ecology and evolution of viruses infecting uncultivated SUP05 bacteria as revealed by single-cell- and meta-genomics.

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    Roux, Simon; Hawley, Alyse K; Torres Beltran, Monica; Scofield, Melanie; Schwientek, Patrick; Stepanauskas, Ramunas; Woyke, Tanja; Hallam, Steven J; Sullivan, Matthew B

    2014-08-29

    Viruses modulate microbial communities and alter ecosystem functions. However, due to cultivation bottlenecks, specific virus-host interaction dynamics remain cryptic. In this study, we examined 127 single-cell amplified genomes (SAGs) from uncultivated SUP05 bacteria isolated from a model marine oxygen minimum zone (OMZ) to identify 69 viral contigs representing five new genera within dsDNA Caudovirales and ssDNA Microviridae. Infection frequencies suggest that ∼1/3 of SUP05 bacteria is viral-infected, with higher infection frequency where oxygen-deficiency was most severe. Observed Microviridae clonality suggests recovery of bloom-terminating viruses, while systematic co-infection between dsDNA and ssDNA viruses posits previously unrecognized cooperation modes. Analyses of 186 microbial and viral metagenomes revealed that SUP05 viruses persisted for years, but remained endemic to the OMZ. Finally, identification of virus-encoded dissimilatory sulfite reductase suggests SUP05 viruses reprogram their host's energy metabolism. Together, these results demonstrate closely coupled SUP05 virus-host co-evolutionary dynamics with the potential to modulate biogeochemical cycling in climate-critical and expanding OMZs.

  2. Bacteria activate sensory neurons that modulate pain and inflammation

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    Chiu, Isaac M.; Heesters, Balthasar A.; Ghasemlou, Nader; Von Hehn, Christian A.; Zhao, Fan; Tran, Johnathan; Wainger, Brian; Strominger, Amanda; Muralidharan, Sriya; Horswill, Alexander R.; Wardenburg, Juliane Bubeck; Hwang, Sun Wook; Carroll, Michael C.; Woolf, Clifford J.

    2013-01-01

    Nociceptor sensory neurons are specialized to detect potentially damaging stimuli, protecting the organism by initiating the sensation of pain and eliciting defensive behaviours. Bacterial infections produce pain by unknown molecular mechanisms, although they are presumed to be secondary to immune a

  3. STUDY ON SURGICAL SITE INFECTIONS CAUSED BY ESBL PRODUCING GRAM NEGATIVE BACTERIA

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    Rambabu

    2015-09-01

    Full Text Available Surgical site infections have been a major problem, because of the emergence of drug resistant bacteria, in particular B - lactamase producing bacteria. Extended spectrum beta lactamase producing gram negative organisms pose a great challenge in treatment o f SSI present study is aimed at determining multiple drug resistance in gram negative bacteria & to find out ESBL producers, in correlation with treatment outcome. A total of 120 wound infected cases were studied. Staphylococcus aureus was predominant bact erium - 20.Among gram negative bacteria, Pseudomonas species is predominant (14 followed by Escherichia coli (13 , Klebsiella species (12 , Proteus (9 Citrobacter (4 Providencia (2 & Acinetobacter species (2 . Out of 56 gramnegative bacteria isolated, 20 were i dentified as ESBL producers, which was statistically significant. Delay in wound healing correlated with infection by ESBL producers, which alarms the need of abstinence from antibiotic abuse

  4. The Use of Predatory Bacteria to Control Select Pathogens and Treat Respiratory Infections

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    2015-04-13

    bacteria are able to serve as a novel therapeutic agent in controlling intractable bacterial infections. By co-culturing Select Agents in the presence...of predator bacteria , we have confirmed that Bdellovibrio bacteriovorus and Micavibrio aeruginosavorus are able to 1. REPORT DATE (DD-MM-YYYY) 4...16-Dec-2013 15-Jan-2015 Approved for Public Release; Distribution Unlimited Final Report: The Use of Predatory Bacteria to Control Select Pathogens

  5. European multicenter study on antimicrobial resistance in bacteria isolated from companion animal urinary tract infections

    DEFF Research Database (Denmark)

    Marques, Cátia; Gama, Luís Telo; Belas, Adriana

    2016-01-01

    of antimicrobial resistant bacteria causing urinary tract infection (UTI) in companion animals in Europe. The antimicrobial susceptibility of 22 256 bacteria isolated from dogs and cats with UTI was determined. Samples were collected between 2008 and 2013 from 16 laboratories of 14 European countries...

  6. Commensal enteric bacteria lipopolysaccharide impairs host defense against disseminated Candida albicans fungal infection.

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    Jiang, T T; Chaturvedi, V; Ertelt, J M; Xin, L; Clark, D R; Kinder, J M; Way, S S

    2015-07-01

    Commensal enteric bacteria maintain systemic immune responsiveness that protects against disseminated or localized infection in extra-intestinal tissues caused by pathogenic microbes. However, as shifts in infection susceptibility after commensal bacteria eradication have primarily been probed using viruses, the broader applicability to other pathogen types remains undefined. In sharp contrast to diminished antiviral immunity, we show commensal bacteria eradication bolsters protection against disseminated Candida albicans fungal infection. Enhanced antifungal immunity reflects more robust systemic expansion of Ly6G(hi)Ly6C(int) neutrophils, and their mobilization into infected tissues among antibiotic-treated compared with commensal bacteria-replete control mice. Reciprocally, depletion of neutrophils from expanded levels or intestinal lipopolysaccharide reconstitution overrides the antifungal protective benefits conferred by commensal bacteria eradication. This discordance in antifungal compared with antiviral immunity highlights intrinsic differences in how commensal bacteria control responsiveness for specific immune cell subsets, because pathogen-specific CD8(+) T cells that protect against viruses were suppressed similarly after C. albicans and influenza A virus infection. Thus, positive calibration of antiviral immunity by commensal bacteria is counterbalanced by restrained activation of other immune components that confer antifungal immunity.

  7. Modulation of respiratory dendritic cells during Klebsiella pneumonia infection

    OpenAIRE

    Hackstein, Holger; Kranz, Sabine; Lippitsch, Anne; Wachtendorf, Andreas; Kershaw, Olivia; Achim D Gruber; Michel, Gabriela; Lohmeyer, Jürgen; Bein, Gregor; Baal, Nelli; Herold, Susanne

    2013-01-01

    Background: Klebsiella pneumoniae is a leading cause of severe hospital-acquired respiratory tract infections and death but little is known regarding the modulation of respiratory dendritic cell (DC) subsets. Plasmacytoid DC (pDC) are specialized type 1 interferon producing cells and considered to be classical mediators of antiviral immunity. Method: By using multiparameter flow cytometry analysis we have analysed the modulation of respiratory DC subsets after intratracheal Klebsi...

  8. A clinical study of sepsis patients with hypophosphatemia infected by different bacteria

    Institute of Scientific and Technical Information of China (English)

    张晓丽

    2014-01-01

    Objective To compare hypophosphatemia between the sepsis patients and the non-sepsis patients,and between the subgroups of sepsis patients.Methods We collected 312 sepsis cases and 300 non-sepsis cases by stratified random sampling method yearly.In the sepsis cases,the number infected by gram-negative bacteria was 170,and by gram-positive bacteria was 142,containing 4 different bacteria infected cases in each one.Serum phosphorus of cases in each group were collected.

  9. Does virus-bacteria coinfection increase the clinical severity of acute respiratory infection?

    Science.gov (United States)

    Damasio, Guilherme A C; Pereira, Luciane A; Moreira, Suzana D R; Duarte dos Santos, Claudia N; Dalla-Costa, Libera M; Raboni, Sonia M

    2015-09-01

    This retrospective cohort study investigated the presence of bacteria in respiratory secretions of patients hospitalized with acute respiratory infections and analyzed the impact of viral and bacterial coinfection on severity and the mortality rate. A total of 169 patients with acute respiratory infections were included, viruses and bacteria in respiratory samples were detected using molecular methods. Among all samples, 73.3% and 59.7% were positive for viruses and bacteria, respectively; 45% contained both virus and bacteria. Bacterial coinfection was more frequent in patients infected by community respiratory viruses than influenza A H1N1pdm (83.3% vs. 40.6%). The most frequently bacteria detected were Streptococcus pneumoniae and Haemophilus influenzae. Both species were co-detected in 54 patients and identified alone in 22 and 21 patients, respectively. Overall, there were no significant differences in the period of hospitalization, severity, or mortality rate between patients infected with respiratory viruses alone and those coinfected by viruses and bacteria. The detection of mixed respiratory pathogens is frequent in hospitalized patients with acute respiratory infections, but its impact on the clinical outcome does not appear substantial. However, it should be noted that most of the patients received broad-spectrum antibiotic therapy, which may have contributed to this favorable outcome.

  10. The role of beta-lactamase-producing-bacteria in mixed infections

    Directory of Open Access Journals (Sweden)

    Brook Itzhak

    2009-12-01

    Full Text Available Abstract Beta-lactamase-producing bacteria (BLPB can play an important role in polymicrobial infections. They can have a direct pathogenic impact in causing the infection as well as an indirect effect through their ability to produce the enzyme beta-lactamase. BLPB may not only survive penicillin therapy but can also, as was demonstrated in in vitro and in vivo studies, protect other penicillin-susceptible bacteria from penicillin by releasing the free enzyme into their environment. This phenomenon occurs in upper respiratory tract, skin, soft tissue, surgical and other infections. The clinical, in vitro, and in vivo evidence supporting the role of these organisms in the increased failure rate of penicillin in eradication of these infections and the implication of that increased rate on the management of infections is discussed.

  11. Bacteriocins active against multi-resistant gram negative bacteria implicated in nosocomial infections.

    Science.gov (United States)

    Ghodhbane, Hanen; Elaidi, Sabrine; Sabatier, Jean-Marc; Achour, Sami; Benhmida, Jeannette; Regaya, Imed

    2015-01-01

    Multiresistant Gram-negative bacteria are the prime mover of nosocomial infections. Some are naturally resistant to antibiotics, their genetic makes them insensitive to certain families of antibiotics and they transmit these resistors to their offspring. Moreover, when bacteria are subjected to antibiotics, they eventually develop resistance against drugs to which they were previously sensitive. In recent years, many bacteriocins active against gram-negative bacteria have been identified proving their efficacy in treating infections. While further investigation remains necessary before the possibilities for bacteriocins in clinical practice can be described more fully, this review provides an overview of bacteriocins acting on the most common infectious gram negative bacteria (Klebsiella, Acinetobacter, Pseudomonas aeruginosa and E. coli).

  12. Prostaglandin E2 As a Modulator of Viral Infections

    Science.gov (United States)

    Sander, Willem J.; O'Neill, Hester G.; Pohl, Carolina H.

    2017-01-01

    Viral infections are a major cause of infectious diseases worldwide. Inflammation and the immune system are the major host defenses against these viral infection. Prostaglandin E2 (PGE2), an eicosanoid generated by cyclooxygenases, has been shown to modulate inflammation and the immune system by regulating the expression/concentration of cytokines. The effect of PGE2 on viral infection and replication is cell type- and virus-family-dependent. The host immune system can be modulated by PGE2, with regards to immunosuppression, inhibition of nitrogen oxide (NO) production, inhibition of interferon (IFN) and apoptotic pathways, and inhibition of viral receptor expression. Furthermore, PGE2 can play a role in viral infection directly by increasing the production and release of virions, inhibiting viral binding and replication, and/or stimulating viral gene expression. PGE2 may also have a regulatory role in the induction of autoimmunity and in signaling via Toll-like receptors. In this review the known effects of PGE2 on the pathogenesis of various infections caused by herpes simplex virus, rotavirus, influenza A virus and human immunodeficiency virus as well the therapeutic potential of PGE2 are discussed. PMID:28261111

  13. The Wnt/β-catenin signaling pathway controls the inflammatory response in infections caused by pathogenic bacteria.

    Science.gov (United States)

    Silva-García, Octavio; Valdez-Alarcón, Juan J; Baizabal-Aguirre, Víctor M

    2014-01-01

    Innate immunity against pathogenic bacteria is critical to protect host cells from invasion and infection as well as to develop an appropriate adaptive immune response. During bacterial infection, different signaling transduction pathways control the expression of a wide range of genes that orchestrate a number of molecular and cellular events to eliminate the invading microorganisms and regulate inflammation. The inflammatory response must be tightly regulated because uncontrolled inflammation may lead to tissue injury. Among the many signaling pathways activated, the canonical Wnt/β-catenin has been recently shown to play an important role in the expression of several inflammatory molecules during bacterial infections. Our main goal in this review is to discuss the mechanism used by several pathogenic bacteria to modulate the inflammatory response through the Wnt/β-catenin signaling pathway. We think that a deep insight into the role of Wnt/β-catenin signaling in the inflammation may open new venues for biotechnological approaches designed to control bacterial infectious diseases.

  14. Modulation of host-cell MAPkinase signaling during fungal infection

    Directory of Open Access Journals (Sweden)

    Nir Osherov

    2015-10-01

    Full Text Available Fungal infections contribute substantially to human suffering and mortality. The interaction between fungal pathogens and their host involves the invasion and penetration of the surface epithelium, activation of cells of the innate immune system and the generation of an effective response to block infection. Numerous host-cell signaling pathways are activated during fungal infection. This review will focus on the main fungal pathogens Aspergillus fumigatus, Candida albicans and Cryptococcus neoformans and their ability to activate the host MAP-kinase signaling pathways leading to cytokine secretion, increased cell motility and killing of the pathogen. Both epithelial and innate immune cells specifically recognize fungal antigens and in particular cell surface polysaccharides such as β-glucans and react to them by activating multiple signaling pathways, including those containing MAP-kinase modules. Recent findings suggest that the host response to fungal infection utilizes the MAP-kinase pathway to differentiate between commensal and pathogenic fungi to selectively react only to the pathogenic forms. However, the paucity of relevant publications strongly emphasize that our understanding of host MAP-kinase signaling in response to fungal infection is still at a very early stage. It is clear, based on studies of host MAP-kinase signaling during viral and bacterial infections, that in fungi as well, a wealth of exciting findings await us.

  15. Gamma-aminobutyric acid-modulated benzodiazepine binding sites in bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Lummis, S.C.R.; Johnston, G.A.R. (Univ. of Sydney, New South Wales (Australia)); Nicoletti, G. (Royal Melbourne Inst. of Tech. (Australia)); Holan, G. (CSIRO, Melbourne (Australia))

    1991-01-01

    Benzodiazepine binding sites, which were once considered to exist only in higher vertebrates, are here demonstrated in the bacteria E. coli. The bacterial ({sup 3}H)diazepam binding sites are modulated by GABA; the modulation is dose dependent and is reduced at high concentrations. The most potent competitors of E.Coli ({sup 3}H)diazepam binding are those that are active in displacing ({sup 3}H)benzodiazepines from vertebrate peripheral benzodiazepine binding sites. These vertebrate sites are not modulated by GABA, in contrast to vertebrate neuronal benzodiazepine binding sites. The E.coli benzodiazepine binding sites therefore differ from both classes of vertebrate benzodiazepine binding sites; however the ligand spectrum and GABA-modulatory properties of the E.coli sites are similar to those found in insects. This intermediate type of receptor in lower species suggests a precursor for at least one class of vertebrate benzodiazepine binding sites may have existed.

  16. [A Case of Hyperammonemia Caused by Urinary Tract Infection Due to Urease-Producing Bacteria].

    Science.gov (United States)

    Emura, Masahiro; Tsuchihashi, Kazunari; Shimizu, Yosuke; Kanamaru, Sojun; Matoba, Shun; Ito, Noriyuki

    2016-08-01

    We present here a rare case of hyperammonemia without liver dysfunction or portal-systemic shunting. The patient was an 80-year-old woman with a history of neurogenic bladder. She was admitted to a nearby hospital for vomiting, diarrhea and consciousness disturbance. Two days after admission, she was transferred to our hospital because of persistant consciousness disturbance. Laboratory data revealed hyperammonemia, but there was no indication of liver dysfunction. Moreover abdominal computed tomography did not reveal any clear finding of liver disease or portal-systemic shunting, but we noted multiple large bladder diverticula. Antibiotic therapy, tracheal intubation, ventilator management and bladder catheterization were performed. The patient's level of consciousness improved rapidly. Urinary culture revealed Bacteroides ureolyticus (urease-producing bacteria). The patient was diagnosed with hyperammonemia and a urinary tract infection due to urease-producing bacteria. Thus, physicians should be aware that obstructive urinary tract infections due to urease-producing bacteria can also be the cause of hyperammonemia.

  17. Bloodstream infections in intensive care unit patients: distribution and antibiotic resistance of bacteria

    Directory of Open Access Journals (Sweden)

    Russotto V

    2015-08-01

    Full Text Available Vincenzo Russotto,1 Andrea Cortegiani,1 Giorgio Graziano,2 Laura Saporito,2 Santi Maurizio Raineri,1 Caterina Mammina,2 Antonino Giarratano1 1Department of Biopathology and Medical Biotechnologies (DIBIMED, Section of Anaesthesia, Analgesia, Intensive Care and Emergency, Paolo Giaccone University Hospital, University of Palermo, Palermo, Italy; 2Department of Sciences for Health Promotion and Mother-Child Care, University of Palermo, Palermo, Italy Abstract: Bloodstream infections (BSIs are among the leading infections in critically ill patients. The case-fatality rate associated with BSIs in patients admitted to intensive care units (ICUs reaches 35%–50%. The emergence and diffusion of bacteria with resistance to antibiotics is a global health problem. Multidrug-resistant bacteria were detected in 50.7% of patients with BSIs in a recently published international observational study, with methicillin resistance detected in 48% of Staphylococcus aureus strains, carbapenem resistance detected in 69% of Acinetobacter spp., in 38% of Klebsiella pneumoniae, and in 37% of Pseudomonas spp. Prior hospitalization and antibiotic exposure have been identified as risk factors for infections caused by resistant bacteria in different studies. Patients with BSIs caused by resistant strains showed an increased risk of mortality, which may be explained by a higher incidence of inappropriate empirical therapy in different studies. The molecular genetic characterization of resistant bacteria allows the understanding of the most common mechanisms underlying their resistance and the adoption of surveillance measures. Knowledge of epidemiology, risk factors, mechanisms of resistance, and outcomes of BSIs caused by resistant bacteria may have a major influence on global management of ICU patients. The aim of this review is to provide the clinician an update on BSIs caused by resistant bacteria in ICU patients. Keywords: bloodstream infections, multidrug resistant

  18. Plant-activated bacterial receptor adenylate cyclases modulate epidermal infection in the Sinorhizobium meliloti-Medicago symbiosis.

    Science.gov (United States)

    Tian, Chang Fu; Garnerone, Anne-Marie; Mathieu-Demazière, Céline; Masson-Boivin, Catherine; Batut, Jacques

    2012-04-24

    Legumes and soil bacteria called rhizobia have coevolved a facultative nitrogen-fixing symbiosis. Establishment of the symbiosis requires bacterial entry via root hair infection threads and, in parallel, organogenesis of nodules that subsequently are invaded by bacteria. Tight control of nodulation and infection is required to maintain the mutualistic character of the interaction. Available evidence supports a passive bacterial role in nodulation and infection after the microsymbiont has triggered the symbiotic plant developmental program. Here we identify in Sinorhizobium meliloti, the Medicago symbiont, a cAMP-signaling regulatory cascade consisting of three receptor-like adenylate cyclases, a Crp-like regulator, and a target gene of unknown function. The cascade is activated specifically by a plant signal during nodule organogenesis. Cascade inactivation results in a hyperinfection phenotype consisting of abortive epidermal infection events uncoupled from nodulation. These findings show that, in response to a plant signal, rhizobia play an active role in the control of infection. We suggest that rhizobia may modulate the plant's susceptibility to infection. This regulatory loop likely aims at optimizing legume infection.

  19. Outcome of infections due to pandrug-resistant (PDR Gram-negative bacteria

    Directory of Open Access Journals (Sweden)

    Bliziotis Ioannis A

    2005-04-01

    Full Text Available Abstract Background The increasing problem of infections due to multidrug-resistant Gram-negative bacteria has led to re-use of polymyxins in several countries. However, there are already clinical isolates of Gram-negative bacteria that are resistant to all available antibiotics, including polymyxins. Methods We present a case series of patients with infections due to pathogens resistant to all antimicrobial agents tested, including polymyxins. An isolate was defined as pandrug-resistant (PDR if it exhibited resistance to all 7 anti-pseudomonal antimicrobial agents, i.e. antipseudomonal penicillins, cephalosporins, carbapenems, monobactams, quinolones, aminoglycosides, and polymyxins. Results Clinical cure of the infection due to pandrug-resistant (PDR Gram-negative bacteria, namely Pseudomonas aeruginosa or Klebsiella pneumoniae was observed in 4 out of 6 patients with combination of colistin and beta lactam antibiotics. Conclusion Colistin, in combination with beta lactam antibiotics, may be a useful agent for the management of pandrug-resistant Gram-negative bacterial infections. The re-use of polymyxins, an old class of antibiotics, should be done with caution in an attempt to delay the rate of development of pandrug-resistant Gram-negative bacterial infections.

  20. Detection of Fastidious Vaginal Bacteria in Women with HIV Infection and Bacterial Vaginosis

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    Caroline Mitchell

    2009-01-01

    Full Text Available Background. Fastidious bacteria have been associated with bacterial vaginosis (BV using PCR methods. We assessed the prevalence of these bacteria in HIV-1 infected women and their relationship with vaginal pH and shedding of HIV-1 RNA. Methods. 64 cervicovaginal lavage (CVL samples were collected from 51 women. Vaginal microbiota were characterized using 8 bacterium-specific quantitative PCR assays. Results. Women with the fastidious bacteria Bacterial Vaginosis Associated Bacterium (BVAB 1, 2, and 3 showed a trend to increased HIV-1 shedding (OR 2.59–3.07, P=.14–.17. Absence of Lactobacillus crispatus (P<.005 and presence of BVAB2 (P<.001 were associated with elevated vaginal pH. BVAB1, 2, and 3 were highly specific indicators of BV in HIV-infected women, with specificities of 89%–93%. Conclusions. Fastidious bacteria (BVAB 1, 2, and 3 remain specific indicators of BV in HIV-infected women, and BVAB2 may contribute to the elevated vaginal pH that is a hallmark of this syndrome.

  1. Iron metabolism and resistance to infection by invasive bacteria in the social amoeba Dictyostelium discoideum.

    Science.gov (United States)

    Bozzaro, Salvatore; Buracco, Simona; Peracino, Barbara

    2013-01-01

    Dictyostelium cells are forest soil amoebae, which feed on bacteria and proliferate as solitary cells until bacteria are consumed. Starvation triggers a change in life style, forcing cells to gather into aggregates to form multicellular organisms capable of cell differentiation and morphogenesis. As a soil amoeba and a phagocyte that grazes on bacteria as the obligate source of food, Dictyostelium could be a natural host of pathogenic bacteria. Indeed, many pathogens that occasionally infect humans are hosted for most of their time in protozoa or free-living amoebae, where evolution of their virulence traits occurs. Due to these features and its amenability to genetic manipulation, Dictyostelium has become a valuable model organism for studying strategies of both the host to resist infection and the pathogen to escape the defense mechanisms. Similarly to higher eukaryotes, iron homeostasis is crucial for Dictyostelium resistance to invasive bacteria. Iron is essential for Dictyostelium, as both iron deficiency or overload inhibit cell growth. The Dictyostelium genome shares with mammals many genes regulating iron homeostasis. Iron transporters of the Nramp (Slc11A) family are represented with two genes, encoding Nramp1 and Nramp2. Like the mammalian ortholog, Nramp1 is recruited to phagosomes and macropinosomes, whereas Nramp2 is a membrane protein of the contractile vacuole network, which regulates osmolarity. Nramp1 and Nramp2 localization in distinct compartments suggests that both proteins synergistically regulate iron homeostasis. Rather than by absorption via membrane transporters, iron is likely gained by degradation of ingested bacteria and efflux via Nramp1 from phagosomes to the cytosol. Nramp gene disruption increases Dictyostelium sensitivity to infection, enhancing intracellular growth of Legionella or Mycobacteria. Generation of mutants in other "iron genes" will help identify genes essential for iron homeostasis and resistance to pathogens.

  2. Iron metabolism and resistance to infection by invasive bacteria in the social amoeba Dictyostelium discoideum

    Directory of Open Access Journals (Sweden)

    Salvatore eBozzaro

    2013-09-01

    Full Text Available Dictyostelium cells are forest soil amoebae, which feed on bacteria and proliferate as solitary cells until bacteria are consumed. Starvation triggers a change in life style, forcing cells to gather into aggregates to form multicellular organisms capable of cell differentiation and morphogenesis. As a soil amoeba and a phagocyte that grazes on bacteria as the obligate source of food, Dictyostelium could be a natural host of pathogenic bacteria. Indeed, many pathogens that occasionally infect humans are hosted for most of their time in protozoa or free-living amoebae, where evolution of their virulence traits occurs. Due to these features and its amenability to genetic manipulation, Dictyostelium has become a valuable model organism for studying strategies of both the host to resist infection and the pathogen to escape the defence mechanisms. Similarly to higher eukaryotes, iron homeostasis is crucial for Dictyostelium resistance to invasive bacteria. Iron is essential for Dictyostelium, as both iron deficiency or overload inhibit cell growth. The Dictyostelium genome shares with mammals many genes regulating iron homeostasis. Iron transporters of the Nramp (Slc11A family are represented with two genes, encoding Nramp1 and Nramp2. Like the mammalian ortholog, Nramp1 is recruited to phagosomes and macropinosomes, whereas Nramp2 is a membrane protein of the contractile vacuole network, which regulates osmolarity. Nramp1 and Nramp2 localization in distinct compartments suggests that both proteins synergistically regulate iron homeostasis. Rather than by absorption via membrane transporters, iron is likely gained by degradation of ingested bacteria and efflux via Nramp1 from phagosomes to the cytosol. Nramp gene disruption increases Dictyostelium sensitivity to infection, enhancing intracellular growth of Legionella or Mycobacteria. Generation of mutants in other "iron genes" will help identify genes essential for iron homeostasis and resistance to

  3. Isolation and life-cycle characterization of lytic viruses infecting heterotrophic bacteria and cyanobacteria

    DEFF Research Database (Denmark)

    Middelboe, Mathias; Chan, Amy; Bertelsen, Sif Koldborg

    2010-01-01

    Basic knowledge on viruses infecting heterotrophic bacteria and cyanobacteria is key to future progress in understanding the role of viruses in aquatic systems and the influence of virus–host interactions on microbial mortality, biogeochemical cycles, and genetic exchange. Such studies require......, and discusses the applications and limitations of different isolation procedures. Most work on phage isolation has been carried out with aerobic heterotrophic bacteria and cyanobacteria, culturable both on agar plates and in enriched liquid cultures. The procedures presented here are limited to lytic viruses...

  4. [Necrotizing mucosal ulcers cause by anaerobic bacteria. Fusiform bacterial and spirochete infections].

    Science.gov (United States)

    Hollandt, J H; Hollandt, H

    1996-12-01

    Vincent's angina (Plaut-Vincent) is the most prominent disease caused by coinciding infections from fusibacteria and spirochaeta both belonging to obligate anaerobic bacteria. A possible symbiotic infection of both anaerobics may become manifest on the mucous membranes of the oral cavity and the oropharynx beside the tonsillas. The clinical outcome may be different and pose difficulties in the differential diagnosis. We report the case of a 29 year old female patient with necrotizing ulcera of the soft palate suspicious for stomatitis ulceromembranacea. In case necrotizing inflammations of the oral cavity area were to be found infections due to anaerobic bacteria should be considered mostly occurring as mixed infections. The correct identification by cultivation turns out to be difficult in that it requires special conditions. Furthermore, reliable detection of these bacteria necessitates careful collection and transport of patients specimens. In case of Fusospirochaetosis (Fusotreponematose) a specimen should be prepared for microscopic examination beside setting up a special culture. This is because the staining is the most suitable procedure for bacteril identification to support the clinical diagnosis of stomatitis ulceromembranacea.

  5. Fluorescence in situ hybridization rapidly detects three different pathogenic bacteria in urinary tract infection samples.

    Science.gov (United States)

    Wu, Qing; Li, Yan; Wang, Ming; Pan, Xiao P; Tang, Yong F

    2010-11-01

    The detection of pathogenic bacteria in urine is an important criterion for diagnosing urinary tract infections (UTIs). By using fluorescence in situ hybridization (FISH) with rRNA-targeted, fluorescently labeled oligonucleotide probes, bacterial pathogens present in urine samples were identified within 3-4 h. In this study, three probes that are specific for Escherichia coli, Enterococcus faecalis and Staphylococcus aureus were designed based on the conserved 16S RNA sequences, whereas probe Eub338 broadly recognizes all bacteria. We collected a total of 1000 urine samples, and 325 of these samples tested positive for a UTI via traditional culturing techniques; additionally, all 325 of these samples tested positive with the Eub338 probe in FISH analysis. FISH analyses with species-specific probes were performed in parallel to the test the ability to differentiate among several pathogenic bacteria. The samples for these experiments included 76 E. coli infected samples, 32 E. faecalis infected samples and 9 S. aureus infected samples. Compared to conventional methods of bacterial identification, the FISH method produced positive results for >90% of the samples tested. FISH has the potential to become an extremely useful diagnostic tool for UTIs because it has a quick turnaround time and high accuracy.

  6. Host factors and genetic susceptibility to infections due to intracellular bacteria and fastidious organisms.

    Science.gov (United States)

    Asner, S A; Morré, S A; Bochud, P-Y; Greub, G

    2014-12-01

    While genetic polymorphisms play a paramount role in tuberculosis (TB), less is known about their contribution to the severity of diseases caused by other intracellular bacteria and fastidious microorganisms. We searched electronic databases for observational studies reporting on host factors and genetic predisposition to infections caused by intracellular fastidious bacteria published up to 30 May 2014. The contribution of genetic polymorphisms was documented for TB. This includes genetic defects in the mononuclear phagocyte/T helper cell type 1 (Th1) pathway contributing to disseminated TB disease in children and genome-wide linkage analysis (GWAS) in reactivated pulmonary TB in adults. Similarly, experimental studies supported the role of host genetic factors in the clinical presentation of illnesses resulting from other fastidious intracellular bacteria. These include IL-6 -174G/C or low mannose-binding (MBL) polymorphisms, which are incriminated in chronic pulmonary conditions triggered by C. pneumoniae, type 2-like cytokine secretion polymorphisms, which are correlated with various clinical patterns of M. pneumoniae infections, and genetic variation in the NOD2 gene, which is an indicator of tubal pathology resulting from Chamydia trachomatis infections. Monocyte/macrophage migration and T lymphocyte recruitment defects are corroborated to ineffective granuloma formation observed among patients with chronic Q fever. Similar genetic polymorphisms have also been suggested for infections caused by T. whipplei although not confirmed yet. In conclusion, this review supports the paramount role of genetic factors in clinical presentations and severity of infections caused by intracellular fastidious bacteria. Genetic predisposition should be further explored through such as exome sequencing.

  7. Intestinal Shiga toxin-producing Escherichia coli bacteria mitigate bovine leukemia virus infection in experimentally infected sheep.

    Science.gov (United States)

    Ferens, Witold A; Cobbold, Rowland; Hovde, Carolyn J

    2006-05-01

    Ruminants often carry gastrointestinal Shiga toxin (Stx)-producing Escherichia coli (STEC). Stxs belong to a large family of ribosome-inactivating proteins (RIPs), found in many plants and some bacteria. Plant RIPs, secreted into extracellular spaces, limit the spread of viruses through plant tissues by penetrating and killing virally infected cells. Previously, we showed Stx activity against bovine leukemia virus (BLV)-infected cells in vitro and hypothesized that STEC bacteria have antiviral activity in ruminant hosts. Here, we investigated the impact of STEC on the initial phases of BLV infection in sheep. Sheep were treated with biweekly oral doses of E. coli O157:H7 (an STEC) or an isogenic stx mutant strain. A different group of sheep were similarly treated with five naturally occurring ovine STEC isolates or stx-negative E. coli. Intestinal STEC bacteria were enumerated and identified by standard fecal culture and DNA hybridization. Oral STEC treatment did not always result in carriage of STEC, although many animals consistently presented with >10(4) CFU/g feces. BLV viremia was assessed by spontaneous lymphocyte proliferation (SLP) in cultures of blood mononuclear cells and by syncytium formation in cocultures of the same with F-81 indicator cells. SLP was lower (P < 0.05) and syncytia were fewer (P < 0.05) in STEC-treated sheep than in untreated sheep. Both lower SLP and fewer syncytia positively correlated with fecal STEC numbers. Average weight gain post-BLV challenge was higher in STEC-treated sheep than in untreated sheep (P < 0.05). These results support the hypothesis that in ruminants, intestinal STEC bacteria have antiviral activity and mitigate BLV-induced disease.

  8. O-antigen modulates infection-induced pain states.

    Directory of Open Access Journals (Sweden)

    Charles N Rudick

    Full Text Available The molecular initiators of infection-associated pain are not understood. We recently found that uropathogenic E. coli (UPEC elicited acute pelvic pain in murine urinary tract infection (UTI. UTI pain was due to E. coli lipopolysaccharide (LPS and its receptor, TLR4, but pain was not correlated with inflammation. LPS is known to drive inflammation by interactions between the acylated lipid A component and TLR4, but the function of the O-antigen polysaccharide in host responses is unknown. Here, we examined the role of O-antigen in pain using cutaneous hypersensitivity (allodynia to quantify pelvic pain behavior and using sacral spinal cord excitability to quantify central nervous system manifestations in murine UTI. A UPEC mutant defective for O-antigen biosynthesis induced chronic allodynia that persisted long after clearance of transient infections, but wild type UPEC evoked only acute pain. E. coli strains lacking O-antigen gene clusters had a chronic pain phenotype, and expressing cloned O-antigen gene clusters altered the pain phenotype in a predictable manner. Chronic allodynia was abrogated in TLR4-deficient mice, but inflammatory responses in wild type mice were similar among E. coli strains spanning a wide range of pain phenotypes, suggesting that O-antigen modulates pain independent of inflammation. Spinal cords of mice with chronic allodynia exhibited increased spontaneous firing and compromised short-term depression, consistent with centralized pain. Taken together, these findings suggest that O-antigen functions as a rheostat to modulate LPS-associated pain. These observations have implications for an infectious etiology of chronic pain and evolutionary modification of pathogens to alter host behaviors.

  9. Micro-electro-fluidic module to control magnetotactic bacteria for micromanipulation tasks under an optical microscope

    Science.gov (United States)

    André, Walder; Lu, Zhao; Moufarrej, Bechara; Martel, Sylvain

    2007-10-01

    This project describes a Multi-Chip Module (MCM) that contains a microelectronic circuit and a microfluidic device that could be combined to implement a "bacterial microfactory". The microchip contains two decoders connected to arrays of horizontal and vertical wires respectively, forming a matrix used to process commands received from an external computer. The electrical current flowing through the matrix is generated from internal voltage-to-current converters. The electrical current circulating through a metal conductor generates a magnetic field that is used to guide the movement of Magnetotactic Bacteria (MTB) in the microfluidic device. The dedicated microfluidic device is micro-fabricated on a glass wafer. Preliminary results show that a single MC-1 MTB can push a 2 μm microbead at speeds reaching 100μm/s under the control of an external magnetic field of less than 10 Gauss. A Carl Zeiss microscopy software (AxioVision) is used to control and configure the Axio Imager Z1 optical microscope and allows us to develop customized plug-in with Visual Basic for Application (VBA). The control electronic die was hence programmed as a VBA module, simplifying interoperability between the control, data recordings and microscopy observations. The parallel port of an Intel Pentium 4, 3.0 GHz equipped with 2.87 Go of RAM running Windows XP was used to communicate with the circuit. Connected to the parallel port, two demultiplexers interface the chip and the port. Patterns to control the bacteria such as left-right and up-down displacements were implemented and tested. Other more complex patterns to capture, attract and repel the bacteria from the center of the chip were also designed and validated.

  10. Composition of symbiotic bacteria predicts survival in Panamanian golden frogs infected with a lethal fungus.

    Science.gov (United States)

    Becker, Matthew H; Walke, Jenifer B; Cikanek, Shawna; Savage, Anna E; Mattheus, Nichole; Santiago, Celina N; Minbiole, Kevin P C; Harris, Reid N; Belden, Lisa K; Gratwicke, Brian

    2015-04-22

    Symbiotic microbes can dramatically impact host health and fitness, and recent research in a diversity of systems suggests that different symbiont community structures may result in distinct outcomes for the host. In amphibians, some symbiotic skin bacteria produce metabolites that inhibit the growth of Batrachochytrium dendrobatidis (Bd), a cutaneous fungal pathogen that has caused many amphibian population declines and extinctions. Treatment with beneficial bacteria (probiotics) prevents Bd infection in some amphibian species and creates optimism for conservation of species that are highly susceptible to chytridiomycosis, the disease caused by Bd. In a laboratory experiment, we used Bd-inhibitory bacteria from Bd-tolerant Panamanian amphibians in a probiotic development trial with Panamanian golden frogs, Atelopus zeteki, a species currently surviving only in captive assurance colonies. Approximately 30% of infected golden frogs survived Bd exposure by either clearing infection or maintaining low Bd loads, but this was not associated with probiotic treatment. Survival was instead related to initial composition of the skin bacterial community and metabolites present on the skin. These results suggest a strong link between the structure of these symbiotic microbial communities and amphibian host health in the face of Bd exposure and also suggest a new approach for developing amphibian probiotics.

  11. Isolation of bacteria causing secondary bacterial infection in the lesions of cutaneous leishmaniasis

    Directory of Open Access Journals (Sweden)

    Ziaie Hengameh

    2008-01-01

    Full Text Available Background: Cutaneous Leishmaniasis (CL is a parasitic disease characterized by single or multiple ulcerations. Secondary bacterial infection is one of the complications of the disease that can increase the tissue destruction and the resulting scar. Objective: To effectively determine the incidence of real secondary bacteria infection in cutaneous leishmaniasis, we designed the current study. Methods and Materials: This was a cross-sectional study performed in Skin Diseases and Leishmaniasis Research Centre, Isfahan, Iran. In this study, 854 patients with confirmed CL were enrolled. Samples were taken from all the patients. Sterile swaps were achieved for the ulcer exudates and scraping was used for nonulcerated lesions. All the samples were transferred to tryptic soy broth medium. After 24 h of incubation in 37°C, they were transferred to eosin methylene blue agar (EBM and blood agar. Laboratory tests were used to determine the species of bacteria. All of the collected data were analyzed by SPSS software and chi-square. Results: Among 854 patients with confirmed cutaneous leishmaniasis, 177 patients (20.7% had positive cultures for secondary bacterial infection. Bacteria isolated from the lesions were as follows: Staphylococcus aureus - 123 cases (69.4%, coagulase negative Staphylococcus - 41 cases (23.1%, E. coil - 7 cases (3.9%, Proteus - 3 cases (1.7% and Klebsiella - 3 cases (1.7%. Conclusions: The incidence of secondary bacterial infection in lesions of CL was 20.7%. The most common isolated pathogen was Staphylococcus aureus . The incidence of secondary bacterial infection was significantly more in the ulcerated lesions as compared with nonulcerated lesions ( P = 0.00001.

  12. The application of loop-mediated isothermal amplification for detection of common pathogenic bacteria in lower respiratory tract infections

    Institute of Scientific and Technical Information of China (English)

    陈愉生

    2014-01-01

    Objective To investigate the spectrum of common pathogenic bacteria of low respiratory tract infection by loop-mediated isothermal amplification(LAMP)of nucleic acid test and to prove the clinical significance of this method.Methods A total of 289 qualified sputum samples from patients with lower respiratory tract infections in Fujian Province were detected by LAMP technique,and then the distribution of pathogenic bacteria was analyzed.The positive cases(the patients whose specific3

  13. Commensal bacteria modulate innate immune responses of vaginal epithelial cell multilayer cultures.

    Science.gov (United States)

    Rose, William A; McGowin, Chris L; Spagnuolo, Rae Ann; Eaves-Pyles, Tonyia D; Popov, Vsevolod L; Pyles, Richard B

    2012-01-01

    The human vaginal microbiome plays a critical but poorly defined role in reproductive health. Vaginal microbiome alterations are associated with increased susceptibility to sexually-transmitted infections (STI) possibly due to related changes in innate defense responses from epithelial cells. Study of the impact of commensal bacteria on the vaginal mucosal surface has been hindered by current vaginal epithelial cell (VEC) culture systems that lack an appropriate interface between the apical surface of stratified squamous epithelium and the air-filled vaginal lumen. Therefore we developed a reproducible multilayer VEC culture system with an apical (luminal) air-interface that supported colonization with selected commensal bacteria. Multilayer VEC developed tight-junctions and other hallmarks of the vaginal mucosa including predictable proinflammatory cytokine secretion following TLR stimulation. Colonization of multilayers by common vaginal commensals including Lactobacillus crispatus, L. jensenii, and L. rhamnosus led to intimate associations with the VEC exclusively on the apical surface. Vaginal commensals did not trigger cytokine secretion but Staphylococcus epidermidis, a skin commensal, was inflammatory. Lactobacilli reduced cytokine secretion in an isolate-specific fashion following TLR stimulation. This tempering of inflammation offers a potential explanation for increased susceptibility to STI in the absence of common commensals and has implications for testing of potential STI preventatives.

  14. A prebiotic role of Ecklonia cava improves the mortality of Edwardsiella tarda-infected zebrafish models via regulating the growth of lactic acid bacteria and pathogen bacteria.

    Science.gov (United States)

    Lee, WonWoo; Oh, Jae Young; Kim, Eun-A; Kang, Nalae; Kim, Kil-Nam; Ahn, Ginnae; Jeon, You-Jin

    2016-07-01

    In this study, the beneficial prebiotic roles of Ecklonia cava (E. cava, EC) were evaluated on the growth of lactic acid bacteria (LAB) and pathogen bacteria and the mortality of pathogen-bacteria infected zebrafish model. The result showed that the original E. cava (EC) led to the highest growth effects on three LABs (Lactobacillus brevis, L. brevis; Lactobacillus pentosus, L. pentosus; Lactobacillus plantarum; L. plantarum) and it was dose-dependent manners. Also, EC, its Celluclast enzymatic (ECC) and 100% ethanol extracts (ECE) showed the anti-bacterial activities on the fish pathogenic bacteria such as (Edwardsiella tarda; E. tarda, Streptococcus iniae; S. iniae, and Vibrio harveyi; V. harveyi). Interestingly, EC induced the higher production of the secondary metabolites from L. plantarum in MRS medium. The secondary metabolites produced by EC significantly inhibited the growth of pathogen bacteria. In further in vivo study, the co-treatment of EC and L. plantarum improved the growth and mortality of E. tarda-infected zebrafish as regulating the expression of inflammatory molecules such as iNOS and COX2. Taken together, our present study suggests that the EC plays an important role as a potential prebiotic and has a protective effect against the infection caused by E. tarda injection in zebrafish. Also, our conclusion from this evidence is that EC can be used and applied as a useful prebiotic.

  15. Taurine modulates neutrophil function but potentiates uropathogenic E. coli infection in the murine bladder.

    LENUS (Irish Health Repository)

    Condron, Claire

    2010-08-01

    Eradication of a urinary tract infection (UTI) appears to be related to a number of innate host defence mechanisms and their interactions with invading bacteria. Recurrent UTIs (rUTIs) pose a difficult problem in that these bacteria use both host and bacterial factors to evade elimination. Neutrophil bactericidal function is depressed, both systemically and in urine, in patients with a history of recurrent UTI. Taurine is a semi-essential amino acid and is successful in preserving neutrophil bactericidal function in urine. Taurine may preserve neutrophil function at the urothelium and thus aid UTI resolution. Adult female (6 weeks old) C57Bl\\/6 mice were randomised into three groups: a saline gavage only control group, a saline gavage + E. coli group, and a taurine gavage + E. coli group [21 g\\/70 kg taurine in 0.9% normal saline (N\\/S) for 5 days]. Whilst taurine gavage pre-treatment resulted in increased serum neutrophils respiratory burst activity, at the urothelial-endothelial interface it caused higher colony forming units in the urine and a higher incidence of E. coli invasion in the bladder wall with no evidence of increased bladder wall neutrophils infiltration on MPO assay of histological assessment. Histologically there was also evidence of reduced bladder inflammation and urothelial cell apoptosis. In conclusion, taurine effectively increases neutrophils activity but given its anti-inflammatory properties, at the expense of decreased urothelial-endothelial activation thus preventing clearance of active E. coli infection in the bladder. Despite the negative results, this study demonstrates the importance of modulating interactions at the urothelial interface.

  16. ``Fatal Scream'' Of Bacteria Infected By Phages: Nanoscale Detection Of Bacteriophage Triggered Ion Cascade

    Science.gov (United States)

    King, Maria D.; Seo, Sungkyu; Kim, Jong; Cheng, Mosong; Young, Ryland; Biard, Robert J.; Bezrukov, Sergey M.; Granqvist, Claes-Goran; Kish, Laszlo B.

    2005-11-01

    A rapid, inexpensive and specific identification of arbitrary bacteria under field conditions is urgently needed. To this end, we have introduced and tested a new technology, called SEPTIC, SEnsing of Phage-Triggered Ion Cascade. In its prototype form based on a nanowell chip, SEPTIC has already been shown to be capable of unambiguous identification of live bacteria on a time scale of seconds to minutes, many times faster than any other system. The technology is based on using noise analysis to detect the massive ionic fluxes associated with the initial step of bacteriophage infection, the injection of the phage DNA into the cell. Here we show the results and pose a number of unsolved problems of noise. Ultimately, sensors based on this new technology would be able to save many lifes.

  17. Sequential exposure to carbon nanotubes and bacteria enhances pulmonary inflammation and infectivity.

    Science.gov (United States)

    Shvedova, Anna A; Fabisiak, James P; Kisin, Elena R; Murray, Ashley R; Roberts, Jenny R; Tyurina, Yulia Y; Antonini, James M; Feng, Wei Hong; Kommineni, Choudari; Reynolds, Jeffrey; Barchowsky, Aaron; Castranova, Vince; Kagan, Valerian E

    2008-05-01

    Carbon nanotubes (CNT), with their applications in industry and medicine, may lead to new risks to human health. CNT induce a robust pulmonary inflammation and oxidative stress in rodents. Realistic exposures to CNT may occur in conjunction with other pathogenic impacts (microbial infections) and trigger enhanced responses. We evaluated interactions between pharyngeal aspiration of single-walled CNT (SWCNT) and bacterial pulmonary infection of C57BL/6 mice with Listeria monocytogenes (LM). Mice were given SWCNT (0, 10, and 40 mug/mouse) and 3 days later were exposed to LM (10(3) bacteria/mouse). Sequential exposure to SWCNT/LM amplified lung inflammation and collagen formation. Despite this robust inflammatory response, SWCNT pre-exposure significantly decreased the pulmonary clearance of LM-exposed mice measured 3 to 7 days after microbial infection versus PBS/LM-treated mice. Decreased bacterial clearance in SWCNT-pre-exposed mice was associated with decreased phagocytosis of bacteria by macrophages and a decrease in nitric oxide production by these phagocytes. Pre-incubation of naïve alveolar macrophages with SWCNT in vitro also resulted in decreased nitric oxide generation and suppressed phagocytizing activity toward LM. Failure of SWCNT-exposed mice to clear LM led to a continued elevation in nearly all major chemokines and acute phase cytokines into the later course of infection. In SWCNT/LM-exposed mice, bronchoalveolar lavage neutrophils, alveolar macrophages, and lymphocytes, as well as lactate dehydrogenase level, were increased compared with mice exposed to SWCNT or LM alone. In conclusion, enhanced acute inflammation and pulmonary injury with delayed bacterial clearance after SWCNT exposure may lead to increased susceptibility to lung infection in exposed populations.

  18. Biotherapy for and protection against gastrointestinal pathogenic infections via action of probiotic bacteria

    Directory of Open Access Journals (Sweden)

    Mongkol Thirabunyanon

    2011-03-01

    Full Text Available The microbiota in the human intestine play an important function in human health and disease. Gastrointestinal infections by foodborne pathogens are a main cause of morbidity and mortality worldwide. Such infections can be caused by contaminated foods or other sources which come in contact with human intestinal epithelial cells. In recent years, probiotics have been recommended as alternative biotherapeutic agents against intestinal pathogenic infections. Two genera of probiotics, Lactobacillus and Bifidobacterium, are commercially valuable applications, several forms of which are available as capsules or in functional food products such as yogurt, fermented juices and sausages. Probiotics protect against gastrointestinal pathogenic infection via several mechanisms. These include production of antimicrobial substances, competition for nutrient substrates, competitive exclusion, enhancement of intestinal barrier function, and immunomodulation. Probiotic bacteria have been documented as being effective in biotherapeutic applications against gastrointestinal pathogens, e.g. Helicobacter pylori, Salmonella, Escherichia coli, Listeria monocytogenes, and rotaviruses. This alternative therapeutic application of probiotics to protect against gastrointestinal pathogenic infections may be of great importance for future medicinal use.

  19. [Bacteria and viruses modulate FcεRI-dependent mast cell activity].

    Science.gov (United States)

    Słodka, Aleksandra; Brzezińska-Błaszczyk, Ewa

    2013-03-08

    Undoubtedly, mast cells play a central role in allergic processes. Specific allergen cross-linking of IgE bound to the high affinity receptors (FcεRI) on the mast cell surface leads to the release of preformed mediators and newly synthesized mediators, i.e. metabolites of arachidonic acid and cytokines. More and more data indicate that bacteria and viruses can influence FcεRI-dependent mast cell activation. Some bacterial and viral components can reduce the surface expression of FcεRI. There are also findings that ligation of Toll-like receptors (TLRs) by bacterial or viral antigens can affect IgE-dependent mast cell degranulation and preformed mediator release as well as eicosanoid production. The synergistic interaction of TLR ligands and allergen can also modify cytokine synthesis by mast cells stimulated via FcεRI. Moreover, data suggest that specific IgE for bacterial or viral antigens can influence mast cell activity. What is more, some bacterial and viral components or some endogenous proteins produced during viral infection can act as superantigens by interacting with the VH3 domain of IgE. All these observations indicate that bacterial and viral infections modify the course of allergic diseases by affecting FcεRI-dependent mast cell activation. 

  20. Bacteria and viruses modulate FcεRI-dependent mast cell activity 

    Directory of Open Access Journals (Sweden)

    Aleksandra Słodka

    2013-03-01

    Full Text Available Undoubtedly, mast cells play a central role in allergic processes. Specific allergen cross-linking of IgE bound to the high affinity receptors (FcεRI on the mast cell surface leads to the release of preformed mediators and newly synthesized mediators, i.e. metabolites of arachidonic acid and cytokines. More and more data indicate that bacteria and viruses can influence FcεRI-dependent mast cell activation. Some bacterial and viral components can reduce the surface expression of FcεRI. There are also findings that ligation of Toll-like receptors (TLRs by bacterial or viral antigens can affect IgE-dependent mast cell degranulation and preformed mediator release as well as eicosanoid production. The synergistic interaction of TLR ligands and allergen can also modify cytokine synthesis by mast cells stimulated via FcεRI. Moreover, data suggest that specific IgE for bacterial or viral antigens can influence mast cell activity. What is more, some bacterial and viral components or some endogenous proteins produced during viral infection can act as superantigens by interacting with the VH3 domain of IgE. All these observations indicate that bacterial and viral infections modify the course of allergic diseases by affecting FcεRI-dependent mast cell activation. 

  1. Evaluation of the antibacterial potential of Petroselinum crispum and Rosmarinus officinalis against bacteria that cause urinary tract infections.

    Science.gov (United States)

    Petrolini, Fernanda Villas Boas; Lucarini, Rodrigo; de Souza, Maria Gorete Mendes; Pires, Regina Helena; Cunha, Wilson Roberto; Martins, Carlos Henrique Gomes

    2013-01-01

    In this study we evaluated the antibacterial activity of the crude hydroalcoholic extracts, fractions, and compounds of two plant species, namely Rosmarinus officinalis and Petroselinum crispum, against the bacteria that cause urinary tract infection. The microdilution method was used for determination of the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The crude hydroalcoholic extract of R. officinalis displayed in vitro activity against Gram-positive bacteria, with satisfactory MBC for the clinical isolate S. saprophyticus. The fractions and the pure compound rosmarinic acid did not furnish promising results for Gram-negative bacteria, whereas fractions 2, 3, and 4 gave encouraging results for Gram-positive bacteria and acted as bactericide against S. epidermidis as well as E. faecalis (ATCC 29212) and its clinical isolate. R. officinalis led to promising results in the case of Gram-positive bacteria, resulting in a considerable interest in the development of reliable alternatives for the treatment of urinary infections.

  2. Evaluation of the antibacterial potential of Petroselinum crispum and Rosmarinus officinalis against bacteria that cause urinary tract infections

    Directory of Open Access Journals (Sweden)

    Fernanda Villas Boas Petrolini

    2013-09-01

    Full Text Available In this study we evaluated the antibacterial activity of the crude hydroalcoholic extracts, fractions, and compounds of two plant species, namely Rosmarinus officinalis and Petroselinum crispum, against the bacteria that cause urinary tract infection. The microdilution method was used for determination of the minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC. The crude hydroalcoholic extract of R. officinalis displayed in vitro activity against Gram-positive bacteria, with satisfactory MBC for the clinical isolate S. saprophyticus. The fractions and the pure compound rosmarinic acid did not furnish promising results for Gram-negative bacteria, whereas fractions 2, 3, and 4 gave encouraging results for Gram-positive bacteria and acted as bactericide against S. epidermidis as well as E. faecalis (ATCC 29212 and its clinical isolate. R. officinalis led to promising results in the case of Gram-positive bacteria, resulting in a considerable interest in the development of reliable alternatives for the treatment of urinary infections.

  3. Effects of BmCPV Infection on Silkworm Bombyx mori Intestinal Bacteria.

    Directory of Open Access Journals (Sweden)

    Zhenli Sun

    Full Text Available The gut microbiota has a crucial role in the growth, development and environmental adaptation in the host insect. The objective of our work was to investigate the microbiota of the healthy silkworm Bombyx mori gut and changes after the infection of B. mori cypovirus (BmCPV. Intestinal contents of the infected and healthy larvae of B. mori of fifth instar were collected at 24, 72 and 144 h post infection with BmCPV. The gut bacteria were analyzed by pyrosequencing of the 16S rRNA gene. 147(135 and 113(103 genera were found in the gut content of the healthy control female (male larvae and BmCPV-infected female (male larvae, respectively. In general, the microbial communities in the gut content of healthy larvae were dominated by Enterococcus, Delftia, Pelomonas, Ralstonia and Staphylococcus, however the abundance change of each genus was depended on the developmental stage and gender. Microbial diversity reached minimum at 144 h of fifth instar larvae. The abundance of Enterococcus in the females was substantially lower and the abundance of Delftia, Aurantimonas and Staphylococcus was substantially higher compared to the males. Bacterial diversity in the intestinal contents decreased after post infection with BmCPV, whereas the abundance of both Enterococcus and Staphylococcus which belongs to Gram-positive were increased. Therefore, our findings suggested that observed changes in relative abundance was related to the immune response of silkworm to BmCPV infection. Relevance analysis of plenty of the predominant genera showed the abundance of the Enterococcus genus was in negative correlation with the abundance of the most predominant genera. These results provided insight into the relationship between the gut microbiota and development of the BmCPV-infected silkworm.

  4. Effects of BmCPV Infection on Silkworm Bombyx mori Intestinal Bacteria.

    Science.gov (United States)

    Sun, Zhenli; Lu, Yahong; Zhang, Hao; Kumar, Dhiraj; Liu, Bo; Gong, Yongchang; Zhu, Min; Zhu, Liyuan; Liang, Zi; Kuang, Sulan; Chen, Fei; Hu, Xiaolong; Cao, Guangli; Xue, Renyu; Gong, Chengliang

    2016-01-01

    The gut microbiota has a crucial role in the growth, development and environmental adaptation in the host insect. The objective of our work was to investigate the microbiota of the healthy silkworm Bombyx mori gut and changes after the infection of B. mori cypovirus (BmCPV). Intestinal contents of the infected and healthy larvae of B. mori of fifth instar were collected at 24, 72 and 144 h post infection with BmCPV. The gut bacteria were analyzed by pyrosequencing of the 16S rRNA gene. 147(135) and 113(103) genera were found in the gut content of the healthy control female (male) larvae and BmCPV-infected female (male) larvae, respectively. In general, the microbial communities in the gut content of healthy larvae were dominated by Enterococcus, Delftia, Pelomonas, Ralstonia and Staphylococcus, however the abundance change of each genus was depended on the developmental stage and gender. Microbial diversity reached minimum at 144 h of fifth instar larvae. The abundance of Enterococcus in the females was substantially lower and the abundance of Delftia, Aurantimonas and Staphylococcus was substantially higher compared to the males. Bacterial diversity in the intestinal contents decreased after post infection with BmCPV, whereas the abundance of both Enterococcus and Staphylococcus which belongs to Gram-positive were increased. Therefore, our findings suggested that observed changes in relative abundance was related to the immune response of silkworm to BmCPV infection. Relevance analysis of plenty of the predominant genera showed the abundance of the Enterococcus genus was in negative correlation with the abundance of the most predominant genera. These results provided insight into the relationship between the gut microbiota and development of the BmCPV-infected silkworm.

  5. A Study on Infections Caused By Metallo Beta Lactamase Producing Gram Negative Bacteria in Intensive Care Unit Patients

    Directory of Open Access Journals (Sweden)

    Debasrita Chakraborty

    2010-01-01

    Full Text Available Problem statement: Metallo Beta Lactamse (MBL producing bacteria is gradually increasing throughout the globe. There is no report of MBL producing bacteria from the city of Kolkata so far although it is a very big metropolice city in India. Thus this study was aimed to investigate the impact of this highly virulent group of bacteria in this city. Approach: In this experiment we studied the prevalence, following standard methods of isolation and identification techniques of these bacteria from clinical materials and also studied some characteristics and clinical data in relation to MBL producing bacterial infections in this locality. Results: It was seen that a high prevalence of MBL producing bacteria was present in this city and there were many differences between MBL producing bacterial infection in comparison to the MBL non producing bacterial infection, particularly in relation to age distribution, sex predominance, mortality rate, hematological changes, nature of primary diseases in which infection occurred. There were also some electron microscopic morphological alterations in MBL positive bacterial isolates. Conclusion: This study confirmed significant occurrence of MBL producing bacterial infections in Kolkata showing distinct clinic microbial changes in this type of infection.

  6. Isolation of bacteria causing urinary tract infection and their antibiotic resistance profile

    Directory of Open Access Journals (Sweden)

    Leandro Antonio Soares

    2010-11-01

    Full Text Available Urinary tract infection (UTI is among the most frequent causes bringing male and female patients to the municipal health units in search of treatment. This paper aims at identifying the microorganisms responsible for this infection and at establishing their resistance profile against the antibiotics most commonly used in the municipal network. One hundred and twenty samples from patients clinically suspect to have UTI were collected and differentiated in CLED, MacConkey e chromogenic EC culture media in the Microbiology Laboratory I of the “Centro Universitário Positivo-UNICEP”. Positive samples were identified and characterized by antibiogram. 63,64% of the infections were caused by Escherichia coli and 18,18% by Staphylococcus aureus. More than 60% of the infections occurred in the age range from 12 to 33 years. The high number of samples found contaminated is an indicator for a certain difficulty in following the instructions for sample collection. Another relevant data is that 35,8% of the analyzed samples came from pregnant women. The antibiotics to which the bacteria responsible for UTI are sensitive are in great part not available at the Unified Health System but most of the isolated E.coli bacteria and 100% of Saureus showed sensitivity to the drugs Nitrofurantoin and Sulfametoxazole-trimetropim, which are available in the health units. With a compatible clinical picture, an empirical treatment with the referred drugs can be considered adequate, however post-therapy control examinations would be ideal for avoiding the appearance of resistant strains in the community.

  7. Opportunistic infection of Aspergillus and bacteria in captive Cape vultures (Gyps coprotheres)

    Institute of Scientific and Technical Information of China (English)

    Stephen Chege; Judith Howlett; Majid Al Qassimi; Arshad Toosy; Joerg Kinne; Vincent Obanda

    2013-01-01

    Objective: To describe clinical signs, pathology, diagnosis and treatment of Cape vultures in which Aspergillus fumigatus (A. fumigatus) and mixed species of bacteria were isolated. Methods: Six Cape vultures sourced from South Africa for exhibition at Al Ain Zoo developed illness manifesting as anorexia, dyspnea, polyuria and lethargy. Three vultures died manifesting‘‘pneumonia-like syndrome’’. These three vultures were necropsied and gross lesions recorded, while organ tissues were collected for histopathology. Internal organs were swabbed for bacteriology and mycology. From live vultures, blood was collected for hematology and biochemistry, oropharyngeal and cloacal swabs were collected for mycology and bacteriology. Results: A. fumigatus was isolated from the three dead vultures and two live ones that eventually survived. One of the dead vulture and two live vultures were co-infected with A. fumigatus and mixed species of bacteria that included Clostridium perfringens, Pseudomonas, Staphylococcus, Escherichia, Proteus, Enterococcus and Enterbacter. One of the Cape vulture and a Lappet-faced vulture, however, were free of Aspergillus or bacterial infections. At necropsy, intestinal hemorrhages were observed and the lungs were overtly congested with granulomas present on caudal air sac. Histopathological examinations demonstrated granulomatous lesions that were infiltrated by mononuclear cells and giant cells. Conclusions: Aspergillosis is a persistent threat to captive birds and we recommend routine health assessments so that early diagnosis may prompt early treatment. It is likely that prompt prophylaxis by broad spectrum antibiotics and antifungals medication contributed to the survival of some of the vultures.

  8. Risk factors for infection with multidrug-resistant bacteria in non-ventilated patients with hospital-acquired pneumonia

    Directory of Open Access Journals (Sweden)

    Renato Seligman

    2013-06-01

    Full Text Available OBJECTIVE: To identify risk factors for the development of hospital-acquired pneumonia (HAP caused by multidrug-resistant (MDR bacteria in non-ventilated patients. METHODS: This was a retrospective observational cohort study conducted over a three-year period at a tertiary-care teaching hospital. We included only non-ventilated patients diagnosed with HAP and presenting with positive bacterial cultures. Categorical variables were compared with chi-square test. Logistic regression analysis was used to determine risk factors for HAP caused by MDR bacteria. RESULTS: Of the 140 patients diagnosed with HAP, 59 (42.1% were infected with MDR strains. Among the patients infected with methicillin-resistant Staphylococcus aureus and those infected with methicillin-susceptible S. aureus, mortality was 45.9% and 50.0%, respectively (p = 0.763. Among the patients infected with MDR and those infected with non-MDR gram-negative bacilli, mortality was 45.8% and 38.3%, respectively (p = 0.527. Univariate analysis identified the following risk factors for infection with MDR bacteria: COPD; congestive heart failure; chronic renal failure; dialysis; urinary catheterization; extrapulmonary infection; and use of antimicrobial therapy within the last 10 days before the diagnosis of HAP. Multivariate analysis showed that the use of antibiotics within the last 10 days before the diagnosis of HAP was the only independent predictor of infection with MDR bacteria (OR = 3.45; 95% CI: 1.56-7.61; p = 0.002. CONCLUSIONS: In this single-center study, the use of broad-spectrum antibiotics within the last 10 days before the diagnosis of HAP was the only independent predictor of infection with MDR bacteria in non-ventilated patients with HAP.

  9. Identifying the major bacteria causing intramammary infections in individual milk samples of sheep and goats using traditional bacteria culturing and real-time polymerase chain reaction.

    Science.gov (United States)

    Rovai, M; Caja, G; Salama, A A K; Jubert, A; Lázaro, B; Lázaro, M; Leitner, G

    2014-09-01

    Use of DNA-based methods, such as real-time PCR, has increased the sensitivity and shortened the time for bacterial identification, compared with traditional bacteriology; however, results should be interpreted carefully because a positive PCR result does not necessarily mean that an infection exists. One hundred eight lactating dairy ewes (56 Manchega and 52 Lacaune) and 24 Murciano-Granadina dairy goats were used for identifying the main bacteria causing intramammary infections (IMI) using traditional bacterial culturing and real-time PCR and their effects on milk performance. Udder-half milk samples were taken for bacterial culturing and somatic cell count (SCC) 3 times throughout lactation. Intramammary infections were assessed based on bacteria isolated in ≥2 samplings accompanied by increased SCC. Prevalence of subclinical IMI was 42.9% in Manchega and 50.0% in Lacaune ewes and 41.7% in goats, with the estimated milk yield loss being 13.1, 17.9, and 18.0%, respectively. According to bacteriology results, 87% of the identified single bacteria species (with more than 3 colonies/plate) or culture-negative growth were identical throughout samplings, which agreed 98.9% with the PCR results. Nevertheless, the study emphasized that 1 sampling may not be sufficient to determine IMI and, therefore, other inflammatory responses such as increased SCC should be monitored to identify true infections. Moreover, when PCR methodology is used, aseptic and precise milk sampling procedures are key for avoiding false-positive amplifications. In conclusion, both PCR and bacterial culture methods proved to have similar accuracy for identifying infective bacteria in sheep and goats. The final choice will depend on their response time and cost analysis, according to the requirements and farm management strategy.

  10. Specific Strains of Lactic Acid Bacteria Differentially Modulate the Profile of Adipokines In Vitro

    Science.gov (United States)

    Fabersani, Emanuel; Abeijon-Mukdsi, María Claudia; Ross, Romina; Medina, Roxana; González, Silvia; Gauffin-Cano, Paola

    2017-01-01

    Obesity induces local/systemic inflammation accompanied by increases in macrophage infiltration into adipose tissue and production of inflammatory cytokines, chemokines, and hormones. Previous studies have shown that probiotics could improve the intestinal dysbiosis induced by metabolic diseases such as obesity, diabetes, and metabolic syndrome. Microorganisms could (directly or indirectly) affect adipokine levels due to their capacity to induce translocation of several intestinal microbial antigens into systemic circulation, which could lead to metabolic endotoxemia or produce immunomodulation in different organs. The aim of the present study was to select non-inflammatory lactic acid bacteria (LAB) strains with the capacity to modulate adipokine secretion by the adipose tissue. We wish to elucidate the role of potential probiotic strains in the regulation of the cross talking between immune cells such as macrophages and adipose cells. Mouse macrophage cell line RAW 264.7 was used for evaluating the ability of 14 LAB strains to induce cytokine production. The LAB strains were chosen based on their previously studied beneficial properties in health. Then, in murine adipocyte culture and macrophage–adipocyte coculture, we determined the ability of these strains to induce cytokines and leptin secretion. Tumor necrosis factor alpha, interleukin 6 (IL-6), IL-10, monocyte chemoattractant protein-1, and leptin levels were measured in cell supernatants. We also performed the detection and quantification of leptin receptor (Ob-Rb) expression in macrophage cell lines stimulated by these LAB strains. Differential secretion profile of cytokines in macrophage cells induced by LAB strains was observed. Also, the levels of Ob-Rb expression diverged among different LAB strains. In LAB-stimulated coculture cells (adipocytes and macrophages), we observed differential production of leptin and cytokines. Furthermore, we detected lower production levels in single culture than

  11. Ability of procalcitonin to diagnose bacterial infection and bacteria types compared with blood culture findings

    Directory of Open Access Journals (Sweden)

    Watanabe Y

    2016-09-01

    Full Text Available Yuji Watanabe,1,2 Nozomi Oikawa,1,2 Maya Hariu,1,2 Ryota Fuke,1 Masafumi Seki1 1Division of Infectious Diseases and Infection Control, 2Laboratory for Clinical Microbiology, Tohoku Medical and Pharmaceutical University Hospital, Sendai City, Miyagi, Japan Abstract: Procalcitonin (PCT and C-reactive protein serve as biomarkers of infection in patients with sepsis/bacteremia. The present study assessed the clinical characteristics of 280 patients with suspected sepsis who were admitted to Tohoku Medical and Pharmaceutical University Hospital between January 2012 and December 2013. Among the patients, 133 and 147 were positive and negative for PCT, respectively. Patients who were PCT positive were older and more frequently male, had reduced levels of platelets and albumin, and increased levels of aspartate aminotransferase, alanine aminotransferase, blood urea nitrogen, creatinine, and C-reactive protein. Patients who were PCT positive had significantly higher blood culture positivity compared with those who were PCT negative, and the sensitivity and specificity of PCT for detecting positive blood cultures were 74.5% and 59.1%, respectively. Escherichia coli was detected in PCT-positive patients, whereas Staphylococcus epidermidis and Staphylococcus lugdunensis were frequently detected in PCT-negative patients. Levels of PCT were higher in the patients infected with gram-negative rods than those with gram-positive cocci. Furthermore, extended-spectrum β-lactamase (ESBL-producing bacteria cases showed higher levels of PCT than those of non-ESBL cases. These results suggest that PCT may be a useful biomarker of sepsis, and it might serve as a strong tool to detect patients with severe gram-negative rod bacteremia including ESBL-producing bacteria cases early due to its relative high sensitivity. Keywords: biomarker, sepsis, Escherichia coli, gram-negative rods, ESBL

  12. Exopolysaccharides isolated from hydrothermal vent bacteria can modulate the complement system.

    Science.gov (United States)

    Courtois, Anthony; Berthou, Christian; Guézennec, Jean; Boisset, Claire; Bordron, Anne

    2014-01-01

    The complement system is involved in the defence against bacterial infection, or in the elimination of tumour cells. However, disturbances in this system contributes to the pathogenesis of various inflammatory diseases. The efficiency of therapeutic anti-tumour antibodies is enhanced when the complement system is stimulated. In contrast, cancer cells are able to inhibit the complement system and thus proliferate. Some marine molecules are currently being developed as new drugs for use in humans. Among them, known exopolyssacharides (EPSs) generally originate from fungi, but few studies have been performed on bacterial EPSs and even fewer on EPSs extracted from deep-sea hydrothermal vent microbes. For use in humans, these high molecular weight EPSs must be depolymerised. Furthermore, the over-sulphation of EPSs can modify their biological activity. The aim of this study was to investigate the immunodulation of the complement system by either native or over-sulphated low molecular weight EPSs isolated from vent bacteria in order to find pro or anti-activators of complement.

  13. Early immune response patterns to pathogenic bacteria are associated to increased risk of lower respiratory infections in children

    DEFF Research Database (Denmark)

    Vissing, N. H.; Larsen, Jeppe Madura; Rasmussen, Mette Annelie

    2014-01-01

    Neonatal colonisation of the airways with respiratory pathogens is associated with increased risk of lower respiratory infections (LRI) in early childhood (1). Therefore, we hypothesized that children developing LRI have an abnormal immune response to pathogenic bacteria in infancy. We aimed...... to characterise the systemic immune response to pathogenic bacteria at the age of 6 months and study the association with incidence of LRI during the first 3 years of life....

  14. Primed Immune Responses Triggered by Ingested Bacteria Lead to Systemic Infection Tolerance in Silkworms.

    Directory of Open Access Journals (Sweden)

    Atsushi Miyashita

    Full Text Available In the present study, we examined whether microorganisms collaterally ingested by insects with their food activate the innate immune system to confer systemic resistance against subsequent bacterial invasion. Silkworms orally administered heat-killed Pseudomonas aeruginosa cells showed resistance against intra-hemolymph infection by P. aeruginosa. Oral administration of peptidoglycans, cell wall components of P. aeruginosa, conferred protective effects against P. aeruginosa infection, whereas oral administration of lipopolysaccharides, bacterial surface components, did not. In silkworms orally administered heat-killed P. aeruginosa cells, P. aeruginosa growth was inhibited in the hemolymph, and mRNA amounts of the antimicrobial peptides cecropin A and moricin were increased in the hemocytes and fat body. Furthermore, the amount of paralytic peptide, an insect cytokine that activates innate immune reactions, was increased in the hemolymph of silkworms orally administered heat-killed P. aeruginosa cells. These findings suggest that insects sense bacteria present in their food by peptidoglycan recognition, which activates systemic immune reactions to defend the insects against a second round of infection.

  15. Effect of respiratory syncytial virus (RSV) infection on the adherence of pathogenic bacteria to human epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Faden, H.; Hong, J.J.; Ogra, P.L.

    1986-03-01

    The effect of RSV infection on the adherence of Streptococcus pneumoniae (SP), Haemophilus influenzae (HI) and Staphylococcus aureus (SA) to human epithelial cells was determined. RSV-infected Hep-2 cell cultures at different stages of expression of surface viral antigens and bacteria labeled with /sup 3/H-thymidine were employed to examine the kinetics of bacterial adherence to virus-infected cells. RSV infection did not alter the magnitude of adherence of HI or SA to HEp-2 cells. However, adherence of SP to HEp-2 cells was significantly (P < 0.01) enhanced by prior RSV infection. The degree of adherence was directly related to the amount of viral antigen expressed on the cell surface. The adherence was temperature dependent, with maximal adherence observed at 37/sup 0/C. Heat-inactivation of SP did not alter adherence characteristics. These data suggest that RSV infection increases adherence of SP to the surface of epithelial cells in vitro. Since attachment of bacteria to mucosal surfaces is the first step in many infections, it is suggested that viral infections of epithelial cells render them more susceptible to bacterial adherence. Thus, RSV infection in vivo may predispose children to SP infections, such as in otitis media, by increasing colonization with SP.

  16. Contrasting life strategies of viruses that infect photo- and heterotrophic bacteria, as revealed by viral tagging.

    Science.gov (United States)

    Deng, Li; Gregory, Ann; Yilmaz, Suzan; Poulos, Bonnie T; Hugenholtz, Philip; Sullivan, Matthew B

    2012-10-30

    Ocean viruses are ubiquitous and abundant and play important roles in global biogeochemical cycles by means of their mortality, horizontal gene transfer, and manipulation of host metabolism. However, the obstacles involved in linking viruses to their hosts in a high-throughput manner bottlenecks our ability to understand virus-host interactions in complex communities. We have developed a method called viral tagging (VT), which combines mixtures of host cells and fluorescent viruses with flow cytometry. We investigated multiple viruses which infect each of two model marine bacteria that represent the slow-growing, photoautotrophic genus Synechococcus (Cyanobacteria) and the fast-growing, heterotrophic genus Pseudoalteromonas (Gammaproteobacteria). Overall, viral tagging results for viral infection were consistent with plaque and liquid infection assays for cyanobacterial myo-, podo- and siphoviruses and some (myo- and podoviruses) but not all (four siphoviruses) heterotrophic bacterial viruses. Virus-tagged Pseudoalteromonas organisms were proportional to the added viruses under varied infection conditions (virus-bacterium ratios), while no more than 50% of the Synechococcus organisms were virus tagged even at viral abundances that exceeded (5 to 10×) that of their hosts. Further, we found that host growth phase minimally impacts the fraction of virus-tagged Synechococcus organisms while greatly affecting phage adsorption to Pseudoalteromonas. Together these findings suggest that at least two contrasting viral life strategies exist in the oceans and that they likely reflect adaptation to their host microbes. Looking forward to the point at which the virus-tagging signature is well understood (e.g., for Synechococcus), application to natural communities should begin to provide population genomic data at the proper scale for predictively modeling two of the most abundant biological entities on Earth. Viral study suffers from an inability to link viruses to hosts en

  17. Outcome of Transplantation Using Organs From Donors Infected or Colonized With Carbapenem-Resistant Gram-Negative Bacteria.

    Science.gov (United States)

    Mularoni, A; Bertani, A; Vizzini, G; Gona, F; Campanella, M; Spada, M; Gruttadauria, S; Vitulo, P; Conaldi, P; Luca, A; Gridelli, B; Grossi, P

    2015-10-01

    Donor-derived infections due to multidrug-resistant bacteria are a growing problem in solid organ transplantation, and optimal management options are not clear. In a 2-year period, 30/214 (14%) recipients received an organ from 18/170 (10.5%) deceased donors with infection or colonization caused by a carbapenem-resistant gram-negative bacteria that was unknown at the time of transplantation. Among them, 14/30 recipients (47%) received a transplant from a donor with bacteremia or with infection/colonization of the transplanted organ and were considered at high risk of donor-derived infection transmission. The remaining 16/30 (53%) recipients received an organ from a nonbacteremic donor with colonization of a nontransplanted organ and were considered at low risk of infection transmission. Proven transmission occurred in 4 of the 14 high-risk recipients because donor infection was either not recognized, underestimated, or not communicated. These recipients received late, short or inappropriate posttransplant antibiotic therapy. Transmission did not occur in high-risk recipients who received appropriate and prompt antibiotic therapy for at least 7 days. The safe use of organs from donors with multidrug-resistant bacteria requires intra- and inter-institutional communication to allow appropriate management and prompt treatment of recipients in order to avoid transmission of infection.

  18. Volatile organic compounds generated by cultures of bacteria and viruses associated with respiratory infections.

    Science.gov (United States)

    Abd El Qader, Amir; Lieberman, David; Shemer Avni, Yonat; Svobodin, Natali; Lazarovitch, Tsilia; Sagi, Orli; Zeiri, Yehuda

    2015-12-01

    Respiratory infections (RI) can be viral or bacterial in origin. In either case, the invasion of the pathogen results in production and release of various volatile organic compounds (VOCs). The present study examines the VOCs released from cultures of five viruses (influenza A, influenza B, adenovirus, respiratory syncitial virus and parainfluenza 1 virus), three bacteria (Moraxella catarrhalis, Haemophilus influenzae and Legionella pneumophila) and Mycoplasma pneumoniae isolated colonies. Our results demonstrate the involvement of inflammation-induced VOCs. Two significant VOCs were identified as associated with infectious bacterial activity, heptane and methylcyclohexane. These two VOCs have been linked in previous studies to oxidative stress effects. In order to distinguish between bacterial and viral positive cultures, we performed principal component analysis including peak identity (retention time) and VOC concentration (i.e. area under the peak) revealing 1-hexanol and 1-heptadecene to be good predictors.

  19. Modulation of host-cell MAPkinase signaling during fungal infection

    OpenAIRE

    2015-01-01

    Fungal infections contribute substantially to human suffering and mortality. The interaction between fungal pathogens and their host involves the invasion and penetration of the surface epithelium, activation of cells of the innate immune system and the generation of an effective response to block infection. Numerous host-cell signaling pathways are activated during fungal infection. This review will focus on the main fungal pathogens Aspergillus fumigatus, Candida albicans and Cryptococcus n...

  20. The Wnt/β-Catenin Signaling Pathway Controls the Inflammatory Response in Infections Caused by Pathogenic Bacteria

    OpenAIRE

    Octavio Silva-García; Valdez-Alarcón, Juan J.; Baizabal-Aguirre, Víctor M.

    2014-01-01

    Innate immunity against pathogenic bacteria is critical to protect host cells from invasion and infection as well as to develop an appropriate adaptive immune response. During bacterial infection, different signaling transduction pathways control the expression of a wide range of genes that orchestrate a number of molecular and cellular events to eliminate the invading microorganisms and regulate inflammation. The inflammatory response must be tightly regulated because uncontrolled inflammati...

  1. Dengue virus life cycle : viral and host factors modulating infectivity

    NARCIS (Netherlands)

    Rodenhuis-Zybert, Izabela A.; Wilschut, Jan; Smit, Jolanda M.

    2010-01-01

    Dengue virus (DENV 1-4) represents a major emerging arthropod-borne pathogen. All four DENV serotypes are prevalent in the (sub) tropical regions of the world and infect 50-100 million individuals annually. Whereas the majority of DENV infections proceed asymptomatically or result in self-limited de

  2. Dietary modulation of the resistance to intestinal infections.

    NARCIS (Netherlands)

    Bovee-Oudenhoven, I.M.J.

    1998-01-01

    Gastrointestinal infections are still a major health problem, not only in developing countries. Even in Europe and the United States about 10-15 % of the population contracts an intestinal infection each year, mostly of foodborne origin. The growing resistance of pathogens to antibiotics stresses th

  3. CIPROFLOXACIN RESISTANCE PATTERN AMONG BACTERIA ISOLATED FROM PATIENTS WITH COMMUNITY-ACQUIRED URINARY TRACT INFECTION

    Directory of Open Access Journals (Sweden)

    Ana Carolina Costa REIS

    2016-01-01

    Full Text Available SUMMARY Objective: To identify the main bacterial species associated with community-acquired urinary tract infection (UTI and to assess the pattern of ciprofloxacin susceptibility among bacteria isolated from urine cultures. Methods: We conducted a retrospective study in all the patients with community-acquired UTI seen in Santa Helena Laboratory, Camaçari, Bahia, Brazil during five years (2010-2014. All individuals who had a positive urine culture result were included in this study. Results: A total of 1,641 individuals met the inclusion criteria. Despite the fact that participants were female, we observed a higher rate of resistance to ciprofloxacin in males. The most frequent pathogens identified in urine samples were Escherichia coli, Klebsiella pneumoniae and Staphylococcus saprophyticus. Antimicrobial resistance has been observed mainly for ampicillin, sulfamethoxazole + trimethoprim and ciprofloxacin. Moreover, E. coli has shown the highest rate of ciprofloxacin resistance, reaching 36% of ciprofloxacin resistant strains in 2014. Conclusion: The rate of bacterial resistance to ciprofloxacin observed in the studied population is much higher than expected, prompting the need for rational use of this antibiotic, especially in infections caused by E. coli. Prevention of bacterial resistance can be performed through control measures to limit the spread of resistant microorganisms and a rational use of antimicrobial policy.

  4. CIPROFLOXACIN RESISTANCE PATTERN AMONG BACTERIA ISOLATED FROM PATIENTS WITH COMMUNITY-ACQUIRED URINARY TRACT INFECTION

    Science.gov (United States)

    REIS, Ana Carolina Costa; SANTOS, Susana Regia da Silva; de SOUZA, Siane Campos; SALDANHA, Milena Góes; PITANGA, Thassila Nogueira; OLIVEIRA, Ricardo Riccio

    2016-01-01

    SUMMARY Objective: To identify the main bacterial species associated with community-acquired urinary tract infection (UTI) and to assess the pattern of ciprofloxacin susceptibility among bacteria isolated from urine cultures. Methods: We conducted a retrospective study in all the patients with community-acquired UTI seen in Santa Helena Laboratory, Camaçari, Bahia, Brazil during five years (2010-2014). All individuals who had a positive urine culture result were included in this study. Results: A total of 1,641 individuals met the inclusion criteria. Despite the fact that participants were female, we observed a higher rate of resistance to ciprofloxacin in males. The most frequent pathogens identified in urine samples were Escherichia coli, Klebsiella pneumoniae and Staphylococcus saprophyticus. Antimicrobial resistance has been observed mainly for ampicillin, sulfamethoxazole + trimethoprim and ciprofloxacin. Moreover, E. coli has shown the highest rate of ciprofloxacin resistance, reaching 36% of ciprofloxacin resistant strains in 2014. Conclusion: The rate of bacterial resistance to ciprofloxacin observed in the studied population is much higher than expected, prompting the need for rational use of this antibiotic, especially in infections caused by E. coli. Prevention of bacterial resistance can be performed through control measures to limit the spread of resistant microorganisms and a rational use of antimicrobial policy. PMID:27410913

  5. Immune modulation in the treatment of respiratory infection

    Directory of Open Access Journals (Sweden)

    Nelson Steve

    2000-06-01

    Full Text Available Abstract The limitations of currently available treatment for severe respiratory infection are demonstrated by the relatively fixed mortality associated with these infections despite advances in nutrition, vaccines, antibiotics, and critical care. This might be due in part to the changing spectrum of pathogens and development of drug resistance. Cytokines are potent molecules that function as growth factors and orchestrate both innate and adaptive immune responses. Several of these factors have entered the clinical arena to support or augment the immune response. Moreover, the use of cytokines has recently been expanded to patients without an overtly defective immune system but who have either significant infection or infection with drug resistant organisms. The use of cytokines as adjuvants in the treatment of respiratory infections is reviewed.

  6. Effect of Probiotic Bacteria on Microbial Host Defense, Growth, and Immune Function in Human Immunodeficiency Virus Type-1 Infection

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    Stig Bengmark

    2011-12-01

    Full Text Available The hypothesis that probiotic administration protects the gut surface and could delay progression of Human Immunodeficiency Virus type1 (HIV-1 infection to the Acquired Immunodeficiency Syndrome (AIDS was proposed in 1995. Over the last five years, new studies have clarified the significance of HIV-1 infection of the gut associated lymphoid tissue (GALT for subsequent alterations in the microflora and breakdown of the gut mucosal barrier leading to pathogenesis and development of AIDS. Current studies show that loss of gut CD4+ Th17 cells, which differentiate in response to normal microflora, occurs early in HIV-1 disease. Microbial translocation and suppression of the T regulatory (Treg cell response is associated with chronic immune activation and inflammation. Combinations of probiotic bacteria which upregulate Treg activation have shown promise in suppressing pro inflammatory immune response in models of autoimmunity including inflammatory bowel disease and provide a rationale for use of probiotics in HIV-1/AIDS. Disturbance of the microbiota early in HIV-1 infection leads to greater dominance of potential pathogens, reducing levels of bifidobacteria and lactobacillus species and increasing mucosal inflammation. The interaction of chronic or recurrent infections, and immune activation contributes to nutritional deficiencies that have lasting consequences especially in the HIV-1 infected child. While effective anti-retroviral therapy (ART has enhanced survival, wasting is still an independent predictor of survival and a major presenting symptom. Congenital exposure to HIV-1 is a risk factor for growth delay in both infected and non-infected infants. Nutritional intervention after 6 months of age appears to be largely ineffective. A meta analysis of randomized, controlled clinical trials of infant formulae supplemented with Bifidobacterium lactis showed that weight gain was significantly greater in infants who received B. lactis compared to

  7. Infection status of hospitalized diarrheal patients with gastrointestinal protozoa, bacteria, and viruses in the Republic of Korea.

    Science.gov (United States)

    Cheun, Hyeng-Il; Cho, Shin-Hyeong; Lee, Jin-Hee; Lim, Yi-Young; Jeon, Ji-Hye; Yu, Jae-Ran; Kim, Tong-Soo; Lee, Won-Ja; Cho, Seung-Hak; Lee, Deog-Yong; Park, Mi-Seon; Jeong, Hye-Sook; Chen, Doo-Sung; Ji, Yeong-Mi; Kwon, Mi-Hwa

    2010-06-01

    To understand protozoan, viral, and bacterial infections in diarrheal patients, we analyzed positivity and mixed-infection status with 3 protozoans, 4 viruses, and 10 bacteria in hospitalized diarrheal patients during 2004-2006 in the Republic of Korea. A total of 76,652 stool samples were collected from 96 hospitals across the nation. The positivity for protozoa, viruses, and bacteria was 129, 1,759, and 1,797 per 10,000 persons, respectively. Especially, Cryptosporidium parvum was highly mixed-infected with rotavirus among pediatric diarrheal patients (29.5 per 100 C. parvum positive cases), and Entamoeba histolytica was mixed-infected with Clostridium perfringens (10.3 per 100 E. histolytica positive cases) in protozoan-diarrheal patients. Those infected with rotavirus and C. perfringens constituted relatively high proportions among mixed infection cases from January to April. The positivity for rotavirus among viral infection for those aged or = 50 years. The information for association of viral and bacterial infections with enteropathogenic protozoa in diarrheal patients may contribute to improvement of care for diarrhea as well as development of control strategies for diarrheal diseases in Korea.

  8. Clinical identification of bacteria in human chronic wound infections: culturing vs. 16S ribosomal DNA sequencing

    Directory of Open Access Journals (Sweden)

    Rhoads Daniel D

    2012-11-01

    Full Text Available Abstract Background Chronic wounds affect millions of people and cost billions of dollars in the United States each year. These wounds harbor polymicrobial biofilm communities, which can be difficult to elucidate using culturing methods. Clinical molecular microbiological methods are increasingly being employed to investigate the microbiota of chronic infections, including wounds, as part of standard patient care. However, molecular testing is more sensitive than culturing, which results in markedly different results being reported to clinicians. This study compares the results of aerobic culturing and molecular testing (culture-free 16S ribosomal DNA sequencing, and it examines the relative abundance score that is generated by the molecular test and the usefulness of the relative abundance score in predicting the likelihood that the same organism would be detected by culture. Methods Parallel samples from 51 chronic wounds were studied using aerobic culturing and 16S DNA sequencing for the identification of bacteria. Results One hundred forty-five (145 unique genera were identified using molecular methods, and 68 of these genera were aerotolerant. Fourteen (14 unique genera were identified using aerobic culture methods. One-third (31/92 of the cultures were determined to be Staphylococcus aureus, Pseudomonas aeruginosa, and Enterococcus faecalis with higher relative abundance scores were more likely to be detected by culture as demonstrated with regression modeling. Conclusion Discordance between molecular and culture testing is often observed. However, culture-free 16S ribosomal DNA sequencing and its relative abundance score can provide clinicians with insight into which bacteria are most abundant in a sample and which are most likely to be detected by culture.

  9. Plant-activated bacterial receptor adenylate cyclases modulate epidermal infection in the Sinorhizobium meliloti–Medicago symbiosis

    OpenAIRE

    Tian, Chang Fu; Garnerone, Anne-Marie; Mathieu-Demazière, Céline; Masson-Boivin, Catherine; Batut, Jacques

    2012-01-01

    Legumes and soil bacteria called rhizobia have coevolved a facultative nitrogen-fixing symbiosis. Establishment of the symbiosis requires bacterial entry via root hair infection threads and, in parallel, organogenesis of nodules that subsequently are invaded by bacteria. Tight control of nodulation and infection is required to maintain the mutualistic character of the interaction. Available evidence supports a passive bacterial role in nodulation and infection after the microsymbiont has trig...

  10. Relevance of biofilm bacteria in modulating the larval metamorphosis of Balanus amphitrite

    Digital Repository Service at National Institute of Oceanography (India)

    Khandeparker, L.; Anil, A.C.; Raghukumar, S.

    Balanus amphitrite, on its larval metamorphosis. The effect of multispecies bacterial film was also assessed. The production of different molecules by the bacteria was influenced by the nutrient media under which they were grown. It was observed...

  11. Environmental modulation of mucosal immunity : Opportunities in respiratory viral infections

    NARCIS (Netherlands)

    Schijf, M.A.

    2013-01-01

    The exact cause of severe disease in children during primary RSV infections is not completely clear. There is a link with viral load, but differences virus strains do not seem to be the major reason why in some children the disease manifests as a mild cold while others suffer from a severe lower res

  12. Modulation of pathogen-induced CCL20 secretion from HT-29 human intestinal epithelial cells by commensal bacteria.

    LENUS (Irish Health Repository)

    Sibartie, Shomik

    2009-01-01

    BACKGROUND: Human intestinal epithelial cells (IECs) secrete the chemokine CCL20 in response to infection by various enteropathogenic bacteria or exposure to bacterial flagellin. CCL20 recruits immature dendritic cells and lymphocytes to target sites. Here we investigated IEC responses to various pathogenic and commensal bacteria as well as the modulatory effects of commensal bacteria on pathogen-induced CCL20 secretion. HT-29 human IECs were incubated with commensal bacteria (Bifidobacterium infantis or Lactobacillus salivarius), or with Salmonella typhimurium, its flagellin, Clostridium difficile, Mycobacterium paratuberculosis, or Mycobacterium smegmatis for varying times. In some studies, HT-29 cells were pre-treated with a commensal strain for 2 hr prior to infection or flagellin stimulation. CCL20 and interleukin (IL)-8 secretion and nuclear factor (NF)-kappaB activation were measured using enzyme-linked immunosorbent assays. RESULTS: Compared to untreated cells, S. typhimurium, C. difficile, M. paratuberculosis, and flagellin activated NF-kappaB and stimulated significant secretion of CCL20 and IL-8 by HT-29 cells. Conversely, B. infantis, L. salivarius or M. smegmatis did not activate NF-kappaB or augment CCL20 or IL-8 production. Treatment with B. infantis, but not L. salivarius, dose-dependently inhibited the baseline secretion of CCL20. In cells pre-treated with B. infantis, C. difficile-, S. typhimurium-, and flagellin-induced CCL20 were significantly attenuated. B. infantis did not limit M. Paratuberculosis-induced CCL20 secretion. CONCLUSION: This study is the first to demonstrate that a commensal strain can attenuate CCL20 secretion in HT-29 IECs. Collectively, the data indicate that M. paratuberculosis may mediate mucosal damage and that B. infantis can exert immunomodulatory effects on IECs that mediate host responses to flagellin and flagellated enteric pathogens.

  13. Pseudomonas aeruginosa airway infection recruits and modulates neutrophilic myeloid-derived suppressor cells

    Directory of Open Access Journals (Sweden)

    Hasan Halit Öz

    2016-11-01

    Full Text Available Pseudomonas aeruginosa is an opportunistic pathogen that causes infections mainly in patients with cystic fibrosis (CF lung disease. Despite innate and adaptive immune responses upon infection, P. aeruginosa is capable of efficiently escaping host defenses, but the underlying immune mechanisms remain poorly understood. Myeloid-derived suppressor cells (MDSCs are innate immune cells that are functionally characterized by their potential to suppress T- and natural killer (NK-cell responses. Here we demonstrate, using an airway in vivo infection model, that P. aeruginosa recruits and activates neutrophilic MDSCs, which functionally suppress T-cell responses. We further show that the CF gene defect (cystic fibrosis transmembrane conductance regulator, CFTR modulates the functionality, but not the recruitment or generation of neutrophilic MDSCs. Collectively, we define a mechanism by which P. aeruginosa airway infection undermines host immunity by modulating neutrophilic MDSCs in vivo.

  14. A gastrointestinal rotavirus infection mouse model for immune modulation studies

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    van Amerongen Geert

    2011-03-01

    Full Text Available Abstract Background Rotaviruses are the single most important cause of severe diarrhea in young children worldwide. The current study was conducted to assess whether colostrum containing rotavirus-specific antibodies (Gastrogard-R® could protect against rotavirus infection. In addition, this illness model was used to study modulatory effects of intervention on several immune parameters after re-infection. Methods BALB/c mice were treated by gavage once daily with Gastrogard-R® from the age of 4 to 10 days, and were inoculated with rhesus rotavirus (RRV at 7 days of age. A secondary inoculation with epizootic-diarrhea infant-mouse (EDIM virus was administered at 17 days of age. Disease symptoms were scored daily and viral shedding was measured in fecal samples during the post-inoculation periods. Rotavirus-specific IgM, IgG and IgG subclasses in serum, T cell proliferation and rotavirus-specific delayed-type hypersensitivity (DTH responses were also measured. Results Primary inoculation with RRV induced a mild but consistent level of diarrhea during 3-4 days post-inoculation. All mice receiving Gastrogard-R® were 100% protected against rotavirus-induced diarrhea. Mice receiving both RRV and EDIM inoculation had a lower faecal-viral load following EDIM inoculation then mice receiving EDIM alone or Gastrogard-R®. Mice receiving Gastrogard-R® however displayed an enhanced rotavirus-specific T-cell proliferation whereas rotavirus-specific antibody subtypes were not affected. Conclusions Preventing RRV-induced diarrhea by Gastrogard-R® early in life showed a diminished protection against EDIM re-infection, but a rotavirus-specific immune response was developed including both B cell and T cell responses. In general, this intervention model can be used for studying clinical symptoms as well as the immune responses required for protection against viral re-infection.

  15. Immunity and immune modulation in Trypanosoma cruzi infection.

    Science.gov (United States)

    Cardillo, Fabíola; de Pinho, Rosa Teixeira; Antas, Paulo Renato Zuquim; Mengel, José

    2015-12-01

    Chagas disease is caused by the protozoan Trypanosoma cruzi. The parasite reaches the secondary lymphoid organs, the heart, skeletal muscles, neurons in the intestine and esophagus among other tissues. The disease is characterized by mega syndromes, which may affect the esophagus, the colon and the heart, in about 30% of infected people. The clinical manifestations associated with T. cruzi infection during the chronic phase of the disease are dependent on complex interactions between the parasite and the host tissues, particularly the lymphoid system that may either result in a balanced relationship with no disease or in an unbalanced relationship that follows an inflammatory response to parasite antigens and associated tissues in some of the host organs and/or by an autoimmune response to host antigens. This review discusses the findings that support the notion of an integrated immune response, considering the innate and adaptive arms of the immune system in the control of parasite numbers and also the mechanisms proposed to regulate the immune response in order to tolerate the remaining parasite load, during the chronic phase of infection. This knowledge is fundamental to the understanding of the disease progression and is essential for the development of novel therapies and vaccine strategies.

  16. Human Ezrin-Moesin-Radixin Proteins Modulate Hepatitis C Virus Infection

    OpenAIRE

    Bukong, Terence N; Kodys, Karen; Szabo, Gyongyi

    2013-01-01

    Host cytoskeletal proteins of the ezrin-moesin-radixin (EMR) family have been shown to modulate single-stranded RNA virus infection through regulating stable microtubule formation. Antibody engagement of CD81, a key receptor for HCV entry, induces ezrin phosphorylation. Here we tested the role of EMR proteins in regulating HCV infection and explored potential therapeutic targets. We show that HCV E2 protein induces rapid ezrin phosphorylation and its cellular redistribution with F-actin via s...

  17. Coincident helminth infection modulates systemic inflammation and immune activation in active pulmonary tuberculosis.

    Directory of Open Access Journals (Sweden)

    Parakkal Jovvian George

    Full Text Available Helminth infections are known to modulate innate and adaptive immune responses in active and latent tuberculosis (TB. However, the role of helminth infections in modulating responses associated with inflammation and immune activation (reflecting disease activity and/or severity in TB is not known.We measured markers of inflammation and immune activation in active pulmonary TB individuals (ATB with co-incidental Strongyloides stercoralis (Ss infection. These included systemic levels of acute phase proteins, matrix metalloproteinases and their endogenous inhibitors and immune activation markers. As a control, we measured the systemic levels of the same molecules in TB-uninfected individuals (NTB with or without Ss infection.Our data confirm that ATB is associated with elevated levels of the various measured molecules when compared to those seen in NTB. Our data also reveal that co-incident Ss infection in ATB individuals is associated with significantly decreased circulating levels of acute phase proteins, matrix metalloproteinases, tissue inhibitors of matrix metalloproteinases as well as the systemic immune activation markers, sCD14 and sCD163. These changes are specific to ATB since they are absent in NTB individuals with Ss infection.Our data therefore reveal a profound effect of Ss infection on the markers associated with TB disease activity and severity and indicate that co-incidental helminth infections might dampen the severity of TB disease.

  18. In vitro interactions between bacteria, osteoblast-like cells and macrophages in the pathogenesis of biomaterial-associated infections.

    Science.gov (United States)

    Subbiahdoss, Guruprakash; Fernández, Isabel C Saldarriaga; Domingues, Joana F da Silva; Kuijer, Roel; van der Mei, Henny C; Busscher, Henk J

    2011-01-01

    Biomaterial-associated infections constitute a major clinical problem that is difficult to treat and often necessitates implant replacement. Pathogens can be introduced on an implant surface during surgery and compete with host cells attempting to integrate the implant. The fate of a biomaterial implant depends on the outcome of this race for the surface. Here we studied the competition between different bacterial strains and human U2OS osteoblast-like cells (ATCC HTB-94) for a poly(methylmethacrylate) surface in the absence or presence of macrophages in vitro using a peri-operative contamination model. Bacteria were seeded on the surface at a shear rate of 11 1/s prior to adhesion of U2OS cells and macrophages. Next, bacteria, U2OS cells and macrophages were allowed to grow simultaneously under low shear conditions (0.14 1/s). The outcome of the competition between bacteria and U2OS cells for the surface critically depended on bacterial virulence. In absence of macrophages, highly virulent Staphylococcus aureus or Pseudomonas aeruginosa stimulated U2OS cell death within 18 h of simultaneous growth on a surface. Moreover, these strains also caused cell death despite phagocytosis of adhering bacteria in presence of murine macrophages. Thus U2OS cells are bound to loose the race for a biomaterial surface against S. aureus or P. aeruginosa, even in presence of macrophages. In contrast, low-virulent Staphylococcus epidermidis did not cause U2OS cell death even after 48 h, regardless of the absence or presence of macrophages. Clinically, S. aureus and P. aeruginosa are known to yield acute and severe biomaterial-associated infections in contrast to S. epidermidis, mostly known to cause more low-grade infection. Thus it can be concluded that the model described possesses features concurring with clinical observations and therewith has potential for further studies on the simultaneous competition for an implant surface between tissue cells and pathogenic bacteria in

  19.  Mycolic acids – potential biomarkers of opportunistic infections caused by bacteria of the suborder Corynebacterineae

    Directory of Open Access Journals (Sweden)

    Konrad Kowalski

    2012-06-01

    Full Text Available  Mycolic acids are one of the basic elements of the cell wall structure of bacteria belonging to the suborder Corynebacterineae, constituting from 20�0to 40�0of dry weight. Additionally, they show high structural diversity within each family and species. Nowadays, profiles of mycolic acids are widely described for the genus Mycobacterium, the causative agent of tuberculosis. However, the suborder Corynebacterineae also includes many representatives of opportunistic human pathogens, e.g. Dietzia, Gordonia, Nocardia and Rhodococcus. Currently, an increased infection risk caused by this group of microorganisms especially in immunocompromised patients has been observed. Better knowledge of mycolic acid profiles for Corynebacterineae may allow identification of mycolic acids as diagnostic markers in the detection of opportunistic bacterial infections. Modern techniques of chemical analysis, including mass spectrometry, may enable the development of new chemotaxonomic methods for the detection and differentiation of bacteria within the suborder Corynebacterineae.

  20. Vertebrate Cell Cycle Modulates Infection by Protozoan Parasites

    Science.gov (United States)

    Dvorak, James A.; Crane, Mark St. J.

    1981-11-01

    Synchronized HeLa cell populations were exposed to Trypanosoma cruzi or Toxoplasma gondii, obligate intracellular protozoan parasites that cause Chagas' disease and toxoplasmosis, respectively, in humans. The ability of the two parasites to infect HeLa cells increased as the HeLa cells proceeded from the G1 phase to the S phase of their growth cycle and decreased as the cells entered G2-M. Characterization of the S-phase cell surface components responsible for this phenomenon could be beneficial in the development of vaccines against these parasitic diseases.

  1. A study on the prevention of salmonella infection by using the aggregation characteristics of lactic Acid bacteria.

    Science.gov (United States)

    Kim, Min-Soo; Yoon, Yeo-Sang; Seo, Jae-Gu; Lee, Hyun-Gi; Chung, Myung-Jun; Yum, Do-Young

    2013-06-01

    Salmonella is one of the major pathogenic bacteria that cause food poisoning. This study investigated whether heat-killed as well as live Lactobacillus protects host animal against Salmonella infection. Live and heat-killed Lactobacillusacidophilus was administered orally to Sprague-Dawley rats for 2 weeks before the rats were inoculated with Salmonella. Rise in body temperature was moderate in the group that was treated with heat-killed bacteria as compared to the Salmonella control group. The mean amount of feed intake and water consumption of each rat in the heat-killed bacteria group were nearly normal. The number of fecal Salmonellae was comparable between the live and the heat-killed L. acidophilus groups. This finding shows that L. acidophilus facilitates the excretion of Salmonella. Moreover, the levels of pro inflammatory cytokines, including tumor necrosis factor (TNF)-alpha and interleukin (IL)-1 beta, in the heat-killed L. acidophilus group were significantly lower when compared to the levels in the Salmonella control group. These results indicate that nonviable lactic acid bacteria also could play an important role in preventing infections by enteric pathogens such as Salmonella.

  2. Antibacterial activity of Thymus maroccanus and Thymus broussonetii essential oils against nosocomial infection - bacteria and their synergistic potential with antibiotics.

    Science.gov (United States)

    Fadli, Mariam; Saad, Asmaa; Sayadi, Sami; Chevalier, Jacqueline; Mezrioui, Nour-Eddine; Pagès, Jean-Marie; Hassani, Lahcen

    2012-03-15

    The aim of this study was to evaluate the antibacterial effect of the association between conventional antibiotics and essential oils (EOs) of endemic Moroccan thyme species, Thymus maroccanus and T. broussonetii, on antibiotic-resistant bacteria involved in nosocomial infections. Synergistic interactions between antibiotics (ciprofloxacin, gentamicin, pristinamycin, and cefixime) and EOs, and between T. maroccanus and T. Broussonetii EOs were determined by the checkerboard test. Serial dilutions of two antimicrobial agents were mixed together so that each row (and column) contained a fixed amount of the first agent and increasing amounts of the second one. The results indicate that the oils had a high inhibitory activity against tested bacteria, except for Pseudomonas aeruginosa. In parallel with the increase of cellular killing, the release of 260nm-absorbing materials from bacterial cells, treated with EOs, increased in response to oil concentration. Out of 80 combinations tested between EOs and antibiotics, 71% showed total synergism, 20% had partial synergistic interaction and 9% showed no effect. Combination with carvacrol, the major constituent of T. maroccanus and T. broussonetii, showed also an interesting synergistic effect in combination with ciprofloxacin. The effect on Gram-positive bacteria was more important than on Gram-negative bacteria. These findings are very promising since the use of these combinations for nosocomial infections treatment is likely to reduce the minimum effective dose of the antibiotics, thus minimizing their possible toxic side effects and treatment cost. However, further investigations are needed to assess the potential for therapeutic application.

  3. Estimating the morbidity and mortality associated with infections due to multidrug-resistant bacteria (MDRB, France, 2012

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    M. Colomb-Cotinat

    2016-12-01

    Full Text Available Abstract Background A study based on 2007 data estimated that 386,000 infections due to multidrug-resistant bacteria (MDRB occurred in Europe that year and 25,000 patients died from these infections. Our objective was to estimate the morbidity and mortality associated with these infections in France. Methods The MDRB considered were methicillin-resistant Staphylococcus aureus (MRSA, glycopeptide-resistant enterococci, third-generation cephalosporin-resistant (3GC-R Escherichia coli and Klebsiella pneumoniae, carbapenem-resistant Klebsiella pneumoniae, Acinetobacter spp. and Pseudomonas aeruginosa (CR P. aeruginosa. The number of invasive infections (infections with bacteria isolated from blood or cerebrospinal fluid due to MDRB, as reported by France to EARS-Net in 2012, was corrected for the coverage of our surveillance network and extrapolated to other body sites using ratios from the French healthcare-associated infections point prevalence survey and the literature. Mortality associated with MDRB infection was estimated using proportions from the literature. Methods and parameters were reviewed by a panel of experts. Results We estimate that 158,000 (127,000 to 245,000 infections due to MDRB occurred in 2012 in France (incidence: 1.48 to 2.85 per 1000 hospital days, including 16,000 invasive infections. MRSA, 3GC-R E. coli and K. pneumoniae were responsible for 120,000 (90,000 to 172,000 infections, i.e., 75% of the total. An estimated 12,500 (11,500 to 17,500 deaths were associated with these infections, including 2,700 associated with invasive infections. MRSA, 3GC-R E. coli and CR P. aeruginosa accounted for 88% of these deaths. Conclusion These first estimates confirm that MRSA, 3GC-R Escherichia coli and Klebsiella pneumoniae account for the largest portion of the morbidity and mortality of infections due to MDRB in France. These results are not directly comparable with the European study because the methodology used differs in many

  4. Evaluation of the antibacterial potential of Petroselinum crispum and Rosmarinus officinalis against bacteria that cause urinary tract infections

    OpenAIRE

    Fernanda Villas Boas Petrolini; Rodrigo Lucarini; Maria Gorete Mendes de Souza; Regina Helena Pires; Wilson Roberto Cunha; Carlos Henrique Gomes Martins

    2013-01-01

    In this study we evaluated the antibacterial activity of the crude hydroalcoholic extracts, fractions, and compounds of two plant species, namely Rosmarinus officinalis and Petroselinum crispum, against the bacteria that cause urinary tract infection. The microdilution method was used for determination of the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The crude hydroalcoholic extract of R. officinalis displayed in vitro activity against Gram-positive ...

  5. Mucosal and systemic immune modulation by Trichuris trichiura in a self-infected individual

    DEFF Research Database (Denmark)

    Dige, Anders; Rasmussen, Tue Kruse; Nejsum, Peter

    2016-01-01

    trichiura colonization induced equally increased expressions of T-helper (h)1-, Th2-, Th17- and Treg-associated cytokines and transcription factors, measured by quantitative polymerase chain reaction. We observed several indicators of modulation of systemic immunity during the T. trichiura infection. Plasma...

  6. Susceptibility to cephalosporins of bacteria causing intramammary infections in dairy cows with a high somatic cell count in Germany.

    Science.gov (United States)

    Wente, N; Zoche-Golob, V; Behr, M; Krömker, V

    2016-09-01

    The objective of this cross-sectional study was to determine the minimal inhibitory concentrations of cephalosporins of the first (cefalonium and cefapirin) and fourth generation (cefquinome) against bacteria isolated from intramammary infections in dairy cows with elevated somatic cell counts in Germany. Additionally, possible regional differences of the minimal inhibitory concentrations within Germany should be evaluated. In total, 6936 quarter milk samples from cows with a somatic cell count >200,000cells/ml were taken in 43 herds. The concentrations of the first generation cephalosporins inhibiting at least 90% of the isolates of a pathogen (MIC90) were ≥64μg/ml against Gram-negative bacteria and enterococci whereas the respective MIC90 against the other Gram-positive bacteria were ≤4μg/ml. The MIC90 of cefquinome were ≥16μg/ml against Gram-negative bacteria, bacilli and enterococci, and ≤2μg/ml against the other Gram-positive bacteria. Only the minimal inhibitory concentrations against coagulase-negative staphylococci differed significantly between regions in parametric survival models with shared frailties for the herds. However, the minimal inhibitory concentrations of cefquinome against staphylococci were higher than the minimal inhibitory concentrations of the tested cephalosporins of the first generation. Therefore, cefquinome should not be the first choice to treat staphylococcal mastitis in dairy cows.

  7. Clofazimine modulates the expression of lipid metabolism proteins in Mycobacterium leprae-infected macrophages.

    Directory of Open Access Journals (Sweden)

    Yang Degang

    Full Text Available Mycobacterium leprae (M. leprae lives and replicates within macrophages in a foamy, lipid-laden phagosome. The lipids provide essential nutrition for the mycobacteria, and M. leprae infection modulates expression of important host proteins related to lipid metabolism. Thus, M. leprae infection increases the expression of adipophilin/adipose differentiation-related protein (ADRP and decreases hormone-sensitive lipase (HSL, facilitating the accumulation and maintenance of lipid-rich environments suitable for the intracellular survival of M. leprae. HSL levels are not detectable in skin smear specimens taken from leprosy patients, but re-appear shortly after multidrug therapy (MDT. This study examined the effect of MDT components on host lipid metabolism in vitro, and the outcome of rifampicin, dapsone and clofazimine treatment on ADRP and HSL expression in THP-1 cells. Clofazimine attenuated the mRNA and protein levels of ADRP in M. leprae-infected cells, while those of HSL were increased. Rifampicin and dapsone did not show any significant effects on ADRP and HSL expression levels. A transient increase of interferon (IFN-β and IFN-γ mRNA was also observed in cells infected with M. leprae and treated with clofazimine. Lipid droplets accumulated by M. leprae-infection were significantly decreased 48 h after clofazimine treatment. Such effects were not evident in cells without M. leprae infection. In clinical samples, ADRP expression was decreased and HSL expression was increased after treatment. These results suggest that clofazimine modulates lipid metabolism in M. leprae-infected macrophages by modulating the expression of ADRP and HSL. It also induces IFN production in M. leprae-infected cells. The resultant decrease in lipid accumulation, increase in lipolysis, and activation of innate immunity may be some of the key actions of clofazimine.

  8. Cellular immune activation in children with acute dengue virus infections is modulated by apoptosis.

    Science.gov (United States)

    Myint, Khin S; Endy, Timothy P; Mongkolsirichaikul, Duangrat; Manomuth, Choompun; Kalayanarooj, Siripen; Vaughn, David W; Nisalak, Ananda; Green, Sharone; Rothman, Alan L; Ennis, Francis A; Libraty, Daniel H

    2006-09-01

    Apoptosis is an important modulator of cellular immune responses during systemic viral infections. Peripheral-blood mononuclear cell (PBMC) apoptosis and plasma soluble levels of CD95, a mediator of apoptosis, were determined in sequential samples from children participating in a prospective study of dengue virus (DV) infections. During the period of defervescence, levels of PBMC apoptosis were higher in children developing dengue hemorrhagic fever (DHF), the most severe form of illness, than in those with dengue fever (DF) and other, nondengue, febrile illnesses. CD8(+) T lymphocytes made up approximately half of the peak circulating apoptotic PBMCs in DHF and DF. Maximum plasma levels of soluble CD95 were also higher in children with DHF than in those with DF. The level of PBMC apoptosis correlated with dengue disease severity. Apoptosis appears to be involved in modulation of the innate and adaptive immune responses to DV infection and is likely involved in the evolution of immune responses in other viral hemorrhagic fevers.

  9. Engineering bioinspired bacteria-adhesive clay nanoparticles with a membrane-disruptive property for the treatment of Helicobacter pylori infection.

    Science.gov (United States)

    Ping, Yuan; Hu, Xiurong; Yao, Qi; Hu, Qida; Amini, Shahrouz; Miserez, Ali; Tang, Guping

    2016-09-28

    We present a bioinspired design strategy to engineer bacteria-targeting and membrane-disruptive nanoparticles for the effective antibiotic therapy of Helicobacter pylori (H. pylori) infection. Antibacterial nanoparticles were self-assembled from highly exfoliated montmorillonite (eMMT) and cationic linear polyethyleneimine (lPEI) via electrostatic interactions. eMMT functions as a bioinspired 'sticky' building block for anchoring antibacterial nanoparticles onto the bacterial cell surface via bacteria-secreted extracellular polymeric substances (EPS), whereas membrane-disruptive lPEI is able to efficiently lyse the bacterial outer membrane to allow topical transmembrane delivery of antibiotics into the intracellular cytoplasm. As a result, eMMT-lPEI nanoparticles intercalated with the antibiotic metronidazole (MTZ) not only efficiently target bacteria via EPS-mediated adhesion and kill bacteria in vitro, but also can effectively remain in the stomach where H. pylori reside, thereby serving as an efficient drug carrier for the direct on-site release of MTZ into the bacterial cytoplasm. Importantly, MTZ-intercalated eMMT-lPEI nanoparticles were able to efficiently eradicate H. pylori in vivo and to significantly improve H. pylori-associated gastric ulcers and the inflammatory response in a mouse model, and also showed superior therapeutic efficacy as compared to standard triple therapy. Our findings reveal that bacterial adhesion plays a critical role in promoting efficient antimicrobial delivery and also represent an original bioinspired targeting strategy via specific EPS-mediated adsorption. The bacteria-adhesive eMMT-lPEI nanoparticles with membrane-disruptive ability may constitute a promising drug carrier system for the efficacious targeted delivery of antibiotics in the treatment of bacterial infections.

  10. Schistosoma mansoni infection modulates the immune response against allergic and auto-immune diseases

    Directory of Open Access Journals (Sweden)

    Maria Ilma Araújo

    2004-08-01

    Full Text Available Chronic Schistosoma mansoni infection leads to a type 2-immune response with increased production of interleukin (IL-10. Evidence indicates chronic exposure to S. mansoni down regulates the type 1 immune response and prevents the onset of Th1-mediated diseases such as multiple sclerosis, diabetes mellitus and Cronh's disease. Furthermore, our own studies have revealed that chronic exposure to S. mansoni also down regulates atopic disease, Th2-mediated diseases. Our studies show an inverse association between the skin prick test reactivity and infection with S. mansoni and show the severity of asthma is reduced in subjects living in an endemic area of S. mansoni. Moreover, we hypothesize the mechanisms involved in the modulation of inflammatory response in atopic individuals, is likely dependent on IL-10 production, an anti-inflammatory cytokine elevated during helminth infections. Patients with asthma and helminth infections produced less IL-5 than patients with asthma without helminth infections, and this down regulation could, in part, be mediated by IL-10. In conclusion, helminthic infections, through induction of regulatory mechanisms, such as IL-10 production, are able to modulate the inflammatory immune response involved in the pathology of auto-immune and allergic disease.

  11. Highly active modulators of indole signaling alter pathogenic behaviors in Gram-negative and Gram-positive bacteria.

    Science.gov (United States)

    Minvielle, Marine J; Eguren, Kristen; Melander, Christian

    2013-12-16

    Indole is a universal signal that regulates various bacterial behaviors, such as biofilm formation and antibiotic resistance. To generate mechanistic probes of indole signaling and control indole-mediated pathogenic phenotypes in both Gram-positive and Gram-negative bacteria, we have investigated the use of desformylflustrabromine (dFBr) derivatives to generate highly active indole mimetics. We have developed non-microbicidal dFBr derivatives that are 27-2000 times more active than indole in modulating biofilm formation, motility, acid resistance, and antibiotic resistance. The activity of these analogues parallels indole, because they are dependent on temperature, the enzyme tryptophanase TnaA, and the transcriptional regulator SdiA. This investigation demonstrates that molecules based on the dFBr scaffold can alter pathogenic behaviors by mimicking indole-signaling pathways.

  12. EV71-infected CD14(+) cells modulate the immune activity of T lymphocytes in rhesus monkeys.

    Science.gov (United States)

    Wang, Jingjing; Pu, Jing; Huang, Hongtai; Zhang, Ying; Liu, Longding; Yang, Erxia; Zhou, Xiaofang; Ma, Na; Zhao, Hongling; Wang, Lichun; Xie, Zhenfeng; Tang, Donghong; Li, Qihan

    2013-07-01

    Preliminary studies of the major pathogen enterovirus 71 (EV71), a member of the Picornaviridae family, have suggested that EV71 may be a major cause of fatal hand, foot and mouth disease cases. Currently, the role of the pathological changes induced by EV71 infection in the immunopathogenic response remains unclear. Our study focused on the interaction between this virus and immunocytes and indicated that this virus has the ability to replicate in CD14(+) cells. Furthermore, these EV71-infected CD14(+) cells have the capacity to stimulate the proliferation of T cells and to enhance the release of certain functional cytokines. An adaptive immune response induced by the back-transfusion of EV71-infected CD14(+) cells was observed in donor neonatal rhesus monkeys. Based on these observations, the proposed hypothesis is that CD14(+) cells infected by the EV71 virus might modulate the anti-EV71 adaptive immune response by inducing simultaneous T-cell activation.

  13. Monitoring in vitro antibacterial efficacy of 26 Indian spices against multidrug resistant urinary tract infecting bacteria

    Directory of Open Access Journals (Sweden)

    Sibanarayan Rath

    2014-09-01

    Conclusion: The most effective and unique 16 spice plants recorded for the in vitro control of MDR uropathogens could further be pursued for the development of complementary and supplementary medicine against MDR bacteria.

  14. Susceptibility to Lower Respiratory Infections in Childhood is Associated with Perturbation of the Cytokine Response to Pathogenic Airway Bacteria

    DEFF Research Database (Denmark)

    Vissing, Nadja Hawwa; Larsen, Jeppe Madura; Rasmussen, Morten Arendt

    2016-01-01

    BACKGROUND: Neonatal colonization of the airways with respiratory pathogens is associated with increased risk of lower respiratory infections (LRI) in early childhood. Therefore, we hypothesized that children developing LRI have an aberrant immune response to pathogenic bacteria in infancy....... OBJECTIVE: To characterize in vitro the early life systemic immune response to pathogenic bacteria and study the possible association with incidence of LRI during the first 3 years of life. METHODS: The Copenhagen Prospective Study on Asthma in Childhood2000 (COPSAC2000) is a clinical birth cohort study......, IL-5, IL-10, IL-13, and IL-17 in peripheral blood mononuclear cells isolated at age 6 months from 291 infants. Data were analyzed by Poisson regression against incidence of LRI in infancy. RESULTS:: A multivariable model including all cytokine responses from the three different bacterial stimulations...

  15. Multi-bacteria multi-antibiotic testing using surface enhanced Raman spectroscopy (SERS) for urinary tract infection (UTI) diagnosis

    Science.gov (United States)

    Hadjigeorgiou, Katerina; Kastanos, Evdokia; Pitris, Costas

    2013-06-01

    The inappropriate use of antibiotics leads to antibiotic resistance, which is a major health care problem. The current method for determination of bacterial susceptibility to antibiotics requires overnight cultures. However most of the infections cannot wait for the results to receive treatment, so physicians administer general spectrum antibiotics. This results in ineffective treatments and aggravates the rising problem of antibiotic resistance. In this work, a rapid method for diagnosis and antibiogram for a bacterial infection was developed using Surface Enhanced Raman Spectroscopy (SERS) with silver nanoparticles. The advantages of this novel method include its rapidness and efficiency which will potentially allow doctors to prescribe the most appropriate antibiotic for an infection. SERS spectra of three species of gram negative bacteria, Escherichia coli, Proteus spp., and Klebsiella spp. were obtained after 0 and 4 hour exposure to the seven different antibiotics. Bacterial strains were diluted in order to reach the concentration of (2x105 cfu/ml), cells/ml which is equivalent to the minimum concentration found in urine samples from UTIs. Even though the concentration of bacteria was low, species classification was achieved with 94% accuracy using spectra obtained at 0 hours. Sensitivity or resistance to antibiotics was predicted with 81%-100% accuracy from spectra obtained after 4 hours of exposure to the different antibiotics. This technique can be applied directly to urine samples, and with the enhancement provided by SERS, this method has the potential to be developed into a rapid method for same day UTI diagnosis and antibiogram.

  16. Aminoglycoside resistance rates, phenotypes, and mechanisms of Gram-negative bacteria from infected patients in upper Egypt.

    Directory of Open Access Journals (Sweden)

    Gamal F Gad

    Full Text Available With the re-emergence of older antibiotics as valuable choices for treatment of serious infections, we studied the aminoglycoside resistance of Gram-negative bacteria isolated from patients with ear, urinary tract, skin, and gastrointestinal tract infections at Minia university hospital in Egypt. Escherichia coli (mainly from urinary tract and gastrointestinal tract infections was the most prevalent isolate (28.57%, followed by Pseudomonas aeruginosa (25.7% (mainly from ear discharge and skin infections. Isolates exhibited maximal resistance against streptomycin (83.4%, and minimal resistance against amikacin (17.7% and intermediate degrees of resistance against neomycin, kanamycin, gentamicin, and tobramycin. Resistance to older aminoglycosides was higher than newer aminoglycosides. The most common aminoglycoside resistance phenotype was that of streptomycin resistance, present as a single phenotype or in combination, followed by kanamycin-neomycin as determined by interpretative reading. The resistant Pseudomonas aeruginosa strains were capable of producing aminoglycoside-modifying enzymes and using efflux as mechanisms of resistance. Using checkerboard titration method, the most frequently-observed outcome in combinations of aminoglycosides with β-lactams or quinolones was synergism. The most effective combination was amikacin with ciprofloxacin (100% Synergism, whereas the least effective combination was gentamicin with amoxicillin (53.3% Synergistic, 26.7% additive, and 20% indifferent FIC indices. Whereas the studied combinations were additive and indifferent against few of the tested strains, antagonism was never observed. The high resistance rates to aminoglycosides exhibited by Gram-negative bacteria in this study could be attributed to the selective pressure of aminoglycoside usage which could be controlled by successful implementation of infection control measures.

  17. Aminoglycoside resistance rates, phenotypes, and mechanisms of Gram-negative bacteria from infected patients in upper Egypt.

    Science.gov (United States)

    Gad, Gamal F; Mohamed, Heba A; Ashour, Hossam M

    2011-02-17

    With the re-emergence of older antibiotics as valuable choices for treatment of serious infections, we studied the aminoglycoside resistance of Gram-negative bacteria isolated from patients with ear, urinary tract, skin, and gastrointestinal tract infections at Minia university hospital in Egypt. Escherichia coli (mainly from urinary tract and gastrointestinal tract infections) was the most prevalent isolate (28.57%), followed by Pseudomonas aeruginosa (25.7%) (mainly from ear discharge and skin infections). Isolates exhibited maximal resistance against streptomycin (83.4%), and minimal resistance against amikacin (17.7%) and intermediate degrees of resistance against neomycin, kanamycin, gentamicin, and tobramycin. Resistance to older aminoglycosides was higher than newer aminoglycosides. The most common aminoglycoside resistance phenotype was that of streptomycin resistance, present as a single phenotype or in combination, followed by kanamycin-neomycin as determined by interpretative reading. The resistant Pseudomonas aeruginosa strains were capable of producing aminoglycoside-modifying enzymes and using efflux as mechanisms of resistance. Using checkerboard titration method, the most frequently-observed outcome in combinations of aminoglycosides with β-lactams or quinolones was synergism. The most effective combination was amikacin with ciprofloxacin (100% Synergism), whereas the least effective combination was gentamicin with amoxicillin (53.3% Synergistic, 26.7% additive, and 20% indifferent FIC indices). Whereas the studied combinations were additive and indifferent against few of the tested strains, antagonism was never observed. The high resistance rates to aminoglycosides exhibited by Gram-negative bacteria in this study could be attributed to the selective pressure of aminoglycoside usage which could be controlled by successful implementation of infection control measures.

  18. Genetic battle between Helicobacter pylori and humans. The mechanism underlying homologous recombination in bacteria, which can infect human cells.

    Science.gov (United States)

    Hanada, Katsuhiro; Yamaoka, Yoshio

    2014-10-01

    Helicobacter pylori is a gram-negative pathogenic bacterium that colonises the human stomach. The chronic infection it causes results in peptic ulcers and gastric cancers. H. pylori can easily establish a chronic infection even if the immune system attacks this pathogen with oxidative stress agents and immunoglobulins. This is attributed to bacterial defence mechanisms against these stresses. As a defence mechanism against oxidative stresses, in bacterial genomes, homologous recombination can act as a repair pathway of DNA's double-strand breaks (DSBs). Moreover, homologous recombination is also involved in the antigenic variation in H. pylori. Gene conversion alters genomic structures of babA and babB (encoding outer membrane proteins), resulting in escape from immunoglobulin attacks. Thus, homologous recombination in bacteria plays an important role in the maintenance of a chronic infection. In addition, H. pylori infection causes DSBs in human cells. Homologous recombination is also involved in the repair of DSBs in human cells. In this review, we describe the roles of homologous recombination with an emphasis on the maintenance of a chronic infection.

  19. Precise temporal modulation in the response of the SOS DNA repair network in individual bacteria.

    Directory of Open Access Journals (Sweden)

    Nir Friedman

    2005-07-01

    Full Text Available The SOS genetic network is responsible for the repair/bypass of DNA damage in bacterial cells. While the initial stages of the response have been well characterized, less is known about the dynamics of the response after induction and its shutoff. To address this, we followed the response of the SOS network in living individual Escherichia coli cells. The promoter activity (PA of SOS genes was monitored using fluorescent protein-promoter fusions, with high temporal resolution, after ultraviolet irradiation activation. We find a temporal pattern of discrete activity peaks masked in studies of cell populations. The number of peaks increases, while their amplitude reaches saturation, as the damage level is increased. Peak timing is highly precise from cell to cell and is independent of the stage in the cell cycle at the time of damage. Evidence is presented for the involvement of the umuDC operon in maintaining the pattern of PA and its temporal precision, providing further evidence for the role UmuD cleavage plays in effecting a timed pause during the SOS response, as previously proposed. The modulations in PA we observe share many features in common with the oscillatory behavior recently observed in a mammalian DNA damage response. Our results, which reveal a hitherto unknown modulation of the SOS response, underscore the importance of carrying out dynamic measurements at the level of individual living cells in order to unravel how a natural genetic network operates at the systems level.

  20. Clearance of Pseudomonas aeruginosa Foreign-Body Biofilm Infections through Reduction of the Cyclic Di-GMP Level in the Bacteria

    DEFF Research Database (Denmark)

    Christensen, Louise D.; van Gennip, Maria; Rybtke, Morten Theil

    2013-01-01

    Opportunistic pathogenic bacteria can engage in biofilm-based infections that evade immune responses and develop into chronic conditions. Because conventional antimicrobials cannot efficiently eradicate biofilms, there is an urgent need to develop alternative measures to combat biofilm infections....... It has recently been established that the secondary messenger cyclic diguanosine monophosphate (c-di-GMP) functions as a positive regulator of biofilm formation in several different bacteria. In the present study we investigated whether manipulation of the c-di-GMP level in bacteria potentially can...... of the majority of the bacteria in in vitro-grown P. aeruginosa biofilms. Subsequently, we demonstrated that P. aeruginosa biofilms growing on silicone implants, located in the peritoneal cavity of mice, dispersed after induction of the YhjH protein. Bacteria accumulated temporarily in the spleen after induction...

  1. New Mouse Model for Chronic Infections by Gram-Negative Bacteria Enabling the Study of Anti-Infective Efficacy and Host-Microbe Interactions

    Science.gov (United States)

    Pletzer, Daniel; Mansour, Sarah C.; Wuerth, Kelli; Rahanjam, Negin

    2017-01-01

    ABSTRACT Only a few, relatively cumbersome animal models enable long-term Gram-negative bacterial infections that mimic human situations, where untreated infections can last for weeks. Here, we describe a simple murine cutaneous abscess model that enables chronic or progressive infections, depending on the subcutaneously injected bacterial strain. In this model, Pseudomonas aeruginosa cystic fibrosis epidemic isolate LESB58 caused localized high-density skin and soft tissue infections and necrotic skin lesions for up to 10 days but did not disseminate in either CD-1 or C57BL/6 mice. The model was adapted for use with four major Gram-negative nosocomial pathogens, Acinetobacter baumannii, Klebsiella pneumoniae, Enterobacter cloacae, and Escherichia coli. This model enabled noninvasive imaging and tracking of lux-tagged bacteria, the influx of activated neutrophils, and production of reactive oxygen-nitrogen species at the infection site. Screening antimicrobials against high-density infections showed that local but not intravenous administration of gentamicin, ciprofloxacin, and meropenem significantly but incompletely reduced bacterial counts and superficial tissue dermonecrosis. Bacterial RNA isolated from the abscess tissue revealed that Pseudomonas genes involved in iron uptake, toxin production, surface lipopolysaccharide regulation, adherence, and lipase production were highly upregulated whereas phenazine production and expression of global activator gacA were downregulated. The model was validated for studying virulence using mutants of more-virulent P. aeruginosa strain PA14. Thus, mutants defective in flagella or motility, type III secretion, or siderophore biosynthesis were noninvasive and suppressed dermal necrosis in mice, while a strain with a mutation in the bfiS gene encoding a sensor kinase showed enhanced invasiveness and mortality in mice compared to controls infected with wild-type P. aeruginosa PA14. PMID:28246361

  2. Epigenetic modulations in activated cells early after HIV-1 infection and their possible functional consequences.

    Directory of Open Access Journals (Sweden)

    Juliana T Maricato

    Full Text Available Epigenetic modifications refer to a number of biological processes which alter the structure of chromatin and its transcriptional activity such as DNA methylation and histone post-translational processing. Studies have tried to elucidate how the viral genome and its products are affected by epigenetic modifications imposed by cell machinery and how it affects the ability of the virus to either, replicate and produce a viable progeny or be driven to latency. The purpose of this study was to evaluate epigenetic modifications in PBMCs and CD4+ cells after HIV-1 infection analyzing three approaches: (i global DNA- methylation; (ii qPCR array and (iii western blot. HIV-1 infection led to methylation increases in the cellular DNA regardless the activation status of PBMCs. The analysis of H3K9me3 and H3K27me3 suggested a trend towards transcriptional repression in activated cells after HIV-1 infection. Using a qPCR array, we detected genes related to epigenetic processes highly modulated in activated HIV-1 infected cells. SETDB2 and RSK2 transcripts showed highest up-regulation levels. SETDB2 signaling is related to transcriptional silencing while RSK2 is related to either silencing or activation of gene expression depending on the signaling pathway triggered down-stream. In addition, activated cells infected by HIV-1 showed lower CD69 expression and a decrease of IL-2, IFN-γ and metabolism-related factors transcripts indicating a possible functional consequence towards global transcriptional repression found in HIV-1 infected cells. Conversely, based on epigenetic markers studied here, non-stimulated cells infected by HIV-1, showed signs of global transcriptional activation. Our results suggest that HIV-1 infection exerts epigenetic modulations in activated cells that may lead these cells to transcriptional repression with important functional consequences. Moreover, non-stimulated cells seem to increase gene transcription after HIV-1 infection

  3. Anaerobic bacteria in upper respiratory tract and head and neck infections: microbiology and treatment.

    Science.gov (United States)

    Brook, Itzhak

    2012-04-01

    Anaerobes are the predominant components of oropharyngeal mucous membranes bacterial flora, and are therefore a common cause of bacterial infections of endogenous origin of upper respiratory tract and head and neck. This review summarizes the aerobic and anaerobic microbiology and antimicrobials therapy of these infections. These include acute and chronic otitis media, mastoiditis and sinusitis, pharyngo-tonsillitis, peritonsillar, retropharyngeal and parapharyngeal abscesses, suppurative thyroiditis, cervical lymphadenitis, parotitis, siliadenitis, and deep neck infections including Lemierre Syndrome. The recovery from these infections depends on prompt and proper medical and when indicated also surgical management.

  4. [Antimicrobial therapy in severe infections with multidrug-resistant Gram-negative bacterias].

    Science.gov (United States)

    Duszyńska, Wiesława

    2010-01-01

    Multidrug-resistant Gram-negative bacteria pose a serious and rapidly emerging threat to patients in healthcare settings, and are especially prevalent and problematic in intensive therapy units. Recently, the emergence of pandrug-resistance in Gram-negative bacteria poses additional concerns. This review examines the clinical impact and epidemiology of multidrug-resistant Gram-negative bacteria as a cause of increased morbidity and mortality among ITU patients. Beta-lactamases, cephalosporinases and carbapenemases play the most important role in resistance to antibiotics. Despite the tendency to increased resistance, carbapenems administered by continuous infusion remain the most effective drugs in severe sepsis. Drug concentration monitoring, albeit rarely used in practice, is necessary to ensure an effective therapeutic effect.

  5. Bovine herpesvirus type 4 infection modulates autophagy in a permissive cell line.

    Science.gov (United States)

    Montagnaro, Serena; Ciarcia, Roberto; Pagnini, Francesco; De Martino, Luisa; Puzio, Maria Valeria; Granato, Giovanna Elvira; Avino, Franca; Pagnini, Ugo; Iovane, Giuseppe; Giordano, Antonio

    2013-07-01

    Bovine herpesvirus type 4 (BoHV-4), like other herpesviruses, induces a series of alterations in the host cell that modify the intracellular environment in favor of viral replication, survival and spread. This research examined the impact of BoHV-4 infection on autophagy in BoHV-4 infected Madin Darby bovine kidney (MDBK) cells. Protein extracts of BoHV-4 infected and control MDBK cells were subjected to Western blot. The concentrations of the autophagy and apoptosis-related proteins Beclin 1, p21, PI3 kinase, Akt1/2, mTOR, phospho mTOR, p62 and the light chain three (LC3) were normalized to the actin level and expressed as the densitometric ratio. Western blot analysis of virus-infected cells revealed that autophagic degradation pathway was induced in the late phase of BoHV-4 infection. After 48 h post-infection the protein LC3II, which is essential for autophagy was found to be markedly increased, while infection of MDBK cells with BoHV-4 resulted in a depletion of p62 levels. Becline 1, PI3 kinase, Akt1/2 and p21 expression increased between 24 and 48 h post-infection. Surprisingly, mTOR and its phosphorylated form, which are negative regulators of autophagy, also increased after 24 h post-infection. In conclusion, our findings suggest that BoHV-4 has developed mechanisms for modulation of autophagy that are probably part of a strategy designed to enhance viral replication and to evade the immune system. Additional studies on the relationship between autophagy and BoHV-4 replication and survival, in both lytic and latent replication phases, are needed to understand the role of autophagy in BoHV-4 pathogenesis.

  6. Electrochemical sensing of biomarker for diagnostics of bacteria-specific infections

    DEFF Research Database (Denmark)

    Al Atraktchi, Fatima Al-Zahraa; Johansen, Helle Krogh; Molin, Søren;

    2016-01-01

    Aim: Pseudomonas aeruginosa is a pathogen that is prevalent in serious infections in compromised patients worldwide. A unique virulence factor of this bacterium is the redox-active molecule pyocyanin, which is a potential biomarker for the identification of P. aeruginosa infections. Here we repor...

  7. Non-destructive evaluation of bacteria-infected watermelon seeds using Vis/NIR hyperspectral imaging

    Science.gov (United States)

    It is needed to minimize the economic loss by sorting infected seeds from healthy seeds before seeding. However, current methods of detecting infection seeds such as seedling grow-out, enzyme-linked immunosorbent assay (ELISA), polymerase chain reaction (PCR), and real-time polymerase chain reaction...

  8. The Role of Cationic Polypeptides in Modulating HIV-1 Infection of the Cervicovaginal Mucosa

    Science.gov (United States)

    Cole, Amy Liese; Cole, Alexander M.

    2014-01-01

    The mucosa and overlying fluid of the female reproductive tract (FRT) are portals for the heterosexual transmission of HIV-1. Toward the ongoing development of topically applied microbicides and mucosal vaccines against HIV-1, it is evermore important to understand how the dynamic FRT mucosa is involved in controlling transmission and infection of HIV-1. Cationic peptides and proteins are the principal innate immune effector molecules of mucosal surfaces, and interact in a combinatorial fashion to modulate HIV-1 infection of the cervix and vagina. While cationic peptides and proteins have historically been categorized as antimicrobial or have other host-benefitting roles, an increasing number of these molecules have been found to augment HIV-1 infection and potentially antagonize host defense. Complex environmental factors such as hormonal fluctuations and/or bacterial and viral co-infections provide additional challenges to both experimentation and interpretation of results. In the context of heterosexual transmission of HIV-1, this review explores how various cationic peptides and proteins participate in modulating host defense against HIV-1 of the cervicovaginal mucosa. PMID:27025760

  9. The Role of Cationic Polypeptides in Modulating HIV-1 Infection of the Cervicovaginal Mucosa

    Directory of Open Access Journals (Sweden)

    Amy Liese Cole

    2014-11-01

    Full Text Available The mucosa and overlying fluid of the female reproductive tract (FRT are portals for the heterosexual transmission of HIV-1. Toward the ongoing development of topically applied microbicides and mucosal vaccines against HIV-1, it is evermore important to understand how the dynamic FRT mucosa is involved in controlling transmission and infection of HIV-1. Cationic peptides and proteins are the principal innate immune effector molecules of mucosal surfaces, and interact in a combinatorial fashion to modulate HIV-1 infection of the cervix and vagina. While cationic peptides and proteins have historically been categorized as antimicrobial or have other host-benefitting roles, an increasing number of these molecules have been found to augment HIV-1 infection and potentially antagonize host defense. Complex environmental factors such as hormonal fluctuations and/or bacterial and viral co-infections provide additional challenges to both experimentation and interpretation of results. In the context of heterosexual transmission of HIV-1, this review explores how various cationic peptides and proteins participate in modulating host defense against HIV-1 of the cervicovaginal mucosa.

  10. TRPV1 Antagonism by Capsazepine Modulates Innate Immune Response in Mice Infected with Plasmodium berghei ANKA

    Directory of Open Access Journals (Sweden)

    Elizabeth S. Fernandes

    2014-01-01

    Full Text Available Thousands of people suffer from severe malaria every year. The innate immune response plays a determinant role in host’s defence to malaria. Transient receptor potential vanilloid 1 (TRPV1 modulates macrophage-mediated responses in sepsis, but its role in other pathogenic diseases has never been addressed. We investigated the effects of capsazepine, a TRPV1 antagonist, in malaria. C57BL/6 mice received 105 red blood cells infected with Plasmodium berghei ANKA intraperitoneally. Noninfected mice were used as controls. Capsazepine or vehicle was given intraperitoneally for 6 days. Mice were culled on day 7 after infection and blood and spleen cell phenotype and activation were evaluated. Capsazepine decreased circulating but not spleen F4/80+Ly6G+ cell numbers as well as activation of both F4/80+and F4/80+Ly6G+ cells in infected animals. In addition, capsazepine increased circulating but not spleen GR1+ and natural killer (NK population, without interfering with natural killer T (NKT cell numbers and blood NK and NKT activation. However, capsazepine diminished CD69 expression in spleen NKT but not NK cells. Infection increased lipid peroxidation and the release of TNFα and IFNγ, although capsazepine-treated group exhibited lower levels of lipid peroxidation and TNFα. Capsazepine treatment did not affect parasitaemia. Overall, TRPV1 antagonism modulates the innate immune response to malaria.

  11. Dengue virus type 2 infections of Aedes aegypti are modulated by the mosquito's RNA interference pathway.

    Directory of Open Access Journals (Sweden)

    Irma Sánchez-Vargas

    2009-02-01

    Full Text Available A number of studies have shown that both innate and adaptive immune defense mechanisms greatly influence the course of human dengue virus (DENV infections, but little is known about the innate immune response of the mosquito vector Aedes aegypti to arbovirus infection. We present evidence here that a major component of the mosquito innate immune response, RNA interference (RNAi, is an important modulator of mosquito infections. The RNAi response is triggered by double-stranded RNA (dsRNA, which occurs in the cytoplasm as a result of positive-sense RNA virus infection, leading to production of small interfering RNAs (siRNAs. These siRNAs are instrumental in degradation of viral mRNA with sequence homology to the dsRNA trigger and thereby inhibition of virus replication. We show that although dengue virus type 2 (DENV2 infection of Ae. aegypti cultured cells and oral infection of adult mosquitoes generated dsRNA and production of DENV2-specific siRNAs, virus replication and release of infectious virus persisted, suggesting viral circumvention of RNAi. We also show that DENV2 does not completely evade RNAi, since impairing the pathway by silencing expression of dcr2, r2d2, or ago2, genes encoding important sensor and effector proteins in the RNAi pathway, increased virus replication in the vector and decreased the extrinsic incubation period required for virus transmission. Our findings indicate a major role for RNAi as a determinant of DENV transmission by Ae. aegypti.

  12. A comparative study on invasion, survival, modulation of oxidative burst, and nitric oxide responses of macrophages (HD11), and systemic infection in chickens by prevalent poultry Salmonella serovars.

    Science.gov (United States)

    He, Haiqi; Genovese, Kenneth J; Swaggerty, Christina L; Nisbet, David J; Kogut, Michael H

    2012-12-01

    Poultry is a major reservoir for foodborne Salmonella serovars. Salmonella Typhimurium, Salmonella Enteritidis, Salmonella Heidelberg, Salmonella Kentucky, and Salmonella Senftenberg are the most prevalent serovars in U.S. poultry. Information concerning the interactions between different Salmonella species and host cells in poultry is lacking. In the present study, the above mentioned Salmonella serovars were examined for invasion, intracellular survival, and their ability to modulate oxidative burst and nitric oxide (NO) responses in chicken macrophage HD11 cells. All Salmonella serovars demonstrated similar capacity to invade HD11 cells. At 24 h post-infection, a 36-43% reduction of intracellular bacteria, in log(10)(CFU), was observed for Salmonella Typhimurium, Salmonella Heidelberg, Salmonella Kentucky, and Salmonella Senftenberg, whereas a significantly lower reduction (16%) was observed for Salmonella Enteritidis, indicating its higher resistance to the killing by HD11 cells. Production of NO was completely diminished in HD11 cells infected with Salmonella Typhimurium and Salmonella Enteritidis, but remained intact when infected with Salmonella Heidelberg, Salmonella Kentucky, and Salmonella Senftenberg. Phorbol myristate acetate-stimulated oxidative burst in HD11 cells was greatly impaired after infection by each of the five serovars. When newly hatched chickens were challenged orally, a high rate (86-98%) of systemic infection (Salmonella positive in liver/spleen) was observed in birds challenged with Salmonella Typhimurium, Salmonella Enteritidis, Salmonella Heidelberg, and Salmonella Kentucky, while only 14% of the birds were Salmonella Senftenberg positive. However, there was no direct correlation between systemic infection and in vitro differential intracellular survival and modulation of NO response among the tested serovars.

  13. Plasma needle treatment of bacteria known to cause infections of the soft tissue of the oral region and bones

    Science.gov (United States)

    Maletic, Dejan; Lazovic, Sasa; Puac, Nevena; Malovic, Gordana; Petrovic, Zoran Lj.; Miletic, Maja P.; Pavlica, Dusan B.; Jovanovic, Milena Z.; Milenkovic, Pavle

    2009-10-01

    Plasma needle can be used for non-contact disinfection of dental cavities and wounds, minimum-destructive precise treatment, as well as the removal of damaged tissue. The effect of bacterial deactivation is probably caused by reactive oxygen species while nitric oxide provided by plasma plays major role in many processes in the organism. Mass spectrometry was done to provide better insight into plasma-cell interactions. Our measurements were performed on a plasma needle that we originally used for the treatment of plant cells.Our research was done on species that are known to cause primary and secondary infections of the soft tissue of the oral region, as well as bones. The bacteria cultures used are bacterial reference culture species Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212, Pseudomonas aeruginosa ATCC 27853, and Escherichia coli ATCC 25922. We investigated the effect of the plasma needle discharge on different concentration of bacteria using several exposure times and power transmitted to the plasma. It was found that excellent removal of this and other bacteria may be achieved by the plasma needle treatment.

  14. Non-invasive imaging of infection after treatment with tumor-homing bacteria using chemical exchange saturation transfer (CEST) MRI

    Science.gov (United States)

    Liu, Guanshu; Bettegowda, Chetan; Qiao, Yuan; Staedtke, Verena; Chan, Kannie W.Y.; Bai, Renyuan; Li, Yuguo; Riggins, Gregory J.; Kinzler, Kenneth W.; Bulte, Jeff W.M.; McMahon, Michael T.; Gilad, Assaf A.; Vogelstein, Bert; Zhou, Shibin; van Zijl, Peter C.M.

    2013-01-01

    Purpose To develop a non-invasive MRI method for determining the germination and infection of tumor-homing bacteria in bacteriolytic cancer therapy using endogenous CEST contrast. Methods The CEST parameters of the anaerobic gram-positive bacterium Clostridium novyi-NT (C. novyi-NT) were first characterized in vitro, then used to detect C. novyi-NT germination and infection in subcutaneous CT26 colorectal tumor-bearing mice (n=6) after injection of 300 million bacterial spores. Lipopolysacharide (LPS) injected mice were used to exclude that the changes of CEST MRI were due to inflammation. Results CEST contrast was observed over a broad frequency range for bacterial suspensions in vitro, with the maximum contrast around 2.6 ppm from the water resonance. No signal could be detected for bacterial spores, demonstrating the specificity for germination. In vivo, a significant elevation of CEST contrast was identified in C. novyi-NT infected tumors as compared to those before bacterial germination and infection (p 0.05, n=4). Conclusions Endogenous bacterial CEST contrast (bacCEST) can be used to monitor the germination and proliferation of the therapeutic bacterium C. novyi-NT without a need for exogenous cell labeling probes. PMID:24123389

  15. Competitive interactions between methane- and ammonia-oxidizing bacteria modulate carbon and nitrogen cycling in paddy soil

    Science.gov (United States)

    Zheng, Y.; Huang, R.; Wang, B. Z.; Bodelier, P. L. E.; Jia, Z. J.

    2014-06-01

    Pure culture studies have demonstrated that methanotrophs and ammonia oxidizers can both carry out the oxidation of methane and ammonia. However, the expected interactions resulting from these similarities are poorly understood, especially in complex, natural environments. Using DNA-based stable isotope probing and pyrosequencing of 16S rRNA and functional genes, we report on biogeochemical and molecular evidence for growth stimulation of methanotrophic communities by ammonium fertilization, and that methane modulates nitrogen cycling by competitive inhibition of nitrifying communities in a rice paddy soil. Pairwise comparison between microcosms amended with CH4, CH4+Urea, and Urea indicated that urea fertilization stimulated methane oxidation activity 6-fold during a 19-day incubation period, while ammonia oxidation activity was significantly suppressed in the presence of CH4. Pyrosequencing of the total 16S rRNA genes revealed that urea amendment resulted in rapid growth of Methylosarcina-like MOB, and nitrifying communities appeared to be partially inhibited by methane. High-throughput sequencing of the 13C-labeled DNA further revealed that methane amendment resulted in clear growth of Methylosarcina-related MOB while methane plus urea led to an equal increase in Methylosarcina and Methylobacter-related type Ia MOB, indicating the differential growth requirements of representatives of these genera. An increase in 13C assimilation by microorganisms related to methanol oxidizers clearly indicated carbon transfer from methane oxidation to other soil microbes, which was enhanced by urea addition. The active growth of type Ia methanotrops was significantly stimulated by urea amendment, and the pronounced growth of methanol-oxidizing bacteria occurred in CH4-treated microcosms only upon urea amendment. Methane addition partially inhibited the growth of Nitrosospira and Nitrosomonas in urea-amended microcosms, as well as growth of nitrite-oxidizing bacteria. These

  16. Competitive interactions between methane- and ammonia-oxidizing bacteria modulate carbon and nitrogen cycling in paddy soil

    Directory of Open Access Journals (Sweden)

    Y. Zheng

    2014-03-01

    Full Text Available Pure culture studies have demonstrated that methanotrophs and ammonia oxidizers can both carry out the oxidation of methane and ammonia. However, the expected interactions resulting from these similarities are poorly understood, especially in complex, natural environments. Using DNA-based stable isotope probing and pyrosequencing of 16S rRNA and pmoA genes, we report on biogeochemical and molecular evidence for growth stimulation of methanotrophic communities by ammonium fertilization, and that methane modulates nitrogen cycling by competitive inhibition of nitrifying communities in a rice paddy soil. Pairwise comparison between microcosms amended with CH4, CH4+Urea, and Urea indicated that urea fertilization stimulated methane oxidation activity by 6-fold during a 19 day incubation period, while ammonia oxidation activity was significantly inhibited in the presence of CH4. Pyrosequencing of the total 16S rRNA genes revealed that urea amendment resulted in rapid growth of Methylosarcina-like type Ia MOB, and nitrifying communities appeared to be suppressed by methane. High-throughput sequencing of the 13C-labeled DNA further revealed that methane amendment resulted in clear growth of Methylosarcina-related MOB while methane plus urea led to equal increase in Methylosarcina and Methylobacter-related MOB, indicating the differential growth requirements of representatives of these genera. Strikingly, type Ib MOB did not respond to methane nor to urea. Increase in 13C-assimilation by microorganisms related to methanol oxidizers clearly indicated carbon transfer from methane oxidation to other soil microbes, which was enhanced by urea addition. The active growth of type Ia methanotrops was significantly stimulated by urea amendment, and the pronounced growth of methanol-oxidizing bacteria occurred in CH4-treated microcosms only upon urea amendment. Methane addition inhibited the growth of Nitrosospira and Nitrosomonas in urea-amended microcosms, in

  17. Abundance and Diversity of CO2-Assimilating Bacteria and Algae Within Red Agricultural Soils Are Modulated by Changing Management Practice.

    Science.gov (United States)

    Yuan, Hongzhao; Ge, Tida; Chen, Xiangbi; Liu, Shoulong; Zhu, Zhenke; Wu, Xiaohong; Wei, Wenxue; Whiteley, Andrew Steven; Wu, Jinshui

    2015-11-01

    Elucidating the biodiversity of CO(2)-assimilating bacterial and algal communities in soils is important for obtaining a mechanistic view of terrestrial carbon sinks operating at global scales. "Red" acidic soils (Orthic Acrisols) cover large geographic areas and are subject to a range of management practices, which may alter the balance between carbon dioxide production and assimilation through changes in microbial CO(2)-assimilating populations. Here, we determined the abundance and diversity of CO(2)-assimilating bacteria and algae in acidic soils using quantitative PCR and terminal restriction fragment length polymorphism (T-RFLP) of the cbbL gene, which encodes the key CO(2) assimilation enzyme (ribulose-1,5-bisphosphate carboxylase/oxygenase) in the Calvin cycle. Within the framework of a long-term experiment (Taoyuan Agro-ecosystem, subtropical China), paddy rice fields were converted in 1995 to four alternative land management regimes: natural forest (NF), paddy rice (PR), maize crops (CL), and tea plantations (TP). In 2012 (17 years after land use transformation), we collected and analyzed the soils from fields under the original and converted land management regimes. Our results indicated that fields under the PR soil management system harbored the greatest abundance of cbbL copies (4.33 × 10(8) copies g(-1) soil). More than a decade after converting PR soils to natural, rotation, and perennial management systems, a decline in both the diversity and abundance of cbbL-harboring bacteria and algae was recorded. The lowest abundance of bacteria (0.98 × 10(8) copies g(-1) soil) and algae (0.23 × 10(6) copies g(-1) soil) was observed for TP soils. When converting PR soil management to alternative management systems (i.e., NF, CL, and TP), soil edaphic factors (soil organic carbon and total nitrogen content) were the major determinants of bacterial autotrophic cbbL gene diversity. In contrast, soil phosphorus concentration was the major regulator

  18. Lanthionine Synthetase C-Like 2 Modulates Immune Responses to Influenza Virus Infection

    Science.gov (United States)

    Leber, Andrew; Bassaganya-Riera, Josep; Tubau-Juni, Nuria; Zoccoli-Rodriguez, Victoria; Lu, Pinyi; Godfrey, Victoria; Kale, Shiv; Hontecillas, Raquel

    2017-01-01

    Broad-based, host-targeted therapeutics have the potential to ameliorate viral infections without inducing antiviral resistance. We identified lanthionine synthetase C-like 2 (LANCL2) as a new therapeutic target for immunoinflammatory diseases. To examine the therapeutic efficacy of oral NSC61610 administration on influenza, we infected C57BL/6 mice with influenza A H1N1pdm virus and evaluated influenza-related mortality, lung inflammatory profiles, and pulmonary histopathology. Oral treatment with NSC61610 ameliorates influenza virus infection by down-modulating pulmonary inflammation through the downregulation of TNF-α and MCP-1 and reduction in the infiltration of neutrophils. NSC61610 treatment increases IL10-producing CD8+ T cells and macrophages in the lungs during the resolution phase of disease. The loss of LANCL2 or neutralization of IL-10 in mice infected with influenza virus abrogates the ability of NSC61610 to accelerate recovery and induce IL-10-mediated regulatory responses. These studies validate that oral treatment with NSC61610 ameliorates morbidity and mortality and accelerates recovery during influenza virus infection through a mechanism mediated by activation of LANCL2 and subsequent induction of IL-10 responses by CD8+ T cells and macrophages in the lungs.

  19. Neutrophils are dispensable in the modulation of T cell immunity against cutaneous HSV-1 infection

    Science.gov (United States)

    Hor, Jyh Liang; Heath, William R.; Mueller, Scott N.

    2017-01-01

    Neutrophils rapidly infiltrate sites of inflammation during peripheral infection or tissue injury. In addition to their well described roles as pro-inflammatory phagocytes responsible for pathogen clearance, recent studies have demonstrated a broader functional repertoire including mediating crosstalk between innate and adaptive arms of the immune system. Specifically, neutrophils have been proposed to mediate antigen transport to lymph nodes (LN) to modulate T cell priming and to influence T cell migration to infected tissues. Using a mouse model of cutaneous herpes simplex virus type 1 (HSV-1) infection we explored potential contributions of neutrophils toward anti-viral immunity. While a transient, early influx of neutrophils was triggered by dermal scarification, we did not detect migration of neutrophils from the skin to LN. Furthermore, despite recruitment of neutrophils into LN from the blood, priming and expansion of CD4+ and CD8+ T cells was unaffected following neutrophil depletion. Finally, we found that neutrophils were dispensable for the migration of effector T cells into infected skin. Our study suggests that the immunomodulatory roles of neutrophils toward adaptive immunity may be context-dependent, and are likely determined by the type of pathogen and anatomical site of infection. PMID:28112242

  20. Tuberculosis and the risk of infection with other intracellular bacteria: a population-based study.

    Science.gov (United States)

    Huaman, M A; Fiske, C T; Jones, T F; Warkentin, J; Shepherd, B E; Ingram, L A; Maruri, F; Sterling, T R

    2015-04-01

    SUMMARY Persons who develop tuberculosis (TB) may have subtle immune defects that could predispose to other intracellular bacterial infections (ICBIs). We obtained data on TB and five ICBIs (Chlamydia trachomatis, Salmonella spp., Shigella spp., Yersinia spp., Listeria monocytogenes) reported to the Tennessee Department of Health, USA, 2000-2011. Incidence rate ratios (IRRs) comparing ICBIs in persons who developed TB and ICBIs in the Tennessee population, adjusted for age, sex, race and ethnicity were estimated. IRRs were not significantly elevated for all ICBIs combined [IRR 0.87, 95% confidence interval (CI) 0.71-1.06]. C. trachomatis rate was lowest in the year post-TB diagnosis (IRR 0.17, 95% CI 0.04-0.70). More Salmonella infections occurred in extrapulmonary TB compared to pulmonary TB patients (IRR 14.3, 95% CI 1.67-122); however, this appeared to be related to HIV co-infection. TB was not associated with an increased risk of other ICBIs. In fact, fewer C. trachomatis infections occurred after recent TB diagnosis. Reasons for this association, including reduced exposure, protection conferred by anti-TB drugs or macrophage activation by Mycobacterium tuberculosis infection warrant further investigation.

  1. Endotracheal tube: friend or foe? Bacteria, the endotracheal tube, and the impact of colonization and infection.

    Science.gov (United States)

    Gibbs, Kathleen; Holzman, Ian R

    2012-12-01

    The microbiology of the endotracheal tube culture plays a role in diagnosing a variety of diseases in the newborn intensive care unit, including subglottic stenosis, bronchopulmonary dysplasia, and ventilator-associated pneumonia. Bacterial production of a biofilm that coats the endotracheal tube acts as a reservoir for infection, prevents eradication, and may play a role in the development of subglottic stenosis. The diagnosis of ventilator-associated pneumonia is limited by the CDC definition as well as currently available diagnostic methods. Biomarkers could aid in differentiating colonization from infection, but are not available to most clinicians. The etiology of ventilator-associated pneumonia is often polymicrobial. Failure to differentiate colonization from infection results in unnecessary prescription of antibiotics, which could contribute to antimicrobial resistance. Measures to prevent ventilator-associated pneumonia have been described, primarily in the adult population.

  2. A toll-like receptor 2-responsive lipid effector pathway protects mammals against skin infections with gram-positive bacteria.

    Science.gov (United States)

    Georgel, Philippe; Crozat, Karine; Lauth, Xavier; Makrantonaki, Evgenia; Seltmann, Holger; Sovath, Sosathya; Hoebe, Kasper; Du, Xin; Rutschmann, Sophie; Jiang, Zhengfan; Bigby, Timothy; Nizet, Victor; Zouboulis, Christos C; Beutler, Bruce

    2005-08-01

    flake (flk), an N-ethyl-N-nitrosourea-induced recessive germ line mutation of C57BL/6 mice, impairs the clearance of skin infections by Streptococcus pyogenes and Staphylococcus aureus, gram-positive pathogens that elicit innate immune responses by activating Toll-like receptor 2 (TLR2). Positional cloning and sequencing revealed that flk is a novel allele of the stearoyl coenzyme A desaturase 1 gene (Scd1). flake homozygotes show reduced sebum production and are unable to synthesize the monounsaturated fatty acids (MUFA) palmitoleate (C(16:1)) and oleate (C(18:1)), both of which are bactericidal against gram-positive (but not gram-negative) organisms in vitro. However, intradermal MUFA administration to S. aureus-infected mice partially rescues the flake phenotype, which indicates that an additional component of the sebum may be required to improve bacterial clearance. In normal mice, transcription of Scd1-a gene with numerous NF-kappaB elements in its promoter--is strongly and specifically induced by TLR2 signaling. Similarly, the SCD1 gene is induced by TLR2 signaling in a human sebocyte cell line. These observations reveal the existence of a regulated, lipid-based antimicrobial effector pathway in mammals and suggest new approaches to the treatment or prevention of infections with gram-positive bacteria.

  3. Bryostatin modulates latent HIV-1 infection via PKC and AMPK signaling but inhibits acute infection in a receptor independent manner.

    Directory of Open Access Journals (Sweden)

    Rajeev Mehla

    Full Text Available HIV's ability to establish long-lived latent infection is mainly due to transcriptional silencing in resting memory T lymphocytes and other non dividing cells including monocytes. Despite an undetectable viral load in patients treated with potent antiretrovirals, current therapy is unable to purge the virus from these latent reservoirs. In order to broaden the inhibitory range and effectiveness of current antiretrovirals, the potential of bryostatin was investigated as an HIV inhibitor and latent activator. Bryostatin revealed antiviral activity against R5- and X4-tropic viruses in receptor independent and partly via transient decrease in CD4/CXCR4 expression. Further, bryostatin at low nanomolar concentrations robustly reactivated latent viral infection in monocytic and lymphocytic cells via activation of Protein Kinase C (PKC -alpha and -delta, because PKC inhibitors rottlerin and GF109203X abrogated the bryostatin effect. Bryostatin specifically modulated novel PKC (nPKC involving stress induced AMP Kinase (AMPK inasmuch as an inhibitor of AMPK, compound C partially ablated the viral reactivation effect. Above all, bryostatin was non-toxic in vitro and was unable to provoke T-cell activation. The dual role of bryostatin on HIV life cycle may be a beneficial adjunct to the treatment of HIV especially by purging latent virus from different cellular reservoirs such as brain and lymphoid organs.

  4. Limited Specificity in the Injury and Infection Priming against Bacteria in Aedes aegypti Mosquitoes

    Science.gov (United States)

    Vargas, Valeria; Moreno-García, Miguel; Duarte-Elguea, Erika; Lanz-Mendoza, Humberto

    2016-01-01

    Injury and infection priming has been observed in several insect groups, reported as host immune protection against contact with a pathogen caused by a previous infection with the same. However, the specific response against a pathogen has not been demonstrated in all insect species. Investigating the specific priming response in insects is important because their immune strategies probably reflect particular selective pressures exerted by different pathogens. Here, we determined whether previous infection of Aedes aegypti would enhance survival and/or lead to greater and specific AMP expression after a second exposure to the same or a distinct bacterium. Mosquitoes previously immunized with a low dose of Escherichia coli, but not Staphylococcus aureus, showed increased survival. Although the host protection herein demonstrated was not specific, each bacterium elicited differential AMP expression. These results can be explained by the susceptible-primed-infected (SPI) epidemiological model, which poses that in the evolution of memory-like responses (priming), a pivotal role is played by pathogen virulence, associated host damage, and the host capacity of pathogen recognition. PMID:27446016

  5. Tissue reactions to bacteria-challenged implantable leads with enhanced infection resistance

    NARCIS (Netherlands)

    van Wachem, PB; Blaauw, EH; de Vries-Hospers, HG; Geerdes, BP; Woloszko, J; Verhoeven, MLPM; Hendriks, M; Cahalan, PT; van Luyn, MJA

    1998-01-01

    Tissue reactions to implantable pacemaker leads were investigated in an early infection model in rabbits. Both standard leads and surface-modified leads were used. The surface modification technique was applied to achieve controlled release of the antibiotic gentamicin. The insulating polyurethane t

  6. Epidemiology of Ocular Infection Due to Bacteria and Fungus – A Prospective Study

    Directory of Open Access Journals (Sweden)

    AK Verma

    2008-07-01

    Full Text Available A total number of 400 cases of eye infection were studied. Among them, 250 were conjunctivitis (59.2%,120were keratitis (53.34% 15 were endophthalmitis (26.67% and 15 were suffering from other infections(40%. The corneal scrapping, conjunctival swab and biopsy material ( endophthalmitis cases was collectedasceptically. The material was examined using 10% Potassium hydroxide, Gram staining and Giemsastaining. The specimens were cultured on sheeps’ blood agar, chocolate agar and sabourauds’ dextroseagar. In the bacterial cause of eye infection Staphylococcus aureus (19.13% was the most commonlyisolated organism and other pathogens isolated were Streptococcus pneumoniae (10.93%, Streptococcuspyogens (0.55%, Pseudomonas aeruginosa (4.92%, Klebsiella species(2.74%, Escherichia colli (1.10%and Proteus mirabilis (0.55%. Among the opportunistic pathogens, Staphylococcus epidermidis, (19.13%were the most common isolate followed by Acinetobacter species(2.74%. Alkaligenes faecalis (1.10%,Staphylococcus saprophyticus (0.55%, Staphylococcus cohnii (0.55%, Staphylococcus haemolyticus(0.55%. In the endopthalmitis patients only Pseudomonas aeruginosa (20% and Staphylococcusepidermidis (6.67% were isolated. In the fungal keratitis, the total fungal isolates were 32.50%. Amongthem Aspergillus species (56.42% was the most common fungus isolated followed by Curvurlaria (17.95%,Cladosporium (7.70%, Candida species (5.13%, Fusarium (5.13%, Alternaria (5.13%, Penicillium(2.57%. Fungal infection is a life threatening condition, which needs early diagnosis and treatment tosave the patients’ eye. Staphylococcus aureus and Staphylococcus epidermidis are still the most commonisolates among the known and opportunistic pathogens in ocular infection. Pseudomonas is the mostcommon cause of endophthalmitis. Aspergillus remains most common cause for fungal keratitis.

  7. Stromal IFN-γR-signaling modulates goblet cell function during Salmonella Typhimurium infection.

    Directory of Open Access Journals (Sweden)

    Pascal Songhet

    Full Text Available Enteropathogenic bacteria are a frequent cause of diarrhea worldwide. The mucosal defenses against infection are not completely understood. We have used the streptomycin mouse model for Salmonella Typhimurium diarrhea to analyze the role of interferon gamma receptor (IFN-γR-signaling in mucosal defense. IFN-γ is known to contribute to acute S. Typhimurium diarrhea. We have compared the acute mucosal inflammation in IFN-γR(-/- mice and wild type animals. IFN-γR(-/- mice harbored increased pathogen loads in the mucosal epithelium and the lamina propria. Surprisingly, the epithelium of the IFN-γR(-/- mice did not show the dramatic "loss" of mucus-filled goblet cell vacuoles, a hallmark of the wild type mucosal infection. Using bone marrow chimeric mice we established that IFN-γR-signaling in stromal cells (e.g. goblet cells, enterocytes controlled mucus excretion/vacuole loss by goblet cells. In contrast, IFN-γR-signaling in bone marrow-derived cells (e.g. macrophages, DCs, PMNs was required for restricting pathogen growth in the gut tissue. Thus IFN-γR-signaling influences different mucosal responses to infection, including not only pathogen restriction in the lamina propria, but, as shown here, also goblet cell function.

  8. Melatonin and zinc treatment: distinctive modulation of cytokine production in chronic experimental Trypanosoma cruzi infection.

    Science.gov (United States)

    Brazão, Vânia; Del Vecchio Filipin, Marina; Santello, Fabricia Helena; Caetano, Leony Cristina; Abrahão, Ana Amélia Carraro; Toldo, Míriam Paula Alonso; do Prado, José Clóvis

    2011-12-01

    Melatonin by exhibiting antioxidant, anti-aging, and immunomodulatory properties favorably modulate the immune function, protecting the hosts from several infectious diseases. Zinc is an essential trace element important for the efficiency of the immune system in reason of its widespread role in the activity of enzymes, transcription factors and cytokines. The etiology of Chagas' disease, caused by a protozoan parasite Trypanosoma cruzi, has been the focus of considerable discussion, although chronic phase still remains not fully understood. This study showed that zinc and melatonin treatment did not affect the percentage of both CD4+ and CD8+ T lymphocytes subsets in chronically infected animals. Increased levels of IL-2 and IL-10, as well as, enhanced thymocyte proliferation in T. cruzi infected groups under zinc and melatonin therapy was observed as compared to untreated group. Conversely, during the chronic phase of infection, macrophages counts were reduced in melatonin and zinc-melatonin treated animals. The combined actions of zinc and melatonin have beneficial effects in counteracting parasite-induced immune dysregulation, protecting animals against the harmful actions of chronic T. cruzi infection. Furthermore, our results provide an experimental basis for further studies on the role of immunomodulatory therapies.

  9. Exported Epoxide Hydrolases Modulate Erythrocyte Vasoactive Lipids during Plasmodium falciparum Infection

    Directory of Open Access Journals (Sweden)

    Natalie J. Spillman

    2016-10-01

    Full Text Available Erythrocytes are reservoirs of important epoxide-containing lipid signaling molecules, including epoxyeicosatrienoic acids (EETs. EETs function as vasodilators and anti-inflammatory modulators in the bloodstream. Bioactive EETs are hydrolyzed to less active diols (dihydroxyeicosatrienoic acids by epoxide hydrolases (EHs. The malaria parasite Plasmodium falciparum infects host red blood cells (RBCs and exports hundreds of proteins into the RBC compartment. In this study, we show that two parasite epoxide hydrolases, P. falciparum epoxide hydrolases 1 (PfEH1 and 2 (PfEH2, both with noncanonical serine nucleophiles, are exported to the periphery of infected RBCs. PfEH1 and PfEH2 were successfully expressed in Escherichia coli, and they hydrolyzed physiologically relevant erythrocyte EETs. Mutations in active site residues of PfEH1 ablated the ability of the enzyme to hydrolyze an epoxide substrate. Overexpression of PfEH1 or PfEH2 in parasite-infected RBCs resulted in a significant alteration in the epoxide fatty acids stored in RBC phospholipids. We hypothesize that the parasite disruption of epoxide-containing signaling lipids leads to perturbed vascular function, creating favorable conditions for binding and sequestration of infected RBCs to the microvascular endothelium.

  10. IL-37 Confers Protection against Mycobacterial Infection Involving Suppressing Inflammation and Modulating T Cell Activation

    Science.gov (United States)

    Yang, Hua; He, Xin; Ji, Qun; Bai, Wenjuan; Chen, Hao; Chen, Jianxia; Peng, Wenxia; Liu, Siyu; Liu, Zhonghua; Ge, Baoxue

    2017-01-01

    Interleukin-37 (IL-37), a novel member of the IL-1 family, plays fundamental immunosuppressive roles by broadly reducing both innate inflammation and acquired immunity, but whether it is involved in the pathogenesis of tuberculosis (TB) has not been clearly elucidated. In this study, single nucleotide polymorphism (SNP) analysis demonstrated an association of the genetic variant rs3811047 of IL-37 with TB susceptibility. In line with previous report, a significant elevated IL-37 abundance in the sera and increased expression of IL-37 protein in the peripheral blood mononuclear cells (PBMC) were observed in TB patients in comparison to healthy controls. Moreover, release of IL-37 were detected in either macrophages infected with Mycobacterium tuberculosis (Mtb) or the lung of BCG-infected mice, concurrent with reduced production of proinflammatory cytokines including IL-6 and TNF-α. Furthermore, in contrast to wild-type mice, BCG-infected IL-37-Tg mice manifested with reduced mycobacterial burden and tissue damage in the lung, accompanied by higher frequency of Th1 cell and less frequencies of regulatory T cells and Th17 cells in the spleen. Taken together, our findings demonstrated that IL-37 conferred resistance to Mtb infection possibly involving suppressing detrimental inflammation and modulating T cell responses. These findings implicated that IL-37 may be employed as a new molecular target for the therapy and diagnosis of TB. PMID:28076390

  11. Streptococcus pyogenes arginine and citrulline catabolism promotes infection and modulates innate immunity.

    Science.gov (United States)

    Cusumano, Zachary T; Watson, Michael E; Caparon, Michael G

    2014-01-01

    A bacterium's ability to acquire nutrients from its host during infection is an essential component of pathogenesis. For the Gram-positive pathogen Streptococcus pyogenes, catabolism of the amino acid arginine via the arginine deiminase (ADI) pathway supplements energy production and provides protection against acid stress in vitro. Its expression is enhanced in murine models of infection, suggesting an important role in vivo. To gain insight into the function of the ADI pathway in pathogenesis, the virulence of mutants defective in each of its enzymes was examined. Mutants unable to use arginine (ΔArcA) or citrulline (ΔArcB) were attenuated for carriage in a murine model of asymptomatic mucosal colonization. However, in a murine model of inflammatory infection of cutaneous tissue, the ΔArcA mutant was attenuated but the ΔArcB mutant was hyperattenuated, revealing an unexpected tissue-specific role for citrulline metabolism in pathogenesis. When mice defective for the arginine-dependent production of nitric oxide (iNOS(-/-)) were infected with the ΔArcA mutant, cutaneous virulence was rescued, demonstrating that the ability of S. pyogenes to utilize arginine was dispensable in the absence of nitric oxide-mediated innate immunity. This work demonstrates the importance of arginine and citrulline catabolism and suggests a novel mechanism of virulence by which S. pyogenes uses its metabolism to modulate innate immunity through depletion of an essential host nutrient.

  12. Effectiveness of probiotic Phaeobacter bacteria grown in biofilters against Vibrio anguillarum infections in the rearing of Turbot (Psetta maxima) larvae.

    Science.gov (United States)

    Prol-García, María J; Pintado, José

    2013-12-01

    The rearing environment of first-feeding turbot larvae, usually with high larvae densities and organic matter concentrations, may promote the growth of opportunistic pathogenic Vibrionaceae bacteria, compromising the survival of the larvae. The aim of this study was to assess the effectiveness of the biofilm-forming probiotic Phaeobacter 27-4 strain grown on a ceramic biofilter (probiofilter) in preventing Vibrio anguillarum infections in turbot larvae. In seawater with added microalgae and maintained under turbot larvae rearing conditions, the probiofilter reduced the total Vibrionaceae count and the concentration of V. anguillarum, which was undetectable after 144 h by real-time PCR. The probiofilter also improved the survival of larvae challenged with V. anguillarum, showing an accumulated mortality similar to that of uninfected larvae (35-40 %) and significantly (p biofilters can constantly inoculate probiotics into rearing tanks and are therefore potentially useful for bacterial control in both open and recirculating industrial units.

  13. Mechanisms of infection by pathogens transmitted by ticks on the example of bacteria: Anaplasma phagocytophilum and Borrelia burgdorferi

    Directory of Open Access Journals (Sweden)

    Paula Wróblewska

    2016-06-01

    Full Text Available Tick-borne diseases are transmission diseases belonging to the group of zoonoses but carried by ticks. These diseases are a major public health problem but also a problem for groups occupationally exposed to tick bites. Ixodes ricinus is a species of ticks which is the most common reservoir and the vector of a large number of microorganisms pathogenic to humans. It transfers, among others, bacteria of the species: Anaplasma phagocytophilum and Borrelia burgdorferi. The article discusses the mechanisms of infection with Borrelia burgdorferi and Anaplasma phagocytophilum for both ticks as well as for animals and humans. The two microorganisms discussed have developed many characteristics and mechanisms of adaptation to the environment, as well as defense mechanisms against the body's immune response. Understanding the biology of ticks and the function of proteins produced by ticks and pathogenic microorganisms is the key in the development of effective treatments and prevention of Lyme disease and anaplasmosis.

  14. Using In Vitro Immunomodulatory Properties of Lactic Acid Bacteria for Selection of Probiotics against Salmonella Infection in Broiler Chicks.

    Science.gov (United States)

    Feng, Junchang; Wang, Lihong; Zhou, Luoxiong; Yang, Xin; Zhao, Xin

    2016-01-01

    Poultry is known to be a major reservoir of Salmonella. The use of lactic acid bacteria has become one of successful strategies to control Salmonella in poultry. The purpose of this study was to select lactic acid bacteria strains by their in vitro immunomodulatory properties for potential use as probiotics against Salmonella infection in broiler chicks. Among 101 isolated lactic acid bacteria strains, 13 strains effectively survived under acidic (pH 2.5) and bile salt (ranging from 0.1% to 1.0%) conditions, effectively inhibited growth of 6 pathogens, and adhered to Caco-2 cells. However, their in vitro immunomodulatory activities differed significantly. Finally, three strains with higher in vitro immunomodulatory properties (Lactobacillus plantarum PZ01, Lactobacillus salivarius JM32 and Pediococcus acidilactici JH231) and three strains with lower in vitro immunomodulatory activities (Enterococcus faecium JS11, Lactobacillus salivarius JK22 and Lactobacillus salivarius JM2A1) were compared for their inhibitory effects on Salmonella adhesion and invasion to Caco-2 cells in vitro and their antimicrobial effects in vivo. The former three strains inhibited Salmonella adhesion and invasion to Caco-2 cells in vitro, reduced the number of Salmonella in intestinal content, spleen and liver, reduced the levels of lipopolysaccharide-induced TNF-α factor (LITAF), IL-1β, IL-6 and IL-12 in serum and increased the level of IL-10 in serum during a challenge study in vivo more efficiently than the latter three strains. These results suggest that in vitro immunomodulatory activities could be used as additional parameters to select more effective probiotics as feed supplements for poultry.

  15. Using In Vitro Immunomodulatory Properties of Lactic Acid Bacteria for Selection of Probiotics against Salmonella Infection in Broiler Chicks.

    Directory of Open Access Journals (Sweden)

    Junchang Feng

    Full Text Available Poultry is known to be a major reservoir of Salmonella. The use of lactic acid bacteria has become one of successful strategies to control Salmonella in poultry. The purpose of this study was to select lactic acid bacteria strains by their in vitro immunomodulatory properties for potential use as probiotics against Salmonella infection in broiler chicks. Among 101 isolated lactic acid bacteria strains, 13 strains effectively survived under acidic (pH 2.5 and bile salt (ranging from 0.1% to 1.0% conditions, effectively inhibited growth of 6 pathogens, and adhered to Caco-2 cells. However, their in vitro immunomodulatory activities differed significantly. Finally, three strains with higher in vitro immunomodulatory properties (Lactobacillus plantarum PZ01, Lactobacillus salivarius JM32 and Pediococcus acidilactici JH231 and three strains with lower in vitro immunomodulatory activities (Enterococcus faecium JS11, Lactobacillus salivarius JK22 and Lactobacillus salivarius JM2A1 were compared for their inhibitory effects on Salmonella adhesion and invasion to Caco-2 cells in vitro and their antimicrobial effects in vivo. The former three strains inhibited Salmonella adhesion and invasion to Caco-2 cells in vitro, reduced the number of Salmonella in intestinal content, spleen and liver, reduced the levels of lipopolysaccharide-induced TNF-α factor (LITAF, IL-1β, IL-6 and IL-12 in serum and increased the level of IL-10 in serum during a challenge study in vivo more efficiently than the latter three strains. These results suggest that in vitro immunomodulatory activities could be used as additional parameters to select more effective probiotics as feed supplements for poultry.

  16. Antibacterial activity of silver nanoparticle-coated fabric and leather against odor and skin infection causing bacteria.

    Science.gov (United States)

    Velmurugan, Palanivel; Lee, Sang-Myeong; Cho, Min; Park, Jung-Hee; Seo, Sang-Ki; Myung, Hyun; Bang, Keuk-Soo; Oh, Byung-Taek

    2014-10-01

    We present a simple, eco-friendly synthesis of silver and gold nanoparticles using a natural polymer pine gum solution as the reducing and capping agent. The pine gum solution was combined with silver nitrate (AgNO3) or a chloroauric acid (HAuCl4) solution to produce silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs), respectively. The reaction process was simple; formation of the nanoparticles was achieved by autoclaving the silver and gold ions with the pine gum. UV-Vis spectra showed surface plasmon resonance (SPR) for silver and gold nanoparticles at 432 and 539 nm, respectively. The elemental forms of AgNPs and AuNPs were confirmed by energy-dispersive X-ray spectroscopy (EDX). Fourier transform infrared spectroscopy (FTIR) showed the biomolecules present in the pine gum, AgNPs, and AuNPs. Transmission electron microscopy (TEM) images showed the shape and size of AgNPs and AuNPs. The crystalline nature of synthesized AgNPs and AuNPs was confirmed by X-ray crystallography [X-ray diffraction (XRD)]. Application of synthesized AgNPs onto cotton fabrics and leather, in order to evaluate their antibacterial properties against odor- or skin infection-causing bacteria, is also discussed. Among the four tested bacteria, AgNP-coated cotton fabric and leather samples displayed excellent antibacterial activity against Brevibacterium linens.

  17. Clinical identification of bacteria in human chronic wound infections: culturing vs. 16S ribosomal DNA sequencing

    OpenAIRE

    Rhoads Daniel D; Cox Stephen B; Rees Eric J; Sun Yan; Wolcott Randall D

    2012-01-01

    Abstract Background Chronic wounds affect millions of people and cost billions of dollars in the United States each year. These wounds harbor polymicrobial biofilm communities, which can be difficult to elucidate using culturing methods. Clinical molecular microbiological methods are increasingly being employed to investigate the microbiota of chronic infections, including wounds, as part of standard patient care. However, molecular testing is more sensitive than culturing, which results in m...

  18. Virulence factors in Proteus bacteria from biofilm communities of catheter-associated urinary tract infections.

    Science.gov (United States)

    Hola, Veronika; Peroutkova, Tereza; Ruzicka, Filip

    2012-07-01

    More than 40% of nosocomial infections are those of the urinary tract, most of these occurring in catheterized patients. Bacterial colonization of the urinary tract and catheters results not only in infection, but also various complications, such as blockage of catheters with crystalline deposits of bacterial origin, generation of gravels and pyelonephritis. The diversity of the biofilm microbial community increases with duration of catheter emplacement. One of the most important pathogens in this regard is Proteus mirabilis. The aims of this study were to identify and assess particular virulence factors present in catheter-associated urinary tract infection (CAUTI) isolates, their correlation and linkages: three types of motility (swarming, swimming and twitching), the ability to swarm over urinary catheters, biofilm production in two types of media, urease production and adherence of bacterial cells to various types of urinary tract catheters. We examined 102 CAUTI isolates and 50 isolates taken from stool samples of healthy people. Among the microorganisms isolated from urinary catheters, significant differences were found in biofilm-forming ability and the swarming motility. In comparison with the control group, the microorganisms isolated from urinary catheters showed a wider spectrum of virulence factors. The virulence factors (twitching motility, swimming motility, swarming over various types of catheters and biofilm formation) were also more intensively expressed.

  19. Lactobacillus paracasei modulates the immune system of Galleria mellonella and protects against Candida albicans infection

    Science.gov (United States)

    Rossoni, Rodnei Dennis; Fuchs, Beth Burgwyn; de Barros, Patrícia Pimentel; Velloso, Marisol dos Santos; Jorge, Antonio Olavo Cardoso; Junqueira, Juliana Campos; Mylonakis, Eleftherios

    2017-01-01

    Probiotics have been described as a potential strategy to control opportunistic infections due to their ability to stimulate the immune system. Using the non-vertebrate model host Galleria mellonella, we evaluated whether clinical isolates of Lactobacillus spp. are able to provide protection against Candida albicans infection. Among different strains of Lactobacillus paracasei, Lactobacillus rhamnosus and Lactobacillus fermentum, we verified that L. paracasei 28.4 strain had the greatest ability to prolong the survival of larvae infected with a lethal dose of C. albicans. We found that the injection of 107 cells/larvae of L. paracasei into G. mellonella larvae infected by C. albicans increased the survival of these insects compared to the control group (P = 0.0001). After that, we investigated the immune mechanisms involved in the protection against C. albicans infection, evaluating the number of hemocytes and the gene expression of antifungal peptides. We found that L. paracasei increased the hemocyte quantity (2.38 x 106 cells/mL) in relation to the control group (1.29 x 106 cells/mL), indicating that this strain is capable of raising the number of circulating hemocytes into the G. mellonella hemolymph. Further, we found that L. paracasei 28.4 upregulated genes that encode the antifungal peptides galiomicin and gallerymicin. In relation to the control group, L. paracasei 28.4 increased gene expression of galiomicin by 6.67-fold and 17.29-fold for gallerymicin. Finally, we verified that the prophylactic provision of probiotic led to a significant reduction of the number of fungal cells in G. mellonella hemolymph. In conclusion, L. paracasei 28.4 can modulate the immune system of G. mellonella and protect against candidiasis. PMID:28267809

  20. How to Manage Infections Caused by Antibiotic Resistant Gram-negative Bacteria - EBMT Educational Meeting from the Severe Aplastic Anaemia and Infectious Diseases Working Parties, Naples, Italy, 2014.

    Science.gov (United States)

    Mikulska, Małgorzata

    2015-02-23

    Multidrug resistant (MDR) Gram-negative bacteria are increasingly frequent in hematopoietic stem cell transplant (HSCT) recipients, yet their prevalence is highly variable among transplant centres. Thus, the knowledge of local epidemiology is mandatory for deciding the most appropriate management protocols. Empirical therapy of febrile neutropenia should be individualized. Either escalation or de-escalation strategy could be chosen, based on local epidemiology, individual risk factors for infection due to resistant strains, such as previous infection or colonization with a resistant pathogen, and clinical presentation. De-escalation approach is recommended in case of severe clinical presentation in patients who are at high risk of drug-resistant infection. Targeted therapy of MDR Gram-negatives, in particular carbapenem-resistant strains, calls for a combination treatment, usually including colistin. No large randomized trials exist in this setting. Local epidemiology dictates which resistant bacteria should be routinely screened for, and infection control precautions are mandatory to limit the spread of resistant strains. Antimicrobial stewardship, with the aim of the best possible management of bacterial infections, should be put in place in every transplant centre. In conclusion, infections caused by resistant Gram-negative bacteria in HSCT population warrant currently particular attention in order to limit their negative impact on transplant outcomes.

  1. A host basal transcription factor is a key component for infection of rice by TALE-carrying bacteria.

    Science.gov (United States)

    Yuan, Meng; Ke, Yinggen; Huang, Renyan; Ma, Ling; Yang, Zeyu; Chu, Zhaohui; Xiao, Jinghua; Li, Xianghua; Wang, Shiping

    2016-07-29

    Transcription activator-like effectors (TALEs) are sequence-specific DNA binding proteins found in a range of plant pathogenic bacteria, where they play important roles in host-pathogen interactions. However, it has been unclear how TALEs, after they have been injected into the host cells, activate transcription of host genes required for infection success. Here, we show that the basal transcription factor IIA gamma subunit TFIIAγ5 from rice is a key component for infection by the TALE-carrying bacterium Xanthomonas oryzae pv. oryzae, the causal agent for bacterial blight. Direct interaction of several TALEs with TFIIAγ5 is required for activation of disease susceptibility genes. Conversely, reduced expression of the TFIIAγ5 host gene limits the induction of susceptibility genes and thus decreases bacterial blight symptoms. Suppression or mutation of TFIIAγ5 can also reduce bacterial streak, another devastating disease of rice caused by TALE-carrying X. oryzae pv. oryzicola. These results have important implications for formulating a widely applicable strategy with which to improve resistance of plants to TALE-carrying pathogens.

  2. DIFFERENTIAL BANDING PATTERN BASED IDENTIFICATION OF URINARY TRACT INFECTION CAUSING BACTERIA

    Directory of Open Access Journals (Sweden)

    Poulomi Nandy

    2013-01-01

    Full Text Available Urinary Tract Infection (UTI affects all age groups, but women are more susceptible than men. These infections are typically caused by E coli, Proteus mirabilis, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, Enterococcus fecalis and so on. Since uncultivable microbes are numerically abundant in urine samples, culture independent detection seems to be the method of choice for diagnosing UTI. This study was an attempt to design a database of banding pattern of microbial variety inhabiting normal and infected subjects. The 16S rDNA Polymerase Chain Reaction (PCR product was digested with 14 different restriction enzymes and run on a 2% agarose gel. From the restriction digestion images, their banding pattern and dendogram analysis, it was possible to differentiate and distinguish between E.coli, Pseudomonas, Klebsiella, Staphylococcus and Enterococci genus. Most of the enzymes like XbaI, ApaI, KpnI, PstI gave similar banding patterns for Klebsiella, E.coli and Pseudomonas, which could be differentiated from the Staphylococcus members. BgII and SmaI gave similar patterns for Klebsiella and E.coli, which was in turn different from that of Pseudomonas and Staphylococcus. Enzyme BamHI not only differentiated among Staphylococcus and the other three groups but was also able to show a distinct variation in banding pattern among Staphylococcus members. The database generated was used to identify pathogens from unknown patient samples without cultivating them. HindIII and HinfI can be used as two separate potential enzymes to differentiate and distinguish between the various microbes.

  3. Poly I:C enhances susceptibility to secondary pulmonary infections by gram-positive bacteria.

    Directory of Open Access Journals (Sweden)

    Xiaoli Tian

    Full Text Available Secondary bacterial pneumonias are a frequent complication of influenza and other respiratory viral infections, but the mechanisms underlying viral-induced susceptibility to bacterial infections are poorly understood. In particular, it is unclear whether the host's response against the viral infection, independent of the injury caused by the virus, results in impairment of antibacterial host defense. Here, we sought to determine whether the induction of an "antiviral" immune state using various viral recognition receptor ligands was sufficient to result in decreased ability to combat common bacterial pathogens of the lung. Using a mouse model, animals were administered polyinosine-polycytidylic acid (poly I:C or Toll-like 7 ligand (imiquimod or gardiquimod intranasally, followed by intratracheal challenge with Streptococcus pneumoniae. We found that animals pre-exposed to poly I:C displayed impaired bacterial clearance and increased mortality. Poly I:C-exposed animals also had decreased ability to clear methicillin-resistant Staphylococcus aureus. Furthermore, we showed that activation of Toll-like receptor (TLR3 and Retinoic acid inducible gene (RIG-I/Cardif pathways, which recognize viral nucleic acids in the form of dsRNA, both contribute to poly I:C mediated impairment of bacterial clearance. Finally, we determined that poly I:C administration resulted in significant induction of type I interferons (IFNs, whereas the elimination of type I IFN signaling improved clearance and survival following secondary bacterial pneumonia. Collectively, these results indicate that in the lung, poly I:C administration is sufficient to impair pulmonary host defense against clinically important gram-positive bacterial pathogens, which appears to be mediated by type I IFNs.

  4. Electrochemical sensing of biomarker for diagnostics of bacteria-specific infections

    DEFF Research Database (Denmark)

    Al Atraktchi, Fatima Al-Zahraa; Johansen, Helle Krogh; Molin, Søren;

    2016-01-01

    a direct, selective and rapid detection technique of pyocyanin. Materials & methods: Pyocyanin was detected by amperometry at a relatively high potential where the pyocyanin signal was unaffected by background contributions. Results & conclusion: Pyocyanin was detected at concentrations down to 125 n......M in a 50 μM mixture of interfering compounds with a reproducibility of r2 = 0.999 (n = 5) within 200 s. The results document a step toward a point-of-care technique for diagnosis of P. aeruginosa infections....

  5. Antiadhesive and antibiofilm activity of hyaluronic acid against bacteria responsible for respiratory tract infections.

    Science.gov (United States)

    Drago, Lorenzo; Cappelletti, Laura; De Vecchi, Elena; Pignataro, Lorenzo; Torretta, Sara; Mattina, Roberto

    2014-10-01

    To address the problem of limited efficacy of existing antibiotics in the treatment of bacterial biofilm, it is necessary to find alternative remedies. One candidate could be hyaluronic acid; this study therefore aimed to evaluate the in vitro antiadhesive and antibiofilm activity of hyaluronic acid toward bacterial species commonly isolated from respiratory infections. Interference exerted on bacterial adhesion was evaluated by using Hep-2 cells, while the antibiofilm activity was assessed by means of spectrophotometry after incubation of biofilm with hyaluronic acid and staining with crystal violet. Our data suggest that hyaluronic acid is able to interfere with bacterial adhesion to a cellular substrate in a concentration-dependent manner, being notably active when assessed as pure substance. Moreover, we found that Staphylococcus aureus biofilm was more sensitive to the action of hyaluronic acid than biofilm produced by Haemophilus influenzae and Moraxella catarrhalis. In conclusion, hyaluronic acid is characterized by notable antiadhesive properties, while it shows a moderate activity against bacterial biofilm. As bacterial adhesion to oral cells is the first step for colonization, these results further sustain the role of hyaluronic acid in prevention of respiratory infections.

  6. The Syndrome of Sea Cucumber (Apostichopus japonicus) Infected by Virus and Bacteria

    Institute of Scientific and Technical Information of China (English)

    Huan DENG; Zun-chun ZHOU; Nian-bin WANG; Chang LIU

    2008-01-01

    A outbreak of disease with symptoms of evisceration and skin ulteration led to mass mortality in sea cucumber Apostichopus japonicus cultivated in indoor ponds near the Dalian coast from December 2004 to April 2005. Spherical virus particles with a diameter of 75-200 nm were found in the cytoplasm of cells in the water-system, the alimentary canal and in the respiratory trees of the diseased and dying sea cucumber individuals by electron microscopic observation of ultrathin sections. Examination by negative stained samples revealed that all the diseased sea cucumbers were infected by the virus, while the healthly ones cultivated outside the contagious area were not. Two bacterial strains were also isolated from the diseased animals. When exposed to a medium containing the virus particles, regardless of whether the bacterial suspension was added,healthy sea cucumbers exhibited identical disease symptoms as the ones in the indoor ponds, and had a mortality of 90%-100%. However, when exposed to a medium in which there was only one of the two bacterial strains, 30%-80% of the sea cucumbers were infected and nearly 20% died. Negative staining showed that the viral particles were detected only in the bodies of the tested animals that were exposed to the viral medium. Histopathologically, the diseased sea cucumbers are characterized by karyopycnosis, and disintegration of the endoplasmic reticula and mitochondria in the epithelial cells in the water-system, the respiratory tree and the alimentary canal.

  7. Modulation of inflammation and pathology during dengue virus infection by p38 MAPK inhibitor SB203580.

    Science.gov (United States)

    Fu, Yilong; Yip, Andy; Seah, Peck Gee; Blasco, Francesca; Shi, Pei-Yong; Hervé, Maxime

    2014-10-01

    Dengue virus (DENV) infection could lead to dengue fever (DF), dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS). The disease outcome is controlled by both viral and host factors. Inflammation mediators from DENV-infected cells could contribute to increased vascular permeability, leading to severe DHF/DSS. Therefore, suppression of inflammation could be a potential therapeutic approach for treatment of dengue patients. In this context, p38 MAPK (mitogen-activated protein kinase) is a key enzyme that modulates the initiation of stress and inflammatory responses. Here we show that SB203580, a p38 MAPK inhibitor, suppressed the over production of DENV-induced pro-inflammatory mediators such as TNF-α, IL-8, and RANTES from human PBMCs, monocytic THP-1, and granulocyte KU812 cell lines. Oral administration of SB203580 in DENV-infected AG129 mice prevented hematocrit rise and lymphopenia, limited the development of inflammation and pathology (including intestine leakage), and significantly improved survival. These results, for the first time, have provided experimental evidence to imply that a short term inhibition of p38 MAPK may be beneficial to reduce disease symptoms in dengue patients.

  8. Human Invariant Natural Killer T cells possess immune-modulating functions during Aspergillus infection.

    Science.gov (United States)

    Beitzen-Heineke, Antonia; Bouzani, Maria; Schmitt, Anna-Lena; Kurzai, Oliver; Hünniger, Kerstin; Einsele, Hermann; Loeffler, Juergen

    2016-02-01

    Aspergillus fumigatus is the most common cause for invasive fungal infections, a disease associated with high mortality in immune-compromised patients. CD1d-restricted invariant natural killer T (iNKT) cells compose a small subset of T cells known to impact the immune response toward various infectious pathogens. To investigate the role of human iNKT cells during A. fumigatus infection, we studied their activation as determined by CD69 expression and cytokine production in response to distinct fungal morphotypes in the presence of different CD1d(+) antigen presenting cells using flow cytometry and multiplex enzyme-linked immunosorbent assay (ELISA). Among CD1d(+) subpopulations, CD1d(+)CD1c(+) mDCs showed the highest potential to activate iNKT cells on a per cell basis. The presence of A. fumigatus decreased this effect of CD1d(+)CD1c(+) mDCs on iNKT cells and led to reduced secretion of TNF-α, G-CSF and RANTES. Production of other Th1 and Th2 cytokines was not affected by the fungus, suggesting an immune-modulating function for human iNKT cells during A. fumigatus infection.

  9. An anti-infective peptide that selectively modulates the innate immune response.

    Science.gov (United States)

    Scott, Monisha G; Dullaghan, Edie; Mookherjee, Neeloffer; Glavas, Natalie; Waldbrook, Matthew; Thompson, Annick; Wang, Aikun; Lee, Ken; Doria, Silvana; Hamill, Pam; Yu, Jie Jessie; Li, Yuexin; Donini, Oreola; Guarna, M Marta; Finlay, B Brett; North, John R; Hancock, Robert E W

    2007-04-01

    We show that an innate defense-regulator peptide (IDR-1) was protective in mouse models of infection with important Gram-positive and Gram-negative pathogens, including methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus and Salmonella enterica serovar Typhimurium. When given from 48 h before to 6 h after infection, the peptide was effective by both local and systemic administration. Because protection by IDR-1 was prevented by in vivo depletion of monocytes and macrophages, but not neutrophils or B- and T-lymphocytes, we conclude that monocytes and macrophages are key effector cells. IDR-1 was not directly antimicrobial: gene and protein expression analysis in human and mouse monocytes and macrophages indicated that IDR-1, acting through mitogen-activated protein kinase and other signaling pathways, enhanced the levels of monocyte chemokines while reducing pro-inflammatory cytokine responses. To our knowledge, an innate defense regulator that counters infection by selective modulation of innate immunity without obvious toxicities has not been reported previously.

  10. Ecological aspects of the antimicrobial resistence in bacteria of importance to humn infections

    Directory of Open Access Journals (Sweden)

    Meirelles-Pereira Frederico de

    2002-01-01

    Full Text Available In view of the intimate relationship of humans with coastal lagoons (used for recreation, tourism, water supply, etc., the discharge of domestic effluents may lead to the establishment of routes of dissemination of pathogenic microorganisms, including microorganisms carrying genes for resistance to antimicrobials, through the surrounding human communities. The objective of the present investigation was to relate the presence of antimicrobial-resistant bacteria to the environmental characteristics of three coastal lagoons, comparing the results with those from hospital sewage. Of the lagoons evaluated, two (Geribá and Imboassica receive domestic sewage discharge, and the other (Cabiúnas is still in a natural state. We isolated in a culture medium containing 32 ¼ µg/ml of Cephalothin, fecal coliforms (E. coli, non-fecal coliforms (Klebsiella, Enterobacter, Serratia, and Citrobacter, non-glucose-fermenting Gram-negative bacilli, and Aeromonas sp. In cultures from the hospital drain we found strains showing numerous markers for resistance to most of the 11 antimicrobials tested. On the other hand, in cultures from Cabiúnas and Imboassica lagoons, we found strains showing resistance only to antibiotics frequently observed in non-selective situations (considered as "common" markers. The capacity for dilution in the ecosystem, and salinity appeared related with the occurrence of multi-resistant bacterial strains. The intensity of recent fecal contamination was not shown to be associated with the numbers and types of markers found.

  11. Population Density Modulates Drug Inhibition and Gives Rise to Potential Bistability of Treatment Outcomes for Bacterial Infections

    Science.gov (United States)

    Maltas, Jeff; Brumm, Peter; Wood, Kevin B.

    2016-01-01

    The inoculum effect (IE) is an increase in the minimum inhibitory concentration (MIC) of an antibiotic as a function of the initial size of a microbial population. The IE has been observed in a wide range of bacteria, implying that antibiotic efficacy may depend on population density. Such density dependence could have dramatic effects on bacterial population dynamics and potential treatment strategies, but explicit measures of per capita growth as a function of density are generally not available. Instead, the IE measures MIC as a function of initial population size, and population density changes by many orders of magnitude on the timescale of the experiment. Therefore, the functional relationship between population density and antibiotic inhibition is generally not known, leaving many questions about the impact of the IE on different treatment strategies unanswered. To address these questions, here we directly measured real-time per capita growth of Enterococcus faecalis populations exposed to antibiotic at fixed population densities using multiplexed computer-automated culture devices. We show that density-dependent growth inhibition is pervasive for commonly used antibiotics, with some drugs showing increased inhibition and others decreased inhibition at high densities. For several drugs, the density dependence is mediated by changes in extracellular pH, a community-level phenomenon not previously linked with the IE. Using a simple mathematical model, we demonstrate how this density dependence can modulate population dynamics in constant drug environments. Then, we illustrate how time-dependent dosing strategies can mitigate the negative effects of density-dependence. Finally, we show that these density effects lead to bistable treatment outcomes for a wide range of antibiotic concentrations in a pharmacological model of antibiotic treatment. As a result, infections exceeding a critical density often survive otherwise effective treatments. PMID:27764095

  12. Multidrug-resistant Gram-negative bacteria-resistant infections: epidemiology, clinical issues and therapeutic options

    Directory of Open Access Journals (Sweden)

    Matteo Bassetti

    2016-12-01

    Full Text Available In the last decade, we have witnessed a dramatic increase in the number of multidrug resistant Gram-negative (MDRGN bacterial pathogens, both in Italy and worldwide, with Enterobacteriacae (mostly Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii being the major threats in clinical practice. Inadequate empirical antimicrobial therapy of severe infections caused by MDR Enterobacteriacae has been associated with an increased morbidity and mortality. However, a careful selection of patients who may receive empirical treatment covering MDR Enterobacteriacae is important to avoid the overuse of broad-spectrum antibiotics. The aim of this review is to describe the mechanism of resistance, epidemiology, risk factors, clinical issues, and therapeutic options for MDRGN pathogens.

  13. mBin1b transgenic mice show enhanced resistance to epididymal infection by bacteria challenge.

    Science.gov (United States)

    Fei, Z; Hu, S; Xiao, L; Zhou, J; Diao, H; Yu, H; Fang, S; Wang, Y; Wan, Y; Wang, W; He, Y; Wang, C; Xu, G; Wang, Z; Zhang, Y; Fei, J

    2012-09-01

    The mBin1b is a beta-defensin gene identified in the mouse epididymis. In the current report, its expression pattern and antibacterial activities were characterized, and a transgenic (TG) mouse model was developed in which mBin1b was exclusively overexpressed by up to 50-fold over normal levels in the caput epididymis. The experimental animals are healthy with normal reproductive activity, but are more resistant to epididymal infection from Escherichia coli than normal animals. The expression of IL1α and IL1β in the epididymis was decreased in the TG mice, which suggests that mBin1b has a role in the regulation of inflammatory response in the epididymis.

  14. Surface properties of catheters, stents and bacteria associated with urinary tract infections

    Science.gov (United States)

    Reid, Gregor; Busscher, Henk J.; Sharma, Sunaina; Mittelman, Marc W.; McIntyre, Stewart

    Applications of surface and physico-chemical techniques to the clinical setting, in particular related to the urogenital tract, have been sporadic, often concentrating on aspects of biocompatibility and interactions of blood cells with materials. In an era where billions of such devices are implanted annually, it is important to utilize such techniques to improve our understanding of material-host interactions. In an effort to encourage further such interactive investigations, this review will illustrate some practical biomedical examples where utilization of sophisticated surface-science techniques has provided valuable insight into interfacial events between host components, micro-organisms and material surfaces. Techniques to reduce bacterial infection and encrustations will be discussed, and suggestions given for future lines of enquiry.

  15. [Infections caused by multi-resistant Gram-positive bacteria (Staphylococcus aureus and Enterococcus spp.)].

    Science.gov (United States)

    Cantón, Rafael; Ruiz-Garbajosa, Patricia

    2013-10-01

    Methicillin -resistant Staphylocccus aureus (MRSA) and multirresistant entorococci are still problematic in nosocomial infections and new challenges have emerged for their containment. MRSA has increased the multiresistant profile; it has been described vancomycin and linezolid resistant isolates and isolates with decreased daptomycin susceptibility. Moreover, new clones (ST398) have emerged, initially associated with piggeries, and new mec variants (mecC) with livestock origin that escape to the detection with current molecular methods based on mecA gene have been detected. In enterococci, linzeolid resistant isolates and isolates with deceased susceptibility to daptomycin have been described. Moreover, ampicillin resistant Enterococcus faecium due to β-lactamase production has been recently found in Europe. Control of MRSA isolates and multiresistant enteroccocci should combined antibiotic stewardship strategies and epidemiological measures, including detection of colonized patients in order to reduce colonization pressure and their transmission.

  16. Limitations of beta-lactam therapy for infections caused by susceptible Gram-positive bacteria.

    Science.gov (United States)

    English, B Keith

    2014-11-01

    Penicillin and related beta-lactam agents have been the most widely used and most important antimicrobials in medical history, and remain the recommended therapy for many infectious diseases 85 years after the discovery of penicillin by Alexander Fleming. Yet the efficacy of these agents has been undermined by two factors - the emergence of clinically significant resistance to the antimicrobial activity of these agents, and clinical situations in which these drugs may be suboptimal (even though the bacterial pathogens are not "resistant" to the drugs). Observations in experimental infection models in animals (group A streptococcal myositis, pneumococcal meningitis and pneumonia, group B streptococcal sepsis) and in some cases clinical studies suggest that monotherapy with beta-lactam antibiotics may be inferior to treatment with other types of antibiotics, alone or in combination with beta-lactams - even in situations where the bacterial pathogens remain fully "susceptible" to beta-lactams in vitro.

  17. Urinary Tract Infections Due to Catheterization and Drug Resistance Patterns of Isolated Bacteria

    Directory of Open Access Journals (Sweden)

    M. Mosavian

    2004-07-01

    Full Text Available UTI is the most common infection in all ages and urinary catheters especially long-term catheterization are important predisposing factors of UTI. Urinary catheters are used in different hospital wards as a complementary curative method for the patients who are undergone various surgical procedures, such as : cesarean, hysterectomy , laparotomy, etc and they who are unable to control their voided urine . 226 urine specimens were collected from 119 catheterized patients which had been hospitalized in seven wards of Razi and Golestan hospitals in Ahwas city . At least two urine specimens were collected from each patient , before and after the insertion of the catheter . All of the specimens were inoculated to suitable Media, after transportation to the Microbiology Lab . Isolated colonies were identified and their resistance patterns were determined by the standard disk diffusion method (Kirby –Bauer procedure to 8 different antibiotics. 38 cases (43.6% out of 87 patients showed Bacteriuria in the end of catheterization . They had no bacteriuria symptoms or sign before the catheterization. The most cases(28.9% of bacteriuria occured in 30-39 years group and the lowest cases (2.6 % of them occured in 60-69 years group. Out of 50 bacterial strains isolated from urine cultures , E.coil (with 17 cases was the highest (34% and Staphylococcus aureus , Klebsiella pneumoniae , Edwardsiella tarda , Enterobacter sakazakii (with 2% for each were the lowest cases. E.coli, Enterobacter and Kl. rhinoscleromatis , showed the most resistance to Ampicillin, Penicillin , Cephalexin , and the lowest rate to Nalidixic acid, Gentamicin and Nitrofurantoin . Staphylococcus epidermidis isolates ,also,showed the most resistance (100% to Penicillin and Ampicillin , and the lowest rate to Gentamicin (with 66.7%, Cotrimoxazol and Nitrofurantoin (with 50% .The results of this study suggested that catheterization , especially long- term catheterization causes the rise of

  18. In vitro modulation of tumor necrosis factor α production in THP-1 cells by lactic acid bacteria isolated from healthy human infants.

    Science.gov (United States)

    Ladda, Boonyarut; Theparee, Talent; Chimchang, Juntana; Tanasupawat, Somboon; Taweechotipatr, Malai

    2015-06-01

    The human microbiota is a source of probiotics capable of modulating the host immune system. In this study, we collected fecal samples from 100 healthy infants and isolated lactic acid bacteria which were screened for immune modulating effects on tumor necrosis factor α (TNF-α) production. Cell-free culture supernatants from 26 isolates were able to decrease TNF-α production in vitro and three of the isolates were selected as candidate probiotics (MSMC39-1, MSMC39-3, MSMC57-1). These isolates were identified using 16S ribosomal DNA sequencing as Lactobacillus paracasei, Lactobacillus casei, and Weissella confusa respectively. All three isolates were acid tolerant and bile tolerant to pH 3.0 and 4% bile respectively. Preparations of cell-free culture supernatants were processed and tested, and revealed that cell-free culture supernatants of isolates L. paracasei MSMC39-1, L. casei MSMC39-3, and W. confusa MSMC57-1 decreased the production of TNF-α significantly and were heat resistant. Only L. paracasei MSMC39-1 supernatant was proteinase-K sensitive. The effects of viable bacteria, heat-killed bacteria, and sonicated bacteria were compared. The heat-killed preparations of isolate W. confusa MSMC57-1 decreased the production of TNF-α. Sonicated cell preparations did not significantly alter TNF-α production. For isolates L. paracasei MSMC39-1 and L. casei MSMC39-3, this suggests that a substance in the cell-free culture supernatant may be responsible for in vitro cytokine modulation.

  19. Modulation of cytokine release by differentiated CACO-2 cells in a compartmentalized coculture model with mononuclear leucocytes and nonpathogenic bacteria

    DEFF Research Database (Denmark)

    Parlesak, Alexandr; Haller, D.; Brinz, S.

    2004-01-01

    To further investigate the interaction between human mononuclear leucocytes [peripheral blood mononuclear cells (PBMC)] and enterocytes, the effect of a confluent layer of differentiated CACO-2 cells on cytokine kinetics during challenge with bacteria in a compartmentalized coculture model...... cells when leucocytes were stimulated directly with bacteria. This suppression was not paralleled by changes in the production of IL-10, IL-6 and transforming growth factor (TGF)-beta. When the bacteria were applied apically to the CACO-2 cell layer, the production of TNF-alpha, IL-12, IL-1beta, IL-8...... analysis revealed that IL-8 gene expression was equally induced in both CACO-2 and PBMC after apical stimulation with bacteria. Of note, bacteria-stimulated CACO-2 cells produced little or no cytokines in the absence of leucocytes, supporting the concept of leucocyte-epithelial cell cross...

  20. Exposure to ozone modulates human airway protease/antiprotease balance contributing to increased influenza A infection.

    Directory of Open Access Journals (Sweden)

    Matthew J Kesic

    Full Text Available Exposure to oxidant air pollution is associated with increased respiratory morbidities and susceptibility to infections. Ozone is a commonly encountered oxidant air pollutant, yet its effects on influenza infections in humans are not known. The greater Mexico City area was the primary site for the spring 2009 influenza A H1N1 pandemic, which also coincided with high levels of environmental ozone. Proteolytic cleavage of the viral membrane protein hemagglutinin (HA is essential for influenza virus infectivity. Recent studies suggest that HA cleavage might be cell-associated and facilitated by the type II transmembrane serine proteases (TTSPs human airway trypsin-like protease (HAT and transmembrane protease, serine 2 (TMPRSS2, whose activities are regulated by antiproteases, such as secretory leukocyte protease inhibitor (SLPI. Based on these observations, we sought to determine how acute exposure to ozone may modulate cellular protease/antiprotease expression and function, and to define their roles in a viral infection. We utilized our in vitro model of differentiated human nasal epithelial cells (NECs to determine the effects of ozone on influenza cleavage, entry, and replication. We show that ozone exposure disrupts the protease/antiprotease balance within the airway liquid. We also determined that functional forms of HAT, TMPRSS2, and SLPI are secreted from human airway epithelium, and acute exposure to ozone inversely alters their expression levels. We also show that addition of antioxidants significantly reduces virus replication through the induction of SLPI. In addition, we determined that ozone-induced cleavage of the viral HA protein is not cell-associated and that secreted endogenous proteases are sufficient to activate HA leading to a significant increase in viral replication. Our data indicate that pre-exposure to ozone disrupts the protease/antiprotease balance found in the human airway, leading to increased influenza susceptibility.

  1. CXCL14 displays antimicrobial activity against respiratory tract bacteria and contributes to clearance of Streptococcus pneumoniae pulmonary infection.

    Science.gov (United States)

    Dai, Chen; Basilico, Paola; Cremona, Tiziana Patrizia; Collins, Paul; Moser, Bernhard; Benarafa, Charaf; Wolf, Marlene

    2015-06-15

    CXCL14 is a chemokine with an atypical, yet highly conserved, primary structure characterized by a short N terminus and high sequence identity between human and mouse. Although it induces chemotaxis of monocytic cells at high concentrations, its physiological role in leukocyte trafficking remains elusive. In contrast, several studies have demonstrated that CXCL14 is a broad-spectrum antimicrobial peptide that is expressed abundantly and constitutively in epithelial tissues. In this study, we further explored the antimicrobial properties of CXCL14 against respiratory pathogens in vitro and in vivo. We found that CXCL14 potently killed Pseudomonas aeruginosa, Streptococcus mitis, and Streptococcus pneumoniae in a dose-dependent manner in part through membrane depolarization and rupture. By performing structure-activity studies, we found that the activity against Gram-negative bacteria was largely associated with the N-terminal peptide CXCL141-13. Interestingly, the central part of the molecule representing the β-sheet also maintained ∼62% killing activity and was sufficient to induce chemotaxis of THP-1 cells. The C-terminal α-helix of CXCL14 had neither antimicrobial nor chemotactic effect. To investigate a physiological function for CXCL14 in innate immunity in vivo, we infected CXCL14-deficient mice with lung pathogens and we found that CXCL14 contributed to enhanced clearance of Streptococcus pneumoniae, but not Pseudomonas aeruginosa. Our comprehensive studies reflect the complex bactericidal mechanisms of CXCL14, and we propose that different structural features are relevant for the killing of Gram-negative and Gram-positive bacteria. Taken together, our studies show that evolutionary-conserved features of CXCL14 are important for constitutive antimicrobial defenses against pneumonia.

  2. Antibiotic resistance of bacteria responsible of acute respiratory tract infections in children

    Directory of Open Access Journals (Sweden)

    Makhtar Camara

    2017-03-01

    Full Text Available Background and aims. Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis are the most common causative agents of acute respiratory tract infections (RTIs. The objective of this study was to assess their susceptibility to several antibiotics.Materials and methods. A total of 58 strains (16 S. pneumoniae, 19 H. influenzae and 23 M. catarrhalis were isolated from samples collected in two paediatric centres, and their susceptibility to commonly used antibiotics tested by E-test. Results. Among H. influenzae isolates, 10.5% were resistant to ampicillin (all β-lactamase-positive, and 88.9% were susceptible to cefaclor. High β-lactam resistance rates (penicillin: 31.3% and cephalosporins: 18.7 to 31.3% had been observed among S. pneumonia strains. Only 50% of isolates were susceptible to azithromycine. 91.3% of M. catarrhalis isolates β-lactamases producers were resistant to ampicillin while susceptible to the most tested antibiotics. Conclusions. Except M. catarrhalis β-lactamases producing strains, frequency of antibiotic resistance was mainly observed among S. pneumoniae, and to a lesser extent among H. influenzae clinical isolates, suggesting the need for continuous surveillance of antimicrobial resistance patterns in the management of RTIs.

  3. A Possible Link between Infection with Burkholderia Bacteria and Systemic Lupus Erythematosus Based on Epitope Mimicry

    Directory of Open Access Journals (Sweden)

    Wei Zhang

    2008-01-01

    Full Text Available We previously demonstrated that purified polyclonal and monoclonal anti-dsDNA antibodies bind a 15-mer peptide ASPVTARVLWKASHV in ELISA and Dot blot. This 15-mer peptide partial sequence ARVLWKASH shares similarity with burkholderia bacterial cytochrome B 561 partial sequence ARVLWRATH. In this study, we show that purified anti-dsDNA antibodies react with burkholderia fungorum bacterial cell lysates in Western blot. We used anti-dsDNA antibodies to make an anti-dsDNA antibodies affinity column and used this column to purify the burkholderia fungorum bacterial protein. Purified anti-dsDNA antibodies bind specifically to purified bacterial antigen and purified bacterial antigen blocked the anti-dsDNA antibodies binding to dsDNA antigen. Sera with anti-dsDNA antibodies bind specifically to purified bacterial antigen. We obtained protein partial sequence of RAGTDEGFG which is shared with burkholderia bacterial transcription regulator protein sequence. Sera with anti-dsDNA antibodies bind to RAGTDEGFG peptide better than control groups. These data support our hypothesis that the origin of anti-dsDNA antibodies in SLE may be associated with burkholderia bacterial infection.

  4. Association with Soil Bacteria Enhances p38-Dependent Infection Resistance in Caenorhabditis elegans

    Science.gov (United States)

    Montalvo-Katz, Sirena; Huang, Hao; Appel, Michael David; Berg, Maureen

    2013-01-01

    The importance of our inner microbial communities for proper immune responses against invading pathogens is now well accepted, but the mechanisms underlying this protection are largely unknown. In this study, we used Caenorhabditis elegans to investigate such mechanisms. Since very little is known about the microbes interacting with C. elegans in its natural environment, we began by taking the first steps to characterize the C. elegans microbiota. We established a natural-like environment in which initially germfree, wild-type larvae were grown on enriched soil. Bacterial members of the adult C. elegans microbiota were isolated by culture and identified using 16S rRNA gene sequencing. Using pure cultures of bacterial isolates as food, we identified two, Bacillus megaterium and Pseudomonas mendocina, that enhanced resistance to a subsequent infection with the Gram-negative pathogen Pseudomonas aeruginosa. Whereas protection by B. megaterium was linked to impaired egg laying, corresponding to a known trade-off between fecundity and resistance, the mechanism underlying protection conferred by P. mendocina depended on weak induction of immune genes regulated by the p38 MAPK pathway. Disruption of the p38 ortholog, pmk-1, abolished protection. P. mendocina enhanced resistance to P. aeruginosa but not to the Gram-positive pathogen Enterococcus faecalis. Furthermore, protection from P. aeruginosa was similarly induced by a P. aeruginosa gacA mutant with attenuated virulence but not by a different C. elegans-associated Pseudomonas sp. isolate. Our results support a pivotal role for the conserved p38 pathway in microbiota-initiated immune protection and suggest that similarity between microbiota members and pathogens may play a role in such protection. PMID:23230286

  5. [DISTRIBUTION OF BACTERIA OF THE KLEBSIELLA STRAIN IN WATER OBJECTS AND THEIR VALUE IN DEVELOPING OF THE WATER CAUSED ACUTE INTESTINAL INFECTIONS].

    Science.gov (United States)

    Rakhmanin, Yu A; Ivanova, L V; Artyomova, T Z; Gipp, E K; Zagaynova, A V; Maksimkina, T N; Krasnyak, A V; Zhuravlev, P V; Aleshnya, V V; Panasovets, O P

    2016-01-01

    The wide circulation of Klebsiella bacteria in water ofwater objects of different climatic zones of Russia and various function is established. So bacteria of the Klebsiella strain are in superficial sources of the centralized water supply depending on extent of their biological and chemical pollution; underground waters at the unprotected water-bearing horizons; in drinking water at insufficiently effective system of its cleaning and disinfecting. Klebsiella circulating in water was shown to keep properties of pathogenicity and a virulence, possess resistance both to modern preparations and disinfecting agents (chlorine, an ultraviolet to radiation). Bacteria of the Klebsiella strain have high penetration in the water-bearing horizons. At strains of Klebsiella there is allocated considerable pathogenic potential (adhesive, invasive, phosphatase, lecithinase, DNA-ase, hemolytic activity) and genetic markers of pathogenicity of cnf-1. The etiologic role of bacteria of Klebsiella and an infecting (100, COE/dm3) dose emergence of acute intestinal infections (AII) is established. Detection of Klebsiella in water objects and especially in water of drinking appointment, in the absence of total coliform bacteria (TCB) contributes to the epidemic danger of water use.

  6. Ultrastructural characterization and multilocus sequence analysis (MLSA) of 'Candidatus Rickettsiella isopodorum', a new lineage of intracellular bacteria infecting woodlice (Crustacea: Isopoda).

    Science.gov (United States)

    Kleespies, Regina G; Federici, Brian A; Leclerque, Andreas

    2014-07-01

    The taxonomic genus Rickettsiella (Gammaproteobacteria; Legionellales) comprises intracellular bacteria associated with a wide range of arthropods including insects, arachnids and crustaceans. The present study provides ultrastructural together with genetic evidence for a Rickettsiella bacterium in the common rough woodlouse, Porcellio scaber (Isopoda, Porcellionidae), occurring in Germany, and shows that this bacterium is very closely related to one of the same genus occurring in California that infects the pill bug, Armadillidium vulgare (Isopoda, Armadillidiidae). Both bacterial isolates displayed the ultrastructural features described previously for crustacean-associated bacteria of the genus Rickettsiella, including the absence of well-defined associated protein crystals; occurrence of the latter is a typical characteristic of infection by this type of bacteria in insects, but has not been reported in crustaceans. A molecular systematic approach combining multilocus sequence analysis (MLSA) with likelihood-based significance testing demonstrated that despite their distant geographic origins, both bacteria form a tight sub-clade within the genus Rickettsiella. In the 16S rRNA gene trees, this sub-clade includes other bacterial sequences from woodlice. Moreover, the bacterial specimens from P. scaber and A. vulgare are found genetically or morphologically different from each of the four currently recognized Rickettsiella species. Therefore, the designation 'Candidatus Rickettsiella isopodorum' is introduced for this new lineage of isopod-associated Rickettsiella bacteria.

  7. Isolation and identification of pathogenic bacteria from genital tract of the Arabian mares affected with genital tract infection and antimicrobial sensitivity

    Directory of Open Access Journals (Sweden)

    H. F. AL-Abidy

    2010-01-01

    Full Text Available This study was conducted for isolation and identification of the pathogenic bacteria presented in the genital tract infectionof the Arabian mares, and shows the anti microbial sensitivity. The study included 75 samples taken from infected maressuffering from genital tract infection diagnosed on the basis of case history and clinical signs which included bloody purulentdischarge ranched from yellow to green in colure, fetid oder with congested and oedematous vagina and from some abortioncases, and from mares suffered from tetanus disease symptoms during the period between October 2007 to April 2008 in studfarms breeding mares in Mosul. The samples were collected by swabs from the clitoris, clitorial fossa and the vagina. Isolationof bacteria was performed using aerobic and anaerobic culture techniques. Results of the present study showed a total ofisolation 75% from all samples taken with a high percentage isolation of Clostridium tetani (16.6%, followed by Archanobacterium pyogenes (10.6%, and Pseudomonas aeruginosa (8%, (6.7% for each Enterobacter aerogenes, Klebsiellapneumonia, Streptococcus dysagalactiae subsp equisimilis, and (5.3% for each bacteria Actinobacillus equilli, Streptococcuszooepidemicus, Staphylococcus aureus, then Proteus vulgaris (2.6%, and Escherichia coli (1.3%. The most bacterial isolateswere resistant to amoxicillin (100%, ampicillin (90.9 %, and erythromycin (65.9%, while the most isolates were sensitive tokanamycin (70.4%. It could be concluted that the most important bacteria causing genital tract infection of mares could beClostridium tetani and Archanobacterium pyogenes, Pseudomonas aeruginosa. The most bacterial isolates were resistant toamoxicillin, ampicillin and erythromycin.

  8. Infection with diverse immune-modulating poxviruses elicits different compositional shifts in the mouse gut microbiome

    Science.gov (United States)

    Hernáez, Bruno; Rastrojo, Alberto; Alcamí, Antonio

    2017-01-01

    It is often not possible to demonstrate causality within the context of gut microbiota dysbiosis-linked diseases. Thus, we need a better understanding of the mechanisms whereby an altered host immunophysiology shapes its resident microbiota. In this regard, immune-modulating poxvirus strains and mutants could differentially alter gut mucosal immunity in the context of a natural immune response, providing a controlled natural in vivo setting to deepen our understanding of the immune determinants of microbiome composition. This study represents a proof-of-concept that the use of an existing collection of different immune-modulating poxviruses may represent an innovative tool in gut microbiome research. To this end, 16S rRNA amplicon sequencing and RNAseq transcriptome profiling were employed as proxies for microbiota composition and gut immunophysiological status in the analysis of caecal samples from control mice and mice infected with various poxvirus types. Our results show that different poxvirus species and mutants elicit different shifts in the mice mucosa-associated microbiota and, in some instances, significant concomitant shifts in gut transcriptome profiles, thus providing an initial validation to the proposed model. PMID:28282449

  9. A comparative evaluation of antibacterial effectiveness of sodium hypochlorite, Curcuma longa, and Camellia sinensis as irrigating solutions on isolated anaerobic bacteria from infected primary teeth

    Directory of Open Access Journals (Sweden)

    Neha Shashikant Dhariwal

    2016-01-01

    Full Text Available Context: In endodontics, most of the commercial intra-canal medicaments have cytotoxic reactions and because of their inability to eliminate bacteria from dentinal tubules, recent medicine has turned its attention to the usage of biologic medication prepared from natural plants. The literature to testify the efficacy of natural alternatives in primary teeth is meagre and its effects as irrigating solutions need to be evaluated. Aim: To evaluate the antibacterial effectiveness of sodium hypochlorite, ethanolic extracts of Curcuma longa (turmeric and Camellia sinensis (green tea as irrigating solutions against the anaerobic bacteria isolated from the root canals of infected primary teeth. Materials and Methods: Thirty patients were selected based on the selected inclusion and exclusion criteria. Preoperative radiographs were taken. Rubber dam isolation and working length estimation were done, following which thirty samples were taken from the root canals of infected primary teeth using sterile absorbent paper points and transferred to tubes containing thioglycolate transport medium. The bacteria were then isolated using standard microbiological protocols and were subjected to antibiotic sensitivity testing using the three test irrigants. Statistical Analysis: SPSS 18 software using Chi-square test was used for statistical analysis. Results: The most commonly isolated bacteria included Porphyromonas sp., Bacteroides fragilis, Peptostreptococcus, and Staphylococcus aureus. Sodium hypochlorite and C. longa (turmeric showed good antibacterial effect and were effective against most of the isolated bacteria. There was statistically significant difference in the antibacterial effect among the three tested groups (P < 0.001. The least effective was C. sinensis (green tea. Conclusion: The infected primary teeth almost always present with a polymicrobial structure with a wide variety of anaerobic bacteria. The chemo-mechanical preparation plays an important

  10. Alternative fluorescent labeling strategies for characterizing gram-positive pathogenic bacteria: Flow cytometry supported counting, sorting, and proteome analysis of Staphylococcus aureus retrieved from infected host cells.

    Science.gov (United States)

    Hildebrandt, Petra; Surmann, Kristin; Salazar, Manuela Gesell; Normann, Nicole; Völker, Uwe; Schmidt, Frank

    2016-10-01

    Staphylococcus aureus is a Gram-positive opportunistic pathogen that is able to cause a broad range of infectious diseases in humans. Furthermore, S. aureus is able to survive inside nonprofessional phagocytic host cell which serve as a niche for the pathogen to hide from the immune system and antibiotics therapies. Modern OMICs technologies provide valuable tools to investigate host-pathogen interactions upon internalization. However, these experiments are often hampered by limited capabilities to retrieve bacteria from such an experimental setting. Thus, the aim of this study was to develop a labeling strategy allowing fast detection and quantitation of S. aureus in cell lysates or infected cell lines by flow cytometry for subsequent proteome analyses. Therefore, S. aureus cells were labeled with the DNA stain SYTO(®) 9, or Vancomycin BODIPY(®) FL (VMB), a glycopeptide antibiotic binding to most Gram-positive bacteria which was conjugated to a fluorescent dye. Staining of S. aureus HG001 with SYTO 9 allowed counting of bacteria from pure cultures but not in cell lysates from infection experiments. In contrast, with VMB it was feasible to stain bacteria from pure cultures as well as from samples of infection experiments. VMB can also be applied for histocytochemistry analysis of formaldehyde fixed cell layers grown on coverslips. Proteome analyses of S. aureus labeled with VMB revealed that the labeling procedure provoked only minor changes on proteome level and allowed cell sorting and analysis of S. aureus from infection settings with sensitivity similar to continuous gfp expression. Furthermore, VMB labeling allowed precise counting of internalized bacteria and can be employed for downstream analyses, e.g., proteomics, of strains not easily amendable to genetic manipulation such as clinical isolates. © 2016 International Society for Advancement of Cytometry.

  11. Activation of unfolded protein response and autophagy during HCV infection modulates innate immune response.

    Science.gov (United States)

    Estrabaud, Emilie; De Muynck, Simon; Asselah, Tarik

    2011-11-01

    Autophagy, a process for catabolizing cytoplasmic components, has been implicated in the modulation of interactions between RNA viruses and their host. However, the mechanism underlying the functional role of autophagy in the viral life cycle still remains unclear. Hepatitis C virus (HCV) is a single-stranded, positive-sense, membrane-enveloped RNA virus that can cause chronic liver disease. Here we report that HCV induces the unfolded protein response (UPR), which in turn activates the autophagic pathway to promote HCV RNA replication in human hepatoma cells. Further analysis revealed that the entire autophagic process through to complete autolysosome maturation was required to promote HCV RNA replication and that it did so by suppressing innate antiviral immunity. Gene silencing or activation of the UPR-autophagy pathway activated or repressed, respectively, IFN-β activation mediated by an HCV-derived pathogen-associated molecular pattern (PAMP). Similar results were achieved with a PAMP derived from Dengue virus (DEV), indicating that HCV and DEV may both exploit the UPR-autophagy pathway to escape the innate immune response. Taken together, these results not only define the physiological significance of HCV-induced autophagy, but also shed light on the knowledge of host cellular responses upon HCV infection as well as on exploration of therapeutic targets for controlling HCV infection.

  12. Analysis on the infected bacteria spectrum and drug-resistant bacteria spectrum of the diabetes moist gangrene%糖尿病湿性坏疽感染菌谱及耐药菌谱分析

    Institute of Scientific and Technical Information of China (English)

    范洪; 王元松

    2012-01-01

    目的 了解糖尿病湿性坏疽感染菌谱和耐药菌谱特点,使临床选择抗菌药物治疗更有针对性.方法 取糖尿病湿性坏疽分泌物进行需氧菌、真菌培养和药敏试验以及厌氧菌培养.结果 357例患者中,细菌培养结果阳性率为100%,共培养出469株细菌,其中感染率革兰阳性菌(G+)45.4%、革兰阴性菌(G-) 26.0%、厌氧菌23.7%、真菌4.9%,细菌混合感染率为29.9%. G+菌中葡萄菌属有5种药物的耐药菌株大于50%、肠球菌属有11种药物的耐药菌株大于50%,G-菌中肠杆菌科有3种药物的耐药菌株大于50%、不动杆菌属和假单胞菌属有8种药物的耐药菌株大于50%,真菌中光滑念珠菌有3种药物的耐药菌株大于50%,其余菌属药物的耐药菌株均小于50%.结论 糖尿病湿性坏疽感染菌谱特点是革兰阳性菌>革兰阴性菌、厌氧菌>真菌,混合感染较为突出.G+菌感染中的肠球菌属、G-菌感染中的不动杆菌属和假单胞菌属、真菌感染中的光滑念珠菌耐药性较高.%OBJECTIVE To comprehend the characteristic of diabetes moist gangrene infection and drug-resistant bacteria spectrum, make targeted clinical antibiotics choice. METHODS Diabetes moist gangrene secretions were extracted.Aerobic bacteria, fungus and anaerobe cultivation, and drug sensitivity text were performed to them. RESULTS In 357 cases of patients, we cultivated 469 strains of bacteria (gram-positive bacilli 45.4%, gram-negative bacilli 26.0%, anaerobic 23.7%, fungi 4.9% and mixed infection 29.9%), and the positive rate of bacterial culture was 100%. Five drug-resistant strains of the staphylococcus were more than 50% , and 11 strains of enterococcus genera, 11 trains of enterobacteriaceae, 8 strains of acinetobacter and pseudomonas and 3 strains of smooth Candida of fungi showed durg-resistance above 50%. CONCLUSION The characteristic of infected bacteria spectrum of the diabetes moist gangrene is that

  13. Modulation of pro- and anti-inflammatory cytokines in active and latent tuberculosis by coexistent Strongyloides stercoralis infection.

    Science.gov (United States)

    George, Parakkal Jovvian; Pavan Kumar, Nathella; Jaganathan, Jeeva; Dolla, Chandrakumar; Kumaran, Paul; Nair, Dina; Banurekha, Vaithilingam V; Shen, Kui; Nutman, Thomas B; Babu, Subash

    2015-12-01

    Helminth infections are known to induce modulation of both innate and adaptive immune responses in active and latent tuberculosis (TB). However, the role of helminth infections in modulating systemic cytokine responses in active and latent tuberculosis (LTB) is not known. To define the systemic cytokine levels in helminth-TB coinfection, we measured the circulating plasma levels of Type 1, Type 2, Type 17, other pro-inflammatory and regulatory cytokines in individuals with active TB (ATB) with or without coexistent Strongyloides stercoralis (Ss) infection by multiplex ELISA. Similarly, we also measured the same cytokine levels in individuals with LTB with or without concomitant Ss infection in a cross-sectional study. Our data reveal that individuals with ATB or LTB and coexistent Ss infection have significantly lower levels of Type 1 (IFNγ, TNFα and IL-2) and Type 17 (IL-17A and IL-17F) cytokines compared to those without Ss infection. In contrast, those with ATB and LTB with Ss infection have significantly higher levels of the regulatory cytokines (IL-10 and TGFβ), and those with LTB and Ss infection also have significantly higher levels of Type 2 cytokines (IL-4, IL-5 and IL-13) as well. Finally, those with LTB (but not ATB) exhibit significantly lower levels of other pro-inflammatory cytokines (IFNα, IFNβ, IL-6, IL-12 and GM-CSF). Our data therefore reveal a profound effect of Ss infection on the systemic cytokine responses in ATB and LTB and indicate that coincident helminth infections might influence pathogenesis of TB infection and disease.

  14. Enhancement of the immune response against Salmonella infection of mice by heat-killed multispecies combinations of lactic acid bacteria.

    Science.gov (United States)

    Chen, Chih-Yuan; Tsen, Hau-Yang; Lin, Chun-Li; Lin, Chien-Ku; Chuang, Li-Tsen; Chen, Chin-Shuh; Chiang, Yu-Cheng

    2013-11-01

    Heat-killed lactic acid bacteria (LAB) has advantages over live LAB in that it has a long shelf-life and is therefore easy to store and transport. From four LAB strains selected by immunomodulatory activity and adherent properties, we prepared the heat-killed multispecies combination of LAB (MLAB) and the cell walls from MLAB under two conditions (100 °C for 30 min and 121 °C for 15 min). Different effects on the adherent properties of these four LAB strains were observed, depending on the heating conditions. With mouse macrophage cells, the two heat-killed MLABs (HMLABs) showed significantly higher induction activities on the production of interleukin 12 (IL-12) than their individual strains did. Heat-killed MLABs and cell-wall preparations were able to reduce the Salmonella invasion of Caco-2 and mouse macrophage cells. Feeding mice with HMLAB could inhibit the Salmonella invasion of mice significantly. For these mice, the expression level of pro-inflammatory cytokines, such as TNF-α and IL-6, in mouse serum was reduced while that of the anti-inflammatory cytokine, i.e. IL-10, was enhanced. The HMLABs developed in this study showed higher protective effect against Salmonella invasion either of Caco-2 cells or of mice, relative to the heat-killed lactobacilli, which consisted of Lactobacillus acidophilus strains selected at random. In conclusion, the HMLABs were potentially useful for the protection of mice against Salmonella infection and the induced inflammation.

  15. Pedilanthus tithymaloides Inhibits HSV Infection by Modulating NF-κB Signaling.

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    Durbadal Ojha

    Full Text Available Pedilanthus tithymaloides (PT, a widely used ethnomedicinal plant, has been employed to treat a number of skin conditions. To extend its utility and to fully exploit its medicinal potential, we have evaluated the in vitro antiviral activity of a methanolic extract of PT leaves and its isolated compounds against Herpes Simplex Virus type 2 (HSV-2. Bioactivity-guided studies revealed that the extract and one of its constituents, luteolin, had potent antiviral activity against wild-type and clinical isolates of HSV-2 (EC50 48.5-52.6 and 22.4-27.5 μg/ml, respectively, with nearly complete inhibition at 86.5-101.8 and 40.2-49.6 μg/ml, respectively. The inhibitory effect was significant (p<0.001 when the drug was added 2 h prior to infection, and was effective up to 4 h post-infection. As viral replication requires NF-κB activation, we examined whether the observed extract-induced inhibition of HSV-2 was related to NF-κB inhibition. Interestingly, we observed that treatment of HSV-2-infected cells with extract or luteolin suppressed NF-κB activation. Although NF-κB, JNK and MAPK activation was compromised during HSV replication, neither the extract nor luteolin affected HSV-2-induced JNK1/2 and MAPK activation. Moreover, the PT leaf extract and luteolin potently down-regulated the expression of tumor necrosis factor (TNF-α, Interleukin (IL-1β, IL-6, NO and iNOS and the production of gamma interferon (IFN-γ, which are directly involved in controlling the NF-κB signaling pathway. Thus, our results indicate that both PT leaf extract and luteolin modulate the NF-κB signaling pathway, resulting in the inhibition of HSV-2 replication.

  16. In utero infection with PRRS virus modulates cellular functions of blood monocytes and alveolar lung macrophages in piglets

    DEFF Research Database (Denmark)

    Riber, Ulla; Nielsen, Jens; Lind, Peter

    2004-01-01

    . Phagocytic capacity of blood monocytes against Salmonella bacteria was investigated by flow cytometry. Oxidative burst in blood monocytes and in alveolar lung macrophages was investigated by luminol- and lucigenin-enhanced chemiluminescence, respectively. Decreased phagocytosis against Salmonella was found...... burst capacity of alveolar lung macrophages was decreased, especially in 2- and 4-week-old piglets, compared to age-matched control piglets. The present results indicate that in utero infection with PRRSV inhibits phagocytosis against Salmonella in blood monocytes as well as the oxidative burst capacity...... in blood monocytes from 4- and 6-week-old infected piglets compared to controls. In contrast, 2-week-old infected piglets showed phagocytic responses comparable to age matched control piglets. While oxidative burst capacity was increased in blood (PBMC) from in utero PRRSV infected piglets, the oxidative...

  17. Urease-positive bacteria in the stomach induce a false-positive reaction in a urea breath test for diagnosis of Helicobacter pylori infection.

    Science.gov (United States)

    Osaki, Takako; Mabe, Katsuhiro; Hanawa, Tomoko; Kamiya, Shigeru

    2008-07-01

    This study investigated the influence of urease-positive non-Helicobacter pylori bacteria on the results of a urea breath test (UBT) to evaluate the diagnostic utility of a UBT using film-coated [(13)C]urea tablets. The UBT was performed in 102 patients treated with a proton pump inhibitor and antibiotics for the eradication of H. pylori. Urease-producing bacteria other than H. pylori were isolated and identified from the oral cavity and stomach. In 4/102 patients, the UBT gave false-positive results. These false-positive results were found to be caused by the presence of urease-positive bacteria in the oral cavity and stomach. Five bacterial species with urease activity (Proteus mirabilis, Citrobacter freundii, Klebsiella pneumoniae, Enterobacter cloacae and Staphylococcus aureus) were subsequently isolated from the oral cavity and/or stomach. As there was no correlation between the in vitro urease activity of urease-positive non-H. pylori bacteria and the UBT value, and all of the patients with a false-positive UBT result were suffering from atrophic gastritis, it is possible that the false-positive results in the UBT were a result of colonization of urease-positive bacteria and gastric hypochlorhydric conditions. Thus, for the diagnosis of H. pylori infection using a UBT, the influence of stomach bacteria must be considered when interpreting the results.

  18. Evaluation of the in vitro growth of urinary tract infection-causing gram-negative and gram-positive bacteria in a proposed synthetic human urine (SHU) medium.

    Science.gov (United States)

    Ipe, Deepak S; Ulett, Glen C

    2016-08-01

    Bacteriuria is a hallmark of urinary tract infection (UTI) and asymptomatic bacteriuria (ABU), which are among the most frequent infections in humans. A variety of gram-negative and gram-positive bacteria are associated with these infections but Escherichia coli contributes up to 80% of cases. Multiple bacterial species including E. coli can grow in human urine as a means to maintain colonization during infections. In vitro bacteriuria studies aimed at modeling microbial growth in urine have utilized various compositions of synthetic human urine (SHU) and a Composite SHU formulation was recently proposed. In this study, we sought to validate the recently proposed Composite SHU as a medium that supports the growth of several bacterial species that are known to grow in normal human urine and/or artificial urine. Comparative growth assays of gram-negative and gram-positive bacteria E. coli, Pseudomonas aeruginosa, Proteus mirabilis, Streptococcus agalactiae, Staphylococcus saprophyticus and Enterococcus faecalis were undertaken using viable bacterial count and optical density measurements over a 48h culture period. Three different SHU formulations were tested in various culture vessels, shaking conditions and volumes and showed that Composite SHU can support the robust growth of gram-negative bacteria but requires supplementation with 0.2% yeast extract to support the growth of gram-positive bacteria. Experiments are also presented that show an unexpected but major influence of P. mirabilis towards the ability to measure bacterial growth in generally accepted multiwell assays using absorbance readings, predicted to have a basis in the release of volatile organic compound(s) from P. mirabilis during growth in Composite SHU medium. This study represents an essential methodological validation of a more chemically defined type of synthetic urine that can be applied to study mechanisms of bacteriuria and we conclude will offer a useful in vitro model to investigate the

  19. The Comparison of Antagonistic Effects of Normal Vaginal Lactobacilli and Some Commonly used Antibiotics on Isolated Bacteria of Uterine Infections in Dairy Cows

    Directory of Open Access Journals (Sweden)

    Pouya Dini

    2012-12-01

    Full Text Available Uterine infections are one of the major reproductive complications during postpartum. The antibiotics and antiseptic agents used in the treatment of postpartum infections have residues in food, induce bacterial resistance, increase the financial costs and cause failure in defense mechanism of host. On the other hand, nowadays the administration of probiotics is considered as an alternative method for the prevention and treatment of infections. Therefore, preventive treatment with probiotic product could decrease the usage of antibiotic and bring advantages in dairy farm systems. The objective of this study was screening of the antagonistic properties of isolated vaginal Lactic Acid Bacteria (LAB against the most prevalent bacteria in uterine infections in order to investigate their probiotic potentials as an alternative approach for prevention of uterine infections. LAB were isolated from sampling of cranial part of vagina during estrus phase and luteal phase of Holstein dairy cattle and pathogens bacteria were isolated from merits and endometritis specimens which referred to our veterinary laboratory. The antagonistic activity of isolated LAB against uterine pathogens was tested by Agar spot test. Antibiotic susceptibilities of pathogenic strains to commonly used antibiotics were investigated by using disc diffusion method. Inhibition zones around both the probiotic spots and the antibiotic discs were classified to weak, moderate and strong categories and their antagonistic efficacies were compared. Isolated LAB had antagonistic effects against all the pathogenic strains including both gram negative and gram positive, Arcanobacterium pyogenes and Pseudomonas aeroginosa were the most sensitive bacteria (with 12.60 and 14 mm an average inhibition zone, respectively. LAB had the least antagonistic effects on Clostridium perfringens (3.6 mm of an average inhibition zone. Comparing the antagonistic efficacies, the percentages of overall

  20. Dengue virus infection of the Aedes aegypti salivary gland and chemosensory apparatus induces genes that modulate infection and blood-feeding behavior.

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    Shuzhen Sim

    Full Text Available The female Aedes aegypti salivary gland plays a pivotal role in bloodmeal acquisition and reproduction, and thereby dengue virus (DENV transmission. It produces numerous immune factors, as well as immune-modulatory, vasodilatory, and anti-coagulant molecules that facilitate blood-feeding. To assess the impact of DENV infection on salivary gland physiology and function, we performed a comparative genome-wide microarray analysis of the naïve and DENV infection-responsive A. aegypti salivary gland transcriptomes. DENV infection resulted in the regulation of 147 transcripts that represented a variety of functional classes, including several that are essential for virus transmission, such as immunity, blood-feeding, and host-seeking. RNAi-mediated gene silencing of three DENV infection-responsive genes--a cathepsin B, a putative cystatin, and a hypothetical ankyrin repeat-containing protein--significantly modulated DENV replication in the salivary gland. Furthermore, silencing of two DENV infection-responsive odorant-binding protein genes (OBPs resulted in an overall compromise in blood acquisition from a single host by increasing the time for initiation of probing and the probing time before a successful bloodmeal. We also show that DENV established an extensive infection in the mosquito's main olfactory organs, the antennae, which resulted in changes of the transcript abundance of key host-seeking genes. DENV infection, however, did not significantly impact probing initiation or probing times in our laboratory infection system. Here we show for the first time that the mosquito salivary gland mounts responses to suppress DENV which, in turn, modulates the expression of chemosensory-related genes that regulate feeding behavior. These reciprocal interactions may have the potential to affect DENV transmission between humans.

  1. Plasmacytoid dendritic cell-derived IFNα modulates Th17 differentiation during early Bordetella pertussis infection in mice.

    Science.gov (United States)

    Wu, V; Smith, A A; You, H; Nguyen, T A; Ferguson, R; Taylor, M; Park, J E; Llontop, P; Youngman, K R; Abramson, T

    2016-05-01

    Whooping cough is a highly contagious respiratory disease caused by Bordetella pertussis (B. pertussis). T helper 17 (Th17) cells have a central role in the resolution of the infection. Emerging studies document that type I interferons (IFNs) suppress Th17 differentiation and interleukin (IL)-17 responses in models of infection and chronic inflammation. As plasmacytoid dendritic cells (pDCs) are a major source of type I IFNs, we hypothesize that during B. pertussis infection in mice, pDC-derived IFNα inhibits a rapid increase in Th17 cells. We found that IFNα-secreting pDCs appear in the lungs during the early stages of infection, while a robust rise of Th17 cells in the lungs is detected at 15 days post-infection or later. The presence of IFNα led to reduced Th17 differentiation and proliferation in vitro. Furthermore, in vivo blocking of IFNα produced by pDCs during infection with B. pertussis infection resulted in early increase of Th17 frequency, inflammation, and reduced bacterial loads in the airways of infected mice. Taken together, the experiments reported here describe an inhibitory role for pDCs and pDC-derived IFNα in modulating Th17 responses during the early stages of B. pertussis infection, which may explain the prolonged nature of whooping cough.

  2. A new approach for the discovery of antibiotics by targeting non-multiplying bacteria: a novel topical antibiotic for staphylococcal infections.

    Directory of Open Access Journals (Sweden)

    Yanmin Hu

    Full Text Available In a clinical infection, multiplying and non-multiplying bacteria co-exist. Antibiotics kill multiplying bacteria, but they are very inefficient at killing non-multipliers which leads to slow or partial death of the total target population of microbes in an infected tissue. This prolongs the duration of therapy, increases the emergence of resistance and so contributes to the short life span of antibiotics after they reach the market. Targeting non-multiplying bacteria from the onset of an antibiotic development program is a new concept. This paper describes the proof of principle for this concept, which has resulted in the development of the first antibiotic using this approach. The antibiotic, called HT61, is a small quinolone-derived compound with a molecular mass of about 400 Daltons, and is active against non-multiplying bacteria, including methicillin sensitive and resistant, as well as Panton-Valentine leukocidin-carrying Staphylococcus aureus. It also kills mupirocin resistant MRSA. The mechanism of action of the drug is depolarisation of the cell membrane and destruction of the cell wall. The speed of kill is within two hours. In comparison to the conventional antibiotics, HT61 kills non-multiplying cells more effectively, 6 logs versus less than one log for major marketed antibiotics. HT61 kills methicillin sensitive and resistant S. aureus in the murine skin bacterial colonization and infection models. No resistant phenotype was produced during 50 serial cultures over a one year period. The antibiotic caused no adverse affects after application to the skin of minipigs. Targeting non-multiplying bacteria using this method should be able to yield many new classes of antibiotic. These antibiotics may be able to reduce the rate of emergence of resistance, shorten the duration of therapy, and reduce relapse rates.

  3. A new approach for the discovery of antibiotics by targeting non-multiplying bacteria: a novel topical antibiotic for staphylococcal infections.

    Science.gov (United States)

    Hu, Yanmin; Shamaei-Tousi, Alireza; Liu, Yingjun; Coates, Anthony

    2010-07-27

    In a clinical infection, multiplying and non-multiplying bacteria co-exist. Antibiotics kill multiplying bacteria, but they are very inefficient at killing non-multipliers which leads to slow or partial death of the total target population of microbes in an infected tissue. This prolongs the duration of therapy, increases the emergence of resistance and so contributes to the short life span of antibiotics after they reach the market. Targeting non-multiplying bacteria from the onset of an antibiotic development program is a new concept. This paper describes the proof of principle for this concept, which has resulted in the development of the first antibiotic using this approach. The antibiotic, called HT61, is a small quinolone-derived compound with a molecular mass of about 400 Daltons, and is active against non-multiplying bacteria, including methicillin sensitive and resistant, as well as Panton-Valentine leukocidin-carrying Staphylococcus aureus. It also kills mupirocin resistant MRSA. The mechanism of action of the drug is depolarisation of the cell membrane and destruction of the cell wall. The speed of kill is within two hours. In comparison to the conventional antibiotics, HT61 kills non-multiplying cells more effectively, 6 logs versus less than one log for major marketed antibiotics. HT61 kills methicillin sensitive and resistant S. aureus in the murine skin bacterial colonization and infection models. No resistant phenotype was produced during 50 serial cultures over a one year period. The antibiotic caused no adverse affects after application to the skin of minipigs. Targeting non-multiplying bacteria using this method should be able to yield many new classes of antibiotic. These antibiotics may be able to reduce the rate of emergence of resistance, shorten the duration of therapy, and reduce relapse rates.

  4. Antibiofilm and Antimicrobial Efficacy of DispersinB (registered trademark)-KSL-W Peptide-Based Wound Gel Against Chronic Wound Infection Associated Bacteria

    Science.gov (United States)

    2014-01-21

    16, 21–23]. The DispersinB-KSL-W wound gel exhibited a sus- tained antibacterial activity over a period of 72 h against all the chronic wound...Antibiofilm and Antimicrobial Efficacy of DispersinB-KSL-W Peptide-Based Wound Gel Against Chronic Wound Infection Associated Bacteria Purushottam V...and Acinetobacter baumannii. In addition, the wound gel formulation comprising DispersinB, KSL-W peptide, and a gelling agent Pluronic F-127 showed a

  5. Detection of bacteria bearing resistant biofilm forms, by using the universal and specific PCR is still unhelpful in the diagnosis of periprosthetic joint infections(PJI.

    Directory of Open Access Journals (Sweden)

    Batool eZegaer

    2014-09-01

    Full Text Available Intraoperative conventional bacteriological cultures were compared with different polymerase chain reaction (PCR methods in patients with total joint arthroplasties. The isolated bacteria were investigated for biofilm formation, and the biofilm forming strains, in their planktonic and biofilm forms, were further tested for their antimicrobial resistance against several clinically important antimicrobials. Forty four bone and joint samples were included and classified as infected or non-infected according to standard criteria for periprosthetic hip and knee infections. For the bacteriological diagnosis, conventional culture, two types of universal PCR and species specific PCR for three selected pathogens (S. aureus, S. epidermidis, P. aeruginosa were applied. Biofilm formation determination was performed by the tissue culture plate method. Antimicrobial susceptibility of the planktonic bacteria was performed by the minimal inhibitory concentration determination and, of the biofilm forms, by the minimal inhibitory concentration for bacterial regrowth from the biofilm. Twenty samples were culture positive, with S. epidermidis, S. aureus or P. aeruginosa. All PCR methods were very ineffective in detecting only one pathogen. All isolates were biofilm positive and their biofilm forms, were highly resistant. In this study, compared to PCR, culture remains the gold standard. The biofilm formation by the causative bacteria and the concomitant manifold increased antimicrobial resistance may explain the clinical failure of treatment in some cases and should be considered in the future for therapeutic planning.

  6. Diminazene aceturate (Berenil modulates the host cellular and inflammatory responses to Trypanosoma congolense infection.

    Directory of Open Access Journals (Sweden)

    Shiby Kuriakose

    Full Text Available BACKGROUND: Trypanosoma congolense are extracellular and intravascular blood parasites that cause debilitating acute or chronic disease in cattle and other domestic animals. Diminazene aceturate (Berenil has been widely used as a chemotherapeutic agent for trypanosomiasis in livestock since 1955. As in livestock, treatment of infected highly susceptible BALB/c mice with Berenil leads to rapid control of parasitemia and survival from an otherwise lethal infection. The molecular and biochemical mechanisms of action of Berenil are still not very well defined and its effect on the host immune system has remained relatively unstudied. Here, we investigated whether Berenil has, in addition to its trypanolytic effect, a modulatory effect on the host immune response to Trypanosoma congolense. METHODOLOGY/PRINCIPAL FINDINGS: BALB/c and C57BL/6 mice were infected intraperitoneally with T. congolense, treated with Berenil and the expression of CD25 and FoxP3 on splenic cells was assessed directly ex vivo. In addition, serum levels and spontaneous and LPS-induced production of pro-inflammatory cytokines by splenic and hepatic CD11b⁺ cells were determined by ELISA. Berenil treatment significantly reduced the percentages of CD25⁺ cells, a concomitant reduction in the percentage of regulatory (CD4⁺Foxp3⁺ T cells and a striking reduction in serum levels of disease exacerbating pro-inflammatory cytokines including IL-6, IL-12, TNF and IFN-γ. Furthermore, Berenil treatment significantly suppressed spontaneous and LPS-induced production of inflammatory cytokines by splenic and liver macrophages and significantly ameliorated LPS-induced septic shock and the associated cytokine storm. CONCLUSIONS/SIGNIFICANCE: Collectively, these results provide evidence that in addition to its direct trypanolytic effect, Berenil also modulates the host immune response to the parasite in a manner that dampen excessive immune activation and production of pathology

  7. SURVAILANCE REPORT ON INFECTION OF HOSPITAL DRUG- RESISTANT BACTERIA%医院耐药菌感染监测报告

    Institute of Scientific and Technical Information of China (English)

    徐遂转; 魏春玲

    2011-01-01

    Objective To know the epidemic status of drug - resistant bacteria, and to make control measurements of drug - resistant bacteria infection. Methods Retrospective investigation and bacteria detection technology were used to investigate drug - resistant bacteria infection from 2008 to 2010. Results S31 strains of pathogenic bacteria were detected out for consecutive three years, which include 173 strains of drug - resistant, accounted for 32.58%. Drug - resistant bacteria conclude Baumanii, Pseudomonas aeruginosa and Escherichia coli, which were 48.94% , 53. 33% and 41. 56% respectively. S. Aureus was the highest rate of drug - resistant. Baumarmii and P. Aeruginosa were widely resistance. Part of Enterococcus strains resistant to vancomycin. Conclusion Antibiotic resistant bacteria rate in this hospital is high. It should improve infection specimens susceptibility test rate and reasonable use of antibiotics, adopt effective disinfection measurements.%目的 了解医院耐药菌感染流行情况,制定耐药菌感染控制措施.方法采用回顾性调查和细菌检验鉴定技术,对2008-2010年本医院住院病人耐药菌感染情况进行了调查.结果该医院连续3年从医院感染患者标本中共检出致病菌531株,其中耐药菌株为173株,占32.58%;耐药菌构成比以鲍曼不动杆菌、铜绿假单胞菌和大肠埃希菌比较高,分别为53.33% 、48.94%和41.56%.金黄色葡萄球菌耐药率最高,鲍曼不动杆菌和铜绿假单胞菌呈广泛耐药;肠球菌中部分菌株耐万古霉素.结论该医院医院感染致病菌中耐药菌比例较高,必须提高感染标本送检率和药敏试验率,合理使用抗生素和采取有效消毒隔离措施.

  8. 新生儿感染性肺炎的病原菌状况分析%Investigation of pathogenic bacteria and antibiotic susceptibility in neonatal infective pneumonia

    Institute of Scientific and Technical Information of China (English)

    卓少宏; 伍成峰; 马兴灶; 詹世产

    2012-01-01

    Objective To investigate the pathogenic bateria of neonatal infective pneumonia in Shantou area. Method The identification of bacteria and susceptibility test were performed by AMS VITEK-60. Reslut Gram-negative bacteria were the prominent pathogens, which accounted for 92.81% (142/153) of the pathogens in neonatal infective pneumonia. The most common pathogens were Klebsialla pneumonia. There were less pathogens of Gram-positive bacteria found in the neonatal infective pneumonia. The resistance rates of Gram-negative bacteria to cephalosporins and aminoglycosides were significantly higher than to imipenem and fluroguinlones. Conclusion Klebsialla pneumonia is the prominent pathogen of neonatal infective pneumonia in Shantou area. The first choices of antibiotics in treating Gram-negative bacteria infection are imipenem, cefotetan and ciprofloxacin. Use of antibiotics in clinical therapy should be based on the results of susceptibility of pathogens.%目的 了解本地区新生儿感染性肺炎的病原菌的菌种、构成比及耐药情况,探索临床合理选用抗生素.方法 细菌鉴定及药敏试验采用VITEK-60全自动细菌鉴定仪.结果 本地区新生儿感染性肺炎的病原菌主要为革兰阴性杆菌(92.81%),其中以肺炎克雷伯菌最为常见,革兰阳性球菌感染较少(7.19%).革兰阴性杆菌对头孢二代、三代和氨基糖苷类抗生素的耐药率均较高,对喹诺酮类抗生素耐药率较低.亚胺培南具有良好的抗菌活性.结论 肺炎克雷伯菌是本地区新生儿感染性肺炎的主要病原菌.经验性治疗用药可首选亚胺培南、头孢替坦、环丙沙星等,建议临床根据药敏结果选用抗生素.

  9. ANALYSIS OF MULTIDRUG -RESISTANT BACTERIA INFECTIONS IN THE GERIATRIC WARD%老年病房患者多重耐药菌感染的调查

    Institute of Scientific and Technical Information of China (English)

    陈英; 杨军; 张剑江

    2014-01-01

    目的:了解医院老年病房住院患者多重耐药菌感染特点,探讨有效防控措施。方法采用回顾性调查方法,对某医院老年病房住院患者多重耐药菌感染特征、病原菌分布以及危险因素进行调查。结果该医院老年病房在2年内共调查老年患者957例,发生多重耐药菌感染30例,感染率为3.14%,病死率70%。老年患者多重耐药菌感染以下呼吸道感染为主,其构成比达到66.67%。分离出的多重耐药菌主要是产超广谱β-内酰胺酶( ES-BLs)肺炎克雷伯菌、大肠埃希菌及耐碳青酶烯铜绿假单菌。病人的年龄、基础疾病、住院时间、侵入性操作、激素使用等构成感染的主要危险因素。结论该医院老年患者多重耐药菌感染率较高,以下呼吸道感染最多见,免疫力的改善、无菌技术保障和合理使用抗菌药物为主要防控措施。%Objective To study the clinical features of multidrug-resistant bacteria infection in the geriatric wards,so as to explore the effective measures for prevention and control. Methods The retrospective investigation was used to ana-lyze multi-resistant bacteria infection characteristics,pathogen distribution and risk factors of the inpatients in geriatric ward of a hospital. Results 957 elderly patients in the hospital geriatric ward were investigated in 2 years. 30 cases oc-curred multidrug-resistant bacteria infection and the infection rate was 3. 14%,the mortality was 70%. Most of them were lower respiratory tract infections and the constituent ratio was 66. 67%. The main pathogens included ESBLs -produing Escherichia coli,Klebsiella pneumoniae and Carbapenems-resistant Pseudomonas aeruginosa. The risk factors of multidrug-resistant bacteria infection were age,disease kind and extent,hospitalization,invasive operation and glucocorticoid u-sing,et al. Conclusion The infection rate of the elderly patients with multiple drug-resistant bacteria is

  10. B cells enhance antigen-specific CD4 T cell priming and prevent bacteria dissemination following Chlamydia muridarum genital tract infection.

    Science.gov (United States)

    Li, Lin-Xi; McSorley, Stephen J

    2013-10-01

    B cells can contribute to acquired immunity against intracellular bacteria, but do not usually participate in primary clearance. Here, we examined the endogenous CD4 T cell response to genital infection with Chlamydia muridarum using MHC class-II tetramers. Chlamydia-specific CD4 T cells expanded rapidly and persisted as a stable memory pool for several months after infection. While most lymph node Chlamydia-specific CD4 T cells expressed T-bet, a small percentage co-expressed Foxp3, and RORγt-expressing T cells were enriched within the reproductive tract. Local Chlamydia-specific CD4 T cell priming was markedly reduced in mice lacking B cells, and bacteria were able to disseminate to the peritoneal cavity, initiating a cellular infiltrate and ascites. However, bacterial dissemination also coincided with elevated systemic Chlamydia-specific CD4 T cell responses and resolution of primary infection. Together, these data reveal heterogeneity in pathogen-specific CD4 T cell responses within the genital tract and an unexpected requirement for B cells in regulating local T cell activation and bacterial dissemination during genital infection.

  11. Penicillin kills Chlamydia following the fusion of bacteria with lysosomes and prevents genital inflammatory lesions in C. muridarum-infected mice.

    Science.gov (United States)

    Dumoux, Maud; Le Gall, Sylvain M; Habbeddine, Mohamed; Delarbre, Christiane; Hayward, Richard D; Kanellopoulos-Langevin, Colette; Verbeke, Philippe

    2013-01-01

    The obligate intracellular bacterium Chlamydia exists as two distinct forms. Elementary bodies (EBs) are infectious and extra-cellular, whereas reticulate bodies (RBs) replicate within a specialized intracellular compartment termed an 'inclusion'. Alternative persistent intra-cellular forms can be induced in culture by diverse stimuli such as IFNγ or adenosine/EHNA. They do not grow or divide but revive upon withdrawal of the stimulus and are implicated in several widespread human diseases through ill-defined in vivo mechanisms. β-Lactam antibiotics have also been claimed to induce persistence in vitro. The present report shows that upon penicillin G (pG) treatment, inclusions grow as fast as those in infected control cells. After removal of pG, Chlamydia do not revert to RBs. These effects are independent of host cell type, serovar, biovar and species of Chlamydia. Time-course experiments demonstrated that only RBs were susceptible to pG. pG-treated bacteria lost their control over host cell apoptotic pathways and no longer expressed pre-16S rRNA, in contrast to persistent bacteria induced with adenosine/EHNA. Confocal and live-video microscopy showed that bacteria within the inclusion fused with lysosomal compartments in pG-treated cells. That leads to recruitment of cathepsin D as early as 3 h post pG treatment, an event preceding bacterial death by several hours. These data demonstrate that pG treatment of cultured cells infected with Chlamydia results in the degradation of the bacteria. In addition we show that pG is significantly more efficient than doxycycline at preventing genital inflammatory lesions in C. muridarum-C57Bl/6 infected mice. These in vivo results support the physiological relevance of our findings and their potential therapeutic applications.

  12. Shigella Infections

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old Shigella Infections KidsHealth > For Parents > Shigella Infections Print A ... the Doctor en español Infecciones por Shigella About Shigella Shigella are bacteria that can infect the digestive ...

  13. 耐药菌感染调查与管理对策%Investigation and Management of Drug-resistant Bacteria Infection

    Institute of Scientific and Technical Information of China (English)

    胡泰欢

    2009-01-01

    OBJECTIVE To investigate antibiotic-resistant bacteria infection status of hospital patients and to propose management strategies to prevent the spread of antibiotic-resistant bacteria. METHODS Antibiotic-resistant bacteria infection status of hospital patients was investigated during Dec 2006 to June 2009. RESULTS 31 cases of infections occurred in 26 patients. Infection rate in hospital was 61.54%. and the death rate was 34.62%. In all parts of infection, lower respiratory tract infection reached 54.84%. Causes of infection includeed:severe diseases, long time of hospital stay, application of broad-spectrum antibiotics, invasive opera-tions and so on. Positive rate of antibiotic-resistant bacteria in wards was 9.91%, Contamination rate of medical supplies was 32.14%. The aggregation of multiple resistance bacteria was related to the contamination of medical supplies. CONCLUSIONS Supervision focus on hospital infection should be that strengthening the management of antibiotics, developing supervision of antibiotics-resistance of pathogens, ensuring disinfection and isolation methodstaking effects, standardizing operations of diagnostics and treatment and preventing spread of antibiotics-resistant bacteria in hospitals.%目的 对住院患者耐药菌感染情况进行调查,提出管理对策,防止耐药菌在医院内传播.方法 对医院2006年11月--2009年6月住院患者耐药菌感染情况进行现况调查.结果 同期住院患者耐药菌感染26例31例次,医院感染比例高达61.54%,死亡率占34.62%;感染部位下呼吸道感染发生率最高,占54.84%;感染危险因素包括:严重基础疾病、住院时间长、广谱抗菌药物使用、采用侵入性操作等;病区环境耐药菌的检出率为9.91%,诊疗用品的污染率为32.14%;多药耐药菌感染的聚集性发生,与诊疗器械污染密切相关.结论 加强对抗菌药物使用的管理,合理使用抗菌药物,防止细菌产生耐药性;积极开展感染病原菌及其

  14. Clinical significance of pathogenic bacteria after the postoperative infection of total joint replacement%人工关节置换术后感染病原菌谱的临床意义

    Institute of Scientific and Technical Information of China (English)

    高川渤; 袁绍辉

    2015-01-01

    Infection is the most common and most serious complication after the artiifcial joint replacement, while it is disastrous for patients once diagnosed. Although the treatment of the infection has been considerably developed, pathogenic bacteria and drug resistance of bacteria species are changing due to the widespread and unreasonable application of antibiotics. Therefore, the mastering of pathogen spectrum, skilled and targeted use of antibiotics are the key points.

  15. The Complete Nucleotide Sequence of the Carbapenem Resistance-Conferring Conjugative Plasmid pLD209 from a Pseudomonas putida Clinical Strain Reveals a Chimeric Design Formed by Modules Derived from Both Environmental and Clinical Bacteria

    Science.gov (United States)

    Marchiaro, Patricia M.; Brambilla, Luciano; Morán-Barrio, Jorgelina; Revale, Santiago; Pasteran, Fernando; Vila, Alejandro J.; Viale, Alejandro M.

    2014-01-01

    The complete sequence of the carbapenem-resistance-conferring conjugative plasmid pLD209 from a Pseudomonas putida clinical strain is presented. pLD209 is formed by 3 well-defined regions: an adaptability module encompassing a Tn402-like class 1 integron of clinical origin containing blaVIM-2 and aacA4 gene cassettes, partitioning and transfer modules, and a replication module derived from plasmids of environmental bacteria. pLD209 is thus a mosaic of modules originating in both the clinical and environmental (nonclinical) microbiota. PMID:24395220

  16. Modulation of chemokine and chemokine receptor expression following infection of porcine macrophages with African swine fever virus.

    Science.gov (United States)

    Fishbourne, Emma; Abrams, Charles C; Takamatsu, Haru-H; Dixon, Linda K

    2013-03-23

    African swine fever virus (ASFV) is the only member of the Asfarviridae, a large DNA virus family which replicates predominantly in the cytoplasm. Most isolates cause a fatal haemorrhagic disease in domestic pigs, although some low virulence isolates cause little or no mortality. The modulation of chemokine responses following infection of porcine macrophages with low and high virulence isolates was studied to indicate how this may be involved in the induction of pathogenesis and of effective immune responses. Infection with both low and high virulence isolates resulted in down-regulation of mRNA levels for chemokines CCL2, CCL3L, CXCL2 and chemokine receptors CCR1, CCR5, CXCR3, CXCR4 and up-regulation in expression of mRNAs for CCL4, CXCL10 and chemokine receptor CCR7. Levels of CCL4, CXCL8, CXCL10 mRNAs were higher in macrophages infected with low virulence isolate OURT88/3 compared to high virulence isolate Benin 97/1. Levels of CXCL8 and CCL2 protein were significantly reduced in supernatants from macrophages infected with Benin 97/1 isolate compared to OURT88/3 and mock-infected macrophages. There was also a decreased chemotactic response of donor cells exposed to supernatants from Benin 97/1 infected macrophages compared to those from OURT88/3 and mock-infected macrophages. The data show that infection of macrophages with the low virulence strain OURT88/3 induces higher expression of key inflammatory chemokines compared to infection with high virulence strain Benin 97/1. This may be important for the induction of effective protective immunity that has been observed in pigs immunised with the OURT88/3 isolate.

  17. Infections

    Science.gov (United States)

    ... Infections Adenovirus Bronchiolitis Campylobacter Infections Cat Scratch Disease Cellulitis Chickenpox Chlamydia Cold Sores Common Cold Coxsackievirus Infections Croup Cytomegalovirus (CMV) Dengue Fever Diphtheria E. Coli ...

  18. A multidisciplinary intervention to reduce infections of ESBL- and AmpC-producing, gram-negative bacteria at a University Hospital.

    Directory of Open Access Journals (Sweden)

    Jenny Dahl Knudsen

    Full Text Available In response to a considerable increase in the infections caused by ESBL/AmpC-producing Klebsiella pneumonia in 2008, a multidisciplinary intervention, with a main focus on antimicrobial stewardship, was carried out at one university hospital. Four other hospitals were used as controls. Stringent guidelines for antimicrobial treatment and prophylaxis were disseminated throughout the intervention hospital; cephalosporins were restricted for prophylaxis use only, fluoroquinolones for empiric use in septic shock only, and carbapenems were selected for penicillin-allergic patients, infections due to ESBL/AmpC-producing and other resistant bacteria, in addition to their use in severe sepsis/septic shock. Piperacillin-tazobactam ± gentamicin was recommended for empiric treatments of most febrile conditions. The intervention also included education and guidance on infection control, as well as various other surveillances. Two year follow-up data on the incidence rates of patients with selected bacterial infections, outcomes, and antibiotic consumption were assessed, employing before-and-after analysis and segmented regression analysis of interrupted time series, using the other hospitals as controls. The intervention led to a sustained change in antimicrobial consumption, and the incidence of patients infected with ESBL-producing K. pneumoniae decreased significantly (p<0.001. The incidences of other hospital-associated infections also declined (p's<0.02, but piperacillin-tazobactam-resistant Pseudomonas aeruginosa and Enterococcus faecium infections increased (p's<0.033. In wards with high antimicrobial consumption, the patient gut carrier rate of ESBL-producing bacteria significantly decreased (p = 0.023. The unadjusted, all-cause 30-day mortality rates of K. pneumoniae and E. coli were unchanged over the four-year period, with similar results in all five hospitals. Although not statistically significant, the 30-day mortality rate of patients

  19. Plant growth-promoting bacteria Bacillus amyloliquefaciens NBRISN13 modulates gene expression profile of leaf and rhizosphere community in rice during salt stress.

    Science.gov (United States)

    Nautiyal, Chandra Shekhar; Srivastava, Suchi; Chauhan, Puneet Singh; Seem, Karishma; Mishra, Aradhana; Sopory, Sudhir Kumar

    2013-05-01

    Growth and productivity of rice and soil inhabiting microbial population is negatively affected by soil salinity. However, some salt resistant, rhizosphere competent bacteria improve plant health in saline stress. Present study evaluated the effect of salt tolerant Bacillus amyloliquefaciens NBRISN13 (SN13) inoculation on rice plants in hydroponic and soil conditions exposed to salinity. SN13 increased plant growth and salt tolerance (NaCl 200 mM) and expression of at least 14 genes under hydroponic and soil conditions in rice. Among these 14 genes 4 (NADP-Me2, EREBP, SOSI, BADH and SERK1) were up-regulated and 2 (GIG and SAPK4) repressed under salt stress in hydroponic condition. In greenhouse experiment, salt stress resulted in accumulation of MAPK5 and down-regulation of the remaining 13 transcripts was observed. SN13 treatment, with or without salt gave similar expression for all tested genes as compared to control. Salt stress caused changes in the microbial diversity of the rice rhizosphere and stimulated population of betaine-, sucrose-, trehalose-, and glutamine-utilizing bacteria in salt-treated rice rhizosphere (SN13 + salt). The observations imply that SN13 confers salt tolerance in rice by modulating differential transcription in a set of at least 14 genes. Stimulation of osmoprotectant utilizing microbial population as a mechanism of inducing salt tolerance in rice is reported for the first time in this study to the best of our knowledge.

  20. 肺部感染常见病原菌与感染正相关因素分析%Analysis of Positive-related Factors between Pathogenic bacteria and Infection in Pulmonary Infection Patients

    Institute of Scientific and Technical Information of China (English)

    张建伟; 邵瑞芳; 赵天海

    2014-01-01

    目的:了解肺部感染常见的病原菌,探讨其感染相关因素及致病菌构成比,为防治和治疗提供指导。方法:对诊断为肺部感染的316例患者进行痰菌培养及药敏试验,并对感染相关因素进行分析。结果:痰菌培养阳性率41.77%。病原菌中革兰氏阴性菌占49.24%;真菌40.91%;革兰氏阳性菌9.84%。与肺部感染关系密切的相关因素中,使用广谱抗生素94例,占71.21%;侵入性操作史者34例,占25.75%;腹部或胸部手术史者24例,占18.18%;使用激素和免疫抑制剂13例,占9.84%。结论:肺部感染的致病菌主要为革兰氏阴性菌,其次为真菌和革兰氏阳性菌。致病菌中占比例较高的主要有铜绿假单胞菌、肺炎克雷伯菌、大肠埃希菌、白色念珠菌和金黄色葡萄球菌等。不合理使用广谱抗生素和免疫抑制剂;侵入性操作;原有基础疾病所引起的抵抗力下降;胸腹部手术等是引起或加重肺部感染的主要因素。%Objective:To explore the common pathogenic bacteria of lung infection,the infection related factors and percentage so as to provide direction of prevention and therapy.Method:The sputum samples of 316 patients with pulmonary infection were cultured and given drug sensitivity test,along with analyzing infection-related factors.Result:The positive proportion of sputum culture were 41.77%,including Gram-negative bacteria(49.24%),fungi(40.91%)and gram-positive bacteria(9.84%). In the factors of close-related with pulmonary infection,using broad-spectrum antibiotic were 94(71.21%)cases,invasive operation were 34(25.75%)cases,abdomen and thoracic surgical operation were 24(18.18%) cases,using glucocorticoid and immunosuppressants were 13(9.84%)cases.Conclusion:The main pathogenic bacteria of pulmonary infection are gram-negative bacteria,followed by fungi and gram-positive bacteria. The below are the high percentage of pathogenic bacteria,such as Pseudomonas

  1. Infection of C57BL/6 mice by Trypanosoma musculi modulates host immune responses during Brucella abortus cocolonization.

    Science.gov (United States)

    Lowry, Jake E; Leonhardt, Jack A; Yao, Chaoqun; Belden, E Lee; Andrews, Gerard P

    2014-01-01

    Brucellosis, which results in fetal abortions in domestic and wildlife animal populations, is of major concern in the US and throughout much of the world. The disease, caused by Brucella abortus, poses an economic threat to agriculture-based communities. A moderately efficacious live attenuated vaccine (B. abortus strain RB51) exists. However, even with vaccine use, outbreaks occur. Evidence suggests that elk (Cervus canadensis), a wild host reservoir, are the source of recent outbreaks in domestic cattle herds in Wyoming, USA. Brucella abortus establishes a chronic, persistent infection in elk. The molecular mechanisms allowing the establishment of this persistent infective state are currently unknown. A potential mechanism could be that concurrent pathogen burdens contribute to persistence. In Wyoming, elk are chronically infected with Trypanosoma cervi, which may modulate host responses in a similar manner to that documented for other trypanosomes. To identify any synergistic relationship between the two pathogens, we simulated coinfection in the well-established murine brucellosis model using Trypanosoma musculi and B. abortus S19. Groups of C57BL/6 mice (Mus musculus) were infected with either B. abortus strain 19 (S19) or T. musculi or both. Sera were collected weekly; spleens from euthanized mice were tested to determine bacterial load near the end of normal brucellosis infection. Although changes in bacterial load were observed during the later stages of brucellosis in those mice coinfected with T. musculi, the most significant finding was the suppression of gamma interferon early during the infection along with an increase in interleukin-10 secretion compared with mice infected with either pathogen alone. These results suggest that immune modulatory events occur in the mouse during coinfection and that further experiments are warranted to determine if T. cervi impacts Brucella infection in elk.

  2. Normocaloric low cholesterol diet modulates Th17/Treg balance in patients with chronic hepatitis C virus infection.

    Directory of Open Access Journals (Sweden)

    Roberta Maggio

    Full Text Available Hepatitis C virus (HCV infection is associated with hepatic and extrahepatic manifestations, including immunological disorders. Chronic Hepatitis C (CHC is often characterized by cholesterol and lipid metabolism alterations, leading to hepatic steatosis. Cholesterol metabolism, in fact, is crucial for the viral life cycle. Recent works described that a higher dietary cholesterol intake is associated with the progression of HCV-related liver disease. CHC patients have increased levels of T helper 17 (Th17-cells, a lymphocytic population involved in the pathogenesis of liver inflammation and autoimmune hepatitis. The balance between Th17 and regulatory T (Treg cells is crucial for chronic inflammation and autoimmunity. Th17-cell differentiation is deeply influenced by the activation LXRs, nuclear receptors modulating cholesterol homeostasis. Moreover, HCV may affect these nuclear receptors, and cholesterol metabolism, through both direct and indirect mechanisms. On these bases, we hypothesized that modulation of cholesterol levels through Normocaloric Low Cholesterol Diet (NLCD may represent an innovative strategy to reduce the progression of HCV infection, through the modulation of peripheral Th17/Treg balance. To this end, we performed a pilot study to investigate whether a Normocaloric Low Cholesterol Diet may be able to modulate Th17/Treg balance in patients affected by chronic HCV infection. After 30 days of NLCD CHC patients showed a significant reduction in Th17 cells frequency, which correlated with strong reduction of IL-17 and IL-22 serum levels. At the same time, we appreciated an increase in the percentage of Treg cells, thus improving Treg/Th17 balance. Moreover, we observed an increased expression of LXRs and their target genes: SREBP-1c and ABCA-1. In conclusion, NLCD finely regulates Th17/Treg balance, improving immune system response in CHC patients. This study could pave the way for new treatments of CHC patients, suggesting that

  3. Drug resistance and distribution of pathogenic bacteria in urinary tract infection%泌尿系感染病原菌分布及耐药性分析

    Institute of Scientific and Technical Information of China (English)

    程锦娥; 卢月梅; 李文青; 吴劲松; 吴伟元

    2012-01-01

    目的 了解深圳市人民医院泌尿系感染病原菌的分布及耐药性,为临床医师合理使用抗菌药物提供科学依据.方法 对655株泌尿系统感染病原菌进行常规鉴定,用k-B法或ATB-FUNGUS 3对其进行药敏试验.结果 病原菌构成比前5位分别为大肠埃希菌(37.9%)、假丝酵母(18.0%)、肠球菌(13.1%)、肺炎克雷伯菌(6.6%)、铜绿假单胞菌(6.3%).病原菌对各种抗菌药物产生了不同程度的耐药,肺炎克雷伯菌、铜绿假单胞菌对亚胺培南和美罗培南的耐药率为14.3%~26.8%.结论 深圳市人民医院泌尿系感染病原菌主要以大肠埃希菌、假丝酵母和肠球菌等为主,病原菌对抗菌药物已产生了一定的耐药性,应加强监测与控制.%Objective To investigate the distribution and drag resislance of pathogenic bacteria in urinary tract infection and offer scientific basis for reasonable usage of antibiotics. Method All 655 strains of pathogenic bacteria isolated from urinary tract infection specimens were identified and drug susceptibility tests were performed by using K-B methods or ATB FUNGUS 3. Results Among the pathogenic bacteria isolated, the top five ones were Escherichia coli (37.9%), Candida (18.0%), Enterococci (13.1%), Klebsiella pneumeniae (6.6%), and Pseudomonas aeruginosa (6.3%). The pathogens showed varying degrees of resistance to various antimicrobial agents ; the resistance rates of Klebswlla pncumoniae and Pseudomonas aeruginosa to Imipenem and Meropenem were 14.3%-26.8%. Conclusion In Shenzhen People's Hospital, the main pathogens of urinary tract infection are Escherichia coli, Candida, and Enterococci. Drug resistance has been emerging in pathogenic bacteria in urinary tract infections. We should take better monitor and control of them.

  4. Intracellular Bacteria in Protozoa

    Science.gov (United States)

    Görtz, Hans-Dieter; Brigge, Theo

    Intracellular bacteria in humans are typically detrimental, and such infections are regarded by the patients as accidental and abnormal. In protozoa it seems obvious that many bacteria have coevolved with their hosts and are well adapted to the intracellular way of life. Manifold interactions between hosts and intracellular bacteria are found, and examples of antibacterial resistance of unknown mechanisms are observed. The wide diversity of intracellular bacteria in protozoa has become particularly obvious since they have begun to be classified by molecular techniques. Some of the bacteria are closely related to pathogens; others are responsible for the production of toxins.

  5. Efficacy of an Immune Modulator in Experimental Chlamydia trachomatis Infection of the Female Genital Tract

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available Objective. The aim of this study was to determine if vaginal application of the immune response modifier imiquimod (Aldara cream, 3M Pharmaceuticals, St Paul, Minn would alter the course and/or outcome of female genital tract infection with a human isolate of Chlamydia trachomatis in a murine model. Methods. Groups of CF-1 mice were treated with Aldara on three different schedules: (1 ongoing beginning 5 days prior to and continuing through day 5 of infection; (2 a single prophylactic dose 2 hours prior to infection; and (3 therapeutic from day 4 to day 14 of infection. Mice were infected vaginally with a serovar D strain of C trachomatis, and monitored by culture to determine the level of shedding and duration of infection. Results. We observed a significant reduction in both duration of infection and the level of shedding during the acute phase in mice treated on an ongoing basis commencing 5 days prior to infection. There was no effect with respect to the other regimens. Conclusion. These results demonstrate that ongoing Aldara treatment has efficacy and may enhance local innate immunity which reduces the duration of subsequent infection with human isolates of C trachomatis in a murine model of female genital tract infection.

  6. Persistent Wolbachia and cultivable bacteria infection in the reproductive and somatic tissues of the mosquito vector Aedes albopictus.

    Directory of Open Access Journals (Sweden)

    Karima Zouache

    Full Text Available BACKGROUND: Commensal and symbiotic microbes have a considerable impact on the behavior of many arthropod hosts, including hematophagous species that transmit pathogens causing infectious diseases to human and animals. Little is known about the bacteria associated with mosquitoes other than the vectorized pathogens. This study investigated Wolbachia and cultivable bacteria that persist through generations in Ae. albopictus organs known to host transmitted arboviruses, such as dengue and chikungunya. METHODOLOGY/PRINCIPAL FINDINGS: We used culturing, diagnostic and quantitative PCR, as well as in situ hybridization, to detect and locate bacteria in whole individual mosquitoes and in dissected tissues. Wolbachia, cultivable bacteria of the genera Acinetobacter, Comamonas, Delftia and Pseudomonas co-occurred and persisted in the bodies of both males and females of Ae. albopictus initially collected in La Réunion during the chikungunya outbreak, and maintained as colonies in insectaries. In dissected tissues, Wolbachia and the cultivable Acinetobacter can be detected in the salivary glands. The other bacteria are commonly found in the gut. Quantitative PCR estimates suggest that Wolbachia densities are highest in ovaries, lower than those of Acinetobacter in the gut, and approximately equal to those of Acinetobacter in the salivary glands. Hybridization using specific fluorescent probes successfully localized Wolbachia in all germ cells, including the oocytes, and in the salivary glands, whereas the Acinetobacter hybridizing signal was mostly located in the foregut and in the anterior midgut. CONCLUSIONS/SIGNIFICANCE: Our results show that Proteobacteria are distributed in the somatic and reproductive tissues of mosquito where transmissible pathogens reside and replicate. This location may portend the coexistence of symbionts and pathogens, and thus the possibility that competition or cooperation phenomena may occur in the mosquito vector Ae

  7. Modulation of Cell Sialoglycophenotype: A Stylish Mechanism Adopted by Trypanosoma cruzi to Ensure Its Persistence in the Infected Host

    Science.gov (United States)

    Freire-de-Lima, Leonardo; da Fonseca, Leonardo M.; da Silva, Vanessa A.; da Costa, Kelli M.; Morrot, Alexandre; Freire-de-Lima, Célio G.; Previato, Jose O.; Mendonça-Previato, Lucia

    2016-01-01

    Trypanosoma cruzi, the etiological agent of Chagas disease exhibits multiple mechanisms to guarantee its establishment and persistence in the infected host. It has been well demonstrated that T. cruzi is not able to synthesize sialic acids (Sia). To acquire the monosaccharide, the parasite makes use of a multifunctional enzyme called trans-sialidase (Tc-TS). Since this enzyme has no analogous in the vertebrate host, it has been used as a target in drug therapy development. Tc-TS preferentially catalyzes the transfer of Sia from the host glycoconjugates to the terminal β-galactopyranosyl residues of mucin-like molecules present on the parasite’s cell surface. Alternatively, the enzyme can sialylate/re-sialylate glycoconjugates expressed on the surface of host cells. Since its discovery, several studies have shown that T. cruzi employs the Tc-TS activity to modulate the host cell sialoglycophenotype, thus favoring its perpetuation in the infected vertebrate. In this review, we summarize the dynamic of host/parasite sialoglycophenotype modulation, highlighting its role in the subversion of host immune response in order to promote the establishment of persistent chronic infection. PMID:27242722

  8. period-Regulated Feeding Behavior and TOR Signaling Modulate Survival of Infection.

    Science.gov (United States)

    Allen, Victoria W; O'Connor, Reed M; Ulgherait, Matthew; Zhou, Clarice G; Stone, Elizabeth F; Hill, Vanessa M; Murphy, Keith R; Canman, Julie C; Ja, William W; Shirasu-Hiza, Mimi M

    2016-01-25

    Most metazoans undergo dynamic, circadian-regulated changes in behavior and physiology. Currently, it is unknown how circadian-regulated behavior impacts immunity against infection. Two broad categories of defense against bacterial infection are resistance, control of microbial growth, and tolerance, control of the pathogenic effects of infection. Our study of behaviorally arrhythmic Drosophila circadian period mutants identified a novel link between nutrient intake and tolerance of infection with B. cepacia, a bacterial pathogen of rising importance in hospital-acquired infections. We found that infection tolerance in wild-type animals is stimulated by acute exposure to dietary glucose and amino acids. Glucose-stimulated tolerance was induced by feeding or direct injection; injections revealed a narrow window for glucose-stimulated tolerance. In contrast, amino acids stimulated tolerance only when ingested. We investigated the role of a known amino-acid-sensing pathway, the TOR (Target of Rapamycin) pathway, in immunity. TORC1 is circadian regulated and inhibition of TORC1 decreased resistance, as in vertebrates. Surprisingly, inhibition of the less well-characterized TOR complex 2 (TORC2) dramatically increased survival, through both resistance and tolerance mechanisms. This work suggests that dietary intake on the day of infection by B. cepacia can make a significant difference in long-term survival. We further demonstrate that TOR signaling mediates both resistance and tolerance of infection and identify TORC2 as a novel potential therapeutic target for increasing survival of infection.

  9. Influence of environmental factors on phage-bacteria interaction and on the efficacy and infectivity of phage P100

    Directory of Open Access Journals (Sweden)

    Susanne Fister

    2016-07-01

    Full Text Available When using bacteriophages to control food-borne bacteria in food production plants and processed food, it is crucial to consider that environmental conditions influence their stability. These conditions can also affect the physiological state of bacteria and consequently host-virus interaction and the effectiveness of the phage ability to reduce bacteria numbers. In this study we investigated the stability, binding and replication capability of phage P100 and its efficacy to control L. monocytogenes under conditions typically encountered in dairy plants. The influences of SDS, Lutensol AO 7, salt, smear water and different temperatures were investigated. Results indicate that phage P100 is stable and able to bind to the host under most conditions tested. Replication was dependent upon the growth of L. monocytogenes and efficacy was higher when bacterial growth was reduced by certain environmental conditions. In long-term experiments at different temperatures phages were initially able to reduce bacteria up to seven log10 units after two weeks at 4 °C. However, thereafter re-growth and development of phage-resistant L. monocytogenes isolates were encountered.

  10. The Potential Application and Risks Associated With the Use of Predatory Bacteria as a Biocontrol Agent Against Wound Infections

    Science.gov (United States)

    2014-09-01

    antibiotics or phage therapy, the selective pressure of predation does not generate genetically stable resistant variants in the host. Since the...and resistance. It was proposed that, unlike antibiotics or phage therapy, the selective pressure of predation does not generate genetically stable...agents such as medical maggots, phage , biodebridement, and predatory bacteria. Our main hypothesis is that predatory prokaryotes are able to

  11. Modulation of HIV-1 infectivity and cyclophilin A-dependence by Gag sequence and target cell type

    Directory of Open Access Journals (Sweden)

    Dam Elisabeth

    2009-03-01

    interactions between host-cell factors and Gag can strongly affect HIV-1 infectivity, and these vary according to target cell type and the origin of the Gag sequence. Two of the cellular activities involved appear to be modulated in opposite directions by CypA-CA interactions, and Gag sequences determine the intrinsic sensitivity of a given virus to each of these cellular activities.

  12. Anaerobic bacteria in otitis media.

    Science.gov (United States)

    Fulghum, R S; Daniel, H J; Yarborough, J G

    1977-01-01

    Anaerobic bacteria, Peptostrepotococcus intermedius and Propionibacterium acnes, were found in mixed culture specimens from four to ten tested cases of chronic secretory otitis media. These anaerobic bacteria were in a mixed infection flora with aerobic bacteria most often Staphylococcus epidermidis and Cornybacterium sp. which do not fit any established species. The findings of anaerobic bacteria in otitis media is consistent with the sporadic report of the involvement of anaerobic bacteria in otitis media in the literature since 1898.

  13. Exposure to ozone modulates human airway protease/antiprotease balance contributing to increased influenza A infection

    Science.gov (United States)

    Exposure to oxidant air pollution is associated with Increased respiratory morbiditses and susceptibility to Infections Ozone is a commonly encountered oxidant air pollutant, yet Its effects on influenza infections in humans are not known ‘the greater Mexico City area was the pri...

  14. Modulation of inflammatory bowel disease in a mouse model following infection with Trichinella spiralis

    Science.gov (United States)

    Infection of mice with Trichinella spiralis redirects the mucosal immune system from a Th1 to a protective Th2 response with a reduction in the severity of trinitrobenzesulfonic acid-induced colonic damage. T. spiralis infection induced IL-10 production in a dose-dependent manner in oxazolone (OXZ)-...

  15. Innate immunity modulation in the duodenal mucosa induced by REM sleep deprivation during infection with Trichinella spirallis

    Science.gov (United States)

    Ibarra-Coronado, Elizabeth G.; Pérez-Torres, Armando; Pantaleón-Martínez, Ana M.; Velazquéz-Moctezuma, Javier; Rodriguez-Mata, Veronica; Morales-Montor, Jorge

    2017-01-01

    Sleep is considered to be an important predictor of the immunity, since the absence of sleep can affect the development of the immune response, and consequently increase the susceptibility to contract an infection. The aim of the present study was to investigate if sleep deprivation and stress induce dysregulation of the duodenal mucous membrane during the acute infection with Trichinella spiralis. Our results shows that, in the intestinal mucous membrane, stress and sleep deprivation, produces different effect in the cells, and this effect depends on the studied duodenal compartment, glands or villi. The sleep deprivation affect mast cells mainly, and the stress response is more heterogeneous. Interestingly, in the duodenal mucous membrane, none population of cells in the infected groups responded equally to both conditions. These findings suggest that the response of the intestinal mucous membrane during the infection caused for T. spiralis turns out to be affected in the sleep-deprived rats, therefore, the results of the present study sustain the theory that sleep is a fundamental process that is capable of modulating the immune response of mucous membranes, particularly the one generated against the parasite Trichinella spiralis. PMID:28374797

  16. Antimicrobial Susceptibility of Bacteria Causing Neonatal Infections%新生儿临床标本抗生素敏感性分析

    Institute of Scientific and Technical Information of China (English)

    余加林; 吴仕孝

    2001-01-01

    目的:探索新生儿感染病原菌分布及常见抗菌药物敏感性,为经验性治疗提供依据。方法:按《全国临床检验操作规程》鉴定细菌,纸片扩散法做药敏试验。结果:1987~1998年内分离出病原菌2 244株。院外感染前三位是表皮葡萄球菌、腐生葡萄球菌及大肠埃希菌,院内感染前三位是大肠埃希菌、克雷白菌及绿脓杆菌。院内外感染菌株对青霉素、氨苄西林等15种抗生素的耐药率差异显著。阿米卡星的总敏感率86.2%,与青霉素联用敏感率增至89.0%。结论:院外感染致病菌以革兰阳性菌为主,而院内感染致病菌以革兰阴性菌为主,后者对许多抗菌药物更易产生耐药性,阿米卡星联合青霉素作为第一线抗菌药物值得推广。%Objective:To investigate the epidemiological characteristics of bacteria and their susceptibility to antimicrobials and to establish a basis for empirical treatment of the neonatal infections.  Methods:Identification of bacteria were performed according to the National Standard of Clinical Microbiological Test. Disk diffusion were used for antimicrobial susceptibility test. Results: A total of 2,244 strains were isolated from the samples collected in our neonatal ward from Jan. 1987 to Dec. 1998. The predominant species ranked the first three were Staphylococcus epidermidis, Staphylococcus saprophyticus and Escherichia coli in the group I (infections acquired outside of hospital). Escherichia coli, Klebsiella and pseudomonas aeruginosa ranked the first three in the group Ⅱ(nosocomial infections). The resistance rates of bacterial isolates from group Ⅱ to antimicrobial agents including penicillin and ampicillin were significantly higher than that from group I (P<0.05). The sensitivity rate was 82.2% by using amikacin only, but raised to 89% when combined with penicillin.  Conclusion: Gram-negative bacteria were the main pathogens of nosocomial infections

  17. Treatment with omeprazole, metronidazole, and amoxicillin in captive South African cheetahs (Acinonyx jubatus) with spiral bacteria infection and gastritis.

    Science.gov (United States)

    Lane, Emily; Lobetti, Remo; Burroughs, Richard

    2004-03-01

    Six captive cheetahs (Acinonyx jubatus) with severe gastritis diagnosed by gastric endoscopy and mucosal histopathology were treated with omeprazole, metronidazole, and amoxicillin for 3 wk. Endoscopic biopsies were performed before therapy, immediately after treatment, and 3, 7, and 19 mo after treatment. Macroscopic appearance of the stomach, histologic scoring of gastric inflammation, and the presence or absence of spiral bacteria were recorded. Spiral bacteria were absent histologically immediately after treatment but reappeared in endoscopic biopsies by 3 mo after treatment. Gastritis scores fluctuated widely during the trial but improved in five of six cheetahs by 3 mo after treatment. By 19 mo after treatment, scores were close to the pretreatment scores. Therapy with omeprazole, amoxicillin, and metronidazole was associated with temporary improvement in the degree and distribution of gastritis in some cheetahs with gastritis, suggesting that treatment may be warranted once severe gastric inflammation has been diagnosed.

  18. Mechanisms of infection by pathogens transmitted by ticks on the example of bacteria: Anaplasma phagocytophilum and Borrelia burgdorferi

    OpenAIRE

    2016-01-01

    Tick-borne diseases are transmission diseases belonging to the group of zoonoses but carried by ticks. These diseases are a major public health problem but also a problem for groups occupationally exposed to tick bites. Ixodes ricinus is a species of ticks which is the most common reservoir and the vector of a large number of microorganisms pathogenic to humans. It transfers, among others, bacteria of the species: Anaplasma phagocytophilum and Borrelia burgdorferi. The...

  19. Surveillance of multidrug resistant suppurative infection causing bacteria in hospitalized patients in an Indian tertiary care hospital

    Institute of Scientific and Technical Information of China (English)

    Nabakishore Nayak; Rajesh K Lenka; Rabindra N Padhy

    2014-01-01

    Objective:To examine antibiograms of a cohort of suppurative bacteria isolated from wound-swabs from hospitalized patients of all economic groups of a typicalIndian teaching hospital. Methods:In surveillance, antibiotic resistance patterns of10 species of suppurative bacteria isolated from wound-swabs over a period of24 months were recorded.Those were subjected to antibiotic sensitivity test, using16 prescribed antibiotics of5 different groups(3 aminoglycosides, 4 beta-lactams,3 cephalosporins,4 fluoroquinolones, and2 stand-alone) in each6-month interval of the study period.Results:Of1156 samples collected,819 samples yielded pathogenic bacteria, of which,Staphylococcus aureus(S. aureus),Streptococcus pyogenes(S. pyogenes), Escherichia coli(E. coli),Pseudomonas aeruginosa(P. aeruginosa),Enterococcus faecalis(E. faecalis), Klebsiella pneumoniae(K. pneumoniae),Acinetobacter baumannii(A. baumannii),Enterobacter aerogenes(E. aerogenes),Proteus mirabilis(P. mirabilis) andProteus vulgaris(P. vulgaris) were isolated in the order of predominance.Isolated bacterial strains were floridly multidrug resistant.Strains ofE. faecalis andS. aureus were found resistant to vancomycin, one of the newly introduced antibiotics.Conclusions:Of theseS. aureus, particularly the methicillin resistant strain predominates, followed by strains ofS. pyogenes andP. aeruginosa that were in the higher proportions of multidrug resistance.

  20. The Association between GABA-Modulators and Clostridium difficile Infection – A Matched Retrospective Case-Control Study

    Science.gov (United States)

    Ström, Jonathan; Tham, Johan; Månsson, Fredrik; Ahl, Jonas; Savidge, Tor C.; Dann, Sara M.

    2017-01-01

    Objective Recently, metabolomics studies have suggested that the neurotransmitter γ-amino butyric acid (GABA) may modulate C. difficile infection (CDI) pathogenesis. In the present study, we investigated the association between GABA-modulating pharmaceuticals and CDI development. Methods In July-December 2013, we performed a matched, retrospective case-control study in Skåne county, Sweden, to assess the association between the use of GABA-modulators (defined as regular use of at least one of the following: zolpidem, zopiclone, benzodiazepines, gabapentin, pregabalin or baclofen) and CDI. Multivariate regression models, adjusted for known risk factors for CDI, were fitted to assess the associations and a propensity score-adjusted analysis was performed. Results The study included 292 cases and 292 matched controls. In a multivariate regression model only recent antibiotic use (clindamycin, cephalosporins and fluoroquinolones) and nursing home residency was significantly associated with CDI. The regular use of any GABA-modulator was not associated with CDI (OR = 1.07, 95%CI 0.69–1.66, p = 0.76). The association between regular use of the selective GABA-agonist zolpidem and CDI trended towards significance (OR = 2.31, 95%CI 0.91–5.86, p = 0.078). These associations remained when only cases treated with antibiotics were included. Corresponding findings for zolpidem was observed in a propensity-score adjusted analysis (OR = 2.52, 95% CI 0.91–6.97, p = 0.075). Severe initial CDI was significantly associated with CDI recurrence (OR = 3.77, 95% CU 1.20–11.86, p = 0.023). Conclusion This study did not identify a general association between GABA-modulators and CDI. A trend towards a significant association between zolpidem and CDI was observed, an association that should be re-assessed in a study appropriately powered for this particular hypothesis. PMID:28060888

  1. Antiviral treatment for chronic hepatitis B virus infection--immune modulation or viral suppression?

    NARCIS (Netherlands)

    E.H.C.J. Buster (Erik); H.L.A. Janssen (Harry)

    2006-01-01

    textabstractThe availability of nucleoside analogues has broadened treatment options for chronic hepatitis B virus (HBV ) infection. Registered treatment for chronic hepatitis B currently consists of (pegylated) interferon, lamivudine and adefovir, while entecavir is expected to be

  2. Innate invariant NKT cells recognize Mycobacterium tuberculosis-infected macrophages, produce interferon-gamma, and kill intracellular bacteria.

    Directory of Open Access Journals (Sweden)

    Isabel Sada-Ovalle

    2008-12-01

    Full Text Available Cellular immunity to Mycobacterium tuberculosis (Mtb requires a coordinated response between the innate and adaptive arms of the immune system, resulting in a type 1 cytokine response, which is associated with control of infection. The contribution of innate lymphocytes to immunity against Mtb remains controversial. We established an in vitro system to study this question. Interferon-gamma is produced when splenocytes from uninfected mice are cultured with Mtb-infected macrophages, and, under these conditions, bacterial replication is suppressed. This innate control of bacterial replication is dependent on CD1d-restricted invariant NKT (iNKT cells, and their activation requires CD1d expression by infected macrophages as well as IL-12 and IL-18. We show that iNKT cells, even in limiting quantities, are sufficient to restrict Mtb replication. To determine whether iNKT cells contribute to host defense against tuberculosis in vivo, we adoptively transferred iNKT cells into mice. Primary splenic iNKT cells obtained from uninfected mice significantly reduce the bacterial burden in the lungs of mice infected with virulent Mtb by the aerosol route. Thus, iNKT cells have a direct bactericidal effect, even in the absence of synthetic ligands such as alpha-galactosylceramide. Our finding that iNKT cells protect mice against aerosol Mtb infection is the first evidence that CD1d-restricted NKT cells mediate protection against Mtb in vivo.

  3. Chicken-specific kinome array reveals that Salmonella enterica serovar Enteritidis modulates host immune signaling pathways in the cecum to establish a persistence infection

    Science.gov (United States)

    Non-typhoidal Salmonella enterica induce an early, short-lived, pro-inflammatory response in chickens that is asymptomatic of clinical disease and results in a persistent colonization of the gastrointestinal (GI) tract that transmits infections to naïve hosts via fecal shedding of bacteria. The und...

  4. Interactions between bacteria and the gut mucosa: Do enteric neurotransmitters acting on the mucosal epithelium influence intestinal colonization or infection?

    Science.gov (United States)

    The intestinal epithelium is a critical barrier between the internal and external milieux of the mammalian host. Epithelial interactions between these two host environments have been shown to be modulated by several different, cross-communicating cell types residing in the gut mucosa. These include ...

  5. The Use of Recombinant Feline Interferon Omega Therapy as an Immune-Modulator in Cats Naturally Infected with Feline Immunodeficiency Virus: New Perspectives

    Directory of Open Access Journals (Sweden)

    Rodolfo Oliveira Leal

    2016-10-01

    Full Text Available Type I interferons (IFNs are well-known cytokines that, among their main functions, are key components of the host immune response against viral infections. Due to its immune modulation properties, they are commonly used in the therapeutic approach of various retroviral infections, namely human immunodeficiency virus (HIV and feline immunodeficiency virus (FIV. In HIV infection, it has been shown that IFN therapy limits early viral replication, particularly useful on post-exposure prophylaxis. In veterinary medicine, recombinant feline interferon omega (rFeIFN-ω was the first interferon licensed for use in cats. Several studies have recently shown that this compound seems to stimulate the innate immunity, decreasing clinical signs and co-infections in naturally FIV-infected cats. More than summarizing the main conclusions about rFeIFN-ω in cats, this review emphasizes the immune-modulation properties of IFN therapy, opening new perspectives for its use in retroviral infections. Either in FIV-infected cats or in HIV individuals, type I IFNs seem to induce an innate immune-modulation and should not be overlooked as a therapeutic option in retroviral infections.

  6. Modulation of Microglial Cell Fcγ Receptor Expression Following Viral Brain Infection

    Science.gov (United States)

    Chauhan, Priyanka; Hu, Shuxian; Sheng, Wen S.; Prasad, Sujata; Lokensgard, James R.

    2017-01-01

    Fcγ receptors (FcγRs) for IgG couple innate and adaptive immunity through activation of effector cells by antigen-antibody complexes. We investigated relative levels of activating and inhibitory FcγRs on brain-resident microglia following murine cytomegalovirus (MCMV) infection. Flow cytometric analysis of microglial cells obtained from infected brain tissue demonstrated that activating FcγRs were expressed maximally at 5 d post-infection (dpi), while the inhibitory receptor (FcγRIIB) remained highly elevated during both acute and chronic phases of infection. The highly induced expression of activating FcγRIV during the acute phase of infection was also noteworthy. Furthermore, in vitro analysis using cultured primary microglia demonstrated the role of interferon (IFN)γ and interleukin (IL)-4 in polarizing these cells towards a M1 or M2 phenotype, respectively. Microglial cell-polarization correlated with maximal expression of either FcγRIV or FcγRIIB following stimulation with IFNγ or IL-4, respectively. Finally, we observed a significant delay in polarization of microglia towards an M2 phenotype in the absence of FcγRs in MCMV-infected Fcer1g and FcgR2b knockout mice. These studies demonstrate that neuro-inflammation following viral infection increases expression of activating FcγRs on M1-polarized microglia. In contrast, expression of the inhibitory FcγRIIB receptor promotes M2-polarization in order to shut-down deleterious immune responses and limit bystander brain damage. PMID:28165503

  7. Modulation of the immune response to Mycobacterium tuberculosis during malaria/M. tuberculosis co-infection.

    Science.gov (United States)

    Chukwuanukwu, R C; Onyenekwe, C C; Martinez-Pomares, L; Flynn, R; Singh, S; Amilo, G I; Agbakoba, N R; Okoye, J O

    2017-02-01

    Tuberculosis (TB) causes significant morbidity and mortality on a global scale. The African region has 24% of the world's TB cases. TB overlaps with other infectious diseases such as malaria and HIV, which are also highly prevalent in the African region. TB is a leading cause of death among HIV-positive patients and co-infection with HIV and TB has been described as a syndemic. In view of the overlapping epidemiology of these diseases, it is important to understand the dynamics of the immune response to TB in the context of co-infection. We investigated the cytokine response to purified protein derivative (PPD) in peripheral blood mononuclear cells from TB patients co-infected with HIV or malaria and compared it to that of malaria- and HIV-free TB patients. A total of 231 subjects were recruited for this study and classified into six groups; untreated TB-positive, TB positive subjects on TB drugs, TB- and HIV-positive, TB- and malaria-positive, latent TB and apparently healthy control subjects. Our results demonstrate maintenance of interferon (IFN)-γ production in HIV and malaria co-infected TB patients in spite of lower CD4 counts in the HIV-infected cohort. Malaria co-infection caused an increase in the production of the T helper type 2 (Th2)-associated cytokine interleukin (IL)-4 and the anti-inflammatory cytokine IL-10 in PPD-stimulated cultures. These results suggest that malaria co-infection diverts immune response against M. tuberculosis towards a Th-2/anti-inflammatory response which might have important consequences for disease progression.

  8. Differences in APOBEC3G expression in CD4+ T helper lymphocyte subtypes modulate HIV-1 infectivity.

    Directory of Open Access Journals (Sweden)

    Michael L Vetter

    2009-02-01

    Full Text Available The cytidine deaminases APOBEC3G and APOBEC3F exert anti-HIV-1 activity that is countered by the HIV-1 vif protein. Based on potential transcription factor binding sites in their putative promoters, we hypothesized that expression of APOBEC3G and APOBEC3F would vary with T helper lymphocyte differentiation. Naive CD4+ T lymphocytes were differentiated to T helper type 1 (Th1 and 2 (Th2 effector cells by expression of transcription factors Tbet and GATA3, respectively, as well as by cytokine polarization. APOBEC3G and APOBEC3F RNA levels, and APOBEC3G protein levels, were higher in Th1 than in Th2 cells. T cell receptor stimulation further increased APOBEC3G and APOBEC3F expression in Tbet- and control-transduced, but not in GATA3-transduced, cells. Neutralizing anti-interferon-gamma antibodies reduced both basal and T cell receptor-stimulated APOBEC3G and APOBEC3F expression in Tbet- and control-transduced cells. HIV-1 produced from Th1 cells had more virion APOBEC3G, and decreased infectivity, compared to virions produced from Th2 cells. These differences between Th1- and Th2-produced virions were greater for viruses lacking functional vif, but also seen with vif-positive viruses. Over-expression of APOBEC3G in Th2 cells decreased the infectivity of virions produced from Th2 cells, and reduction of APOBEC3G in Th1 cells increased infectivity of virions produced from Th1 cells, consistent with a causal role for APOBEC3G in the infectivity difference. These results indicate that APOBEC3G and APOBEC3F levels vary physiologically during CD4+ T lymphocyte differentiation, that interferon-gamma contributes to this modulation, and that this physiological regulation can cause changes in infectivity of progeny virions, even in the presence of HIV-1 vif.

  9. CD4(+) T-cell activation is differentially modulated by bacteria-primed dendritic cells, but is generally down-regulated by n-3 polyunsaturated fatty acids.

    Science.gov (United States)

    Brix, Susanne; Lund, Pia; Kjaer, Tanja M R; Straarup, Ellen M; Hellgren, Lars I; Frøkiaer, Hanne

    2010-03-01

    Appropriate activation of CD4(+) T cells is fundamental for efficient initiation and progression of acquired immune responses. Here, we showed that CD4(+) T-cell activation is dependent on changes in membrane n-3 polyunsaturated fatty acids (PUFAs) and is dynamically regulated by the type of signals provided by dendritic cells (DCs). Upon interaction with DCs primed by different concentrations and species of gut bacteria, CD4(+) T cells were activated according to the type of DC stimulus. The levels of CD80 were found to correlate to the levels of expression of CD28 and to the proliferation of CD4(+) T cells, while the presence of CD40 and CD86 on DCs inversely affected inducible costimulator (ICOS) and cytotoxic T-lymphocyte antigen-4 (CTLA-4) levels in CD4(+) T cells. For all DC stimuli, cells high in n-3 PUFAs showed reduced ability to respond to CD28 stimulation, to proliferate, and to express ICOS and CTLA-4. Diminished T-cell receptor (TCR) and CD28 signalling was found to be responsible for n-3 PUFA effects. Thus, the dietary fatty acid composition influences the overall level of CD4(+) T-cell activation induced by DCs, while the priming effect of the DC stimuli modulates CD80, CD86 and CD40 levels, thereby affecting and shaping activation of acquired immunity by differential regulation of proliferation and costimulatory molecule expression in CD4(+) T cells.

  10. Oregano Essential Oil Improves Intestinal Morphology and Expression of Tight Junction Proteins Associated with Modulation of Selected Intestinal Bacteria and Immune Status in a Pig Model

    Directory of Open Access Journals (Sweden)

    Yi Zou

    2016-01-01

    Full Text Available Oregano essential oil (OEO has long been used to improve the health of animals, particularly the health of intestine, which is generally attributed to its antimicrobial and anti-inflammatory effects. However, how OEO acts in the intestine of pig is still unclear. This study was aimed at elucidating how OEO promotes the intestinal barrier integrity in a pig model. Pigs were fed a control diet alone or one supplemented with 25 mg/kg of OEO for 4 weeks. The OEO-treated pigs showed decreased (P<0.05 endotoxin level in serum and increased (P<0.05 villus height and expression of occludin and zonula occludens-1 (ZO-1 in the jejunum. These results demonstrated that the integrity of intestinal barrier was improved by OEO treatment. The OEO-treated pigs had a lower (P<0.05 population of Escherichia coli in the jejunum, ileum, and colon than the control. This is in accordance with the greater inactivation (P<0.05 of inflammation, which was reflected by the mitogen-activated protein kinase (MAPK, protein kinase B (Akt, and nuclear factor κB (NF-κB signaling pathways and expression of inflammatory cytokines in the jejunum. Our results show that OEO promotes intestinal barrier integrity, probably through modulating intestinal bacteria and immune status in pigs.

  11. Relationship between black-pigmented bacteria and dental pulp infections%产黑色素类杆菌与牙髓感染相关性分析

    Institute of Scientific and Technical Information of China (English)

    马珅; 吕朋君; 李桂红

    2015-01-01

    OBJECTIVE To investigate the species of the black‐pigmented bacteria isolated from the patient with dental pulp infections and explore the relationship between the black‐pigmented bacteria and the clinical symptoms of dental pulp infections so as to provide guidance for clinical treatment of the dental pulp infections .METHODS A total of 102 patients with dental pulp infections who were treated in department of stomatology from Aug 2012 to Dec 2013 were enrolled in the study and divided into the symptomatic group with 95 cases and the asymptomatic group with 7 cases according to the clinical symptoms .The clinical symptoms of all the patients ,including the toothache ,diameter of shadow of root tip ,and pus in fistula and root canal ,were examined and recorded .The an‐aerobic bacteria extracted from the root canal were cultured ,and the black‐pigmented bacteria were identified by u‐sing polymerase‐chain‐reaction .RESULTS The detection rate of the black‐pigmented bacteria was 80 .0% in the symptomatic group ,28 .6% in the asymptomatic group ,and there was significant difference between the two groups (P<0 .05) .Among the 137 strains of black‐pigmented bacteria isolated ,there were 5 (70 .1% ) sugar so‐lution species and 2 (29 .9% ) species of Peptoniphilus asaccharolyticus (P< 0 .05) .The detection rate of the black‐pigmented bacteria was higher in the patients with the clinical symptoms such as toothache ,local swelling , and pus in root canal than in the patients without the clinical symptoms (P<0 .05);the bacterial colony counts of the root canal of the symptomatic group were significantly higher than those of the asymptomatic group .CONCLUSION The clinical symptoms of dental pulp infection is closely associated with the black‐pigmented bacteria ,which is dominated by sugar solution species ,and it is necessary for the hospital to pay attention to the root canal .%目的:分析牙髓感染患者患牙的产黑色素类杆菌种属以

  12. siRNA Screen Identifies Trafficking Host Factors that Modulate Alphavirus Infection.

    Science.gov (United States)

    Radoshitzky, Sheli R; Pegoraro, Gianluca; Chī, Xi Olì; D Ng, Lián; Chiang, Chih-Yuan; Jozwick, Lucas; Clester, Jeremiah C; Cooper, Christopher L; Courier, Duane; Langan, David P; Underwood, Knashka; Kuehl, Kathleen A; Sun, Mei G; Caì, Yíngyún; Yú, Shu Qìng; Burk, Robin; Zamani, Rouzbeh; Kota, Krishna; Kuhn, Jens H; Bavari, Sina

    2016-03-01

    Little is known about the repertoire of cellular factors involved in the replication of pathogenic alphaviruses. To uncover molecular regulators of alphavirus infection, and to identify candidate drug targets, we performed a high-content imaging-based siRNA screen. We revealed an actin-remodeling pathway involving Rac1, PIP5K1- α, and Arp3, as essential for infection by pathogenic alphaviruses. Infection causes cellular actin rearrangements into large bundles of actin filaments termed actin foci. Actin foci are generated late in infection concomitantly with alphavirus envelope (E2) expression and are dependent on the activities of Rac1 and Arp3. E2 associates with actin in alphavirus-infected cells and co-localizes with Rac1-PIP5K1-α along actin filaments in the context of actin foci. Finally, Rac1, Arp3, and actin polymerization inhibitors interfere with E2 trafficking from the trans-Golgi network to the cell surface, suggesting a plausible model in which transport of E2 to the cell surface is mediated via Rac1- and Arp3-dependent actin remodeling.

  13. siRNA Screen Identifies Trafficking Host Factors that Modulate Alphavirus Infection.

    Directory of Open Access Journals (Sweden)

    Sheli R Radoshitzky

    2016-03-01

    Full Text Available Little is known about the repertoire of cellular factors involved in the replication of pathogenic alphaviruses. To uncover molecular regulators of alphavirus infection, and to identify candidate drug targets, we performed a high-content imaging-based siRNA screen. We revealed an actin-remodeling pathway involving Rac1, PIP5K1- α, and Arp3, as essential for infection by pathogenic alphaviruses. Infection causes cellular actin rearrangements into large bundles of actin filaments termed actin foci. Actin foci are generated late in infection concomitantly with alphavirus envelope (E2 expression and are dependent on the activities of Rac1 and Arp3. E2 associates with actin in alphavirus-infected cells and co-localizes with Rac1-PIP5K1-α along actin filaments in the context of actin foci. Finally, Rac1, Arp3, and actin polymerization inhibitors interfere with E2 trafficking from the trans-Golgi network to the cell surface, suggesting a plausible model in which transport of E2 to the cell surface is mediated via Rac1- and Arp3-dependent actin remodeling.

  14. The attribution of human infections with antimicrobial resistant Salmonella bacteria in Denmark to sources of animal origin

    DEFF Research Database (Denmark)

    Hald, Tine; Lo Fo Wong, Danilo M. A.; Aarestrup, Frank Møller

    2007-01-01

    that of resistant isolates, which in turn was higher than that of susceptible isolates. This may be due to quinolone-resistant isolates having a higher ability to survive food processing and/or cause disease. This study showed domestic food to be the most important source of Salmonella infections in Denmark...

  15. Does nuclear tissue infected with bacteria following disc herniations lead to Modic changes in the adjacent vertebrae?

    DEFF Research Database (Denmark)

    Albert, H. B.; Lambert, Peter; Rollason, Jess

    2013-01-01

    ) in vertebrae are observed in 6 % of the general population and in 35-40 % of people with low back pain. These changes are strongly associated with low back pain. There are probably a mechanical cause and an infective cause that causes MC. Several studies on nuclear tissue from herniated discs have demonstrated...

  16. Investigating the Effect of Different Treatments with Lactic Acid Bacteria on the Fate of Listeria monocytogenes and Staphylococcus aureus Infection in Galleria mellonella Larvae

    Science.gov (United States)

    Grounta, Athena; Harizanis, Paschalis; Mylonakis, Eleftherios; Nychas, George-John E.; Panagou, Efstathios Z.

    2016-01-01

    The use of Galleria mellonella as a model host to elucidate microbial pathogenesis and search for novel drugs and therapies has been well appreciated over the past years. However, the effect of microorganisms with functional appeal in the specific host remains scarce. The present study investigates the effect of treatment with selected lactic acid bacteria (LAB) with probiotic potential, as potential protective agents by using live or heat-killed cells at 6 and 24 h prior to infection with Listeria monocytogenes and Staphylococcus aureus or as potential therapeutic agents by using cell-free supernatants (CFS) after infection with the same pathogens. The employed LAB strains were Lactobacillus pentosus B281 and Lactobacillus plantarum B282 (isolated from table olive fermentations) along with Lactobacillus rhamnosus GG (inhabitant of human intestinal tract). Kaplan-Meier survival curves were plotted while the pathogen’s persistence in the larval hemolymph was determined by microbiological analysis. It was observed that the time (6 or 24 h) and type (live or heat-killed cells) of challenge period with LAB prior to infection greatly affected the survival of infected larvae. The highest decrease of L. monocytogenes population in the hemolymph was observed in groups challenged for 6 h with heat-killed cells by an average of 1.8 log units compared to non challenged larvae for strains B281 (p 0.0322), B282 (p 0.0325), and LGG (p 0.0356). In the case of S. aureus infection, the population of the pathogen decreased in the hemolymph by 1 log units at 8 h post infection in the groups challenged for 6 h with heat-killed cells of strains B281 (p 0.0161) and B282 (p 0.0096) and by 1.8 log units in groups challenged with heat-killed cells of LGG strain (p 0.0175). Further use of CFS of each LAB strain did not result in any significant prolonged survival but interestingly it resulted in pronounced decrease of L. monocytogenes in the hemolymph at 24 h and 48 h after infection by

  17. Prevalence of Device-associated Nosocomial Infections Caused By Gram-negative Bacteria in a Trauma Intensive Care Unit in Libya

    Directory of Open Access Journals (Sweden)

    Abdulaziz Zorgani

    2015-07-01

    Full Text Available Objectives: Device-associated nosocomial infections (DANIs have a major impact on patient morbidity and mortality. Our study aimed to determine the distribution rate of DANIs and causative agents and patterns of antibiotic resistance in the trauma-surgical intensive care unit (ICU. Methods: Our study was conducted at Abusalim Trauma Hospital in Tripoli, Libya. All devices associated with nosocomial infections, including central venous catheters (CVC, endotracheal tubes (ETT, Foley’s urinary catheters, chest tubes, nasogastric tubes (NGT, and tracheostomy tubes, were removed aseptically and examined for Gram-negative bacteria (GNB. Results: During a one-year study period, 363 patients were hospitalized; the overall mortality rate was 29%. A total of 79 DANIs were identified, the most common site of infection was ETT (39.2%, followed by urinary catheters (19%, NGTs (18%, tracheostomy tubes (11%, CVCs (10%, and chest tubes (3%. The most frequently isolated organisms were Klebsiella pneumonia, Acinetobacter baumannii, and Pseudomonas aeruginosa (30%, 20%, and 14%, respectively. Extremely high resistance rates were observed among GNB to ampicillin (99%, cefuroxime (95%, amoxicillin-clavulante (92%, and nitrofurantoin (91%. Lower levels of resistance were exhibited to amikacin (38%, imipenem (38%, and colistin (29%. About 39% of the isolates were defined as multi-drug resistant (MDR. Overall, extended spectrum β-lactmase producers were expressed in 39% of isolates mainly among K. pneumonia (88%. A. baumannii isolates exhibited extremely high levels of resistance to all antibiotics except colistin (100% sensitive. In addition, 56.3% of A. baumannii isolates were found to be MDR. P. aeruginosa isolates showed 46%–55% effectiveness to anti-pseudomonas antibiotics. Conclusion: High rates of DANI’s and the emergence of MDR organisms poses a serious threat to patients. There is a need to strengthen infection control within the ICU environment

  18. Anaplasmataceae and Borrelia burgdorferi sensu lato in the sand lizard Lacerta agilis and co-infection of these bacteria in hosted Ixodes ricinus ticks

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    Ekner Anna

    2011-09-01

    Full Text Available Abstract Background Anaplasmataceae and Borrelia burgdorferi s.l. are important tick-borne bacteria maintained in nature by transmission between ticks and vertebrate hosts. However, the potential role of lizards as hosts has not been sufficiently studied. Results The current study showed that 23 of 171 examined sand lizards Lacerta agilis were PCR positive for Anaplasmataceae. The nucleotide sequences of the several selected PCR products showed 100% homology with Anaplasma spp. found in Ixodes ricinus collected in Tunisia and Morocco (AY672415 - AY672420. 1.2% of lizard collar scale samples were PCR positive for B. lusitaniae. In addition, 12 of 290 examined I. ricinus were PCR positive for B. burgdorferi s.l. and 82 were PCR positive for Anaplasmatacea. The number of ticks per lizard and the number of ticks PCR positive for both microorganisms per lizard were strongly correlated. Moreover, we found a significant correlation between numbers of ticks infected with Anaplasmataceae and with B. burgdorferi s.l. living on the same lizard. However, there was no significant correlation between detection of both bacteria in the same tick. Conclusions To the best of our knowledge, this is the first report of Anaplasmataceae DNA and additionally the second report of B. burgdorferi s.l DNA detection in the sand lizard.

  19. Frequency and Susceptibility of Bacteria Caused Urinary Tract Infection in Neonates: Eight-Year Study at Neonatal Division of Bahrami Children's Hospital, Tehran Iran.

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    Peymaneh Alizadeh Taheri

    2013-10-01

    Full Text Available Susceptibility pattern of organisms causing urinary tract infection (UTI in neonate would potentially improve the clinical management by enabling clinicians to choose most reasonable first line empirical antibiotics. This study aimed to this end by studying isolated organisms from neonates with UTI in an inpatient setting.Current retrospective study has recruited all cases of neonatal UTI diagnosed through a suprapubic/catheterized sample, admitted to Neonatal Division of Bahrami Children's Hospital, Tehran, Iran, from June 2004 to June 2012.Escherichia coli was the dominant (64.4% bacteria among a total of 73 cases (69.9% boys and 30.1% girls; aged 14.14 ± 7.68 days; birth weight of 3055.85 ± 623.00 g and Enterobacter (19.2%, Klebsiella (12.3%, and Staphylococcus epidermdisis (4.1% were less frequent isolated bacteria. E. coli was mostly resistant to ampicillin (93.6%, cefixime (85.7% and cephalexin (77.3%, and sensitive to cefotaxime (63.6%. Enterobacter found to be most resistant to amikacin (100%, ampicillin (92.85%, and most sensitive to ceftizoxime (71.4%.A high ratio (> 92.85% of resistance toward ampicillin was observed among common neonatal UTI bacterial agents. Having this finding along with previous reports of emerging resistance of neonatal uropathogensto ampicillin could be a notion that a combination of a third generation cephalosporin and an aminoglycoside would be a more reasonable first choice than ampicillin plus an aminoglycoside.

  20. Results of a double-blind, randomized trial of ceftobiprole treatment of complicated skin and skin structure infections caused by gram-positive bacteria.

    Science.gov (United States)

    Noel, Gary J; Strauss, Richard S; Amsler, Karen; Heep, Markus; Pypstra, Rienk; Solomkin, Joseph S

    2008-01-01

    Ceftobiprole is the first broad-spectrum cephalosporin with activity against methicillin-resistant Staphylococcus aureus (MRSA) to be assessed in late-stage clinical trials. As a pivotal step in the clinical development of ceftobiprole, a multicenter, global, randomized, double-blind trial was conducted to compare the efficacy of ceftobiprole to that of vancomycin in patients with complicated skin and skin structure infections (cSSSIs) caused by gram-positive bacteria. The primary objective was to assess noninferiority on the basis of the cure rates 7 to 14 days after the completion of therapy in patients administered ceftobiprole 500 mg every 12 h or vancomycin 1 g every 12 h. Of 784 patients randomized, 282 receiving ceftobiprole and 277 receiving vancomycin were clinically evaluable. Of these patients, 93.3% treated with ceftobiprole and 93.5% treated with vancomycin were cured (95% confidence interval of difference, -4.4%, 3.9%). The cure rates for patients with MRSA infections were 91.8% (56/61) with ceftobiprole treatment and 90.0% (54/60) with vancomycin treatment (95% confidence interval of difference, -8.4%, 12.1%). At least one adverse event (AE) was reported by 52% of the ceftobiprole-treated patients and 51% of the vancomycin-treated patients. The most common AEs reported by the ceftobiprole-treated patients were nausea (14%) and taste disturbance (8%). Discontinuation of the study drug because of treatment-emergent AEs occurred in 4% (n = 17) of the ceftobiprole-treated patients and 6% (n = 22) of the vancomycin-treated patients. The results of this trial support the use of ceftobiprole as an effective and well-tolerated treatment option for patients with cSSSIs caused by a spectrum of gram-positive bacteria.

  1. Kupffer cells modulate hepatic fatty acid oxidation during infection with PR8 influenza.

    Science.gov (United States)

    Tarasenko, Tatyana N; Singh, Larry N; Chatterji-Len, Milani; Zerfas, Patricia M; Cusmano-Ozog, Kristina; McGuire, Peter J

    2015-11-01

    In response to infection, patients with inborn errors of metabolism may develop a functional deterioration termed metabolic decompensation. The biochemical hallmarks of this disruption of metabolic homeostasis are disease specific and may include acidosis, hyperammonemia or hypoglycemia. In a model system previously published by our group, we noted that during influenza infection, mice displayed a depression in hepatic mitochondrial enzymes involved in nitrogen metabolism. Based on these findings, we hypothesized that this normal adaptation may extend to other metabolic pathways, and as such, may impact various inborn errors of metabolism. Since the liver is a critical organ in inborn errors of metabolism, we carried out untargeted metabolomic profiling of livers using mass spectrometry in C57Bl/6 mice infected with influenza to characterize metabolic adaptation. Pathway analysis of metabolomic data revealed reductions in CoA synthesis, and long chain fatty acyl CoA and carnitine species. These metabolic adaptations coincided with a depression in hepatic long chain β-oxidation mRNA and protein. To our surprise, the metabolic changes observed occurred in conjunction with a hepatic innate immune response, as demonstrated by transcriptional profiling and flow cytometry. By employing an immunomodulation strategy to deplete Kupffer cells, we were able to improve the expression of multiple genes involved in β-oxidation. Based on these findings, we are the first to suggest that the role of the liver as an immunologic organ is central in the pathophysiology of hepatic metabolic decompensation in inborn errors of metabolism due to respiratory viral infection.

  2. Modulation of the cellular immune response during Plasmodium falciparum infections in sickle cell trait individuals

    DEFF Research Database (Denmark)

    Abu-Zeid, Y A; Theander, T G; Abdulhadi, N H

    1992-01-01

    Plasma and peripheral blood mononuclear cells (PBMC) were obtained from P. falciparum-infected individuals with and without the sickle cell trait at diagnosis and 7 days after treatment. HbAA and HbAS patients were compared for levels of plasma soluble IL-2 receptors (IL-2R) and the in vitro...

  3. Papain-Based Vaccination Modulates Schistosoma mansoni Infection-Induced Cytokine Signals.

    Science.gov (United States)

    Abdel Aziz, N; Tallima, H; Hafez, E A; El Ridi, R

    2016-02-01

    We have previously shown that immunization of outbred rodents with cysteine peptidases-based vaccine elicited type 2-biased immune responses associated with consistent and reproducible protection against challenge Schistosoma mansoni. We herein start to elucidate the molecular basis of C57BL/6 mouse resistance to S. mansoni following treatment with the cysteine peptidase, papain. We evaluated the early cytokine signals delivered by epidermal, dermal, and draining lymph node cells of naïve, and S. mansoni -infected mice treated 1 day earlier with 0 or 50 μg papain, or immunized twice with papain only (10 μg/mouse), papain-free recombinant S. mansoni glyceraldehyde 3-phosphate dehydrogenase and 2-Cys peroxiredoxin peptide (10 and 15 μg/mouse, respectively = antigen Mix), or papain-adjuvanted antigen Mix. Schistosoma mansoni infection induced epidermal and lymph node cells to release type 1, type 2 and type 17 cytokines, known to counteract each other. Expectedly, humoral immune responses were negligible until patency. Papain pretreatment or papain-based vaccination diminished or shut off S. mansoni infection early induction of type 1, type 17 and type 2 cytokines except for thymic stromal lymphopoietin and programmed the immune system towards a polarized type 2 immune milieu, associated with highly significant (P < 0.005 - <0.0001) resistance to S. mansoni infection.

  4. Modulating Innate Immunity Improves Hepatitis C Virus Infection and Replication in Stem Cell-Derived Hepatocytes

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    Xiaoling Zhou

    2014-07-01

    Full Text Available In this study, human embryonic stem cell-derived hepatocytes (hESC-Heps were investigated for their ability to support hepatitis C virus (HCV infection and replication. hESC-Heps were capable of supporting the full viral life cycle, including the release of infectious virions. Although supportive, hESC-Hep viral infection levels were not as great as those observed in Huh7 cells. We reasoned that innate immune responses in hESC-Heps may lead to the low level of infection and replication. Upon further investigation, we identified a strong type III interferon response in hESC-Heps that was triggered by HCV. Interestingly, specific inhibition of the JAK/STAT signaling pathway led to an increase in HCV infection and replication in hESC-Heps. Of note, the interferon response was not evident in Huh7 cells. In summary, we have established a robust cell-based system that allows the in-depth study of virus-host interactions in vitro.

  5. Plasmalemmal vesicle associated protein (PV1) modulates SV40 virus infectivity in CV-1 cells.

    Science.gov (United States)

    Tse, Dan; Armstrong, David A; Oppenheim, Ariella; Kuksin, Dmitry; Norkin, Leonard; Stan, Radu V

    2011-08-26

    Plasmalemmal vesicle associated protein (Plvap/PV1) is a structural protein required for the formation of the stomatal diaphragms of caveolae. Caveolae are plasma membrane invaginations that were implicated in SV40 virus entry in primate cells. Here we show that de novo Plvap/PV1 expression in CV-1 green monkey epithelial cells significantly reduces the ability of SV40 virus to establish productive infection, when cells are incubated with low concentrations of the virus. However, in presence of high viral titers PV1 has no effect on SV40 virus infectivity. Mechanistically, PV1 expression does not reduce the cell surface expression of known SV40 receptors such as GM1 ganglioside and MHC class I proteins. Furthermore, PV1 does not reduce the binding of virus-like particles made by SV40 VP1 protein to the CV-1 cell surface and does not impact their internalization when cells are incubated with either high or low VLP concentrations. These results suggest that PV1 protein is able to block SV40 infectivity at low but not at high viral concentration either by interfering with the infective internalization pathway at the cell surface or at a post internalization step.

  6. Antibiotic Resistance of Bacteria Involved in Urinary Infections in Brazil: A Cross-Sectional and Retrospective Study

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    Wellington Francisco Rodrigues

    2016-09-01

    Full Text Available Empirical and prolonged antimicrobial treatment of urinary tract infections caused by Escherichia coli is associated with the emergence of bacterial resistance, and not all countries have strict policies against the indiscriminate use of drugs in order to prevent resistance. This cross-sectional and retrospective study (2010–2015 aimed to evaluate the sensitivity and resistance of patient-derived E. coli to different drugs broadly used to treat urinary infections in Brazil: ampicillin + sulbactam, cephalothin, ciprofloxacin, norfloxacin, and nitrofurantoin. We obtained 1654 E. coli samples from ambulatory patients with disease symptoms of the urinary tract from a Brazilian public hospital. While all antibiotics were effective in killing E. coli to a large degree, nitrofurantoin was the most effective, with fewer samples exhibiting antibiotic resistance. We assessed the costs of generic and brand name versions of each antibiotic. Nitrofurantoin, the most effective antibiotic, was the cheapest, followed by the fluoroquinolones (ciprofloxacin and norfloxacin, ampicillin + sulbactam and, lastly, cephalothin. Finally, assessment of antibiotic resistance to fluoroquinolones over the study period and extrapolation of the data led to the conclusion that these antibiotics could no longer be effective against E. coli-based urinary infections in approximately 20 years if their indiscriminate use in empirical treatment continues.

  7. Antibiotic Resistance of Bacteria Involved in Urinary Infections in Brazil: A Cross-Sectional and Retrospective Study

    Science.gov (United States)

    Rodrigues, Wellington Francisco; Miguel, Camila Botelho; Nogueira, Ana Paula Oliveira; Ueira-Vieira, Carlos; Paulino, Tony De Paiva; Soares, Siomar De Castro; De Resende, Elisabete Aparecida Mantovani Rodrigues; Lazo-Chica, Javier Emilio; Araújo, Marcelo Costa; Oliveira, Carlo José

    2016-01-01

    Empirical and prolonged antimicrobial treatment of urinary tract infections caused by Escherichia coli is associated with the emergence of bacterial resistance, and not all countries have strict policies against the indiscriminate use of drugs in order to prevent resistance. This cross-sectional and retrospective study (2010–2015) aimed to evaluate the sensitivity and resistance of patient-derived E. coli to different drugs broadly used to treat urinary infections in Brazil: ampicillin + sulbactam, cephalothin, ciprofloxacin, norfloxacin, and nitrofurantoin. We obtained 1654 E. coli samples from ambulatory patients with disease symptoms of the urinary tract from a Brazilian public hospital. While all antibiotics were effective in killing E. coli to a large degree, nitrofurantoin was the most effective, with fewer samples exhibiting antibiotic resistance. We assessed the costs of generic and brand name versions of each antibiotic. Nitrofurantoin, the most effective antibiotic, was the cheapest, followed by the fluoroquinolones (ciprofloxacin and norfloxacin), ampicillin + sulbactam and, lastly, cephalothin. Finally, assessment of antibiotic resistance to fluoroquinolones over the study period and extrapolation of the data led to the conclusion that these antibiotics could no longer be effective against E. coli-based urinary infections in approximately 20 years if their indiscriminate use in empirical treatment continues. PMID:27649224

  8. C. difficile Infection

    Science.gov (United States)

    ... Patients Home / Digestive Health Topic / C. Difficile Infection C. Difficile Infection Basics Overview Diarrhea is a frequent ... that change the normal colon bacteria allowing the C. difficile bacteria to grow and produce its toxins. ...

  9. Development of aptamers for use as radiopharmaceuticals in the bacterial infection identification; Desenvolvimento de aptameros especificos para aplicacao como radiofarmacos na identificacao de bacterias

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Ieda Mendes

    2013-08-01

    The difficulty in early detection of specific foci caused by bacteria in the bacterial infection has raised the need to search for new techniques for this purpose, since these foci require prolonged treatment with antibiotics and in some cases even drainage or, if applicable, removal of prostheses or grafts. Detection of bacterial infections by scintigraphy had the advantage that a whole body image could be obtained, since specific tracers were available. This study aims to obtain aptamers specific for bacteria identification for future use as radiopharmaceutical. The SELEX (Systematic Evolution of Ligands by Exponential Enrichment) methodology can generate oligonucleotides (aptamers) that are able to bind with high affinity and specificity to a specific target, from small molecules to complex proteins, by using rounds of enrichment and amplification. Aptamers can be labeled with different radionucleotides such as {sup 99}mTc, {sup 18}F and {sup 32}P. In this study, aptamers anti-peptidoglycan, the main component of the bacterial outer cell wall, were obtained through SELEX. Whole cells of Staphylococcus aureus were also used to perform the SELEX to cells (cell-SELEX). The selection of aptamers was performed by two different procedures (A and B). The A process has been accomplished by 15 SELEX rounds in which the separation of the oligonucleotides bound to the peptidoglycan of unbound ones was performed by filtration. In the B process 15 SELEX rounds were performed using the centrifugation for this separation, followed by 5 rounds cell-SELEX. The SELEX started with a pool of ssDNA (single stranded DNA). For A process, initially a library of ssDNA was incubated with peptidoglycan and the amplification of oligonucleotides that were able to bind to peptidoglycan was performed by PCR (Polymerase Chain Reation). The amplified oligonucleotides were again incubated with peptidoglycan, amplified and purified. At the end of 15 selection rounds the selected oligonucleotides

  10. Macrophages and lymphocytes differentially modulate the ability of RANTES to inhibit HIV-1 infection.

    Science.gov (United States)

    Gross, Eleanore; Amella, Carol A; Pompucci, Lorena; Franchin, Giovanni; Sherry, Barbara; Schmidtmayerova, Helena

    2003-11-01

    The beta-chemokines MIP-1alpha, MIP-1beta, and RANTES inhibit HIV-1 infection of CD4+ T cells by inhibiting interactions between the virus and CCR5 receptors. However, while beta-chemokine-mediated inhibition of HIV-1 infection of primary lymphocytes is well documented, conflicting results have been obtained using primary macrophages as the virus target. Here, we show that the beta-chemokine RANTES inhibits virus entry into both cellular targets of the virus, lymphocytes and macrophages. However, while virus entry is inhibited at the moment of infection in both cell types, the amount of virus progeny is lowered only in lymphocytes. In macrophages, early-entry restriction is lost during long-term cultivation, and the amount of virus produced by RANTES-treated macrophages is similar to the untreated cultures, suggesting an enhanced virus replication. We further show that at least two distinct cellular responses to RANTES treatment in primary lymphocytes and macrophages contribute to this phenomenon. In lymphocytes, exposure to RANTES significantly increases the pool of inhibitory beta-chemokines through intracellular signals that result in increased production of MIP-1alpha and MIP-1beta, thereby amplifying the antiviral effects of RANTES. In macrophages this amplification step does not occur. In fact, RANTES added to the macrophages is efficiently cleared from the culture, without inducing synthesis of beta-chemokines. Our results demonstrate dichotomous effects of RANTES on HIV-1 entry at the moment of infection, and on production and spread of virus progeny in primary macrophages. Since macrophages serve as a reservoir of HIV-1, this may contribute to the failure of endogenous chemokines to successfully eradicate the virus.

  11. Salmonella infection induces recruitment of Caspase-8 to the inflammasome to modulate IL-1β production.

    Science.gov (United States)

    Man, Si Ming; Tourlomousis, Panagiotis; Hopkins, Lee; Monie, Tom P; Fitzgerald, Katherine A; Bryant, Clare E

    2013-11-15

    Nucleotide-binding oligomerization domain-like receptors (NLRs) detect pathogens and danger-associated signals within the cell. Salmonella enterica serovar Typhimurium, an intracellular pathogen, activates caspase-1 required for the processing of the proinflammatory cytokines, pro-IL-1β and pro-IL-18, and pyroptosis. In this study, we show that Salmonella infection induces the formation of an apoptosis-associated specklike protein containing a CARD (ASC)-Caspase-8-Caspase-1 inflammasome in macrophages. Caspase-8 and caspase-1 are recruited to the ASC focus independently of one other. Salmonella infection initiates caspase-8 proteolysis in a manner dependent on NLRC4 and ASC, but not NLRP3, caspase-1 or caspase-11. Caspase-8 primarily mediates the synthesis of pro-IL-1β, but is dispensable for Salmonella-induced cell death. Overall, our findings highlight that the ASC inflammasome can recruit different members of the caspase family to induce distinct effector functions in response to Salmonella infection.

  12. The epigenetic control of hepatitis B virus modulates the outcome of infection

    Directory of Open Access Journals (Sweden)

    Lemonica eKoumbi

    2016-01-01

    Full Text Available Epigenetic modifications are stable alterations in gene expression that do not involve mutations of the genetic sequence itself. It has become increasingly clear that epigenetic factors contribute to the outcome of chronic hepatitis B virus (HBV infection by affecting cellular and virion gene expression, viral replication and the development of hepatocellular carcinoma. HBV persists in the nucleus of infected hepatocytes as a stable non-integrated covalently closed circular DNA (cccDNA which functions as a minichromosome. There are two major forms of HBV epigenetic regulation: posttranslational modification of histone proteins associated with the cccDNA minichromosome and DNA methylation of viral and host genomes. This review explores how HBV can interphase with host epigenetic regulation in order to evade host defences and to promote its own survival and persistence. We focus on the effect of cccDNA bound-histone modifications and the methylation status of HBV DNA in regulating viral replication. Investigation of HBV epigenetic control has important clinical correlates with regards to the development of potential therapeutic regimens that will successfully eradicate HBV infection and deal with HBV reactivation in those undergoing treatment with demethylating agents.

  13. Fusion and infection of influenza and Sendai viruses as modulated by dextran sulfate: a comparative study.

    Science.gov (United States)

    Ramalho-Santos, J; de Lima, M C

    2001-06-01

    We have directly compared the effect of two types of dextran sulfate with distinct molecular weights (500 kDa and 5 kDa) on the fusion activity and infectivity of both Sendai and influenza viruses, two lipid-enveloped viruses that differ in their routes of entry into target cells. To correlate membrane merging and infectivity MDCK cells were used as targets for the viruses in both approaches. In either case pronounced inhibition of virus-cell interactions by dextran sulfate was only observed at low pH, even though Sendai virus fuses maximally at pH 7.4. Although membrane merging could not be fully abolished, the inhibitory effect was always greater when the higher molecular weight dextran sulfate was used. The presence of this residual fusion activity, that could not be reduced even with high concentrations of agent, suggests that a limited number of binding sites for dextran sulfate may exist on the viral envelopes. The compounds also inhibited fusion of bound virions, and all results could be reproduced using erythrocyte ghosts as target membranes in the fusion assay, instead of MDCK cells. In agreement with these observations only the infectivity of influenza virus (which requires a low pH-dependent step to enter target cells) was affected by dextran sulfate, again the higher molecular weight compound showing a more pronounced inhibitory effect.

  14. Cathepsin B modulates lysosomal biogenesis and host defense against Francisella novicida infection.

    Science.gov (United States)

    Qi, Xiaopeng; Man, Si Ming; Malireddi, R K Subbarao; Karki, Rajendra; Lupfer, Christopher; Gurung, Prajwal; Neale, Geoffrey; Guy, Clifford S; Lamkanfi, Mohamed; Kanneganti, Thirumala-Devi

    2016-09-19

    Lysosomal cathepsins regulate an exquisite range of biological functions, and their deregulation is associated with inflammatory, metabolic, and degenerative diseases in humans. In this study, we identified a key cell-intrinsic role for cathepsin B as a negative feedback regulator of lysosomal biogenesis and autophagy. Mice and macrophages lacking cathepsin B activity had increased resistance to the cytosolic bacterial pathogen Francisella novicida Genetic deletion or pharmacological inhibition of cathepsin B down-regulated mechanistic target of rapamycin activity and prevented cleavage of the lysosomal calcium channel TRPML1. These events drove transcription of lysosomal and autophagy genes via transcription factor EB, which increased lysosomal biogenesis and activation of autophagy initiation kinase ULK1 for clearance of the bacteria. Our results identified a fundamental biological function of cathepsin B in providing a checkpoint for homeostatic maintenance of lysosome populations and basic recycling functions in the cell.

  15. The Battle between Virus and Host: Modulation of Toll-Like Receptor Signaling Pathways by Virus Infection

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    Shin-ichi Yokota

    2010-01-01

    Full Text Available In order to establish an infection, viruses need to either suppress or escape from host immune defense systems. Recent immunological research has focused on innate immunity as the first line of host defense, especially pattern recognition molecules such as Toll-like receptors (TLRs, RIG-I-like receptors (RLRs, and NOD-like receptors (NLRs. Various microbial components are recognized by their vague and common molecular shapes so-called, pathogen-associated molecular patterns (PAMPs. PAMPs induce inflammatory reactions mediated by the activation of the transcription factor, NF-B, and by interferons, which lead to an antiviral immune response. Viruses have the capacity to suppress or escape from this pattern recognition molecule-mediated antimicrobial response in various ways. In this paper, we review the various strategies used by viruses to modulate the pattern recognition molecule-mediated innate immune response.

  16. HIV-1 Infection of T Cells and Macrophages Are Differentially Modulated by Virion-Associated Hck: A Nef-Dependent Phenomenon

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    Gilda Tachedjian

    2013-09-01

    Full Text Available The proline repeat motif (PxxP of Nef is required for interaction with the SH3 domains of macrophage-specific Src kinase Hck. However, the implication of this interaction for viral replication and infectivity in macrophages and T lymphocytes remains unclear. Experiments in HIV-1 infected macrophages confirmed the presence of a Nef:Hck complex which was dependent on the Nef proline repeat motif. The proline repeat motif of Nef also enhanced both HIV-1 infection and replication in macrophages, and was required for incorporation of Hck into viral particles. Unexpectedly, wild-type Hck inhibited infection of macrophages, but Hck was shown to enhance infection of primary T lymphocytes. These results indicate that the interaction between Nef and Hck is important for Nef-dependent modulation of viral infectivity. Hck-dependent enhancement of HIV-1 infection of T cells suggests that Nef-Hck interaction may contribute to the spread of HIV-1 infection from macrophages to T cells by modulating events in the producer cell, virion and target cell.

  17. 革兰阴性菌与NSICU医院感染的关系%Relationship between gram-negative bacteria and nosocomial infections in neurological intensive care unit

    Institute of Scientific and Technical Information of China (English)

    于垚; 元艺; 元小冬; 许亚茹; 王淑娟; 刘顺莉; 王小玲; 郑秀芬; 徐应军

    2012-01-01

    目的 研究革兰阴性菌在NSICU环境中的分布及其所致医院感染的特征,为其防治提供理论依据.方法 选取2010年10月-2011年9月某医院NSICU发生医院感染患者进行病原学检查及药敏试验,同时监测NSICU空气和病床单位的细菌学分布特征.结果 209例患者中有61例发生医院感染,感染率为29.2%;其中42例进行了病原学检测,检出革兰阴性菌占77.9%,其中肺炎克雷伯菌和铜绿假单胞菌分别占25.9%和23.3%,均对左氧氟沙星敏感;在病房环境中检出的病原菌以革兰阴性杆菌为主,主要为鲍氏不动杆菌.结论 革兰阴性杆菌是引发NSICU医院感染最重要的病原菌之一,下呼吸道是最易发生医院感染的部位,其病原菌主要为肺炎克雷伯菌和铜绿假单胞菌;NSICU环境是除肺炎克雷伯菌以外的其他革兰阴性杆菌感染的主要传播途径,肺炎克雷伯菌对大多数抗菌药物敏感,而其他革兰阴性杆菌对于多数抗菌药物具有不同程度的耐药性.%OBJECTIVE To analyze the distribution of the gram-negative in neurological intensive care unit environment and the clinical characteristics of nosocomial infection patients in neurological intensive care unit,so as to institute prevention strategy for nosocomial infection caused by G~ bacteria. METHODS All inpatients admitted to neurological intensive care unit of the hospital from Dec. 2010 to Sep. 2011were collected as monitoring objectives. The results of pathogen identification and drug susceptibility test were recorded. The microbiological characteristics of indoor environment (air-environment and the bed-unit) of the ward were also monitored. RESULTS During the study period, there were 61 patients got nosocomial infection among all 209 monitoring objectives,the incidence was 29. 2%. 42 patients received the pathogenic examination, and G~ bacteria accounted for 77. 9%. Among the gram-negative bacilli,K. Pneumoniae and P. Aeruginosa

  18. Antibacterial activity of Valeriana jatamansi against extended-spectrum β-lactamase producing Gramnegative bacteria causing urinary tract infections

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    Babar Habib

    2016-10-01

    Full Text Available Objective: To find out the antibacterial activity of Valeriana jatamansi (V. jatamansi rhizomes against the extended-spectrum β-lactamases (ESBLs producing isolates of Enterobacteriaceae family. Methods: Confirmation of ESBLs producing Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae and Hafnia alvei isolated from urinary tract infections was performed by double disc diffusion assay. Antimicrobial susceptibility of all ESBLs producing isolates was determined by disc diffusion method following guidelines of Clinical and Laboratory Standards Institute. Successive extraction of rhizomes of V. jatamansi was performed with hexane, chloroform and methanol using Soxhelt apparatus. These extracts were tested against the ESBLs producing isolates using well diffusion method. Results: Hexane extract showed significant results as compared to chloroform and methanol extracts with the maximum zone of inhibition (21 mm while ciprofloxacin and amikacin were used as standard drugs. Conclusions: Findings of the study suggested that hexane extract of V. jatamansi can be used in combination with other antibiotics as alternative treatment for urinary tract infections caused by ESBLs producing strains of Enterobacteriaceae.

  19. Horse species symposium: a novel approach to monitoring pathogen progression during uterine and placental infection in the mare using bioluminescence imaging technology and lux-modified bacteria.

    Science.gov (United States)

    Ryan, P L; Christiansen, D L; Hopper, R M; Walters, F K; Moulton, K; Curbelo, J; Greene, J M; Willard, S T

    2011-05-01

    Uterine and placental infections are the leading cause of abortion, stillbirth, and preterm delivery in the mare. Whereas uterine and placental infections in women have been studied extensively, a comprehensive examination of the pathogenic processes leading to this unsatisfactory pregnancy outcome in the mare has yet to be completed. Most information in the literature relating to late-term pregnancy loss in mares is based on retrospective studies of clinical cases submitted for necropsy. Here we report the development and application of a novel approach, whereby transgenically modified bacteria transformed with lux genes of Xenorhabdus luminescens or Photorhabdus luminescens origin and biophotonic imaging are utilized to better understand pathogen-induced preterm birth in late-term pregnant mares. This technology uses highly sensitive bioluminescence imaging camera systems to localize and monitor pathogen progression during tissue invasion by measuring the bioluminescent signatures emitted by the lux-modified pathogens. This method has an important advantage in that it allows for the potential tracking of pathogens in vivo in real time and over time, which was hitherto impossible. Although the application of this technology in domestic animals is in its infancy, investigators were successful in identifying the fetal lungs, sinuses, nares, urinary, and gastrointestinal systems as primary tissues for pathogen invasion after experimental infection of pregnant mares with lux-modified Escherichia coli. It is important that pathogens were not detected in other vital organs, such as the liver, brain, and cardiac system. Such precision in localizing sites of pathogen invasion provides potential application for this novel approach in the development of more targeted therapeutic interventions for pathogen-related diseases in the equine and other domestic species.

  20. Analysis of pathogenic bacteria distribution and drug resistance in oral and maxillofacial infection%口腔颌面部间隙感染患者多药耐药菌分析

    Institute of Scientific and Technical Information of China (English)

    徐贤寅; 沈波; 林莉莉

    2016-01-01

    Objective To observe the multi -drug resistant bacteria in oral and maxillofacial space infection , so as to provide the basis for the control of clinical infections .Methods A total of 51 cases of patients with oral and maxillofacial infection were selected , and a total 10 strains of the multi -drug resistant bacteria were detected .The antibiotic sus-ceptibility tests were carried out .The species and drug resistance of the bacteria were compared with that of the multi -drug resistant bacteria de-tected during the same period in our hospital .Statistical analysis of the data was carried out with the software SPSS 19.0.Results The main multi-drug resistant bacteria in oral and maxillofacial infection were gram-positive bacteria accounting for 80.00%, and gram -negative bacteria accounting for 20.00%.During the same period in our hospital , 1773 strains of multi-drug resistant bacteria were isolated .A total of 431 strains were gram -positive bacteria accounting for 24.31%, and 1342 strains were gram -negative bacteria accounting for 75.69%. The Staphylococcus aureus in oral and maxillofacial infection were highly resistant to penicillin, clindamycin and erythromycin.There was no signifi-cant difference in the drug resistance between pathogenic bacteria in oral and maxillofacial region and those in our hospital .Conclusion Gram positive bacteria were the main multi-drug resistant bacteria in oral and maxillofa-cial region infection.In the treatment, pathogenic bacteria detection and antibiotic susceptibility tests should be performed in time , so as to make the use of antibiotics more reasonably in clinic .%目的 观察口腔颌面部感染的多药耐药菌,为临床感染的控制提供相关的依据. 方法 口腔科共送检感染标本51例,检出多药耐药菌10株,与同期医院检出的多药耐药菌种类及耐药情况进行比较,用SPSS 19.0软件进行统计分析.结果 口腔颌面部感染的多药耐药菌10株,以革兰阳性菌为主(占80

  1. Modulation of the immune response to Mycobacterium tuberculosis during malaria/M. tuberculosis co-infection

    OpenAIRE

    Chukwuanukwu, Rebecca C.; Charles C. Onyenekwe; Martinez-Pomares, Luisa; Flynn, Robin J.; Singh, Sonali; Amilo, Grace I.; Agbakoba, Nneka R.; Okoye, Jude O.

    2016-01-01

    Tuberculosis (TB) causes significant morbidity and mortality on a global scale. The African region has 24% of the world's TB cases. TB overlaps with other infectious diseases such as malaria and HIV, which are also highly prevalent in the African region. TB is a leading cause of death among HIV-positive patients and co-infection with HIV and TB has been described as a syndemic. In view of the overlapping epidemiology of these diseases, it is important to understand the dynamics of the immune ...

  2. Clinical Test of Pathogenic Bacteria in Elderly Patients With Respiratory Tract Infections%老年呼吸道感染者的病原体细菌培养检验方法研究

    Institute of Scientific and Technical Information of China (English)

    王淼; 焦冬梅

    2016-01-01

    Objective To study the clinical test of pathogenic bacteria in elderly patients with respiratory tract infection. Methods Sputum of 191 cases of elderly patients with respiratory tract infection were tested by bacterial culture. Results 191 samples were tested and 184 strains were isolated with 96.34%positive rates,the pathogens were gram negative bacteria(55.43%)and gram positive bacteria(35.33%),fungi(13.04%),the resistance was higher in gram negative bacteria to ampicil in,and it was higher in gram positive bacteria to penicil in. Conclusion Gram negative bacteria is the main pathogenic bacteria in elderly patients with respiratory tract infection,the most efficient test method is should choosed,strengthen quality control.%目的:探讨老年呼吸道感染者的病原体细菌培养检验方法。方法选择191例老年呼吸道感染患者的痰液进行细菌培养检验。结果检测191份标本,分离阳性菌株184份,阳性率为96.34%,其中革兰阴性菌占55.43%,革兰阳性菌占35.33%,真菌占13.04%。革兰阴性菌对氨苄西林的耐药性较高,革兰阳性菌对青霉素耐药率较高。结论老年呼吸道感染者的病原体主要为革兰阴性菌,应选择有效的检测方法,加强质量控制。

  3. C-Myc regulation by costimulatory signals modulates the generation of CD8+ memory T cells during viral infection.

    Science.gov (United States)

    Haque, Mohammad; Song, Jianyong; Fino, Kristin; Wang, Youfei; Sandhu, Praneet; Song, Xinmeng; Norbury, Christopher; Ni, Bing; Fang, Deyu; Salek-Ardakani, Shahram; Song, Jianxun

    2016-01-01

    The signalling mechanisms of costimulation in the development of memory T cells remain to be clarified. Here, we show that the transcription factor c-Myc in CD8(+) T cells is controlled by costimulatory molecules, which modulates the development of memory CD8(+) T cells. C-Myc expression was dramatically reduced in Cd28(-/-) or Ox40(-/-) memory CD8(+) T cells, and c-Myc over-expression substantially reversed the defects in the development of T-cell memory following viral infection. C-Myc regulated the expression of survivin, an inhibitor of apoptosis, which promoted the generation of virus-specific memory CD8(+) T cells. Moreover, over-expression of survivin with bcl-xL, a downstream molecule of NF-κB and intracellular target of costimulation that controls survival, in Cd28(-/-) or Ox40(-/-) CD8(+) T cells, reversed the defects in the generation of memory T cells in response to viral infection. These results identify c-Myc as a key controller of memory CD8(+) T cells from costimulatory signals.

  4. Intravascular catheter related infections and antimicrobial susceptibility pattern of isolated bacteria in a tertiary care hospital of Bangladesh

    Directory of Open Access Journals (Sweden)

    F J Mansur

    2014-01-01

    Full Text Available The aim of this study was to evaluate the rate of bacterial colonisation and catheter related blood stream infections (CRBSI together with the antibiotic susceptibility patterns in a tertiary care hospital. CRBSI was detected with semi-quantitative and quantitative methods. The antimicrobial susceptible patterns of the isolated organisms were performed by Kirby Bauer disk diffusion method. The rate of catheter colonisation and CRBSI were 42.1% and 14% (16.1/1000 catheter days respectively. The most common causative pathogens were Pseudomonas sp. (23.7%, Acinetobacter sp. (18.4%, Staphylococcus aureus (13.2% and Enterobacteriaceae (10.5%. The rate of isolation of methicillin resistance S. aureus, imipenem resistant Pseudomonas sp. and extended spectrum β lactamase producing Enterobacteriaceae were 60%, 44.0% and 100%. The result of this study would be useful for control and treatment of CRBSI.

  5. The modulation of phosphatase expression impacts the proliferation efficiency of HSV-1 in infected astrocytes.

    Directory of Open Access Journals (Sweden)

    Lei Yue

    Full Text Available Herpes Simplex Virus 1 (HSV-1 is a major pathogen that causes human neurological diseases, including herpes simplex encephalitis (HSE. Previous studies have shown that astrocytes are involved in HSV-1 systemic pathogenesis in the central nervous system (CNS, although the mechanism remains unclear. In this study, a high-throughput RNAi library screening method was used to analyze the effect of host phosphatase gene regulation on HSV-1 replication using Macaca mulatta primary astrocytes in an in vitro culture system. The results showed that the downregulation of five phosphatase genes (PNKP, SNAP23, PTPRU, LOC714621 and PPM1M significantly inhibited HSV-1 infection, suggesting that these phosphatases were needed in HSV-1 replication in rhesus astrocytes. Although statistically significant, the effect of downregulation of these phosphatases on HSV-1 replication in a human astrocytoma cell line appears to be more limited. Our results suggest that the phosphatase genes in astrocytes may regulate the immunological and pathological reactions caused by HSV-1 CNS infection through the regulation of HSV-1 replication or of multiple signal transduction pathways.

  6. Immune Modulation of Recombinant OmpA against Brucella abortus 544 Infection in Mice.

    Science.gov (United States)

    Simborio, Hannah Leah Tadeja; Reyes, Alisha Wehdnesday Bernardo; Hop, Huynh Tan; Arayan, Lauren Togonon; Min, Wongi; Lee, Hu Jang; Lee, Jin Ju; Chang, Hong Hee; Kim, Suk

    2016-03-01

    Brucellosis affects a wide range of host species, including humans and many livestock animals. Chronic infections of the disease make antibiotic treatment costly, and the current vaccine used in livestock has not been approved for human use. This study investigated the possible use of the Brucella abortus outer membrane protein A (OmpA) as a candidate subunit vaccine in an infected mouse model. The ompA gene was cloned and overexpressed, and the recombinant OmpA (rOmpA) protein fused to maltose binding protein (MBP) was purified in Escherichia coli. Immunogenicity was verified through western blotting, and mice were immunized and challenged to evaluate its protective effect. Mice treated with rOmpA exhibited induced humoral and host cell-mediated responses, with a significant increase in immunoglobulin G (IgG1 and IgG2a) and cytokine levels, especially TNF-α and IL-12, compared with the control groups treated with either MBP or PBS. In conclusion, rOmpA should be highly considered as a future subunit vaccine for brucellosis, and further studies regarding rOmpA and its protective ability are suggested.

  7. Infection of a human respiratory epithelial cell line with rhinovirus. Induction of cytokine release and modulation of susceptibility to infection by cytokine exposure.

    OpenAIRE

    Subauste, M C; Jacoby, D B; Richards, S M; Proud, D

    1995-01-01

    Rhinovirus infections cause over one third of all colds and are a contributing factor to exacerbations of asthma. To gain insights into the early biochemical events that occur in infected epithelial cells, we develop, for the first time, a model in which a pure respiratory epithelial cell population can be routinely infected by rhinovirus. Viral infection was confirmed by demonstrating that viral titers of supernatants and lysates from infected cell increased with time and by PCR. Infection b...

  8. Treatment of febrile geriatric patients with suspected urinary tract infections in a hospital with high rates of ESBL producing bacteria: a cohort study

    Science.gov (United States)

    Shimoni, Zvi; Cohen, Regev; Avdiaev, Ruslan; Froom, Paul

    2016-01-01

    Purpose To determine the consequences of treating febrile geriatric patients with a suspected urinary tract infection (UTI) with antibiotics that have high resistance rates due primarily to extended-spectrum β-lactamase (ESBL) producing bacteria. Methods In this cohort study, we selected 257 consecutive hospitalised patients aged ≥70 years with a chief symptom of fever, possibly due to a UTI and initially treated with antibiotics with rates in our hospital of urinary culture resistance >20%. Patients with severe sepsis were excluded. The main outcomes measures were in vitro bacterial resistance to initial antibiotic therapy (BRIAT), response to therapy, hospitalisation days and mortality. Results Urine cultures were positive in 64.2% (165 of 257) of the patients and BRIAT occurred in 28.0% (72 of 257). Response rates were 100% (93 of 93) in those with bacteria sensitive to initial antibiotic therapy, 95.7% (88 of 92) in the culture negative patients, and 66.7% (48 of 72) in those with BRIAT (p<0.001). There were no deaths due to deterioration during the initial treatment period because of BRIAT. In the patients with BRIAT, the median length of hospitalisation was 3 days longer than that in the other patients (7 and 4 days, respectively, p<0.001). Conclusions We conclude that initial broad spectrum antibiotic treatment could potentially lower the median length of hospitalisation by 3 days in many hospitalised geriatric patients without an extra-urinary tract source for their fever. This benefit needs to be balanced against the risk to the individual patient and to the general public of increasing bacterial resistance rates to broader spectrum antibiotics often held in reserve. PMID:27986743

  9. Determination of the Antimicrobial Effects of Hydro-Alcoholic Extract of Cannabis Sativa on Multiple Drug Resistant Bacteria Isolated from Nosocomial Infections

    Directory of Open Access Journals (Sweden)

    Hossein Sarmadyan

    2014-02-01

    Full Text Available Background: The science of identification and employment of medicinal plants dates back to the early days of man on earth. Cannabis (hashish is the most common illegal substance used in the United States and was subjected to extensive research as a powerful local disinfecting agent for mouth cavity and skin and an anti-tubercular agent in 1950. Methods: Clinical strains were isolated from hospitalized patients in Vali-e-Asr Hospital of Arak. The hydro-alcoholic extract of cannabis (5 g was prepared following liquid-liquid method and drying in 45˚C. The antimicrobial properties of the extract were determined through disk diffusion and determination of MIC (Minimum Inhibitory Concentration. Results: First, the sensitivity of bacteria was detected based on disk diffusion method and the zone of inhibition was obtained for MRSA (12 mm, S.aureus 25923 (14 mm, E. coli ESBL+: (10 mm, and Klebsiella pneumoniae (7 mm. Disk diffusion for Pseudomonas and Acinetobacter demonstrated no inhibitory zones. Through Broth dilution method, MIC of cannabis extract on the bacteria was determined: E.coli 25922: 50µg/ml, E.coli ESBL+:100 µg/ml, S.aureus 25923:25 µg/ml, MRSA: 50 µg/ml, Pseudomona aeroginosaESBL+> 100 µg/ml, Pseudomonas: 100 µg/ml, Klebsiella pneumoniae: 100 µg/ml, and Acinetobacter baumannii> 1000. Conclusion: The maximum anti-microbial effect of the hydro-alcoholic extract of cannabis was seen for gram positive cocci, especially S. aureus, whereas non-fermentative gram negatives presented resistance to the extract. This extract had intermediate effect on Enterobacteriacae family. Cannabis components extracted through chemical analysis can perhaps be effective in treatment of nosocomial infections.

  10. Analysis of Clinical Method and Pathogenic Bacteria of 60 Cases with Diabetic Foot Infection%60例糖尿病足感染患者临床及病原菌分析

    Institute of Scientific and Technical Information of China (English)

    张明

    2016-01-01

    目的:目的分析糖尿病足感染患者的临床治疗方法,研究其病原菌情况。方法选取该院在2014年6月—2015年8月收治的60例糖尿病足感染者作为研究对象,对所有患者的临床资料进行回顾性分析,总结患者糖尿病足感染的临床治疗方法,并分析患者病原菌的相关情况。结果通过有效的治疗,本研究60例糖尿病足患者等临床症状均得到好转,共培养出病原菌52株,病原菌主要以革兰氏阳性菌为主,同时也有革兰氏阴性菌和白色念球菌。结论临床上对于糖尿病毒感染者,其感染的病原菌主要为革兰氏阳性菌,对患者进行有针对性的治疗能够促进患者的恢复。%Objective To analyze the clinical treatment method of patients with diabetic foot infection and research their patho-genic bacteria. Methods 60 cases of patients with diabetic foot infection admitted and treated in our hospital from June 2014 to August 2015 were selected as the research objects, and the clinical data of all patients were retrospectively analyzed, the clini-cal treatment methods of patients were summarized and the relevant conditions of pathogenic bacteria of patients were analyzed. Results After effective treatment, the clinical symptoms of 60 cases of patients with diabetic foot infection in the research were improved, 52 strains of pathogenic bacteria were cultured in total, and the pathogenic bacteria were mainly gram-positive bac-teria, and included gram-negative bacteria and candida albicans at the same time. Conclusion For patients with diabetes virus infection in clinic, the infected pathogenic bacteria were mainly gram-positive bacteria, and the targeted treatment can promote the recovery of patients.

  11. Modulation of monocyte/macrophage-derived cytokine and chemokine profile by persistent Hepatitis C virus (HCV infection leads to chronic inflammation

    Directory of Open Access Journals (Sweden)

    Penelope Mavromara

    2012-02-01

    Full Text Available HCV infection presents a major public health problem, with more than 170 million people infected worldwide. Chronicity and persistence of infection constitute the hallmark of the disease. Although HCV is a hepatotropic virus, subsets of immune cells have been found to be permissive to infection and viral replication. Peripheral blood monocytes, attracted to the site of infection and differentiated into macrophages, and resident hepatic macrophages, known as Kupffer cells, are important mediators of innate immunity, through production of several chemokines and cytokines in addition to their phagocytic activity. HCV proteins have been shown to modulate the cytokine and chemokine production profile of monocytes/macrophages, as it is suggested by both in vitro and clinical studies. This modified expression profile appears crucial for the establishment of aberrant inflammation that leads to liver cirrhosis and hepatocellular carcinoma.

  12. Infections

    Science.gov (United States)

    ... Does My Child Need? How to Safely Give Acetaminophen Is It a Cold or the Flu? Is the Flu Vaccine a Good Idea for Your Family? Too Late for the Flu Vaccine? Common Childhood Infections Can Chronic Ear Infections Cause Long-Term Hearing Loss? Chickenpox Cold Sores Common Cold Diarrhea Fever and ...

  13. Role of Phenothiazines and Structurally Similar Compounds of Plant Origin in the Fight against Infections by Drug Resistant Bacteria

    Directory of Open Access Journals (Sweden)

    Leonard Amaral

    2013-02-01

    Full Text Available Phenothiazines have their primary effects on the plasma membranes of prokaryotes and eukaryotes. Among the components of the prokaryotic plasma membrane affected are efflux pumps, their energy sources and energy providing enzymes, such as ATPase, and genes that regulate and code for the permeability aspect of a bacterium. The response of multidrug and extensively drug resistant tuberculosis to phenothiazines shows an alternative therapy for the treatment of these dreaded diseases, which are claiming more and more lives every year throughout the world. Many phenothiazines have shown synergistic activity with several antibiotics thereby lowering the doses of antibiotics administered to patients suffering from specific bacterial infections. Trimeprazine is synergistic with trimethoprim. Flupenthixol (Fp has been found to be synergistic with penicillin and chlorpromazine (CPZ; in addition, some antibiotics are also synergistic. Along with the antibacterial action described in this review, many phenothiazines possess plasmid curing activities, which render the bacterial carrier of the plasmid sensitive to antibiotics. Thus, simultaneous applications of a phenothiazine like TZ would not only act as an additional antibacterial agent but also would help to eliminate drug resistant plasmid from the infectious bacterial cells.

  14. Analysis of Bark -rot Disease Infection of Dictyophora Rubrovalvata Bacteria Egg under Different Temperature and Moisture%红托竹荪不同温湿度涂抹烂皮病菌感染分析

    Institute of Scientific and Technical Information of China (English)

    潘高潮; 代丽华; 孙燕; 王玉珠; 龙汉武; 邹方伦

    2016-01-01

    In order to explore the infectivity,transmissibility and production conditions of dictyophora rubrovalvata bacteria bark -rot disease,collecting bark -rot disease egg as material from the disease shed,using bark -rot disease egg as the couses of infection site, to condust the normal dictyophora rubrovalvata bacteria egg infection test of the injury and without injury daubing disease,using without daubing disease as contral,having experimental observation in different temperature and moisture gradient.The results showed that the normal dictyophora rubrovalvata bacteria egg of the injury and without injury do not occur infection at the temperature 25℃ and mois-ture 85%;the dictyophora rubrovalvata bacteria egg of the injury and without injury,and daubing and without daubing disease occur infection at the temperature 35℃and moisture 75% in 48 h.This shows hot and humid environment is the key induced factor of the dic-tyophora rubrovalvata bacteria egg infection.When the bacteria egg is injury by hot,disease leads to low immune function,and infection.%为探明红托竹荪菌蛋烂皮病菌侵染性、传播性及产生条件,从病害棚采集烂皮菌蛋为材料,以烂皮菌蛋部位为感染病菌,用于对正常红托竹荪菌蛋进行伤和无伤涂抹病菌感染试验,以不涂抹病菌为对照,在不同温度湿度梯度下试验观察。结果表明:在温度25℃相对湿度85%条件下,病菌对正常红托竹荪菌蛋伤和无伤都不发生感染,在温度35℃相对湿度75%条件下进行48h 的培养,红托竹荪菌蛋伤或无伤、涂抹和不涂抹病菌都发生菌蛋烂皮现象。说明高温高湿是诱发红托竹荪菌蛋发病的关键,病菌是因菌蛋受高温损伤,导致菌蛋免疫功能低下,病菌侵染。

  15. 肛肠科医院感染特点与多药耐药菌感染的分析%Characteristics of nosocomial infections in patients of anorectal department and prevalence of multidrug-resistant bacteria infections

    Institute of Scientific and Technical Information of China (English)

    王世华; 潘娟; 刘桂花; 祁芝花; 张海云

    2015-01-01

    OBJECTIVE To explore the characteristics of nosocomial infections in the patients of anorectal depart‐ment and observe the drug resistance of multidrug‐resistant pathogens so as to provide theoretical basis for preven‐tion and treatment of the nosocomial infections .METHODS A total of 634 patients who underwent the anorectal surgery in the hospital from Jan 2012 to Jun 2014 were enrolled in the study ,then the clinical data of the partici‐pants were retrospectively analyzed ,and the types of nosocomial infections and the distribution of pathogens and multidrug‐resistant bacteria were observed .RESULTS The nosocomial infections occurred in 98 of 634 patients un‐dergoing the anorectal surgery ,with the infection rate of 15 .46% ;the surgical incision ,respiratory tract ,urinary tract ,and gastrointestinal tract were the main infection sites .Totally 98 strains of pathogens have been isolated , including 59 (60 .20% ) strains of gram‐negative bacteria ,25 (25 .51% ) strains of gram‐positive bacteria ,and 12 (12 .25% ) strains of fungi .The Escherichia coli ,Klebsiella pneumoniae ,Bacillus fragilis ,Staphylococcus au‐reus ,and Staphylococcus epidermidis were multidrug‐resistant ;the drug resistance rates of the E .coli strains to ceftriaxone ,ceftazidime ,amoxicillin‐clavulanic acid ,and gatifloxacin were 100 .00% ;the drug resistance rates of the K .pneumoniae strains to ceftriaxone ,cefepime ,ceftazidime ,and amoxicillin‐clavulanic acid were more than 75 .00% ;the drug resistance rates of the S .aureus and S .epidermidis strains to penicillin ,cefazolin ,and amoxi‐cillin‐clavulanic acid were more than 90 .00% .CONCLUSION The incidence of nosocomial infections is high in the patients of anorectal department .The gram‐negative bacteria are dominant among the pathogens causing infections and are highly resistant to the commonly used antibiotics .It is necessary for the hospital to reasonably use antibiot‐ics based on the results of the

  16. Clinical analysis on 355 cases of gram-negative bacteria blood infection%革兰阴性杆菌血流感染355例临床及病原学特点分析

    Institute of Scientific and Technical Information of China (English)

    邝咏云; 单斌; 段勇

    2015-01-01

    ABSTRACT:Objective In order to offer guides for experimental medication,we analyzed the clinical and microbiological characteristics of patients with gram-negative bacteria blood infection in the People’s Hospital of Chuxiongl.Methods Microbiological and clinical data of 355 patients with gram-negative bacteria blood infection were retrospectively collected and evaluated.Results Compared with other patients,the patients with diabetes and urinary tract disease were more easily attacked by gram-negative bacteria blood infection.The patients using mechanical ventilation and patients with the urinary tract and gastrointestinal tract infection source were more likely attacked by gram-negative bacteria blood infection.The patients with the skin infection source,the catheter infection source,and the central nervous infection source were liable to cause non gram-negative bacteria blood infection.Septic shock was more likely to occur in patients of gram-negative bacteria blood infection.Gram-negative bacteria species in the hospital were still highly susceptible to Carbapenems.Conclusion Analysis of route of pathogen invasion,basic diseases, laboratory indicators and bacterial drug resistance could help forecast for gram-negative bacteria blood infection and guide the early experience administration.%目的:分析革兰阴性杆菌血流感染病例的临床及病原学特点,为临床诊治提供帮助。方法收集确诊355例革兰阴性杆菌血流感染患者的临床资料及病原学结果,进行回顾性分析研究。结果糖尿病和泌尿系疾病的患者、接受机械通气的患者及有胃肠道感染的患者易发生革兰阴性杆菌血流感染;使用静脉导管、有皮肤黏膜和中枢神经感染的患者易发生非革兰阴性杆菌血流感染。革兰阴性杆菌血流感染患者更易引发脓毒性休克。革兰阴性杆菌血流感染组的降钙素原(PCT)和白细胞介素6(IL-6)水平高于非革兰阴性杆菌血流感染

  17. Plant growth-promoting endophytic bacteria versus pathogenic infections: an example of Bacillus amyloliquefaciens RWL-1 and Fusarium oxysporum f. sp. lycopersici in tomato

    Science.gov (United States)

    Shahzad, Raheem; Khan, Abdul Latif; Bilal, Saqib

    2017-01-01

    Fungal pathogenic attacks are one of the major threats to the growth and productivity of crop plants. Currently, instead of synthetic fungicides, the use of plant growth-promoting bacterial endophytes has been considered intriguingly eco-friendly in nature. Here, we aimed to investigate the in vitro and in vivo antagonistic approach by using seed-borne endophytic Bacillus amyloliquefaciens RWL-1 against pathogenic Fusarium oxysporum f. sp. lycopersici. The results revealed significant suppression of pathogenic fungal growth by Bacillus amyloliquefaciens in vitro. Further to this, we inoculated tomato plants with RWL-1 and F. oxysporum f. sp. lycopersici in the root zone. The results showed that the growth attributes and biomass were significantly enhanced by endophytic-inoculation during disease incidence as compared to F. oxysporum f. sp. lycopersici infected plants. Under pathogenic infection, the RWL-1-applied plants showed increased amino acid metabolism of cell wall related (e.g., aspartic acid, glutamic acid, serine (Ser), and proline (Pro)) as compared to diseased plants. In case of endogenous phytohormones, significantly lower amount of jasmonic acid (JA) and higher amount of salicylic acid (SA) contents was recorded in RWL-1-treated diseased plants. The phytohormones regulation in disease incidences might be correlated with the ability of RWL-1 to produce organic acids (e.g., succinic acid, acetic acid, propionic acid, and citric acid) during the inoculation and infection of tomato plants. The current findings suggest that RWL-1 inoculation promoted and rescued plant growth by modulating defense hormones and regulating amino acids. This suggests that bacterial endophytes could be used for possible control of F. oxysporum f. sp. lycopersici in an eco-friendly way. PMID:28321368

  18. Plant growth-promoting endophytic bacteria versus pathogenic infections: an example of Bacillus amyloliquefaciens RWL-1 and Fusarium oxysporum f. sp. lycopersici in tomato

    Directory of Open Access Journals (Sweden)

    Raheem Shahzad

    2017-03-01

    Full Text Available Fungal pathogenic attacks are one of the major threats to the growth and productivity of crop plants. Currently, instead of synthetic fungicides, the use of plant growth-promoting bacterial endophytes has been considered intriguingly eco-friendly in nature. Here, we aimed to investigate the in vitro and in vivo antagonistic approach by using seed-borne endophytic Bacillus amyloliquefaciens RWL-1 against pathogenic Fusarium oxysporum f. sp. lycopersici. The results revealed significant suppression of pathogenic fungal growth by Bacillus amyloliquefaciens in vitro. Further to this, we inoculated tomato plants with RWL-1 and F. oxysporum f. sp. lycopersici in the root zone. The results showed that the growth attributes and biomass were significantly enhanced by endophytic-inoculation during disease incidence as compared to F. oxysporum f. sp. lycopersici infected plants. Under pathogenic infection, the RWL-1-applied plants showed increased amino acid metabolism of cell wall related (e.g., aspartic acid, glutamic acid, serine (Ser, and proline (Pro as compared to diseased plants. In case of endogenous phytohormones, significantly lower amount of jasmonic acid (JA and higher amount of salicylic acid (SA contents was recorded in RWL-1-treated diseased plants. The phytohormones regulation in disease incidences might be correlated with the ability of RWL-1 to produce organic acids (e.g., succinic acid, acetic acid, propionic acid, and citric acid during the inoculation and infection of tomato plants. The current findings suggest that RWL-1 inoculation promoted and rescued plant growth by modulating defense hormones and regulating amino acids. This suggests that bacterial endophytes could be used for possible control of F. oxysporum f. sp. lycopersici in an eco-friendly way.

  19. Antimicrobial susceptibility of Gram-negative bacteria causing intra-abdominal infections in China: SMART China 2011

    Institute of Scientific and Technical Information of China (English)

    Zhang Hui; Yang Qiwen; Xiao Meng; Chen Minjun; Robert E.Badal; Xu Yingchun

    2014-01-01

    Background The Study for Monitoring Antimicrobial Resistance Trends program monitors the activity of antibiotics against aerobic and facultative Gram-negative bacilli (GNBs) from intra-abdominal infections (IAIs) in patients worldwide.Methods In 2011,1 929 aerobic and facultative GNBs from 21 hospitals in 16 cities in China were collected.All isolates were tested using a panel of 12 antimicrobial agents,and susceptibility was determined following the Clinical Laboratory Standards Institute guidelines.Results Among the Gram-negative pathogens causing IAIs,Escherichia coli (47.3%) was the most commonly isolated,followed by Klebsiella pneumoniae (17.2%),Pseudomonas aeruginosa (10.1%),and Acinetobacter baumannii (8.3%).Enterobacteriaceae comprised 78.8% (1521/1929) of the total isolates.Among the antimicrobial agents tested,ertapenem and imipenem were the most active agents against Enterobacteriaceae,with susceptibility rates of 95.1% and 94.4%,followed by amikacin (93.9%) and piperacillin/tazobactam (87.7%).Susceptibility rates of ceftriaxone,cefotaxime,ceftazidime,and cefepime against Enterobacteriaceae were 38.3%,38.3%,61.1%,and 50.8%,respectively.The leastactive agent against Enterobacteriaceae was ampicillin/sulbactam (25.9%).The extended-spectrum β-lactamase (ESBL) rates among E.coli,K.pneumoniae,Klebsiella oxytoca,and Proteus mirabilis were 68.8%,38.1%,41.2%,and 57.7%,respectively.Conclusions Enterobacteriaceae were the major pathogens causing IAIs,and the most active agents against the study isolates (including those producing ESBLs) were ertapenem,imipenem,and amikacin.Including the carbapenems,most agents exhibited reduced susceptibility against ESBL-positive and multidrug-resistant isolates.

  20. Modulation of La Crosse virus infection in Aedes albopictus mosquitoes following larval exposure to coffee extracts

    Directory of Open Access Journals (Sweden)

    Nicole E. Eastep

    2012-03-01

    Full Text Available The mosquito-borne La Crosse virus (LACV; Family Bunyaviridae may cause encephalitis, primarily in children, and is distributed throughout much of the eastern United States. No antivirals or vaccines are available for LACV, or most other mosquito-borne viruses, and prevention generally relies on mosquito control. We sought to determine whether coffee extracts could interfere with LACV replication and vector mosquito development. Both regular and decaffeinated coffee demonstrated significant reductions in LACV replication in direct antiviral assays. This activity was not due to the presence of caffeine, which did not inhibit the virus life cycle. Aedes albopictus (Skuse (Diptera: Culicidae mosquito larvae suffered near total mortality when reared in high concentrations of regular and decaffeinated coffee and in caffeine. Following larval exposure to sublethal coffee concentrations, adult Ae. albopictus mosquitoes had signficantly reduced whole-body LACV titers five days post-infection, compared to larvae reared in distilled water. These results suggest that it may be possible to both control mosquito populations and alter the vector competence of mosquitoes for arthropod-borne viruses by introducing antiviral compounds into the larval habitat.

  1. Viral Interleukin-10 Expressed by Human Cytomegalovirus during the Latent Phase of Infection Modulates Latently Infected Myeloid Cell Differentiation ▿ †

    OpenAIRE

    Avdic, Selmir; Cao, John Z.; Cheung, Allen K.L.; Abendroth, Allison; Slobedman, Barry

    2011-01-01

    The human cytomegalovirus UL111A gene is expressed during latent and productive infections, and it codes for homologs of interleukin-10 (IL-10). We examined whether viral IL-10 expressed during latency altered differentiation of latently infected myeloid progenitors. In comparison to infection with parental virus or mock infection, latent infection with a virus in which the gene encoding viral IL-10 has been deleted upregulated cytokines associated with dendritic cell (DC) formation and incre...

  2. 医院感染病原菌的分布及耐药性分析%Analysis of Distribution and Tolerance of Hospital Infection Pathogenic Bac-teria

    Institute of Scientific and Technical Information of China (English)

    蒋红蕾

    2016-01-01

    Objective To study the distribution and tolerance of hospital infection pathogenic bacteria situation at present and lay foundation for preventing the hospital infection. Methods Various types of pathogenic bacteria of all patients diag-nosed in our hospital from February 2015 to February 2016 were analyzed and tested, and the pathogenic bacteria tolerance analysis was conducted by using the corresponding reagent. Results In this study, 3658 strains of pathogenic bacteria were tested including 603 cases of gram positive bacteria (16.48%), 2256 cases of gram negative bacteria (61.67%), and 799 cas-es of funguses (21.84%), in the 2859 cases of bacteria, pseudomonas aeruginosa accounted for 21% in all bacteria, acineto-bacter baumannii accounted for 12% in all bacteria, Escherichia coli accounted for 10% in all bacteria, klebsiella pneumo-niae accounted for 7%in all bacteria, and staphylococcus aureus accounted for 8% in all bacteria, and the tolerance results showed that the tolerance of staphylococcus aureus was the highest in all bacteria, and the resistance of quinolones, clin-damycin and tetracycline antibiotics was as high as 52%. Conclusion The common pathogenic bacteria are the gram nega-tive bacteria, and the pathogenic bacteria are generally resistant, therefore, the detection of bacteria and analysis of toler-ance contributes to clinical medication selection and treatment.%目的:探究目前医院内感染的病原菌的分布以及耐药情况,为防止院内感染奠定基础。方法选取2015年2月—2016年2月期间就诊于该院患者中采集的各类病原菌,并利用相应试剂进行病原菌耐药分析。结果该次探究共检测出3658株病原菌,其中革兰阳性菌例数为603例,占总数的16.48%,革兰阴性菌例数为2256例,占总数的61.67%,真菌例数为799例,占总数的21.84%。在2859例细菌中,铜绿假单胞菌占所有细菌的21%、鲍氏不动杆菌占所有细菌的12%、大

  3. Smokeless Tobacco May Contain Potentially Harmful Bacteria

    Science.gov (United States)

    ... 160769.html Smokeless Tobacco May Contain Potentially Harmful Bacteria Infections, diarrhea and vomiting are possible consequences, FDA ... products can harbor several species of potentially harmful bacteria, researchers warn. Two types in particular -- Bacillus licheniformis ...

  4. Control of Vibrio harveyi Infection in Blue Swimming Crab, Portunus pelagicus Larvae by the Gut Isolated Lactic Acid Bacteria under Challenge Bioassay

    Directory of Open Access Journals (Sweden)

    Allah Dad Talpur*§, Abdul Jabbar Memon§, Muhammad Iqbal Khan§, Muhammad Ikhwanuddin, Muhammad Mhd Danish Daniel2 and Ambok Bolong Abol-Munafi

    2012-06-01

    Full Text Available Five isolates of lactic acid bacteria (LAB isolated from the gut of female Portunus pelagicus with inhibitory activity against shellfish pathogens and validation as probiotics via small scale in vivo model were tested for hatchery trials pathogen probiotic assay. Vibrio harveyi previously isolated from the gut of P. pelagicus, was added at 104 cfu mL-1 to test larvae for 10h. Test (LAB isolates were inoculated at a concentration of 106 cfu mL-1 to pathogen addition aquaria once and until day four during the experiment. 20 larvae/liter were stocked and larval survival was determined over five days. Lactobacillus plantarum did produce highest survival 28.33% to 48.33% in one day and daily inoculations respectively and in probiotic control it produced 58.33% survival followed by L. rhamnosus 55% and L. salivarius 53.33% respectively over non inoculated control 43.33% and 0% survival in V. harveyi inoculated control. However, Weissella confusa and W. cibaria did show less probiotic activity compared to rests of three LAB isolates. In the present study, it was determined that three LAB probiotics were effective in hatchery trials challenge assays which may significantly control the infection and increased the survival of larvae.

  5. HuR interacts with human immunodeficiency virus type 1 reverse transcriptase, and modulates reverse transcription in infected cells

    Directory of Open Access Journals (Sweden)

    Ennifar Eric

    2008-06-01

    Full Text Available Abstract Reverse transcription of the genetic material of human immunodeficiency virus type 1 (HIV-1 is a critical step in the replication cycle of this virus. This process, catalyzed by reverse transcriptase (RT, is well characterized at the biochemical level. However, in infected cells, reverse transcription occurs in a multiprotein complex – the reverse transcription complex (RTC – consisting of viral genomic RNA associated with viral proteins (including RT and, presumably, as yet uncharacterized cellular proteins. Very little is known about the cellular proteins interacting with the RTC, and with reverse transcriptase in particular. We report here that HIV-1 reverse transcription is affected by the levels of a nucleocytoplasmic shuttling protein – the RNA-binding protein HuR. A direct protein-protein interaction between RT and HuR was observed in a yeast two-hybrid screen and confirmed in vitro by homogenous time-resolved fluorescence (HTRF. We mapped the domain interacting with HuR to the RNAse H domain of RT, and the binding domain for RT to the C-terminus of HuR, partially overlapping the third RRM RNA-binding domain of HuR. HuR silencing with specific siRNAs greatly impaired early and late steps of reverse transcription, significantly inhibiting HIV-1 infection. Moreover, by mutagenesis and immunoprecipitation studies, we could not detect the binding of HuR to the viral RNA. These results suggest that HuR may be involved in and may modulate the reverse transcription reaction of HIV-1, by an as yet unknown mechanism involving a protein-protein interaction with HIV-1 RT.

  6. Salicylic acid is a modulator of catalase isozymes in chickpea plants infected with Fusarium oxysporum f. sp. ciceri.

    Science.gov (United States)

    Gayatridevi, S; Jayalakshmi, S K; Sreeramulu, K

    2012-03-01

    The relationship between salicylic acid level catalases isoforms chickpea cv. ICCV-10 infected with Fusarium oxysporum f. sp. ciceri was investigated. Pathogen-treated chickpea plants showed high levels of SA compared with the control. Two isoforms of catalases in shoot extract (CAT-IS and CAT-IIS) and single isoform in root extract (CAT-R) were detected in chickpea. CAT-IS and CAT-R activities were inhibited in respective extracts treated with pathogen whereas, CAT-IIS activity was not inhibited. These isoforms were purified and their kinetic properties studied in the presence or absence of SA. The molecular mass determined by SDS-PAGE of CAT-IS, CAT-IIS and CAT-R was found to be 97, 40 and 66 kDa respectively. Kinetic studies indicated that Km and V(max) of CAT-IS were 0.2 mM and 300 U/mg, 0.53 mM and 180 U/mg for CAT-IIS and 0.25 mM and 280 U/mg for CAT-R, respectively. CAT-IS and CAT-R were found to be more sensitive to SA and 50% of their activities were inhibited at 6 and 4 μM respectively, whereas CAT-IIS was insensitive to SA up to 100 μM. Quenching of the intrinsic tryptophan fluorescence of purified catalases were used to quantitate SA binding; the estimated K(d) value for CAT-IS, CAT-IIS and CAT-R found to be 2.3 μM, 3.1 mM and 2.8 μM respectively. SA is a modulator of catalase isozymes activity, supports its role in establishment of SAR in chickpea plants infected with the pathogen.

  7. L型菌慢性泌尿系感染诊断及抗生素运用%Diagnosis of L model bacteria in chronic urinary tract infection and antibiotic use

    Institute of Scientific and Technical Information of China (English)

    杨葵

    2012-01-01

    OBJECTIVE To explore L model bacteria in the urinary tract infection situation and the resistance to antibiotics, to provide scientific bases for clinical diagnosis and treatment. METHODS Used improved Kagan culture medium (L model flat) to separate and cultivate urine, which were from the clinical urinary tract infections patients. RESULTS From 128 patients' urine samples, we found that the detection rate of bacteria infection with L model bacteria was 82.8% (106/128), and the rate of ordinary cultivating bacteria was 66.4% (85/128). Among them, the separating rate of bacteria infection with L model bacteria in chronic urinary tract infection of patients was 93.8% (90/96), the rate of L model bacteria was 19.8% (19/96), and the rate of bacteria infection was 74.0% (71/96). CONCLUSION The highest antibiotic resistance is in penicillin class (penicillin G), the followed cephalosporin (ceftriaxone sodium, cefazolin, cefotaxime) , aminoglycoside (gentamicin, amikacin, tobramycin) and erythromycin; while vancomycin, chloromycetin and neomycina are with low antibiotic resistance. In chronic urinary tract infections, patients should also be detected bacteria and L model bacteria, and we should combine using drugs according to antimicrobial susceptibility test, to sterilize and prevent it from transforming to L model.%目的 探讨L型细菌在泌尿系的感染情况及其抗生素的耐药性,为临床诊治提供科学依据.方法 用改良Kagan培养基(L型平板)对临床泌尿系感染者的尿液进行分离培养,并对所获得的L型细菌进行药物敏感试验.结果 从128例患者的尿液标本中,检出L型伴细菌型感染率为82.8% (106/128),普通培养细菌检出率为66.4% (85/128).其中,慢性泌尿系感染L型伴细菌型分离率93.8% (90/96),L型细菌分离率19.8% (19/96),共19株,细菌型分离率为74.0% (71/96).结论 对抗生素而言,耐药性最高的是青霉素类(青霉素G),其次依次为头孢菌素类(头孢三

  8. Bacteria clustering by polymers induces the expression of quorum-sensing-controlled phenotypes

    Science.gov (United States)

    Lui, Leong T.; Xue, Xuan; Sui, Cheng; Brown, Alan; Pritchard, David I.; Halliday, Nigel; Winzer, Klaus; Howdle, Steven M.; Fernandez-Trillo, Francisco; Krasnogor, Natalio; Alexander, Cameron

    2013-12-01

    Bacteria deploy a range of chemistries to regulate their behaviour and respond to their environment. Quorum sensing is one method by which bacteria use chemical reactions to modulate pre-infection behaviour such as surface attachment. Polymers that can interfere with bacterial adhesion or the chemical reactions used for quorum sensing are therefore a potential means to control bacterial population responses. Here, we report how polymeric ‘bacteria sequestrants’, designed to bind to bacteria through electrostatic interactions and therefore inhibit bacterial adhesion to surfaces, induce the expression of quorum-sensing-controlled phenotypes as a consequence of cell clustering. A combination of polymer and analytical chemistry, biological assays and computational modelling has been used to characterize the feedback between bacteria clustering and quorum sensing signalling. We have also derived design principles and chemical strategies for controlling bacterial behaviour at the population level.

  9. Differential modulation of ATP-induced P2X7-associated permeabilities to cations and anions of macrophages by infection with Leishmania amazonensis.

    Directory of Open Access Journals (Sweden)

    Camila Marques-da-Silva

    Full Text Available Leishmania and other parasites display several mechanisms to subvert host immune cell function in order to achieve successful infection. The ATP receptor P2X7, an agonist-gated cation channel widely expressed in macrophages and other cells of the immune system, is also coupled to inflammasome activation, IL-1 beta secretion, production of reactive oxygen species, cell death and the induction of the permeabilization of the plasma membrane to molecules of up to 900 Da. P2X7 receptors can function as an effective microbicidal triggering receptor in macrophages infected with several microorganisms including Mycobacteria tuberculosis, Chlamydia and Leishmania. We have previously shown that its expression is up-regulated in macrophages infected with L. amazonensis and that infected cells also display an increase in P2X7-induced apoptosis and membrane permeabilization to some anionic fluorescent dyes. In an independent study we recently showed that the phenomenon of macrophage membrane permeabilization can involve at least two distinct pathways for cations and anions respectively. Here, we re-addressed the effects of ATP-induced P2X7-associated phenomena in macrophages infected with L. amazonensis and demonstrated that the P2X7-associated dye uptake mechanisms are differentially modulated. While the membrane permeabilization for anionic dyes is up-modulated, as previously described, the uptake of cationic dyes is strongly down-modulated. These results unveil new characteristics of two distinct permeabilization mechanisms associated with P2X7 receptors in macrophages and provide the first evidence indicating that these pathways can be differentially modulated in an immunologically relevant situation. The possible importance of these results to the L. amazonensis escape mechanism is discussed.

  10. Differential modulation of ATP-induced P2X7-associated permeabilities to cations and anions of macrophages by infection with Leishmania amazonensis.

    Science.gov (United States)

    Marques-da-Silva, Camila; Chaves, Mariana Martins; Rodrigues, Juliany Cola; Corte-Real, Suzana; Coutinho-Silva, Robson; Persechini, Pedro Muanis

    2011-01-01

    Leishmania and other parasites display several mechanisms to subvert host immune cell function in order to achieve successful infection. The ATP receptor P2X7, an agonist-gated cation channel widely expressed in macrophages and other cells of the immune system, is also coupled to inflammasome activation, IL-1 beta secretion, production of reactive oxygen species, cell death and the induction of the permeabilization of the plasma membrane to molecules of up to 900 Da. P2X7 receptors can function as an effective microbicidal triggering receptor in macrophages infected with several microorganisms including Mycobacteria tuberculosis, Chlamydia and Leishmania. We have previously shown that its expression is up-regulated in macrophages infected with L. amazonensis and that infected cells also display an increase in P2X7-induced apoptosis and membrane permeabilization to some anionic fluorescent dyes. In an independent study we recently showed that the phenomenon of macrophage membrane permeabilization can involve at least two distinct pathways for cations and anions respectively. Here, we re-addressed the effects of ATP-induced P2X7-associated phenomena in macrophages infected with L. amazonensis and demonstrated that the P2X7-associated dye uptake mechanisms are differentially modulated. While the membrane permeabilization for anionic dyes is up-modulated, as previously described, the uptake of cationic dyes is strongly down-modulated. These results unveil new characteristics of two distinct permeabilization mechanisms associated with P2X7 receptors in macrophages and provide the first evidence indicating that these pathways can be differentially modulated in an immunologically relevant situation. The possible importance of these results to the L. amazonensis escape mechanism is discussed.

  11. Conserved residues in Lassa fever virus Z protein modulate viral infectivity at the level of the ribonucleoprotein.

    Science.gov (United States)

    Capul, Althea A; de la Torre, Juan Carlos; Buchmeier, Michael J

    2011-04-01

    Arenaviruses are negative-strand RNA viruses that cause human diseases such as lymphocytic choriomeningitis, Bolivian hemorrhagic fever, and Lassa hemorrhagic fever. No licensed vaccines exist, and current treatment is limited to ribavirin. The prototypic arenavirus, lymphocytic choriomeningitis virus (LCMV), is a model for dissecting virus-host interactions in persistent and acute disease. The RING finger protein Z has been identified as the driving force of arenaviral budding and acts as the viral matrix protein. While residues in Z required for viral budding have been described, residues that govern the Z matrix function(s) have yet to be fully elucidated. Because this matrix function is integral to viral assembly, we reasoned that this would be reflected in sequence conservation. Using sequence alignment, we identified several conserved residues in Z outside the RING and late domains. Nine residues were each mutated to alanine in Lassa fever virus Z. All of the mutations affected the expression of an LCMV minigenome and the infectivity of virus-like particles, but to greatly varying degrees. Interestingly, no mutations appeared to affect Z-mediated budding or association with viral GP. Our findings provide direct experimental evidence supporting a role for Z in the modulation of the activity of the viral ribonucleoprotein (RNP) complex and its packaging into mature infectious viral particles.

  12. Modulation of α-enolase post-translational modifications by dengue virus: increased secretion of the basic isoforms in infected hepatic cells.

    Directory of Open Access Journals (Sweden)

    Luiza M Higa

    Full Text Available Hepatic cells are major sites of dengue virus (DENV replication and liver injury constitutes a characteristic of severe forms of dengue. The role of hepatic cells in dengue pathogenesis is not well established, but since hepatocytes are the major source of plasma proteins, changes in protein secretion by these cells during infection might contribute to disease progression. Previously, we showed that DENV infection alters the secretion pattern of hepatic HepG2 cells, with α-enolase appearing as one of the major proteins secreted in higher levels by infected cells. ELISA analysis demonstrated that DENV infection modulates α-enolase secretion in HepG2 cells in a dose-dependent manner, but has no effect on its gene expression and on the intracellular content of the protein as assessed by PCR and western blot analyses, respectively. Two-dimensional western blots showed that both intracellular and secreted forms of α-enolase appear as five spots, revealing α-enolase isoforms with similar molecular weights but distinct isoeletric points. Remarkably, quantification of each spot content revealed that DENV infection shifts the isoform distribution pattern of secreted α-enolase towards the basic isoforms, whereas the intracellular protein remains unaltered, suggesting that post-translational modifications might be involved in α-enolase secretion by infected cells. These findings provide new insights into the mechanisms underlying α-enolase secretion by hepatic cells and its relationship with the role of liver in dengue pathogenesis. In addition, preliminary results obtained with plasma samples from DENV-infected patients suggest an association between plasma levels of α-enolase and disease severity. Since α-enolase binds plasminogen and modulates its activation, it is plausible to speculate the association of the increase in α-enolase secretion by infected hepatic cells with the haemostatic dysfunction observed in dengue patients including the

  13. A critical role of IL-17 in modulating the B-cell response during H5N1 influenza virus infection

    Institute of Scientific and Technical Information of China (English)

    Xiaohui Wang; Bo-Jian Zheng; Liwei Lu; Chris CS Chan; Min Yang; Jun Deng; Vincent KM Poon; Virtual HC Leung; King-Hung Ko; Jie Zhou; Kwok Yung Yuen

    2011-01-01

    Interleukin-17 (IL-17),a member of the IL-17 cytokine family,plays a crucial role in mediating the immune response against extracellular bacteria and fungi in the lung.Although there is increasing evidence that IL-17 is involved in protective immunity against H 1 and H3 influenza virus infections,little is known about the role of IL-17 in the highly pathogenic H5N 1 influenza virus infection.In this study,we show that H5N1-infected IL-17 knockout (KO) mice exhibit markedly increased weight loss,more pronounced lung immunopathology and significantly reduced survival rates as compared with infected wild-type controls.Moreover,the frequency of B cells in the lung were substantially decreased in IL-17 KO mice after virus infection,which correlated with reduced CXCR5 expression in B cells and decreased CXCL13 production in the lung tissue of IL-17 KO mice.Consistent with this observation,B cells from IL-17 KO mice exhibited a significant reduction in chemokine-mediated migration in culture.Taken together,these findings demonstrate a critical role for IL-17 in mediating the recruitment of B cells to the site of pulmonary influenza virus infection in mice.

  14. The clinical value of PCT levels in bacteria identification in ICU patients with bloodstream infection%血清降钙素原对ICU血流感染患者菌种鉴别中的应用研究

    Institute of Scientific and Technical Information of China (English)

    王建; 庄国华; 牛野; 李宏; 夏建萍

    2015-01-01

    目的 探讨血清降钙素原(PCT)水平测定在ICU血流感染患者菌种鉴别中的应用价值.方法 对本院ICU 2007年12月至2013年12月收治的540例血流感染患者的PCT水平进行检测并对患者标本分离的菌种进行鉴别,分析PCT水平在鉴别血流感染菌种的有效性.结果 540例血流感染患者中,G+菌感染患者比例最高(49.63%),G-菌感染患者比例次之(38.52%),真菌感染患者比例最低(11.85%),三者间差异有统计学意义(P<0.05).G-菌感染组PCT水平及阳性率均显著高于G+菌感染组和真菌感染组,差异有统计学意义(P<0.05),G+菌和真菌感染组之间差异无统计学意义(P>0.05).PCT界定为2.04 ng/ml时,血清PCT水平区分G-和G+的灵敏度和特异度分别为82.18%和76.09%;PCT界定为3.16 ng,/ml时,血清PCT水平鉴别血流感染G-菌与真菌种的灵敏度和特异度分别为59.42%和65.73%.结论 应用血清PCT水平鉴别G-菌与G+菌、真菌所致血流感染具有较高的临床价值,PCT水平≥2.04 ng/ml时,发生G-菌感染几率较大,PCT水平对G+菌与真菌的鉴别准确度较差.%Objective To investigate the clinical value of procalcitonin (PCT) levels in bacteria identification in intensive care unit (ICU) patients with bloodstream infection.Methods There were 540 cases of patients with bloodstream infection in our ICU between December 2007 and December 2013.The PCT levels and bacteria were identified.The application effectiveness of PCT levels in the bacteria identification was studied.Results The G+ bacteria infection rate was 49.63% (268/540),G-bacteria infection rate was 38.52% (208/540),and the fungal infection rate was 11.85% (64/540).The patients of G-bacteria had significant difference with G + bacteria and fungal infection (P < 0.05).The PCT average and positive rate of G-bacteria were significantly higher than G + bacteria and fungi group (P < 0.05),respectively.G+ bacteria and fungi infection did not

  15. Stability evaluation of reference genes for real-time PCR in zebrafish (Danio rerio) exposed to cadmium chloride and subsequently infected by bacteria Aeromonas hydrophila

    Energy Technology Data Exchange (ETDEWEB)

    Lang, Xingping; Wang, Lan, E-mail: lanwang@sxu.edu.cn; Zhang, Zuobing, E-mail: zbzhang@sxu.edu.cn

    2016-01-15

    Highlights: • Cd exposure affects the stability of reference genes for real-time PCR in zebrafish. • Reference genes present different stability in the five tissues (spleen, kidney, liver, gills and intestine) of zebrafish after Cd exposure. • Bacterial infection further affects the stability of reference genes in Cd-treated zebrafish. - Abstract: Environmental and occupational cadmium (Cd) toxicity is a global concern, and the model organism zebrafish is an ideal species to investigate Cd toxicity. Among various detecting techniques, quantitative real-time PCR (qPCR) is a sensitive and efficient tool. Stable reference genes are critical for relative qPCR analysis. However, accumulated evidence shows that conventional reference genes can vary significantly under different experimental setups. Here we evaluated the stability of eight candidate reference genes of zebrafish with or without exposure to different concentrations of Cd. The results showed that the best four suitable reference genes in the five selected organs were: (1) spleen: β-actin > gapdh > ef1α > rpl13α; (2) kidney: rplp2 > rpl7 > β-actin > ef1α; (3) liver: rpl7 > rpl13α > β-actin > ef1α; (4) gills: rplp2 > gapdh > rnf7 > ef1α; (5) intestine: ef1α > rnf7 > rplp2 > rpl13α. Moreover, we further assessed the expression stability of the four reference genes for Cd immunotoxicology studies in zebrafish. The expression profiles showed that ef1α in spleen and kidney, rpl13a in liver and rplp2 in intestine were the most suitable reference genes at 12 h and 9 days after the injection with Aeromonas hydrophila following Cd exposure. In gills, the expression of gapdh was more stable than ef1α after 9 days of bacteria challenge while ef1α showed a higher stability than gapdh at 12 h after bacteria injection. In conclusion, this study has demonstrated that different tissues of zebrafish have different suitable reference genes after Cd exposure and the subsequently pathogenic insults for q

  16. The monitoring analysis of multiple drug-resistant bacteria infection of hospitalized patients%住院患者多重耐药菌感染的监测分析

    Institute of Scientific and Technical Information of China (English)

    金英; 王永梅; 郝巧歆; 李燕

    2015-01-01

    目的:调查医院住院患者多重耐药菌感染情况,为预防和控制医院多重耐药菌感染提供依据。方法采取细菌分离培养方法和药敏试验,对医院临床多重耐药菌感染及其致病菌分布情况进行调查与分析。结果从2013年共检出致病菌1331株,其中革兰氏阴性菌715株,革兰氏阳性球菌499株,多重耐药菌致病菌171株,占致病菌总数的12.83%。多重耐药菌依次为产超广谱β-内酰胺酶的细菌(ESBLs)、耐碳青酶烯类抗菌药物鲍曼不动杆菌(CR-AB)、耐甲氧西林金黄色葡萄球菌(MRSA)、多重耐药铜绿假单胞菌(MDR-RA)、耐万古肠球菌(VRE);引起医院感染部位主要是呼吸系统和泌尿系统;感染的主要科室分布为ICU、神经内科、呼吸内科,分别为25.15%、12.28%和12.28%。结论加强医院感染监测,了解相关流行病学信息,有针对的采取预防与控制措施能有效遏制医院感染的暴发与流行。%Objective To provide basis for preventing and controlling hospital multiple drug-resistant bacteria infection by investigating the multiple drug-resistant bacteria infection of hospitalized patients. Methods The bacterial cultiure and drug sensitivity test were adopted to analyze and investigate the clinical multiple drug-resistant bacteria infection and the distri-bution of in the hospital pathogenic bacteria. Results A total of 1 331 pathogenic bacteria were surveyed in 2013 , which in-cluded 715 strains of Gram-negative bacteria, 499 strains of Gram positive coccus and 171 strains of multiple drug-resistant pathogenic bacteria. The species of multiple drug-resistant bacteria , accounting for 12.83% of the total number were extended spectrum β-lactamase bacteria(ESBLs), resistance to carbapenems Bauman Acinetobacter bacillus (CR-AB), methicillin-re-sistant staphylococcus aureus (MRSA), multiple drug resistance pseudomonas aeruginosa (MDR-RA) and resistant enterococ

  17. 口腔正畸治疗感染患者病原菌分布及耐药性分析%The distribution and drug resistance of pathogenic bacteria for infection patients of orthodontic treatment

    Institute of Scientific and Technical Information of China (English)

    杨刚岭; 王岩莉; 舒明芳

    2014-01-01

    OBJECTIVE To study the distribution and drug resistance of pathogenic bacteria for infection patients of orthodontic treatment ,so as to control the occurrence of infections .METHODS A total of 765 cases of patients with orthodontic treatment from Jan .2011 to Jun .2013 were chosen ,and pathogenic bacteria were isolated and cultured ,with the drug sensitivity tests were conducted by K-B test .RESULTS A total of 85 cases with infections after orthodontic treatment and the occurrence rate was 11 .11% .A total of 91 strains of bacteria were isolated , including 25 strains of the respiratory tract accounting for 27 .47% ,19 strains of urinary tract accounting for 20 .88% ,14 strains of the gastrointestinal tract accounting for 15 .38% , 11 strains of skin accounting for 12 .09% ,7 strains from blood accounting for 7 .69% ,15 strains of other accounting for 16 .48% .There were 38 strains of gram-positive bacteria accounted for 41 .76% .53 strains of gram-negative bacteria accounted for 58 . 24% .gram-positive bacteria had no resistance on acetazolamide and linezolid .gram-negative bacteria had no re-sistance on meropenem and imipenem .CONCLUSION The infection occurrence rate for orthodontic treatment pa-tients is high ,especially more by drug-resistance bacteria .Therefore measures should be taken to control infec-tions .Pathogenic bacteria should be isolated and tested .The antibacterial with low resistance should be used for treating infections once infections occurred .%目的:研究口腔正畸治疗感染患者病原菌的分布及其耐药性,控制口腔正畸治疗感染的发生。方法选取2011年1月-2013年6月医院口腔正畸治疗765例,对其发生感染患者分离培养出的病原菌,采用K-B琼脂法进行药敏试验。结果经口腔正畸治疗后发生感染的患者共85例,感染率为11.11%;分离出病原菌91株,感染部位呼吸道25株占27.47%,泌尿道19株占20.88%,胃肠道14株占15.38

  18. Infections

    Directory of Open Access Journals (Sweden)

    Virginia Vanzzini Zago

    2012-01-01

    Full Text Available This is a retrospective, and descriptive study about the support that the laboratory of microbiology aids can provide in the diagnosis of ocular infections in patients whom were attended a tertiary-care hospital in México City in a 10-year-time period. We describe the microbiological diagnosis in palpebral mycose; in keratitis caused by Fusarium, Aspergillus, Candida, and melanized fungi; endophthalmitis; one Histoplasma scleritis and one mucormycosis. Nowadays, ocular fungal infections are more often diagnosed, because there is more clinical suspicion and there are easy laboratory confirmations. Correct diagnosis is important because an early medical treatment gives a better prognosis for visual acuity. In some cases, fungal infections are misdiagnosed and the antifungal treatment is delayed.

  19. 呼吸科院内尿路感染患者病原菌及耐药分析%Distribution and resistance of pathogenic bacteria in patients with nosocomial urinary tract infections

    Institute of Scientific and Technical Information of China (English)

    刘宇

    2015-01-01

    Objective To analyze the distribution and drug resistance of the pathogenic bacteria in patients with nosocomial urinary tract infections.Methods The results of urine culture in 35 patients with nosocomial urinary tract infection were analyzed.Results There were 58 strains of pathogenic bacteria isolated,including 27 strains of Gram-negative bacteria (46.55%),1 0 strains of Gram-positive bacteria (1 7.24%),and 21 strains of fungi (36.21%).The top three pathogens were escherichia coli (1 8.97%),Candida albicans (1 7.24%)and Klebsiella pneumoniae (1 0.34%).Drug sensitivity test showed that high drug resistance occurred in both Gram-negative bacte-ria and Gram-positive bacteria.Conclusion Nosocomial urinary tract infection in respiratory department is mainly caused by Gram-negative bacteria,showing multi-drug resistance.Fungal infection shows a higher detection rate, which should be paid more attention in clinic.%目的:分析呼吸科院内尿路感染患者的病原菌种类分布及其耐药性,为合理用药提供参考。方法回顾性分析呼吸科明确诊断的院内尿路感染患者35例,分析其尿培养病原菌结果。结果35例患者共分离出58株病原菌,其中革兰阴性菌27株,占46.55%,革兰阳性菌10株,占17.24%,真菌21株,占36.21%。病原菌按检测率排序前3位依次是大肠埃希菌(18.97%)、白色念珠菌(17.24%)、肺炎克雷伯杆菌(10.34%),药物敏感试验显示:革兰阴性菌及革兰阳性菌耐药性严重。结论呼吸科院内尿路感染病原菌以革兰阴性菌为主,且呈多重耐药现象。真菌感染检出率明显增高,临床需加以重视。

  20. Lipopolysaccharides in diazotrophic bacteria.

    Science.gov (United States)

    Serrato, Rodrigo V

    2014-01-01

    Biological nitrogen fixation (BNF) is a process in which the atmospheric nitrogen (N2) is transformed into ammonia (NH3) by a select group of nitrogen-fixing organisms, or diazotrophic bacteria. In order to furnish the biologically useful nitrogen to plants, these bacteria must be in constant molecular communication with their host plants. Some of these molecular plant-microbe interactions are very specific, resulting in a symbiotic relationship between the diazotroph and the host. Others are found between associative diazotrophs and plants, resulting in plant infection and colonization of internal tissues. Independent of the type of ecological interaction, glycans, and glycoconjugates produced by these bacteria play an important role in the molecular communication prior and during colonization. Even though exopolysaccharides (EPS) and lipochitooligosaccharides (LCO) produced by diazotrophic bacteria and released onto the environment have their importance in the microbe-plant interaction, it is the lipopolysaccharides (LPS), anchored on the external membrane of these bacteria, that mediates the direct contact of the diazotroph with the host cells. These molecules are extremely variable among the several species of nitrogen fixing-bacteria, and there are evidences of the mechanisms of infection being closely related to their structure.

  1. Lipopolysaccharides in diazotrophic bacteria

    Directory of Open Access Journals (Sweden)

    Rodrigo Vassoler Serrato

    2014-09-01

    Full Text Available Biological nitrogen fixation is a process in which the atmospheric nitrogen (N2 is transformed into ammonia (NH3 by a select group of nitrogen-fixing organisms, or diazotrophic bacteria. In order to furnish the biologically useful nitrogen to plants, these bacteria must be in constant molecular communication with their host plants. Some of these molecular plant-microbe interactions are very specific, resulting in a symbiotic relationship between the diazotroph and the host. Others are found between associative diazotrophs and plants, resulting in plant infection and colonization of internal tissues. Independent of the type of ecological interaction, glycans and glycoconjugates produced by these bacteria play an important role in the molecular communication prior and during colonization. Even though exopolysaccharides (EPS and lipochitooligosaccharides (LCO produced by diazotrophic bacteria and released onto the environment have their importance in the microbe-plant interaction, it is the lipopolysaccharides (LPS, anchored on the external membrane of these bacteria, that mediates the direct contact of the diazotroph with the host cells. These molecules are extremely variable among the several species of nitrogen fixing-bacteria, and there are evidences of the mechanisms of infection being closely related to their structure.

  2. Bovine viral diarrhea virus type 2 in vivo infection modulates TLR4 responsiveness in differentiated myeloid cells which is associated with decreased MyD88 expression.

    Science.gov (United States)

    Schaut, Robert G; McGill, Jodi L; Neill, John D; Ridpath, Julia F; Sacco, Randy E

    2015-10-02

    Symptoms of bovine viral diarrhea virus (BVDV) infection range from subclinical to severe, depending on strain virulence. Several in vitro studies showed BVDV infection impaired leukocyte function. Fewer studies have examined the effects of in vivo BVDV infection on monocyte/macrophage function, especially with strains of differing virulence. We characterized cytokine production by bovine myeloid cells isolated early or late in high (HV) or low virulence (LV) BVDV2 infection. Given BVDV infection may enhance susceptibility to secondary bacterial infection, LPS responses were examined as well. Monocytes from HV and LV infected calves produced higher levels of cytokines compared to cells from controls. In contrast, monocyte-derived macrophage cytokine levels were generally reduced. Modulated cytokine expression in HV BVDV2 macrophages was associated with decreased MyD88 expression, likely due to its interaction with viral NS5A. These data and those of others, suggest that certain Flaviviridae may have evolved strategies for subverting receptor signaling pathways involving MyD88.

  3. Campylobacter infection

    Science.gov (United States)

    ... in the small intestine from a bacteria called Campylobacter jejuni . It is a type of food poisoning. Causes ... testing for white blood cells Stool culture for Campylobacter jejuni Treatment The infection almost always goes away on ...

  4. 多药耐药菌医疗相关感染经济损失评价%Evaluation of economic losses induced by multidrug-resistant bacteria health care-associated infections

    Institute of Scientific and Technical Information of China (English)

    孙吉花; 邢敏; 姜雪锦; 王琳; 邱会芬; 赵爱荣; 李卫光

    2015-01-01

    OBJECTIVE To observe the effect of multidrug‐resistant bacteria health care‐associated infections (HAIs) on length of hospital stay and hospitalization expenses and evaluate the economical losses induced by the multidrug‐resistant bacteria HAIs .METHODS In 2012 and 2013 ,a retrospective survey was conducted to collect the related data of the patients with multidrug‐resistant bacteria HAIs and the patients without multidrug‐resistant bacteria HAIs ,and the occurrence tendency of HAIs ,length of hospital stay ,and hospitalization expenses were statistically analyzed by using SPSS17 .0 software .RESULTS The detection rate of the multidrug‐resistant bacteria HAIs was 44 .16% in 2012 and dropped to 23 .68% in 2013 .The average length of hospital stay of the patients with multidrug‐resistant bacteria HAIs was 51 .48 days in 2012 ,significantly longer than 20 .67 days of the pa‐tients without multidrug‐resistant bacteria HAIs ;it was 45 .16 days in 2013 ,significantly longer than 21 .19 days of the patients without multidrug‐resistant bacteria HAIs .The total hospitalization expense of the patients with multidrug‐resistant bacteria HAI was 130 749 .80 yuan in 2012 ,significantly more than 20 919 .86 yuan of the pa‐tients without multidrug‐resistant bacteria infections ;it was 127 473 .29 yuan in 2013 ,significantly more than 29 225 .12 yuan of the patients without multidrug‐resistant bacteria infections .CONCLUSIONS The multidrug‐resist‐ant bacteria HAIs may increase the length of hospital stay and the economic losses ,and it is urgent to take effec‐tive prevention measures .%目的:了解多药耐药菌(MDROs)医疗相关感染(HAIs)对住院日及住院费用的影响,评价其导致的经济损失。方法回顾性调查2012及2013年多药耐药菌 H A Is及非多药耐药菌 H A Is患者的相关资料,采用SPSS17.0软件对 HAIs发生趋势、两组患者的住院日及住院费用进行统计

  5. 呼吸内科下呼吸道感染病原菌及耐药探讨%Exploration of the Pathogenic Bacteria and Drug Resistance for Patients with Lower Respiratory Infection

    Institute of Scientific and Technical Information of China (English)

    郭宝明

    2015-01-01

    目的:分析呼吸内科下呼吸道感染病原菌及耐药。方法:收集2013年1月-2014年1月本院收治的120例下呼吸道感染患者的临床资料,分析痰培养结果及药敏试验结果,并探讨患者病原菌分布情况和耐药性。结果:革兰阴性菌所占百分率明显高于革兰阳性球菌和真菌,差异有统计学意义(P0.05);革兰阴性杆菌对磺胺甲噁唑耐药率明显高于革兰阳性球菌,敏感率明显低于革兰阳性球菌,差异有统计学意义(P0.05).The drug resistance rate for sulfamethoxazole with gram negative bacteria were higher than gram-positive bacteria,with significant difference(P<0.05), the susceptibility were lower than gram-positive bacteria,with significant difference(P<0.05);The drug resistance rate of amoxicillin ,gentamicin,levofloxacin, imipenem with gram negative bacteria were lower than gram-positive bacteria,with significant difference(P<0.05),the susceptibility were higher than gram-positive bacteria,with significant difference(P<0.05). Conclusion:Most of respiratory medicine lower respiratory infection pathogens in gram-negative bacteria,in the clinical drug susceptibility test must be based on patients,provide a reasonable regimen for patients,in order to improve patients’ prognosis.

  6. Analysis of predisposing factors, pathogenic bacteria and their drug sensitivity of pulmonary infection in lung cancer patients%肺癌患者肺部感染的易感因素、病原菌及药敏分析

    Institute of Scientific and Technical Information of China (English)

    费君; 陆友金; 赵大海

    2013-01-01

    Objective To analyze the predisposing factors, pathogenic bacteria and their drug sensitivity of pulmonary infection in lung cancer patients so as to provide clinical evidence for the anti-infective therapy of lung cancer. Methods The sputum samples of 103 patients with lung cancer complicated with pulmonary infection were cultured and given drug sensitivity test. Besides, the predisposing factors were analyzed. Results There were 252 qualified sputum samples, and 75 strains of pathogenic bacteria were detected, including 45. 3% fungi, 44% Gram-negative bacteria, and 10.7% Gram-positive bacteria. The 6 major kinds of pathogenic bacteria all showed different degrees of drug resistance. In addition, the major predisposing factors were age, duration of hospital stay, chemicotherapy and clinical stages. Conclusion The monitoring of pulmonary infection pathogenic bacteria should be strengthened in lung cancer patients, which can provide the basic clinical evidence for the use of antibacterials.%目的 分析肺癌患者肺部感染的易感因素、病原菌变迁及药敏状况,为肺癌患者的抗感染治疗提供临床依据.方法 对103例肺癌合并肺部感染患者易感因素、痰标本进行培养及药敏分析.结果 103例患者送检252份合格痰标本,其易感因素主要为年龄、住院时间、放化疗、临床分期.检出病原菌75株,其中真菌45.3%,革兰阴性菌44%,革兰阳性菌10.7%.6种主要病原菌对抗菌药物都具有不同程度的耐药性.结论 加强肺癌患者肺部感染病原菌的监测,为临床合理使用抗菌药物提供参考依据.

  7. Infection

    Science.gov (United States)

    2010-09-01

    Interactions between biofilms and the environment. FEMS Microbiol Rev. 1997;20:291–303. 4. Webb LX, Wagner W, Carroll D, et al. Osteomyelitis and...treatment of osteomyelitis . Biomed Mater. 2008;3: 034114. 6. Gristina AG. Biomaterial-centered infection: microbial adhesion versus tissue integration...vertebral osteomyelitis . Spine. 2007;32: 2996–3006. 15. Beckham JD, Tuttle K, Tyler KL. Reovirus activates transforming growth factor ß and bone

  8. Leishmania panamensis infection and antimonial drugs modulate expression of macrophage drug transporters and metabolizing enzymes: impact on intracellular parasite survival

    Science.gov (United States)

    Gómez, Maria Adelaida; Navas, Adriana; Márquez, Ricardo; Rojas, Laura Jimena; Vargas, Deninson Alejandro; Blanco, Victor Manuel; Koren, Roni; Zilberstein, Dan; Saravia, Nancy Gore

    2014-01-01

    Objectives Treatment failure is multifactorial. Despite the importance of host cell drug transporters and metabolizing enzymes in the accumulation, distribution and metabolism of drugs targeting intracellular pathogens, their impact on the efficacy of antileishmanials is unknown. We examined the contribution of pharmacologically relevant determinants in human macrophages in the antimony-mediated killing of intracellular Leishmania panamensis and its relationship with the outcome of treatment with meglumine antimoniate. Methods Patients with cutaneous leishmaniasis who failed (n = 8) or responded (n = 8) to treatment were recruited. Gene expression profiling of pharmacological determinants in primary macrophages was evaluated by quantitative RT–PCR and correlated to the drug-mediated intracellular parasite killing. Functional validation was conducted through short hairpin RNA gene knockdown. Results Survival of L. panamensis after exposure to antimonials was significantly higher in macrophages from patients who failed treatment. Sixteen macrophage drug-response genes were modulated by infection and exposure to meglumine antimoniate. Correlation analyses of gene expression and intracellular parasite survival revealed the involvement of host cell metallothionein-2A and ABCB6 in the survival of Leishmania during exposure to antimonials. ABCB6 was functionally validated as a transporter of antimonial compounds localized in both the cell and phagolysosomal membranes of macrophages, revealing a novel mechanism of host cell-mediated regulation of intracellular drug exposure and parasite survival within phagocytes. Conclusions These results provide insight into host cell mechanisms regulating the intracellular exposure of Leishmania to antimonials and variations among individuals that impact parasite survival. Understanding of host cell determinants of intracellular pharmacokinetics/pharmacodynamics opens new avenues to improved drug efficacy for intracellular

  9. 许昌地区新型甲型H1N1流感合并细菌感染分析%Analyze on Novel A/H1N1 influenza infected by bacteria in Xuchang area

    Institute of Scientific and Technical Information of China (English)

    任丽娟; 艾根伟

    2011-01-01

    目的 研究新型甲型H1N1流感患者合并细菌感染情况.方法 收集咽拭子标本800份,检测其甲型H1N1流感病毒RNA,同时做咽拭子的细菌培养,根据结果 分析甲型H1N1流感患者合并细菌感染及致病菌的药敏情况.结果 800份样本中423例H1N1 RNA阳性;其中73例合并不同的细菌感染,占甲流患者的17%,多数细菌的耐药性较强.结论 许昌地区2009年的甲流疫情中,甲流患者合并细菌感染的情况值得关注,治疗中要注意细菌培养并合理用药.%Objective To research the patients with Novel A/H1N1 who had infected by bacteria.Methods To collect 800 examples of fauces swabs and incubat the swabs and detect the novel A( H1N1 ) influenza virus RNA,on the basis of the results,we could analyze whether the novel A/H1N1 influenza patients infected by bacteria.Results There were 423 patients who had infected by novel A/H1N1 influenza and 73( 17% ) of them had co-infected by bacteria,most of the bacteria were drug fast.Conclusions During the epidemic disease of novel A/H1N1 influenza in Xuchang area in 2009, the co-infected by bacteria and A/H1N1 should be payed more attention, furthermore, we should gave our attention to germicultue and prescribe medicines in reason.

  10. Analysis of Clinical Lower Respiratory Infection Pathogenic Bacteria Species and Drug Resistance in A Hospital%某院临床下呼吸道感染病原菌种类及耐药性的分析

    Institute of Scientific and Technical Information of China (English)

    孙凤国

    2015-01-01

    Objective To understand and grasp our hospital in 2013 clinical lower respiratory infection pathogenic bacteria species and drug resistance, to guide clinical rational drug use.Methods The BD phoenix 100 automatic bacteria identification application database data in 2013 and drug susceptibility testing system WHONET5.5 retrospective statistical analysis of bacterial drug resistance monitoring software.Results Gram-negative bacteria 60.42%;Gram-positive bacteria 9.98%; Fungi was 29.60%. Gram-negative bacteria klebsiella pneumoniae in 31.01%, 13.62% E. coli, pseudomonas aeruginosa 7.83%; Gram positive bacterium staphylococcus aureus 54.39%, streptococcus pneumoniae 22.81%; Fungi white candida yeast 55.03%, and 31.95% tropical candida.Conclusions The lower respiratory tract infection is given priority to with gram-negative bacteria 60.42%, klebsiella pneumoniae detection rate is highest, its to amoxicillin/clavulanic acid, piperacillin, ampicillin/shu ba present high drug resistance. E. coli resistance, resistance to an average of 33.68%. Gram-positive bacteria infection is given priority to with staphylococcus aureus, sugar peptide, pbo alkane ketone is still the most effective treatment of gram-positive bacteria infection. Bacteria merged fungi double infection should not be ignored, to strengthen the resistant monitoring and to guide clinical rational drug use.%目的:了解并掌握2013年我院临床下呼吸道感染病原菌种类及耐药性,指导临床合理用药。方法美国BD phoenix 100全自动细菌鉴定药敏检测系统数据库2013年数据并应用WHONET5.5细菌耐药监测软件进行回顾性统计分析。结果革兰阴性菌60.42%;革兰阳性菌9.98%;真菌29.60%。革兰阴性菌中肺炎克雷伯菌31.01%,大肠埃希菌13.62%,铜绿假单胞菌7.83%;革兰阳性菌中金黄色葡萄球菌54.39%,肺炎链球菌22.81%;真菌中白假丝酵母菌55.03%,热带假丝酵母菌31.95%。结论下呼吸道

  11. The alternative sigma factor B modulates virulence gene expression in a murine Staphylococcus aureus infection model but does not influence kidney gene expression pattern of the host.

    Science.gov (United States)

    Depke, Maren; Burian, Marc; Schäfer, Tina; Bröker, Barbara M; Ohlsen, Knut; Völker, Uwe

    2012-01-01

    Infections caused by Staphylococcus aureus are associated with significant morbidity and mortality and are an increasing threat not only in hospital settings. The expression of the staphylococcal virulence factor repertoire is known to be affected by the alternative sigma factor B (SigB). However, its impact during infection still is a matter of debate. Kidney tissues of controls or mice infected with S. aureus HG001 or its isogenic sigB mutant were analyzed by transcriptome profiling to monitor the host response, and additionally expression of selected S. aureus genes was monitored by RT-qPCR. Direct transcript analysis by RT-qPCR revealed significant SigB activity in all mice infected with the wild-type strain, but not in its isogenic sigB mutant (p<0.0001). Despite a clear-cut difference in the SigB-dependent transcription pattern of virulence genes (clfA, aur, and hla), the host reaction to infection (either wild type or sigB mutant) was almost identical. Despite its significant activity in vivo, loss of SigB did neither have an effect on the outcome of infection nor on murine kidney gene expression pattern. Thus, these data support the role of SigB as virulence modulator rather than being a virulence determinant by itself.

  12. Adrenal steroids modulate the immune response during Brucella abortus infection by a mechanism that depends on the regulation of cytokine production.

    Science.gov (United States)

    Gentilini, María Virginia; Velásquez, Lis Noelia; Barrionuevo, Paula; Arriola Benitez, Paula Constanza; Giambartolomei, Guillermo Hernán; Delpino, María Victoria

    2015-05-01

    Human brucellosis is a protean disease with a diversity of clinical signs and symptoms resulting from infection with Brucella species. Recent reports suggest a cross-regulation between adrenal steroids (cortisol and dehydroepiandrosterone [DHEA]) and the immune system. Monocytes and macrophages are the main replication niche for Brucella. Therefore, we investigated the role of adrenal hormones on the modulation of the immune response mediated by macrophages in B. abortus infection. Cortisol treatment during B. abortus infection significantly inhibits cytokine, chemokine, and MMP-9 secretion. In contrast, DHEA treatment had no effect. However, DHEA treatment increases the expression of costimulatory molecules (CD40, CD86), the adhesion molecule CD54, and major histocompatibility complex class I (MHC-I) and MHC-II expression on the surface of B. abortus-infected monocytes. It is known that B. abortus infection inhibits MHC-I and MHC-II expression induced by gamma interferon (IFN-γ) treatment. DHEA reverses B. abortus downmodulation of the MHC-I and -II expression induced by IFN-γ. Taken together, our data indicate that DHEA immune intervention may positively affect monocyte activity during B. abortus infection.

  13. Necator americanus and helminth co-infections: further down-modulation of hookworm-specific type 1 immune responses.

    Directory of Open Access Journals (Sweden)

    Stefan Michael Geiger

    2011-09-01

    Full Text Available BACKGROUND: Helminth co-infection in humans is common in tropical regions of the world where transmission of soil-transmitted helminths such as Ascaris lumbricoides, Trichuris trichiura, and the hookworms Necator americanus and Ancylostoma duodenale as well as other helminths such as Schistosoma mansoni often occur simultaneously. METHODOLOGY: We investigated whether co-infection with another helminth(s altered the human immune response to crude antigen extracts from either different stages of N. americanus infection (infective third stage or adult or different crude antigen extract preparations (adult somatic and adult excretory/secretory. Using these antigens, we compared the cellular and humoral immune responses of individuals mono-infected with hookworm (N. americanus and individuals co-infected with hookworm and other helminth infections, namely co-infection with either A. lumbricoides, Schistosoma mansoni, or both. Immunological variables were compared between hookworm infection group (mono- versus co-infected by bootstrap, and principal component analysis (PCA was used as a data reduction method. CONCLUSIONS: Contrary to several animal studies of helminth co-infection, we found that co-infected individuals had a further downmodulated Th1 cytokine response (e.g., reduced INF-γ, accompanied by a significant increase in the hookworm-specific humoral immune response (e.g. higher levels of IgE or IgG4 to crude antigen extracts compared with mono- infected individuals. Neither of these changes was associated with a reduction of hookworm infection intensity in helminth co-infected individuals. From the standpoint of hookworm vaccine development, these results are relevant; i.e., the specific immune response to hookworm vaccine antigens might be altered by infection with another helminth.

  14. Characteristics of distribution of drug resistance detection of common pathogenic bacteria for surgical infection in our hospital%我院外科感染常见病原菌分布特点及耐药性检测

    Institute of Scientific and Technical Information of China (English)

    陆学安; 杨春水; 秦文静; 王龙安; 张治中

    2014-01-01

    目的:了解外科感染常见病原菌分布特点以及对常用抗生素的耐药情况,为临床合理用药提供科学依据。方法采用纸片扩散法(Kirby-Bauer法)对来自外科感染患者的临床分离菌进行药敏试验。按CLSI 2011版标准判断结果。结果临床分离菌共305株,革兰阴性菌183株,革兰阳性菌122株。在各类细菌中,主要分离菌为:革兰阴性菌的大肠埃希菌、铜绿假单胞菌、肺炎克雷伯杆菌;革兰阳性菌的凝固酶阴性葡萄球菌和金黄色葡萄球菌。耐甲氧西林金黄色葡萄球菌(MRSA)和耐甲氧西林凝固酶阴性葡萄球菌(MRCNS)检出率为23.3%和31.3%,都未发现对万古霉素耐药菌株。大肠埃希菌、肺炎克雷伯菌中产超广谱β-内酰胺酶(ESBLs)株检出率分别为34.4%和21.9%。铜绿假单胞菌对亚胺培南的耐药率为5.3%。结论定期分析医院病原菌的耐药性,可以为临床治疗和预防感染提供依据。临床重视病原菌的检查,根据药敏试验选择合理的抗生素,可以减少细菌耐药的发生。%Objective To understand the characteristics of distribution of common pathogenic bacteria for surgical infection, and their drug resistance to common antibacterial agents, so as to provide scientific basis for reasonable clinical drug use. Methods Antimicobial susceptibility testing was carried out for the clinical isolated bacteria from patients with surgical infection by Kirby-Bauer method. The results were analyzed according to CLSI 2011 criterion. Results A total of 305 clinical isolated bacteria were collected. Among them, there were 183 strains of gram-negative bacteria, and 122 strains of gram-positive bacteria. The main isolated bacteria were Escherichia coli, pseudomonas aeruginosa, and klebsiella pneumonia in gram-negative bacteria, and coagulase negative staphylococcus and staphylococcus aureus in gram-positive bacteria. The detection rates of methicillin

  15. 大鲵细菌性感染综合症的病原分离与药敏试验分析%Isolation and Identification of Pathogenic Bacteria from Giant Salamander with Bacterial Infection Syndrome and Drug Sensitivity Analysis

    Institute of Scientific and Technical Information of China (English)

    于喆; 江辉; 钟蕾; 肖克宇; 谭情; 毛盼

    2012-01-01

    On the base of the experiment of isolating and purifying bacterial from the body surface, liver, kidney, intestine, limb, ascites of Giant salamander with bacterial infection syndrome, a total of 12 strains bacteria were obtained. The identification of the morphological structure, physiological and biochemical characteristics and artificial infection experiment of the bacteria showed that Citrobacter braakii, Aeromonas hydrophila and Acinetobact-er lwoffi isolated from the Giant salamander are the 3 main strains pathogenic bacteria. Drug sensitive test showed that the 3 strains pathogenic bacteria put up different degrees of drug resistance on many antibiotics, even these pathogenic bacteria were extremely sensitive to Meropenem. Therefore it is concluded that Meropenem can be used as the first option for preventing this disease.%对细菌性感染综合症病鲵的体表、肝脏、肾脏、肠道、四肢、腹水等进行细菌分离培养与纯化,共得到12株细菌.经细菌的形态结构、生理生化特性鉴定和人工感染试验证实,布拉克枸橼酸杆菌(Citrobacter braakii),嗜水气单胞菌(Aeromonas hydrophila)和洛菲不动杆菌(Acinetobacter lwoffi)为主要致病菌.药敏试验结果表明,3种病原菌对很多抗生素均存在不同程度的耐药性,而对美洛培南(Meropenem)高度敏感,其可作为防治该病的首选药物.

  16. Conjugated bilirubin affects cytokine profiles in hepatitis A virus infection by modulating function of signal transducer and activator of transcription factors.

    Science.gov (United States)

    Castro-García, Flor P; Corral-Jara, Karla F; Escobedo-Melendez, Griselda; Sandoval-Hernandez, Monserrat A; Rosenstein, Yvonne; Roman, Sonia; Panduro, Arturo; Fierro, Nora A

    2014-12-01

    Hepatitis A virus (HAV) infection is the major cause of acute liver failure in paediatric patients. The clinical spectrum of infection is variable, and liver injury is determined by altered hepatic enzyme function and bilirubin concentration. We recently reported differences in cytokine profiles between distinct HAV-induced clinical courses, and bilirubin has been recognized as a potential immune-modulator. However, how bilirubin may affect cytokine profiles underlying the variability in the course of infection has not been determined. Herein, we used a transcription factor (TF) binding site identification approach to retrospectively analyse cytokine expression in HAV-infected children and to predict the entire set of TFs associated with the expression of specific cytokine profiles. The results suggested that modulation of the activity of signal transducers and activators of transcription proteins (STATs) may play a central role during HAV infection. This led us to compare the degree of STAT phosphorylation in peripheral blood lymphoid cells (PBLCs) from paediatric patients with distinct levels of conjugated bilirubin (CB). Low CB levels in sera were associated with increased STAT-1 and STAT-5 phosphorylation. A positive correlation was observed between the serum interleukin-6 (IL-6) content and CB values, whereas higher levels of CB correlated with reduced serum IL-8 values and with a reduction in the proportion of PBLCs positive for STAT-5 phosphorylation. When CB was used to stimulate patients' PBLCs in vitro, the levels of IL-6 and tumour necrosis factor-α were increased. The data showed that bilirubin plays a role in STAT function and affects cytokine profile expression during HAV infection.

  17. 职业病患者医院内感染及病原菌特点分析%Nosocomial Infection and Pathogenic Bacteria Analysis in Patients with Occupational Diseases

    Institute of Scientific and Technical Information of China (English)

    宗士香; 朱杉; 何青秀

    2015-01-01

    目的:了解职业病患者医院内感染及病原菌分布特点,指导临床抗菌药物的正确应用并为制定院感防控措施提供科学依据。方法由感控专职人员和科室感控兼职人员联合协作,采用患者床旁询问、查阅运行病历和出院病历回顾性调查相结合,对2012年1月-2014年12月收治的1976例职业病患者,46例次医院感染病例,230株病原菌进行统计分析。结果2012年要2014年职业病例次感染率分别是1.06%、3.67%、1.89%,平均例次感染率是2.33%;感染部位以呼吸道为主占60%,其次是泌尿道占20%;胃肠道占13.33;病原菌以革兰氏阴性杆菌为主占91.30%。结论职业病患者医院感染率低于卫计委规定的二级综合性医院感染率≤8%的标准,感染部位和病原菌与国内文献报道一致。以后该院要提高病原菌送检率和药敏试验以指导抗菌药物的合理应用。%Objective To investigate the distribution of nosocomial infections and pathogenic bacteria in patients with occupational diseases, and to provide the correct application of antibiotics and provide scientific basis for the prevention and control of nosoco-mial infections.Methods By the sense of control full-time staff and Department of part-time staff joint collaboration of infection control, adopted at the patient's bedside inquiry, access to medical and hospital records retrospective study combined, in January 2012-2014 December 1976 cases of occupational disease patients, 46 cases nosocomial infection cases and 230 strains of pathogenic bacteria were statistically analyzed. Results In 2012-2014 occupational disease infection rate respectively is 1.06%and 3.67%, 1.89%, average case infection rate is 2.33%; site of infection in respiratory tract accounted for 60%, followed by uri-nary tract accounted for 20%; gastrointestinal accounted for 13.33; pathogenic bacteria in gram negative bacteria dominated (91.30%). Conclusion Patients with

  18. Co-infection with Ascaris lumbricoides modulates protective immune responses against Giardia duodenalis in school Venezuelan rural children.

    Science.gov (United States)

    Hagel, I; Cabrera, M; Puccio, F; Santaella, C; Buvat, E; Infante, B; Zabala, M; Cordero, R; Di Prisco, M C

    2011-03-01

    We evaluated the effect of Ascaris lumbricoides on Giardia duodenalis infection and TH1/TH2 type immune mechanisms toward this parasite in 251 rural parasitized and 70 urban non-parasitized school children. The children were classified according to light (0-5000 eggs/g faeces) or moderate (>5001-50,000 eggs/g faeces) A. lumbricoides infection. Anti G. duodenalis skin hyper-reactivity, IgE, IgG, IL-13, IFN γ, IL6 and IL-10 levels were compared among G. duodenalis infected and non-infected children according to light or moderate A. lumbricoides infection. It was found that 62% of the A. lumbricoides moderately infected children were co-infected by G. duodenalis compared to 45% of the lightly infected group. After treatment, 42% of the A. lumbricoides moderately group were infected with G. duodenalis compared to 11% of their lightly counterparts, being A. lumbricoides IL-10 levels higher (p0.0001) and A. lumbricoides IL-10 levels (p>0.0001), suggesting that co-infection with A. lumbricoides may affect both TH1 and TH2 type immunity against G. duodenalis that may play an important role in the susceptibility to the infection after chemotherapy in children from endemic areas.

  19. 骨外科老年感染患者的病原菌分布及耐药监测研究%The Distribution of Pathogenic Bacteria and Drug Resistance Monitoring of Senile Patients with Infection in Bone Surgery

    Institute of Scientific and Technical Information of China (English)

    周亚丽

    2014-01-01

    Objective To analyze the distribution of main pathogenic bacteria and drug resistance of senile patients with infection in bone surgery so as to provide a reference for clinical use of antibiotic drugs. Methods 300 cases of senile orthopedic patients admitted in our hospital from April, 2011 to April, 2013 were randomly selected. Secretion samples were collected from the wound of the patients for bacteria culture and bacteria identification, and drug sensitive test was conducted. Results Of the 300 cases of patients, a total of 298 strains of bacteria were detected, including 142 strains of gram negative bacteria (47.7%), 150 strains of gram positive bacteria (50.3%), 6 strains of fungi (2%). Conclusion The drug resistance of nosocomial infection pathogens is relatively complex, which changes quickly, so appropriate antibiotic drugs for the treatment of senile orthopedic patients, should be chosen in accordance with the pathogen resistance test and the result of appraisal strictly in order to reduce the infection rate of the patients.%目的:分析骨外科老年感染患者主要病原菌的分布情况及耐药率,为临床抗菌药用药提供参考。方法随机选取该院300例骨科老年患者,从患者的伤口中采集分泌物标本,并对标本进行细菌培养及细菌鉴定,并进行药敏试验。结果在300例患者中,共检出298株细菌,142株格兰阴性菌(47.7%),150株格兰阳性菌(50.3%),6株真菌(2%)。结论医院感染病原菌的耐药性较复杂,构成变化快,应严格按照病原菌耐药性检测及鉴定结果,选择合适的抗生素药物为骨科老年患者进行治疗,降低患者感染率。

  20. Nano-ZnO/ZnO-HAPw prepared via sol-gel method and antibacterial activities of inorganic agents on six bacteria associated with oral infections

    Science.gov (United States)

    Jin, Jianfeng; Liu, Wenying; Zhang, Wenyun; Chen, Qinghua; Yuan, Yanbo; Yang, Lidou; Wang, Qintao

    2014-10-01

    The antibacterial activity of zinc oxide (ZnO) and the strengthening of hydroxylapatite whiskers (HAPws) have been widely studied and applied. However, the antibacterial properties of ZnO-HAPws have scarcely been researched. The aim of this study was to further investigate several types of nano-ZnO morphologies of ZnO-HAPws that were prepared using the sol-gel method at different pondus hydrogenii (pH) values and temperatures. The four morphologies of ZnO-HAPws that were investigated here were granule, triangle, short rod and disc type, and these morphologies were investigated at 70 °C at pH 6.4, 37 °C at pH 6.6, 70 °C at pH 6.6 and 70 °C at pH 6.6, respectively. Next, the antibacterial activity of ZnO-HAPw was compared to that of nano-ZnO, commercially available ZnO and tetrapod-like ZnO whiskers (T-ZnOw) with six bacteria that are associated with oral infections: Streptococcus mutans, Lactobacillus casei, Candida albicans, Actinomyces viscosus, Staphylococcus aureus and Escherichia coli. The results of examinations of the minimal inhibitory concentrations (MICs) and minimal bactericidal concentrations (MBCs) showed that the antibacterial activity of ZnO-HAPw exceeded that of the commercially available ZnO and T-ZnOw. Additionally, analysis of variance (ANOVA) analysis of the MBCs revealed that the four tested antibacterial agents had significantly different effects on S. mutans ( F = 8.940; P = 0.006), S. aureus ( F = 6.924; P = 0.013) and E. coli ( F = 4.468; P = 0.04). ANOVA analyses of the MICs revealed that the four tested antibacterial agents had significantly different effects on S. mutans ( F = 6.183; P = 0.018), A. viscosus ( F = 4.531; P = 0.039) and S. aureus ( F = 18.976; P = 0.001).

  1. Certain surfactants significantly enhance the activity of antibiotics in the mouse model of MTB and drug resistant MTB infection and effectively remove the bacteria from a pulmonary cavity in human ex-vivo study.

    Science.gov (United States)

    Risin, Semyon A; Hunter, Robert L; Kobak, Mikhail; Ariel, Boris; Vishnevsky, Boris; Erokhin, Vladislav; Demikhova, Olga; Bocharova, Irina; Stoops, James K

    2014-01-01

    Surfactants have the potential to overcome natural resistance of MTB to antibiotics which is mediated by barriers that impede the penetration of drugs to their targets. A major component of this barrier is trehalose dimycolate (TDM) which surrounds the bacteria with a thick lipid shield. In this study dodecyl maltoside (DDM) was evaluated for this purpose. This surfactant is an excellent cellular permeabilizing agent with associated low toxicity. The administration of the surfactant as an aerosol into the lungs of the infected mice achieved a 5-10 times enhancement of the isoniazid (INH) treatment gauged by the reduction of the colony forming units. This study also established proof of principle that surfactants alone applied as an aerosol can reduce the bacteria count in lungs infected with MTB. The potential of the surfactant in the therapy of human cavitary TB was also investigated using a surgically removed lung from a patient with extreme drug resistant MTB (XDR-TB). A cavity in this lung was flushed with DDM solution ex-vivo. The procedure readily removed the bacteria, excessive amounts of TDM and necrotic tissue from the cavity. These studies demonstrate that DDM can disrupt the layers of TDM and free embedded MTB and, consequently, surfactants have promise as a proficient modality for the treatment of pulmonary MTB.

  2. Modulation of the pro-inflammatory molecules E-selectin and TNF-α gene transcription in Eimeria ninakohlyakimovae-infected primary caprine host endothelial cells.

    Science.gov (United States)

    Pérez, D; Ruiz, A; Muñoz, M C; Molina, J M; Hermosilla, C; López, A M; Matos, L; Ortega, L; Martín, S; Taubert, A

    2015-10-01

    Eimeria ninakohlyakimovae is an important coccidian parasite of goats which causes severe hemorrhagic typhlocolitis in young animals, thereby leading to high economic losses in goat industry worldwide. The first merogony of E. ninakohlyakimovae occurs within host endothelial cells (ECs) of the lacteal capillaries of the villi of the distal ileum resulting in the formation of macromeronts (up to 170 μm) within 10-12 days post-infection (p.i.) and releasing >120,000 merozoites I. The E. ninakohlyakimovae-macromeront formation within highly immunoreactive host endothelial cells (ECs) should rely on several regulatory processes to fulfill this massive replication. Here host EC-parasite interactions were investigated to determine the extent of modulation carried out by E. ninakohlyakimovae in primary caprine umbilical vein endothelial cells (CUVEC) during the first merogony. Gene transcription of the adhesion molecule E-selectin and the cytokine TNF-α were significantly enhanced in the first hours and days p.i. in E. ninakohlyakimovae-infected CUVEC. The activation of CUVEC was also demonstrated by enhanced chemokine CCL2 and cytokine GM-CSF gene transcription, whereas no differences of the eNOS gene transcription were observed in E. ninakohlyakimovae-infected CUVEC when compared to un-infected controls. The data presented here suggest that infection of caprine host ECs by E. ninakohlyakimovae results in EC activation associated with enhanced gene transcription encoding for pro-inflammatory as well as immunomodulatory molecules, which might be important for the defense against this intracellular parasite.

  3. Staphylococcal Infections

    Science.gov (United States)

    ... you should be familiar with include the following: Cellulitis is a bacterial skin infection that first affects the outer layers of the ... skin. Although other types of bacteria can cause cellulitis, Saureus ... may diagnose the infection by examining the area. The doctor may take ...

  4. Oral administration of a probiotic Lactobacillus modulates cytokine production and TLR expression improving the immune response against Salmonella enterica serovar Typhimurium infection in mice

    Directory of Open Access Journals (Sweden)

    Perdigón Gabriela

    2011-08-01

    Full Text Available Abstract Background Diarrheal infections caused by Salmonella, are one of the major causes of childhood morbidity and mortality in developing countries. Salmonella causes various diseases that range from mild gastroenteritis to enteric fever, depending on the serovar involved, infective dose, species, age and immune status of the host. Probiotics are proposed as an attractive alternative possibility in the prevention against this pathogen infection. Previously we demonstrated that continuous Lactobacillus casei CRL 431 administration to BALB/c mice before and after challenge with Salmonella enterica serovar Typhimurium (S. Typhimurium decreased the severity of Salmonella infection. The aim of the present work was to deep into the knowledge about how this probiotic bacterium exerts its effect, by assessing its impact on the expression and secretion of pro-inflammatory (TNFα, IFNγ and anti-inflammatory (IL-10 cytokines in the inductor and effector sites of the gut immune response, and analyzing toll-like receptor (TLR2, TLR4, TLR5 and TLR9 expressions in both healthy and infected mice. Results Probiotic administration to healthy mice increased the expression of TLR2, TLR4 and TLR9 and improved the production and secretion of TNFα, IFNγ and IL-10 in the inductor sites of the gut immune response (Peyer's patches. Post infection, the continuous probiotic administration, before and after Salmonella challenge, protected the host by modulating the inflammatory response, mainly in the immune effector site of the gut, decreasing TNFα and increasing IFNγ, IL-6 and IL-10 production in the lamina propria of the small intestine. Conclusions The oral administration of L. casei CRL 431 induces variations in the cytokine profile and in the TLRs expression previous and also after the challenge with S. Typhimurium. These changes show some of the immune mechanisms implicated in the protective effect of this probiotic strain against S. Typhimurium, providing

  5. Incidence and risk factors for carbapenemases-producing gram-negative bacteria infections%产碳青霉烯酶革兰阴性菌感染的发生及其相关危险因素分析

    Institute of Scientific and Technical Information of China (English)

    张颖; 何杰; 谢志宏

    2012-01-01

    OBJECTIVE To investigate the status of carbapenemases-producing gram-negative bacteria infections and analyze the related risk factors. METHODS The determination of the gram-negative bacteria isolated from the hospitalized patients during Jan - Dec 2010 whose drug susceptibility to carbapenem antibiotics decreased was performed by PCR, and the risk factors for carbapenemases-producing gram-negative bacteria infections were analyzed. RESULTS Of the gram-negative bacteria whose drug susceptibility to carbapenems decreased, the detection rates of carbapenemases from Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, Enterobactercloacae and Acinetobacter baumannii were 57. 14%, 50. 00%, 46. 67%, 46. 15% and 36.36%, respectively; sputum, urine and blood were the top three specimens from which carbapenemases were detected, accounting for 33. 85% , 24. 61% and 15. 38% , respectively; univariate factor analysis and multivariate factors analysis revealed that the duration of hospital stay , invasive operation within one week, hospitalized departments and ICU, readmission or transfer, and use of carbapenem antibiotics were the risk factors for carbapenemases-producing gram-negative bacteria infections. CONCLUSION The bacteria whose drug susceptibility to carbapenems decreases take a large proportion among carbapenemases-producing gram-negative bacteria; to reasonably use carbapenems antibiotics and shorten the hospital stay as much as possible is crucial to the control of carbapenemase-producing gram-negative bacteria infections.%目的 探讨医院产碳青霉烯酶(KPC)革兰阴性菌的感染状况以及可能危险因素.方法 将2010年1-12月医院住院患者中分离对碳青霉烯类抗菌药物敏感性下降的革兰阴性菌,以PCR法分别进行KPC测定,并分析产KPC革兰阴性菌感染的危险因素.结果 对碳青霉烯类抗菌药物敏感性下降的革兰阴性菌中,肺炎克雷伯菌、大肠埃希菌、铜绿假单胞菌、阴沟肠

  6. Bacteria, phages and septicemia.

    Directory of Open Access Journals (Sweden)

    Ausra Gaidelyte

    Full Text Available The use of phages is an attractive option to battle antibiotic resistant bacteria in certain bacterial infections, but the role of phage ecology in bacterial infections is obscure. Here we surveyed the phage ecology in septicemia, the most severe type of bacterial infection. We observed that the majority of the bacterial isolates from septicemia patients spontaneously secreted phages active against other isolates of the same bacterial strain, but not to the strain causing the disease. Such phages were also detected in the initial blood cultures, indicating that phages are circulating in the blood at the onset of sepsis. The fact that most of the septicemic bacterial isolates carry functional prophages suggests an active role of phages in bacterial infections. Apparently, prophages present in sepsis-causing bacterial clones play a role in clonal selection during bacterial invasion.

  7. 感染性心内膜炎患者血培养病原菌及其耐药性分析%Analysis of Pathogenic Bacteria and Drug Resistance in Patients with Endocarditis Infected Blood Culture

    Institute of Scientific and Technical Information of China (English)

    邱宗利

    2014-01-01

    目的:分析感染性心内膜炎患者血培养病原菌及其耐药性,为临床提供参考。方法:通过对52例2003年9月-2013年9月本院收治的感染性心内膜炎患者进行血培养实验和病原菌耐药性实验,分析感染性心内膜炎患者血培养病原菌及其耐药性。结果:52例患者共筛选出32株病原菌,感染率为61.54%,其中革兰阳性菌株28株,占87.50%,主要为金黄色葡萄球菌、草绿色链球菌、粪肠球菌、牛链球菌、口腔链球菌和表皮葡萄球菌,革兰阳性菌对环丙沙星和庆大霉素耐药性较强,对万古霉素耐药性较差;革兰阴性菌4株,占12.50%,主要为铜绿假单胞、产气肠杆菌和大肠埃希菌,革兰阴性菌对庆大霉素耐药性较强,对头孢哌酮和环丙沙星耐药性较差。结论:金黄色葡萄球菌和草绿色链球菌是感染性心内膜炎的主要致病菌,而这两株菌对万古霉素的耐药性均较差,所以临床上可以用万古霉素作为预防和治疗感染性心内膜炎的主要抗生素,这对临床治疗感染性心内膜炎有重要的指导意义。%Objective:To analyze pathogenic bacteria and drug resistance in blood of patients with infective endocarditis,and to provide reference for clinical.Method:52 cases of patients with infective endocarditis were obtained from 2003 September to 2013 September in our hospital,which were used to do pathogen resistance experiment and blood culture experiment,and the endocarditis culture and drug resistance of pathogens were analyzed.Result:32 strains of pathogenic bacteria were screened from 52 patients,the infection rate was 61.54%,of which 28 strains were gram positive strains,accounting for 87.50%,mainly included Staphylococcus aureus,Streptococcus viridans,Enterococcus faecalis,Streptococcus bovis,oral Streptococcus and Staphylococcus epidermidis,the resistance of gram positive bacteria to ciprofloxacin and gentamicin was strong,but the

  8. 急诊革兰阳性菌感染危险因素分析%Analysis of risk factors related to infections by gram-positive bacteria in emergency depart-ment patients

    Institute of Scientific and Technical Information of China (English)

    唐韵; 曹同瓦; 刘珏; 翁丽贞

    2014-01-01

    目的:探讨本院急诊科病房革兰阳性菌感染患者的危险因素,为其防治提供科学依据。方法回顾性分析本院急诊科感染病例中103例革兰阳性菌感染情况。采用单因素分析和多因素Logistic回归分析其危险因素。结果分离患者血液、尿液、痰、胆汁、穿刺液、分泌液、脓汁及伤口引流液送检标本共1796份,检出阳性标本631份,总菌株培养检出阳性率为35.1%。分离出病原菌共593株,其中革兰阳性菌169株。465例感染病例中有103例检获革兰阳性菌感染,占22.2%。多因素Logistic回归分析发现,中心静脉置管、慢性肾功能不全、住院天数≥20 d是急诊科革兰阳性菌感染的独立危险因素。结论医院急诊科革兰阳性菌感染率在逐年增高,有针对性地合理选用抗生素,谨慎使用有肾毒性药物,保护肾功能,减少侵入性置管,缩短住院天数,将有助于控制医院急诊科革兰阳性菌感染。%Objective Objectives To study the risk factors related to the infections by gram-positive bacteria and to discuss how to control .Methods A case control study was performed .Data of 103 cases of nosocomial infection caused by gram-positive bacte-ria were analyzed .As a control ,the 362 cases of nosocomial infection caused by other bacteria were selected at the same time .The uni-variate analysis and multivariate Logistic regression were used for statistics analysis .Results During the period of 3 years,1796 sam-ples were obtained,in which positive samples were 631(35.1%),and 593 strains were separated,among which G+bacteria were 169. There were totally 465 patients with the infections by gram-positive bacteria ( incidence rate was 22.2%) .Results from unconditioned Logistic regression analysis showed that the risk factors were the central venous catheterization ,the chronic kidney insufficiency and the length of hospital stay .Conclusion There was an obvious ascending

  9. Corneal ulcers and infections

    Science.gov (United States)

    Bacterial keratitis; Fungal keratitis; Acanthamoeba keratitis; Herpes simplex keratitis ... infection with bacteria, viruses, fungi, or a parasite. Acanthamoeba keratitis occurs in contact lens users. It is ...

  10. 脑梗塞患者呼吸道感染的病原菌及耐药分析%Analysis of Pathogenic Bacteria and Drug Resistance of Respiratory Infection on Cerebral Infarction Patients

    Institute of Scientific and Technical Information of China (English)

    周晶

    2015-01-01

    Objective To investigate the species of pathogenic bacteria and drug resistance of respiratory infection on cerebral infarction patients. Methods An retrospective review was adopted to analyze the results of sputum culture and drug sensitive test among 226 cases of cerebral infarction patients with respiratory infection. Results 235 strains of 32 kinds of pathogenic bacteria were found, including 78.6% Gram-negative bacteria ,17.5% strains of fungus and 3.9% Gram-positive bacteria. The Gram negative bacil i with higher separation rate were Klebesiel a pneumoniae, Escherichia coli,Acinetobacter baumanni , Pseudomonas aeruginosa and they constituted a dominant flora,which were resistant to common antibiotics. Conclusion The respiratory infection in patients with cerebral infarction was mainly due to Gram-negative bacteria,which were resistant to common antibiotics.Clinicians should strengthen the supervision and drug sensitive test and drug resistance.%目的了解住院脑梗塞患者引起呼吸道感染的病原菌的种类及耐药情况。方法回顾分析226例脑梗塞伴呼吸道感染患者的痰培养及药敏试验的临床资料。结果检出病原菌32种235株,其中革兰阴性杆菌占78.6%,真菌占17.4%,革兰阳性球菌占3.9%。革兰阴性杆菌中以肺炎克雷伯菌、大肠埃希菌、鲍曼不动杆菌、铜绿假单胞菌比例较高,构成优势菌群且常用抗生素耐药。结论脑梗塞患者的呼吸道感染病菌多为革兰阴性菌,常用抗生素耐药明显。临床医生应加强耐药菌监测和药敏试验。

  11. Treatment strategies for children with hematonosis and multi-drug resistant bacteria infection%儿童血液病多重耐药菌感染的治疗对策

    Institute of Scientific and Technical Information of China (English)

    李春富; 孙树梅

    2015-01-01

    儿童血液病患者自身免疫功能低下,同时治疗过程中反复化疗对患儿免疫系统和造血功能的进一步损害,导致血液病患者医院感染高发,其中尤其以耐药菌及真菌感染较常见;血液病患儿常见的耐药菌感染有以下几种:多重耐药的大肠埃希菌、肺炎克雷伯杆菌等肠杆菌科细菌;多重耐药的铜绿假单胞菌、鲍曼不动杆菌等非发酵菌;甲氧西林耐药的凝固酶阴性葡萄球菌、金黄色葡萄球菌及多重耐药的粪肠球菌和屎肠球菌等阳性耐药菌;现就上述耐药菌目前的治疗进展进行讨论.%Children with hematological diseases usually accompanied by low autoimmune function,and repeated chemotherapy exacerbated the damage to their immune system and hematopoietic function.Those lead to high incidence of nosocomial infection,most of infection were caused by multi-drug resistant bacteria and fungi.The major infections in hematological children are the following:multi-drug resistant Escherichia coli/Klebsiella pneumonia bacteria;multi-drug resistance Pseudomonas and Acinetobacte;Methicillin-resistant coagulase negative Staphylococcus and aureus;multi-drug resistance Enterococcus faecium.This review presents updated treatment strategies from the published clinical literature and provides recommendations for clinical treatment of multi-drug resistant bacteria in children with hematonosis.

  12. 肿瘤医院ICU血流感染病原菌致炎症反应的比较%Comparison of inflammatory reaction between pathogenic bacteria bloodstream infections in ICU of tumor hospital

    Institute of Scientific and Technical Information of China (English)

    吴莉; 方敏峰; 许华; 杨峰

    2013-01-01

    目的 比较肿瘤医院ICU血流感染病原菌炎症反应指标及引起的临床表现与炎症反应程度,以此指导ICU严重感染患者的早期经验性抗菌药物选择.方法 回顾性分析入住ICU 48 h后血培养阳性患者60例,根据血培养结果,分为革兰阳性菌血流感染组及革兰阴性菌血流感染组,比较两组患者的一般资料及临床炎症反应的各项指标.结果 两组患者体温、心率、白细胞计数、中性粒细胞计数、C反应蛋白及降钙素原比较,差异均无统计学意义;革兰阳性菌血流感染组与革兰阴性菌血流感染组严重脓毒症或脓毒症休克发生率分别为4.1%与22.0%(P<0.05),血清脑肽素值分别为(112.0±15.2)pg/ml与(812.0±25.3) pg/ml(P<0.05),行机械通气感染率分别为75.0%与94.4% (P=0.016);两组肾脏替代治疗例数、ICU住院时间、临床死亡率分别为10例与12例、(34.3±16.5)与(26.0±27.1)d及12.50%与22.20%,两组比较差异无统计学意义;共分离出病原菌60株,其中革兰阴性菌36株占60.0%,以大肠埃希菌、肺炎克雷伯菌为主,分别占25.0%、11.7%,革兰阳性菌24株占40.0%,以金黄色葡萄球菌、肠球菌属为主,分别占16.7%、13.3%.结论 肿瘤医院ICU血流感染中革兰阴性菌的发生率偏高,与革兰阳性菌血流感染患者相比较,革兰阴性菌血流感染患者的炎症反应较重,临床表现严重,预后差.%OBJECTIVE To compare the clinical manifestations and the inflammatory reaction degrees caused by the pathogens causing bloodstream infections in the ICU of a tumor hospital so as to guide the empirical use of antibiotics for the ICU patient with severe infections.METHODS A total of 60 blood culture-positive patients,who have been hospitalized in the ICU for 48 hours,were enrolled in the study and divided into two groups(the gram-negative bacteria bloodstream infection patients and gram-positive bacteria bloodstream infection

  13. Mechanical ventilation enhances lung inflammation and caspase activity in a model of mouse pneumovirus infection

    NARCIS (Netherlands)

    R.A. Bem; J.B.M. van Woensel; A.P. Bos; A. Koski; A.W. Farnand; J.B. Domachowske; H.F. Rosenberg; T.R. Martin; G. Matute-Bello

    2009-01-01

    Severe infection with respiratory syncytial virus (RSV) in children can progress to respiratory distress and acute lung injury (ALI). Accumulating evidence suggests that mechanical ventilation (MV) is an important cofactor in the development of ALI by modulating the host immune responses to bacteria

  14. Clinical Analysis of Pathogenic Bacteria Infection in Elderly Patients with Chronic Obstructive Pulmonary Disease%老年慢性阻塞性肺疾病患者医院感染病原菌的临床分析

    Institute of Scientific and Technical Information of China (English)

    叶青; 邝军

    2014-01-01

    目的:探讨老年慢性阻塞性肺疾病(COPD)患者发生医院感染病原菌分布特点及感染危险因素,以指导临床治疗和预防.方法:回顾性分析2012年12月-2013年12月本院569例老年COPD患者的临床资料,观察患者医院感染发生率,并对发生感染患者的痰液、血液或尿液进行分离培养.结果:569例老年COPD患者中有86例发生医院感染,发生率为15.1%;感染患者送检的标本中共分离出病原株105例,其中革兰氏阴性菌64株占61.0%,革兰氏阳性菌29株占27.6%,真菌12株占11.4%;高龄、慢性病(高血压、冠心病、糖尿病等)、长期卧床、侵入性操作是老年COPD患者发生医院感染的主要危险因素.结论:老年COPD患者医院感染发生率较高,年龄≥80岁、合并慢性疾病(高血压、冠心病、糖尿病等)、长期卧床、侵入性操作均为导致医院感染的危险因素.%Objective To investigate the distribution characteristics of pathogenic bacteria and risk factors for nosocomial infection in elderly patients with chronic obstructive pulmonary disease(COPD),and to guide the clinical treatment and prevention.Methods The clinical data of 569 elderly patients with COPD was retrospectively analyzed from December 2012 to December 2013.The incidence of nosocomial infection was calculated,meanwhile the pathogenic bacteria were isolated from sputum,blood or urine samples of infected patients and then cultured in vitro.Results The incidence of nosocomial infection was 15.1% (86/569)in these patients; total 105 strains of pathogenic bacteria were isolated from the samples of infected patients,including 64 strains of gram negative bacteria accounted for 61.0%,29 strains of gram positive bacteria accounted for 27.6% and 12 strains of fungi accounted for 11.4%.Furthermore,the increased incidence of nosocomial infection were closely related to the advanced age,chronic diseases (hypertension,coronary heart disease,diabetes and so on

  15. Big bacteria

    DEFF Research Database (Denmark)

    Schulz, HN; Jørgensen, BB

    2001-01-01

    A small number of prokaryotic species have a unique physiology or ecology related to their development of unusually large size. The biomass of bacteria varies over more than 10 orders of magnitude, from the 0.2 mum wide nanobacteria to the largest cells of the colorless sulfur bacteria......, Thiomargarita namibiensis, with a diameter of 750 mum. All bacteria, including those that swim around in the environment, obtain their food molecules by molecular diffusion. Only the fastest and largest swimmers known, Thiovulum majus, are able to significantly increase their food supply by motility...... and by actively creating an advective flow through the entire population. Diffusion limitation generally restricts the maximal size of prokaryotic cells and provides a selective advantage for mum-sized cells at the normally low substrate concentrations in the environment. The largest heterotrophic bacteria...

  16. Anaerobic bacteria

    Science.gov (United States)

    Brook I, Goldstein EJ. Diseases caused by non-spore forming anaerobic bacteria. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine . 25th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 297. Stedman's Online ...

  17. Gammaherpesvirus infection modulates the temporal and spatial expression of SCGB1A1 (CCSP) and BPIFA1 (SPLUNC1) in the respiratory tract

    Science.gov (United States)

    Leeming, Gail H; Kipar, Anja; Hughes, David J; Bingle, Lynne; Bennett, Elaine; Moyo, Nathifa A; Tripp, Ralph A; Bigley, Alison L; Bingle, Colin D; Sample, Jeffery T; Stewart, James P

    2015-01-01

    Murine γ-herpesvirus 68 (MHV-68) infection of Mus musculus-derived strains of mice is an established model of γ-herpesvirus infection. We have previously developed an alternative system using a natural host, the wood mouse (Apodemus sylvaticus), and shown that the MHV-68 M3 chemokine-binding protein contributes significantly to MHV-68 pathogenesis. Here we demonstrate in A. sylvaticus using high-density micro-arrays that M3 influences the expression of genes involved in the host response including Scgb1a1 and Bpifa1 that encode potential innate defense proteins secreted into the respiratory tract. Further analysis of MHV-68-infected animals showed that the levels of both protein and RNA for SCGB1A1 and BPIFA1 were decreased at day 7 post infection (p.i.) but increased at day 14 p.i. as compared with M3-deficient and mock-infected animals. The modulation of expression was most pronounced in bronchioles but was also present in the bronchi and trachea. Double staining using RNA in situ hybridization and immunohistology demonstrated that much of the BPIFA1 expression occurs in club cells along with SCGB1A1 and that BPIFA1 is stored within granules in these cells. The increase in SCGB1A1 and BPIFA1 expression at day 14 p.i. was associated with the differentiation of club cells into mucus-secreting cells. Our data highlight the role of club cells and the potential of SCGB1A1 and BPIFA1 as innate defense mediators during respiratory virus infection. PMID:25531566

  18. Related factors for multiple resistant bacteria infections and prevention measures in respiratory department%呼吸科多重耐药菌感染的相关因素及预防措施

    Institute of Scientific and Technical Information of China (English)

    冯保英; 耿荣华

    2015-01-01

    Objective To explore the prevention measures for multiple resistant bacteria infections, and to prevent the multiple resistant bacteria infections. Methods Total of 70 patients with multiple resistant bacteria infections, who were treated in the Respiratory Department, Aviation General Hospital of China Medical University from October 2013 to September 2014, then the routine sputum culture, uncle culture and blood culture, the bacterial susceptibilities to majority of antimicrobial agents were determined by VITEK-2 compact, respectively. The results were analyzed with WHONET 5.6 software. Results Total of 68 strains of multiple resistant bacteric were isolated, among which the Acinetobacter baumannii, Pseudomonas aeruginosa and Serratia marcescens ranked the top three species, accounting for 42.6% (29/68), 39.7%(27/68) and 8.8%(6/68), respectively. The main Gram-positive bacteria remained high antibacterial activity against vancomycin, with the drug resistance rates of 7.9%, the main Gram-negative bacteria remained high antibacterial activity against tigecycline, with the drug resistance rates of 1.7%. Conclusions It is necessary to strengthen the detection of the multiple resistant bacteria, with the detection and diagnosis in a timely manner. It is necessary to choose sensitive antibiotics based on the result of drug susceptibility testing, strictly implement the hand hygiene, reinforce medical staff’s sterile operation concept. Train nursing workers and cleaning staff to better know multiple resistant bacteria. Intensify environment disinfection to avoid infections.%目的:探讨多重耐药菌感染在医院的预防措施,以期指导控制医院多重耐药菌的感染。方法收集中国医科大学航空总医院呼吸科病房2013年10月至2014年9月多重耐药菌感染者共70例,进行常规痰培养、尿培养和血培养,应用VITEK-2鉴定系统进行微生物鉴定和药敏分析,采用WHONET 5.6软件对药敏结果进行分析。

  19. 神经外科肺部感染多重耐药菌调查分析与防控对策%ANALYSIS AND PREVENTION STRATEGIES FOR MULTI-RESISTANT BACTERIA IN PATIENTS WITH PULMONARY INFECTION IN NEUROSURGERY DEPARTMENT

    Institute of Scientific and Technical Information of China (English)

    吴惠文; 丘宇茹; 洪丽霞

    2013-01-01

    目的 研究医院神经外科住院患者肺部感染多重耐药菌特点,探讨有效防控对策.方法 通过回顾性调查的方法,对某医院神经外科住院患者肺部感染的病原菌进行了分离鉴定与分析.结果 从63例肺部感染患者标本中共分离出病原菌20种134株,包括革兰阴性杆菌82株、革兰阳性球菌33株以及真菌19株.82株革兰阴性杆菌中鲍曼不动杆菌、肺炎克雷伯菌和铜绿假单胞菌分居前三位,构成比分别为15.67%、13.43%和13.43%;革兰阳性球菌居首位的是金黄色葡萄球菌,占13.43%.所检出的病原菌多数呈多重耐药,同时耐受三种或三种以上抗菌药物.结论 神经外科住院患者肺部感染以革兰阴性杆菌为主,多数呈多重耐药,以控制侵入性操作和消毒隔离为主要防控对策.%Objective To investigate the characteristics of multi - resistant bacteria in patients with pulmonary infection in neurosurgery department and to discuss effective prevention strategies. Methods The retrospective investigation was used to investigate the pathogenic bacteria infected in pulmonary of inpatients in neurosurgery department of this hospital. Results 134 strains of pathogenic bacteria with 20 species were isolated from 63 cases of pulmonary infection patients, which including 82 strains Gram - negative bacilli, 33 strains Gram - positive coccus and 19 strains fungi. Within 82 strains of Gram - negative bacilli, the top three were Acinelobacter baumannii, Klebsiella pneumoniae and Pseudomonas aeruginosa and the ratios were 15. 67% ,13. 43% and 13. 43% , respectively. Slaphylococcus aureus was the primary pathogenic bacteria in Gram - positive coccus, accounting for 13. 43% . Most of the detected pathogenic bacteria were multi - resistant to three or more antibiotics. Conclusion Gram - negative bacteria is presented as the main pathogenic bacteria in hospitalized patients with pulmonary infection in neurosurgery department, and

  20. Evidence that Vpu modulates HIV-1 Gag-envelope interaction towards envelope incorporation and infectivity in a cell type dependent manner.

    Directory of Open Access Journals (Sweden)

    Archana Gautam

    Full Text Available The HIV-1 Vpu is required for efficient virus particle release from the plasma membrane and intracellular CD4 degradation in infected cells. In the present study, we found that the loss of virus infectivity as a result of envelope (Env incorporation defect caused by a Gag matrix (MA mutation (L30E was significantly alleviated by introducing a start codon mutation in vpu. Inactivation of Vpu partially restored the Env incorporation defect imposed by L30E substitution in MA. This effect was found to be comparable in cell types such as 293T, HeLa, NP2 and GHOST as well as in peripheral blood mononuclear cells (PBMC and monocyte-derived macrophages (MDM. However, in HeLa cells BST-2 knockdown was found to further alleviate the effect of Vpu inactivation on infectivity of L30E mutant. Our data demonstrated that the impaired infectivity of virus particles due to Env incorporation defect caused by MA mutation was modulated by start codon mutation in Vpu.

  1. Host antioxidant enzymes and TLR-2 neutralization modulate intracellular survival of Staphylococcus aureus: Evidence of the effect of redox balance on host pathogen relationship during acute staphylococcal infection.

    Science.gov (United States)

    Nandi, Ajeya; Bishayi, Biswadev

    2015-12-01

    Staphylococcus aureus is an important pathogen in bone disease and innate immune recognition receptor, TLR-2 is reported to be crucial for inflammatory bone loss. Role of TLR-2 in bacterial clearance and cytokine response to S. aureus infection in murine bone marrow macrophages has been reported but the role of host derived ROS in host-pathogen relationship still remains an obvious question. In the present study, blocking of SOD and catalase in TLR-2 neutralized fresh bone marrow cells (FBMC) with Diethyldithiocarbamic acid (DDC) and 3-Amino-1,2,4-triazole (ATZ), separately, during acute S. aureus infection, produces moderate level of ROS and limits inflammation as compared with only TLR-2 non-neutralized condition and leads to decreased bacterial count compared with only TLR-2 neutralized condition. In summary, host SOD and catalase modulates ROS generation, cytokine levels and TLR-2 expression in FBMCs during acute S. aureus infection which might be useful in the alleviation of S. aureus infection and bone loss.

  2. Roles of oral bacteria in cardiovascular diseases--from molecular mechanisms to clinical cases: Treatment of periodontal disease regarded as biofilm infection: systemic administration of azithromycin.

    Science.gov (United States)

    Wang, Pao-Li

    2010-01-01

    Periodontal disease as a biofilm infectious disease is considered. Periodontal disease-associated bacteria formed biofilm in periodontal pockets or on the surface of cementum. Planktonic bacteria from biofilm invade into periodontal tissues and lead to inflammation and destruction of tissues directly and indirectly by eliciting the host defense mechanism. Supragingival dental plaques (biofilm) are easily removed by professional mechanical tooth cleaning, while subgingival dental plaques and bacteria invading into periodontal tissues are difficult to remove. Therefore, the development of a method for periodontal disease based on the concept that regards periodontal disease as a biofilm infectious disease is needed. Hereby, I report the effect of antibiotics on an in vitro biofilm model of periodontal disease and the systemic administration of azithromycin for early-onset (aggressive) periodontitis like a treatment resistant periodontitis.

  3. Distribution and Resistance Analysis of Pathogenic Bacteria Causing Catheter Associated Urinary Tract Infection in ICU%ICU导尿管相关性尿路感染的病原菌分布及耐药性分析

    Institute of Scientific and Technical Information of China (English)

    邵俊; 郑瑞强; 林华; 卢年芳; 於江泉

    2013-01-01

    Objective :To explore the distribution and resistance of pathogenic bacteria causing catheter associated uri-nary tract infection in ICU so as to guide the clinical rational use of antibiotics .Methods :Urine culture and its drug sus-ceptibility results of patients who were diagnosed catheter associated urinary tract infection were analyzed retrospective-ly from July 2009 to June 2013 in ICU of Subei People’s Hospital of Jiangsu Province .Results:226 strains of pathogenic bacteria was detected from 4558 urine specimens ,of which 138 strains of gram-negative bacteria (61 .06% ) ,57 strains of gram-positive bacteria(25 .22% ) ,31 fungi strains(13 .72% ) .Top five of pathogenic bacteria was followed by acine-tobacter baumannii ,pneumonia klebsiella ,Escherichia coli ,Enterococcus faecalis ,candida albicans .Resistance of acine-tobacter baumannii in most drug was >50% .Under 50% of the resistance was just cefoperazone/sulbactam ,meropen-em ,imipenem/Cilastatin ,SMZ/TMP .Conclusion:Gram-negative bacteria is still the main pathogenic bacteria of catheter associated urinary tract infections in ICU .Acinetobacter baumannii has risen to the first pathogenic bacteria ,and drug resistance is very severe .Rational use of antibiotics and good hand hygiene is very important according to the results of drug susceptibility .%目的:探讨IC U导尿管相关性尿路感染的病原学分布及耐药性,为临床合理使用抗菌药物提供依据。方法:回顾性对2009年7月-2013年6月入住我院IC U确诊导尿管相关性尿路感染的患者送检的尿液标本培养及药敏结果进行统计分析。结果:4558份尿标本共检出226株致病菌,其中革兰氏阴性菌138株,占61.06%,革兰氏阳性菌株57株,占25.22%,真菌株31株,占13.72%。排名前五位的病原菌依次是鲍曼不动杆菌、肺炎克雷伯氏菌、大肠埃希菌、粪肠球菌、白色念珠菌。鲍曼不动杆菌对大部分药物耐药性均>50

  4. Distribution of infecting bacteria and an analysis of drug resistance after abdominal surgery in children%小儿腹部伤口术后感染细菌分布及耐药分析

    Institute of Scientific and Technical Information of China (English)

    于琳琳

    2016-01-01

    目的:对小儿腹部伤口术后感染细菌分布以及耐药情况进行分析探讨,为今后的临床检验工作提供可靠的理论依据。方法:抽取2012年6月-2014年6月我院收治的小儿腹部伤口感染患者1022例,对其术后感染引流物病原菌进行培养、分离、鉴定,并展开药敏试验,统计分析试验结果。结果:在1022例感染患儿中,腹部外科病原菌分离率依次为铜绿假单胞菌、大肠埃希菌、克雷伯菌属,除此之外还包括革兰阳性需氧菌、厌氧菌、变形梭杆菌等,药敏结果证实,革兰阴性需氧菌对亚胺培南的敏感性较高,对氨苄西林的耐药率较高。结论:小儿腹部伤口术后感染病原菌分布较广,对抗生素存在明显的耐药现象,临床应对其给予重视,积极采取有效手段进行干预,减少耐药的发生。coli, klebsiella, gram-positive aerobic and anaerobic bacteria, fusobacterius varium. Drug allergy test conifrmed the higher susceptibility of gram-negative aerobic bacteria to imipenem, and higher resistance rate to ampicillin. Conclusion: Infecting bacteria are widespread and signiifcantly resist to antibiotic. In clinic, the phenomenon should be paid more attention.%Objective: To analyze distribution of infecting bacteria and on analysis of drug resistance after abdominal surgery in children, in order to provide a reliable theoretical basis for future clinical inspection. Methods: Pathogenic bacteria of drain in 1022 cases were cultured, separated, identiifed and tested by drug allergy. Results: Pathogens can be divided into pseudomonas aeruginosa, escherichia coli, klebsiella, gram-positive aerobic and anaerobic bacteria, fusobacterius varium. Drug allergy test confirmed the higher susceptibility of gram-negative aerobic bacteria to imipenem, and higher resistance rate to ampicillin. Conclusion: Infecting bacteria are widespread and significantly resist to antibiotic. In clinic, the

  5. 医院感染细菌的临床分布及耐药性分析%Clinical distribution and antibiotic resistance analysis on bacteria of nosocomial infection

    Institute of Scientific and Technical Information of China (English)

    陈映; 乔岩; 赵燕

    2013-01-01

    Objective To investigate the distribution and antibiotic resistance of hospitalized infection bacteria in clinical departments and specimens. Methods French biology-bioMerieux ATB bacterial identification system, susceptibility detection instrument and supporting microbial detection reagent were applied for bacterial identification and susceptibility testing. The distribution of bacterial infection and antibiotic resistance data from January 2011 to December 2011 were analyzed, respectively. Results Among 455 bacteria, Escherichia coli, Klebsiella pneumoniae, Candida albicans, Staphylococcus epidermidis, Acinetobacter baumannii, Pseudomonas aeruginosa, Staphylococcus aureus were the seven major infection bacteria, accounting for 68. 13% of the total detected bacteria. Methicillin-resistant Staphylococcus aureus ( MRSA ) and Staphylococcus epidermidis ( MRSE ) were with 46. 43% and 75. 68% detection, no vancomycin-resistant and teicoplain-resistant Staphylococcus aureus were detected. There were 38 cases with multiple antibiotic resistant bacteria with positive rate as 8. 35% . There was 37. 93% ( 11/29 ) Acinetobacter baumannii detected as pan-resistant bacteria. The sources of bacterial were mainly from respiratory medicine and intensive care unit ( ICU ). Sputum samples had the highest positive bacteria with 178 ( 39. 12% ). Conslusions That conducting regular surveillance of antibiotic resistance could help analyze changes of antibiotic resistant of hospital bacteria, providing a theoretical basis for the clinical experience of drug use.%目的 了解医院感染细菌在临床科室和标本中的分布及耐药情况.方法 回顾性分析2011年1月~2011年12月本院感染菌的分布及耐药情况.使用法国生物-梅里埃ATB细菌鉴定系统,应用药敏测试仪及配套微生物检测试剂进行细菌鉴定和药敏试验.结果 本研究分离的455株感染菌中,大肠埃希菌、肺炎克雷伯菌、白假丝酵母菌、表皮葡萄球菌、

  6. Protective Effect of Galectin-1 during Histoplasma capsulatum Infection Is Associated with Prostaglandin E2 and Nitric Oxide Modulation

    Science.gov (United States)

    Secatto, Adriana; Sorgi, Carlos A.; Prado, Morgana Kelly Borges; Ramos, Simone Gusmão; Cummings, Richard D.; Stowell, Sean R.

    2016-01-01

    Histoplasma capsulatum is a dimorphic fungus that develops a yeast-like morphology in host's tissue, responsible for the pulmonary disease histoplasmosis. The recent increase in the incidence of histoplasmosis in immunocompromised patients highlights the need of understanding immunological controls of fungal infections. Here, we describe our discovery of the role of endogenous galectin-1 (Gal-1) in the immune pathophysiology of experimental histoplasmosis. All infected wild-type (WT) mice survived while only 1/3 of Lgals1−/− mice genetically deficient in Gal-1 survived 30 days after infection. Although infected Lgals1−/− mice had increased proinflammatory cytokines, nitric oxide (NO), and elevations in neutrophil pulmonary infiltration, they presented higher fungal load in lungs and spleen. Infected lung and infected macrophages from Lgals1−/− mice exhibited elevated levels of prostaglandin E2 (PGE2, a prostanoid regulator of macrophage activation) and prostaglandin E synthase 2 (Ptgs2) mRNA. Gal-1 did not bind to cell surface of yeast phase of H. capsulatum, in vitro, suggesting that Gal-1 contributed to phagocytes response to infection rather than directly killing the yeast. The data provides the first demonstration of endogenous Gal-1 in the protective immune response against H. capsulatum associated with NO and PGE2 as an important lipid mediator in the pathogenesis of histoplasmosis. PMID:27698545

  7. Reduced sTWEAK and increased sCD163 levels in HIV-infected patients: modulation by antiretroviral treatment, HIV replication and HCV co-infection.

    Directory of Open Access Journals (Sweden)

    Luis M Beltrán

    Full Text Available BACKGROUND: Patients infected with the human immunodeficiency virus (HIV have an increased risk of cardiovascular disease due to increased inflammation and persistent immune activation. CD163 is a macrophage scavenger receptor that is involved in monocyte-macrophage activation in HIV-infected patients. CD163 interacts with TWEAK, a member of the TNF superfamily. Circulating levels of sTWEAK and sCD163 have been previously associated with cardiovascular disease, but no previous studies have fully analyzed their association with HIV. OBJECTIVE: The aim of this study was to analyze circulating levels of sTWEAK and sCD163 as well as other known markers of inflammation (hsCRP, IL-6 and sTNFRII and endothelial dysfunction (sVCAM-1 and ADMA in 26 patients with HIV before and after 48 weeks of antiretroviral treatment (ART and 23 healthy subjects. RESULTS: Patients with HIV had reduced sTWEAK levels and increased sCD163, sVCAM-1, ADMA, hsCRP, IL-6 and sTNFRII plasma concentrations, as well as increased sCD163/sTWEAK ratio, compared with healthy subjects. Antiretroviral treatment significantly reduced the concentrations of sCD163, sVCAM-1, hsCRP and sTNFRII, although they remained elevated when compared with healthy subjects. Antiretroviral treatment had no effect on the concentrations of ADMA and sTWEAK, biomarkers associated with endothelial function. The use of protease inhibitors as part of antiretroviral therapy and the presence of HCV-HIV co-infection and/or active HIV replication attenuated the ART-mediated decrease in sCD163 plasma concentrations. CONCLUSION: HIV-infected patients showed a proatherogenic profile characterized by increased inflammatory, immune-activation and endothelial-dysfunction biomarkers that partially improved after ART. HCV-HIV co-infection and/or active HIV replication enhanced immune activation despite ART.

  8. Close Encounters of Lymphoid Cells and Bacteria

    Science.gov (United States)

    Cruz-Adalia, Aranzazu; Veiga, Esteban

    2016-01-01

    During infections, the first reaction of the host against microbial pathogens is carried out by innate immune cells, which recognize conserved structures on pathogens, called pathogen-associated molecular patterns. Afterward, some of these innate cells can phagocytose and destroy the pathogens, secreting cytokines that would modulate the immune response to the challenge. This rapid response is normally followed by the adaptive immunity, more specific and essential for a complete pathogen clearance in many cases. Some innate immune cells, usually named antigen-presenting cells, such as macrophages or dendritic cells, are able to process internalized invaders and present their antigens to lymphocytes, triggering the adaptive immune response. Nevertheless, the traditional boundary of separated roles between innate and adaptive immunity has been blurred by several studies, showing that very specialized populations of lymphocytes (cells of the adaptive immunity) behave similarly to cells of the innate immunity. These “innate-like” lymphocytes include γδ T cells, invariant NKT cells, B-1 cells, mucosal-associated invariant T cells, marginal zone B cells, and innate response activator cells, and together with the newly described innate lymphoid cells are able to rapidly respond to bacterial infections. Strikingly, our recent data suggest that conventional CD4+ T cells, the paradigm of cells of the adaptive immunity, also present innate-like behavior, capturing bacteria in a process called transinfection. Transinfected CD4+ T cells digest internalized bacteria like professional phagocytes and secrete large amounts of proinflammatory cytokines, protecting for further bacterial challenges. In the present review, we will focus on the data showing such innate-like behavior of lymphocytes following bacteria encounter.

  9. THE ECOLOGY OF BACTERIA IN THE ALFRESCO ATMOSPHERE

    Science.gov (United States)

    This MiniReview is concerned with the sources,flux and the spacial and temporal distributions of culturable airborne bacteria; how meteorological conditions modulate these distributions; and how death, culture media, and experimental devices relate to measuring airborne bacteria....

  10. Nonstructural 3 Protein of Hepatitis C Virus Modulates the Tribbles Homolog 3/Akt Signaling Pathway for Persistent Viral Infection

    OpenAIRE

    Tran, Si C.; Pham, Tu M.; Nguyen, Lam N.; Park, Eun-Mee; Lim, Yun-Sook; Hwang, Soon B.

    2016-01-01

    Hepatitis C virus (HCV) infection often causes chronic hepatitis, liver cirrhosis, and ultimately hepatocellular carcinoma. However, the mechanisms underlying HCV-induced liver pathogenesis are still not fully understood. By transcriptome sequencing (RNA-Seq) analysis, we recently identified host genes that were significantly differentially expressed in cell culture-grown HCV (HCVcc)-infected cells. Of these, tribbles homolog 3 (TRIB3) was selected for further characterization. TRIB3 was init...

  11. Suppression of Foxo1 activity and down-modulation of CD62L (L-selectin) in HIV-1 infected resting CD4 T cells.

    Science.gov (United States)

    Trinité, Benjamin; Chan, Chi N; Lee, Caroline S; Mahajan, Saurabh; Luo, Yang; Muesing, Mark A; Folkvord, Joy M; Pham, Michael; Connick, Elizabeth; Levy, David N

    2014-01-01

    HIV-1 hijacks and disrupts many processes in the cells it infects in order to suppress antiviral immunity and to facilitate its replication. Resting CD4 T cells are important early targets of HIV-1 infection in which HIV-1 must overcome intrinsic barriers to viral replication. Although resting CD4 T cells are refractory to infection in vitro, local environmental factors within lymphoid and mucosal tissues such as cytokines facilitate viral replication while maintaining the resting state. These factors can be utilized in vitro to study HIV-1 replication in resting CD4 T cells. In vivo, the migration of resting naïve and central memory T cells into lymphoid tissues is dependent upon expression of CD62L (L-selectin), a receptor that is subsequently down-modulated following T cell activation. CD62L gene transcription is maintained in resting T cells by Foxo1 and KLF2, transcription factors that maintain T cell quiescence and which regulate additional cellular processes including survival, migration, and differentiation. Here we report that HIV-1 down-modulates CD62L in productively infected naïve and memory resting CD4 T cells while suppressing Foxo1 activity and the expression of KLF2 mRNA. Partial T cell activation was further evident as an increase in CD69 expression. Several other Foxo1- and KLF2-regulated mRNA were increased or decreased in productively infected CD4 T cells, including IL-7rα, Myc, CCR5, Fam65b, S1P1 (EDG1), CD52, Cyclin D2 and p21CIP1, indicating a profound reprogramming of these cells. The Foxo1 inhibitor AS1842856 accelerated de novo viral gene expression and the sequella of infection, supporting the notion that HIV-1 suppression of Foxo1 activity may be a strategy to promote replication in resting CD4 T cells. As Foxo1 is an investigative cancer therapy target, the development of Foxo1 interventions may assist the quest to specifically suppress or activate HIV-1 replication in vivo.

  12. Suppression of Foxo1 activity and down-modulation of CD62L (L-selectin in HIV-1 infected resting CD4 T cells.

    Directory of Open Access Journals (Sweden)

    Benjamin Trinité

    Full Text Available HIV-1 hijacks and disrupts many processes in the cells it infects in order to suppress antiviral immunity and to facilitate its replication. Resting CD4 T cells are important early targets of HIV-1 infection in which HIV-1 must overcome intrinsic barriers to viral replication. Although resting CD4 T cells are refractory to infection in vitro, local environmental factors within lymphoid and mucosal tissues such as cytokines facilitate viral replication while maintaining the resting state. These factors can be utilized in vitro to study HIV-1 replication in resting CD4 T cells. In vivo, the migration of resting naïve and central memory T cells into lymphoid tissues is dependent upon expression of CD62L (L-selectin, a receptor that is subsequently down-modulated following T cell activation. CD62L gene transcription is maintained in resting T cells by Foxo1 and KLF2, transcription factors that maintain T cell quiescence and which regulate additional cellular processes including survival, migration, and differentiation. Here we report that HIV-1 down-modulates CD62L in productively infected naïve and memory resting CD4 T cells while suppressing Foxo1 activity and the expression of KLF2 mRNA. Partial T cell activation was further evident as an increase in CD69 expression. Several other Foxo1- and KLF2-regulated mRNA were increased or decreased in productively infected CD4 T cells, including IL-7rα, Myc, CCR5, Fam65b, S1P1 (EDG1, CD52, Cyclin D2 and p21CIP1, indicating a profound reprogramming of these cells. The Foxo1 inhibitor AS1842856 accelerated de novo viral gene expression and the sequella of infection, supporting the notion that HIV-1 suppression of Foxo1 activity may be a strategy to promote replication in resting CD4 T cells. As Foxo1 is an investigative cancer therapy target, the development of Foxo1 interventions may assist the quest to specifically suppress or activate HIV-1 replication in vivo.

  13. Study on pathogenic bacteria causing surgical incision infections in patients with anorectal disease%肛肠疾病手术切口感染病原菌的临床调查分析

    Institute of Scientific and Technical Information of China (English)

    朱锡元; 郭景泉; 蒋清平; 邹武军; 程涛; 卢吉英

    2013-01-01

    目的 分析肛肠疾病手术切口感染(SSI)的病原菌特点,并分析了其相关的危险因素,以期为肛肠疾病SSI的预防治疗提供科学依据.方法 回顾性分析医院2010年7月-2012年6月因肛肠疾病手术的患者临床资料287例,统计分析肛肠疾病患者SSI的危险因素.结果 287例肛肠疾病手术患者共有59例发生SSI,感染率为20.6%,其中痔疮感染38例感染率为20.4%、肛瘘12例感染率为20.7%、肛裂9例感染率为20.9%,3组之间差异无统计学意义;59例SSI患者中共分离培养出病原菌38株,阳性率为64.4%,其中革兰阴性菌占了81.5%,革兰阳性菌占了13.2%,真菌占了5.3%;革兰阴性菌主要以大肠埃希菌、变形菌属、克雷伯菌属和肠杆菌属为主,分别占了42.1%、15.8%、10.5%和7.9%,革兰阳性菌以肠球菌属和表皮葡萄球菌为主,分别占了7.9和5.3%;单因素x2检验显示,年龄>40岁、手术时间>100min,体重指数(BMI)≥25的患者具有较高的SSI发生率(P<0.05).结论 肛肠疾病术后具有高的SSI发生率,感染的病原菌主要是革兰阴性菌,患者的年龄、手术时间和BMI是其SSI发生的高危因素,积极采取相应的预防措施有利于降低肛肠疾病SSI的发生.%OBJECTIVE To investigate the characteristics of pathogenic bacteria causing surgical incision infections in the patients with anorectal disease and to explore the related risk factors so as to provide scientific basis for the prevention of surgical incision infections. METHODS The clinical data of 287 patients with anorectal diseases who underwent surgery from Jul 2010 to Jun 2012 were retrospectively analyzed, and the risk factors of surgical incision infections in the patients were statistically analyzed. RESULTS Of totally 287 cases of patients investigated, the surgical incision infections occurred in 59 cases with the infection rate of 20. 6% , among which there were 37 (20. 4%)cases with hemorrhoids

  14. Chemokine binding protein M3 of murine gammaherpesvirus 68 modulates the host response to infection in a natural host.

    Directory of Open Access Journals (Sweden)

    David J Hughes

    2011-03-01

    Full Text Available Murine γ-herpesvirus 68 (MHV-68 infection of Mus musculus-derived strains of mice is an attractive model of γ-herpesvirus infection. Surprisingly, however, ablation of expression of MHV-68 M3, a secreted protein with broad chemokine-binding properties in vitro, has no discernable effect during experimental infection via the respiratory tract. Here we demonstrate that M3 indeed contributes significantly to MHV-68 infection, but only in the context of a natural host, the wood mouse (Apodemus sylvaticus. Specifically, M3 was essential for two features unique to the wood mouse: virus-dependent inducible bronchus-associated lymphoid tissue (iBALT in the lung and highly organized secondary follicles in the spleen, both predominant sites of latency in these organs. Consequently, lack of M3 resulted in substantially reduced latency in the spleen and lung. In the absence of M3, splenic germinal centers appeared as previously described for MHV-68-infected laboratory strains of mice, further evidence that M3 is not fully functional in the established model host. Finally, analyses of M3's influence on chemokine and cytokine levels within the lungs of infected wood mice were consistent with the known chemokine-binding profile of M3, and revealed additional influences that provide further insight into its role in MHV-68 biology.

  15. Chemokine Binding Protein M3 of Murine Gammaherpesvirus 68 Modulates the Host Response to Infection in a Natural Host

    Science.gov (United States)

    Hughes, David J.; Kipar, Anja; Leeming, Gail H.; Bennett, Elaine; Howarth, Deborah; Cummerson, Joanne A.; Papoula-Pereira, Rita; Flanagan, Brian F.; Sample, Jeffery T.; Stewart, James P.

    2011-01-01

    Murine γ-herpesvirus 68 (MHV-68) infection of Mus musculus-derived strains of mice is an attractive model of γ-herpesvirus infection. Surprisingly, however, ablation of expression of MHV-68 M3, a secreted protein with broad chemokine-binding properties in vitro, has no discernable effect during experimental infection via the respiratory tract. Here we demonstrate that M3 indeed contributes significantly to MHV-68 infection, but only in the context of a natural host, the wood mouse (Apodemus sylvaticus). Specifically, M3 was essential for two features unique to the wood mouse: virus-dependent inducible bronchus-associated lymphoid tissue (iBALT) in the lung and highly organized secondary follicles in the spleen, both predominant sites of latency in these organs. Consequently, lack of M3 resulted in substantially reduced latency in the spleen and lung. In the absence of M3, splenic germinal centers appeared as previously described for MHV-68-infected laboratory strains of mice, further evidence that M3 is not fully functional in the established model host. Finally, analyses of M3's influence on chemokine and cytokine levels within the lungs of infected wood mice were consistent with the known chemokine-binding profile of M3, and revealed additional influences that provide further insight into its role in MHV-68 biology. PMID:21445235

  16. Modulation of the expression of mimivirus-encoded translation-related genes in response to nutrient availability during Acanthamoeba castellanii infection

    Directory of Open Access Journals (Sweden)

    Lorena eSilva

    2015-06-01

    Full Text Available The complexity of giant virus genomes is intriguing, especially the presence of genes encoding components of the protein translation machinery such as transfer RNAs and aminoacyl-tRNA-synthetases; these features are uncommon among other viruses. Although orthologs of these genes are codified by their hosts, one can hypothesize that having these translation-related genes might represent a gain of fitness during infection. Therefore, the aim of this study was to evaluate the expression of translation-related genes by mimivirus during infection of Acanthamoeba castellanii under different nutritional conditions. In silico analysis of amino acid usage revealed remarkable differences between the mimivirus isolates and the A. castellanii host. Relative expression analysis by quantitative PCR revealed that mimivirus was able to modulate the expression of eight viral translation-related genes according to the amoebal growth condition, with a higher induction of gene expression under starvation. Some mimivirus isolates presented differences in translation-related gene expression; notably, polymorphisms in the promoter regions correlated with these differences. Two mimivirus isolates did not encode the tryptophanyl-tRNA synthetase in their genomes, which may be linked with low conservation pressure based on amino acid usage analysis. Taken together, our data suggest that mimivirus can modulate the expression of translation-related genes in response to nutrient availability in the host cell, allowing the mimivirus to adapt to different hosts growing under different nutritional conditions.

  17. Antimicrobial resistance of pathogenic bacteria causing nosocomial infection in patients with cerebrovascular diseases%脑血管疾病患者医院感染病原菌耐药性分析

    Institute of Scientific and Technical Information of China (English)

    黄娥; 董虹; 刘天春; 范文

    2014-01-01

    OBJECTIVE To explore the vulnerable sites and antimicrobial resistance of pathogenic bacteria causing nosocomial infection in patients with cerebrovascular diseases and provide the scientific laboratory reference for prevention and control of nosocomial infection following cerebrovascular diseases .METHODS The retrospective review was performed for the clinical data of 3 978 cases of hospitalized patients with cerebrovascular diseases from Jan .2011 to Jun .2013 .The pathogenic bacteria were isolated ,cultured and identified .The WHONET 5 .5 soft‐ware was used to process the data .RESULTS Totally 369 out of 3 978 patients with cerebrovascular diseases had nosocomial infection .The infection rate was 9 .3% .The infection sites were mostly respiratory tract (55 .3% ) , followed by urinary tract (24 .1% ) .Totally 407 pathogenic bacteria were isolated ,including gram negative bacte‐ria (70 .3% ) ,gram positive bacteria (24 .1% ) and fungi (5 .6% ) .Detection rate of methicillin‐resistant Staphy‐lococci (MRS) was 51 .7% .The detection rates of pan‐resistant Pseudomonas aeruginosa and Acinetobacter bau‐mannii were 16 .5% and 21 .8% ,respectively .The detection rate of ESBLs‐producing K lebsiella pneumoniae and Escherichia coli were 55 .0% .CONCLUSION The patients with cerebrovascular diseases were prone to nosocomial infection .The antimicrobial resistance was increasing .Therefore ,the effective measures should be carried out and the management of antibacterial use should be strengthened to prevent and control the outbreak and prevalence of nosocomial infection .%目的:探讨医院脑血管疾病住院患者医院感染的易感部位及病原菌耐药性,为预防脑血管疾病患者继发医院感染及感染控制提供实验室参考依据。方法调查2011年1月-2013年6月收治的3978例脑血管疾病患者的临床资料;病原菌分离培养及菌种鉴定;数据处理采用WHONET 5.5软件。结果3978例脑血管

  18. Investigation of common pathogenic bacteria and drug resistance in gerontism with bronchieetasis concurrent infection.%老年支气管扩张合并感染的常见病原菌及其耐药性调查

    Institute of Scientific and Technical Information of China (English)

    许立; 张锡林

    2011-01-01

    目的 调查分析老年支气管扩张合并感染的常见病原菌及其耐药情况,为临床合理应用抗菌药物提供依据.方法 对189例老年支气管扩张合并感染的住院患者的痰培养和药敏结果进行回顾性调查分析.结果 189例患者病原菌检测阳性122例,阳性率为64.6%,病原菌以革兰阴性杆菌为和真菌为主,分别占59.5%和10.8%;主要致病的革兰阴性杆菌对头孢呋辛、氨苄西林等药物耐药率高,对β-内酰胺类、碳青酶烯类、氨基糖甙类和喹诺酮类药物的耐药率相对较低.结论 老年支气管扩张合并感染病原菌以革兰阴性杆菌和真菌为主要条件致病菌,主要致病菌耐药率高,建议在药敏指导下用药.在未取得细菌药敏结果前可根据其病原菌分布特点经验性选择抗生素,宜采用联合抗菌药物治疗.%To investigate common pathogenic bacteria and drug resistance m gerontism with bronchiectasis concurrent infection, to make reasonable use of antibacterials. Methods Retrospectively analyzed sputum culture and drug sensitivity of 189 old patients with bronchiectasis concurrent infection. Results 122 people had masculine pathogenic bacteria, the masculine rate was 64.6%, then the rate of gram negative bacilli (GNB) was 59.5%, fungus was 10.8%; the drug resistance rate of GNB to Cefuroxime and Ampicillin was high, but to β-lactam antibiotics, carbapenem antibiotics, aminoglycosides and quinolones was low. Conclusion The main pathogenic bacteria in gerontism with bronchiectasis concurrent infection was gram negative bacilli and fungus, the rate of drug resistance was high, used antibiotics on the basis of drug sensitivity, selected antibiotics on the basis of the disposition feature of pathogenic bacteria, there was the best to use combination antibacterial drug therapy.

  19. Pathogenic bacteria and their drug sensitivity in patients with advanced lung cancer accompanying lung infection%晚期肺癌患者并发肺部感染的病原菌及药敏分析

    Institute of Scientific and Technical Information of China (English)

    于海容; 张丽娜; 薛庆亮; 薛新颖; 王娜; 杨冰; 汪建新

    2012-01-01

    目的 探讨晚期肺癌患者并发肺部感染的病原菌种类及药敏情况.方法 统计我院2009 年3 月-2011 年5 月收治的56 例Ⅳ期肺癌伴肺部感染的患者,对所有患者的痰菌培养及药敏试验结果进行回顾性分析.结果 共分离菌株228 株,其中G- 菌113 株(49.56%),以铜绿假单孢菌占首位(18.86%),其次为鲍曼氏不动杆菌、嗜麦芽窄食单胞菌、肺炎克雷伯杆菌及大肠埃希氏菌等;G+ 菌47 株(20.61%),以凝固酶阴性葡萄球菌为主(10.09%),其次为屎肠球菌、金黄色葡萄球菌等.真菌菌株68 株(29.82%),以白色念珠菌为主(14.04%).G- 菌主要对头孢他啶、氨基糖甙类、碳青酶烯类敏感,G+ 菌主要对万古霉素、替考拉宁、利奈唑胺敏感,真菌主要对氟康唑敏感.结论 晚期肺癌合并肺部感染主要以G- 菌为主,常伴有真菌感染,根据药敏结果合理应用抗生素是治疗的关键.%Objective To study the pathogenic bacteria and their drug sensitivity in patients with advanced lung cancer accompanying lung infection. Methods Sputum culture and drug sensitivity test data about 56 patients with advanced lung cancer accompanying lung infection admitted to our hospital from March 2009 to May 2011 were retrospectively analyzed. Results Two hundred and twenty-eight strains were isolated from sputum. Of these strains,113 (49.56%)were Gram-negative bacteria with Pseudomonas aeruginosa accounted for 18.86% followed by Bowman amobile bacteria, Klebsiella pneumoniae and E.coli, 47(20.61 %)were Gram-positive bacteria with coagulase negative staphylococcus accounted for 10.09% followed by Mycobacterium stercoris and Staphylococcus aureus, 68(29.82%)were fungi with Candida albicans accounted for 14.04%. The Gram-negative bacteria were sensitive to ceftazidime, aminoglycoside and carbapenem. The Gram-positive bacteria were sensitive to vancomycin, teicoplanin and linezolid. Fungi were sensitive to fluconazole. Conclusion Gram

  20. Drug susceptibility of multidrug-resistant bacteria causing nosocomial infections%医院感染多药耐药菌的临床调查与药敏分析

    Institute of Scientific and Technical Information of China (English)

    佟青; 张一兵; 刘阳

    2012-01-01

    OBJECTIVE To investigate the distribution and drug resistance of multiple drug resistant bacteria causing nosocomial infections so as to raise the level of infection prevention and guide clinical rational administration. METHODS The specimens of nosocomial infection were isolated routinely from Jan to Jul 2011} the identification of bacteria and drug susceptibility testing were finished by VITEK2 automatic microbial analyzer. RESULTS A total of 230 strains of pathogenic bacteria were isolated, including 129 (56.1%) multidrug-resistant bacteria. The isolation rate of gram-positive multidrug-resistant bacteria was 4. 8%, Stuphylococcus aureus accounted for 0. 9% and Enlerococci accounted for 3. 9% ; the isolation rate of gram-negative multidrug resistant bacteria was 45. 0% , Escherichia coli accounted for 16. 9%, KUbsiella pneumoniae accounted for 13.0%. CONCLUSION The distribution of multiple resistant bacteria isolated in our hospital is partly different from the target strains reported by the Ministry of Health, which indicates that the antibiotics should be used reasonably on the basis of the species of the pathogens isolated, drug resistance as well as the drug susceptibility testing.%目的 了解医院感染多药耐药菌的分布及耐药性,提高预防感染水平,指导临床合理使用抗菌药物.方法 对2011年1-7月临床标本按常规进行病原菌分离,采用VITEK IMS全自动细菌鉴定与药敏分析仪,对病原菌进行鉴定.结果 共检出病原菌230株,其中多药耐药菌129株,检出率为56.1%;革兰阳性多药耐药菌检出率为4.8%,主要为金黄色葡萄球菌占0,9%,屎肠球菌占3.9%;革兰阴性多药耐药菌检出率为45.0%,主要为大肠埃希菌占16,9%、肺炎克雷伯菌占13.0%.结论 医院分离的多药耐药菌分布与卫生部公布的主要多药耐药目标菌有一定差异,提示临床医师在使用抗菌药物时应根据病原菌的分离株种类、耐药性特点及药敏试验,合理选用抗菌药物.

  1. The distribution of bacteria infected by urinary tract in adolescent patients and the analysis of drug resistance ability%青少年尿路感染细菌分布以及耐药性分析

    Institute of Scientific and Technical Information of China (English)

    吴斌

    2016-01-01

    目的:探究近一年来深圳光明新区尿路感染青少年患者细菌分布情况和耐药情况。方法将2014年7月到2015年7月就诊光明新区医院的18~20岁尿路感染患者44例作为研究对象,收集中段尿分离培养细菌共得1382株菌落,分析尿路感染细菌的种类、分布和通过药敏试验分析耐药性。结果革兰氏阳性菌20.12%,真菌3.04%,革兰氏阴性菌76.85%;屎肠球菌37.41%,近平滑假丝酵母菌38.10%,大肠埃希菌50.47%。金黄色葡萄球菌对环丙沙星耐药性最强,屎肠球菌耐药性最强的为左氧氟沙星,粪肠球菌耐药性最强的为克林霉素,大肠埃希菌耐药性最强的为头孢曲松,铜绿假单胞菌耐药性最强的为氨曲南,肺炎克雷伯菌耐药性最强的为头孢曲松,柠檬酸杆菌耐药性最强的为环丙沙星。结论对于18~20的青少年岁的尿路感染患者,革兰氏阴性菌尤其是大肠埃希菌为主产生耐药性较为广泛。%Objective To investigate the bacterial distribution and drug resistance of urinary tract infection in adolescent patients. Methods From July 2014 to July 2015, 44 patients (aged between 18 and 20) with urinary tract infections were assigned as research subjects. Urine specimen were collected in the middle of urination for urine culture. A total of 1382 isolated bacterial colonies were found. The kinds of pathogens responsible for urinary tract infection,bacterial distribution,antimicrobial susceptibility and resistant strains were analyzed. Results The causative organisms included gram-positive bacteria 20.12%, 3.04% fungi, Gram-negative bacteria 76.85%. Most of the bacteria were E.faecium and E.faecalis in the detected gram-positive bacteria (76.91%), E.coli and Pseudomonas aeruginosa in the detected gram-negative bacteria (73.54%),Candida parapsilosis and Candida albicans in the detected fungi. Staphylococcus aureus was the highest resistant to Ciprofloxacin, and E.faecium was

  2. Porphyromonas gingivalis as a Model Organism for Assessing Interaction of Anaerobic Bacteria with Host Cells.

    Science.gov (United States)

    Wunsch, Christopher M; Lewis, Janina P

    2015-12-17

    Anaerobic bacteria far outnumber aerobes in many human niches such as the gut, mouth, and vagina. Furthermore, anaerobic infections are common and frequently of indigenous origin. The ability of some anaerobic pathogens to invade human cells gives them adaptive measures to escape innate immunity as well as to modulate host cell behavior. However, ensuring that the anaerobic bacteria are live during experimental investigation of the events may pose challenges. Porphyromonas gingivalis, a Gram-negative anaerobe, is capable of invading a variety of eukaryotic non-phagocytic cells. This article outlines how to successfully culture and assess the ability of P. gingivalis to invade human umbilical vein endothelial cells (HUVECs). Two protocols were developed: one to measure bacteria that can successfully invade and survive within the host, and the other to visualize bacteria interacting with host cells. These techniques necessitate the use of an anaerobic chamber to supply P. gingivalis with an anaerobic environment for optimal growth. The first protocol is based on the antibiotic protection assay, which is largely used to study the invasion of host cells by bacteria. However, the antibiotic protection assay is limited; only intracellular bacteria that are culturable following antibiotic treatment and host cell lysis are measured. To assess all bacteria interacting with host cells, both live and dead, we developed a protocol that uses fluorescent microscopy to examine host-pathogen interaction. Bacteria are fluorescently labeled with 2',7'-Bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein acetoxymethyl ester (BCECF-AM) and used to infect eukaryotic cells under anaerobic conditions. Following fixing with paraformaldehyde and permeabilization with 0.2% Triton X-100, host cells are labeled with TRITC phalloidin and DAPI to label the cell cytoskeleton and nucleus, respectively. Multiple images taken at different focal points (Z-stack) are obtained for temporal

  3. Prolactin: does it exert an up-modulation of the immune response in Trypanosoma cruzi-infected rats?

    Science.gov (United States)

    Filipin, Marina Del Vecchio; Brazão, Vânia; Santello, Fabricia Helena; Caetano, Leony Cristina; Toldo, Míriam Paula Alonso; do Prado, José Clóvis

    2011-09-27

    During the course of infection by Trypanosoma cruzi, the host immune system is involved in distinct, complex interactions with the endocrine system, and prolactin (PRL) is one of several hormones involved in immunoregulation. Although intensive studies attempting to understand the mechanisms that underlie Chagas' disease have been undertaken, there are still some pieces missing from this complex puzzle. Because data are scarce concerning the role of PRL involvement in Chagas' disease and taking into account the existence of crosstalk between neuroendocrine hormones and the immune system, the current study evaluates a possible up-regulation of the cellular immune response triggered by PRL in T. cruzi-infected rats and the role of PRL in reversing immunosuppression caused by the parasitic infection. The data shown herein demonstrate that PRL induces the proliferation of T lymphocytes, coupled with an activation of macrophages and the production of nitric oxide (NO), leading to a reduction in the number of blood trypomastigotes during the peak of parasitemia. During the acute phase of T. cruzi infection, an enhancement of both CD3+CD4+ and CD3+CD8+ T cell populations were observed in infected groups, with the highest numbers of these T cell subsets found in the infected group treated with PRL. Because NO is a signaling molecule involved in a number of cellular interactions with components of the immune system and the neuroendocrine system, PRL can be considered an alternative hormone able to up-regulate the host's immune system, consequently lowering the pathological effects of a T. cruzi infection.

  4. A multidisciplinary intervention to reduce infections of ESBL- and AmpC-producing, gram-negative bacteria at a University Hospital

    DEFF Research Database (Denmark)

    Knudsen, Inge Jenny Dahl; Andersen, Stig Ejdrup

    2014-01-01

    In response to a considerable increase in the infections caused by ESBL/AmpC-producing Klebsiella pneumonia in 2008, a multidisciplinary intervention, with a main focus on antimicrobial stewardship, was carried out at one university hospital. Four other hospitals were used as controls. Stringent...... guidelines for antimicrobial treatment and prophylaxis were disseminated throughout the intervention hospital; cephalosporins were restricted for prophylaxis use only, fluoroquinolones for empiric use in septic shock only, and carbapenems were selected for penicillin-allergic patients, infections due to ESBL...... led to a sustained change in antimicrobial consumption, and the incidence of patients infected with ESBL-producing K. pneumoniae decreased significantly (pPseudomonas...

  5. The Mannose Receptor (CD206) is an important pattern recognition receptor (PRR) in the detection of the infective stage of the helminth Schistosoma mansoni and modulates IFNγ production.

    Science.gov (United States)

    Paveley, Ross A; Aynsley, Sarah A; Turner, Joseph D; Bourke, Claire D; Jenkins, Stephen J; Cook, Peter C; Martinez-Pomares, Luisa; Mountford, Adrian P

    2011-11-01

    In this study, infective larvae of the parasitic helminth Schistosoma mansoni were shown to contain a large number of glycosylated components specific for the Mannose Receptor (MR; CD206), which is an important pattern recognition receptor (PRR) of the innate immune system. MR ligands were particularly rich in excretory/secretory (E/S) material released during transformation of cercariae into schistosomula, a process critical for infection of the host. E/S material from carboxyfluorescein diacetate succinimidyl ester (CFDA-SE)-labelled cercariae showed enhanced binding by cells lines that over-express the MR. Conversely, uptake was significantly lower by bone marrow-derived macrophages (MΦ) from MR(-/-) mice, although they were more active as judged by enhanced pro-inflammatory cytokine production and CD40 expression. After natural percutaneous infection of MR(-/-) mice with CFDA-SE-labelled parasites, there were fewer cells in the skin and draining lymph nodes that were CFDA-SE(+) compared with wild-type mice, implying reduced uptake and presentation of larval parasite antigen. However, antigen-specific proliferation of skin draining lymph node cells was significantly enhanced and they secreted markedly elevated levels of IFNγ but decreased levels of IL-4. In conclusion, we show that the MR on mononuclear phagocytic cells, which are plentiful in the skin, plays a significant role in internalising E/S material released by the invasive stages of the parasite which in turn modulates their production of pro-inflammatory cytokines. In the absence of the MR, antigen-specific CD4(+) cells are Th1 biased, suggesting that ligation of the MR by glycosylated E/S material released by schistosome larvae modulates the production of CD4(+) cell specific IFNγ.

  6. TLR2-Modulating Lipoproteins of the Mycobacterium tuberculosis Complex Enhance the HIV Infectivity of CD4+ T Cells.

    Directory of Open Access Journals (Sweden)

    Ciaran Skerry

    Full Text Available Co-infection with Mycobacterium tuberculosis accelerates progression from HIV to AIDS. Our previous studies showed that M. tuberculosis complex, unlike M. smegmatis, enhances TLR2-dependent susceptibility of CD4+ T cells to HIV. The M. tuberculosis complex produces multiple TLR2-stimulating lipoproteins, which are absent in M. smegmatis. M. tuberculosis production of mature lipoproteins and TLR2 stimulation is dependent on cleavage by lipoprotein signal peptidase A (LspA. In order to determine the role of potential TLR2-stimulating lipoproteins on mycobacterial-mediated HIV infectivity of CD4+ T cells, we generated M. smegmatis recombinant strains overexpressing genes encoding various M. bovis BCG lipoproteins, as well as a Mycobacterium bovis BCG strain deficient in LspA (ΔlspA. Exposure of human peripheral blood mononuclear cells (PBMC to M. smegmatis strains overexpressing the BCG lipoproteins, LprF (p<0.01, LprH (p<0.05, LprI (p<0.05, LprP (p<0.001, LprQ (p<0.005, MPT83 (p<0.005, or PhoS1 (p<0.05, resulted in increased HIV infectivity of CD4+ T cells isolated from these PBMC. Conversely, infection of PBMC with ΔlspA reduced HIV infectivity of CD4+ T cells by 40% relative to BCG-infected cells (p<0.05. These results may have important implications for TB vaccination programs in areas with high mother-to-child HIV transmission.

  7. Modulation of innate immune responses and induction of oxidative stress biomarkers in Pangasianodon hypophthalmus following an experimental infection with dactylogyrid monogeneans.

    Science.gov (United States)

    Kumar, Saurav; Raman, R P; Prasad, K Pani; Srivastava, P P; Kumar, Sanath; Rajendran, K V

    2017-04-01

    Modulation of innate immune activity and oxidative stress response of Pangasianodon hypophthalmus through experimental infection with (Thaparocleidus sp.) dactylogyrid monogenean was studied. A standard cohabitation method was used to infect healthy experimental fish. After 14 days, dactylogyrid (gill monogenean) infested fish were sampled and categorised into three different infected groups namely (T1) low (50 mean dactylogyrid per gill arch per fish) along with a control group T0 (un-infested fish). Serum and tissues (gills and liver) were collected from experimental fish and analyzed for markers of innate immune and oxidative stress, respectively. The results showed that respiratory burst activity, myeloperoxidase level, serum lysozyme, α-2 macroglobulin and total serum immunoglobulin level were significantly (p hypophthalmus by lowering albumin, total serum antiprotease and ceruloplasmin and inducing respiratory burst activity, phagocytic activity, myeloperoxidase, lysozyme, α-2 macroglobulin and total immunoglobulins, but also the oxidative stress biomarkers. The baseline data obtained in the present study will be valuable in understanding the host-parasite relationship and the dynamics of innate, oxidative stress responses and susceptibility of P. hypophthalmus to different degrees of parasitosis.

  8. Analysis of pathogenic bacteria and drug resistance of hospital infection in department of digestion%消化科住院患者医院感染病原菌及耐药性分析

    Institute of Scientific and Technical Information of China (English)

    于剑瑞; 王卫明; 牛贺丽

    2014-01-01

    目的:分析消化科住院患者医院感染病原菌的种类及构成比,并对病原菌的耐药性进行分析,指导消化科医院感染患者的治疗。方法选取2011年6月-2013年6月消化科医院感染患者128例,取患者标本,分离培养病原菌,利用K‐B琼脂法进行耐药性分析。结果消化科住院患者医院感染的发生率为11.80%,感染的部位主要为消化系统感染43例占33.59%、上呼吸道感染25例占19.53%、下呼吸道感染22例占17.19%;28例消化科医院感染患者共分离培养出病原菌130株,其中革兰阳性菌57株占43.85%,革兰阴性菌66株占50.77%,真菌7株占5.38%;消化科医院感染患者的主要革兰阳性菌对乙酰唑胺耐药率为0。结论消化科住院患者医院感染发生率高,且病原菌多为耐药菌感染,临床应选取耐药率低的抗菌药物进行治疗。%OBJECTIVE To study the type and distribution of pathogenic bacteria and drug resistance of nosocomial infection in department of digestion so as to provide some instruction to the treatment of nosocomial infection in department of digestion .METHODS Totally 128 cases of patients with nosocomial infection in department of digestion were chosen ,and pathogenic bacteria were isolated and cultured .The drug sensitivity tests were conduc‐ted by K‐B test .RESULTS The prevalence rate of nosocomial infection in department of digestion was 11 .8% . The main infection sites were digestive system ,upper respiratory tract ,and lower respiratory tract which accoun‐ted for 33 .59% ,19 .53% ,and 17 .19% ,respectively .Totally 130 strains of pathogens were isolated in the 28 pa‐tients ,in which there were 57 strains (43 .85% ) of gram‐positive bacilli ,66 strains (50 .77% ) of gram‐negative bacilli ,and 7 strains (5 .38% ) of fungi .The resistance rate of gram‐positive bacilli against acetazolamide was 0 . CONCLUSION The prevalence rate of

  9. Viral Dose and Immunosuppression Modulate the Progression of Acute BVDV-1 Infection in Calves: Evidence of Long Term Persistence after Intra-Nasal Infection.

    Directory of Open Access Journals (Sweden)

    Rebecca Strong

    Full Text Available Bovine viral diarrhoea virus (BVDV infection of cattle causes a diverse range of clinical outcomes from being asymptomatic, or a transient mild disease, to producing severe cases of acute disease leading to death. Four groups of calves were challenged with a type 1 BVDV strain, originating from a severe outbreak of BVDV in England, to study the effect of viral dose and immunosuppression on the viral replication and transmission of BVDV. Three groups received increasing amounts of virus: Group A received 10(2.55TCID50/ml, group B 10(5.25TCID50/ml and group C 10(6.7TCID 50/ml. A fourth group (D was inoculated with a medium dose (10(5.25TCID50/ml and concomitantly treated with dexamethasone (DMS to assess the effects of chemically induced immunosuppression. Naïve calves were added as sentinel animals to assess virus transmission. The outcome of infection was dose dependent with animals given a higher dose developing severe disease and more pronounced viral replication. Despite virus being shed by the low-dose infection group, BVD was not transmitted to sentinel calves. Administration of dexamethasone (DMS resulted in more severe clinical signs, prolonged viraemia and virus shedding. Using PCR techniques, viral RNA was detected in blood, several weeks after the limit of infectious virus recovery. Finally, a recently developed strand-specific RT-PCR detected negative strand viral RNA, indicative of actively replicating virus, in blood samples from convalescent animals, as late as 85 days post inoculation. This detection of long term replicating virus may indicate the way in which the virus persists and/or is reintroduced within herds.

  10. [Synergistic action of entomopathogenic hyphomycetes and the bacteria Bacillus thuringiensis ssp. morrisoni in the infection of Colorado potato beetle Leptinotarsa decemlineata].

    Science.gov (United States)

    Kriukov, V Iu; Khodyrev, V P; Iaroslavtseva, O N; Kamenova, A S; Duĭsembekov, B A; Glupov, V V

    2009-01-01

    A synchronous coinfection of the Colorado potato beetle Leptinotarsa decemlineata (Say) with the entomopathogenic bacteria Bacillus thuringiensis ssp. morrisoni Bonnifoi & de Barjak var. tenebrionis Krieg et al. and hyphomycete Metarhizium anisopliae (Metsch.) Sorokin or Beauveria bassiana (Bals.) Vuill leads to the rapid death of 95-100% of larvae. The bacteria arrest the nutrition of insects, while the fungal spores kill the weakened larvae. The synergistic effect of two pathogens is recorded at a relatively low hyphomycete titer (1-5 x 10(6) conidia/ml) and is evident in the mortality dynamics at all larval ages. These bacterial and fungal pathogens display no antagonism on artificial nutrient media. This microbial complex is highly efficient under natural conditions (80-90% larval mortality rate and no plant defoliation).

  11. The Potential Application and Risks Associated With the Use of Predatory Bacteria as a Bio-control Agent Against Wound Infections

    Science.gov (United States)

    2015-10-01

    CFU enumeration, and compared to the initial host concentration and predator-free control. Cell viability was measured following 24 and 48 hrs of...Subtask 2.1. Determining the toxicity of predatory bacteria on mammalian cells . Subtask 2.2. Determining the influence of predator exposure on cell ...examined the change in cell viability . The effect of B. bacteriovorus 109J and HD100 on mammalian cell viability was investigated. Initial

  12. Distribution and Antimicrobial Susceptibility Pattern of Gram Negative Bacteria Causing Urinary Tract Infection (UTI and Detection New Delhi Metallo-beta-lactamase-1 (NDM-1 Producing Isolates in Ahwaz

    Directory of Open Access Journals (Sweden)

    Parviz Afrugh

    2016-04-01

    Full Text Available Background: Urinary tract infection (UTI is the commonest bacterial infectious disease in worldwide (especially in developing countries with a high rate of morbidity and financial cost. The management of UTI infections has been jeopardized by increase in immergence of antimicrobial drug resistance. Knowledge of the local bacterial etiology and susceptibility patterns is required to trace any change that might have occurred in time so that updated recommendation for optimal empirical therapy of UTI can be made. The aim of this investigation was distribution and antimicrobial susceptibility pattern of gram negative bacteria causing urinary tract infection (UTI and detection NDM-1 (new-delhi-metallo-beta-lactamase-1 producing isolates in Ahwaz. Materials and Methods: This cross-sectional study was done during a period of one year from April 2013 to March 2014. Clean catch midstream urine samples were collected from suspected patients to UTI. The isolates were identified based on morphological and biochemical testes. Culture was performed on routine microbiological media. Susceptibility testing was performed according CLSI (2013 guidelines. Detection of carbapenemase producing isolates was performed by modified hodge test (MHT. Metallo-beta-lactamase isolates were detected by imipenem-EDTA combined disc test (CDT. Results: In this study 708 gram negative organisms were isolated from urine samples. E.coli was the most common isolated bacteria (67% followed by Klebsiella spp. (26.5% and Enterobacter spp. (2.5%. In antibiotic susceptibility testing more than 90% of isolates were sensitive to tetracycline, ceftazidime, meropenem, amikacin, cefotaxime, imipenem, and cefepime. Isolates were more resistant to cephalothin (32%, co-trimoxazol (30.5%, and nalidixic acid (25%. Conclusion: In our results isolated organisms from outpatients showed very high sensitivity to common antibiotics. Continuous and regular monitoring of susceptibility pattern of

  13. Bacteria-surface interactions.

    Science.gov (United States)

    Tuson, Hannah H; Weibel, Douglas B

    2013-05-14

    The interaction of bacteria with surfaces has important implications in a range of areas, including bioenergy, biofouling, biofilm formation, and the infection of plants and animals. Many of the interactions of bacteria with surfaces produce changes in the expression of genes that influence cell morphology and behavior, including genes essential for motility and surface attachment. Despite the attention that these phenotypes have garnered, the bacterial systems used for sensing and responding to surfaces are still not well understood. An understanding of these mechanisms will guide the development of new classes of materials that inhibit and promote cell growth, and complement studies of the physiology of bacteria in contact with surfaces. Recent studies from a range of fields in science and engineering are poised to guide future investigations in this area. This review summarizes recent studies on bacteria-surface interactions, discusses mechanisms of surface sensing and consequences of cell attachment, provides an overview of surfaces that have been used in bacterial studies, and highlights unanswered questions in this field.

  14. The alkaloid compound harmane increases the lifespan of Caenorhabditis elegans during bacterial infection, by modulating the nematode's innate immune response

    DEFF Research Database (Denmark)

    Jakobsen, Henrik; Bojer, Martin Saxtorph; Marinus, Martin G.

    2013-01-01

    The nematode Caenorhabditis elegans has in recent years been proven to be a powerful in vivo model for testing antimicrobial compounds. We report here that the alkaloid compound Harmane (2-methyl-β-carboline) increases the lifespan of nematodes infected with a human pathogen, the Shiga toxin...

  15. Pre-treatment with curcumin modulates acetylcholinesterase activity and proinflammatory cytokines in rats infected with Trypanosoma evansi.

    Science.gov (United States)

    Wolkmer, Patrícia; Silva, Cássia B da; Paim, Francine C; Duarte, Marta M M F; Castro, Verônica; Palma, Heloisa E; França, Raqueli T; Felin, Diandra V; Siqueira, Lucas C; Lopes, Sonia T A; Schetinger, Maria Rosa C; Monteiro, Silvia G; Mazzanti, Cinthia M

    2013-04-01

    The potent activity against Trypanosomes and health beneficial effects of curcumin (Cur) has been demonstrated in various experimental models. In this study, we evaluated the in vivo effect of Cur as trypanocide and as potential anti-inflammatory agent, through the evaluation of immunomodulatory mechanisms in rats infected with Trypanosoma evansi. Daily oral Cur was administered at doses of 0, 20 or 60mg/kg as preventive treatment (30 and 15days pre infection) and as treatment (post infection). The treatment of the groups continued until the day of euthanasia. Fifteen days after inoculation, parasitemia, plasma proinflammatory cytokines (IFN-γ, TNF-α, IL-1, IL-6), anti-inflammatory cytokines (IL-10) and blood acetylcholinesterase activity (AChE) were analyzed. Pretreatment with Cur reduced parasitemia and lethality. Cur inhibited AChE activity and improved immunological response by cytokines proinflammatory, fundamental during T. evansi infection. We found that Cur is not so important as an antitrypanosomal activity but as immunomodulator agent. These findings reveal that the preventive use of Cur stimulates anti-inflammatory mechanisms, reducing an excessive inflammatory response.

  16. 尿路感染病原菌的分布及药物敏感分析%Distribution on etiological bacteria and drug sensitivity analysis in urinary tract infection

    Institute of Scientific and Technical Information of China (English)

    肖观清; 孔耀中; 李导; 陈斌鸿; 叶佩仪; 邵咏红; 陈统清

    2012-01-01

    OBJECTIVE To understand the distribution of etiological bacteria for urinary tract infection in the region and analyse drug sensitivity, and to provide a scientific basis for the correct and rational using antimicrobial drugs in clinical. METHODS Accordance with procedures of national clinical laboratory, we used the French company bioMerieux VITEK-32 identified strains of bacteria identification instrument to identify 966 of urinary tract infection pathogens which isolated from clinical urine samples. RESULTS 49 species were in the separation of 966 pathogens, and 675 gram-negative bacteria accounted for 69.9%; 183 gram-positive bacteria accounted for 18.9%; 108 fungi accounted far 11.2%; Escherichia coli bacteria was the main in the gram-negative bacteria; Gram-positive bacteria mainly belonged to Enterococcus faecalis! Candida albicans bacteria was the main in the fungi; Separation of the first seven bacteria were Escherichia coli (49.0%), Enterococcus faecalis (9.6%), Kleb-siella pneumoniae (7.0%), Candida albicans (6.8%), Proteus mirabilis (3.9%), Pseudomonas aerugiaosa (3.3%), Staphy-lococcus epidermidis (3.0%). The detection rate of ESBLs producing by Escherichia cob' was 47.3%, and 33.8% by Klebsiella pneumoniae. The detection rate of oxacillin-resistant coagulase -negative staphylococci was 37.5%, and the detection rate of MRSA was 50.0%. The sensitivity of escherichia coli on cefepime, ceftazidime, piperacillin/tazobactam, amikacin, imipenem was good (70.6%-100%). CONCLUSION The pathogens of causing urinary tract infection are widely distributed, and escherichia coli are the major pathogens of urinary tract infection in the region. Clinicians should pay attention to bacteriological culture, combined with the drug susceptibility testing and drug-resistant strains of the special report, rational use of antibiotics to reduce drug—resistant strains and an outbreak of hospital infection.%目的 了解泌尿系感染的病原菌分布及药物敏感性,为

  17. Related factors for multidrug-resistant bacteria infections and prevention and treatment measures%多药耐药菌感染相关因素分析及预防措施

    Institute of Scientific and Technical Information of China (English)

    冯广华; 孟宪刚; 孙雪春

    2014-01-01

    OBJECTIVE To analyze the related factors for multidrug-resistant bacteria infections in respiratory de-partment and explore the prevention measures for multidrug-resistant bacteria infections so as to prevent the multi-drug-resistant bacteria infections .METHODS Totally 74 patients with multidrug-resistant bacteria infections ,who were treated in the respiratory department from Mar 2012 to Feb 2013 ,were enrolled in the study ,then the rou-tine sputum culture and the drug susceptibility testing were performed ,the drug susceptibility testing was per-formed with the use of MIC method ,the isolated bacteria were screened out by using VITEK-2 Compact automatic bacterial analyzer of BioMérieux ,France and the drug susceptibility plate ,and the result of the drug susceptibility testing was interpreted according to the standards of NCCLS .RESULTS A total of 78 strains of multidrug-resistant bacteria have been isolated ,among which the Escherichia coli ,Streptococcus pneumoniae ,Pseudomonas aerugi-nosa ,Staphylococcus aureus ,and Acinetobacter baumannii ranked the top five species ,accounting for 25 .64% , 15 .38% ,14 .10% ,12 .82% ,and 10 .26% ,respectively .The main gram-positive bacteria remained high antibacte-rial activity against vancomycin and linezolid ,with the drug resistance rates of 0 ;the main gram-negative bacteria remained high antibacterial activity against imipenem and amikacin ,with the drug resistance rate varying from 0 to 37 .5% ,and the strains varied in the drug resistance to other antibiotics .CONCLUSION It is necessary to strength-en the targeted detection of the multidrug-resistant bacteria ,with the detection in a timely manner ,diagnosis in a early stage ;once the drug-resistant strains emerge ,it is necessary to choose sensitive antibiotics based on the re-sult of drug susceptibility testing ,strictly implement the hand hygiene ,and take disinfection and isolation meas-ures in a timely manner so as to effectively avoid the spread of

  18. International Nosocomial Infection Control Consortium (INICC) report, data summary of 43 countries for 2007-2012. Device-associated module.

    Science.gov (United States)

    Rosenthal, Víctor Daniel; Maki, Dennis George; Mehta, Yatin; Leblebicioglu, Hakan; Memish, Ziad Ahmed; Al-Mousa, Haifaa Hassan; Balkhy, Hanan; Hu, Bijie; Alvarez-Moreno, Carlos; Medeiros, Eduardo Alexandrino; Apisarnthanarak, Anucha; Raka, Lul; Cuellar, Luis E; Ahmed, Altaf; Navoa-Ng, Josephine Anne; El-Kholy, Amani Ali; Kanj, Souha Sami; Bat-Erdene, Ider; Duszynska, Wieslawa; Van Truong, Nguyen; Pazmino, Leonardo N; See-Lum, Lucy Chai; Fernández-Hidalgo, Rosalia; Di-Silvestre, Gabriela; Zand, Farid; Hlinkova, Sona; Belskiy, Vladislav; Al-Rahma, Hussain; Luque-Torres, Marco Tulio; Bayraktar, Nesil; Mitrev, Zan; Gurskis, Vaidotas; Fisher, Dale; Abu-Khader, Ilham Bulos; Berechid, Kamal; Rodríguez-Sánchez, Arnaldo; Horhat, Florin George; Requejo-Pino, Osiel; Hadjieva, Nassya; Ben-Jaballah, Nejla; García-Mayorca, Elías; Kushner-Dávalos, Luis; Pasic, Srdjan; Pedrozo-Ortiz, Luis E; Apostolopoulou, Eleni; Mejía, Nepomuceno; Gamar-Elanbya, May Osman; Jayatilleke, Kushlani; de Lourdes-Dueñas, Miriam; Aguirre-Avalos, Guadalupe

    2014-09-01

    We report the results of an International Nosocomial Infection Control Consortium (INICC) surveillance study from January 2007-December 2012 in 503 intensive care units (ICUs) in Latin America, Asia, Africa, and Europe. During the 6-year study using the Centers for Disease Control and Prevention's (CDC) U.S. National Healthcare Safety Network (NHSN) definitions for device-associated health care-associated infection (DA-HAI), we collected prospective data from 605,310 patients hospitalized in the INICC's ICUs for an aggregate of 3,338,396 days. Although device utilization in the INICC's ICUs was similar to that reported from ICUs in the U.S. in the CDC's NHSN, rates of device-associated nosocomial infection were higher in the ICUs of the INICC hospitals: the pooled rate of central line-associated bloodstream infection in the INICC's ICUs, 4.9 per 1,000 central line days, is nearly 5-fold higher than the 0.9 per 1,000 central line days reported from comparable U.S. ICUs. The overall rate of ventilator-associated pneumonia was also higher (16.8 vs 1.1 per 1,000 ventilator days) as was the rate of catheter-associated urinary tract infection (5.5 vs 1.3 per 1,000 catheter days). Frequencies of resistance of Pseudomonas isolates to amikacin (42.8% vs 10%) and imipenem (42.4% vs 26.1%) and Klebsiella pneumoniae isolates to ceftazidime (71.2% vs 28.8%) and imipenem (19.6% vs 12.8%) were also higher in the INICC's ICUs compared with the ICUs of the CDC's NHSN.

  19. Distribution and antibiotic resistance of pathogenic bacteria causing lower respiratory tract infection in ICU%ICU下呼吸道感染病原菌分布与耐药现状分析

    Institute of Scientific and Technical Information of China (English)

    金晓冰; 邓敏; 邹俊宁; 江新姣; 吴艳艳

    2011-01-01

    目的 了解重症监护病房(ICU)患者下呼吸道感染的病原菌分布和耐药谱,为临床治疗提供依据. 方法 入选2008年1月-2009年6月入住ICU下呼吸道感染患者,进行深部痰液病原菌培养,分析病原菌分布情况和耐药性. 结果 革兰阴性杆菌是下呼吸道感染的主要病原菌,占66.9%,以鲍氏不动杆菌占优势,为31.6%;革兰阳性球菌占10.3%,以金黄色葡萄球菌为主,占8.1%;真菌感染占22.8%,除真菌耐药率较低外,其他病原菌均有较高耐药性,多药耐药鲍氏不动杆菌检出率达69.8%. 结论 ICU下呼吸道感染病原菌的菌群分布发生了变化,真菌感染率上升,多药耐药菌增多,临床医师需密切关注分离菌的变迁及耐药情况,合理使用抗菌药物.%OBJECTIVE To investigate the distribution and antibiotic resistance status of pathogenic bacteria from lower respiratory tract in patients of intensive care unit (ICU) in hospital, and provide basis for rational selection of clinical drugs. METHODS Totally 89 cases of lower respiratory infection admitted to the ICU from Jan 2008 to Jun 2009 were reviewed. Pathogens in the sputum were isolated and indenified,and the distribution of pathogenic bactieria and their drug resistance profile were analyzed. RESULTS 66. 9 % of pathogenic bacteria were Gramnegative ones, among which Acinetobater baumannii occupy 31.6 %, 10.3 % were Gram-positive bacteria, Staphylococcus aureus (8. 1 %)was the most prominent bacteria. Fungi accounted for 22.8%. All pathogenic bacteria showed high resistance to the antibiotics but fungi. Multi-drug resistant (MDR) Acinetobater baumannii were test out with 69.8 % occurrence. CONCLUSION The pathogenic bacteria and their resistance to the antibiotic have been changed in ICU. The fungal infection rate is increased and there is an increasing trend in the detection rate of MDR. Clinicians should pay close attention to the changes and resistance of pathogenic bacteria and

  20. Infection Control Full-time Team and Checklist in the Application of ICU in the Control of Multiple Drug Resistant Bacteria in Nosocomial Infection%感控专职小组联合查检单在ICU多重耐药菌医院感染控制中的应用

    Institute of Scientific and Technical Information of China (English)

    杜华; 秦存玲; 刘敏

    2016-01-01

    Objective To understand the application effect of a combined checklist for the infection control ful-time team in multidrug-resistant bacteria infection management.Methods To establish a multidrug-resistant bacteria infection control ful-time team, and introduce the quality management tool of “checklist” to intervene the hospital patients being infected with ICU MDRO.ResultsThe compliance rate and various indexes by taking prevention and control measures for the interfered group were improved(P<0.05),and the length of stay in ICU was shorter than that of the control group(P<0.05).Conclusion The combined checklist for the infection control ful-time team can promote compliance of the multidrug-resistant bacteria infection control and isolation measures, effectively improve various indexes for hospital infection management quality control of MDRO, and shorten the length of stay in ICU.%目的:了解感控专职小组联合查检单在多重耐药菌感染管理中应用的效果。方法成立多重耐药菌感控专职小组,引用“查检单”质量管理工具对ICU MDRO感染的住院患者进行干预。结果干预组防控措施依从率及各项指标均有改善(P<0.05);ICU住院时间也低于对照组(P<0.05)。结论感控专职小组联合查检单能提高多重耐药菌感染控制隔离措施依从性,有效改善MDRO医院感染管理质量控制的各项指标;缩短ICU住院时间。

  1. EFSA NDA Panel (EFSA Panel on Dietetic Products, Nutrition and Allergies), 2014. Scientific Opinion on the substantiation of a health claim related to CranMax® and reduction of the risk of urinary tract infection by inhibiting the adhesion of certain bacteria in the urinary tract pursuant

    DEFF Research Database (Denmark)

    Tetens, Inge

    related to CranMax® and reduction of the risk of urinary tract infection by inhibiting the adhesion of certain bacteria in the urinary tract. The food that is the subject of the claim is CranMax®. The Panel considers that the food, CranMax®, which is the subject of the claim is sufficiently characterised...... in relation to the claimed effect. The Panel considers that reduction of the risk of urinary tract infection by inhibiting the adhesion of certain bacteria in the urinary tract is a beneficial physiological effect. One human study from which conclusions could be drawn for the scientific substantiation...... of the claim did not show an effect of CranMax® on reduction of the risk of urinary tract infection by inhibiting the adhesion of certain bacteria in the urinary tract. The Panel concludes that a cause and effect relationship has not been established between the consumption of CranMax® and reduction...

  2. HIV-1 infected lymphoid organs upregulate expression and release of the cleaved form of uPAR that modulates chemotaxis and virus expression.

    Directory of Open Access Journals (Sweden)

    Manuela Nebuloni

    Full Text Available Cell-associated receptor for urokinase plasminogen activator (uPAR is released as both full-length soluble uPAR (suPAR and cleaved (c-suPAR form that maintain ability to bind to integrins and other receptors, thus triggering and modulating cell signaling responses. Concerning HIV-1 infection, plasma levels of suPAR have been correlated with the severity of disease, levels of immune activation and ineffective immune recovery also in individuals receiving combination anti-retroviral therapy (cART. However, it is unknown whether and which suPAR forms might contribute to HIV-1 induced pathogenesis and to the related state of immune activation. In this regard, lymphoid organs represent an import site of chronic immune activation and virus persistence even in individuals receiving cART. Lymphoid organs of HIV-1(+ individuals showed an enhanced number of follicular dendritic cells, macrophages and endothelial cells expressing the cell-associated uPAR in comparison to those of uninfected individuals. In order to investigate the potential role of suPAR forms in HIV-1 infection of secondary lymphoid organs, tonsil histocultures were established from HIV-1 seronegative individuals and infected ex vivo with CCR5- and CXCR4-dependent HIV-1 strains. The levels of suPAR and c-suPAR were significantly increased in HIV-infected tonsil histocultures supernatants in comparison to autologous uninfected histocultures. Supernatants from infected and uninfected cultures before and after immunodepletion of suPAR forms were incubated with the chronically infected promonocytic U1 cell line characterized by a state of proviral latency in unstimulated conditions. In the contest of HIV-conditioned supernatants we established that c-suPAR, but not suPAR, inhibited chemotaxis and induced virus expression in U1 cells. In conclusion, lymphoid organs are an important site of production and release of both suPAR and c-suPAR, this latter form being endowed with the capacity of

  3. ICU住院患者感染病原菌分布与耐药性监测%DISTRIBUTION AND DRUG RESISTANCE OF PATHOGENIC BACTERIA INFECTED BY INPATIENT OF ICU

    Institute of Scientific and Technical Information of China (English)

    汪斌; 高敏; 王鲜平; 吕岩; 张娜; 刘敏

    2013-01-01

    Objective To evaluate the distribution and drug resistance of pathogenic bacteria causing nosocomial infection in ICU providing basis of clinic rational drug use. Methods The identification of isolated bacteria and K - B test were used to monitor the specimens from the ICU inpatients of one hospital for the pathogenic bacteria and their drug resistance. Results From July 2011 to July 2012, 1 109 strains of pathogenic bacteria were isolated; 685 strains were gram - negative and accounted for 61.77% ; 249 strains were fungi, the ratio of that was 22.45% ; 175 strains were gram - positive, which accounted for 15.78%. Conclusion Gram - negative bacilli are the main pathogenic bacteria in ICU, and the rate of drug resistance is high. It is important to enhance local surveillance of bacterial resistance.%目的 了解医院重症监护病房(ICU)住院患者感染病原菌分布及耐药现状,为临床合理用药提供依据.方法 通过分离鉴定方法和K-B试验法,对某医院ICU住院患者送检病原学标本进行了病原菌分离鉴定和耐药性监测.结果 2011年7月-2012年7月,从该医院ICU住院患者送检的标本中共分离出病原菌1 109株,其中革兰阴性菌685株,占61.77%;真菌249株,占22.45%;革兰阳性菌175株,占15.78%.结论 该医院ICU住院患者医院感染病原菌以革兰阴性菌占优势,且耐药率高,必须加强耐药菌监测与防范.

  4. Immune modulation by group B Streptococcus influences host susceptibility to urinary tract infection by uropathogenic Escherichia coli.

    Science.gov (United States)

    Kline, Kimberly A; Schwartz, Drew J; Gilbert, Nicole M; Hultgren, Scott J; Lewis, Amanda L

    2012-12-01

    Urinary tract infection (UTI) is most often caused by uropathogenic Escherichia coli (UPEC). UPEC inoculation into the female urinary tract (UT) can occur through physical activities that expose the UT to an inherently polymicrobial periurethral, vaginal, or gastrointestinal flora. We report that a common urogenital inhabitant and opportunistic pathogen, group B Streptococcus (GBS), when present at the time of UPEC exposure, undergoes rapid UPEC-dependent exclusion from the murine urinary tract, yet it influences acute UPEC-host interactions and alters host susceptibility to persistent outcomes of bladder and kidney infection. GBS presence results in increased UPEC titers in the bladder lumen during acute infection and reduced inflammatory responses of murine macrophages to live UPEC or purified lipopolysaccharide (LPS), phenotypes that require GBS mimicry of host sialic acid residues. Taken together, these studies suggest that despite low titers, the presence of GBS at the time of polymicrobial UT exposure may be an overlooked risk factor for chronic pyelonephritis and recurrent UTI in susceptible groups, even if it is outcompeted and thus absent by the time of diagnosis.

  5. Modulation of Lipoprotein Cholesterol Levels in Plasmodium berghei Malarial Infection by Crude Aqueous Extract of Ganoderma lucidum

    Directory of Open Access Journals (Sweden)

    Olarewaju M. Oluba

    2012-01-01

    Full Text Available In this study, attempt is made to establish changes in serum and liver lipoprotein cholesterols accompanying Plasmodium berghei malarial infection in mice treated with aqueous extract of Ganoderma lucidum at 100, 250, and 500 mg/kg body weight in comparison with 15 mg/kg chloroquine (CQ. Significant increases in all the lipoprotein fractions were observed in infected untreated mice compared with normal control mice. Treatment with 100 and 250 mg/kg G. lucidum extract produced significant reduction in serum total cholesterol (TC and low-density cholesterol (LDL-C contents compared with 500 mg/kg G. lucidum and CQ. Treatment with CQ, however, produced significant reduction in hepatic TC and LDL-C compared with the extract. A dose-dependent significant increase in serum high-density lipoprotein cholesterol (HDL-C was observed in the G. lucidum treated mice compared with normal control but significantly lower compared with CQ-treated mice. Liver HDL-C level was significantly higher in CQ-treated mice compared with normal control and significantly lower compared with G. lucidum-treated and infected untreated mice. A dose-dependent effect of the extract was observed in both serum and liver very-low density lipoprotein cholesterol (VLDL-C. The implication of these results is discussed with respect to the parasite survival and proliferation in the serum and liver.

  6. Ammonium secretion during Colletotrichum coccodes infection modulates salicylic and jasmonic acid pathways of ripe and unripe tomato fruit.

    Science.gov (United States)

    Alkan, Noam; Fluhr, Robert; Prusky, Dov

    2012-01-01

    The postharvest pathogens Colletotrichum coccodes remains quiescent after infection of unripe fruit. However, during fruit ripening, the pathogen assumes a necrotrophic life style, rapidly colonizing the tissue. C. coccodes secretes ammonium during germination and colonization of host tissue that induces host programmed cell death. We further examined the role of ammonia in the infection process by analyzing transcriptome expression from infected and ammonia-treated fruit tissue compared with healthy tissue. The analysis revealed 82 and 237 common upregulated and downregulated genes, respectively. Quantitative reverse-transcriptase polymerase chain reaction analysis of select transcripts in normal and transgenic NADPH oxidase antisense plants revealed that their expression was NADPH oxidase dependent. Common-upregulated genes showed overrepresentation of salicylic acid (SA)-dependent genes as well as genes related to biotic stress. The downregulated genes showed overrepresentation of jasmonic acid (JA)-dependent genes. Indeed, direct application of SA to the fruit enhanced C. coccodes necrotrophic colonization, whereas the application of JA delayed colonization. Importantly, green fruit and red fruit displayed similar gene expression patterns although only red fruit is susceptible to colonization. Thus, it is likely that the resistance of green fruit to C. coccodes colonization is due to additional factors.

  7. 579株泌尿道感染病原菌分布与耐药性分析%Distribution and antimicrobial resistance of 579 strains of pathogenic bacteria isolated from patients with a urinary tract infection

    Institute of Scientific and Technical Information of China (English)

    赵蓬波; 杨广民; 侯晓杰; 荣爱红; 孙大勇

    2012-01-01

    Objective To investigate the distribution and antimicrobial resistance of pathogenic bacteria responsible for urinary tract infections (UTIs). Methods Five hundred and seventy-nine strains of pathogenic bacteria isolated from u-rine were identified by VITEK 32 from January 2008 to December 2010. Antimicrobial susceptibility testing was performed via a disk diffusion test, and the distribution and antimicrobial resistance of pathogenic bacteria was analyzed with WHONET 5.4, Results Among 579 strains of pathogenic bacteria, the most common was Gram-negative bacilli, the predominant strain of which was Escherichia coli (45.94 %). The predominant strains of Gram-positive bacteria were En-. terococcus faecalis (12.6%) and Enterococcus faecium (15.0%). The rate of ESBL-producing E. coli, Klebsiella pneumonia , and Proteus mirabilis was 53. 00% , 36. 00% , and 36. 59%. The antimicrobial resistance of these pathogenic bacteria differed. Resistance to most antibiotics was greater than 50%, although resistance to cefoperazone-sulbactam, pip-eracillin-tazobactam, imipenem, meropenem, amikacin, vancomycin, and teicoplanin was relatively low. Conclusion The predominant bacteria from UTIs were Gram-negative bacteria, the most common of which was E. coli. Antibiotics should be used based on results of susceptibility testing.%目的 了解泌尿道感染的病原菌分布及其耐药情况.方法 采用VITEK32细菌鉴定系统对2008年1月~2010年12月尿培养分离的579株病原菌进行鉴定,纸片扩散法做药敏试验.结果 579株病原菌以革兰阴性杆菌为主(404株),优势菌为大肠埃希菌(266株),占45.94%,其次为肺炎克雷伯菌(50株)和奇异变形杆菌(41株);革兰阳性菌(175株)的优势菌为屎肠球菌(87株)和粪肠球菌(73株).产ESBL的大肠埃希菌、肺炎克雷伯菌和奇异变形杆菌的检出率分别为53.00%、36.00%和36.59%.病原菌对各抗生素的耐药率不同,对多数抗生素的耐药率高于50%,

  8. Urinary Tract Infections (For Kids)

    Medline Plus

    Full Text Available ... Your pee smells bad. These things happen because bacteria have caused an infection somewhere in your urinary ... shorter than boys' urethras. The shorter urethra means bacteria can get up into the bladder more easily ...

  9. Japanese encephalitis virus infection modulates the expression of suppressors of cytokine signaling (SOCS) in macrophages: implications for the hosts' innate immune response.

    Science.gov (United States)

    Kundu, Kiran; Dutta, Kallol; Nazmi, Arshed; Basu, Anirban

    2013-01-01

    Viruses have evolved various mechanisms to subvert the host's immune system and one of them is preventing the infected cells from sending out chemotactic signals to activate the adaptive immune response. Japanese encephalitis virus (JEV) is a neuropathologic flavivirus that is responsible for significant number of child mortalities in various parts of South-East Asia. In this study we show that JEV modulates suppressors of cytokine signaling (SOCS)1 and 3 expression in macrophages to bring about changes in the JAK-STAT signaling cascade, so as to inhibit proinflammatory cyto/chemokine release. Using real time PCR, immunoblotting and immunofluorescent staining, we show that the expression of type 1 interferons and intracellular expression of viral genes are also affected over time. Also, following the initial activation of SOCS1 and 3, there is production of interferon-inducible anti-viral proteins in the cells which may be responsible for inhibiting viral replication. However, even at later time points, viral genes were still detected from the macrophages, albeit at lesser quantities, than earlier time points, indicative of intracellular persistence of the virus in a latent form. On knocking down SOCS1 and SOCS3 we found a significant decrease in viral gene expression at an early time point, indicating the dysregulation of the signaling cascade leading to increased production of interferon-inducible anti-viral proteins. Taken together, our study provides an insight into the role of JEV infection in modulating the JAK-STAT pathway with the help of SOCS leading to the generation of an antiviral innate immune response.

  10. The cell surface receptor Slamf6 modulates innate immune responses during Citrobacter rodentium-induced colitis.

    Science.gov (United States)

    van Driel, Boaz; Wang, Guoxing; Liao, Gongxian; Halibozek, Peter J; Keszei, Marton; O'Keeffe, Michael S; Bhan, Atul K; Wang, Ninghai; Terhorst, Cox

    2015-09-01

    The homophilic cell surface receptors CD150 (Slamf1) and CD352 (Slamf6) are known to modulate adaptive immune responses. Although the Th17 response was enhanced in Slamf6(-/-) C57BL/6 mice upon oral infection with Citrobacter rodentium, the pathologic consequences are indistinguishable from an infection of wild-type C57BL/6 mice. Using a reporter-based binding assay, we show that Slamf6 can engage structures on the outer cell membrane of several Gram(-) bacteria. Therefore, we examined whether Slamf6, like Slamf1, is also involved in innate responses to bacteria and regulates peripheral inflammation by assessing the outcome of C. rodentium infections in Rag(-/-) mice. Surprisingly, the pathology and immune responses in the lamina propria of C. rodentium-infected Slamf6(-/-) Rag(-/-) mice were markedly reduced as compared with those of Rag(-/-) mice. Infiltration of inflammatory phagocytes into the lamina propria was consistently lower in Slamf6(-/-) Rag(-/-) mice than in Rag(-/-) animals. Concomitant with the reduced systemic translocation of the bacteria was an enhanced production of IL-22, suggesting that Slamf6 suppresses a mucosal protective program. Furthermore, administering a mAb (330) that inhibits bacterial interactions with Slamf6 to Rag(-/-) mice ameliorated the infection compared with a control antibody. We conclude that Slamf6-mediated interactions of colonic innate immune cells with specific Gram(-) bacteria reduce mucosal protection and enhance inflammation, contributing to lethal colitis that is caused by C. rodentium infections in Rag(-/-) mice.

  11. Common duckweed (Lemna minor is a versatile high-throughput infection model for the Burkholderia cepacia complex and other pathogenic bacteria.

    Directory of Open Access Journals (Sweden)

    Euan L S Thomson

    Full Text Available Members of the Burkholderia cepacia complex (Bcc have emerged in recent decades as problematic pulmonary pathogens of cystic fibrosis (CF patients, with severe infections progressing to acute necrotizing pneumonia and sepsis. This study presents evidence that Lemna minor (Common duckweed is useful as a plant model for the Bcc infectious process, and has potential as a model system for bacterial pathogenesis in general. To investigate the relationship between Bcc virulence in duckweed and Galleria mellonella (Greater wax moth larvae, a previously established Bcc infection model, a duckweed survival assay was developed and used to determine LD50 values. A strong correlation (R(2 = 0.81 was found between the strains' virulence ranks in the two infection models, suggesting conserved pathways in these vastly different hosts. To broaden the application of the duckweed model, enteropathogenic Escherichia coli (EPEC and five isogenic mutants with previously established LD50 values in the larval model were tested against duckweed, and a strong correlation (R(2 = 0.93 was found between their raw LD50 values. Potential virulence factors in B. cenocepacia K56-2 were identified using a high-throughput screen against single duckweed plants. In addition to the previously characterized antifungal compound (AFC cluster genes, several uncharacterized genes were discovered including a novel lysR regulator, a histidine biosynthesis gene hisG, and a gene located near the gene encoding the recently characterized virulence factor SuhB(Bc. Finally, to demonstrate the utility of this model in therapeutic applications, duckweed was rescued from Bcc infection by treating with bacteriophage at 6-h intervals. It was observed that phage application became ineffective at a timepoint that coincided with a sharp increase in bacterial invasion of plant tissue. These results indicate that common duckweed can serve as an effective infection model for the investigation of bacterial

  12. 血清IgG抗体含量与口腔厌氧菌致牙髓感染的关系%Relationship between contents of serum IgG antibody and pulp infections caused by oral anaerobic bacteria

    Institute of Scientific and Technical Information of China (English)

    吕朋君; 马珅; 刘晓斌

    2015-01-01

    OBJECTIVE To observe the relationship between the level of serum IgG antibody and the pulp infections caused by oral anaerobic bacteria by referring to the characteristics of specific response between antigen and anti‐body so as to reduce the infection rate .METHODS The patients with pulp diseases who were treated in the hospi‐tal from Jan 2013 to Jan 2014 were enrolled in the study and divided into the group B ,C ,and D ,with 10 cases in each ;meanwhile 10 healthy subjects were chosen as the group A .The IgG antibody contents in the 10 internation‐al standard anaerobic bacteria strains isolated from the serum of the patients with infections and the healthy sub‐jects were determined by using ELISA method ,the relationship between the pulp infections and the oral anaerobic bacteria was specifically analyzed ,and the statistical analysis of data was performed with the use of SPSS 17 .0 software .RESULTS The average level of serum antibody in Prevotella intermedia was significantly lower in the group A than in the group B ,C ,and D (P<0 .05) .As compared with the group A ,the OD values of other three groups were more than 2 .1 ,and all were positive .There was significant difference in the average level of serum antibody in Porphyromonas gingivalis among the healthy subjects ,the patients with pulp infections ,and the pa‐tients with pulp‐periodontal diseases (P<0 .05) ,as compared with the patients with periodontal disease ,howev‐er ,the difference was not significant .There was no significant difference in the OD value of serum antibody in the anaerobic bacteria among the four groups .CONCLUSION The ELISA ,as is applied for the analysis of the anaero‐bic bacteria causing the pulp infections ,may contribute to considerably higher isolation rate and accuracy than the traditional microbial culture ,and it can be used as a conventional method for the detection of pathogenic bacteria causing pulp infections .%目的:利用抗原与抗体特异反应的

  13. Distribution and drug sensitivity of pathogenic bacteria from patients with diabetic nephropathy complicated with foot infection%糖尿病肾病合并足感染的病原菌分布及药敏性观察

    Institute of Scientific and Technical Information of China (English)

    钟益芳; 王倩; 周颖; 刘五高

    2016-01-01

    OBJECTIVE To learn the distribution and drug sensitivity of pathogenic bacteria from patients with dia-betic nephropathy complicated with foot infection ,so as to provide research basis for the clinical diagnosis and ra-tional use of drugs of the disease .METHODS A total of 115 cases of patients with diabetic nephropathy complicat-ed with foot infection from Jan .2013 to Dec .2015 were chosen .Superficial wound and deep abscess cavity of foot specimens were collected ,strain kinds of specimens were identified ,and drug susceptibilities of the main patho-genic bacteria were tested .RESULTS Totally 157 strains of pathogenic bacteria were isolated from 143 specimens of the 115 cases of patients ,and the pathogenic bacteria primarily were gram-positive bacteria ,was accounting for 57 .86% .Totally 14 strains of MASA were detected from 39 strains of Staphylococcus aureus ,and the positive rate of MRSA was 35 .90% .Eight ESBLs-producing strains were detected from 28 strains of Escherichia coli ,ac-counting for 28 .57% .Sensitive rates of S . aureus and Enterococcus f aecalis to linezolid and vancomycin were both 100 .00% .CONCLUSION By monitoring the distribution ,changes and susceptibility characteristics of patho-gens ,rational antimicrobial application solutions can be established ,and it is beneficial for the treatment of diabet-ic nephropathy complicated with foot infection .%目的:了解糖尿病肾病合并足感染的病原菌分布及药敏性,为该疾病的临床诊断和合理用药提供研究依据。方法选择2013年1月—2015年12月收治的糖尿病肾病合并足感染患者115例,采集足部浅表创面与深部脓腔标本,鉴定标本中的菌株种类,并对主要病原菌进行药敏试验。结果115例患者共取得143份有效标本,分离出175株病原菌,以革兰阳性菌为主,占57.86%;39株金黄色葡萄球菌中检测出M RS A菌株14株,M RS A阳性率为35.90%;28株大肠埃

  14. Using Fluorescent Viruses for Detecting Bacteria in Water

    Science.gov (United States)

    Tabacco, Mary Beth; Qian, Xiaohua; Russo, Jaimie A.

    2009-01-01

    A method of detecting water-borne pathogenic bacteria is based partly on established molecular-recognition and fluorescent-labeling concepts, according to which bacteria of a species of interest are labeled with fluorescent reporter molecules and the bacteria can then be detected by fluorescence spectroscopy. The novelty of the present method lies in the use of bacteriophages (viruses that infect bacteria) to deliver the fluorescent reporter molecules to the bacteria of the species of interest.

  15. Species and antimicrobial resistance of pathogenic bacteria causing urinary tract infection in children%儿童尿路感染病原菌种类与耐药性分析

    Institute of Scientific and Technical Information of China (English)

    付敏; 洪艳华; 陈前进; 卢忠友; 洪敏

    2015-01-01

    OBJECTIVE To discuss the distribution of species and antimicrobial resistance of pathogenic bacteria causing urinary tract infection in children and provide the reference for clinical selection of antibiotics .METHODS The clean specimens of midstream urine or urethral catheterization from children with urinary tract infection in two hospitals in Ezhou city during Jan .2010 to Dec .2013 were collected by aseptic technique ,then were inspected im‐mediately .Colony counting ,quantitative cultivation and bacterial identification were performed according to Na‐tional Clinical Laboratory Procedure by the Ministry of Health .The susceptibility testing was performed by disc diffusion method .The statistical analysis was performed with the use of WHONET5 .6 software .RESULTS From 3937 samples collected from the children ,197 pathogenic bacteria were isolated ,with a positive rate of 5 .0% .A‐mong the 197 isolates ,the majority was Escherichiacoli which accounted for 39 .1% ,followed by coagulase nega‐tive Staphylococcus for 17 .8% .Except for 100% sensitivity rate of gram‐negative bacilli to carbapenems ,the pathogenic bacteria causing urinary tract infection in children were resistant to the most commonly used antibiotics in varying degrees . The detection rate of ESBLs‐producing bacteria and Methicillin‐resistant Staphylococcus (MRS) were 37 .1% and 36 .6% ,respectively .CONCLUSION Pathogenic species of urinary tract infection in chil‐dren were similar to those in adults .Resistance was on the rise .In view of this ,effective measures should be taken to intervene bacterial drug resistance .%目的:探讨儿童尿路感染常见病原菌的种类分布及耐药现状,为临床医师抗感染治疗选择敏感的抗菌药物提供参考依据。方法无菌手法采集2010年1月-2013年12月在鄂州市两所医院就诊的尿路感染患儿清洁中段尿或导尿标本3937份,进行尿液细菌计数、定量培养、细菌鉴定;药敏试验

  16. Effect of multidrug resistance modulators on the activity of ivermectin and moxidectin against selected strains of Haemonchus contortus infective larvae

    Directory of Open Access Journals (Sweden)

    Molento Marcelo B.

    2001-01-01

    Full Text Available Nematode parasites have shown resistance to the anthelmintics, ivermectin and moxidectin, and there is evidence that the over-expression of parasite P-glycoprotein (P-gp may account, at least in part, for resistance to ivermectin. The objective of this study was to evaluate whether the multidrug resistance (MDR modulators, verapamil, CL 347.099 (an analog of verapamil and cyclosporin A, would enhance the efficacy of ivermectin and moxidectin against selected strains of Haemonchus contortus using an in vitro larval migration assay. The modulators had no effects on the number of migrating larvae when used alone. Ivermectin and moxidectin showed a significant (P<0.05 increase in its efficacy by 52.8 and 58.5% respectively, when used in association with verapamil against a moxidectin-selected strain. CL 347,099 also increased significantly (P<0.05 the ivermectin and moxidectin efficacy by 24.2 and 40.0% respectively, against an ivermectin-selected strain and by 40.0 and 75.6% respectively, against an moxidectin-selected strain. At the concentrations tested cyclosporin A showed a variable effect on increasing the efficacy of the anthelmintics against the susceptible and resistant strains.

  17. The relationship between putative periodontopathic bacteria and lower respiratory tract infection%牙周可疑致病菌与下呼吸道感染的关系

    Institute of Scientific and Technical Information of China (English)

    谭丽思; 潘亚萍

    2011-01-01

    The biofilm of dental plaque is the initiation factor of periodontitis.It is known to all that there are relationships between periodontitis and many multi-organ or systemic diseases, such as cardiovascular and cerebrovascular diseases, diabetes mellitus, alimentary tract and respiratory tract disease.Recently, people pay close attention to the relationship between putative periodontopathic bacteria and the respiratory tract disease, and this review will summarize the path and the role of the putative periodontopathic bacteria infecting the lower respiratory tract.%牙菌斑生物膜是牙周炎的始动因子.研究发现,牙周炎与全身多器官或系统的感染性疾病有关,如心脑血管疾病、糖尿病、消化道和呼吸道疾病.近年来,牙周炎与呼吸道疾病之间的关系备受关注,本文将近期对牙周可疑致病菌感染下呼吸道的途径及其作用研究做简要综述.

  18. Modulation of cytokine secretion by mesenteric lymph node cells from vitamin A-deficient mice during Hymenolepis nana infection.

    Science.gov (United States)

    Ikeda, K; Matsuo, S; Asano, K; Okamoto, K

    1994-01-01

    The influence of vitamin A deficiency on the development of cellular immune responses was examined using vitamin A-deficient mice (A mice)/Hymenolepis nana system. Mesenteric lymph node cells (MLNC) prepared from both normal BALB/c mice and A mice during H. nana infection proliferated extensively when cultured with soluble egg antigen of H. nana as assessed by 3H-thymidine incorporation. MLNC from normal mice secreted significantly more IL-2 and significantly less IFN-gamma than A mice when the cells were cultured in the presence of soluble egg antigen.

  19. Pretreatment with Cry1Ac Protoxin Modulates the Immune Response, and Increases the Survival of Plasmodium-Infected CBA/Ca Mice

    Directory of Open Access Journals (Sweden)

    Martha Legorreta-Herrera

    2010-01-01

    Full Text Available Malaria is a major global health problem that kills 1-2 million people each year. Despite exhaustive research, naturally acquired immunity is poorly understood. Cry1A proteins are potent immunogens with adjuvant properties and are able to induce strong cellular and humoral responses. In fact, it has been shown that administration of Cry1Ac protoxin alone or with amoebic lysates induces protection against the lethal infection caused by the protozoa Naegleria fowleri. In this work, we studied whether Cry1Ac is able to activate the innate immune response to induce protection against Plasmodium berghei ANKA (lethal and P. chabaudi AS (nonlethal parasites in CBA/Ca mice. Treatment with Cry1Ac induced protection against both Plasmodium species in terms of reduced parasitaemia, longer survival time, modulation of pro- and anti-inflammatory cytokines, and increased levels of specific antibodies against Plasmodium. Understanding how to boost innate immunity to Plasmodium infection should lead to immunologically based intervention strategies.

  20. Pretreatment with a heat-killed probiotic modulates monocyte chemoattractant protein-1 and reduces the pathogenicity of influenza and enterovirus 71 infections.

    Science.gov (United States)

    Chen, M-F; Weng, K-F; Huang, S-Y; Liu, Y-C; Tseng, S-N; Ojcius, D M; Shih, S-R

    2017-01-01

    It has been proposed that inactivated probiotics may modulate the host immune system and contribute to mitigation of viral infections. This study demonstrated that administration of heat-killed Enterococcus faecalis, a widely used probiotic, can protect host animals against viral infections. The influenza-mediated morbidity and lung inflammation in E. faecalis-treated mice decreased significantly compared with those of the control mice. Furthermore, we found that the protection is associated with production of monocyte chemoattractant protein-1 (MCP-1). The intratracheal injection of a recombinant mouse MCP-1 protein abrogated the antiviral effects elicited by pretreatment with E. faecalis. CC chemokine receptor 2 (CCR2) is a receptor for MCP-1, and the intraperitoneal administration of a CCR2 antagonist effectively inhibited viral pathogenicity. The reduced pathogenicity was also observed in CCR2-deficient mice. Finally, E. faecalis significantly attenuated neuropathogenicity induced by another RNA virus, enterovirus 71. This study demonstrates that killed probiotics can reduce viral disease severity and identify that the MCP-1 pathway might act as a key mediator in the improved antiviral immune response. Our findings suggest that MCP-1 and its related signaling pathway can serve as critical therapeutic targets for development of new antiviral strategies.

  1. Patent filarial infection modulates malaria-specific type 1 cytokine responses in an IL-10-dependent manner in a filaria/malaria-coinfected population.

    Science.gov (United States)

    Metenou, Simon; Dembélé, Benoit; Konate, Siaka; Dolo, Housseini; Coulibaly, Siaka Y; Coulibaly, Yaya I; Diallo, Abdallah A; Soumaoro, Lamine; Coulibaly, Michel E; Sanogo, Dramane; Doumbia, Salif S; Wagner, Marissa; Traoré, Sekou F; Klion, Amy; Mahanty, Siddhartha; Nutman, Thomas B

    2009-07-15

    The effect of filarial infections on malaria-specific immune responses was investigated in Malian villages coendemic for filariasis (Fil) and malaria. Cytokines were measured from plasma and Ag-stimulated whole blood from individuals with Wuchereria bancrofti and/or Mansonella perstans infections (Fil(+); n = 19) and those without evidence of filarial infection (Fil(-); n = 19). Plasma levels of IL-10 (geometric mean [GM], 22.8 vs 10.4) were higher in Fil(+) compared with Fil(-), whereas levels of IFN-inducible protein (IP)-10 were lower in Fil(+) (GM, 66.3 vs 110.0). Fil(+) had higher levels of spontaneously secreted IL-10 (GM, 59.3 vs 6.8 pg/ml) and lower levels of IL-2 (1.0 vs 1.2 pg/ml) than did Fil(-). Although there were no differences in levels of Staphylococcus aureus enterotoxin B-induced cytokines between the two groups, Fil(+) mounted lower IL-12p70 (GM, 1.11 vs 3.83 pg/ml; p = 0.007), IFN-gamma (GM, 5.44 vs 23.41 pg/ml; p = 0.009), and IP-10 (GM, 29.43 vs 281.7 pg/ml; p = 0.007) responses following malaria Ag (MalAg) stimulation compared with Fil(-). In contrast, Fil(+) individuals had a higher MalAg-specific IL-10 response (GM, 7318 pg/ml vs 3029 pg/ml; p = 0.006) compared with those without filarial infection. Neutralizing Ab to IL-10 (but not to TGFbeta) reversed the down-regulated MalAg-specific IFN-gamma and IP-10 (p < 0.001) responses in Fil(+). Together, these data demonstrate that filarial infections modulate the Plasmodium falciparum-specific IL-12p70/IFN-gamma secretion pathways known to play a key role in resistance to malaria and that they do so in an IL-10-dependent manner.

  2. 多药耐药菌医院感染控制措施%Measures to control nosocomial infections caused by multidrug-resistant bacteria

    Institute of Scientific and Technical Information of China (English)

    陈京; 杨怀; 徐艳; 牟霞; 郑金鼎

    2011-01-01

    OBJECTIVE To implement the multi-resistant hospital infection control measures to reduce hospital infection and protect patients and medical staff safety. METHODS Developed control programs and work plans of clinical multi-drug resistant hospital infection,through the medical quality management system, multi-disciplinary efforted to cooperate on the implementation of multi-drug resistant clinical control to all aspects of hospital infection. RESULTS After a multi-sectoral, clinical departments implemented specific communication control program of multi-drug resistant, hospital infection control department for inspectors, and medical quality assessment and feedback. Dissemination of multiple drug-resistant control measures continued to be implemented. Subjects of medical staff and patients under the protection of preventive measures in isolation, diagnosis and treatment of normal activities. CONCLUSION The multi-resistant hospital infection control programs in the medical quality management system in the management level attention. Multiple drug-resistant hospital infection control inspectors at the quality of evaluation in the hospital announce that director of undergraduate responsible the problems to the individual, so that clinicians and nurses, enhance the sense of responsibility, self-awareness increased substantially and facilitate the hospital infection control programs and measures to more comprehensive efforts in the promotion and clinical implementation.%目的 落实多药耐药菌医院感染控制措施,减少医院感染发生,保障患者和医务人员安全.方法 制定临床多药耐药菌医院感染控制方案及工作计划,通过医疗质量管理体系,多学科努力合作,落实到临床控制多药耐药菌医院感染的各个环节.结果 经过多部门合作,临床科室具体落实多药耐药菌传播控制方案,医院感染科进行督察,结合医疗质量考评、反馈,多药耐药菌传播控制措施不断得到落实;各

  3. Campylobacter Infections

    Science.gov (United States)

    ... fecal matter from an infected person (especially a child in diapers). Household pets can carry and transmit the bacteria to their ... by the person with diarrhea. Also, if a pet dog or cat has diarrhea, wash your hands often and check ... lab tests also might be needed, especially if your child has blood in the stool. If your doctor ...

  4. Pathogenic bacteria causing nosocomial infections in hospitalized patients and related factors%住院患者医院感染病原学类型与相关因素的关系

    Institute of Scientific and Technical Information of China (English)

    李万兰; 郭晨霞; 邓艳芳; 郑春梅; 祝中年; 余凤姣

    2012-01-01

    OBJECTIVE To analyze the correlation between the species and distribution of the pathogenic bacteria causing nosocomial infections in the hospitalized patients and the ward environment and the medical facilities so as to provide reliable bases for the effective prevention and control of nosocomial infections in grass-roots hospital. METHODS The patients who were enrolled in the hospital from Jan to Sep 2011 were selected as the monitoring subjects, the etiological examination of the patients with infections was performed, the air of the ward, bed unit and objects and the used medical facilities were set as the microbiologic monitoring indexes. RESULTS Of totally 18 037 case-times of hospitalized patients monitored, nosocomial infections occurred in 227 patients with the infection rate of 1. 26%; the etiological examination showed that the gram-negative bacteria accounted for 52. 01% , higher than 31. 51% of gram-positive bacteria and 16. 44% of the fungi; Esckerichia coli (28. 94%) , Pseudomonas aeruginosa (18. 42%), and Acinetobacter baumannii (10. 53%) were the predominant species of gram-negative bacteria; Staphylococcus aureus (34. 78%) and S. haemolyticus (21. 74%), and S. epidermidis (21. 74%) were the predominant gram-positive bacteria; Micrococcus luteus and S. epidermidis were the predominant species of gram-positive cocci in the ward, followed by Bacillus subtilis and other gram-positive bacilli; medical facilities to Bacillus cereus bacteria, Bacillus subtilis and other gram-positive bacilli, followed by the gram-positive bacilli such as black variant spores of Bacillus subtilis ; Cereus and black variant spores of Bacillus subtilis were predominant species of gram-positive bacilli on the medical facilities, followed by the gram-positive cocci such as S. epidermidis; the difference in the constituent ratio of the bacterial species between the air, pillow, quilts and thr bedstands was statistically significant. CONCLUSION It is an effective measure to

  5. A High-Affinity Native Human Antibody Disrupts Biofilm from Staphylococcus aureus Bacteria and Potentiates Antibiotic Efficacy in a Mouse Implant Infection Model.

    Science.gov (United States)

    Estellés, Angeles; Woischnig, Anne-Kathrin; Liu, Keyi; Stephenson, Robert; Lomongsod, Evelene; Nguyen, Da; Zhang, Jianzhong; Heidecker, Manfred; Yang, Yifan; Simon, Reyna J; Tenorio, Edgar; Ellsworth, Stote; Leighton, Anton; Ryser, Stefan; Gremmelmaier, Nina Khanna; Kauvar, Lawrence M

    2016-04-01

    Many serious bacterial infections are difficult to treat due to biofilm formation, which provides physical protection and induces a sessile phenotype refractory to antibiotic treatment compared to the planktonic state. A key structural component of biofilm is extracellular DNA, which is held in place by secreted bacterial proteins from the DNABII family: integration host factor (IHF) and histone-like (HU) proteins. A native human monoclonal antibody, TRL1068, has been discovered using single B-lymphocyte screening technology. It has low-picomolar affinity against DNABII homologs from important Gram-positive and Gram-negative bacterial pathogens. The disruption of established biofilm was observedin vitroat an antibody concentration of 1.2 μg/ml over 12 h. The effect of TRL1068in vivowas evaluated in a murine tissue cage infection model in which a biofilm is formed by infection with methicillin-resistantStaphylococcus aureus(MRSA; ATCC 43300). Treatment of the established biofilm by combination therapy of TRL1068 (15 mg/kg of body weight, intraperitoneal [i.p.] administration) with daptomycin (50 mg/kg, i.p.) significantly reduced adherent bacterial count compared to that after daptomycin treatment alone, accompanied by significant reduction in planktonic bacterial numbers. The quantification of TRL1068 in sample matrices showed substantial penetration of TRL1068 from serum into the cage interior. TRL1068 is a clinical candidate for combination treatment with standard-of-care antibiotics to overcome the drug-refractory state associated with biofilm formation, with potential utility for a broad spectrum of difficult-to-treat bacterial infections.

  6. High-dose vitamin D3 supplementation is a requisite for modulation of skin-homing markers on regulatory T cells in HIV-infected patients.

    Science.gov (United States)

    Khoo, Ai-Leng; Koenen, Hans J P M; Michels, Meta; Ooms, Sharon; Bosch, Marjolein; Netea, Mihai G; Joosten, Irma; van der Ven, André J A M

    2013-02-01

    Vitamin D(3) is known to have an effect on the immune function. We investigated the immunomodulatory capability of vitamin D(3) in HIV-infected patients and studied the expression of chemokine receptors on regulatory T cells (Treg). Vitamin D(3)-deficient HIV-1-seropositive subjects were treated with cholecalciferol (vitamin D(3)) at a dose of 800 IU daily for 3 months (n=9) or 25,000 IU weekly for 2 months (n=7). Peripheral blood mononuclear cells (PBMCs) were isolated and analyzed for skin-homing (CCR4 and CCR10) and gut-homing (CCR9 and integrin α(4)β(7)) marker expression on Treg, by flow cytometry, before and after supplementation. Serum 25(OH)D(3) and parathyroid hormone (PTH) levels were determined at baseline and after the treatment period. Weekly doses of 25,000 IU cholecalciferol effectively achieved the optimal target serum 25(OH)D(3) concentration of >75 nmol/liter (30 ng/ml) in HIV-infected patients. High-dose cholecalciferol supplementation differentially influenced skin-homing markers on Treg with an increased level of CCR10 expression and while a reduction in CCR4 expression level was observed together with a lower percentage of Treg expressing CCR4. For both dosing regimens, there were no significant differences in the expression of gut-homing markers, CCR9, and integrin α(4)β(7). High-dose vitamin D(3) supplementation is needed to reverse vitamin D(3) deficiency in HIV-infected individuals and this results in modulation of skin-homing markers but not gut-homing markers expression on Treg. At a standard dose of 800 IU/day, vitamin D(3) is not effective in achieving an optimal 25(OH)D(3) concentration in patients with an underlying T cell dysfunction and is unable to exert any immunomodulatory effects.

  7. Interferon regulatory factor modulation underlies the bystander suppression of malaria antigen-driven IL-12 and IFN-γ in filaria-malaria co-infection.

    Science.gov (United States)

    Metenou, Simon; Kovacs, Michael; Dembele, Benoit; Coulibaly, Yaya I; Klion, Amy D; Nutman, Thomas B

    2012-03-01

    In areas where polyparasitism is highly prevalent, the impact of multiple parasites on the host response is underestimated. In particular, the presence of helminth infection coincident with malaria profoundly alters the production of malaria-specific IFN-γ, IL-12p70, CXCL9, CXCL10 and CXCL11, cytokines/chemokines known to be critical in mediating malaria-specific immunity. In order to elucidate the mechanisms underlying the suppression of malaria-specific cytokines/chemokines, we assessed the expression of malaria-specific IL-12Rβ1, IL-12Rβ2 and interferon regulatory factor (IRF)-1 in blood obtained from 18 filaria-infected (Fil(+)) and 17 filaria-uninfected (Fil(-)) individuals in a filaria-malaria co-endemic region of Mali. We found that Fil(+) individuals had significantly lower RNA expression of IRF-1 but not IL-12Rβ1 or IL-12Rβ2 in response to malaria antigen stimulation. We also measured the frequency of IL-12-producing DCs from these subjects and found that Fil(+) subjects had lower frequencies of IL-12(+) mDCs after malaria antigen stimulation than did the Fil(-) subjects. Modeling these data in vitro, we found that mDCs pre-exposed to live microfilariae not only produced significantly lower levels of CXCL-9, CXCL-10, IL-12p35, IL-12p40, IL-12p19 and CXCL-11 following stimulation with malaria antigen but also markedly downregulated the expression of IRF-1, IRF-2 and IRF-3 compared with microfilaria-unexposed mDCs. siRNA-inhibition of irf-1 in mDCs downregulated the production of IL-12p70 through repression of IL-12p35. Our data demonstrate that the modulation of IRFs seen in filarial (and presumably other tissue-invasive helminths) infection underlies the suppression of malaria-specific cytokines/chemokines that play a crucial role in immunity to malaria.

  8. Playing Hide and Seek: How Glycosylation of the Influenza Virus Hemagglutinin Can Modulate the Immune Response to Infection

    Directory of Open Access Journals (Sweden)

    Michelle D. Tate

    2014-03-01

    Full Text Available Seasonal influenza A viruses (IAV originate from pandemic IAV and have undergone changes in antigenic structure, including addition of glycans to the hemagglutinin (HA glycoprotein. The viral HA is the major target recognized by neutralizing antibodies and glycans have been proposed to shield antigenic sites on HA, thereby promoting virus survival in the face of widespread vaccination and/or infection. However, addition of glycans can also interfere with the receptor binding properties of HA and this must be compensated for by additional mutations, creating a fitness barrier to accumulation of glycosylation sites. In addition, glycans on HA are also recognized by phylogenetically ancient lectins of the innate immune system and the benefit provided by evasion of humoral immunity is balanced by attenuation of infection. Therefore, a fine balance must exist regarding the optimal pattern of HA glycosylation to offset competing pressures associated with recognition by innate defenses, evasion of humoral immunity and maintenance of virus fitness. In this review, we examine HA glycosylation patterns of IAV associated with pandemic and seasonal influenza and discuss recent advancements in our understanding of interactions between IAV glycans and components of innate and adaptive immunity.

  9. Gonadal Steroids Negatively Modulate Oxidative Stress in CBA/Ca Female Mice Infected with P. berghei ANKA

    Directory of Open Access Journals (Sweden)

    Néstor Aarón Mosqueda-Romo

    2014-01-01

    Full Text Available We decreased the level of gonadal steroids in female and male mice by gonadectomy. We infected these mice with P. berghei ANKA and observed the subsequent impact on the oxidative stress response. Intact females developed lower levels of parasitaemia and lost weight faster than intact males. Gonadectomised female mice displayed increased levels of parasitaemia, increased body mass, and increased anaemia compared with their male counterparts. In addition, gonadectomised females exhibited lower specific catalase, superoxide dismutase, and glutathione peroxidase activities in their blood and spleen tissues compared with gonadectomised males. To further study the oxidative stress response in P. berghei ANKA-infected gonadectomised mice, nitric oxide levels were assessed in the blood and spleen, and MDA levels were assessed in the spleen. Intact, sham-operated, and gonadectomised female mice exhibited higher levels of nitric oxide in the blood and spleen compared with male mice. MDA levels were higher in all of the female groups. Finally, gonadectomy significantly increased the oxidative stress levels in females but not in males. These data suggest that differential oxidative stress is influenced by oestrogens that may contribute to sexual dimorphism in malaria.

  10. Leishmania donovani activates SREBP2 to modulate macrophage membrane cholesterol and mitochondrial oxidants for establishment of infection.

    Science.gov (United States)

    Mukherjee, Madhuchhanda; Basu Ball, Writoban; Das, Pijush K

    2014-10-01

    Establishment of infection by an intracellular pathogen depends on successful internalization with a concomitant neutralization of host defense machinery. Leishmania donovani, an intramacrophage pathogen, targets host SREBP2, a critical transcription factor, to regulate macrophage plasma membrane cholesterol and mitochondrial reactive oxygen species generation, favoring parasite invasion and persistence. Leishmania infection triggered membrane-raft reorientation-dependent Lyn-PI3K/Akt pathway activation which in turn deactivated GSK3β to stabilize nuclear SREBP2. Moreover, cells perceiving less available intracellular cholesterol due to its sequestration at the plasma membrane resulted in the deregulation of the ER-residing SCAP-SREBP2-Insig circuit thereby assisting increased nuclear translocation of SREBP2. Both increased nuclear transport and stabilization of SREBP2 caused HMGCR-catalyzed cholesterol biosynthesis-mediated plasma membrane cholesterol enrichment leading to decreased membrane-fluidity and plausibly assisting delay in phagosomal acidification. Parasite survival ensuing entry was further ensured by SREBP2-dependent transcriptional up-regulation of UCP2, which suppressed mitochondrial ROS generation, one of the primary microbicidal molecules in macrophages recognized for its efficacy against Leishmania. Functional knock-down of SREBP2 both in vitro and in vivo was associated with reduction in macrophage plasma membrane cholesterol, increased ROS production and lower parasite survival. To our knowledge, this study, for the first time, reveals that Leishmania exploits macrophage cholesterol-dependent SREBP2 circuit to facilitate its entry and survival within the host.

  11. Use of a non-radioactive hybridisation assay for direct detection of gram-negative bacteria carrying TEM beta-lactamase genes in infected urine.

    Science.gov (United States)

    Carter, G I; Towner, K J; Pearson, N J; Slack, R C

    1989-02-01

    DNA in infected urines from 81 patients with urinary tract infection was hybridised directly with a non-radioactive DNA probe specific for bacterial genes coding for TEM-type beta-lactamase. The results were assessed by means of a computerised image analysis system and compared with those obtained following isolation of the infecting organism, conventional sensitivity testing and isoelectric focusing (IEF) procedures for the detection of TEM-type beta-lactamase. Of the 27 ampicillin-resistant gram-negative organisms isolated in pure culture from the urines, 14 were shown by both hybridisation and IEF to carry a gene for TEM beta-lactamase production. Only four discordant results were obtained: three "false positive" direct hybridisation results, one due to urine pigmentation, and one, possibly, to a TEM beta-lactamase gene which was not being expressed, and one "false negative" result due to insufficient cell numbers in the urine. The system is capable of screening large numbers of samples and is applicable to any gene for which a suitable DNA probe is available.

  12. 剖宫产手术切口感染的菌群分布及药敏分析%Distribution and antimicrobial resistance of pathogenic bacteria causing surgical incision infections in cesarean section

    Institute of Scientific and Technical Information of China (English)

    罗永慧; 段颖卿; 舒向荣

    2013-01-01

    OBJECTIVE To explore the distribution and antimicrobial resistance of pathogenic bacteria causing surgical incision infections in cesarean section and provide reference for clinical prevention and control of incision infections.METHODS The secretions from infected wounds were cultured in order to identify pathogens,and MicroScan Walk Away96 microbial analyzer was employed to conduct automatic bacterial identification and the drug susceptibility testing,the resistance rate of bacteria was analyzed.RESULTS Totally 52 strains of pathogenic bacteria causing incision infections were mainly Escherichia coli,Staphylococcus aureus and Enterococcus faecalis,accounting for 34.6%,13.5% and 13.5%,respectively.E.coli strains varied in the drug resistance except hypersensitivity to imipenem and piperacillin/tazobactam and showed multiple and cross drug resistance; there were 10 (55.6%) strains of ESBLs-producing E.coli isolated; S.aureus strains showed high drug resistance to penicillin drugs and were highly sensitive to other antibiotics; the penicillin drugs maintained better antibacterial activity against the E.faecalis strains.CONCLUSION Preventive measures should be taken to prevent and control the surgical incision infections.%目的 探讨剖宫产手术切口感染病原菌的分布及耐药性,为临床预防控制切口感染提供参考依据.方法 采集伤口分泌物进行细菌培养,分离病原菌,采用MicroScan WalkAway96微生物分析仪系统进行细菌鉴定与药敏分析,并对病原菌耐药率进行分析.结果 从剖宫产手术切口感染部位分离到的52株病原菌中,主要为大肠埃希菌、金黄色葡萄球菌和粪肠球菌,分别占34.6%、13.5%和13.5%;大肠埃希菌除对亚胺培南和哌拉西林/他唑巴坦高敏外,对其他抗菌药物呈现不同程度的耐药,且显示了多药和交叉耐药性;产超广谱β-内酰胺酶(ESBLs)大肠埃希菌分离到10株,占55.6%;金黄色葡萄球菌除对青

  13. Distribution characteristics and drug resistance of bacteria causing double infection in respiratory system%医院患者呼吸系统二重感染菌群分布特征及耐药性分析

    Institute of Scientific and Technical Information of China (English)

    黄承乐; 班副植; 丁凯宏

    2011-01-01

    目的 了解医院住院患者呼吸系统二重感染菌群分布及耐药性.方法 回顾性分析2007-2009年医院住院患者送检的痰及咽拭子标本分离培养出的细菌合并真菌感染者的菌株种类和耐药率.结果 细菌感染菌株首位是铜绿假单胞菌,占14.4%,其次是肺炎克雷伯菌和表皮葡萄球菌,分别占12.6%、11.9%;真菌感染前3位是白色假丝酵母菌、热带假丝酵母菌、克柔假丝酵母菌,分别占36.4%、8.7%、3.1%;革兰阴性杆菌对氨苄西林、庆大霉素、头孢噻肟、头孢他啶、头孢噻吩的耐药性均>60.0%;革兰阳性球菌对青霉素类的耐药性>80.0%;真菌对5-氟胞嘧啶、氟康唑、制霉菌素、两性霉素B、咪康唑较敏感,敏感率均>80.0%,酮康唑和益康唑的耐药性较高,耐药率约20.0%.结论 住院患者呼吸系统二重感染细菌菌株耐药率较高,定期对医院进行病原菌监测及耐药性分析,对预防医院感染和合理使用抗菌药物意义重大.%OBJECTIVE To understand the hospital inpatients with respiratory system double infection bacteria distribution and the situation of drug resistance.METHODS The phlegm this courtyard in hospital inpatients delivered examination and swallows the cotton swab specimen isolated culture bacterium merge fungus infected person's strain type and the medicine sensitive situation.RESULTS The bacterial infection strain first place was (36.4%), next was pneumonia gram Reber fungus (27.6%) and the Staphylococcus epidermis (12.6%).Before the fungus infection three are Candida albicans (36.4%), Candida tropicalis (8.7%) and Candida glabrata (3.1%).Gram-negative bacteria to ampicillin, gentamicin, cefotaxime, ceftazidime, cephalothin resistance to surpass 60.0%; Gram-positive cocci to penicillin resistance as high as 80%.The fungus to 5-fluorine cytosine, fluconazole, nystatin, amphotericin B, miconazole is sensitive, Sensitive rate above 80.0%; ketoconazole and econazole

  14. 老年患者医院感染病原菌分布与耐药性分析%Distribution and antimicrobial resistance of pathogenic bacteria causing nosocomial infections in senile patients

    Institute of Scientific and Technical Information of China (English)

    蔡秀娟; 杨家宏; 杨爱明; 孙建军; 彭先贵

    2016-01-01

    目的:了解老年患者医院感染病原菌的种类及耐药性,为医师控制感染选择针对性抗菌药物提供参考依据。方法调查2012年1月-2014年12月3328例老年住院患者的临床资料;细菌培养参照临床细菌学检验技术进行;药敏监测与数据读取遵循K-B法及CLSI当年折点认定敏感或耐药,检验全程坚持室内质控方案,采用WHONET5.5-5.6软件进行统计分析。结果3328例老年患者发生医院感染296例、319例次,感染率8.9%、例次感染率为9.6%;感染部位以呼吸道、泌尿道为主,分别占50.5%、26.6%;共分离病原菌319株,其中革兰阴性菌占65.5%,革兰阳性菌占23.8%,真菌占10.7%;革兰阴性菌对磺胺甲噁唑/甲氧苄啶耐药率最高,均>60.0%,对阿米卡星和亚胺培南的耐药率较低,均<31.0%;检出耐甲氧西林葡萄球菌(MRS)25株,检出率44.6%,检出产ESBLs菌37株,检出率46.3%。结论≥60岁老年人属于感染高发组,医师用药时务必针对老年人生理特点,选择对肝、肾功能低损害的药物抗感染,降低药物不良反应的风险性。%OBJECTIVE To understand the species composition and antimicrobial resistance of pathogenic bacteria causing nosocomial infections in senile patients and provide the reference for controlling the infections .METHODS The clinical data of 3328 senile inpatients from Jan .2012 to Dec .2014 were investigated in this study .Bacterial culture was performed according to the clinical bacteriology inspection specification .Susceptibility testing was car-ried out and results were assessed by K-B methods recommended by CLSI .The indoor quality control was per-formed throughout the experiment .The WHONET 5 .5-5 .6 software was used for statistical analysis .RESULTS Among 3328 cases of elderly patients ,nosocomial infections occurred in 296 cases .The infection rate was 8 .9%and the case

  15. CD3zeta down-modulation may explain Vgamma9Vdelta2 T lymphocyte anergy in HIV-infected patients.

    Science.gov (United States)

    Sacchi, Alessandra; Tempestilli, Massimo; Turchi, Federica; Agrati, Chiara; Casetti, Rita; Cimini, Eleonora; Gioia, Cristiana; Martini, Federico

    2009-02-01

    The aim of the present study was to explain the observed anergy of Vgamma9Vdelta2 T cells from human immunodeficiency virus (HIV)-positive patients. CD3zeta expression and interferon (IFN)-gamma production by Vgamma9Vdelta2 T cells from HIV-positive and HIV-negative subjects were analyzed. We demonstrated that Vgamma9Vdelta2 T cells from HIV-infected patients expressed a lower level of CD3zeta than did Vgamma9Vdelta2 T cells from healthy donors. A direct correlation was found between CD3zeta expression and IFN-gamma production capability by Vgamma9Vdelta2 T cells. However, activation of protein kinase C by phorbol myristate acetate is able to restore CD3zeta expression and IFN-gamma production. Our findings may contribute to clarification of the molecular mechanisms of Vgamma9Vdelta2 T cell anergy found in HIV-positive patients.

  16. NKLP27: a teleost NK-lysin peptide that modulates immune response, induces degradation of bacterial DNA, and inhibits bacterial and viral infection.

    Science.gov (United States)

    Zhang, Min; Li, Mo-fei; Sun, Li

    2014-01-01

    NK-lysin is an antimicrobial protein produced by cytotoxic T lymphocytes and natural killer cells. In this study, we examined the biological property of a peptide, NKLP27, derived from tongue sole (Cynoglossus semilaevis) NK-lysin. NKLP27 is composed of 27 amino acids and shares little sequence identity with known NK-lysin peptides. NKLP27 possesses bactericidal activity against both Gram-negative and Gram-positive bacteria including common aquaculture pathogens. The bactericidal activity of NKLP27 was dependent on the C-terminal five residues, deletion of which dramatically reduced the activity of NKLP27. During its interaction with the target bacterial cells, NKLP27 destroyed cell membrane integrity, penetrated into the cytoplasm, and induced degradation of genomic DNA. In vivo study showed that administration of tongue sole with NKLP27 before bacterial and viral infection significantly reduced pathogen dissemination and replication in tissues. Further study revealed that fish administered with NKLP27 exhibited significantly upregulated expression of the immune genes including those that are known to be involved in antibacterial and antiviral defense. These results indicate that NKLP27 is a novel antimicrobial against bacterial and viral pathogens, and that the observed effect of NKLP27 on bacterial DNA and host gene expression adds new insights to the action mechanism of fish antimicrobial peptides.

  17. NKLP27: a teleost NK-lysin peptide that modulates immune response, induces degradation of bacterial DNA, and inhibits bacterial and viral infection.

    Directory of Open Access Journals (Sweden)

    Min Zhang

    Full Text Available NK-lysin is an antimicrobial protein produced by cytotoxic T lymphocytes and natural killer cells. In this study, we examined the biological property of a peptide, NKLP27, derived from tongue sole (Cynoglossus semilaevis NK-lysin. NKLP27 is composed of 27 amino acids and shares little sequence identity with known NK-lysin peptides. NKLP27 possesses bactericidal activity against both Gram-negative and Gram-positive bacteria including common aquaculture pathogens. The bactericidal activity of NKLP27 was dependent on the C-terminal five residues, deletion of which dramatically reduced the activity of NKLP27. During its interaction with the target bacterial cells, NKLP27 destroyed cell membrane integrity, penetrated into the cytoplasm, and induced degradation of genomic DNA. In vivo study showed that administration of tongue sole with NKLP27 before bacterial and viral infection significantly reduced pathogen dissemination and replication in tissues. Further study revealed that fish administered with NKLP27 exhibited significantly upregulated expression of the immune genes including those that are known to be involved in antibacterial and antiviral defense. These results indicate that NKLP27 is a novel antimicrobial against bacterial and viral pathogens, and that the observed effect of NKLP27 on bacterial DNA and host gene expression adds new insights to the action mechanism of fish antimicrobial peptides.

  18. Distribution of pathogenic bacteria and analysis of drug resistance in urinary tract infections%泌尿系统感染病原菌分布及耐药性分析

    Institute of Scientific and Technical Information of China (English)

    邹桂玲; 杜雪飞; 孙哲; 孟晓玉; 陈国玉

    2011-01-01

    To understand the changes of urinary tract infection pathogens in classification and drug resistance and to guide more rational use of antibiotics in clinic. Methods Pathogenic bacteria from patients diagnosed urinary tract infection and their susceptibility test results in vitro from 2001 to 2008 were collected and analyzed, ATCC25922, ATCC25923,ATCC27853 were selected as internal quality control strains. Results The positive rate of urine culture and ratios.of various of pathogenic bacteria had no difference between from 2001 to 2004 and from 2005 to 2008. Escherichia coli, Enterococcus, Fungi, Enterobacter spp were the main grape isolated, Escherichia coli bacteria accounted for the most part, followed by enterococci. Gram-negative genus Bacillus had no difference in rates in various of pathogenic bacteria, but gram-positive cocci was significantly different between from 2001 to 2004 and from 2005 to 2008. From 2005 to 2008, the drug resistance rates in pathogen isolated from urine culture was significantly increased and quinolones was no longer the first choice for treatment of;urinary tract infection. Conclusion With increasing in resistance to antibiotics of pathogens,clinicians should use antibiotics according to susceptibility test results.%目的 了解本院2001~2008年泌尿系统感染病原菌分类及耐药性的变化,指导临床更合理的应用抗生素.方法 收集2001~2008年诊断为泌尿系统感染的病原菌及其体外药敏试验的结果进行分析,室内质控菌株选用ATCC25922、ATCC25923、ATCC27853.结果 2001~2004年与2005~2008年尿培养阳性率及各种病原菌的比率无差异,大肠埃希菌、肠球菌属、真菌、肠杆菌属、葡萄菌属等为主要分离菌,其中大肠埃希菌占首位,肠球菌次之.2001~2004年与2005~2008年病原菌中革兰氏阴性杆菌属比率无差别,但革兰氏阳性球菌属比率有明显差别,并且2005~2008年尿培养分离出的病原菌耐药率明显增

  19. Analysis of pathogenic bacteria of 412 pulmonary tuberculosis hospitalized patients accompanied with infection%412例住院肺结核患者合并感染的致病菌分析

    Institute of Scientific and Technical Information of China (English)

    李君秀; 邵世峰; 吴琦

    2009-01-01

    目的 探讨肺结核合并肺部感染的特点、致病菌的分布及药敏情况,为临床合理使用抗生素提供依据.方法 对天津市海河医院2004年5月至2007年12月的412例痰细菌培养发现致病菌的肺结核住院患者的痰培养结果进行回顾性分析.结果 412例患者共培养出致病菌858株.革兰阴性杆菌占68.6%,革兰阳性球菌占12.7%·真菌占18.6%.其中肺炎克雷伯菌、铜绿假单胞菌、白色念珠菌为主要细菌.药敏试验提示多数致病菌对未加β内酰胺酶抑制的青霉素耐药在78.6%~98.8%之间,对第一、二代头孢菌素等的耐药率在11.1%~97.4%之间,对一三代头孢类的耐药率在9.8%~70.6%之间,对碳青霉烯类抗生素敏感率较高.结论 肺结核合并下呼吸道感染以及耐药情况严重,因此在结核患者合并感染临床选用抗生素治疗时应以药敏试验为依据,选择合理有效的抗生素,减少盲目用药和不良反应的产生.减少耐药菌株的产生.%Objective To investigate the characteristics of pulmonary tuberculosis in patients with lung infection,the distribution of pathogens and susceptibility,and provide a reasonable basis for the clinical use of antibiotics.Methods The pathogens sputum culture results were reviewed and analyzed on 412 cases of of tuberculosis patients.Results 858 bacteria were cultivated in 412 cases of the patients.Gram-negative bacilli accounted for 68.6%,gram-positive cocci accounted for 12.7%,fungi accounted for 18.6%.Klebsiella pneumoniae,Pseudomonas aeruginosa,Candida albicans were the main bacteria.Sensitivity tests demonstrated that drug-resistant rate of penicillin without β-lactamase inhibitor for the bacteria was 78.6%-98.8%.For the first or second generation cephalosporins,the drug-resistant rate was 11.1%-97.4%.For some of the third-generation cephalosporins,the drug-resistant rate was 9.8%-70.6%.The sensitivity of carbapenem antibiotic for bacteria was higher

  20. Analysis of the Characteristics and Drug Resistance of Pathogenic Bacteria in Lower Respiratory Infection%试论下呼吸道感染病原菌特点及耐药性

    Institute of Scientific and Technical Information of China (English)

    李文阳

    2015-01-01

    目的:为临床合理选择抗菌药物、加强疗效提供参考依据。方法:收集2013年1月-2014年12月青海大学附属医院呼吸科下呼吸道感染患者痰液及支气管肺泡灌洗液标本进行送检,对普通病房患者和ICU病房患者病原菌分布情况进行分析,统计所分离菌株的分布特点及耐药性特点。结果:本次调查以革兰阴性杆菌最为多见,其次为真菌,革兰阳性杆菌所占比例最少。在革兰阴性杆菌中,检出率最高的病原菌排前四位的分别是铜绿假单胞菌、肺炎克雷伯菌、鲍曼氏不动杆菌和大肠埃希菌。革兰阳性杆菌主要以金黄色葡萄球菌为主。革兰阴性杆菌和革兰阳性杆菌均普遍出现了多重耐药菌株。真菌主要以白假丝酵母菌为主。结论:下呼吸道感染主要致病菌是革兰阴性菌,其次是真菌,不同菌种对抗菌药物的耐药性不同,在临床上,应合理选择靶向抗感染治疗药物。%OBJECTIVE To provide some references for the rational choice of antimicrobial agents and enhancement of curative effect for clinical. METHODS Collect Department of Respiratory Medicine lower respiratory infection patients’ sputum and bronchoalveolar lavage fluid samples inspection in January 2013 -December 2014,then analyze pathogen distribution of common ward patients and ICU patients,and then conduct statistical distribution of the characteristics of isolated strains and drug resistance. RESULTS The survey shows the most common germ is gram negative bacillus, followed by the fungus, and the proportion of gram positive bacteria is the least. As for the gram-negative bacilli,the highest detection rate of pathogen row of the top four are respectively pseudomonas aeruginosa, klebsiella pneumoniae, bowman's acinetobacter and escherichia coli. Gram-positive bacteria are mainly composed of staphylococcus aureus;Gram-negative bacilli and gram-positive bacilli generally generate

  1. Study on Infections Path of Pathogenic Bacteria of Ventilator-associated Pneumonia and its Nursing Interventions%根据呼吸机相关感染的菌谱探讨感染路径的护理

    Institute of Scientific and Technical Information of China (English)

    赵志菲; 谭晓骏; 谷金玲; 王萍; 王振华

    2012-01-01

    Objective: To analyze the species of pathogenic bacteria of ventilator-associated Pneumonia in department of thoracic surgery and to explore its infections path, so as to investigate the prevention measures and nursing interventions of reducing ventilator-associated Pneumonia. Methods: The clinical data of 98 cases patients with mechanical ventilation respiratory secretions bacteria spectrum were retrospectively analyzed. The infection path were analyzed on the base of clinical characteristics. Results: Average onset time of VAP is for 4.2 d after mechanical ventilation. A total of 268 strain of pathogens were separated, including 194 Gram-negative bacilli (72.37%), 59 Gram-positive bacilli (22%), 15 Fungi (5.63%). Conclusion: The major pathogens of ventilator-associated pneumonia are Gram-negative bacilli. The major causes of lower respiratory tract infection on mechanical patients are Gastrointestinal engraftment bacteria retrograding and oropharyngeal secretions inhaling. The key to prevent and control VAP is to enhance the disinfection of the breathing apparatus and oral care, to clean air stranded things around promptly, and to avoid retentate leakage and Gastrointestinal engraftment bacteria retrogradation.%目的:分析我院胸外科呼吸机相关性肺炎(VAP)的病原菌种类,寻找其感染路径,探讨预防和减少呼吸机相关性肺炎的有效护理措施.方法:回顾分析98例机械通气患者的呼吸道分泌物细菌谱情况,再依据临床特征分析感染路径.结果:VAP平均发病时间为机械通气后4.2 d,共分离出病原菌268株,其中,革兰阴性菌194株(占72.37%),革兰阳性菌59株(占22%),真菌15株(占5.63%).结论:呼吸机相关性肺炎的主要病原菌为革兰阴性杆菌,胃肠道定植菌逆行、口咽部的分泌物吸入是导致机械患者下呼吸道感染的主要原因.加强口腔护理、及时引流气囊周围滞留物、避免滞留物渗漏,避免胃肠道定植菌逆行吸入,加强

  2. Antisense RNA modulation of alkyl hydroperoxide reductase levels in Helicobacter pylori correlates with organic peroxide toxicity but not infectivity.

    Science.gov (United States)

    Croxen, Matthew A; Ernst, Peter B; Hoffman, Paul S

    2007-05-01

    Much of the gene content of the human gastric pathogen Helicobacter pylori ( approximately 1.7-Mb genome) is considered essential. This view is based on the completeness of metabolic pathways, infrequency of nutritional auxotrophies, and paucity of pathway redundancies typically found in bacteria wit